bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Three-Dimensional Network of the Thylakoid Membranes in Plants: Quasihelical Model of the Granum-Stroma Assembly
Authors: Mustárdy László , Buttle Karolyn , Steinbach Gábor , Garab Győző 
Published: October 2008

AbstractThe three-dimensional (3-D) network of the granum-stroma thylakoid assembly of vascular plant chloroplasts exhibits complex structural/functional heterogeneity. A complete understanding of the ultrastructure of this assembly is critical for our understanding of thylakoid function. The prevailing historical model of thylakoid structure, based on information derived from serial section analyses of electron microscopy (EM) images, suggests a helical arrangement of stroma membranes wound around the granum stacks. More recently, electron tomography has emerged as the leading method for the study of thylakoid ultrastructure, as it provides for higher resolution in the depth dimension. The first detailed 3D topological model derived from electron tomography was in disagreement with the helical model, whereas a more recent electron tomography study, conducted under somewhat different experimental conditions, suggested that basic features of the helical model are still valid. Here, we review the conventional EM data and present a critical discussion of the two electron tomography data sets in an attempt to establish a consensus model that accommodates all the information presently available.
Phytochrome A Regulates the Intracellular Distribution of Phototropin 1–Green Fluorescent Protein in Arabidopsis thaliana
Authors: Han In-Seob , Tseng Tong-Seung , Eisinger William , Briggs Winslow R. 
Published: October 2008

Abstract
It has been known for decades that red light pretreatment has complex effects on subsequent phototropic sensitivity of etiolated seedlings. Here, we demonstrate that brief pulses of red light given 2 h prior to phototropic induction by low fluence rates of blue light prevent the blue light–induced loss of green fluorescent protein–tagged phototropin 1 (PHOT1-GFP) from the plasma membrane of cortical cells of transgenic seedlings of Arabidopsis thaliana expressing PHOT1-GFP in a phot1-5 null mutant background. This red light effect is mediated by phytochrome A and requires ∼2 h in the dark at room temperature to go to completion. It is fully far red reversible and shows escape from photoreversibility following 30 min of subsequent darkness. Red light–induced inhibition of blue light–inducible changes in the subcellular distribution of PHOT1-GFP is only observed in rapidly elongating regions of the hypocotyl. It is absent in hook tissues and in mature cells below the elongation zone. We hypothesize that red light–induced retention of the PHOT1-GFP on the plasma membrane may account for the red light–induced increase in phototropic sensitivity to low fluence rates of blue light.
The Phytocalpain Defective Kernel 1 Is a NovelArabidopsisGrowth Regulator Whose Activity Is Regulated by Proteolytic Processing
Authors: Johnson Kim Leonie , Faulkner Christine , Jeffree Chris Edward , Ingram Gwyneth Christina 
Published: October 2008

AbstractThe role of the unique plant calpain Defective Kernel 1 (DEK1) in development has remained unclear due to the severity of mutant phenotypes. Here, we used complementation studies of the embryo-lethal mutant to dissect DEK1 protein behavior and to show that DEK1 plays a key role in growth regulation in Arabidopsis thaliana. We show that although full-length DEK1 protein localizes to membranes, it undergoes intramolecular autolytic cleavage events that release the calpain domain into the cytoplasm. The active calpain domain alone is not only necessary for DEK1 function but is sufficient for full complementation of dek1 mutants. A novel set of phenotypes, including leaf ruffling, increased leaf thickness, and abnormalities of epidermal cell interdigitation, was caused by expression of the constitutively active calpain domain. This analysis of the novel phenotypes produced by DEK1 under- and overexpression, as well as DEK1 subcellular localization and protein processing, has revealed a fundamental role for DEK1-mediated signaling in growth regulation.
A Novel Class of Gibberellin 2-Oxidases Control Semidwarfism, Tillering, and Root Development in Rice
Authors: Lo Shuen-Fang , Yang Show-Ya , Chen Ku-Ting , Hsing Yue-Ie , Zeevaart Jan A.D. , Chen Liang-Jwu , Yu Su-May 
Published: October 2008

