bluuebunny/crossref_metadata_2025 huggingface dataset:
On-board road condition monitoring system using slip-based tyre-road friction estimation and wheel speed signal analysis
Authors: Li K , Misener J A , Hedrick K
Published: April 2007

This paper presents an on-board road condition monitoring system. The road condition is continuously evaluated in terms of slipperiness and coarseness and is classified into four grades, normal (μmax ≤ 0.5), slippery (0.3 ≤ μmax< 0.5), very slippery (μmax< 0.3), and rough surface (gravel). A non-linear curve fitting technique is adopted to estimate the maximum tyre-road friction coefficient using the so-called ‘magic formula’. The characteristic of the relationship between friction coefficient and slip, i.e. the value of maximum friction coefficient μmax varies significantly with different surfaces, but its corresponding slip value λmax does not vary much, is exploited in the road condition classification algorithm. For surface coarseness analysis, a separate classifier based on the variance of filtered wheel speed signal is implemented. Experimental results demonstrate the feasibility of the road condition monitoring system for detecting slippery and rough road surfaces in close to real-time. In addition, the proposed slip-based friction estimation algorithm has the merits of robustness to vehicle-tyre variance and easy calibration as opposed to past slip-based friction estimation approaches in the literature.
Using Bayesian statistics to support testing of software systems
Authors: Coolen F. P. A. , Goldstein M , Wooff D. A.
Published: April 2007

Testing of software systems is crucial for reliability, but is often difficult owing to the many uncertainties and practical constraints involved. The nature of the software development process often prevents straightforward application of standard statistical methods. In recent years, the current authors have developed a Bayesian statistical approach to support software testers, in particular for high reliability testing of software systems near the end of the development process. Throughout this period, they have been collaborating with an industrial partner to ensure practical relevance of the methods. An important difference when compared with existing methods to support software testing is that the judgements and current practice of the software testers are central, so the method helps testers to structure their judgements and optimize corresponding test actions, the latter process being far too complex to be done effectively without the support of such sophisticated statistical methods. In the present paper, an overview is given of this approach and of results to date. Recent progress is also discussed, together with related future research topics aimed at wide practical applicability of the approach.
Ensemble feature selection for diagnosing multiple faults in rotating machinery
Authors: Zio E , Baraldi P , Gola G
Published: April 2007

Recent research in fault classification has shown that one of the benefits of using ensembles of classifiers is that they achieve higher accuracy than single ones. For an ensemble to be effective, it should consist of base classifiers that give diverse predictions. One method for constructing an ensemble is to have the base classifiers work on different feature sets. In the current paper, the problem of selecting the feature sets for the base classifiers is handled by means of genetic algorithms aimed at maximizing the fault classification performance and at minimizing the number of features. A voting technique is then used to combine effectively the outputs of the base classifiers to construct the ensemble output. For verification, some numerical experiments are conducted on multiple fault classification in rotating machinery and the results are compared with those obtained using an optimal single classifier.
Genetic and Environmental Influences on Plasma Homocysteine: Results from a Danish Twin Study
Authors: Bathum Lise , Petersen Inge , Christiansen Lene , Konieczna Agnieszka , Sørensen Thorkild IA , Kyvik Kirsten O
Published: April 2007

Background: Increased plasma homocysteine has been linked to many clinical conditions including atherosclerosis and ischemic stroke. We assessed the genetic and environmental influences on homocysteine in adult twins and tested the influence of 3 candidate polymorphisms.

Methods: Homocysteine was analyzed in 1206 healthy twins, who were genotyped for 3 polymorphisms: MTHFR 677C>T, MTR 2756A>G, and NNMT (dbSNP: rs694539). To perform quantitative trait linkage analysis of the MTHFR locus, the genotyping was supplemented with 2 genetic markers localized on each site of the MTHFR locus. The twin data were analyzed using biometric structural equation models as well as a combined association and linkage analysis in 2 age cohorts.

Results: Age, sex, and MTHFR genotype have a significant impact on homocysteine concentrations, whereas the other genotypes were not associated with homocysteine concentrations. The variance in homocysteine could be solely ascribed to additive genetic and nonshared environmental factors, with an estimated additive genetic proportion of total variation at age 18–39 years of 0.63 (95% CI, 0.53–0.71) and at age 40–65 years of 0.27 (95% CI, 0.10–0.41). The impact of the MTHFR locus is estimated to explain 53% (95% CI, 0.07–0.67) of the total phenotypic variation in persons 18–39 years old and 24% (95% CI, 0.00–0.39) in persons 40–65 years old, i.e., almost all additive genetic variance.

