bluuebunny/crossref_metadata_2025 huggingface dataset:
Phloem Loading. A Reevaluation of the Relationship between Plasmodesmatal Frequencies and Loading Strategies
Authors: Turgeon Robert , Medville Richard
Published: November 2004

The incidence of plasmodesmata in the minor vein phloem of leaves varies widely between species. On this basis, two pathways of phloem loading have been proposed: symplastic where frequencies are high, and apoplastic where they are low. However, putative symplastic-loading species fall into at least two categories. In one, the plants translocate raffinose-family oligosaccharides (RFOs). In the other, the primary sugar in the phloem sap is sucrose (Suc). While a thermodynamically feasible mechanism of symplastic loading has been postulated for species that transport RFOs, no such mechanism is known for Suc transporters. We used p-chloromercuribenzenesulfonic acid inhibition of apoplastic loading to distinguish between the two pathways in three species that have abundant minor vein plasmodesmata and are therefore putative symplastic loaders. Clethra barbinervis and Liquidambar styraciflua transport Suc, while Catalpa speciosa transports RFOs. The results indicate that, contrary to the hypothesis that all species with abundant minor vein plasmodesmata load symplastically, C. barbinervis and L. styraciflua load from the apoplast. C. speciosa, being an RFO transporter, loads from the symplast, as expected. Data from these three species, and from the literature, also indicate that plants with abundant plasmodesmata in the minor vein phloem have abundant plasmodesmata between mesophyll cells. Thus, plasmodesmatal frequencies in the minor veins may be a reflection of overall frequencies in the lamina and may have limited relevance to phloem loading. We suggest that symplastic loading is restricted to plants that translocate oligosaccharides larger than Suc, such as RFOs, and that other plants, no matter how many plasmodesmata they have in the minor vein phloem, load via the apoplast.
Sequence and Comparative Analysis of the Maize NB Mitochondrial Genome
Authors: Clifton Sandra W. , Minx Patrick , Fauron Christiane M.-R. , Gibson Michael , Allen James O. , Sun Hui , Thompson Melissa , Barbazuk W. Brad , Kanuganti Suman , Tayloe Catherine , Meyer Louis , Wilson Richard K. , Newton Kathleen J.
Published: November 2004

The NB mitochondrial genome found in most fertile varieties of commercial maize (Zea mays subsp. mays) was sequenced. The 569,630-bp genome maps as a circle containing 58 identified genes encoding 33 known proteins, 3 ribosomal RNAs, and 21 tRNAs that recognize 14 amino acids. Among the 22 group II introns identified, 7 are trans-spliced. There are 121 open reading frames (ORFs) of at least 300 bp, only 3 of which exist in the mitochondrial genome of rice (Oryza sativa). In total, the identified mitochondrial genes, pseudogenes, ORFs, and cis-spliced introns extend over 127,555 bp (22.39%) of the genome. Integrated plastid DNA accounts for an additional 25,281 bp (4.44%) of the mitochondrial DNA, and phylogenetic analyses raise the possibility that copy correction with DNA from the plastid is an ongoing process. Although the genome contains six pairs of large repeats that cover 17.35% of the genome, small repeats (20–500 bp) account for only 5.59%, and transposable element sequences are extremely rare. MultiPip alignments show that maize mitochondrial DNA has little sequence similarity with other plant mitochondrial genomes, including that of rice, outside of the known functional genes. After eliminating genes, introns, ORFs, and plastid-derived DNA, nearly three-fourths of the maize NB mitochondrial genome is still of unknown origin and function.
Investigations into the Role of the Plastidial Peptide Methionine Sulfoxide Reductase in Response to Oxidative Stress in Arabidopsis
Authors: Romero Hernán M. , Berlett Barbara S. , Jensen Philip J. , Pell Eva J. , Tien Ming
Published: November 2004

Peptidyl Met residues are readily oxidized by reactive oxygen species to form Met sulfoxide. The enzyme peptide Met sulfoxide reductase (PMSR) catalyzes the reduction of Met sulfoxides back to Met. In doing so, PMSR is proposed to act as a last-chance antioxidant, repairing proteins damaged from oxidative stress. To assess the role of this enzyme in plants, we generated multiple transgenic lines with altered expression levels of the plastid form of PMSR (PMSR4). In transgenic plants, PMSR4 expression ranged from 95% to 40% (antisense) and more than 600% (overexpressing lines) of wild-type plants. Under optimal growing conditions, there is no effect of the transgene on the phenotype of the plants. When exposed to different oxidative stress conditions—methyl viologen, ozone, and high light—differences were observed in the rate of photosynthesis, the maximum quantum yield (F  v/F  m ratio), and the Met sulfoxide content of the isolated chloroplast. Plants that overexpressed PMSR4 were more resistant to oxidative damage localized in the chloroplast, and plants that underexpressed PMSR4 were more susceptible. The Met sulfoxide levels in proteins of the soluble fraction of chloroplasts were increased by methyl viologen and ozone, but not by high-light treatment. Under stress conditions, the overexpression of PMSR4 lowered the sulfoxide content and underexpression resulted in an overall increase in content.
Downstream Divergence of the Ethylene Signaling Pathway for Harpin-Stimulated Arabidopsis Growth and Insect Defense
Authors: Dong Hong-Ping , Peng Jianling , Bao Zhilong , Meng Xiangdong , Bonasera Jean M. , Chen Guangyong , Beer Steven V. , Dong Hansong
Published: November 2004

