bluuebunny/crossref_metadata_2025 huggingface dataset:
Caterers’ knowledge and attitude towards healthy eating
Authors: Bull Caroline E. , Wise Alan
Published: July 2002

The typical Scottish diet is high in meat, dairy products and confectionery and low in cereals, vegetables and fresh fruit, although evidence suggests that consumers are becoming more “health” conscious. Research indicates that more people are eating out nowadays and requesting “healthy” choices when doing so. This present study examined, by means of a questionnaire, chefs’ knowledge of nutrition and their ability to apply this to recipes. A total of 25 chefs completed the study. Most chefs had received training and had a positive attitude towards “healthy” eating. The changes chefs made to recipes were partly in keeping with current dietary guidelines, particularly for fat and energy. Further research is needed into whether chefs actually know and understand specific dietary guidelines or whether they lack the practical skills needed to prepare “healthy” dishes. It is recommended that college courses should teach chefs “healthy” eating theory reinforced by practical skills.
Management competence development for professional service SMEs: the case of community pharmacy
Authors: Ottewill Roger , Jennings Peter L. , Magirr Peter
Published: July 2002

Over the last two decades there has been a substantial increase in the number and range of service sector SMEs. The management competence of the owner‐manager and/or senior staff is crucial to their success. Developing appropriate competencies presents a particular challenge for professional service SMEs, since the key players are more likely to be motivated by the perceived attractions of professional practice than the commercial and managerial aspects of the enterprise. Drawing upon the experiences of community pharmacists in the UK as an empirical frame of reference, consideration is given to the key management competencies, both operational and strategic, which are required to operate a professional service enterprise successfully. Issues concerning the provision of management training for community pharmacists are also highlighted.
The use of computer mediated communication in the industrial placement year
Authors: Gush Jacqui
Published: July 2002

This paper sets out to examine the potential and limitations of computer mediated communication (CMC) in an educational context, and to relate this to an early pilot project run in the 1996/97 academic year at Bournemouth University on two courses to serve the needs of students out on their work placement year. The purpose and use of CMC in this context is evaluated and the findings present an opportunity to discuss the benefits and limitations of the use of this technology in this context with a view to suggesting how the use of CMC could be extended in the future.
Strategic HRM and the gendered division of labour in the hotel industry
Authors: Biswas Rashmi , Cassell Catherine
Published: July 2002

Numerous studies have documented the ways in which work is structured along gender lines. Predominantly such investigations have reported on the inequity of the sexual division of labour and have argued that such gender segregation operates in favour of males, with the majority of female economic activity concentrated in the low‐paid areas of the service sector. Further research has explored the sexual stereotyping of the service encounter, and in particular the personification of the service provider epitomizing the service to the consumer. Presents the findings of an in‐depth case study conducted within the hotel industry designed to examine the views of hotel workers in a large hotel about the sexual division of labour and sexual stereotyping of individuals within their organization. Explores the origins of these gender divisions within the hotel industry, and locates the prevalence of such an imbalance firmly in the sphere of overall business strategy and hence the human resource strategy of the organization. Discusses the conclusions in terms of the relationship between equal opportunities policies and strategic HRM.
Ageism and the labour process: towards a research agenda
Authors: Glover Ian , Branine Mohamed
Published: July 2002

Offers a fairly general discussion of the significance of ageism in work and employment and then proceeds to suggest that labour process researchers might very usefully pay some attention to it. Writers about the labour process tend to emphasize the issue of labour exploitation and gender and race discrimination but, to some extent, seem to overlook the problem of ageism in work and employment. In this context, considers the character of links between a number of economic and social phenomena and ageism, namely life cycles, divisions of labour, managerialism and industrialization. Specific aspects of ageism in the UK are discussed and the need for debate and policy formulation about the issue of ageism is called for.
Service quality and human resource management
Authors: Redman Tom , Mathews Brian P.
Published: July 2002

Service organisations are striving to increase the quality of the services they offer. They are also using a wide variety of people management techniques. These two activities can sometimes come into conflict. This article examines a variety of management practices, particularly from human resource management (HRM), used by the service sector, and assesses their potential impact on service quality and total quality management (TQM). Many techniques are identified as being potentially supportive of quality improvement but some pose threats, particularly those most closely associated with cost minimisation and the less subtle forms of managerial control. In order to encourage research in this area a number of research propositions and an agenda for further research are developed.
Competent managers? – The development and validation of a normative model using the MCI standards
Authors: Thompson John E. , Harrison Jeanette
Published: July 2002

Increasing demands in university management in the 1990s in the UK requires a re‐examination of the head of school’s role. The Standards are part of a radical change in the system of vocational education and training in the UK which began in 1982. A questionnaire was distributed to deans and senior officers, heads and staff. Respondents gave their ratings of importance of 62 activities in the effective leading and managing of a school derived from the Standards. In feedback workshops heads and deans commented on changes to the proposed model. The validity of the standards and their future usefulness is evidenced by few changes to the proposed model and willingness by heads and deans to use the model as the platform for future development.
A model for library support of distance education in the USA
Authors: Cooper Jean L.
Published: July 2002

