bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact resistance of fibre-reinforced concrete
Authors: Mindess S. , Zhang L.
Published: January 2009

Fibre reinforcement increases the toughness of plain concrete under static compressive loading. The compressive toughness of fibre-reinforced concrete (FRC) under impact loading has not, however, previously been investigated. The current paper reviews the behaviour of high-strength fibre-reinforced concrete under uniaxial compressive impact loading. An instrumented drop weight impact machine was used to carry out compressive impact tests on various FRC systems with compressive strengths ranging from about 60 MPa to 120 MPa. The deformations of the FRC cylinders were determined using a high-speed video camera system. As expected, the compressive strength was found to increase with increasing drop height (or impact velocity). The dynamic compressive toughness was also found to increase with increasing drop height and with increasing matrix strength. It was observed that the mode of failure of the FRC was dependent upon the properties of the matrix and of the fibres, as well as on the drop height. Thus, the dynamic compressive toughness of FRC appeared to be dependent on the constitutive behaviour of the matrix, the fibre type and volume, the impact velocity and the mode of failure.
Investigation on penetration resistance of foamed concrete
Authors: Ahmad Zaidi A. M. , Li Q. M.
Published: January 2009

This paper studies the penetration resistance of lightweight foamed concrete subjected to impact by hard projectiles. Experiments were performed to obtain the mechanical properties of the material and the penetration depth. Complete stress–strain curves in compression are presented, based on which several important parameters for the description of the compressive strength and energy absorption of the foamed concrete were determined. The penetration depths of hard projectiles were measured at various impact velocities between 10 m/s and 150 m/s with different types of projectile nose shapes including flat, cone and spherical noses. A simulation model based on rigid body dynamics and a shock resistance function is proposed to predict the penetration depth. Reasonably good agreement between experimental and simulating results is achieved.
Modelling urban river catchment: a case study in Malaysia
Authors: Leow C. S. , Abdullah R. , Zakaria N. A. , Ghani A. Ab. , Chang C. K.
Published: January 2009

Generally, many rivers within urban catchments in Malaysia are being altered from their natural states to meet the demand of developments. Most of these rivers have also become the receiving water body for urban drainage systems. Therefore, it has become extremely difficult to separate river from the rest of the drainage system. Study of interaction between such river and urban drainage is necessary for urban drainage planning and design. Present study showcases how urban river modelling using InfoWorks Collection System (CS) on Berop River, Perak (Malaysia), can assist stormwater system design. Calibrated using historical flood event, the developed model was used for evaluation of various design storms, possible scenarios as well as existing and future landuse condition. The study found that within a data scarcity condition, InfoWorks CS played a significant role in providing good platform for stormwater system modelling as well as satisfactory simulations and analyses for complex combination of river and urban drainage stormwater system. This is the much needed advantage for practising engineers in time saving stormwater system design.
Water quality monitoring of Maong River, Malaysia
Authors: Said S. , Mah D. Y. S. , Sumok P. , Lai S. H.
Published: January 2009

A water quality simulation model for Maong River, which flows through Kuching City, in Malaysia was explored with a focus on predicting the dissolved oxygen (DO) parameter. The model simulated the DO levels using the hourly data collected in December 2006. The water quality model was developed to simulate the inflow water conditions and estimate the DO levels at various locations along the river reaches as it flows through the highly populated Maong River catchments. The model adopted a hydrodynamic flow simulation to capture advection and diffusion due to different flow conditions. From the results, it is clear that DO concentrations are clearly affected as the river flows downstream. The correlation of the observed and simulated DO concentration was 0·82.
Longitudinal Examination of Physical and Relational Aggression as Precursors to Later Problem Behaviors in Adolescents
Authors: Herrenkohl Todd I. , Catalano Richard F. , Hemphill Sheryl A. , Toumbourou John W.
Published: January 2009

Research has addressed the consequences of being a victim of physical and relational aggression but less so the consequences of being an aggressor during adolescence. Consequently, relatively little is known about the extent to which aggression in early adolescence increases the risk of later aggression and other psychosocial problems. This study involves a representative sample of seventh- and ninth-grade students from Washington State (N = 1,942). Students were surveyed on recruitment and then again 1 and 2 years later to learn about ongoing behavior problems, substance use, depression, and self-harm behaviors. Surveys also included measures of several hypothesized promotive factors: attachment to family, school commitment, and academic achievement. Findings suggest that being physically and/or relationally aggressive in grades 7 to 9 increases the risk of aggression and possibly other problem behaviors after accounting for age, gender, race, and a prior measure of each outcome. Independent promotive effects were observed in most analyses, although family attachment appeared a less robust predictor overall. Implications for prevention include acting on the behavior itself and enhancing promotive influences to lessen the risk of agression and other related problems.
Relationships Between Mobbing at Work and MMPI-2 Personality Profile, Posttraumatic Stress Symptoms, and Suicidal Ideation and Behavior
Authors: Balducci Cristian , Alfano Vincenzo , Fraccaroli Franco
Published: January 2009

