bluuebunny/crossref_metadata_2025 huggingface dataset:
Photopolymerization kinetics of an epoxy‐based resin for stereolithography
Authors: Esposito Corcione C. , Greco A. , Maffezzoli A.
Published: March 2004

Curing reactions of photoactivated epoxy resins are assuming an increasing relevance in many industrial applications, such as coatings, printing, and adhesives. Besides these processes, stereolithography (SL) makes use of photoactivated resins in a laser‐induced polymerization for 3D building. The kinetic behavior of photocuring is a key point for full comprehension of the cure conditions occurring in the small zone irradiated by the laser beam during the building process. Furthermore, the kinetic analysis is very important to determine the cure time needed for part building in a stereolithographic equipment. The mechanisms involved in a cationic photopolymerization are complex compared with radical photopolymerization. In this paper the photoinitiated polymerization of a commercially available epoxy‐based resin for stereolithography (SL5170) was studied by means of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Substantial information about the SL5170 chemical composition and curing mechanism was determined through FTIR analysis. The polymerization rate and the maximum degree of reaction were determined directly from experimental DSC curves. Kinetic characterization of epoxy photopolymerization was carried out as a function of the temperature and irradiation intensity and experimental results were compared with an original mathematical model. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3484–3491, 2004
Natural rubber/ethylene propylene diene blends for high insulation iron crossarms
Authors: Kiatkamjornwong Suda , Pairpisit Kornteenee
Published: March 2004

This research studied the composition and behavior of natural rubber (NR) and ethylene propylene diene monomer (EPDM) blends at various carbon black concentrations (0–30 phr) in terms of electrical resistivity, dielectric breakdown voltage testing, and physical properties. The blends having electrical properties suitable for application in high‐insulation iron crossarms were selected for investigation of compatibility and increased physical properties. The effect of the homogenizing agent concentration on improvement of compatibility of blends was studied by scanning electron microscopy, pulsed nuclear magnetic resonance spectroscopy, and rheology techniques. We also examined mechanical properties such as tensile strength, tear strength, elongation at break, and hardness. The NR/EPDM blends filled with a fixed concentration of silica were investigated for ozone resistance. A carbon black content as high as 10 phr is still suitable for the insulation coating material, which can withstand electrical voltage at 10 kVac. Addition of the homogenizing agent at 5 phr can improve the mechanical compatibility of blends, as evidenced by the positive deviation of shear viscosity of the rubber blend, that is, the calculated shear viscosity being higher than that of experimental data. Moreover, the pulsed NMR results indicated that the spin‐spin relaxation (T2) of all three components of the rubber blend was compressed upon the addition of the homogenizing agent. The ratio of NR/EPDM in the blend to best resist the ozone gas is 80/20 with the addition of silica of 30 phr into the blend. Also, the NR/EPDM filled with silica had a decreased change in thermal and mechanical properties of blends after thermal aging. The synergistic effect of silica content and high NR content (80) in 20 phr EPDM could improve antioxidation by ozone in the absence of a normal antioxidant for natural rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3401–3416, 2004
Preparation of superabsorbent polymer with slow‐release phosphate fertilizer
Authors: Zhan Falu , Liu Mingzhu , Guo Mingyu , Wu Lan
Published: March 2004

A superabsorbent polymer with slow‐release phosphate fertilizer was prepared by esterification of polyvinyl alcohol (PVA) and phosphoric acid (H3PO4), which was a slow‐release fertilizer at the same time. The product's water absorbency (WA) was about 480 times its own weight if it was allowed to swell in distilled water at room temperature for 24 h. WA under various conditions, such as varying the reaction time, the amount of sodium carbonate (Na2CO3), the reaction temperature, and the concentration of phosphoric acid ([H3PO4]), were investigated and optimized. The optimal sample of the product was characterized by FTIR and elemental analysis. The results showed that phosphoric groups had grafted on PVA molecule chains, and the content of P2O5 in the product was 31.2%. The water retention property and phosphate slow‐release mechanism of the product were studied as well. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3417–3421, 2004
Superabsorbent polymeric materials. XII. Effect of montmorillonite on water absorbency for poly(sodium acrylate) and montmorillonite nanocomposite superabsorbents
Authors: Lee Wen‐Fu , Yang Lin‐Gi
Published: March 2004

A series of novel xerogels based on sodium acrylate (NaA), montmorillonite (MMT), and N,N′‐methylene‐bisacrylamide (NMBA) were prepared by inverse suspension polymerization and water solution polymerization. The influences of pure MMT, intercalated MMT, the method of polymerization, and the content of the MMT in the copolymeric gels on the water absorbency and the initial absorption rate in deionized water and various salt solutions were investigated. Results showed that the water absorbency was increased by adding a small amount of the pure MMT into the copolymeric gels, but decreased by adding intercalated MMT into the gels. In addition, the water absorbency of the gels prepared by water solution polymerization was lower than that prepared by inverse suspension polymerization. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3422–3429, 2004
Preparation and structure and mechanical properties of poly(styrene‐b‐butadiene)/clay nanocomposites
Authors: Liao Mingyi , Zhu Jiedong , Xu Hongde , Li Yang , Shan Wei
Published: March 2004

