bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous processing of plasma carburization and carburization prevention by hollow cathode discharge
Authors: Urao R. , Khoo K. P. , Kuramochi Y. , Takeuchi H. , Funaki Y. , Takeuchi M.
Published: October 2002

A simultaneous treatment for carburization and carburization prevention by hollow cathode discharge was carried out with methane and hydrogen mixing gas for preheating, carburization and diffusion treating in the same chamber simultaneously. The hardness, carbon distribution and microstructure of carburized chromium–molybdenum steel were investigated after the treatment of simultaneous plasma carburization and carburization prevention. It was found that the simultaneous treatment of carburization and carburization prevention depended on the methane content in the mixing gas, the flow rate of the mixing gas and the treating temperature. The experimental results indicate the possibilities for simultaneous treatment of plasma carburization and carburization prevention. Copyright © 2002 John Wiley & Sons, Ltd.
Surface passivation of gallium selenide by nitrogen implantation
Authors: Márquez F. , Segura A. , Muñoz V. , González G.
Published: October 2002

In this paper we report on the characterization of nitrogen‐implanted single‐crystal GaSe samples. Nitrogen atoms were implanted at 80 keV, with doses ranging from 4 × 1013 to 1015 N+ ions cm−2. Next, samples were aged in open air and characterized by small‐area XPS, together with an unimplanted clean surface, in order to quantify the effects of the nitrogen implantation. In general, we found that the oxidation was fully prevented in N+‐implanted samples. Copyright © 2002 John Wiley & Sons, Ltd.
Combined use of GDOES and SEM + EDS for the microchemical study of oxide layers grown at high temperature on Nimonic 80 A nickel‐based superalloy
Authors: Ingo G. M. , Angelini E. , Calliari I. , Dabalà M. , De Caro T.
Published: October 2002

The microchemical structure of the oxide scale grown on a polycrystalline Nimonic 80 A nickel‐based superalloy as a function of the air high‐temperature treatment (up to 950°C) has been studied by means of the combined use of glow discharge optical emission spectrometry (GDOES), scanning electron microscopy with energy‐dispersive spectrometry (SEM + EDS) and x‐ray diffraction (XRD). The results disclose the morphology, the microchemical structure and the in‐depth elemental chemical composition of the oxide layers and their variation as a function of the temperature of the air thermal treatment. Furthermore, GDOES, SEM + EDS and XRD results show the different oxidation behaviours of both main alloying and minor reactive elements that induce the formation of a stratified oxide structure. Copyright © 2002 John Wiley & Sons, Ltd.
Micro‐ and nanocomposites of Keggin heteropolymetalates in cellulose esters
Authors: Oliveira Francílio de C. , Schneider José , Siervo Abner , Landers Richard , Plepis Ana M. G. , Pireaux Jean‐Jacques , Rodrigues‐Filho Ubirajara Pereira
Published: October 2002

Composites of Keggin heteropolymetalates have been prepared and characterized by SEM, XPS, 31P‐magic angle spinning/nuclear magnetic resonance and differential scanning calorimetry. The phosphotungstic acid and phosphomolybdic acid form nanocomposites where the oxocluster structure is preserved and is highly dispersed over the material, probably inserted between the polymeric chains. Phosphovanadotungstic clusters suffer partial decomposition during composite formation, resulting in a biphasic microcomposite. The decomposition product, phosphotungstic acid presents surface segregation as shown by comparison of XPS and nuclear magnetic resonance results. Copyright © 2002 John Wiley & Sons, Ltd.
UHV–liquid cell transfer system for Auger electron spectroscopy on electrodes
Authors: Reniers F. , Rooryck V. , Pace S. , Buess‐Herman C.
Published: October 2002

Many chemical reactions take place at the liquid/solid interface that are responsible for dramatic environmental, industrial and economic problems. For a long time, these reactions have been studied by conventional electrochemical techniques and the influence of most of the macroscopic parameters involved in the reaction (solution pH and composition, redox potential, etc.) are known for many systems. The resulting oxidized surface is often analysed by XPS and AES, but the measurements are performed after air exposure and thus after surface contamination or post‐oxidation. Most of the time, no direct information on the surface composition at the liquid/solid interface is available because of the lack of in situ available techniques for chemical analysis.

In order to combine the intrinsic advantage of electrochemical techniques (superior for the study of the redox reactions in solution) and the power of surface analysis techniques such as XPS and AES used under ultrahigh vacuum (UHV), we have designed, built and validated an original versatile UHV–electrochemical cell transfer system. This system allows the preparation of a clean electrode surface under UHV and its characterization by low‐energy electron diffraction and AES before its transfer to an electrochemical cell under a controlled atmosphere (no oxygen, no contamination). The study of model electrochemical reactions can take place and is followed by transfer of the electrode back to the UHV chamber for surface analysis by AES, without exposure to air. The transfer procedure takes 4 min.

Model systems were used to validate the system:

Bromide ions were electrochemically adsorbed on gold at various electrode potentials, inducing different surface compositions. Evolution of the Br content on the surface as a function of the electrode potential, estimated after transfer by AES, is in good agreement with the Br surface excess extracted from the electrochemical data, indicating that the transfer process induces no significant alteration of the surface, despite the weak bonding of bromide on gold and the brutal transfer from liquid to UHV. Results were compared with the literature.

