bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulatory Role of the N Terminus of the Vacuolar Calcium-ATPase in Cauliflower
Authors: Malmström Susanna , Åkerlund Hans-Erik , Askerlund Per
Published: July 2002

The vacuolar calmodulin (CaM)-stimulated Ca2+-ATPase, BCA1p, in cauliflower (Brassica oleracea) has an extended N terminus, which was suggested to contain a CaM-binding domain (S. Malmström, P. Askerlund, M.G. Palmgren [1997] FEBS Lett 400: 324–328). The goal of the present study was to determine the role of the N terminus in regulating BCA1p. Western analysis using three different antisera showed that the N terminus of BCA1p is cleaved off by trypsin and that the N terminus contains the CaM-binding domain. Furthermore, the expressed N terminus binds CaM in a Ca2+-dependent manner. A synthetic peptide corresponding to the CaM-binding domain of BCA1p (Ala-19 to Leu-43) strongly inhibited ATP-dependent Ca2+pumping by BCA1p in cauliflower low-density membranes, indicating that the CaM-binding region of BCA1p also has an autoinhibitory function. The expressed N terminus of BCA1p and a synthetic peptide (Ala-19 to Met-39) were good substrates for phosphorylation by protein kinase C. Sequencing of the phosphorylated fusion protein and peptide suggested serine-16 and/or serine-28 as likely targets for phosphorylation. Phosphorylation of serine-28 had no effect on CaM binding to the alanine-19 to methionine-39 peptide. Our results demonstrate the regulatory importance of the N terminus of BCA1p as a target for CaM binding, trypsin cleavage, and phosphorylation, as well as its importance as an autoinhibitory domain.
Ectoine, the Compatible Solute of Halomonas elongata, Confers Hyperosmotic Tolerance in Cultured Tobacco Cells
Authors: Nakayama Hideki , Yoshida Kazuya , Ono Hisayo , Murooka Yoshikatsu , Shinmyo Atsuhiko
Published: July 2002

1,4,5,6-Tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) functions as a compatible osmolyte in the moderate halophile Halomonas elongata OUT30018. Ectoine is biosynthesized by three successive enzyme reactions from aspartic β-semialdehyde. The genes encoding the enzymes involved in the biosynthesis, ectA, ectB, andectC, encoding l-2,4-diaminobutyric acid acetyltransferase, l-2,4-diaminobutyric acid transaminase, and l-ectoine synthase, respectively, have been previously cloned. To investigate the function of ectoine as a compatible solute in plant cells, the three genes were individually placed under the control of the cauliflower mosaic virus 35S promoter and introduced together into cultured tobacco (Nicotiana tabacum L.) cv Bright Yellow 2 (BY2) cells. The transgenic BY2 cells accumulated a small quantity of ectoine (14–79 nmol g−1 fresh weight) and showed increased tolerance to hyperosmotic shock (900 mOsm). Furthermore, the transgenic BY2 cells exhibited a normal growth pattern even under hyperosmotic conditions (up to 530 mOsm), in which the growth of the untransformed BY2 (wild type) cells was obviously delayed. These results suggest that genetically engineered synthesis of ectoine results in the increased hyperosmotic tolerance of cultured tobacco BY2 cells despite the low level of accumulation of the solute.
The Carboxyl-Terminal Extension of the Precursor D1 Protein of Photosystem II Is Required for Optimal Photosynthetic Performance of the Cyanobacterium Synechocystis sp. PCC 6803
Authors: Ivleva Natalia B. , Shestakov Sergey V. , Pakrasi Himadri B.
Published: July 2002

The D1 protein is an integral component of the photosystem II reaction center complex. In the cyanobacteriumSynechocystis sp. PCC 6803, D1 is synthesized with a short 16-amino acids-long carboxyl-terminal extension. Removal of this extension is necessary to form active oxygen-evolving photosystem II centers. Our earlier studies have shown that this extension is cleaved by CtpA, a specific carboxyl-terminal processing protease. The amino acid sequence of the carboxyl-terminal extension is conserved among D1 proteins from different organisms, although at a level lower than that of the mature protein. In the present study we have analyzed a mutant strain of Synechocystis sp. PCC 6803 with a duplicated extension, and a second mutant that lacks the extension, to investigate the effects of these alterations on the function of the D1 protein in vivo. No significant difference in the growth rates, photosynthetic pigment composition, fluorescence induction, and oxygen evolution rates was observed between the mutants and the control strain. However, using long-term mixed culture growth analysis, we detected significant decreases in the fitness of these mutant strains. The presented data demonstrate that the carboxyl-terminal extension of the precursor D1 protein is required for optimal photosynthetic performance.
Developmental Regulation of Indole-3-Acetic Acid Turnover in Scots Pine Seedlings
Authors: Ljung Karin , Östin Anders , Lioussanne Laetitia , Sandberg Göran
Published: July 2002