This study investigates the relationships between the experience of mobbing at work and personality traits and symptom patterns as assessed by means of the revised version of the Minnesota Multiphasic Personality Inventory (MMPI-2). Participants were 107 workers who had contacted mental health services because they perceived themselves as victims of mobbing. In line with previous research, the results showed that the MMPI-2 mean profile was characterized by a neurotic component as evidenced by elevations of Scales 1, 2, and 3 and a paranoid component as indicated by elevation of Scale 6. Contrary to previous research, a pattern of positive and significant correlations was found between the frequency of exposure to mobbing behaviors and the MMPI-2 clinical, supplementary, and content scales, including the posttraumatic stress scale. Only about half the participants showed a severity of posttraumatic stress symptoms indicative of a posttraumatic stress disorder. The frequency of exposure to mobbing predicted suicidal ideation and behavior, with depression only partially mediating this relationship.
Conceptual Foundations of the Transdiagnostic Approach to CBT
Authors: Mansell Warren , Harvey Allison , Watkins Ed , Shafran Roz
Published: January 2009

This article defines and explains the transdiagnostic approach to cognitive-behavioral therapy (CBT) and elaborates on its conceptual foundations and implications for research and practice. We argue that the approach has good philosophical, historical, pragmatic, and empirical foundations. We distinguish between transdiagnostic approaches based on multiple processes that are universally applied (e.g., Harvey, Watkins, Mansell, & Shafran, 2004), multiple processes limited in the range of disorders covered (e.g., Fairburn, Cooper, & Shafran, 2003), symptom-based accounts (e.g., Persons, 1986), and universal single process accounts (e.g., experiential avoidance, self-absorption). We summarize existing evidence and identify key issues relating to the methodology of future research on the transdiagnostic approach. The article concludes by highlighting the great potential benefits of the approach and highlights significant practical, political, and scientific obstacles to putting it into practice on a large scale.
Looming Vulnerability and Posttraumatic Stress Disorder: How Are They Related?
Authors: Taylor Steven
Published: January 2009

In recent years there has been growing interest in the concept of looming vulnerability as a vulnerability factor for various anxiety disorders. This article considers the extent to which looming vulnerability may play a role in posttraumatic stress disorder (PTSD). We conclude that looming vulnerability plays a role in some PTSD symptoms but is unlikely to be involved in others. Important directions for research are discussed.
Mapping of QTL Associated with Maize Weevil Resistance in Tropical Maize
Authors: García‐Lara Silverio , Khairallah Mirelle M. , Vargas Mateo , Bergvinson David J.
Published: January 2009

The maize weevil (MW), Sitophilus zeamais (Motsch.), is an important pest of stored maize (Zea mays L.) in tropical areas. Quantitative trait loci (QTL) associated with MW resistance were analyzed. A total of 163 F2 progeny derived from the cross CML290 (susceptible) × Muneng‐8128 C0 HC1‐18‐2‐1‐1 (resistant), were genotyped with 151 molecular markers. Resistance was evaluated using bioassays on replicated F2:3 progenies. Grain damage (GD), grain weight losses (GWL), MW susceptibility index (Dobie index [DI]), and numbers of adult progeny (AP) were evaluated on grain from F2 lines across two environments. Grain hardness and pericarp/grain ratio were evaluated as putative components of resistance. Composite interval mapping was used for QTL analysis. Five QTL dispersed across the genome explained 28% of the phenotypic variance (σp2) and 50% of the genotypic variance (σg2) for GD. Six QTL were detected with effects on GWL and explained 22% of σp2 and 47% of σg2 Seven QTL (27% σp2 and 78% σg2) were identified for DI and three QTL (10% σp2 and 23% σg2) for AP. Both parents contributed resistance alleles. Genetic effects were mainly dominant (GD, GWL, and DI) and additive (AP). Quantitative trait loci × environment interaction was significant for 50% of the QTL. Since the identified QTL accounted for less than a third of σp2, additional mapping populations are required for mapping MW susceptibility.
Genetic Structure of Local Populations and Cultivars of Meadow Fescue from the Nordic and Baltic Regions
Authors: Fjellheim Siri , PaŠakinskiené Izolda , Grønnerød Siri , Paplauskiené Vanda , Rognli Odd Arne
Published: January 2009

The genetic diversity within and among 81 local populations from Norway and Lithuania and 26 cultivars of meadow fescue (Festuca pratensis Huds.) from Norway, Sweden, Finland, Denmark, Lithuania, Latvia, and Estonia was investigated using amplified fragment length polymorphism markers. Genetic diversity was high, with nearly 70% of the molecular variation within populations. Principal coordinates (PCO) analyses indicate that local populations from Norway and Lithuania consist of both older natural populations and naturalized populations established recently by migration from sown meadows. This is based on the fact that naturalized populations cluster with cultivars from the respective countries. The PCO analysis separates the natural local populations from Norway and Lithuania. They belong to different gene pools and reflect dispersal from different glacial refugia after the last glaciation. The Nordic and Baltic cultivars are quite similar (6.25% of variation between groups), and the Baltic cultivars are highly homogenous, with 91% of variation within the cultivars, indicating narrow breeding populations of this species in the Nordic–Baltic region. All cultivars are most closely related to local populations from the Baltic. The results can be used to improve management and utilization of gene bank resources of meadow fescue. Conservation of gene bank accessions should focus on those local populations least influenced by gene flow from cultivated meadow fescue since they probably represent pure natural populations.
Assignment of Individual Genotypes to Specific Forage Cultivars of Perennial Ryegrass Based on SSR Markers
Authors: Wang Junping , Dobrowolski Mark P. , Cogan Noel O.I. , Forster John W. , Smith Kevin F.
Published: January 2009