Aluminium was taken as a standard to study the residual oxidation due to the composition of the atmosphere during the transfer process. The residual contamination (carbon) induced by the transfer process was also analysed. Carbon‐free transfer procedures were established.

In conclusion, such a transfer system combines the unique advantages of electrochemical methods to study corrosion processes with the power of a UHV technique such as AES. Copyright © 2002 John Wiley & Sons, Ltd.
Adsorption of cationic ‘gemini’ surfactants at the TiO2/solution interface
Authors: Ardizzone S. , Bianchi C. L. , Quagliotto P. , Viscardi G.
Published: October 2002

Adsorption isotherms of cationic pyridinium surfactants at the solid/liquid interface were obtained on aqueous dispersions of titanium dioxide as a function of the electrification features of the adsorbent. The surfactants, prepared in the laboratory, were a symmetric ‘gemini‐like’ dimer (1,1′‐bidodecyl‐4,4′‐bipyridinium chloride) and its related simple monomeric salt (1‐dodecyl‐4‐methylpyridinium chloride). X‐ray photoelectron spectroscopy analyses were performed both on the bare adsorbent and in the presence of the adsorbates. The XPS regions of Ti 2p, O 1s, N 1s and C 1s were specifically investigated. The nature of the interactions supporting the adsorption and the molecule orientation/co‐area are discussed in the light of the different experimental evidence. Copyright © 2002 John Wiley & Sons, Ltd.
In situ spectroscopic ellipsometry as a sensor for hard coatings and steel nitriding
Authors: Bonanni A. , Stifter D. , Hingerl K. , Störi H. , Werner W. S. M. , Brenner J. , Weithaler C. , Gruska B. , Prunel G. , Delaire V. , Sanvito T.
Published: October 2002

In this work, where the major emphasis has been given to in situ and on‐line measurements, we extend the available experience in the field of spectroscopic ellipsometry to plasma‐assisted chemical vapour deposition (PACVD) hard coatings and diffusion layers on steel, namely TiN, TiCN, TiAIN and FexNy. Furthermore, Auger electron spectroscopy was carried out in order to correlate the spectroscopic ellipsometry data on an absolute scale to their composition. It could be shown that monitoring of whole standard industrial processes (up to 24 h) for the control of nitriding/deposition processes is easily achievable. Thus, the formation of compound layers, the effectiveness of sputtering and the nitriding process as well as the composition of hard coatings (TiN and compounds) can be determined in real time in order to control and tune on‐line the fabrication of PACVD hard coatings. Copyright © 2002 John Wiley & Sons, Ltd.
Study of InP(100) surface nitridation by x‐ray photoelectron spectroscopy
Authors: Bideux L. , Ould‐Metidji Y. , Gruzza B. , Matolin V.
Published: October 2002

Ion beam nitridation of indium phosphide (100) substrates was studied using x‐ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). Argon ion bombardment of the InP(100) surface removes the native oxides and induces the formation of three‐dimensional indium clusters. After cleaning, the samples were nitrided in an ultrahigh vacuum chamber using a home‐made radiofrequency plasma source (13.56 MHz) that allows nitridation at low pressures (10−4 Pa). We have studied the influence of temperature on the nitridation mechanisms. For low temperature (T < 200°C), no variation of the metallic indium droplets was observed; for high temperature (T > 270°C), the first layers of the substrate were damaged. The optimal temperature for the nitridation of InP(100) was found to be 250°C. Copyright © 2002 John Wiley & Sons, Ltd.
Electron spectroscopic studies of iron and iridium silicides
Authors: Probst M. , Denecke R. , Whelan C. , Kinne M. , Borgmann D. , Steinrück H.‐P.
Published: October 2002

The formation of iron and iridium silicides was studied by means of highly resolved photoelectron spectroscopy of core and valence levels as well as by means of low‐energy electron diffraction (LEED). The experiments were carried out at BESSY II in Berlin using synchrotron radiation for the photoemission studies. After evaporation of seven monolayers of Fe on Si(111) at room temperature and annealing to 410 K for 420 s, an ordering of the surface structure and the formation of an (1 × 1) LEED pattern is observed. Upon further heating to 500 K a strong change in both UPS and XPS spectra occurs. This behaviour is attributed to the formation of FeSix (1 ≤ x ≤ 2). After annealing of a thin Ir layer on Si(100) to 1130 K, a p(2 × 2) LEED pattern with respect to the silicon substrate is observed, which indicates the formation of a well‐ordered surface compound. Comparison with the literature shows that the formation of an IrSi species is well known, but only an amorphous and a polycrystalline modification have been described upto now. Copyright © 2002 John Wiley & Sons, Ltd.
Characterization of the boundaries of thin films of TiO2 by atomic force microscopy and optical methods
Authors: Franta D. , Ohlídal I. , Klapetek P. , Pokorný P.
Published: October 2002

In this paper slight roughness of the upper boundaries of TiO2 thin films prepared on substrates formed by single‐crystal silicon is studied. Atomic force microscopy (AFM) and an optical method based on combining variable‐angle spectroscopic ellipsometry and near‐normal spectroscopic reflectometry are used for this purpose. It is shown that the values of the basic statistical quantities characterizing this roughness depend quite strongly on the values of the thicknesses of these films (they increase with increasing thickness). Differences observed between the values of the basic statistical parameters determined by AFM and the optical method are explained. It is also shown that the TiO2 films exhibit an inhomogeneity represented by a profile of the complex refractive index. Copyright © 2002 John Wiley & Sons, Ltd.
Spatially resolved microchemical analysis of chromate‐conversion‐coated aluminum alloy AA2024‐T3
Authors: Jaime Vasquez M. , Kearns J. R. , Halada G. P. , Clayton C. R.
Published: October 2002

