bluuebunny/crossref_metadata_2025 huggingface dataset:
Single‐crystalline photochromism of diarylethene dimers bridged by a spiro structure
Authors: Kobatake Seiya , Kuma Shunpei , Irie Masahiro
Published: May 2007

New types of diarylethene dimers bridged by a spiro structure were synthesized. One of their dimers formed three kinds of polymorphic forms by recrystallization from different solvents: hexane (1a‐α), acetone (1a‐β), and acetonitrile (1a‐γ). In crystals of 1a‐α and 1a‐β the molecules are packed in solvent‐free crystal structures, whereas crystal 1a‐γ includes acetonitrile molecules in the crystal. The difference of significant photochromic reactivities in their polymorphic crystals was observed for photocoloration reactions. Crystals 1a‐β and 1a‐γ showed photochromism in the single‐crystal phase, but 1a‐α did not do so. Their photochromic reactivity was found to depend on the distance between the reactive carbon atoms by X‐ray crystallographic analysis. When the distance is less than 4.2 Å in the antiparallel conformation, the molecule can undergo photochromism in the crystal. On the other hand, crystals of bromo‐substituted diarylethene dimer (2a) cannot be suitable for X‐ray crystallographic analysis when it was recrystallized from hexane, acetone, and acetonitrile. However, it formed single crystal by recrystallization from p‐xylene, which showed photochromism in the crystalline phase. The edge‐to‐face aromatic interaction between p‐xylene molecules assisted the crystal growth of the diarylethene dimer. Upon irradiation with ultraviolet light, two kinds of the enantiomers, (M,SS)‐ and (P,RR)‐2b, are produced. Partial photobleaching reactions of either of the two enantiomers by irradiation with linearly polarized visible light were confirmed by polarized absorption spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.
Phototriggered release of photolabile drugs via two‐photon absorption‐induced cleavage of polymer‐bound dicoumarin
Authors: Härtner Sebastian , Kim Hee‐Cheol , Hampp Norbert
Published: May 2007

7‐(tert‐Butyldimethylsiloxy)‐7′‐(methacryloxy)dicoumarin (TBS‐Cum‐D‐MA) is introduced as a versatile polymerizable and photocleavable linker system for drug attachment to acrylic polymers. Following the copolymerization of the TBS‐Cum‐D‐MA with monomeric methylmethacrylate, a model drug chlorambucil was attached in a simple reaction. Phototriggered drug release via single‐ and two‐photon absorption induced cycloreversion of the cyclobutane of the dicoumarin part was investigated. The bound drug chlorambucil is sensitive to UV light being required for single‐photon induced cleavage of the dicoumarin linker and decomposes upon UV exposure. However, under the conditions of two‐photon absorption induced drug release, no photodegradation of chlorambucil was observed. As the only effective two‐photon absorber in the molecule is the cyclobutane structure, even high energies of visible light do not cause any degradation of the drug. This suggests that two‐photon‐triggered drug release may be successfully accomplished even with UV light sensitive drugs. The concept introduced here may be a powerful strategy in polymer design for photocontrolled drug delivery devices. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2443–2452, 2007
New sulfur‐centered radicals as photopolymerization initiating species
Authors: Lalevée Jacques , Zadoina Lacramioara , Allonas Xavier , Fouassier Jean Pierre
Published: May 2007

New thiols and disulfides are proposed as radical polymerization photoinitiators or coinitiators. The drawback of the bad smell is strongly limited for the proposed compounds. Among the systems investigated, the disulfides photosensitized by isopropylthioxanthone and the tetrazole‐derived thiols in the presence of benzophenone, camphorquinone, or isopropylthioxanthone have been found to be highly reactive and, in some cases, even better than a reference type I or type II photoinitiator. These thiols can also be incorporated into a combination of chloro‐hexaaryl bisimidazole (Cl‐HABI) and a photosensitizer, such as a coumarin or ketocoumarin. Interestingly, a photosensitizer/Cl‐HABI/tetrazolethiol derivative system exhibits a higher reactivity than a commonly used photosensitizer/Cl‐HABI/N‐phenylglycine system. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2494–2502, 2007
Chitosan‐graft‐poly(ϵ‐caprolactone)s: An optimized chemical approach leading to a controllable structure and enhanced properties
Authors: Guan Xipeng , Quan Daping , Shuai Xintao , Liao Kairong , Mai Kancheng
Published: May 2007

A novel synthetic approach was developed for the controllable modification of chitosan (CS) with poly(ϵ‐caprolactone) (PCL). 6‐O‐Triphenylmethyl‐chitosan (TMCS) was synthesized as a highly soluble intermediate in organic solvents to facilitate an efficient grafting reaction of PCL onto CS in a homogeneous reaction medium. Subsequently, the syntheses of CS‐g‐PCL copolymers with different degrees of substitution (ds) and various chain lengths of PCL (number‐average molecular weight = 1200–11,000) were carried out by a coupling reaction between the carboxylic terminal groups of PCL chains and the amino groups of TMCS. The successful grafting reaction was confirmed by GPC measurements, which indicated that the products were graft copolymers rather than physical blends. The ds, defined as the number of PCL chains per saccharide unit, of the graft copolymers could be adjusted simply by changes in the molar feed ratios of PCL to CS, and graft copolymers with different ds values ranging from 0.28 to 0.49 were synthesized, as calculated by 1H NMR and elemental analysis. DSC and X‐ray measurements showed that the melting temperature and enthalpy of the PCL grafts of these graft copolymers could be adjusted by the ds and the chains length of PCL, respectively. Meanwhile, the CS‐g‐PCL copolymers exhibited better solubility in various solvents, such as in chloroform for some of the resultant graft copolymers, than the original CS. Finally, nanoparticles of 100–200 nm, having hydrophobic PCL domains and cationic hydrophilic surfaces, were obtained through the self‐assembly of the copolymers in selective solvents. These types of graft copolymers have great potential in various applications, such as targeted drug and gene delivery as well as tissue engineering. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2556–2568, 2007
Circadian phase entrainment via nonlinear model predictive control
Authors: Bagheri N. , Stelling J. , Doyle F.J.
Published: May 2007

