bluuebunny/crossref_metadata_2025 huggingface dataset:
Short‐range ±J interaction Ising spin glass in a transverse field on a Bethe lattice: a quantum‐spherical approach
Authors: Kopeć T. K. , Usadel K. D.
Published: December 2005

We consider the short‐range interaction disordered quantum Ising model with symmetric binary ±J bond distribution on the Bethe lattice (with coordination number z). The system exhibits quantum phase transition separating the spin glass and disordered phases where the quantum effect are regulated by a param‐ eter Δ describing the transverse field. By introducing a mapping of the quantum Hamiltonian of the model onto a soft‐spin action we consider it truncated version in a form of the solvable quantized spherical model. Quantum dynamics is examined via various correlation functions on the infinite tree which are evaluated in a closed form. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The study of structural transitions in liquid crystal droplets doped with magnetic particles
Authors: Kopčanský P. , Koneracká M. , Timko M. , Jadzyn J.
Published: December 2005

The magnetically active ferronematic droplets were prepared in solutions of nematic liquid crystal 6CHBT with fine magnetic particles, dissolved in phenyl isocyanate. The phase diagram of the transitions between isotropic, droplet and nematic phases in prepared sample was found. The structural transitions in 6CHBT‐based ferronematic and in 6CHBT ferronematic droplets, exposed to external fields, were investigated. The possibility to use the observations of structural transitions for the determination of the type of anchoring of nematic molecules on magnetic particles surfaces was demonstrated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin transport and spin relaxation in semiconductor heterostructures with Rashba spin–orbit interaction
Authors: Bleibaum O.
Published: December 2005

Spin diffusion equations, which also contain the coupling between spins and charges, are discussed for semiconductor heterostructures with Rashba spin–orbit interaction in the presence of an electric field. The diffusion equations are applied to an investigation of the decay of a homogeneous initial magnetization. A field induced precession, which is observable if the electric field exceeds a characteristic field, is obtained. Moreover, the impact of quantum corrections on the spin transport coefficients is discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enantiomeric separation and quantification of pindolol in human plasma by chiral liquid chromatography/tandem mass spectrometry using staggered injection with a CTC Trio Valve system
Authors: Wang Haiping , Shen Zhongzhou
Published: December 2005

Pindolol is a non‐selective β‐adrenergic antagonist (β‐blocker) for the treatment of cardiovascular diseases such as hypertension and angina pectoris. It has one chiral center, and, therefore, two optical isomers. It was essential to develop an enantioselective assay to measure each enantiomer in human plasma. However, separation of enantiomers using chiral chromatography usually requires relatively long retention times. This can pose a problem for rapid turnaround of a large number of samples (i.e., clinical studies). In the present study, a simple and sensitive chiral liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) method was developed and validated for the determination of S‐(−)‐ and R‐(+)‐pindolol in human plasma. To increase throughput, staggered sample injection was employed using a CTC Trio Valve system on a CTC HTS PAL autosampler. The method exhibited good intra‐ and inter‐day accuracy and precision, and was linear over a dynamic range of 250 pg/mL to 250 ng/mL for each pindolol enantiomer. Intra‐ and inter‐day accuracy ranged between 90.0–106% and 91.6–104% for both quality control (QC) samples of S‐(−)‐ and R‐(+)‐pindolol, respectively. The respective intra‐ and inter‐day precision ranged between 4.24–7.86% and 4.98–10.4%. Copyright © 2005 John Wiley & Sons, Ltd.
Fragmentation of mycosporine‐like amino acids by hydrogen/deuterium exchange and electrospray ionisation tandem mass spectrometry
Authors: Cardozo Karina H. M. , Carvalho Valdemir M. , Pinto Ernani , Colepicolo Pio
Published: December 2005

The determination and identification of mycosporine‐like amino acids (MAAs) from algae remain a major challenge due to the low concentration. Mass spectrometry (MS) can make an invaluable contribution in the search and identification of MAAs because of its high sensitivity, possibility of coupling with liquid chromatography, and the availability of powerful tandem mass spectrometric techniques. However, the unequivocal determination of the presence and location of important functional groups present on the basic skeleton of the MAAs is often elusive due to their inherent instability under MS conditions. In this study, the use of hydrogen/deuterium (H/D) exchange and electrospray ionisation tandem mass spectrometry (ESI‐MS/MS) for characterisation of four MAAs (palythine, asterina, palythinol and shinorine) isolated from the macroalgae Gracilaria tenuistipitata Chang et Xia was investigated. The accurate‐mass confirmation of the protonated molecules was performed on a Q‐TOF instrument. We demonstrate that employing deuterium labelling in ESI‐MS/MS analysis provides a convenient tool for the determination of new MAAs. Although the fragmentation patterns of MAAs were discussed earlier, to our knowledge, this is the first time that mechanisms are proposed. Copyright © 2005 John Wiley & Sons, Ltd.
Experimental apparatus for investigation of sputtering and secondary ion emission induced by energetic ion beams
Authors: Drozdziel A. , Pyszniak K. , Sielanko J. , Turek M. , Wójtowicz A.
Published: December 2005

