bluuebunny/crossref_metadata_2025 huggingface dataset:
Iron toxicity in rice—conditions and management concepts
Authors: Becker Mathias , Asch Folkard
Published: July 2005

Iron toxicity is a syndrome of disorder associated with large concentrations of reduced iron (Fe2+) in the soil solution. It only occurs in flooded soils and hence affects primarily the production of lowland rice. The appearance of iron toxicity symptoms in rice involves an excessive uptake of Fe2+ by the rice roots and its acropetal translocation into the leaves where an elevated production of toxic oxygen radicals can damage cell structural components and impair physiological processes. The typical visual symptom associated with these processes is the “bronzing” of the rice leaves and substantial associated yield losses.

The circumstances of iron toxicity are quite well established. Thus, the geochemistry, soil microbial processes, and the physiological effects of Fe2+ within the plant or cell are documented in a number of reviews and book chapters. However, despite our current knowledge of the processes and mechanisms involved, iron toxicity remains an important constraint to rice production, and together with Zn deficiency, it is the most commonly observed micronutrient disorder in wetland rice. Reported yield losses in farmers' fields usually range between 15% and 30%, but can also reach the level of complete crop failure.

A range of agronomic management interventions have been advocated to reduce the Fe2+ concentration in the soil or to foster the rice plants' ability to cope with excess iron in either soil or the plant. In addition, the available rice germplasm contains numerous accessions and cultivars which are reportedly tolerant to excess Fe2+. However, none of those options is universally applicable or efficient under the diverse environmental conditions where Fe toxicity is expressed. Based on the available literature, this paper categorizes iron‐toxic environments, the steps involved in toxicity expression in rice, and the current knowledge of crop adaptation mechanisms in view of establishing a conceptual framework for future constraint analysis, research approaches, and the targeting of technical options.
Plant responses to drought and phosphorus deficiency: contribution of phytohormones in root‐related processes
Authors: Wittenmayer Lutz , Merbach Wolfgang
Published: July 2005

Environmental stresses are one of the most limiting factors in agricultural productivity. A large portion of the annual crop yield is lost to pathogens (biotic stress) or the detrimental effects of abiotic‐stress conditions. There are numerous reports about chemical characterization of quantitatively significant substrate fluxes in plant responses to stress factors in the root‐rhizosphere system, e.g., nutrient mobilization, heavy‐metal and aluminum immobilization, or establishment of plant‐growth‐promoting rhizobacteria (PGPR) by exudation of organic anions, phytosiderophores, or carbohydrates into the soil, respectively. The hormonal regulation of these responses is not well understood. This paper highlights this complex process, stressing the involvement of phytohormones in plant responses to drought and phosphorus deficiency as examples. Beside ethylene, abscisic acid (ABA) plays an important role in drought‐stress adaptation of plants. This hormone causes morphological and chemical changes in plants, ensuring plant survival under water‐limited conditions. For example, ABA induces stomata closure, reduction in leaf surface, and increase in root : shoot ratio and, thus, reduction in transpiration and increase in soil volume for water uptake. Furthermore, it supports water uptake in soil with decreasing water potential by osmotic adjustment. Suitability of hormonal parameters in the selection for improving stress resistance is discussed. Auxins, ethylene, and cytokinins are involved in morphological adaption processes to phosphorus (P) deficiency (increase in root surface, e.g., by the formation of more dense root hairs or cluster roots). Furthermore, indole‐3‐acetic acid increases root exudation for direct and indirect phosphorus mobilization in soil. Nevertheless, the direct use of the trait “hormone content” of a particular plant organ or tissue, for example the use of the drought‐stress‐induced ABA content of detached leaves in plant breeding for drought‐stress‐resistant crops, seems to be questionable, because this procedure does not consider the systemic principle of hormonal regulation in plants.
Does apoplastic ascorbic acid enhance manganese tolerance of Vigna unguiculata and Phaseolus vulgaris?
Authors: Fecht‐Christoffers Marion M. , Horst Walter J.
Published: July 2005

In cowpea (Vigna unguiculata), the development of manganese (Mn) toxicity is considered to be accompanied by the formation of reactive oxygen species, oxidized Mn, and phenoxy radicals in the leaf apoplast. Ascorbic acid (AA) is a common antioxidant in plants, and the oxidation of AA, particularly in the leaf apoplast, contributes to the first line of defence against several biotic and abiotic stress factors. The objective of the present study was to contribute to a better understanding of the role of AA in Mn leaf‐tissue tolerance of cowpea and common bean (Phaseolus vulgaris). Five cowpea cultivars (cvs.) differed greatly in Mn tolerance, which was expressed in differences in numbers of brown spots on leaves and in peroxidase (POD) activity in the apoplastic washing fluid (AWF). In a Mn‐sensitive cv., after 3 d of Mn treatment, brown spots were formed, and POD activities were increased, accompanied by a release of proteins into the apoplast. In the AWF, the concentration of AA and the ratio of AA : (AA+DHA) decreased already after 1 d, and to only 2% after 3 d. In the leaf tissue, the ratio was nearly unaffected, and the total AA+DHA content in the leaf tissue was even increased with advanced expression of Mn toxicity. The application of AA solutions in the range of 5–10 μM via the petiole slightly enhanced Mn tolerance as indicated by the reduction of brown spots (however inconsistently) and POD activity (consistently) in the AWF. Common bean cultivars differing in ozone tolerance, which has been reported to be due to a high AA availability in the leaf apoplast, were studied for their Mn tolerance. Clear differences in Mn tolerance between the cultivars existed, however, these differences were not related to their ozone tolerance. From these results, we conclude that the maintenance of sufficient AA levels in the leaf apoplast contribute to Mn tolerance, but does not fully explain genotypic differences in Mn tolerance in cowpea and common bean.
Development of a quick on‐farm test to determine nitrate levels in soil
Authors: Schmidhalter Urs
Published: July 2005