A nonlinear model predictive control algorithm is developed to investigate the phase‐resetting properties of robust nonlinear biological oscillators; in particular, those of the circadian rhythm. This pacemaker is an autonomous biochemical oscillator with a free‐running period close to 24 h. Research in chronobiology indicates that light stimuli may delay or advance the phase of the oscillator, allowing it to synchronize physiological processes and entrain to the environment. In this paper, a closed‐loop optimal phase tracking control algorithm is developed and applied to a mammalian circadian model. The integration of MPC‐based light pulses, coupled with environmental light:dark cycles, allows the circadian system to recover phase differences within 1.5 days—a fraction of the natural open‐loop simulated mammalian recovery time. Accelerated phase entrainment may alleviate disorders caused by circadian rhythms that are out of phase with the environment, and improve performance. Copyright © 2007 John Wiley & Sons, Ltd.
Sample size calculation for the Wilcoxon–Mann–Whitney test adjusting for ties
Authors: Zhao Yan D. , Rahardja Dewi , Qu Yongming
Published: May 2007

In this paper we study sample size calculation methods for the asymptotic Wilcoxon–Mann–Whitney test for data with or without ties. The existing methods are applicable either to data with ties or to data without ties but not to both cases. While the existing methods developed for data without ties perform well, the methods developed for data with ties have limitations in that they are either applicable to proportional odds alternatives or have computational difficulties. We propose a new method which has a closed‐form formula and therefore is very easy to calculate. In addition, the new method can be applied to both data with or without ties. Simulations have demonstrated that the new sample size formula performs very well as the corresponding actual powers are close to the nominal powers. Copyright © 2007 John Wiley & Sons, Ltd.
Multifunctionalized Polymer Microcapsules: Novel Tools for Biological and Pharmacological Applications
Authors: Sukhorukov Gleb B. , Rogach Andrey L. , Garstka Malgorzata , Springer Sebastian , Parak Wolfgang J. , Muñoz‐Javier Almudena , Kreft Oliver , Skirtach Andre G. , Susha Andrei S. , Ramaye Yannic , Palankar Raghavendra , Winterhalter Mathias
Published: May 2007

We describe recent developments with multifunctional nanoengineered polymer capsules. In addition to their obvious use as a delivery system, multifunctional nanocontainers find wide application in enzymatic catalysis, controlled release, and directed drug delivery in medicine. The multifunctionality is provided by the following components: 1) Luminescent semiconductor nanocrystals (quantum dots) that facilitate imaging and identification of different capsules, 2) superparamagnetic nanoparticles that allow manipulation of the capsules in a magnetic field, 3) surface coatings, which target the capsules to desired cells, 4) metallic nanoparticles in the capsule wall that act as an absorbing antenna for electromagnetic fields and provide heat for controlled release, and 5) enzymes and pharmaceutical agents that allow specific reactions. The unique advantage of multifunctional microcapsules in comparison to other systems is that they can be simultaneously loaded/functionalized with the above components, allowing for the combination of their properties in a single object.
Formalizing the interference temperature model
Authors: Clancy T. Charles
Published: May 2007

To combat recent spectral overcrowding in unlicensed bands, the FCC has been investigating new ways to manage RF resources. The idea is to let people use licensed frequencies, provided they can guarantee interference perceived by the primary license holders will be minimal. With advances in software and cognitive radio, practical ways of doing this are on the horizon. In 2003, the FCC released a memorandum seeking comment on the interference temperature model (ITM) for controlling spectrum use. Formally defining and analyzing techniques for implementing this model are the primary goals of this paper.

Two interpretations of the ITM are developed and for each, we examine tradeoffs between power, bandwidth, and capacity. From these relationships, algorithms for computing RF transmission parameters are developed. These algorithms seek to maximize both capacity and spectral efficiency for a given RF environment. Additionally, we describe ways to choose a center frequency that will optimize future performance, subject to the constraints of the ITM. Copyright © 2007 John Wiley & Sons, Ltd.
From affiliative behaviors to romantic feelings: A role of nanopeptides
Authors: Dębiec Jacek
Published: May 2007

Love is one of the most desired experiences. The quest for understanding human bonds, especially love, was traditionally a domain of the humanities. Recent developments in biological sciences yield new insights into the mechanisms underlying the formation and maintenance of human relationships. Animal models of reproductive behaviors, mother–infant attachment and pair bonding complemented by human studies reveal neuroendocrine foundations of prosocial behaviors and emotions. Amongst various identified neurotransmitters and modulators, which control affiliative behaviors, the particular role of nanopeptides has been indicated. New studies suggest that these chemicals are not only involved in regulating bonding processes in animals but also contribute to generating positive social attitudes and feelings in humans.
An efficient chemoenzymatic production of small molecule glucosides with in situ UDP‐glucose recycling
Authors: Masada Sayaka , Kawase Yoji , Nagatoshi Mai , Oguchi Yukie , Terasaka Kazuyoshi , Mizukami Hajime
Published: May 2007

