bluuebunny/crossref_metadata_2025 huggingface dataset:
Convergence of variational eigenvalues and eigenfunctions to the Dirichlet problem for the p-Laplacian in domains with fine-grained boundary
Authors: Drábek Pavel , Namlyeyeva Yuliya , Nečasová Šárka
Published: May 2010

We study the problem of the homogenization of Dirichlet eigenvalue problems for the p-Laplace operator in a sequence of perforated domains with fine-grained boundary. Using the asymptotic expansion method, we derive the homogenized problem for the new equation with an additional term of capacity type. Moreover, we show that a sequence of eigenvalues for the problem in perforated domains converges to the corresponding critical levels of the homogenized problem.
Reliability and Validity of the Short Schema Mode Inventory (SMI)
Authors: Lobbestael Jill , van Vreeswijk Michiel , Spinhoven Philip , Schouten Erik , Arntz Arnoud
Published: May 2010

Background: This study presents a new questionnaire to assess schema modes: the Schema Mode Inventory (SMI). Method: First, the construction of the short SMI (118 items) was described. Second, the psychometric properties of this short SMI were assessed. More specifically, its factor structure, internal reliability, inter-correlations between the subscales, test-retest reliability and monotonically increase of the modes were tested. This was done in a sample of N = 863 non-patients, Axis I and Axis II patients. Results: Results indicated a 14-factor structure of the short SMI, acceptable internal consistencies of the 14 subscales (Cronbach α's from .79 to .96), adequate test-retest reliability and moderate construct validity. Certain modes were predicted by a combination of the severity of Axis I and II disorders, while other modes were mainly predicted by Axis II pathology. Conclusions: The psychometric results indicate that the short SMI is a valuable measure that can be of use for mode assessment in SFT.
Localization of the source of terrestrial neutron bursts detected in thunderstorm atmosphere
Authors: Babich Leonid P. , Bochkov Evgenii I. , Kutsyk Igor M. , Roussel‐Dupré Robert A.
Published: May 2010

To localize an altitude of the neutron source responsible for the neutron flux enhancements observed on the ground, numerical simulations of photonuclear production and transport to on‐ground detector locations were carried out. The neutron fluence calculated for the volumetric source located at the altitudes 8–12 km is consistent with that estimated from neutron numbers measured on the ground. This altitude range is consistent with the idea that the burst of hard γ rays detected recently by Tsuchiya et al. (2007, 2009) originate from a volumetric intracloud γ ray source. Most likely, the photonuclear reactions caused by bremsstruhlung of descending relativistic runaway electron avalanches account for the neutron flux increases observed in the thunderstorm atmosphere.
Optical properties of an epitaxial Na0.5Bi0.5TiO3 thin film grown by laser ablation: Experimental approach and density functional theory calculations
Authors: Bousquet M. , Duclère J.-R. , Orhan E. , Boulle A. , Bachelet C. , Champeaux C.
Published: May 2010

This study reports on the determination of the optical constants of a lead-free ferroelectric material, Na0.5Bi0.5TiO3. The optical transmission measurements were carried out in the 300–3000 nm wavelength range, on a (100)-oriented Na0.5Bi0.5TiO3 thin film, epitaxially grown by laser ablation on a (100)MgO single crystal substrate. Applying the “method of the envelopes,” developed by Manifacier et al. [J. Phys. E 9, 1002 (1976)] and by Swanepoel [J. Phys. E 16, 1214 (1983)], the analysis of the observed interference fringes allowed extracting some optical data for Na0.5Bi0.5TiO3, namely the linear refractive and extinction indices n and k, the absorption coefficient α, and as well the nature (direct or indirect transition) and value of the optical band gap. It was found that n∞=2.321 and the transmission data suggested a 3.30 eV indirect transition. Our experimental results are thus in opposition to the few data reported so far for Na0.5Bi0.5TiO3, where a direct transition was evoked. Therefore, we have confronted the optical transmission data to supplementary diffuse reflectance and ellipsometry measurements, and finally, to first principles calculations. The diffuse reflectance data, collected for Na0.5Bi0.5TiO3 powders, indicate a 3.26 eV optical band gap. In addition, the ellipsometry measurements reveal a refractive index of 2.346 at 2.066 μm, an energy gap of ∼3.20 eV, and also confirm the thickness of the layer. These additional data are then in very good agreement with the data derived from the optical transmission measurements. Finally, first principles calculations were carried out in the framework of the density functional theory for the three Na0.5Bi0.5TiO3 polymorphs (i.e., rhombohedral, tetragonal, and cubic). For each polymorph, in order to consider the Na/Bi disorder on the perovskite A-site, three different Na/Bi distributions within the unit cell were investigated, leading to nine atomic configurations. The electronic structure of these nine configurations was then calculated after geometry optimization and only one of them did not converge. These calculations complete the above experimental data, as six electronic structures over eight presented an indirect band gap, with a band gap energy Eg falling in the 3.90–4.60 eV energy range. The latter value is higher than the experimental ones but is definitely more compatible with the energy band gap expected for ferroelectric oxide materials.
Measurements of the motion of filaments in a plasma ball
Authors: Campanell M. D. , Laird J. N. , Provost T. , Vasquez S. W. , Zweben S. J.
Published: May 2010