Crop management can be optimized and nitrogen (N) losses can be reduced with a better knowledge of soil‐nitrogen availability, especially if this information becomes directly available on‐site in a fast and cost‐effective way. In this paper, simple on‐farm methods to determine nitrate‐N in field‐moist soil samples immediately after sampling are described. The procedures include volumetric soil sampling, extraction based on manual shaking with tap water as universally available extractant, filtering soil/extractant mixtures on‐site, on‐site determination of the soil water content, and reflectometric nitrate measurements based on test strips. Using correction factors can compensate the impact of the temperature during the final nitrate measurement. An excellent agreement was found between the developed quick‐test procedures and the standard laboratory procedure. The proposed quick‐test has great potential to enable economical savings for farmers as well as benefiting the environment.
HPLC–SPE–NMR hyphenation in natural products research: optimization of analysis of Croton membranaceus extract
Authors: Lambert Maja , Stærk Dan , Hansen Steen Honoré , Jaroszewski Jerzy W.
Published: July 2005

The HPLC–SPE–NMR technique was used for the analysis of a root‐bark extract of Croton membranaceus. The components of the extract were separated on an analytical‐size reversed‐phase HPLC column, the chromatographic peaks were trapped on SPE (solid‐phase extraction) cartridges after post‐column dilution of the eluate with water and the compounds were eluted from the cartridges with acetonitrile‐d3 into a 30 µl 600 MHz NMR probe in a fully automated procedure. The trapping efficiency of scopoletin (1), the major extract constituent, was much higher on a GP (general phase, a polystyrene‐type polymer) SPE phase than on a C18 phase. Thus, under the conditions used, up to 100 µg of scopoletin per cartridge could be accumulated linearly after repeated trappings. The maximum achievable NMR signal‐to‐noise ratio using the GP cartridges was at least four times higher than that achievable with the C18 cartridges. It was shown that excessively long T1 relaxation times may compromise experiments in which acetonitrile‐d3 is used as the cartridge eluent. Nevertheless, the sensitivity gain provided by the HPLC–SPE–NMR technique through repeated peak trappings allowed the acquisition of good‐quality proton‐detected 2D NMR spectra without the need for solvent suppression. Copyright © 2005 John Wiley & Sons, Ltd.
HPLC–NMR of fatty alcohol ethoxylates
Authors: Hiller Wolf , Brüll Adele , Argyropoulos Dimitris , Hoffmann Eberhard , Pasch Harald
Published: July 2005

The application of HPLC–NMR for the analysis of a mixture of fatty alcohol ethoxylates (FAEs) is described. The use of the new generation, cryogenically cooled probes is investigated in respect of the sensitivity advantage that they provide. The FAE mixture is separated using liquid chromatography at the critical point of adsorption. The ability of the method to differentiate between the different end groups and the degree of polymerization of the mixture constituents is investigated. Both on‐flow and stop‐flow HPLC–NMR techniques were used together with two‐dimensional NMR spectroscopy. The results are compared with those obtained by using an evaporative light scattering detector for the HPLC. Copyright © 2005 John Wiley & Sons, Ltd.
Phytochemistry in the microgram domain—a LC–NMR perspective
Authors: Wolfender Jean‐Luc , Queiroz Emerson F. , Hostettmann Kurt
Published: July 2005

Plants represent an extraordinary reservoir of novel molecules and there is currently a resurgence of interest in the vegetable kingdom as a possible source of new lead compounds for introduction into therapeutical screening programs. In order to discover potential new bioactive natural products, the dereplication of crude plant extracts performed prior to isolation work is of crucial importance for avoiding the isolation of a known constituent. In this respect, chemical screening strategies have been developed using hyphenated techniques (LC/UV–DAD, LC–MS and LC–NMR). In our laboratory, these techniques have been fully integrated into the isolation process and are used for the chemical screening of crude plant extracts in complement with on‐line or at‐line bioassays. LC–UV–MS is used as a first dereplication step in combination with UV and MS databases, while LC–NMR is performed in a second step for de novo on‐line structure determination. This approach enables the partial or the complete on‐line identification of natural products in complex matrices such as crude plant extracts. These methods also give a unique possibility to study unstable compounds, which rapidly degrade or which are not separable at a preparative level.