A one‐pot system for efficient enzymatic synthesis of curcumin glucosides is described. The method couples the activities of two recombinant enzymes, UDP‐glucose: curcumin glucosyltransferase from Catharanthus roseus (CaUGT2) and sucrose synthase from Arabidopsis thaliana (AtSUS1). UDP, a product inhibitor of UDP‐glucosyltransferase, was removed from the system and used for regeneration of UDP‐glucose by the second enzyme, AtSUS1. The productivity was increased several‐fold and UDP‐glucose initially added to the reaction mixture could be reduced to one‐tenth of the normal level. The concept of enhancing glucosylation efficiency by coupling a UDP‐glucose regeneration system with glucosyltransferases should be applicable to enzymatic production of a wide range of glucosides.
ClpP: A distinctive family of cylindrical energy‐dependent serine proteases
Authors: Yu Angela Yeou Hsiung , Houry Walid A.
Published: May 2007

Processes maintaining protein homeostasis in the cell are governed by the activities of molecular chaperones that mainly assist in the folding of polypeptide chains and by a large class of proteases that regulate protein levels through degradation. ClpP proteases define a distinctive family of cylindrical, energy‐dependent serine proteases that are highly conserved throughout bacteria and eukaryota. They typically interact with ATP‐dependent AAA+ chaperones that bind and unfold target substrates and then translocate them into ClpP for degradation. Structural and functional studies have provided a detailed view of the mechanism of function of this class of proteases.
c‐Myc is required for transformation of FDC‐P1 cells by EGFRvIII
Authors: Rath Oliver , Himmler Adi , Baum Anke , Sommergruber Wolfgang , Beug Hartmut , Metz Thomas
Published: May 2007

In contrast to wtEGFR, its truncated version EGFRvIII transformed non‐tumorigenic FDC‐P1 cells only when c‐Myc was coexpressed. In nude mice, EGFRvIII/c‐Myc coexpressing cells induced tumors, whereas wtEGFR‐expressing EGF‐dependent FDC‐P1 cells did not. EGFRvIII function was required for both the induction and maintenance of tumor growth. Cellular proliferation was inhibited by a selective EGFR tyrosine kinase inhibitor indicating intrinsic tyrosine kinase activities for both receptors. Unlike wtEGFR, constitutive signaling by EGFRvIII was refractory to stimulation by the EGFR ligands EGF and TGF‐α. Summarized, EGFRvIII is a constitutively active receptor tyrosine kinase whose transforming capacity is lower than that of EGF‐stimulated wtEGFR.
Cell stress induced HSP are targets of regulatory T cells: A role for HSP inducing compounds as anti‐inflammatory immuno‐modulators?
Authors: Wieten Lotte , Broere Femke , van der Zee Ruurd , Koerkamp Elles Klein , Wagenaar Josée , van Eden Willem
Published: May 2007

T cell responses to heat shock proteins (HSP) have disease suppressive activities through production of anti‐inflammatory cytokines in patients and in models of inflammatory diseases. There is evidence that the anti‐inflammatory activity of HSP‐specific T cells depends on their recognition of endogenous HSP epitopes as expressed by stressed cells at sites of inflammation. Previously, we have demonstrated that such T cells can be induced by conserved sequences of microbial HSP. Now we propose that drug induced up‐regulation of endogenous HSP can contribute to anti‐inflammatory T cell regulation.
Structural basis of diversification of fungal retinal proteins probed by site‐directed mutagenesis of Leptosphaeria rhodopsin
Authors: Fan Ying , Shi Lichi , Brown Leonid S.
Published: May 2007

Numerous fungal genomes encode homologs of bacteriorhodopsin (BR), but only two fungal rhodopsins were overexpressed and characterized spectroscopically. Neurospora rhodopsin (NR) is a slow‐cycling sensory rhodopsin‐like protein, while Leptosphaeria rhodopsin (LR) is a BR‐like proton pump. Recently, we found that a conservative replacement of the cytoplasmic proton donor Asp150 by Glu converts LR into an NR‐like protein. In this work, we search for structural reasons for the dramatic differences in their photochemistry by mutating the hydrogen‐bonding partner of Asp150 (Thr87) and three additional residues (Thr233, Asp248, and Gly271) selected by comparison of the primary structures of NR and LR. We conclude that while these residues may contribute to the differences between LR and NR, they are not crucial for the optimization of the Schiff base reprotonation by Asp150, and that the dramatic effect of the D150E mutation is not a simple result of the introduction of a bulkier glutamate sidechain.
PRINCESS MARY'S HOUSEHOLD AND THE SUCCESSION CRISIS, JULY 1553
Authors: WHITELOCK ANNA , MACCULLOCH DIARMAID
Published: May 2007

This article reconsiders Mary Tudor's victory in the succession crisis of July 1553. It challenges the traditional interpretation which accounts for Mary's unexpected triumph as the result of a ‘spontaneous’ rising of the East Anglian gentry. Instead it reclaims a central role for Mary's household affinity in the succession crisis and as such presents a longer-term perspective than accounts of Mary's coup d’état have provided hitherto. It concludes by pointing to the implications of the role of Mary's household for interpreting the politics and religion of her reign.
THUGGEE AND SOCIAL BANDITRY RECONSIDERED
Authors: WAGNER KIM A.
Published: May 2007

