bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical response of a liquid crystal cell: The role of Debye’s layer
Authors: Barbero G. , Cipparrone G. , Martins O. G. , Pagliusi P. , Figueiredo Neto A. M.
Published: September 2006

The authors investigate the effect of the surface treatment on the electrical response of a nematic liquid crystal cell. The theoretical analysis is performed by describing, from the electrical point of view, the liquid crystal and the surface treatment by means of the dielectric constants and the electrical conductivities. The predictions of the model are compared with the measurements performed on a nematic cell submitted to an external voltage steplike or linear in time. They show that to correctly interpret the experimental data it is necessary to take into account the surface layer of Debye, connected with the presence of the ions, responsible for the electrical conduction in nematics.
High-performance 1.55μm low-temperature-grown GaAs resonant-cavity-enhanced photodetector
Authors: Han Q. , Niu Z. C. , Peng L. H. , Ni H. Q. , Yang X. H. , Du Y. , Zhao H. , Wu R. H. , Wang Q. M.
Published: September 2006

A 1.55μm low-temperature-grown GaAs (LT-GaAs) photodetector with a resonant-cavityenhanced structure was designed and fabricated. A LT-GaAs layer grown at 200°C was used as the absorption layer. Twenty- and fifteen-pair GaAs∕AlAs-distributed Bragg reflectors were grown as the bottom and top mirrors. A responsivity of 7.1mA∕W with a full width at half maximum of 4nm was obtained at 1.61μm. The dark current densities are 1.28×10−7A∕cm2 at the bias of 0V and 3.5×10−5A∕cm2 at the reverse bias of 4.0V. The transient response measurement showed that the photocarrier lifetime in LT-GaAs is 220fs.
Attitudinal manipulation of an optically trapped bacillary probe by controlling the distance between focal points for local dosing in cells
Authors: Yasokawa Toshiki , Ishimaru Ichirou , Nakagawa Yuki , Kuriyama Shigeki , Masaki Tsutomu , Nakai Seiji , Takegawa Kaoru , Tanaka Naotaka
Published: September 2006

Technology for the attitudinal manipulation of medical equipment for local dosing to single living cells is presented. The authors developed a “juggling probe” which can manipulate a bacillary probe with multiple degrees of freedom and high accuracy without physical contact by using light pressure. With this technology, the authors cause two beams to focus on the probe from both the top and bottom faces. When the two focal points coincide, the probe becomes trapped immediately in a stable fixed attitude. Furthermore, the probe remains at rest in an arbitrary tilted attitude simply by controlling the distance between the two focal points.
The Deformation and Recrystallization of an Alloy containing Two Phases
Authors: Honeycombe RWK , Boas W
Published: September 2006

The deformation and recrystallization of a duplex brass containing 60 per cent. copper and 40 per cent. zinc has been studied using microscopic and X-ray methods. In compression and tensile tests the α phase commences to deform plastically at a lower stress than the β phase, and even after heavy deformations, it is deformed more severely. Which of the two phases starts to recrystallize first on annealing depends on the rate of cooling of the alloy prior to deformation.
In the quenched wires the α phase commences to recrystallize about 100�C. below the β phase, whereas in the slowly cooled wires the β phase commences to recrystallize before the a phase. In the former case, the β recrystallizes at a lower temperature, the smaller the amount of β present, i.e. the lower the temperature of quenching. It has been shown that the order-disorder transformation is responsible for the difference of behaviour of the slowly cooled wires from that of the quenched wires.
Microscopic examination shows that the α phase starts to recrystallize at random whereas the β phase tends to nucleate at the boundaries between the two phases. The experiments indicate that it is not possible to conclude that a phase has suffered more severe
deformation because it commences to recrystallize at a lower temperature.
Alkaloids of the Australian Rutaceae: Acronychia baueri Schott. IV. Alkaloids present in the leaves
Authors: Lamberton JA , Price JR
Published: September 2006

The leaves of Acronychia baueri Schott.
contain the acridine alkaloids melicopine, melicopidine, and melicopicine and
the furoquinolines skimmianine, acronycidine, and kokusaginine, the structures
of which have all been established previously. In addition two new alkaloids
are present. These are 2,4-dimethoxy-10-methylacridone (I) and a
dimethoxydimethylpyranofuroquinoline which has been named acronidine.
Acronidine has been degraded to a phenol which on methylation gives
isokokusaginine (II). The alkaloid must therefore possess structure III or IV,
the latter being preferred.
Synthesis and Solid-State Structure of the Unsymmetrical Squaraine Dye 2-[4-(Dibutylamino)-2-hydroxyphenyl]-4-[4-(dibutylamino)phenyl]-cyclobutenebis(ylium)-1,3-diolate
Authors: Hamilton DG , Lynch DE , Smith G
Published: September 2006

