bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservation and functional significance of gene topology in the genome of Caenorhabditis elegans
Authors: Chen Nansheng , Stein Lincoln D.
Published: April 2006

We have systematically examined the correlation between transcriptional expression pattern and the physical layout of gene pairs in the genome of Caenorhabditis elegans using a public tissue-specific SAGE library data set. We find a strong positive correlation in the expression patterns of neighboring gene pairs that are close together and transcribed in the same direction as well as for neighboring pairs that are located on opposing strands and transcribed in divergent directions. Coupling between members of nonoverlapping neighboring gene pairs is independent of operons and decreases to background levels as the distance increases beyond 10 kb. These findings suggest the existence of regional transcriptional domains in the C. elegans genome. In contrast, genes that are on opposing strands and transcribed in convergent directions are less transcriptionally coupled than the genome-wide background, suggesting a mutual inhibition mechanism. We have also examined the conservation and functional consequences of extreme cases of topological entanglement in the C. elegans genome, in which two or more genes physically overlap in their UTRs or coding regions. We have found that overlapping gene pairs are more conserved and are enriched in essential genes and genes that cause various defined phenotypes revealed by RNAi trials. SAGE analysis indicates that genes that are on the same strand, physically overlap, and transcript at the same directions are very highly correlated in gene expression, while overlapping gene pairs in which one member of the pair resides within an intron of the other are weakly, if at all, coupled, similar to convergent overlapping genes.
Probing genomic diversity and evolution of Escherichia coli O157 by single nucleotide polymorphisms
Authors: Zhang Wei , Qi Weihong , Albert Thomas J. , Motiwala Alifiya S. , Alland David , Hyytia-Trees Eija K. , Ribot Efrain M. , Fields Patricia I. , Whittam Thomas S. , Swaminathan Bala
Published: April 2006

Infections by Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) are the predominant cause of bloody diarrhea and hemolytic uremic syndrome in the United States. In silico comparison of the two complete STEC O157 genomes (Sakai and EDL933) revealed a strikingly high level of sequence identity in orthologous protein-coding genes, limiting the use of nucleotide sequences to study the evolution and epidemiology of this bacterial pathogen. To systematically examine single nucleotide polymorphisms (SNPs) at a genome scale, we designed comparative genome sequencing microarrays and analyzed 1199 chromosomal genes (a total of 1,167,948 bp) and 92,721 bp of the large virulence plasmid (pO157) of eleven outbreak-associated STEC O157 strains. We discovered 906 SNPs in 523 chromosomal genes and observed a high level of DNA polymorphisms among the pO157 plasmids. Based on a uniform rate of synonymous substitution for Escherichia coli and Salmonella enterica (4.7 × 10−9 per site per year), we estimate that the most recent common ancestor of the contemporary β-glucuronidase-negative, non-sorbitolfermenting STEC O157 strains existed ca. 40 thousand years ago. The phylogeny of the STEC O157 strains based on the informative synonymous SNPs was compared to the maximum parsimony trees inferred from pulsed-field gel electrophoresis and multilocus variable numbers of tandem repeats analysis. The topological discrepancies indicate that, in contrast to the synonymous mutations, parts of STEC O157 genomes have evolved through different mechanisms with highly variable divergence rates. The SNP loci reported here will provide useful genetic markers for developing high-throughput methods for fine-resolution genotyping of STEC O157. Functional characterization of nucleotide polymorphisms should shed new insights on the evolution, epidemiology, and pathogenesis of STEC O157 and related pathogens.
Haplotype variation in structure and expression of a gene cluster associated with a quantitative trait locus for improved yield in rice
Authors: He Guangming , Luo Xiaojin , Tian Feng , Li Kegui , Zhu Zuofeng , Su Wei , Qian Xiaoyin , Fu Yongcai , Wang Xiangkun , Sun Chuanqing , Yang Jinshui
Published: April 2006

By constructing nearly isogenic lines (NILs) that differ only at a single quantitative trait locus (QTL), we fine-mapped the yield-improving QTL qGY2–1 to a 102.9-kb region on rice chromosome 2. Comparison analysis of the genomic sequences in the mapped QTL region between the donor (Dongxiang wild rice, Oryza rufipogon Griff.) and recurrent (Guichao2, Oryza sativa ssp. indica) parents used for the development of NILs identified the haplotypes of a leucine-rich repeat receptor kinase gene cluster, which showed extensive allelic variation. The sequences between genes in the cluster had a very high rate of divergence. More importantly, the genes themselves also differed between two haplotypes: Only 92% identity was observed for one allele, and another allele was found to have completely lost its allelic counterpart in Guichao2. The other six shared genes all showed >98% identity, and four of these exhibited obvious regulatory variation. The same haplotype segments also differed in length (43.9-kb in Guichao2 vs. 52.6-kb in Dongxiang wild rice). Such extensive sequence variation was also observed between orthologous regions of indica (cv. 93–11) and japonica (cv. Nipponbare) subspecies of Oryza sativa. Different rates of sequence divergence within the cluster have resulted in haplotype variability in 13 rice accessions. We also detected allelic expression variation in this gene cluster, in which some genes gave unequal expression of alleles in hybrids. These allelic variations in structure and expression suggest that the leucine-rich repeat receptor kinase gene cluster identified in our study should be a particularly good candidate for the source of the yield QTL.
Genome-wide computational prediction of transcriptional regulatory modules reveals new insights into human gene expression
Authors: Blanchette Mathieu , Bataille Alain R. , Chen Xiaoyu , Poitras Christian , Laganière Josée , Lefèbvre Céline , Deblois Geneviève , Giguère Vincent , Ferretti Vincent , Bergeron Dominique , Coulombe Benoit , Robert François
Published: April 2006