Eric Hobsbawm's concept of ‘social banditry’, as presented in Bandits of 1969, is probably the single most influential idea in the modern study of bandits and outlaws. Key to Hobsbawm's argument is the assumption of a more or less direct relation between ‘a bandit's real behaviour and his subsequent myth’ – in other words, that the popular perception of bandits reflected the social reality of banditry, and that accordingly the Robin Hood myth had some basis in historical events. This article seeks to qualify some of the basic premises of Eric Hobsbawm's concept of social banditry by examining the context and process by which popular and official knowledge of banditry emerged. This analysis is based on a case-study of the thugs of early nineteenth-century colonial India. Though seldom described as such, thuggee is one of the best-documented instances of banditry historically speaking. This makes the findings and theoretical considerations made in connection with thuggee pertinent to banditry worldwide and during various periods. By focusing on issues of methodology it is hoped that a critical discussion of Hobsbawm's model, rather than just being a polemic deconstruction, may suggest a new approach to the study of banditry more generally.
ARISTOTELIANISM, DESCARTES, AND HOBBES
Authors: EDWARDS MICHAEL
Published: May 2007

The historiography of early modern Aristotelian philosophy and its relationship with its seventeenth-century critics, such as Hobbes and Descartes, has expanded in recent years. This article explores the dynamics of this project, focusing on a tendency to complicate and divide up the category of Aristotelianism into multiple ‘Aristotelianisms’, and the significance of this move for attempts to write a contextual history of the relationship of Hobbes and Descartes to their Aristotelian contemporaries and predecessors. In particular, it considers recent work on Cartesian and Hobbesian natural philosophy, and the ways in which historians have related the different forms of early modern Aristotelianism to the projects of the novatores.
AGRICULTURAL HISTORY, RURAL HISTORY, OR COUNTRYSIDE HISTORY?
Authors: BURCHARDT JEREMY
Published: May 2007

This article assesses the state of modern English rural history. It identifies an ‘orthodox’ school, focused on the economic history of agriculture. This has made impressive progress in quantifying and explaining the output and productivity achievements of English farming since the ‘agricultural revolution’. Its celebratory account was, from the outset, challenged by a dissident tradition emphasizing the social costs of agricultural progress, notably enclosure. Recently a new school, associated with the journal Rural History, has broken away from this narrative of agricultural change, elaborating a wider social history. The work of Alun Howkins, the pivotal figure in the recent historiography, is located in relation to these three traditions. It is argued that Howkins, like his precursors, is constrained by an increasingly anachronistic equation of the countryside with agriculture. The concept of a ‘post-productivist’ countryside, dominated by consumption and representation, has been developed by geographers and sociologists and may have something to offer historians here, in conjunction with the well-established historiography of the ‘rural idyll’. The article concludes with a call for a new countryside history, giving full weight to the cultural and representational aspects that have done so much to shape twentieth-century rural England. Only in this way will it be possible to move beyond a history of the countryside that is merely the history of agriculture writ large.
CULTURE AND CHRONOLOGY IN AFRICAN HISTORY
Authors: PETERSON DEREK R.
Published: May 2007

Sources and methods in African history: spoken, written, unearthed. Edited by T. Falola and C. Jennings. Rochester: University of Rochester Press, 2004. Pp. xxi+409. ISBN 1-58046-140-9. £50.00.

Honour in African history. By John Iliffe. Cambridge: Cambridge University Press, 2005. Pp. xv+404. ISBN 0-521-54685-0. £16.99.

Black experience and the empire. Edited by P. Morgan and S. Hawkins. Oxford: Oxford University Press, 2004. Pp. xv+416. ISBN 0-19-926029-x. £39.00.

Muslim societies in African history. By D. Robinson. Cambridge: Cambridge University Press, 2004. Pp. xx+220. ISBN 0-521-533566-x. £10.99.

The study of African culture stands in a uneasy relationship with the study of African history. Historians work by pegging people, places, and events to a place on time's ever-lengthening yardstick. For the historical discipline, time is a structure that stands behind and lends meaning to human events. Culture, by contrast, is often claimed to be timeless, the unique inheritance of a distinct group of people. Culture builders work by short-circuiting chronology. They poach events, names, clothing styles, and other inspirational elements from the past and marshal them as a tradition to be proud of. The study of cultural history enters into a field where the partitions between past and present are being trampled by the traffic of human imagination.
Application of EPMA Data for the Development of the Code Systems
TRANSURANUS and ALEPH
Authors: Haeck Wim , Verboomen Bernard , Schubert Arndt , Van Uffelen Paul
Published: May 2007

In the present article, electron probe microanalysis data for Pu and
Nd is being used for validating the predictions of the radial power
profile in a nuclear fuel rod at an ultrahigh burn-up of 95 and 102
MWd/kgHM. As such the validation of both the new Monte Carlo burn-up
code ALEPH and the simpler TUBRNP model of the fuel rod performance code
TRANSURANUS has been extended. The analysis of the absolute concentrations
and individual isotopes also indicates potential improvements in the
predictive capabilities of the simple TUBRNP model, based on the one-group
cross sections inferred from the neutron transport calculations in the
ALEPH code. This is a first important step toward extending the
application range of the fuel rod performance code to burn-up values
projected in nuclear power rods based on current trends.
Microbeam Analysis of Irradiated Materials: Practical Aspects
Authors: Lamontagne Jérôme , Blay Thierry , Roure Ingrid
Published: May 2007