Star‐shaped and linear block thermoplastic poly(styrene‐b‐butadiene) copolymer (SBS)/organophilic montmorillonite clays (OMMT) were prepared by a solution approach. The intercalation spacing in the nanocomposites and the degree of dispersion of nanocomposites were investigated by X‐ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The mechanical properties, dynamic mechanical properties, and thermal stability of these nanocomposites were determined. Results showed that SBS chains were well intercalated into the clay galleries and an intercalated nanocomposite was obtained. The mechanical strength of nanocomposites with the star‐shaped SBS/OMMT were significantly increased. The addition of OMMT also gave an increase of the elongation, the dynamic storage modulus, the dynamic loss modulus, and the thermal stability of nanocomposites. The increase of the elongation of nanocomposites indicates that SBS has retained good elasticity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3430–3434, 2004
Organomodified montmorillonite as filler in natural and synthetic rubber
Authors: Bala P. , Samantaray B. K. , Srivastava S. K. , Nando G. B.
Published: March 2004

The filler action of dodecylamine (12C) intercalated montmorillonite (MNT) referred to as organomodified montmorillonite (12C‐MNT) up to 4 wt % on natural rubber (NR) and styrene butadiene rubber (SBR) was studied and findings were compared with respect to the unmodified Na‐MNT. X‐ray analysis was used to calculate the interchain separation (R and R′), degree of crystallinity (Xc), and distortion factor (k). It is noted that R and R′ showed the opposite trend, whereas Xc as well as k showed overall increasing trend with an increasing amount of 12C‐MNT on both NR and SBR. For Na‐MNT (1 wt %) filled NR and SBR, the corresponding magnitude of R and R ′ and Xc showed nearly no change, whereas kc increased significantly. The crosslinking density (vc) does not show any significant changes in NR, whereas for SBR, it increases with increasing 12C‐MNT as filler. Interestingly, in the case of 1 wt % pure Na‐MNT used as filler for both NR and SBR, vc was lower compared to the virgin rubbers. Both swelling index (si) and sol fraction (Q) do not show any significant variation for NR composites, whereas these decrease for SBR composites with increasing concentration of 12C‐MNT filler. On the contrary, NR and SBR with 1 wt % of Na‐MNT filler show greater magnitude of si and Q corresponding to the pure ones. Measurements of mechanical properties showed a significant increase in tensile strength and elongation at break for NR‐12C‐MNT (4 wt %) when compared with either virgin NR. In addition, modulus at the elongation at 100 and 200% in general increases with increasing loading of 12C‐MNT filler in NR. Similar observations were also noted in the case of SBR. Interestingly, when only pure Na‐MNT is used as filler, the strength of NR and SBR decreases drastically. Scanning electron microscopic studies were also to used support the mechanical behavior of NR‐12MNT and SBR‐12CMNT composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3583–3592, 2004
Thermal bonding of polypropylene nonwovens: Effect of bonding variables on the structure and properties of the fabrics
Authors: Bhat Gajanan S. , Jangala Praveen K. , Spruiell Joseph E.
Published: March 2004

Properties of the point‐bonded nonwoven fabrics are dependent on the bonding conditions, in addition to those of the polymer/fiber. Thermally bonded carded webs were produced and characterized to investigate the role of bond area, bond size, and bonding temperature on the structure and properties of point‐bonded nonwoven fabrics. It was observed that the bond strength increases with bond area and bond size. The effects of bond area and bond size on fiber morphology were negligible. Significant morphological differences were observed in the bonded and the unbonded regions of the thermally bonded webs. To see how the staple fiber studies relate to the behavior of continuous filaments, similar sets of samples were produced and characterized by using the spunbond system. The observed trends for properties with respect to bonding conditions were similar for spunbond samples. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3593–3600, 2004
Short tandem repeats are associated with diverse mRNAs encoding membrane‐targeted proteins
Authors: Riley Donald E. , Krieger John N.
Published: March 2004

Within the genomes of multicellular organisms, short tandem repeating sequences (STRs) are ubiquitous, yet usage patterns remain obscure. The repeats (AC)n and (GU)n appear frequently in the untranslated regions (UTRs) of messenger RNAs (mRNAs). To investigate STR usage patterns, we used three approaches: (1) comparisons of individual mRNA database sequences including annotations and linked references, (2) statistical analysis of complete, UTR databases and (3) study of a large gene family, the aquaporins. Among 500 (AC)n‐ or (GU)n‐containing mRNAs, 58 (12%) had known functions. Of these, 50 (86%) encoded proteins whose activities involved membranes or lipids, including integral membrane proteins, peripheral membrane proteins, ion channels, lipid enzymes, receptors and secreted proteins. A control sequence (AU)n also occurred in mRNAs, but only 5% encoded membrane‐related functions. Investigation of all reported 3′ UTR sequences, demonstrated that the STR (AC)n was 9 times more common in mRNAs encoding membrane functions than in the total UTR database (P < 0.001). Similarly, (GU)n was 8 times more common in membrane‐function mRNAs than in the total database (P < 0.001). These observations suggest that (AC)n and (GU)n may be UTR signals for some mRNAs encoding membrane‐targeted proteins. This article contains supplementary material which may be viewed at the BioEssays website at http://www.interscience.wiley. com/jpages/0265‐9247/suppmat/index.html. BioEssays 26:434–444, 2004. © 2004 Wiley Periodicals, Inc.
Hedgehog: an unusual signal transducer
Authors: Bijlsma Maarten F. , Spek C. Arnold , Peppelenbosch Maikel P.
Published: March 2004