The corrosion of aerospace aluminum alloys has been linked to the electrochemical behavior and chemical composition of constituent intermetallic compounds (IMCs). In this study, secondary ion mass spectrometry (SIMS), x‐ray photoelectron spectroscopy (XPS), synchrotron infrared microspectrometry (SIRMS) and x‐ray absorption near‐edge structure spectroscopy (XANES) were used to characterize chromate conversion coatings (CCCs) formed on AA2024‐T3 sheet and cast IMC analogs. The nascent surface film formed on IMC and matrix surfaces was characterized to reveal the influence of microstructure on CCC structure and composition. Copper‐rich regions were found on the outermost CCC surface. Intermetallic compounds rich in Cu were found to be surface depleted of Cr and enriched in CN from the ferricyanide present in the CCC as an accelerator compound. By distinguishing particle morphology and chemistry, SIMS data demonstrated that heterogeneities in CCC composition were associated with IMCs. Copyright © 2002 John Wiley & Sons, Ltd.
Size isn't everything
Authors: Hampton J. R.
Published: October 2002

Clinical trials now often involve thousands of patients, and statisticians emphasize the importance of trial size in ensuring that ‘correct’ answers are obtained. However, when a good treatment appears for a disease that was hitherto untreatable – for example, oranges for scurvy or streptomycin for tuberculosis – only a small trial is needed. Large trials are only needed to demonstrate small effects. The meta‐analysis of small trials is often misleading, and may hide undesirable effects of individual drugs. The concept of equivalence between treatments is important, and while a statistically adequate equivalence trial may have to be very large, many clinicians will question the need for extreme statistical propriety. Clinical trials often do not reflect ‘real world’ practice, and the clinical relevance of a trial is more important than its size. Copyright © 2002 John Wiley & Sons, Ltd.
Parents and campus safety
Authors: Sells Debra
Published: October 2002

Parents are demanding greater inclusion in issues relating to campus safety and security. This chapter examines the historical evolution of relations between parents, students, and universities, discussing two pieces of key legislation and describing strategies to optimize common interrelationships between parents and institutions.
Collaboration with the local community
Authors: Jackson Michael L. , Cherrey Cynthia
Published: October 2002

Colleges and universities continually search for ways to enhance the safety and security of their educational programs and physical plant. This chapter examines how the University of Southern California and other institutions are using collaborative efforts with the local community to enhance their mutual safety and security through dynamic partnerships and expanded service learning, volunteer, and teaching experiences for students, faculty, staff, and campus neighbors.
Technology—safety and security
Authors: Schaefer Robert M.
Published: October 2002

This chapter reviews safety and security issues as they relate to technology, both for individuals and for the institution.
Some issues related to the feedback control of a baffled plate
Authors: Preumont A. , De Man P. , François A.
Published: October 2002

This paper addresses a few issues related to the active structural acoustic control (ASAC) of a baffled plate. The first part proposes a feedback control strategy according to which a SISO control system is built by using a volume displacement sensor and a set of actuators driven with a single amplifier. The location of the actuators is then optimized to achieve an open‐loop transfer function with alternating poles and zeros, as for systems with co‐located actuators and sensors. This important feature allows the use of low‐order controllers. The second part of the paper discusses the volume displacement sensor; the spatial aliasing of a discrete array sensor is first demonstrated and a new electrode design is proposed, which makes it possible to tailor the effective piezoelectric properties of PVDF films. This electrode is used to design a volume displacement sensor. Copyright © 2002 John Wiley & Sons, Ltd.
Experimental study on the behaviour of aluminium panels for seismic energy dissipation
Authors: Foti D. , Nobile R.
Published: October 2002

The aim of this work is to provide the results of a series of experimental tests to study the behaviour of frames equipped with energy‐dissipating devices. The frame has been mounted on a shaking table and subjected to increasing seismic actions. Energy‐dissipating devices are built by assembling panels in aluminium and steel, designed in such a manner that the local plasticization allows seismic energy dissipation. Two different types of panels have been considered, which differ in plate junction technology. The dissipation capacities are evaluated by measuring the change of the dynamic characteristics of the frame. Copyright © 2002 John Wiley & Sons, Ltd.
Repolarization of the presynaptic action potential and short‐term synaptic plasticity in the chick ciliary ganglion
Authors: Poage Robert E. , Zengel Janet E.
Published: October 2002

