bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Moisture and Time on Stiffness of Unbound Aggregate Base Coarse Materials
Authors: Toros Ulas , Hiltunen Dennis R.
Published: November 2008

Resilient modulus and Young's modulus are parameters increasingly used to characterize the behavior of pavement materials, both in the laboratory and in the field. The small-strain modulus response of unbound aggregate base coarse materials to various moisture environments was documented. Modulus is not constant, even when held at constant moisture, and significant changes in modulus occur with drying and wetting of the material. The response to drying and wetting cycles appears to be repeatable and suggests that the underlying mechanism that controls the response is reversible. This behavior can have a significant effect on the use of modulus for pavement design and quality acceptance.
Long-Term Performance of Chemically Modified Subgrade Soils in Indiana
Authors: Jung Chulmin , Bobet Antonio , Siddiki Nayyar Zia , Kim Daehyeon
Published: November 2008

Chemical modification of soils with lime in Indiana is widely used to improve the workability and compactability of weak subgrade soils. Although the modification process is primarily aimed at construction expediency, additional effects such as long-term improvement of stiffness or strength by pozzolanic and carbonation cementation processes of the treated soils have been expected but have not been quantified. Because of a lack of confidence in the long-term performance of the chemically modified soils, their enhanced stiffness has not been taken into account in pavement design, leading to a conservative design of the asphalt or concrete pavement layers. Six roads that have been in service for 5 to 11 years were selected to conduct field tests. The selection was performed considering (a) location of road project in Indiana, (b) class of road, (c) year when chemical treatment was done, (d) type of chemical modifier used, (e) type of pavement, (f) availability of geotechnical information for postconstruction evaluation, and (g) traffic and safety control for field testing. The results from the field tests show that the long-term stiffness or strength of subgrades that were chemically treated 5 to 11 years ago is 4 to 11 times higher than that of natural sub-grades. This finding suggests that the enhanced stiffness of the chemically modified subgrade could be accounted for in pavement design, which would lead to a reduction of the thickness of asphalt or concrete pavement layers.
Assessing Rutting Susceptibility of Cement-Treated Base Material under Early Trafficking with Heavy Clegg Impact Soil Tester
Authors: Guthrie W. Spencer , Reese G. Benjamin
Published: November 2008

To avoid the occurrence of early-age damage, cement-treated base (CTB) materials must be allowed to cure for a period of time before the pavement can be opened to early trafficking. As an alternative to specifying a set curing duration, a field-testing method was developed. The specific objectives of the project were to examine correlations between Clegg impact values (CIVs) determined using a heavy Clegg impact soil tester and rut depths measured in newly constructed CTB and to subsequently establish a threshold CIV at which unacceptable rutting should not occur. From data collected in the field and laboratory, one may conclude that successive wheel passes each cause less incremental rutting than previous passes and that rutting should be absent when the CIV exceeds 35. The maximum measured rut depth did not exceed 0.35 in. in this research, probably because of the high-quality limestone base material used to construct the CTB. In identifying a recommended threshold CIV at which CTB layers may be opened to early trafficking, researchers proposed a maximum tolerable rut depth of 0.10 in. for this project, which corresponds to a CIV of approximately 25. Because a CIV of 25 is also achievable within a reasonable amount of time under normal curing conditions and is consistent with earlier research, this threshold is recommended as the minimum average value that must be attained by a given CTB construction section before it can be opened to early trafficking.
Physicochemical Behavior of Cement Kiln Dust–Treated Kaolinite Clay
Authors: Peethamparan Sulapha , Olek Jan , Diamond Sidney
Published: November 2008

The physicochemical responses induced in kaolinite clay treated with 25% of a high free lime content cement kiln dust (CKD) were investigated. Atterberg limits, unconfined compressive strength, and stiffness of the compacted, CKD-treated kaolinite were measured as functions of the curing period. These properties were compared with those of the untreated clay and of the clay treated with quicklime, so as to determine the comparative extent of enhancement induced by the CKD treatment. The CKD-treated clay developed significantly higher strength than quicklime-treated clay containing the same amount of lime. The remarkable enhancement in clay properties observed suggests significant potential for use of some CKDs as soil stabilizers. The mineralogi-cal and morphologic changes induced in the clay by the CKD addition were characterized using X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray analyses, so as to help provide an understanding of the CKD-clay interaction mechanism. These examinations indicated that the preexisting stacks of kaolinite clay particles were disaggregated and that the individual clay flakes had absorbed calcium hydroxide that had been previously generated by the hydration of quicklime in the CKD. However, direct evidences for production of calcium silicate hydrate (C-S-H) by pozzolanic reaction between the clay and the calcium hydroxide was not found, despite high likelihood that this had occurred. The same basic interaction mechanisms appeared to operate in both the CKD-treated and the lime-treated clays. The 90-day cured specimens were found to be well cemented and not affected by water immersion.
Georgia's Use of Lime in Full-Depth Reclamation
Authors: Smith Charles R. , Lewis Dwayne E. , Turner James , Jared David M.
Published: November 2008

