bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical unfolding of RNA hairpins
Authors: Hyeon Changbong , Thirumalai D.
Published: March 2005

Mechanical unfolding trajectories, generated by applying constant force in optical-tweezer experiments, show that RNA hairpins and the P5abc subdomain of the group I intron unfold reversibly. We use coarse-grained Go-like models for RNA hairpins to explore forced unfolding over a broad range of temperatures. A number of predictions that are amenable to experimental tests are made. At the critical force, the hairpin jumps between folded and unfolded conformations without populating any discernible intermediates. The phase diagram in the force–temperature (
f
,
T
) plane shows that the hairpin unfolds by an all-or-none process. The cooperativity of the unfolding transition increases dramatically at low temperatures. Free energy of stability, obtained from time averages of mechanical unfolding trajectories, coincides with ensemble averages, which establishes ergodicity. The hopping time between the native basin of attraction (NBA) and the unfolded basin increases dramatically along the phase boundary. Thermal unfolding is stochastic, whereas mechanical unfolding occurs in “quantized steps” with great variations in the step lengths. Refolding times, upon force quench, from stretched states to the NBA are at least an order of magnitude greater than folding times by temperature quench. Upon force quench from stretched states, the NBA is reached in at least three stages. In the initial stages, the mean end-to-end distance decreases nearly continuously, and there is a sudden transition to the NBA only in the last stage. Because of the generality of the results, we propose that similar behavior should be observed in force quench refolding of proteins.
The cellular HIV-1 Rev cofactor hRIP is required for viral replication
Authors: Yu Zhong , Sánchez-Velar Nuria , Catrina Irina E. , Kittler Ellen L. W. , Udofia Enyeneama B. , Zapp Maria L.
Published: March 2005

An important goal of contemporary HIV type 1 (HIV-1) research is to identify cellular cofactors required for viral replication. The HIV-1 Rev protein facilitates the cytoplasmic accumulation of the intron-containing viral
gag-pol
and
env
mRNAs and is required for viral replication. We have previously shown that a cellular protein, human Rev-interacting protein (hRIP), is an essential Rev cofactor that promotes the release of incompletely spliced HIV-1 RNAs from the perinuclear region. Here, we use complementary genetic approaches to ablate hRIP activity and analyze HIV-1 replication and viral RNA localization. We find that ablation of hRIP activity by a dominant-negative mutant or RNA interference inhibits virus production by mislocalizing Rev-directed RNAs to the nuclear periphery. We further show that depletion of endogenous hRIP by RNA interference results in the loss of viral replication in human cell lines and primary macrophages; virus production was restored to wild-type levels after reintroduction of hRIP protein. Taken together, our results indicate that hRIP is an essential cellular cofactor for Rev function and HIV-1 replication. Because hRIP is not required for cell viability, it may be an attractive target for the development of new antiviral strategies.
Atmospheric brown clouds: Impacts on South Asian climate and hydrological cycle
Authors: Ramanathan V. , Chung C. , Kim D. , Bettge T. , Buja L. , Kiehl J. T. , Washington W. M. , Fu Q. , Sikka D. R. , Wild M.
Published: March 2005

South Asian emissions of fossil fuel SO
2
and black carbon increased≈6-fold since 1930, resulting in large atmospheric concentrations of black carbon and other aerosols. This period also witnessed strong negative trends of surface solar radiation, surface evaporation, and summer monsoon rainfall. These changes over India were accompanied by an increase in atmospheric stability and a decrease in sea surface temperature gradients in the Northern Indian Ocean. We conducted an ensemble of coupled ocean-atmosphere simulations from 1930 to 2000 to understand the role of atmospheric brown clouds in the observed trends. The simulations adopt the aerosol radiative forcing from the Indian Ocean experiment observations and also account for global increases in greenhouse gases and sulfate aerosols. The simulated decreases in surface solar radiation, changes in surface and atmospheric temperatures over land and sea, and decreases in monsoon rainfall are similar to the observed trends. We also show that greenhouse gases and sulfates, by themselves, do not account for the magnitude or even the sign in many instances, of the observed trends. Thus, our simulations suggest that absorbing aerosols in atmospheric brown clouds may have played a major role in the observed regional climate and hydrological cycle changes and have masked as much as 50% of the surface warming due to the global increase in greenhouse gases. The simulations also raise the possibility that, if current trends in emissions continue, the subcontinent may experience a doubling of the drought frequency in the coming decades.
Syne proteins anchor muscle nuclei at the neuromuscular junction
Authors: Grady R. Mark , Starr Daniel A. , Ackerman Gail L. , Sanes Joshua R. , Han Min
Published: March 2005