The identification of regulatory regions is one of the most important and challenging problems toward the functional annotation of the human genome. In higher eukaryotes, transcription-factor (TF) binding sites are often organized in clusters called cis-regulatory modules (CRM). While the prediction of individual TF-binding sites is a notoriously difficult problem, CRM prediction has proven to be somewhat more reliable. Starting from a set of predicted binding sites for more than 200 TF families documented in Transfac, we describe an algorithm relying on the principle that CRMs generally contain several phylogenetically conserved binding sites for a few different TFs. The method allows the prediction of more than 118,000 CRMs within the human genome. A subset of these is shown to be bound in vivo by TFs using ChIP-chip. Their analysis reveals, among other things, that CRM density varies widely across the genome, with CRM-rich regions often being located near genes encoding transcription factors involved in development. Predicted CRMs show a surprising enrichment near the 3′ end of genes and in regions far from genes. We document the tendency for certain TFs to bind modules located in specific regions with respect to their target genes and identify TFs likely to be involved in tissue-specific regulation. The set of predicted CRMs, which is made available as a public database called PReMod (http://genomequebec.mcgill.ca/PReMod), will help analyze regulatory mechanisms in specific biological systems.
A preliminary comparative analysis of primate segmental duplications shows elevated substitution rates and a great-ape expansion of intrachromosomal duplications
Authors: She Xinwei , Liu Ge , Ventura Mario , Zhao Shaying , Misceo Doriana , Roberto Roberta , Cardone Maria Francesca , Rocchi Mariano ,   NISC Comparative Sequencing Program, Green Eric D. , Archidiacano Nicoletta , Eichler Evan E.
Published: April 2006

Compared with other sequenced animal genomes, human segmental duplications appear larger, more interspersed, and disproportionately represented as high-sequence identity alignments. Global sequence divergence estimates of human duplications have suggested an expansion relatively recently during hominoid evolution. Based on primate comparative sequence analysis of 37 unique duplication–transition regions, we establish a molecular clock for their divergence that shows a significant increase in their effective substitution rate when compared with unique genomic sequence. Fluorescent in situ hybridization (FISH) analyses from 1053 random nonhuman primate BACs indicate that great-ape species have been enriched for interspersed segmental duplications compared with representative Old World and New World monkeys. These findings support computational analyses that show a 12-fold excess of recent (>98%) intrachromosomal duplications when compared with duplications between nonhomologous chromosomes. These architectural shifts in genomic structure and elevated substitution rates have important implications for the emergence of new genes, gene-expression differences, and structural variation among humans and great apes.
Bruxism: its multiple causes and its effects on dental implants – an updated review*
Authors: LOBBEZOO F. , VAN DER ZAAG J. , NAEIJE M.
Published: April 2006

summary  There is a growing interest in bruxism, as evidenced by the rapidly increasing number of papers about this subject during the past 5 years. The aim of the present review was to provide an update of two previous reviews from our department (one about the aetiology of bruxism and the other about the possible role of this movement disorder in the failure of dental implants) and to describe the details of the literature search strategies used, thus enabling the readers to judge the completeness of the review. Most studies that were published about the etiology during the past 5 years corroborate the previously drawn conclusions. Similarly, the update of the review about the possible causal relationship between bruxism and implant failure reveals no new points of view. Thus, there is no reason to assume otherwise than that bruxism is mainly regulated centrally, not peripherally, and that there is still insufficient evidence to support or refute a causal relationship between bruxism and implant failure. This illustrates that there is a vast need for well‐designed studies to study both the aetiology of bruxism and its purported relationship with implant failure.
Measuring chewing ability in randomized controlled trials with edentulous populations wearing implant prostheses*
Authors: FEINE J. S. , LUND J. P.
Published: April 2006

summary  In this article, the authors review methods commonly used to measure the masticatory ability of patients wearing conventional and implant prostheses. Measurement approaches are viewed in two broad categories: laboratory based and patient based. The laboratory based measures discussed are mastication time, particle size, force measurements, patterns of jaw movement and electromyographic (EMG) bursts and total EMG activity. Patient based measures include satisfaction and chewing difficulty. Oral health‐related quality of life measures and diet/nutrition variables are briefly mentioned. Patient‐based outcomes are recommended as the most appropriate variables of masticatory efficiency.
Jaw motor inputs originating from osseointegrated oral implants*
Authors: VAN STEENBERGHE D. , JACOBS R.
Published: April 2006

summary  Jaw motor inputs from endosseous oral implants have been investigated to a limited extent. Observations of jaw muscle reflexes in edentulous patients rehabilitated by means of implants do not prove that they originate from the implants unless the stimuli are properly defined. Few studies have isolated inputs, such as electrical of mechanical stimuli, to make sure that they are conveyed through the implants. Even under these conditions one should be aware that such stimuli can trigger distant receptors. The most striking difference is that tapping an upper jaw implant in a fully edentulous patient does not give lead to a silent period in the jaw closing muscles. At the clinical level the changes in neuromuscular reflexes do not lead to significant problems.
Corrosive induced carcinoma of esophagus: Report of three patients and review of literature
Authors: Kochhar Rakesh , Sethy Pradeepta Kumar , Kochhar Suman , Nagi Birinder , Gupta Narinder Mohan
Published: April 2006