The construction of an experimental apparatus, for investigation of implantation, secondary ion emission and sputtering processes, during irradiation of samples with an ion beam of up to 70 keV energy, is described. The basis of the apparatus is an electromagnetic mass separator equipped with a quadrupole mass spectrometer located in the collector chamber. The computer data acquisition control system makes it possible to perform the experimental measurements with high accuracy and precision. Preliminary results of secondary ion mass spectral measurements, obtained for C, Al, Si and Cu targets bombarded with Ar+ and Kr+ ions, are presented. Copyright © 2005 John Wiley & Sons, Ltd.
Molecular Signatures in the Transport Properties of Molecular Wire Junctions: What Makes a Junction “Molecular”?
Authors: Troisi Alessandro , Ratner Mark A.
Published: December 2005

The simplest component of molecular electronics consists of a single‐molecule transport junction: a molecule sandwiched between source and drain electrodes, with or without a third gate electrode. In this Concept article, we focus on how molecules control transport in metal‐electrode molecular junctions, and where the molecular signatures are to be found. In the situation where the molecule is relatively short and the gap between injection energy and molecular eigenstates is large, transport occurs largely by elastic tunneling, stochastic switching is common, and the vibronic signature can be found using inelastic electron tunneling spectroscopy (IETS). As the energy gaps for injection become smaller, one begins to see stronger molecular signatures – these include Franck–Condon‐like structures in the current/voltage characteristic and strong vibronic interactions, which can lead to hopping behavior at the polaron limit. Conformational changes induced by the strong electric field lead to another strong manifestation of the molecular nature of the junction. We overview some of this mechanistic landscape, focusing on significant effects of switching (both stochastic and controlled by the electric field) and of molecular vibronic coupling.
Homocystinuria: The effect of pyridoxine supplementation on cultured skin fibroblasts
Authors: Bittles A. H. , Carson N. A. J.
Published: December 2005

Six skin fibroblast cultures, two derived from pyridoxine responsive homocystinurics, two from pyridoxine non‐responsive homocystinurics, one from an obligate heterozygote and one from a normal control were grown for three passages in the presence of 9.7 µmol/l, 243 µmol/l and 486 µmol/l of pyridoxine respectively. Cystathionine β‐synthase activity was stimulated in all four homocystinuric cell strains at 486 µmol/l; aspartate and alanine aminotransferase activity was also increased, particularly in the pyridoxine responsive cell strains. There was, however, evidence of cytotoxicity at the pyridoxine levels of 243 µmol/l and 486 µmol/l.
Plasma amino acids in a patient with Wilson's disease presenting with an acute haemolytic anaemia
Authors: Green A.
Published: December 2005

A 10‐year‐old girl with Wilson's disease presented with an acute haemolytic anaemia. Plasma amino acids, studied during two haemolytic episodes, were abnormal, especially cystine, which was increased approximately tenfold.
Acute hereditary tyrosinaemia type I: Clinical, biochemical and haematological studies in twins
Authors: Gray R. G. F. , Patrick A. D. , Preston F. E. , Whitfield M. F.
Published: December 2005

Affected twins with acute hereditary tyrosinaemia type I are described. Attempts at therapy with a phenylalanine‐tyrosine‐methionine restricted diet supplemented with cysteine, vitamin E and ascorbic acid failed to influence the course of the disorder. The bleeding diathesis was due to a morbid reduction of a number of clotting factors, particularly factor VII, and this was associated with impaired platelet aggregation and release. The liver of one showed a marked reduction in fumarylacetoacetate lyase activity and her urine contained a potent inhibitor of red cell δ‐aminolaevulinic acid dehydratase. Biochemical investigations of cultured fibroblasts suggest that these do not express the disorder and are unlikely to prove useful diagnostically.
Hepatic phenylalanine hydroxylase activity in hyperphenylalaninaemia
Authors: Dhondt J. L. , Farriaux J. P.
Published: December 2005

Phenylalanine tolerancein vivo has been compared with the phenylalanine hydroxylase activity of liver biopsy specimens in 14 newly detected cases of hyperphenylalaninaemia. Hepatic phenylalanine hydroxylase activity does not predict the degree of dietary restriction that will be required.
Hyperornithinaemia associated with gyrate atrophy of the choroid and retina:In vivo andIn vitro response to vitamin B6
Authors: Tada K. , Saito T. , Omura K. , Hayasaka S. , Mizuno K.
Published: December 2005

Three Japanese cases of hyperornithinaemia due to a defect in ornithine ketoacid transaminase are described. Different types of disease in responsiveness to vitamin B6 were found.In vivo response to B6 correlated within vitro data.
Transaminative metabolism ofl‐cysteine in rat tissues
Authors: Ubuka T. , Ishimoto Y. , Akagi R.
Published: December 2005

The transamination ofl‐cysteine in rat tissues is reviewed. At least four different enzyme proteins may be involved.
Late onset type of propionic acidaemia: Case report and biochemical studies
Authors: Merinero B. , DelValle J. A. , Jiménez A. , Garcia M. J. , Ugarte M. , Solaguren R. , López O. , Condado I.
Published: December 2005

A late‐onset case of propionic acidaemia with favourable response to restriction of dietary protein is described. During a keto‐acidotic crisis, this patient demonstrated unexpectedly low concentrations of propionic acid and glycine in blood and urine but increased urinary output of some secondary metabolites.
Neonatal I‐cell disease: Clinical and biochemical observations
Authors: Ohta H. , Mori T. , Eto Y. , Maekawa K.
Published: December 2005