Ethylene (ET) signal transduction may regulate plant growth and defense, depending on which components are recruited into the pathway in response to different stimuli. We report here that the ET pathway controls both insect resistance (IR) and plant growth enhancement (PGE) in Arabidopsis (Arabidopsis thaliana) plants responding to harpin, a protein produced by a plant pathogenic bacterium. PGE may result from spraying plant tops with harpin or by soaking seeds in harpin solution; the latter especially enhances root growth. Plants treated similarly develop resistance to the green peach aphid (Myzus persicae). The salicylic acid pathway, although activated by harpin, does not lead to PGE and IR. By contrast, PGE and IR are induced in both wild-type plants and genotypes that have defects in salicylic acid signaling. In response to harpin, levels of jasmonic acid (JA) decrease, and the COI1 gene, which is indispensable for JA signal transduction, is not expressed in wild-type plants. However, PGE and IR are stimulated in the JA-resistant mutant jar1-1. In the wild type, PGE and IR develop coincidently with increases in ET levels and the expression of several genes essential for ET signaling. The ET receptor gene ETR1 is required because both phenotypes are arrested in the etr1-1 mutant. Consistently, inhibition of ET perception nullifies the induction of both PGE and IR. The signal transducer EIN2 is required for IR, and EIN5 is required for PGE because IR and PGE are impaired correspondingly in the ein2-1 and ein5-1 mutants. Therefore, harpin activates ET signaling while conscribing EIN2 and EIN5 to confer IR and PGE, respectively.
ARIA, an Arabidopsis Arm Repeat Protein Interacting with a Transcriptional Regulator of Abscisic Acid-Responsive Gene Expression, Is a Novel Abscisic Acid Signaling Component
Authors: Kim Sunmi , Choi Hyung-in , Ryu Hyun-Ju , Park Ji Hye , Kim Myoung Duck , Kim Soo Young
Published: November 2004

Arabidopsis (Arabidopsis thaliana) genome contains more than 90 armadillo (arm) repeat proteins. However, their functions are largely unknown. Here, we report that an Arabidopsis arm repeat protein is involved in abscisic acid (ABA) response. We carried out two-hybrid screens to identify signaling components that modulate ABA-responsive gene expression. Employing a transcription factor, ABF2, which controls the ABA-dependent gene expression via the G-box type ABA-responsive elements, we isolated an arm repeat protein. The ABF2-interacting protein, designated as ARIA (arm repeat protein interacting with ABF2), has another conserved sequence motif, BTB/POZ (broad complex, tramtrak, and bric-a-brac/poxvirus and zinc finger) domain, in the C-terminal region. The physiological relevance of ABF2-ARIA interaction was supported by their similar expression patterns and similar subcellular localization. Plants overexpressing ARIA are hypersensitive to ABA and high osmolarity during germination and insensitive to salt during subsequent seedling growth. By contrast, an ARIA knockout mutant exhibits ABA and glucose insensitivities. Changes in the expression levels of several ABF2-regulated genes were also observed in ARIA overexpression lines, indicating that ARIA modulates the transcriptional activity of ABF2. Together, our data indicate that ARIA is a positive regulator of ABA response.
Profiling of Oligolignols Reveals Monolignol Coupling Conditions in Lignifying Poplar Xylem
Authors: Morreel Kris , Ralph John , Kim Hoon , Lu Fachuang , Goeminne Geert , Ralph Sally , Messens Eric , Boerjan Wout
Published: November 2004

Lignin is an aromatic heteropolymer, abundantly present in the walls of secondary thickened cells. Although much research has been devoted to the structure and composition of the polymer to obtain insight into lignin polymerization, the low-molecular weight oligolignol fraction has escaped a detailed characterization. This fraction, in contrast to the rather inaccessible polymer, is a simple and accessible model that reveals details about the coupling of monolignols, an issue that has raised considerable controversy over the past years. We have profiled the methanol-soluble oligolignol fraction of poplar (Populus spp.) xylem, a tissue with extensive lignification. Using liquid chromatography-mass spectrometry, chemical synthesis, and nuclear magnetic resonance, we have elucidated the structures of 38 compounds, most of which were dimers, trimers, and tetramers derived from coniferyl alcohol, sinapyl alcohol, their aldehyde analogs, or vanillin. All structures support the recently challenged random chemical coupling hypothesis for lignin polymerization. Importantly, the structures of two oligomers, each containing a γ-p-hydroxybenzoylated syringyl unit, strongly suggest that sinapyl p-hydroxybenzoate is an authentic precursor for lignin polymerization in poplar.
Circadian Regulation of the PhCCD1 Carotenoid Cleavage Dioxygenase Controls Emission of β-Ionone, a Fragrance Volatile of Petunia Flowers
Authors: Simkin Andrew J. , Underwood Beverly A. , Auldridge Michele , Loucas Holly M. , Shibuya Kenichi , Schmelz Eric , Clark David G. , Klee Harry J.
Published: November 2004