The Georgia Department of Transportation completed its first roadway project using lime as a stabilizing agent in full-depth reclamation (FDR). The roadway is performing well after 1 year of service. The FDR was performed on a rural route (Huckabee Road) in Jones County, Georgia, where base and pavement failures had been observed along the roadway. This route served as an excellent candidate for the new process, because the base and pavement failures observed were mainly caused by the instability of the underlying subgrade material, which consisted of micaceous, clay–silt soils. Rather than total reconstruction, lime stabilization was recommended, and a provisional specification was written. Construction began in April 2006 and included reclamation to a depth of 14 in. (35 cm) and incorporation of 56.0 lb/yd2 (30 kg/m2) of lime. The provisional specification required the use of hydrated lime, commercial granular lime, or pelletized quicklime for stabilization; the pelletized quicklime was used. Soil and falling weight deflectometer testing before and after reclamation indicated that substantial improvement, both in the soil properties and structural strength, was achieved by the new process.
Length Requirements for New Single-Arc Unsymmetrical Vertical Curve
Authors: Easa Said M.
Published: November 2008

Traditional unsymmetrical vertical curves consist of two parabolic arcs smoothly connected at the point of common curvature. A new single-arc unsymmetrical vertical curve that takes the form of a cubic instead of parabolic function has been recently developed. The curve has a rate of change in grade that gradually varies between the start and end of the vertical curve. The single-arc curve eliminates the sudden change that exists in curvature of traditional two-arc unsymmetrical vertical curves. This paper first develops the sight distance (SD) relationships for the new single-arc curve (crest type). With these relationships, the SD profile for the new curve is established and its shape shows a substantial improvement over the abrupt-type SD profiles of the two-arc curves. The length requirements that satisfy stopping, passing, and decision SD guidelines of AASHTO are then presented. Some examples are used to illustrate the use of the developed design aids. The new single-arc curve builds on previously developed unsymmetrical vertical curves to improve curve characteristics that hopefully will promote road safety.
Safety Evaluation and Improvements for Highway Intersections
Authors: Yuan Li , Lu Jian
Published: November 2008

Intersection safety is one of the most important issues in transportation. Traffic crash analysis—the most popular method to evaluate or assess the safety performance of an intersection—has been used for a long time. However, it is based on a lot of crash data, which need to be accumulated over a long period. In addition, traffic crashes sometimes occur randomly as a result of human driving behavior. Therefore, without sufficient data and crash history, traffic crash analysis may not give an overall evaluation of an intersection's safety performance. This paper introduces an approach to evaluating highway intersection safety performance. It is fully based on the existing conditions of the intersection, including geometrics, sight distance, pavement surface conditions, traffic control devices, traffic signal timing, and phasing. The non-accident-based approach is based on field surveys under the conditions mentioned previously. The approach will also result in a safety index to indicate the safety performance of the intersection. Corresponding countermeasures are ranked and recommended based on cost–benefit analysis. This paper is based on research results from part of a project (entitled Safety Design of Highway Intersections) sponsored by the China Department of Transportation. In this paper, the approach (called a diagnostic approach) is practically applied to evaluate the safety performance of some intersections in Shan Dong Province. Results from the real application indicate that the approach has good applicability and can be used by field safety engineers in real applications.
Midwest Guardrail System Adjacent to a 2:1 Slope
Authors: Polivka Karla A. , Sicking Dean L. , Faller Ronald K. , Bielenberg Robert W.
Published: November 2008

A W-beam guardrail is often used to protect motorists from steep roadside slopes adjacent to high-speed roadways. Although previously designed systems have demonstrated acceptable safety performance, the long posts and half-post spacing have proven to be costly and introduce maintenance challenges. Using longer posts is more economical to users than having a system with posts installed at half-post spacing. Furthermore, the improved redirective capacity of the Midwest Guardrail System (MGS) provides the opportunity to eliminate the need for half-post spacing and thereby greatly reduces the cost of placing a barrier at the slope break point. A stiffened version of the MGS was developed for use adjacent to steep roadside slopes. The new design incorporates 2,743-mm (9-ft) long posts with 1,905-mm (75-in.) spacing. With the top of the W-beam mounted at a height of 787 mm (31 in.), this guardrail was successfully crash tested according to the currently proposed NCHRP Report 350 Update safety performance evaluation criteria. Hence, the stiffened MGS guardrail design with full post spacing is acceptable for use on the National Highway System. This new guardrail design will provide a safe and economical alternative for use along highways with steep slopes very close to the travelway.
Overland Flow Time of Concentration on Very Flat Terrains
Authors: Li Ming-Han , Chibber Paramjit
Published: November 2008