Patients with corrosive induced esophageal strictures have more than a 1000‐fold risk of developing carcinoma of the esophagus. We report three cases of corrosion carcinoma seen by us (a team of gastroenterologists, radiologists and a surgeon) in the last 15 years. Two cases were among 156 patients with corrosive induced strictures on our follow‐up, and constituted the only corrosion carcinoma out of 650 esophageal carcinomas operated on by us. Nearly all reported patients with corrosion carcinoma in the published literature had consumed an alkali, but two of our three patients had consumed an acid.
Ocular lesions in Watanabe heritable hyperlipidemic rabbits
Authors: Kouchi Mami , Ueda Yoshinaka , Horie Hiroshi , Tanaka Kohji
Published: April 2006

Hyperlipidemic ocular lesions are described for Watanabe heritable hyperlipidemic (WHHL) rabbits. Male WHHL rabbits 8 months old exhibited serum hyperlipidemia and ophthalmoscopically yellowish‐white lesions along the corneoscleral junction and in the iris. Histopathologically, foamy macrophages aggregated in the stroma of the cornea, iris, and ciliary body were observed. These findings have been interpreted as lipid keratopathy. In addition, multiple clusters of a large number of foamy macrophages occurred throughout the choroid and sclera in association with the blood vessels. The lesions in the choroid and sclera could not be detected ophthalmoscopy, yet were much more prominent than those in the cornea, iris, and ciliary body, suggesting greater involvement and earlier onset of lipidosis at these sites associated with hyperlipidemia in WHHL rabbits.
Ophthalmomyiasis interna anterior in a cat: surgical resolution
Authors: Stiles Jean , Rankin Amy
Published: April 2006

A 4‐year‐old Domestic short‐haired cat was presented for severe anterior uveitis in the right eye associated with a Cuterebra spp. larva in the anterior chamber. This report describes successful surgical removal of the parasite with preservation of vision.
Drusen and lipid‐filled retinal pigment epithelium cells in a rhesus macula
Authors: Anderson Mark , Dawson William W. , Gonzalez‐Martinez Janis , Curcio Christine A.
Published: April 2006

A middle‐aged rhesus monkey with detailed clinical history exhibited progression of a macular abnormality with a variety of clinical drusen and pigment changes typical of the Cayo Santiago phenotype. Numerous frozen sections of one sample of the macular retina/retinal pigment epithelium (RPE)/choroid showed a single classical druse but extensive single and clustered lipid‐filled RPE cells. The monkey exhibited functional outer retinal decline and an insignificant number of ‘window defects’ as found among signs of relatively benign human macular aging. The clinical and histologically defined results agree if lipid‐filled RPE cells are included among the clinically apparent signs of drusen.
Leptospirosis and panuveitis in a dog
Authors: Townsend Wendy M. , Stiles Jean , Krohne Sheryl G.
Published: April 2006

A case of panuveitis as a result of leptospiral infection in an 8‐year‐old Jack Russell Terrier is reported. Mild hyphema, aqueous flare, and partial serous retinal detachments were noted in both eyes on initial ophthalmic examination. The serum microscopic agglutination testing forLeptospiraserovarieties revealed titers of 1 : 12 800 forLeptospira canicola and1 : 200 forLeptospira icterohemorrhagiae.With medical therapy, the panuveitis resolved and functional vision was regained. Four weeks after the initial presentation, convalescent titers were 1 : 200 forL. canicolaand 1 : 100 forL. icterohemorrhagiae. The incidence of leptospirosis, along with difficulties diagnosing, and current medical therapies for this disease are also discussed.
Evaluation of canine serum for the presence of antiretinal autoantibodies in sudden acquired retinal degeneration syndrome
Authors: Keller Rachel L. , Kania Stephen A. , Hendrix Diane V. H. , Ward Daniel A. , Abrams Kenneth
Published: April 2006

Objective To determine the presence of serum antiretinal antibodies in sudden acquired retinal degeneration syndrome (SARDS) affected dogs and the size of the antigen to which these antibodies bind via the use of enzyme‐linked immunosorbent assay (ELISA) and Western blot immunoassays.

Animals studied Serum was collected from 13 dogs affected by SARDS and five dogs with normal ocular examinations.

Procedures All serum samples were subjected to ELISA with saline‐soluble canine retinal tissue and Western blot analyses with SDS solubilized normal canine retinal tissue as the antigen. Antirecoverin (23 kDa) and antiheat shock cognate (65 kDa) antibodies were used as positive controls for both procedures. Affinity‐purified goat antidog IgG and IgM labeled with horseradish peroxidase were used for all clinical samples and goat antirabbit IgG was used as the secondary antibody for the positive controls.

Results ELISA demonstrated antibody reaction with all samples. Western blot immunoassays identified multiple bands in all canine serum samples, as well as in negative controls. Approximate sizes of the bands were 25 and 50 kDa, corresponding to IgG light and heavy chains, respectively.