Measurements were made of the motion of the filamentary structures in a plasma ball using high-speed cameras and other optical detectors. These filaments traverse the ball radially at ∼106 cm/s at the driving frequency of ∼26 kHz and drift upward through the ball at ∼1 cm/s. The number of filaments and their radial speed increase approximately linearly with the applied voltage above some threshold. A custom plasma ball was constructed to observe the effects of varying gas pressure, gas species, and electrode properties on the filament structures.
Magnetic configuration of submicron-sized magnetic patterns in domain wall motion memory
Authors: Ohshima Norikazu , Numata Hideaki , Fukami Shunsuke , Nagahara Kiyokazu , Suzuki Tetsuhiro , Ishiwata Nobuyuki , Fukumoto Keiki , Kinoshita Toyohiko , Ono Teruo
Published: May 2010

We observed magnetic configuration and its change by external magnetic fields in submicron-sized U- and H-shaped NiFe patterns with an x-ray magnetic circular dichroism photoemission electron microscope. The microscope images showed the formation of a single domain wall (DW) with transverse structure at one corner of the U- and H-shaped patterns by applying the magnetic field from the oblique direction. By applying the magnetic field from the direction parallel to a horizontal bar in the patterns, the magnetic configuration in the U-shaped pattern was changed and four patterns were formed: (1) the DW moved from one trap site to another, (2) the DW moved beyond the trap site and formed a single domain, (3) the DW moved and stopped between the trap sites, and (4) the DW remained at the initial position. Only pattern (1) showed reversible DW motion, although pattern (2) was predominantly formed. In contrast, the magnetization configurations showed pattern (1), and reversible DW motion was observed for more than 80% of the H-shaped patterns. Micromagnetic simulation revealed that the DW in the U-shaped pattern was not sufficiently fixed at the corner and easily moved and vanished at the edge of the patterns because the magnetization in the two parallel bars rotated with a magnetic field. The DW was trapped with sufficient strength at the corner, and DW motion occurred only between the trap sites for the H-shaped patterns. The DW motion process was observed with an in situ magnetic field using the x-ray magnetic circular dichroism photoemission electron microscope and the process could be optimized by controlling the pattern shape.
Quantifying electronic charge trap states and the effect of imprint on ferroelectric poly(vinylidene fluoride-trifluoroethylene) thin films
Authors: Lew Connie , Thompson Michael O.
Published: May 2010

Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] thin films have been extensively studied for their ferroelectric properties and are a promising material for sensing and memory applications. Imprint, the time-dependent resistance to polarization reversal, is a key material property that limits applications and is poorly understood. We have used a fast ramp rate thermally stimulated current (FR-TSC) technique to investigate the proposed link between imprint time and filling of charge trap states, and to characterize these traps in an appropriate time-frame. Thin films of P(VDF-TrFE) on oxidized Si substrates were characterized following controlled initialization, fatigue, polarization, and imprint. Traps were allowed to fill during room temperature imprint for times from 1 to 104 s. Remaining unfilled traps were subsequently filled and quantified by FR-TSC temperature cycling from 20 to 100 °C at 1 K/s. Results confirm that charge trap filling occurs both with time, under isothermal conditions, as well as with increasing temperature. The rate of charge accumulation induced by FR-TSC exhibits the same logarithmic dependence with time as the experimentally measured imprint voltage; this strongly suggests a direct link between these trapped charges and the imprint field. Furthermore, measurements of the switching speed in post FR-TSC films were found to be independent of the imprint time, confirming that thermal cycling brought all samples to a common final state. These results provide further understanding of the polarization dynamics and materials interactions affecting the ferroelectric properties of P(VDF-TrFE).
Three component model of cylindrical electric double layers containing mixed electrolytes: A systematic study by Monte Carlo simulations and density functional theory
Authors: Goel Teena , Patra Chandra N. , Ghosh Swapan K. , Mukherjee Tulsi
Published: May 2010

The structure of electric double layer around a hard rigid impenetrable cylindrical polyion is studied using density functional theory as well as Monte Carlo simulations. The three component model, presented here, is an extension of solvent primitive model where the solvent molecules are treated as the neutral hard spheres, counterions and coions as the charged hard spheres, all of equal diameters, and in addition the mixture of mono- and multivalent counterions are also considered. The theory is partially perturbative where the hard sphere interactions are treated within the weighted density approach and the corresponding ionic interactions have been evaluated through second-order functional Taylor expansion with respect to the bulk electrolyte. The theoretical predictions in terms of the density profiles and the mean electrostatic potential profiles are found to be in good agreement with the simulation results. The presence of neutral hard spheres incorporate the effects of exclude volume interactions (ionic size correlations) while the mixture of mono- and multivalent counterions enhance the ionic charge correlation effects. Thus, this model study shows clear manipulations of ionic size and charge correlations in dictating the ionic density profiles as well as mean electrostatic potential profiles of the diffuse layer. The behavior of diffused double layer has been characterized at varying ionic concentrations, at different concentration ratios of mono- and multivalent counterions of mixed electrolytes, at different diameters of hard spheres, and at varying polyion surface charge density.
In situ determination of the static inductance and resistance of a plasma focus capacitor bank
Authors: Saw S. H. , Lee S. , Roy F. , Chong P. L. , Vengadeswaran V. , Sidik A. S. M. , Leong Y. W. , Singh A.
Published: May 2010

