bluuebunny/crossref_metadata_2025 huggingface dataset:
Zeppo1 is a novel metastasis promoter that repressesE-cadherinexpression and regulates p120-catenin isoform expression and localization
Authors: Slorach Euan M. , Chou Jonathan , Werb Zena
Published: February 2011

Amplification of 8p11-12 in human breast cancers is associated with increased proliferation and tumor grade and reduced metastasis-free patient survival. We identifiedZeppo1(zinc finger elbow-related proline domain protein 1) (FLJ14299/ZNF703) within this amplicon as a regulator of cell adhesion, migration, and proliferation in mammary epithelial cells. Overexpression ofZeppo1reduces cell–cell adhesion and stimulates migration and proliferation. Knockdown ofZeppo1induces adhesion and lumen formation. Zeppo1 regulates transcription, complexing with Groucho and repressingE-cadherinexpression and Wnt and TGFβ reporter expression. Zeppo1 promotes expression of metastasis-associated p120-catenin isoform 1 and alters p120-catenin localization upon cell contact with the extracellular matrix. Significantly,Zeppo1overexpression in a mouse breast cancer model increases lung metastases, while reducingZeppo1expression reduces both tumor size and the number of lung metastases. These results indicate thatZeppo1is a key regulator of breast cancer progression.
Activated Ras requires autophagy to maintain oxidative metabolism and tumorigenesis
Authors: Guo Jessie Yanxiang , Chen Hsin-Yi , Mathew Robin , Fan Jing , Strohecker Anne M. , Karsli-Uzunbas Gizem , Kamphorst Jurre J. , Chen Guanghua , Lemons Johanna M.S. , Karantza Vassiliki , Coller Hilary A. , DiPaola Robert S. , Gelinas Celine , Rabinowitz Joshua D. , White Eileen
Published: February 2011

Autophagy is a catabolic pathway used by cells to support metabolism in response to starvation and to clear damaged proteins and organelles in response to stress. We report here that expression of a H-rasV12 or K-rasV12 oncogene up-regulates basal autophagy, which is required for tumor cell survival in starvation and in tumorigenesis. In Ras-expressing cells, defective autophagosome formation or cargo delivery causes accumulation of abnormal mitochondria and reduced oxygen consumption. Autophagy defects also lead to tricarboxylic acid (TCA) cycle metabolite and energy depletion in starvation. As mitochondria sustain viability of Ras-expressing cells in starvation, autophagy is required to maintain the pool of functional mitochondria necessary to support growth of Ras-driven tumors. Human cancer cell lines bearing activating mutations in Ras commonly have high levels of basal autophagy, and, in a subset of these, down-regulating the expression of essential autophagy proteins impaired cell growth. As cancers with Ras mutations have a poor prognosis, this “autophagy addiction” suggests that targeting autophagy and mitochondrial metabolism are valuable new approaches to treat these aggressive cancers.
EZH1 and EZH2 cogovern histone H3K27 trimethylation and are essential for hair follicle homeostasis and wound repair
Authors: Ezhkova Elena , Lien Wen-Hui , Stokes Nicole , Pasolli H. Amalia , Silva Jose M. , Fuchs Elaine
Published: February 2011

Polycomb protein group (PcG)-dependent trimethylation on H3K27 (H3K27me3) regulates identity of embryonic stem cells (ESCs). How H3K27me3 governs adult SCs and tissue development is unclear. Here, we conditionally target H3K27 methyltransferases Ezh2 and Ezh1 to address their roles in mouse skin homeostasis. Postnatal phenotypes appear only in doubly targeted skin, where H3K27me3 is abolished, revealing functional redundancy in EZH1/2 proteins. Surprisingly, while Ezh1/2-null hair follicles (HFs) arrest morphogenesis and degenerate due to defective proliferation and increased apoptosis, epidermis hyperproliferates and survives engraftment. mRNA microarray studies reveal that, despite these striking phenotypic differences, similar genes are up-regulated in HF and epidermal Ezh1/2-null progenitors. Featured prominently are (1) PcG-controlled nonskin lineage genes, whose expression is still significantly lower than in native tissues, and (2) the PcG-regulated Ink4a/Inkb/Arf locus. Interestingly, when EZH1/2 are absent, even though Ink4a/Arf/Ink4b genes are fully activated in HF cells, they are only partially so in epidermal progenitors. Importantly, transduction of Ink4b/Ink4a/Arf shRNAs restores proliferation/survival of Ezh1/2-null HF progenitors in vitro, pointing toward the relevance of this locus to the observed HF phenotypes. Our findings reveal new insights into Polycomb-dependent tissue control, and provide a new twist to how different progenitors within one tissue respond to loss of H3K27me3.
Whole Genome Analysis of Gene Expression Reveals Coordinated Activation of Signaling and Metabolic Pathways during Pollen-Pistil Interactions in Arabidopsis
Authors: Boavida Leonor C. , Borges Filipe , Becker Jörg D. , Feijó José A.
Published: February 2011