In the multi‐hyphenated approach used (hypernation), LC–NMR plays a key role since it provides the most detailed structural information. The relatively low sensitivity of this technique, however, requires that strategies for high loading of plant extracts are developed and compromises for solvent selection have to be made. For more demanding experiments, at‐line strategies based on the microfractionation of the LC‐peak of interest and recording of spectra in fully deuterated solvents in microflow probes represent a promising alternative. Copyright © 2005 John Wiley & Sons, Ltd.
Production of inbred and hybrid transgenic mice carrying large (> 200 kb) foreign DNA fragments by intracytoplasmic sperm injection
Authors: Osada Tomoharu , Toyoda Atsushi , Moisyadi Stefan , Akutsu Hidenori , Hattori Masahira , Sakaki Yoshiyuki , Yanagimachi Ryuzo
Published: July 2005

We have developed a mouse transgenesis technique that facilitates the insertion of large (∼200 kilo base pairs) DNA fragments into host genomes of both inbred and hybrid mice. Six inbred and three hybrid transgenic mice carrying a single bacterial artificial chromosome (BAC) clone with genes located in the Down syndrome critical region of human chromosome 21 were produced using this technology. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Comparison of voiding parameters in men and women with lower urinary tract symptoms
Authors: Ku Ja Hyeon , Oh Seung‐June
Published: July 2005

Aim

The aim of this study was to compare voiding parameters by using urodynamic investigations in men and women with lower urinary tract symptoms (LUTS).

Methods

A total of 164 individuals (76 men and 88 women) completed the International Prostate Symptom Score (IPSS) and underwent a detailed urodynamic investigation. Patients were stratified by voiding function, which included bladder voiding efficiency (BVE) of < 80% and of ≥ 80%.

Results

IPSSs were similar in the men and women except for voiding symptoms for those with a BVE of ≥ 80% (12 for men vs. 9 for women, P = 0.016). When voiding parameters were compared according to BVE in men and women, respectively, maximum flow rate (Qmax) (P = 0.002), average flow rate (Qave) (P = 0.003), voided volume (P = 0.037), post‐void residual (PVR) (P < 0.001), and bladder outlet obstruction index (P = 0.016) were different for men with a BVE of < 80% and men with a BVE of ≥ 80%. However, for women with a BVE of < 80% or ≥ 80%, PVR (P < 0.001), detrusor pressure at maximum flow rate (P = 0.022), and opening detrusor pressure (P = 0.024) were different.

Conclusions

The voiding parameters of women differ from those of men according to voiding function. The present results show that a pressure‐flow study may represent a difference according to BVE in women as well as in men. Our findings suggest that opening detrusor pressure in women reflects the urethral and detrusor during voiding phase accurately as detrusor pressure at maximum flow rate does. Neurourol. Urodynam. © 2005 Wiley‐Liss, Inc.
Rubber composites reinforced by soy spent flakes
Authors: Jong L
Published: July 2005

Soy spent flakes (SSF) is a plentiful renewable material from the waste stream of commercial soy protein extraction. SSF contains mostly soy carbohydrate and a small fraction of soy protein. Dry SSF is a rigid material and has a shear elastic modulus of ∼4 GPa. Aqueous dispersions of SSF were blended with styrene‐butadiene (SB) latex to form rubber composites. Soy carbohydrate increased the tensile stress in the small strain region, but also decreased the elongation at break. The shear elastic modulus of the composites showed an increase in the small strain region, consistent with the stress–strain behavior. The SSF composites showed a slightly better modulus recovery than the protein composite after eight cycles of strain sweep. In the small strain region, the shear elastic modulus of 30 % filled composites at 140 °C was about 160 times greater than that of the unfilled elastomer, showing a significant reinforcement effect caused by SSF. Compared with soy protein isolate, the recovery behavior after eight cycles of dynamic strain suggests that SSF composites have a slightly stronger filler–rubber interaction. In general, SSF composites gave a slightly higher composite strength compared with the protein composites, but at a much lower cost. Published in 2005 by John Wiley & Sons, Ltd.
Synthesis of zinc glutarates with various morphologies using an amphiphilic template and their catalytic activities in the copolymerization of carbon dioxide and propylene oxide
Authors: Kim Jong‐Seong , Kim Hyunchul , Yoon Jihwan , Heo Kyuyoung , Ree Moonhor
Published: July 2005

Various heterogeneous zinc glutarate (ZnGA) catalysts were synthesized in solvent systems of various polarities from zinc acetate dihydrate and glutaric acid with and without the aid of an amphiphilic block copolymer, poly(ethylene glycol‐b‐propylene glycol‐b‐ethylene glycol) (PE6400), as a template. The presence of the PE6400 template and the polarity of the solvent significantly affected the morphology, particle size, surface area, and crystallinity of the resulting catalyst. However, all the catalysts had the same crystal lattice unit cell structure and similar surface compositions. The surface compositions of the catalysts were quite different from those of conventionally prepared ZnGA catalysts, that is, those prepared from zinc oxide and glutaric acid in toluene. All these characteristics of the catalysts influenced the ZnGA‐catalyzed copolymerization of carbon dioxide and propylene oxide. The catalytic activities of the catalysts in this copolymerization depended primarily on their surface area and secondarily on their crystallinity; a larger surface area and a higher crystallinity resulted in higher catalytic activity. Of the catalysts that we prepared, the ZnGA catalyst that was prepared in ethanol containing 5.5 wt % water with the PE6400 template, ZnGA‐PE3, exhibited the highest catalytic activity in the copolymerization. The catalytic activity of ZnGA‐PE3 was attributed to its wrinkled petal bundle morphology, which provided a large surface area and high crystallinity. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4079–4088, 2005
Friction and wear mechanisms of polyamide 66/high density polyethylene blends
Authors: Chen Zhaobin , Li Tongsheng , Liu Xujun , Lü Renguo
Published: July 2005