Hedgehog proteins are of pivotal importance for development and maintenance of tissue patterns in adult organisms. Despite the role of Hedgehogs in differentiation and tumorigenesis, signal transduction of Hedgehog remains a relatively uncharted area of signalling biochemistry. For proper Hedgehog distribution into tissues, two highly unusual covalent modifications are necessary, palmitoylation of a secreted protein and the attachment of a cholesterol group, making Hedgehog the only established sterolated protein in nature. Hedgehog exerts its function via two membrane‐bound receptors, Patched and Smoothened; presumably, Patched transports a cholesterol derivate out of cells which inhibits Smoothened. Binding of Hedgehog to Patched impedes this proposed pump function and thus Inhibition of Smoothened, which leads to expression of genetic Hedgehog targets via relief of transcriptional repression. These atypical features make Hedgehog physiology unique in biology and may explain why this field has attracted such significant attention. BioEssays 26:387–394, 2004. © 2004 Wiley Periodicals, Inc.
Anterior eye development and ocular mesenchyme: new insights from mouse models and human diseases
Authors: Cvekl Aleš , Tamm Ernst R.
Published: March 2004

During development of the anterior eye segment, cells that originate from the surface epithelium or the neuroepithelium need to interact with mesenchymal cells, which predominantly originate from the neural crest. Failures of proper interaction result in a complex of developmental disorders such Peters' anomaly, Axenfeld–Rieger's syndrome or aniridia. Here we review the role of transcription factors that have been identified to be involved in the coordination of anterior eye development. Among these factors is PAX6, which is active in both epithelial and mesenchymal cells during ocular development, albeit at different doses and times. We propose that PAX6 is a key element that synchronizes the complex interaction of cell types of different origin, which are all needed for proper morphogenesis of the anterior eye. We discuss several molecular mechanisms that might explain the effects of haploinsufficiency of PAX6 and other transcription factors, and the broad variation of the resulting phenotypes. BioEssays 26:374–386, 2004. © 2004 Wiley Periodicals, Inc.
Plant hormones and homeoboxes: bridging the gap?
Authors: Hay Angela , Craft Judith , Tsiantis Miltos
Published: March 2004

Plant hormones are signalling molecules that control growth and development. Growth of the aerial parts of higher plants requires the continuous activity of the shoot apical meristem, a small mound of cells at the apex of a plant. KNOTTED1‐like HOMEOBOX (KNOX) genes are involved in regulating meristem activity, however, little is known about how this regulation is mediated. Recent evidence suggests that KNOX transcription factors may control meristem development by regulating the balance of activities of multiple hormones. BioEssays 26:395–404, 2004. © 2004 Wiley Periodicals, Inc.
Under cover: causes, effects and implications of Hsp90‐mediated genetic capacitance
Authors: Sangster Todd A. , Lindquist Susan , Queitsch Christine
Published: March 2004

The environmentally responsive molecular chaperone Hsp90 assists the maturation of many key regulatory proteins. An unexpected consequence of this essential biochemical function is that genetic variation can accumulate in genomes and can remain phenotypically silent until Hsp90 function is challenged. Notably, this variation can be revealed by modest environmental change, establishing an environmentally responsive exposure mechanism. The existence of diverse cryptic polymorphisms with a plausible exposure mechanism in evolutionarily distant lineages has implications for the pace and nature of evolutionary change. Chaperone‐mediated storage and release of genetic variation is undoubtedly rooted in protein‐folding phenomena. As we discuss, proper protein folding crucially affects the trajectory from genotype to phenotype. Indeed, the impact of protein quality‐control mechanisms and other fundamental cellular processes on evolution has heretofore been overlooked. A true understanding of evolutionary processes will require an integration of current evolutionary paradigms with the many new insights accruing in protein science. BioEssays 26:348–362, 2004. © 2004 Wiley Periodicals, Inc.
The transcriptome: malariologists ride the wave
Authors: Wilson R.J.M.(Iain)
Published: March 2004

The Plasmodium falciparum genome‐sequencing project has provided malariologists with vast amounts of new information pertinent to a multitude of cellular processes that previously were only guessed about. In exploring this morass of predicted genes and proteins, there is now a danger of simply re‐inventing the cell. Fortunately, new global transcriptional analyses reassure malariologists that they are not dealing with just “any old cell.” The informative papers on the plasmodial transcriptome by Le Roch et al. (2003)1 and Bozdech et al. (2003)2 discussed below forge a bridge between the genomics and proteomics of P. falciparum. They are likely to act as a fulcrum upon which much future research will turn: for example, the study of regulation and feed‐back loops. BioEssays 26:339–342, 2004. © 2004 Wiley Periodicals, Inc.
Sexual conjugation in yeast: A paradigm to study G‐protein‐coupled receptor domain structure
Authors: Naider Fred , Estephan Racha , Englander Jacqueline , Suresh babu V. V. , Arevalo Enrique , Samples Karen , Becker Jeffrey M.
Published: March 2004