Vertebrate skeletal muscle fibers contain hundreds of nuclei, of which three to six are functionally specialized and stably anchored beneath the postsynaptic membrane at the neuromuscular junction (NMJ). The mechanisms that localize synaptic nuclei and the roles they play in neuromuscular development are unknown. Syne-1 is concentrated at the nuclear envelope of synaptic nuclei; its
Caenorhabditis elegans
orthologue ANC-1 functions to tether nuclei to the cytoskeleton. To test the involvement of Syne proteins in nuclear anchoring, we generated transgenic mice overexpressing the conserved C-terminal Klarsicht/ANC-1/Syne homology domain of Syne-1. The transgene acted in a dominant interfering fashion, displacing endogenous Syne-1 from the nuclear envelope. Muscle nuclei failed to aggregate at the NMJ in transgenic mice, demonstrating that localization and positioning of synaptic nuclei require Syne proteins. We then exploited this phenotype to show that synaptic nuclear aggregates are dispensable for maturation of the NMJ.
Impact of genetic variation on metabolic response of bone to diet
Authors: Cusack Siobhán , Cashman Kevin D.
Published: March 2005

There is compelling evidence to suggest that both the development of bone to peak bone mass at maturity and subsequent loss depend on the interaction between genetic, hormonal, environmental and nutritional factors. The major part (≤80%) of the age-specific variation in bone turnover and bone density is genetically determined. However, the notion of genetic determinant is of little value unless the specific genes that are involved can be identified. Most work in this area of osteoporosis research has focused on the candidate gene approach, which has identified several candidate genes for osteoporosis, including genes encoding the vitamin D receptor (VDR), oestrogen receptors (α and β), apolipoprotein E, collagen type I α 1 and methylenetetrahydrofolate reductase, amongst many others. However, in general, findings from numerous studies of the association between such genes and various bone variables have been inconsistent. In addition to possible gene—gene interactions it is likely that there are interactions between these genes and certain environmental factors, especially nutrition, that may mediate expression of bone-related phenotypes. While these potential interactions add a level of complexity to our understanding of these apparent genetic effects on bone, identification of a role for genetic factors without knowledge of their interaction with nutrients can do little to advance prevention and treatment of osteoporosis. This information is especially important because, unlike genotype, diet and nutrition can be modified. The aim of the present review is to critically evaluate current knowledge relating to candidate genes for osteoporosis, with particular emphasis on their interaction with nutrients and dietary factors in determining bone health.
Essential role for interleukin-2 for CD4+CD25+ T regulatory cell development during the neonatal period
Authors: Bayer Allison L. , Yu Aixin , Adeegbe Dennis , Malek Thomas R.
Published: March 2005

Although many aspects of CD4+CD25+ T regulatory (Treg) cell development remain largely unknown, signaling through the IL-2R represents one feature for the production of Treg cells. Therefore, the present study was undertaken to further define early developmental steps in the production of Treg cells, including a more precise view on the role of interleukin (IL)-2 in this process. After adoptive transfer of wild-type Treg cells into neonatal IL-2Rβ−/− mice, only a small fraction of donor Treg cells selectively seeded the lymph node (LN). These donor Treg cells underwent rapid and extensive IL-2–dependent proliferation, followed by subsequent trafficking to the spleen. Thus, IL-2 is essential for Treg cell proliferation in neonatal LN. The number and distribution of Treg cells in the periphery of normal neonatal mice closely paralleled that seen for IL-2Rβ−/− mice that received Treg cells. However, for normal neonates, blockade of IL-2 decreased Treg cells in both the thymus and LN. Therefore, two steps of Treg cell development depend upon IL-2 in neonatal mice, thymus production, and subsequent expansion in the LN.
Proteomic Analysis of Somatic Embryogenesis in Medicago truncatula. Explant Cultures Grown under 6-Benzylaminopurine and 1-Naphthaleneacetic Acid Treatments
Authors: Imin Nijat , Nizamidin Mahira , Daniher Daniel , Nolan Kim E. , Rose Ray J. , Rolfe Barry G.
Published: March 2005

The Medicago truncatula line 2HA has a 500-fold greater capacity to regenerate plants in culture by somatic embryogenesis than wild-type Jemalong. We have compared proteomes of tissue cultures from leaf explants of these two lines. Both 2HA and Jemalong explants were grown on media containing the auxin 1-naphthaleneacetic acid and the cytokinin 6-benzylaminopurine. Proteins were extracted from the cultures at different time points (2, 5, and 8 weeks), separated by two-dimensional gel electrophoresis, and detected by silver staining. More than 2,000 proteins could be reproducibly resolved and detected on each gel. Statistical analysis showed that 54 protein spots were significantly (P < 0.05) changed in expression (accumulation) during the 8 weeks of culture, and most of these spots were extracted from colloidal Coomassie-stained two-dimensional gel electrophoresis gels and were subjected to matrix-assisted laser desorption ionization time-of-flight mass spectrometry or liquid chromatography-tandem mass spectrometry analysis. Using a publicly available expressed sequence tag database and the Mascot search engine, we were able to identify 16 differentially expressed proteins. More than 60% of the differentially expressed protein spots had very different patterns of gene expression between 2HA and Jemalong during the 8 weeks of culture.
A Mitogen-Activated Protein Kinase Cascade Regulating Infection-Related Morphogenesis in Magnaporthe grisea
Authors: Zhao Xinhua , Kim Yangseon , Park Gyungsoon , Xu Jin-Rong
Published: March 2005

