bluuebunny/crossref_metadata_2025 huggingface dataset:
Localization of a bacterial protein in starch granules of transgenic maize kernels
Authors: Chikwamba Rachel K. , Scott M. Paul , Mejía Lorena B. , Mason Hugh S. , Wang Kan
Published: September 2003

The B subunit of
Escherichia coli
heat labile enterotoxin (LT-B) is a potent oral immunogen with potential for use as a vaccine, a carrier molecule to deliver antigens to gut-associated lymphoid tissues, and possibly an adjuvant to make coadministered vaccines more effective. LT-B produced in plants was shown to be functional and immunogenic in animals and humans. In this work, we show that maize-derived LT-B is strongly associated with starch granules in endosperm. Using immunogold labeling/electron microscopy, cell fractionation, and protein analysis techniques, we observed that LT-B protein could be detected both internally and externally in starch granules. This strong association confers an effective copurification of the antigen with the starch fraction of maize kernels, thermostability desirable in maize processing, and resistance to peptic degradation in simulated gastric fluid digests, an important attribute for an orally delivered antigen.
The entry of entry inhibitors: A fusion of science and medicine
Authors: Moore John P. , Doms Robert W.
Published: September 2003

For HIV-1 to enter a cell, its envelope protein (Env) must sequentially engage CD4 and a chemokine coreceptor, triggering conformational changes in Env that ultimately lead to fusion between the viral and host cell membranes. Each step of the virus entry pathway is a potential target for novel antiviral agents termed entry inhibitors. A growing number of entry inhibitors are under clinical development, with one having already been licensed by the Food and Drug Administration. With the emergence of virus strains that are largely resistant to existing reverse transcriptase and protease inhibitors, the development of entry inhibitors comes at an opportune time. Nonetheless, because all entry inhibitors target in some manner the highly variable Env protein of HIV-1, there are likely to be challenges in their efficient application that are unique to this class of drugs. Env density, receptor expression levels, and differences in affinity and receptor presentation are all factors that could influence the clinical response to this promising class of new antiviral agents.
Age-dependent deficiency in import of mitochondrial DNA glycosylases required for repair of oxidatively damaged bases
Authors: Szczesny Bartosz , Hazra Tapas K. , Papaconstantinou John , Mitra Sankar , Boldogh Istvan
Published: September 2003

The mitochondria are the major source of chronic oxidative stress, which has been implicated in the aging process. Along with other cellular changes, aged cells accumulate mutations in both their nuclear and mitochondrial genomes, and they contain increased amounts of oxidatively damaged mutagenic bases such as 7,8-dihydro-8-oxoguanine, suggesting age-dependent inhibition of its repair. Surprisingly, the level and activity of 8-oxoguanine-DNA glycosylase (OGG1), responsible for repair of 7,8-dihydro-8-oxoguanine, was found to be higher in the liver mitochondrial extract from old rodents than in that from young ones. We addressed this paradox by analyzing OGG1 in the mitochondria of young vs. old mouse livers, as well as in replicating vs. presenescent human fibroblasts. We show here that although the total OGG1 activity is higher in old mitochondria, a large fraction of the enzyme is stuck to the membrane in the precursor form, which could not be translocated to and processed in the mitochondrial matrix. A nearly identical phenomenon was observed with the mitochondrial uracil-DNA glycosylase responsible for repair of mutagenic uracil. These results indicate an age-dependent decline in the mitochondrial import of proteins needed for DNA repair and possibly for other functions.
Coordination of central odor representations through transient, non-oscillatory synchronization of glomerular output neurons
Authors: Christensen Thomas A. , Lei Hong , Hildebrand John G.
Published: September 2003

At the first stage of processing in the olfactory pathway, the patterns of glomerular activity evoked by different scents are both temporally and spatially dynamic. In the antennal lobe (AL) of some insects, coherent firing of AL projection neurons (PNs) can be phase-locked to network oscillations, and it has been proposed that oscillatory synchronization of PN activity may encode the chemical identity of the olfactory stimulus. It remains unclear, however, how the brain uses this time-constrained mechanism to encode chemical identity when the stimulus itself is unpredictably dynamic. In the olfactory pathway of the moth
Manduca sexta
,we find that different odorants evoke gamma-band oscillations in the AL and the mushroom body (a higher-order network that receives input from the AL), but oscillations within or between these two processing stages are not temporally coherent. Moreover, the timing of action potential firing in PNs is not phase-locked to oscillations in either the AL or mushroom body, and the correlation between PN synchrony and field oscillations remains low before, during, and after olfactory stimulation. These results demonstrate that olfactory circuits in the moth are specialized to preserve time-varying signals in the insect's olfactory space, and that stimulus dynamics rather than intrinsic oscillations modulate the uniquely coordinated pattern of PN synchronization evoked by each olfactory stimulus. We propose that non-oscillatory synchronization provides an adaptive mechanism by which PN ensembles can encode stimulus identity while concurrently monitoring the unpredictable dynamics in the olfactory signal that typically occur under natural stimulus conditions.
VEGF induces S1P
1
receptors in endothelial cells: Implications for cross-talk between sphingolipid and growth factor receptors
Authors: Igarashi Junsuke , Erwin Phillip A. , Dantas Ana Paula V. , Chen Hongjie , Michel Thomas
Published: September 2003