Until the past few years, distance education has been slow to find support in the USA, particularly for advanced degree programmes. As distance education gains popularity in the USA, academic departments in US colleges and universities have seen the opportunity to expand into off‐site programmes. Much attention has been given to the logistics and methodology of teaching such off‐site courses. Less attention has been given to providing information services for the off‐site programme. This paper discusses the collaboration of the University of Virginia Library with the UVa Division of Continuing Education to provide library services for off‐site students.
Lignin from waste black liquor 3‐treated lignin in phenol formaldehyde resin
Authors: Nada A.M.A. , Yousef M.A. , Shaffei K.A. , Salah A.
Published: July 2002

Bagasse and rice straw lignins undergo different treatments, e.g. acid hydrolysis, oxidation with hydrogen peroxide and thermal treatment, before being used as a partial replacement for phenol in phenol formaldehyde resin. These treatments improved the resin formation properties of the lignin. The effect of these treatments on the improvement of the properties of the resin produced has the following sequence: lignin treated with HCl (1‐3N) > lignin treated with H2O2 (1‐3 per cent) > thermally treated lignin (120‐140°C). The improvement of the properties of the resin produced from bagasse lignin is greater than that produced from rice straw lignin. The treatment of rice straw lignin with acid increases its ability to form a resin. Treatment of rice straw lignin with acid leads to its increased concentration in the phenol lignin formaldehyde resin with good properties. In general, the resin produced from treated lignin has better properties than resin produced from untreated lignin.
Disloyalty: a closer look at non‐loyals
Authors: Rowley Jennifer , Dawes Jillian
Published: July 2002

Seeks to revisit the theoretical basis for the concept of loyalty through a consideration of the state of “no loyalty”, which we term “disloyalty”. This category is present in the model proposed by Dick and Basu, but is seen to be of less interest than other categories. Here we argue that a more analytical approach to this category might provide a unique insight into loyalty behaviours, but specifically might aid an understanding of the nature of the challenge associated with widening the loyal customer base. We propose the following categories of disloyals: disturbed, disenchanted, disengaged and disruptive. These four categories can be mapped onto a grid with attitudinal and behavioural dimensions. The characteristics of each of these groups are outlined. Segmentation on the basis of these different types of disloyalty could have implications for marketing strategies. The relationships between the different categories of disloyals and Dick and Basu’s categories of loyals may be important in mapping the development of customer relationships. Finally, proposals are made for further research.
Application of total quality management in education: retrospect and prospect
Authors: Kwan Paula Y.K.
Published: July 2002

Points out that recent discussion has centred on the application of total quality management (TQM) in education. Most writers appear inclined to suggest that TQM is a unique solution for effective school management. Nonetheless, TQM was initiated in the manufacturing sector and its successful application in the educational setting should only be justified with ample theoretical support and concrete evidence. Attempts to trace the literature that discusses the application of TQM in education. Also addresses the differences between industry and education. Aims to explore the relevance of employing TQM in education.
Managing progress monitoring in United Arab Emirate schools
Authors: Hokal Abdullah , Shaw K.E.
Published: July 2002

This paper examines managerial and associated aspects of monitoring pupil progress in United Arab Emirate state schools, based on an empirical study carried out over five years in the Dubai Educational Zone. Such monitoring has been recognised as of importance to school effectiveness and improvement. It is of special concern in the Gulf because of the prevalence of underachievement and drop‐out there. The Ministry requires only raw data of test and examination performance. Gathering this consumes much time and energy but contributes little to student learning. Data concerning “at‐risk” students are not shared. Recommendations are made. Study of this aspect of schooling allows the opportunity to examine other significant managerial aspects of UAE schools.
Developing a new national management accounting framework – the Spanish case
Authors: Blake John , Amat Oriol , Wraith Philip
Published: July 2002

Comparative national management accounting is a young discipline. A recent survey of management accounting practice in Europe reveals five major issues that contrast across national management accounting practice. In the light of this work we undertook a survey of Spanish management accounts and found that there is declining use of official government guidance on management accounting; the emerging management accounting profession is qualified by university education, and is not generally involved in any professional body; although the literature indicates a strong Anglo‐American influence on modern Spanish management accounting, we found a strong, previously unreported, German influence; a wide range of innovative management accounting approaches have been tried; there is a move towards a planning objective as the focus of the management accountant’s work.
Water vapour transfer in waterproof breathable fabrics
Authors: Ruckman J.E.
Published: July 2002

