bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface‐enhanced Raman scattering studies on chemically transformed carbon nanotube thin films
Authors: Lefrant S. , Baltog I. , Baibarac M.
Published: July 2005

We review our experimental data obtained by Raman spectroscopy on single‐walled carbon nanotubes (SWNTs) using surface‐enhanced Raman scattering (SERS). We focused on the study of the dependence of the SERS spectra of SWNTs on both the rough metallic substrate type and the film thickness. In particular, we show that degradation of the nanotubes, mainly metallic, occurs for very thin films with the formation of graphitic, fullerene‐like or amorphous carbon particles. We show also that SWNTs reacting with H2SO4 form a salt of the hydrogensulfate type similar to that resulting from graphite–H2SO4 interaction. SWNTs exhibit a complicated spectroelectrochemical behavior in aqueous and non‐aqueous H2SO4 solutions that depends also on the sweep potential range. We demonstrate that the oxidation–reduction processes have a quasi‐reversible or irreversible character. Finally, SERS studies on compressed SWNTs in different host matrices, inorganic and organic, reveal nanotube breaking and that tube fragments may react or not with the host matrix used. Copyright © 2005 John Wiley & Sons, Ltd.
Genetic studies on several bean traits of Coffea canephora coffee in Cameroon
Authors: Cilas Christian , Bouharmont Pierre
Published: July 2005

The genetic parameters of several bean traits of coffee from the species Coffea canephora were estimated using two mating designs: a triangular diallel with 6 parents and a partial diallel with 18 parents. The traits studied were: normal bean weight, the percentage of peaberries, the length, width and thickness of the beans. These characteristics were studied along with yield. The yield data came from harvests obtained over 14 years divided into an initial cycle of 6 years, a second cycle of 5 years after cutting back and a third cycle of 3 years after topping. The general combining abilities (GCA) were the principal sources of significant variation for the traits studied. Transmission of these traits was therefore mostly additive. Yield over 14 years was the most heritable trait. The rank correlations between the GCA of the bean traits and those of yield were not significant. The genetic correlations estimated in the partial diallel did not reveal any link between bean traits and yield. Only one genetic correlation between the peaberry rate and yield was significant. The peaberry rate was linked to fertility, which thus appeared to be a genetic component of yield. Index‐based selection combining an increase in yield with improved bean traits could therefore be carried out without any particular difficulty. Copyright © 2005 Society of Chemical Industry
Multidetector row computed tomography for diagnosing intraductal extension of breast carcinoma
Authors: Fujita Takeo , Doihara Hiroyoshi , Takabatake Daisuke , Takahashi Hirotoshi , Yoshitomi Seiji , Ishibe Yoichi , Ogasawara Yutaka , Shimizu Nobuyoshi
Published: July 2005

Objectives

Several reports supported the association of higher ipsilateral breast tumor recurrence rates with positive or intermediate margins compared with negative pathologic margins. Precise evaluation of intraductal component and adequate surgical margin are important factors affecting the tumor recurrence after breast conserving surgery. Numerous studies have reported the utility of magnetic resonance imaging for diagnosing developing intraductal extension of breast cancer, but few have investigated multidetector‐row computed tomography (MD‐CT). The present study evaluated the clinical utility of MD‐CT for detecting intraductal extension of breast carcinoma, and analyzed clinical parameters affecting the detection of intraductal extension under MD‐CT.

Methods

Subjects comprised 44 patients grouped into three categories according to degree of intraductal extension of the main tumor under MD‐CT (Intraductal spread grade 1∼3: IDS 1∼3). Tumors were also categorized histopathologically (p‐IDS 0∼3), and CT‐pathological correlations were examined retrospectively. Clinical parameters were evaluated to determine the affect on detection of intraductal components.

Results

MD‐CT detected 44 breast lesions (100%). Sensitivity for detection of intraductal component was 81.2%, specificity was 67.8%, and accuracy was 72.7%. Regarding extent of intraductal components, significant correlations were found between histopathological and MD‐CT findings. A strong correlation was found in postmenopausal women between T2 tumor and high histological grade.

