bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Up-Regulation of HKT1, a High-Affinity Potassium Transporter Gene, in Roots of Barley and Wheat following Withdrawal of Potassium
Authors: Wang Tie-Bang , Gassmann Walter , Rubio Francisco , Schroeder Julian I. , Glass Anthony D.M.
Published: July 2002

High-affinity K+ uptake in plant roots is rapidly up-regulated when K+ is withheld and down-regulated when K+ is resupplied. These processes make important contributions to plant K+ homeostasis. A cDNA coding for a high-affinity K+ transporter, HKT1, was earlier cloned from wheat (Triticum aestivum L.) roots and functionally characterized. We demonstrate here that in both barley (Hordeum vulgare L.) and wheat roots, a rapid and large up-regulation ofHKT1 mRNA levels resulted when K+ was withdrawn from growth media. This effect was specific for K+; withholding N caused a modest reduction ofHKT1 mRNA levels. Up-regulation of HKT1transcript levels in barley roots occurred within 4 h of removing K+, which corresponds to the documented increase of high-affinity K+ uptake in roots following removal of K+. Increased expression of HKT1 mRNA was evident before a decline in total root K+ concentration could be detected. Resupply of 1 mm K+ was sufficient to strongly reduce HKT1 transcript levels. In wheat root cortical cells, both membrane depolarizations in response to 100 μm K+, Cs+, and Rb+, and high-affinity K+ uptake were enhanced by K+ deprivation. Thus, in both plant systems the observed physiological changes associated with manipulating external K+ supply were correlated with levels ofHKT1 mRNA expression. Implications of these findings for K+ sensing and regulation of the HKT1 mRNA levels in plant roots are discussed.
Involvement of Ureides in Nitrogen Fixation Inhibition in Soybean1
Authors: Serraj Rachid , Vadez Vincent , Denison R. Ford , Sinclair Thomas R.
Published: July 2002

The sensitivity of N2 fixation to drought stress in soybean (Glycine max Merr.) has been shown to be associated with high ureide accumulation in the shoots, which has led to the hypothesis that N2 fixation during drought is decreased by a feedback mechanism. The ureide feedback hypothesis was tested directly by measuring the effect of 10 mm ureide applied by stem infusion or in the nutrient solution of hydroponically grown plants on acetylene reduction activity (ARA). An almost complete inhibition of ARA was observed within 4 to 7 d after treatment, accompanied by an increase in ureide concentration in the shoot but not in the nodules. The inhibition of ARA resulting from ureide treatments was dependent on the concentration of applied ureide. Urea also inhibited ARA but asparagine resulted in the greatest inhibition of nodule activity. Because ureides did not accumulate in the nodule upon ureide treatment, it was concluded that they were not directly inhibitory to the nodules but that their influence mediated through a derivative compound, with asparagine being a potential candidate. Ureide treatment resulted in a continual decrease in nodule permeability to O2 simultaneous with the inhibition of nitrogenase activity during a 5-d treatment period, although it was not clear whether the latter phenomenon was a consequence or a cause of the decrease in the nodule permeability to O2.
Phosphoenolpyruvate Carboxykinase Is Involved in the Decarboxylation of Aspartate in the Bundle Sheath of Maize1
Authors: Wingler Astrid , Walker Robert P. , Chen Zhi-Hui , Leegood Richard C.
Published: July 2002

We recently showed that maize (Zea mays L.) leaves contain appreciable amounts of phosphoenolpyruvate carboxykinase (PEPCK; R.P. Walker, R.M. Acheson, L.I. Técsi, R.C. Leegood [1997] Aust J Plant Physiol 24: 459–468). In the present study, we investigated the role of PEPCK in C4 photosynthesis in maize. PEPCK activity and protein were enriched in extracts from bundle-sheath (BS) strands compared with whole-leaf extracts. Decarboxylation of [4-14C]aspartate (Asp) by BS strands was dependent on the presence of 2-oxoglutarate and Mn2+, was stimulated by ATP, was inhibited by the PEPCK-specific inhibitor 3-mercaptopicolinic acid, and was independent of illumination. The principal product of Asp metabolism was phosphoenolpyruvate, whereas pyruvate was a minor product. Decarboxylation of [4-14C]malate was stimulated severalfold by Asp and 3-phosphoglycerate, was only slightly reduced in the absence of Mn2+ or in the presence of 3-mercaptopicolinic acid, and was light dependent. Our data show that decarboxylation of Asp and malate in BS cells of maize occurs via two different pathways: Whereas malate is mainly decarboxylated by NADP-malic enzyme, decarboxylation of Asp is dependent on the activity of PEPCK.
Characterization of Two Photosynthetic Mutants of Maize1
Authors: Heck Donald A. , Miles Donald , Chitnis Parag R.
Published: July 2002