Acid hydrolases have been determined in serum, urine and brain of a neonatal case of I‐cell disease. Hexosamine and hexose contents of several tissues were elevated and the urinary excretion of bound sialic acid was very much increased.
Multiple sulphatase deficiency with early onset
Authors: Vamos E. , Liebaers I. , Bousard N. , Libert J. , Perlmutter N.
Published: December 2005

This male infant was first brought to attention in the neonatal period because he presented clinical and radiological evidence of multiple bone deformities. He was readmitted at 2 1/2 months for hydrocephaly, hepatosplenomegaly and poor somatic and psychomotor development. In addition, coarse facies, corneal opacities and stiff joints were noticed. Bone X‐ray anomalies and vacuolized lymphocytes supported the clinical presumption of lysosomal storage disorder. The diagnosis of multiple sulphatase deficiency rests on the presence of MPS and sulphatides in the urine, the finding of a mixed storage process in conjunctival biopsy and the demonstration of deficiencies in arylsulphatases A, B, C, iduronate sulphatase and heparan sulphatase in serum, leukocytes and cultured fibroblasts.
Biotin‐responsive immunoregulatory dysfunction in multiple carboxylase deficiency
Authors: Munnich A. , Fischer A. , Saudubray J. M. , Griscelli C. , Coude F. X. , Ogier H. , Charpentier C. , Frezal J.
Published: December 2005

Multiple carboxylase deficiency could be associated with defects of the immunoregulatory system. A boy with documented multiple carboxylase deficiency was found to display a fatty acid and biotin‐responsive impairment of his lymphocyte suppressive activityin vitro. Furthermore, prostaglandin E2 (PGE2), a major product of unsaturated fatty acid elongation required forin vitro activation of the immunoregulatory system, was found to be very low in the patient's monocytes. Finally, PGE2 monocytic production responded well to biotin therapy. PGE2 deficiency could result from the combination of an essential fatty acid deficiency with an impaired elongation of unsaturated fatty acids possibly due to a defect of the biotin‐dependent acetyl‐CoA carboxylase reaction.
Some inborn errors of metabolism at a local institute for mentally retarded patients
Authors: Reinecke C. J. , Mienie L. J.
Published: December 2005

A survey of mentally retarded patients in an institution in the Republic of South Africa has shown a low incidence of phenylketonuria and the presence of two cases of histidinaemia.
Effect of saccharopine on urea cycle metabolism
Authors: Ameen M. , Palmer T.
Published: December 2005

The effects of saccharopine and a number of other amino acids on the synthesis ofN‐acetylglutamate in rat liver mitochondria have been investigated.
Corrective factor of bloom syndrome: Further characteristics
Authors: Bartram C. R. , Rüdiger H. W.
Published: December 2005

Bloom syndrome is an autosomal recessive inherited disease characterizedin vitro by chromosomal instability and an increased rate of sister chromatid exchanges (SCE). Co‐cultivation of Bloom syndrome and normal fibroblasts results in correction of chromosomal instability in Bloom syndrome. We report our studies of the effects of co‐cultivation on homozygous Bloom cells with heterozygous cells. Additionally, we used fibroblasts from a patient with Fanconi anaemia and with xeroderma pigmentosum.
Glycopeptidosis: A new inherited disorder of glycoconjugate metabolism affecting the central nervous system
Authors: Federico A. , Guazzi G. , Fruschelli C. , Palladini G. , Medoloago‐Albani L. , Michalski J. C. , Strecker G.
Published: December 2005

A patient with progressive neurological deterioration and myoclonus epilepsy showed an increased excretion of glycoprotein in the urine and storage material in lymphocytes and fibroblasts. This is probably a new disorder of glycoprotein metabolism.
Subcellular distribution of lysosomal hydrolases in mucolipidosis III and a mucolipidosis III variant
Authors: Kalaydjieva L. , Cantz M.
Published: December 2005

The subcellular distribution of lysosomal hydrolases and of [35S]sulphate‐labelled storage materials in cultured fibroblasts from typical and variant mucolipidosis III patients shows that these disorders probably have different pathogenetic mechanisms.
Abnormal cobalamin metabolism in a case of juvenile pernicious anaemia with neurological symptoms
Authors: Linnell J. C. , Quadros E. V. , England J. M. , Down M. C. , Reynolds E. H.
Published: December 2005

Studies of cobalamin metabolism in case of juvenile pernicious anaemia during haematological remission showed that while plasma cobalamins were normal there was some depletion of erythrocyte cobalamins. In addition, the plasma distribution of apo‐ and holo‐transcobalamins was markedly abnormal, holo‐TCII being increased, yet the patient's plasma promoted less cellular synthesis of adenosylcobalamin by cultured lymphocytes than did plasma from a control subject. The results suggest that holo‐TCII may in this case have been ineffective and provide further evidence for the importance of TCII in intracellular synthesis of adenosylcobalamin.
Partial HGPRT‐deficiency in a patient with the Lesch‐Nyhan syndrome: Evidence for a structural mutation affecting the PRPP binding site
Authors: Rijksen G. , Staal G. E. J. , van der Vlist M. J. M. , Beemer F. A. , Troost J. , van Laarhoven J. P. R. M. , de Bruyn C. H. M. M.
Published: December 2005

The residual HGPRT activity in a patient with the Lesch‐Nyhan syndrome was 10–15% in haemolysate and about 30% in fibroblast lysate. Due to a structural mutation affecting the PRPP site of the enzyme (increasedKm PRPP, absence of product inhibition, absence of stabilization by PRPP) thein vivo activity in intact erythrocytes was negligible.
Organic acidaemia and hyperammonaemia: Review
Authors: Walser M. , Stewart P. M.
Published: December 2005