To clarify the principles and mechanisms of water vapour transfer by diffusion in waterproof breathable fabrics for clothing, experiments using a simple glass dish were carried out under steady state conditions with and without a temperature gradient in the climatic chamber. It was found that both vapour pressure and natural convection within the air gap affect water vapour transfer. The rates of water vapour transfer are ranked microfibre fabrics, cotton ventiles, PTFE‐laminated fabrics, poromeric polyurethane laminated fabrics, hydrophilic laminated fabrics, and polyurethane‐coated fabrics. In the presence of a temperature gradient, condensation was also found to be a major factor, especially at air temperatures below 0°C. Condensation occurred the least on the inner surface of PTFE‐laminated fabrics followed by cotton ventiles, microfibre fabrics, hydrophilic‐laminated fabrics, poromeric polyurethane‐laminated fabrics, and polyurethane coated fabrics.
Effect of hem edges on the interface pressure of pressure garments
Authors: Fun Frency Ng Sau , Leung Patrick Hui Chi
Published: July 2002

Pressure garments are mainly made of elastic Lycra fabrics and tailor‐made to individual patients’ measurements to provide an appropriate amount of skin‐garment interface pressure for burn rehabilitation. However, the fabric tension would be different at various locations from the hem edges of pressure garments, and thus the skin‐garment interface pressure cannot be uniformly maintained over the interface surface. Aims to investigate the pattern of interface pressure changes caused by the different types of edge finish used for making pressure garments. The effect of garment sizes on the change of interface pressure was also examined. Experiments were carried out using two selected elastic Lycra fabrics, four types of hem finish and three different garment sizes. The results of the study provide a guideline for designing the edge finish of pressure garments, and a minimum margin from the hem edges of garments to the scar area is also recommended.
Administrative practice
Authors: Kingsley Hugh
Published: July 2002

Understandings of administrative practice do not seem to reflect the current status of administrative practice, and when administrative practice is conceptualised as an iceberg it becomes clear that much of this knowledge was derived through the application of the research method structured observational studies. However, argues that the application of this research method in an unstructured form is where greater insights and more current knowledge of administrative practice can be gained.
Measuring the perception of the primary school deputy principal′s
responsibilities
Authors: Harvey Michael , Sheridan Barry
Published: July 2002

The deputy principalship remains one of the least understood roles
in the schools of contemporary education systems. Research which
contributes to theory building about the deputy principalship has been
hampered by the lack of survey instruments with known psychometric
properties. Reports an exploratory study which uses latent trait theory
to construct a variable which describes and conceptualizes practitioner
perspectives of the deputy principalship in the self‐managing school.
The logic of constructing the variable is explained in terms of the
requirements of the measurement model employed. A sample of 403 deputy
principals, 179 principals and 138 teachers in government primary
schools in Western Australia provided data for analysing the actual and
ideal perceptions of these practitioners in terms of the variable as
conceptualized. In this way, the variable provided the knowledge base
for describing the “professional horizon” of school
practitioners with respect to the traditional and emergent facets of the
deputy principalship. Considers the outcomes of the analysis for further
research about mapping the responsibilities of the deputy principal in a
changing environment.
Collaborative power
Authors: Harchar Rayma L. , Hyle Adrienne E.
Published: July 2002

Suggests that the research literature provides no clear perspective of the tasks needed for effective instructional leadership and no definitive set of traits for instructional leaders. Describes a study which sought to develop a theory of instructional leadership grounded in data from practising administrators and their teachers. Grounded theory served as both the theoretical structure and research design. Findings indicated effective elementary instructional leaders engaged in a variety of strategies designed to balance power inequities in their school and school community. The strategies are not linear and not all are used by every administrator; they occur both simultaneously and at varying times, building on each other. The theory known as collaborative power was developed as a model designed to equalize power inequities, fostering instructional leadership strategies and perspectives at the elementary level.
The dynamics of emergency transhipment supply chains
Authors: Hong‐Minh S.M. , Disney S.M. , Naim M.M.
Published: July 2002

Considers the dynamical effect of lateral emergency transhipments within a supply chain. It tests various different strategies for improving customer service via the MIT Beer Game. Four distinct strategies are considered. “Electronic point of sales (EPOS)”, where marketplace information is forwarded to all players throughout the supply chain; “Excel”, where the stock levels in all echelons are controlled by the factory; “Emergency transhipments”, where an express transportation route bypassing an echelon in the supply chain is permitted; “Eliminate”, where an echelon is removed from the supply chain. The Beer Game strategies are also studied via a simulation exercise. Results show that the Excel strategy is flawed, whereas the EPOS strategy has a strong impact on inventory cost, Emergency transhipments has a strong impact on customer service level and Eliminate results in less stock for an improved customer service level. Combinations of the three viable strategies are also tested. This paper concludes that the three strategies can be integrated to significantly improve supply chain performance.
Implementation of a free boundary condition to Navier‐Stokes equations
Authors: Wang Morten M.T. , Sheu Tony W.H.
Published: July 2002