Conclusions: Homocysteine concentrations have a high heritability that decreases with age. The MTHFR gene locus is responsible for almost all the variation attributable to genetic factors, leaving very little influence of other genetic variations.
Morphological variation of two Alexandrium species responsible for paralytic shellfish poisoning in Southeast Asia
Authors: Lim Po-Teen , Leaw Chui-Pin , Ogata Takehiko
Published: April 2007

We examined in clonal cultures the morphological variation of two toxic dinoflagellates, Alexandrium tamiyavanichii and A. minutum, responsible for paralytic shellfish poisoning events in Southeast Asia. The Malaysian strain of A. tamiyavanichii had either a straight or oblique posterior margin on the first apical plate, and a triangular, square to trapezoid-shaped precingular part of the anterior sulcal plate. Morphological variability was also detected in the shape of the first apical plate, its connection to the apical pore, and the position of the ventral pore. In A. minutum, the Malaysian strains showed variation in the sixth precingular plate and the anterior sulcal plate. The length:width ratio of the sixth precingular plate varied from one to two. An anterior sulcal plate with a long left extension also occurred in both of the Malaysian strains. Several characters that have been extensively used in the identification of Alexandrium species have been proven quite variable.
Evolution of DNA Double-Strand Break Repair by Gene Conversion: Coevolution Between a Phage and a Restriction-Modification System
Authors: Yahara Koji , Horie Ryota , Kobayashi Ichizo , Sasaki Akira
Published: April 2007

The necessity to repair genome damage has been considered to be an immediate factor responsible for the origin of sex. Indeed, attack by a cellular restriction enzyme of invading DNA from several bacteriophages initiates recombinational repair by gene conversion if there is homologous DNA. In this work, we modeled the interaction between a bacteriophage and a bacterium carrying a restriction enzyme as antagonistic coevolution. We assume a locus on the bacteriophage genome has either a restriction-sensitive or a restriction-resistant allele, and another locus determines whether it is recombination/repair proficient or defective. A restriction break can be repaired by a co-infecting phage genome if one of them is recombination/repair proficient. We define the fitness of phage (resistant/sensitive and repair-positive/-negative) genotypes and bacterial (restriction-positive/-negative) genotypes by assuming random encounter of the genotypes, with given probabilities of single and double infections, and the costs of resistance, repair, and restriction. Our results show the evolution of the repair allele depends on $\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(b_{1}/b_{0},\) \end{document}$ the ratio of the burst size $\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(b_{1}\) \end{document}$ under damage to host cell physiology induced by an unrepaired double-strand break to the default burst size $\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(b_{0}.\) \end{document}$ It was not until this effect was taken into account that the evolutionary advantage of DNA repair became apparent.
Genomewide Association Analysis in Diverse Inbred Mice: Power and Population Structure
Authors: McClurg Phillip , Janes Jeff , Wu Chunlei , Delano David L , Walker John R , Batalov Serge , Takahashi Joseph S , Shimomura Kazuhiro , Kohsaka Akira , Bass Joseph , Wiltshire Tim , Su Andrew I
Published: April 2007

The discovery of quantitative trait loci (QTL) in model organisms has relied heavily on the ability to perform controlled breeding to generate genotypic and phenotypic diversity. Recently, we and others have demonstrated the use of an existing set of diverse inbred mice (referred to here as the mouse diversity panel, MDP) as a QTL mapping population. The use of the MDP population has many advantages relative to traditional F2 mapping populations, including increased phenotypic diversity, a higher recombination frequency, and the ability to collect genotype and phenotype data in community databases. However, these methods are complicated by population structure inherent in the MDP and the lack of an analytical framework to assess statistical power. To address these issues, we measured gene expression levels in hypothalamus across the MDP. We then mapped these phenotypes as quantitative traits with our association algorithm, resulting in a large set of expression QTL (eQTL). We utilized these eQTL, and specifically cis-eQTL, to develop a novel nonparametric method for association analysis in structured populations like the MDP. These eQTL data confirmed that the MDP is a suitable mapping population for QTL discovery and that eQTL results can serve as a gold standard for relative measures of statistical power.
Adaptation of a Quantitative Trait to a Moving Optimum
Authors: Kopp Michael , Hermisson Joachim
Published: April 2007

We investigate adaptive evolution of a quantitative trait under stabilizing selection with a moving optimum. We characterize three regimes, depending on whether (1) the beneficial mutation rate, (2) the fixation time, or (3) the rate of environmental change is the limiting factor for adaptation. If the environment is rate limiting, mutations with a small phenotypic effect are prefered over large mutations, in contrast to standard theory.
A Novel Type of Sequence Variation: Multiple-Nucleotide Length Polymorphisms Discovered in the Bovine Genome
Authors: Jiang Zhihua , Wang Zeping , Kunej Tanja , Williams Galen A , Michal Jennifer J , Wu Xiao-Lin , Magnuson Nancy S
Published: April 2007

Three types of sequence variations—single-nucleotide polymorphisms (SNPs), insertions and deletions (indels), and short tandem repeats (STRs)—have been extensively reported in mammalian genomes. In this study, we discovered a novel type of sequence variation, i.e., multiple-nucleotide length polymorphisms (MNLPs) in bovine UCN3 (Urocortin 3) and its receptor CRHR2 (corticotropin-releasing hormone receptor 2) genes. Both MNLPs featured involvement of multiple-nucleotide length polymorphisms (5–18 bases), low sequence identity, and 1.7- to 11-fold changes in promoter activity between two alleles. Therefore, this novel genetic complexity would contribute significantly to the evolutionary, functional, and phenotypic complexity of genomes within or among species.
Transcriptional Interferences in cis Natural Antisense Transcripts of Humans and Mice
Authors: Osato Naoki , Suzuki Yoshiyuki , Ikeo Kazuho , Gojobori Takashi
Published: April 2007