Many fungal pathogens invade plants by means of specialized infection structures called appressoria. In the rice (Oryza sativa) blast fungus Magnaporthe grisea, the pathogenicity mitogen-activated protein (MAP) kinase1 (PMK1) kinase is essential for appressorium formation and invasive growth. In this study, we functionally characterized the MST7 and MST11 genes of M. grisea that are homologous with the yeast MAP kinase kinase STE7 and MAP kinase kinase kinase STE11. Similar to the pmk1 mutant, the mst7 and mst11 deletion mutants were nonpathogenic and failed to form appressoria. When a dominant MST7 allele with S212D and T216E mutations was introduced into the mst7 or mst11 mutant, appressorium formation was restored in the resulting transformants. PMK1 phosphorylation also was detected in the vegetative hyphae and appressoria of transformants expressing the MST7  S212D T216E allele. However, appressoria formed by these transformants failed to penetrate and infect rice leaves, indicating that constitutively active MST7 only partially rescued the defects of the mst7 and mst11 mutants. The intracellular cAMP level was reduced in transformants expressing the MST7  S212D T216E allele. We also generated MST11 mutant alleles with the sterile alpha motif (SAM) and Ras-association (RA) domains deleted. Phenotype characterizations of the resulting transformants indicate that the SAM domain but not the RA domain is essential for the function of MST11. These data indicate that MST11, MST7, and PMK1 function as a MAP kinase cascade regulating infection-related morphogenesis in M. grisea. Although no direct interaction was detected between PMK1 and MST7 or MST11 in yeast two-hybrid assays, a homolog of yeast STE50 in M. grisea directly interacted with both MST7 and MST11 and may function as the adaptor protein for the MST11-MST7-PMK1 cascade.
Timing of the Maternal-to-Zygotic Transition during Early Seed Development in Maize
Authors: Grimanelli Daniel , Perotti Enrico , Ramirez Jorge , Leblanc Olivier
Published: March 2005

In animals, early embryonic development is largely dependent on maternal transcripts synthesized during gametogenesis. Recent data in plants also suggest maternal control over early seed development, but the actual timing of zygotic genome activation is unclear. Here, we analyzed the timing of the maternal-to-zygotic transition during early Zea mays seed development. We show that for 16 genes expressed during early seed development, only maternally inherited alleles are detected during 3 d after fertilization in both the embryo and the endosperm. Microarray analyses of precocious embryonic development in apomictic hybrids between maize and its wild relative, Tripsacum, demonstrate that early embryo development occurs without significant quantitative changes to the transcript population in the ovule before fertilization. Precocious embryo development is also correlated with a higher proportion of polyadenylated mRNA in the ovules. Our data suggest that the maternal-to-zygotic transition occurs several days after fertilization. By contrast, novel transcription accompanies early endosperm development, indicating that different mechanisms are involved in the initiation of endosperm and embryo development.
Novel Functions of Plant Cyclin-Dependent Kinase Inhibitors, ICK1/KRP1, Can Act Non-Cell-Autonomously and Inhibit Entry into Mitosis
Authors: Weinl Christina , Marquardt Sebastian , Kuijt Suzanne J.H. , Nowack Moritz K. , Jakoby Marc J. , Hülskamp Martin , Schnittger Arp
Published: March 2005

In animals, cyclin-dependent kinase inhibitors (CKIs) are important regulators of cell cycle progression. Recently, putative CKIs were also identified in plants, and in previous studies, Arabidopsis thaliana plants misexpressing CKIs were found to have reduced endoreplication levels and decreased numbers of cells consistent with a function of CKIs in blocking the G1-S cell cycle transition. Here, we demonstrate that at least one inhibitor from Arabidopsis, ICK1/KRP1, can also block entry into mitosis but allows S-phase progression causing endoreplication. Our data suggest that plant CKIs act in a concentration-dependent manner and have an important function in cell proliferation as well as in cell cycle exit and in turning from a mitotic to an endoreplicating cell cycle mode. Endoreplication is usually associated with terminal differentiation; we observed, however, that cell fate specification proceeded independently from ICK1/KRP1-induced endoreplication. Strikingly, we found that endoreplicated cells were able to reenter mitosis, emphasizing the high degree of flexibility of plant cells during development. Moreover, we show that in contrast with animal CDK inhibitors, ICK1/KRP1 can move between cells. On the one hand, this challenges plant cell cycle control with keeping CKIs locally controlled, and on the other hand this provides a possibility of linking cell cycle control in single cells with the supracellular organization of a tissue or an organ.
A Mechanism of Nonphotochemical Energy Dissipation, Independent from PsbS, Revealed by a Conformational Change in the Antenna Protein CP26
Authors: Dall'Osto Luca , Caffarri Stefano , Bassi Roberto
Published: March 2005