Conclusion No antiretinal autoantibodies were identified in the serum of dogs affected by SARDS as compared to normal canine patients.
Canine limbal melanoma: 30 cases (1992–2004). Part 2. Treatment with lamellar resection and adjunctive strontium‐90β plesiotherapy – efficacy and morbidity
Authors: Donaldson David , Sansom Jane , Adams Vicky
Published: April 2006

Objectives To evaluate the efficacy of lamellar resection and adjunctive90Sr‐β plesiotherapy in the management of canine limbal melanoma and the frequency and morbidity of early and late‐onset side effects following treatment.

Design Retrospective study.

Animals studied Thirty dogs treated for limbal melanoma at the Animal Health Trust (AHT), between 1992 and 2004.

Methods Medical records were reviewed and information collected on the radiation dose administered, duration of follow‐up, and the frequency of early‐ and late‐onset ocular side effects. Follow‐up information was obtained by re‐examination of patients or completion of a telephone interview with the referring veterinary surgeons or the owners.

Results Recurrence of limbal melanoma occurred in 1 of 30 cases (3%; 95% CI: 0.2–14%). One or more side effects occurred in 16 of 30 cases (53%; 95% CI: 28.1–74.9). The occurrence of side effects was not associated with the number of sites treated or the total surface dose of radiation. Short‐term side effects were reported in 16/30 cases (53%) and included corneal scarring (12/30), corneal neovascularization (6/30), conjunctivitis with or without granulation tissue formation (5/30), lipid keratopathy (1/30), and localized bullous keratopathy (2/30). Long‐term side effects were reported in 6 of 30 cases (20%) cases and included deep scleral thinning (5/30), focal scleromalacia (3/30), globe perforation (2/30), lipid keratopathy (3/30), localized bullous keratopathy (1/30), and sectoral cortical cataract (1/30).

Conclusions Lamellar resection and adjunctive90Sr‐β plesiotherapy is relatively easy to perform, is minimally invasive, and extremely well tolerated by patients. The treatment is highly efficacious in the management of canine limbal melanoma. Modification of the radiation dosimetry, in particular reducing the total dose of radiation and the dose per radiation fraction, is necessary to reduce the incidence of late onset side effects.
An intelligent semantic e‐learning framework using context‐aware Semantic Web technologies
Authors: Huang Weihong , Webster David , Wood Dawn , Ishaya Tanko
Published: April 2006

Recent developments of e‐learning specifications such as Learning Object Metadata (LOM), Sharable Content Object Reference Model (SCORM), Learning Design and other pedagogy research in semantic e‐learning have shown a trend of applying innovative computational techniques, especially Semantic Web technologies, to promote existing content‐focused learning services to semantic‐aware and personalised learning services. To facilitate this transforming process, this paper presents a novel context‐aware semantic e‐learning approach to integrate content provision, learning process and learner personality in an integrated semantic e‐learning framework. As the basis of the computational framework, a scalable and extensible generic context model is proposed to structure the semantics of contextual relations and concepts in various contexts, such as learning content description, learning model, knowledge object representation and learner personality. Corresponding technical and pedagogical developments of this framework also consider compatibility issues with existing technologies (eg, XML/Resource Description Framework) and specifications (eg, IEEE LOM) in order to achieve the best interoperability.
Semantic‐aware components and services of ActiveMath
Authors: Melis Erica , Goguadze Giorgi , Homik Martin , Libbrecht Paul , Ullrich Carsten , Winterstein Stefan
Published: April 2006

ActiveMath is a complex web‐based adaptive learning environment with a number of components and interactive learning tools. The basis for handling semantics of learning content is provided by its semantic (mathematics) content markup, which is additionally annotated with educational metadata. Several components, tools and external services can make use of that content markup, eg, a course generator, a semantic search engine and user input evaluation services. The components and services have to communicate, pass content and state changes, actions, etc including mathematical semantics and educational markup. The novel event infrastructure supports this communication. This paper focuses on the usage of the content's semantics by selected novel components and sketches the communication.
A prototype Semantic Web‐based digital content exchange for schools in Singapore
Authors: Shabajee Paul , McBride Brian , Steer Damian , Reynolds Dave
Published: April 2006

Singapore has many large and educationally valuable digital collections and is planning the development of many more. These digital collections contain historical, cultural and scientific multimedia objects, along with learning objects. At present, school teachers and pupils find it hard to locate many of these resources using traditional search engines. This paper describes a research investigation into the design and subsequent development of a prototype digital resource discovery portal (Digital Content Exchange) based on Semantic Web technologies, and explores some of the educational issues raised. The research project explored how the features of the Semantic Web might offer valuable additional educational benefits and affordances beyond that of those based on existing information retrieval technologies.
The Civil Society–State Relationship in Contemporary Discourse: A Complementary Account from Giddens' Perspective
Authors: Müller Karel B.
Published: April 2006

The article attempts to offer a framework for understanding the interdependence between modern civil society and the democratic state in its complexity. The author seeks inspiration mainly from two very significant sources—in Toqueville's social theory and in Giddens' theory of reflexive modernity. In the first stage the author summarises basic arguments in empirical discussions on the civil society concept. In the second stage he offers the overview of a robust normative perspective of the concept and, in the third stage, he tries to outline the complex interpretative framework for an empirical analysis of state–civil society relations. The author follows the ambition of overcoming to a certain extent the crucial sociological paradox between the macro- and micro-sociological approaches and considering both the functional-structural perspective and the empirical point of view of the civil society concept.
The Rationality of Voting: A Response to Dowding
Authors: Parsons Stephen
Published: April 2006