For a significant fraction of mRNAs, their expression is regulated by other RNAs, including cis natural antisense transcripts (cis-NATs) that are complementary mRNAs transcribed from opposite strands of DNA at the same genomic locus. The regulatory mechanism of mRNA expression by cis-NATs is unknown, although a few possible explanations have been proposed. To understand this regulatory mechanism, we conducted a large-scale analysis of the currently available data and examined how the overlapping arrangements of cis-NATs affect their expression level. Here, we show that for both human and mouse the expression level of cis-NATs decreases as the length of the overlapping region increases. In particular, the proportions of the highly expressed cis-NATs in all cis-NATs examined were ∼36 and 47% for human and mouse, respectively, when the overlapping region was <200 bp. However, both proportions decreased to virtually zero when the overlapping regions were >2000 bp in length. Moreover, the distribution of the expression level of cis-NATs changes according to different types of the overlapping pattern of cis-NATs in the genome. These results are consistent with the transcriptional collision model for the regulatory mechanism of gene expression by cis-NATs.
Inorganic Phosphate Deprivation Causes tRNA Nuclear Accumulation via Retrograde Transport inSaccharomyces cerevisiae
Authors: Hurto Rebecca L , Tong Amy Hin Yan , Boone Charles , Hopper Anita K
Published: April 2007

Nuclear export of tRNA is an essential eukaryotic function, yet the one known yeast tRNA nuclear exporter, Los1, is nonessential. Moreover recent studies have shown that tRNAs can move retrograde from the cytosol to the nucleus by an undefined process. Therefore, additional gene products involved in tRNA nucleus–cytosol dynamics have yet to be identified. Synthetic genetic array (SGA) analysis was employed to identify proteins involved in Los1-independent tRNA transport and in regulating tRNA nucleus–cytosol distribution. These studies uncovered synthetic interactions between los1Δ and pho88Δ involved in inorganic phopshate uptake. Further analysis revealed that inorganic phosphate deprivation causes transient, temperature-dependent nuclear accumulation of mature cytoplasmic tRNA within nuclei via a Mtr10- and retrograde-dependent pathway, providing a novel connection between tRNA subcellular dynamics and phosphate availability.
A Microsatellite-Based, Gene-Rich Linkage Map Reveals Genome Structure, Function and Evolution in Gossypium
Authors: Guo Wangzhen , Cai Caiping , Wang Changbiao , Han Zhiguo , Song Xianliang , Wang Kai , Niu Xiaowei , Wang Cheng , Lu Keyu , Shi Ben , Zhang Tianzhen
Published: April 2007

The mapping of functional genes plays an important role in studies of genome structure, function, and evolution, as well as allowing gene cloning and marker-assisted selection to improve agriculturally important traits. Simple sequence repeats (SSRs) developed from expressed sequence tags (ESTs), EST–SSR (eSSR), can be employed as putative functional marker loci to easily tag corresponding functional genes. In this paper, 2218 eSSRs, 1554 from G. raimondii-derived and 754 from G. hirsutum-derived ESTs, were developed and used to screen polymorphisms to enhance our backbone genetic map in allotetraploid cotton. Of the 1554 G. raimondii-derived eSSRs, 744 eSSRs were able to successfully amplify polymorphisms between our two mapping parents, TM-1 and Hai7124, presenting a polymorphic rate of 47.9%. However, only a 23.9% (159/754) polymorphic rate was produced from G. hirsutum-derived eSSRs. No relationship was observed between the level of polymorphism, motif type, and tissue origin, but the polymorphism appeared to be correlated with repeat type. After integrating these new eSSRs, our enhanced genetic map consists of 1790 loci in 26 linkage groups and covers 3425.8 cM with an average intermarker distance of 1.91 cM. This microsatellite-based, gene-rich linkage map contains 71.96% functional marker loci, of which 87.11% are eSSR loci. There were 132 duplicated loci bridging 13 homeologous At/Dt chromosome pairs. Two reciprocal translocations after polyploidization between A2 and A3, and between A4 and A5, chromosomes were further confirmed. A functional analysis of 975 ESTs producing 1122 eSSR loci tagged in the map revealed that 60% had clear BLASTX hits (<1e−10) to the Uniprot database and that 475 were associated mainly with genes belonging to the three major gene ontology categories of biological process, cellular component, and molecular function; many of the ESTs were associated with two or more category functions. The results presented here will provide new insights for future investigations of functional and evolutionary genomics, especially those associated with cotton fiber improvement.
Stepping-Stone Spatial Structure Causes Slow Decay of Linkage Disequilibrium and Shifts the Site Frequency Spectrum
Authors: De Arkendra , Durrett Richard
Published: April 2007

The symmetric island model with D demes and equal migration rates is often chosen for the investigation of the consequences of population subdivision. Here we show that a stepping-stone model has a more pronounced effect on the genealogy of a sample. For samples from a small geographical region commonly used in genetic studies of humans and Drosophila, there is a shift of the frequency spectrum that decreases the number of low-frequency-derived alleles and skews the distribution of statistics of Tajima, Fu and Li, and Fay and Wu. Stepping-stone spatial structure also changes the two-locus sampling distribution and increases both linkage disequilibrium and the probability that two sites are perfectly correlated. This may cause a false prediction of cold spots of recombination and may confuse haplotype tests that compute probabilities on the basis of a homogeneously mixing population.
Toxicity of 5% Rotenone to Nonindigenous Asian Swamp Eels
Authors: Schofield Pamela J. , Nico Leo G.
Published: April 2007

