bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth of
Yersinia pseudotuberculosis
in Mice Occurs Independently of Toll-Like Receptor 2 Expression and Induction of Interleukin-10
Authors: Auerbuch Victoria , Isberg Ralph R.
Published: April 2007

Pathogenic
Yersinia
translocates effector proteins into target cells via a type III secretion system (TTSS), modulating the host immune response. A component of the TTSS translocon, LcrV, has been implicated in preventing inflammation through Toll-like receptor 2 (TLR2) by inducing expression of the anti-inflammatory cytokine interleukin-10 (IL-10). TLR2
−/−
mice were reported to be less susceptible to the enteropathogen
Yersinia enterocolitica
. To determine whether TLR2 also plays a role in recognition of the enteropathogen
Yersinia pseudotuberculosis
and whether this results in an immune response that is detrimental to the host, we evaluated the macrophage cytokine response to live
Y. pseudotuberculosis
and analyzed the susceptibility of TLR2
−/−
mice to enteropathogenic
Yersinia
. We find that
Yersinia
induction of macrophage IL-10 occurs independently of TLR2 and LcrV and is blocked by the TTSS. In particular, the TTSS effector protein YopJ, which inhibits production of the inflammatory cytokine tumor necrosis factor alpha (TNF-α), also inhibits IL-10 expression. Consistent with these results, IL-10 is undetectable in
Y. pseudotuberculosis
-infected mouse tissues until advanced stages of infection. In addition, we find that TLR2
−/−
mice (derived independently from those used in previous studies) do not display altered susceptibility to enteropathogenic
Yersinia
compared to wild-type mice. Tissue levels of IL-10, as well as the inflammatory cytokines TNF-α, IL-6, and gamma interferon and the chemokine macrophage chemotactic protein 1, are similar in TLR2
+/+
and TLR2
−/−
mice during enteropathogenic
Yersinia
infection. Therefore, the absence of TLR2 alone does not affect the cytokine response of macrophages to, or the in vivo growth and survival of, enteropathogenic
Yersinia
.
A novel strategy for identifying mutations that sensitizeDrosophilaeye development to caffeine and hydroxyurea
Authors: Silva E.A. , Lee B.J. , Caceres L.S. , Renouf D. , Vilay B.R. , Yu O. , Bradley J.A. , Campbell S.D.
Published: April 2007

This report describes a novel strategy for isolating Drosophila mutants with conditional eye phenotypes that should be generally applicable for identifying genes required for cellular responses to specific drugs. To test the strategy, we screened 3 of the 5 major chromosome arms for hydroxyurea- and (or) caffeine-sensitive (huc) mutants, and isolated mutations affecting 5 different complementation groups. Most of these were represented by single alleles; however, we also isolated multiple alleles of huc29DEgene, an essential gene that is also associated with a nonconditional pupal lethal phenotype. We also identified huc95Emutants, which are extremely sensitive to caffeine. Although huc95Eis a nonessential gene, mutant imaginal disc cells undergo caffeine-dependent apoptosis, and huc95Egene function is required for the viability of the organism when mutant larvae are exposed to levels of caffeine that controls can easily tolerate. We have mapped the cytological positions of huc29Dand huc95Eas a first step toward molecularly characterizing the relevant genes.
Nucleotide-binding site (NBS) profiling of genetic diversity in durum wheat
Authors: Mantovani Paola , van der Linden Gerard , Maccaferri Marco , Sanguineti Maria Corinna , Tuberosa Roberto
Published: April 2007

Molecular markers are effective tools to investigate genetic diversity for resistance to pathogens. NBS (nucleotide-binding site) profiling is a PCR (polymerase chain reaction)-based approach to studying genetic variability that specifically targets chromosome regions containing R-genes and R-gene analogues. We used NBS profiling to measure genetic diversity among 58 accessions of durum wheat. Mean polymorphism rates detected using MseI and AluI as restriction enzymes were 34% and 22%, respectively. Mean number of polymorphisms per enzyme–primer combination was equal to 23.8 ± 5.9, ranging from 13 to 31 polymorphic bands. In total, 96 markers over 190 indicated a good capacity to discriminate between accessions (the polymorphic index content ranging from 0.30 to 0.50). The results obtained with NBS profiling were compared with simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) data of the same set of accessions. The genetic distances computed with 190 NBS profiling markers were in close agreement with those obtained with AFLP and SSR markers (r = 0.73 and 0.76, respectively). Our results indicate that NBS profiling provides an effective means to investigate genetic diversity in durum wheat.
Population structure of Sclerotinia sclerotiorum in an Australian canola field at flowering and stem-infection stages of the disease cycle
Authors: Sexton Adrienne C. , Whitten Athol R. , Howlett Barbara J.
Published: April 2007

Populations of the ascomycete pathogen Sclerotinia sclerotiorum sampled from a canola field were analysed using microsatellite markers. Fifty isolates were collected from ascospore-infested canola petals and, later in the season, another 55 isolates were obtained from stem lesions; these isolates were used to compare inoculum and disease-causing populations. Fifty-five unique haplotypes were identified, with gene diversity ranging from 0.40 to 0.71. Genotypic diversity was higher in the inoculum population than it had been in the previous year, but analysis of molecular variance (AMOVA) showed that less than 10% of the variation was attributable to differences between the 2 years. Genotypic disequilibrium measures were consistent with the occurrence of both clonal reproduction and out-crossing. There was no significant population subdivision between the ascospore and stem-lesion populations, as measured with fixation indices (RST= 0.015, p = 0.90) and AMOVA, suggesting that there are no genetically defined subgroups of isolates more likely to proceed from petal colonization to cause stem infection. This might be because S. sclerotiorum possesses wide-ranging pathogenicity mechanisms that account for the lack of host specificity observed to date.
Tracing B-genome chromatin in Brassica napus × B. juncea interspecific progeny
Authors: Schelfhout C.J. , Snowdon R. , Cowling W.A. , Wroth J.M.
Published: April 2007