Polyamide 66 (PA66)/high density polyethylene (HDPE) blends having miscible structure were produced by compatibilization of HDPE grafted with maleic anhydride (HDPE‐g‐MAH). Mechanical and tribological properties of blends in different compositions were tested. It was found that the polymer blends greatly improved the mechanical properties of PA66 and HDPE. Blending HDPE with PA66 significantly decreased the friction coefficient of PA66; the friction coefficients of blends with different compositions were almost the same and approximately equal to that of pure HDPE; the blends with 80 vol % PA66 exhibited the best wear resistance. The transfer films, counterpart surfaces, and wear debris formed during sliding were investigated by Scanning Electron Microscopy (SEM), and Differential Scanning Calorimetry (DSC) analysis was further carried out on wear debris. These investigations indicated that the thermal control of friction model is applicable to PA66/HDPE blend, that is the friction coefficient of blend is governed by the HDPE component, which possesses a lower softening point relative to the PA66 component in this system. The wear mechanism of PA66/HDPE blend transforms from PA66 to HDPE as the HDPE content increases. PA66, as the component with higher softening point, increases the hardness of blend, enhances the ability of blend to form a transfer film on the counterface, and inhibits the formation of larger belt‐like debris of HDPE, at the same time, the presence of self‐lubricating HDPE in the system decreases the friction coefficient and the frictional heat, all of these factors are favorable for the wear resistance of PA66/HDPE blend. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2514–2523, 2005
Voltage dips at the terminals of wind power installations
Authors: Bollen Math H. J. , Olguin Gabriel , Martins Marcia
Published: July 2005

This article gives an overview of the kind of voltage dips that can be expected at the terminals of a wind power installation. The overview is based on the study of those dips at the terminals of industrial installations and provides a guideline for the testing of wind power installations against voltage dips. For voltage dips due to faults, a classification into different types is presented. Five types appear at the terminals of sensitive equipment and thus have to be included when testing the wind power installation against disturbances coming from the grid. A distinction is made between installations connected at transmission level and those connected at distribution level. For the latter the phase angle jump has to be considered. Dips due to other causes (motor, transformer and capacitor switching) are briefly discussed as well as the voltage recovery after a dip. Finally some thoughts are presented on the way in which voltage tolerance requirements should be part of the design process for wind power installations. Copyright © 2005 John Wiley & Sons, Ltd.
Large‐scale wind power farms as power plants
Authors: Gjengedal Terje
Published: July 2005

The integration of large‐scale wind power into weak power systems raises several issues that must be clarified. Typically these include the practical connection to the network, integration with the network system, system stability, system operation, necessary installations and extensions of the network, etc. At the same time, careful attention must be paid to the functional requirements such wind farms should meet in order to enhance system responses. Different wind power technologies have different characteristics and control possibilities. In this article, three technologies have been studied with respect to their dynamic performance, and a transient stability study has been performed in order to illustrate the differences in the three technologies. The results clearly show that there are differences in behaviour and in control possibilities. Hence there are also differences in how well they can meet functional requirements. When discussing to what degree strict requirements should be imposed on wind power, it should be kept in mind that some requirements can be met with small or moderate costs, while others may be expensive or difficult to meet. Some requirements may also mean a reduction in generation and hence in revenues. Rather than imposing strict requirements on wind turbines as such, ancillary services should be met in the most suitable way. It is not obvious that the same requirements should apply to wind power in hydro power‐dominated systems compared with, for instance, systems with a large share of nuclear or thermal power. It may well be cheaper to incorporate primary power control and system‐stabilizing equipment in other power plants or grid points than in many small wind turbine generators. General conclusions cannot be made on this, but the issue should be the focal point of system operators everywhere. Copyright © 2005 John Wiley & Sons, Ltd.
Stability of two superposed viscoelastic fluid‐particle mixtures
Authors: Kumar P. , Mohan H. , Singh G.J.
Published: July 2005

The stability of the plane interface separating two viscoelastic (Walters B′) superposed fluids of uniform densities in the presence of suspended particles is considered. The stability analysis has been carried out, for mathematical simplicity, for two highly viscoelastic fluids of equal kinematic viscosities and equal kinematic visco‐elasticities. For the (density wise) stable configuration, the system is found to be stable or unstable for the wave number range k ≤ or > \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$ {{1} \over {{\sqrt{2\nu \prime}}}} $\end{document} depending on the kinematic viscoelasticity ν′. However, the system is found to be unstable for the unstable configuration.
On upper bounds for real proportional stabilizing controllers
Authors: Batra P.
Published: July 2005

The explicit determination of the largest admissible constant controller is difficult. For linear systems with all poles in the domain of stability but at least one non‐minimum phase zero outside, an improved upper bound on real proportional gain controllers is given. Examples show the improvement and further possible margins.
Phylogeography of the endangered tideland snail Batillaria zonalis in the Japanese and Ryukyu Islands
Authors: Kojima Shigeaki , Kamimura Satomi , Iijima Akiko , Kimura Taeko , Mori Keisuke , Hayashi Ikuo , Furota Toshio
Published: July 2005