The synthesis of an unsymmetrical squaraine dye, 2-[4-( dibutylamino )-2-hydroxyphenyl]-4-[4-( dibutylamino )phenyl] cyclobutenebis ( ylium )-1,3-diolate, has been achieved via a cross condensation reaction. In the solid state the compound is isomorphous with the known symmetrical dye bis [4-( dibutylamino )phenyl] squaraine. The single hydroxy group is found to be disordered equally over the centrosymmetrically trans-related ortho and ortho' phenyl ring sites.
Bim and Bad mediate imatinib-induced killing of Bcr/Abl
+
leukemic cells, and resistance due to their loss is overcome by a BH3 mimetic
Authors: Kuroda Junya , Puthalakath Hamsa , Cragg Mark S. , Kelly Priscilla N. , Bouillet Philippe , Huang David C. S. , Kimura Shinya , Ottmann Oliver G. , Druker Brian J. , Villunger Andreas , Roberts Andrew W. , Strasser Andreas
Published: September 2006

Cell killing is a critical pharmacological activity of imatinib to eradicate Bcr/Abl
+
leukemias. We found that imatinib kills Bcr/Abl
+
leukemic cells by triggering the Bcl-2-regulated apoptotic pathway. Imatinib activated several proapoptotic BH3-only proteins:
bim
and
bmf
transcription was increased, and both Bim and Bad were activated posttranslationally. Studies using RNAi and cells from gene-targeted mice revealed that Bim plays a major role in imatinib-induced apoptosis of Bcr/Abl
+
leukemic cells and that the combined loss of Bim and Bad abrogates this killing. Loss of Bmf or Puma had no effect. Resistance to imatinib caused by Bcl-2 overexpression or loss of Bim (plus Bad) could be overcome by cotreatment with the BH3 mimetic ABT-737. These results demonstrate that Bim and Bad account for most, perhaps all, imatinib-induced killing of Bcr/Abl
+
leukemic cells and suggest previously undescribed drug combination strategies for cancer therapy.
Asymmetric phospholipid distribution drives
in vitro
reconstituted SNARE-dependent membrane fusion
Authors: Vicogne Jérôme , Vollenweider Daniel , Smith Jeffery R. , Huang Ping , Frohman Michael A. , Pessin Jeffrey E.
Published: September 2006

Insulin-stimulated glucose uptake requires the fusion of GLUT4 transporter-containing vesicles with the plasma membrane, a process that depends on the SNARE (soluble
N
-ethylmaleimide-sensitive fusion factor attachment receptor) proteins VAMP2 (vesicle-associated membrane protein 2) and syntaxin 4 (Stx4)/SNAP23 (soluble
N
-ethylmaleimide-sensitive fusion factor attachment protein 23). Efficient SNARE-dependent fusion has been shown in many settings
in vivo
to require the generation of both phosphatidylinositol-4,5-bisphosphate (PIP2) and phosphatidic acid (PA). Addition of PA to Stx4/SNAP23 vesicles markedly enhanced the fusion rate, whereas its addition to VAMP2 vesicles was inhibitory. In contrast, addition of PIP2 to Stx4/SNAP23 vesicles inhibited the fusion reaction, and its addition to VAMP2 vesicles was stimulatory. The optimal distribution of phospholipids was found to trigger the progression from the hemifused state to full fusion. These findings reveal an unanticipated dependence of SNARE complex-mediated fusion on asymmetrically distributed acidic phospholipids and provide mechanistic insights into the roles of phospholipase D and PIP kinases in the late stages of regulated exocytosis.
The effects of PCBs and dioxins on child health
Authors: LUNDQVIST CHRISTOFER , ZUURBIER MONIEK , LEIJS MARIKE , JOHANSSON CAROLINA , CECCATELLI SANDRA , SAUNDERS MARGARET , SCHOETERS GREET , TUSSCHER GAVIN Ten , KOPPE JANNA G.
Published: September 2006

Background/exposure: Dioxins and PCBs are highly persistent and highly toxic environmental pollutants which at present are derived mainly from waste incineration and food contamination. They are widespread in nature and pollute human food, including breast milk so that basically all children in Europe are exposed to measurable levels. Results/toxicity in children: The toxicity of dioxins and PCBs are well described both from animal studies and from a number of human epidemiological studies including several large cohort studies. Especially developmental exposure has been shown to affect endocrine and cognitive systems negatively. Measurable outcomes include reduced IQ and changed behaviour. Foetotoxic effects with reduced birth weight and increased congenital anomalies such as cleft lip have also been described. Exposure to PCBs and dioxins must be considered also in the context of multiple exposure to several toxins simultaneously or sequentially.

Conclusion/suggested action: Some measures aimed at reducing exposure to dioxins have been partly successful in that the dioxin content of breast milk is going down. However, further steps to reduce exposure must be taken. We suggest legislative measures for reducing the re‐entry of especially PCBs from waste into the environment. Individual pre‐conception counselling is recommended in order to reduce developmental exposure and its consequences. Biomonitoring of the substances themselves in breast milk and foods is recommended as well as monitoring possible endocrine effects.
Histomorphometric Estimation of Air Cell Development in Experimental Otitis Media
Authors: Mey Kristianna H. , Sørensen Mads Sølvsten , Homøe Preben
Published: September 2006

Objectives: The objectives of this study were to examine the effect of acute otitis media on the bony development of the growing middle ear air cell system with a reliable and concise stereologic histomorphometric method and to generate a standard baseline growth plot for the middle ear of the rat.

Study Design: The authors conducted a histomorphometric analysis of bullar volume during the entire growth period after early induction of unilateral otitis media.