Assignment or exclusion of an individual to specific populations or cultivars based on molecular genetic markers provides an attractive approach for varietal identification at the individual level in cross‐pollinated plant species. The objectives of this study were (i) to explore the molecular diversity and relationships between Australasian perennial ryegrass (Lolium perenne L.) populations; (ii) to investigate accuracy of assignment of individuals to different types of populations including ecotypic, nonrestricted‐ and restricted‐based cultivars; and (iii) to determine the effect of variable number of SSR loci and different statistical analysis methods on assignment accuracy. Eight forage perennial ryegrass populations comprising 48 individual plants per population were genotyped with 29 simple sequence repeat (SSR) marker loci. The number of alleles per locus ranged from 3.72 to 6.76. The mean observed heterozygosity varied from 0.419 to 0.538. Various genetic distance estimates and clustering methods obtained results consistent with breeding history. Genetic variation among (8.7%) and within populations (91.3%) was significant. Accuracy of individual assignment differed by population type, and it was higher (>90%) for restricted‐based cultivars than for ecotypic and nonrestricted‐based populations. These results indicate that SSR marker profiles can be effectively used to assign individuals for outbreeding populations such as perennial ryegrass. The approach used in this study may be useful for ryegrass germplasm management issues such as cultivar identification at the individual level.
Production of Dryland Barley for Human Food: Quality and Agronomic Performance
Authors: Rey J. I. , Hayes P. M. , Petrie S. E. , Corey A. , Flowers M. , Ohm J. B. , Ong C. , Rhinhart K. , Ross A. S.
Published: January 2009

Grain β‐glucan content is the most important attribute for barley (Hordeum vulgare L.) varieties destined for the human food market. This trait is important because of the blood glucose and cholesterol‐reducing properties of β‐glucans. High levels of grain protein content, test weight, and seed size and endosperm color may also add value. Seed yield potential, in part, determines the economic feasibility of producing human food varieties. To determine the potential of food barley production in the dryland production areas of the Pacific Northwest of the United States, 33 cultivars and advanced lines reported to vary in β‐glucan content were grown in 2006 and 2007 at two locations in northeastern Oregon under dryland cropping conditions. Seed yield, test weight, percentage of plump kernels, grain β‐glucan, and grain protein were measured on replicated samples from the four environments, allowing for assessment of average performance as well as genotype × environment interaction. Estimates of variance components showed that ∼66% of the variability in β‐glucan content was attributable to genotype. Cultivars and lines with waxy starch had an average β‐glucan value of 55 g kg−1 compared with 35 g kg−1 for cultivars and lines with nonwaxy starch. We found significant two‐ and three‐way interactions, but these accounted for much less of the total variation in the measured phenotypes than the main effects of variety, year, and location. Hulless accessions produced an average of 3580 kg grain ha−1 compared with 4260 kg grain ha−1 for the hulled accessions. Hulled, waxy‐starch varieties appear to have the greatest agronomic potential for dryland production, as they combine high yield potential and grain β‐glucan percentage.
Inbreeding Depression for Fertility and Biomass in Advanced Generations of Inter‐ and Intrasubspecific Hybrids of Tetraploid Alfalfa
Authors: Li Xuehui , Brummer E. Charles
Published: January 2009

Hybrids between Medicago sativa subsp. sativa L. (hereafter “sativa”) and M. sativa subsp. falcata (L.) Arcang. (hereafter “falcata”) often express heterosis for yield. Yield generally declines when hybrids are inbred due to the loss of desirable dominant alleles or epistatic combinations. We hypothesized that inbreeding sativa–falcata hybrids may show more extensive yield loss than intrasubspecific crosses because of the large genetic difference between subspecies. Our objective was to compare fertility in the greenhouse and biomass production in the field of F1 hybrids and their F2 and S1 generations in both intra‐ and intersubspecific crosses. Field experiments including F1, F2, S1, and double‐cross populations were planted in two locations in Iowa in 2003 and evaluated for yield in 2 yr. Sativa × falcata crosses (SFC) showed greater F1 fertility than intrasubspecific crosses, suggesting that the two subspecies have similar chromosome structure. The SFC did not show high‐parent F1 heterosis, probably because of an intensive harvest schedule favoring sativa × sativa hybrids. However, SFC showed greater inbreeding depression in both F2 and S1 generations than intrasubspecific crosses, possibly reflecting a greater loss of favorable complementary gene interactions. These results suggest that selection within each parental population followed by intercrossing to produce population hybrids may be a better way to improve biomass with this germplasm than advancing hybrids into a recurrent selection program.
Full‐Sib Reciprocal Recurrent Selection with the Use of Doubled Haploids
Authors: Gallais A.
Published: January 2009