Plant reproduction depends on the concerted activation of many genes to ensure correct communication between pollen and pistil. Here, we queried the whole transcriptome of Arabidopsis (Arabidopsis thaliana) in order to identify genes with specific reproductive functions. We used the Affymetrix ATH1 whole genome array to profile wild-type unpollinated pistils and unfertilized ovules. By comparing the expression profile of pistils at 0.5, 3.5, and 8.0 h after pollination and applying a number of statistical and bioinformatics criteria, we found 1,373 genes differentially regulated during pollen-pistil interactions. Robust clustering analysis grouped these genes in 16 time-course clusters representing distinct patterns of regulation. Coregulation within each cluster suggests the presence of distinct genetic pathways, which might be under the control of specific transcriptional regulators. A total of 78% of the regulated genes were expressed initially in unpollinated pistil and/or ovules, 15% were initially detected in the pollen data sets as enriched or preferentially expressed, and 7% were induced upon pollination. Among those, we found a particular enrichment for unknown transcripts predicted to encode secreted proteins or representing signaling and cell wall-related proteins, which may function by remodeling the extracellular matrix or as extracellular signaling molecules. A strict regulatory control in various metabolic pathways suggests that fine-tuning of the biochemical and physiological cellular environment is crucial for reproductive success. Our study provides a unique and detailed temporal and spatial gene expression profile of in vivo pollen-pistil interactions, providing a framework to better understand the basis of the molecular mechanisms operating during the reproductive process in higher plants.
TheArabidopsisMultistress Regulator TSPO Is a Heme Binding Membrane Protein and a Potential Scavenger of Porphyrins via an Autophagy-Dependent Degradation Mechanism
Authors: Vanhee Celine , Zapotoczny Grzegorz , Masquelier Danièle , Ghislain Michel , Batoko Henri
Published: February 2011

TSPO, a stress-induced, posttranslationally regulated, early secretory pathway-localized plant cell membrane protein, belongs to the TspO/MBR family of regulatory proteins, which can bind porphyrins. This work finds that boosting tetrapyrrole biosynthesis enhanced TSPO degradation in Arabidopsis thaliana and that TSPO could bind heme in vitro and in vivo. This binding required the His residue at position 91 (H91), but not that at position 115 (H115). The H91A and double H91A/H115A substitutions stabilized TSPO and rendered the protein insensitive to heme-regulated degradation, suggesting that heme binding regulates At-TSPO degradation. TSPO degradation was inhibited in the autophagy-defective atg5 mutant and was sensitive to inhibitors of type III phosphoinositide 3-kinases, which regulate autophagy in eukaryotic cells. Mutation of the two Tyr residues in a putative ubiquitin-like ATG8 interacting motif of At-TSPO did not affect heme binding in vitro but stabilized the protein in vivo, suggesting that downregulation of At-TSPO requires an active autophagy pathway, in addition to heme. Abscisic acid–dependent TSPO induction was accompanied by an increase in unbound heme levels, and downregulation of TSPO coincided with the return to steady state levels of unbound heme, suggesting that a physiological consequence of active TSPO downregulation may be heme scavenging. In addition, overexpression of TSPO attenuated aminolevulinic acid–induced porphyria in plant cells. Taken together, these data support a role for TSPO in porphyrin binding and scavenging during stress in plants.
Metabolic Engineering in Nicotiana benthamiana Reveals Key Enzyme Functions in Arabidopsis Indole Glucosinolate Modification
Authors: Pfalz Marina , Mikkelsen Michael Dalgaard , Bednarek Paweł , Olsen Carl Erik , Halkier Barbara Ann , Kroymann Juergen
Published: February 2011

Indole glucosinolates, derived from the amino acid Trp, are plant secondary metabolites that mediate numerous biological interactions between cruciferous plants and their natural enemies, such as herbivorous insects, pathogens, and other pests. While the genes and enzymes involved in the Arabidopsis thaliana core biosynthetic pathway, leading to indol-3-yl-methyl glucosinolate (I3M), have been identified and characterized, the genes and gene products responsible for modification reactions of the indole ring are largely unknown. Here, we combine the analysis of Arabidopsis mutant lines with a bioengineering approach to clarify which genes are involved in the remaining biosynthetic steps in indole glucosinolate modification. We engineered the indole glucosinolate biosynthesis pathway into Nicotiana benthamiana, showing that it is possible to produce indole glucosinolates in a noncruciferous plant. Building upon this setup, we demonstrate that all members of a small gene subfamily of cytochrome P450 monooxygenases, CYP81Fs, are capable of carrying out hydroxylation reactions of the glucosinolate indole ring, leading from I3M to 4-hydroxy-indol-3-yl-methyl and/or 1-hydroxy-indol-3-yl-methyl glucosinolate intermediates, and that these hydroxy intermediates are converted to 4-methoxy-indol-3-yl-methyl and 1-methoxy-indol-3-yl-methyl glucosinolates by either of two family 2 O-methyltransferases, termed indole glucosinolate methyltransferase 1 (IGMT1) and IGMT2.
Food safety infosheets
Authors: Chapman Benjamin , MacLaurin Tanya , Powell Douglas
Published: February 2011

Purpose

Despite extensive investments in food handler training, research suggests that training programs are inconsistent, and rarely evaluated for efficacy. The generic prescriptive content and school‐like delivery methods used in current food safety training may be a barrier to application. The purpose of this paper is to develop a food safety communication tool, food safety infosheets, targeted specifically to foodservice food handlers, utilizing popular media stories to illustrate the consequences of poor food handling.