Methods: The authors conducted undecalcified processing of 27 rat skulls sectioned horizontally at various ages from 20 to 83 days after unilateral transtympanic injection of Streptococcus pneumoniae at 19 days postpartum. Stereologic estimation of bullar volume was performed in the experimental and the control ear with Cavalieri's principle. Body mass and air cell volume were plotted as functions of subject age using standard developmental equations on the experimental results.

Results: Volumes of the middle ear air cell system were consistently smaller in the otitis ears. Bullar growth was completed at 60 days regardless of otitis history, but body mass was increasing throughout the experimental period.

Conclusions: A single incident of otitis media introduced early in life is sufficient to significantly reduce the final volume of the bulla in rats. This finding may mimic the effect of otitis media contracted in early childhood on the development of the mastoid air cells. The standard growth plot provides a timeframe for studies of signaling molecules responsible for bone modeling in pneumatization.
Large Expression Differences in Genes for Iron and Zinc Homeostasis, Stress Response, and Lignin Biosynthesis Distinguish Roots ofArabidopsis thalianaand the Related Metal HyperaccumulatorThlaspi caerulescens
Authors: van de Mortel Judith E. , Almar Villanueva Laia , Schat Henk , Kwekkeboom Jeroen , Coughlan Sean , Moerland Perry D. , Ver Loren van Themaat Emiel , Koornneef Maarten , Aarts Mark G.M.
Published: September 2006

The micronutrient zinc has an essential role in physiological and metabolic processes in plants as a cofactor or structural element in 300 catalytic and noncatalytic proteins, but it is very toxic when available in elevated amounts. Plants tightly regulate their internal zinc concentrations in a process called zinc homeostasis. The exceptional zinc hyperaccumulator species Thlaspi caerulescens can accumulate up to 3% of zinc, but also high amounts of nickel and cadmium, without any sign of toxicity. This should have drastic effects on the zinc homeostasis mechanism. We examined in detail the transcription profiles of roots of Arabidopsis thaliana and T. caerulescens plants grown under deficient, sufficient, and excess supply of zinc. A total of 608 zinc-responsive genes with at least a 3-fold difference in expression level were detected in A. thaliana and 352 in T. caerulescens in response to changes in zinc supply. Only 14% of these genes were also zinc responsive in A. thaliana. When comparing A. thaliana with T. caerulescens at each zinc exposure, more than 2,200 genes were significantly differentially expressed (≥5-fold and false discovery rate < 0.05). While a large fraction of these genes are of yet unknown function, many genes with a different expression between A. thaliana and T. caerulescens appear to function in metal homeostasis, in abiotic stress response, and in lignin biosynthesis. The high expression of lignin biosynthesis genes corresponds to the deposition of lignin in the endodermis, of which there are two layers in T. caerulescens roots and only one in A. thaliana.
Functional Classification, Genomic Organization, Putatively cis-Acting Regulatory Elements, and Relationship to Quantitative Trait Loci, of Sorghum Genes with Rhizome-Enriched Expression
Authors: Jang Cheol Seong , Kamps Terry L. , Skinner D. Neil , Schulze Stefan R. , Vencill William K. , Paterson Andrew H.
Published: September 2006

Rhizomes are organs of fundamental importance to plant competitiveness and invasiveness. We have identified genes expressed at substantially higher levels in rhizomes than other plant parts, and explored their functional categorization, genomic organization, regulatory motifs, and association with quantitative trait loci (QTLs) conferring rhizomatousness. The finding that genes with rhizome-enriched expression are distributed across a wide range of functional categories suggests some degree of specialization of individual members of many gene families in rhizomatous plants. A disproportionate share of genes with rhizome-enriched expression was implicated in secondary and hormone metabolism, and abiotic stimuli and development. A high frequency of unknown-function genes reflects our still limited knowledge of this plant organ. A putative oligosaccharyl transferase showed the highest degree of rhizome-specific expression, with several transcriptional or regulatory protein complex factors also showing high (but lesser) degrees of specificity. Inferred by the upstream sequences of their putative rice (Oryza sativa) homologs, sorghum (Sorghum bicolor) genes that were relatively highly expressed in rhizome tip tissues were enriched for cis-element motifs, including the pyrimidine box, TATCCA box, and CAREs box, implicating the gibberellins in regulation of many rhizome-specific genes. From cDNA clones showing rhizome-enriched expression, expressed sequence tags forming 455 contigs were plotted on the rice genome and aligned to QTL likelihood intervals for ratooning and rhizomatous traits in rice and sorghum. Highly expressed rhizome genes were somewhat enriched in QTL likelihood intervals for rhizomatousness or ratooning, with specific candidates including some of the most rhizome-specific genes. Some rhizomatousness and ratooning QTLs were shown to be potentially related to one another as a result of ancient duplication, suggesting long-term functional conservation of the underlying genes. Insight into genes and pathways that influence rhizome growth set the stage for genetic and/or exogenous manipulation of rhizomatousness, and for further dissection of the molecular evolution of rhizomatousness.
An Investigation of Boron Toxicity in Barley Using Metabolomics
Authors: Roessner Ute , Patterson John H. , Forbes Megan G. , Fincher Geoffrey B. , Langridge Peter , Bacic Anthony
Published: September 2006