Indole-3-acetic acid (IAA) homeostasis was investigated during seed germination and early seedling growth in Scots pine (Pinus sylvestris). IAA-ester conjugates were initially hydrolyzed in the seed to yield a peak of free IAA prior to initiation of root elongation. Developmental regulation of IAA synthesis was observed, with tryptophan-dependent synthesis being initiated around 4 d and tryptophan-independent synthesis occurring around 7 d after imbibition. Induction of catabolism to yield 2-oxindole-3-acetic acid and irreversible conjugation to indole-3-acetyl-N-aspartic acid was noticed at the same time as de novo synthesis was first detected. As a part of the homeostatic regulation IAA was further metabolized to two new conjugates: glucopyranosyl-1-N-indole-3-acetyl-N-aspartic acid and glucopyranosyl-1-N-indole-3-acetic acid. The initial supply of IAA thus originates from stored pools of IAA-ester conjugates, mainly localized in the embryo itself rather than in the general nutrient storage tissue, the megagametophyte. We have found that de novo synthesis is first induced when the stored pool of conjugated IAA is used up and additional hormone is needed for elongation growth. It is interesting that when de novo synthesis is induced, a distinct induction of catabolic events occurs, indicating that the seedling needs mechanisms to balance synthesis rates for the homeostatic regulation of the IAA pool.
Two Types of Pea Leghemoglobin Genes Showing Different O2-Binding Affinities and Distinct Patterns of Spatial Expression in Nodules
Authors: Kawashima Kazuya , Suganuma Norio , Tamaoki Masanori , Kouchi Hiroshi
Published: July 2002

Five distinct cDNA clones for leghemoglobin (Lb) were isolated from pea (Pisum sativum) nodules. They were classified into two groups designated PsLbA and PsLbB according to sequence homology, O2-binding affinities of the recombinant proteins, and in situ localization of the mRNAs. The PsLbB group was comprised of four cDNA clones: PsLb120-1, -8, -29, and -34. They showed a high similarity of deduced amino acid sequences and O2-binding affinities of their recombinant proteins. Among them, the spatial expression pattern of PsLb120-1 was investigated in great detail, indicating that its transcripts were localized in the region from infection zone II to the distal part of nitrogen fixation zone III in effective nodules. PsLb5-10, which is the only cDNA clone of the PsLbA type, differed considerably from the PsLbB type in amino acid sequence, and the recombinant protein had a higher O2-binding affinity than those of the PsLbB type. The transcripts ofPsLb5-10 were detected throughout the central tissue of effective nodules. However, in ineffective nodules on the pea mutant E135 (sym13), transcripts of PsLb5-10were restricted to the distal portion of the central tissue as well as those of PsLb120-1. These findings indicate that the pea genome contains two types of Lb genes and suggest that they have different roles in the development of nitrogen-fixing symbiosis in pea nodules.
Pea Legumin Overexpressed in Wheat Endosperm Assembles into an Ordered Paracrystalline Matrix
Authors: Stöger Eva , Parker Mary , Christou Paul , Casey Rod
Published: July 2002

Legumin, a major component of pea seed storage vacuoles, is synthesized by a number of paralogous genes. The polypeptides are cleaved posttranslationally and can form mixed hexamers. This heterogeneity hampers structural studies, based on the production of hexamer crystals in vitro. To study a single type of homogenous legumin we produced pea legumin A in transgenic wheat (Triticum aestivum) endosperm where prolamins are predominant and only small amounts of globulins accumulate in separate inclusions. We demonstrated that the legumin precursor was cleaved posttranslationally and we confirmed assembly into 11S hexamers. Legumin was deposited within specific regions of the inclusion bodies. Angular legumin crystals extended from the inclusion bodies into the vacuole, correlating with the high legumin content. This suggests that the high-level production of a single type of legumin polypeptide resulted in the spontaneous formation of crystals in vivo. The use of a heterologous cereal system such as wheat endosperm to produce, isolate, and recrystallize homogenous 11S legume globulins offers exciting possibilities for structural analysis and characterization of these important seed storage proteins.
A Novel Dark-Inducible Protein, LeDI-2, and Its Involvement in Root-Specific Secondary Metabolism inLithospermum erythrorhizon
Authors: Yazaki Kazufumi , Matsuoka Hideaki , Shimomura Koichiro , Bechthold Andreas , Sato Fumihiko
Published: July 2002

Lithospermum erythrorhizon produces red naphthoquinone pigments that are shikonin derivatives. They are accumulated exclusively in the roots of this plant. The biosynthesis of shikonin is strongly inhibited by light, even though other environmental conditions are optimized. Thus, L. erythrorhizon dark-inducible genes (LeDIs) were isolated to investigate the regulatory mechanism of shikonin biosynthesis. LeDI-2, showing the strict dark-specific expression, was further characterized by use of cell suspension cultures and hairy root cultures as model systems. Its mRNA accumulation showed a similar pattern with that of shikonin. In the intact plants LeDI-2 expression was observed solely in the root, and the longitudinal distribution of its mRNA was also in accordance to that of shikonin. LeDI-2 encoded a very hydrophobic polypeptide of 114 amino acids that shared significant similarities with some root-specific polypeptides such as ZRP3 (maize) and RcC3 (rice). Reduction of LeDI-2 expression by its antisense DNA in hairy roots of L. erythrorhizon decreased the shikonin accumulation, whereas other biosynthetic enzymes, e.g.p-hydroxybenzoic acid:geranyltransferase, which catalyzed a critical biosynthetic step, showed similar activity as the wild-type clone. This is the first report of the gene that is involved in production of secondary metabolites without affecting biosynthetic enzyme activities.
Multiple Functions for the C Terminus of the PsaD Subunit in the Cyanobacterial Photosystem I Complex
Authors: Lagoutte Bernard , Hanley Jonathan , Bottin Hervé
Published: July 2002