Two types of laboratory experiments were conducted to measure overland flow times on surfaces with very low slopes. One was a rainfall test using a mobile artificial rainfall simulator; the other was an impulse runoff test. Test plots were 6 ft (1.83 m) wide by 30 ft (9.14 m) long with slopes ranging from 0.24% to 0.48%. Surface types tested include bare clay, lawn (short grass), pasture (tall grass), asphalt, and concrete. A regression analysis was conducted to construct models for predicting flow times. Results predicted with regressed models were compared with those from empirical models in the literature. It was found that the slope variable in the regressed model from rainfall test data is less influential than that in existing models. Furthermore, the exponent for the slope variable in the regressed model for the impulse runoff condition is only 1/10th of those in existing models. Overall, most empirical models underestimate overland flow time for laboratory plots with very low slopes. The slope variable becomes insignificant in governing overland flow time when the slope is small. Antecedent soil moisture, not included in most empirical models, significantly affects time of concentration, which is included in the regressed models.
Analysis of Naturalistic Driving Data
Authors: Shankar Venky , Jovanis Paul P. , Aguero-Valverde Jonathan , Gross Frank
Published: November 2008

Recently completed naturalistic (i.e., unobtrusive) driving studies provide safety researchers with an unprecedented opportunity to study and analyze the occurrence of crashes and a range of near-crash events. Rather than focus on the details of the events immediately before the crash, this study seeks to identify methodological paradigms that can be used to answer questions long of interest to safety researchers. In particular, an attempt is made to shed some light on the four important components of methodological paradigms for naturalistic driving analysis: surrogates, evaluative aspects related to model structures, interpretation of driving context, and assessment of risk and associated sampling issues. The methodological paradigms are founded on a formal definition of the attributes of a valid crash surrogate that can be used in model formulation and testing. After a brief summary of the type of data collected in the studies, an overall framework for the analysis and a range of specific models to test hypotheses of interest are presented. A summary is given of how the systematic analyses with statistical models can extend safety knowledge beyond an assessment of “causes” of individual crashes.
Adjustment for Maximum Likelihood Estimate of Negative Binomial Dispersion Parameter
Authors: Park Byung-Jung , Lord Dominique
Published: November 2008

The negative binomial (NB) (or Poisson–gamma) model has been used extensively by highway safety analysts because it can accommodate the overdispersion often exhibited in crash data. However, it has been reported in the literature that the maximum likelihood estimate of the dispersion parameter of NB models can be significantly affected when the data are characterized by small sample size and low sample mean. Given the important roles of the dispersion parameter in various types of highway safety analyses, there is a need to determine whether the bias could be potentially corrected or minimized. The objectives of this study are to explore whether a systematic relationship exists between the estimated and true dispersion parameters, determine the bias as a function of the sample size and sample mean, and develop a procedure for correcting the bias caused by these two conditions. For this purpose, simulated data were used to derive the relationship under the various combinations of sample mean, dispersion parameter, and sample size, which encompass all simulation conditions performed in previous research. The dispersion parameter was estimated by using the maximum likelihood method. The results confirmed previous studies and developed a reasonable relationship between the estimated and true dispersion parameters for reducing the bias. Details for the application of the correction procedure were also provided by using the crash data collected at 458 three-leg unsignalized intersections in California. Finally, the study provided several discussion points for further work.
Variable Selection Issues in Tree-Based Regression Models
Authors: Qin Xiao , Han Junhee
Published: November 2008

Recently, there has been increasing interest in the use of classification and regression tree (CART) analysis. A tree-based regression model can be constructed by recursively partitioning the data with such criteria as to yield the maximum reduction in the variability of the response. Unfortunately, the exhaustive search may yield a bias in variable selection, and it tends to choose a categorical variable as a splitter that has many distinct values. In this study, an unbiased tree-based regression generalized unbiased interaction detection and estimation (GUIDE) model is introduced for its robustness against the variable selection bias. Not only are the underlying theoretical differences behind CART and GUIDE in variable selection presented, but also the outcomes of the two different tree-based regression models are compared and analyzed by utilizing intersection inventory and crash data. The results underscore GUIDE's strength in selecting variables equally. A simulation shed additional light on the resulting negative impact when an algorithm was inappropriately applied to the data. This paper concludes by addressing the strengths and weaknesses of—and, more important, the differences between—the two hierarchical tree-based regression models, CART and GUIDE, and advises on the appropriate application. It is anticipated that the GUIDE model will provide a new perspective for users of tree-based models and will offer an advantage over existing methods. Users in transportation should choose the appropriate method and utilize it to their advantage.
Extended Grunwald-Winstein Analysis - LFER Used to Gauge Solvent Effects in p-Nitrophenyl Chloroformate Solvolysis
Authors: D’Souza Malcolm J. , Shuman Kevin E. , Carter Shannon E. , Kevill Dennis N.
Published: November 2008

Specific rates of solvolysis at 25oC for p-nitrophenyl chloroformate (1) are analyzed using the extended (two-term) Grunwald-Winstein equation. For 39 solvents, the sensitivities (l = 1.68±0.06 and m = 0.46±0.04) towards changes in solvent nucleophilicity (l) and solvent ionizing power (m) obtained, are similar to those previously observed for phenyl chloroformate (2) and p-methoxyphenyl chloroformate (3). The observations incorporating new kinetic data in several fluoroalcohol-containing mixtures, are rationalized in terms of the reaction being sensitive to substituent effects and the mechanism of reaction involving the addition (association) step of an additionelimination (association-dissociation) pathway being rate-determining. The l/m ratios obtained for 1, 2, and 3, are also compared to the previously published l/m ratios for benzyl chloroformate (4) and p-nitrobenzyl chloroformate (5).
Interferometric Phase Improvement Based on Polarimetric Data Fusion
Authors: Xiong Tao , Yang Jian , Zhang Weijie
Published: November 2008

