bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional Dissection of Naturally Occurring Amino Acid Substitutions in eIF4E That Confers Recessive Potyvirus Resistance in Plants
Authors: Yeam Inhwa , Cavatorta Jason R. , Ripoll Daniel R. , Kang Byoung-Cheorl , Jahn Molly M. 
Published: September 2007

AbstractNaturally existing variation in the eukaryotic translation initiation factor 4E (eIF4E) homolog encoded at the pvr1 locus in Capsicum results in recessively inherited resistance against several potyviruses. Previously reported data indicate that the physical interaction between Capsicum-eIF4E and the viral genome-linked protein (VPg) is required for the viral infection in the Capsicum-Tobacco etch virus (TEV) pathosystem. In this study, the potential structural role(s) of natural variation in the eIF4E protein encoded by recessive resistance alleles and their biological consequences have been assessed. Using high-resolution three-dimensional structural models based on the available crystallographic structures of eIF4E, we show that the amino acid substitution G107R, found in many recessive plant virus resistance genes encoding eIF4E, is predicted to result in a substantial modification in the protein binding pocket. The G107R change was shown to not only be responsible for the interruption of VPg binding in planta but also for the loss of cap binding ability in vitro, the principal function of eIF4E in the host. Overexpression of the Capsicum-eIF4E protein containing the G107R amino acid substitution in Solanum lycopersicum indicated that this polymorphism alone is sufficient for the acquisition of resistance against several TEV strains.
A Cluster of Disease Resistance Genes inArabidopsisIs Coordinately Regulated by Transcriptional Activation and RNA Silencing
Authors: Yi Hankuil , Richards Eric J. 
Published: September 2007

AbstractThe RPP5 (for recognition of Peronospora parasitica 5) locus in the Arabidopsis thaliana Columbia strain contains a cluster of paralogous disease Resistance (R) genes that play important roles in innate immunity. Among the R genes in this locus, RPP4 confers resistance to two races of the fungal pathogen Hyaloperonospora parasitica, while activation of SNC1 (for suppressor of npr1-1, constitutive 1) results in the resistance to another race of H. parasitica and to pathovars of the bacterial pathogen Pseudomonas syringae through the accumulation of salicylic acid (SA). Here, we demonstrate that other Columbia RPP5 locus R genes can be induced by transgenic overexpression of SNC1, which itself is regulated by a positive amplification loop involving SA accumulation. We also show that small RNA species that can target RPP5 locus R genes are produced in wild-type plants and that these R genes can be cosuppressed in transgenic plants overexpressing SNC1. Steady state expression levels of SNC1 increase in some mutants (dcl4-4, ago1-36, and upf1-5) defective in RNA silencing as well as in transgenic plants expressing the P1/Helper Component-Protease viral suppressor of RNA silencing. However, steady state levels of small RNA species do not change in mutants that upregulate SNC1. These data indicate many Columbia RPP5 locus R genes can be coordinately regulated both positively and negatively and suggest that the RPP5 locus is poised to respond to pathogens that disturb RNA silencing.
TheGIGANTEA-Regulated MicroRNA172 Mediates Photoperiodic Flowering Independent ofCONSTANSinArabidopsis
Authors: Jung Jae-Hoon , Seo Yeon-Hee , Seo Pil Joon , Reyes Jose Luis , Yun Ju , Chua Nam-Hai , Park Chung-Mo 
Published: September 2007

AbstractRegulated RNA metabolism appears to be a critical component of molecular mechanisms directing flowering initiation in plants. A group of RNA binding proteins exerts their roles through the autonomous flowering pathway. Posttranscriptional mechanisms regulated by microRNAs (miRNAs) also play a key role in flowering-time control. Here, we demonstrate that the GIGANTEA (GI)-regulated miR172 defines a unique genetic pathway that regulates photoperiodic flowering by inducing FLOWERING LOCUS T (FT) independent of CONSTANS (CO). A late-flowering mutant in which a miR172 target gene, TARGET OF EAT1, is constitutively activated by the nearby insertion of the cauliflower mosaic virus 35S enhancer normally responded to vernalization and gibberellic acid treatments. By contrast, its response to daylength changes was severely disrupted. In the mutant, FT was significantly repressed, but other flowering genes were unaffected. Notably, miR172 abundance is regulated by photoperiod via GI-mediated miRNA processing. Accordingly, miR172-overproducing plants exhibit early flowering under both long days and short days, even in the absence of functional CO, indicating that miR172 promotes photoperiodic flowering through a CO-independent genetic pathway. Therefore, it appears that GI-mediated photoperiodic flowering is governed by the coordinated interaction of two distinct genetic pathways: one mediated via CO and the other mediated via miR172 and its targets.
How socially connected are citers to those that they cite?
Authors: Johnson Ben , Oppenheim Charles 
Published: September 2007