Numerical simulation of a fluid flow involves the specification of boundary conditions along all or part of the boundary. Designs a means of handling outflow boundary conditions for the incompressible Navier‐Stokes equations. Addresses through‐flow problems involving the specification of outflow conditions at the synthetic boundary. This outflow boundary condition is applicable to a developing flow problem. The underlying objectives behind designing the boundary condition at the truncated boundary are three‐fold, namely: matching with Navier‐Stokes equations inside the domain; taking both non‐linear and diffusive contributions into account; and ensuring the discrete divergence‐free condition. In order to meet these requirements, follows the concept of a free boundary condition by taking the outflow nodal values of u, v and p as unknowns, which are coupled with the interior unknowns through the surface integrals in the momentum equations. The computed solutions can be legitimately regarded as solutions to conservation equations under consideration when both components of the surface traction vector approach zero. With the convergent property accommodated in the present mixed finite element analysis, the task remains to simply improve the accuracy. Demonstrates the capability of the proposed non‐linear outflow boundary conditions through several benchmark tests.
Librarians and the informed user
Authors: Johnson Ian M.
Published: July 2002

This paper points to the challenges arising from the emergency of the “information society”: the high level of skills required to take full advantage of the new information and communication technologies, and their expanding information content; a greater awareness of information and its potential contribution to all aspects of life; and the social and political challenges of ensuring equality in information provision. It considers the need for information professionals to have a greater commitment to user empowerment; a higher level of skills in facilitating the use of information; and a more visible and effective presence in the “political” arena. It discusses some solutions which have been adopted by schools of librarianship in the UK to help students acquire the necessary knowledge, skills, and enthusiasm, and some of the outstanding areas for development: broader perspectives in the context of information work, and the encouragement of continuing professional development.
Quality standards and the reflective tutor
Authors: Ashcroft Kate , Foreman‐Peck Lorraine
Published: July 2002

Discusses various definitions of quality and standards used within the college and university sector and highlights their advantages and disadvantages. Looks particularly at their implications for reflective practice. Argues that the various definitions of quality have implications for the ways in which professionalism is defined, and that some definitions may be inimical to the values encapsulated in the “reflective practitioner” model.
The China Education Research Network (CERNET) and library services
Authors: Zongying Yang , Haoming Lin , Qiaoying Zheng
Published: July 2002

Introduces the major objectives in establishing the China Education and Research Network (CERNET). Describes the major goals, the topological structure, the organisation of the network and the application systems of CERNET. It details current applications in library and information services on CERNET.
A qualitative study and model of the use of e‐mail in organisations
Authors: Ruggeri Stevens G. , McElhill J.
Published: July 2002

A huge upsurge in the growth of e‐mail is expected but there has been relatively little published advice on how to take a corporate view of electronic mail, despite demonstration of its operational benefits and of the consequences of its misuse in economic, human and lately in legal terms. This article contributes to formation of such advice. Employing a mix of questionnaire and interview methods, a set of disparate organisations was studied – a global financial services company, an upmarket hotel group, a well‐established mobile‐telecommunications company, and three universities. The results were used to devise a multi‐dimensional “positioning” model, for practical use by managers to understand their organisations’ present use of e‐mail on four dimensions: information management, people influences, corporate culture, and knowledge management. Shows how an organisation can find/change its present position on the model.
Essai: weaving postmodernism
Authors: Berthon Pierre , Katsikeas Constantine
Published: July 2002

As more and more organizations establish their presence on the World Wide Web, the question of interacting in the new medium presents challenges to practitioners and academics alike. How should economic and symbolic activity be conducted and conceptualized? Different assumptions about the new medium will result in disparate activities ‐ and concomitantly varying degrees of success or failure. In this article we explore the phenomenon of the Web using themes which characterize postmodernism. Postmodernism is a rubric of praxes and thoughts that “dis‐embodies” the information age, and thus offers unique insights into information‐rich contexts such as the Web. The article is set out as follows. First, the signifiers of “modern” and “postmodern” are discussed. Second, the Web is explored using key themes of postmodernism. We conclude that a postmodern perspective will illuminate thinking in the new information medium, just as modernism facilitated thinking in traditional physical medium.
A security framework for online distance learning and training
Authors: Furnell S.M. , Onions P.D. , Knahl M. , Sanders P.W. , Bleimann U. , Gojny U. , Röder H.F.
Published: July 2002

Considers the requirement for information security within the
domain of online distance learning. A generic module
structure is presented which represents a high level abstraction
of the different stages of the educational process.
Discusses the main security issues that must be considered at
each stage. These various requirements are being addressed
in practice by the security framework being developed by the
SDLearn research project, a collaborative initiative between
higher academic establishments in the UK and Germany.
A comparative analysis of Scottish property rents
Authors: White Michael , Mackay Daniel , Gibb Kenneth
Published: July 2002