We describe here the biochemical characteristics of the hcf44 and hcf47 (high chlorophyll fluorescence) mutants of maize (Zea mays L.). Both mutants were sensitive to high light intensities, exhibiting reduced growth and fluorescence intensity. Electron transport through the mutants' photosystem (PS) I and PSII reaction centers was reduced and NADP+ photoreduction was absent. Western analysis revealed that the hcf44 mutant was missing some or all of the PsaC, PsaD, and PsaE polypeptides of the PSI reaction center, and reverse transcriptase-polymerase chain reaction demonstrated that this loss was the result of a posttranscriptional event. The hcf47 mutant had reduced levels of many PSI and PSII polypeptides. These data indicate a possible defect in the synthesis or assembly of the PsaC subunit in thehcf44 mutant, whereas the hcf47 mutant may have a more general defect in the biogenesis of photosynthetic membranes. Our results demonstrate the coordinated assembly of the peripheral proteins into the PSI complexes of higher plants and demonstrate the in vivo requirement of PsaC, PsaD, and PsaE subunits for the function of PSI in higher plants.
Major Protein of Resting Rhizomes of Calystegia sepium (Hedge Bindweed) Closely Resembles Plant RNases But Has No Enzymatic Activity
Authors: Van Damme Els J.M. , Hao Qiang , Barre Annick , Rougé Pierre , Van Leuven Fred , Peumans Willy J.
Published: July 2002

The most abundant protein of resting rhizomes of Calystegia sepium (L.) R.Br. (hedge bindweed) has been isolated and its corresponding cDNA cloned. The native protein consists of a single polypeptide of 212 amino acid residues and occurs as a mixture of glycosylated and unglycosylated isoforms. Both forms are derived from the same preproprotein containing a signal peptide and a C-terminal propeptide. Analysis of the deduced amino acid sequence indicated that the C. sepium protein shows high sequence identity and structural similarity with plant RNases. However, no RNase activity could be detected in highly purified preparations of the protein. This apparent lack of activity results most probably from the replacement of a conserved His residue, which is essential for the catalytic activity of plant RNases. Our findings not only demonstrate the occurrence of a catalytically inactive variant of an S-like RNase, but also provide further evidence that genes encoding storage proteins may have evolved from genes encoding enzymes or other biologically active proteins.
Ectopic Deposition of Lignin in the Pith of Stems of Two Arabidopsis Mutants
Authors: Zhong Ruiqin , Ripperger Amy , Ye Zheng-Hua
Published: July 2002

The biosynthesis of lignin in vascular plants is regulated both developmentally and environmentally. In the inflorescence stems of Arabidopsis, lignin is mainly deposited in the walls of xylem cells and interfascicular fiber cells during normal plant growth and development. The mechanisms controlling the spatial deposition of lignin remain unknown. By screening ethyl methanesulfonate-mutagenized populations of Arabidopsis, we have isolated two allelic elp1 (ectopic deposition of lignin in pith) mutants with altered lignin deposition patterns. In elp1 stems, lignin was ectopically deposited in the walls of pith parenchyma cells in addition to its normal deposition in the walls of xylem and fiber cells. Lignin appeared to be deposited in patches of parenchyma cells in the pith of both young and mature elp1 stems. The ectopic deposition of lignin in the pith of elp1 stems was accompanied by an increase in the activities of enzymes in the lignin biosynthetic pathway and with the ectopic expression of caffeoyl coenzyme AO-methyltransferase in pith cells. These results indicate that the ELP1 locus is involved in the repression of the lignin biosynthetic pathway in the pith. Isolation of the elp1 mutants provides a novel means with which to study the molecular mechanisms underlying the spatial control of lignification.
Characterization of Brassinazole, a Triazole-Type Brassinosteroid Biosynthesis Inhibitor
Authors: Asami Tadao , Min Yong Ki , Nagata Noriko , Yamagishi Kazutoshi , Takatsuto Suguru , Fujioka Shozo , Murofushi Noboru , Yamaguchi Isomaro , Yoshida Shigeo
Published: July 2002

Screening for brassinosteroid (BR) biosynthesis inhibitors was performed to find chemicals that induce dwarfism in Arabidopsis, mutants that resembled BR biosynthesis mutants that can be rescued by BR. Through this screening experiment, the compound brassinazole was selected as the most potent chemical. In dark-grown Arabidopsis, brassinazole-induced morphological changes were nearly restored to those of wild type by treatment with brassinolide. The structure of brassinazole is similar to pacrobutrazol, a gibberellin biosynthesis inhibitor. However, in assays with cress (Lepidium sativum) plants, brassinazole-treated plants did not show recovery after the addition of gibberellin but showed good recovery after the addition of brassinolide. These data demonstrate that brassinazole is a specific BR biosynthesis inhibitor. Brassinazole-treated cress also showed dwarfism, with altered leaf morphology, including the downward curling and dark green color typical of Arabidopsis BR-deficient mutants, and this dwarfism was reversed by the application of 10 nm brassinolide. This result suggests that BRs are essential for plant growth, and that brassinazole can be used to clarify the function of BRs in plants as a complement to BR-deficient mutants. The brassinazole action site was also investigated by feeding BR biosynthesis intermediates to cress grown in the light.
Isolation and Characterization of Plant N-Acetyl Glucosaminyltransferase I (GntI) cDNA Sequences. Functional Analyses in the Arabidopsis cgl Mutant and in Antisense Plants
Authors: Wenderoth Irina , von Schaewen Antje
Published: July 2002