Design/methodology/approach

Food safety infosheets were designed to be surprising, connect food handlers' actions and consequences, and generate discussion through a verbal narrative framework. A Delphi‐like exercise (n=19), a posting pilot (n=8) were carried out to assess the appropriateness of the concept of food safety infosheets. An intense participatory ethnographic study with an Ontario, Canada, restaurant, and in‐depth interviews with food service operators in Manhattan, Kansas, and Lansing, Michigan, (n=17) were conducted to gather qualitative data on the food service kitchen environment, including barriers to food safety practices, and the communication preferences of those who work in such kitchens.

Findings

The expert group, foodservice operators, and food handlers accepted food safety infosheets as an appropriate concept and valued storytelling as an effective communication strategy. Learning in the kitchen environment is largely hands‐on and visual, and time pressure dictates practices. It is often difficult to attract and keep the attention of food handlers. Storytelling, celebrity and local outbreaks are of interest to the target audience.

Originality/value

This paper provides a blueprint for the design and refinement of food safety communication tools targeted towards a specific audience. By utilizing multiple methodologies, it provides a framework for other researchers to follow.
Nutritionally balanced school meal model for a comprehensive school
Authors: Tikkanen Irma
Published: February 2011

Purpose

This paper seeks to construct and describe a nutritionally balanced school meal model for a comprehensive school. The aim of the model is to illustrate an holistic view to school meals based on the pupils' needs.

Design/methodology/approach

The paper introduces Maslow's hierarchy of needs and eight theoretical views to school meals. The empirical data were collected in 2007 from the pupils (168), their parents (82) and the school officials (42) of four comprehensive schools in Finland by using a structured questionnaire which included open questions. Consequently, a description of a nutritionally balanced school meal model for a comprehensive school was constructed.

Findings

A constructed model for serving school meals consists of the following views: pupil's needs; nutrition, food choice and waste views; well‐being and energy; education; social‐ecological environment and school meal environment, as well as maintaining good health and preventing health problems. The model is structured according to the theoretical views as well as suggestions from the pupils, parents, and experts. Also the subjects responsible for the activities are included.

Practical implications

The constructed nutritionally balanced school meal model can be utilized as a standard model when serving school meals in a comprehensive school.

Originality/value

The model may act as a reference model for the school catering organisations and the school officials when decisions related to school meals are made.
Children's perceptions of obesity as explained by the common sense model of illness representation
Authors: Babooram Melanie , Mullan Barbara Ann , Sharpe Louise
Published: February 2011

Purpose

The aim of this paper is to qualitatively examine the ways in which primary school children, aged between 7 and 12, perceive various facets of obesity as defined by the common sense model of illness representation (CCM).

Design/methodology/approach

The study was qualitative in nature. Semi‐structured interviews were conducted with 33 children on all dimensions of the CSM. Twenty four children were normal weight and nine were overweight. A drawing task formed the methodology for the “identity” section of the interview.

Findings

Although children identified food intake as a main cause of obesity, almost half did not name sedentary behaviours as a cause of obesity. Duration (timeline) of obesity was regarded by most children as reliant on a person's undertaking of positive health behaviours. Normal weight children were found to list more severe consequences of obesity than the overweight group. It was found that experience contributed to the detailed knowledge of overweight children's perceptions of cures of obesity. Overweight children also spoke of personal incidents of barriers to cures.

Practical imlications

The findings suggest that the CSMs can be used to classify children's perceptions of obesity. Future childhood obesity interventions can utilise these findings to create campaigns and strategies that are more consistent with children's understandings of this condition.

Originality/value

To the authors' knowledge, no previous study has examined children's perceptions of obesity beyond perceived causes.
Portrait value questionnaire's (PVQ) usefulness in explaining quality food‐related consumer behavior
Authors: Fotopoulos Christos , Krystallis Athanasios , Anastasios Pagiaslis
Published: February 2011

Purpose

Schwartz's portrait value questionnaire (PVQ) has extensively been used in personal values research. The present paper aims to validate the 40‐item PVQ typology, using a nationally representative sample of 997 consumers. The main objective of the survey was to investigate whether higher‐than‐average regular purchasing of quality food products (i.e. organic and PDO labelled products) coincides with stronger identification with specific PVQ values.

Design/methodology/approach

A questionnaire was distributed nationwide. Data were collected through personal interviews with 997 consumers. Confirmatory factor analysis and cluster analysis were the main analytical techniques used.

