bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional development and the tasks of vocational education and training professionals
Authors: Santema Martinus
Published: July 2002

The EUROPROF project has as a broad aim the development of new programmes for the education of vocational education and training (VET) professionals. To achieve this aim the project has developed a new methodology of collaborative research between researchers in different regions and countries. The project has explored the influence of regional development on vocational education and training. Looks at the development of the Dutch vocational education and training system and the motivation and possibilities for cross‐border co‐operation between The Netherlands and Germany. Examines the different ideas and research traditions in different institutions and countries as a basis for mutual learning and collaboration.
Understanding and managing diversity among groups at work: key issues for organisational training and development
Authors: Moore Sarah
Published: July 2002

Explores the concept of diversity in organisational settings, reviewing a variety of key and associated concepts. The concept of diversity is explained as being context dependent, selective and relative. The links between diversity and performance are discussed and the implications for diversity supportive organisational development are explored. The need for support policies, networks, mentors and role models is identified. Finally the issues, barriers and implications associated with the introduction of diversity training are investigated.
Innovation and creativity in organisations: a review of the implications for training and development
Authors: Roffe Ian
Published: July 2002

Reviews the contributions to the understanding of creativity and innovation in organisations and interprets the implications for training and development. Highlights key and recurrent principles: the benefits of an integrated organisational approach, the right climate for creativity, appropriate incentives for innovators, a structured means of search and a systematic way to convert an opportunity into an innovation. It implies a broad range of skills development including: team working, communications, coaching, project management, learning to learn, visioning, change management and leadership. Even though techniques for the development of innovation and enhancing creativity in individuals are well founded, there are relatively few reports on the practice of mainstreaming creativity in an organisational setting. Likewise, although the transition from idea to innovation can be systematised, problems arise from customised applications that involve the management of the change process. The application of Internet and intranet communications for innovation are beginning to emerge but the literature base lags the speed of applications. The paper concludes with a synopsis of the training and development implications of stimulating creativity and innovation in organisations.
Low‐cost multipurpose coatings from alkyd‐ketonic blends
Authors: Athawale V.D. , Chamankar A.V.
Published: July 2002

Reports a comprehensive study of the effects of blend ratios (aliphatic alkyd and cyclohexanone formaldehyde resins) on coating properties. Solvent and drier systems used for preparation of blends are also included in the present work. The properties studied were hardness, adhesion, flexibility, gloss, storage stability, impact resistance, chemical resistance and drying time. A blend ratio of 50:50 (w/w) aliphatic alkyd‐ketonic resins showed a significant improvement in adhesion, hardness, gloss, storage stability and acid resistance.
The communication experiences of education managers: identifying strengths, weaknesses and critical incidents
Authors: Hunt Orlagh , Tourish Dennis , Hargie Owen D.W.
Published: July 2002

Education managers from various education settings were asked to record the three most typical work‐related incidents of communication within a specified time‐frame. They were also asked to identify the strengths and weaknesses of communication practices at work. The resultant data provide insight into the existing communication climate within education organisations, and the problems which need to be overcome. Specifically, the main findings were of persistent communication problems between managers and staff, the organisation of meetings, the transmission of information and the use of appropriate communication channels. The data suggest that there is a need for improved communication to facilitate the more effective management of education organisations, and to improve relationships between education managers and their staff. Greater communication skills training for managers is therefore recommended. This paper also considers areas where further research is indicated.
Restructuring schools in Malta: the road to improvement
Authors: Bezzina Christopher
Published: July 2002

Examines a process of how schools and their members can develop the capacity to reflect on the nature and purpose of their work together. The focus is on school‐site management practices as the way forward to improve the quality of education being provided. Argues that for schools to function better, a professional culture which offers choice, authority and responsibility through more decision‐making powers and a participative structure at school level needs to be nurtured. Proposes that a combination of top‐down and bottom‐up strategies to improvement needs to be encouraged as against purely a top‐down or bottom‐up approach. Also proposes a framework for professional development at school‐site level.
An insight into elementary principalship in Cyprus: the teachers’ perspective
Authors: Pashiardis Petros , Orphanou Stelios
Published: July 2002

Explores the perceptions of elementary school teachers regarding their principals and their leadership styles. The underlying and guiding) assumption for this project was that the effectiveness of a leader mainly depended on how others view him/her as a leader. As indicated in the results, teachers have a positive attitude towards their principals in general, but there are some areas where principals need to improve, such as, personnel management and professional growth and development. Furthermore, the bureaucratic and highly centralized structure of the Cyprus educational system proved to be ineffective and should be abandoned. Principals must be given motives for self‐improvement.
The commercialisation of public sector information within UK government departments
Authors: Abd Hadi Zakaria , McBride Neil
Published: July 2002