Boron (B) is an essential micronutrient that affects plant growth at either deficient or toxic concentrations in soil. The aim of this work was to investigate the adaptation of barley (Hordeum vulgare) plants to toxic B levels and to increase our understanding of B toxicity tolerance mechanisms. We used a metabolomics approach to compare metabolite profiles in root and leaf tissues of an intolerant, commercial cultivar (cv Clipper) and a B-tolerant Algerian landrace (cv Sahara). After exposure to elevated B (200 and 1,000 μ  m), the number and amplitude of metabolite changes in roots was greater in Clipper than in Sahara. In contrast, leaf metabolites of both cultivars only responded following 1,000 μ  m treatment, at which B toxicity symptoms (necrosis) were visible. In addition, metabolite levels were dramatically altered in the tips of leaves of the sensitive cultivar Clipper after growth in 1,000 μ  m B compared to those of Sahara. This correlates with a gradual accumulation of B from leaf base to tip in B-intolerant cultivars. Overall, there were always greater differences between tissue types (roots and leaves) than between the two cultivars. This work has provided insights into metabolic differences of two genetically distinct barley cultivars and information about how they respond metabolically to increasing B levels.
The Arabidopsis Tetratricopeptide Repeat-Containing Protein TTL1 Is Required for Osmotic Stress Responses and Abscisic Acid Sensitivity
Authors: Rosado Abel , Schapire Arnaldo L. , Bressan Ray A. , Harfouche Antoine L. , Hasegawa Paul M. , Valpuesta Victoriano , Botella Miguel A.
Published: September 2006

Mutations in the Arabidopsis (Arabidopsis thaliana) TETRATRICOPEPTIDE-REPEAT THIOREDOXIN-LIKE 1 (TTL1) cause reduced tolerance to NaCl and osmotic stress that is characterized by reduced root elongation, disorganization of the root meristem, and impaired osmotic responses during germination and seedling development. Expression analyses of genes involved in abscisic acid (ABA) biosynthesis and catabolism suggest that TTL1 is not involved in the regulation of ABA levels but is required for ABA-regulated responses. TTL1 regulates the transcript levels of several dehydration-responsive genes, such as the transcription factor DREB2A, and genes encoding dehydration response proteins, such as ERD1 (early response to dehydration 1), ERD3, and COR15a. The TTL1 gene encodes a novel plant protein with tetratricopeptide repeats and a region with homology to thioredoxin proteins. Based on homology searches, there are four TTL members in the Arabidopsis genome with similar intron-exon structure and conserved amino acid domains. Proteins containing tetratricopeptide repeat motifs act as scaffold-forming multiprotein complexes and are emerging as essential elements for plant hormonal responses (such as gibberellin responses and ethylene biosynthesis). In this report, we identify TTL1 as a positive regulator of ABA signaling during germination and seedling development under stress.
The Arabidopsis Unannotated Secreted Peptide Database, a Resource for Plant Peptidomics
Authors: Lease Kevin A. , Walker John C.
Published: September 2006

In the era of genomics, if a gene is not annotated, it is not investigated. Due to their small size, genes encoding peptides are often missed in genome annotations. Secreted peptides are important regulators of plant growth, development, and physiology. Identification of additional peptide signals by sequence homology searches has had limited success due to sequence heterogeneity. A bioinformatics approach was taken to find unannotated Arabidopsis (Arabidopsis thaliana) peptides. Arabidopsis chromosome sequences were searched for all open reading frames (ORFs) encoding peptides and small proteins between 25 and 250 amino acids in length. The translated ORFs were then sequentially queried for the presence of an amino-terminal cleavable signal peptide, the absence of transmembrane domains, and the absence of endoplasmic reticulum lumenal retention sequences. Next, the ORFs were filtered against the The Arabidopsis Information Resource 6.0 annotated Arabidopsis genes to remove those ORFs overlapping known genes. The remaining 33,809 ORFs were placed in a relational database to which additional annotation data were deposited. Genome-wide tiling array data were compared with the coordinates of the ORFs, supporting the possibility that many of the ORFs may be expressed. In addition, clustering and sequence similarity analyses revealed that many of the putative peptides are in gene families and/or appear to be present in the rice (Oryza sativa) genome. A subset of the ORFs was evaluated by reverse transcription-PCR and, for one-fifth of those, expression was detected. These results support the idea that the number and diversity of plant peptides is broader than currently assumed. The peptides identified and their annotation data may be viewed or downloaded through a searchable Web interface at peptidome.missouri.edu.
Exogenous Free Ubiquitin Enhances Lily Pollen Tube Adhesion to an in Vitro Stylar Matrix and May Facilitate Endocytosis of SCA
Authors: Kim Sun Tae , Zhang Kangling , Dong Juan , Lord Elizabeth M.
Published: September 2006