We report on the isolation and characterization of full-length cDNA sequences coding for N-acetylglucosaminyltransferase I (GnTI) from potato (Solanum tuberosum L.), tobacco (Nicotiana tabacum L.), and Arabidopsis. The deduced polypeptide sequences show highest homology among the solanaceous species (93% identity between potato and tobacco compared with about 75% with Arabidopsis) but share only weak homology with human GnTI (35% identity). In contrast to the corresponding enzymes from animals, all plant GnTI sequences identified are characterized by a much shorter hydrophobic membrane anchor and contain one putativeN-glycosylation site that is conserved in potato and tobacco, but differs in Arabidopsis. Southern-blot analyses revealed that GntI behaves as a single-copy gene. Northern-blot analyses showed that GntI-mRNA expression is largely constitutive. Arabidopsis cgl mutants deficient in GnTI activity also possess GntI mRNA, indicating that they result from point mutations. GntI-expression constructs were tested for the ability to relieve the GnTI block in protoplasts of the Arabidopsis cgl mutant and used to obtain transgenic potato and tobacco plants that display a substantial reduction of complex glycan patterns. The latter observation indicates that production of heterologous glycoproteins with little or no antigenic glycans can be achieved in whole plants, and not in just Arabidopsis, using antisense technology.
Calcium-Mediated Signaling during Sandalwood Somatic Embryogenesis. Role for Exogenous Calcium as Second Messenger
Authors: Anil Veena S. , Rao K. Sankara
Published: July 2002

The possible involvement of Ca2+-mediated signaling in the induction/regulation of somatic embryogenesis from pro-embryogenic cells of sandalwood (Santalum album) has been investigated. 45Ca2+-uptake studies and fura-2 fluorescence ratio photometry were used to measure changes in [Ca2+]cyt of pro-embryogenic cells in response to culture conditions conducive for embryo development. Sandalwood pro-embryogenic cell masses (PEMs) are obtained in the callus proliferation medium that contains the auxin 2,4-dichlorophenoxyacetic acid. Subculture of PEMs into the embryo differentiation medium, which lacks 2,4-dichlorophenoxyacetic acid and has higher osmoticum, results in a 4-fold higher45Ca2+ incorporation into the symplast. Fura-2 ratiometric analysis corroboratively shows a 10- to 16-fold increase in the [Ca2+]cyt of PEMs, increasing from a resting concentration of 30 to 50 nm to 650 to 800 nm. Chelation of exogenous Ca2+ with ethyleneglycol-bis(aminoethyl ether)-N,N′-tetraacetic acid arrests such an elevation in [Ca2+]cyt. Exogenous Ca2+ when chelated or deprived also arrests embryo development and inhibits the accumulation of a sandalwood Ca2+-dependent protein kinase. However, such culture conditions do not cause cell death as the PEMs continue to proliferate to form larger cell clumps. Culture treatment withN-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide reduced embryogenic frequency by 85%, indicating that blockage of Ca2+-mediated signaling pathway(s) involving sandalwood Ca2+-dependent protein kinase and/or calmodulin causes the inhibition of embryogenesis. The observations presented are evidence to suggest a second messenger role for exogenous Ca2+ during sandalwood somatic embryogenesis.
Ethylene Perception by the ERS1 Protein in Arabidopsis
Authors: Hall Anne E. , Findell Jennifer L. , Schaller G. Eric , Sisler Edward C. , Bleecker Anthony B.
Published: July 2002

Ethylene perception in Arabidopsis is controlled by a family of five genes, including ETR1, ERS1(ethylene response sensor 1), ERS2, ETR2, and EIN4. ERS1, the most highly conserved gene with ETR1, encodes a protein with 67% identity to ETR1. To clarify the role of ERS1 in ethylene sensing, we biochemically characterized the ERS1 protein by heterologous expression in yeast. ERS1, like ETR1, forms a membrane-associated, disulfide-linked dimer. In addition, yeast expressing the ERS1 protein contains ethylene-binding sites, indicating ERS1 is also an ethylene-binding protein. This finding supports previous genetic evidence that isoforms of ETR1 also function in plants as ethylene receptors. Further, we used the ethylene antagonist 1-methylcyclopropene (1-MCP) to characterize the ethylene-binding sites of ERS1 and ETR1. We found 1-MCP to be both a potent inhibitor of the ethylene-induced seedling triple response, as well as ethylene binding by yeast expressing ETR1 and ERS1. Yeast expressing ETR1 and ERS1 showed nearly identical sensitivity to 1-MCP, suggesting that the ethylene-binding sites of ETR1 and ERS1 have similar affinities for ethylene.
Radial Distribution Pattern of Pectin Methylesterases across the Cambial Region of Hybrid Aspen at Activity and Dormancy
Authors: Micheli Fabienne , Sundberg Björn , Goldberg Renée , Richard Luc
Published: July 2002