Sphingosine 1-phosphate (S1P) is a platelet-derived sphingolipid that binds to S1P
1
(EDG-1) receptors and activates the endothelial isoform of NO synthase (eNOS). S1P and the polypeptide growth factor vascular endothelial growth factor (VEGF) act independently to modulate angiogenesis and activate eNOS. In these studies, we explored the cross-talk between S1P and VEGF signaling pathways. When cultured bovine aortic endothelial cells were treated with VEGF (10 ng/ml), the expression of S1P
1
protein and mRNA increased by ≈4-fold. S1P
1
up-regulation by VEGF was seen within 30 min of VEGF addition and reached a maximum after 1.5 h. By contrast, expression of neither bradykinin B2 receptors nor the scaffolding protein caveolin-1 was altered by VEGF treatment. The EC
50
for VEGF-promoted induction of S1P
1
expression was ≈2 ng/ml, within its physiological concentration range. S1P
1
induction by VEGF was attenuated by the tyrosine kinase inhibitor genistein and by the PKC inhibitor calphostin C. Preincubation of bovine aortic endothelial cells with VEGF (10 ng/ml for 90 min) markedly enhanced subsequent S1P-dependent eNOS activation. VEGF pretreatment of cultured endothelial cells also markedly potentiated S1P-promoted eNOS phosphorylation at Ser-1179, as well as S1P-mediated activation of kinase Akt. In isolated rat arteries, VEGF pretreatment markedly potentiated S1P-mediated vasorelaxation and eNOS Ser-1179 phosphorylation. Taken together, these data indicate that VEGF specifically induces expression of S1P
1
receptors, associated with enhanced intracellular signaling responses to S1P and the potentiation of S1P-mediated vasorelaxation. We suggest that VEGF acts to sensitize the vascular endothelium to the effects of lipid mediators by promoting the induction of S1P
1
receptors, representing a potentially important point of cross-talk between receptor-regulated eNOS signaling pathways in the vasculature.
Stearoyl-CoA desaturase 1 deficiency elevates insulin-signaling components and down-regulates protein-tyrosine phosphatase 1B in muscle
Authors: Rahman Shaikh Mizanoor , Dobrzyn Agnieszka , Dobrzyn Pawel , Lee Seong-Ho , Miyazaki Makoto , Ntambi James M.
Published: September 2003

We have shown previously that mice with a targeted disruption in the stearoyl-CoA desaturase 1 gene (
SCD1
-/-
) have increased insulin sensitivity compared with control mice. Here we show that the
SCD1
-/-
mice have increased insulin signaling in muscle. The basal tyrosine phosphorylation of the insulin receptor and insulin receptor substrates 1 and 2 are elevated. The tyrosine phosphorylation of insulin-like growth factor-1 receptor was similar between
SCD1
+/+
and
SCD1
-/-
mice. The association of insulin receptor substrates 1 and 2 with αp85 subunit of phosphatidylinositol 3-kinase as well as the phosphorylation of Akt-Ser-473 and Akt-Thr-308 are also elevated in the
SCD1
-/-
mice. Interestingly, the mRNA levels, protein mass, and activity of the protein-tyrosine phosphatase-1B implicated in the attenuation of the insulin signal are reduced in the
SCD1
-/-
mice, whereas the levels of the leukocyte antigen-related protein phosphatase are similar between two groups of mice. The content of glucose transporter 4 in the plasma membrane and basal as well as insulin-mediated glucose uptake are increased in the
SCD1
-/-
mice. In addition, the muscle glycogen content and the activities of glycogen synthase and phosphorylase are increased in the
SCD1
-/-
mice. We hypothesize that loss of
SCD1
function induces increased insulin signaling at least in part by a reduction in the expression of protein-tyrosine phosphatase 1B.
SCD1
could be a therapeutic target in the treatment of diabetes.
The first external loop of the metal ion transporter DCT1 is involved in metal ion binding and specificity
Authors: Cohen Adiel , Nevo Yaniv , Nelson Nathan
Published: September 2003