The static (unloaded) electrical parameters of a capacitor bank are of utmost importance for the purpose of modeling the system as a whole when the capacitor bank is discharged into its dynamic electromagnetic load. Using a physical short circuit across the electromagnetic load is usually technically difficult and is unnecessary. The discharge can be operated at the highest pressure permissible in order to minimize current sheet motion, thus simulating zero dynamic load, to enable bank parameters, static inductance L0, and resistance r0 to be obtained using lightly damped sinusoid equations given the bank capacitance C0. However, for a plasma focus, even at the highest permissible pressure it is found that there is significant residual motion, so that the assumption of a zero dynamic load introduces unacceptable errors into the determination of the circuit parameters. To overcome this problem, the Lee model code is used to fit the computed current trace to the measured current waveform. Hence the dynamics is incorporated into the solution and the capacitor bank parameters are computed using the Lee model code, and more accurate static bank parameters are obtained.
Temperature performance analysis of terahertz quantum cascade lasers: Vertical versus diagonal designs
Authors: Mátyás Alpár , Belkin Mikhail A. , Lugli Paolo , Jirauschek Christian
Published: May 2010

Resonant phonon depopulation terahertz quantum cascade lasers based on vertical and diagonal lasing transitions are systematically compared using a well established ensemble Monte Carlo approach. The analysis shows that for operating temperatures below 200 K, diagonal designs may offer superior temperature performance at lasing frequencies of about 3.5 THz and above; however, vertical structures are more advantageous for good temperature performance at lower frequencies.
Ultrafast all-optical magnetic switching in NaTb(WO4)2
Authors: Jin Zuanming , Ma Hong , Wang Lihua , Ma Guohong , Guo Feiyun , Chen Jianzhong
Published: May 2010

The operation of an all-optical magnetic switching based on the paramagnetic NaTb(WO4)2 crystals is carried out by the time-resolved magneto-optical Faraday effect. Our results demonstrate that the switching time can be as fast as ∼500 fs at room temperature. The switching amplitude shows a linear dependence on the excitation intensity, which is proportional to the magnetization induced by the circularly polarized light. Based on the inverse Faraday effect in magneto-optical crystal, the switching mechanisms arising from circular dichroism and birefringence are discussed. By tailoring the magneto-optical properties of NaTb(WO4)2 crystal, the switching magnitude can be modulated.
Evolution of resistive switching over bias duration of single Ag2S nanowires
Authors: Liao Zhi-Min , Hou Chong , Zhang Hong-Zhou , Wang Ding-Sheng , Yu Da-Peng
Published: May 2010

We report resistive switching in single Ag2S nanowires contacted with two silver electrodes. The resistance evolution over time was studied by persistently applying a fixed 0.1 V bias at 10 K, and it is found that the device alternated at the ON and OFF states. The resistive switching behaviors are ascribed to the formation and rupture of metallic Ag filament inside the Ag2S nanowire. The wait time for such switching was significantly longer than those previously reported (a few seconds for the initial switching on, by Liang et al., [Small 1, 971 (2005)]), which was discussed by considering the local Joule heat and charge accumulation during the wait time. The devices may have potential applications on nonvolatile memory.
Atomically resolved scanning tunneling microscopy on perovskite manganite single crystals
Authors: Rößler Sahana , Padmanabhan B. , Elizabeth Suja , Bhat H. L. , Steglich F. , Wirth S.
Published: May 2010

Atomically resolved scanning tunneling microscopy was conducted on cleaved single crystals of the cubic perovskite Pr0.68Pb0.32MnO3. Several different surface configurations could be resolved including a frequent square arrangement with atomic distances in excellent agreement to the bulk lattice constant of the cubic structure. We also observed stripe formation and a surface reconstruction. The latter is likely related to a polar rare earth-oxygen terminated surface.
The Road to Greener Applied Organic Synthesis: Performing Organic Reactions in Micelle-Based and Host-Guest Aqueous Nanoreactors
Authors: Stavber Gaj
Published: May 2010

The micellar and supramolecular catalysis of organic reactions in water, utilizing nanometre-sized micelles of ionic, non-ionic amphiphiles or host-guest inclusion complexes using appropriate host macrocyclic molecules able to accommodate a hydrophobic organic substrates are taken under a brief account. A focus on Heck-type C-C couplings, ring closing metathesis, and halo-transformations of organic compounds in aqueous environment, is presented.
A role for tetrahydrofolates in the metabolism of iron-sulfur clusters in all domains of life
Authors: Waller Jeffrey C. , Alvarez Sophie , Naponelli Valeria , Lara-Nuñez Aurora , Blaby Ian K. , Da Silva Vanessa , Ziemak Michael J. , Vickers Tim J. , Beverley Stephen M. , Edison Arthur S. , Rocca James R. , Gregory Jesse F. , de Crécy-Lagard Valérie , Hanson Andrew D.
Published: May 2010