The regulation of light harvesting in higher plant photosynthesis, defined as stress-dependent modulation of the ratio of energy transfer to the reaction centers versus heat dissipation, was studied by means of carotenoid biosynthesis mutants and recombinant light harvesting complexes (LHCs) with modified chromophore binding. The npq2 mutant of Arabidopsis thaliana, blocked in the biosynthesis of violaxanthin and thus accumulating zeaxanthin, was shown to have a lower fluorescence yield of chlorophyll in vivo and, correspondingly, a higher level of energy dissipation, with respect to the wild-type strain and npq1 mutant, the latter of which is incapable of zeaxanthin accumulation. Experiments on purified thylakoid membranes from all three mutants showed that the major source of the difference between the npq2 and wild-type preparations was a change in pigment to protein interactions, which can explain the lower chlorophyll fluorescence yield in the npq2 samples. Analysis of the xanthophyll binding LHC proteins showed that the Lhcb5 photosystem II subunit (also called CP26) undergoes a change in its pI upon binding of zeaxanthin. The same effect was observed in wild-type CP26 upon treatment that leads to the accumulation of zeaxanthin in the membrane and was interpreted as the consequence of a conformational change. This hypothesis was confirmed by the analysis of two recombinant proteins obtained by overexpression of the Lhcb5 apoprotein in Escherichia coli and reconstitution in vitro with either violaxanthin or zeaxanthin. The V and Z containing pigment-protein complexes obtained by this procedure showed different pIs and high and low fluorescence yields, respectively. These results confirm that LHC proteins exist in multiple conformations, an idea suggested by previous spectroscopic measurements (Moya et al., 2001), and imply that the switch between the different LHC protein conformations is activated by the binding of zeaxanthin to the allosteric site L2. The results suggest that the quenching process induced by the accumulation of zeaxanthin contributes to qI, a component of NPQ whose origin was previously poorly understood.
A Novel Plant Cysteine Protease Has a Dual Function as a Regulator of 1-Aminocyclopropane-1-Carboxylic Acid Synthase Gene Expression
Authors: Matarasso Noa , Schuster Silvia , Avni Adi
Published: March 2005

The hormone ethylene influences plant growth, development, and some defense responses. The fungal elicitor Ethylene-Inducing Xylanase (EIX) elicits ethylene biosynthesis in tomato (Lycopersicon esculentum) and tobacco (Nicotiana tabacum) leaves by induction of 1-aminocyclopropane-1-caboxylic acid synthase (Acs) gene expression. A minimal promoter element in the LeAcs2 gene required for EIX responsiveness was defined by deletion analysis in transgenic tomato plants. The sequence between −715 and −675 of the tomato Acs2 gene was found to be essential for induction by EIX. A Cys protease (LeCp) was isolated that specifically binds to this cis element in vitro. Ectopic expression of LeCp in tomato leaves induced the expression of Acs2. Moreover, chromatin immunoprecipitation showed that LeCp binds in vivo to the Acs promoter. We propose a mechanism for the dual function of the LeCp protein. The protease acts enzymatically in the cytoplasm. Then, upon signaling, a small ubiquitin-related modifier protein binds to it, enabling entrance into the nucleus, where it acts as a transcription factor. Thus, LeCp can be considered a dual-function protein, having enzymatic activity and, upon elicitor signaling, exhibiting transcriptional factor activity that induces LeAcs2 expression.
Preference structure for cheese consumers
Authors: Tendero Antonio , Bernabéu Rodolfo
Published: March 2005

Purpose

The purpose of this paper is to contribute to knowledge on the preferences of cheese consumers in Spain. The first step was to determine where and how frequently cheeses are purchased and consumed, along with different aspects relating to the recognition of cheeses certified by a denomination of origin (DO). The second step consisted in determining how consumer preferences are structured.

Design/methodology/approach

The methodology consisted of a survey of 412 consumers in the Castilla‐La Mancha Region who were buying food items for their homes. In order to process data related to the first step, a descriptive analysis was undertaken. For the second step, a conjoint analysis was carried out, with three types of attributes (price, certification and type).

Findings

The results show that cheese is a food which is present and also consumed within Spanish homes, while being bought in supermarkets at least once a week. Consumers value most the DO labels as a guarantee of quality and food safety. The cheese that is best known to consumers is the Manchego DO. Consumers prefer cheeses which are well‐priced, aged and, if possible, certified.

Originality/value

This paper analyses current consumer behaviour and, by means of conjoint analysis, identifies consumer preferences for cheeses in Spain. Internationally, conjoint analysis has rarely been used for cheeses, and this would appear to be the first time it has been applied in Spain.
Notions of region and the Mediterranean diet in food advertising
Authors: Cannon Jackie
Published: March 2005

Purpose

The paper aims to review the perceived benefits of the Mediterranean diet alongside traditional or regional foodstuffs, and to examine the extent to which food producers and retailers make use of these labels in order to enhance the perceived value of their products.