The yeast null mutant
smf1
Δ cannot grow on medium containing EGTA. Expression of Smf1p or the mammalian transporter DCT1 (Slc11a2) suppresses the above-mentioned phenotype. Both can also be expressed in
Xenopus
oocytes, and the uptake activity and their electrophysiological properties can be studied. We used these systems to analyze the properties of mutations in the predicted external loop I of DCT1. The sensitivity of the transporter to amino acid substitutions in this region is manifested by the mutation G119A, which resulted in almost complete inhibition of the metal ion uptake activity and marked changes in the pre-steady-state currents in
Xenopus
oocytes. The mutation Q126D abolished the uptake and the electrophysiology, but the double mutant D124A/Q126D partially restored it and changed the metal ion specificity in favor of Fe
2
+
. The maximal pre-steady-state currents at negatively imposed potentials shifted to a lower pH of ≈5. The triple mutant G119A/D124A/Q126D, which has no apparent transport activity, exhibited remarkable pre-steady-state currents at pH 7.5. Moreover, Zn
2
+
had a dual effect on this mutant; at pH 7.5 it eliminated the pre-steady state without generating steady-state currents, and at pH 5.5 it induced large pre-steady-state currents. The mutant D124A retained appreciable Fe
2
+
uptake activity but exhibited very little Mn
2
+
uptake at pH 5.5 and was abolished at pH 6.5. The properties of the various mutants suggest that loop I is involved in the metal ion binding and its coupling to the proton-driving force.
Single-channel SCAM Identifies Pore-lining Residues in the First Extracellular Loop and First Transmembrane Domains of Cx46 Hemichannels
Authors: Kronengold J. , Trexler E.B. , Bukauskas F.F. , Bargiello T.A. , Verselis V.K.
Published: September 2003

Gap junction (GJ) channels provide an important pathway for direct intercellular transmission of signaling molecules. Previously we showed that fixed negative charges in the first extracellular loop domain (E1) strongly influence charge selectivity, conductance, and rectification of channels and hemichannels formed of Cx46. Here, using excised patches containing Cx46 hemichannels, we applied the substituted cysteine accessibility method (SCAM) at the single channel level to residues in E1 to determine if they are pore-lining. We demonstrate residues D51, G46, and E43 at the amino end of E1 are accessible to modification in open hemichannels to positively and negatively charged methanethiosulfonate (MTS) reagents added to cytoplasmic or extracellular sides. Positional effects of modification along the length of the pore and opposing effects of oppositely charged modifying reagents on hemichannel conductance and rectification are consistent with placement in the channel pore and indicate a dominant electrostatic influence of the side chains of accessible residues on ion fluxes. Hemichannels modified by MTS-EA+, MTS-ET+, or MTS-ES− were refractory to further modification and effects of substitutions with positively charged residues that electrostatically mimicked those caused by modification with the positively charged MTS reagents were similar, indicating all six subunits were likely modified. The large reductions in conductance caused by MTS-ET+ were visible as stepwise reductions in single-channel current, indicative of reactions occurring at individual subunits. Extension of single-channel SCAM using MTS-ET+ into the first transmembrane domain, TM1, revealed continued accessibility at the extracellular end at A39 and L35. The topologically complementary region in TM3 showed no evidence of reactivity. Structural models show GJ channels in the extracellular gap to have continuous inner and outer walls of protein. If representative of open channels and hemichannels, these data indicate E1 as constituting a significant portion of this inner, pore-forming wall, and TM1 contributing as pore-lining in the extracellular portion of transmembrane span.
Adenoviral Vectors Expressing siRNAs for Discovery and Validation of Gene Function
Authors: Arts Gert-Jan , Langemeijer Ellen , Tissingh Rudi , Ma Libin , Pavliska Heidi , Dokic Kristina , Dooijes Richele , Mešić Emir , Clasen Remko , Michiels Frits , van der Schueren Jan , Lambrecht Mark , Herman Sofie , Brys Reginald , Thys Kim , Hoffmann Marcel , Tomme Peter , van Es Helmuth
Published: September 2003

RNA interference is a powerful tool for studying gene function and for drug target discovery in diverse organisms and cell types. In mammalian systems, small interfering RNAs (siRNAs), or DNA plasmids expressing these siRNAs, have been used to down-modulate gene expression. However, inefficient transfection protocols, in particular, for primary cell types, have hampered the use of these tools in disease-relevant cellular assays. To be able to use this technology for genome-wide function screening, a more robust transduction protocol, resulting in a longer duration of the knock-down effect, is required. Here, we describe the validation of adenoviral vectors that express hairpin RNAs that are further processed to siRNAs. Infection of cell lines, or primary human cells, with these viruses leads to an efficient, sequence-specific, and prolonged reduction of the corresponding target mRNA, resulting in a reduction of the encoded protein level in the cell. For knock-down of one of the targets, GαS, we have measured inhibition of ligand-dependant, G-protein-coupled signaling. It is expected that this technology will prove to be of great value in target validation and target discovery efforts.
Representational Oligonucleotide Microarray Analysis: A High-Resolution Method to Detect Genome Copy Number Variation
Authors: Lucito Robert , Healy John , Alexander Joan , Reiner Andrew , Esposito Diane , Chi Maoyen , Rodgers Linda , Brady Amy , Sebat Jonathan , Troge Jennifer , West Joseph A. , Rostan Seth , Nguyen Ken C.Q. , Powers Scott , Ye Kenneth Q. , Olshen Adam , Venkatraman Ennapadam , Norton Larry , Wigler Michael
Published: September 2003