Iron-sulfur (Fe/S) cluster enzymes are crucial to life. Their assembly requires a suite of proteins, some of which are specific for particular subsets of Fe/S enzymes. One such protein is yeast Iba57p, which aconitase and certain radical
S
-adenosylmethionine enzymes require for activity. Iba57p homologs occur in all domains of life; they belong to the COG0354 protein family and are structurally similar to various folate-dependent enzymes. We therefore investigated the possible relationship between folates and Fe/S cluster enzymes using the
Escherichia coli
Iba57p homolog, YgfZ. NMR analysis confirmed that purified YgfZ showed stereoselective folate binding. Inactivating
ygfZ
reduced the activities of the Fe/S tRNA modification enzyme MiaB and certain other Fe/S enzymes, although not aconitase. When successive steps in folate biosynthesis were ablated,
∆folE
(lacking pterins and folates) and
∆folP
(lacking folates) mutants mimicked the
∆ygfZ
mutant in having low MiaB activities, whereas
∆folE
∆thyA
mutants supplemented with 5-formyltetrahydrofolate (lacking pterins and depleted in dihydrofolate) and
∆gcvP
∆glyA
mutants (lacking one-carbon tetrahydrofolates) had intermediate MiaB activities. These data indicate that YgfZ requires a folate, most probably tetrahydrofolate. Importantly, the
∆ygfZ
mutant was hypersensitive to oxidative stress and grew poorly on minimal media. COG0354 genes of bacterial, archaeal, fungal, protistan, animal, or plant origin complemented one or both of these growth phenotypes as well as the MiaB activity phenotype. Comparative genomic analysis indicated widespread functional associations between COG0354 proteins and Fe/S cluster metabolism. Thus COG0354 proteins have an ancient, conserved, folate-dependent function in the activity of certain Fe/S cluster enzymes.
Syntactic classes of the Arabic passive participle: And how they should be rendered into English
Authors: Gadalla Hassan A.H.
Published: May 2010

The main concern of this article is to provide an analysis of the syntactic classes of Arabic passive participle forms and discuss their translations based on a comparative study of two English Quranic translations by Ali (1934) and Pickthall (1930). The study attempts to answer two questions: (a) Should we translate the Arabic passive participle into an English nominal, verbal, adjectival or adverbial? and (b) What are the factors that determine the choice of one translation or the other? So, it compares the two translations to analyze the different English translations of the Arabic passive participle.
A corpus of 350 sentences has been randomly selected from the source text, together with their 700 translations in the target texts. The two translations of all the sentences are compared and analyzed in terms of syntactic and semantic features. The various English translations of the Arabic passive participle forms are presented with a count of the examples representing them in the corpus and their percentages. Then, the contextual reference of each translation is studied and accounted for.
Study of the translation errors in the light of the Skopostheorie: Samples from the websites of some tourist attractions in China
Authors: Jiangbo He , Ying Tao
Published: May 2010

More and more overseas tourists are coming to China for a visit after the 2008 Beijing Olympics, and websites with relevant information will undoubtedly become their first channel to know about the desired places in China. However, they are always confused about the English translation of the scenic spots. Based on the Skopostheorie and from the perspective of purpose of translation, this paper attempts to make a detailed analysis of translation errors in the English versions on the websites of some tourist attractions in China, in comparison to their parallel texts on the websites of similar scenic spots in other parts of the world.
With the help of ‘non-equivalence at culture level’ proposed by Christiane Nord, causes for errors have been found. In the light of the Skopostheorie, translation brief of websites for tourism has been defined, and errors have been classified into three categories: ‘pragmatic translation errors’, ‘cultural translation errors’, and ‘linguistic translation errors’. A number of error samples of each type have been listed and suggested versions have been given. Parallel texts have been provided as a comparison and good examples to learn from.
Through this study, we may conclude that non-equivalence at culture level and word level pose great difficulty in translation, and errors will be committed if the translator is unaware of the skopos or purpose of the translation. However, these errors can be avoided if more effective and flexible strategies are adopted by the translator, such as ‘translation by cultural substitution’, ‘omission’, and ‘translation by a more general word’. This study may serve as a reference for further study on a larger and wider range of errors, and as a reference for future tourism-websites translators.
Sound symbolism, schemes & literary translation
Authors: Jawad Hisham A.
Published: May 2010

The paper examines sound schemes in Arabic original poetic prose and English translation. These are reverse rhyme, rhyme, pararhyme and consonance. Looked at from the vantage point of sound symbolism, an attempt is made to verify their expressive and thematic functions in ST. In some cases, the concept has apparently been proven applicable and the claims made in this regard are plausible.
As to the interlingual patterns of sound symbolism, the study has come to the conclusion that ST and TT diverge when it comes to how onomatopoeic elements evoke meaning. The strategic decisions taken by translators in addressing translation problems depend largely on how sensitive they are towards the ST phonic aspect and affiliations. They employ compensation in kind and in place whenever and wherever that is felt to be required, hence, replacing ST phonological recurrence with morphological and lexical ones. These higher-level devices are but one means of achieving parallel effects in the TT. However, consonance is regularly used as a prime solution for the problem of equivalence.
It is axiomatic that in any attempt of translation a certain degree of loss is expected in terms of failure to relay the ST message content intact. Another kind of damage consists in the impossibility of rendering ST scripts into TT. The significance of Arabic letters to the readers of Arabic will definitely be mismatched in the TT as they imply culturally broader connotations and allusions to the Islamic heritage. The graphological input to the message in the Arabic text will hardly be imparted by the TT Roman script.
Translating multilingual Singapore: An anthological perspective
Authors: Lee Tong King
Published: May 2010

This paper explores the ideological function of translation in negotiating power relations among languages in multilingual Singapore. Based on an analysis of the discursive roles of translation in multilingual literary anthologies published between 1985 and 2008, the paper argues that the power relation between English and the mother tongue languages has shifted over the past two decades. Central to this ideological shift is translation, the underlying discursive mechanism in all multilingual publications in Singapore. It has been found that the potential of a language to be translated into, as opposed to its being translated out of, is directly proportional to its symbolic capital in a multilingual society. It has also been predicted that the future trend in multilingual literary translation in Singapore will tend towards a multi-directional approach whereby the four official languages engage one another multilaterally in a complex dynamic of translation relations.
Classification-based scientific term detection in patient information
Authors: Hoste Véronique , Vanopstal Klaar , Lefever Els , Delaere Isabelle
Published: May 2010