Pollen tube adhesion and guidance on extracellular matrices within the pistil are essential processes that convey the pollen tube cell and the sperm cells to the ovule. In this study, we purified an additional molecule from the pistil that enhances pollen tube adhesion when combined with the SCA (stigma/stylar cysteine-rich adhesin)/pectin matrix in our in vitro assay. The enhancer of adhesion was identified as free ubiquitin (Ub). This was confirmed by use of bovine Ub as a substitute for lily (Lilium longiflorum Thunb.) stigma Ub. To study the interaction of SCA and Ub with the lily pollen tube, we labeled both proteins with biotin. We observed uptake of biotin-labeled SCA and Ub into the pollen tube cells in vitro using confocal microscopy. For SCA, a strong signal occurred first at the tip of the pollen tube, suggestive of an endocytosis event, and then progressively throughout the tube cytoplasm. SCA was also localized inside the in vivo pollen tube using immunogold electron microscopy and found to be present in endosomes, multivesicular bodies, and vacuoles, all known to be endocytic compartments. It was also confirmed that SCA is endocytosed in the in vitro adhesion assay. Internalization of SCA was increased in pollen tubes treated with exogenous Ub compared to those without Ub, suggesting that Ub may facilitate SCA endocytosis. These results show that Ub can act as an enhancer of pollen tube adhesion in vitro and that it is taken up into the pollen tube as is SCA. The Ub machinery may play a role in pollen tube adhesion and guidance in lily.
Improved Resistance to Controlled Deterioration in Transgenic Seeds
Authors: Prieto-Dapena Pilar , Castaño Raúl , Almoguera Concepción , Jordano Juan
Published: September 2006

We show that seed-specific overexpression of the sunflower (Helianthus annuus) HaHSFA9 heat stress transcription factor (HSF) in tobacco (Nicotiana tabacum) enhances the accumulation of heat shock proteins (HSPs). Among these proteins were HSP101 and a subset of the small HSPs, including proteins that accumulate only during embryogenesis in the absence of thermal stress. Levels of late embryogenesis abundant proteins or seed oligosaccharides, however, were not affected. In the transgenic seeds, a high basal thermotolerance persisted during the early hours of imbibition. Transgenic seeds also showed significantly improved resistance to controlled deterioration in a stable and transgene-dependent manner. Furthermore, overexpression of HaHSFA9 did not have detrimental effects on plant growth or development, including seed morphology and total seed yield. Our results agree with previous work tentatively associating HSP gene expression with phenotypes important for seed longevity. These findings might have implications for improving seed longevity in economically important crops.
An Arabidopsis Glutathione Peroxidase Functions as Both a Redox Transducer and a Scavenger in Abscisic Acid and Drought Stress Responses
Authors: Miao Yuchen , Lv Dong , Wang Pengcheng , Wang Xue-Chen , Chen Jia , Miao Chen , Song Chun-Peng
Published: September 2006

We isolated two T-DNA insertion mutants of Arabidopsis thaliana GLUTATHIONE PEROXIDASE3 (ATGPX3) that exhibited a higher rate of water loss under drought stress, higher sensitivity to H2O2 treatment during seed germination and seedling development, and enhanced production of H2O2 in guard cells. By contrast, lines engineered to overexpress ATGPX3 were less sensitive to drought stress than the wild type and displayed less transpirational water loss, which resulted in higher leaf surface temperature. The atgpx3 mutation also disrupted abscisic acid (ABA) activation of calcium channels and the expression of ABA- and stress-responsive genes. ATGPX3 physically interacted with the 2C-type protein phosphatase ABA INSENSITIVE2 (ABI2) and, to a lesser extent, with ABI1. In addition, the redox states of both ATGPX3 and ABI2 were found to be regulated by H2O2. The phosphatase activity of ABI2, measured in vitro, was reduced approximately fivefold by the addition of oxidized ATGPX3. The reduced form of ABI2 was converted to the oxidized form by the addition of oxidized ATGPX3 in vitro, which might mediate ABA and oxidative signaling. These results suggest that ATGPX3 might play dual and distinctive roles in H2O2 homeostasis, acting as a general scavenger and specifically relaying the H2O2 signal as an oxidative signal transducer in ABA and drought stress signaling.
First steps towards effective methods in exploiting high-throughput technologies for the determination of human protein structures of high biomedical value
Authors: Banci L. , Bertini I. , Cusack S. , de Jong R. N. , Heinemann U. , Jones E. Y. , Kozielski F. , Maskos K. , Messerschmidt A. , Owens R. , Perrakis A. , Poterszman A. , Schneider G. , Siebold C. , Silman I. , Sixma T. , Stewart-Jones G. , Sussman J. L. , Thierry J.-C. , Moras Dino
Published: September 2006

The EC `Structural Proteomics In Europe' contract is aimed specifically at the atomic resolution structure determination of human protein targets closely linked to health, with a focus on cancer (kinesins, kinases, proteins from the ubiquitin pathway), neurological development and neurodegenerative diseases and immune recognition. Despite the challenging nature of the analysis of such targets, ∼170 structures have been determined to date. Here, the impact of high-throughput technologies, such as parallel expression of multiple constructs, the use of standardized refolding protocols and optimized crystallization screens or the use of mass spectrometry to assist sample preparation, on the structural biology of mammalian protein targets is illustrated through selected examples.
The impact of protein characterization in structural proteomics
Authors: Geerlof Arie , Brown J. , Coutard B. , Egloff M.-P. , Enguita F. J. , Fogg M. J. , Gilbert R. J. C. , Groves M. R. , Haouz A. , Nettleship J. E. , Nordlund P. , Owens R. J. , Ruff M. , Sainsbury S. , Svergun D. I. , Wilmanns Matthias
Published: September 2006