Doubled haploids are increasingly used in plant breeding, especially in maize (Zea mays L.) breeding. Their use can deeply change the interest of recurrent selection for the development of new hybrids. To show this, a full‐sib reciprocal recurrent selection scheme using doubled haploids (DH FS‐RRS) is proposed. Doubled haploid lines are derived from each population and they are then pair‐crossed, one line from one population being crossed to one line from the other population. After evaluation of the progenies, for each population, the parents of the best crosses are selected and intercrossed. As compared to the reciprocal recurrent selection using S0 plants (S0 FS‐RRS), DH FS‐RRS can be easily applied to maize in the absence of prolificacy. It is shown that, in the case of maize, for the same decrease in the effective population size and the same average number of plots per year, and with the use of winter nursery, the expected genetic advance per year for DH FS‐RRS can be 38.6% better than that for S0 FS‐RRS. The main advantage of DH FS‐RRS is to allow direct hybrid development.
Genetic Dissection of Seed Production Traits and Identification of a Major‐Effect Seed Retention QTL in Hybrid Leymus (Triticeae) Wildryes
Authors: Larson Steven R. , Kellogg Elizabeth A.
Published: January 2009

Many native grasses display seed shattering and other seed production problems. Basin wildrye [Leymus cinereus (Scribn. & Merr.) Á. Löve] and creeping wildrye [L. triticoides (Buckley) Pilg.] are perennial Triticeae grasses native to western North America. In this study, variation in the number of florets per inflorescence, percent seed set, seed mass, seed shattering, and seed dormancy was measured in clonally replicated multiyear field evaluations of 164 progeny derived from a backcross between a creeping × basin wildrye hybrid and a true creeping wildrye tester. Genomewide quantitative trait locus (QTL) scans detected independent gene effects for all five traits and one pleiotropic QTL, located on Triticeae homeologous chromosome group 6, associated with major seed shattering (43.1% R2, 26.9 log of odds likelihood ratio [LOD]) and seed dormancy (24.1% R2, 10.6 LOD) effects. We hypothesize that a dominant basin wildrye gene creates an abscission that promotes seed disarticulation but hinders seed development and seed ripening in the creeping wildrye backcross family. Alignments of Leymus chromosome 6 expressed sequence tag markers to the rice (Oryza) genome reveal well‐defined correspondence of Leymus wildrye and American wildrice (Zizania palustris L.) seed shatter QTLs.
Genetic Variation and the Effectiveness of Early‐Generation Selection for Soft Winter Wheat Quality and Gluten Strength
Authors: Knott Carrie A. , Van Sanford David A. , Souza Edward J.
Published: January 2009

Selection for milling and baking quality in wheat (Triticum aestivum L.) head‐rows could increase the efficiency of most soft winter wheat (SWW) breeding programs. We evaluated whole grain‐wheat meal (WM) assays for their ability to select lines with acceptable SWW quality and high gluten strength in early‐generations and estimated heritability of SWW quality and gluten strength. One hundred fourteen lines from a cross of strong and weak gluten parents was assessed over three location‐years. Flour quality and gluten strength were measured using flour and WM measures. Correlations between WM assays on head‐rows and flour‐based assays conducted on replicated trials from two locations were significant (P < 0.05). Wheat meal sedimentation volume (WM‐SED) was correlated with flour lactic acid solvent retention capacity (SRC; r = 0.37). Wheat meal sodium carbonate SRC (WM‐SRC) was correlated with flour sucrose (r = 0.37), flour sodium carbonate (r = 0.46) and flour water (r = 0.47) SRC and negatively correlated with wire‐cut cookie diameter (r = −0.33) and flour yield (r = −0.40). Soft winter wheat quality and gluten strength improved when selections were based on WM‐SRC and WM‐SED, respectively. Early‐generation selection for SWW quality and gluten strength using WM tests should increase the frequency of SWW selections with desirable quality characteristics in replicated yield trials.
Characterization, Genetic Variation, and Combining Ability of Maize Traits Relevant to the Production of Cellulosic Ethanol
Authors: Lorenz A. J. , Coors J. G. , de Leon N. , Wolfrum E. J. , Hames B. R. , Sluiter A. D. , Weimer P. J.
Published: January 2009

Maize (Zea mays L.) stover has been identified as an important feedstock for the production of cellulosic ethanol. Our objectives were to measure hybrid effect and combining ability patterns of traits related to cellulosic ethanol production, determine if germplasm and mutations used for silage production would also be beneficial for feedstock production, and examine relationships between traits that are relevant to selective breeding. We evaluated grain hybrids, germplasm bred for silage production, brown‐midrib hybrids, and a leafy hybrid. Yield and composition traits were measured in four environments. There was a 53% difference in stover yield between commercial grain hybrids that were equivalent for other production‐related traits. Silage germplasm may be useful for increasing stover yield and reducing lignin concentration. We found much more variation among hybrids than either in vitro ruminal fermentability or polysaccharide concentration. Correlations between traits were mostly favorable or nonexistent. Our results suggest that utilizing standing genetic variation of maize in breeding programs could substantially increase the amount of biofuels produced from stover per unit area of land.
Genetic Basis of the Low‐Phytate Trait in the Soybean Line CX1834
Authors: Maroof M.A. Saghai , Glover Natasha M. , Biyashev Ruslan M. , Buss Glenn R. , Grabau Elizabeth A.
Published: January 2009