Biochemical microanalysis combined with tangential cryosectioning was used to visualize the distribution of pectin methylesterases (PMEs) across the cambial region in active and dormant hybrid aspen (Populus tremula L. × Populus tremuloides Michx). These novel techniques allowed us to relate activity and isoforms of PMEs to specific tissues and developmental stages of the stem to get more information on the physiological function of PMEs in cambial growth. Isoelectrofocusing analysis revealed numerous isoforms that were differentially distributed according to the tissue-type and to the cambial stage. A neutral isoform was found to be distributed ubiquitously across the stem of both active and dormant trees, which suggests that it is a housekeeping isoform involved in the maintenance of the cell wall integrity throughout the stem. In addition, two distinct isoforms having different isoelectric points were found to be related to the differentiation of cambial derivatives. A basic isoform appears to be a physiological marker of the dormant stage involved in the cessation of meristematic radial growth, whereas an acidic isoform is functionally related to the immediate expansion of the cambial daughter cells that occurs bilaterally on each side of the cambium at the active stage.
The Arabidopsis UVH1 Gene Is a Homolog of the Yeast Repair Endonuclease RAD1
Authors: Fidantsef Ana Lena , Mitchell David Lewis , Britt Anne Bagg
Published: July 2002

Ultraviolet radiation induces DNA damage products, largely in the form of pyrimidine dimers, that are both toxic and mutagenic. In most organisms, including Arabidopsis, these lesions are repaired both through a dimer-specific photoreactivation mechanism and through a less efficient light-independent mechanism. Several mutants defective in this “dark repair” pathway have been previously described. The mechanism of this repair has not been elucidated, but is thought to be homologous to the nucleotide excision repair mechanisms found in other eukaryotes. Here we report the complementation of the Arabidopsisuvh1 dark repair mutant with the Arabidopsis homolog of the yeast nucleotide excision repair gene RAD1, which encodes one of the subunits of the 5′-repair endonuclease. Theuvh1-2 mutant allele carries a glycine→aspartate amino acid change that has been previously identified to produce a null allele of RAD1 in yeast. Although Arabidopsis homologs of genes involved in nucleotide excision repair are readily identified by searching the genomic database, it has not been established that these homologs are actually required for dark repair in plants. The complementation of the Arabidopsisuvh1 mutation with the Arabidopsis RAD1homolog clearly demonstrates that the mechanism of nucleotide excision repair is conserved among the plant, animal, and fungal kingdoms.
Localization of a Nod Factor-Binding Protein in Legume Roots and Factors Influencing Its Distribution and Expression
Authors: Kalsi Gurpreet , Etzler Marilynn E.
Published: July 2002

The roots of the legume Dolichos biflorus contain a lectin/nucleotide phosphohydrolase (Db-LNP) that binds to the Nod factor signals produced by rhizobia that nodulate this plant. In this study we show that Db-LNP is differentially distributed along the surface of the root axis in a pattern that correlates with the zone of nodulation of the root. Db-LNP is present on the surface of young and emerging root hairs and redistributes to the tips of the root hairs in response to treatment of the roots with a rhizobial symbiont or with a carbohydrate ligand. This redistribution does not occur in response to a non-symbiotic rhizobial strain or a root pathogen. Db-LNP is also present in the root pericycle where its level decreases upon initiation of nodule formation. Maximum levels of Db-LNP are found in 2-d-old roots, and the expression of this root protein is increased when the plants are grown in the absence of NO3  − and NH4  +. These results support the possibility that Db-LNP is involved in the initiation of theRhizobium legume symbiosis.
Dynamic Localization of Rop GTPases to the Tonoplast during Vacuole Development
Authors: Lin Yakang , Seals Darren F. , Randall Stephen K. , Yang Zhenbiao
Published: July 2002

Vacuoles are essential pleomorphic organelles that undergo dynamic changes during cell growth and differentiation in plants. How developmental signals are linked to vacuole biogenesis and development is poorly understood. In this report, we show that a Rop GTPase is localized to developing vacuoles in pea (Pisum sativum cv Extra Early Alaska). Rop belongs to the RHO family of Ras-related small GTP-binding proteins that are key molecular switches in a wide variety of eukaryotic signal transduction pathways. Using indirect immunofluorescence and an anti-Rop antibody, we showed that Rop proteins accumulate to high levels in rapidly growing tapetal cells of pea anthers. In these cells, Rop is localized to an endomembrane system that exists as dynamic pleomorphic networks: a perinuclear fine network decorated with punctate dots, a network composed of small spheres and tubules, and interconnected chambers. Colocalization with a tonoplast annexin VCaB42 shows that these dynamic networks represent the tonoplast. Our results suggest that the dynamic Rop-containing tonoplast networks represent a unique stage of vacuole development. The specific localization of Rop to developing vacuoles supports a role for Rop in signal transduction that mediates vacuole development in plants.
A Role for Inositol 1,4,5-Trisphosphate in Gravitropic Signaling and the Retention of Cold-Perceived Gravistimulation of Oat Shoot Pulvini
Authors: Perera Imara Y. , Heilmann Ingo , Chang Soo Chul , Boss Wendy F. , Kaufman Peter B.
Published: July 2002