Our primary goal was to determine whether rotenone would be a useful control against introduced populations of Asian swamp eels (family Synbranchidae, genus Monopterus). We report the results of a laboratory experiment comparing the efficacy of various rotenone concentrations (1, 2, 4, and 8 mg of 5% liquid rotenone/L of water) in killing nonindigenous swamp eels of various sizes (1–350 g) from the three known Florida populations. Although most small swamp eels were killed at concentrations of 2 and 4 mg/L, 100% mortality of adult swamp eels was achieved only at 8 mg/L. We conclude that the effective use of rotenone to control established Florida swamp eel populations would be difficult, based on the relatively high concentration of rotenone needed to kill swamp eels; the complexity of the swamp eel's habitat; and our observations of the species' habitat use and behavior, including its widespread distribution and life history characteristics (e.g., burrowing and overland movement) that enhance its invasion and survival in multiple environments. Nevertheless, control of swamp eels may be achieved in certain situations. A combination of rotenone and electroshocking may be an effective way to eradicate swamp eels from small water bodies and to control populations in larger habitats. However, we are cautious in this recommendation and provide details related to the technical aspects of this type of strategy and caveats related to the toxicity of the chemical.
Impact of Tournaments on the Largemouth Bass Population at Sam Rayburn Reservoir, Texas
Authors: Driscoll M. T. , Smith J. L. , Myers R. A.
Published: April 2007

There have been concerns regarding tournament-related impacts on black bass Micropterus spp. for 40 years, but few studies have quantified those impacts. About 52% of anglers at Sam Rayburn Reservoir (46,356 ha) participate in tournaments, and the annual number of events probably exceeds 300. In 2003, we tagged and released 6,021 largemouth bass M. salmoides to estimate the annual proportion of the population caught and retained by tournament anglers. Tag returns were obtained via creel sampling to avoid nonreporting uncertainty, adjusted for recruitment and tag loss, and expanded to estimate the total annual tagged fish catch and harvest. We conducted simulations to evaluate the impacts of tournament mortality using rates of 10, 30, and 50% and compared those estimates with nontournament harvest and catch-and-release mortality (simulated at 5, 10, and 15%) to assess the specific contributions to annual angling and total mortality. From 3,447 angler interviews, creel clerks identified 40 largemouth bass caught by anglers during the interview day (27 of which were immediately released, 6 harvested by nontournament anglers, and 7 retained by tournament anglers). Expansion of tag returns resulted in 1,620 fish immediately released (27% of tagged population), 372 harvested by nontournament anglers (6% of tagged population), and 274 retained by tournament anglers (5% of tagged population; 242 were released). Tournament and catch-and-release mortality each comprised a total of 1–6% of the population losses across all simulations. Tournament mortality comprised 6–28% of total angling mortality, whereas catch-and-release mortality was 10–31%. Tournament mortality contributed 1–16% of total annual mortality, compared with 2–17% for catch-and-release mortality and 16–38% for nontournament harvest. We conclude that the tournament-related impacts on the largemouth bass population at Sam Rayburn Reservoir were low.
Evaluation of Visible Implant Elastomer for Marking Juvenile Red Drum
Authors: Bushon Amanda M. , Stunz Gregory W. , Reese Megan M.
Published: April 2007

Visible implant elastomer (VIE) was evaluated for marking juvenile red drum Sciaenops ocellatus in experimental studies. We tested VIE on hatchery-reared red drum (standard length, 29.6–38.7 mm; SE, 0.23) in a laboratory study to examine mortality, tag retention, and growth effects associated with the marking method. We examined two tagging locations and two control treatments in anesthetized and unanesthetized fish. Red drum were tagged below and parallel to the dorsal fin and above and parallel to the anal fin. Five fish were anesthetized, marked, and stocked into replicated tanks and held for 14 d. Tag retention was 100%, and overall mortality was 10%. The mortality of fish tagged below the dorsal fin was 0%, whereas that of fish tagged above the anal fin was 40% (SE, 30.5). No significant difference in growth rates was observed between the marked and unmarked treatment groups. A field study was performed with wild and hatchery-reared red drum marked with VIE and released at three replicate sites in sea grass beds. The recapture rate was 1.3%, and marked fish were collected at 1 and 3 d postrelease at distances of 15–45 and 200 m from the release point. The results suggest that VIE marking of red drum has little effect on mortality and growth when fish are tagged dorsally and that VIE is a viable tool for short-term experiments requiring identification of small, juvenile red drum.
Partnering contracts in practice at Blackpool, UK
Authors: Cunningham L. S. , Pomfret M. A.
Published: April 2007

Over the past ten years, Blackpool Council has undertaken several major capital works schemes within a partnering environment. During this period, the council has sought to develop the partnering process with a view to optimising the design, construction and commissioning of projects. Currently engaged in the £64 million central area coast protection scheme under a partnering contract, numerous advantages over traditional forms of contract have been realised. This paper outlines the process of partnering through contract selection and administration. The method of incentivisation through the use of key performance indicators and associated benchmarking is also described. The effect of partnering and early contractor involvement on product quality is highlighted through improved buildability and defect minimisation. Allied to this, the centralised and inclusive environment fostered by partnering contracts has lent itself to improved health and safety throughout design, construction and commissioning. Finally, the wider benefits of the partnering approach for the local community and the delivery of quality urban regeneration are described.
Development of a Web‐Based Decision Support System For Crop Managers:Structural Considerations and Implementation Case
Authors: Fernandez Carlos J. , Trolinger T. Neal
Published: April 2007