Design/methodology/approach

The paper draws on marketing literature relating to origin cues within the food industry. It first analyses criteria used by the EU for food labelling, following this with a review of the perceived value of authenticity in foodstuffs, offering an evaluation of Mediterranean‐labelled products available from a leading UK supermarket chain.

Findings

The paper involves an exploration into the descriptors used by food producers, suggesting they are designed to respond to consumers’ subjective criteria in food choices with only tenuous links to the promoted origins and corresponding quality designations. It is concluded that regional and Mediterranean labels do not display common dietary or preparation features but are convenient marketing labels designed to enhance food product attributes.

Originality/value

It appears that regional links or the term “Mediterranean”, when linked to foodstuffs, suggest a level of authenticity that is not always borne out in product ingredients and preparation methods. Origin and authenticity are widely held to enhance the perceived attributes of food products but this paper highlights certain mismatches between regional quality marks and food marketing practices. Greater awareness of the practices employed to satisfy “subjective criteria” when making food choices is of benefit to consumers.
Agro‐biotechnology and organic food purchase in the United Kingdom
Authors: Rimal Arbindra P. , Moon Wanki , Balasubramanian Siva
Published: March 2005

Purpose

The objective of this paper is to evaluate the role of consumers’ perceived risks and benefits of agro‐biotechnology in shaping the purchase pattern for organic food among UK consumers.

Design/methodology/approach

An on‐line household survey of UK consumers was conducted using household panels maintained by the National Panel Diary (NPD) group. The data included organic food purchase pattern, perceived risks and benefits of agro‐biotechnology, and socio‐demographic information about the respondents. A regression model was used to examine the impact of consumers’ general purchase behavior, perceived risks and benefits of GM technology, and socio‐demographic on organic food purchase.

Findings

Only 4 percent of the respondents purchased organic foods all the time, while 26 percent never purchased. Perceived risks of agro‐biotechnology played a dominant role in influencing organic food purchase decisions. As the risk perception increased consumers were likely to buy organic food more often. Although premium prices of organic foods were of concern to many consumers, food safety was the most important consideration when making organic food purchase decisions. Household income positively influenced consumers’ likelihood of buying organic food. Female respondents were likely to purchase organic foods more often than their male counter parts. Older respondents were less likely to buy organic foods compared to younger respondents.

Practical implications

The results of this study provide valuable information in formulating short and long‐term marketing programs for organic producers. Following the study results, food safety concern and perceived risks of GM food products need to be the overall theme of marketing programs for organic products.

Originality/value

The study uses a large sample size in examining the relationship between perceived risks of agro‐biotechnology and organic food purchase. The results are more robust and representative.
Valorization of traditional foods
Authors: Di Monaco Rossella , Di Marzo Sabrina , Cavella Silvana , Masi Paolo
Published: March 2005

Purpose

This study aimed to assess if an Italian artisanal pasta filata cheese, named Provolone del Monaco, is perceived by consumers as typical or not and if any variability exists among cheeses made by different dairies.

Design/methodology/approach

Two experiments were performed. In the first experiment, two artisanal Provolone del Monaco having different ripening times and two industrial Provolone cheeses were evaluated. A total of 95 subjects, divided into three homogeneous groups, first rated the samples in blind condition, then, after having received information about typicality; price, and both sets of information. In the second experiment, the quantitative descriptive profiles of eight Provolone del Monaco samples aged six months and made by different dairies were compared with the quantitative descriptive profiles of the same cheese aged ten months and provolone cheeses made by industrial dairies.

Findings

Consumer results revealed that consumers knowing typicality information gave a better score to cheeses markedly different. The price together with typicality information, represented a quality indicator. Cluster analysis of descriptive scores revealed homogeneity between the equally aged Provolone del Monaco samples. Moreover descriptive data showed that cheese was characterized by several specific attributes, that the consumer, probably, recognized as typical.

Research limitations

It must be noticed that once it was performed in Campania, the results extrapolation to other regions or countries should not be made unless similar results are found.

Originality/value

This study will contribute to better addressing consumer needs and enhancing the competitiveness of traditional foods.
Tribological design of hydrodynamic sliding journal bearings – formulating new functional charts
Authors: Pandazaras C. , Petropoulos G.
Published: March 2005

Purpose

This paper aims to introduce an innovative methodology for the determination of operational characteristics of journal bearings (j‐bs) through using new type charts based upon a numerical solution of the Reynolds equation.

Design/methodology/approach

The present paper proposes the mapping of the behaviour of a smooth, isothermal and hydrodynamic (j‐b) as a first step towards a future representation of the behaviour of j‐b's with limited length and high lubricating clearance with or without macro or micro topographic features operating under high loads, high temperatures and low linear velocities leading to conditions of mixed or boundary lubrication.

Findings

The derived analytical relationships between dimensionless quantities lead to the development of high precision synthetic operational charts regarding sliding j‐b of any given geometry and varying operational characteristics.