Plants sense positional changes relative to the gravity vector. To date, the signaling processes by which the perception of a gravistimulus is linked to the initiation of differential growth are poorly defined. We have investigated the role of inositol 1,4,5-trisphosphate (InsP3) in the gravitropic response of oat (Avena sativa) shoot pulvini. Within 15 s of gravistimulation, InsP3 levels increased 3-fold over vertical controls in upper and lower pulvinus halves and fluctuated in both pulvinus halves over the first minutes. Between 10 and 30 min of gravistimulation, InsP3 levels in the lower pulvinus half increased 3-fold over the upper. Changes in InsP3 were confined to the pulvinus and were not detected in internodal tissue, highlighting the importance of the pulvinus for both graviperception and response. Inhibition of phospholipase C blocked the long-term increase in InsP3, and reduced gravitropic bending by 65%. Short-term changes in InsP3 were unimpaired by the inhibitor. Gravitropic bending of oat plants is inhibited at 4°C; however, the plants retain the information of a positional change and respond at room temperature. Both short- and long-term changes in InsP3 were present at 4°C. We propose a role for InsP3 in the establishment of tissue polarity during the gravitropic response of oat pulvini. InsP3 may be involved in the retention of cold-perceived gravistimulation by providing positional information in the pulvini prior to the redistribution of auxin.
Cellular and Subcellular Localization ofS-Adenosyl-l-Methionine:Benzoic Acid Carboxyl Methyltransferase, the Enzyme Responsible for Biosynthesis of the Volatile Ester Methylbenzoate in Snapdragon Flowers
Authors: Kolosova Natalia , Sherman Debra , Karlson Dale , Dudareva Natalia
Published: July 2002

The benzenoid ester, methylbenzoate is one of the most abundant scent compounds detected in the majority of snapdragon (Antirrhinum majus) varieties. It is produced in upper and lower lobes of petals by enzymatic methylation of benzoic acid in the reaction catalyzed byS-adenosyl-l-methionine:benzoic acid carboxyl methyltransferase (BAMT). To identify the location of methylbenzoate biosynthesis, we conducted an extensive immunolocalization study by light and electron microscopy at cellular and subcellular levels using antibodies against BAMT protein. BAMT was immunolocalized predominantly in the conical cells of the inner epidermal layer and, to a much lesser extent, in the cells of the outer epidermis of snapdragon flower petal lobes. It was also located in the inner epidermis of the corolla tube with little BAMT protein detected in the outer epidermis and in the yellow hairs within the tube on the bee's way to the nectar. These results strongly suggest that scent biosynthetic genes are expressed almost exclusively in the epidermal cells of floral organs. Immunogold labeling studies reveal that BAMT is a cytosolic enzyme, suggesting cytosolic location of methylbenzoate biosynthesis. The concentration of scent production on flower surfaces that face the pollinators during landing may increase pollination efficiency and also help to minimize the biosynthetic cost of advertising for pollinators.
Eukaryotic Peptide Deformylases. Nuclear-Encoded and Chloroplast-Targeted Enzymes in Arabidopsis
Authors: Dirk Lynnette M.A. , Williams Mark A. , Houtz Robert L.
Published: July 2002

Arabidopsis (ecotype Columbia-0) genes,AtDEF1and AtDEF2, represent eukaryotic homologs of the essential prokaryotic gene encoding peptide deformylase. Both deduced proteins contain three conserved protein motifs found in the active site of all eubacterial peptide deformylases, and N-terminal extensions identifiable as chloroplast-targeting sequences. Radiolabeled full-lengthAtDEF1 was imported and processed by isolated pea (Pisum sativum L. Laxton's Progress No. 9) chloroplasts and AtDEF1 and 2 were immunologically detected in Arabidopsis leaf and chloroplast stromal protein extracts. The partial cDNAs encoding the processed forms of Arabidopsis peptide deformylase 1 and 2 (pAtDEF1 and 2, respectively) were expressed inEscherichia coli and purified using C-terminal hexahistidyl tags. Both recombinant Arabidopsis peptide deformylases had peptide deformylase activity with unique kinetic parameters that differed from those reported for the E. coli enzyme. Actinonin, a specific peptide deformylase inhibitor, was effective in vitro against Arabidopsis peptide deformylase 1 and 2 activity, respectively. Exposure of several plant species including Arabidopsis to actinonin resulted in chlorosis and severe reductions in plant growth and development. The results suggest an essential role for peptide deformylase in protein processing in all plant plastids.
Inhibition effect of oxalic acid on copper corrosion
Authors: Baah C.A. , Baah J.I.
Published: July 2002

This paper deals with the inhibition effect of oxalic acid on the corrosion of copper in concentrated propionic and dilute citric acid solutions. The copper samples (in acid solutions) were left in a water bath for a period of six days and were examined on a daily basis. The solutions were continuously fed with oxygen (air) and the temperature of the solutions was always maintained at 30°C. The oxalic acid in all three cases behaved like an inhibitor under the experimental conditions. The mass of the copper samples increased due to the formation of oxide layers on the surfaces of the samples.
Energy conservation with the use of solar selective coatings
Authors: Lata Pandey Jyoti , Banerjee M.K.
Published: July 2002