Stimulation‐induced increases in synaptic efficacy have been described as being composed of multiple independent processes that arise from the activation of distinct mechanisms at the presynaptic terminal. In the chick ciliary ganglion, four components of short‐term synaptic plasticity have been described: F1 and F2 components of facilitation, augmentation, and potentiation. In the present study, intracellular recording from the presynaptic calyciform nerve terminal of the chick ciliary ganglion revealed that the late repolarization and afterhypolarization (AHP) phases of the presynaptic action potential are affected by repetitive stimulation and that the time course of these effects parallel that of facilitation. The effects of these changes in the presynaptic action potential time course on calcium influx were tested by using the recorded action potential waveforms as voltage command stimuli during whole‐cell patch‐clamp recordings from acutely isolated chick ciliary ganglion neurons. The “facilitated” action potential waveform (slowed repolarization, decreased AHP amplitude) evoked calcium current with slightly but significantly greater total calcium influx. Taken together, these results are consistent with the hypothesis that activity‐dependent changes in the presynaptic action potential are one of several mechanisms contributing to the facilitation phase of stimulation‐induced increases in transmitter release in this preparation. Synapse 46:189–198, 2002. © 2002 Wiley‐Liss, Inc.
Wrapping and Inclusion of Organic Molecules with Ultrathin, Amorphous Metal Oxide Films
Authors: Ichinose Izumi , Kunitake Toyoki
Published: October 2002

In this review, we overview metal oxide nanostructures in which organic molecules play important roles as templates, as structural units, and, in some cases, as hosts. Their structural precision and diversity are discussed from the viewpoint of the topology of a metal‐oxygen network. Supramolecular capsules of metal oxides are prepared by the self‐assembly of polyoxometalates. Zeolites and mesoporous materials are synthesized by using organic molecules with their assemblies acting as templates. The topological networking of silsesquioxanes makes it possible to produce novel nanocomposites and microporous materials. In the final section, we demonstrate our recent studies into molecular imprinting, the encapsulation of a fluorescent dye, and the wrapping of individual polymer chains. Ultrathin, amorphous metal oxide films can retain the shape of organic molecules and can be used to create molecular composites by precisely wrapping individual molecules. These films are also effective in insulating molecular functions from external environments. The advantages of amorphous metal oxides are discussed in relation to the properties of the corresponding crystalline metal oxides and their potential prospects in nanotechnology. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 339–351, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10032
Enzymatic Radical Catalysis: Coenzyme B12‐Dependent Diol Dehydratase
Authors: Toraya Tetsuo
Published: October 2002

A peculiar function resides in a peculiar structure. Coenzyme B12 or adenosylcobalamin, a naturally occurring organometallic compound, serves as a cofactor for enzymatic radical reactions. How do the enzymes form catalytic radicals at the active sites? How do the enzymes utilize and control the high reactivity of the radicals for catalysis? Recently, three‐dimensional structures of several radical‐containing or radical‐forming enzymes including B12 enzymes have been reported, enabling the analysis of the fine mechanisms of the action of these interesting enzymes. Our biochemical, mutational, and crystallographic studies as well as theoretical calculations on diol dehydratase, an adenosylcobalamin–dependent enzyme, revealed that its structure is adapted for its function—that is, activation of the CoC bond toward homolysis, abstraction of a specific hydrogen atom from the substrate and its recombination to a particular product, and transition state stabilization in the hydroxyl group migration of a substrate‐derived radical. The functions of K+ and the active‐site amino acid residues in enzyme catalysis are also investigated. Based on the results, the fine mechanism of the enzyme and the energetic feasibility of enzymatic radical catalysis are described here. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 352–366, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10035
Preparing students for assessment in the on‐line class
Authors: Ford Michele L.
Published: October 2002

Professors with limited technological expertise or resources can use features of their existing computer networks, such as e‐mail and Web postings, to communicate assessment expectations to their on‐line students.
Assessing the usability of on‐line instructional materials
Authors: Mehlenbacher Brad
Published: October 2002

This chapter focuses on the user interface and instructional design of on‐line materials: accessibility, aesthetic appeal, consistency and layout, customizability and maintainability, help and support documentation, intimacy and presence, metaphors and maps, and other items.
Quantification of the monochromatic photon flux of refractive x‐ray monochromators in the energy range from 10 to 30 keV
Authors: Ebel Horst
Published: October 2002

The refractive properties of matter at incidence angles close to total reflection are used for monochromatization of continuous x‐radiation. Possible radiation sources are standard diffraction tubes with different target materials and either regular line focus or with fine focus. Theoretical considerations include Snell's law, dispersion theory and Fresnel's equations. The results of Monte Carlo calculations are as follows. The photon flux of the band‐shaped monochromatic beam with thicknesses of 20–40 µm, divergence of 0.01° and width of 10 mm depends on the x‐ray source, the refractor material, the angular combination of incidence and take‐off angle and, thus, on the pass energy of the monochromator. Numerical values of 104 photons s−1 were obtained with a tube with Mo anode, fine focus, 45 kV and 40 mA. Pass energies of 5–30 keV and widths of the pass energy range of 0.2–3.5 keV were obtained. The refractor materials were Si and n‐C33H68. The hydrocarbon refractor is characterized by a comparably much smaller photoelectric absorption and, consequently, better efficiency. Copyright © 2002 John Wiley & Sons, Ltd.
Mitochondria hyperpolarization is an early event in oxidized low‐density lipoprotein‐induced apoptosis in Caco‐2 intestinal cells
Authors: Giovannini Claudio , Matarrese Paola , Scazzocchio Beatrice , Sanchez Massimo , Masella Roberta , Malorni Walter
Published: October 2002