PsaD subunit of Synechocystis sp PCC 6803 photosystem I (PSI) plays a critical role in the stability of the complex and is part of the docking site for ferredoxin (Fd). In the present study we describe major physiological and biochemical effects resulting from mutations in the accessible C-terminal end of the protein. Four basic residues were mutated: R111, K117, K131, and K135, and a large 36-amino acid deletion was generated at the C terminus. PSI from R111C mutant has a 5-fold decreased affinity for Fd, comparable with the effect of the C terminus deletion, and NADP+ is photoreduced with a 2-fold decreased rate, without consequence on cell growth. The K117A mutation has no effect on the affinity for Fd, but decreases the stability of PsaE subunit, a loss of stability also observed in R111C and the deletion mutants. The double mutation K131A/K135A does not change Fd binding and reduction, but decreases the overall stability of PSI and impairs the cell growth at temperatures above 30°C. Three mutants, R111C, K117A, and the C-terminal deleted exhibit a higher content of the trimeric form of PSI, in apparent relation to the removal of solvent accessible positive charges. Various regions in the C terminus of cyanobacterial PsaD thus are involved in Fd strong binding, PSI stability, and accumulation of trimeric PSI.
Functional Characterization and Subcellular Localization of Poplar (Populus trichocarpa × Populus deltoides) Cinnamate 4-Hydroxylase
Authors: Ro Dae Kyun , Mah Nancy , Ellis Brian E. , Douglas Carl J.
Published: July 2002

Cinnamic acid 4-hydroxylase (C4H), a member of the cytochrome P450 monooxygenase superfamily, plays a central role in phenylpropanoid metabolism and lignin biosynthesis and possibly anchors a phenylpropanoid enzyme complex to the endoplasmic reticulum (ER). A full-length cDNA encoding C4H was isolated from a hybrid poplar (Populus trichocarpa × P. deltoides) young leaf cDNA library. RNA-blot analysis detectedC4H transcripts in all organs tested, but the gene was most highly expressed in developing xylem. C4Hexpression was also strongly induced by elicitor-treatment in poplar cell cultures. To verify the catalytic activity of the putative C4H cDNA, two constructs, C4H and C4H fused to the FLAG epitope (C4H::FLAG), were expressed in yeast. Immunoblot analysis showed that C4H was present in the microsomal fraction and microsomal preparations from strains expressing both enzymes efficiently converted cinnamic acid to p-coumaric acid with high specific activities. To investigate the subcellular localization of C4H in vivo, a chimeric C4H-green fluorescent protein (GFP) gene was engineered and stably expressed in Arabidopsis. Confocal laser microscopy analysis clearly showed that in Arabidopsis the C4H::GFP chimeric enzyme was localized to the ER. When expressed in yeast, the C4H::GFP fusion enzyme was also active but displayed significantly lower specific activity than either C4H or C4H::FLAG in in vitro and in vivo enzyme assays. These data definitively show that C4H is localized to the ER in planta.
The Involvement of Two P450 Enzymes, CYP83B1 and CYP83A1, in Auxin Homeostasis and Glucosinolate Biosynthesis
Authors: Bak Søren , Feyereisen René
Published: July 2002

The first committed step in the biosynthesis of indole glucosinolates is the conversion of indole-3-acetaldoxime into an indole-3-S-alkyl-thiohydroximate. The initial step in this conversion is catalyzed by CYP83B1 in Arabidopsis (S. Bak, F.E. Tax, K.A. Feldmann, D.A. Galbraith, R. Feyereisen [2001] Plant Cell 13: 101–111). The knockout mutant of the CYP83B1 gene (rnt1-1) shows a strong auxin excess phenotype and are allelic to sur-2. CYP83A1 is the closest relative to CYP83B1 and shares 63% amino acid sequence identity. Although expression of CYP83A1 under control of its endogenous promoter in thernt1-1 background does not prevent the auxin excess and indole glucosinolate deficit phenotype caused by the lack of the CYP83B1 gene, ectopic overexpression of CYP83A1 using a 35S promoter rescues the rnt1-1 phenotype. CYP83A1 and CYP83B1 heterologously expressed in yeast (Saccharomyces cerevisiae) cells show marked differences in their substrate specificity. Both enzymes convert indole-3-acetaldoxime to a thiohydroximate adduct in the presence of NADPH and a nucleophilic thiol donor. However, indole-3-acetaldoxime has a 50-fold higher affinity toward CYP83B1 than toward CYP83A1. Both enzymes also metabolize the phenylalanine- and tyrosine-derived aldoximes. Enzyme kinetic comparisons of CYP83A1 and CYP83B1 show that indole-3-acetaldoxime is the physiological substrate for CYP83B1 but not for CYP83A1. Instead, CYP83A1 catalyzes the initial conversion of aldoximes to thiohydroximates in the synthesis of glucosinolates not derived from tryptophan. The two closely related CYP83 subfamily members therefore are not redundant. The presence of putative auxin responsive cis-acting elements in the CYP83B1 promoter but not in the CYP83A1 promoter supports the suggestion that CYP83B1 has evolved to selectively metabolize a tryptophan-derived aldoxime intermediate shared with the pathway of auxin biosynthesis in Arabidopsis.
Assessment of variable‐cycle propulsion systems for ASTOVL
Authors: Yin J. , Pilidis P. , Ramsden K.W. , Probert S.D.
Published: July 2002