We used polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) techniques to demonstrate the presence of Brassica B-genome chromosomes and putative B-genome introgressions in B. napus × B. juncea interspecific progeny. The B-genome - specific repeat sequence pBNBH35 was used to generate PCR products and FISH probes. The highest frequencies of viable progeny were obtained when B. napus was the maternal parent of the interspecific hybrid and the first backcross. B-genome - positive PCR assays were found in 34/51 fertile F2 progeny (67%), which was more than double the proportion found in fertile BC1 progeny. Four B-genome - positive F2-derived families and 1 BC1-derived family were fixed or segregating for B. juncea morphology in the F4 and BC1S2, respectively, but in only 2 of these families did B. juncea-type plants exhibit B. juncea chromosome count (2n = 36) and typical B-genome FISH signals on 16 chromosomes. The remaining B. juncea-type plants had B. napus chromosome count (2n = 38) and no B-genome FISH signals, except for 1 exceptional F4-derived line that exhibited isolated and weak B-genome FISH signals on 11 chromosomes and typical A-genome FISH signals. B. juncea morphology was associated with B-genome - positive PCR signals but not necessarily with 16 intact B-genome chromosomes as detected by FISH. B-genome chromosomes tend to be eliminated during selfing or backcrossing after crossing B. juncea with B. napus, and selection of lines containing B-genome chromatin during early generations would be promoted by use of this B-genome repetitive marker.
Chiasmata and chromosome breakages are related to crossing over in Drosophila ananassae males
Authors: Goñi Beatriz , Matsuda Muneo , Tobari Yoshiko N.
Published: April 2007

A cytogenetic analysis of male crossing over in Drosophila ananassae revealed that cytological exchanges resulted in genetic crossing over, and that chiasma frequency and the genetic recombination correlated positively in chromosomes 2 and 3. Furthermore, the frequency of chromosome breakages correlated positively with chiasma frequency. Paracentric inversion heterozygosity had no detectable influence on the chromosome pairing or exchange events within the inversion loop at meiosis. Scoring of the chiasma demonstrated that males homozygous for the previously mapped enhancers of male crossing over had low frequencies of chiasmata, whereas higher frequencies of chiasmata were observed in males heterozygous for enhancers. The results presented here indicate that the genetic factors controlling male crossing over are involved in the origin of chromosome breakages and in exchange events.
Defeatingnumts: Semi-pure mitochondrial DNA from eggs and simple purification methods for field-collected wildlife tissues
Authors: Ibarguchi Gabriela , Friesen Vicki L. , Lougheed Stephen C.
Published: April 2007

Mitochondrial DNA (mtDNA) continues to play a pivotal role in phylogeographic, phylogenetic, and population genetic studies. PCR amplification with mitochondrial primers often yields ambiguous sequences, in part because of the coamplification of nuclear copies of mitochondrial genes (numts) and true mitochondrial heteroplasmy arising from mutations, hybridization with paternal leakage, gene duplications, and recombination. Failing to detect numts or to distinguish the origin of such homologous sequences results in the incorrect interpretation of data. However, few studies obtain purified mtDNA to confirm the mitochondrial origin of the first reference sequences for a species. Here, we demonstrate the importance and ease of obtaining semi-pure mtDNA from wildlife tissues, preserved under various typical field conditions, and investigate the success of 3 commercial extraction kits, cesium-chloride gradient mtDNA purification, long-template PCR amplification, cloning, and more species-specific degenerate primers. Using more detailed avian examples, we illustrate that unfertilized or undeveloped eggs provide the purest sources of mtDNA; that kits provide an alternative to cesium-chloride gradient methods; and that long-template PCR, cloning, and degenerate primers cannot be used to produce reliable mitochondrial reference sequences, but can be powerful tools when used in conjunction with purified mtDNA stocks to distinguish numts from true heteroplasmy.
Molecular characterization and chromosome-specific TRAP-marker development for Langdon durum D-genome disomic substitution lines
Authors: Li J. , Klindworth D.L. , Shireen F. , Cai X. , Hu J. , Xu S.S.
Published: April 2007