According to rational choice theory, voting is an irrational act as the possibility of one vote influencing an election is minimal, yet voting incurs costs. However, individuals do vote. Keith Dowding has recently attempted to resolve this ‘paradox of voting’ through modifying the rational choice framework. Dowding argues that individuals vote out of a sense of duty, where this modification preserves the idea that individuals maximise their utility. This article rejects this claim. In order to retain any explanatory force, ‘duty’ must be modelled as a modified lexicographic preference. However, such preferences are prohibited by the axiom of continuity, required in order that a preference ordering can be represented by a utility function. The act of voting out of a sense of duty is not a utility-maximising act.
Searching for the Successor Generation: Public Diplomacy, the US Embassy's International Visitor Program and the Labour Party in the 1980s
Authors: Scott-Smith Giles
Published: April 2006

This article looks at the influence of US public diplomacy in the UK, in particular the use of the International Visitor Program as a channel for encouraging dialogue and the introduction of new ideas into the Labour party during the 1980s. The drift towards the left and the adoption of unilateralism caused great concern for the Americans. What was at stake was the future direction of the party and the need to realign its international stance with American interests. A keen eye was always kept on new talent entering the House of Commons after each election. In 1983 the ‘best and the brightest’ were undoubtedly Tony Blair and Gordon Brown. By using the Program to open up the United States to these young politicians and their political allies, the Embassy contributed to the linkage and cross-fertilisation between those who would become New Labour and the New Democrats a decade later.
Unionism and the Peace Process in Northern Ireland
Authors: Farrington Christopher
Published: April 2006

This article will provide a framework for analysing unionist responses and reactions to the Northern Irish peace process. It identifies four responses to the Belfast Agreement that have reflected unionist divisions over the peace process: a principled yes position, a pragmatic yes, a pragmatic no and a principled no. However, these positions hide a common interpretation of the process in general and this interpretation is outlined. The article then seeks to understand why these different positions on the Agreement have emerged from this common narrative and it identifies how contextual factors and the actions of other political actors have done this. In doing so it uses an interpretative methodology and seeks to critique the dominant frameworks of analysis of the peace process and the Agreement.
The Impact of Chinese Exports on Global Import Prices*
Authors: Kamin Steven B. , Marazzi Mario , Schindler John W.
Published: April 2006

This paper evaluates the evidence bearing on the question of whether China's buoyant export growth has led to significant changes in the import prices, and thus inflation performance, of its trading partners. This evidence suggests that the impact of Chinese exports on global import prices has been, while non‐ negligible, fairly modest. We identify a statistically significant effect of US imports from China on US import prices, but given the size of this effect and the relatively low share of imports in US GDP, the ultimate impact on US consumer prices has likely been quite small. Moreover, imports from China had little apparent effect on US producer prices. Finally, using a multi‐country database of trade transactions, we estimate that, since 1993, Chinese exports lowered annual import inflation in a large set of economies by 0.25 percentage point or less on average.
Long‐run Lunacy, Short‐run Sanity: a Simple Model of Trade with Labor Market Turnover*
Authors: Davidson Carl , Matusz Steven J.
Published: April 2006

It is often argued that international trade is all about long‐run relationships. In this paper, we argue that this view is flawed when factor markets are characterized by turnover. Toward that end, we provide a simple dynamic model of trade with labor market turnover and show that the relationship between the economy's short‐run and long‐run behavior is more complex than in traditional trade models. For example, in the short run, the economy may produce outside of its long‐run frontier. We show that focusing on long‐run relationships can lead one to draw faulty policy conclusions, while focusing on its short‐run behavior restores sanity. The implication is that in the presence of factor market turnover, international trade issues can only be understood by studying the entire dynamic path of the economy. Long‐run relationships should be ignored.
GOVERNMENT‐MANDATED DISCRIMINATORY POLICIES: THEORY AND EVIDENCE*
Authors: Fang Hanming , Norman Peter
Published: April 2006

We study an economy with private and public sectors in which workers invest in imperfectly observable skills that are important to the private sector but not to the public sector. Government regulation allows native majority workers to be employed in the public sector with positive probability while excluding the minority from it. We show that even when the public sector offers the highest wage rate, it is still possible that the discriminated group is, on average, economically more successful. The widening Chinese/Malay wage gap in Malaysia since the adoption of its New Economic Policy in 1970 supports our model.
LUXURY AND WEALTH*
Authors: Ikeda Shinsuke
Published: April 2006

I develop a dynamic theory of luxury consumption, particularly emphasizing the causal effect that pursuit of luxury goods has on wealth accumulation. A quasi‐luxury is defined as a good whose marginal rate of substitution is increasing in a utility index. Under certain conditions, it is indeed a luxury good. When current wealth holding falls short of (exceeds) long‐run needs, luxury consumption is postponed more (less) easily than necessity consumption, due to a lower (higher) time preference for luxury and/or a higher intertemporal elasticity of substitution thereof. Preferences for quasi‐luxuries lead to a higher steady‐state value of wealth or capital.

Countries which have sumptuary laws, are generally poor.