Findings

At the value‐based segmentation level of the analysis, identification with the PVQ value domains decreased per cluster progressively and jointly for almost all value domains, a trend that led to the identification of five distinctive national consumer segments. The trend of stronger identification with security, universalism and benevolence that appeared at the sample level re‐emerged for the “urban upper class”, the “countryside class I” and the “countryside class II”, which accounted for two‐thirds of the overall sample and were the clusters with the most dynamic quality food purchasing profile.

Research limitations/implications

Despite the emergence of a clear relation between consumers' self‐transcendence and security value similarity and higher‐than‐average frequency of quality food purchasing, quality food consumers did not form a separate and clearly diversified cluster if the PVQ inventory functions as a basis for segmentation. Future models should incorporate values together with intermediate‐level constructs (e.g. beliefs and/or attitudes) when attempting to predict consumer behaviour towards quality food products.

Originality/value

The paper shows that while values can be used to meaningfully segment quality food consumers, there is still much to learn regarding the direct and indirect determinants of quality food purchase behaviour.
Deteminants of cross‐contamination during home food preparation
Authors: Kennedy J. , Nolan A. , Gibney S. , O'Brien S. , McMahon M.A.S. , McKenzie K. , Healy B. , McDowell D. , Fanning S. , Wall P.G.
Published: February 2011

Purpose

This paper aims to determine the potential for the spread of bacteria from raw meat and poultry during home food preparation to the surrounding kitchen environment, hands and prepared food due to unsafe handling practices, which are predicted by consumers' knowledge, behaviour and attitudes.

Design/methodology/approach

The potential for transfer of E.coli and C. jejuni was monitored in a simulated domestic kitchen environment while food preparation was filmed (n=60 respondents). A survey was also administered.

Findings

The results of the study show that transfer of bacteria around the kitchen environment and onto prepared meals are predicted by a lack of thoroughly washing contaminated hands, knives and chopping boards both during and after meal preparation. A higher level of perceived importance of correct food handling behaviour is associated with higher levels of educational attainment and age and food risk perceptions are positively associated with age.

Practical implications

The results highlight the importance of promoting preventative measures and the means of employing them specifically to the young and less educated public who do not frequently cook and prepare food.

Originality/value

This paper is the first to include a verifiable audit of consumer food safety behaviour, microbiological sampling of surfaces, food and hands as well as a consumer survey of knowledge, behaviour and attitudes.
Quality of service in networks supporting cultural multimedia applications
Authors: Kanellopoulos Dimitris N.
Published: February 2011

Purpose

This paper aims to provide an overview of representative multimedia applications in the cultural heritage sector, as well as research results on quality of service (QoS) mechanisms in internet protocol (IP) networks that support such applications.

Design/methodology/approach

The paper's approach is a literature review.

Findings

Cultural heritage multimedia applications require greater bandwidth capacity, especially where multiple users share the connections. For such applications, scalability and reliability of quality of service depend on packet‐level QoS mechanisms operating in a full end‐to‐end basis.

Research limitations/implications

The paper provides a foundation for future research directions in the professional communication context. For instance, the QoS mechanisms in possible network infrastructures could be used to explore effective multimedia data dissemination across cultural heritage institutions.

Practical implications

The paper provides an overview of which technologies/mechanisms are being used most broadly and which might provide the most potential for cultural heritage institutions managers considering experimenting in the multimedia communications area.

Originality/value

QoS mechanisms that support multimedia applications in the cultural heritage sector need to become well known by cultural heritage institutions managers and professional associations in the fields of libraries, museums and archives. This paper provides a useful overview of the topic.
A survey of the use of electronic resources at seven universities in Wuhan, China
Authors: Zhang Liyi , Ye Pinghao , Liu Qihua
Published: February 2011

Purpose

The purpose of this paper is to report on users' information behaviour in China, a topic which has not been researched extensively. The aim is to help producers and providers collect and develop more electronic resources.

Design/methodology/approach

The study investigates users' information behaviour at seven “211 Project” universities in Wuhan, a city in central China. These universities all have access to the resources of the National Science and Technology Library (NSTL). The questionnaire includes questions about respondents' basic identifying information (educational level, job, etc.) and their information service requirements. Correlations among users' education level, users' jobs, users' retrieval methods, literature use, etc. were analysed.

Findings

The results show that most NSTL users are graduate students and young staff members. and the number of male users surpasses female ones slightly. The purpose of the utilisation of electronic resources for customers is scientific research, teaching and the need for self‐development. During a year, the demand of users is the highest in March and the lowest in August. The users' knowledge service types include learning the progress of science and technology, citation retrieval and analysis, statistical analysis, intelligent retrieval and knowledge aggregation.

Practical implications

The findings suggest that electronic resource producers should offer more foreign literature and providers should improve the quality of services.