Conclusions

MD‐CT findings of intraductal extension from breast carcinoma correlate with histological degree of intraductal extension, and MD‐CT may be useful for preoperative assessment of breast‐conserving surgery, particularly for postmenopausal women with histological high nuclear grade and T2 tumor. J. Surg. Oncol. 2005;91:10–16. © 2005 Wiley‐Liss, Inc.
First Aldehyde‐Functionalized Poly(2‐oxazoline)s for Chemoselective Ligation
Authors: Taubmann Christian , Luxenhofer Robert , Cesana Sonia , Jordan Rainer
Published: July 2005

Summary: A protected aldehyde‐functionalized 2‐oxazoline, 2‐[3‐(1,3)‐dioxolan‐2‐ylpropyl]‐2‐oxazoline (DPOx), was synthesized from commercially available compounds in high yields. The polymerization of DPOx with different initiators proceeds via a living ionic mechanism; thus, the polymers were of low polydispersity and the degree of polymerization could be precisely adjusted. Copolymerization with 2‐methyl‐2‐oxazoline gave water‐soluble statistical copolymers. Hydrolysis of the homo‐ and copolymers resulted in well‐defined, aldehyde‐bearing poly(2‐oxazoline)s. The aldehyde side functions reacted quantitatively with an amino‐oxy compound to form the corresponding oxime.

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Fracture behaviors of silane‐cured metallocene‐catalyzed polyethylene thermoplastic vulcanizate
Authors: Lai S.‐M. , Wu T.‐H.
Published: July 2005

Silane moisture‐cured metallocene‐catalyzed polyethylene (mPE) blend to form a novel thermoplastic vulcanizate (TPV) has been prepared. Metallocene polyethylenes with two different levels of comonomer contents were grafted with various amounts of vinyltriethoxy silane. As a result, tensile strength varies slightly with increasing the levels of silane concentrations, at all test temperatures. Tear strength generally decreases with reduced energy dissipation, at higher degrees of cure. “Threshold” fracture energy is roughly proportional to the reciprocal square root of Young's modulus. By relating tensile strength to tear strength, it was found that the corrected average depth of flaw is in the range of 29.3 ± 7.2 μm, which successfully confirms the extension of Rivlin and Thomas's theory for conventional elastomers to TPVs under an elaborate treatment, due to the limitation of the theory. Cutting strength of mPE TPVs gives an intermediate value when compared with that of crystalline plastics and conventional elastomers, which further signifies the importance of crystalline yielding even in the nanofracture zone of deformation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2207–2218, 2005
Insecticidal and fungicidal activity of new synthesized chitosan derivatives
Authors: Rabea Entsar I , Badawy Mohamed EI , Rogge Tina M , Stevens Christian V , Höfte Monica , Steurbaut Walter , Smagghe Guy
Published: July 2005

Chitosan, the N‐deacetylated derivative of chitin, is a potential biopolysaccharide owing to its specific structure and properties. In this paper, we report on the synthesis of 24 new chitosan derivatives, N‐alkyl chitosans (NAC) and N‐benzyl chitosans (NBC), that are soluble in dilute aqueous acetic acid. The different derivatives were synthesized by reductive amination and analyzed by 1H NMR spectroscopy. A high degree of substitution (DS) was obtained with N‐(butyl)chitosan (DS 0.36) at a 1:1 mole ratio for NAC derivatives and N‐(2,4‐dichlorobenzyl)chitosan (DS 0.52) for NBC derivatives. Their insecticidal and fungicidal activities were tested against larvae of the cotton leafworm Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae), the grey mould Botrytis cinerea Pers (Leotiales: Sclerotiniaceae) and the rice leaf blast Pyricularia grisea Cavara (Teleomorph: Magnaporthe grisea (Hebert) Barr). The oral feeding bioassay indicated that all the derivatives had significant insecticidal activity at 5 g kg−1 in artificial diet. The most active was N‐(2‐chloro‐6‐fluorobenzyl)chitosan, which caused 100% mortality at 0.625 g kg−1, with an estimated LC50 of 0.32 g kg−1. Treated larvae ceased feeding after 2–3 days; the mechanism of action remains unknown. In a radial hyphal growth bioassay with both plant pathogens, all derivatives showed a higher fungicidal action than chitosan. N‐Dodecylchitosan, N‐(p‐isopropylbenzyl)chitosan and N‐(2,6‐dichlorobenzyl)chitosan were the most active against B cinerea, with EC50 values of 0.57, 0.57 and 0.52 g litre−1, respectively. Against P grisea, N‐(m‐nitrobenzyl)chitosan was the most active, with 77% inhibition at 5 g litre−1. The effect of different substitutions is discussed in relation to insecticidal and fungicidal activity. Copyright © 2005 Society of Chemical Industry
Understanding strongly correlated many‐body systems with quantum Monte Carlo simulations
Authors: Lavalle Catia , Rigol Marcos , Muramatsu Alejandro
Published: July 2005