This paper uses time series econometric techniques to model regional property rents in order to build a picture of the distinctiveness and commonality of the Scottish property sector. Data used comes from a series stretching from 1970‐1998 and allows Scotland’s market performance (in terms of rents) in each of the three main property sectors to be benchmarked against a selective comparison of other UK regions. In doing so, we pay particular attention to the statistical properties of the time series used, applying tests of data stationarity and cointegration to develop a reduced form model of rents comprising both demand and supply‐side variables. The paper develops a predictive approach to property rents based on the autoregressive moving average (ARMA) methodology. Initial within‐sample predictive power is reasonably high. The implications of our results for a better understanding of the Scottish property market, as well as the more general modelling, are sketched out.
Effect of pH and salt bridges on structural assembly: Molecular structures of the monomer and intertwined dimer of the Eps8 SH3 domain
Authors: Kishan K.V. Radha , Newcomer Marcia E. , Rhodes Thomas H. , Guilliot Stephen D.
Published: July 2002

The SH3 domain of Eps8 was previously found to form an intertwined, domain‐swapped dimer. We report here a monomeric structure of the EPS8 SH3 domain obtained from crystals grown at low pH, as well as an improved domain‐swapped dimer structure at 1.8 Å resolution. In the domain‐swapped dimer the asymmetric unit contains two “hybrid‐monomers.” In the low pH form there are two independently folded SH3 molecules per asymmetric unit. The formation of intermolecular salt bridges is thought to be the reason for the formation of the dimer. On the basis of the monomer SH3 structure, it is argued that Eps8 SH3 should, in principle, bind to peptides containing a PxxP motif. Recently it was reported that Eps8 SH3 binds to a peptide with a PxxDY motif. Because the “SH3 fold” is conserved, alternate binding sites may be possible for the PxxDY motif to bind. The strand exchange or domain swap occurs at the n‐src loops because the n‐src loops are flexible. The thermal b‐factors also indicate the flexible nature of n‐src loops and a possible handle for domain swap initiation. Despite the loop swapping, the typical SH3 fold in both forms is conserved structurally. The interface of the acidic form of SH3 is stabilized by a tetragonal network of water molecules above hydrophobic residues. The intertwined dimer interface is stabilized by hydrophobic and aromatic stacking interactions in the core and by hydrophilic interactions on the surface.
Small Area Variation in Hospital Admission Rates: Bayesian Adjustment for Primary Care and Hospital Factors
Authors: Congdon Peter , Best Nicky
Published: July 2002

Hospital admission rates are often used as a proxy to reflect patterns of morbidity or health need in population subgroups or across geographic areas. This paper considers the estimation of small area variations in relative health need, as measured by routinely collected hospital admissions data, after allowing for variation in general practice (primary care) and hospital (supply) effects. A fully Bayesian hierarchical modelling framework is adopted, using combinations of electoral ward populations and general practice patients’ lists to define catchment groups for analysis. Hospitals create a further stratum, with flows of patients between catchment groups and hospitals being represented by a gravity model. Variations in health outcomes are modelled by using a range of random-effects structures for each cross-classification of strata, together with a consideration of ward, practice, hospital and crossed level covariates. The approach is applied to case-studies of child respiratory and total emergency hospital admissions for residents in a London health authority.
SPIN VERLINDE SPACES AND PRYM THETA FUNCTIONS
Authors: OXBURY W. M.
Published: July 2002

It is shown that the theta functions of level $n$ on the principally polarised Prym varieties of an algebraic curve are dual to the sections of the orthogonal theta line bundle on the moduli space of Spin($n$)-bundles over the curve. As a by-product of our computations, we also note that when $n$ is odd, the Pfaffian line bundle on moduli space has a basis of sections labelled by the even theta characteristics of the curve.
Sequential control signals determine arm and trunk contributions to hand transport during reaching in humans
Authors: Rossi Elena , Mitnitski Arnold , Feldman Anatol G.
Published: July 2002

When reaching towards objects placed outside the arm workspace, the trunk assumes an active role in transport of the hand by contributing to the extent of movement while simultaneously maintaining the direction of reach. We investigated the spatial‐temporal aspects of the integration of the trunk motion into reaching. Specifically, we tested the hypothesis that the efficiency (‘gain’) of the arm‐trunk co‐ordination determining the contribution of the trunk to the extent of hand movement may vary substantially with the phase of reaching. Sitting subjects made fast pointing movements towards ipsi‐ and a contralateral targets placed beyond the reach of the right arm so that a forward trunk motion was required to assist in transporting the hand to the target. Sight of the arm and target was blocked before the movement onset. In randomly selected trials, the trunk motion was unexpectedly prevented by an electromagnet. Subjects were instructed to make stereotypical movements whether or not the trunk was arrested. In non‐perturbed trials, most subjects began to move the hand and trunk simultaneously. In trunk‐blocked trials, it was impossible for the hand to cover the whole pointing distance but the hand trajectory and velocity profile initially matched those from the trials in which the trunk motion was free, approximately until the hand reached its peak velocity. The arm inter‐joint co‐ordination substantially changed in response to the trunk arrest at a minimal latency of 40 ms after the perturbation onset. The results suggest that when the trunk was free, the influence of the trunk motion on the hand trajectory and velocity profile was initially neutralized by appropriate changes in the arm joint angles. Only after the hand had reached its peak velocity did the trunk contribute to the extent of pointing. Previous studies suggested that the central commands underlying the transport component of arm movements are completed when the hand reaches peak velocity. These studies, together with the present finding that the trunk only begins to contribute to the hand displacement at peak hand velocity, imply that the central commands that determine the contributions of the arm and the trunk to the transport of the hand are generated sequentially, even though the arm and trunk move in parallel.
Hypoxia‐induced secretion of serotonin from intact pulmonary neuroepithelial bodies in neonatal rabbit
Authors: Fu X. W. , Nurse C. A. , Wong V. , Cutz E.
Published: July 2002