In this paper, a method is proposed to improve the interferometric phase quality, based on fusing data from different polarimetric channels. Since lower amplitude implies less reliable phase in general, the phase quality of polarimetric interferometric data can be improved by seeking optimal fusion of data from different polarizations to maximize the resulting amplitude. In the proposed approach, for each pixel, two coherent polarimetric scattering vectors are synchronously projected onto a same optimum direction, maximizing the lower amplitude of the two projections. In the single-look case, the fused phase is equivalent to the weighted average of phases in all polarimetric channels. It provides a good physical explanation of the proposed approach. Without any filtering, the phase noise and the number of residue points are significantly reduced, and the interferometric phase quality is greatly improved. It is a useful tool to preprocess the phase ahead of phase unwrapping. The Cloude’s coherence optimization method is used for a comparison. Using the data collected by SIR-C/X-SAR, the authors demonstrate the effectiveness and the robustness of the proposed approach.
Recent Updates of DNA Incorporated in Carbon Nanotubes and Nanoparticles for Electrochemical Sensors and Biosensors
Authors: Yogeswaran Umasankar , Thiagarajan Soundappan , Chen Shen-Ming
Published: November 2008

Innovations in the field of electrochemical sensors and biosensors are of much importance nowadays. These devices are designed with probes and micro electrodes. The miniaturized designs of these sensors allow analyses of materials without damaging the samples. Some of these sensors are also useful for real time analysis within the host system, so these sensors are considered to be more advantageous than other types of sensors. The active sensing materials used in these types of sensors can be any material that acts as a catalyst for the oxidation or reduction of particular analyte or set of analytes. Among various kinds of sensing materials, deoxyribonucleic acid (DNA), carbon nanotubes (CNTs) and nanoparticles have received considerable attraction in recent years. DNA is one of the classes of natural polymers, which can interact with CNTs and nanoparticles to form new types of composite materials. These composite materials have also been used as sensing materials for sensor applications. They have advantages in characteristics such as extraordinary low weight and multifunctional properties. In this article, advantages of DNA incorporated in CNT and nanoparticle hybrids for electrochemical sensors and biosensors are presented in detail, along with some key results noted from the literature.
Analysis of Land Use Change and Urbanization in the Kucukcekmece Water Basin (Istanbul, Turkey) with Temporal Satellite Data using Remote Sensing and GIS
Authors: Coskun H. Gonca , Alganci Ugur , Usta Gokce
Published: November 2008

Accurate and timely information about land use and land cover (LULC) and its changes in urban areas are crucial for urban land management decision-making, ecosystem monitoring and urban planning. Also, monitoring and representation of urban sprawl and its effects on the LULC patterns and hydrological processes of an urbanized watershed is an essential part of water resource planning and management. This paper presents an image analysis study using multi temporal digital satellite imagery of LULC and changes in the Kucukcekmece Watershed (Metropolitan Istanbul, Turkey) from 1992 to 2006. The Kucukcekmece Basin includes portions of the Kucukcekmece District within the municipality of Istanbul so it faces a dramatic urbanization. An urban monitoring analysis approach was first used to implement a land cover classification. A change detection method controlled with ground truth information was then used to determine changes in land cover. During the study period, the variability and magnitude of hydrological components based on land-use patterns were cumulatively influenced by urban sprawl in the watershed. The proposed approach, which uses a combination of Remote Sensing (RS) and Geographical Information System (GIS) techniques, is an effective tool that enhances land-use monitoring, planning, and management of urbanized watersheds.
Vascular Endothelial Growth Factor in Rabbits During Development of Corticosteroid-Induced Osteonecrosis: A Controlled Experiment
Authors: KABATA TAMON , MATSUMOTO TADAMI , YAGISHITA SHINICHI , WAKAYAMA TOMOHIKO , ISEKI SHOICHI , TOMITA KATSURO
Published: November 2008

Objective

Vascular endothelial growth factor (VEGF) is an angiogenic promoter that is rapidly induced as a response to local hypoxia. We investigated VEGF expression in rabbits in a controlled experiment to clarify the onset of ischemic events in corticosteroid-induced osteonecrosis (ON).

Methods

Ninety-nine mature Japanese white rabbits were divided into 6 treatment groups and an untreated control group. The treatment groups received a single intramuscular injection of 4 mg/kg methylprednisolone acetate; they were euthanized at different times, and tissue samples were obtained from their femora. We examined the development of ON and the expression of VEGF using histopathology, immunohistochemistry, Northern blot analysis, and Western blot analysis.