Our understanding of the physical properties of quantum many‐particle systems relies normally on the identification of elementary excitations that can be considered as weakly interacting building blocks of the whole system. In systems characterized by the presence of strong interactions between the elementary components, like high‐temperature superconductors and related materials or like ultra‐cold atoms in optical lattices, well known theoretical techniques like mean‐field or perturbation theories fail. On the contrary, quantum Monte Carlo simulations allow to handle such systems in a “numerically exact” way. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Field‐induced effects in the S = 1 two‐dimensional Heisenberg antiferromagnet
Authors: Gouvêa M. E. , Pires A. S. T.
Published: July 2005

We use the self‐consistent harmonic approximation to study the spin S = 1 Heisenberg antiferromagnet on a two‐dimensional lattice in a uniform applied magnetic field. The magnetic field destroys the 𝒪(3) symmetry and an XY‐like behavior, with a Berezinskii–Kosterlitz–Thouless (BKT) transition, is expected. We obtain the field dependence of the transition temperature for fields varying in a wide range. There has been experimental evidence that, for low dimensional spin systems, a gap can be induced by the applied magnetic field. We also investigate the behavior of this field‐induced gap. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear optical properties of ionic NLO chromophores: An attempt to bridge the gap between computation and experiment
Authors: Sainudeen Zuhail , Ray Paresh Chandra
Published: July 2005

We present a quantum chemical analysis of the molecular structure and first hyperpolarizabilities of a series of stilbazolium ions and compare their results with corresponding neutral molecules. The molecular geometries are obtained via B3LYP/6‐31G** optimization, including the self‐consistent reaction field/polarizable continuum model (SCRF/PCM) approach. The static first hyperpolarizabilities (β0) are calculated using the ab initio coupled perturbed Hartree–Fock (CPHF) method, while the dynamic first hyperpolarizability (β) is investigated using the ZINDO/correction vector (CV) method, including solvent effects. The effects of donor–acceptor properties, solvent polarity, the dispersion effect, and aggregation on the first hyperpolarizibility are methodically evaluated with an attempt toward developing the engineering guidelines for the enhancement of the molecular optical nonlinearities of charged chromophores. We compare our theoretical results with the experimental values wherever available in the literature and evaluate the results in detail about the agreements and disagreements between theoretical and experimental findings. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Density functional theory study of the origin of IR and Raman band shifts in H‐bond complexes of triethylamine with water
Authors: Zhanpeisov N. U. , Ohta K. , Kajimoto S. , Hobley J. , Hatanaka K. , Fukumura H.
Published: July 2005

The present article discusses the results of density functional calculations obtained using B3LYP functional and the standard 6‐31G* basis sets for mono‐, di‐, and triethylamines (MEA, DEA, and TEA, respectively) and their H‐bonded complexes with water molecules. In particular, the origin of the observed experimentally clear red shift for methylene νCHmode due to the nanosecond laser T‐jump in TEA/H2O system is validated theoretically by explicit consideration of related infrared (IR) and Raman peaks appeared at the CH absorbance region. All theoretical calculations were performed with full geometry optimizations without imposing any constraints, and followed by direct harmonic frequency calculations. The effects of nonspecific and specific solvations were accounted for using simple Onsager model and explicit water molecules. It was shown that the former continuum model does not strongly perturb the observed spectral changes in the CH region because of shallow potential energy surface for the interacting subsystems. Both the structural changes in geometry and electron redistribution as a result of H‐bonding were found to be main factors to explain the observed experimental spectral changes in IR and Raman spectra. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Time‐dependent density functional theory (TD‐DFT) study of the excited state proton transfer in hypoxanthine
Authors: Shukla M. K. , Leszczynski Jerzy
Published: July 2005