Reports that there are increasing trends towards the commercialisation of public sector information. Explains the concepts of information trading and discusses the role of the public sector. Describes three case studies within the UK government. Identifies the lack of a uniform approach to information trading within UK government departments in terms of attitudes to information provision, information costing and pricing and the resourcing of an information trading function. Discusses issues concerning the national and departmental policy on information distribution and trading; the resourcing and management of information technology to support the information trading function; the development of an information‐aware culture within the government and its departments and the development of contractual relationships with marketing agents within the private sector. Examines the effect of online information provision on information trading. Discusses the application of agency theory to the study of the role of marketing agents and identifies their importance in the development of a public sector information trading market. Concludes that there is a lack of clear direction for government departments concerning information trading.
Development of three‐dimensional apparel CAD system
Authors: Kang Tae J. , Min Kim Sung
Published: July 2002

A fast response three dimensional garment drape shape prediction system has been developed. A human body model generator has been established for the garment draping on it. For the mass production of different size of garments for the various sized body models, the cross‐sectional value from the anthropometric data was used as the standard for the size accommodation to make a resizable human body model. To construct the cloth drape shape prediction system, the finite element analysis method has been utilized. The designed garment pieces were divided into fine quadrilateral elements using a specially coded mesh generating program, then some appropriate sewing conditions were assigned to transform two dimensional patterns into three dimensional shapes. The final drape shape of the garment was determined from the solutions of the contact condition with human body, deformations, and the weights of the elements constituting the garment pieces, as well as the surface texture of the cloth.
A Study of Thread Tensions on a Lockstitch Sewing Machine (Part I)
Authors: Ferreira F.B.N. , Harlock S.C. , Grosberg P.
Published: July 2002

A study of thread tensions on a lockstitch sewing machine was made, measuring simultaneously both the needle and bobbin thread tensions. Experiments were carried out under specified sewing conditions, whereby needle and bobbin thread tensioner adjustment, sewing speed, number of plies, fabric quality and sewing thread quality were varied in order to investigate the effect of these factors on the needle and bobbin thread tensions. The patterns of the thread tension traces obtained were analysed as well as the effect of these factors on the peak tensions detected on both thread tension traces. Four significant peak tensions on the needle thread tension trace and two significant peak tensions on the bobbin thread tension trace were detected, during a stitch cycle. It was found that no significant variations occurred as far as the timing and shape of the peak tensions were concerned. However, variations were detected in the peak tensions according to the sewing conditions, as expected. From the analysis of the data obtained, multiple regression equations were derived to predict, with a good degree of accuracy, the peak tensions generated, according to the sewing conditions.
Three models for garment simulation
Authors: Imaoka Haruki , Atkinson J.
Published: July 2002

Gives an overview of the technique of current garment simulation and of the problems for more advanced simulation. To simulate the behaviour of a garment, three important models are usually used. They are: a garment model, a human body and an environment model. The models and the interaction among them are discussed using the conceptual‐mathematical‐posed problem structure of a model proposed by Barzel (1992).
Aspiring and Practising Principals′ Perceptions of Critical Skills for
Beginning Leaders
Authors: Daresh John C. , Playko Marsha A.
Published: July 2002

As a result of increasing attention to the problems faced by beginning
school leaders around the world, this study was conducted to determine
the nature of skills needed by beginning principles in the USA. Data
were collected from both practising and aspiring principals. It was
determined that there are major perceptual differences between these two
groups with regard to essential skills for principals. Aspiring
administrators believe that demonstration of technical skills is most
important, while their experienced colleagues believe that it is more
important for novices to show socialization and self‐awareness skills.
Based on these findings, notes implications for the improvement of
pre‐service, induction and in‐service programmes for school
administrators.
School managerial control: validating a social concept
Authors: Bogotch Ira E. , Williams Paul , Hale Jim
Published: July 2002

School managerial control is derived from perceptions of behavioural interactions between teachers and administrators along two dimensions: regular patterns of formal and informal structures and rules; and discretionary behaviours reflecting the quality of managerial performance. Analyses the interactive effects of these two dimensions across processes of control labelled as standards, information processing, assessments and incentives – all within the task domain of curriculum and instruction. The discussion of structure and discretion is significant in terms of the relationship, seemingly contradictory, between uniform guidelines of administrative practice and qualitative discretion.
Contaminant transfer during the processing of thick three‐layer food packages with a recycled polymer between two virgin polymer layers
Authors: Perou A.L. , Vergnaud J.M.
Published: July 2002

Studies are made on food three‐layer packages, where a contaminated recycled polymer layer is located between two virgin polymer layers. As the thick food packages are made by pressing the polymer layers in a mould kept at around the melting temperature of the polymer, the process is thus rather complex with heat transfer and contaminant transfer. Heat transfer is controlled by conduction through the package with a high coefficient of heat transfer in the mould, and conduction through the package and free convection at the surface during the cooling period in motionless air. The contaminant transfer is controlled by diffusion through the polymer with a temperature‐dependent diffusivity. A numerical model taking into account both the heat and mass transfer is built in order to resolve the problem. Various parameters appear of interest, such as the conditions of the processing with the temperature of the mould and time in the mould, the thicknesses of the polymer layers. Two types of sandwich are considered with different thicknesses for each layer. The profiles of concentration of the contaminant are obtained through the polymer packages.
Disaster business continuity: promoting staff capability
Authors: Paton Douglas
Published: July 2002