The yeast Saccharomyces cerevisiae undergoes cell fusion during sexual conjugation to form diploid cells. The haploids participating in this process signal each other through secreted peptide‐mating factors (α‐factor and a‐factor) that are recognized by G‐protein‐coupled receptors. The receptor (Ste2p) recognizing the tridecapeptide α‐factor is used as a model system in our laboratory to understand various aspects of peptide–receptor interactions and receptor structure. Using chemical procedures we have synthesized peptides corresponding to the seven transmembrane domains of Ste2p and studied their structures in membrane mimetic environments. Extension of these studies requires preparation of longer fragments of Ste2p. This article discusses strategies used in our laboratory to prepare peptides containing multiple domains of Ste2p. Data are presented on the use of chemical synthesis, biosynthesis, and native chemical ligation. Using biosynthetic approaches fusion proteins have been expressed that contain single receptor domains, two transmembrane domains connected by the contiguous loop, and the tail connected to the seventh transmembrane domain. Tens of milligrams of fusion protein were obtained per liter, and multimilligram quantities of the isotopically labeled target peptides were isolated using such biosynthetic approaches. Initial circular dichroism results on a chemically synthesized 64‐residue peptide containing a portion of the cytosolic tail and the complete seventh transmembrane domain showed that the tail portion and the hydrophobic core of this peptide maintained individual conformational preferences. Moreover, this peptide could be studied at near millimolar concentrations in the presence of micelles and did not aggregate under these conditions. Thus, these constructs can be investigated using high‐resolution nuclear magnetic resonance techniques, and the cytosolic tail of Ste2p can be used as a hydrophilic template to improve solubility of transmembrane peptides for structural analysis. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004
Peptide arrays with designed secondary structures for protein characterization using fluorescent fingerprint patterns
Authors: Usui Kenji , Ojima Tetsunori , Takahashi Mizuki , Nokihara Kiyoshi , Mihara Hisakazu
Published: March 2004

To realize a practical high‐throughput protein‐detection system, novel peptide arrays have been constructed using designed peptide libraries with loop, α‐helix, or β‐strand structures. Here, we describe the overview of the reported deigned peptide arrays with loop and α‐helix structures and the new results of those with β‐strand structures. Initially, several model peptides known to interact with model structured proteins were selected to establish the present strategy for high‐throughput detection of proteins. The fluorescent probes and suitable scaffolds of peptides were examined for the effective detection of proteins. The detection methods were established in solution and in an immobilized manner using the model systems. In the case of α‐helix peptide, the response of a peptide with fluorescent resonance energy transfer between two probes at both termini was several times higher than that of a peptide with a single probe. In the cases of peptides with other structures, however, proteins were effectively detectable even by the fluorescent change of one probe. Furthermore, structurally focused libraries consisting of a total of ca. 250 different peptides based on the model peptides with secondary and/or tertiary structures were constructed with systematic replacement of residues. Using these libraries, various proteins were characterized effectively to give their own fluorescent “protein fingerprint” patterns. The resulting protein fingerprints correlated with the recognition properties of the proteins. These studies demonstrate that arrays with peptide libraries based on designed structures can be promising tools for detecting the target proteins. Designed synthetic peptides play roles as the capturing agents to be developed for practical protein chips. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004
Epitope mapping and features of the epitope for monoclonal antibodies inhibiting enzymatic activity of Helicobacter pylori urease
Authors: Fujii Ryoji , Morihara Fumiko , Oku Takashi , Hifumi Emi , Uda Taizo
Published: March 2004

Two characteristic monoclonal antibodies (HpU‐2 and ‐18) out of 26 monoclonal antibodies (HpU‐1≈26) produced against Helicobacter pylori (H. pylori) urease showed a strong inhibitory effect against the enzymatic activity of the urease. Epitope mapping about some monoclonal antibodies of the HpU‐series inhibiting enzymatic activity was performed by using a surface plasmon resonance apparatus and by digesting H. pylori urease with trypsin, followed by mass spectroscopy. The sequences of the epitopes recognized by HpU‐2 and ‐18 were SVELIDIGGNRRIFGFNALVDR (22 mer) and IFGFNALVDR (10 mer), respectively. The former sequence is present as a part of a loop structure at a position close to the C‐terminal of the α‐subunit of H. pylori urease, although it has been suggested that the active site of the urease resides in the β‐subunit. The above peptide (22 mer) was chemically synthesized in a linear and cyclic form, and its conjugate with BSA was immunized in rabbits. The resultant serum induced by the linear form could specifically bind to H. pylori infecting human gastric mucosa. These results suggest that the above sequence (22 mer) must be an important epitope, although it locates in the α‐subunit but not in the β‐subunit. © 2004 Wiley Periodicals, Inc.
Treatment of MEK and toluene mixtures in biofilters: Effect of operating strategy an performance during transient loading
Authors: Atoche Jorge C. , Moe William M.
Published: March 2004

In recent years, biofiltration has been increasingly applied as an air pollution control technology to minimize or eliminate emissions of volatile organic compounds from industrial sources and environmental remediation activities. Although the ability of this technology to maintain high removal efficiency during relatively steady loading conditions has been well established for many waste streams, relatively little research has focused on development of operating strategies that could improve treatment performance during transient loading conditions typical of industrial operations. In the research described herein, two operating strategies were evaluated over a period of 295 days in biofilters treating a model waste gas stream containing a two‐component mixture of methyl ethyl ketone (MEK) and toluene. One biofilter was operated as a sequencing batch biofilter (SBB), and the other was operated as a conventional continuous‐flow biofilter (CFB). During “normal” steady loading conditions, the model waste stream contained MEK concentrations ranging from 80 to 89 ppmv and toluene concentrations ranging from 28 to 30 ppmv. Both biofilter operating strategies resulted in stable long‐term performance with greater than 99% contaminant removal during these normal loading conditions. On a regular basis, the influent MEK and toluene concentrations were temporarily increased to five times the normal influent concentration for the duration of 1 h to test performance during transient “shock loading” conditions. Biofilter performance during the model shock loading conditions demonstrate that SBB operating strategies can result in superior treatment in two important areas: (1) overall mass of contaminants removed and (2) minimum instantaneous removal efficiency. © 2004 Wiley Periodicals, Inc.
Quantifying anisotropic solute transport in protein crystals using 3‐D laser scanning confocal microscopy visualization
Authors: Cvetkovic A. , Straathof A. J. J. , Hanlon D. N. , van der Zwaag S. , Krishna R. , van der Wielen L. A. M.
Published: March 2004