Results

On histopathological examination, the earliest indication of ON was 5 days after the corticosteroid treatment. The frequency of ON occurrence reached a plateau at or after Week 1. VEGF expression was accompanied by the development of ON. VEGF-positive cells detected by immunohistochemistry were found among bone marrow cells, frequently located in the area surrounding ON, suggesting that VEGF production was switched on as a result of the ischemic events that cause ON. The level of VEGF-mRNA expression indicated by Northern blot analysis peaked at 3 days after the corticosteroid treatment and decreased gradually to the levels present in the control group at 7 days after treatment. Western blot analysis revealed VEGF protein production at 3 days after the corticosteroid treatments. Levels of VEGF expression 2 weeks or more after the corticosteroid treatment were almost the same as in the control group.

Conclusion

We observed early expression of VEGF in the cells around the corticosteroid-induced ON lesions in rabbits. These results suggest that the ischemic events that cause ON begin soon after the initial corticosteroid treatment.
Association Between the Aggrecan Gene and Rheumatoid Arthritis
Authors: de SOUZA THAIS B. , MENTZ ELISA F. , BRENOL CLAITON V. , XAVIER RICARDO M. , BRENOL JOÃO C.T. , CHIES JOSÉ A. , SIMON DANIEL
Published: November 2008

Objective

Genetic and environmental factors seem to be involved in the onset of rheumatoid arthritis (RA). We analyzed whether a variable number of tandem repeats (VNTR) polymorphism in the aggrecan gene was associated to RA.

Methods

The study population comprised 170 European-derived Brazilian patients with diagnosis of RA. The control group comprised 148 European-derived Brazilian healthy blood donors. The aggrecan VNTR polymorphism was genotyped by DNA amplification by polymerase chain reaction, followed by electrophoresis in polyacrylamide gel.

Results

There was a statistically significant higher frequency of alleles of shorter length in the patient group compared to controls (p = 0.001), suggesting that individuals carrying short alleles are more likely to develop RA. There was no association between short alleles and clinical characteristics of RA.

Conclusion

Our results provide evidence of an association between the aggrecan gene VNTR polymorphism and RA.
Changes in the Incidence of Endstage Renal Disease Due to Lupus Nephritis in the United States, 1996–2004
Authors: WARD MICHAEL M.
Published: November 2008

Objective

To determine if the incidence of endstage renal disease (ESRD) due to lupus nephritis has decreased from 1996 to 2004.

Methods

Patients age 15 years or older with incident ESRD due to lupus nephritis in 1996–2004 and living in one of the 50 United States or the District of Columbia were identified using the US Renal Data System, a national population-based registry of all patients receiving renal replacement therapy for ESRD. Incidence rates were computed for each calendar year, using population estimates of the US census as denominators.

Results

Over the 9-year study period, 9199 new cases of ESRD due to lupus nephritis were observed. Incidence rates, adjusted to the age, sex, and race composition of the US population in 2000, were 4.4 per million in 1996 and 4.9 per million in 2004. Compared to the pooled incidence rate in 1996–1998, the relative risk of ESRD due to lupus nephritis in 1999–2000 was 0.99 (95% CI 0.93–1.06), in 2001–2002 was 0.99 (95% CI 0.92–1.06), and in 2003–2004 was 0.96 (95% CI 0.89–1.02). Findings were similar in analyses stratified by sex, age group, race, and socioeconomic status.

Conclusion

There was no decrease in the incidence of ESRD due to lupus nephritis between 1996 and 2004. This may reflect the limits of effectiveness of current treatments, or limitations in access, use, or adherence to treatment.
Frontiers in Nanoparticle Research: Toward Greater Complexity of Structure and Function of Nanomaterials
Authors: Kotov Nicholas A. , Stellacci Francesco
Published: November 2008

In this Editorial, our Special Issue Guest Editors Nick Kotov and Francesco Stellacci present a snapshot of the state‐of‐the‐art in research into nanoparticles, and give their views on the outlook and potential development of the fascinating research field.
Cognition and behavior in pre‐pubertal children with Prader–Willi syndrome and associations with sleep‐related breathing disorders
Authors: Festen Dederieke A.M. , Wevers Maaike , de Weerd Al W. , van den Bossche Renilde A.S. , Duivenvoorden Hugo J. , Hokken‐Koelega Anita C.S.
Published: November 2008