Carotenoids are thought to be the precursors of terpenoid volatile compounds that contribute to flavor and aroma. One such volatile, β-ionone, is important to fragrance in many flowers, including petunia (Petunia hybrida). However, little is known about the factors regulating its synthesis in vivo. The petunia genome contains a gene encoding a 9,10(9′,10′) carotenoid cleavage dioxygenase, PhCCD1. The PhCCD1 is 94% identical to LeCCD1A, an enzyme responsible for formation of β-ionone in tomato (Lycopersicon esculentum; Simkin AJ, Schwartz SH, Auldridge M, Taylor MG, Klee HJ [2004] Plant J [in press]). Reduction of PhCCD1 transcript levels in transgenic plants led to a 58% to 76% decrease in β-ionone synthesis in the corollas of selected petunia lines, indicating a significant role for this enzyme in volatile synthesis. Quantitative reverse transcription-PCR analysis revealed that PhCCD1 is highly expressed in corollas and leaves, where it constitutes approximately 0.04% and 0.02% of total RNA, respectively. PhCCD1 is light-inducible and exhibits a circadian rhythm in both leaves and flowers. β-Ionone emission by flowers occurred principally during daylight hours, paralleling PhCCD1 expression in corollas. The results indicate that PhCCD1 activity and β-ionone emission are likely regulated at the level of transcript.
The Biochemical and Molecular Basis for the Divergent Patterns in the Biosynthesis of Terpenes and Phenylpropenes in the Peltate Glands of Three Cultivars of Basil
Authors: Iijima Yoko , Davidovich-Rikanati Rachel , Fridman Eyal , Gang David R. , Bar Einat , Lewinsohn Efraim , Pichersky Eran
Published: November 2004

Surface glandular trichomes distributed throughout the aerial parts of sweet basil (Ocimum basilicum) produce and store monoterpene, sesquiterpene, and phenylpropene volatiles. Three distinct basil chemotypes were used to examine the molecular mechanisms underlying the divergence in their monoterpene and sesquiterpene content. The relative levels of specific terpenes in the glandular trichomes of each cultivar were correlated with the levels of transcripts for eight genes encoding distinct terpene synthases. In a cultivar that produces mostly (R)-linalool, transcripts of (R)-linalool synthase (LIS) were the most abundant of these eight. In a cultivar that synthesizes mostly geraniol, transcripts of geraniol synthase were the most abundant, but the glands of this cultivar also contained a transcript of an (R)-LIS gene with a 1-base insertion that caused a frameshift mutation. A geraniol synthase-LIS hybrid gene was constructed and expressed in Escherichia coli, and the protein catalyzed the formation of both geraniol and (R)-linalool from geranyl diphosphate. The total amounts of terpenes were correlated with total levels of terpene synthase activities, and negatively correlated with levels of phenylpropanoids and phenylalanine ammonia lyase activity. The relative levels of geranyl diphosphate synthase and farnesyl diphosphate synthase activities did not correlate with the total amount of terpenes produced, but showed some correlation with the ratio of monoterpenes to sesquiterpenes.
Characterization of a Xyloglucan Endotransglucosylase Gene That Is Up-Regulated by Gibberellin in Rice
Authors: Jan Asad , Yang Guangxiao , Nakamura Hidemitsu , Ichikawa Hiroaki , Kitano Hidemi , Matsuoka Makoto , Matsumoto Hiroshi , Komatsu Setsuko
Published: November 2004

Xyloglucan endotransglucosylases/hydrolases (XTHs) that mediate cleavage and rejoining of the β (1-4)-xyloglucans of the primary cell wall are considered to play an important role in the construction and restructuring of xyloglucan cross-links. A novel rice (Oryza sativa) XTH-related gene, OsXTH8, was cloned and characterized after being identified by cDNA microarray analysis of gibberellin-induced changes in gene expression in rice seedlings. OsXTH8 was a single copy gene; its full-length cDNA was 1,298 bp encoding a predicted protein of 290 amino acids. Phylogenetic analysis revealed that OsXTH8 falls outside of the three established subfamilies of XTH-related genes. OsXTH8 was preferentially expressed in rice leaf sheath in response to gibberellic acid. In situ hybridization and OsXTH8 promoter GUS fusion analysis revealed that OsXTH8 was highly expressed in vascular bundles of leaf sheath and young nodal roots where the cells are actively undergoing elongation and differentiation. OsXTH8 gene expression was up-regulated by gibberellic acid and there was very little effect of other hormones. In two genetic mutants of rice with abnormal height, the expression of OsXTH8 positively correlated with the height of the mutants. Transgenic rice expressing an RNAi construct of OsXTH8 exhibited repressed growth. These results indicate that OsXTH8 is differentially expressed in rice leaf sheath in relation to gibberellin and potentially involved in cell elongation processes.
High-pressure neutron powder diffraction study of theIm\bar{3} phase of ReO3
Authors: Jørgensen J.-E. , Marshall W. G. , Smith R. I. , Staun Olsen J. , Gerward L.
Published: November 2004

The structure of ReO3has been studied over the pressure range from 1.27 to 8.01 GPa by neutron powder time-of-flight diffraction as well as by X-ray diffraction up to 41 GPa using Fluorinert as the pressure-transmitting medium. The cubic Im\bar{3} phase was found to be stable in the pressure range 0.5 to 13.2 GPa and to be highly compressible with a zero-pressure bulk modulus ofBo= 43 (1) GPa. The neutron data were used in least-squares refinements, showing that the ReO6octahedra remain almost undistorted, while the Re—O—Re bond angle decreases from 166.5 (1) to 146.4 (3)° within the investigated pressure range of 1.27 to 8.01 GPa. The compression mechanism is also described in terms of sphere-packing models of the oxygen anions.
STEREOPOLE: software for the analysis of X-ray diffraction pole figures with IDL
Authors: Salzmann Ingo , Resel Roland
Published: November 2004