Among the microanalytical techniques, electron probe microanalysis
(EPMA) is one of the most powerful. Its performances can be used to
provide an accurate characterization. In the present article the
differences between the EPMA of highly irradiated materials and standard
EPMA are highlighted. It focuses on the shielded EPMA specificities. Then,
the article presents the difficulties encountered during the sample
preparation and the analysis (mainly due to the radioactive background).
In spite of these difficulties, some valuable results can be provided by a
shielded EPMA on the in-pile behavior of nuclear irradiated fuel. Some
results of specific examples analyzed by EPMA in nuclear fuel research are
presented.
Characterization of Uranium Particles Produced by Hydrolysis of UF6Using SEM and SIMS
Authors: Kips Ruth , Leenaers Ann , Tamborini Gabriele , Betti Maria , Van den Berghe Sven , Wellum Roger , Taylor Philip
Published: May 2007

Environmental sampling (ES) is a powerful technique used by safeguards inspectors of the International Atomic Energy Agency and the European Safeguards Office for the detection of undeclared nuclear activities. Since its implementation in the 1990s, ES has proven to be very sensitive and effective. Considering the consequences, the measurements should be carried out under a quality management programme. At the Institute for Reference Materials and Measurements, a new production method is under development for the preparation of reference uranium particles from well-certified UF6, allowing uranium particles with certified isotopic abundances to be prepared that are representative of those found in uranium enrichment facilities. Using an aerosol deposition chamber designed and built for the purpose, particles are formed by the hydrolysis of UF6and their morphology and (isotopic) composition measured using SEM-EDX and SIMS. The SEM measurements show that by varying the relative humidity of the air in the reaction chamber, the morphology of the particles can be changed. By making a distribution map of the chemical composition of the particles, the relationship between fluorine and uranium as main constituents of the particle could be established. The presence of fluorine is a valuable indicator for the occurrence of nondeclared enrichment activities.
Internal Conversion in Energy Dispersive X-ray Analysis of Actinide-Containing Materials
Authors: Wiss Thierry , Thiele Hartmut , Cremer Bert , Ray Ian
Published: May 2007

The use of X-ray elemental analysis tools like energy dispersive X-ray (EDS) is described in the context of the investigation of nuclear materials. These materials contain radioactive elements, particularly alpha-decaying actinides that affect the quantitative EDS measurement by producing interferences in the X-ray spectra. These interferences originating from X-ray emission are the result of internal conversion by the daughter atoms from the alpha-decaying actinides. The strong interferences affect primarily the L X-ray lines from the actinides (in the typical energy range used for EDS analysis) and would require the use of the M lines. However, it is typically at the energy of the actinide's M lines that the interferences are dominant. The artifacts produced in the X-ray analysis are described and illustrated by some typical examples of analysis of actinide-bearing material.
EDITORIAL
Authors: LEGUIN ELISABETH
Published: May 2007

Some weeks ago I was chatting with a colleague, comparing notes about how we came to be academics. In the course of this very casual conversation – more than half of it the gossip and good-natured complaining that are the grist of workplace talk – she said something that brought me up short, and which I am still sorting out. Speaking of her ambitions as a singer, and of the decision to become a musicologist, she remarked, a little sadly, ‘It was the fork in the road, you know. . .’.
HAYDN’S MELANCHOLY VOICE: LOST DIALECTICS IN HIS LATE CHAMBER MUSIC AND ENGLISH SONGS
Authors: NOVEMBER NANCY
Published: May 2007

From the nineteenth century onwards the stereotype of Haydn as cheerful and jesting has dominated the reception of his music. This study contributes to the recent scholarship that broadens this view, with a new approach: I set works by Haydn in the context of eighteenth-century ideas about melancholy, those of Edmund Burke, Francisco Goya, Henry Home (Lord Kames), Immanuel Kant and Johann Georg Zimmermann. Their conceptions of melancholy were dialectical, involving the interplay of such elements as pleasure and pain, freedom and fettering, and self-reflection and absorption. I consider the relevance of these dialectics to Haydn’s English songs, his dramatic cantata Arianna a Naxos and two late chamber works. Musical melancholy arises, I argue, when the protagonist of a work – be it the vocal character in a song or the ‘composer’s voice’ in an instrumental work – exhibits an ironic distance from his or her own pain. The musical dialectics in these works prompt listeners, for their part, to take a step back to contemplate the borders and limits of emotional experience and communication.
A SHORT BIOGRAPHY OF BENIGNO ZERAFA (1726-1804): A MID-EIGHTEENTH-CENTURY MALTESE COMPOSER OF SACRED MUSIC
Authors: AQUILINA FREDERICK
Published: May 2007

The outstanding (though still insufficiently recognized) development of Maltese sacred music in the mid-eighteenth century culminated in the works of Benigno Zerafa (1726–1804), a highly talented priest-composer who served as maestro di cappella at the Cathedral of St Paul at Mdina from 1744 to 1786. Zerafa’s entire collection of sacred vocal works, with one exception, was discovered in 1969 by the then-curator of the Archives of Mdina, Mgr Rev John Azzopardi. The collection, comprising, among others, masses, Credo settings, psalms, graduals, offertories, litanies, hymns, sequences, antiphons, Holy Week responsories and motets, was transferred to the archives of the cathedral, where it was professionally catalogued and shelved. One work, a recently discovered Requiem Mass for four voices and organ, is preserved in the Archivio Crypta Sancti Pauli (CSP) at Rabat. The compositions, numbering 148, are divided into two categories – (1) for voices and instruments (104), and (2) for voices and organ (44) – and range, in scoring, from works for eight, five, four, three and two voices, to others for solo voice. This essay aims to provide information on Benigno Zerafa’s life.
UNVEILING CHERUBINO
Authors: RUMPH STEPHEN
Published: May 2007