(Sir Dudley North, Discourses Upon Trade, 1691, p. 14)
MODELLING ASYMMETRIC EXCHANGE RATE DEPENDENCE*
Authors: Patton Andrew J.
Published: April 2006

We test for asymmetry in a model of the dependence between the Deutsche mark and the yen, in the sense that a different degree of correlation is exhibited during joint appreciations against the U.S. dollar versus during joint depreciations. We consider an extension of the theory of copulas to allow for conditioning variables, and employ it to construct flexible models of the conditional dependence structure of these exchange rates. We find evidence that the mark–dollar and yen–dollar exchange rates are more correlated when they are depreciating against the dollar than when they are appreciating.
WELFARE IMPLICATIONS OF THE INTERACTION BETWEEN HABITS AND CONSUMPTION EXTERNALITIES*
Authors: Alonso‐Carrera Jaime , Caballé Jordi , Raurich Xavier
Published: April 2006

We analyze the welfare properties of the equilibrium path of a growth model where both habits and consumption externalities affect the utility of consumers. Our analysis highlights the crucial role played by complementarities between externalities and habits in order to generate an inefficient dynamic equilibrium. In particular, we show that the competitive equilibrium is inefficient when consumption externalities and habit‐adjusted consumption are not perfect substitutes.
ANXIETY AND PERFORMANCE: AN ENDOGENOUS LEARNING‐BY‐DOING MODEL*
Authors: Rauh Michael T. , Seccia Giulio
Published: April 2006

In this article, we show that a standard economic model, the endogenous learning‐by‐doing model, captures several major themes from the anxiety literature in psychology. In our model, anxiety is a fully endogenous construct that can be separated naturally into its cognitive and physiological components. As such, our results are directly comparable with hypotheses and evidence from psychology. We show that anxiety can serve a motivating function, which suggests potential applications in the principal–agent literature.

It doesn't take much technique to roll a 1.68 inch ball along a smooth, level surface into, or in the immediate vicinity of, a 4.5 inch hole. With no pressure on you, you can do it one‐handed most of the time. But there is always pressure on the shorter putts … 90 percent of the rounds I play in major championships, I play with a bit of a shake.

Jack Nicklaus, quoted in Patmore (1986, p. 75)
DIRECTED SEARCH ON THE JOB AND THE WAGE LADDER*
Authors: Delacroix Alain , Shi Shouyong
Published: April 2006

We model a labor market where employed workers search on the job and firms direct workers' search using wage offers and employment probabilities. Applicants observe all offers and face a trade‐off between wage and employment probability. There is wage dispersion among workers, even though all workers and jobs are homogeneous. Equilibrium wages form a ladder, as workers optimally choose to climb the ladder one rung at a time. This is because low‐wage applicants are relatively more sensitive to employment probability than to wage and thus forgo the opportunity to apply for a high wage, with a lower chance of success.
Computer Assisted Clinical Assessment
Authors: Berger Michael
Published: April 2006

The number and range of computer‐based assessment procedures for children and young people have increased greatly over the past few years. Over this time as well, other technological advances have occurred with a potential for application in services for young people. This paper provides an overview of the range of applications of relevance to practitioners, with a focus on assessment. Some of the benefits and disadvantages of computerised procedures for test administration and report writing are considered. The paper concludes with an examination of the issue of access to tests and some of the implications of the introduction of other new technologies.
Acute Alcohol Intoxication: Sex Comparisons on Pharmacokinetic and Mood Measures
Authors: Sutker Patricia B. , Goist Kenneth C. , Allain Albert N. , Bugg Franlynn
Published: April 2006

This study explored sex differences in pharmacokinetic and mood state responses to acute alcohol intoxication among socially drinking women demonstrated to be normally cycling across two consecutive menstrual cycles and men with similar drinking habits. Subjects were administered moderate or high alcohol doses in six experimental sessions over a 60‐day period. Women were tested during the early follicular, ovulatory, and midluteal phases of the cycle, and men were administered alcohol at comparable time intervals. Results showed that men did not differ in alcohol pharmacokinetics across sessions, but women showed significantly shorter elimination times and faster disappearance rates during the midluteal phase of the menstrual cycle compared to the early follicular and ovulatory phases and to their male counterparts. There were no sex or within‐group differences in self‐reported negative mood states prior to alcohol administration, but women described increased anxiety and depression while intoxicated during the early follicular compared to ovulatory and midluteal phases. Affective responses to intoxication were a complex function of sex, limb of the blood alcohol concentration‐time curve, and dose.
Alterations in Brain Aldehyde Dehydrogenase Activity Modify Ethanol‐induced Conditioned Taste Aversion
Authors: Spivak Karen , Aragon Carlos M. G. , Amit Zalman
Published: April 2006