PurposeThe purpose of this paper is to report an investigation into the social and citation networks of three information scientists: David Nicholas, Peter Williams and Paul Huntington.Design/methodology/approachSimilarities between citation patterns and social closeness were identified and discussed. A total of 16 individuals in the citation network were identified and investigated using citation analysis, and a matrix formed of citations made between those in the network. Social connections between the 16 in the citation network were then investigated by means of a questionnaire, the results of which were merged into a separate matrix. These matrices were converted into visual social networks, using multidimensional scaling. A new deviance measure was devised for drawing comparisons between social and citation closeness in individual cases.FindingsNicholas, Williams and Huntington were found to have cited 527 authors in the period 2000‐2003, the 16 most cited becoming the subjects of further citation and social investigation. This comparison, along with the examination of visual representations indicates a positive correlation between social closeness and citation counts. Possible explanations for this correlation are discussed, and implications considered. Despite this correlation, the information scientists were found to cite widely outside their immediate social connections.Originality/valueSocial network analysis has not been often used in combination with citation analysis to explore inter‐relationships in research teams.
Chat reference communication patterns and implications: applying politeness theory
Authors: Westbrook Lynn 
Published: September 2007

PurposeThe purpose of this study is to examine the use of formality indicators in chat reference interchanges within the context of politeness theory, with its corollaries of face‐threat and social relationship development.Design/methodology/approachThis discourse analysis identifies the syntactic and content indicators and patterns of formality levels in a purposive sample of 402 chat transcripts (covering 6,572 minutes) from one academic year at a large, US, public university.FindingsSyntactic formality markers include regular use of contractions, slang, sentence fragments, and non‐standard punctuation as well as limited use of acronyms and abbreviations with rare use of emoticons. Content‐based markers included apologies, self‐disclosure, and expressions of extreme need. Use patterns are related to the level of responsibility assumed by the librarian as well as the interview stages.Research limitations/implicationsA limited data source and potential coder bias are the two limitations of this study. The research implications point to the need for chat reference librarians to assume greater control of formality nuances in order to encourage a more effective search for the user.Practical implicationsThe fundamentals of politeness theory, particularly in terms of formality indicators, should be incorporated into staff training and behavioral standards for reference librarians. While future research is needed to determine the most effective means of employing this theoretical construct, this study implies that a self‐reflective, culturally sensitive use of the nuances of formality can enhance the user's experience.Originality/valueThis study is the first to systematically examine formality indicators in the context of politeness theory. The use of two coders, a full academic year's worth of data, and a substantial sample provide great depth.
Web searchers' attributions of success and failure: an empirical study
Authors: Mansourian Yazdan , Ford Nigel 
Published: September 2007

PurposeThis paper reports the findings of a study designed to explore web searchers' perceptions of the causes of their search failure and success. In particular, it seeks to discover the extent to which the constructs locus of control and attribution theory might provide useful frameworks for understanding searchers' perceptions.Design/methodology/approachA combination of inductive and deductive approaches were employed. Perceptions of failed and successful searches were derived from the inductive analysis of using open‐ended qualitative interviews with a sample of 37 biologists at the University of Sheffield. These perceptions were classified into “internal” and “external” attributions, and the relationships between these categories and “successful” and “failed” searches were analysed deductively to test the extent to which they might be explainable using locus of control and attribution theory interpretive frameworks.FindingsAll searchers were readily able to recall “successful” and “unsuccessful” searches. In a large majority of cases (82.4 per cent), they clearly attributed each search to either internal (e.g. ability or effort) or external (e.g. luck or information not being available) factors. The pattern of such relationships was analysed, and mapped onto those that would be predicted by locus of control and attribution theory. The authors conclude that the potential of these theoretical frameworks to illuminate one's understanding of web searching, and associated training, merits further systematic study.Research limitations/implicationsThe findings are based on a relatively small sample of academic and research staff in a particular subject area. Importantly, also, the study can at best provide a prima facie case for further systematic study since, although the patterns of attribution behaviour accord with those predictable by locus of control and attribution theory, data relating to the predictive elements of these theories (e.g. levels of confidence and achievement) were not available. This issue is discussed, and recommendations made for further work.Originality/valueThe findings provide some empirical support for the notion that locus of control and attribution theory might – subject to the limitations noted above – be potentially useful theoretical frameworks for helping us better understand web‐based information seeking. If so, they could have implications particularly for better understanding of searchers' motivations, and for the design and development of more effective search training programmes.
Search persistence and failure on the web: a “bounded rationality” and “satisficing” analysis
Authors: Mansourian Yazdan , Ford Nigel 
Published: September 2007