We examined the effects of hypoxia on the release of serotonin (5‐HT) from intact neuroepithelial body cells (NEB), presumed airway chemoreceptors, in rabbit lung slices, using amperometry with carbon fibre microelectrodes. Under normoxia (PO2∼155 mmHg; 1 mmHg ≈133 Pa), most NEB cells did not exhibit detectable secretory activity; however, hypoxia elicited a dose‐dependent (PO2 range 95–18 mmHg), tetrodotoxin (TTX)‐sensitive stimulation of spike‐like exocytotic events, indicative of vesicular amine release. High extracellular K+ (50 mm) induced a secretory response similar to that elicited by severe hypoxia. Exocytosis was stimulated in normoxic NEB cells after exposure to tetraethylammonium (20 mm) or 4‐aminopyridine (2 mm). Hypoxia‐induced secretion was abolished by the non‐specific Ca2+ channel blocker Cd2+ (100 μm). Secretion was also largely inhibited by the L‐type Ca2+ channel blocker nifedipine (2 μm), but not by the N‐type Ca2+ channel blocker ω‐conotoxin GVIA (1 μm). The 5‐HT3 receptor blocker ICS 205 930 also inhibited secretion from NEB cells under hypoxia. These results suggest that hypoxia stimulates 5‐HT secretion from intact NEBs via inhibition of K+ channels, augmentation of Na+‐dependent action potentials and calcium entry through L‐type Ca2+ channels, as well as by positive feedback activation of 5‐HT3 autoreceptors.
Evidence for two distinct processes in the final stages of neurotransmitter release as detected by binomial analysis in calcium and strontium solutions
Authors: Searl T. J. , Silinsky E. M.
Published: July 2002

The statistical parameters underlying acetylcholine (ACh) release were studied using Ca2+ and Sr2+ ions to promote ACh secretion. Experiments were performed at frog neuromuscular junctions using electrophysiological recording techniques. Increases in asynchronous ACh release, reflected as the frequency of occurrence of miniature end‐plate potentials (MEPPf), were evoked by high potassium depolarization in either Ca2+ or Sr2+ solutions. Increases in MEPPf mediated by Ca2+ were of very low probability and well‐described by a Poisson distribution whilst similar MEPPf increases mediated by Sr2+ were best described as a simple binomial distribution. From the binomial distribution in Sr2+ solutions, values for the average probability of release (p) and the number of releasable ACh quanta (n) may be determined (whereby mean MEPPf=np). In Sr2+ solutions, values of p were independent of both bin width and of the value of n, suggesting that both n and p were stationary. Calculations of p using the simple binomial distribution in Sr2+ solutions gave theoretical values for the third moment of the mean which were indistinguishable from the experimental distribution. These results, in conjunction with Monte Carlo simulations of the data, suggest that spatial and temporal variance do not measurably affect the analysis. Synchronous ACh release evoked by nerve impulses (end‐plate potentials, EPPs) follow a simple binomial distribution in both Ca2+ and Sr2+ solutions. Similar mean levels of synchronous ACh release (m, where m=np) were produced by lower values of p and higher values of n in Ca2+ as compared to Sr2+. The statistical analyses suggest the presence of two different Ca2+‐dependent steps in the final stages of neurotransmitter release. The results are discussed in accordance with (i) statistical models for quantal neurotransmitter release, (ii) the role of Sr2+ as a partial agonist for evoked ACh release, and (iii) the specific loci that may represent the sites of Ca2+ and Sr2+ sensitivity.
Activity‐dependent bidirectional regulation of GABAA receptor channels by the 5‐HT4 receptor‐mediated signalling in rat prefrontal cortical pyramidal neurons
Authors: Cai Xiang , Flores‐Hernandez Jorge , Feng Jian , Yan Zhen
Published: July 2002