We have developed a methodology we call ROMA (representational oligonucleotide microarray analysis), for the detection of the genomic aberrations in cancer and normal humans. By arraying oligonucleotide probes designed from the human genome sequence, and hybridizing with “representations” from cancer and normal cells, we detect regions of the genome with altered “copy number.” We achieve an average resolution of 30 kb throughout the genome, and resolutions as high as a probe every 15 kb are practical. We illustrate the characteristics of probes on the array and accuracy of measurements obtained using ROMA. Using this methodology, we identify variation between cancer and normal genomes, as well as between normal human genomes. In cancer genomes, we readily detect amplifications and large and small homozygous and hemizygous deletions. Between normal human genomes, we frequently detect large (100 kb to 1 Mb) deletions or duplications. Many of these changes encompass known genes. ROMA will assist in the discovery of genes and markers important in cancer, and the discovery of loci that may be important in inherited predispositions to disease.
Annotating Large Genomes With Exact Word Matches
Authors: Healy John , Thomas Elizabeth E. , Schwartz Jacob T. , Wigler Michael
Published: September 2003

We have developed a tool for rapidly determining the number of exact matches of any word within large, internally repetitive genomes or sets of genomes. Thus we can readily annotate any sequence, including the entire human genome, with the counts of its constituent words. We create a Burrows-Wheeler transform of the genome, which together with auxiliary data structures facilitating counting, can reside in about one gigabyte of RAM. Our original interest was motivated by oligonucleotide probe design, and we describe a general protocol for defining unique hybridization probes. But our method also has applications for the analysis of genome structure and assembly. We demonstrate the identification of chromosome-specific repeats, and outline a general procedure for finding undiscovered repeats. We also illustrate the changing contents of the human genome assemblies by comparing the annotations built from different genome freezes.
Latent consumers’ attitude to farmers’ markets in North West England
Authors: Archer G.P. , García Sánchez Judit , Vignali Gianpaolo , Chaillot Aurélie
Published: September 2003

The purpose of the research was to extend on previous research by studying latent consumers’ attitude to farmers’ markets. Findings will be used to improve the marketing and publicity of farmers’ markets in order to attract other consumers groups. The people surveyed were not always aware of the term farmers’ market. Some think it is a place where farmers go to buy what they need. Around 94 per cent of people who have already been to a farmers’ market will return because they enjoy the food which is fresh, different, local, etc. and to support farmers. Latent consumers think that farmers’ markets sell fresh, quality, locally produced, tastier, healthier and seasonal food. However they do not expect the food to be cheaper. The most important criteria are quality, freshness and the fact that food is produced locally. Latent consumers would enjoy supporting local producers, information about the products and how to prepare them.
Consumer direct initiatives in North West England farmers’ markets
Authors: Youngs Julie
Published: September 2003

An investigation into the viability, sustainability and future developments of farmers’ markets in North West England was carried out in 2001. For this purpose, the attitudes of consumers, traders and organisers were surveyed. A primary research study was developed specifically to study North West farmers’ markets and to survey consumer attitudes to other direct selling initiatives. Both qualitative and quantitative methods were used for data collection. A total of 34 farmers’ markets were active in the North West .The highest density was found in Cumbria. Over half of the markets in the North West were thriving or developing. However, more than 60 per cent of those in Lancashire were classified as surviving. Findings showed that customer loyalty was a key factor. A lack of funding for promotion and low produce diversity were identified as major problems. The study concluded that there appears to be a potential for growing and sustainable farmers’ markets, provided that the problems identified by this study are addressed.
A study of farm outlets in North West England
Authors: Youngs Julie
Published: September 2003

The purpose of this case was to help verify and support consumer direct initiatives in line with strategic priority, market development of the North West Food Alliance (NWFA) agri‐food sector strategy for the North West. To achieve this, a study was made into the viability, sustainability and future development of farmers’ markets in North West England and also a consumer attitude survey into direct selling initiatives such as farm outlets. There was a correlation in the type of consumer frequenting farmers’ markets and farm outlets. Most people purchasing were female, aged 55+ and retired. A total of 36 per cent of people heard of the farm outlet by word of mouth or just drove past the outlet. Therefore, convenience of parking was important to most consumers along with the presentation of the shop. Consumers’ perceptions of purchasing at a farm outlet were that they were purchasing fresh, quality, tasty and healthy produce that was often from a local source but not necessarily. Consumers did not always expect the produce to be cheaper. Many expressed an interest in the availability of refreshments – café facilities.
German libraries at the starting line for the new task of teaching information literacy
Authors: Homann Benno
Published: September 2003