Originality/value

The paper provides suggestions for the further improvement of NSTL to fulfill the information needs and requirements of users.
The application of intelligent agents in libraries: a survey
Authors: Liu Guoying
Published: February 2011

Purpose

The purpose of this article is to provide a comprehensive literature review on the utilisation of intelligent agent technology in the library environment.

Design/methodology/approach

Research papers since 1990 on the use of various intelligent agent technologies in libraries are divided into two main application areas: digital library (DL), including agent‐based DL projects, multi‐agent architecture for DLs, intelligent agents for distributed heterogeneous information retrieval and agent support to information search process in DLs; and services in traditional libraries, including user interface for library information systems, automatic reference services and multi‐agent architecture for library services. For each paper on the topic, its new ideas or models, referred work, analyses, experiments, findings and conclusions are addressed.

Findings

The majority of the literature covers DLs and there have been fewer studies about services in traditional libraries. A variety of architecture, framework and models integrating agent technology in library systems or services are proposed, but only a few have been implemented in the practical environment. The application of agent technology is still at the research and experimentation stage. Agent technology has great potential in many areas in the library context; however it presents challenges to libraries that want to be involved in its adoption.

Practical implications

The survey has practical implications for libraries, librarians and computer professionals in developing projects that employ intelligent agent technology to meet end‐users' expectations as well as to improve information services within limited resources in library settings.

Originality/value

The paper provides a comprehensive survey on the development and research of intelligent agents in libraries in literature.
Disappearing act
Authors: Nagaraja Aragudige , Joseph Shine A. , Polen Hyla H. , Clauson Kevin A.
Published: February 2011

Purpose

The aim of this paper is to assess and catalogue the magnitude of URL attrition in a high‐impact, open access (OA) general medical journal.

Design/methodology/approach

All Public Library of Science Medicine (PLoS Medicine) articles for 2005‐2007 were evaluated and the following items were assessed: number of entries per issue; type of article; number of references per entry; number of references that contained URLs; and the access date listed for each URL citation. URLs were then evaluated for accessibility status (i.e. active or defunct).

Findings

In total, 1,133 articles were published from 2005‐2007 in PLoS Medicine. The 1,133 articles contained 28,177 references, with 2,503 (8.9 per cent) identified as URLs. Non‐research articles accounted for a substantially higher percentage of URL references (17.4 per cent) compared to research articles (4.2 per cent). Almost 17 per cent of the URL references were defunct and the rate of URL attrition increased as time elapsed.

Research limitations/implications

Information management policy makers need to re‐examine the importance of preserving the internet materials long term. Both publisher and author should expand efforts to preserve internet materials. Common guidelines should be developed (e.g. by the International Committee of Medical Journal Editors) and implemented by all publishers to address URL use as references.

Originality/value

This article will be of interest to those in the field.
Information literacy among medical students in the College of Health Sciences in Niger Delta University, Nigeria
Authors: Baro Emmanuel E. , Endouware Benake‐ebide C. , Ubogu Janet O.
Published: February 2011

Purpose

The aim of this paper is to investigate whether undergraduate students in the College of Health Sciences in Niger Delta University are information literate, and to determine whether they are aware of and use different information resources including electronic ones, and to assess their ability to evaluate information before use.

Design/methodology/approach

Questionnaire and interview methods were used to collect data from the students.

Findings

The students mostly rely on textbooks, medical journals, the internet, colleagues, and the Nigerian National University Commission's virtual library for information. They rarely use electronic resources such as MEDLINE, HINARI, the Cochrane Library, and EbscoHost. This could be because of a lack of awareness and skills necessary to search databases. Problems such as lack of time, the challenge of locating “good citable stuff”, inability to use effectively the medical library, and poor skills in information searching were mentioned. The study recommends that medical librarians and faculty should collaborate in integrating information literacy skills into the medical school curriculum.

Originality/value

This paper may help inform discussion about students' competences for locating, selecting, evaluating and using information essential for lifelong learning.
A numerical approach to hydromagnetic squeezed flow and heat transfer between two parallel disks
Authors: Refik Bahadir Ahmet , Abbasov Teymuraz
Published: February 2011

Purpose

The paper aims to investigate the effect of the electromagnetic field on the convective events which occur when electrically conducting fluid is squeezed between two parallel disks.

Design/methodology/approach

The effects of the current occurring due to the direct voltage power supply at the thin electrical conducting fluid layer squeezed between the parallel disks, the magnetic field inducted by this current, and Ohmic heating on the squeezing process and heat convection are considered. Both approximate analytical and numerical solutions of the problem are obtained and a good agreement is observed between them.

Findings

The effects of the basic parameters such as Hartmann number, Reynolds number, the ratio of the distance between the disks to the radius of the disks, Prandtl number, Eckert number, heat conduction, and electric current on the squeezing event, and load capacity of the fluid between two parallel disks are able to be determined from the solutions. These solutions also enable the effects of the basic parameters such as Hartmann number, Reynolds number, the ratio of the distance between the disks to the radius of the disks, Prandtl number, Eckert number, heat conduction, and electric current on the squeezing event and load capacity of the fluid between two parallel disks to be determined.