STEREOPOLEis a software package for the analysis of X-ray diffraction pole figures. It allows experimental data to be compared graphically with simulated results, and epitaxic relationships to be evaluated between up to five different crystal layers.STEREOPOLEhas been developed in IDL 6.0 (Interactive Data Language) and can be run within the freely obtainable IDL runtime environment (IDL Virtual Machine) of Research Systems Inc.
A new technique for angle-dispersive powder diffraction using an energy-dispersive setup and synchrotron radiation
Authors: Wang Yanbin , Uchida Takeyuki , Von Dreele Robert , Rivers Mark L. , Nishiyama Norimasa , Funakoshi Ken-ichi , Nozawa Akifumi , Kaneko Hiroshi
Published: November 2004

A new diffraction technique for combined angle- and energy-dispersive structural analysis and refinement (CAESAR), by collecting angle-dispersive data using a solid-state detector (SSD) and white synchrotron radiation, is introduced. By step scanning a well calibrated SSD over a limited 2θ range, a series of one-dimensional energy-dispersive data (intensityversusenergy) are obtained as a function of 2θ. The entire intensity (Int) data set consists of several thousand channels covering a range of photon energies,E(up to ∼150 keV), at each of the ∼1000 2θ steps, forming a 2–4 mega-element two-dimensional array, Int(E, 2θ). These intensity data are then regrouped according to photon energies, which are defined in the multichannel SSD as individual channels, yielding a large number of intensityversus2θ (angle-dispersive) data sets, Int(E= const., 2θ), each of which corresponds to a given photon energy or wavelength. The entire data set, selected subsets or composite scans can be used for multiple data set Rietveld refinement. Data collected both on α-Al2O3(a NIST diffraction standard) at ambient conditions and on a mixture of MgO and Au at high pressure were analyzed using the Rietveld technique, with varying schemes of data treatment. Furthermore, it is demonstrated that data within certain energy bands (ΔE/E= ±10%) may be binned together to improve counting statistics in a composite angle-dispersive scan, even when collected with much coarser scan steps of 0.1 or 0.2°. This technique is useful for high-pressure as well as general purpose powder diffraction studies that have limited X-ray access to the sample using synchrotron radiation. Several advantages are discussed.
A simplified correction function for the effect of surface roughness in X-ray powder diffraction
Authors: Sidey Vasyl
Published: November 2004

The empirical monoparametric functionSR= (θ/90)(S/θ)(whereSis the refinable parameter and the angle θ is given in degrees) has been suggested for Rietveld analysis as a practical replacement for the commonly used surface roughness correction functions.
Size–strain line-broadening analysis of the ceria round-robin sample
Authors: Balzar D. , Audebrand N. , Daymond M. R. , Fitch A. , Hewat A. , Langford J. I. , Le Bail A. , Louër D. , Masson O. , McCowan C. N. , Popa N. C. , Stephens P. W. , Toby B. H.
Published: November 2004

The results of both a line-broadening study on a ceria sample and a size–strain round robin on diffraction line-broadening methods, which was sponsored by the Commission on Powder Diffraction of the International Union of Crystallography, are presented. The sample was prepared by heating hydrated ceria at 923 K for 45 h. Another ceria sample was prepared to correct for the effects of instrumental broadening by annealing commercially obtained ceria at 1573 K for 3 h and slowly cooling it in the furnace. The diffraction measurements were carried out with two laboratory and two synchrotron X-ray sources, two constant-wavelength neutron and a time-of-flight (TOF) neutron source. Diffraction measurements were analyzed by three methods: the model assuming a lognormal size distribution of spherical crystallites, Warren–Averbach analysis and Rietveld refinement. The last two methods detected a relatively small strain in the sample, as opposed to the first method. Assuming a strain-free sample, the results from all three methods agree well. The average real crystallite size, on the assumption of a spherical crystallite shape, is 191 (5) Å. The scatter of results given by different instruments is relatively small, although significantly larger than the estimated standard uncertainties. The Rietveld refinement results for this ceria sample indicate that the diffraction peaks can be successfully approximated with a pseudo-Voigt function. In a common approximation used in Rietveld refinement programs, this implies that the size-broadened profile cannot be approximated by a Lorentzian but by a full Voigt or pseudo-Voigt function. In the second part of this paper, the results of the round robin on the size–strain line-broadening analysis methods are presented, which was conducted through the participation of 18 groups from 12 countries. Participants have reported results obtained by analyzing data that were collected on the two ceria samples at seven instruments. The analysis of results received in terms of coherently diffracting, both volume-weighted and area-weighted apparent domain size are reported. Although there is a reasonable agreement, the reported results on the volume-weighted domain size show significantly higher scatter than those on the area-weighted domain size. This is most likely due to a significant number of results reporting a high value of strain. Most of those results were obtained by Rietveld refinement in which the Gaussian size parameter was not refined, thus erroneously assigning size-related broadening to other effects. A comparison of results with the average of the three-way comparative analysis from the first part shows a good agreement.
New hermetic sample holder for radioactive materials fitting to Siemens D5000 and Bruker D8 X-ray diffractometers: application to the Rietveld analysis of plutonium dioxide
Authors: Belin Renaud C. , Valenza Philippe J. , Reynaud Muriel A. , Raison Philippe E.
Published: November 2004