Solar selective coatings are designed and formulated for effective collection and retention of solar energy. Several types of coatings can be utilized for economical collection of solar energy, the most common and simplest will be ordinary non‐glass, heat resistant black paint. The coatings may be moderately selective or non‐selective absorbers, consisting of organic or inorganic matt black paints. These are easiest to apply and the least expensive of all collector coatings. In this category other types are ceramic and organic enamels and chemical or electrochemical metal conversion coatings. An impending energy crisis has already aroused interest and scientific pursuit in the field. An analysis of the state‐of‐the‐art in solar selective coatings was felt necessary at this time.
Developing and Measuring the Learning Organization
Authors: Campbell Terry , Cairns Heather
Published: July 2002

Definitions, development and measurement must be applied to the concept of the learning organization to move it towards implementation. Many definitions have captured the essence of the learning organization but, until the characteristics or “attributes” are defined, it will remain difficult to move the concept forward, because it is the definition of these attributes that allows an examination of the behaviours which will either encourage or inhibit organizational learning. These behaviours can be measured using behaviourally anchored rating scales which indicate strengths and weaknesses which can be improved through action.
Nutritional effects of microwave cooking
Authors: Lassen Anne , Ovesen Lars
Published: July 2002

Several studies have shown that microwave cooking, if properly
used, does not change the nutrient content of foods to a larger extent
than conventional heating. In fact, suggests that there is a tendency
towards greater retention of many micronutrients with microwaving,
probably due to the shorter preparation time. Does not describe
non‐thermal effects. The main problem with microwaving is the uneven
heating of the food, which has raised concern regarding microbiological
safety. Microwaving infant formula and breast milk has become
increasingly popular. The content of nutrients and antibacterial factors
in milk are maintained unchanged provided the final temperature does not
exceed 60°C.
Students’ perspectives of workplace learning and training in vocational education
Authors: Velde Christine , Cooper Tom
Published: July 2002

Reports on the evaluation of a programme which was designed to enable students to complete a traineeship or apprenticeship, and their senior certificate in accordance with a variety of combined school and work programmes, including the New Apprenticeship Scheme. A multimethod approach was adopted which includes interviews with students, vocational educators and employers regarding their perceptions of: competencies, learning outcomes and training acquired during the programme. The results of the interviews with the students illustrated some similar and different perceptions between teachers and students, and showed that students’ main reason for undertaking the vocational education programme were the opportunity to gain “hands on” experience, and a “headstart” to employment. Implications for further research included: an investigation into the perceived status barrier between vocational and general education, the development of work attitudes; and the implementation of a strategic business and marketing plan.
Executive learning in entrepreneurial firms and the role of external directors
Authors: Deakins David , O’Neill Eileen , Mileham Patrick
Published: July 2002

Provides an analysis of the role of “external” or non‐executive directors and their relationship with executive entrepreneurs in small but entrepreneurial (growing) companies, focusing on their influence on executive learning. We provide qualitative analysis of research based on 45 face‐to‐face interviews. Despite the importance given to individual executive and organisational learning in large companies, comparatively little literature exists on executive entrepreneurial learning in small companies. The factors that can affect such learning are discussed with emphasis on the role played by external directors who, it is argued, are likely to be appointed in such companies due to the need for additional expertise and knowledge in a rapidly changing environment.
The role of employee development in the growth of intellectual capital
Authors: Mayo Andrew
Published: July 2002

The focus on costs that characterised organisations in the 1980s and early 1990s is now being replaced by an interest in the concept of value. In assessing value, it is the “intangible assets” of an organisation that are likely to be worth considerably more than the measured tangible ones. Traditional accounting systems find themselves challenged as a result. These intangible assets need to be understood and identified. People form a very critical part of them, and indeed the “human capital” can be logically argued to be the ultimate driver of all value growth. The contribution of human capital to current and future value for stakeholders is examined. The key conditions for such growth are suggested as individual capability, individual motivation, leadership, the organisational climate, and workgroup effectiveness. Each of these is examined in some detail together with options for quantifiable measures. Employee development, including the continuing generation and exchange of knowledge and experience, is concluded to be the key driver of value growth in any kind of organisation.
The employment situation of young Chinese adults in the British labour market
Authors: Pang Mary
Published: July 2002

Chinese participation in the catering industry is conspicuous in Britain, but there also appears to be an emergence of young Chinese adults diversifying into other occupations and sectors in the British labour market. This paper seeks to gain an understanding of where young Chinese adults are positioned in the occupational structure, why they are situated there, and their attitudes towards their current jobs. The findings indicate that as a result of the interaction between structure and culture there is an emerging bimodal distribution of young Chinese adults in the British labour market with a tendency for young Chinese adults either to work in the professions and other white collar jobs or conversely to be employed in the service sector (that is, the Chinese catering industry).
Academics and their managers: a comparative study in job satisfaction
Authors: Oshagbemi Titus
Published: July 2002