Emerging evidence has implicated a potential role for 5‐HT4 receptors in cognition and anxiolysis. One of the main target structures of 5‐HT4 receptors on ‘cognitive and emotional’ pathways is the prefrontal cortex (PFC). As GABAergic signalling plays a key role in regulating PFC functions, we examined the effect of 5‐HT4 receptors on GABAA receptor channels in PFC pyramidal neurons. Application of 5‐HT4 receptor agonists produced either an enhancement or a reduction of GABA‐evoked currents in PFC neurons, which are both mediated by anchored protein kinase A (PKA). Although PKA phosphorylation of GABAA receptor β3 or β1 subunits leads to current enhancement or reduction respectively in heterologous expression systems, we found that β3 and β1 subunits are co‐expressed in PFC pyramidal neurons. Interestingly, altering PKA activation levels can change the direction of the dual effect, switching enhancement to reduction and vice versa. In addition, increased neuronal activity in PFC slices elevated the PKA activation level, changing the enhancing effect of 5‐HT4 receptors on the amplitude of GABAergic inhibitory postsynaptic currents (IPSCs) to a reduction. These results suggest that 5‐HT4 receptors can modulate GABAergic signalling bidirectionally, depending on the basal PKA activation levels that are determined by neuronal activity. This modulation provides a unique and flexible mechanism for 5‐HT4 receptors to dynamically regulate synaptic transmission and neuronal excitability in the PFC network.
Renal, cardiovascular and endocrine responses of fetal sheep at 0.8 of gestation to an infusion of amino acids
Authors: Marsh Amanda C. , Lumbers Eugenie R. , Gibson Karen J.
Published: July 2002

Amino acid infusions increase renal blood flow (RBF) and glomerular filtration rate (GFR) and stimulate tubular reabsorption in adults. To characterize the effects of amino acids on fetal renal haemodynamics, tubular sodium reabsorption, acid‐base homeostasis and plasma renin levels, 11 chronically catheterized fetal sheep aged 121 ± 1 days (term ∼150 days) were infused i.vfor 4 h with alanine, glycine, proline and serine (0.1, 0.1, 0.06 and 0.06 mmol min−1, respectively) in 0.15 m saline at 0.165 ml min−1. Eight control fetuses were given saline. During amino acid infusion, plasma amino acid levels increased up to 20‐fold (P < 0.005). GFR increased by 50 ± 8 % (P < 0.001); there was only a small transient increase in RBF. Proximal fractional sodium reabsorption fell from 74.6 ± 2.9 to 55.5 ± 5.4 % (P < 0.005). Distal sodium delivery increased, but a smaller percentage of this distal sodium load was reabsorbed (P < 0.005). Thus fractional sodium reabsorption fell from 95.5 ± 0.9 to 81.4 ± 2.0 % (P < 0.005). There was a large diuresis, natriuresis, kaliuresis and increase in osmolar excretion (P < 0.005). Plasma sodium and chloride concentrations fell (P < 0.005). Plasma osmolality did not change. Plasma renin levels fell (P < 0.05), cortisol levels increased (P < 0.05), and there was a compensated metabolic acidosis. Thus the fetal sheep kidney demonstrated a remarkable functional capacity to respond to amino acid infusion. The increase in filtration fraction and the lack of an increase in RBF suggest that efferent arteriolar vasoconstriction occurred, a very different response from the renal vasodilatation seen in adult animals.
Swept Surface Synthesis With Visibility
Authors: Wang Ming-En , Chen Lin-Lin , Woo Tony C.
Published: July 2002

The visibility of a surface has wide applications in manufacturing, where accessibility of the workpiece to the processing agent is of critical importance. A surface is visible to a direction d if for every point on the surface a line-of-sight can be established along d. Important applications, such as die-face design, arise in manufacturing where surfaces must be constructed visible to a given direction. In this paper we present a family of swept surfaces with built-in visibility. In particular, methods are laid out to build translational, rotational and spined sweeps visible to a given direction by sweeping monotone section curves. In these methods, minimal limitations are imposed besides those needed to avoid surface singularities. To increase modeling flexibility, the methods are extended to sweeps with distinct end sections and nonuniform scaling functions. [S1087-1357(00)00103-9]
Effective Elastic Properties of Porous Materials With Randomly Dispersed Pores: Finite Deformation
Authors: Levin V. A. , Lokhin V. V. , Zingerman K. M.
Published: July 2002

A method is developed for the analysis of the effective properties of porous nonlinear elastic materials with randomly distributed interacting pores under finite deformations. The method is based on the solution of the problems of nonlinear elasticity for a representative region using Signorini’s expansion. The constitutive equations for the matrix material and for the comparison material are written in a form corresponding to Murnaghan’s potential. The technique, which is used for ensemble averaging, approximately simulates the uniform distribution of pores. The computations are performed for plane strain, when pores are equal in size, and a circular cylindrical shape in the undeformed state is assumed. [S0021-8936(00)01802-X]
An Analytical Model to Predict Condensation of R-410A in a Horizontal Rectangular Channel
Authors: Guo Z. , Anand N. K.
Published: July 2002

An analytical model to predict condensation heat transfer coefficient in a horizontal rectangular channel was developed. The total local condensation heat transfer coefficient was represented as the weighted average of heat transfer coefficients for each wall. The analytical predictions compared well with the experimental data on the condensation of R-410A in a rectangular channel. The mean deviation was 6.75 percent. [S0022-1481(00)00503-X]
Feasibility of Contact Elimination of a Mechanical Face Seal Through Clearance Adjustment
Authors: Zou Min , Dayan Joshua , Green Itzhak
Published: July 2002