A new hermetic sample holder to be used with radioactive or air- and moisture-sensitive samples has been developed; it has been designed to fit most of the commercial Siemens/Bruker diffractometers (e.g.D5000 and D8 series). Thanks to the design of the sample holder and to a sample preparation process allowing two-containment-barrier protection, X-ray data can be collected using a standard uncontaminated diffractometer mounted in a Bragg–Brentano geometry. The design offers very accurate and reliable sample positioning. In order to demonstrate the high quality of the data obtained, the Rietveld analysis of plutonium dioxide is presented. Good agreement between the refinement and published data demonstrates the quality of the sample preparation and the accuracy of the sample holder. High-quality X-ray diffraction powder patterns can be recorded for use in Rietveld refinements, even on highly absorbing radioactive materials.
Bent crystals in Laue geometry: dynamical focusing of a polychromatic incident beam
Authors: Mocella V. , Guigay J. P. , Hrdý J. , Ferrero C. , Hoszowska J.
Published: November 2004

The main limitation of Laue geometry for the achievement of a small focus size is the focus broadening caused by the intrinsic Darwin width and the spread of the beam in the Borrmann triangle, resulting from propagation inside the crystal. A method, based on dynamical focusing, is suggested that allows improvement of the quality of high-energy polychromatic focusing by bent crystals in Laue geometry.
Structure determination of nitrato-κO-bis[2-(2-pyridyl-κN)amino-5,6-dihydro-4H-1,3-thiazine-κN]copper(II) nitrateviamolecular modelling coupled with X-ray powder diffractometry
Authors: García-Cuesta M. C. , Lozano A. M. , Meléndez-Martínez J. J. , Luna-Giles F. , Ortiz A. L. , González-Méndez L. M. , Cumbrera F. L.
Published: November 2004

The title copper(II) coordination compound, C18H22CuN8O6S2{[Cu(NO3)(PyTz)2]NO3}, was synthesized in the form of small crystals unsuitable for structure determination by single-crystal X-ray diffractometry. It was therefore characterized by molecular modelling coupled with X-ray powder diffractometry [monoclinic, space groupP21/n,a= 20.695 (7) Å,b= 8.054 (2) Å,c= 15.157 (4) Å, β = 112.09 (2)° andRwp= 0.129]. The procedure used to resolve the structure followed direct space methods with a `Monte Carlo/parallel tempering' search algorithm, where the starting configuration was obtained by means of molecular mechanics. A final refinement was performed with the Rietveld method. Bond distances, bond angles and torsion angles were compared with those of similar compounds deposited in the Cambridge Structural Database.
Focusing optics for molybdenum radiation: a bright laboratory source for small-molecule crystallography
Authors: Coles Simon J. , Hursthouse Michael B.
Published: November 2004

This paper reports the design, installation and testing of a set of multilayer confocal mirrors in a side-by-side arrangement, built to increase the intensity from a molybdenum rotating-anode X-ray source. Ray-tracing experiments were performed in order to evaluate the best design parameters for the system, which are shown to be a side-by-side configuration of 100 mm length. Measurements of the primary beam intensity show an increase by a factor of approximately five. Comparative data collections were performed which highlight significant enhancements in the derived crystal structure, arising from the increased intensity of the primary beam.
Sodium Survey of the usage and functionality of salt as an ingredient in UK manufactured food products
Authors: Brady Maeve
Published: November 2004

The Food and Drink Federation carried out a survey in 1999 to clarify the usage and functionality of salt as an ingredient in UK manufactured branded food products. The results demonstrate the availability of a choice of labelled products, with a wide range of sodium content within product categories. Salt serves a variety of purposes in manufactured foods particularly as a preservative and flavouring. Many UK manufacturers have implemented recipe alterations to reduce the sodium content of their products or are keeping this possibility under review. In many product categories, there are constraints to reducing the sodium content of products, including detrimental effects on product safety, quality and consumer acceptance. The industry is responsive to consumer demand and is committed to providing nutrition labelling information about sodium content, when practicable, on the pack.
Vision applications emerge at Manufacturing Week
Authors: Rooks Brian
Published: November 2004

A report on some industrial applications of vision systems at the Manufacturing Week exhibition. Describes installations of one type of system at a disk drive manufacturer and at an electricity meter manufacturer, in which both inspect for the presence of components critical to the performance of the two products. Another system highlighted is for measuring sheet metal stampings at high speeds. Also, new products reviewed at the show include a completely digital machine vision measuring system; a PCB inspection system and a video camera‐based measuring machine.
The use of noncontact laser gauging systems for online measurement
Authors: Peoples John , Weinstein Larry B.
Published: November 2004

Increased worldwide competition has driven industry to find ever faster and more accurate techniques for product inspection. Although developed only recently, noncontact laser gauging systems (NCLGSs) are quickly becoming an accepted technology for manufacturing, in particular for large volume producers of wire who require online diameter measurement. This paper describes the major components of an NCLGS and how its technology enables manufacturers to incorporate extremely accurate online product measurement. The paper also describes the benefits and issues for concern associated with use of this new technology.
The hidden workforce: volunteers’ learning in the Olympics
Authors: Kemp Sharon
Published: November 2004