The phylogeography of the endangered tideland snail Batillaria zonalis in the Japanese and Ryukyu Islands was analyzed on the basis of nucleotide sequences of a mitochondrial gene for cytochrome oxidase c subunit I (COI). Extremely low genetic diversity was found in populations at both the northern and southern boundaries of the geographic distribution of this species in Japan, i.e., Sendai Bay and Iriomotejima Island, respectively, which might be attributed to the population bottleneck due to historical environmental variations and/or the recent foundation of populations in the marginal part of the inhabitable range. Most populations contained unique rare haplotypes, and significant genetic differentiation on the whole was shown, while no clear geographic genetic structure was detected between the Japanese and Ryukyu Islands or over the distribution area of B. zonalis in Japan, with the exception of significant genetic divergences in Ago Bay in the central part of Honshu and the southern part of Okinawajima Island.
Of circles and spirals: Bridging the gap between the leading circle and spiral wave concepts of cardiac reentry
Authors: Comtois P. , Kneller J. , Nattel S.
Published: July 2005

The “leading circle model” was the first detailed attempt at understanding the mechanisms of functional reentry, and remains a widely-used notion in cardiac electrophysiology. The “spiral wave” concept was developed more recently as a result of modern theoretical analysis and is the basis for consideration of reentry mechanisms in present biophysical theory. The goal of this paper is to present these models in a way that is comprehensible to both the biophysical and electrophysiology communities, with the idea of helping clinical and experimental electrophysiologists to understand better the spiral wave concept and of helping biophysicists to understand why the leading circle concept is so attractive and widely used by electrophysiologists. To this end, the main properties of the leading circle and spiral wave models of reentry are presented. Their basic assumptions and determinants are discussed and the predictions of the two concepts with respect to pharmacological responses of arrhythmias are reviewed. A major difference between them lies in the predicted responses to Na+-channel blockade, for which the spiral wave paradigm appears more closely to correspond to the results of clinical and experimental observations. The basis of this difference is explored in the context of the fundamental properties of the models.
Re‐evaluating the role of strongly charged sequences in amphipathic cell‐penetrating peptides
Authors: Henriques Sónia T. , Costa Júlia , Castanho Miguel A.R.B.
Published: July 2005

Cell‐penetrating peptides (CPPs) are able to translocate across biological membranes and deliver bioactive proteins. Cellular uptake and intracellular distribution of CPPs is commonly evaluated with fluorescent labels, which can alter peptide properties. The effect of carboxyfluorescein label in the Lys‐rich domain of the amphipathic CPP pep‐1, was evaluated and compared with non‐labelled pep‐1 in vitro and in vivo. A reduced membrane affinity and an endosomal‐dependent translocation mechanism, at variance with non‐labelled pep‐1, were detected. Therefore, the charged domain is not a mere enabler of peptide adsorption but has a crucial role in the translocation pathway of non‐labelled pep‐1.
Puppets and Machines of the Mind: Robert Lepage and the Modernist Heritage
Authors: INNES CHRISTOPHER
Published: July 2005

The work of Robert Lepage is examined in the context of the avant-garde, from Robert Wilson and Peter Brook, through the French Surrealists, back to Edward Gordon Craig. As well as being an icon of post-modernism, analysis of productions such as Needles and Opium, Elsinore and Zulu Time show the degree to which Lepage has realized Craig's ideals of the Übermarionette, and his screens, as well as ‘Scene’, his concept of a flexible, mechanized performance space. What this demonstrates is the unity of the modernist movement throughout the twentieth century.
Reading and Performing Uncertainty: Michael Frayn's Copenhagen and the Postdramatic Theatre
Authors: BARNETT DAVID
Published: July 2005

Michael Frayn's play about quantum mechanics, memory and history, Copenhagen, has taken a lot of criticism for ‘misrepresenting’ its historical characters, primarily Werner Heisenberg. This essay analyses the dramaturgy of the play and argues for a postdramatic reading in which questions of representation are dissolved by formal strategies that ally themselves with the thematics of the work. The text is viewed as a hybrid, somewhere between the dramatic and the postdramatic, set, as it is, in a fictional afterlife where conventional human categories no longer function. The postdramatic theatre, in refusing to interpret text, becomes a viable mode for performance in that the indeterminacy of meaning on stage equates with the uncertainty principle that lies at the scientific and moral heart of Copenhagen.
Two Against Nature: Rehearsing and Performing Howard Barker's Production of his Play The Twelfth Battle of Isonzo
Authors: RABEY DAVID IAN
Published: July 2005

The English dramatist/director Howard Barker has, through a unique combination of style, content, theoretical argument and mise-en-scène, persistently countered conventional presumptions and propositions of the supposedly ‘natural’ diminutions or ‘inevitable’ restrictions whereby one might think, feel, speak, act, love and exist. His work offers a purposefully anti-naturalistic expansion of vocabulary: of language, terms of experience, scenic and physical expression, and being. This article presents an actor's account of preparing and playing a role, under Barker's direction, in a two-hander play, and offers a reading of the play's strategic dynamics based on these experiences, and of the characters' uses of self-conscious performances in order to sustain and subvert artifice, with references to Greenblatt's theories of theatrical charisma and eroticism, and Baudrillard's theories of seduction.
Very high altitude aurora observations with the Solar Mass Ejection Imager
Authors: Mizuno D. R. , Buffington A. , Cooke M. P. , Eyles C. J. , Hick P. P. , Holladay P. E. , Jackson B. V. , Johnston J. C. , Kuchar T. A. , Mozer J. B. , Price S. D. , Radick R. R. , Simnett G. M. , Sinclair D. , Tappin S. J. , Webb D. F.
Published: July 2005