Recent clinical and experimental evidence on the effects of organic acids in producing or ameliorating hyperammonaemia is reviewed. The importance of hepatic mitochondrialN‐acetylglutamate and its precursors, glutamate and acetyl‐CoA, in the control of ureagenesis and thus blood ammonia levels is emphasized by recent work. The hypothesis is proposed that protein loads stimulate urea cycle activity via glutamate‐induced changes inN‐acetylglutamate concentration, while the effects of organic acids on ureagenesis are related in a predictable way to their effects on hepatic concentrations of acetyl‐CoA.
Studies on human phenylalanine mono‐oxygenase. I. Restricted expression
Authors: Crawfurd M. A. , Gibbs D. A. , Sheppard D. M.
Published: December 2005

Enzyme assays for phenylalanine mono‐oxygenase have been performed on a variety of non‐hepatic human cell types under varying conditions. The cell types studied were cultured fibroblasts, short‐term lymphocyte cultures, long‐term lymphoblastoid cultures, cultured amniotic fluid cells, hair roots and placental extracts. The cultured cells were assayed after growth under standard conditions and in the presence of a high concentration of substrate, a low concentration of end‐product, added hydrocortisone or dexamethasone and under combinations of these conditions. In no instance was a significant enzyme activity obtained.
S‐Adenosylhomocysteine hydrolase activity in a lymphoblastoid cell line from a patient with adenosine deaminase deficiency disease
Authors: Tsuchiya S. , Nakae S. , Konno T. , Tada K.
Published: December 2005

S‐Adenosylhomocysteine (S‐AdoHcy) hydrolase activity in a lymphoblastoid cell line from a patient with adenosine deaminase deficiency disease (ADA(−)LCL) was found to be approximately 60% of that in ADA(+)lymphoblastoid cell lines.S‐AdoHcy hydrolase of ADA(−)LCL was more sensitive to inhibition by 2′‐deoxyadenosine as compared with that of ADA(+)LCL. The inhibitory effect of 2′‐deoxyadenosine was evident in cell growth and immunoglobulin production of lymphoblastoid cell lines.
Hypoxanthine‐guanine phosphoribosyltransferase variants: Correlation of clinical phenotype with enzyme activity
Authors: Page T. , Bakay B. , Nissinen E. , Nyhan W. L.
Published: December 2005

A deficiency of the enzyme hypoxanthine‐guanine phosphoribosyltransferase (HGPRT) is associated with a varying clinical picture which may include hyperuricaemia, neurological abnormalities and bizarre self‐multilating behaviour. Due to technical problems with the usualin vitro enzyme assays, it has not been possible to establish a correlation between the degree of the enzyme deficiency and the severity of the clinical manifestations. In this study, the HGPRT activity of 12 patients with various clinical features was measured by quantitative analysis of the incorporation of radioactive precursors into purine compounds in intact fibroblasts. The results demonstrate that a correlation between the severity of the clinical symptoms and the degree of the enzyme deficiency as measured in intact fibroblasts does in fact exist.
Formiminoglutamic aciduria in a slightly retarded boy with chronic obstructive lung disease
Authors: Beck B. , Christensen E. , Brandt N. J. , Pedersen M.
Published: December 2005

A 2‐year‐old boy excreted massive amounts of formiminoglutamic acid in urine. The substance was identified as authentic formiminoglutamic acid by two‐dimensional thin‐layer chromatography, column chromatography and enzymatic determination. After alkaline hydrolysis the substance was converted to glutamic acid. Serum amino acid concentrations were normal. The patient had normal serum and erythrocyte folate levels. The red blood cell picture was normal. The leukocytes showed slight hypersegmentation. From the age of 3 months he exhibited recurrent otitis media and severe pulmonary infections.

He had a peculiar narrow‐headed look and marked universal hypotonia. The mental development was slightly retarded.

Glutamate formiminotransferase deficiency is postulated. The findings lend support to the theory of glutamate formiminotransferase deficiency being a rather benign disorder of metabolism.
Aspartylglycosaminuria in an Italian family: Clinical and biochemical characteristics
Authors: Gehler J. , Sewell A. C. , Becker Christa , Spranger J. , Hartmann J.
Published: December 2005

Two members of a consanguineous Italian family are described with symptoms of aspartylglycosaminuria. Both patients exhibit mental retardation, some facial dysmorphism and discrete radiological abnormalities affecting the skull and vertebrae. Peripheral blood smears revealed multi‐vacuolated lymphocytes. Enzyme studies in leukocytes showed an absence of aspartylglucosaminidase activity. Urine analysis demonstrated abnormal oligosacchariduria. Angiokeratoma corporis diffusum was observed in one patient. The disease is seen as not being limited to Scandinavia or to patients of Scandinavian descent.
Crystal structure of a plant immunophilin domain involved in regulation of MDR‐type ABC transporters
Authors: Weiergräber Oliver H. , Eckhoff Andreas , Granzin Joachim
Published: December 2005

We present the three‐dimensional structure of the N‐terminal FK506‐binding protein (FKBP)‐like domain of the immunophilin FKBP42 from Arabidopsis thaliana. The data provide the structural background for the explanation of key functional properties reported previously.
Patronage Regimes and American Party Development from ‘The Age of Jackson’ to the Progressive Era
Authors: JAMES SCOTT C.
Published: December 2005