The diffusion of a solute, fluorescein into lysozyme protein crystals has been studied by confocal laser scanning microscopy (CLSM). Confocal laser scanning microscopy makes it possible to non‐invasively obtain high‐resolution three‐dimensional (3‐D) images of spatial distribution of fluorescein in lysozyme crystals at various time steps. Confocal laser scanning microscopy gives the fluorescence intensity profiles across horizontal planes at several depths of the crystal representing the concentration profiles during diffusion into the crystal. These intensity profiles were fitted with an anisotropic model to determine the diffusivity tensor. Effective diffusion coefficients obtained range from 6.2 × 10−15 to 120 × 10−15 m2/s depending on the lysozyme crystal morphology. The diffusion process is found to be anisotropic, and the level of anisotropy depends on the crystal morphology. The packing of the protein molecules in the crystal seems to be the major factor that determines the anisotropy. © 2004 Wiley Periodicals, Inc.
Moving the participation agenda forward
Authors: Hill Malcolm , Davis John , Prout Alan , Tisdall Kay
Published: March 2004

This article sets the scene for the other papers in this Special Issue on children's and young people's participation, by outlining the nature of the ESRC Seminar Series from which all are derived and by developing the main themes discussed at the seminars. The focus of this Issue is participation by children and young people as this relates to differing notions of social exclusion and inclusion. This article critically examines participation in the contexts of policy, practice, research and theory. In many respects the environments in each of these domains is supportive of increased participation, yet there is also much evidence of limited impact by recent participative measures and of disillusionment by many young people who have been engaged in consultation and decision‐making. A way forward is suggested, which entails collaboration among all the key stakeholders including children and young people, connects participatory and social inclusion aims and mechanisms, and is committed to achieving tangible outcomes based on the wishes of children and young people.
Participation—for a change: Disabled young people lead the way
Authors: Badham Bill
Published: March 2004

Virtually every Government programme for children and every Government Department in the UK is expected to involve children and young people in its policy development and service delivery (Children and Young People's Unit, 2001). It is the new orthodoxy. Yet, hard questions are often avoided when reciting the mantra of participation. Why bother? What has changed as a result? This paper first seeks to explore the constraints and limitations of this drive in public policy in England. Secondly, by looking at one specific example, it considers elements of practice to enable participation to be effective as a catalyst for change. Third, it proposes a framework that sets out an agenda for social inclusion that is itself influenced by children and young people and not reliant on the changing and often clashing fashions in Government.
Children's experience of public space
Authors: Elsley Susan
Published: March 2004

Children and young people regard the external physical environment as important for their needs. Their use of space varies according to age and circumstance and includes designated play and leisure facilities as well as other informal areas within their neighbourhoods. However, children have little influence over the development of public space as they do not have the opportunity to contribute their views to local processes. This paper explores children's and young people's views and experience of public space in regeneration areas. It considers whether children's perspectives are accurately reflected in public policy. It draws on primary research with young people aged ten to 14 years and representatives from local organisations in a disadvantaged urban area in Scotland.
Setting the agenda: social inclusion, children and young people
Authors:   ESRC Seminar Series Participants
Published: March 2004

This paper was prepared collectively by participants of the third seminar in a series with the title Challenging ‘Social Inclusion’: Perspectives for and from Children and Young People. Three 3‐day seminars took place at the Universities of Edinburgh, Glasgow and Stirling in 2002–3 attended by academics, professionals from voluntary sector children's agencies, young people, representatives from central government and postgraduate students. Funding was provided by the Economic and Social Research Council (ESRC) and the Children's Society.
Auswirkungen der Zellaufschlussmethode auf die Zelltrümmer von Bacillus megaterium
Authors: Kampen I. , Nolte A. , Schwedes J.
Published: March 2004

No abstracts.
Hochkonzentrierte carotinoidhaltige Emulsionen
Authors: Ribeiro H. S. , Cruz R. C. D.
Published: March 2004

No abstracts.
Schüttgutbestrahlung im Vibrationsförderer mit Elektronen (10 MeV) – Transportphänomene und Dosimetrie
Authors: Stahl M. R. , Cutrubinis M. , Schuchmann H. P. , Ehlermann D. E. A.
Published: March 2004

No abstracts.
Anwendungen der Magnetresonanz zur Untersuchung von Wasser‐, Temperatur‐ und Porenverteilung bei lebensmittelverfahrenstechnischen Prozessen
Authors: Regier M. , Knörzer K. , Badolato G. B.
Published: March 2004