Originality/value

Some important results and comparisons are presented graphically.
Tribological performance of Nano‐Tin as lubrication additives used in steel‐copper tribo‐pair
Authors: Mo Yun‐hui , Tao De‐hua
Published: February 2011

Purpose

The purpose of the paper is to study a new type of lubrication additive with Nano‐Tin, and to analyze the tribological performance of the friction coatings that are formed by the lubricants.

Design/methodology/approach

The Tin‐base additives were prepared and activated, friction testing was performed on an improved type MS‐800 four‐ball tester, and the nanometer additives with different contents of Tin were used as lubricants in steel‐copper tribo‐pair. The surface elements of friction coatings were investigated with Auger electron spectrum, and the thickness and element distribution of the coating were measured with scanning electron microscope.

Findings

The ultra‐thick friction coating (10‐20 μm) with abundant Tin was carried out and combined well with the surface of the copper sample when lubricated with oil containing this additive. The coating exhibited excellent anti‐wear and friction‐reducing capacities.

Research limitations/implications

The anticorrosion properties have not been estimated.

Practical implications

A useful Nano‐Tin base lubricating oil additive is prepared and the activate method is explored. It may provide the potential lubricating oil additive for steel‐copper tribo‐pair, such as steel worm‐copper worm wheel transmission.

Originality/value

This paper provides a Nano‐Tin base‐activated additive which, when used in lubricating oil, can form an ultra‐thick friction coating. It has the same self‐repairing properties as a steel‐copper tribo‐pair.
Evaluation on synergistic antioxidation of molybdenum dialkydithiocarbamate with arylamine antioxidant
Authors: Hu Jian‐Qiang , Wang Xin‐Lin , Dai Ge‐Lin , Fei Yi‐Wei , Wei Xian‐Yong , Zong Zhi‐Min
Published: February 2011

Purpose

Molybdenum dithiocarbamate (MoDDC) has good antiwear and friction‐reducing properties in lubricants, and can be protected against thermo‐oxidative degradation. However, MoDDC‐containing lubricants may lose their ability to reduce friction over time, which may result from its concentration in oils below a critical concentration owing to oxidative degradation of MoDDC. Thus, in order to enhance the durability of the low friction performance of MoDDC, the paper aims to investigate good synergistic antioxidants with MoDDC.

Design/methodology/approach

The antioxidation properties of molybdenum dialkyldithiocarbamate (M 807) – and p,p‐dioctyldiphenylalmine (V 81) – or mixed octylated and butylated diphenylalmines (V 961)‐containing poly‐α‐olefin (PAO)‐derived lubricants were evaluated by differential scanning calorimetry (DSC) and modified penn state micro‐oxidation test (PMOT). DSC test measures incipient oxidation temperature (OT) and oxidation induction time (IT) of the lubricant at high temperatures and the oxidation stability of oil weight loss is measured by PMOT. Moreover, the oxidized samples were analyzed by Fourier transform infrared (FTIR) and electron spin resonance (ESR).

Findings

A DSC test shows that OT and IT of V 81‐ or V 961‐containing PAO were improved significantly by M 807 addition. A PMOT indicates that when combining with V 81 antioxidants, M 807 can also effectively reduce the increase in weight loss of PAO and deposits formed in oils. These results suggest that the M 807 shows a good antioxidative synergism with alkylated diphenylamine antioxidants. In addition, FTIR results from a PMOT confirm that the addition of M 807 can significantly enhance the oxidation IT of oils containing V 81 and inhibit formation of oxidation products including carbonyl bonds or hydroxyl group. ESR analysis from a PMOT indicates that M 807 may form stable radicals with arylamine by the coordination effect.

Originality/value

This paper provides simple and quick methods to evaluate synergistic antioxidation properties between different types of additives, and a mechanism of the inhibition involving a synergy was proposed. They can offer practical help in industrial applications and to an individual starting out on an academic career.
An investigation of palliation of fretting wear in gross slip regime with grease lubrication
Authors: Wang Z.A. , Zhou Z.R. , Chen G.X.
Published: February 2011

Purpose

The paper aims to study comparatively the fretting behavior in gross slip regime of fretting both under grease lubrication and dry condition and to investigate the mechanism of palliation of fretting wear with grease lubrication.

Design/methodology/approach

All fretting tests were carried out on high‐temperature fretting devices with standard GCr15 bearing steel ball against 45 steel flat and against GCr15 bearing steel flat contact pairs. The wear scar was examined by optical microscope, surface profiler and the confocal laser scanning microscope as well as energy dispersive X‐ray spectroscopy.

Findings

Compared with dry condition, the coefficient of friction and wear are decreased drastically and wear occurs mainly at the early stage of fretting under grease lubrication. The palliation effect of grease lubrication is closely associated with the amount of oil separated from the grease, the low‐oxidation corrosion and high‐hardness white layer. However, the bubbles which expelled from the contact edges have little influence on fretting wear.