This article introduces the concept of patronage regimes and, through it, extends the research on American party development. No systematic empirical inquiry into the operation of American patronage practices has yet been undertaken. Its analysis investigates the strategic allocation of public jobs by party elites to enhance cadre performance in presidential elections. Utilizing a dataset of 49,000 Senate-confirmed, presidential appointments, presidential patronage removals between the years 1829 and 1917 are analysed. Two distinctive patronage regimes are identified: an antebellum regime structured by pure-and-simple spoils politics and a postbellum regime conforming to principles of machine rationality. Factors central to the process of regime transformation are pinpointed. The presence of two successive patronage regimes highlights the importance of endogenous political incentives and elite strategic choice to the emergent character of party organization, shedding new light on the historical development of these pre-eminent nineteenth-century American political institutions.
Do Campaigns Help Voters Learn? A Cross-National Analysis
Authors: ARCENEAUX KEVIN
Published: December 2005

Recent empirical studies on American elections suggest that campaigns provide voters with the necessary information to make reasoned voting decisions. Specifically, campaigns help voters learn about the electoral relevance of ‘fundamental variables’, such as the economy and party stances, that have been consistently shown to predict electoral outcomes. Do these findings generalize beyond the American case? This article uses cross-national survey data in order to subject this thesis to a more comprehensive test. The analysis provides further support for the hypothesis that campaigns ‘enlighten’ voters as the election draws near. Moreover, the article shows that some voters learn more from campaigns than others. Campaign effects are more pronounced among individuals with low political sophistication and those living in party list systems. Implications for future research are explored, suggesting a ripe research agenda using under-tapped cross-national data.
ASYMPTOTIC RUIN PROBABILITIES IN FINITE HORIZON WITH SUBEXPONENTIAL LOSSES AND ASSOCIATED DISCOUNT FACTORS
Authors: Tang Qihe
Published: December 2005

Consider a discrete-time insurance risk model with risky investments. Under the assumption that the loss distribution belongs to a certain subclass of the subexponential class, Tang and Tsitsiashvili (Stochastic Processes and Their Applications 108(2): 299–325 (2003)) established a precise estimate for the finite time ruin probability. This article extends the result both to the whole subexponential class and to a nonstandard case with associated discount factors.
EFFECTS OF MEASUREMENT AND PARAMETER UNCERTAINTIES ON THE POWER TRANSFER DISTRIBUTION FACTORS
Authors: Evrenosoglu Cansin Y. , Abur Ali
Published: December 2005

This paper investigates the effects of measurement and parameter errors on the calculation of power transfer distribution factors (PTDFs). Calculation of PTDFs depends mainly on two factors: the operating conditions and the network topology. Both of these factors change in real time and are monitored through the use of a state estimator. The role of the state estimator in providing not only the state information but also the real-time network model is shown to influence power market operations via PTDF-based decisions such as congestion management and pricing. The IEEE 14 bus test system is used for the illustration of these influences.
Crosslinguistic influence in bilingual acquisition: subject omission in learners of Inuktitut and English
Authors: ZWANZIGER ELIZABETH E. , ALLEN SHANLEY E. M. , GENESEE FRED
Published: December 2005

This study investigates subject omission in six English-Inuktitut simultaneous bilingual children, aged 1;8–3;9, to examine whether there are cross-language influences in their language development. Previous research with other language pairs has shown that the morphosyntax of one language can influence the development of morphosyntax in the other language. Most of this research has focused on Romance-Germanic language combinations using case studies. In this study, we examined a language pair (English-Inuktitut) with radically different morphosyntactic structures. Analysis of the English-only and Inuktitut-only utterances of the children revealed monolingual-like acquisition patterns and subject omission rates. The data indicate that these bilingual children possessed knowledge of the target languages that was language-specific and that previously identified triggers for crosslinguistic influence do not operate universally.
Building walls – a philosophy of engagement
Authors: Chandler Alan
Published: December 2005

Experiments with an innovative in situ casting technique question assumptions about the nature of concrete, the workmanship of risk, and the familiar relationship between design and making.
Proposal for an iron tower: 300 metres in height
Authors: Roland Claudette , Weidman Patrick
Published: December 2005

In this previously untranslated text, Gustave Eiffel explains the technical rationale of his then controversial tower and argues persuasively for its practical uses and cultural value to Paris.
Small Jurisdictions…Big Ideas
Authors: Matthews Nancy , Otterwell Angela
Published: December 2005

How do you get two solo information professionals in two separate small island jurisdictions to give one presentation, talking as one? Especially two who had never met together until the day before they were due to give the presentation at the 2005 BIALL conference in Harrogate The way this came about neatly sums up what it is like to be an information professional in a small jurisdiction. You spend a long time on the telephone and email, you take the initiative, collaborate, share ideas and bring out the best in each other. In short, you reach out beyond your little island, because not to do so means not to operate effectively.
Practical Legal Research and the Legal Practice Course
Authors: Fry Eileen
Published: December 2005

This article by Eileen Fry, Law Society Chief Examiner for Skills and Pervasives, gives an overview of the Practical Legal Research element of the Legal Practice Course, including looking at why the Law Society regard it as important, the course objectives, how it is taught and assessed, and proposals for the future. It should be read in conjunction with the article by Martin Hannibal and Alison Pope which also appears in this issue.
Checklist - Bringing Harmony to the Workplace?
Authors: Harman Phillip
Published: December 2005