Es werden verschiedene Methoden der kernmagnetischen Resonanz (NMR) und ihrer Anwendung zur Bestimmung von Wasser‐, Temperaturverteilungen und Selbstdiffusionskoeffizienten im Verlauf von Prozessen im Bereich der Lebensmittelverfahrenstechnik vorgestellt. Ausgehend von den physikalischen Grundlagen der Magnetresonanz werden verschiedene Anwendungen gezeigt, die das Potenzial besitzen, zum tieferen Verständnis der verfahrenstechnischen Prozesse beizutragen: Beispielhaft wird die Bestimmung von Wasserverteilungen bei der Rehydratation von getrockneten Proben, die Ermittlung von Temperaturverteilungen bei der Mikrowellenerwärmung und von beobachtungszeitabhängigen Selbstdiffusionskoeffizienten bei der Mikrowellen‐Vakuumtrocknung gezeigt. Letztere können dazu genutzt werden, um weitere Aussagen über die innere Gewebestruktur wie Tortuosität und Porenradien zu erlangen.
Abriebfestigkeit von agglomerierten pulverförmigen Lebensmitteln: Vergleich zwischen Friabilator‐ und Vibrationstests
Authors: Gerhards C. , Kaell C.
Published: March 2004

No abstracts.
Emulgieren mit mikrostrukturierten Systemen
Authors: Lambrich U. , Vladisavljevic G. T.
Published: March 2004

Emulsionen sind disperse Systeme zweier ineinander unlöslicher oder schlecht löslicher flüssiger Phasen. Beispiele hierfür sind Mayonnaise, in der kleine Öltropfen in einer kontinuierlichen Wasserphase dipsergiert sind, oder Margarine, die aus einer Ölphase besteht, in der kleine Wassertropfen verteilt sind. Anfang der neunziger Jahre des 20. Jahrhunderts begann Nakashima die Entwicklung alternativer Emulgierverfahren mit dem Membranemulgieren. Hierbei wird eine Phase durch die Poren einer mikroporösen Membran in der zweiten Phase dispergiert. Durch das Ablösen der Tropfen von der Membranoberfläche bildet sich eine Emulsion mit einer engen Tropfengrößenverteilung. Die hierbei herrschenden Prozessbedingungen sind aufgrund geringer mechanischer Belastungen geeignet für Emulsionen mit empfindlichen Bestandteilen. Einige Jahre später verwendete Suzuki Membranen, um Tropfen in einer Rohemulsion beim Durchtritt durch die Membran zu zerkleinern. Mit diesem Verfahren, dass als Premix‐Membranemulgieren bezeichnet wird, lassen sich größere Mengen von Emulsion herstellen, als dies mit der zuvor erwähnten Methode möglich ist. Nakajima setzte so genannte Mikrokanalsysteme ein. Bei diesem Emulgierverfahren sind die Prozessbedingungen schonender als beim konventionellen Membranemulgieren.
Vesicular glutamate transporters in the spinal cord, with special reference to sensory primary afferent synapses
Authors: Alvarez Francisco J. , Villalba Rosa M. , Zerda Ricardo , Schneider Stephen P.
Published: March 2004

Spinal cord sensory synapses are glutamatergic, but previous studies have found a great diversity in synaptic vesicle structure and have suggested additional neurotransmitters. The identification of several vesicular glutamate transporters (VGLUTs) similarly revealed an unexpected molecular diversity among glutamate‐containing terminals. Therefore, we quantitatively investigated VGLUT1 and VGLUT2 content in the central synapses of spinal sensory afferents by using confocal and electron microscopy immunocytochemistry. VGLUT1 localization (most abundant in LIII/LIV and medial LV) is consistent with an origin from cutaneous and muscle mechanoreceptors. Accordingly, most VGLUT1 immunoreactivity disappeared after rhizotomy and colocalized with markers of cutaneous (SSEA4) and muscle (parvalbumin) mechanoreceptors. With postembedding colloidal gold, intense VGLUT1 immunoreactivity was found in 88–95% (depending on the antibody used) of CII dorsal horn glomerular terminals and in large ventral horn synapses receiving axoaxonic contacts. VGLUT1 partially colocalized with CGRP in some large dense‐core vesicles (LDCVs). However, immunostaining in neuropeptidergic afferents was inconsistent between VGLUT1 antibodies and rather weak with light microscopy. VGLUT2 immunoreactivity was widespread in all spinal cord laminae, with higher intensities in LII and lateral LV, complementing VGLUT1 distribution. VGLUT2 immunoreactivity did not change after rhizotomy, suggesting a preferential intrinsic origin. However, weak VGLUT2 immunoreactivity was detectable in primary sensory nociceptors expressing lectin (GSA‐IB4) binding and in 83–90% of CI glomerular terminals in LII. Additional weak VGLUT2 immunoreactivity was found over the small clear vesicles of LDCV‐containing afferents and in 50–60% of CII terminals in LIII. These results indicate a diversity of VGLUT isoform combinations expressed in different spinal primary afferents. J. Comp. Neurol. 472:257–280, 2004. © 2004 Wiley‐Liss, Inc.
Organization of binaural excitatory and inhibitory inputs to the inferior colliculus from the superior olive
Authors: Loftus William C. , Bishop Deborah C. , Saint Marie Richard L. , Oliver Douglas L.
Published: March 2004