The requirements imposed upon advanced short take‐off and vertical landing (ASTOVL) aircraft give rise to challenging demands on their propulsion systems. One possible approach is to have a high‐performance turbofan of traditional design and an additional, but separate, fan to provide a major part of the lift during the take‐off and landing manoeuvres. For such a design, there are several quite‐different choices of layout for providing the power to drive the remote fan by means of the core engine. These include shaft‐driven and bleed‐driven options. The choice will depend on the anatomy and required thermodynamic‐performance of the whole system. In this paper, several pertinent alternative engine‐designs are discussed. Four of these, based on a high‐performance low‐bypass‐ratio core engine, are studied in detail and their behaviours compared. Prima facie, the preferred choice is the engine with the shaft‐driven fan. A slightly less acceptable choice is the high‐pressure turbine exit‐bleed driven remote‐fan.
Deposition of high wear resistance of Ni‐composite coatings
Authors: Shawki Saher , Abdel Hamid Z.
Published: July 2002

Electrodeposited Ni‐P composite coatings incorporating a variety of inorganic particles were obtained from Watt’s nickel bath containing sodium hypophosphite. The mechanism of co‐deposition of various particles (SiC, Al2O3, quartz and sand) was studied in view of the electro‐kinetic charge characterizing the solid particles. Means to improve the mobility of the particles in the plating solution were investigated using sodium oleate as surface active agent. The purpose was to increase particle content in the coating to attain high hardness values. Special attention was given to the deposition process using SiC particles. The surface morphology, hardness and wear resistance of the composite coatings were determined. Hardness values were maximized by simple heat treatment in air atmosphere which led to the precipitation of the hard Ni3P phase. Sound, coherent and high wear resistance coatings could be produced.
The relevance of total quality management in the food supply and distribution industry: a study
Authors: Beardsell M.L. , Dale B.G.
Published: July 2002

The paper reports the findings of a study of two major companies in the UK food supply and distribution industry to assess the relevance of total quality management (TQM). The focus of the research was two case studies of major organisations which are considered to be representative of the industry. Examination of the academic literature found little work linking TQM and the industry. The study confirms the applicability of TQM in the food supply and distribution industry. The list of TQM characteristics identified are not dissimilar to those in other industries. However, as part of the service sectors, there is a requirement of organisationds in this business sector to be highly focused on customer needs and changes in market trends.
Wine routes in Northern Greece: consumer perceptions
Authors: Tzimitra‐Kalogianni Irene , Papadaki‐Klavdianou Afroditi , Alexaki Anastasia , Tsakiridou Efthimia
Published: July 2002

Attempts to identify consumer perceptions about wine and wine attributes in Greece. In addition, a brief presentation of the development of wine routes in Greece is considered. According to the results, wine emerges as a staple kind of drink in everyday meals, and seems to be more preferable compared to other alcoholic drinks. Furthermore, taste, clarity, appelation of origin, aroma and label are the most important wine attributes expressed by Greek consumers. Taking into account that Greece is one of the most important wine producing countries in the EU, an effective wine promotion policy needs to be organised. In the light of the interdependence between the new activities introduced by regional wine enterprises and the consumer level of information about “typical wines”, further market research could improve wine promotion both in Greek and the European markets.
Stop the Organization – I Want to Change It! Part 2
Authors: Grubb Irene M. , Silvestro Norrie W. , Ward David F.
Published: July 2002

Describes and reviews one major initiative within the context of a
ten‐year organization development strategy. Outlines the key steps
involved in extending a performance management and planning process to
over 600 supervisory and clinical staff. Indicates that high levels of
external uncertainty and change can have a disabling effect on senior
managers. This effect also has implications on the ability and scope for
middle managers to play a direct and active role in the change
interventions. A key lesson is the need to continually support managers
to work with their own staff to help the new systems to be understood
and to operate them effectively. The final section reviews the main
lessons and how previous work will act as a foundation for ongoing
initiatives based on principles which are consistent with the original
OD strategy.
Training for growth: how can education providers assist in the development of small businesses?
Authors: Sargeant Adrian
Published: July 2002

It would be difficult to find a college or university business school that is not currently offering a training programme for small business. Yet despite the enthusiasm with which providers have entered the market, the take‐up rates remain low. Examines the underlying reasons why this might be so and discusses the findings of a detailed survey of 400 small businesses residing in the county of Devon. Shows that education providers are out of touch with the market and, moreover, have a very negative image which must be overcome before small business training can be utilized to its full potential. Calls for greater co‐operation between institutional providers and local Training and EnterpriseCouncils to ensure that this situation is rectified.
Illumination for machine vision
Authors: Braggins Don
Published: July 2002

Summarises the presentations made at the UK Industrial Vision Association’s annual general meeting in September 1999, Nottiungham, UK, entitled “Innovations in illumination for machine vision”.
Dissatisfaction with stock condition surveys in social housing
Authors: Chapman Keith P.
Published: July 2002

This paper arises from findings which emerged during the preparation of the Good Practice Guide to Maintenance Cost Forecasting. This Guide was commissioned by the Housing Corporation to assist Registered Social Landlords forecast the future maintenance costs of their stocks. It became apparent during the work that client experiences of stock condition surveys had been far from satisfactory. The surveys had often been carried out by professional surveyors and yet many had fundamental weaknesses in their specification, execution and use of data. The level of dissatisfaction expressed, coupled with recent evidence regarding the quality of domestic building surveys, should give cause for concern to the surveying profession. The paper identifies some causes of this dissatisfaction and suggests lessons that can be drawn from the experience. Further investigation is recommended into this crucial area of practice.
Fuzzy Mealy machines
Authors: Mordeson J.N. , Nair P.S.
Published: July 2002