Research limitations/implications

The tested greases do not contain any additives for preventing possible misinterpretations of the results, but it is necessary to investigate the influence of different lubricant additives added to grease on friction and wear at different fretting conditions.

Practical implications

The research reveals that the palliation effect of grease lubrication on fretting wear is related closely to the amount of oil separated from the grease. The bigger penetration and more susceptible greases, which are easier to separate from the base oil, should be taken into account for palliation of fretting wear.

Originality/value

The presented results help to understand the palliation mechanism of grease lubrication and could be useful for designers of engineering assembly for which fretting wear is an issue.
Experimental investigation into the effect of 3D surface roughness parameters on flash temperature
Authors: Ray Sudipto , Roy Chowdhury S.K.
Published: February 2011

Purpose

Although dependence of contact surface temperatures between rough sliding bodies on surface topography is more explicitly described in terms of three‐dimensional (3D) topographic parameters, no work has yet been reported on this aspect. The paper seeks to carry out experiments to systematically correlate the 3D surface parameters to the contact temperature rise.

Design/methodology/approach

The surface temperatures at the contact between a relatively smooth zinc sulphide pin held against a rotating mild steel disc of varying surface topography were measured using an infrared thermal imaging system under different load and sliding velocity conditions. The main objective was to study the effect of 3D surface roughness parameters on the contact temperature rise.

Findings

The results indicate a rise in maximum contact temperature with the increase in a number of 3D parameters, such as, average surface roughness Sa, ten‐point height parameter Sz, skewness of the surface height distribution Ssk, mean summit curvature Ssc, and developed interfacial area ratio parameter Sdr while temperature was found to decrease with increasing values of another set of parameters, such as, kurtosis of the 3D surface texture Sku, summit density of the surface Sds, surface bearing index Sbi, core fluid retention index Sci, valley fluid retention index Svi, and root mean square slope of the surface Sdq.

Practical implications

In any sliding system, with mixed or boundary lubricated conditions, it can be attempted to find the optimum value of the roughness parameters so that on suitable processing of the surfaces a lower contact temperature rise can be achieved.

Originality/value

No work has yet been reported on the effect of 3D roughness parameters on contact temperature.
Design for static stiffness of hydrostatic bearings: single‐action variable compensations
Authors: Kang Yuan , Chen Cheng‐Hsien , Lee Hsing‐Han , Hung Yu‐Hong , Hsiao Shun‐Te
Published: February 2011

Purpose

This study aims to utilize the equations of flow equilibrium to determine the variations of film thickness or worktable displacement with respect to the recess pressure for both open‐ and closed‐type hydrostatic flat bearings. The static stiffness can be not only presented directly by these variations but also determined by the differentiation of flow equilibrium equations.

Design/methodology/approach

The single‐action variable compensations of three types including cylindrical‐spool, conical‐spool and membrane restrictors are taken into consideration in this study. Specifically, this study presents that membrane restrictor and both spool restrictors with or without preload whilst considering initial opening.

Findings

Consequently, the usage range of recess pressure and optimal parameters of appropriate compensation type can be obtained from maximum stiffness and also according to smallest gradient in variations of worktable displacement or film thickness.

Originality/value

This article studies the influences of single‐action variable compensations for its design varieties. The determination of stiffness comes from the differentiating recess pressure with respect to worktable displacement. The large and small positive stiffness correspond to a negative slope in steep and plain gradient, respectively; the negative stiffness and infinite stiffness are obtained by positive gradient and zero gradient, respectively, in the variations of film thickness. The finding results can be expressed further in the relationship between the static stiffness and the static load.
Studies on several key problems of water hydraulic vane pump
Authors: Lu Yong , Zhang Wei , Zhao Yuan‐yang , Wang Zhi‐zhong , Shu Peng‐cheng
Published: February 2011

Purpose

The balanced vane pump is a common transmission component in hydraulic systems. Since the physicochemical properties of water and seawater are different from that of mineral oil, some problems can occur, for instance, poor lubrication, more leakage, and more corrosion. The paper aims to demonstrate the technical feasibility for the water hydraulic vane pump.

Design/methodology/approach

The material combinations were selected based on related research in literature. The volumetric efficiency and suction performance were measured in the current experiment. The relations between gap clearances and leakage flow, the contact and the friction forces between a vane tip and a cam contour were simulated based on mathematic models.

Findings

The soft‐hard material combinations in the prototype pump show preferable friction characteristics during tests. The axial clearances are the main channels of leakage flow. Pin type vane pump can reduce the contact force of the vane tip.

Originality/value

This paper outlines some key problems of the water hydraulic vane pump, such as the friction pair material,the structure, and the contact force of the vane tip by means of testing the basic performance of pump and mathematic model.
Research on wear characteristics of AISI 1035 steel boronized at various parameters
Authors: Kiratli N. , Findik F.
Published: February 2011

Purpose

This paper aims to research the tribological features of AISI 1035 steel, boronized at various parameters.