Prader–Willi syndrome (PWS) is characterized by hypotonia, hypogonadism, obesity, and short stature. Neurobehavioral abnormalities, cognitive impairment, and sleep‐related breathing disorders (SRBD) are common. In the general population associations between neurobehavioral and cognitive abnormalities and SRBD have been found. We investigated cognition, behavior, and SRBD in children with PWS. Thirty‐one pre‐pubertal PWS children were evaluated (5 with paternal deletion, 14 with maternal disomy, 4 with imprinting‐center mutation, and in 8 the defect was not specified). Cognition was assessed by Wechsler scale subtests, and behavior by parent–questionnaires. Polysomnography was performed. Cognition, behavior, and associations with SRBD were evaluated. All cognitive subtests were significantly below O SDS, with the lowest median (interquartile range) scores for the Block design subtest (−2.7 SDS (−3.0 to −0.3)). In 60%, verbal subtests were less affected than performance subtests. Parents reported problem behavior related to “emotions/behavior not adapted to the social situation” and “insensitivity to social information.” All children had SRBD, with an Apnea Hypopnea Index of 4.1/hr (2.6–7.9). One performance subtest score was significantly higher in children with better sleep efficiency, and daytime sleepiness was associated with more autistic‐like social impairment. In contrast to our expectations, behavior was worse in children with better sleep‐related breathing. In pre‐pubertal PWS children, cognition is impaired. Neurobehavioral abnormalities are common, particularly autistic‐like social impairment. Sleep efficiency was associated with better performance on one of the performance subtests, and neurobehavioral abnormalities were associated with daytime sleepiness. In contrast, we could not confirm a positive association of neurobehavioral abnormalities with SRBD in PWS. © 2008 Wiley‐Liss, Inc.
Chondrodysplasia punctata associated with maternal autoimmune diseases: Expanding the spectrum from systemic lupus erythematosus (SLE) to mixed connective tissue disease (MCTD) and scleroderma report of eight cases
Authors: Chitayat David , Keating Sarah , Zand Dina J. , Costa Teresa , Zackai Elaine H. , Silverman Earl , Tiller George , Unger Sheila , Miller Stephen , Kingdom John , Toi Ants , Curry Cynthia J.R.
Published: November 2008

Chondrodysplasia punctata (CDP) is etiologically a heterogeneous condition and has been associated with single gene disorders, chromosome abnormalities and teratogenic exposures. The first publication of the association between CDP and maternal autoimmune connective tissue disorder was by Curry et al. 1993]. Chondrodysplasia punctata associated with maternal collagen vascular disease. A new etiology? Presented at the David W. Smith Workshop on Morphogenesis and Malformations, Mont Tremblant, Quebec, August 1993] and subsequently, other cases have been reported. We report on eight cases of maternal collagen vascular disease associated with fetal CDP and included the cases reported by Curry et al. 1993. Chondrodysplasia punctata associated with maternal collagen vascular disease. A new etiology? Presented at the David W. Smith Workshop on Morphogenesis and Malformations, Mont Tremblant, Quebec, August 1993] and Costa et al. [1993]. Maternal systemic lupus erythematosis (SLE) and chondrodysplasia punctata in two infants. Coincidence or association? 1st Meeting of Bone Dysplasia Society, Chicago, June 1993] which were reported in an abstract form. We suggest that maternal autoimmune diseases should be part of the differential diagnosis and investigation in newborns/fetuses with CDP. Thus, in addition to cardiac evaluation, fetuses/newborn to mothers with autoimmune diseases should have fetal ultrasound/newborn examination and if indicated, X‐rays, looking for absent/hypoplastic nasal bone, brachydactyly, shortened long bones and epiphyseal stippling. © 2008 Wiley‐Liss, Inc.
Community consultation and communication for a population‐based DNA biobank: The Marshfield clinic personalized medicine research project
Authors: McCarty Catherine A. , Chapman‐Stone Donna , Derfus Teresa , Giampietro Philip F. , Fost Norman
Published: November 2008

The purpose of this article is to describe community consultation and communication efforts for the Personalized Medicine Research Project (PMRP), a population‐based biobank. A series of focus group discussions was held in the year preceding initial recruitment efforts with potentially eligible community residents and slightly less than a year after initial recruitment with eligible residents who had declined participation in PMRP. A Community Advisory Group, with 19 members reflecting the demographics of the eligible community, was formed and meets twice yearly to provide advice and feedback to the PMRP Principal Investigator and the local IRB. Ongoing communication with study subjects, who consent on the condition that personal genetic results will not be disclosed, takes place through a newsletter that is distributed twice yearly, community talks and media coverage. Most focus group participants were concerned about the confidentiality of both their medical and genetic data. Focus group discussions with eligible residents who elected not to participate in PMRP revealed that many knew very little about the project, but thought that too much information had been provided, leading them to believe that it would take too long for them to understand and enroll in the study. In conclusion, an engaged community advisory group can provide a sounding board to study investigators for many study issues and can provide guidance for broader communication activities. Researchers need to balance the provision of information for potential subjects to make informed decisions about study participation, with respect for individuals' time to read and interpret study materials. © 2008 Wiley‐Liss, Inc.
Distal 22q11.2 microduplication encompassing the BCR gene
Authors: Descartes Maria , Franklin Judy , de Ståhl Teresita Diaz , Piotrowski Arkadiusz , Bruder Carl E.G. , Dumanski Jan P. , Carroll Andrew J. , Mikhail Fady M.
Published: November 2008