Rapid developments since the mid 1990s of the Internet and the World Wide Web have created great opportunities to develop new approaches for the transfer of technology to farmers in the form of online computer‐assisted decision support systems. This paper discusses structural considerations regarding the development of Web‐based decision support systems in general and describes the development and deployment of The Crop Weather Program for South Texas, a decision support system for crop managers using modern Web‐based technology. The primary goal of this online system was to provide cotton growers easy access to (a) weather data collected by a network of weather stations and (b) a suite of powerful numerical simulation tools for field‐specific calculations of a variety of state variables describing the crop and its environment, such as heat unit calculation, occurrence of phenological events, soil moisture content, canopy growth, and crop water use. The online tools currently available to registered users are briefly described. After more than 6 yr, the Crop Weather Program for South Texas is still growing and continues to be a robust, reliable, and easy‐to‐use Web‐based decision support system for crop managers.
Government Subsidies and Crop Insurance Effects on the Economics of Conservation Cropping Systems in Eastern Washington
Authors: Nail Elizabeth L. , Young Douglas L. , Schillinger William F.
Published: April 2007

Government subsidies and crop insurance indemnities provide important support for many U.S. farmers. Economists often justify omitting government subsidies when comparing cropping systems because subsidies were decoupled from production in the 1996 Farm Bill. However, coupled loan deficiency payments (LDPs) were continued in the 1996 and 2002 Farm Bills for grains and were extended to several pulses and oilseeds in the 2002 Farm Bill. Furthermore, crop insurance premiums and indemnity payments have always been coupled to production. This paper calculates the impacts of including government subsidies and crop insurance on the results of two long‐term cropping systems experiments in eastern Washington. Both studies compared the agronomic and economic feasibility of annual cropping no‐till systems with traditional tillage‐based winter wheat (Triticum aestivum L.)–summer fallow (WW–SF). Net returns for WW–SF exceeded those for most annual no‐till systems in both experiments. No government subsidies or insurance impacts were included in previous analyses of these cropping systems. The present analysis shows that including government subsidies and crop insurance effects does not alter the profitability rankings of the annual no‐till vs. WW–SF cropping systems in these experiments. However, including crop insurance indemnities did slightly alter the rankings of the three most profitable no‐till systems in one experiment. The exclusion of government subsidies and crop insurance from previous research on conservation cropping systems in eastern Washington produced relatively sound economic rankings. To test the generality of this conclusion, similar comparisons would be required with other crops and in other regions.
Sorghum Management Practices Suited to Varying Irrigation Strategies: A Simulation Analysis
Authors: Baumhardt R. L. , Tolk J. A. , Howell T. A. , Rosenthal W. D.
Published: April 2007

Increasing pumping costs and declining well capacities in regions like the Southern High Plains of Texas are requiring producers to adapt cropping practices for use with irrigation levels that vary between complete replacement of crop evapotranspiration (ET) to none (i.e., dryland production). Grain sorghum [Sorghum bicolor (L.) Moench] is a crop suited to both dryland and various deficit irrigation production systems. Our objectives were to (i) identify cultural practices (planting date, population, and cultivar maturity) that maximize sorghum grain yield for widely varying irrigation strategies; and (ii) consider effective means to allocate available water among irrigation strategies that maximizes the ratio of yield to ET, that is, water use efficiency (WUE). Using the model SORKAM and long‐term (1958–1999) weather records from Bushland, TX, we simulated sorghum grain yields on a Pullman soil (fine, mixed, superactive, thermic Torrertic Paleustoll) under dryland (rain) and three deficit irrigation levels (rain + irrigation = 2.5, 3.75, or 5.0 mm d−1) for all combinations of planting date (mid‐May, 15 May; early June, 5 June; and late June, 25 June), cultivar maturity (early, 95 d; medium, 105 d; late, 120 d), and plant density (12 and 16 plants m−2). For 2.5 mm d−1 irrigation level, simulated grain yields were maximized with either early or medium‐maturing cultivars planted in early June. In contrast, simulated sorghum yield and WUE increased with a mid‐May planting date and later‐maturing cultivars for irrigation levels of 3.75 and 5.0 mm d−1. We conclude that spreading water to uniformly irrigate a field with 2.5 mm d−1 produces ∼16% less grain than concentrating the same water resources to variably irrigate a field at 3.75 or 5.0 mm d−1 with complementary (2:1 and 1:1) dryland areas.
Nutrient Assessment of a Dryland Wheat Agroecosystem after 12 Years of Biosolids Applications
Authors: Barbarick K. A. , Ippolito J. A.
Published: April 2007