Although intended for the “average layman”, both in terms of readability and contents, the current patient information still contains many scientific terms. Different studies have concluded that the use of scientific terminology is one of the factors, which greatly influences the readability of this patient information. The present study deals with the problem of automatic term recognition of overly scientific terminology as a first step towards the replacement of the recognized scientific terms by their popular counterpart. In order to do so, we experimented with two approaches, a dictionary-based approach and a learning-based approach, which is trained on a rich feature vector. The research was conducted on a bilingual corpus of English and Dutch EPARs (European Public Assessment Report). Our results show that we can extract scientific terms with a high accuracy (> 80%, 10% below human performance) for both languages. Furthermore, we show that a lexicon-independent approach, which solely relies on orthographical and morphological information is the most powerful predictor of the scientific character of a given term.
Variations in terminology
Authors: Condamines Anne
Published: May 2010

The study of variation in terminology came to the fore over the last fifteen years in connection with advances in textual terminology. This new approach to terminology could be a way of improving the management of risk related to language use in the workplace and to contribute to the definition of a “linguistics of the workplace”. As a theoretical field of study, linguistics has hardly found any application in the workplace. Two of its applied branches, however, Sociolinguistics and Natural Language Processing (NLP) are relevant. Both deal with lexical phenomena, — i.e. terminology — sociolinguistics taking into account very subtle inter-individual variations and NLP being more interested in stability in the use. So, taking into account variations in building terminologies could be a means of considering both description and prescription, use and norm. This approach to terminology, which has been made possible thanks to NLP and Knowledge Engineering could be a way of meeting needs in the workplace concerning risk management related to language use.
Multilingual modalities for specialized languages
Authors: Nakao Yukie , Goeuriot Lorraine , Daille Béatrice
Published: May 2010

With the growth of textual data, techniques are necessary for their selection and organization. The organization of textual documents belonging to specialized languages relies mainly on information reflecting the subject domain, the genre of the document and its communication level. This paper aims to distinguish different levels of specialized documents: scientific documents and popular science documents. Identifying the communication level of a document requires a modality analysis that characterizes the relationship between the author and the content. In this paper, we investigate the relevancy of two modality theories defined for general language in order to characterize texts in the medical field. Furthermore, we compare these theories with respect to their multilingual adaptation working on French and Japanese. We show that the automation of both theories using specific features is possible, but because of paucity and ambiguity problems, only one is fully operational and scales efficiently.
Automating the compilation of specialized dictionaries
Authors: Le Serrec Annaïch , L'Homme Marie-Claude , Drouin Patrick , Kraif Olivier
Published: May 2010

In this paper, we study how single-word term extraction and bilingual lexical alignment can be used and combined to assist terminologists when they compile bilingual specialized dictionaries. Two specific tools — namely a term extractor called TermoStat and a sentence and lexical aligner called Alinea — are tested in a specific project the aim of which is the development of an English-French dictionary on climate change. We analyze the results of lexical alignment based on a typology of terminology equivalents. We first extracted French candidate terms that were then submitted to the lexical aligner. The results show that the use of these tools proves to be a valuable asset for compiling bilingual dictionaries. Most equivalents provided by the aligner were valid and the tool was able to locate several valid English equivalents (some of which were structurally different) for candidate terms.
Producing a Robust Body of Data with a Single Technique
Authors: Gandenberger Gregory Stephen
Published: May 2010

When a technique purports to provide information that is not available to the unaided senses, it is natural to think that the only way to validate that technique is by appealing to a theory of the processes that lead from the object of study to the raw data. In fact, scientists have a variety of strategies for validating their techniques. Those strategies can yield multiple independent arguments that support the validity of the technique. Thus, it is possible to produce a robust body of data with a single technique. I illustrate and support these claims with a historical case study.
Arabidopsis GLUTATHIONE REDUCTASE1 Plays a Crucial Role in Leaf Responses to Intracellular Hydrogen Peroxide and in Ensuring Appropriate Gene Expression through Both Salicylic Acid and Jasmonic Acid Signaling Pathways
Authors: Mhamdi Amna , Hager Jutta , Chaouch Sejir , Queval Guillaume , Han Yi , Taconnat Ludivine , Saindrenan Patrick , Gouia Houda , Issakidis-Bourguet Emmanuelle , Renou Jean-Pierre , Noctor Graham
Published: May 2010