The object of business continuity planning is minimising loss after a disaster. Achieving this goal requires that management and information systems are available to facilitate the recovery of core business operations as soon as possible. While safeguarding systems and/or arranging for substitutes is vital, it is equally important to ensure the availability of staff capable of operating these system under adverse disaster conditions. Adopting a human resource perspective, this paper discusses the implications of staff vulnerability, hazard and risk assessment, organisational systems, training and recovery management for disaster business continuity.
Along came a spider ‐ weaving Web resources
Authors: Butler John C.
Published: July 2002

Internet‐based course resources have been used for three years in a freshman‐level course in physical geology at the University of Houston. Although access to the Internet is available on campus in computer clusters and in the library, an increasing percentage of students now have access where they live. Similarly, an increasing number of students possess sufficient computing skills to make immediate use of the Internet as an adjunct to texts, course notes and formal lectures. Students are free to pick and choose among most of the course resources (the syllabus, course notes, course outline, virtual field trips among others) but are required to use the Internet to obtain the homework exercises, gather the required data, and interpret their findings. In addition, the student is responsible for anything “extra” which appears from time‐to‐time during the course. Has the use of Internet‐based resources added value to the course? Meaningful communication has been facilitated through e‐mail exchanges and responses to surveys designed to sample student preparation, expectations, attitude toward the course and toward higher education in general. Internet‐based homework affords students the opportunity to be actively involved in making observations, gathering data and interpretation. Perhaps learning how they will learn in the future will turn out to be the undergraduate student’s most lasting benefit of this experiment with creating a learning environment via the Internet.
From Dewey to Mosaic :considerations in interface design for
children
Authors: Jacobson Frances F.
Published: July 2002

Examines the characteristics of bibliographic information retrieval
systems, particularly online public access systems, in terms of the
difficulties children have in using them. The specialized focus of
library and information science, the highly abstract nature of
bibliographic representation, and the evolving cognitive development of
children are all contributing factors to these difficulties. Describes
recent research and development in interface design, followed by
implications for the design of Internet navigators. The new generation
of Internet browsers can give students the ability not only to search
for information, but also to create and disseminate information using
the same medium. Such capacity adds a significant dimension and new
meaning to the concept of information retrieval. Concludes that
thoughtful and developmentally appropriate interface design is critical
to the success of children′s use of this powerful new resource.
The first decade of behavioral research in the discipline of property
Authors: Diaz Julian
Published: July 2002

This paper examines behavioral research in property. Such research is relatively new in the property field and is still in its first decade. The behavioral approach is examined and compared with the more traditional approach. Its aims and its accomplishments are also discussed. The previous literature upon the subject is examined and the future of behavioral research in property is alluded to as a conclusion.
Testing the role of chain connectivity on the stability and structure of dihydrofolate reductase fromE. coli: Fragment complementation and circular permutation reveal stable, alternatively folded forms
Authors: Smith Virginia F. , Matthews C. Robert
Published: July 2002

The effects of chain cleavage and circular permutation on the structure, stability, and activity of dihydrofolate reductase (DHFR) fromEscherichia coliwere investigated by various spectroscopic and biochemical methods. Cleavage of the backbone after position 86 resulted in two fragments, {1–86} and {87–159}, each of which are poorly structured and enzymatically inactive. When combined in a 1 : 1 molar ratio, however, the fragments formed a high‐affinity (Ka= 2.6 × 107M−1) complex that displays a weakly cooperative urea‐induced unfolding transition at micromolar concentrations. The retention of about 15% of the enzymatic activity of full‐length DHFR is surprising, considering that the secondary structure in the complex is substantially reduced from its wild‐type counterpart. In contrast, a circularly permuted form with its N‐terminus at position 86 has similar overall stability to full‐length DHFR, about 50% of its activity, substantial secondary structure, altered side‐chain packing in the adenosine binding domain, and unfolds via an equilibrium intermediate not observed in the wild‐type protein. After addition of ligand or the tight‐binding inhibitor methotrexate, both the fragment complex and the circular permutant adopt more native‐like secondary and tertiary structures. These results show that changes in the backbone connectivity can produce alternatively folded forms and highlight the importance of protein‐ligand interactions in stabilizing the active site architecture of DHFR.
Disulfide bond effects on protein stability: Designed variants of Cucurbita maxima trypsin inhibitor‐V
Authors: Zavodszky Maria , Chen Chao‐Wei , Huang Jenq‐Kuen , Zolkiewski Michal , Wen Lisa , Krishnamoorthi Ramaswamy
Published: July 2002