Biosolids beneficial‐use programs effectively recycle plant nutrients when these waste materials are applied at an agronomic rate. Plant‐nutrient availability questions have arisen relating to Littleton and Englewood (L/E), Colorado Wastewater Treatment Plant bio‐solids applications to dryland wheat (Triticum aestivum L.)‐fallow agroecosystems. What is the long‐term estimated nitrogen equivalency (NE) of the biosolids? Can we estimate long‐term micronutrient distribution with continuous biosolids application? How does plant‐nutrient availability change with continuous application? Before each growing season we added biosolids at rates of 0 to 11.2 dry Mg ha−1 to plots arranged in randomized complete blocks with four replications per treatment. We found 12 years of application (6 applications to two sites in a 2‐yr wheat–fallow rotation) produced N equivalencies, based on wheat‐grain N uptake, of about 9 kg N Mg−1 biosolids. Estimated first‐year mineralization rates were ≈21 to 33%. Since P, Cu, Ni, and Zn grain removal were <1% of biosolids‐applied concentrations, we estimated that tillage‐layer (top 20 cm of soil) concentrations could be predicted within 5% of actual total soil contents based on biosolids additions of these nutrients. Biosolids additions produced linear increases in NH4HCO3‐diethylenetriaminepentaacetic acid (AB‐DTPA) soil extract concentrations of P, Cu, Ni, and Zn. Soils initially were Zn deficient; biosolids application provided plant‐available Zn for dryland wheat. If biosolids agronomic rates were based on P instead of N availability, these soils could not receive biosolids. Also, if the Colorado Phosphorus Index was utilized, agronomic rates would continue to be based on N. Biosolids addition to dryland winter wheat according to N agronomic rates is a feasible method of recycling plant nutrients.
Approximating common fixed points of asymptotically nonexpansive mappings by composite algorithm in Banach spaces
Authors: Qin Xiaolong , Su Yongfu , Shang Meijuan
Published: April 2007

Let E be a uniformly convex Banach space and K a nonempty convex closed subset which is also a nonexpansive retract of E. Let T
1, T
2 and T
3: K → E be asymptotically nonexpansive mappings with {k
n}, {l
n} and {j
n}. [1, ∞) such that Σn=1∞(k
n − 1) < ∞, Σn=1∞(l
n − 1) < ∞ and Σn=1∞(j
n − 1) < ∞, respectively and F nonempty, where F = {x ∈ K: T
1x
= T
2x
= T
3
x} = x} denotes the common fixed points set of T
1, T
2 and T
3. Let {α
n}, {α′
n} and {α″
n} be real sequences in (0, 1) and ∈ ≤ {α
n}, {α′
n}, {α″
n} ≤ 1 − ∈ for all n ∈ N and some ∈ > 0. Starting from arbitrary x
1 ∈ K define the sequence {x
n} by
$$\left\{ \begin{gathered} z_n = P(\alpha ''_n T_3 (PT_3 )^{n - 1} x_n + (1 - \alpha ''_n )x_n ), \hfill \\ y_n = P(\alpha '_n T_2 (PT_2 )^{n - 1} z_n + (1 - \alpha '_n )x_n ), \hfill \\ x_{n + 1} = P(\alpha _n T_1 (PT_1 )^{n - 1} y_n + (1 - \alpha _n )x_n ). \hfill \\ \end{gathered} \right.$$
(i) If the dual E* of E has the Kadec-Klee property then {x
n} converges weakly to a common fixed point p ∈ F; (ii) If T satisfies condition (A′) then {x
n} converges strongly to a common fixed point p ∈ F.
Variation in the uptake of Arsenic, Cadmium, Lead, and Zinc by different species of willows Salix spp. grown in contaminated soils
Authors: Tlustoš Pavel , Száková Jir̆ina , Vysloužilová Markéta , Pavlíková Daniela , Weger Jan , Javorská Hana
Published: April 2007

The experiment assessed the variability of in seven clones of willow plants of high biomass production (Salix smithiana S-218, Salix smithiana S-150, Salix viminalis S-519, Salix alba S-464, Salix ’Pyramidalis’ S-141, Salix dasyclados S-406, Salix rubens S-391). They were planted in a pots for three vegetation periods in three soils differing in the total content of risk elements. Comparing the calculated relative decrease of total metal contents in soils, the phytoextraction potential of willows was obtained for cadmium (Cd) and zinc (Zn), moderately contaminated Cambisol and uncontaminated Chernozem, where aboveground biomass removed about 30% Cd and 5% Zn of the total element content, respectively. The clones showed variability in removing Cd and Zn, depending on soil type and contamination level: S. smithiana (S-150) and S. rubens (S-391) demonstrated the highest phytoextraction effect for Cd and Zn. For lead (Pb) and arsenic (As), the ability to accumulate the aboveground biomass of willows was found to be negligible in both soils. The results confirmed that willow plants show promising results for several elements, mainly for mobile ones like cadmium and zinc in moderate levels of contamination. The differences in accumulation among the clones seemed to be affected more by the properties of clones, not by the soil element concentrations or soil properties. However, confirmation and verification of the results in field conditions as well as more detailed investigation of the mechanisms of cadmium uptake in rhizosphere of willow plants will be determined by further research.
The neuroprotective effect of Withania somnifera root extract in MPTP-intoxicated mice: An analysis of behavioral and biochemical varibles
Authors: Sankar Srinivasagam , Manivasagam Thamilarasan , Krishnamurti Arumugam , Ramanathan Manickam
Published: April 2007

We studied the influence of Withania somnifera (Ws) root extract (100 mg/kg body weight) on parkinsonism induced by 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine (MPTP; i.p, 20 mg/kg body weight for 4 days), via the analysis of behavioral features and the oxidant-antioxidant imbalance in the midbrain of mice. A significant alteration in behavior, increased levels of thiobarbituric acid reactive substance (TBARS), and increased activities of superoxide dismutase (SOD) and catalase (CAT) were noticed in this region of brain in MPTP-treated mice. Oral treatment with the root extract resulted in a significant improvement in the mice’s behavoiur and antioxidant status, along with a significant reduction in the level of lipid peroxidation. The results indicated that at least part of the chronic stress-induced pathology may be due to oxidative stress, which is mitigated by Ws. Further studies are needed to assess the precise mechanism to support the clinical use of the plant as an antiparkinsonic drug.
Analysis of helminth communities of the pine marten, Martes martes, in Spain: Mainland and insular data
Authors: Segovia Juan-Matías , Torres Jordi , Miquel Jordi , Sospedra Enric , Guerrero Ricardo , Feliu Carlos
Published: April 2007