The low‐phytate (LP) trait in plant seeds offers important nutritional and environmental benefits for food and feed uses. Mutants with reduced phytate content are commonly produced by chemical mutagenesis, as is the case for soybean [Glycine max (L.) Merr.] line CX1834. Quantitative trait loci (QTL) for LP in CX1834 have previously been reported, however the genetic basis for this trait has not been identified. In this study, we examined several possible chromosomal map locations for the LP mutation in CX1834. After eliminating the myo‐inositol phosphate synthase (MIPS) gene family as the location of the LP mutations based on mapping studies, we focused on candidate genes in regions of known low‐phytate QTL on linkage groups (LGs) L and N. Using the soybean whole‐genome sequence, we identified genes encoding two putative multidrug resistance‐associated proteins (MRPs). The sequence of a segment of the CX1834 MRP gene on LG N was compared with sequences from 16 other soybean lines with normal phytate content. A single nucleotide mutation from A to T, resulting in substitution of a stop codon for an Arg residue, was detected in the MRP gene on LG N of the low phytate line, but not in the normal counterparts. Further comparative sequence analysis of normal and LP progeny from a cross of CX1834 with V99‐3337 (normal phytate) also indicated the A to T substitution in LP individuals, suggesting a mutation in an MRP gene as the possible cause of the low‐phytate phenotype.
Identification of Candidate Gene Mutation Associated With Low Stachyose Phenotype in Soybean Line PI200508
Authors: Skoneczka J. A. , Maroof M. A. Saghai , Shang C. , Buss G. R.
Published: January 2009

To investigate the genetic factors underlying a major quantitative trait locus (QTL) contributing to low seed stachyose content in two separate populations derived from soybean [Glycine max (L.) Merr.] line PI200508, the recently released ‘Williams 82’ whole genome shotgun (WGS) sequence was exploited for candidate gene discovery. The physical interval containing a low stachyose QTL from PI200508 was identified in the WGS, and screened for areas that could be exploited for linkage mapping purposes. Microsatellite sequences designed in these areas were used to develop new markers, creating tighter linkage with the QTL. Examination of the Williams 82 sequence in this interval and the corresponding glyma0.1b gene model, available through the Phytozome website (http://www.phytozome.org), revealed one candidate gene with significant homology to previously characterized galactosyltransferase genes from Arabidopsis, pea, and cucumber. Sequencing of the annotated coding region for this gene revealed a single unique sequence polymorphism between PI200508, and lines exhibiting wild‐type expression of stachyose content. The mutant phenotype appears to have arisen from a 3 bp deletion, and is easily distinguished from the wild‐type allele via a marker presented in this study. This mutation‐specific marker explained 88 to 94% of the phenotypic variation for seed stachyose content, and 76% for seed sucrose content, traits that exhibited a strong negative correlation in this study (p < 0.01).
Genomic Selection for Crop Improvement
Authors: Heffner Elliot L. , Sorrells Mark E. , Jannink Jean‐Luc
Published: January 2009

Despite important strides in marker technologies, the use of marker‐assisted selection has stagnated for the improvement of quantitative traits. Biparental mating designs for the detection of loci affecting these traits (quantitative trait loci [QTL]) impede their application, and the statistical methods used are ill‐suited to the traits' polygenic nature. Genomic selection (GS) has been proposed to address these deficiencies. Genomic selection predicts the breeding values of lines in a population by analyzing their phenotypes and high‐density marker scores. A key to the success of GS is that it incorporates all marker information in the prediction model, thereby avoiding biased marker effect estimates and capturing more of the variation due to small‐effect QTL. In simulations, the correlation between true breeding value and the genomic estimated breeding value has reached levels of 0.85 even for polygenic low heritability traits. This level of accuracy is sufficient to consider selecting for agronomic performance using marker information alone. Such selection would substantially accelerate the breeding cycle, enhancing gains per unit time. It would dramatically change the role of phenotyping, which would then serve to update prediction models and no longer to select lines. While research to date shows the exceptional promise of GS, work remains to be done to validate it empirically and to incorporate it into breeding schemes.
Tool with Road-Level Crash Prediction for Transportation Safety Planning
Authors: Tarko Andrew P. , Inerowicz Mike , Ramos Jorge , Li Wei
Published: January 2009

The growing use of packages based on geographic information systems (GISs) in transportation planning is assisting in the development and implementation of methods that facilitate consideration of safety. This paper presents a method of predicting safety for planning alternatives. Although applicable to large road networks, the method predicts crashes at the road facility level (intersections and segments). Thus it is suitable for joint evaluation of modifications of the road network, changes in network traffic flows, and improvements in road geometry considered by planners. A complete set of crash prediction models was developed by the authors for seven types of road segments and four types of road nodes on the basis of crashes reported on Indiana highways from 2003 to 2005. A mainstream research method has been used: negative binomial regression with a stepwise method for variable selection and the Akaike information criterion. The obtained equations are transparent to transportation planners and allow efficient computations for large road networks. The crash prediction equations have been implemented in the GIS-based planning package TransCAD as an add-on tool. The calibration procedure included in the tool allows a planner to search for optimal values of calibration factors if calibration of crash prediction models is needed.
Relationships between Safety and Both Congestion and Number of Lanes on Urban Freeways
Authors: Kononov Jake , Bailey Barbara , Allery Bryan K.
Published: January 2009