The Solar Mass Ejection Imager (SMEI) is a sensitive scanning instrument mounted on the Coriolis satellite that assembles an approximately all‐sky image of the heliosphere in red‐biased visible light once per orbit. Its lines of sight pass obliquely through the topside ionosphere and magnetosphere. We present serendipitous observations of a visual phenomenon detected at high altitudes (≥840 km) over the auroral zones and polar caps. The phenomenon is observed in two basic forms. The first, and more common, are periods of brief (1–3 min), nearly uniform illumination of the imager's field of view, which we interpret as transits of the satellite through a luminous medium. The second appear as localized filamentary structures, which we interpret as columns of luminous material, viewed from a distance, possibly extending to visible altitudes of 2000 km or higher. More than 1000 occurrences of these phenomena were recorded during the first full year of operations. These observations are well correlated in brightness and frequency with periods of enhanced geomagnetic activity.
Magnetospheric field‐line resonances: Ground‐based observations and modeling
Authors: Rankin R. , Kabin K. , Lu J. Y. , Mann I. R. , Marchand R. , Rae I. J. , Tikhonchuk V. T. , Donovan E. F.
Published: July 2005

We present theory and ground‐based observations of field‐line resonances (FLRs) excited in Earth's magnetosphere. Three FLR observations are reported, which correspond to large‐scale standing shear Alfvén wave (SAW) oscillations on nightside field lines extending from premidnight to close to dawn. The eigenfrequencies for these events are modeled using a nonorthogonal covariant‐contravariant analysis of the ideal magnetohydrodynamic (MHD) equations. This allows us to use a general field‐line topology, an example of which is computed using the Tsyganenko 1996 magnetic field model. We show that field‐line stretching, along with assumptions regarding the distribution of density along field lines, is sufficient to explain the observed FLR frequencies. Then, we consider dispersive effects operating at the level of the electron inertial scale near the ionosphere or the ion‐acoustic gyroradius in the vicinity of the equatorial plane. Specifically, we estimate the spatial saturation widths and phase mixing timescales based on a simple model of dispersive SAWs. By considering a new model for ionospheric Pedersen conductivity modification by field‐aligned currents in SAWs and numerical (finite element model) solutions to the reduced MHD equations, we model specific FLR observations in an approximate axisymmetric field topology. We discuss the interplay of linear and nonlinear phase mixing, along with gradients in dispersion and time‐dependent losses due to Pedersen conductivity enhancements.
Evidence of strong inertia‐gravity wave activity during the POMME experiment
Authors: Bouruet‐Aubertot Pascale , Mercier H. , Gaillard F. , Lherminier P.
Published: July 2005

The purpose of this paper is to characterize inertia‐gravity waves (IGW) activity and to investigate the variability of these waves in relationship to atmospheric forcing and larger‐scale motions. To this aim, we analyzed Eulerian measurements of horizontal currents and temperature collected over 1 year during the Programme Océan Multidisciplinaire Méso Echelle (POMME). We focused on the main frequency components of the IGW spectrum, namely the inertial frequency f and the semidiurnal frequency M2. Time evolution of the relative energy of these two components gave evidence of isolated events of high intensity. We performed a detailed analysis of these events and identified mechanisms of generation of these waves. Localized spots of intense, near‐inertial IGW were observed in winter. During the mixed layer deepening, one event was correlated with plume‐like structures resulting from peaks of intense surface cooling. This suggests a local generation process driven by strong downward vertical motions. Instead, other events of strong IGW could be related to submesoscale features, characteristic of a frontal region, in particular, wave trapping within anticyclonic eddies. In contrast, a downward energy propagation down to about 500 m below the mixed layer was isolated after a stormy period. Eventually, internal tidal beams, possibly generated at a nearby seamount, intermittently crossed the mooring, though less energetically than the previous events. Last, we estimated the eddy diffusivity from the velocity vertical shear. Large variations were obtained, from 10−6 m2/s up to 10−3 m2/s, consistent with the intense events previously isolated.
Thermal model for approach of a spreading ridge to subduction zones and its implications for high‐P/high‐T metamorphism: Importance of subduction versus ridge approach ratio
Authors: Uehara Shin‐ichi , Aoya Mutsuki
Published: July 2005

The approach of oceanic ridges to subduction zones finally resulting in ridge subduction is observed on the present Earth's surface. The thermal effects of the ridge approach event are studied using a two‐dimensional numerical model around subduction zones with particular emphasis on the implications for the associated high‐P/high‐T metamorphism. The ridge approach occurs when the subduction rate (v) is larger than the half‐spreading rate at the ridge. The difference between the two rates represents the ridge approach rate to the trench, u, which is newly incorporated in the present thermal model. The calculated thermal structure along the slab surface when a ridge reaches the trench generally depends only on u/v when shear heating or mantle flow is not taken into account. If u/v is small, or the ridge approach is slow compared to the subduction rate, the thermal effect of the ridge approach is large enough to explain the “hot” general P‐T conditions of high‐P/high‐T metamorphism relative to the steady state conditions predicted by numerical simulations. In addition, when the ridge is close to the trench, the subduction stage P‐T paths experienced by high‐P/high‐T metamorphic rocks show a strongly curved trajectory with the dP/dT progressively increasing with pressure. This suggests that the slope of petrologically determined subduction P‐T paths may indicate if ridge approach contributed to the formation of the metamorphic rocks.
Seismic‐related variations in the chemical and isotopic composition of thermal springs near Acapulco, Guerrero, Mexico
Authors: Taran Yuri A. , Ramirez‐Guzman Alejandro , Bernard Ruben , Cienfuegos Edith , Morales Pedro
Published: July 2005