On 1 October 2004 the Government introduced a new set of statutory dispute resolution procedures which apply to all employers. The new rules set out a series of basic procedural steps that an employer must follow when dealing with disciplinary hearings, dismissals and grievances. The Government's stated aim was to encourage employers and employees to resolve their disputes internally and thus reduce the number of claims being brought in the Employment Tribunal.
Melt distribution in olivine rocks based on electrical conductivity measurements
Authors: ten Grotenhuis Saskia M. , Drury Martyn R. , Spiers Chris J. , Peach Colin J.
Published: December 2005

Properties of partially molten rocks depend strongly on the grain‐scale melt distribution. Experimental samples show a variety of microstructures, such as melt lenses, layers, and multigrain melt pools, which are not readily explained using the theory for melt distribution based on isotropic interface energies. These microstructures affect the melt distribution and the porosity‐permeability relation. It is still unclear how the melt distribution changes with increasing melt fraction. In this study, electrical conductivity measurements and microstructural investigation with scanning electron microscopy and electron backscatter diffraction are combined to analyze the melt distribution in synthetic, partially molten, iron‐free olivine rocks with 0.01–0.1 melt fraction. The electrical conductivity data are compared with the predictions of geometric models for melt distribution. Both the conductivity data and the microstructural data indicate that there is a gradual change in the melt distribution with melt fraction (Xm) between 0.01 and 0.1. At a melt fraction of 0.01, the melt is situated in a network of triple junction tubes, and almost all grain boundaries are free from melt layers. At 0.1, the melt is situated in a network of grain boundary melt layers, as well as occupying the triple junctions. Between melt fractions 0.01 and 0.1, the number of grain boundary melt layers increases gradually. The electrical conductivity of the partially molten samples is best described by Archie's law (σsample/σmelt = CXmn) with parameters C = 1.47 and n = 1.30.
Zonally non‐uniform distribution of equatorial gravity waves in an atmospheric general circulation model
Authors: Kawatani Yoshio , Tsuji Koichiro , Takahashi Masaaki
Published: December 2005

The results from an atmospheric general circulation model without gravity wave (GW) drag parameterization include quasi‐biennial oscillation (QBO)‐like oscillations in the equatorial lower stratosphere. The zonal distribution of gravity waves with periods of less than 3 days over the equatorial region is analyzed for 2 months (July–August) during the westerly shear phase of the QBO. The westerly acceleration of the QBO is associated with the zonal forcing due to resolved waves of all components, and GWs account for about 60% of the forcing. The vertical flux of the zonal momentum of GWs in the upper troposphere has a non‐uniform distribution. Large (relatively small) magnitude upward fluxes with westerly (easterly) momentum dominate in the Eastern (Western) Hemisphere. The wave momentum flux divergence also varies with longitude. The westerly acceleration of the zonal wind due to GWs in the Eastern Hemisphere is much greater than that in the Western Hemisphere.
E‐region bifurcation and magnetic field related Bragg backscattered spectral events observed at high‐latitude by MF radar
Authors: Morris R. J. , Holdsworth D. A. , Murphy D. J. , Monselesan D. M.
Published: December 2005

We report on novel spectral characteristics of E‐region backscatter acquired using a 1.94 MHz Medium Frequency (MF) radar above the high‐latitude Antarctic station Davis (68.6°S). Two distinctive Doppler spectra are observed: one that exhibits bifurcation in Doppler velocity (or frequency) with one, or occasionally more, near symmetrical spectral side‐bands (here labelled SSE); and a second that exhibits broad‐band spectra related to the magnetic field topology (here labelled FRE). Both spectral forms reveal a characteristic quasi‐hyperbolic spectral form that diverges in Doppler velocity with range. We discuss the properties of these two spectral forms including: Doppler spectral shape; power spectra; angle‐of‐arrival (AOA) of backscattered sources; and their diurnal and day‐to‐day occurrence distributions for our campaign interval. Interestingly, the E‐region SSE observed at a height near 100 km were observed coincidentally with D‐region polar mesosphere summer echoes (PMSE) in the height range 82–92 km, when colocated data were available.
Atmospheric response function over land: Strong asymmetries in daily temperature fluctuations
Authors: Bartos I. , Jánosi I. M.
Published: December 2005

This communication presents global statistics of daily mean temperature changes as a function of previous day temperature anomaly. The relationship obtained clearly exhibits properties of response functions: the larger the anomaly, the larger the expected magnitude of temperature change backward to the long‐term average value. Worldwide statistics reveals that this temperature response function is inherently nonlinear and climate specific. However the central part around the origin can be approximated well by a linear fit. At a large number of geographic locations, the intercepts have small offsets toward nonzero values, and these offsets are geographically correlated. We show that one possible reason is a marked asymmetry of temperature fluctuations, that is warming steps have significantly higher frequencies and lower average magnitudes than those of cooling steps, almost everywhere. These two opposing effects could result in stationary fluctuations around an annual cycle, however, our statistics clearly indicates the presence of global warming.
Observations of positively charged nanoparticles in the nighttime polar mesosphere
Authors: Rapp M. , Hedin J. , Strelnikova I. , Friedrich M. , Gumbel J. , Lübken F.‐J.
Published: December 2005