The aneuploid stocks of durum wheat ( Triticum turgidum L. subsp. durum (Desf.) Husnot) and common wheat ( T. aestivum L.) have been developed mainly in ‘Langdon’ (LDN) and ‘Chinese Spring’ (CS) cultivars, respectively. The LDN-CS D-genome chromosome disomic substitution (LDN-DS) lines, where a pair of CS D-genome chromosomes substitute for a corresponding homoeologous A- or B-genome chromosome pair of LDN, have been widely used to determine the chromosomal locations of genes in tetraploid wheat. The LDN-DS lines were originally developed by crossing CS nulli-tetrasomics with LDN, followed by 6 backcrosses with LDN. They have subsequently been improved with 5 additional backcrosses with LDN. The objectives of this study were to characterize a set of the 14 most recent LDN-DS lines and to develop chromosome-specific markers, using the newly developed TRAP (target region amplification polymorphism)-marker technique. A total of 307 polymorphic DNA fragments were amplified from LDN and CS, and 302 of them were assigned to individual chromosomes. Most of the markers (95.5%) were present on a single chromosome as chromosome-specific markers, but 4.5% of the markers mapped to 2 or more chromosomes. The number of markers per chromosome varied, from a low of 10 (chromosomes 1A and 6D) to a high of 24 (chromosome 3A). There was an average of 16.6, 16.6, and 15.9 markers per chromosome assigned to the A-, B-, and D-genome chromosomes, respectively, suggesting that TRAP markers were detected at a nearly equal frequency on the 3 genomes. A comparison of the source of the expressed sequence tags (ESTs), used to derive the fixed primers, with the chromosomal location of markers revealed that 15.5% of the TRAP markers were located on the same chromosomes as the ESTs used to generate the fixed primers. A fixed primer designed from an EST mapped on a chromosome or a homoeologous group amplified at least 1 fragment specific to that chromosome or group, suggesting that the fixed primers might generate markers from target regions. TRAP-marker analysis verified the retention of at least 13 pairs of A- or B-genome chromosomes from LDN and 1 pair of D-genome chromosomes from CS in each of the LDN-DS lines. The chromosome-specific markers developed in this study provide an identity for each of the chromosomes, and they will facilitate molecular and genetic characterization of the individual chromosomes, including genetic mapping and gene identification.
Genetic mapping of agronomic traits in false flax (Camelina sativa subsp.sativa)
Authors: Gehringer A. , Friedt W. , Lühs W. , Snowdon R.J.
Published: April 2007

The crucifer oilseed plant false flax (Camelina sativa subsp. sativa) possesses numerous valuable agronomic attributes that make it attractive as an alternative spring-sown crop for tight crop rotations. The oil of false flax is particularly rich in polyunsaturated C18-fatty acids, making it a valuable renewable feedstock for the oleochemical industry. Because of the minimal interest in the crop throughout the 20th century, breeding efforts have been limited. In this study, a genetic map for C. sativa was constructed, using amplified fragment length polymorphism (AFLP) markers, in a population of recombinant inbred lines that were developed, through single-seed descent, from a cross between ‘Lindo’ and ‘Licalla’, 2 phenotypically distinct parental varieties. Three Brassica simple sequence repeat (SSR) markers were also integrated into the map, and 1 of these shows linkage to oil-content loci in both C. sativa and Brassica napus. Fifty-five other SSR primer combinations showed monomorphic amplification products, indicating partial genome homoeology with the Brassica species. Using data from field trials with different fertilization treatments (0 and 80 kg N/ha) at multiple locations over 3 years, the map was used to localize quantitative trait loci (QTLs) for seed yield, oil content, 1000-seed mass, and plant height. Some yield QTLs were found only with the N0 treatment, and might represent loci contributing to the competitiveness of false flax in low-nutrient soils. The results represent a starting point for future marker-assisted breeding.
Complex genome rearrangements reveal evolutionary dynamics of pericentromeric regions in the Triticeae
Authors: Qi Lili , Friebe Bend , Gill Bikram S.
Published: April 2007

Most pericentromeric regions of eukaryotic chromosomes are heterochromatic and are the most rapidly evolving regions of complex genomes. The closely related genomes within hexaploid wheat ( Triticum aestivum L., 2n = 6x = 42, AABBDD), as well as in the related Triticeae taxa, share large conserved chromosome segments and provide a good model for the study of the evolution of pericentromeric regions. Here we report on the comparative analysis of pericentric inversions in the Triticeae, including Triticum aestivum, Aegilops speltoides , Ae. longissima, Ae. searsii, Hordeum vulgare , Secale cereale , and Agropyron elongatum . Previously, 4 pericentric inversions were identified in the hexaploid wheat cultivar ‘Chinese Spring’ (‘CS’) involving chromosomes 2B, 4A, 4B, and 5A. In the present study, 2 additional pericentric inversions were detected in chromosomes 3B and 6B of ‘CS’ wheat. Only the 3B inversion pre-existed in chromosome 3S, 3Sl, and 3Ssof Aegilops species of the Sitopsis section, the remaining inversions occurring after wheat polyploidization. The translocation T2BS/6BS previously reported in ‘CS’ was detected in the hexaploid variety ‘Wichita’ but not in other species of the Triticeae. It appears that the B genome is more prone to genome rearrangements than are the A and D genomes. Five different pericentric inversions were detected in rye chromosomes 3R and 4R, 4Slof Ae. longissima, 4H of barley, and 6E of Ag. elongatum. This indicates that pericentric regions in the Triticeae, especially those of group 4 chromosomes, are undergoing rapid and recurrent rearrangements.
BINARY AMIABLE WORDS
Authors: ATANASIU ADRIAN
Published: April 2007

Using the fact that the Parikh matrix mapping is not an injective mapping, the paper investigates some properties of the set of the binary words having the same Parikh matrix; these words are called "amiable" Some results concerning the conditions when the equivalence classes of amiable words have more than one element, a characterization theorem concerning a graph associated to an equivalence class of amiable words, and some basic properties of a rank distance defined on these classes are the main subjects considered here.
EFFICIENT COLLABORATIVE FILTERING IN CONTENT-ADDRESSABLE SPACES
Authors: BERKOVSKY SHLOMO , EYTANI YANIV , MANEVITZ LARRY
Published: April 2007