We investigated the mechanisms underlying the pro‐apoptotic activity exerted by oxidized low‐density lipoproteins (oxLDL) in Caco‐2 intestinal cells, a cell line which retains many morphological and enzymatic features typical of normal human enterocytes. We found that: (i) oxLDL induced mitochondrial‐mediated apoptosis by provoking first an increase in mitochondrial membrane potential, followed, later, by the typical apoptosis‐associated depolarization (type II apoptosis); accordingly, (ii) caspase‐9 inhibition significantly hindered apoptosis while caspase‐8 inhibition did not; and finally (iii) dietary phenolic antioxidizing compounds exerted a significant protective antiapoptotic activity. These results point to mitochondrial hyperpolarization as ‘sensitizing feature’ in apoptotic proneness of Caco‐2 intestinal cells to oxLDL exposure.
Stress‐induced premature senescence in BJ and hTERT‐BJ1 human foreskin fibroblasts
Authors: de Magalhães João Pedro , Chainiaux Florence , Remacle José , Toussaint Olivier
Published: October 2002

To test the involvement of the telomeres in the senescent phenotype, we used telomerase‐immortalized human foreskin fibroblasts (hTERT‐BJ1). We exposed hTERT‐BJ1 and parental BJ cells to either UVB or H2O2 subcytotoxic stress(es). Both cell lines developed biomarkers of replicative senescence: loss of replicative potential, increase in senescence‐associated β‐galactosidase activity, typical senescence‐like morphology, overexpression of p21WAF‐1 and p16INK‐4a, and decreased level of the hyperphosphorylated form of pRb. Telomere shortening was slightly higher under stress for both BJ and hTERT‐BJ1 but still much lower than that reported for other cell lines. We conclude that pathways alternative to telomere shortening must cause the appearance of the senescence phenotype.
Neuroleptic-induced extrapyramidal symptoms are accompanied by cognitive dysfunction in schizophrenia
Authors: Krausz M. , Moritz S.H. , Naber D. , Lambert M. , Andresen B.
Published: October 2002

Cognitive impairments in schizophrenics have been found to precede tardive dyskinesia and to co-exist with other motor deficits. However, little is yet known about the prevalence of cognitive disturbances in patients with neuroleptic-induced parkinsonism. From the literature on idiopathic parkinson, it was inferred that extrapyramidal symptoms (EPS) are accompanied by cognitive dysfunction. 85 schizophrenic in-patients were divided into EPS high and low scorers according to an established criterion (Simpson Angus Scale, cut-off score: 0.4). Cognitive impairments were assessed using a self-rating instrument measuring disturbances of information processing.

Patients with high EPS exhibited significantly elevated scores in six of ten cognitive and perceptual subscales (t = 2.1—3.1) as compared to low EPS patients. It is concluded that high EPS patients suffer from cognitive disturbances which are assumed to possess high relevance for both psycho-social and medical treatment. Cognitive problems may, when not considered, disturb compliance, insight of illness and transfer of learnt skills into everyday life.
Placing nature: natural history collections and their owners in nineteenth-century provincial England
Authors: ALBERTI SAMUEL J. M. M.
Published: October 2002

The cultural history of museums is crucial to the understanding of nineteenth-century natural history and its place in wider society, and yet although many of the larger metropolitan institutions are well charted, there remains very little accessible work on the hundreds of English collections outside London and the ancient universities. Natural history museums have been studied as part of the imperial project and as instruments of national governments; this paper presents an intermediary level of control, examining the various individuals and institutions who owned and managed museums at a local level in provincial England, and their intended audience constituencies. The shifting forms and functions of collections in Newcastle, Sheffield and Manchester are studied in the hands of private collectors, learned societies, municipal authorities and civic colleges. I argue that the civic elite retained control of museums throughout the nineteenth century, and although the admission criteria of these various groups became ostensibly more inclusive, privileged access continued to be granted to expert and esteemed visitors.
Baroclinic modon equilibria on the beta-plane:
stability and transitions
Authors: KIZNER Z. , BERSON D. , KHVOLES R.
Published: October 2002

The objective of this work is a numerical study of the stability properties and the
evolution of the eastward-travelling baroclinic modons – coherent vortex structures
specific to stratified geophysical fluids where differential rotation (the β-effect) is
of the essence. In the vortices under study, the initial dependence of the potential
vorticity (PV) upon the streamfunction is piecewise-linear, the barotropic component
is dipolar, the baroclinic component is circularly symmetric about the vertical axis,
and the boundary of the trapped-fluid region (in which the vorticity contours are
closed) is a circular cylinder. These modons are shown to be stable for a wide range
of parameters. In two- and three-layer fluids, modons of this type are shown to be
able to transit to even more durable states, in which the trapped-fluid area is oval
in shape and the PV versus streamfunction dependence in this domain is nonlinear.
Possible transition mechanisms and linkage between the circular and oval modons
are discussed.
Response of macrobenthic communities to an hydraulic intervention in an enclosed lagoon (Valle di Gorino, northern Italy)
Authors: Mistri M. , Ghion F. , Modugno S. , Rossi R.
Published: October 2002