We present results of in situ measurements of charged nanoparticles, electrons, and positive ions obtained during a sounding rocket flight in October 2004 from Kiruna, Sweden, under nighttime conditions. The particle measurement reveals positive charge signatures in the altitude range between 80 and 90 km corresponding to peak charge number densities of ∼100 e/cm3 at around 86 km. Aerodynamical analysis of the sampling efficiency of our instrument reveals that the particles must have been larger than 2 nm assuming spherical particles with a density of 3 g/cm3. The plasma environment of the observed particles is dominated by negative and positive ions, with only few free electrons. A calculation of the mean particle charge expected for particles in a plasma consisting of electrons and positive and negative ions shows that the presence of sufficiently heavy and numerous negative ions (i.e., mn > 300 amu and λ ≥ 50) can explain the observed positive particle charge.
Effect of nanoconfinement on liquid-crystal polymer chains
Authors: Micheletti Davide , Muccioli Luca , Berardi Roberto , Ricci Matteo , Zannoni Claudio
Published: December 2005

We apply a Monte Carlo polymerization model for Gay-Berne [J. Chem. Phys. 74, 3316 (1981)] monomers that we have recently introduced [J. Chem. Phys. 121, 9123 (2004)] to investigate with computer simulations the effects of nanoconfinement and anchoring type on the structure of the main-chain liquid-crystal polymers formed in thin films, in the presence of several types of surface alignment: parallel to the interface (random and uniform) or perpendicular to it (homeotropic). We perform first a study of the confined monomers and then we examine the features of the polymer chains obtained from an isotropic or nematic sample. We find a significant effect of the anchoring conditions on the characteristics of the chains and particularly striking differences between planar and homeotropic boundaries. Furthermore, our results indicate that the choice of different anchorings could be used to tune the linearity and degree of polymerization of the chains.
Differential cross sections for collisions of hexapole state-selected NO with He
Authors: Gijsbertsen A. , Linnartz H. , Rus G. , Wiskerke A. E. , Stolte S. , Chandler D. W. , Kłos J.
Published: December 2005

The first measurements of differential inelastic collision cross sections of fully state-selected NO (j=1∕2, Ω¯=1∕2, ϵ=−1) with He are presented. Full state selection is achieved by a 2m long hexapole, which allows for a systematic study of the effect of parity conservation and breaking on the differential cross section. The collisionally excited NO molecules are detected using a resonant (1+1′) REMPI ionization scheme in combination with the velocity-mapped, ion-imaging technique. The current experimental configuration minimizes the contribution of noncolliding NO molecules in other rotational states j,Ω¯,ϵ —that contaminates images— and allows for study of the collision process at an unprecedented level of detail. A simple method to correct ion images for collision-induced alignment is presented as well and its performance is demonstrated. The present results show a significant difference between differential cross sections for scattering into the upper and lower component of the Λ-doublet of NO. This result cannot be due to the energy splitting between these components.
Second-order Kohn-Sham perturbation theory: Correlation potential for atoms in a cavity
Authors: Jiang Hong , Engel Eberhard
Published: December 2005

Second-order perturbation theory based on the Kohn-Sham Hamiltonian leads to an implicit density functional for the correlation energy EcMP2, which is explicitly dependent on both occupied and unoccupied Kohn-Sham single-particle orbitals and energies. The corresponding correlation potential vcMP2, which has to be evaluated by the optimized potential method, was found to be divergent in the asymptotic region of atoms, if positive-energy continuum states are included in the calculation [Facco Bonetti et al., Phys. Rev. Lett. 86, 2241 (2001)]. On the other hand, Niquet et al., [J. Chem. Phys. 118, 9504 (2003)] showed that vcMP2 has the same asymptotic −α∕(2r4) behavior as the exact correlation potential, if the system under study has a discrete spectrum only. In this work we study vcMP2 for atoms in a spherical cavity within a basis-set-free finite differences approach, ensuring a completely discrete spectrum by requiring hard-wall boundary conditions at the cavity radius. Choosing this radius sufficiently large, one can devise a numerical continuation procedure which allows to normalize vcMP2 consistent with the standard choice vc(r→∞)=0 for free atoms, without modifying the potential in the chemically relevant region. An important prerequisite for the success of this scheme is the inclusion of very high-energy virtual states. Using this technique, we have calculated vcMP2 for all closed-shell and spherical open-shell atoms up to argon. One finds that vcMP2 reproduces the shell structure of the exact correlation potential very well but consistently overestimates the corresponding shell oscillations. In the case of spin-polarized atoms one observes a strong interrelation between the correlation potentials of the two spin channels, which is completely absent for standard density functionals. However, our results also demonstrate that EcMP2 can only serve as a first step towards the construction of a suitable implicit correlation functional: The fundamental variational instability of this functional is recovered for beryllium, for which a breakdown of the self-consistent Kohn-Sham iteration is observed. Moreover, even for those atoms for which the self-consistent iteration is stable, the results indicate that the inclusion of vcMP2 in the total Kohn-Sham potential does not lead to an improvement compared to the complete neglect of the correlation potential.
Electrokinetic interactions in microscale cross-slot flow
Authors: Juang Yi-Je , Hu Xin , Wang Shengnian , Lee L. James , Lu Chunmeng , Guan Jingjiao
Published: December 2005