Collaborative Filtering (CF) is currently one of the most popular and most widely used personalization techniques. It generates personalized predictions based on the assumption that users with similar tastes prefer similar items. One of the major drawbacks of the CF from the computational point of view is its limited scalability since the computational effort required by the CF grows linearly both with the number of available users and items. This work proposes a novel efficient variant of the CF employed over a multidimensional content-addressable space. The proposed approach heuristically decreases the computational effort required by the CF algorithm by limiting the search process only to potentially similar users. Experimental results demonstrate that the proposed heuristic approach is capable of generating predictions with high levels of accuracy, while significantly improving the performance in comparison with the traditional implementations of the CF.
IDENTIFYING USER AND GROUP INFORMATION FROM COLLABORATIVE FILTERING DATASETS
Authors: GRIFFITH JOSEPHINE , O'RIORDAN COLM , SORENSEN HUMPHREY
Published: April 2007

This paper considers the information that can be captured about users and groups from a collaborative filtering dataset. The aims of the paper are to create a user model and to use this model to explain the performance of a collaborative filtering approach. A number of user and group features are defined and the performance of a collaborative filtering system in producing recommendations for users with different feature values is tested. Graph-based representations of the collaborative filtering space are presented and these are used to define some of the user and group features as well as being used in a recommendation task.
KNOWLEDGE-BASED RECOMMENDER TECHNOLOGIES FOR MARKETING AND SALES
Authors: FELFERNIG ALEXANDER , TEPPAN ERICH , GULA BARTOSZ
Published: April 2007

Recommender applications support decision-making processes by helping online customers to identify products more effectively. Recommendation problems have a long history as a successful application area of Artificial Intelligence (AI) and the interest in recommender applications has dramatically increased due to the demand for personalization technologies by large and successful e-Commerce environments. Knowledge-based recommender applications are especially useful for improving the accessibility of complex products such as financial services or computers. Such products demand a more profound knowledge from customers than simple products such as CDs or movies. In this paper we focus on a discussion of AI technologies needed for the development of knowledge-based recommender applications. In this context, we report experiences from commercial projects and present the results of a study which investigated key factors influencing the acceptance of knowledge-based recommender technologies by end-users.
PERSONALIZED SEARCH BASED ON A MEMORY RETRIEVAL THEORY
Authors: GASPARETTI FABIO , MICARELLI ALESSANDRO
Published: April 2007

Personalization is the ability to retrieve information content related to users' profile and facilitate their information-seeking activities. Several environments, such as the Web, take advantage of personalization techniques because of the large amount of available information. For this reason, there is a growing interest in providing automated personalization processes during the human-computer interaction.

In this paper we introduce a new approach for user modeling, which grounds in the Search of Associative Memory (SAM) theory. By means of implicit feedback techniques, the approach is able to unobtrusively recognize user needs and monitor the user working context in order to provide important information useful to personalize traditional search tools and implement recommender systems. Experimental results based on precision and recall measures indicate improvements in comparison with traditional user models.
UNOBTRUSIVE USER MODELING FOR ADAPTIVE HYPERMEDIA
Authors: HOLZ HILARY J. , HOFMANN KATJA , REED CATHERINE
Published: April 2007

We propose a technique for user modeling in Adaptive Hypermedia (AH) that is unobtrusive at both the level of observable behavior and that of cognition. Unobtrusive user modeling is complementary to transparent user modeling. Unobtrusive user modeling induces user models appropriate for Educational AH (EAH) based on metaphors characterized by a shared locus of control over learning, such as small group learning. Transparent user modeling, on the other hand, induces user models appropriate for EAH based on metaphors characterized by an independent locus of control, such as social navigation.

We extend an existing decomposition model of adaptation in AH to incorporate summative evaluation of unobtrusive user modeling. Summative evaluation examines the effects or outcomes of a system, while formative evaluation is used to improve a system under development. We also introduce a separate, two-stage model for formative evaluation of unobtrusive user modeling. We then present results from a field study for the first of the two developmental stages and describe the current field study of the second developmental stage. Finally, we compare unobtrusive and transparent user modeling, and explain the role of each.
EXPERIMENTAL ANALYSIS OF DESIGN CHOICES IN MULTIATTRIBUTE UTILITY COLLABORATIVE FILTERING
Authors: MANOUSELIS NIKOS , COSTOPOULOU CONSTANTINA
Published: April 2007

Recommender systems have already been engaging multiple criteria for the production of recommendations. Such systems, referred to as multicriteria recommenders, demonstrated early the potential of applying Multi-Criteria Decision Making (MCDM) methods to facilitate recommendation in numerous application domains. On the other hand, systematic implementation and testing of multicriteria recommender systems in the context of real-life applications still remains rather limited. Previous studies dealing with the evaluation of recommender systems have outlined the importance of carrying out careful testing and parameterization of a recommender system, before it is actually deployed in a real setting. In this paper, the experimental analysis of several design options for three proposed multiattribute utility collaborative filtering algorithms is presented for a particular application context (recommendation of e-markets to online customers), under conditions similar to the ones expected during actual operation. The results of this study indicate that the performance of recommendation algorithms depends on the characteristics of the application context, as these are reflected on the properties of evaluations' data set. Therefore, it is judged important to experimentally analyze various design choices for multicriteria recommender systems, before their actual deployment.
USING TIN-BASED STRUCTURES FOR THE MODELLING OF FUZZY GIS OBJECTS IN A DATABASE
Authors: VERSTRAETE JÖRG , DE TRÉ GUY , HALLEZ AXEL , DE CALUWE RITA
Published: April 2007