Daniel Leeson recently noted an intriguing thematic borrowing in the Act 1 trio of Le nozze di Figaro (No. 7, ‘Cosa sento!’). As Leeson demonstrated, Basilio’s theme, first introduced in bars 16–23, derives from Cherubino’s preceding aria, ‘Non so più cosa son, cosa faccio’. This veiled allusion echoes throughout the trio, most dramatically during the narrative in which the Count reveals the hidden page. The quotation of Cherubino’s theme, Leeson argued, supplies the stage director with precious information. It proves that Basilio has eavesdropped on the previous scene, and explains why Susanna reacts so sharply to his seemingly innocuous opening lines: ‘By singing a disguised version of Cherubino’s tune to Susanna, Basilio suggests a nasty perspective on what might have transpired in the previous scene. Any possible accusation against the Count has, by Basilio’s hidden musical threat, been redirected: the insinuation targets Cherubino as the recipient of Susanna’s favours.’
Crustal structure and magmato‐tectonic processes in an active rift (Asal‐Ghoubbet, Afar, East Africa): 1. Insights from a 5‐month seismological experiment
Authors: Doubre C. , Manighetti I. , Dorbath C. , Dorbath L. , Jacques E. , Delmond J. C.
Published: May 2007

We seek to characterize how magmatic and tectonic activities combine and interact during the continental rifting process. We address this question in two companion papers. In both, we analyze the seismicity that occurs in an active magmato‐tectonic rift, Asal‐Ghoubbet (East Africa), to identify the features and/or processes responsible for its activity. Here, we report results from a 5‐month experiment that we conducted in the rift. Eleven seismometers were deployed to complement the eight‐station permanent network. This allowed recording ∼400 earthquakes in the rift; 200 events could be well located (precision <40 m) and used in a tomographic inversion. Focal mechanisms were also determined for 71 events. The results show that current activity in the rift is mainly magmatically induced or accommodated. A ∼2‐km‐wide pipe of hot rock is evidenced below the central Fieale‐Shark Bay volcanic complex, likely above a deeper (>5–6 km) magma reservoir. Most events concentrate at the roof of the pipe (at 3–4 km) and result from up and down slip ruptures on both the volcanic (ring) and tectonic faults that enclose the pipe at depth. The up and down motions are likely driven by pressure changes in the magma reservoir. Hence, although a few rift faults were associated with seismicity, most remained seismically silent during the experiment. In the companion paper, we analyze the seismic activity in the rift over the 23 years that followed its last rifting episode. This confirms the importance of the Fieale‐Shark Bay plumbing system in the overall rift behavior.
Seasonal variations of the vertical fluxes of heat and horizontal momentum in the mesopause region at Starfire Optical Range, New Mexico
Authors: Gardner Chester S. , Liu Alan Z.
Published: May 2007

Lidar observations of wind and temperature profiles between 85 and 100 km, conducted at the Starfire Optical Range (SOR), New Mexico, are used to characterize the seasonal variations of the vertical fluxes of heat and horizontal momentum and their relationships to gravity wave activity in this region. The wind and temperature variances exhibit strong 6‐month oscillations with maxima during the summer and winter that are about 3 times larger than the spring and fall minima. The vertical heat flux also exhibits strong 6‐month oscillations with maximum downward flux during winter and summer. The downward heat flux peaks near 88 km where it exceeds −3 K m s−1 in mid‐winter and is nearly zero during the spring and fall equinoxes. The heat flux is significantly different from zero only when the local instability probability exceeds 8%, i.e., the annual mean for the mesopause region. The momentum fluxes also exhibit strong seasonal variations, which are related to the horizontal winds. Two‐thirds of the time the horizontal momentum flux is directed against the mean wind field.
Multiscale analysis of waves reflected by granular media: Acoustic experiments on glass beads and effective medium theories
Authors: Le Gonidec Yves , Gibert Dominique
Published: May 2007

The wavelet response is a multiscale method based on the continuous wavelet transform. We use it to characterize the acoustic reflectivity of a layer of glass beads with diameter d = 1 mm randomly arranged in water. The volumetric concentration is ϕ ≃ 63% of spherical inclusions. The wavelet response is measured over a large frequency range (100 kHz ≤ f ≤ 5 MHz) where five different acoustic regimes are identified on the basis of scattering phenomena. A strong decrease in the reflectivity occurs when the wavelength of the incident wave is twice the bead diameter, a situation where lateral scattering is dominant. The energy ratio of the ballistic and the coda parts of the wavelet response reveals a clear transition from a ballistic propagation regime to a diffusion regime where multiple scattering occurs. The experimental data are explained with an effective medium theory approach: the reflectivity data in the low‐frequency domain of the spanned frequency range are correctly reproduced with quasi‐static models. For higher frequencies, more sophisticated models accounting for multiple scattering must be used. The high‐frequency part of the experimental reflectivity curve may be explained by strong multiple scattering at the top of the glass beads located at the surface of the layer and corresponds to the optical geometric limit.
Analysis of Global Positioning System (GPS) radio occultation measurement errors based on Satellite de Aplicaciones Cientificas‐C (SAC‐C) GPS radio occultation data recorded in open‐loop and phase‐locked‐loop mode
Authors: Lohmann Martin S.
Published: May 2007