Initiatives by German librarians on taking on board educational work in the field of information literacy or “Informationskomptenz” now seem to be successful. Although a lot of unfavorable organizational and political conditions still exist and much remains to be done, there are now many indicators showing that the mediation of information literacy will be institutionalized within the education system and the everyday work of librarians. In the last ten years of user education work, a lot of methodological experience has been gained and promising pedagogical concepts have been developed, influenced by Anglo‐American concepts of information literacy. However, a great disadvantage for the development of these concepts and for their evaluation is the absence of any central institution capable of supporting this particular aspect of libraries’ work.
Developing entrepreneurship in West Yorkshire: West Yorkshire universities’ partnership and Business Start‐Up@Leeds Met
Authors: Robertson Martyn , Collins Amanda
Published: September 2003

West Yorkshire universities together with Yorkshire Forward, the Regional Development Agency (RDA) for Yorkshire and Humberside, are collaborating on a graduate entrepreneurship programme. This paper outlines the national and regional context for the role of entrepreneurial education in producing new business and a climate in which creativity and innovation may thrive.
Direct computation of instability points with inequality constraints using the FEM
Authors: Tschöpe H. , Wriggers P. , Oñate E.
Published: September 2003

The subject of this paper is the computation of instability points in mechanical problems with the finite element method. The objective is to extend the application of critical point detection methods to problems with inequality constraints originating from damage and contact. A simple bilinear model is considered for the damage problems. A bilateral, frictionless contact formulation is used for the contact problems. Among the critical point detection methods the focus is laid on the critical displacement method and the extended system. At first a possible combination of both methods is evaluated by applying them to damage problems. A prediction method based on the extended system is developed to facilitate the comparison of both methods. Secondly, the extended system is used as a computation method for critical points in two‐dimensional contact problems.
Simulation of unsteady flow and solute transport in a tidal river network
Authors: Zhan Xiaoyong
Published: September 2003

A mathematical model and numerical method for water flow and solute transport in a tidal river network is presented. The tidal river network is defined as a system of open channels or rivers with junctions and cross sections. As an example, the Pearl River in China is represented by a network of 104 channels, 62 nodes, and a total of 330 cross sections with 11 boundary sections for one of the applications. The simulations are performed with a supercomputer for seven scenarios of water flow and/or solute transport in the Pearl River, China, with different hydrological and weather conditions. Comparisons with available data are shown. The intention of this study is to summarize previous works and to provide a useful tool for water environmental management in a tidal river network, particularly for the Pearl River, China.
Internal change agents’ view of the management of change problem
Authors: Saka Ayse
Published: September 2003

The vital importance of change management in today's competitive climate has been widely investigated. While the need for successful change management is intensively proclaimed by “expert” consultants, the response for some time has been regarded as falling short of what is required. The heavy emphasis in the literature on a rational‐linear approach to understanding organisational change overlooks the significance of the cultural and political dimensions of organisational life. This article highlights a systemic‐multivariate view of change by investigating internal change agents’, that is managers’, accounts of the barriers to change management. It addresses the limitations of change management by attending to the perceptions of managers, that is those actors who generally determine organisational priorities and make crucial resource allocation decisions. This article illustrates the systemic line of thinking adopted by managers undergoing major restructuring efforts in their organisations. This line of thinking is shown to differ from the espoused values of managers that constitute the rational‐linear view of change management.
United we stand, or else?
Authors: Driver Michaela
Published: September 2003

The purpose of this paper is to explore the control of emotions in organizations. An analysis of stories collected from members of different organizations who experienced the events of September 11, 2001 (when the USA was attacked by terrorists killing thousands of people) in their workplaces seems to validate previous findings that organizations respond to the expression of strong emotion with equally strong controls. However, organizations seem to differ by the types of emotional control they use and the reactions these controls elicit in their members. All four of Ashforth and Humphrey's organizational control behaviors were used. While buffering, prescribing and normalizing employee emotions seemed to have a somewhat positive effect on employee morale, the use of neutralizing controls seemed to be damaging to employee commitment. A contingency model of organizational control of emotional expression is developed.
Reviewing the EC Merger Control Regulation – examining competing ways forward
Authors: Davison L.M.
Published: September 2003

The European Commission’s competence to vet mergers at the Community level is primarily derived from the Merger Control Regulation (MCR) 1989, amended 1997, which established a concentration architecture based on separate, non‐overlapping jurisdictional spheres for member states and the Commission, with the Commission alone having jurisdiction over concentrations with a competition concern which potentially have a Community impact. Under the MCR, Community impact is determined by the two Community Dimension (CD) tests employing a numerical form‐based approach. The paper examines the Commission’s 2000 report on aspects of the MCR, particularly the appropriateness of the key CD tests in guaranteeing that all concentrations with a Community impact are centralised to the Commission, while those which are national in impact are dealt with at the member state level. It reveals that the tests are ineffective and undermine the goal of the concentration architecture. A streamlined single CD test is advanced and a radical alternative is put forward – based not on separate jurisdictional spheres but where the Commission and member states competition authorities form a network of co‐operation to regulate concentrations.
Issues in designing personal knowledge exchanges
Authors: Gosain Sanjay
Published: September 2003