Traditional databases can manage only crisp information, a limitation that also holds for geographic information systems and spatial databases. In this paper, we present a technique based on triangulated irregular networks (or TINs for short) and fuzzy set theory to model imprecise or uncertain regions. A fuzzy region is represented by a Extended TIN, which allows for an associated value for each point of the region in the presented approach to be considered; this associated value will be a membership grade. As is common in fuzzy set theory, membership grades can indicate a degree of "belonging to the set"; in our approach these are the degree to which every crisp location belongs to the fuzzy region (membership grades in fuzzy set theory can have other interpretations7 as well, but these are not needed for the modelling of fuzzy regions). While modelling a fuzzy region as described provides a more accurate model of a real world situation, it does require many operators from the geographic realm to be extended and also new operators (mainly from the fuzzy realm) to be added at the object level. In this paper, from the GIS realm, the calculation of the surface area and the minimum bounding rectangle for fuzzy regions are considered; from the fuzzy realm the calculation of the α-cut is considered. Other operations (i.e. convex hull of a fuzzy region, distance between two fuzzy regions, …) are still under development.
F-CUBE FACTORY: A FUZZY OLAP SYSTEM FOR SUPPORTING IMPRECISION
Authors: DELGADO MIGUEL , MOLINA CARLOS , RODRÍGUEZ-ARIZA LÁZARO , SÁNCHEZ DANIEL , VILA M. AMPARO
Published: April 2007

The special needs of the OLAP technology were the main cause of the use of a multidimensional view of the data. Crisp models are not suitable to model complex or non well defined domains. They also fail to integrate data from semi/non-structured sources (e.g. Internet) or with incompatibilities in their schemata. In these situations, as a result of the modelling and/or integration, imprecision appears. So, we need a model able to manage imprecision in the structures and data. If we want to use expert's knowledge in the analysis, we have to keep in mind that expert users are more comfortable when they use linguistic expressions instead of exact values. In this paper we present an extension of a fuzzy multidimensional model to support the use of linguistic labels in the definition of the hierarchies and the OLAP system that implements this model.
A GENERAL FRAMEWORK FOR COMPUTING WITH WORDS IN OBJECT-ORIENTED PROGRAMMING
Authors: BERZAL F. , CUBERO J. C. , MARÍN N. , VILA M. A. , KACPRZYK J. , ZADROŻNY S.
Published: April 2007

Computing with words (CWW) techniques have been shown to be useful in the management of imperfect information. From the programmer's standpoint, new tools are necessary to ease the use of these techniques within current programming platforms. This paper presents a step in this direction by describing a general framework that supports the implementation of applications dealing with fuzzy objects. We pay special attention to the study of the object comparison problem by offering both a theoretical analysis and a simple and transparent way to use our theoretical results in practice.
Does Investors' Sophistication Affect Persistence and Pricing of Discretionary Accruals?
Authors: Kao Lanfeng
Published: April 2007

This paper examines whether the sophistication of market investors influences management's strategy on discretionary accounting choice, and thus changes the persistence of discretionary accruals. The results show that the persistence of discretionary accruals for firms face with naive investors is lower than that for firms face with sophisticated investors. The results also demonstrate that sophisticated investors indeed incorporate the implications of current earnings components into future earnings in a more sufficient manner than naïve investors do.
Price Limit and Volatility in Taiwan Stock Exchange: Some Additional Evidence from the Extreme Value Approach
Authors: Maghyereh Aktham I. , Al Zoubi Haitham A. , Nobanee Haitham
Published: April 2007

We reexamine the effects of price limits on stock volatility of Taiwan Stock Exchange using a new methodology based on the Extreme-Value technique. Consistent with the advocates of price limits, we find that stock market volatility is sharply moderated under more restrictive price limits.
Regime Shifts in the Stock–Bond Relation in Australia
Authors: Hobbes Garry , Lam Frewen , Loudon Geoffrey F.
Published: April 2007

Previous evidence suggests that the implied volatility from equity index options, as a measure of stock market uncertainty, can provide "forward-looking information" about the stock–bond return correlation. This paper uses an alternative regime-switching autoregressive model to characterize state-dependent stock–bond return comovement and to evaluate the contribution of implied volatility in understanding transition dynamics. We confirm that implied volatility provides information about transition dynamics which is not inherent in the stock and bond returns, notwithstanding several different features of our data set and methodological approach.
INTERNATIONAL AGRICULTURAL RESEARCH AS A SOURCE OF ENVIRONMENTAL IMPACTS: CHALLENGES AND POSSIBILITIES
Authors: NELSON MICHAEL , MAREDIA MYWISH K.
Published: April 2007