The present study analyses the helminth communities found in one hundred and two specimens of Martes martes from the Iberian Peninsula and the Balearic Archipelago. The component community is constituted by seventeen helminth species, which frequency and mean abundance show a bimodal pattern. The set of core species is constituted by the trichurids Pearsonema plica, Eucoleus aerophilus and Aonchotheca putorii (72.2% of total helminth individuals found), while the remaining can be considered satellite species. Significant co-occurrences were found among E. aerophilus/A. putorii and E. aerophilus/P. plica. These results demonstrate the great importance of earthworms within the diet of pine marten and contribute to the knowledge of the pine marten’s food ethology, since this kind of prey normally goes undetected in diet studies. Several helminth species, as Sobolevingylus petrowi, Centrorhynchus aluconis, Uncinaria criniformis, Mastophorus muris and Spirura rytipleurites seurati seem to show geographical distributions limited to insular ecosystems. Moreover, helminth communities of M. martes among four Spanish territories, including mainland and insular areas, are characterized and compared.
Infestation of sand lizards (Lacerta agilis) resident in the Northeastern Poland by Ixodes ricinus (L.) ticks and their infection with Borrelia burgdorferi sensu lato
Authors: Gryczyńska-Siemiątkowska Alicja , Siedlecka Alicja , Stańczak Joanna , Barkowska Miłosława
Published: April 2007

Sand lizards (Lacerta agilis) were trapped and examined for ticks from May to September in 2002 and 2003 in Northeastern Poland. A total of 233 Ixodes ricinus (L.) ticks (76 larvae and 157 nymphs) was found on 31 of 235 captured lizards (13.2%). The tick infestation is relatively low compared to that of mammals and passerine birds from the same area (Siński et al. 2006, Gryczyńska et al. 2002). Tick infestation depended on the month of capture, being the highest in spring. In autumn no ticks were recorded on any of the captured lizards. The oldest lizards carried the highest number of ticks but no differences related to sex of the host were found. All the collected ticks were analysed by PCR for the presence of Borrelia burgdorferi sensu lato, the etiological agents of Lyme disease. Spirochetes were detected in 11 out of 233 (4.7%) ticks tested. Genetic analysis confirmed that the spirochetes are members of the Borrelia afzelii, B. garinii and B. burgdorferi sensu stricto genospecies. Mixed infection were not detected. The prevalence of infection was analysed in relation to months of the capture, age and sex of the lizards, but differences were not statistically significant. The obtained results suggest that lizards are probably not B. burgdorferi reservoirs, but further studies are required to confirm this.
A review of methods for synthesis of nanostructured metals with emphasis on iron compounds
Authors: Tavakoli A. , Sohrabi M. , Kargari A.
Published: April 2007

Synthesis of metal nanoparticles with specific properties is a newly established research area attracting a great deal of attention. Several methods have been put forward for synthesis of these materials, namely chemical vapor condensation, arc discharge, hydrogen plasma—metal reaction, and laser pyrolysis in the vapor phase, microemulsion, hydrothermal, sol-gel, sonochemical, and microbial processes taking place in the liquid phase, and ball milling carried out in the solid phase.

The properties of metal nanoparticles depend largely on their synthesis procedures. In this paper the fundamentals, advantages, and disadvantages of each synthesis method are discussed.
Effect of selenium oxidation state on cadmium translocation in chamomile plants
Authors: Král’ová K. , Masarovičová E. , Ondrejkovičová I. , Bujdoš M.
Published: April 2007

Syntheses and spectral characteristics of cadmium(II) compounds (CdSeO4, CdSeO3, and Cd(NCSe)2(nia)2) containing selenium in oxidation states (VI), (IV), and (-II) are described. In Cd(NCSe)2(nia)2, nicotinamide (nia) and selenocyanate anions are bonded to Cd atom as N-donor monodentate ligands. Nicotinamide is coordinated through the ring nitrogen atom. The effects of these selenium compounds as well as Cd(NCS)2(nia)2 on the growth and Cd accumulation in roots and shoots of hydroponically cultivated chamomile plants (cultivar Lutea) were studied. In the applied concentration range (12–60 µmol dm−3) Cd(NCS)2(nia)2 affected neither the length nor the dry mass of roots and shoots. Other compounds applied at 24 µmol dm−3 and 60 µmol dm−3 significantly reduced dry mass of roots and shoots. Selenium oxidation state in the cadmium compounds affected Cd accumulation in plant organs as well as Cd translocation within the plants, which was reflected in the values of bioaccumulation (BAF) and translocation factors (S/R). Cd amount accumulated by shoots was lower than that in the roots. The highest BAF values determined for Cd accumulation in shoots were obtained with CdSeO4. Substitution of S with Se in the Cd(NCX)2(nia)2 (X = Se or S) caused an increase of Cd translocation into the shoots.
Optimization of ammonium nitrate concentration in single-stage continuous cultures of Aspergillus niger with biomass retention
Authors: Janczar M. , Pietkiewicz J.
Published: April 2007