The role of peripherally and centrally acting acetaldehyde in ethanol‐induced conditioned taste aversion (CTA) was investigated using various enzyme manipulations. Cyanamide, an aldehyde dehydrogenase inhibitor (ALDH) elevates blood acetaldehyde levels in the presence of ethanol. Concurrent administration with 4‐methylpyrazole (4MP), an alcohol dehydrogenase inhibitor, prevents peripheral accumulation of acetaldehyde by cyanamide. Under both treatment conditions brain and liver ALDH activity is inhibited. Water‐deprived rats were pretreated 4 hr prior to fluid presentation with intraperitoneal injections of saline (S+S), 4‐methylpyrazole (4MP+S), cyanamide (S+C), or 4‐methylpyrazole + cyanamide (4MP+C). Subsequently, animals were presented with a novel saccharin solution followed immediately by intraperitoneal injection of one of three doses of ethanol (0.4, 0.8, or 1.2 g/kg) or saline vehicle on four occasions. Results suggested that animals pretreated with cyanamide (groups S+C and 4MP+C) drank significantly less saccharin after conditioning with a subthreshold dose of ethanol (0.4 g/kg) in comparison to groups S+S and 4MP+S. Moreover, at the conditioning dose of 1.2 g/kg, cyanamide‐treated animals demonstrated an attenuation of CTA compared to the other two groups. These effects cannot be attributed to elevated blood acetaldehyde levels since pretreatment with 4MP+C prevented peripheral acetaldehyde accumulation. A characteristic common to both cyanamide‐treated groups was the inhibition of brain ALDH. It is therefore suggested that brain ALDH may play a role in the mediation of ethanol‐induced CTAs. It is conceivable that ALDH plays this role by regulating the levels of acetaldehyde in brain.
Naloxone, Ethanol, and the Chlorpropamide Alcohol Flush
Authors: Baraniuk James N. , Murray R. Bruce , Mabbee W. Grant
Published: April 2006

The effects of ethanol and subsequent administration of intravenous naloxone were studied in double‐blind, placebo‐controlled fashion with a group of six male chlorpropamide alcohol flushers (CPAF) and a group of 13 nonflushing males. The effect of ethanol intoxication on fine motor control was measured by a typing test. When sober, the two groups performed in comparable fashion. When intoxicated, the CPAF group displayed significantly greater impairment than the nonflushing group as measured by typing errors committed in 3 min (CPAF: 55.4 ± 10.1 errors, n= 12; vs. nonflushing: 15.6 ± 2.3, n= 32; p= 0.0000015 by Student's unpaired t test). Chlorpropamide alcohol flushers appeared to be more sensitive to ethanol. Naloxone reversed this effect for individuals in the CPAF group (saline treatment: 51.0 ± 11.7 errors per minute; vs. naloxone treatment: 23.7 ± 4.2; p= 0.034 by Student's paired t test, n= 6). Naloxone had no effect in the nonflushing group. Unlike the normal, nonflushing group, the CPAF group demonstrated an increased sensitivity to ethanol that was partially antagonized by naloxone.
Urinary Dolichol—A New Marker of Alcoholism
Authors: Roine Risto P. , Turpeinen Ursula , Ylikahri Reino , Salaspuro Mikko
Published: April 2006

Urinary dolichol levels of 31 skid‐row alcoholics and 49 alcoholics entering a detoxification unit were compared to those of 51 nonalcoholic controls (social drinkers). The mean urinary dolichol content as related to urinary creatinine was significantly (p < 0.001) higher in the two groups of alcoholics than in the controls. In this material the sensitivity of increased urinary dolichol in the detection of alcoholism was 68% as compared to 44% sensitivity of serum γ‐glutamyltransferase. The percentage of false‐positives in the control group was 3.9%. Urinary dolichol is suggested as a potential tool for the detection and follow‐up of alcohol abuse.
Human Aldehyde Dehydrogenase: Metabolism of Putrescine and Histamine
Authors: Ambroziak Wojciech , Pietruszko Regina
Published: April 2006

Imidazoleacetaldehyde and γ‐aminobutyraldehyde, metabolites of histamine and putrescine, respectively, have been shown to be substrates of human liver aldehyde dehydrogenase (EC 1.2.1.3) cytoplasmic (E1) and mitochondrial (E2) isozymes. The Km values at pH 7.4 and 500 μM NAD for imidazoleacetaldehyde and γ‐aminobutyraldehyde for the E1 isozyme are 40 and 800 μM, respectively, and for the E2 isozyme are 50 and 500 μM, respectively. The Km values with γ‐aminobutyraldehyde with both isozymes are high relative to Km values with acetaldehyde (50 μM for E1 and 1 μM for E2). Since activity with both imidazoleacetaldehyde and γ‐aminobutyraldehyde in crude liver homogenates paralleled that of aldehyde dehydrogenase (EC 1.2.1.3) during purification it appears likely that in the human liver this enzyme is responsible for metabolism of both compounds. If this is the case, interaction between metabolism of histamine and putrescine and that of alcohol is likely. Both imidazoleacetaldehyde and γ‐aminobutyraldehyde were synthesized in this laboratory and their stability has been investigated. Procedures for assaying aldehyde dehydrogenase employing synthetic metabolites of histamine and putrescine are provided.
Effects of Paternal Alcohol Consumption in Mice
Authors: Abel Emest L. , Moore Charlene
Published: April 2006

Male mice were divided into four groups, one group was given ad libitum access to a liquid alcohol diet containing 35% ethanol derived calories (EDC). A second group was pair fed an isocaloric control diet containing 17.5% EDC whereas a third was similarly treated with a 0% EDC diet for a minimum of 42 days. A fourth group served as ad libitum nontreated controls to assess the role of pair feeding. Males were then mated with nontreated females. The males consuming alcohol had an increased percentage of abnormal sperm and there was a significant effect of paternal alcohol exposure on implantation sites, but no effect on pre‐ or postnatal mortality or fetal weight. These results suggest that paternal alcohol consumption adversely affects sperm production but does not affect development of offspring in mice.
Cell Cycle Phase‐Specific Perturbation of Hepatic Tumor Cell Growth Kinetics during Short‐Term in Vitro Exposure to Ethanol
Authors: Higgins Paul J.
Published: April 2006