Protein characterization plays a role in two key aspects of structural proteomics. The first is the quality assessment of the produced protein preparations. Obtaining well diffracting crystals is one of the major bottlenecks in the structure-determination pipeline. Often, this is caused by the poor quality of the protein preparation used for crystallization trials. Hence, it is essential to perform an extensive quality assessment of the protein preparations prior to crystallization and to use the results in the evaluation of the process. Here, a protein-production and crystallization strategy is proposed with threshold values for protein purity (95%) and monodispersity (85%) below which a further optimization of the protein-production process is strongly recommended. The second aspect is the determination of protein characteristics such as domains, oligomeric state, post-translational modifications and protein–protein and protein–ligand interactions. In this paper, applications and new developments of protein-characterization methods using MS, fluorescence spectroscopy, static light scattering, analytical ultracentrifugation and small-angle X-ray scattering within the EC Structural Proteomics in Europe contract are described. Examples of the application of the various methods are given.
Automation of sample mounting for macromolecular crystallography
Authors: Cipriani F. , Felisaz F. , Launer L. , Aksoy J.-S. , Caserotto H. , Cusack S. , Dallery M. , di-Chiaro F. , Guijarro M. , Huet J. , Larsen S. , Lentini Mario , McCarthy J. , McSweeney S. , Ravelli R. , Renier M. , Taffut C. , Thompson A. , Leonard G. A. , Walsh M. A.
Published: September 2006

A standard sample holder and vial for cryocooled macromolecular crystals has been defined for use with robotic sample changers. This SPINE standard sample holder is a modified version, with added features and specifications, of sample holders in common use. In particular, the SPINE standard meets the precision required for automatic sample exchange and includes a cap that is identified by a two-dimensional datamatrix code as well as an optional vial. At the ESRF, the sample holder standard is in use with the EMBL/ESRF/BM14 robotic sample changer (SC3) which is installed on eight beamlines. The SC3 can hold up to 50 crystals stored in five baskets. A datamatrix reader in the SC3 ensures safe management of the sample flow and facilitates fully automatic screening and characterization of samples. Tools for handling and transporting 50 samples in a dry shipping dewar have been developed. In addition to the SC3, the SPINE sample holder is currently compatible with a number of other robotic sample changers.
Application of the use of high-throughput technologies to the determination of protein structures of bacterial and viral pathogens
Authors: Fogg M. J. , Alzari P. , Bahar M. , Bertini I. , Betton J.-M. , Burmeister W. P. , Cambillau C. , Canard B. , Carrondo M. , Coll M. , Daenke S. , Dym O. , Egloff M.-P. , Enguita F. J. , Geerlof A. , Haouz A. , Jones T. A. , Ma Qingjun , Manicka S. N. , Migliardi M. , Nordlund P. , Owens R.J. , Peleg Y. , Schneider G. , Schnell R. , Stuart D. I. , Tarbouriech N. , Unge T. , Wilkinson A. J. , Wilmanns M. , Wilson K. S. , Zimhony O. , Grimes J. M.
Published: September 2006

The Structural Proteomics In Europe (SPINE) programme is aimed at the development and implementation of high-throughput technologies for the efficient structure determination of proteins of biomedical importance, such as those of bacterial and viral pathogens linked to human health. Despite the challenging nature of some of these targets, 175 novel pathogen protein structures (∼220 including complexes) have been determined to date. Here the impact of several technologies on the structural determination of proteins from human pathogens is illustrated with selected examples, including the parallel expression of multiple constructs, the use of standardized refolding protocols and optimized crystallization screens.
GRETA, a new multifermenter system for structural genomics and process optimization
Authors: Hedrén Marie , Ballagi Andras , Mörtsell Lars , Rajkai Gyogy , Stenmark Pål , Sturesson Christer , Nordlund Pär
Published: September 2006

As part of the Structural Proteomics In Europe (SPINE) project, the automated multifermenter system GRETA has been developed with structural genomics as a major application. GRETA comprises 6–24 parallel fermentation chambers, each with individual control of fermentation parameters such as temperature, stirring, pH, dissolved oxygen concentration and feed profiles. Six human proteins were used to optimize the GRETA fermentation processes and to compare these processes with typical baffled-flask protocols used in structural genomics projects. The optimized GRETA processes allows several times more protein to be produced per litre of culture with limited manual intervention and constitutes a potentially useful alternative both for scale-up production in structural proteomic projects and for fermentation-process optimization.
Food hygiene knowledge and self‐reported behaviours of UK school children (4‐14 years)
Authors: Eves Anita , Bielby Gill , Egan Bernadette , Lumbers Margaret , Raats Monique , Adams Martin
Published: September 2006

Purpose

The purpose of this research is to show the evaluation of food hygiene knowledge and self‐reported behaviours of school children, assessment of children's attitudes towards food hygiene and evaluation of barriers to the adoption of appropriate food hygiene behaviours.

Design/methodology/approach

The food hygiene knowledge and self‐reported behaviours of pupils (4 and 14 years; Key Stages 1‐3 in the English system – or Scottish equivalent) were determined using age‐appropriate knowledge quizzes completed by 2,259 pupils across England, Scotland, Northern Ireland and Wales. Attitudes towards food hygiene and barriers to performing desirable hygiene‐related behaviours were established through semi‐structured interviews with 82 pupils who completed knowledge tasks in South East England.