Chromosome 22 band q11.2 has been recognized to be highly susceptible to subtle microdeletions and microduplications, which have been attributed to the presence of several large segmental duplications; also known as low copy repeats (LCRs). These LCRs function as mediators of non‐allelic homologous recombination (NAHR), which results in these chromosomal rearrangements as a result of unequal crossover. The four centromeric LCRs at proximal 22q11.2 have been previously implicated in recurrent chromosomal rearrangements including the DiGeorge/Velocardiofacial syndrome (DG/VCFs) microdeletion and its reciprocal microduplication. Recently, we and others have demonstrated that the four telomeric LCRs at distal 22q11.2 are causally implicated in a newly recognized recurrent distal 22q11.2 microdeletion syndrome in the region immediately telomeric to the DG/VCFs typically deleted region. Here we report on the clinical, cytogenetic, and array CGH studies of a 4.5‐year‐old girl with history of failure to thrive, developmental delay (DD), and relative macrocephaly. She carries a paternally inherited ∼2.1 Mb microduplication at distal 22q11.2, which spans approximately 34 annotated genes, and is flanked by two of the four telomeric 22q11.2 LCRs. We conclude that the four telomeric LCRs at distal 22q11.2 can mediate both deletions and duplications in this genomic region. Both deletions and duplication of this region present with subtle clinical features including mild to moderate mental retardation, DD, and mild dysmorphic features. © 2008 Wiley‐Liss, Inc.
Toughness optimization of glass‐fiber reinforced PA 6/PA 66‐based composites: Effect of matrix composition and colorants
Authors: Nase Michael , Langer Beate , Schumacher Siegfried , Grellmann Wolfgang
Published: November 2008

Mixing of polyamide 6 (PA 6) and polyamide 66 (PA 66) is integrated in the trend of development of new and improved materials by combination of different polymers and some reinforcing materials to polymer composites. The specific polymer composite PA 6/PA 66 reinforced with short glass‐fibers combines the good coloring of PA 6, and the small moisture absorption of PA 66. Technical applications of PA 6/PA 66 composites are mainly used in the automotive industry. Specific requirements of this industry lead to the necessity to optimize the material resistance against crack propagation of the PA 6/PA 66 composites, using mechanical and fracture mechanical methods. So, the present investigations focus on fracture mechanics toughness optimization of the PA 6/PA 66 composites, including unstable and stable crack growth. The aim of this toughness optimization is to find out the optimal mixing ratio of PA 6/PA 66. Applications of PA 6/PA 66 in the automotive industry and specific client wishes are the main reasons for black‐coloring of the PA materials. The influence of several black‐colorants (carbon black, nigrosine, spinel, iron oxide) on mechanical and fracture mechanical properties of the PA composites is also investigated using fracture mechanical methods. As experimental fracture mechanical method, preferentially, the instrumented Charpy impact test (ICIT) and the new cut method to determine the stable crack growth of glass‐fiber reinforced materials was used. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and In‐Vitro Activity of New 1β‐Methylcarbapenem Derivatives as Antibacterial Agents
Authors: Jung Myung‐Ho , Hong Joon Hee , Cho Jung‐Hyuck , Oh Chang‐Hyun
Published: November 2008

The synthesis of a new series of 1β‐methylcarbapenems having pyrrolidine and piperidine moieties is described. Their in‐vitro antibacterial activities against both Gram‐positive and Gram‐negative bacteria were tested and the effect of substituents on the pyrrolidine ring was investigated. A particular compound III b having an oxime‐pyrrolidine moiety showed the most potent antibacterial activity.
New 1‐Benzyl‐4‐hydroxypiperidine Derivatives as Non‐imidazole Histamine H3 Receptor Antagonists
Authors: Maslowska‐Lipowicz Iwona , Figlus Marek , Zuiderveld Obbe P. , Walczynski Krzysztof
Published: November 2008

A series of 1‐benzyl‐4‐(3‐aminopropyloxy)piperidine and 1‐benzyl‐4‐(5‐aminopentyloxy)piperidine derivatives has been prepared. The 1‐benzyl‐4‐hydroxypiperidine derivatives obtained were evaluated for their affinities at recombinant human histamine H3 receptor, stably expressed in HEK 293T cells. All compounds investigated show moderate to pronounced in‐vitro affinities. The most potent antagonists in this series 9b2 (hH3R, pKi = 7.09), 9b1 (hH3R, pKi = 6.78), 9b5 (hH3R, pKi = 6.99), and 9b6 (hH3R, pKi = 6.97) were also tested in vitro as H3 receptor antagonists – the electrically evoked contraction of the guinea‐pig jejunum. The histaminergic H1 antagonism of selected compounds 9b1, 9b2, and 9b4–9b6 was established on the isolated guinea‐pig ileum by conventional methods; the pA2 values were compared with the potency of pyrilamine. The compounds did not show any H1 antagonistic activity (pA2 < 4; for pyrilamine pA2 = 9.53).
Effect of streptozotocin‐induced diabetes mellitus on the pharmacokinetics of nelfinavir in rats
Authors: Sugioka Nobuyuki , Sato Kenji , Haraya Kenta , Maeda Yuta , Yasuda Kyohei , Fukushima Keizo , Ito Yukako , Takada Kanji
Published: November 2008