Theoretical investigations on the ground‐ and excited‐state proton transfer in the isolated and monohydrated forms of hypoxanthine have been performed. Ground‐ and transition‐state geometries were optimized at the Hartree–Fock (HF)/6‐311++G(d,p) and B3LYP/6‐311++G(d,p) levels. The geometries of tautomers including the transition states were also optimized in the lowest singlet ππ* excited state at the CIS/6‐311++G(d,p) level. The time‐dependent density function theory augmented with B3LYP functional (TD‐B3LYP) and the 6‐311++G(d,p) basis set were used to compute vertical transition energies using the B3LYP geometries. The TD‐B3LYP/6‐311++G(d,p) calculations were also performed using the CIS/6‐311++G(d,p) geometries to predict the adiabatic transition energies of tautomers and the excited‐state proton transfer barrier heights. The effect of aqueous environments was considered using the polarizable continuum model (PCM). The harmonic vibrational frequency calculations were performed to ascertain the nature of potential energy surfaces. It was found that proton transfer is characterized by a high barrier height both in the gas phase and in aqueous solution. The explicit inclusion of a water molecule in the proton transfer path reduces the barrier height drastically. The excited‐state barrier height was found to be increased as compared with that in the ground state. The transition states corresponding to the proton transfer from the keto to the enol form for the monohydrated forms were found to have a zwitterionic structure. The zwitterionic nature of the hydrated transition‐state structure is increased in the excited state. The transition‐state geometries are more easily expressed in the form of H3O+…HX− for the monohydrated complex of the molecule. The excited‐state geometries, including that of transition states, were found to be largely nonplanar. The nonplanar fragment was localized mostly in the six‐membered ring. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Molecular modeling study of binding to the catalytic site of PDE4 enzymes by a novel class of inhibitors
Authors: Lawrenz Morgan E. , Salter E. A. , Wierzbicki Andrzej , Thompson W. J.
Published: July 2005

Cyclic nucleotide phosphodiesterases (PDEs) comprise a superfamily of enzymes that hydrolyze the second messengers adenosine and guanosine 3′,5′‐cyclic monophosphate (cAMP and cGMP) to their noncyclic nucleotides (5′‐AMP and 5′‐GMP). Selective inhibitors of all 11 gene families of PDEs are being sought based on the different biochemical properties of the different isoforms, including their substrate specificities. The PDE4 gene family consists of cAMP‐specific isoforms; selective PDE4 inhibitors such as rolipram have been developed, and related agents are used clinically as anti‐inflammatory agents for asthma and COPD. The known crystal structures of PDE4 bound with rolipram and IBMX have allowed us to define plausible binding orientations for a novel class of benzylpyridazinone‐based PDE4 inhibitors represented by EMD 94360 and EMD 95832 that are structurally distinct from rolipram. Molecular mechanics modeling with autodocking is used to explore energetically favorable binding orientations within the PDE4 catalytic site. We present two putative orientations for EMD 94360/95832 inhibitor binding. Our estimated interaction energies for rolipram, IBMX, EMD 94360, and EMD 95832 are consistent with the experimental data for their IC50 values. Key binding residues and interactions in these orientations are identified and compared with known binding motifs proposed for rolipram. The experimentally observed improved strength of inhibition exhibited by this novel class of PDE4 inhibitors is explained by the molecular modeling reported here. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Development methods for trusted computer systems
Authors: Thomas Martyn
Published: July 2005

Conclusion

Well-designed computer systems can be safer than hardwired alternatives, and computer systems can control processes which are too complex for hardwired solutions, or where the hardwired solution is uneconomic.
Do-it-yourself type theory
Authors: Backhouse Roland , Chisholm Paul , Malcolm Grant , Saaman Erik
Published: July 2005

This paper provides a tutorial introduction to a constructive theory of types based on, but incorporating some extensions to, that originally developed by Per Martin-Löf. The emphasis is on the relevance of the theory to the construction of computer programs and, in particular, on the formal relationship between program and data structure. Topics discussed include the principle of propositions as types, free types, congruence types, types with information loss and mutually recursive types. Several examples of program development within the theory are also discussed in detail.
VVSL: A language for structured VDM specifications
Authors: Middelburg C. A.
Published: July 2005

VVSL is a VDM specification language of the “British School” with modularisation constructs allowing sharing of hidden state variables and parameterisation constructs for structuring specifications, and with constructs for expressing temporal aspects of the concurrent execution of operations which interfere via state variables. The modularisation and parameterisation constructs have been inspired by the “kernel” design language COLD-K from the ESPRIT project 432: METEOR, and the constructs for expressing temporal aspects by various temporal logics based on linear and discrete time. VVSL is provided with a well-defined semantics by defining a translation to COLD-K extended with constructs which are required for translation of the VVSL constructs for expressing temporal aspects.