Attempts to increase protein stability by insertion of novel disulfide bonds have not always been successful. According to the two current models, cross‐links enhance stability mainly through denatured state effects. We have investigated the effects of removal and addition of disulfide cross‐links, protein flexibility in the vicinity of a cross‐link, and disulfide loop size on the stability of Cucurbita maxima trypsin inhibitor‐V (CMTI‐V; 7 kD) by differential scanning calorimetry. CMTI‐V offers the advantage of a large, flexible, and solvent‐exposed loop not involved in extensive intra‐molecular interactions. We have uncovered a negative correlation between retention time in hydrophobic column chromatography, a measure of protein hydrophobicity, and melting temperature (Tm), an indicator of native state stabilization, for CMTI‐V and its variants. In conjunction with the complete set of thermodynamic parameters of denaturation, this has led to the following deductions: (1) In the less stable, disulfide‐removed C3S/C48S (ΔΔGd50°C = −4 kcal/mole; ΔTm = −22°C), the native state is destabilized more than the denatured state; this also applies to the less‐stable CMTI‐V* (ΔΔGd50°C = −3 kcal/mole; ΔTm = −11°C), in which the disulfide‐containing loop is opened by specific hydrolysis of the Lys44‐Asp45 peptide bond; (2) In the less stable, disulfide‐inserted E38C/W54C (ΔΔGd50°C = −1 kcal/mole; ΔTm = +2°C), the denatured state is more stabilized than the native state; and (3) In the more stable, disulfide‐engineered V42C/R52C (ΔΔGd50°C = +1 kcal/mole; ΔTm = +17°C), the native state is more stabilized than the denatured state. These results show that a cross‐link stabilizes both native and denatured states, and differential stabilization of the two states causes either loss or gain in protein stability. Removal of hydrogen bonds in the same flexible region of CMTI‐V resulted in less destabilization despite larger changes in the enthalpy and entropy of denaturation. The effect of a cross‐link on the denatured state of CMTI‐V was estimated directly by means of a four‐state thermodynamic cycle consisting of native and denatured states of CMTI‐V and CMTI‐V*. Overall, the results show that an enthalpy‐entropy compensation accompanies disulfide bond effects and protein stabilization is profoundly modulated by altered hydrophobicity of both native and denatured states, altered flexibility near the cross‐link, and residual structure in the denatured state.
A “loop entropy reduction” phage‐display selection for folded amino acid sequences
Authors: Minard Philippe , Scalley‐Kim Michelle , Watters Alex , Baker David
Published: July 2002

As a step toward selecting folded proteins from libraries of randomized sequences, we have designed a ‘loop entropy reduction’‐based phage‐display method. The basic premise is that insertion of a long disordered sequence into a loop of a host protein will substantially destabilize the host because of the entropic cost of closing a loop in a disordered chain. If the inserted sequence spontaneously folds into a stable structure with the N and C termini close in space, however, this entropic cost is diminished. The host protein function can, therefore, be used to select folded inserted sequences without relying on specific properties of the inserted sequence. This principle is tested using the IgG binding domain of protein L and the lck SH2 domain as host proteins. The results indicate that the loop entropy reduction screen is capable of discriminating folded from unfolded sequences when the proper host protein and insertion point are chosen.
A model of dynamic side‐chain–side‐chain interactions in the α‐lactalbumin molten globule
Authors: Bai Ping , Song Jianxing , Luo Li , Peng Zheng‐Yu
Published: July 2002

Proteins in the molten globule state contain high levels of secondary structure, as well as a rudimentary, nativelike tertiary topology. Thus, the structural similarity between the molten globule and native proteins may have a significant bearing in understanding the protein‐folding problem. To explore the nature of side‐chain–side‐chain interactions in the α‐lactalbumin (α‐LA) molten globule, we determined the effective concentration for formation of the 28–111 disulfide bond in 14 double‐mutant proteins, each containing two hydrophobic core residues replaced by alanine. We compared our results with those of single‐alanine substitutions using the framework of double‐mutant cycle analysis and found that, in the majority of cases, the effects of two alanine substitutions are additive. Based on these results, we propose a model of side‐chain–side‐chain interactions in the α‐LA molten globule, which takes into consideration the dynamic nature of this partially folded species.
Direct comparison of binding equilibrium, thermodynamic, and rate constants determined by surface‐ and solution‐based biophysical methods
Authors: Day Yasmina S.N. , Baird Cheryl L. , Rich Rebecca L. , Myszka David G.
Published: July 2002

The binding interactions of small molecules with carbonic anhydrase II were used as model systems to compare the reaction constants determined from surface‐ and solution‐based biophysical methods. Interaction data were collected for two arylsulfonamide compounds, 4‐carboxybenzenesulfonamide (CBS) and 5‐dimethyl‐amino‐1‐naphthalene‐sulfonamide (DNSA), binding to the enzyme using surface plasmon resonance, isothermal titration calorimetry, and stopped‐flow fluorescence. We demonstrate that when the surface plasmon resonance biosensor experiments are performed with care, the equilibrium, thermodynamic, and kinetic constants determined from this surface‐based technique match those acquired in solution. These results validate the use of biosensor technology to collect reliable data on small molecules binding to immobilized macromolecular targets. Binding kinetics were shown to provide more detailed information about complex formation than equilibrium constants alone. For example, although carbonic anhydrase II bound DNSA with twofold higher affinity than CBS, kinetic analysis revealed that CBS had a fourfold slower dissociation rate. Analysis of the binding and transition state thermodynamics also revealed significant differences in the enthalpy and entropy of complex formation. The lack of labeling requirements, high information content, and high throughput of surface plasmon resonance biosensors will make this technology an important tool for characterizing the interactions of small molecules with enzymes and receptors.
The Valuation of American Options on Multiple Assets
Authors: Broadie Mark , Detemple Jérôme
Published: July 2002