Glutathione is a major cellular thiol that is maintained in the reduced state by glutathione reductase (GR), which is encoded by two genes in Arabidopsis (Arabidopsis thaliana; GR1 and GR2). This study addressed the role of GR1 in hydrogen peroxide (H2O2) responses through a combined genetic, transcriptomic, and redox profiling approach. To identify the potential role of changes in glutathione status in H2O2 signaling, gr1 mutants, which show a constitutive increase in oxidized glutathione (GSSG), were compared with a catalase-deficient background (cat2), in which GSSG accumulation is conditionally driven by H2O2. Parallel transcriptomics analysis of gr1 and cat2 identified overlapping gene expression profiles that in both lines were dependent on growth daylength. Overlapping genes included phytohormone-associated genes, in particular implicating glutathione oxidation state in the regulation of jasmonic acid signaling. Direct analysis of H2O2-glutathione interactions in cat2 gr1 double mutants established that GR1-dependent glutathione status is required for multiple responses to increased H2O2 availability, including limitation of lesion formation, accumulation of salicylic acid, induction of pathogenesis-related genes, and signaling through jasmonic acid pathways. Modulation of these responses in cat2  gr1 was linked to dramatic GSSG accumulation and modified expression of specific glutaredoxins and glutathione S-transferases, but there is little or no evidence of generalized oxidative stress or changes in thioredoxin-associated gene expression. We conclude that GR1 plays a crucial role in daylength-dependent redox signaling and that this function cannot be replaced by the second Arabidopsis GR gene or by thiol systems such as the thioredoxin system.
Alternative polymer precipitants for protein crystallization
Authors: Skálová Tereza , Dušková Jarmila , Hašek Jindřich , Kolenko Petr , Štěpánková Andrea , Dohnálek Jan
Published: May 2010

A set of 16 inexpensive and commercially available polymer precipitants were tested for protein crystallization. Eight of them were found suitable: polyethylene glycol dimethyl ether of molecular weight (MW) 500, 1000 and 2000; di[poly(ethylene glycol)] adipate, MW 900; poly(ethylene glycol-ran-propylene glycol), MW 2500 and 12000; poly(acrylic acid) sodium salt, MW 2100; and polyethylene glycol methyl ether methacrylate, MW 1100. Two new crystallization screens, PolyA and PolyB, were formulated using these eight polymers, each containing 96 solutions – four polymers in combination with 24 common salts and buffers, covering pH values from 4.5 to 9.0. The screens were tested on 29 proteins, 21 of which were crystallized. The tests confirmed the applicability of the eight polymers as precipitants for protein crystallization.
Anomalous thermal expansion of cobalt olivine, Co2SiO4, at low temperatures
Authors: Sazonov Andrew , Hutanu Vladimir , Meven Martin , Heger Gernot , Hansen Thomas , Senyshyn Anatoliy
Published: May 2010

The temperature variation of the Co2SiO4structural parameters has been investigated by means of both neutron powder and single-crystal diffraction. Measurements were performed in a broad temperature range from 5 to 500 K. There is clear evidence of an anomalous thermal expansion related to the magnetic phase transition at 50 K. Below this temperature an abrupt elongation and contraction were observed along thecandbaxes (space groupPnma), respectively, whereas the lattice parameteraremains constant in the range between 5 and 50 K. The resulting volume of the unit cell is contracted below 50 K. This phenomenon is attributed to magnetostriction effects. A model based on the specific heat capacity data was applied for the quantitative description of the anomalous thermal expansion behaviour. On the other hand, no anomalies can be observed in the temperature dependency of the interatomic distances and angles.
Experimental setup forin situX-ray SAXS/WAXS/PDF studies of the formation and growth of nanoparticles in near- and supercritical fluids
Authors: Becker Jacob , Bremholm Martin , Tyrsted Christoffer , Pauw Brian , Jensen Kirsten Marie Ø. , Eltzholt Jakob , Christensen Mogens , Iversen Bo B.
Published: May 2010

The growing interest in inorganic nanoparticles for a wide range of applications is spurring a need for synthesis methods that allow a highly specific tailoring of material properties. Synthesis in supercritical fluids holds great promise for solving this problem, but so far the fundamental chemical processes taking place under these conditions are to a large extent unknown. Here the design, construction and application of a versatile experimental setup are reported; this setup enablesin situsynchrotron small-angle X-ray scattering/wide-angle X-ray scattering/pair distribution function (SAXS/WAXS/PDF) studies of the formation and growth of nanoparticles under supercritical fluid conditions.
Growth of large protein crystals by a large-scale hanging-drop method
Authors: Kakinouchi Keisuke , Nakamura Tsutomu , Tamada Taro , Adachi Hiroaki , Sugiyama Shigeru , Maruyama Mihoko , Takahashi Yoshinori , Takano Kazufumi , Murakami Satoshi , Inoue Tsuyoshi , Kuroki Ryota , Mori Yusuke , Matsumura Hiroyoshi
Published: May 2010

A method for growing large protein crystals is described. In this method, a cut pipette tip is used to hang large-scale droplets (maximum volume 200 µl) consisting of protein and precipitating agents. A crystal grows at the vapor–liquid interface; thereafter the grown crystal can be retrieved by droplet–droplet contact both for repeated macroseeding and for mounting crystals in a capillary. Crystallization experiments with peroxiredoxin ofAeropyrum pernixK1 (thioredoxin peroxidase, ApTPx) and hen egg white lysozyme demonstrated that this large-scale hanging-drop method could produce a large-volume crystal very effectively. A neutron diffraction experiment confirmed that an ApTPx crystal (6.2 mm3) obtained by this method diffracted to beyond 3.5 Å resolution.
Comparative study of two lead-free piezoceramics using diffraction techniques
Authors: Schmitt Ljubomira Ana , Hinterstein Manuel , Kleebe Hans-Joachim , Fuess Hartmut
Published: May 2010