Examines the demographic make‐up of volunteers and their motives for participating in a mega‐event. Compares the Olympic Winter Games held in Lillehammer, Norway in 1994 and the Olympic Summer Games held in Sydney, Australia in 2000. Finds that volunteers in these events had similar demographic characteristics to more conventional volunteers and similar conventional motives. Also finds that volunteers in these events are strongly motivated by pride in their country and its culture, social contact and friendship. Concludes that there are important implications for organizations to glean from these findings in the area of human resource development.
The value of knowledge and the values of the new knowledge worker: generation X in the new economy
Authors: Bogdanowicz Maureen S. , Bailey Elaine K.
Published: November 2004

States that in the new developing economy of the millennium knowledge is an asset that should be valued, developed and managed, since it is a component of the intellectual capital of an organization. Reveals that knowledge is increasingly being regarded as a corporate asset in an age when data and information help sustain competitive advantage. Remarks that knowledge is, however, an intangible asset and so managing it creates a number of challenges in the area of human resource development, especially when workers are more concerned with their employability. Concludes that if a company values knowledge it must value its knowledge workers.
Organisational learning: a new perspective
Authors: O’Keeffe Ted
Published: November 2004

The realities of global competition and increased customer sophistication have focused organisational attention on the need to develop a “learning culture”. However, while much has been written on the importance of evolving a “learning culture”, less attention has been given to understanding in a practical way the characteristics of learning organisations and the ways in which companies can improve their learning systems This study of selected multinationals in Ireland identifies organisational learning antecedents and key characteristics that can be located on a new learning model that is driven by customer and competitive needs, requiring executive management commitment and visible support to be successfully implemented.
Competencies: a new sector
Authors: Brophy Monica , Kiely Tony
Published: November 2004

Outlines the processes involved in the development of a competency based framework for use by middle managers of three‐star Irish hotels within rooms division and the food and beverage department. Secondary research provides an overview of existing generic competency models. Competency models and frameworks have been applied and customised across a broad range of industry sectors. Seeks to address the need for an innovative and fresh approach to HRM within the Irish hotel sector. The primary research is conducted among three‐star hotels nation wide, giving equal representation to all regions of Ireland. Job analysis techniques are used as the basis for the primary research. The research is conducted among general managers and middle managers of three‐star hotels. While this study examines the three‐star hotel market, it is recommended that further research be conducted among four‐ and five‐star properties. It is envisaged that the outcomes of this project will help assist managers in three‐star hotels to benchmark their most important role challenges at a middle managerial level against others in similar roles.
Human resource development and workplace learning: emerging theoretical perspectives and organisational practices
Authors: Garavan Thomas N. , Morley Michael , Gunnigle Patrick , McGuire David
Published: November 2004

Workplace learning and HRD are considered legitimate topics for study and investigation alongside organisational strategies and practices. Considers key themes in the workplace earning literature in addition to its relationship with HRD. Identifies a paradigm shift from formalised, intermittent and discontinuous learning to increasingly informal, experiential, asynchronous and real‐time situated learning. Highlights three contemporary themes in both the workplace learning and HRD literatures, namely: knowledge, expertise, competence and capability; organisational learning; and employability and career issues.
Leadership and organisational learning in the quest for world class schools
Authors: Johnston Carol , Caldwell Brian
Published: November 2004

Reports on a study in a system of public education that is widely believed to be at the forefront of efforts to create world class schools. The aim of the study, thought to be the first of its kind, was to determine the extent to which five disciplines in the Senge model of a learning organisation are apparent in management practices of schools within the system. Concludes that Senge’s model of a learning organisation provides a helpful template for conceptualising progress towards world class schools. Implications for leadership are identified as an avenue through which to energise the quest for world class schools.
The effectiveness of strategies employed by dominant firms in the Portuguese crystal glass industry: an empirical investigation
Authors: Marques Alzira , Lisboa João , Zimmerer Thomas W. , Yasin Mahmoud M.
Published: November 2004

An empirical investigation of the Portuguese crystal industry focused on the current strategies of the 12 firms in the industry that produce 98 percent of the industry’s output. The chief executive officers in each firm completed the survey instrument. The research discovered that the two groups of firms with positive returns on equity pursued a cost leadership strategy based on efficiency of production and cost leadership strategy based on production innovation.
Effective integration of management control systems for competing in global industries
Authors: Kimura Shogo , Mourdoukoutas Panos
Published: November 2004

Extending Simon’s (1990) work, this paper proposes an effective management control system that allows companies to integrate different management control systems in order to improve operational effectiveness, employee creativity, and company competitiveness. Reviews conventional and modern competitive strategies and discusses both positive and negative effects of management control systems. Argues that to be effective, diagnostic management systems must be supplemented by boundary control systems, interactive control systems, and belief systems. Effective integration of the four different management control systems, it is argued, is dependent on companies applying them in a way that maximises operational effectiveness without limiting employee creativity. The importance of starting the design of a management control system with the specification of a system of beliefs which defines the company’s values and direction is highlighted.
Glutamate suppresses GABA release via presynaptic metabotropic glutamate receptors at baroreceptor neurones in rats
Authors: Chen Chao‐Yin , Bonham Ann C.
Published: November 2004