This paper first explores the relationship between safety and congestion and then examines the relationship between safety and the number of lanes on urban freeways. The relationship between safety and congestion on urban freeways was explored with the use of safety performance functions (SPFs) calibrated for multilane freeways in Colorado, California, and Texas. The focus of most SPF modeling efforts to date has been on the statistical technique and the underlying probability distribution, with only limited consideration given to the nature of the phenomenon itself. In this study neural networks have been used to identify the underlying relationship between safety and exposure. The modeling process was informed by the consideration of the traffic operations parameters described by the Highway Capacity Manual. The shape of the SPF is best described by a sigmoid reflecting a dose-response type of relationship between safety and traffic demand on urban freeways. Relating safety to the degree of congestion suggests that safety deteriorates with the degradation in the quality of service expressed through the level of service. Practitioners generally believe that additional capacity afforded by additional lanes is associated with more safety. How much safety and for what time period are generally not considered. Comparison of SPFs of multilane freeways suggests that adding lanes may initially result in a temporary safety improvement that disappears as congestion increases. As annual average daily traffic increases, the slope of SPF, described by its first derivative, becomes steeper, reflecting that accidents are increasing at a faster rate than would be expected from a freeway with fewer lanes.
Accident Modification Factors for Medians on Freeways and Multilane Rural Highways in Texas
Authors: Fitzpatrick Kay , Lord Dominique , Park Byung-Jung
Published: January 2009

With the growing demand for safer streets and highways, state and national transportation agencies are investigating the relationships between roadway characteristics and crashes. The objective of this study was to develop accident modification factors (AMFs) for median characteristics on urban and rural freeways and on rural multilane highways. Data available for use in the evaluation included 458 mi of with-barrier segments (primarily urban, with some rural sites), 359 mi of urban without-barrier segments, and 436 mi of rural without-barrier segments. A series of negative binomial regression models was used to determine the effects of independent variables on crashes. Variables considered in developing the base models included average daily traffic, left-shoulder width, barrier offset, median (with shoulder) width, and pole density. Crashes were examined in relation to median crashes for 5 years (1997 to 2001). An AMF represents the change in safety when a particular geometric design element changes in size from one value to another. In this project, the AMFs were estimated directly from the coefficients of the models. This approach for AMF development assumes that (a) each AMF is independent because the model parameters are assumed to be independent, and (b) the change in crash frequency is exponential. AMF equations were developed for urban and rural medians with rigid barriers, urban medians without barriers, and rural medians without barriers.
Crash Prediction Models for Rural Motorways
Authors: Montella Alfonso , Colantuoni Lucio , Lamberti Renato
Published: January 2009

In this paper, crash prediction models for estimating the safety of rural motorways are presented. Separate models were developed for total crashes and severe (fatal plus all injury) crashes. Generalized linear modeling techniques were used to fit the models, and a negative binomial distribution error structure was assumed. The study used a sample of 2,245 crashes (728 severe crashes) that occurred from 2001 to 2005 on Motorway A16 between Naples and Canosa in Italy. Many characteristics of the motorway were substandard. The motorway allowed investigation of a wide spectrum of geometric configurations. The models were developed by the stepwise-forward procedure with explanatory variables related to traffic volume and composition, horizontal alignment, vertical alignment, design consistency, sight distance, roadside context, cross section, speed limits, and interchange ramps. The decision to keep a variable in the model was based on two criteria. The first was whether the t-ratio of the variable's estimated coefficient was significant at the 5% level. The second criterion was related to the improvement of goodness-of-fit measures of the model that includes that variable. Goodness-of-fit measures were the parameter Rα2 and Akaike's information criterion. All the parameters have a logical and expected sign. The most important result was that design consistency measures significantly affected road safety, not only on two-lane rural highways, but also on motorways.
Comparison of Methodology Approach to Identify Causal Factors of Accident Severity
Authors: Wong Jinn-Tsai , Chung Yi-Shih
Published: January 2009

Identifying the factors that significantly affect accident severity has become one of the many ways to reduce it. While many accident database studies have reported associations between factors and severities, few of them could assert causality, primarily because of uncontrolled confounding effects. This research is an attempt to resolve the issue by comparing the difference between what happened and what would have happened in different circumstances. Data on accidents were analyzed first with rough set theory to determine whether they included complete information about the circumstances of their occurrence by an accident database. The derived circumstances were then compared with each other. For those remaining accidents without sufficient information, logistic regression models were employed to investigate possible associations. Adopting the 2005 Taiwan single-auto-vehicle accident data set, the empirical study showed that an accident could be fatal mainly because of a combination of unfavorable factors instead of a single unfavorable factor. Moreover, the accidents related to rules with high support and those with low support showed distinct features.
Phosphorylated Insulin Like Growth Factor-I Receptor Expression and Its Clinico-Pathological Significance in Histologic Subtypes of Human Thyroid Cancer
Authors: Chakravarty Geetika , Santillan Alfredo A. , Galer Chad , Adams Henry P. , El-Naggar Abdal K. , Jasser Samar A. , Mohsin Sayed , Mondal Debasis , Clayman Gary L. , Myers Jeffrey N.
Published: January 2009