To assess the recovery of the lagoon in the Valle di Gorino, Italy, the macrobenthic assemblages were studied throughout a two year period, i.e. before and after the opening of a floodgate. Three stations were located along a gradient of confinement, and sampled for macrofauna, water and sedimentary parameters. Analyses were performed through univariate and multivariate techniques. The macrobenthic assemblages were characterized by a small total number of species, strong dominance in number by a few of these species, and low diversity, but changes in community structure and composition were clearly recognizable. Significant negative correlations were found between macroalgae and macrobenthic community attributes. The altered hydrological regime due to the opening of the floodgate disrupted macroalgal cycles and altered the related macrofaunal successional dynamics: species linked to the macroalgal degradation phase became dominant throughout the Valle. After the intervention, all areas exhibited similar species composition and abundances, and appeared to be in a permanently disturbed condition. A rescaling of environmental conditions repositioned species roles in the community: those species which were typical of a certain phase of the former successional progression, were successively dominating the whole lagoon, irrespective of time and the estuarine gradient. After the intervention, the spatial and temporal distribution of macrobenthic taxa was under the control of factors linked to organic enrichment of the sediments.
Prolactin action and signalling in the human endometrium
Authors: Jabbour HN , Gubbay O , Critchley HOD
Published: October 2002

Prolactin is a pleiotrophic hormone that is associated with over 300 biological functions. These functions can be broadly classified into growth and development, immune regulation, metabolism, behaviour and reproduction. The human prolactin gene is located on chromosome 6 and is composed of 6 exons. The gene is approximately 10 kilobases (kb) long whereas the mature prolactin mRNA is about 1 kb in length. Prolactin is encoded by 199 amino acids and the protein is approximately 23 kDa in size. Sequence analysis revealed that prolactin is 40% homologous to growth hormone and placental lactogen. These three proteins are thought to have arisen by duplication of an ancestral gene 400 million years ago. The high sequence homology of these proteins enables prolactin, human growth hormone and placental lactogens to bind the prolactin receptor and activate prolactin intracellular signalling pathways.
Poisson–Dirichlet and GEM Invariant Distributions
for Split-and-Merge Transformations of an
Interval Partition
Authors: PITMAN JIM
Published: October 2002

This paper introduces a split-and-merge transformation of interval partitions which combines some features of one model studied by Gnedin and Kerov [12, 11] and another studied
by Tsilevich [30, 31] and Mayer-Wolf, Zeitouni and Zerner [21]. The invariance under this
split-and-merge transformation of the interval partition generated by a suitable Poisson
process yields a simple proof of the recent result of [21] that a Poisson–Dirichlet distribution is invariant for a closely related fragmentation–coagulation process. Uniqueness and
convergence to the invariant measure are established for the split-and-merge transformation
of interval partitions, but the corresponding problems for the fragmentation–coagulation
process remain open.
On the presence or absence of the conjunction þæt in Old English, with special reference to dependent sentences containing a gif-clause
Authors: Otsu Norihiko
Published: October 2002

This article is a corpus-based investigation into the presence or absence of the conjunction þæt in dependent sentences containing a gif-clause in Old English and attempts in the process to shed light on the historical development of indirect speech. Encumbered by the addition of the gif-clause, a complex dependent sentence reveals facts about indirect speech that a simple dependent sentence cannot. Firstly, the article draws attention to a great number of instances of the zero form (the þæt-less construction) in which the dependent sentence is accompanied by a gif-clause, and, noting its structural similarity to direct speech, ascribes the zero form's origins to direct speech. Secondly, it is pointed out that in Old English, constructions with þæt still clearly reflect the influence of direct speech and closely resemble the zero form in structure. Thirdly, all this is attributed to the fact that OE prose was still unregularized and retained traits of spoken language, which may have made it difficult to accommodate a complex dependent sentence.
In vivo quantification of ageing changes in the rat liver from early juvenile to senescent life
Authors: Vollmar Brigitte , Pradarutti Sascha , Richter Sven , Menger Michael D
Published: October 2002

Abstract:  Aims/Method: Using high resolution multifluorescence in vivo microscopy, the present study was undertaken to determine the changes in rat hepatic tissue architecture and microvasculature during the growth associated with juvenile maturation and adult senescence, i.e. the age of 1, 3, 12 and 24 months. Results: By 1 month of age the liver attained its full size and functional capacity, as assessed by relative organ weight and hepatic bile flow. Survey of liver architecture revealed a progressive growth of lobular area with postsinusoidal venules exhibiting a proportional increase in length, diameter and inter‐vascular distance up to the age of 12–24 months. In regard to the 3.5–4‐fold average increase of lobular units, a minor reduction of sinusoidal density to 87% over life strongly implies the recruitment or formation of new sinusoidal microvessels as contributing mechanism to meet oxygen demand due to overall tissue enlargement. The sinusoidal perfusion rate remained above 98% over the whole lifespan. Leukocytic interaction with the hepatic microvascular endothelium was found within the physiological range in all age groups. Moreover, kinetics of clearance of latex beads as well as lobular distribution of Kupffer cells did not differ between animals of different age. Hepatic stellate cell‐associated area of ultraviolet vitamin A‐autofluorescence increased with age and significantly correlated with increasing tissue concentrations of vitamin A metabolites. Biochemical parameters serving as measures of tissue integrity did not indicate age‐associated tissue alterations. Conclusion: These age‐associated physiological changes should be carefully taken into account as a relevant variable in experimental research.
Mechanism of superoxide anion production by hepatic sinusoidal endothelial cells and Kupffer cells during short‐term ethanol perfusion in the rat
Authors: Hasegawa Tadashi , Kikuyama Masataka , Sakurai Kazushi , Kambayashi Yasuhiro , Adachi Masakazu , Saniabadi Abby R. , Kuwano Hiroyuki , Nakano Minoru
Published: October 2002

Abstract:  Background/Aims: The aim of this study was to clarify the candidate cells for and the mechanism of superoxide anion (O2·−) release into the hepatic sinusoids during short‐term exposure to ethanol.