Findings

Children generally had good knowledge of food hygiene. However, there were misconceptions about the nature of micro‐organisms and how they affect food. In addition, a lack of reminders and practical food activities, especially at Key Stage 2 (7‐11 years), coupled with poor hand‐washing facilities, meant that children did not always adopt desirable behaviours. Children gave suggestions for ways to help others to remember good practice.

Originality/value

The study identified areas of weakness in pupils' hygiene knowledge and understanding and has determined barriers to adoption of desirable behaviours at all times. It has also suggested ways in which food hygiene education could be made more engaging for pupils, and other methods to encourage good practice.
Communication needs and food allergy: a summary of stakeholder views
Authors: Miles Susan , Valovirta Erkka , Frewer Lynn
Published: September 2006

Purpose

The purpose of this paper is to elicit information about the specific information needs of different stakeholders and end‐users. An essential part of food allergy prevention includes the development of effective communication strategies to all stakeholders and end‐users of this information, including allergic consumers, their carers, health professionals, public authorities (regulators and compliance authorities) retailers, manufacturers, caterers, and the general public.

Design/methodology/approach

A stakeholder consultation was conducted to solicit the views of different stakeholders regarding what information they required.

Findings

The results of the stakeholder analysis indicated that some information needs were common across all stakeholders and end‐users. An example is the need for information about the causes and symptomology of food allergy. Some specific information needs for different stakeholders were also identified. The industrial sector requires more information about clear guidelines for labelling practices, whereas allergic consumers and health professionals require more information about symptomology, treatment and prevention. Regulators need information from risk assessors regarding issues key to the implementation of an effective regulatory framework, at a more detailed level of technicality than that required by other stakeholders (for example, consumers).

Originality/value

Targeted information strategies may be the most resource‐efficient way to effectively communicate to different stakeholders about food allergy. However, information channels best suited to specific stakeholder needs remain to be investigated and exploited.
A revised model of team roles and some research findings
Authors: Manning Tony , Parker Richard , Pogson Graham
Published: September 2006

Purpose

To provide a critique of Belbin's team role theory, including the provision of a re‐definition of the concept of team role and an adequate framework for relating personality to team roles. The re‐defined concept of team roles has a significant social dimension that relates it to the roles people habitually play in teams, the autonomy provided by such roles and their commitment to them. It also advocates the use of the “Big Five” model for describing individual personality differences and relating them to team role behaviour.

Design/methodology/approach

A revised model of team role behaviour is described, along with a brief account of the “Big Five” model of personality, and findings are presented that relate team role behaviour to three sets of variables, namely, personality, team role expectations and team role orientation, including autonomy and commitment.

Findings

Team role behaviour is described using both self‐assessments and aggregated assessments by others derived from instruments using Likert‐type scales. Information is presented showing the relationship between these measures of team role behaviour and three sets of variables, namely, personality, team role expectations and team role orientation, including autonomy and commitment. These findings support the idea that team roles have a significant social dimension and that the “Big Five” model of personality provides a useful model for relating team role behaviour to individual personality traits.

Research limitations/implications

The research does not look at a number of other issues raised by Belbin's theory of team roles, including the relationship between team composition and team effectiveness. Further research, using the measures described in the article, could be carried out to explore this relationship in actual teams, including exploring team composition in different work contexts.

Practical implications

The main implication of the research is that, while team role behaviour does appear to be related in part to individual personality traits, such traits are much less constraining than Belbin's theory suggests. Team role behaviour can usefully be seen, in part at least, as learned social behaviour, with individuals learning to play different roles in teams. Thus attempts to improve team effectiveness would benefit from looking more at learned behaviour (including leadership, problem solving, work organisation and interpersonal skills, as well as specialist expertise relevant to the particular team), while focusing relatively less on assessment, selection, placement and guidance.

Originality/value

Previous research on, and criticisms of, Belbin's team role theory have challenged it from within the discipline of psychology. This research is unique in criticising it from a more sociological perspective. It is also unique in shifting the practical focus for improving team effectiveness away from assessment, selection, placement and guidance to learned behaviour and skills.
Increasing impact of training investments: an evaluation strategy for building organizational learning capability
Authors: Brinkerhoff Robert O.
Published: September 2006

Purpose

The purpose of this paper is to provide training and human resources development practitioners with a practical, credible and strategically‐useful training evaluation method.

Design/methodology/approach

The suggested evaluation strategy and method are based on the author's experience as a thought leader and consultant with hundreds of organizations world‐wide.

Findings

Human resources development practitioners need a more practical, simple, valid and actionable approach to evaluation.

Practical implications

Evaluation should focus on the entire training and performance improvement process, not solely on training events. Leverage for making improvements to training impact is found in the performance management system factors in the larger organization outside the boundaries of the training department or function.

Originality/value

The paper proposes a new, more simple and valid approach to measurement of training impact that has been tried successfully in several dozen leading companies.
Leveraging levels of information services and developing knowledge services
Authors: Ju Yingjie
Published: September 2006

Purpose

The paper seeks to explore the essential nature of knowledge services, and to identify key issues that impact on the successful implementation of knowledge services in libraries.

Design/methodology/approach

This paper focuses on and discusses the heightened information service levels required in order to aspire to knowledge services. It answers the questions: What is the difference between information services and knowledge services? How do we realize knowledge services? What is knowledge services' blue print?