Personal knowledge exchanges refer to Web‐based institutions that facilitate the matching of individual sources and recipients of knowledge, structure their interaction, set ground rules for price discovery and support the transfer of knowledge. While these exchanges are patterned on electronic marketplaces for tangible products, they need to accommodate the often tacit, situated and complex nature of knowledge and the challenges associated with its transfer and assimilation. It is by recognizing the specific characteristics of knowledge and associated learning processes that knowledge exchanges can enhance their value for members. Based on theory‐driven insights and case studies of first‐mover enterprises, implications for research and practice related to the design of personal knowledge exchanges are discussed.
Global access to knowledge
Authors: Okunoye Adekunle , Karsten Helena
Published: September 2003

A major area of global knowledge management is in the practice of academic research. Studies how the Internet was used to support knowledge management in six non‐corporate research organisations in sub‐Saharan Africa. For knowledge acquisition, abstract and article databases and field‐specific Web sites were considered the most important services. For knowledge transfer, e‐mail, and especially e‐mail attachments, were considered crucial in overcoming the slowness of other means of communication. For knowledge application, communication with collaborators and publishers helped bring African research communities more visibility. Despite limited availability and infrastructure problems, some researchers had made headway in using the Internet to improve acquisition and transfer of knowledge, but not knowledge storage. Researchers in other areas of the globe may benefit from a fuller understanding of the issues and challenges facing their sub‐Saharan colleagues as an important step towards improving collaboration and knowledge sharing.
Optimizing tourism destination development in Canada
Authors: Joppe Marion
Published: September 2003

The Travel and Tourism Research Association‐Canada Chapter held its 27th annual conference in Niagara Falls, Canada, from 14‐16 October 2001, with the theme of optimizing destination development. This paper is a summary of the presentations and workshops. Aside from a research case study of the Niagara region, two keynote addresses and a final plenary session, the conference dealt with six sub‐themes: the environmental and human sides of optimization, innovations in destination development and marketing, challenges associated with them and, finally, the relationship between food, wine and tourism. Two workshops were held on the effective use of online surveys and on the process of developing a tourism optimization management model (TOMM), using Niagara Falls and knowledge gained from the research case study as a basis for building it.
Purchasing for 4,000 hotels: the case of Avendra
Authors: Lawlor Fred , Jayawardena Chandana
Published: September 2003

Avendra is an independent company formed by Marriott International, Inc., Hyatt Hotels Corporation, ClubCorp. USA, Inc., InterContinental Hotel Group, and Fairmont Hotels and Resorts – all leading companies in their respective hospitality markets. Avendra serves the hospitality industry in North America and the Caribbean and is the largest hospitality procurement service company in the world. This viewpoint article presents a few concepts of procurement and purchasing for hotels. Explains the origin, concept, philosophy and operation of Avendra. Identifies the future challenges for the company. Concludes by listing the key benefits for suppliers, hotels and, most importantly, to the customers should similar operations evolve in different parts of the world.
Cross‐functional team working for overall equipment effectiveness (OEE)
Authors: Bamber C.J. , Castka P. , Sharp J.M. , Motara Y.
Published: September 2003

Overall equipment effectiveness (OEE) is being used increasingly in industry. This paper defines OEE and explores the purpose of this concept in modern operations. The paper discusses OEE as a total measure of performance that relates the availability of the process to the productivity and quality of the product. Therefore, the concept of OEE is appropriate to all operations containing plant and machinery. Research has shown that the most successful method of employing OEE is to use cross‐functional teams aimed at improving the competitiveness of business.
Strategies of supply communities
Authors: Katz Jeffrey P. , Pagell Mark D. , Bloodgood James M.
Published: September 2003

Only one customer really counts: the end customer. The final purchaser decides whether each supply chain member adds value, and is thus willing to pay for the added benefit, or whether by‐passing a particular link in the supply chain makes economic sense. It is in this context that profit, based on value‐adding behaviors, provides the primary incentive and reward for supply chain members to organize. This article suggests that successful supply chains are those that are evolving into supply communities. This article presents a framework for more thoroughly understanding the motivation that members of the supply chain have for developing consistent business strategies, thereby enabling the supply community to compete effectively.
Vendor selection and order quantity allocation in volume discount environments
Authors: Dahel Nasr‐Eddine
Published: September 2003