Methods: The rat liver was perfused continuously with ethanol (a substrate for alcohol dehydrogenase) or tert‐buthanol (not a substrate for alcohol dehydrogenase) for 20 min at a final concentration of 40 mM. In order to detect O2·− production, MCLA (2‐methyl‐6‐[p‐methoxyphenyl]‐3,7‐dihydroimidazo[1,2‐a]pyrazin‐3‐one), a Cypridina luciferin analogue, was simultaneously infused and MCLA‐enhanced chemiluminescence was measured. The effects of gadolinium chloride (GdCL3) (a suppressor of Kupffer cells (KCs)), staurosporine (ST) (an inhibitor of serine–threonine kinases, including protein kinase C), diphenyleneiodonium chloride (DPI) (an inhibitor of NADPH oxidase), ibuprofen (IB) (an inhibitor of cyclooxygenase) and 4‐methylpyrazole (4MP) (an inhibitor of ethanol metabolism) on the ethanol‐induced chemiluminescence were also evaluated. Sites where O2·− could be released were determined by histochemical detection of nitro blue tetrazolium reduction.

Results: Both ethanol and tert‐buthanol rapidly caused O2·− release. GdCL3 suppressed the ethanol‐induced O2·− release by 61%. Staurosporine and DPI, but neither IB nor 4‐MP, also significantly inhibited the ethanol‐induced O2·− release. In the histochemical examination, ethanol‐stimulated liver showed blue formazan precipitate on both sinusoidal endothelial cells (SECs) and Kupffer cells (KCs), whereas the GdCl3‐pretreated liver had the precipitate only on SECs.

Conclusions: This study shows that ethanol itself stimulates both SECs and KCs to release O2·− via activation of NADPH oxidase probably involving protein kinase C (PKC).
Binding of C-reactive protein to modified low-density-lipoprotein particles: identification of cholesterol as a novel ligand for C-reactive protein
Authors: TASKINEN Sanna , KOVANEN Petri T. , JARVA Hanna , MERI Seppo , PENTIKÄINEN Markku O.
Published: October 2002

C-reactive protein (CRP), an acute-phase reactant, is present in atherosclerotic human arterial intima in association with lipids. In the present work we studied interactions between CRP and LDL on microtitre wells, where either CRP or LDL was immobilized. LDL was modified by vortex-mixing, oxidation, or by lipolysis with phospholipase A2 or with sphingomyelinase or a combination of trypsin and cholesterol esterase. We found that CRP bound only to LDL modified by trypsin/cholesterol esterase or by sphingomyelinase and that this binding was Ca2+-dependent. In these two forms of modified LDL, non-esterified cholesterol was susceptible to cholesterol oxidase, indicating exposure of non-esterified cholesterol on particle surfaces and suggesting a role for non-esterified cholesterol in mediating CRP binding. Consistent with this hypothesis were the following findings: (i) increasing the amount of non-esterified cholesterol in LDL with cyclodextrin increased, and decreasing its amount decreased, the binding of CRP to LDL; (ii) modification of non-esterified cholesterol in LDL by cholesterol oxidase decreased the binding of CRP to LDL; and (iii) CRP bound to purified non-esterified cholesterol. The binding was Ca2+-dependent and could be competed out with phosphocholine. Taken together, these findings suggest that CRP can bind to modified lipoproteins, notably to the non-esterified cholesterol on their surface. These interactions may be related to the suggested role of CRP in the local inflammation present in atherosclerotic plaques.
Cloning, sequencing and heterologous expression of the gene for lupanine hydroxylase, a quinocytochrome c from a Pseudomonas sp.
Authors: HOPPER David J. , KADERBHAI Mustak A. , MARRIOTT Shirley A. , YOUNG Michael , ROGOZINSKI Jerzy
Published: October 2002

The gene encoding the enzyme lupanine hydroxylase was isolated by PCR using chromosomal DNA from a lupanine-utilizing Pseudomonas sp. as template and primers based on the sequences of the N- and C-termini of the purified protein. The derived sequence for the mature gene product gave a protein with an Mr of 72256, in good agreement with the value found by SDS/PAGE of the pure enzyme, and contained the sequences of several peptides obtained after endoproteinase Lys-C digestion of the pure enzyme. The gene, under the transcriptional control of a phoA promotor and with the Escherichia coli alkaline phosphatase signal sequence, was expressed in E. coli containing a plasmid expressing the genes for cytochrome c maturation proteins constitutively. Haem-containing inactive protein in inclusion bodies was renatured and reactivated with pyrroloquinoline quinone (PQQ) and Ca2+ to give active enzyme. The lupanine hydroxylase (luh) gene coded for a protein with a cleavable 26-residue signal sequence at its N-terminus, required for the transport of the enzyme to its periplasmic location. Analysis of the protein sequence showed that it contains two domains, a large PQQ-binding N-terminal domain and a smaller cytochrome c C-terminal domain. Comparison of the derived sequence with those of other proteins showed considerable similarity with other quino(haemo)proteins, including alcohol dehydrogenases from a variety of bacteria. The PQQ-binding domain sequence contains W motifs, characteristic of the eight-bladed ‘propeller’ structure of methanol dehydrogenase, but lacks the unusual disulphide ring structure formed from two adjacent cysteines seen in this enzyme. The C-terminus shares some similarity with bacterial cytochrome c and includes the haem-binding consensus sequence CXXCH.
Evaluation of serum eosinophil cationic protein as a predictive marker for asthma exacerbation in patients with persistent disease
Authors: Sorkness C. , McGill K. , Busse W. W.
Published: October 2002

Background Eosinophilic inflammation is a feature of asthma. However, serological markers to indicate eosinophil activation in this process are not fully defined.