The HIV protease inhibitor, nelfinavir (NFV), has been used widely for HIV infection. The drug exhibits high binding characteristics to serum protein (unbound fraction: 0.01). The effect of experimentally induced diabetes mellitus on the pharmacokinetics of NFV was investigated, focusing on the change of protein‐binding due to the glycosylation of albumin in streptozotocin‐induced diabetes mellitus rats (diabetic rats). The unbound fraction of NFV in diabetic rats (0.04) was greater than that in the control (0.015). In diabetic rats, although theAUCof NFV was decreased after both intravenous (control: 1.75±0.08, diabetic: 1.36±0.17 µg h/ml) and intraduodenal (control: 1.69±0.25, diabetic: 1.19±0.39 µg h/ml) administrations, the unboundAUCwas increased significantly (intravenous, control: 0.026±0.001, diabetic: 0.054±0.007 µg h/ml, intraduodenal, control: 0.025±0.004, diabetic: 0.048±0.016 µg h/ml). The unbound total clearance (control: 131.3±6.0, diabetic: 64.3±8.0 l/h/kg) and the unbound steady state distribution volume (control: 274.0±18.0, diabetic: 123.0±14.0 l/kg) were decreased significantly; therefore, greater pharmacological effects can be expected in diabetes mellitus. The contribution of increasing the unbound fraction to these results was significantly higher. In addition, there were no significant differences in the systemic and hepatic availability, peak time and mean absorption time between the diabetic and control rats, suggesting that diabetes mellitus did not affect the absorption of NFV. Copyright © 2008 John Wiley & Sons, Ltd.
Assessment of the efficacy and safety of low frequency, low intensity magnetic fields in patients after knee endoprosthesis plasty. Part 1: In vitro safety
Authors: Błaszczak Edward , Franek Andrzej , Taradaj Jakub , Widuchowski Jerzy , Klimczak Jerzy
Published: November 2008

The purpose of this in vitro study was to assess the potential influence of low frequency, low intensity magnetic fields (rectangular pulse, 5 mT, 30 Hz) applied in therapy on the temperature, contact electric potential, and magnetization in knee endoprosthesis, which might be dangerous for implantation and stability of knee prosthesis, and later slacking it off, causing postoperative complications. The experimental investigation was carried out on a knee endoprosthesis which had been placed in a container with physiological saline. The prosthesis located inside the container was under the exposure of the magnetic field applied by a solenoid. The results indicated that magnetic fields did not influence thermal and electromagnetic properties of knee endoprosthesis in vitro. The magnetic fields of examined parameters should not be dangerous for implantation and stability of knee endoprosthesis. Bioelectromagnetics 30:159–162, 2009. © 2008 Wiley‐Liss, Inc.
Use of a microcatheter in a telescopic system to reach difficult targets in complex congenital heart disease
Authors: Brown Stephen C. , Boshoff Derize E. , Eyskens Benedicte , Mertens Luc , Gewillig Marc
Published: November 2008

Background:

Some lesions can be very difficult to reach, especially if acute angles and/or multiple turns “protect” access. Once reached, the guiding system needs to give sufficient support for balloons or stents to be deployed.

Methods:

A “telescopic” system was created consisting of: (1) a microcatheter with guidewire. This system fits into any catheter allowing a 0.035 inch wire. (2) a 4Fr “delivery” catheter. (3) If sharp angles were encountered, the 4Fr catheter was deployed through a 6Fr or larger angulated guiding sheath. This was cut‐off 15 cm out of the groin and re‐valvulated with a standard short introducer sheath.

Patients and results:

Since 2004, 89 microcatheter telescopic systems were used during a 4‐year period in 1,225 procedures (7.3%). The technique allowed probing with a floppy steerable and exchangeable guidewire, securing any gained position as well as exchanges with a stiffer guide wire if required. Procedures where the telescopic system was effective included: complex stenoses e.g. aortopulmonary collaterals (n = 21), tortuous ducts (n = 9), anterograde balloon dilation of critical aortic stenosis (n = 8) and crossing Blalock Taussig shunts (n = 3). Once in place, the telescopic system allowed delivery of embolic material (n = 38), balloon angioplasty (n = 21), stent deployment (n = 23), fulguration of pulmonary valve (n = 1) or introduction of medication (n = 1). The interventionalists felt that using the telescopic system had reduced fluoroscopy and procedure time.

Conclusions:

The microcatheter‐telescopic system is an invaluable tool to reach difficult targets and allows exchange for suitable guidewires permitting balloons, stents, embolisation material or radiofrequency energy to be deployed in such targets. This approach has become our standard when dealing with difficult targets protected by a tortuous route. © 2009 Wiley‐Liss, Inc.
Combined percutaneous revascularization and cell therapy after failed repair of anomalous origin of left coronary artery from pulmonary artery
Authors: de Lezo José Suárez , Pan Manuel , Herrera Concepción
Published: November 2008

This report shows the course of an infant with an abnormal left coronary artery origin arising from the pulmonary artery who underwent failed surgical reimplantation. Treatment entailed combined stent revascularization followed by intracoronary infusion of bone marrow‐derived mononuclear cells. The patient was admitted with an acute coronary syndrome and low cardiac output; he was endotracheally intubated under respiratory assistance. Fourteen months after intracoronary infusion of autologous bone marrow‐derived mononuclear cells, the infant remains symptom‐free with significant recovery of the left ventricular function. These findings suggest that the combination of percutaneous revascularization and cell therapy should be considered in those infants or children in whom salvage therapy for ischemic heart disease is required. © 2009 Wiley‐Liss, Inc.