This article presents a multiobjective mixed integer programming approach to simultaneously determine the number of vendors to employ and the order quantities to allocate to these vendors in a multiple‐product, multiple‐supplier competitive sourcing environment. The selection process is driven by the price, delivery, and quality objectives of the buyer and subject to the capacity constraints of the vendors. In this context, the vendors offer discounts on total amount of sales volumes not on the quantity or variety of products purchased from them. The paper presents a solution methodology to the multiobjective problem. Results of a computational experiment suggest that real‐world applications of the proposed model are both computationally practical and realistic.
E‐business and e‐supply strategy in small and medium sized businesses (SMEs)
Authors: Wagner B.A. , Fillis Ian , Johansson U.
Published: September 2003

The purpose of this research was to investigate e‐business and e‐supply strategies in Scottish small‐ and medium‐sized enterprises (SMEs). The paper reviews academic literature and recent survey reports on the degree of e‐business adoption in the UK and Republic of Ireland. The qualitative methodology undertaken is described, findings are discussed and implications from this study for e‐business strategies outlined. This was an exploratory study using a small sample with possible geographic biases. Nevertheless, the data so far are in line with findings from larger studies. The role of support agencies is examined, as well as how government could better serve the SMEs. Finally conclusions and future research plans are presented.
Automating the balanced scorecard – selection criteria to identify appropriate software applications
Authors: Marr Bernard , Neely Andy
Published: September 2003

The balanced scorecard (BSC) is a management tool that helps to align behavior of all employees to the organization’s strategy. Research suggests that about half of large US firms have already adopted the BSC and many more are considering implementation. Organization‐wide implementation of a BSC requires IT support and numerous software vendors have taken the opportunity to build software solutions to support a BSC implementation. The problem executives face today is that there are over two‐dozen application‐providers to choose from, each of them claiming that their solution offers unique and important features. Selecting the wrong solution can undermine the entire BSC development effort and the credibility of the performance management system. This article addresses the issue of BSC software by (1) explaining why organizations might need software to support their implementation and (2) by developing a framework to assist organizations in this important decision process.
Meta‐tag: a means to control the process of Web indexing
Authors: Alimohammadi Dariush
Published: September 2003

Search engines are used to locate information on the Web, but they cannot always adequately meet the information needs of users. Some schemes have been developed to solve this problem and meta‐tags are one of them. This article provides a comprehensive definition of meta‐tags and explains their function. Then, the possible attributes of meta‐tags and the most important meta‐tags are introduced in detail. It concludes that, although the meta‐tag has shortcomings, as do other schemes of information organizing, it can help improve the retrievability of information on the Web, and should be utilised by Web masters and search engine designers.
Influence of self‐construals on the perception of different self‐presentation styles in Korea
Authors: Kim Jungsik , Kim Min‐Sun , Kam Karadeen Y. , Shin Ho‐Chang
Published: September 2003

The present study investigated how perceivers’ self‐construals influence the perception of others who use self‐enhancement or self‐effacement in communication. It was predicated that independent self and interdependent self would differently affect the evaluation of self‐enhancing presentation and self‐effacing presentation. Two hundred and forty‐six Korean college students read a scenario depicting a person using bragging, and positive and negative self‐presentations for his/her accomplishment, and then evaluated the presenter in the scenario on intention of future interaction, satisfaction with conversation and likeability. Results showed that people with independent self evaluated the positive presentation more favorably than people with interdependent self, whereas people with interdependent self evaluated the negative presentation more favorably than people with independent self. No significant difference was found in the evaluation of bragging presentation. The results imply that although the purpose of self‐presentation is to give positive self to others, it is differently expressed through self‐enhancement in North American culture and through self‐effacement in East Asian culture. The results also supported previous cross‐cultural studies on self‐enhancement and self‐effacement by providing an examination from individual level analysis.
Programmed, Autonomous‐Formal and Spontaneous Organizational Learning
Authors: Pak C. K. , Snell Robin S.
Published: September 2003

Organizational learning (OL) has been represented either as the systematic governance of collective expertise or as a relatively anarchic process of implicit transaction within and across fluid, dispersed communities of practice. Qualitative case‐study research open to both perspectives was conducted in a not‐for‐profit service organization, a franchisee company and a vertically integrated company, all based in Hong Kong. Two forms of OL as systematic governance were found: ‘programmed’ OL (POL) and ‘autonomous‐formal’ OL (AFOL), respectively. The relative emphasis on POL and AFOL appeared to vary from organization to organization, and to be influenced by management philosophy and by institutional frameworks such as professionalization and franchisee status. A ‘spontaneous’ and dispersed form of implicitly transacted OL (SOL) was also found. SOL appeared to reflect natural exuberance but was attenuated when colleagues regarded knowledge as a commodity. There appeared to be synergy between AFOL and SOL.
International Trade under Oligopoly Conditions
Authors: Ruffin Roy J.
Published: September 2003

The paper gives a simple representation of how oligopoly affects the general theory of international trade. Three points are emphasized: the simplicity of trade under oligopoly in the Ricardian model; the equations describing the general equilibrium of a world economy with any number of goods, countries, and factors under oligopolistic conditions and an integrated world market; and a complete description of the solution of a Mill–Ricardo–Cournot model with oligopoly in one sector and perfect competition in the other.
Anticipating Catastrophes through Extreme Value Modelling
Authors: Coles Stuart , Pericchi Luis
Published: September 2003