PurposeThis paper aims to examine our current knowledge of how searchers perceive and react to the possibility of missing potentially important information whilst searching the web is limited. The study reported here seeks to investigate such perceptions and reactions, and to explore the extent to which Simon's “bounded rationality” theory is useful in illuminating these issues.Design/methodology/approachTotally 37 academic staff, research staff and research students in three university departments were interviewed about their web searching. The open‐ended, semi‐structured interviews were inductively analysed. Emergence of the concept of “good enough” searching prompted a further analysis to explore the extent to which the data could be interpreted in terms of Simon's concepts of “bounded rationality” and “satisficing”.FindingsThe results indicate that the risk of missing potentially important information was a matter of concern to the interviewees. Their estimations of the likely extent and importance of missed information affected decisions by individuals as to when to stop searching – decisions based on very different criteria, which map well onto Simon's concepts. On the basis of the interview data, the authors propose tentative categorizations of perceptions of the risk of missing information including “inconsequential” “tolerable” “damaging” and “disastrous” and search strategies including “perfunctory” “minimalist” “nervous” and “extensive”. It is concluded that there is at least a prima facie case for bounded rationality and satisficing being considered as potentially useful concepts in our quest better to understand aspects of human information behaviour.Research limitations/implicationsAlthough the findings are based on a relatively small sample and an exploratory qualitative analysis, it is argued that the study raises a number of interesting questions, and has implications for both the development of theory and practice in the areas of web searching and information literacy.Originality/valueThe paper focuses on an aspect of web searching which has not to date been well explored. Whilst research has done much to illuminate searchers' perceptions of what they find on the web, we know relatively little of their perceptions of, and reactions to information that they fail to find. The study reported here provides some tentative models, based on empirical evidence, of these phenomena.
Sources and use of marketing information by marketing managers
Authors: Bennett Roger 
Published: September 2007

PurposeThe paper aims to establish which formally and informally published sources of knowledge were mainly used by executives in the computer service industry to obtain knowledge of current developments in the field of marketing and to examine the purposes for which the knowledge gathered from these sources was employed.Design/methodology/approachMarketing managers in 141 large computer services businesses completed a questionnaire concerning the extents to which they used books, marketing magazines, academic journals, and grey literature (GL) for instrumental, conceptual, and symbolic purposes. Four “motivating factors” (e.g. occupational learning orientation) were examined plus three other influences (e.g. length of time in a marketing role). The possible consequences of the extensive use of various sources were explored.FindingsOnly 2 per cent of the sample read academic marketing journals, and just 3 per cent looked at marketing textbooks. However, 89 per cent of the sample accessed (mainly internet‐based) grey marketing literature and 62 per cent read marketing magazines. Nearly, one in six of the respondents stated that they had read practitioner “how to do” marketing books. Several hypothesised independent variables exerted positive and significant impacts on the degrees to which magazines; GL and practitioner books were employed to obtain marketing knowledge.Research limitations/implicationsIt was not possible to examine exactly why a particular knowledge source was preferred for a specific purpose. Potential connections between past academic research outputs and the contents of contemporary grey marketing literature and articles in marketing magazines could not be investigated. The results imply that GL must be recognised as a vital source of marketing knowledge. Issues relating to the codification and wider distribution of GL, copyright, the shortage of specialised GL bibliographies in the marketing area, and the long‐term availability of materials in electronic form need to be addressed.Originality/valueThis was the first empirical study to connect the use of marketing knowledge sources to the purposes (instrumental, conceptual, symbolic) for which the knowledge contained within them was required.
Building a faceted classification for the humanities: principles and procedures
Authors: Broughton Vanda , Slavic Aida 
Published: September 2007