The feasibility of eliminating contact in a noncontacting flexibly mounted rotor (FMR) mechanical face seal is studied. The approach for contact elimination is based on a parametric study using FMR seal dynamics. Through clearance adjustment it is possible to reduce the maximum normalized relative misalignment between seal faces and, therefore, eliminate seal face contact. Clearance is measured by proximity probes and varied through a pneumatic adjustment mechanism. Contact is determined phenomenologically from pattern recognition of probe signals and their power spectrum densities as well as angular misalignment orbit plots, all calculated and displayed in real-time. The contact elimination strategy is experimentally investigated for various values of stator misalignment and initial rotor misalignment. Contrary to intuition but compliant with the parametric study, the experimental results show that for the seal under consideration contact can be eliminated through clearance reduction. [S0742-4795(00)01503-9]
Optimization of Pin-Fin Heat Sinks for Impingement Cooling of Electronic Packages
Authors: Kondo Y. , Matsushima H. , Komatsu T.
Published: July 2002

Optimization of pin-fin heat sinks for impingement cooling of electronic components was studied. The study was based on a semi-empirical zonal model for determining thermal resistance as well as pressure drop. To test the validity of the model’s predictions, experiments and flow visualization were performed. The experimental results validated the model. The model enables cost-effective designs to be calculated in order to optimize pin-fin heat sinks. These calculations took into consideration 16 design parameters including pin diameter, minimum spacing between pins, and fin height. For the particular blower considered in our study, the optimum pin diameter was found being 0.35 mm. And the characteristics and limitations of air-cooling for such applications were investigated under various conditions. [S1043-7398(00)01704-7]
Thermal Conduction and Viscous Heating in Microscale Couette Flows
Authors: Ju Y. Sungtaek
Published: July 2002

The direct simulation Monte Carlo (DSMC) method is used to investigate heat conduction and viscous heating in microscale Couette flows. When augmented by the slip boundary conditions, the continuum equations are found to predict thermal conductance accurately even in the transition and ballistic flow regime for Couette flows. The viscous heat generation rate, in contrast, is significantly underpredicted by the slip flow theory. We propose an alternative approach based on kinetic theory and present a compact analytic expression for the viscous dissipation rate. [S0022-1481(00)00104-3]
Thermal Conductivity Measurement of CVD Diamond Films Using a Modified Thermal Comparator Method
Authors: Cheruparambil K. R. , Farouk B. , Yehoda J. E. , Macken N. A.
Published: July 2002

Results from an experimental study on the rapid measurement of thermal conductivity of chemical vapor deposited (CVD) diamond films are presented. The classical thermal comparator method has been used successfully in the past for the measurement of thermal conductivity of bulk materials having high values of thermal resistance. Using samples of known thermal conductivity, a calibration curve is prepared. With this calibration curve, the comparator can be used to determine thermal conductivity of unknown samples. We have significantly modified and extended this technique for the measurement of materials with very low thermal resistance, i.e., CVD diamond films with high thermal conductivity. In addition to the heated probe, the modified comparator employs a thermoelectric cooling element of increase conductive heat transfer through the film. The thermal conductivity measurements are sensitive to many other factors such as the thermal contact resistances, anisotropic material properties, surrounding air currents and temperature, and ambient humidity. A comprehensive numerical model was also developed to simulate the heat transfer process for the modified comparator. The simulations were used to develop a “numerical” calibration curve that agreed well with the calibration curve obtained from our measurements. The modified method has been found to successfully measure the thermal conductivity of CVD diamond films. [S0022-1481(00)00804-5]
Identification of Mistuning Characteristics of Bladed Disks From Free Response Data— Part II
Authors: Rivas-Guerra A. J. , Mignolet M. P. , Delor J. P.
Published: July 2002

The focus of the present two-part investigation is on the estimation of the dynamic properties, i.e., masses, stiffnesses, natural frequencies, mode shapes and their statistical distributions, of turbomachine blades to be used in the accurate prediction of the forced response of mistuned bladed disks. As input to this process, it is assumed that the lowest natural frequencies of the blades alone have been experimentally measured, for example in a broach block test. Since the number of measurements is always less than the number of unknowns, this problem is indeterminate in nature. In this second part of the investigation, the maximum likelihood method (ML) will first be revisited and a thorough assessment of its reliability in a wide variety of conditions, including the presence of measurement noise, different distributions of blade structural properties, etc., will be conducted. Then, a technique that provides a bridge between the two identification methods introduced in Part I, i.e., the random modal stiffnesses (RMS) and maximum likelihood (ML) approaches, will be presented. This technique, termed the improved random modal stiffnesses (IRMS) method is based on the maximum likelihood concepts but yields a mistuning model similar to that of the random modal stiffnesses technique. Finally, the accuracy of the RMS, ML, and IRMS methods in predicting the forced response statistics of mistuned bladed disks will be investigated in the presence of close blade alone natural frequencies.