The error characteristics of Global Positioning System (GPS) radio occultation (RO) measurement errors are studied based on Satellite de Aplicaciones Cientificas‐C (SAC‐C) GPS radio occultation data tracked in both open‐loop (OL) and phase‐locked‐loop (PLL) mode. The error characteristics are derived by applying dynamical error estimation, i.e., without using any external data. The computed error profiles show that the mean measurement errors are the smallest in the height range between about 5–7 km and 20–25 km, about 0.2–1% for bending angles and 0.1–0.2% for refractivity at all latitudes. The largest measurement errors are found in the lower troposphere, where the mean bending angle measurement errors are within the range from 1 to 6%, whereas the mean refractivity measurement errors are within the range from 0.2% to 1%. From the error distributions, it is found that the occultation‐to‐occultation variability of the measurement errors generally spans one order of magnitude. The bending angle error correlation length is about 1 km and 100 m, at high and low altitudes, respectively, corresponding approximately to the cutoff frequency of the applied noise filters. The widths of the refractivity error autocorrelation functions are notably broader. The variability and the magnitude of the OL measurement errors are larger than for the PLL measurement errors. This is mainly attributed to the ability of OL tracking to track RO signals under atmospheric conditions for which PLL tracking fails.
Changes in aerosol parameters during major dust storm events (2001–2005) over the Indo‐Gangetic Plains using AERONET and MODIS data
Authors: Prasad Anup K. , Singh Ramesh P.
Published: May 2007

The Indo‐Gangetic (IG) plains is one of the largest and most densely populated regions in the world. Recent studies over the IG plains using multi‐year (2000–2004) satellite (including Moderate Resolution Imaging Spectroradiometer: MODIS) and ground Aerosol Robotic Network (AERONET) data show strong seasonal variability of aerosol optical depth (AOD) with maximum aerosol loading (>0.6–0.7 at 500 nm) during the pre‐monsoon (summer) season. A number of major dust storms, originating from western arid and desert regions of Africa, Arabia and western part of India (Thar Desert), affect the whole IG plains during the pre‐monsoon season (April–June). The mean AOD increases from 0.4–0.5 to more than 0.6–0.7 throughout the plains (>0.8–0.9 on the western side) as a result of the dust storm events. Pronounced changes in the aerosol optical parameters, derived from AERONET, have been observed over Kanpur (26.45°N, 80.35°E) during dust storm events (2001–2005). The maximum AOD (at 500 nm) during dust event days show increase from ∼1 to ∼2.4 with advance of the pre‐monsoon season (April–June). The aerosol size distribution (ASD) shows increase in radius from 1.71 to 2.24 μm (in coarse fraction) and decrease in the distribution width from 3.76 to 2.56 μm showing changes in the aerosol characteristics during dust events. The aerosol parameters [ASD, single scattering albedo (SSA, total and coarse mode) and real and imaginary parts of the refractive index] change significantly during dust events. The National Oceanic and Atmospheric Administration (NOAA) Hybrid Single‐Particle Lagrangian Integrated Trajectory (HYSPLIT) model (5‐day back‐trajectory) and MODIS level‐3 daily data (AOD and Ångström exponent) have been used to trace the source, path and spatial extent of dust storm events. During major dust events, enhancement of the total column water vapor is observed from MODIS level‐3 daily water vapor data (near‐infrared clear column) showing a strong association (72% correlation) with the AOD along the track of dust storms over the IG plains. A significant rise of 50–100% is observed in the ground level respirable suspended particulate matter (RSPM) concentration showing alarming health risks to the people living in the IG plains during dust storm events.
Monte Carlo studies of directional pair ordering in disordered binary and ternary ferromagnetic BCC crystalline alloys
Authors: Ohodnicki P. R. , McHenry M. E. , Laughlin D. E.
Published: May 2007

Magnetic field annealing can be used to induce uniaxial magnetic anisotropy in ferromagnetic alloys, which is often desirable, for example, to reduce core losses in materials of interest for high frequency inductive components in power conversion applications. An understanding of the compositional dependence of the uniaxial induced anisotropy constant KU is important to develop materials for such applications. In this work, Monte Carlo studies of directional pair ordering in bcc crystalline alloys using the Néel pair model and a Metropolis-type algorithm are reported. The compositional dependence of KU in disordered binary alloys is compared with analytical results and extended to the calculation of KU for ternary alloys. An approximate XB2(1−XB)2 functional dependence of KU is observed for binary alloys, where XB is the atomic fraction of one of the atomic species. For ternary alloys a more complicated functional dependence is observed. These results are used to critically evaluate the potential for increasing KU through ternary alloying additions to binary ferromagnetic alloys.
Phase formation in L10 magnets
Authors: Skomski R.
Published: May 2007

Structural and magnetic properties of substituted L10 compounds are investigated. Focus is on L10 structures of the general type ABC2, where each second layer of the original structure is replaced by a checkerboard of A and B atoms. At low temperatures, L10 compounds with ABC2 stoichiometry will segregate into AC and AB L10 phases, forming an ordered ABC2 compound or exhibit a transition into a more complicated structure. The ordering has a strong impact on the magnetism of the alloys, especially on the anisotropy. The hypothetical new ternary compounds are of potential interest in various areas of magnetism, including magnetic recording and permanent magnetism.
Manipulating the dipolar magnetic interactions in FePt square arrays: The role of edge roughness
Authors: Norpoth J. , Dreyer S. , Jooss Ch. , Sievers S.
Published: May 2007