AbstractGibberellin 2-oxidases (GA2oxs) regulate plant growth by inactivating endogenous bioactive gibberellins (GAs). Two classes of GA2oxs inactivate GAs through 2β-hydroxylation: a larger class of C19 GA2oxs and a smaller class of C20 GA2oxs. In this study, we show that members of the rice (Oryza sativa) GA2ox family are differentially regulated and act in concert or individually to control GA levels during flowering, tillering, and seed germination. Using mutant and transgenic analysis, C20 GA2oxs were shown to play pleiotropic roles regulating rice growth and architecture. In particular, rice overexpressing these GA2oxs exhibited early and increased tillering and adventitious root growth. GA negatively regulated expression of two transcription factors, O. sativa homeobox 1 and TEOSINTE BRANCHED1, which control meristem initiation and axillary bud outgrowth, respectively, and that in turn inhibited tillering. One of three conserved motifs unique to the C20 GA2oxs (motif III) was found to be important for activity of these GA2oxs. Moreover, C20 GA2oxs were found to cause less severe GA-defective phenotypes than C19 GA2oxs. Our studies demonstrate that improvements in plant architecture, such as semidwarfism, increased root systems and higher tiller numbers, could be induced by overexpression of wild-type or modified C20 GA2oxs.
A Cytosolic Pathway for the Conversion of Hydroxypyruvate to Glycerate during Photorespiration in Arabidopsis
Authors: Timm Stefan , Nunes-Nesi Adriano , Pärnik Tiit , Morgenthal Katja , Wienkoop Stefanie , Keerberg Olav , Weckwerth Wolfram , Kleczkowski Leszek A. , Fernie Alisdair R. , Bauwe Hermann 
Published: October 2008

Abstract
Deletion of any of the core enzymes of the photorespiratory cycle, one of the major pathways of plant primary metabolism, results in severe air-sensitivity of the respective mutants. The peroxisomal enzyme hydroxypyruvate reductase (HPR1) represents the only exception to this rule. This indicates the presence of extraperoxisomal reactions of photorespiratory hydroxypyruvate metabolism. We have identified a second hydroxypyruvate reductase, HPR2, and present genetic and biochemical evidence that the enzyme provides a cytosolic bypass to the photorespiratory core cycle in Arabidopsis thaliana. Deletion of HPR2 results in elevated levels of hydroxypyruvate and other metabolites in leaves. Photosynthetic gas exchange is slightly altered, especially under long-day conditions. Otherwise, the mutant closely resembles wild-type plants. The combined deletion of both HPR1 and HPR2, however, results in distinct air-sensitivity and a dramatic reduction in photosynthetic performance. These results suggest that photorespiratory metabolism is not confined to chloroplasts, peroxisomes, and mitochondria but also extends to the cytosol. The extent to which cytosolic reactions contribute to the operation of the photorespiratory cycle in varying natural environments is not yet known, but it might be dynamically regulated by the availability of NADH in the context of peroxisomal redox homeostasis.
Federated search engines and the development of library systems
Authors: Joint Nicholas 
Published: October 2008

PurposeThe purpose of this paper is to discuss the recent history of library systems with a view to illustrating the impact of federated search systems on reinvigorating the role of the library system.Design/methodology/approachA narrative account of the impact of digital library technologies on the function of library systems, together with an outline of how larger principles such as “openness” and “proprietorialness” determine the success or failure of digital information products.FindingsIt was found that the present role of the library system is significantly different from its earlier purpose, and that innovative and visionary responses to the challenges of networked information services have helped reinvent its function.Research limitations/implicationsSome of the ideas in this paper may be worthy of consideration as evidence of the broader research principles underlying the success or failure of digital information products.Practical implicationsThe insights in this piece may clarify for the practitioner the present and future role of the systems division within the larger framework of the academic library.Originality/valueThis paper attempts to create a coherent narrative for a number of otherwise unrelated library developments.
How do school resource centre staff deal with information requests?
Authors: Shenton Andrew K. 
Published: October 2008

PurposeThe purpose of this paper is to use new data to explore the pertinence, to the work of an information professional dealing with inquiries, of an existing typology indicating the forms of action taken by people when approached for information by youngsters.Design/methodology/approachThe study featured here drew on qualitative data from a transaction log maintained in the resource centre of an English high school and from two interviews with the information specialist employed.FindingsBroadly, the results demonstrate that the original typology does reflect accurately the actions taken by the intermediary under scrutiny. However, two of the original categories did not emerge and a new one was detected.Research limitations/implicationsThe study was small‐scale in nature. It was conducted in just one school, with data provided by a solitary information specialist. The transaction log was maintained for one week only. Future research of a similar type but staged in other kinds of library/resource centre would be invaluable.Practical implicationsAn examination of the actions taken by the information specialist reveals that it is possible to identify a series of essential skills and areas of knowledge in which the individual should be expert. Skills associated with liaison may be considered especially important.Originality/valueNo previous paper has applied the original typology of action to the work of an intermediary. The fact that the article seeks to extend the theoretical knowledge base via an investigation of actual inquiry situations will interest both LIS academics and library professionals who work regularly with information users.
Students’ attitudes towards e‐books in a Scottish higher education institute: part 2
Authors: Abdullah Noorhidawati , Gibb Forbes 
Published: October 2008