When catastrophes strike it is easy to be wise after the event. It is also often argued that such catastrophic events are unforeseeable, or at least so implausible as to be negligible for planning purposes. We consider these issues in the context of daily rainfall measurements recorded in Venezuela. Before 1999 simple extreme value techniques were used to assess likely future levels of extreme rainfall, and these gave no particular cause for concern. In December 1999 a daily precipitation event of more than 410 mm, almost three times the magnitude of the previously recorded maximum, caused devastation and an estimated 30000 deaths. We look carefully at the previous history of the process and offer an extreme value analysis of the data—with some methodological novelty—that suggests that the 1999 event was much more plausible than the previous analyses had claimed. Deriving design parameters from the results of such an analysis may have had some mitigating effects on the consequences of the subsequent disaster. The themes of the new analysis are simple: the full exploitation of available data, proper accounting of uncertainty, careful interpretation of asymptotic limit laws and allowance for non-stationarity. The effect on the Venezuelan data analysis is dramatic. The broader implications are equally dramatic; that a naïve use of extreme value techniques is likely to lead to a false sense of security that might have devastating consequences in practice.
Variance Estimation for a Low Income Proportion
Authors: Berger Yves G. , Skinner Chris J.
Published: September 2003

Proportions below a given fraction of a quantile of an income distribution are often estimated from survey data in comparisons of poverty. We consider the estimation of the variance of such a proportion, estimated from Family Expenditure Survey data. We show how a linearization method of variance estimation may be applied to this proportion, allowing for the effects of both a complex sampling design and weighting by a raking method to population controls. We show that, for data for 1998–1999, the estimated variances are always increased when allowance is made for the design and raking weights, the principal effect arising from the design. We also study the properties of a simplified variance estimator and discuss extensions to a wider class of poverty measures.
Receptive field structure of burst and tonic firing in feline lateral geniculate nucleus
Authors: Rivadulla Casto , Martinez Luis , Grieve Kenneth L. , Cudeiro Javier
Published: September 2003

There are two recognised modes of firing activity in thalamic cells, burst and tonic. A low‐threshold (LT) burst (referred to from now on as ‘burst’) comprises a small number of high‐frequency action potentials riding the peak of a LT Ca2+ spike which is preceded by a silent hyperpolarised state > 50 ms. This is traditionally viewed as a sleep‐like phenomenon, with a shift to tonic mode at wake‐up. However, bursts have also been seen in the wake state and may be a significant feature for full activation of recipient cortical cells. Here we show that for visual stimulation of anaesthetised cats, burst firing is restricted to a reduced area within the receptive field centre of lateral geniculate nucleus cells. Consistently, the receptive field size of all the recorded neurons decreased in size proportionally to the percentage of spikes in bursts versus tonic spikes, an effect that is further demonstrated with pharmacological manipulation. The role of this shrinkage may be distinct from that also seen in sleep‐like states and we suggest that this is a mechanism that trades spatial resolution for security of information transfer.
Phorbol esters and adenosine affect the readily releasable neurotransmitter pool by different mechanisms at amphibian motor nerve endings
Authors: Searl T. J. , Silinsky E. M.
Published: September 2003

Phorbol esters and adenosine have been proposed to interact at common sites downstream of calcium entry at amphibian motor nerve endings. We thus studied the actions and interactions of phorbol esters and adenosine using electrophysiological recording techniques in conjunction with both binomial statistical analysis and high‐frequency stimulation at the amphibian neuromuscular junction. To begin this study, we confirmed previous observations that synchronous evoked acetylcholine (ACh) release (reflected as endplate potentials, EPPs) is well described by a simple binomial distribution. We then used binomial analysis to study the effects of the phorbol ester phorbol dibutyrate (PDBu, 100 nm) and adenosine (50 µm) on the binomial parameters n (the number of calcium charged ACh quanta available for release) and p (the average probability of release), where the mean level of evoked ACh release (m) =np. We found that PDBu increased m by increasing the parameter n whilst adenosine reduced m by reducing n; neither agent affected the parameter p. PDBu had no effect on either the potency or efficacy of the inhibition produced by adenosine. Subtle differences between these two agents were revealed by the patterns of EPPs evoked by high‐frequency trains of stimuli. Phorbol esters increased ACh release during the early phase of stimulation but not during the subsequent plateau phase. The inhibitory effect of adenosine was maximal at the beginning of the train and was still present with reduced efficacy during the plateau phase. When taken together with previous findings, these present results suggest that phorbol esters increase the immediately available store of synaptic vesicles by increasing the number of primed vesicles whilst adenosine acts at a later stage of the secretory process to decrease the number of calcium‐charged primed vesicles.