In this paper we provide valuation formulas for several types of American options on two or more assets. Our contribution is twofold. First, we characterize the optimal exercise regions and provide valuation formulas for a number of American option contracts on multiple underlying assets with convex payoff functions. Examples include options on the maximum of two assets, dual strike options, spread options, exchange options, options on the product and powers of the product, and options on the arithmetic average of two assets. Second, we derive results for American option contracts with nonconvex payoffs, such as American capped exchange options. For this option we explicitly identify the optimal exercise boundary and provide a decomposition of the price in terms of a capped exchange option with automatic exercise at the cap and an early exercise premium involving the benefits of exercising prior to reaching the cap. Besides generalizing the current literature on American option valuation our analysis has implications for the theory of investment under uncertainty. A specialization of one of our models also provides a new representation formula for an American capped option on a single underlying asset.
Acute synaptic modulation by nicotinic agonists in developing cerebellar Purkinje cells of the rat
Authors: Kawa Kazuyoshi
Published: July 2002

The synaptic properties of the immature mammalian cerebellum were studied with a focus on the nicotinic modulation of synaptic transmission. Synaptic currents in Purkinje neurones were recorded using whole‐cell patch electrodes applied to cerebellar slices (200 μm thick) obtained from newborn rats at postnatal days 5–10 (P5–P10). When the membrane potential of a Purkinje cell was held at −40 mV, spontaneous synaptic currents occurring in the cell comprised both inward and outward components. The former was glutamatergic and the latter was GABAergic, as confirmed by measuring reversal potentials and by using the specific glutamate and GABA blockers, 6‐cyano‐7‐nitroquinoziline‐2,3‐dione and bicuculline, respectively. Application of ACh (0.1–1000 μm) from a ‘Y tube’ enhanced the occurrence of both glutamatergic and GABAergic synaptic currents in Purkinje cells. These responses appeared within 1 s after the application of ACh, and they were mimicked by nicotinic agonists (10 μm nicotine, 10 μm cytisine, 10 μm 1,1‐dimethyl‐4‐phenyl‐piperazinium iodide, or 10 nm epibatidine), but were sensitive to a specific nicotinic antagonist (1 μm dihydro‐β‐erythroidine). When the generation of action potentials by cerebellar neurones in the slice preparation was blocked by the addition of TTX (1 μm) to the external saline, these ACh‐induced responses almost disappeared. This indicates that the enhanced synaptic activities in Purkinje cells are induced via presynaptic nicotinic receptors on the excitatory and inhibitory interneurones, presumably on the proximal axons or somatodendritic domains of granule cells and basket cells in the cerebellar cortex. Interestingly, these nicotinic effects were remarkable in immature rats (P5–P10), but were barely detectable in older rats (more than 10 days of age), indicating that nicotinic ACh receptors are regulated developmentally and may play a novel role in the maturing cerebellum.
Rapid actions of 17β‐oestradiol on a subset of lactotrophs in the rat pituitary
Authors: Christian H. C. , Morris J. F.
Published: July 2002

Increasingly the role of rapid mechanisms of steroid action in physiological regulation are being recognised. We have investigated rapid effects of 17β‐oestradiol (E) on prolactin (PRL) release in vitro. Pituitary segments from male rats were incubated for 5, 10 or 20 min in Earle's balanced salt solution containing 1.2 mm tannic acid (to enable visualisation of exocytosed secretory granules by electron microscopy) either alone (control) or containing 10−10‐10−8m E conjugated to bovine serum albumin (E‐BSA). PRL and leuteinising hormone (LH) release from pituitary segments were also determined in response to E and E‐BSA by radioimmunoassay. Within 10 min E‐BSA and E (10−12‐10−6m) stimulated a significant (P < 0.05) concentration‐dependent release of PRL but not LH. After exposure to experimental media for 5 min, only occasional exocytosis from type I lactotrophs (characterised by large polymorphic secretory granules) was observed in either control or E‐BSA treated tissue. In contrast, E‐BSA (10−10‐10−8m) induced a significant (P < 0.05) increase in the number of exocytotic profiles from type II lactotrophs (characterized by smaller, spherical granules). This effect was not inhibited by removal of extracellular calcium, or by pre‐treatment of cells with the RNA synthesis inhibitor actinomycin‐D (0.5 μg ml−1), the protein synthesis inhibitor cycloheximide (1 μg ml−1) or the anti‐oestrogen ICI 182,780 (1 μm). FACS analysis demonstrated binding of E‐BSA‐fluorescein isothiocyanate (FITC) (10−10‐10−7m) to a subpopulation of anterior pituitary cells. The E‐BSA‐FITC binding sites assumed a patchy distribution across the cell surface. In conclusion, we report for the first time a rapid, non‐genomic effect of E on PRL secretion in normal pituitary tissue.
The role of histidine residues in modulation of the rat P2X2 purinoceptor by zinc and pH
Authors: Clyne J. Dylan , LaPointe Lisa D. , Hume Richard I.
Published: July 2002