Presents fundamental results on fuzzy Mealy machines. Unlike the classical Mealy machine which requires two functions, one to describe the next state and another to describe the output, a fuzzy Mealy machine requires only one fuzzy function to characterize completely the next state and the output produced. Apart from the obvious generalization that can be obtained from corresponding results on fuzzy finite state machines by introduction of an output associated with each transition, introduces the concept of an interval partition of [0, 1] and uses it to obtain more general results.
Preparation and characterization of some polyesterurethanes and polyesterurethane‐ureas based on hydroxy terminated polyesters
Authors: Radwan Mohamed A.
Published: July 2002

Hydroxy terminated polyesters were prepared by the reaction of tetrabromophthalic, phthalic, and maleic anhydrides with polyethylene glycol via melt condensation technique. They were characterized by hydroxy number, and intrinsic viscosity measurements. Also, the fire retardancy of polyesters was evaluated as varnish films on plywood strips. The polyesters were reacted with excess toluene ‐2, 4‐ diisocyanate to yeild isocyanate terminated prepolymers which were subsequently reacted with 5, 5‐ dihydroxymethyl‐2‐trichloro‐methyl‐1,3‐ dioxane or ethelene diamine. These polymers were characterized by Ir and 1H NMR spectra, viscosity measurements, and thermogravimetric analysis.
The Deputy Principalship: Retrospect and Prospect
Authors: Harvey Michael J.
Published: July 2002

The deputy principalship is one of the least understood roles in the
schools of the restructured education systems of Australia. Little
attention has been given by educational policy makers, academics and
researchers as to how the deputy principal should contribute to the
essential functions of the self‐managing school. Uses the research
literature to identify the traditional role of the deputy principal and
the factors which have constrained the evolution of the role. Assesses
the effects of current policy initiatives for the deputy principalship
in Australian education. An emergent facet of the role is proposed which
gives greater emphasis to educational leadership in an administrative
team. The failure of practitioners to make use of opportunities to
reconceptualize the deputy principalship will marginalize the role to
the central functions of the self‐managing school.
A study of the roll planning of fabric spreading using genetic algorithms
Authors: Hui Patrick C.L. , Ng Frency S.F. , Chan Keith C.C.
Published: July 2002

In the process of fabric spreading, the variance of fabric yardage between fabric rolls may lead to a difference in fabric loss during spreading. As there are numerous combinations the arrangement of the fabric roll sequences for each cutting lay, it is difficult to construct a roll planning to minimise the fabric wastage during spreading in apparel manufacturing. Recent advances in computing technology, especially in the area of computational intelligence, can be used to handle this problem. Among the different computational intelligence techniques, genetic algorithms (GA) are particularly suitable. GAs are probabilistic search methods that employ a search technique based on ideas from natural genetics and evolutionary principles. This paper presents the details of GA and explains how the problem of roll planning can be formulated for GA to solve. The result of the study shows that an optimal roll planning can be worked out by using GA approach. It is possible to save a considerable amount of fabric when the best roll planning is used for the production.
Communication
Authors: Chen F. Frank
Published: July 2002

The purpose of this paper is to perform a contrast study on the technologies and contributions of flexible manufacturing systems (FMS) being in use in apparel and metal cutting/removal industries. Some significant differences in the technologies and operational characteristics of existing FMS in the soft‐goods apparel industry and in the hard‐goods metal working industry are identified. Detailed discussions on interesting comparable contributions of FMS at various dimensions such as quality, productivity, flexibility, etc., are also presented. Recommendations for future research are also provided.
Research on school‐based management in Victoria
Authors: Gamage David T. , Sipple Peter , Partridge Peter
Published: July 2002

Reports on a research project undertaken in 1992‐93, involving 66 state schools which aimed to ascertain the overall effectiveness of school‐based management in the Australian state of Victoria. Discusses the evolution of democratic devolution and reviews previous research.
Metaphorical guidance
Authors: Arnett Ronald C.
Published: July 2002

This essay, undergirded by the insights of Christopher Lasch, outlines the practicality of applying the metaphors of building and renovation to administration. This essay acknowledges the difficulty of applying such metaphors in an era where the importance of discovering meaning through institutional life is often dismissed. However, institutions are well‐served by administrators who function as “builders” and “renovators,” trying to leave something behind of value in their place of work. Institutions are constantly being created and re‐created, and it is the responsibility of the administrator to help “build” and “renovate” an institution capable of passing on ethical values, ideas and beliefs to the next generation of students, faculty and alumni.
A transient analysis of incompressible fluid flow in vessels with moving boundaries
Authors: Sheu Tony W.H. , Chen Harry Y.H.
Published: July 2002

We present in this paper a finite element analysis of Navier‐Stokes equations in a time‐varying domain. The method of weighted residuals is used together with the semi‐discretization approach to obtain the discrete equations. In this approach, where the physical domain is allowed to vary, care is taken to retain the space conservation law property. We describe in detail the transformation of equations between fixed and moving grids. The validity of this method has been tested against two problems which are amenable to analytic solutions. Time accurate results show favorable agreement with analytic solutions. Having verified the applicability of the Galerkin finite element code to problems involving moving grids, we consider the fluid flow in a vessel, where a portion of its boundary moves in time. Results are presented with emphasis on the depiction of vortical flow details.
Parallel computing using Web servers and “servlets”
Authors: Lo Alfred , Bloor Chris , Choi Y.K.
Published: July 2002