PurposeThe purpose of this paper is to present the second part of three inter‐related studies investigating the use and usability of e‐books in higher education based on experiments conducted at the University of Strathclyde.Design/methodology/approachThe research discussed here involved two analyses: an analysis of two e‐book collections in the libraries of the University of Strathclyde and the University of Glasgow and an analysis of a follow‐up study to a web survey into user interactions with e‐books in one of the library's collections.FindingsThe follow‐up study found that in general students found that interacting with e‐books in the library collection was easy. Students indicated that their preferred book formats varied depending on the context of their information need. Despite their positive reaction and attitudes towards e‐books, students commented that e‐books needed to be promoted more strongly and that there were limitations with respect to their use.Research limitations/implicationsThe study presented here was a small‐scale study based only on e‐book collections from one supplier (NetLibrary) and involved only 18 respondents. While this is considered sufficient based on the discount usability testing concept, generalisation of the results should be made with caution.Practical implicationsThe findings should be of value to academic libraries in terms of improving e‐book collection management. This study highlights current attitudes of students towards e‐book in terms of how they interact with them, the features they value and their preferences between e‐books and paper books in a university library.Originality/valueThis paper provides useful information on students’ attitudes towards e‐books.
Keeping a learning diary to enhance researchers’ understanding of and users’ skills in web searching
Authors: Mansourian Yazdan 
Published: October 2008

PurposeThe purpose of this paper is to demonstrate how using a learning diary can enable researchers to gain a deeper insight into end users’ information searching behaviour and how it can improve users’ search skills as well.Design/methodology/approachThe study adopted a qualitative approach and used a learning diary as its data collection tool. A group of 62 Library and Information Science students from Tarbiat Moallem University in Tehran formed the target group. They were asked to keep a search diary for eight weeks to reflect on their search experiences during that period of time. Moreover, 15 of them participated in a follow‐up interview after handing in their diaries.FindingsA tentative model was developed to illustrate a number of elements which contribute to the formation of problematic, satisfying and optimal search situations. Moreover keeping a diary was perceived useful by the participants in improving their search skills.Research limitations/implicationsOnly 34 of the subjects (54 per cent of the target group) recorded a detailed track of their searches which were suitable for the purpose of this study. The technique employed in this study might be helpful for the information literacy trainers to evaluate the progress of their trainees and to gain a better understanding of their difficulties.Originality/valueThere is little research in the area of information seeking on the web using learning diary as a device to reflect on users’ search behaviour.
Scientometric analysis of a sample of physics‐related research output held in the institutional repository Strathprints (2000‐2005)
Authors: Bonilla‐Calero A.I. 
Published: October 2008

PurposeThe purpose of this paper is to describe a “scientometric” analysis of a sample of research output in Physics taken from the institutional repository of the University of Strathclyde (“Strathprints”). The documents in this sample were authored over the period 2000‐2005 but were deposited in the repository during the period from publication up to 2007. The paper aims to analyse these data bibliometrically.Design/methodology/approachUse was more of open access logs for Strathprints which describe the number of downloads per document, revealing how many countries cite and download each document, and analysing the factors that influence the number of citations and downloads per document. The documents retrieved in Strathprints are described by a variety of indicators delineating levels of activity, collaboration and visibility, which in turn are analysed in order to discern patterns characteristic of the repository.FindingsThe number of documents in this open access repository has increased during the period under consideration, as has the number of authors, centres and countries per document. In terms of institutional origin, unsurprisingly Scottish institutions occupy first or final position in 94 per cent of the total documents. Documents published in 2000 (the earliest documents in the repository) are the most cited. There is a positive correlation between the number of citations and downloads and the number of distinct countries that cite and download. The most cited and downloaded types of documents are articles; post‐prints are the most downloaded type of publication. There is no relationship between the journals with the highest average of citations per document in web of science (WoS) and those with the highest number of citations in Strathprints.Originality/valueInstitutional respositories (IRs) are a relatively new phenomenon in the digital library world. Not much in depth analysis of IR statistics has been undertaken to date, so this study is an important attempt to contribute to this new area of research.
Content clouds: classifying content in Web 2.0
Authors: Cosh Kenneth J. , Burns Robert , Daniel Toby 
Published: October 2008