Findings

Information profession services are required to identify, analyze and coordinate the various needs of their potential user groups. Part of this process determines the levels of service. The requirements are changing from data, information to knowledge. The main reasons are library customers' growing and changing needs: from information access, storage, and retrieval to knowledge access, storage and retrieval. The aim of knowledge services is to provide a high level service through the effective use of knowledge. So special repositories must be accessed and used, and then analysis tools can be applied to achieve the user's objectives.

Originality/value

The paper posits how knowledge is pivotal in today's environment and illustrates how it is important to set up new knowledge services modes that make use of knowledge service platforms and knowledge warehouses.
Benefits of general vs vocational/technical education in Singapore using quantile regressions
Authors: Sakellariou Chris
Published: September 2006

Purpose

This study sets out to investigate the pattern of benefits from education along the earnings distribution and compares this pattern between general and vocational/technical education in Singapore, with a particular focus on male‐female differences.

Design/methodology/approach

Quantile regression methodology is used, which allows for estimates of education benefits that differentiate the contribution of the quantity and quality of education along the earnings distribution. The quantile regression estimates highlight where in the income/ability distribution the impact of education is more pronounced.

Findings

Finds that, while the pattern of returns to an additional year of education for general education follows that of other high income countries, exhibiting increasing returns to education as one goes from lower to higher income quantiles, the returns to vocational education exhibit much lower heterogeneity. Based on the findings, the vocational education system in Singapore has served women with secondary vocational qualifications particularly well. They earn more, have higher labor force participation, experience higher employment rates and are associated with a narrower gender earnings gap compared with women with general education. However, this is not the case for women with polytechnic qualifications, who earn much less than men with such qualifications.

Practical implications

The findings suggest that, by and large, Singapore's vocational education system at the secondary level has successfully addressed the needs of the industry and has contributed towards narrowing gender earnings differentials. It has also contributed towards less overall earnings inequality, because it results in less heterogeneity in the returns to education, compared with general education. However, the curricula of polytechnics need to be re‐examined to identify the cause of the sharply lower female benefits from this type of education.

Originality/value

The paper contributes to the empirical literature with its use of the quantile regression methodology in evaluating the benefits of vocational versus general education for men and women.
Job‐search assistance using the internet: experiences from a Swedish randomised experiment
Authors: Hägglund Pathric
Published: September 2006

Purpose

The purpose of this paper is to investigate to what extent the evaluation design in this study manages to avoid common difficulties in experimental evaluation, and to assess the effect of an internet‐based job‐search assistance programme offered at the Swedish employment offices on employment outcome.

Design/methodology/approach

In 2002, the Swedish Labour Market Board initiated a nation‐wide demonstration programme investigating the possibility of pursuing voluntary job‐search club activities on the internet. Participants were randomly selected from a group of voluntary job seekers registered at the employment offices.

Findings

Many experiment‐related problems such as ethical concerns, bureaucratic resistance and randomisation bias were circumvented. With the services being voluntary, however, a considerable fraction of the applicants either failed to show up or dropped out early in the process. Neither the intent‐to‐treat impact estimate, estimating the effect of being offered the services, nor the treatment‐on‐the‐treated estimate, estimating the effect of actual treatment, shows any effect on subsequent job transitions.

Practical implications

With fewer than 1,000 showing interest in the services, and with the large portions of no‐shows and dropouts among the applicants, it is likely that the Swedish Labour Market Board misjudged the clients' interest in this type of internet service.

Originality/value

By using random assignment to these programme services, the study contributes to the sparse literature on experimental evaluation of labour market topics in Europe in general, and in Sweden in particular.
Buyer‐supplier relationships in the Turkish automotive industry
Authors: Nazli Wasti S. , Kamil Kozan M. , Kuman Ayca
Published: September 2006

Purpose

Using a baseline model of buyer‐supplier relationships, the study aims to identify the types of relationships in the Turkish automotive industry, and to test predictions as to how these relations would differ across contextual, managerial, and social climate variables.

Design/methodology/approach

Questionnaire data from 51 buyers in automaker firms and 72 supplier firms were subjected to K‐means cluster analyses to establish relationship groups in the two samples. Differences across the groups were tested using ANOVA and Scheffé tests.

Findings

Three relationship types (captive supplier, market exchange, and strategic partnership) were identified both in the buyer and supplier data. Significant differences were observed in terms of contextual (product and supplier characteristics), managerial (information exchange and cooperation), and social climate variables (mutual understanding, payoff equity, and satisfaction). Turkish buyers were found to strategically segment their suppliers based on product and supplier characteristics, whereas supplier groups were differentiated along social climate variables.

Research limitations/implications

The Turkish results differ somewhat from the ones for developed countries, which suggests that more work should be conducted in emerging economies. Future research that uses matched pairs of buyers and suppliers may provide in‐depth insights.

Practical implications

The results demonstrated a perception (hence, communication) gap between buyers and suppliers in how they differentiated relationship types. Strategic partnership led to cooperation in both samples, and to satisfaction, mutual understanding, and equity in the supplier sample.

Originality/value

This study used data from both parties, contrasted buyer‐supplier relationships in an emerging market with those in developed markets, and highlighted the effects of the industry's historical evolution on the present state of buyer‐supplier relationships.