P2X2 receptor currents are potentiated by acidic pH and zinc. To identify residues necessary for proton and zinc modulation, alanines were singly substituted for each of the nine histidines in the extracellular domain of the rat P2X2 receptor. Wild‐type and mutant receptors were expressed in Xenopus oocytes and analysed with two‐electrode voltage clamp. All mutations caused less than a 2‐fold change in the EC50 of the ATP concentration‐response relation. Decreasing the extracellular pH from 7.5 to 6.5 potentiated the responses to 10 μm ATP of wild‐type P2X2 and eight mutant receptors more than 4‐fold, but the response of the mutant receptor H319A was potentiated only 1.4‐fold. The H319A mutation greatly attenuated the maximal potentiation that could be produced by a drop in pH, shifted the pKa (‐log of dissociation constant) of the potentiation to a more basic pH as compared with P2X2 and revealed a substantial pH‐dependent decrease in the maximum response with a pKa near 6.0. Substituting a lysine for H319 reduced the EC50 for ATP 40‐fold. Zinc (20 μm) potentiated the responses to 10 μm ATP of wild‐type P2X2 and seven histidine mutants by ∼8‐fold but had virtually no effect on the responses of two mutants, H120A and H213A. Neither H120A nor H213A removed the voltage‐independent inhibition caused by high concentrations of zinc. The observation that different mutations selectively eliminated pH or zinc potentiation implies that there are two independent sites of action, even though the mechanisms of pH and zinc potentiation appear similar.
Facilitation of intracellular H+ ion mobility by CO2/HCO3− in rabbit ventricular myocytes is regulated by carbonic anhydrase
Authors: Spitzer K. W. , Skolnick R. L. , Peercy B. E. , Keener J. P. , Vaughan‐Jones R. D.
Published: July 2002

Intracellular H+ mobility was estimated in the rabbit isolated ventricular myocyte by diffusing HCl into the cell from a patch pipette, while imaging pHi confocally using intracellular ratiometric SNARF fluorescence. The delay for acid diffusion between two downstream regions ≈40 μm apart was reduced from ≈25 s to ≈6 s by replacing Hepes buffer in the extracellular superfusate with a 5 % CO2/HCO3− buffer system (at constant pHo of 7.40). Thus CO2/HCO3− (carbonic) buffer facilitates apparent H+i mobility. The delay with carbonic buffer was increased again by adding acetazolamide (ATZ), a membrane permeant carbonic anhydrase (CA) inhibitor. Thus facilitation of apparent H+i mobility by CO2/HCO3− relies on the activity of intracellular CA. By using a mathematical model of diffusion, the apparent intracellular H+ equivalent diffusion coefficient (DHapp) in CO2/HCO3−‐buffered conditions was estimated to be 21.9 × 10−7 cm2 s−1, 5.8 times faster than in the absence of carbonic buffer. Facilitation of H+i mobility is discussed in terms of an intracellular carbonic buffer shuttle, catalysed by intracellular CA. Turnover of this shuttle is postulated to be faster than that of the intrinsic buffer shuttle. By regulating the carbonic shuttle, CA regulates effective H+i mobility which, in turn, regulates the spatiotemporal uniformity of pHi. This is postulated to be a major function of CA in heart.
Evaluating Cutting Fluid Effects on Cylinder Boring Surface Errors by Inverse Heat Transfer and Finite Element Methods
Authors: Zheng Y. , Li H. , Olson W. W. , Sutherland J. W.
Published: July 2002

Sets of dry and wet boring experiments are conducted to estimate the amount of heat transferred into the workpiece and the cutting fluid heat convection coefficient in a boring operation by an inverse heat transfer method. The temperature distribution in the bore is predicted using a heat transfer model that includes heat convection on the inner and outer bore walls. The developed model is solved by an integral transform approach. The thermal expansion of the bore is then calculated using the finite element method (FEM). Surface error due to the cutting forces is also predicted using FEM and added to the thermally induced surface error to give the total surface error. The actual surface error of bores machined under dry and wet cutting conditions are measured and compared with the predicted surface error. Very good agreement between measured and predicted surface errors is observed. [S1087-1357(00)00802-9]
Evaluation of Minimum Zone Straightness by a Nonlinear Optimization Method
Authors: Orady Elsayed , Li Songnian , Chen Yubao
Published: July 2002

In this paper, a new algorithm, based on a nonlinear optimization method (NOM), has been developed. The accuracy as well as the reliability/robustness of the new algorithm have been verified by applying it to more than 200 CMM measured data sets on differently manufactured parts. The results have been compared with that of Least Squares Method (LSM) and Convex Hull (CVH) method applied to the same data sets. A data filter is proposed to be enclosed in the new algorithm to detect and delete outliers in the data sets. [S1087-1357(00)01102-3]
Ingredient-Wise Study of Flux Characteristics in the Ceramic Membrane Filtration of Uncontaminated Synthetic Metalworking Fluids, Part 1: Experimental Investigation of Flux Decline
Authors: Skerlos Steven J. , Rajagopalan N. , DeVor Richard E. , Kapoor Shiv G. , Angspatt V. Don
Published: July 2002