Presents inexpensive ways to implement a virtual parallel computer with multiple Web servers. “Servlets” are used instead of CGI programs. Compares the multiple Web server model with a multiple‐client model. Experiments are conducted to test the performance of these two parallel systems. The performance of these two models is then compared. The advantages and limitations of these models are also discussed.
The authors of academic library home pages: their identity, training and dissemination of Web construction skills
Authors: Evans Beth
Published: July 2002

This article reports on a study designed to identify the authors of academic library home pages and to investigate the nature of their training and their use of newly‐acquired Web design skills. The major finding of the study is that librarians more often than non‐librarians are assuming the responsibility for writing home pages for academic libraries in very large public colleges and universities. In addition to professional identity, factors such as length of service to an institution, current job title, and prior education play a role in determining the likelihood that an individual will write the home page for his or her employing library. Learning the skills needed to write a home page requires time for training. Institutional support for training is considered vital and well worth the investment because training is very often disseminated beyond the home page authors. Teaching others Web construction skills is one of the ways library home page authors most frequently apply their newly acquired abilities.
Two‐phase unfolding pathway of ribonuclease A during denaturation induced by dithiothreitol
Authors: Yan Yong‐Bin , Jiang Bo , Zhang Ri‐Qing , Zhou Hai‐Meng
Published: July 2002

The dynamics of the unfolding process of bovine pancreatic ribonuclease A (RNase A) unfolded by dithiothreitol (DTT) at a low concentration of 1:30 were investigated in alkaline phosphate‐buffered saline solutions at 303K and 313K by using proton nuclear magnetic resonance (1H NMR) spectra. Three NMR spectral parameters including Shannon entropy, mutual information, and correlation coefficient were introduced into the analysis. The results show that the unfolding process of RNase A was slowed to the order of many hours, and the kinetics of the unfolding pathway described by the three parameters is best fit by a model of two consecutive first‐order reactions. Temperature greatly influences the rate constants of the unfolding kinetics with different temperature effects observed for the fast and the slow processes. The consistencies and the differences between the three sets of parameters show that they reflect the same relative denaturation pathway but different spectra windows of the unfolding process of RNase A. The results suggest that the unfolding process of RNase A induced by low concentrations of DTT is a two‐phase pathway containing fast and slow first‐order reactions.
Design, synthesis, and characterization of a novel hemoprotein
Authors: Xu Zhijin , Farid Ramy S.
Published: July 2002

Here we describe a synthetic protein (6H7H) designed to bind four heme groups via bis–histidine axial ligation. The hemes are designed to bind perpendicular to another in an orientation that mimics the relative geometry of the two heme a groups in the active site of cytochrome c oxidase. Our newly developed protein‐design program, called CORE, was implemented in the design of this novel hemoprotein. Heme titration studies resolved four distinct KD values (KD1 = 80 nM, KD2 = 18 nM, KD3 ≥ 3 mM, KD4 ≤ 570 nM, with KD3 × K D4 = 1700); positive cooperativity in binding between the first and second heme, as well as substantial positive cooperativity between the third and forth heme, was observed. Chemical and thermal denaturation studies reveal a stable protein with native‐like properties. Visible circular dichroism spectroscopy of holo‐6H7H indicates excitonic coupling between heme groups. Further electrochemical and spectroscopic characterization of the holo‐protein support a structure that is consistent with the predefined target structure.
Crystal structure of E. coli β–carbonic anhydrase, an enzyme with an unusual pH–dependent activity
Authors: Cronk Jeff D. , Endrizzi James A. , Cronk Michelle R. , O'neill Jason W. , Zhang Kam Y.J.
Published: July 2002

Carbonic anhydrases fall into three distinct evolutionary and structural classes: α, β, and γ. The β‐class carbonic anhydrases (β‐CAs) are widely distributed among higher plants, simple eukaryotes, eubacteria, and archaea. We have determined the crystal structure of ECCA, a β‐CA from Escherichia coli, to a resolution of 2.0 Å. In agreement with the structure of the β‐CA from the chloroplast of the red alga Porphyridium purpureum, the active‐site zinc in ECCA is tetrahedrally coordinated by the side chains of four conserved residues. These results confirm the observation of a unique pattern of zinc ligation in at least some β‐CAs. The absence of a water molecule in the inner coordination sphere is inconsistent with known mechanisms of CA activity. ECCA activity is highly pH‐dependent in the physiological range, and its expression in yeast complements an oxygen‐sensitive phenotype displayed by a β‐CA‐deletion strain. The structural and biochemical characterizations of ECCA presented here and the comparisons with other β‐CA structures suggest that ECCA can adopt two distinct conformations displaying widely divergent catalytic rates.
Areas of the brain concerned with ventilatory load compensation in awake man
Authors: Isaev Gennadi , Murphy Kevin , Guz Abraham , Adams Lewis
Published: July 2002