Objective To evaluate the relationship of serum eosinophil cationic protein (ECP) to asthma worsening and a marker for treatment effectiveness, 26 adult patients with an asthma exacerbation were identified.

Methods Identified asthma subjects were treated with oral corticosteroids (prednisone) for 14 days. The lung function variables, forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF), were determined as percentage of predicted and the blood total eosinophil count and serum ECP levels were measured. Patients were re‐evaluated after 14 days of corticosteroid treatment and then every 3 months thereafter during a 12‐month period.

Results Eighteen patients responded to prednisone treatment, whereas eight did not, assessed as improvement of their lung function parameters. Different serum ECP patterns could be seen in the responders compared with the non‐responders. All 18 responders had considerably increased serum ECP at the time of exacerbation, whereas the non‐responders had lower serum ECP levels. The serum ECP levels decreased to a greater extent in the responder patient group than in the non‐responder patients following prednisone treatment. This difference in patterns was not seen with total blood eosinophil counts.

Conclusion Our findings suggest that serum ECP may be used to predict a response to corticosteroid therapy in adult patients with asthma.
Non‐allergenic antigen in allergic sensitization: responses to the mite ferritin heavy chain antigen by allergic and non‐allergic subjects
Authors: Epton M. J. , Smith W. , Hales B. J. , Hazell L. , Thompson P. J. , Thomas W. R.
Published: October 2002

Background The majority of house dust mite proteins are non‐allergenic. There is, however, no information on the type of immune responses produced to these proteins and if the responses are affected by allergic sensitization.

Objective To identify and produce a non‐allergenic antigen of the house dust mite and compare antibody and T cell responses with the responses to allergens in sensitized and non‐sensitized individuals.

Results Ferritin heavy chain was cloned from a cDNA library as a candidate non‐allergen of the house dust mite. It bound IgG but not IgE in the sera of allergic and non‐allergic subjects and induced high T cell proliferative responses that correlated highly with the responses to the major allergen Der p 2. The cytokine response to the non‐allergen was characterized by the release of high levels of both Th1 and Th2 cytokines from the PBMC of both allergic and non‐allergic subjects. In contrast, the response to Der p 2 showed the expected high level of Th2 cytokine release from the PBMC of allergic subjects, while the Th2 cytokine production from PBMC of non‐allergic subjects was low and even lower than that induced by ferritin heavy chain. The levels of IFN‐γ release were similar for all groups. Der p 2 induced significantly more IL‐10 than ferritin in the non‐allergic group.

Conclusion The T cell responses to a non‐allergenic protein of the house dust mite were high and strongly correlated with the response to the major allergen. The non‐allergenic protein induced high levels of Th1 and Th2 cytokine in both allergic and non‐allergic subjects, while the allergen induced high levels of Th2 cytokine in allergic subjects and low levels in non‐allergic subjects. The responses to the allergen were thus independently up‐ and down‐regulated with no evidence of bystander regulation.
Elastic properties of irradiated RBCs measured by optical tweezers
Authors: Barjas‐Castro M.L. , Brandão M.M. , Fontes Adriana , Costa F.F. , Cesar C.L. , Saad S.T.O.
Published: October 2002

BACKGROUND : Gamma irradiation of RBCs results in the production of reactive oxygen capable of initiating the process of membrane lipid peroxidation and accelerates the leakage of potassium ions from RBCs, resulting in an increase of internal viscosity.

STUDY DESIGN AND METHODS : The elastic properties of irradiated and stored RBC units were studied using laser optical tweezers. The laser trapped the cell and the membrane elasticity was analyzed, measuring the cell deformation in six different drag velocities. Five RBC units were split into two portions. One portion received a gamma irradiation dose of 25 Gy, and the second one was used as a control and was not irradiated. All units were stored (4°C), and the elasticity was examined on Days 1, 14, 21, and 28.

RESULTS
: Elastic properties (μ) from irradiated RBCs stored for 21 and 28 days were significantly affected compared with control cells (21 days: control, 0.3 ± 0.03 × 10
−3
; irradiated, 3.5 ± 1.3 × 10
−3
dyn/cm; p < 0.001; and 28 days: control, 0.5 ± 0.09 × 10
−3
; irradiated, 14 ± 3.2 × 10
−3 dyn/cm; p < 0.001).

CONCLUSION : The sensitivity of the laser optical tweezers method showed that there is no significant change in elasticity over time for up to 14 days of storage, regardless of whether the unit was irradiated or not. However, beyond 21 days of storage, irradiated units demonstrate decreased elasticity.