Chemical and isotopic analyses of waters from 4 thermal springs of the Guerrero Pacific coast, the most seismically active area in Mexico, were performed weekly during a period of 1.5 years (October 2002–March 2004). Within the same time interval more than 200 earthquakes with 3.8 ≤ M ≤ 5.3 occurred in the area. The data display several anomalies in Cl−, SO42−, δD and δ18O, always immediately after an event, with a relaxation time of 3–4 weeks. The responses occurred only to earthquakes with the estimated epicenters very close to the location of a spring. These results indicate that: 1) at least for earthquakes with M < 5.3 within the Guerrero “seismic gap” there were no precursors in the chemical (ionic) and isotopic composition of thermal waters (on a weekly basis); 2) two groups of springs near Acapulco, Dos Arroyos and Paso Real, are sensitive to seismic activity and therefore further monitoring of these springs may help to unravel the mechanisms of the “hydro‐seismo‐interaction” in the area.
Focal mechanisms and the stress regime in NE and SW Tanzania, East Africa
Authors: Brazier Richard A. , Nyblade Andrew A. , Florentin Juliette
Published: July 2005

We report 12 new focal mechanisms from earthquakes in NE and SW Tanzania where the stress regime within the East African rift system is not well constrained. Focal mechanisms for events at the intersection of the Lake Tanganyika and Rukwa rifts in SW Tanzania indicate a complicated stress pattern with possible dextral strike‐slip motion on some faults but oblique motion on others (either sinistral on NW striking faults or dextral on NE striking faults). Within the Rukwa rift, focal mechanisms indicate normal dip‐slip motion with NE‐SW opening. In NE Tanzania where the Eastern rift impinges on the margin of the Tanzania Craton, fault motions are consistent with a zone of distributed block faults and sub E‐W extension. All twelve earthquakes likely nucleated within the crust.
Consistency of TTO‐NAS inorganic carbon data with modern measurements
Authors: Tanhua Toste , Wallace Douglas W. R.
Published: July 2005

We compare alkalinity and total dissolved inorganic carbon (DIC) measurements made during the Transient Tracers in the Ocean, North Atlantic Study (TTO‐NAS) in 1981 with modern measurements from a TTO reoccupation cruise in 2004 (M60/5). We find that the TTO‐NAS alkalinity values are 3.6 ± 2.3 μmol kg−1 higher than modern alkalinity data tied to Certified Reference Materials. The TTO‐NAS DIC values re‐calculated from original alkalinity and discrete‐pCO2 data using currently accepted constants are 3.8 μmol kg−1 higher than those reported in the revised TTO data set. This difference is reduced to 0.7 μmol kg−1 when our suggested correction to the TTO‐NAS alkalinity is applied. These re‐calculated DIC values are 2.4 μmol kg−1 too low relative to contemporaneous measurements made by the vacuum extraction/manometric Certified method. Application of this correction brings the TTO data into almost perfect agreement with modern measurements for slowly‐ventilated deep water of the eastern Atlantic.
Numerical experiments on cloud streets in the lee of island arcs during cold‐air outbreaks
Authors: Kawase Hiroaki , Sato Tomonori , Kimura Fujio
Published: July 2005

Numerous clouds streets often appear in the lee of island arcs during cold‐air outbreak. These clouds are quite similar each other in shape and appearance. We found that two different kinds of cloud streets are coexistent in them, one is formed by a mountain and another is formed by the temperature contrast between islands and the sea. Since difference in the characteristics between them is small, it is difficult to simply discriminate by satellite images. However, two kinds of the cloud streets can be observationally classified by the statistics of the satellite images with the help of numerical experiments.
Quantitative Evaluation of Cerebral Hemodynamics in Patients with Moyamoya Disease by Dynamic Susceptibility Contrast Magnetic Resonance Imaging—Comparison with Positron Emission Tomography
Authors: Tanaka Yoji , Nariai Tadashi , Nagaoka Tsukasa , Akimoto Hideaki , Ishiwata Kiichi , Ishii Kenji , Matsushima Yoshiharu , Ohno Kikuo
Published: July 2005