Design/methodology/approach

The samples were boronized via box boronizing method. By using Ekabor 2 powders, boronizing was conducted at 840, 880, 920, 960 and 1,000°C for two, four and six hours. Wear resistance of boronized samples at determined parameters were analysed. Wear experiments were conducted under 40 N constant load at pin‐on‐disk experiment setup. Also, microstructures and microhardness values of boronized samples were analysed to determine the most suitable boronizing parameters against wearing.

Findings

As a result of this study, the following findings are reported: it was determined as the temperature increased, the thicker the boride layer obtained during the boronizing. In the case of longer boronizing time, the distinct columnar structure was clearer. Whenever applying higher temperature and longer boronizing time, wear decreased and hardness values increased. It was also determined that when boronizing was conducted at 900 and 1,000°C for at least four to six hours, better results were obtained. Furthermore, the increment in the boronizing temperature and longer duration caused an increase in hardness from the surface to inwards and thus a decrease in wear ratio.

Research limitations/implications

In the present study, only 40 N is used for a wear load and that is the limitation of the research.

Practical implications

Boronizing of the parts using 900 and 1,000°C temperature and four to six hours time, the better results can be obtained. Wear resistance can be improved in the determined temperature interval for boronizing process. Therefore, the industrial firms can be gained huge economical profits.

Originality/value

The outcome of the study will be beneficial for the academicians and industrial firms working on wear process. The service life of the steel parts can be extended via boronizing of steels working on quarries.
Values and person‐organization fit
Authors: Andrews Martha C. , Baker Thomas , Hunt Tammy G.
Published: February 2011

Purpose

This study seeks to explore the relationship between corporate ethical values and person‐organization fit (P‐O fit) and the effects on organization commitment and job satisfaction. Further, it aims to examine the construct of moral intensity as a moderator of the P‐O fit‐commitment relationship as well as the P‐O fit‐job satisfaction relationship.

Design/methodology/approach

Using a sample of 489 members of the National Purchasing Association in the USA, a structural model was examined in which it was hypothesized that corporate ethical values would be positively related to person‐organization fit and P‐O fit in turn would be positively related to commitment and job satisfaction. It was further hypothesized that the outcomes associated with P‐O fit would be moderated by moral intensity such that high moral intensity would strengthen the P‐O fit outcomes relationships.

Findings

All of the hypotheses were supported.

Research limitations/implications

All data stem from one data source, introducing the possibility of mono‐source bias. Additionally, all scales use self‐reports, introducing the possibility of mono‐method bias.

Practical implications

These results highlight the importance of corporate ethical values and moral intensity in building and maintaining an ethical and committed workforce.

Originality/value

The findings of this study contribute to the ethics and P‐O fit literature by establishing a link between corporate ethical values and P‐O fit. It further construes moral intensity as a subjective variable based on the perceiver rather than an objective characteristic of ethical issues. Moral intensity was found to strengthen the relationships between P‐O fit and satisfaction and P‐O fit and commitment.
“Trans‐+‐form”
Authors: Kuepers Wendelin M.
Published: February 2011

Purpose

The purpose of this paper is to develop a more comprehensive understanding of the multidimensional, ambivalent and responsive process of transformation, particularly as related to non‐cognitive processes and effects of leader‐ and followership.

Design/methodology/approach

Based on a critical literature review, advanced phenomenology and a relational approach, the significance of form and embodied, emotional and aesthetic dimensions, potential and effects of transforming in general and transformational leadership in particular are discussed.

Findings

Transformations in organisations are recognized as an embodied, emotional and aesthetical as well as inter‐relational event. With an extended understanding, transformational leadership can itself be transformed into an aesthetically in‐formed and more integral practice of leader‐ and followership. Building on the insights gained, practical, theoretical, and methodological implications are provided. Furthermore, limitations and problems are discussed.

Originality/value

The paper contributes to an innovative comprehension and offers critical perspectives on transformative processes in organisation and leadership. By drawing attention to the interrelated embodied, emotional and aesthetic dimensions of transformation, the paper develops a genuine and timely conceptualisation, allowing a creative transformation of conventional understandings and practices of leader‐ and followership in organisations.
Communities of practice: dynamics and success factors
Authors: Retna Kala S. , Tee Ng Pak
Published: February 2011

Purpose

The purpose of this paper is to explore the dynamics and key success factors in the development of communities of practice (CoP).

Design/methodology/approach

A qualitative case study, using in‐depth interviews, was conducted in a multinational company (MNC) in Singapore.

Findings

The findings indicate that CoPs can facilitate the creation, sharing and utilisation of knowledge in an organisation, positively affecting its strategy, operations and bottom line. The key factors that nurture CoPs to promote innovative learning and knowledge‐sharing environments are leadership, culture and individual motivation.

Practical implications

The findings indicate the value of informal CoPs in promoting innovative cultures with high levels of collaboration among organisational members.

Originality/value

This is an empirical study that reveals the dynamics of CoP development in an MNC and the key success factors of CoP development from the point of view of the employees in the company.