Originality/value

By considering the iso‐operational curves which are of a hook form relevant to comparative data becomes directly and rapidly clarified.
On the squeeze film lubrication of long porous journal bearings with couple stress fluids
Authors: Naduvinamani N.B. , Hiremath P.S. , Tasneem Fathima Syeda
Published: March 2005

Purpose

This paper aims to advance the squeeze film characteristics of long partial journal bearings with couple stress fluid studied by Lin to include the effect of permeability on the squeeze film lubrication of long partial porous journal bearings with couple stress fluids.

Design/methodology/approach

A semi‐analytical and semi‐numerical solution for the squeeze film lubrication of long porous partial journal bearings lubricated with couple stress fluid is presented in the paper. The modified Reynolds equation governing the fluid film pressure is derived. The modified Reynolds equation is solved analytically and closed form expressions for the squeeze film pressure and load carrying capacity are presented. The first‐order non‐linear equation for the time‐height relation is solved numerically with the given initial condition. The effect of couple stresses and permeability on the squeeze film characteristics are discussed.

Findings

It is found that the effect of couple stresses is to increase the load carrying capacity and to lengthen the squeeze film time as compared to the corresponding Newtonian case. The effect of permeability is to reduce the load carrying capacity and to decrease the squeeze film time as compared to the corresponding solid case.

Originality/value

In the design of porous partial journal bearings, the reduction in the load carrying capacity and the response time can be compensated by the use of lubricants with proper microstructures by which the bearing life can be increased.
The analysis of the effects of surface texture on the capability of load carriage of journal bearings using neural network
Authors: Si˙nanoğlu Cem
Published: March 2005

Purpose

This paper investigates the load carrying capacity of the journal bearings with steel shafts with varying surface texture in varying revolutions using experimental and neural network (NN) approach.

Design/methodology/approach

In this study, we used a shaft with smooth surface with the same material properties compare their load carrying capacities of the shafts with three different pitches and two different profiles. The experimental data, such as pressure and oil temperature, are employed as training and testing data for NN. Quick Prop algorithm is used to update the weight of the network during the training.

Findings

The designated NN has superior performance for modelling of the system. Therefore, the proposed neural predictor would be used as a predictor for possible experimental applications on modelling bearing system.

Research limitations/implications

Mobil 0W‐40 lubricant was used and kept at temperature of 18°C. The surface of the shafts has been in two types: smooth, that is without and with profiles, that is trapezoidal and saw.

Practical implications

Owing to the parallel structure and fast learning of NN, this kind of algorithm will be utilized to model other types of bearing systems.

Originality/value

Instead of traditional methods, NN has fast learning and parallel processing structure. Moreover, NN can be used to process multiple‐input/multiple‐output data unlike other empirical modelling tools which can map one dependent variable at a time. Therefore, this method is able to predict the load carrying capacity with steel shafts with varying surface texture in varying revolutions satisfactorily where common techniques have failed.
The relationship between work commitment models and employee withdrawal intentions
Authors: Carmeli Abraham , Gefen David
Published: March 2005

Purpose

This study is an attempt to contribute to an emerging stream of research, which attempts to explore how work commitment forms affect one another and how together they serve to influence work behaviour and outcomes.Design/methodology/approach– Drawing on five universal forms of work commitment, we tested the relationships between two work commitment models and two forms of employee withdrawal intentions: from their organisation and from their occupation. To this end, we investigated professional employees (social workers) employed in the Israeli healthcare system through a structured questionnaire.Findings– Path analysis results cast doubt on the applicability of both models in their original form, across scenarios. At the same time, with some modifications, both models show a good potential for explaining variance in employee withdrawal intentions from both their organisation and their occupation.Originality/value– This research contributes to work commitment literature by providing empirical findings and theoretical interpretations regarding the role of a particular professional setting in explaining the interrelationships among models of work commitment, and how some constellations of different work commitment foci explain multiple withdrawal intentions.
Conflict and well‐being at work: the moderating role of personality
Authors: Dijkstra Maria T.M. , van Dierendonck Dirk , Evers Arne , De Dreu Carsten K.W.
Published: March 2005

Purpose

This study examines the moderating influence of the Big Five factors of agreeableness, extraversion, and emotional stability on the relationship between conflict and well‐being.Design/methodology/approach – Two field studies were conducted in which respondents were asked to fill out questionnaires during work hours; the first study involved a health care organization, the second one a manufacturing organization.Findings – In performing sets of hierarchical regressions it was shown that conflict was negatively associated with well‐being, especially when individuals were low in agreeableness, low in emotional stability or low in extraversion.Research limitations/implications – We proposed directional relations between conflict and individual well‐being, however we cannot rule out the alternative in which reduced well‐being leads to more conflict. Future research using a cross‐lagged design with longitudinal data is needed to establish causal relationships.Practical implications – The most straightforward implication for practice seems to be that conflict should become part of the checklist consultant's use when advising organisations with high rates of turnover, sick leave, and absenteeism.Originality/value – This study showed that conflict adversely affects well‐being, especially for disagreeable, emotional unstable, or introverted individuals.
Assessing leadership styles and organisational context
Authors: Dulewicz Victor , Higgs Malcolm
Published: March 2005