This paper deals with conceptual and methodological issues arising in ex post environmental impact assessment of agricultural research. It presents a case study of approaches used (and not used) and challenges associated with the ex post assessment of environmental impacts of research supported by the Consultative Group on International Agricultural Research (CGIAR). The paper illustrates the difficulty of tracking the global effects of agricultural research on natural resources due to a diffused and complex set of decision variables effecting intensification and expansion of land in agriculture, primarily in developing countries. The central point in ex post impact assessment concerns costs and benefits (in terms of relevant budget constraints and time frame for decision) of in-depth empirical versus qualitative analysis. Within this context we conclude that the empirical counterfactual approach ("with" and "without" research) is not an option. As a second best alternative, it is inferred from cases and global statistics that: in specific instances the introduction of high yielding varieties did have unintended impacts on natural resources, in part due to policy distortion and in part due to unforeseen chain reactions in the ecosystems. But on net balance, increased yields attributable to international agricultural research have had positive environmental impacts in the form of net land saving.
ASSESSMENT OF PUBLIC ACCEPTABILITY REGARDING WIND TURBINE CONSTRUCTION AS PERCEIVED BY ENVIRONMENTAL PROFESSIONALS
Authors: COLEBY ALASTOR M. , ASPINALL PETER A. , MILLER DAVID R.
Published: April 2007

Research for this paper was undertaken with the aim of revealing perceptions of a select group of environmental assessment experts with experience in wind power regarding public opinion. The multi criteria decision making (MCDM) software was used to quantify the expert perceptions of what made a wind turbine site publicly acceptable. Seven environmental experts experienced in wind farm environmental assessment were interviewed using the 'Expert Choice' software. The software recorded and tested interviewee decisions regarding acceptable site types and the criteria that would make them acceptable in terms of public opinion. The need for this research was that historically many environmental expert reports used by wind power site developers that attempted to meet the various criteria for planning permission provided little or no information on public opinion regarding the proposed site that could later lead to it being opposed locally.
BUILDING A SUSTAINABLE BUSINESS IN CHINA'S SMALL AND MEDIUM-SIZED ENTERPRISES (SMEs)
Authors: YU JIEQIONG , BELL J. NIGEL B.
Published: April 2007

Given the SMEs a heterogeneous group in the Chinese society due to their inherent characteristics, this paper takes a preliminary step to look into the complicated and dynamic environment for engaging China's SMEs in corporate sustainability. It aims to provide insight into how China's SMEs perceive and practice sustainability, and to explore key drivers and barriers behind their environmental and social engagement. Findings reveal an apparent contradiction in the current status of China's SMEs towards sustainability: a high level of concern vs. a low level of engagement. The most important motivator appears to be improving corporate image, followed by governmental legislation. While barriers hindering SMEs' sustainable engagement vary, predominant problems involve a lack of awareness and perception, insufficient financial resources and insufficient or ill-suited external support. Accordingly, the paper highlights three areas for China's SMEs' further improvements: education, communication and cooperation.
POLITICAL REPRESENTATION: PERSPECTIVE FROM FUZZY SYSTEMS THEORY
Authors: NURMI HANNU , KACPRZYK JANUSZ
Published: April 2007

The theory of fuzzy sets has been applied to social choice primarily in the context where one is given a set of individual fuzzy preference relations and the aim is to find a non-fuzzy choice set of winners or best alternatives. In this article, we discuss the problem of composing multi-member deliberative bodies starting again from a set of individual fuzzy preference relations. We outline methods of aggregating these relations into a measure of how well each candidate represents each voter in terms of the latter's preferences. Our main goal is to show how the considerations discussed in the context of individual non-fuzzy complete and transitive preference relations can be extended into the domain of fuzzy preference relations.
SPECIFYING THEORIES IN COMPARATIVE POLITICS: TOWARD A MORE THOROUGHLY DEDUCTIVE APPROACH
Authors: MORDESON JOHN N. , CLARK TERRY D. , WIERMAN MARK J. , LARSON JENNIFER M. , GRIESER ADAM D.
Published: April 2007

Models in political science are often poorly specified prior to testing. In practice, most analysts rely on regression analysis to determine the weights for each independent variable (causal factor) identified in the model. We demonstrate a method for determining the relative weights of causal factors prior to testing of the model. The approach makes use of expert opinions in the qualitative literature in order to construct a more completely specified model in a deductive manner prior to testing. We also demonstrate several methods for assessing the degree of confidence we might have in the model based on the relative degree of divergence among the experts concerning the causal factors.
CHALLENGES FOR IMPROVING CONSENSUS REACHING PROCESS IN COLLECTIVE DECISIONS
Authors: MARTÍNEZ L. , MONTERO J.
Published: April 2007

The majority rule is frequently presented as a cornerstone of any democratic society, guiding many group decision-making processes where final decision requires the agreement of more than half the people involved. But sometimes, some key decisions require a higher level of agreement. In such cases, an added value would be to reach some consensus about the decision-making problem. Decision making under consensus drives to decisions which are better accepted and appreciated. But it also implies a greater complexity and time consuming process to reach a final decision, and it may even lead to a deadlock or unsuccessful results, whenever the searched agreement is not achieved. Meanwhile, these problems arise because the requirements to achieve the consensus are too strong, and different processes have softened their requirements. In particular, soft consensus is one of the most widespread consensus reaching processes that uses fuzzy logic to soften the consensus requirements. However, several problems still persist despite the softening of the requirements.