A comparative study of two distinct lead-free piezoceramics, (Bi0.5Na0.5TiO3)0.92–(BaTiO3)0.06–(K0.5Na0.5NbO3)0.02and (Bi0.5Na0.5TiO3)0.94–(BaTiO3)0.05–(K0.5Na0.5NbO3)0.01, termed 92-06-02 and 94-05-01, respectively, is presented. The samples were investigated by complementary diffraction techniques, namely X-ray, neutron and electron diffraction. Transmission electron microscopy (TEM) and powder diffraction experiments clearly revealed the presence of both rhombohedral and tetragonal phases in space groupsR3candP4bm, respectively. Superlattice reflections observed in the diffraction patterns were used to identify the two phases. It was found that sample 92-06-02, with a high proportion of the nonpolar tetragonal phase, shows a grainy contrast, whereas specimen 94-05-01 features domain-like contrast, related to a higher rhombohedral phase fraction. The combination of local scale analysesviaTEM with X-ray and neutron diffraction provides the experimental basis for further structural investigations.
Comparison between in vitro qualities of platelets washed with commercially available additive solutions and those washed with M‐sol
Authors: Hirayama J. , Azuma H. , Fujihara M. , Akino M. , Homma C. , Kato T. , Ikeda H.
Published: May 2010

Background and Objectives  We previously developed a novel additive solution (M‐sol) with a high ability to preserve the in vitro qualities of platelets (PLTs) in washed PLTs Here, we compared the ability of M‐sol with that of commercially available additive solutions (ASs) to preserve the in vitro qualities (pH, mean PLT volume, %disc, P‐selectin, %hypotonic shock response and aggregation) of PLTs at a low plasma concentration.

Materials and Methods  The platelet concentrate was divided into two equal aliquots (control group and test group). After centrifugation of both groups and removal of as much supernatant as possible, the pellet of the control group was resuspended in M‐sol and those of the test group were resuspended in other ASs, and subsequently stored in polyolefin bags with agitating at 20–24°C.

Results  Compared with those stored in M‐sol, the qualities of PLTs stored in PAS‐B (alternative name; PAS‐II or T‐sol), PAS‐ C (alternative name; PAS‐III or Intersol) or Plasma Lyte were degraded as early as 24 h after washing. The qualities of PLTs stored in PAS‐D (alternative name; Composol PS) or PAS‐E (alternative name; PAS‐IIIM or SSP+) were comparable to that of those stored in M‐sol 24 h after washing; however, the qualities had deteriorated 72 h after washing.

Conclusions  At a low plasma concentration (5% or less), the M‐sol showed a higher ability to preserve PLTs than the five ASs studied here. Although PAS‐D and PAS‐E are available as an AS for short‐term storage of washed PLTs, M‐sol is thought to be preferable for longer storage.
Evaluating a strain energy fatigue method using cyclic plasticity models
Authors: SHAHROOI S. , METSELAAR I. H. , HUDA Z.
Published: May 2010

For the development of constitutive equations that describe the behaviour of materials under cyclic plastic strains, different kinds of formulations can be adopted. Recently, an energy‐based fatigue damage parameter has been developed to present energy‐fatigue life curves using a calculation of the total strain energy. In this study, the damage criterion is examined by calculation of the plastic strain energy from stress–strain hysteresis loops in the cyclic plasticity models under condition of multi‐axial fatigue. These cyclic plasticity models are the Garud multi‐surface model and the Chaboche nonlinear kinematic hardening model. The models are briefly explained and the general features of their computational procedure are presented. Then, the hysteresis loops of these models will be obtained and the fatigue lives are predicted and compared to experimental data by the ratio of predicted life to experimental life. Consequently, a weighting factor on shear plastic work is presented to decrease the life factors.
Over‐expression of specific HvCslF cellulose synthase‐like genes in transgenic barley increases the levels of cell wall (1,3;1,4)‐β‐d‐glucans and alters their fine structure
Authors: Burton Rachel A. , Collins Helen M. , Kibble Natalie A. J. , Smith Jessica A. , Shirley Neil J. , Jobling Stephen A. , Henderson Marilyn , Singh Rohan R. , Pettolino Filomena , Wilson Sarah M. , Bird Anthony R. , Topping David L. , Bacic Antony , Fincher Geoffrey B.
Published: May 2010

Cell walls in commercially important cereals and grasses are characterized by the presence of (1,3;1,4)‐β‐d‐glucans. These polysaccharides are beneficial constituents of human diets, where they can reduce the risk of hypercholesterolemia, type II diabetes, obesity and colorectal cancer. The biosynthesis of cell wall (1,3;1,4)‐β‐d‐glucans in the Poaceae is mediated, in part at least, by the cellulose synthase‐like CslF family of genes. Over‐expression of the barley CslF6 gene under the control of an endosperm‐specific oat globulin promoter results in increases of more than 80% in (1,3;1,4)‐β‐d‐glucan content in grain of transgenic barley. Analyses of (1,3;1,4)‐β‐d‐glucan fine structure indicate that individual CslF enzymes might direct the synthesis of (1,3;1,4)‐β‐d‐glucans with different structures. When expression of the CslF6 transgene is driven by the Pro35S promoter, the transgenic lines have up to sixfold higher levels of (1,3;1,4)‐β‐d‐glucan in leaves, but similar levels as controls in the grain. Some transgenic lines of Pro35S:CslF4 also show increased levels of (1,3;1,4)‐β‐d‐glucans in grain, but not in leaves. Thus, the effects of CslF genes on (1,3;1,4)‐β‐d‐glucan levels are dependent not only on the promoter used, but also on the specific member of the CslF gene family that is inserted into the transgenic barley lines. Altering (1,3;1,4)‐β‐d‐glucan levels in grain and vegetative tissues will have potential applications in human health, where (1,3;1,4)‐β‐d‐glucans contribute to dietary fibre, and in tailoring the composition of biomass cell walls for the production of bioethanol from cereal crop residues and grasses.
Analysis of leaf appearance, leaf death and phoma leaf spot, caused by Leptosphaeria maculans, on oilseed rape (Brassica napus) cultivars
Authors: Powers S.J. , Pirie E.J. , Latunde‐Dada A.O. , Fitt B.D.L.
Published: May 2010