There is broad agreement that the awake human ventilatory response to a moderate inspiratory load consists of a prolongation of inspiratory time (TI) with a maintenance of tidal volume (VT) and end‐tidalPCO2(PET,CO2), the response being severely blunted in sleep. There is no agreement on the mechanisms underlying this ventilatory response. Six naive healthy males (aged 39–44) were studied supine with their heads in a positron emission tomography (PET) scanner to allow relative regional cerebral blood flow (rCBF) to be measured with H215O given intravenously. A linearised resistive load (24 cmH2O (l s−1)−1) could be added to the inspiratory limb of a breathing valve inserted into a tightly fitting facemask; inspiratory flow was measured with a pneumotachograph. The load was applied, without alerting the subject, when the radioactivity first reached the head. Six scans were performed with and without the load, in each subject. Relative rCBF contrasts between the loaded and unloaded breathing states showed significant activations in inferior parietal cortex, prefrontal cortex, midbrain, basal ganglia and multiple cerebellar sites. No activations were found in the primary sensorimotor cortex. The findings suggest that there is a pattern of motor behavioural response to the uncomfortable sensation that inspiration is impeded. This results in a prolongation ofTI, the maintenance ofVTand a reduction in the degree of discomfort, presumably because of the reduction of mean negative pressure in the airways.
Detailed passive cable models of layer 2/3 pyramidal cells in rat visual cortex at different temperatures
Authors: J. Trevelyan Andrew , Jack Julian
Published: July 2002

We present detailed passive cable models of layer 2/3 pyramidal cells based on somatic voltage transients in response to brief current pulses at physiological and room temperatures and demonstrate how cooling alters the shape of postsynaptic responses. Whole cell recordings were made from cells in visual cortical slices from 20‐ to 22‐day‐old rats. The cells were filled with biocytin and morphologies were reconstructed from three cells which were representative of the full range of physiological responses. These formed the basis for electrotonic models with four electrical variables, namely membrane capacitance (Cm), membrane resistivity (Rm), cytoplasmic resistivity (Ri) and a somatic shunt conductance (Gsh). Simpler models, with a single value for Rm and no Gsh, did not fit the data adequately. Optimal parameter values were derived by simulating the responses to somatic current pulses, varying the parameters to give the best match to the experimental recordings. Gsh and Rm were badly constrained. In contrast, the total membrane conductance (Gtot) was well constrained, and its reciprocal correlated closely with the slowest membrane time constant (τ0). The models showed close agreement for Cm and Ri (ranges at 36 °C: 0.78–0.94 μF cm−2 and 140–170 Ωcm), but a larger range for Gtot (7.2–18.4 nS). Cooling produced consistent effects in all three model cells; Cm remained constant (Q10= 0.96), Ri increased (Q10= 0.80), whilst Gtot dropped (Q10= 1.98). In terms of whole cell physiology, the predominant effect of cooling is to dramatically lengthen the decay of transient voltage shifts. Simulations suggest that this markedly increases the temporal summation of postsynaptic potentials and we demonstrate this effect in the responses of layer 2/3 cells to tetanic extracellular stimulation in layer 4.
Nonlinear Dynamic Behaviors of a Complex Rotor-Bearing System
Authors: Zheng T. , Hasebe N.
Published: July 2002

This paper deals with the long-term dynamic behaviors of a complex rotor-bearing system with multi-degrees-of-freedom and nonclosed form of the bearing forces. Since nonanalytical bearing forces can be available, to increase the numerical accuracy and decrease the CPU time, a new method is presented to calculate the Jacobians of the bearing forces and bearing forces themselves. The algorithm is concise and the computing efforts spent on the Jacobians are very small compared to spend on the bearing forces themselves. In terms of the feature that the nonlinear bearing forces act on the system individually, a new reduction method and corresponding integration technique is proposed to increase the numerical stability and decrease the computing time for the system analysis. The numerical schemes of this study are applied to a rotor system with multi-rigid disks and two elliptical bearing supports. The numerical results reveal very rich and complex nonlinear behavior of the system. [S0021-8936(00)00802-3]
Computational Modeling of Left Heart Diastolic Function: Examination of Ventricular Dysfunction
Authors: Lemmon Jack D. , Yoganathan Ajit P.
Published: July 2002

A computational model that accounts for blood–tissue interaction under physiological flow conditions was developed and applied to a thin-walled model of the left heart. This model consisted of the left ventricle, left atrium, and pulmonary vein flow. The input functions for the model included the pulmonary vein driving pressure and time-dependent relationship for changes in chamber tissue properties during the simulation. The Immersed Boundary Method was used for the interaction of the tissue and blood in response to fluid forces and changes in tissue pathophysiology, and the fluid mass and momentum conservation equations were solved using Patankar’s Semi-Implicit Method for Pressure Linked Equations (SIMPLE). This model was used to examine the flow fields in the left heart under abnormal diastolic conditions of delayed ventricular relaxation, delayed ventricular relaxation with increased ventricular stiffness, and delayed ventricular relaxation with an increased atrial contraction. The results obtained from the left heart model were compared to clinically observed diastolic flow conditions, and to the results from simulations of normal diastolic function in this model 1. Cases involving impairment of diastolic function were modeled with changes to the input functions for fiber relaxation/contraction of the chambers. The three cases of diastolic dysfunction investigated agreed with the changes in diastolic flow fields seen clinically. The effect of delayed relaxation was to decrease the early filling magnitude, and this decrease was larger when the stiffness of the ventricle was increased. Also, increasing the contraction of the atrium during atrial systole resulted in a higher late filling velocity and atrial pressure. The results show that dysfunction can be modeled by changing the relationships for fiber resting-length and/or stiffness. This provides confidence in future modeling of disease, especially changes to chamber properties to examine the effect of local dysfunction on global flow fields. [S0148-0731(00)00104-7]
Power Systems Development Facility: High Temperature, High Pressure Filter System Operations in a Combustion Gas1
Authors: Scarborough Patrick T. , Hendrix Howard L. , Davidson Matthew D. , Guan Xiaofeng , Dahlin Robert S. , Landham E. Carl
Published: July 2002