Cell cycle events associated with the growth suppressive effects of short‐term ethanol exposure on liver cells were investigated using flow cytometric methods to analyze the proliferative kinetics of ethanol‐sensitive 32IIIA rat hepatic tumor cells. A 3‐day exposure of exponentially growing 32IIIA cells to growth medium containing 100 mM ethyl alcohol decreased final population density (to <70% of control values) although viability was unaffected, approximating 94% under all experimental conditions. Comparative flow cytometric analysis of control and ethanol‐treated populations revealed significant ethanol‐associated alterations in the substate composition of G1 phase hepatic tumor cells. An ethanol‐induced 30% increase in mean population doubling time was reflected in an approximately 22% increase in the proportion of G1 phase cells within a culture. Lower overall G1 cellular RNA content typified all ethanol‐treated 32IIIA tumor cell populations. The fraction of G1 cells in the immediate pre‐DNA‐synthetic (G18) compartment was markedly reduced (by 41–80%) during the period of ethanol exposure as were the percentages of S and G2+M phase cells which derive kinetically from cells in G18. This reduction in the proportion of cells with normal G18 RNA levels was not reflected solely in the complement of very low RNA content “G1E‐type” cells generated during the course of ethanol treatment. Net accumulations (of 19 and 34%) of cells residing in the G1A substate were consistent additional concomitants of ethanol treatment. Short‐term ethanol exposure in the 32IIIA hepatic tumor cell system clearly impairs normal progression of such cells through the G1 phase of the cell division cycle. This inhibition appears to be due specifically to interference with orderly transition from G1A into the immediate pre‐DNA‐synthetic G1B substate resulting in a net accumulation of cells in the G1A subcompartment.
A Preliminary Study of Hepatitis B Virus Replication during Short‐Term (7‐Day) Social Drinking
Authors: Novick David M. , Jenkins William J. , Karayiannis Peter , Thomas Howard C.
Published: April 2006

The purpose of this study is to determine the effect of short‐term social drinking on hepatitis B virus (HBV) replication as measured by serum levels of hepatitis B virus DNA (HBV‐DNA). We studied five male carriers of hepatitis B e antigen who were social drinkers. Levels of HBV‐DNA, blood alcohol, and aspartate aminotransferase (AST) were measured during abstinence from alcohol, before and during a test dose (29.8 g) of alcohol which followed one week of abstinence, and before and during the same test dose which followed social drinking for one week. We observed no significant changes in HBV‐DNA or AST levels. These data suggest that a single one‐week period of social drinking in patients with chronic HBV infection does not cause enhanced viral replication. The risks of repeated ingestion of moderate amounts of alcohol by such patients have not been established. Interpretation of our data is limited by the small number of subjects, and further studies are needed. Nevertheless, our results are consistent with published recommendations that social drinking by nonalcoholic HBV carriers should be restricted but need not be totally forbidden.
Effect of Abstinence on the Blood Acetaldehyde Response to a Test Dose of Alcohol in Alcoholics
Authors: Di Padova C. , Worner T. M. , Lieber C. S.
Published: April 2006

Following an acute dose of alcohol (0.15 g/kg intravenously), blood levels of acetaldehyde were significantly higher in nonabstinent alcoholics than in controls. After 2 weeks of abstinence, this blood acetaldehyde response significantly decreased in alcoholics and the acetaldehyde returned towards levels comparable to those observed in nonalcoholics. These results suggest that elevated blood acetaldehyde levels in the alcoholics are secondary to the chronic alcohol consumption rather than reflecting a primary preexisting defect.
Effect of Prenatal Exposure to Ethanol on Body Growth and the Pituitary β‐Endorphin
Authors: Gianoulakis C.
Published: April 2006

Pregnant rats were fed an ethanol diet from the first day of pregnancy until parturition. Control rats were either pair fed with an isocaloric sucrose diet, or fed with standard lab chow (basic control group). Rats fed with the ethanol diet and their pair‐fed controls showed a similar increase in body weight during pregnancy, which was lower than the increase observed in the basic control group. At 10 days after ethanol withdrawal all three groups presented similar body weights. A lower body growth was exhibited by the offspring of both the ethanol and the sucrose pair‐fed rats, implicating a prenatal nutritional factor on the postnatal growth. Furthermore, the rate of body growth was lower in the offspring of the ethanol‐treated animals than in the offspring of both their pair‐fed and the basic control rats, indicating the presence of an additional ethanol‐associated factor. On day 4 of development, the concentration of β‐endorphin peptides (pmol/mg protein) in the pituitary gland and the anterior lobe, of the offspring of the ethanol‐treated animals and their sucrose pair‐fed controls, was significantly higher than that of the offspring of the basic control animals. However, a lower content of β‐endorphin‐like peptides was noticed in the whole pituitary gland, the anterior lobe, and the intermediate lobe of the offspring of the ethanol‐treated rats and their pair‐fed controls on days 8, 14, and 22 postnatally. The decrease in the β‐endorphin content was more pronounced in the pituitaries of the offspring exposed to ethanol in utero, suggesting the implication of both a prenatal nutritional factor and a specific ethanol‐associated factor in the development of the pituitary β‐endorphin system.