Membrane Filtration (MF) technology can remove microbes, particulates, and tramp oils that contaminate metalworking fluids (MWFs). Consequently MF has the potential to reduce health risks and extend MWF life in the machine tool industry. This research assesses the productivity of ceramic membrane filters during filtration of synthetic MWFs and examines the contribution of MWF chemical ingredients to productivity decline. The majority of the chemistry comprising typical synthetic MWFs has negligible impact on MF productivity. However, specialty additives such as lubricants, defoamers, and biocides can significantly reduce MF productivity. Results show that slight variations in formulation can dominate the productivity of the process. Specialty additives can also impart residual effects on the membrane that adversely impact productivity in subsequent applications of the ceramic membrane. [S1087-1357(00)01103-5]
Bond Graph Model of a Squirrel Cage Induction Motor With Direct Physical Correspondence
Authors: Kim Jongbaeg , Bryant Michael D.
Published: July 2002

An existing bond graph of a squirrel cage induction motor was modified to make the bond graph physically more representative. The intent was to form a one-to-one correspondence between motor components and bond graph elements. Components explicitly represented include the stator coils, the squirrel cage rotor bars, and the magnetic flux routing section. The final bond graph spans electrical, magnetic, and mechanical energy domains, and contains common motor faults. From this bond graph. state equations were extracted and simulations performed. Simulated were the response of healthy motors, and motors with shorted stator coils and broken rotor bars. [S0022-0434(00)01203-X]
A Method for Attachment Design Concept Development in Integral Snap-fit Assemblies
Authors: Genc Suat , Messler, Robert W. , Gabriele Gary A.
Published: July 2002

The importance and foundation for attachment-level design of integral snap-fit assemblies was first pointed out by Bonenberger at General Motors [1–3]. Based on that work, a method was developed and tested and is presented here to identify and address important issues at the conceptual stage in a systematic way and generate alternative attachment concepts. The method starts by exploring the design space to generate as many concepts as possible [4]. Alternative concepts are generated by considering variations in attachment interface geometry, assembly procedures, actual snap-fit features, and options for fully constraining all parts of the assembly using locators beyond locks. In the last step, alternatives are evaluated using a quantitative tool, and a “best” attachment concept is selected based on design objectives for a particular application. Applying the method to case studies has confirmed that it is a useful design aid for efficiently generating, and evaluating, or simply checking attachment concepts. [S1050-0472(00)01003-5]
The Nonlinear Response of a Simply Supported Rectangular Metallic Plate to Transverse Harmonic Excitation
Authors: Elbeyli and O. , Anlas G.
Published: July 2002

In this study, the nonlinear response of a simply supported metallic rectangular plate subject to transverse harmonic excitations is analyzed using the method of multiple scales. Stability of solutions, critical points, types of bifurcation in the presence of a one-to-one internal resonance, together with primary resonance, are determined. [S0021-8936(00)00603-6]
Common Errors on Mapping of Nonelliptic Curves in Anisotropic Elasticity
Authors: Ting T. C. T.
Published: July 2002

For an isotropic elastic material under a two-dimensional plane-stress or plane-strain deformation that involves a closed boundary of a given geometry Γ, it is a common practice to use a conformal mapping to map Γ to a circle of unit radius. For an anisotropic elastic material, the mapping produces the correct solution to the physical problem when Γ is an ellipse. There are published (and unpublished) papers that report solutions to anisotropic elasticity problems with a nonelliptic curve Γ. They all fail to solve the physical problem correctly. The purpose of this paper is to show the common errors made by many researchers, and to alert newcomers on the subject so that they do not fall into the same trap. [S0021-8936(00)02403-X]
Influence of Flow Regime, Heat Flux, and Mass Flux on Electrohydrodynamically Enhanced Convective Boiling
Authors: Bryan J. E. , Seyed-Yagoobi J.
Published: July 2002

The influence of quality, flow regime, heat flux, and mass flux on the electrohydrodynamic (EHD) enhancement of convective boiling of R-134a in a horizontal smooth tube was investigated in detail. The EHD forces generated significant enhancements in the heat transfer coefficient, but the enhancements were highly dependent on the quality, flow regime, heat flux, and mass flux. The experimental data provided evidence that an optimum EHD enhancement exists for a given set of these variables with a specific electrode design. However, experimental data also provided evidence that the EHD forces can drastically reduce the rate of heat transfer at certain conditions
Modelling the Integrated Output of Mechanical Wind Pumps
Authors: Mathew Sathyajith , Pandey K. P.
Published: July 2002