The nucleus tractus solitarii (NTS) is essential for coordinating arterial baroreflex control of blood pressure. The primary baroreceptor afferent fibres make their first excitatory synaptic contact at second‐order NTS neurones with glutamate as the major neurotransmitter. Glutamate regulates its own release by activating presynaptic metabotropic glutamate autoreceptors (mGluRs) on the baroreceptor central terminals to suppress its further release in frequency‐dependent manner. γ‐Aminobutyric acid (GABA) interneurones provide the major inhibitory synaptic input. It is the integration of excitatory and inhibitory inputs that shapes the NTS output of baroreceptor signals. We hypothesized that glutamate released from the primary central afferent terminals can spill over to presynaptic mGluRs on GABA interneurones to suppress GABA release at the second‐order baroreceptor neurones. We assessed GABA transmission in second‐order baroreceptor neurones identified by attached aortic depressor nerve (ADN) boutons. The medial NTS was stimulated to evoke GABA inhibitory postsynaptic currents (eIPSCs). Glutamate spillover, generated by brief 2 s, 25 Hz trains of stimuli applied to the tractus solitarius (TS), induced a small (10%) but significant reduction in the eIPSC amplitudes. The depression was enhanced to a 25% decrease by increasing glutamate in the cleft with a glutamate‐uptake inhibitor (M‐trans‐pyrrolidine‐2,4‐dicarboxylic acid, 1 μm), blocked by a Group II mGluR antagonist (LY341495, 200 nm) and mimicked by a Group II agonist ((2S,3S,4S)‐CCG/(2S,1′S,2′S)‐2‐carboxycyclopropyl; L‐CCG‐I). A presynaptic mGluR locus was established by the mGluR agonist‐mediated increase in the paired‐pulse ratio of two consecutive eIPSCs in conjunction with the decrease in the first eIPSC, and a decrease in the frequency (39–46% reduction at EC50concentration), but not amplitude, of spontaneous and miniature GABA IPSCs. The data indicate that endogenous glutamate activation of Group II presynaptic mGluRs can decrease GABA release at the first central synapses, suggesting a heterosynaptic role for the Group II mGluRs in shaping baroreceptor signal transmission.
Excitatory and inhibitory connections show selectivity in the neocortex
Authors: Watts Jo , Thomson Alex M.
Published: November 2004

The cerebral cortex is pivotal in information processing and higher brain function and its laminar structure of six distinct layers, each in receipt of a different constellation of inputs, makes it important to identify connectivity patterns and distinctions between excitatory and inhibitory pathways. The ‘feedforward’ projections from layer 4–3 and from 3–5 target pyramidal cells and to lesser degrees interneurones. ‘Feedback’ projections from layer 5–3 and from 3–4, on the other hand, mainly target interneurones. Understanding the microcircuitry may give some insight into the computation and information processing performed in this brain region.
Subthreshold inactivation of voltage‐gated K+ channels modulates action potentials in neocortical bitufted interneurones from rats
Authors: Korngreen Alon , Kaiser Katharina M. M. , Zilberter Yuri
Published: November 2004

Voltage‐gated K+ channels perform many functions in integration of synaptic input and action potential (AP) generation. In this study we show that in bitufted interneurones from layer 2/3 of the somatosensory cortex, the height and width of APs recorded at the soma are sensitive to changes in the resting membrane potential, suggesting subthreshold activity of voltage‐gated conductances. Attributes of K+ currents examined in nucleated patches revealed a fast subthreshold‐inactivating K+ conductance (Kf) and a slow suprathreshold‐inactivating K+ conductance (Ks). Simulations of these K+ conductances, incorporated into a Hodgkin–Huxley‐type model, suggested that during a single AP or during low frequency trains of APs, subthreshold inactivation of Kf was the primary modulator of AP shape, whereas during trains of APs the shape was governed to a larger degree by Ks resulting in the generation of smaller and broader APs. Utilizing the facilitating function of unitary pyramidal‐to‐bitufted cell synaptic transmission, single back‐propagating APs were initiated in a bitufted interneurone by repeated stimulation of a presynaptic pyramidal cell. Ca2+ imaging and dendritic whole‐cell recordings revealed that modulation of APs, which also affect the shape of back‐propagating APs, resulted in a change in dendritic Ca2+ influx. Compartmental simulation of the back‐propagating AP suggested a mechanism for the modulation of the back‐propagating AP height and width by subthreshold activation of Kf. We speculate that this signal may modulate retrograde GABA release and consequently depression of synaptic efficacy of excitatory input from neighbouring pyramidal neurones.
Molecular diversity of neocortical GABAergic interneurones
Authors: Blatow Maria , Caputi Antonio , Monyer Hannah
Published: November 2004

In addition to being the main source of inhibition in the adult brain, GABAergic interneurones are instrumental in pacing the activity of large ensembles of principal cells. GABAergic interneurones have unique features that enable them to contribute to the generation of synchronized network activity thereby shaping principal cell behaviour. Whereas the anatomical and physiological characteristics of certain interneuronal types have been studied extensively over the last decades, the molecular diversity of interneurones is a more recent focus of investigation in this field. Molecular cloning and expression analysis of many receptor families often revealed differential expression in GABAergic interneurones and pyramidal cells. Here we review recent findings regarding the molecular diversity of GABAergic interneurones in the neocortex. Better knowledge about differential gene expression in GABAergic interneurones is the basis for further investigations aimed at understanding the contribution of specific proteins in interneurones to network function.
Defined types of cortical interneurone structure space and spike timing in the hippocampus
Authors: Somogyi Peter , Klausberger Thomas
Published: November 2004