The effect of ammonium nitrate concentration in the citric acid biosynthesis by Aspergillus niger NC-12 in single-stage continuous cultures with biomass retention was investigated. Experiments were carried out in a BIOMER laboratory fermenter with 5 dm3 working volume. At the initial stage of each cultivation, the substrate in the bioreactor contained 1.5 g NH4NO3 dm−3. After 120 h onwards, the bioreactor was fed continuously at a constant dilution rate of 0.009 h−1. NH4NO3 concentration in the feed was varied from one culture to another, ranging between 0.5 g dm−3 and 2.5 g dm−3. Promising results were obtained when NH4NO3 concentration of 1.5 g dm−3 was used. The observed concentration of citric acid (c P) and yield of citric acid with respect to the introduced sucrose (Y P/S) were 117.88 g dm−3 and 78.59 %, respectively. The efficiency coefficient of citric acid biosynthesis (K ef) was very high, amounting to 83.38.
Profile distribution of As(III) and As(V) species in soil and groundwater in Bozanta area
Authors: Frentiu T. , Vlad S. , Ponta M. , Baciu C. , Kasler I. , Cordos E.
Published: April 2007

The profile distribution of arsenic(III) and arsenic(V) species in soil and groundwater was investigated in the samples collected in 2005 from a hand-drilled well, in the Bozanta area, Baia Mare region, Romania. The total content of arsenic in the soil was in the range of 525–672 mg kg−1 exceeding 21–27 times the action trigger level for sensitive soil. 0.9–11.3 % of the total content was soluble in water, 83.0–92.6 % in 10 mol dm−3 HCl and 2.6–13.3 % was the residual fraction. Arsenic(V) was the dominant arsenic species in the soil in the range of 405–580 mg kg−1. The distribution and mobility of arsenic species was governed by soil pH and contents of Al, Fe, and Mn. The mobility of arsenic(V) decreased with depth, while that of arsenic(III) was high at the surface and in the proximity of groundwater. The total concentration of arsenic in groundwater was (43.40 ± 1.70) µg dm−3, which exceeded the maximum contaminant level of 10 µg dm−3.
Controlled solvothermal synthesis of PbS quasi-nanorods by calix[4]arene
Authors: Yin R. , Wu Q. , Chen Y.
Published: April 2007

A new idea of the nanorods preparation and a novel application of calixarenes are presented. Calix[4]arene was introduced into solvothermal system to produce one-dimensional inorganic nanomaterial. The obtained product was characterized by XRD and TEM. Results of the XRD analysis showed that the product was pure cubic phase of PbS with high crystallinity. TEM images revealed that the diameter and length of the PbS nanorods were about 200 nm and up to 3.5 µm, respectively. Optical properties of the product were also studied. PL emission image showed that the product exhibited an emission peak at 308 nm in ultraviolet region showing a blue shift of 14 nm compared to the bulk material. The formation mechanism of PbS nanorods in the presence of calix[4]arene is discussed.
Some Issues in Benefit-Cost Analysis for Airport Development
Authors: Cohen Jeffrey P.
Published: April 2007

A number of recent Executive Office mandates have outlined the need for U.S. government agencies, including the Federal Aviation Administration, to conduct benefit-cost analyses for policy decisions. Policy decisions concerning local airspace system infrastructure could result in national airspace benefits. If the benefit-cost analyses are to be conducted properly, there is a need to account for these benefits. A method for conducting simulations is developed within a benefit-cost framework to examine the social welfare implications when localities act unilaterally without internalizing potential national airspace system benefits. Rates of return, compensating variation, and equivalent variation are simulated for a hypothetical economy, and social welfare as measured by these techniques improves when localities account for national airspace system benefits. The equivalent variation method enables policy makers to distinguish some equity implications from efficiency improvements that may occur simultaneously when localities move to account for national airspace system benefits in their aviation infrastructure decisions. Other issues in conducting benefit cost analyses for aviation infrastructure projects are discussed, and suggestions concerning how to attain efficient outcomes in compliance with institutional guidelines are made.
Excise Tax Structure of the U.S. Airline Industry: Evolving Rationale and Economic Considerations
Authors: Heimlich John P.
Published: April 2007

New and increased excise taxes on U.S. airlines and travelers have been levied without a thorough examination of the aviation tax structure. The evolution of the tax structure and its rationale is traced, the current tax situation is described, and some implications of aviation taxes from the perspective of commercial airlines and air travelers are explored. Once considered a luxury, air travel first faced taxation to discourage its use during World War II. Rerationalized as user fees in the early 1970s, the taxes became a source of maintaining and improving the airport and airway infrastructure. In the 1990s increased aviation excise taxes have been used to reduce the federal deficit, with secondary arguments for environmental protection. Within each period, the level and scope of taxes fluctuated amidst the industry’s transformation into the dominant public mode of intercity travel. Economic uncertainty, rising congestion, and the prevalence of concentration in many markets should make airlines and travelers more attentive than ever to the tax impact on fares, the dedication of revenues to FAA operations and infrastructure enhancement, and the implications for new entry on unserved or underserved domestic routes. Along with these factors, recent depletion of the Airport and Airway Trust Fund has highlighted the urgency of a comprehensive review of aviation tax policy. Such a review could ensure that the rationale for aviation taxation is consistent with the industry’s current role and that competition does not suffer.