The effects of electroosmosis (EO) and electrophoresis (EP) interactions on the movement of highly charged polystyrene microspheres and lesser-charged liposome nanoparticles were studied, using a microscale cross-slot flow device with different charge density and polarity on the channel surfaces. When the particle EP mobility is greater than the channel surface EO mobility, the flow pattern would be either extensional or extension dominated mixed-shear. The rotation flow only exists when the EO mobility dominates. The surface charge density of top and bottom lids of microchannels plays an important role in microfluidics. Experimental observations agreed fairly well with calculated flow patterns.
Effects of dielectric saturation and ionic screening on the proton self-diffusion coefficients in perfluorosulfonic acid membranes
Authors: Paul Reginald , Paddison Stephen J.
Published: December 2005

Proton transport in perfluorosulfonic acid (PFSA) membranes is investigated through a statistical mechanical model that includes the effects of the interaction of the tethered sulfonate groups with both the water and solvated protons. We first derive a potential that describes the electrostatic field due to the dissociated sulfonic acid groups by extending the work of Grønbech-Jensen et al. [Grønbech-Jensen et al. Mol. Phys. 92, 941 (1997)] to a finite array of point charges. A highly convergent series is obtained which includes the effects of screening due to the protons. We then investigate the effects of both dielectric saturation and two distinct formulations of ionic screening on the proton self-diffusion coefficient in Nafion membranes over a range of water contents. Our computations show that the two phenomena (i.e., dielectric saturation and ionic screening) under constant temperature conditions result in canceling affects. Our calculations provide a radial dependence of the proton mobility suggesting that the dominant self-diffusion occurs in the central region of the pores, well separated from the sulfonate groups. Through comparison of our calculated diffusion coefficients with the experimental values we derived a slightly smaller average separation distance of the hydronium ion from the sulfonate ions than suggested by either electronic structure calculations or multistate empirical valence bond molecular-dynamics simulations.
Rapid shear viscosity calculation by momentum impulse relaxation molecular dynamics
Authors: Kelkar Manish S. , Maginn Edward J.
Published: December 2005

Recently, Arya et al. [J. Chem. Phys. 113, 2079 (2000)] introduced a new molecular dynamics method to rapidly compute the viscosity of fluids. The technique, termed momentum impulse relaxation (MIR), involves the imposition of a Gaussian velocity profile on an equilibrated system, after which the decay in the profile is monitored as a function of time. The shear viscosity is computed by matching the rate of decay of the velocity profile to the corresponding solution of the Navier-Stokes equation. The method was originally applied to simple systems (argon and n-butane) and found to give a comparable accuracy to conventional equilibrium and nonequilibrium methods with more than an order of magnitude reduction in computing time. In this work, we extend and generalize the method to examine larger molecules with higher viscosities than have been examined previously. A detailed analysis of the method is given, including the effect the velocity boundary conditions have on the viscosity, the sensitivity of the results to the velocity profile fitting procedure, the effect of preequilibration of the Gaussian profile, and the effect the system size and box shape have on the accuracy and speed of the method. It is shown that the MIR method can be extended to treat multiatom systems without loss of accuracy or computational efficiency.
Effect of heat treatment on microstructure and magnetic properties of anisotropic Nd–Fe–B films with Mo or Ti buffer layer
Authors: Chen S. L. , Liu W. , Chen C. L. , Zhang Z. D.
Published: December 2005

High coercivity Nd–Fe–B films with c-axis texture perpendicular to the film plane have been prepared by dc magnetron sputtering and subsequent heat treatment. The influences of heat treatment and buffer layer materials (Mo and Ti) on the microstructure and magnetic properties of the Nd–Fe–B films are investigated. For the film with Mo buffer layer, when the substrate temperatures (Ts) are below the crystallization temperature (Tcr), the as-deposited films are identified to be soft magnetic with a mazelike stripe magnetic domain structure. After subsequent heat treatment, Nd2Fe14B phase forms with c-axis texture perpendicular to the film plane, and the domain structure is not mazelike anymore. The coercivity of the annealed films increases with decreasing Ts and the highest coercivity of about 22.8 kOe has been achieved. For the film with Ti buffer layer, the heat treatment also results in changing the magnetic domain structures from a mazelike pattern to a disordered pattern. Atomic force microscopic observation shows that some ridgelike areas exist in the annealed film with Ti buffer layer.
Temperature tuning of dispersion compensation using semiconductor asymmetric coupled waveguides
Authors: Lee Yong , Takei Aki , Taniguchi Takafumi , Uchiyama Hiroyuki
Published: December 2005

Two vertically coupled asymmetric InGaAsP ridge waveguides were fabricated and tested as a tunable dispersion compensator. In this waveguide, two coupled modes, symmetric and antisymmetric, exist simultaneously and have a significant amount of group-velocity dispersion (GVD), making it possible to reduce the size of the dispersion compensators. Since the GVD can be continuously controlled by changing the temperature of the asymmetric coupled waveguide, a semiconductor asymmetric coupled waveguide has great potential as a basis for a compact tunable dispersion compensator. To demonstrate tunable dispersion compensation, we carried out an experiment on the pulse compression of frequency-chirped pulses by using the InGaAsP asymmetric coupled waveguide at various temperatures of the waveguide. We observed a change in the compression ratio, ranging from 42.7% to 84.2%, as the temperature of the waveguide changed from 8to48.9°C. A theoretical study showed that the observed change in the compression ratio was well explained by a temperature tuning of the GVD of the coupled modes resulting from temperature-induced change in the refractive indices of the waveguide materials.