Overexpression of insulin-like growth factor-I receptor (IGF-IR) is seen in a multitude of human thyroid cancers and correlates with poor prognosis. However, recent studies suggest that low phospho-IGF-IR (pIGF-IR) expression rather than its overexpression may be an indicator of poorly differentiated disease. No previous study has evaluated the expression of pIGF-IR to determine if activation or loss of expression of this receptor is associated with thyroid tumor progression. Accordingly, a quantitative immunohistochemical (IHC) method was used to evaluate the clinico-pathological significance of pIGF-IR expression in archival samples of human thyroid carcinomas. Quantitative analysis of pIGF-IR levels revealed a significant difference in the median index of pIGF-IR between different histological subtypes of thyroid cancer ( P < 0.001). Specifically, the median pIGF-IR index of differentiated thyroid cancers was significantly higher than the median index of other poorly differentiated thyroid cancer ( P < 0.001). This was further confirmed in individual tumor sections of thyroid carcinoma where anaplastic and differentiated components co-existed. No significant difference was noted in the pIGF-IR index of tumors grouped by size or stage but a trend towards lower mean pIGF-IR index was noted in older patients. Our data indicates that pIGF-IR is upregulated in a majority of follicular thyroid carcinomas, suggesting it may be a potential target for therapy for patients with this disease. In addition, since low pIGF-IR expression was found to correlate with aggressive human thyroid carcinoma, it also suggests that IGF-IR may not be needed for progression of anaplastic thyroid carcinoma possibly because other cell signaling pathways are activated, obviating the need for IGF-IR signaling. However, more mechanistic studies would be necessary to substantiate the possibility that pIGF-IR may be important for differentiation of thyroid tissues and is lost with disease progression.
In Vivo Expansion of the Mammary Stem/ Progenitor Cell Population by Xanthosine Infusion
Authors: Capuco Anthony V. , Evock-Clover Christina M. , Minuti Andrea , Wood David L.
Published: January 2009

Mammary stem cells provide for growth and maintenance of the mammary gland and are therefore of considerable interest as determinants of productivity and efficiency of dairy animals and as targets of carcinogenesis in humans. Xanthosine treatment was previously shown to promote expansion of hepatic stem cells in vitro. The objective of this study was to determine if in vivo treatment with xanthosine can increase the mammary stem cell population. Xanthosine was infused into the right mammary glands of four female Holstein calves for 5 consecutive days. Immediately after each xanthosine treatment, calves were injected intravenously with 5-bromo-2-deoxyuridine (BrdU). Forty days after the final treatment, calves were euthanized and mammary tissue harvested. BrdU-label retaining epithelial cells (LREC) were detected immunohistochemically and quantified. Retention of BrdU was used as a marker for putative bovine mammary stem cells. Infusion of xanthosine into the bovine mammary gland significantly increased the number of LREC in treated glands compared to contralateral control glands ( P < 0.05). LREC averaged 0.4% of epithelial cells in control glands and 0.8% in xanthosine-treated glands. The increase in LREC in xanthosine-treated glands was supported by a concomitant increase in telomerase activity ( P < 0.01) and a correlation between LREC and telomerase ( P < 0.05; r2 = 0.7). Data indicate that in vivo treatment with xanthosine can be used to increase the number of mammary stem cells. This is the first demonstration of an in vivo treatment to increase the endogenous population of mammary stem cells, with utility for biomedical research and dairy management.
Cruciferous Dithiolethione-Mediated Coordinated Induction of Total Cellular and Mitochondrial Antioxidants and Phase 2 Enzymes in Human Primary Cardiomyocytes: Cytoprotection Against Oxidative/Electrophilic Stress and Doxorubicin Toxicity
Authors: Zhu Hong , Jia Zhenquan , Zhou Kequan , Misra Hara P. , Santo Arben , Gabrielson Kathleen L. , Li Yunbo
Published: January 2009