PurposeThis paper aims to provide an overview of principles and procedures involved in creating a faceted classification scheme for use in resource discovery in an online environment.Design/methodology/approachFacet analysis provides an established rigorous methodology for the conceptual organization of a subject field, and the structuring of an associated classification or controlled vocabulary. This paper explains how that methodology was applied to the humanities in the FATKS project, where the objective was to explore the potential of facet analytical theory for creating a controlled vocabulary for the humanities, and to establish the requirements of a faceted classification appropriate to an online environment. A detailed faceted vocabulary was developed for two areas of the humanities within a broader facet framework for the whole of knowledge. Research issues included how to create a data model which made the faceted structure explicit and machine‐readable and provided for its further development and use.FindingsIn order to support easy facet combination in indexing, and facet searching and browsing on the interface, faceted classification requires a formalized data structure and an appropriate tool for its management. The conceptual framework of a faceted system proper can be applied satisfactorily to humanities, and fully integrated within a vocabulary management system.Research limitations/implicationsThe procedures described in this paper are concerned only with the structuring of the classification, and do not extend to indexing, retrieval and application issues.Practical implicationsMany stakeholders in the domain of resource discovery consider developing their own classification system and supporting tools. The methods described in this paper may clarify the process of building a faceted classification and may provide some useful ideas with respect to the vocabulary maintenance tool.Originality/valueAs far as the authors are aware there is no comparable research in this area.
Beyond information – factors in participation in networks of practice
Authors: Cox Andrew M. 
Published: September 2007

PurposeThis paper aims to explore the pattern and significance of cross‐organizational ties in an emergent professional field, web production in UK higher education.Design/methodology/approachThe research is based on in‐depth interviews with 21 practitioners and analysis of activity in cross‐organizational spaces, such as an online community and a series of annual practitioner conferences on the web in HE (1997).FindingsThe cross‐organizational spaces have support and symbolic roles as well as informational ones. They have overlapping but different membership and agendas. Key factors that govern individual participation and so the shape of cross‐organizational spaces are differential involvement in technical innovation, degree of organizational embedding or marginality, differences in organizational position and role, orientation towards centralization or decentralization and orientation towards marketing or IT. There is some sense of occupational community among web managers, but within that also diversity and a significant fracture line between marketing and IT perspectives on the role. This may explain the lack of formal professionalization. As a more natural boundary practice between organizations than marketing, IT has more public visibility, possibly influencing the course jurisdictional struggles over who should control the web.Originality/valueMost studies of knowledge sharing have focussed on the factors which influence it within an organization, yet cross‐organizational sharing is also of importance, even for established professions as the boundaries of organizations become more open. For new occupations cross‐organizational ties may be a critical resource, and not only for sharing information or support, but for making sense of what the job is about at the deepest level. The research is also original in analysing a relatively little researched occupational group, those producing web sites for a living. It will be relevant to those interested in online and people centered information seeking, in professionalization and occupational identity.
Sliding bearings lubricated with magnetic fluids
Authors: Ochoński W. 
Published: September 2007

PurposeThis paper seeks to present some new designs of sliding bearings lubricated with magnetic fluids (ferrofluids) and the possibility of using them in modern bearing technology, in new computer and audiovisual equipment among others.Design/methodology/approachThe paper presents new designs of journal, thrust and journal‐thrust sliding bearings lubricated and sealed with magnetic fluids such as: magnetic fluid bearing bushing made of magnetizable material, pivot bearings with porous sleeve impregnated with ferrofluid, self‐aligning bearings, hydrodynamic ferrofluid bearings with spiral and herringbone grooves structure are presented. Moreover, examples are shown of applications in modern bearing technology.FindingsThe paper provides information about new designs of magnetic fluid sliding bearings assemblies and gives the main advantages of these bearings over conventional ball bearings, such as extremely low non‐repetitive run‐out (high‐accuracy of rotation), good damping and quietness of operation, maintenance free service and high reliability.Originality/valueThis paper offers some new designs of compact, low friction and self‐contained magnetic fluid sliding bearings and points up their practical applications.