In this paper, we are going to make a brief revision of the different concepts about consensus and about different consensus reaching processes, both in the crisp and fuzzy environment. We shall then analyze how to overcome their lacks, indicating the challenges facing these processes in order to obtain successful results in those group decision problems in which they are required to make a decision under consensus.
CONSENSUS MODELLING IN GROUP DECISION MAKING: DYNAMICAL APPROACH BASED ON FUZZY PREFERENCES
Authors: FEDRIZZI MARIO , FEDRIZZI MICHELE , PEREIRA R. A. MARQUES
Published: April 2007

The. notion of consensus plays an important role in group decision making, particularly when the collective preference structure is generated by a dynamical aggregation process of the single individual preference structures. In this dynamical process of aggregation each single decision maker gradually transforms his/her preference structure by combining it, through iterative weighted averaging, with the preference structures of the remaining decision makers. In this way, the collective decision emerges dynamically as a result of the consensual interaction among the various decision makers in the group. From the point of view of applied mathematics, the models of consensual dynamics stand in the context of multi-agent complex systems, with interactive and nonlinear dynamics. The consensual interaction among the various agents (decision makers) acts on their state variables (the preferences) in order to optimize an appropriate measure of consensus, which can be of type 'hard' (unanimous agreement within the group of decision makers) or 'soft' (partial agreement within the group of decision makers). In this paper, we study the modelling of consensus reaching when the individual testimonies are assumed to be expressed as fuzzy preference relations. Here consensus is meant as the degree to which most of the experts agree on the preferences associated to the most relevant alternatives. First of all we derive a degree of dissensus based on linguistic quantifiers and then we introduce a form of network dynamics in which the quantifiers are represented by scaling functions. Finally, assuming that the decision makers can express their preferences in a more flexible way, i.e. by using triangular fuzzy numbers, we describe the iterative process of opinion transformation towards consensus via the gradient dynamics of a cost function expressed as a linear combination of a dissensus cost function and an inertial cost function.
High glucose induces IL-1β expression in human monocytes: mechanistic insights
Authors: Dasu Mohan R. , Devaraj Sridevi , Jialal Ishwarlal
Published: April 2007

Previously, IL-1β secretion from Type 2 diabetic patients has been shown to be increased compared with controls. In this study, we aimed to delineate the mechanism of IL-1β induction under high-glucose (HG) conditions in human monocytes. THP-1 cells cultured in normal glucose were treated with increasing concentrations of d-glucose (10–25 mM) for 6–72 h. IL-1β and IL-1 receptor antagonist levels were measured by ELISA and Western blots, whereas mRNA was quantitated by RT-PCR. Specific inhibitors and small interfering RNAs of PKC, p38, ERK1/2, NF-κB, and NADPH oxidase were used to determine the mediators in parallel experiments under HG conditions. IL-1β-secreted protein, cellular protein, and mRNA increase under HG conditions is time and dose dependent, with maximum increase at 15 mM (48 h; P < 0.05). IL-1 receptor antagonist release was time and dose dependent, similar to IL-1β expression pattern; however, the molar ratio of IL-1β to IL-1RA was increased. Data from inhibitor and small interfering RNA experiments indicate that IL-1β release under HG is mediated by PKC-α, via phosphorylation of p38 MAPK, and ERK1/2 leading to NF-κB activation, resulting in increased mRNA and protein for IL-1β. At the same time, it appears that NADPH oxidase via p47phox activates NF-κB, resulting in increased IL-1β secretion. Data suggest that, under HG conditions, monocytes release significantly higher amounts of IL-1β through multiple mechanisms, further compounding the disease progression. Targeting signaling pathways mediating IL-1β release could result in the amelioration of inflammation and possibly diabetic vasculopathies.
Androgen-Dependent Gene Expression of Prostate-Specific Antigen Is Enhanced Synergistically by Hypoxia in Human Prostate Cancer Cells
Authors: Horii Kou , Suzuki Yasutomo , Kondo Yukihiro , Akimoto Masao , Nishimura Taiji , Yamabe Yukako , Sakaue Motoharu , Sano Toshihiro , Kitagawa Takayuki , Himeno Seiichiro , Imura Nobumasa , Hara Shuntaro
Published: April 2007

The androgen receptor (AR) is implicated in prostate cancer growth, progression, and angiogenesis. Hypoxia-inducible factor-1 (HIF-1), which transcriptionally regulates hypoxia-inducible angiogenic factors, is up-regulated in prostate cancers compared with adjacent normal tissues. HIF-1 may be involved in prostate cancer as well as the AR, but the involvement of HIF-1 in prostate cancer angiogenesis and progression has not been fully elucidated. In the present study, we found that in prostate cancer LNCaP cells dihydrotestosterone enhanced the expression of GLUT-1, one of the HIF-1 target genes, and also that hypoxia enhanced the expression of prostate-specific antigen (PSA) that is one of the AR target genes and is involved in tumor invasion. Small interfering RNA that specifically inhibits HIF-1 reduced the expression levels of PSA as well as GLUT-1. Reporter gene analysis showed that dihydrotestosterone activated the HIF-1–mediated gene expression and hypoxia enhanced the AR-induced promoter activity of human PSA gene. Deletion and site-directed mutation of the 5′-flanking region of human PSA gene revealed that the sequence ACGTG between −3951 and −3947 was essential in the response to hypoxia. Furthermore, chromatin immunoprecipitation assay indicated that HIF-1 interacts with the AR on the human PSA gene promoter. These results indicated that in prostate cancers, HIF-1 might cooperate with the AR to activate the expression of several genes related to tumor angiogenesis, invasion, and progression. (Mol Cancer Res 2007;5(4):383–91)
Growth Stimulation of Non–Small Cell Lung Cancer Cell Lines by Antibody against Epidermal Growth Factor Receptor Promoting Formation of ErbB2/ErbB3 Heterodimers
Authors: Maegawa Mari , Takeuchi Kenji , Funakoshi Eishi , Kawasaki Katsumi , Nishio Kazuto , Shimizu Nobuyoshi , Ito Fumiaki
Published: April 2007