Development of phoma leaf spot (caused by Leptosphaeria maculans) on winter oilseed rape (canola, Brassica napus) was assessed in two experiments at Rothamsted in successive years (2003–04 and 2004–05 growing seasons). Both experiments compared oilseed rape cultivars Eurol, Darmor, Canberra and Lipton, which differ in their resistance to L. maculans. Data were analysed to describe disease development in terms of increasing numbers of leaves affected over thermal time from sowing. The cultivars showed similar patterns of leaf spot development in the 2003–04 experiment when inoculum concentration was relatively low (up to 133 ascospores m−3 air), Darmor developing 5.3 diseased leaves per plant by 5 May 2004, Canberra 6.6, Eurol 6.8 and Lipton 7.5. Inoculum concentration was up to sevenfold greater in 2004–05, with Eurol and Darmor developing 2.4 diseased leaves per plant by 16 February 2005, whereas Lipton and Canberra developed 2.8 and 3.0 diseased leaves, respectively. Based on three defined periods of crop development, a piece‐wise linear statistical model was applied to the progress of the leaf spot disease (cumulative diseased leaves) in relation to appearance (‘birth’) and death of leaves for individual plants of each cultivar. Estimates of the thermal time from sowing until appearance of the first leaf or death of the first leaf, the rate of increase in number of diseased leaves and the area under the disease progress line (AUDPL) for the first time period were made. In 2004–05, Canberra (1025 leaves ×°C days) and Lipton (879) had greater AUDPL values than Eurol (427) and Darmor (598). For Darmor and Lipton, the severity of leaf spotting could be related to the severity of stem canker at harvest. Eurol had less leaf spotting but severe stem canker, whereas Canberra had more leaf spotting but less severe canker.
Identification of Germline Stem Cells in the Ovary of the Teleost Medaka
Authors: Nakamura Shuhei , Kobayashi Kayo , Nishimura Toshiya , Higashijima Shin-ichi , Tanaka Minoru
Published: May 2010

Keeping Egg Production Going

Whether oogenesis ceases around birth in vertebrate ovaries has been a topic of long-standing interest and considerable debate.

Nakamura
et al.

(p.
1561
, published online 20 May) now identify germline stem cells in the ovary of the teleost fish medaka. The stem cells are found as clusters of germ cells (termed germinal cradles) in a cord-like structure that expresses
sox9
, a gene critical for testis formation in mammals. The cords are buried within the ovary within the germinal epithelium. This work in fish shows that there can indeed be continuing egg production from vertebrate germline stem cells.
ATP-Binding Cassette Transporters and HDL Suppress Hematopoietic Stem Cell Proliferation
Authors: Yvan-Charvet Laurent , Pagler Tamara , Gautier Emmanuel L. , Avagyan Serine , Siry Read L. , Han Seongah , Welch Carrie L. , Wang Nan , Randolph Gwendalyn J. , Snoeck Hans W. , Tall Alan R.
Published: May 2010

Inhibiting Leukocytosis

Leukocytosis—an elevated white blood cell count—contributes by unknown mechanisms to the pathogenesis of atherosclerosis and associated coronary heart disease. Now,

Yvan-Charvet
et al.

(p.
1689
, published online 20 May; see the Perspective by

Hansson and Björkholm

) show that the adenosine triphosphate–binding cassette transporters ABCA1 and ABCG1 are critical suppressors of atherosclerosis-associated leukocytosis. Mice deficient in both transporters in blood-producing hematopoietic cells possessed increased levels of hematopoietic stem and multipotential progenitor cells and accelerated atherosclerosis. ABCA1 and ABGA1 protect against atherosclerosis by promoting cholesterol efflux from cholesterol-laden macrophage foam cells to lipid-poor high-density lipoprotein (HDL) and apolipoprotein A-1. The leukocytosis and atherosclerosis in ABCA1- and ABG1-deficient mice were reversed in the presence of high amounts of HDL. Thus, signaling already known to inhibit atherosclerosis by reducing cholesterol in atherosclerotic plaques also reduces atherosclerosis-associated leukocytosis.
Estimating Growth Parameters for Pacific Halibut from Mark–Recapture Data
Authors: McCaughran Donald A.
Published: May 2010

The parameters in the model L(t) = αtβ were estimated for each fish from mark and recapture lengths. The individual estimates of the parameters were combined to give minimum variance unbiased estimates for the population parameters lnα and β. The age-specific lengths of halibut were found to fit a lognormal distribution; hence, the model was fitted to the median of the lengths instead of the mean. The median of the estimator [Formula: see text] is equal to the population median fork length at time t. In this sense the estimator is "median unbiased." As an example of the method, a growth curve is fitted to a group of halibut born between 1961 and 1965 and recaptured in the Yakutat region.Key words: Pacific halibut, growth, estimation