3 H-1,2-dithiole-3-thione (D3T), a cruciferous organosulfur compound, induces cytoprotective enzymes in animal cardiovascular cells. However, it remains unknown if D3T also upregulates antioxidants and phase 2 enzymes in human cardiomyocytes, and protects against cell injury induced by oxidative/electrophilic species as well as doxorubicin. In this study, we found that D3T (10–50 μM) potently induced a series of antioxidants and phase 2 enzymes in primary cultured human cardiomyocytes, including superoxide dismutase (SOD), glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx) glutathione S-transferase (GST), NAD(P)H:quinone oxidoreductase 1 (NQO1), aldose reductase (AR), and heme oxygenase (HO). D3T treatment also caused elevation of SOD, GSH, GR, GPx and GST in the isolated mitochondria. We also observed a time-dependent induction by D3T of mRNA expression for Cu,ZnSOD, MnSOD, γ-glutamylcysteine ligase, GR, GSTA1, GSTM1, NQO1, AR, and HO-1. Pretreatment with D3T conferred concentration-dependent protection against cell injury induced by xanthine oxidase (XO)/xanthine, H2O2, 3-morpholinosydnonimine, 4-hydroxy-2-nonenal, and doxorubicin. Pretreatment with D3T also reduced the formation of intracellular reactive oxygen species by XO/xanthine, H2O2, and doxorubicin. In conclusion, this study demonstrated that D3T potently upregulated many antioxidants and phase 2 enzymes in human cardiomyocytes, which was accompanied by increased resistance to oxidative/electrophilic stress and doxorubicin toxicity.
Information, Deformed қ-Wehrl Entropies and Semiclassical Delocalization
Authors: Pennini Flavia , Plastino Angelo , Ferri Gustavo  L. , Olivares Felipe , Casas Montse
Published: January 2009

Semiclassical delocalization in phase space constitutes a manifestation of the Uncertainty Principle, one indispensable part of the present understanding of Nature and the Wehrl entropy is widely regarded as the foremost localization-indicator. We readdress the matter here within the framework of the celebrated semiclassical Husimi distributions and their associatedWehrl entropies, suitably қ-deformed. We are able to show that it is possible to significantly improve on the extant phase-space classical-localization power.
B cell depletion with rituximab in patients with diffuse cutaneous systemic sclerosis
Authors: Lafyatis Robert , Kissin Eugene , York Michael , Farina Giuseppina , Viger Kerry , Fritzler Marvin J. , Merkel Peter A. , Simms Robert W.
Published: January 2009

Objective

To determine the safety of rituximab, to provide preliminary data regarding the potential efficacy of rituximab, and to investigate the effects of rituximab on autoimmunity and fibrosis in patients with diffuse cutaneous systemic sclerosis (dcSSc).

Methods

Fifteen patients with dcSSc, all of whom experienced their first non–Raynaud's disease–associated disease manifestation within 18 months of trial entry, were recruited to receive 2 intravenous doses of rituximab (1,000 mg), administered 2 weeks apart. Safety, clinical, and exploratory outcomes were evaluated at baseline and at 6 months. The primary outcome was the change in the modified Rodnan skin thickness score (MRSS) at 6 months compared with baseline.

Results

Adverse events included frequent infusion reactions and rare infections (urinary tract infection and dental abscess occurred in 1 patient each). The mean change in the MRSS between baseline and 6 months was not significant. Results of pulmonary function tests and other measures of major organ involvement were stable. The modest B cell infiltrates that were present in most skin biopsy specimens at baseline were completely depleted at 6 months in most patients. Autoantibody titers showed only modest and variable changes after treatment.

Conclusion

In this pilot study, treatment with rituximab appeared to be safe and well tolerated among patients with dcSSc. Rituximab treatment resulted in both depletion of circulating B cells and depletion of dermal B cells but had little effect on the levels of SSc‐associated autoantibodies. Rituximab treatment did not appear to result in a significant beneficial effect on skin disease. The potential efficacy of rituximab in other organs such as the lung could not be clearly evaluated in this small open‐label trial.
Multi‐round virus filter integrity test sensitivity
Authors: Dowd Christopher J.
Published: January 2009

Virus filtration is becoming increasingly prominent in biopharmaceutical recovery processes as a robust method to remove a broad range of virus types. Increasing batch sizes will require large numbers of individual virus filter elements operating in parallel. Before adopting a more complex strategy for managing the integrity testing of large assemblies of virus filters, it is important to understand the sensitivity of the forward flow diffusion test for a single filter and for multiple filters in a single housing. An approach has been developed to estimate the largest hole that could consistently go undetected in a single filter within a larger assembly of virus filters. The integrity test limited minimum log reduction value (LRV) is determined based on the size of the hole as a function of the number of filters in the housing. This minimum LRV is shown to be largely insensitive to the number of filters within the housing. The likelihood of such damage occurring is expected to be very low. This analysis suggests there is minimal benefit to placing filters in individual housings or to adjusting the test specification to compensate for larger numbers of filters in a given housing. Biotechnol. Bioeng. 2009;103: 574–581. © 2009 Wiley Periodicals, Inc.
Case Studies of Sizing Pressure Relief Valves for Two‐Phase Flow
Authors: Schmidt J. , Egan S.
Published: January 2009

The most widely accepted methods of sizing safety valves for two‐phase‐flow, namely the homogeneous equilibrium model of Leung, the HNE‐DS model proposed in ISO 4126‐10, and the latest version of the API 520 two‐point ω‐model were compared to each other. The thermodynamic and mechanical nonequilibrium effect included in the ISO (HNE‐DS) model dominates the more rigorous property data calculation (API) at low and moderate reduced pressures, whereas the critical flow rates become closer when approaching the thermodynamic critical point. In addition, the predictive accuracy of the ISO (HNE‐DS) model was analyzed by means of roughly 3000 experimental data points from the literature. This data includes flashing steam/water, non‐flashing air/water, and initially subcooled water flowing through safety valves from several manufacturers. The calculated flow rates are in good agreement with the measurements.