The major excitatory, binaural inputs to the central nucleus of the inferior colliculus (ICC) are from two groups of neurons with different functions—the ipsilateral medial superior olive (MSO) and the contralateral lateral superior olive (LSO). A major inhibitory, binaural input emerges from glycinergic neurons in the ipsilateral LSO. To determine whether these inputs converge on the same postsynaptic targets in the ICC, two different anterograde tracers were injected in tonotopically matched areas of the MSO and the LSO on the opposite side in the same animal. The main findings were that the boutons from MSO axons terminated primarily in the central and caudal parts of the ICC laminae but that contralateral LSO terminals were concentrated more rostrally and on the ventral margins of the MSO inputs. In contrast, the ipsilateral LSO projection converged with the MSO inputs and was denser than the contralateral LSO projection. Consistent with this finding, retrograde transport experiments showed that the very low‐frequency areas of the ICC with dense MSO inputs also received inputs from greater numbers of ipsilateral LSO neurons than from contralateral LSO neurons. The results suggest that different binaural pathways through the low‐frequency ICC may be formed by the segregation of excitatory inputs to ICC from the MSO and the contralateral LSO. At the same time, the ipsilateral LSO is a major inhibitory influence in the target region of the MSO. These data support the concept that each frequency‐band lamina in the ICC may comprise several functional modules with different combinations of inputs. J. Comp. Neurol. 472:330–344, 2004. © 2004 Wiley‐Liss, Inc.
Medullary efferent and afferent neurons of the facial nerve of the pit viper Gloydius brevicaudus
Authors: Atobe Yoshitoshi , Nakano Masato , Kadota Tetsuo , Hisajima Tatsuya , Goris Richard C. , Funakoshi Kengo
Published: March 2004

For the purposes of comparative anatomy, we used tracer techniques and immunohistochemistry to study the facial nerve in the pit viper Gloydius brevicaudus and obtained much new data applicable to the function of this nerve in snakes and, in particular, pit vipers. We were able to identify the superior salivatory nucleus in these snakes. Preganglionic fibers from this nucleus pass along the palatine nerve and an anterior communicating branch to reach the pterygopalatine ganglion attached to the deep branch of the trigeminal maxillary nerve. The palatine nerve also contains general somatic afferents and a very few special visceral afferents from some taste buds on the palate. In the mandibular direction, preganglionic fibers from the superior salivatory nucleus join special visceral efferents from the motor nucleus in the hyomandibular nerve, from which they pass into the chorda tympani to course together for a short distance. The special visceral efferents branch off outside the cranium, and the preganglionic fibers continue on to join the trigeminal mandibular nerve to project to small ganglia within the mandible. The chorda tympani also contains general somatic afferents from the mandibular region but no special visceral afferents. This is the first time that the superior salivatory nucleus and its adjuncts have been identified in a snake. The chorda tympani of these snakes is also distinguished from the mammalian condition by lacking any special visceral afferents and by branching outside the cranium. J. Comp. Neurol. 472:345–357, 2004. © 2004 Wiley‐Liss, Inc.
Rostrocaudal distribution of motoneurones and variation in ventral horn area within a segment of the feline thoracic spinal cord
Authors: Meehan Claire F. , Ford Tim W. , Road Jeremy D. , Donga Revers , Saywell Shane A. , Anissimova Natalia P. , Kirkwood Peter A.
Published: March 2004

Retrograde transport of horseradish peroxidase, applied to cut peripheral nerves, was used to determine the rostrocaudal distribution of motoneurones supplying different branches of the ventral ramus for a single mid‐ or caudal thoracic segment in the cat. The motoneurones occupied a length of spinal cord equal to the segmental length but displaced rostrally from the segment as defined by the dorsal roots, with the number of motoneurones per unit length of cord higher in the rostral part of a segment (close to the entry of the most rostral dorsal root) than in the caudal part. The cross‐sectional area of the ventral horn showed a rostrocaudal variation that closely paralleled the motoneurone distribution. The ratio between the number of motoneurones per unit length in the caudal and rostral regions of a segment (0.70) was similar to the ratio previously reported for the strength of functional projections of expiratory bulbospinal neurones (0.63). This is consistent with the motoneurones being the main targets of the bulbospinal neurones. J. Comp. Neurol. 472:281–291, 2004. © 2004 Wiley‐Liss, Inc.
Global multimedia collaboration system
Authors: Fox Geoffrey , Wu Wenjun , Uyar Ahmet , Bulut Hasan , Pallickara Shrideep
Published: March 2004

In order to build an integrated collaboration system over heterogeneous collaboration technologies, we propose a global multimedia collaboration system (Global‐MMCS) based on XGSP A/V Web‐Services framework. This system can integrate multiple A/V services, and support various collaboration clients and communities. Now the prototype is being developed and deployed across many universities in U.S.A. and China. Copyright © 2004 John Wiley & Sons, Ltd.
InteGrade: object‐oriented Grid middleware leveraging the idle computing power of desktop machines
Authors: Goldchleger Andrei , Kon Fabio , Goldman Alfredo , Finger Marcelo , Bezerra Germano Capistrano
Published: March 2004

Grid computing technology improves the computing experiences at organizations by effectively integrating distributed computing resources. However, just a small fraction of currently available Grid infrastructures focuses on reutilization of existing commodity computing resources. This paper introducesInteGrade, a novel object‐oriented middleware Grid infrastructure that focuses on leveraging the idle computing power of shared desktop machines. Its features include support for a wide range of parallel applications and mechanisms to assure that the owners of shared resources do not perceive any loss in the quality of service. A prototype implementation is under construction and the current version is available for download. Copyright © 2004 John Wiley & Sons, Ltd.
Performance evaluation of market‐based resource allocation for Grid computing
Authors: Gomoluch J. , Schroeder M.
Published: March 2004