Purpose

To investigate the new leadership dimensions questionnaire (LDQ) and a related framework for assessing an individual's leadership style in relation to the context in which the leader works; the three new LDQ sub‐scales designed to measure organisational context, follower commitment and leader performance; and the relationship between personality and leadership.Design/methodology/approach – Research is reported on LDQ data from a large sample of leaders and managers (n 222) from a range of public and private organisations. A style score was calculated and then related to data on respondents' biographical – job function, gender, sector and nationality – and FFM personality data.Findings – Results show a reasonably even allocation across all three leadership styles and that the styles are independent of the four important biographical variables. They also show that the five FFM personality factors do not account for any additional variance on any of the styles at a significant level. Results on the factor structure of the organisational context, follower commitment and leader performance scales show them to be reliable scales.Research limitations/implications – A majority of the sample were from the UK, from the private sector and were male. This study did not incorporate measures of job performance or investigate the style and context link. The self‐assessed, not the 360° version of LDQ was used.Practical implications – Some support is provided for the LDQ's use for leadership assessment and development, and for identifying potential, in both public and private sector organisations, with a standardisation sample of more than 1,000 now available. Results also show that the LDQ can be used without losing significant personality‐related variance.Originality/value – LDQ provides a unique opportunity for managers to relate leadership dimensions to three different leadership styles – engaging, goal‐oriented and involving – and, in turn, to the degree of organisational volatility faced by the leader, thus enabling respondents to identify the most appropriate style. Leader performance and follower commitment sub‐scales should facilitate further research by academics into leadership performance.
Managers' cognitive maps and intra‐organisational performance differences
Authors: Goodhew Geoffrey W. , Cammock Peter A. , Hamilton Robert T.
Published: March 2005

Purpose

To explore the relationship between managers' cognitive maps and their performance as managers at the same level in the same organisation.Design/methodology/approach – Field study involving 30 branch managers in a financial services organisation operating in New Zealand. A nomthetic approach was used to develop their cognitive maps. Features of these maps were then related to business‐unit performance.Findings – The managers who were higher performing have maps that were considerably simpler, using fewer concepts and fewer linkages.Research limitations/implications/future research – While limited to one organisation and to one level of management, there is evidence that cognition is related to managers' performance. Future research should explore how cognitive structures differ between managerial levels, and how these are related to appropriate measures of performance.Originality/value – One of few studies that have sought to map managers' cognition and organisation performance.
An empirical exploration of psychological contract violation and individual behaviour
Authors: Lemire Louise , Rouillard Christian
Published: March 2005

Purpose

The purpose of the research is to demonstrate the impact of psychological contract infringement (independent variable) on organizational commitment, exit, voice and neglect (dependent variables) within a Canadian federal public organization located in Quebec, where individual (e.g. age), organizational (e.g. stricter rule enforcement) and situational (e.g., employment alternatives) variables are controlled.Design/methodology/approach – A pre‐tested questionnaire (204 questions) on the psychological contract was distributed to 357 Canadian civil servants in a one site federal department. One hundred and thirty‐two questionnaires were returned and considered usable for research, for a 37 per cent response rate. Bivariate analysis was performed on the various determinants and individual responses to psychological contract violation, including organizational commitment, departure designs and counterproductive behaviors.Findings – Results clearly illustrate the great complexity of the link between organizational variables and individual reactions and shed light, on a higher level, on the need to outgrow arguments that reduce bureaucracy to its mere perverse effects. These results suggest that the managerial challenge is not so much to produce a shift from an environment where the rule of law, standards and regulations prevails to an open and flexible environment where individual autonomy is prized as it is to ensure compliance with normative and regulatory constraints.Originality/value – The research seeks to enrich the knowledge base on the subject area because previous research has dealt almost exclusively with the psychological contract within large private companies.
Factorial constitution of managerial effectiveness
Authors: Singh Chauhan Vinit , Dhar Upinder , Pathak R.D.
Published: March 2005

Purpose

It has been observed time and again by researchers that one must be highly adaptive in order to be effective. Number of instruments are available, but most of them have been developed and then standardized on western population. To ensure utility of some of the well‐known instruments, it is imperative to testify them on Indian population. The present study is an attempt to re‐examine the factorial structure of the instrument developed by Mott.Design/methodology/approach – The work is based on a broad range of published works, including papers, books and reports.Findings – The findings have revealed that this instrument does not replicate its factors in totality, hence indirectly the impact of culture on managerial effectiveness. The study has established that the instrument developed by Mott does not replicate its factorial structure in Indian context. The original version had three factors, such as productivity, flexibility and adaptability, whereas the present study has shown that there are only two factors, such as functional effectiveness and personal effectiveness in the Indian context.Originality/value – Of value for functional effectiveness and personal effectiveness in the Indian context.
The experience of work‐related stress across occupations
Authors: Johnson Sheena , Cooper Cary , Cartwright Sue , Donald Ian , Taylor Paul , Millet Clare
Published: March 2005