The Power Systems Development Facility (PSDF) is a Department of Energy (DOE) sponsored engineering scale demonstration of two advanced coal-fired power systems. Particulate cleanup is achieved by several High Temperature, High Pressure (HTHP) gas filtration systems. The PSDF was designed at sufficient scale so that advanced power systems and components could be tested in an integrated fashion to provide confidence and data for commercial scale-up. This paper provides an operations summary of a Siemens-Westinghouse Particulate Control Device (PCD) filtering combustion gas from a Kellogg, Brown, and Root (KBR) transport reactor located at the PSDF. The transport reactor is an advanced circulating fluidized bed reactor designed to operate as either a combustor or a gasifier. Particulate cleanup is achieved by using one of two PCDs, located downstream of the transport reactor. As of the end of 1998, the transport reactor has operated on coal as a combustor for over 3500 h. To date, filter elements from 3M, Blasch, Coors, Allied Signal (DuPont), IF&P, McDermott, Pall, Schumacher, and Specific Surface have been tested up to 1400 °F in the Siemens-Westinghouse PCD. The PSDF has a unique capability for the collection of samples of suspended dust entering and exiting the PCD with Southern Research Institute’s (SRI) in-situ particulate sampling systems. These systems have operated successfully and have proven to be invaluable assets. Isokinetic samples using a batch sampler, a cascade impactor and a cyclone manifold have provided valuable data to support the operation of the transport reactor and the PCD. Southern Research Institute has also supported the PSDF by conducting filter element material testing. [S0742-4795(00)02203-1]
Variations in Upstream Vane Loading With Changes in Back Pressure in a Transonic Compressor
Authors: Probasco Douglas P. , Leger Tim J. , Wolff J. Mitch , Copenhaver William W. , Chriss Randall M.
Published: July 2002

Dynamic loading of an inlet guide vane (IGV) in a transonic compressor is characterized by unsteady IGV surface pressures. These pressure data were acquired for two spanwise locations at a 105 percent speed operating condition, which produces supersonic relative Mach numbers over the majority of the rotor blade span. The back pressure of the compressor was varied to determine the effects from such changes. Strong bow shock interaction was evident in both experimental and computational results. Variations in the back pressure have significant influence on the magnitude and phase of the upstream pressure fluctuations. The largest unsteady surface pressure magnitude, 40 kPa, was obtained for the near-stall mass flow condition at 75 percent span and 95 percent chord. Radial variation effects caused by the spanwise variation in relative Mach number were measured. Comparisons to a two-dimensional nonlinear unsteady blade/vane Navier–Stokes analysis show good agreement for the 50 percent span results in terms of IGV unsteady surface pressure. The results of the study indicate that significant nonlinear bow shock influences exist on the IGV trailing edge due to the downstream rotor shock system. [S0889-504X(00)00303-2]
Analysis of Contact Deformation and Stiction Between Textured Disk and Textured Slider
Authors: Bai Mingwu , Kato Koji
Published: July 2002

To meet the ever-increasing magnetic recording density, the hard disk industry is focusing on reducing flying height. Texturing the slider surface to reduce the head–disk contact area is one of the most challenging and promising techniques in the current industry. In this study, a mathematical–physical model based on an extension of the Greenwood–Tripp model is proposed for predicting and analyzing the contact deformation and stiction between both textured disk and slider. The contact deformation and stiction of the head–disk interface is analyzed in considering surface texture parameters, lubricant properties, and loading conditions.
On Some Anomalies in Lame´’s Solutions for Elastic Solids With Holes
Authors: Sinclair G. B. , Meda G.
Published: July 2002

Elastic solids with holes under remote tension are reconsidered. When hole dimensions are shrunk so that holes disappear, anomalies occur in the classical elasticity solutions of Lame´. By introducing cohesive laws on hole surfaces as they shrink, these anomalies may be removed.
Sensitivity Analysis for Nonlinear Heat Conduction
Authors: Dowding Kevin J. , Blackwell Bennie F.
Published: July 2002

Parameters in the heat conduction equation are frequently modeled as temperature dependent. Thermal conductivity, volumetric heat capacity, convection coefficients, emissivity, and volumetric source terms are parameters that may depend on temperature. Many applications, such as parameter estimation, optimal experimental design, optimization, and uncertainty analysis, require sensitivity to the parameters describing temperature-dependent properties. A general procedure to compute the sensitivity of the temperature field to model parameters for nonlinear heat conduction is studied. Parameters are modeled as arbitrary functions of temperature. Sensitivity equations are implemented in an unstructured grid, element-based numerical solver. The objectives of this study are to describe the methodology to derive sensitivity equations for the temperature-dependent parameters and present demonstration calculations. In addition to a verification problem, the design of an experiment to estimate temperature variable thermal properties is discussed.