Resource allocation is an important aspect of Grid computing. Over the past few years, various systems have been developed which use market mechanisms to allocate resources. However, the performance of such policies has not been sufficiently studied. In this paper, we investigate under which circumstances market‐based resource allocation by continuous double auctions and by the proportional share protocol, respectively, outperforms a conventional round‐robin approach. We develop a model for clients, servers and the market, and present simulation results. Factors which are studied include the amount of load in the system, the number of resources, different degrees of resource heterogeneity, and communication delays. Copyright © 2004 John Wiley & Sons, Ltd.
An asynchronous middleware for Grid resource monitoring
Authors: Quéma V. , Lachaize R. , Cecchet E.
Published: March 2004

Resource management in a Grid computing environment raises several technical issues. The monitoring infrastructure must be scalable, flexible, configurable and adaptable to support thousands of devices in a highly dynamic environment where operational conditions are constantly changing.

We propose to address these challenges by combining asynchronous communications with reflective component‐based technologies. We introduce DREAM (Dynamic REflective Asynchronous Middleware), a Java component‐based message oriented middleware. Asynchronous communications are used to achieve the scalability and flexibility objectives, whereas the reflective component technology provides the complementary configurability and adaptability features.

We argue that this infrastructure is a viable approach to build a resource monitoring infrastructure for Grid computing. Moreover, DREAM makes the monitoring logic accessible from J2EE application servers. This allows the monitoring information to be presented as a Grid service and to integrate within the Open Grid Software Architecture. Copyright © 2004 John Wiley & Sons, Ltd.
Programming and coordinating Grid environments and applications
Authors: Ururahy Cristina , Rodriguez Noemi
Published: March 2004

The heterogeneous and dynamic nature of Grid environments place new demands on models and paradigms for parallel programming. In this work we discuss how ALua, a programming system based on a dual programming language model, can help the programmer to develop applications for this environment, monitoring the state of resources and controlling the application so that it adapts to changes in this state. Copyright © 2004 John Wiley & Sons, Ltd.
Reorganization of specific chromosomal domains and activation of silent genes in plant cells acquiring pluripotentiality
Authors: Avivi Yigal , Morad Vered , Ben‐Meir Hagit , Zhao Jing , Kashkush Khalil , Tzfira Tzvi , Citovsky Vitaly , Grafi Gideon
Published: March 2004

The transition from leaf cells to protoplasts (plant cells devoid of cell walls) confers pluripotentiality coupled with chromatin reorganization. Here, we sought to identify remodeled chromosomal domains in Arabidopsis protoplasts by tracking DNA sequences undergoing changes in DNA methylation and by identifying up‐regulated genes. We observed a reduction in DNA methylation at a pericentromeric region of chromosome 1, and up‐regulation of several members of the NAC (NAM/ATAF1/CUC2) domain family, two of which are located near the telomeric region of chromosome 1. Fluorescence in situ hybridization (FISH) analysis demonstrated that both pericentromeric and telomeric subdomains underwent chromatin decondensation. This decondensation is subdomain‐specific inasmuch as centromeric repeats remained largely unchanged, whereas the 18S rDNA underwent condensation. Within the pericentromeric subdomain, VIP1, a gene encoding a b‐Zip nuclear protein required for Agrobacterium infectivity, was transcriptionally activated. Overexpression of this gene in tobacco resulted in growth retardation and inhibition of differentiation and shoot formation. Altogether, our data indicate that acquisition of pluripotentiality involves changes in DNA methylation pattern and reorganization of specific chromosomal subdomains. This change leads to activation of silent genes whose products are involved in acquisition or maintenance of pluripotentiality and/or the ensuing fate of the cell. Developmental Dynamics 230:12–22, 2004. © 2004 Wiley‐Liss, Inc.
Dynamic regulation of the Stra13/Sharp/Dec bHLH repressors in mammary epithelium
Authors: St‐Pierre Benoit , Cooper Melissa , Jiang Zhe , Zacksenhaus Eldad , Egan Sean E.
Published: March 2004

Mammary gland development is a dynamic process involving cyclical proliferation, cellular differentiation, and cell death. In this study, we have determined that expression of the Stra13/Sharp/Dec basic helix‐loop‐helix (bHLH) family is dynamically regulated in mammary epithelium. In cultured HC11 cells, epidermal growth factor (EGF) treatment rapidly induces Stra13 protein accumulation, which is blocked by the synthetic glucocorticoid, dexamethasone. Neither the induction of Stra13 by EGF nor its repression by dexamethasone correlates with changes in Stra13 mRNA levels. During mouse mammary gland development in vivo, Stra13 is highly expressed in epithelial ducts during puberty, and strongly induced in both ducts and alveoli during early involution, while the related Sharp‐1 gene is highly expressed only during late stages of involution. Together, these data indicate that Stra13/Dec/Sharp‐family bHLH repressors are dynamically regulated during mammary gland development and may function to regulate apoptosis in this tissue. Developmental Dynamics 230:124–130, 2004. © 2004 Wiley‐Liss, Inc.