A number of research findings have suggested that managers are, in general, more satisfied with their jobs than are workers. This study aims to investigate the job satisfaction of academics and their managers, and to find out whether academics who hold managerial positions are, on the whole, more satisfied with their jobs than academics who do not hold similar administrative posts. The study found that university teachers are fairly satisfied with their jobs, although there are aspects of their jobs from which they derive some dissatisfaction. Using a statistical test of differences, it was found that academics and their managers differ significantly on the levels of satisfaction which they derive from most aspects of their jobs. Sources of these differences are identified, and the general conclusion is that management position, characterised by seniority in age, rank, and length of service, affects university teachers’ level of job satisfaction positively.
Collection Development: The Experience of Kenya Polytechnic Library
Authors: Odini Cephas
Published: July 2002

Discusses fundamental problems encountered at the Kenya Polytechnic
Library in collection development, particularly the problems of
inadequate funding, lack of collection development policy and those
associated with foreign purchases. Highlights the various factors which
librarians at the polytechnic ought to consider in order to realize
brighter collection development prospects. These factors include the
formulation of suitable collection development policy, the organization
of gifts and exchange practices and participation in resource‐sharing
programmes with other national polytechnics and universities. Suggests
an introduction of library development levy and also the practice of
collection weeding.
Personality and leadership: a benchmark study of success and failure
Authors: Havaleschka Finn
Published: July 2002

Does the top‐level management team make the difference between a company’s success and failure? By using two different assessment tools (developed on the model of the Head‐Heart‐Leg work of the personality) to map the personalities of the members of two management teams, including the top executive managers, and by following the development in the companies’ results over a period of five years, it is shown that the personality of the executive manager and the team he is selecting is the key to understanding a company’s rise or decline in the market. Managers with an average level of cognitive skills tend to select managers with the same or lower level of cognitive skills and style. Therefore, when an executive manager is recruiting managers to his team, be sure that someone with authority is a part of the process to ensure that he is not selecting clones of himself.
Leading through communication, conversation and dialogue
Authors: April Kurt A.
Published: July 2002

South Africa has gone through a period of unprecedented change in moving from Apartheid to democracy. These sociological changes have also infiltrated organisational life and behaviour – and new approaches to leadership have become vital. In modern organisational life, dialogue and conversation are core processes for building the organisational intelligence and community which enable other business processes to adapt to change and create results. This paper discusses increasingly important leadership issues – such as diversity, teams, collaboration, trust formation, community, individual change, and relationships – in relation to dialogue and transformation. Where trust is high, change is managed more effectively and, where it is low, communication and co‐operation suffer and there is an increasing tendency to resort to power. It is the author’s concluding opinion that change is a phenomenon that occurs within conversation and dialogue! and is therefore a necessary social construct within twenty‐first century organisations.
Process mapping: a valuable tool for construction management and other professionals
Authors: Anjard Ron
Published: July 2002

Process mapping is a very effective tool, but often overlooked, in determining what the present process is, evaluating other potential improved processes and determining an optimum process. This is an invaluable tool for effective re‐engineering. It is best used at the micro‐level, and it is essential to consider interfaces and time factors. A process map is used to understand your business and improve the performance of your processes.
An alternative linearization technique
Authors: Mueller Keith M. , Burns Scott A.
Published: July 2002

The numerical treatment of non‐linear engineering phenomena often involves some sort of mathematical simplification. In many cases, the system under investigation is linearized about an operating point using the linear part of the Taylor’s series expansion. This allows local representation for use in incremental or iterative methods using well‐established computational tools for linear algebra. Demonstrates a different linearization technique that generally provides a higher quality fit to a certain class of functions than the standard Taylor linearization. This class of functions is general enough to represent all systems of algebraic equations. Presents a graphical demonstration of the quality of fit along with a discussion of why this alternative linearization provides a high quality fit. Also presents an engineering application of the linearization.
The emerging patterns of power in corporate governance – Back to the future in improving corporate decision making
Authors: Cutting Bruce , Kouzmin Alexander
Published: July 2002

Social institutions are experiencing change in their patterns of power as they are re‐aligned to an increasingly complex world and the onset of the new information economy. Attention has been drawn particularly to the need to improve corporate governance as a means to enhance corporate accountability and improve corporate performance. This paper consequently explores the distribution of corporate power and the processes that can foster higher quality decision making and actions by boards. The paper investigates the fundamental difference between the exercise of leadership, management and political power within an organization and, particularly, the responsibility and power relationships between an organization and its board. The authors assert that if the patterns of power are well understood then some things can be said about the patterns that are likely to emerge and what structures might be more effective than others. The paper concludes by arguing that the manner and style of corporate governance could benefit from some further refinement.
The value of the facilities management function in the UK NHS community health‐care sector
Authors: Featherstone Paul , Baldry David
Published: July 2002

This paper stresses the importance of the strategic integration of the organisational facilities management function as being an essential prerequisite towards facilities and organisational effectiveness. The impact of both the strategic and operational facilities management function on community health‐care facility users is also documented. The value of the facilities management function in terms of other health‐care related organisational core deliverables is also observed. Mechanisms for general organisational facilities management improvement are identified and a number of facilities management performance measuring tools outlined.
Flexible circuitry ‐ technology background and important fundamental issues
Authors: Fjelstad Joseph
Published: July 2002