Antibodies are the most rapidly expanding class of human therapeutics, including their use in cancer therapy. Monoclonal antibodies (mAb) against epidermal growth factor (EGF) receptor (EGFR) generated for cancer therapy block the binding of ligand to various EGFR-expressing human cancer cell lines and abolish ligand-dependent cell proliferation. In this study, we show that our mAb against EGFRs, designated as B4G7, exhibited a growth-stimulatory effect on various human cancer cell lines including PC-14, a non–small cell lung cancer cell line; although EGF exerted no growth-stimulatory activity toward these cell lines. Tyrosine phosphorylation of EGFRs occurred after treatment of PC-14 cells with B4G7 mAb, and it was completely inhibited by AG1478, a specific inhibitor of EGFR tyrosine kinase. However, this inhibitor did not affect the B4G7-stimulated cell growth, indicating that the growth stimulation by B4G7 mAb seems to be independent of the activation of EGFR tyrosine kinase. Immunoprecipitation with anti-ErbB3 antibody revealed that B4G7, but not EGF, stimulated heterodimerization between ErbB2 and ErbB3. ErbB3 was tyrosine phosphorylated in the presence of B4G7 but not in the presence of EGF. Further, the phosphorylation and B4G7-induced increase in cell growth were inhibited by AG825, a specific inhibitor of ErbB2. These results show that the ErbB2/ErbB3 dimer functions to promote cell growth in B4G7-treated cells. Changes in receptor-receptor interactions between ErbB family members after inhibition of one of its members are of potential importance in optimizing current EGFR family–directed therapies for cancer. (Mol Cancer Res 2007;5(4):393–401)
Reduced Ventricular Volumes and Improved Systolic Function With Cardiac Resynchronization Therapy
Authors: Rao Rajni K. , Kumar Uday N. , Schafer Jill , Viloria Esperanza , De Lurgio David , Foster Elyse
Published: April 2007

Background—

Cardiac resynchronization therapy has emerged as an important therapy for advanced systolic heart failure. Among available cardiac resynchronization therapy pacing modes that restore ventricular synchrony, it is uncertain whether simultaneous biventricular (BiV), sequential BiV, or left ventricular (LV) pacing is superior. The Device Evaluation of CONTAK RENEWAL 2 and EASYTRAK 2: Assessment of Safety and Effectiveness in Heart Failure (DECREASE-HF) trial is the first randomized trial comparing these 3 cardiac resynchronization therapy modalities.

Methods and Results—

The DECREASE-HF Trial is a multicenter trial in which 306 patients with New York Heart Association class III or IV heart failure, an LV ejection fraction ≤35%, and a QRS duration ≥150 ms were randomized to simultaneous BiV, sequential BiV, or LV pacing. LV volumes and systolic and diastolic function were assessed with echocardiography at baseline, 3 months, and 6 months. All groups had a significant reduction in LV end-systolic and end-diastolic dimensions (
P
<0.001). The simultaneous BiV pacing group had the greatest reduction in LV end-systolic dimension (
P
=0.007). Stroke volume (
P
<0.001) and LV ejection fraction (
P
<0.001) improved in all groups with no difference across groups.

Conclusions—

Compared with LV pacing, simultaneous BiV pacing was associated with a trend toward greater improvement in LV size. There is little difference between simultaneous BiV pacing and sequential BiV pacing as programmed in this trial.
Mechanism Underlying Initiation of Paroxysmal Atrial Flutter/Atrial Fibrillation by Ectopic Foci
Authors: Gong Yunfan , Xie Fagen , Stein Kenneth M. , Garfinkel Alan , Culianu Calin A. , Lerman Bruce B. , Christini David J.
Published: April 2007

Background—

The mechanisms underlying paroxysmal atrial flutter/atrial fibrillation initiation by ectopic foci from various locations are unclear.

Methods and Results—

We used parallel computational techniques to study an anatomically accurate 3-dimensional atrial structure incorporating a detailed ionic-current model of an atrial myocyte. At the single-cell level, upregulation of the L-type Ca
2+
current
I
Ca,L
steepened restitution curves of action potential duration and conduction velocity compared with the control. Spontaneous firings of ectopic foci, coupled with sinus activity, produced dynamic spatial dispersions of repolarization, including discordant alternans, which caused conduction block and reentry only for the elevated
I
Ca,L
case. For each foci location, a vulnerable window for atrial flutter/atrial fibrillation induction was identified as a function of the coupling interval and focus cycle length. For ectopic foci in the pulmonary veins and left atrium, the site of conduction block and reentry gradually shifted, as a function of coupling interval, from the right atrium to the interatrial area and finally to the left atrium. The size of the vulnerable window was largest for pulmonary vein foci, becoming markedly smaller for right atrial foci, especially those near the sinoatrial node.

Conclusions—

These findings suggest that a mechanism of dynamically induced repolarization dispersion, especially discordant alternans, underlies the induction of atrial flutter/atrial fibrillation by atrial ectopic foci. The sites and likelihood of reentry induction varied according to ectopic focus location and timing, with the largest vulnerable window corresponding to the pulmonary vein region.