PurposeWith increasing amounts of user generated content being produced electronically in the form of wikis, blogs, forums etc. the purpose of this paper is to investigate a new approach to classifying ad hoc content.Design/methodology/approachThe approach applies natural language processing (NLP) tools to automatically extract the content of some text, visualizing the results in a content cloud.FindingsContent clouds share the visual simplicity of a tag cloud, but display the details of an article at a different level of abstraction, providing a complimentary classification.Research limitations/implicationsProvides the general approach to creating a content cloud. In the future, the process can be refined and enhanced by further evaluation of results. Further work is also required to better identify closely related articles.Practical implicationsBeing able to automatically classify the content generated by web users will enable others to find more appropriate content.Originality/valueThe approach is original. Other researchers have produced a cloud, simply by using skiplists to filter unwanted words, this paper's approach improves this by applying appropriate NLP techniques.
Strategy execution in emerging economies: assessing strategic diffusion in Mexico and Peru
Authors: Parnell John A. 
Published: October 2008

PurposeMiddle and lower‐level managers play a significant role in the strategic management process, primarily in the execution stage. However, strategic diffusion – the extent to which a strategy is effectively executed and becomes an integral part of the organization – varies across organizations. This paper aims to examine the strategic diffusion process in two emerging economies, Mexico and Peru.Design/methodology/approachParnell's strategic diffusion scale (SDS) was adopted for this study. Respondents also completed Cook and Wall's nine‐item organizational commitment instrument and a three‐item scale measuring satisfaction with firm performance. Surveys were translated into Spanish and completed by 218 Mexican and 270 Peruvian managers.FindingsStrategic diffusion was linked to performance satisfaction among both Mexican and Peruvian managers. Overall, Mexican managers produced higher scores on the strategic diffusion scale (SDS) than did their Peruvian counterparts. The link between strategic diffusion and organizational commitment among middle and lower‐level managers remains unclear.Research limitations/implicationsThis study supports the strategic diffusion construct and the SDS. Three items in the scale were problematic in certain instances, however. The present study linked strategic diffusion to performance satisfaction in both Mexico and Peru. As expected, Mexican managers exhibited higher SDS scores than did their Peruvian counterparts. The link between strategic diffusion and organizational commitment was not strong, however. Additional research is needed in this area.Practical implicationsMiddle and lower level managers in different countries have different views on the process of strategic diffusion. These distinctions are cause by a number of factors, including stages in the economic development cycle, organizational culture, and widely accepted management practices. Executives seeking to implement strategies should recognize the three key components of strategic diffusion – understanding, involvement, and commitment – and how they are influenced by national contexts.Originality/valueThere is a dearth of research assessing management behaviors in emerging nations. It is also important to learn more about processes associated with strategy execution in different organizations. This paper addresses both needs by assessing strategic diffusion in Mexico and Peru.
Decision making in product development: are you outside‐in or inside‐out?
Authors: Summers Gary J. , Scherpereel Christopher M. 
Published: October 2008

PurposeThis paper proposes a relationship between decision making and key qualities of business systems.Design/methodology/approachThe authors explore the relationship between decision making and systems by contrasting the decision making in two well‐known systems: MRP and JIT. The two systems present two sets of opposing qualities. By considering the relationship between a decision and its environment, we propose that these sets of qualities are not unique to MRP and JIT. They arise from two general approaches to decision making. Having introduced the two approaches, we analyze three product development systems: Stage‐Gate, Agile and Lean.FindingsIn manufacturing, MRP is a push system; JIT is a pull system. MRP seeks perfection; JIT seeks consistency. MRP gives decision makers great discretion; JIT constrains decisions. These opposing qualities, and others, arise from two general approaches to decision making: outside‐in and inside‐out. As the difficulty of decisions increase, relative to a decision maker's ability, the cost of mistakes becomes significant. In these situations, the inside‐out approach should outperform the outside‐in approach. The inside‐out approach constrains decision making to limit the cost of errors. The outside‐in approach embraces complexity, exposing itself to more decision errors. In product development, the Lean and Agile systems exploit the inside‐out approach. They constrain decisions and reduce the cost of errors that arise from two sources. Lean addresses interactions, which add complexity to business systems. Agile addresses unpredictability, which adds uncertainty to business systems.Originality/valueThe relationships the authors propose show how decision making affects the development, control and performance of business systems.