We examined whether the degree of hemodynamic stress in patients with chronic occlusive cerebral vascular disease can be quantitatively evaluated with the use of perfusion-weighted magnetic resonance imaging (PWI). Thirty-six patients with moyamoya disease (mean age, 26.8 years; range, 18 to 59) underwent PWI and positron emission tomography (PET) within a month's interval. The PWI data were calculated by three different analytic methods. The cerebral blood flow (CBF) ratio, cerebral blood volume (CBV) ratio, and mean transit time (MTT) of the anterior circulation were calculated using the cerebellum as a control region and compared with PET data on the same three parameters and oxygen extraction fraction (OEF). Parametric maps of PWI attained a higher resolution than the PET maps and revealed focal perfusion failure on a gyrus-by-gyrus level. The relative CBV and MTT obtained with PWI showed significant linear correlations with the corresponding PET values (CBV, R2 = 0.47 to 0.58; MTT, R2 = 0.32 to 0.68). We also found that we could detect regions with abnormally elevated OEF and CBV based on the delay of PWI-measured MTT relative to the control region by defining a 2.0-sec delay as a threshold. The sensitivity and specificity were 92.3% and 100% in detecting regions with abnormally elevated OEF, and 20.0% and 100% in detecting regions with abnormally elevated CBV, respectively. Among the parameters obtained with PWI, our results suggested that the relative CBV value and delay of MTT might be quantitatively manipulated to assist in clinical decision-making for patients with moyamoya disease.
Englitazone administration to late pregnant rats produces delayed body growth and insulin resistance in their fetuses and neonates
Authors: Sevillano Julio , López-Pérez Inmaculada C. , Herrera Emilio , del Pilar Ramos María , Bocos Carlos
Published: July 2005

The level of maternal circulating triacylglycerols during late pregnancy has been correlated with the mass of newborns. PPARγ (peroxisome-proliferator-activated receptor γ) ligands, such as TZDs (thiazolidinediones), have been shown to reduce triacylglycerolaemia and have also been implicated in the inhibition of tissue growth and the promotion of cell differentiation. Therefore TZDs might control cell proliferation during late fetal development and, by extension, body mass of pups. To investigate the response to EZ (englitazone), a TZD, on perinatal development, 0 or 50 mg of englitazone/kg of body mass was given as an oral dose to pregnant rats daily from day 16 of gestation until either day 20 for the study of their fetuses, or until day 21 of gestation for the study of neonates. EZ decreased maternal triacylglycerol levels at day 20 of gestation and neonatal mass, but not fetal mass. Fetuses and neonates from EZ-treated mothers exhibited high levels of insulin and were found to be hyperglycaemic. The apparent insulin-resistant state in neonates from EZ-treated pregnant rats was corroborated, since they showed higher plasma NEFA [non-esterified (‘free’) fatty acid] levels, ketonaemia and liver LPL (lipoprotein lipase) activity and lower plasma IGF-I (type 1 insulin-like growth factor) levels, in comparison with those from control mothers. Moreover, at the molecular level, an increase in Akt phosphorylation was found in the liver of neonates from EZ-treated mothers, which confirms that the insulin pathway was negatively affected. Thus the response of fetuses and neonates to maternal antidiabetic drug treatment is the opposite of what would be expected, and can be justified by the scarce amount of adipose tissue impeding a normal response to PPARγ ligands and by hyperinsulinaemia as being responsible for a major insulin-resistant condition.
Demonstration and characterization of phosphate transport in mammalian peroxisomes
Authors: Visser Wouter F. , van Roermund Carlo W. , Ijlst Lodewijk , Hellingwerf Klaas J. , Wanders Ronald J. A. , Waterham Hans R.
Published: July 2005

It is now well established that the peroxisomal membrane is not freely permeable to small molecules in vivo, which implies the existence of metabolite transporters in the peroxisomal membrane. A few putative peroxisomal metabolite transporters have indeed been identified, but the function of these proteins has remained largely unresolved so far. The only peroxisomal transporter characterized to a significant extent is the adenine nucleotide transporter, which is presumably required to sustain the activity of the intraperoxisomal very-long-chain-acyl-CoA synthetase. In addition to AMP, this acyl-CoA synthetase also produces pyrophosphate, which must be exported from the peroxisome. In the present study, we demonstrate that the peroxisomal membrane contains a transporter activity that facilitates the passage of phosphate and possibly pyrophosphate across the peroxisomal membrane. By reconstitution of peroxisomal membrane proteins in proteoliposomes, some kinetic parameters of the transporter could be established in vitro. The transporter can be distinguished from the mitochondrial phosphate transporter by its different sensitivity to inhibitors.
Characterization of the Bacillus subtilis GTPase YloQ and its role in ribosome function
Authors: Campbell Tracey L. , Daigle Denis M. , Brown Eric D.
Published: July 2005

We present an analysis of the cellular phenotype and biochemical activity of a conserved bacterial GTPase of unknown function (YloQ and YjeQ in Bacillus subtilis and Escherichia coli respectively) using a collection of antibiotics of diverse mechanisms and chemical classes. We created a yloQ deletion strain, which exhibited a slow growth phenotype and formed chains of filamentous cells. Additionally, we constructed a conditional mutant in yloQ, where growth was dependent on inducible expression from a complementing copy of the gene. In phenotypic studies, depletion of yloQ sensitized cells to antibiotics that bind at the peptide channel or peptidyl transferase centre, providing the first chemical genetic evidence linking this GTPase to ribosome function. Additional experiments using these small-molecule probes in vitro revealed that aminoglycoside antibiotics severely affected a previously characterized ribosome-associated GTPase activity of purified, recombinant YjeQ from E. coli. None of the antibiotics tested competed with YjeQ for binding to 30 or 70 S ribosomes. A closer examination of YloQ depletion revealed that the polyribosome profiles were altered and that decreased expression of YloQ led to the accumulation of ribosomal subunits at the expense of intact 70 S ribosomes. The present study provides the first evidence showing that YloQ/YjeQ may be involved in several areas of cellular metabolism, including cell division and ribosome function.