“A patterned arrangement of printed wiring utilizing flexible base material with or without flexible coverlayers”. The balance of this brief article will hopefully serve to help the reader understand this remarkable interconnection technology and appreciate just how widely the technology can be applied.
An energy‐transport model for semiconductor heterostructure devices: application to AlGaAs/GaAs MODFETs
Authors: Lab Cedric , Caussignac Philippe
Published: July 2002

A stationary 3D energy‐transport model valid for semiconductor heterostructure devices is derived from a semiclassical Boltznmann equation by the moment method. In addition to the well‐known conservation equations, we obtain original interface conditions, which are essential to have a mathematically well‐posed problem. An appropriate modelling of the physical parameters appearing in the system of equations is proposed for gallium arsenide. The model being written and its particularities mentioned, we present a novel numerical algorithm to solve it. The discretization of the equations is achieved by means of standard and mixed finite element methods. We apply the model and numerical algorithm to simulate a 2D AlGaAs/GaAs MODFET. Comparisons between expenrimental measurements and calculations are carried out. The influence of the modelling of the physical parameters, especially the electron mobility and the energy relaxation time, is noted. The results show the satisfactory behaviour of our model and numerical algorithm when applied to GaAs heterostructure devices.
The Centre for Professional Development at the University of Auckland: towards creating networks of moral obligations
Authors: Macpherson Reynold J.S.
Published: July 2002

Addresses briefly five complex issues in higher education: professional development spanning all categories of staff; the role of a centre of professional development (CPD) in context; the philosophical framework and models within which a centre might operate; the role of a centre in strategic planning and policy formation, and the contribution that a CPD might make in assessing and enhancing quality. Develops four main arguments with regard to the CPD at the University of Auckland. The CPD should support continuous improvement, promote organizational learning, and provide policy and practical advice regarding the management of quality. It should conduct organizational research and development, primarily through international benchmarking. The CPD also needs to research the implications of information technology, especially in the reconstruction of teaching, research and organization. Above all it needs to understand its organizational role of helping to construct cultural networks of mutual moral obligations.
A preliminary study of the low‐load lateral impact compression of fabrics
Authors: Taylor P.M. , Pollet D.M.
Published: July 2002

A swinging pendulum is arranged to impact and bounce from a fabric sample. The energy losses during impact compression are calculated from the changes in potential energy of the pendulum after allowing for other losses. It is found that the compression energy loss, calculated from the static characteristics, gives only a rough guide to the impact compression losses, so other factors must be considered. Further experimental work is proposed to determine more precisely the contribution of the fabric properties to these differences in the characteristics.
Effect of seams on fabric drape
Authors: Hu Jinlian , Chung Siuping , Lo Ming‐tak
Published: July 2002

Presents a study of the relationships between fabric drapeability and seam allowance, seam position and seam directions in terms of drape coefficient, bending length and draped profile. Concludes that by the results obtained from the sewn specimens, the draped profile of a fabric without a seam can be predicted and proved by extended experimental work. Suggests that the knowledge gained from present research on fabric drape will be useful in the determination of the drape profile on garment in practical use. Moreover, it has significant value in paving the way for establishing clothing CAD systems, and sheds light on fundamental mechanisms operating in fabric drape behaviour.
A Decade of Teacher Empowerment: An Empirical Analysis of Teacher
Involvement in Decision Making, 1980‐1991
Authors: Rice Ellen Marie , Schneider Gail T.
Published: July 2002

During the past decade considerable attention has been placed on
enhancing teacher professionalism primarily through increasing teacher
participation in decision making regarding issues affecting teachers′
schools and classrooms. This focus on teacher involvement in decision
making is not without precedent. Studies pertaining to participative
decision making have guided the field and practice of educational
administration for over 40 years. Nonetheless, questions continue to
persist regarding how to engage teachers most effectively in decision
making. Is a replication of a study conducted in 1980 which investigated
the extent of teacher involvement in schoolwide and instructional
issues, teachers′ interest and expertise in decision issues, and
teachers′ job satisfaction. The intent of the replication was to
determine if, after a decade of attention on enhancing teacher
involvement in decision making, teachers′ perceptions of their actual
and desired involvement and their job satisfaction have changed. This
study tested empirically the relationships between levels of teacher
involvement in decision making, teachers′ interest and expertise
regarding selected decision issues, and teacher job satisfaction. In
addition, this study explored possible relationships between changes in
teachers′ decision involvement and the reform initiatives of site‐based
management.
Principals’ role in policy change: mediating language through professional beliefs
Authors: Binkley Nadine
Published: July 2002

Considers the language of professional development and demonstrates how principals with different professional beliefs and understandings interpret the language of education differently. This work is based on a two‐year study of eight principals in a school district undergoing a policy change in the supervision and evaluation of teachers. Because principals mediate through their professional beliefs the language of both policy change and professional development that leads to policy change, groups of principals within a single district may interpret and implement policy change differently. Shows that principals do not necessarily have a common understanding of the language of education. Without a common understanding of language, policy is open to individual interpretation.