The high magnetocrystalline anisotropy energy in hard magnetic materials may sustain magnetization distributions in the remanent state, which exhibit a high number of magnetic surface charges and thus significant magnetic stray fields. Here, we focus onto the stray field distribution in the exterior and the demagnetization field distribution in the interior of hard magnetic FePt elements without and with artificial saw tooth edge roughness. Our experiments and calculations reveal that external stray fields and internal demagnetization fields are considerably modified by the artificial edge roughness.
Structure and transport properties in YBa2−xEuxCu3O7−δ superconductors
Authors: Qian B. , Xing J. H. , Wu X. S. , Jiang Z. S. , Tang S. L.
Published: May 2007

Structure and transport properties of Eu-doped YBa2−xEuxCu3O7−δ (YBECO) have been studied. Eu is confirmed preferring to replace Ba at Ba sites. The averaged valence state of Eu, which is examined by x-ray photoemission spectroscopy, increases with increasing x. Eu doping in YBECO has a little influence on superconductivity in our studies, and the superconducting transition temperature Tc is almost unchanged.
Anisotropy of ultrathin epitaxial Fe3O4 films on GaAs(100)
Authors: Zhai Y. , Huang Z. C. , Fu Y. , Ni C. , Lu Y. X. , Xu Y. B. , Wu J. , Zhai H. R.
Published: May 2007

Magnetic anisotropies of single crystal ultrathin Fe3O4 films on GaAs(100) have been studied by ferromagnetic resonance (FMR). The dependence of the FMR fields on the field orientation was measured both in plane and out of plane. The ultrathin films show predominantly an in-plane uniaxial magnetic anisotropy with the easy axis along the [0−11] direction of the GaAs substrate. The in-plane uniaxial anisotropy constant decreases with increasing thickness and changes from 7.1×104to2.1×104ergs∕cm3 when the thickness tFe varies from 4to8nm. An in-plane fourfold anisotropy due to cubic magnetocrystalline anisotropy coexists with the uniaxial magnetic anisotropy and increases with increasing film thickness. For tFe=8nm, the cubic anisotropy constant K1 reaches −8.4×104erg∕cm3, which is 76% of the value of bulk spinel Fe3O4. The out-of-plane measurements indicate a negative perpendicular anisotropy in these ultrathin Fe3O4 films.
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Wigner-Racah algebra for embedded Gaussian unitary ensemble of random matrices with spin
Authors: Kota V. K. B.
Published: May 2007

Exact results for embedded Gaussian unitary ensemble of two-body interactions for fermions with spin [EGUE(2)-s] are derived using the Wigner-Racah algebra of the embedding U(2Ω)⊃U(Ω)⊗SU(2) algebra. Explicit formulas, for systems with m fermions and spin S, are given for the lower order cross correlations, between states with (m,S) and (m′,S′), generated by this ensemble and also, in terms of a SU(Ω) Racah coefficient, for the fourth order shape parameter for the fixed-(m,S) density of states.
“All possible steps” approach to the accelerated use of Gillespie’s algorithm
Authors: Lipshtat Azi
Published: May 2007

Many physical and biological processes are stochastic in nature. Computational models and simulations of such processes are a mathematical and computational challenge. The basic stochastic simulation algorithm was published by Gillespie about three decades ago [J. Phys. Chem. 81, 2340 (1977)]. Since then, intensive work has been done to make the algorithm more efficient in terms of running time. All accelerated versions of the algorithm are aimed at minimizing the running time required to produce a stochastic trajectory in state space. In these simulations, a necessary condition for reliable statistics is averaging over a large number of simulations. In this study the author presents a new accelerating approach which does not alter the stochastic algorithm, but reduces the number of required runs. By analysis of collected data the author demonstrates high precision levels with fewer simulations. Moreover, the suggested approach provides a good estimation of statistical error, which may serve as a tool for determining the number of required runs.
Low-noise rotating sample holder for ultrafast transient spectroscopy at cryogenic temperatures
Authors: Fanciulli R. , Cerjak I. , Herek J. L.
Published: May 2007

We present the design and testing of a rotating device that fits within a commercial helium cryostat and is capable of providing at 4K a fresh sample surface for subsequent shots of a 1–10kHz amplified pulsed laser. We benchmark this rotator in a transient-absorption experiment on molecular switches. After showing that the device introduces only a small amount of additional noise, we demonstrate how the effect of signal degradation due to high fluence is completely resolved.
Generic-type hierarchical multi digital signal processor system for hard-field tomography
Authors: Garcia Castillo Sergio , Ozanyan Krikor B.
Published: May 2007

This article introduces the design and implementation of a hierarchical multi digital signal processor system aimed to perform parallel multichannel measurements and data processing of the type widely used in hard-field tomography. Details are presented of a complete tomography system with modular and expandable architecture, capable of accommodating a variety of data processing modalities, configured by software. The configuration of the acquisition and processing circuits and the management of the data flow allow a data frame rate of up to 250kHz. Results of a case study, guided path tomography for temperature mapping, are shown as a direct demonstration of the system’s capabilities. Digital lock-in detection is employed for data processing to extract the information from ac measurements of the temperature-induced resistance changes in an array of 32 noninteracting transducers, which is further exported for visualization.