A method for predicting output of simple multi-bladed windmill mechanically coupled to a reciprocating pump is proposed. The present method adopts an integrated approach by considering the interaction between the rotor, pump and the wind regime to model the wind pump discharge. The wind velocity-power relationship of the rotor is assumed to be quadratic. The wind regime is characterized by the Raleigh distribution. Differences in the starting and running torque requirements of the pump are also considered in the model. Wind data from a few potential sites from the southern part of India were analyzed and the expected outputs at these sites were predicted using the proposed method. [S0199-6231(00)00603-1]
Tissue-Level Thresholds for Axonal Damage in an Experimental Model of Central Nervous System White Matter Injury
Authors: Bain Allison C. , Meaney David F.
Published: July 2002

In vivo, tissue-level, mechanical thresholds for axonal injury were determined by comparing morphological injury and electrophysiological impairment to estimated tissue strain in an in vivo model of axonal injury. Axonal injury was produced by dynamically stretching the right optic nerve of an adult male guinea pig to one of seven levels of ocular displacement (Nlevel=10;Ntotal=70). Morphological injury was detected with neurofilament immunohistochemical staining (NF68, SMI32). Simultaneously, functional injury was determined by the magnitude of the latency shift of the N35 peak of the visual evoked potentials (VEPs) recorded before and after stretch. A companion set of in situ experiments Nlevel=5 was used to determine the empirical relationship between the applied ocular displacement and the magnitude of optic nerve stretch. Logistic regression analysis, combined with sensitivity and specificity measures and receiver operating characteristic (ROC) curves were used to predict strain thresholds for axonal injury. From this analysis, we determined three Lagrangian strain-based thresholds for morphological damage to white matter. The liberal threshold, intended to minimize the detection of false positives, was a strain of 0.34, and the conservative threshold strain that minimized the false negative rate was 0.14. The optimal threshold strain criterion that balanced the specificity and sensitivity measures was 0.21. Similar comparisons for electrophysiological impairment produced liberal, conservative, and optimal strain thresholds of 0.28, 0.13, and 0.18, respectively. With these threshold data, it is now possible to predict more accurately the conditions that cause axonal injury in human white matter. [S0148-0731(00)00906-7]
Dynamic Wetting: Displacement of the Contact Line Induced by Air Pressure Oscillations in Its Close Vicinity
Authors: Woehl P. , Bourgin P.
Published: July 2002

In most studies devoted to dynamic wetting, the viscosity of the ambient air is neglected compared with that of the liquid, which equivalently means that the surrounding air is considered to be static. However, the presence of air flows underneath the sheet leads to an increase of the pressure in the wedge formed by the liquid sheet and the solid substrate. The pressure deforms the interface and tends to separate the liquid sheet from the solid substrate. This is a coupled problem, the two unknown functions being the meniscus shape and the pressure generated in the air wedge. A simple model is proposed here to investigate the possible influence of slight pressure fluctuations in the air on the displacement of the contact line. This model incorporates the liquid wetting properties as well as parameters characteristic of the process and of the air pressure oscillations. The main result is that small amplitude pressure oscillations in the air close to the contact line may generate large lateral displacements of the contact line. At the same time, the air gap is reduced as compared to its value in the static case. [S0021-8936(00)01904-8]
A Sampled-Data Formulation for Boundary Control of a Longitudinal Elastic Bar
Authors: Su Wu-Chung , Drakunov Sergey V. , O¨zgu¨ner U¨mit
Published: July 2002

The sampled-data boundary control problem for a longitudinal flexible bar is formulated as a linear discrete-time control problem in an infinite-dimensional state space. With zero-order-hold applied to the control channel, the system is lifted into an infinite sequence of constant control problems. The finite-dimensional approximation of the discrete-time system is controllable-observable if the sampling period satisfies some inequality constraints, which are related to the associated eigenvalues.
Aerodynamic Loss Characteristics of a Turbine Blade With Trailing Edge Coolant Ejection: Part 2—External Aerodynamics, Total Pressure Losses, and Predictions
Authors: Uzol Oguz , Camci Cengiz
Published: July 2002

Investigation of the internal fluid mechanic losses for a turbine blade with trailing edge coolant ejection was present in Uzol et al. (2001). The current study is a detailed experimental investigation of the external subsonic flowfield near the trailing edge and the investigation of the external aerodynamic loss characteristics of the turbine blade with trailing edge coolant ejection system. Particle Image Velocimetry experiments and total pressure surveys in the near wake of the blade are conducted for two different Reynolds numbers and four different ejection rates. Two different trailing edge configurations with different cut-back lengths are also investigated. Numerical simulations of the flowfield are also performed for qualitative flow visualization purposes. Two-dimensional, incompressible, and steady solutions of Reynolds-averaged Navier–Stokes equations are obtained. A two-equation standard k-ε turbulence model coupled with an Algebraic Reynolds Stress Model is used for the simulation of the turbulent flowfield. The results show that the aerodynamic penalty levels in the wake region near the trailing edge are increased due to the mixing of the coolant and mainstream flows for 0–3 percent ejection rates. However, after a threshold level (5 percent ejection rate), the ejected coolant flow has enough momentum to fill the wake of the blade, which in turn results in a decrease in the aerodynamic penalty levels.