Purpose

To compare the experience of occupational stress across a large and diverse set of occupations. Three stress related variables (psychological well‐being, physical health and job satisfaction) are discussed and comparisons are made between 26 different occupations on each of these measures. The relationship between physical and psychological stress and job satisfaction at an occupational level is also explored.Design/methodology/approach– The measurement tool used is a short stress evaluation tool which provides information on a number of work related stressors and stress outcomes. Out of the full ASSET database 26 occupations were selected for inclusion in this paper.Findings– Six occupations are reporting worse than average scores on each of the factors – physical health, psychological well‐being and job satisfaction (ambulance workers, teachers, social services, customer services – call centres, prison officers and police). Differences across and within occupational groups, for example, teaching and policing, are detailed. The high emotional labour associated with the high stress jobs is discussed as a potential causal factor.Research limitations/implications– This is not an exhaustive list of occupations and only concerns employees working within the UK.Originality/value– There is little information available that shows the relative values of stress across different occupations, which would enable the direct comparison of stress levels. This paper reports the rank order of 26 different occupations on stress and job satisfaction levels.
Strategy‐driven B2B promotions
Authors: Hellman Karl
Published: March 2005

Purpose

Typically, business‐to‐business (B2B) promotions are price cuts that drain profits and erode brand equity for the sake of short‐term volume gains. This paper shows how to elevate B2B promotions to a central place in implementing strategy – creating extra value for customers, building brand equity, improving profits, and permanently increasing sales.

Design/methodology/approach

The article examines nine successful non‐price promotions and shows the patterns and principles that made them work.

Findings

The article posits a new conceptual model that organizes the findings from the nine cases: “the customer learning curve.” Strategy‐driven promotions move customers down this mental process from having a need – but perhaps not even knowing it – all the way through to being advocates for the firm and its products.

Research limitations/implications

The model provides a framework for analyzing existing, and designing future, decision‐oriented market research.

Practical implications

Strategy‐driven promotions focus on overcoming barriers to purchase. The best are specific (don't ask the promotion to do the whole job); creative (go beyond the conventional, “drop the price” thinking); customer‐centered (borrow interest from something the customer really cares about); measurable (if you can't measure it, you can't learn from it); and brand enhancing (don't fall into the trap of eroding brand equity).)

Originality/value

The customer learning curve is an original conceptual model and practical problem‐solving tool. The nine cases provide original examples.
Stress in business relationships
Authors: Holmlund‐Rytkönen Maria , Strandvik Tore
Published: March 2005

Purpose

One of the causes of change in business relationships comes from incidents that deviate in a positive or negative way from the expected and normal relationship pattern. This introduces the concept of stress that captures the effect of negatively deviating incidents in business relationships.

Design/methodology/approach

Presents a technique, the negative critical incident mapping (NCIM), for measuring this kind of stress. The technique is used in an industrial service and a business service setting to measure stress in a dyadic manner.

Findings

The results show that not only were all studied relationships burdened with stress to a varying extent but there were also substantial differences in the degree and content of stress. The relationships showed significant differences when seller‐buyer pairs of stress perceptions were matched. Operator‐level perceptions of stress in the relationships corresponded better than manager‐level perceptions. Research and management implications from the new relationship stress concept conclude the paper.

Originality/value

The new relationship‐stress concept is useful for relationship‐dissolution and relationship‐strength researchers since it reveals a hidden risk factor to a business relationship that complements current understanding. For managers the value lies in being able to diagnose relationships at risk of being lost or to detect fundamental relationship problems.
Salesforce automation, perceived information accuracy and user satisfaction
Authors: Gohmann Stephan F. , Barker Robert M. , Faulds David J. , Guan Jian
Published: March 2005

Purpose

This paper examines how perceptions about salesforce automation (SFA) systems are influenced by the perceived accuracy of the information the system provides.

Design/methodology/approach

Three hypotheses are tested. They are as follows. Sales people who perceive that the information is inaccurate will be less likely to: have a positive perception of the system; think that their training was helpful; and think that the system improves their productivity. Chi‐square tests are used to test the association between the perceptions of information accuracy and the statements in the hypotheses.

Findings

Negative perceptions about the accuracy of information leads to negative perceptions about other aspects of the SFA system.

Research limitations/implications

This study examines the results for only one particular organization. The results may not be generalizable to other organizations. As similar data about other SFA systems become available, this study can be used as a basis for examining the effect of information accuracy on perceptions of SFA systems.

Originality/value

Since the company has some control over the accuracy of the information provided by the system, they should attempt to provide information that the salesforce finds useful. To enure that the proper information is provided, management must seek the user's input about what information should be provided. Additionally, the data should be cleansed and provide an indicator of the probability that a particular lead will result in a sale.