The cerebral cortex encodes, stores and combines information about the internal and external environment in rhythmic activity of multiple frequency ranges. Neurones of the cortex can be defined, recognized and compared on the comprehensive application of the following measures: (i) brain area‐ and cell domain‐specific distribution of input and output synapses, (ii) expression of molecules involved in cell signalling, (iii) membrane and synaptic properties reflecting the expression of membrane proteins, (iv) temporal structure of firing in vivo, resulting from (i)–(iii). Spatial and temporal measures of neurones in the network reflect an indivisible unity of evolutionary design, i.e. neurones do not have separate structure or function. The blueprint of this design is most easily accessible in the CA1 area of the hippocampus, where a relatively uniform population of pyramidal cells and their inputs follow an instantly recognizable laminated pattern and act within stereotyped network activity patterns. Reviewing the cell types and their spatio‐temporal interactions, we suggest that CA1 pyramidal cells are supported by at least 16 distinct types of GABAergic neurone. During a given behaviour‐contingent network oscillation, interneurones of a given type exhibit similar firing patterns. During different network oscillations representing two distinct brain states, interneurones of the same class show different firing patterns modulating their postsynaptic target‐domain in a brain‐state‐dependent manner. These results suggest roles for specific interneurone types in structuring the activity of pyramidal cells via their respective target domains, and accurately timing and synchronizing pyramidal cell discharge, rather than providing generalized inhibition. Finally, interneurones belonging to different classes may fire preferentially at distinct time points during a given oscillation. As different interneurones innervate distinct domains of the pyramidal cells, the different compartments will receive GABAergic input differentiated in time. Such a dynamic, spatio‐temporal, GABAergic control, which evolves distinct patterns during different brain states, is ideally suited to regulating the input integration of individual pyramidal cells contributing to the formation of cell assemblies and representations in the hippocampus and, probably, throughout the cerebral cortex.
Lysosomal Glycosphingolipid Recognition by NKT Cells
Authors: Zhou Dapeng , Mattner Jochen , Cantu Carlos , Schrantz Nicolas , Yin Ning , Gao Ying , Sagiv Yuval , Hudspeth Kelly , Wu Yun-Ping , Yamashita Tadashi , Teneberg Susann , Wang Dacheng , Proia Richard L. , Levery Steven B , Savage Paul B. , Teyton Luc , Bendelac Albert
Published: November 2004

NKT cells represent a distinct lineage of T cells that coexpress a conserved αβ T cell receptor (TCR) and natural killer (NK) receptors. Although the TCR of NKT cells is characteristically autoreactive to CD1d, a lipid-presenting molecule, endogenous ligands for these cells have not been identified. We show that a lysosomal glycosphingolipid of previously unknown function, isoglobotrihexosylceramide (iGb3), is recognized both by mouse and human NKT cells. Impaired generation of lysosomal iGb3 in mice lacking β-hexosaminidase b results in severe NKT cell deficiency, suggesting that this lipid also mediates development of NKT cells in the mouse. We suggest that expression of iGb3 in peripheral tissues may be involved in controlling NKT cell responses to infections and malignancy and in autoimmunity.
Human Prion Protein with Valine 129 Prevents Expression of Variant CJD Phenotype
Authors: Wadsworth Jonathan D. F. , Asante Emmanuel A. , Desbruslais Melanie , Linehan Jacqueline M. , Joiner Susan , Gowland Ian , Welch Julie , Stone Lisa , Lloyd Sarah E. , Hill Andrew F. , Brandner Sebastian , Collinge John
Published: November 2004

Variant Creutzfeldt-Jakob disease (vCJD) is a unique and highly distinctive clinicopathological and molecular phenotype of human prion disease associated with infection with bovine spongiform encephalopathy (BSE)–like prions. Here, we found that generation of this phenotype in transgenic mice required expression of human prion protein (PrP) with methionine 129. Expression of human PrP with valine 129 resulted in a distinct phenotype and, remarkably, persistence of a barrier to transmission of BSE-derived prions on subpassage. Polymorphic residue 129 of human PrP dictated propagation of distinct prion strains after BSE prion infection. Thus, primary and secondary human infection with BSE-derived prions may result in sporadic CJD-like or novel phenotypes in addition to vCJD, depending on the genotype of the prion source and the recipient.
The Zinc Finger Antiviral Protein Directly Binds to Specific Viral mRNAs through the CCCH Zinc Finger Motifs
Authors: Guo Xuemin , Carroll John-William N. , MacDonald Margaret R. , Goff Stephen P. , Gao Guangxia
Published: November 2004

The zinc finger antiviral protein (ZAP) is a recently isolated host antiviral factor. It specifically inhibits the replication of Moloney murine leukemia virus (MLV) and Sindbis virus (SIN) by preventing the accumulation of viral RNA in the cytoplasm. For this report, we mapped the viral sequences that are sensitive to ZAP inhibition. The viral sequences were cloned into a luciferase reporter and analyzed for the ability to mediate ZAP-dependent destabilization of the reporter. The sensitive sequence in MLV was mapped to the 3′ long terminal repeat; the sensitive sequences in SIN were mapped to multiple fragments. The fragment of SIN that displayed the highest destabilizing activity was further analyzed by deletion mutagenesis for the minimal sequence that retained the activity. This led to the identification of a fragment of 653 nucleotides. Any further deletion of this fragment resulted in significantly lower activity. We provide evidence that ZAP directly binds to the active but not the inactive fragments. The CCCH zinc finger motifs of ZAP play important roles in RNA binding and antiviral activity. Disruption of the second and fourth zinc fingers abolished ZAP's activity, whereas disruption of the first and third fingers just slightly lowered its activity.