In this paper, the syntax for the modularisation and parameterisation constructs of VVSL is outlined. Their meaning is informally described by giving an intuitive explanation and by outlining the translation to COLD-K. It is explained in some detail how sharing of hidden state variables is modelled. Examples of the use of the modularisation and parameterisation constructs are also given. These examples are based on a formal definition of the relational data model. With respect to the constructs for expressing temporal aspects, the ideas underlying the use of temporal formulae in VVSL are briefly outlined and a simple example is given.
Program development in the constructive set theory TK
Authors: Henson Martin C.
Published: July 2005

We present a constructive theory of types and kinds designed with program development as the major desideratum. We show how this theory may be employed to derive programs from proofs of specifications (that is, demonstrations that specifications are satisfiable) and how the infrastructure of the theory supports the transformational development of programs in a natural way.
Event fairness and non-interleaving concurrency
Authors: Kwiatkowska Marta Z.
Published: July 2005

Event fairness suitable for non-interleaving concurrency is proposed. Fairness is viewed with respect to concurrency, rather than non-determinism, in the sense that no concurrent component of the system should be delayed indefinitely. Shields' asynchronous transition systems and Mazurkiewicz's traces have been used; the model gives rise to a partial order. A class of generalised notions of (weak, strong and unconditional) event fairness relative to progress requirements is derived. The weakest fairness notion in this class is shown to coincide with maximality with respect to the partial order over traces.
Process simulation and refinement
Authors: Jifeng He
Published: July 2005

In this paper we deal with the problem of (nondeterministic and parallel) process refinement. The basic notion of refinement is defined via the improved failure semantics of CSP [BHR84, BrR85, Hoa85, Ros88]. The concept of simulation of Communicating Systems introduced in [Mil80, Par81] is generalised and proved to be sound for the correctness of refinement. A Galois connection is presented to show that up-simulation and down-simulation together provide a complete proof method. The paper also suggests that simulation can be employed to derive an implementation from a specification.
Automated analysis of mutual exclusion algorithms using CCS
Authors: Walker D. J.
Published: July 2005

A number of mutual exclusion algorithms are studied by representing them as agents in the Calculus of Communicating Systems and using an automated tool embodying some of the theory of the Calculus to analyse the representations. It is determined whether or not each of the algorithms preserves mutual exclusion and is live.
A functional programming approach to the specification and verification of concurrent systems
Authors: Dybjer Peter , Sander Herbert P.
Published: July 2005

Networks of communicating processes can be viewed as networks of stream transformers and programmed in a lazy functional language. Thus the correctness of concurrent systems can be reduced to the correctness of functional programs. In this paper such correctness is proved formally in the
μ
-calculus extended with recursion equations for functional programs. The
μ
-calculus is chosen since it allows the definition of properties by least fixed points (induction) as well as by greatest fixed points (coinduction), and since greatest fixed points are useful for formalising properties, such as fairness, of infinitely proceeding programs. Moreover, non-deterministic processes are represented as incompletely specified deterministic processes, that is, as properties of stream transformers. This method is illustrated by proving the correctness of the alternating bit protocol.
Refinement concepts formalised in higher order logic
Authors: Back R. J. R. , von Wright J.
Published: July 2005

A theory of commands with weakest precondition semantics is formalised using the HOL proof assistant system. The concept of refinement between commands is formalised, a number of refinement rules are proved and it is shown how the formalisation can be used for proving refinements of actual program texts correct.
The projection of systolic programs
Authors: Lengauer C. , Sanders J. W.
Published: July 2005

A scheme is presented which transforms systolic programs with a two-dimensional structure to one dimension. The elementary steps of the transformation are justified by theorems in the theory of communicating sequential processes and the scheme is demonstrated with an example in occam: matrix composition/decomposition.
The fixed point theory of unbounded non-determinism
Authors: Barrett Geoff
Published: July 2005

This paper presents a fixed point theorem for the infinite traces model of CSP. Unlike any other model of CSP, there is no complete partial order over the infinite traces model whose fixed point theory agrees with the operational semantics (A. W. Roscoe, Oxford University Computing Laboratory Technical Monograph PRG-67, 1988). This arises from the introduction of unbounded non-determinism. However, the subset of pre-deterministic processes, that is those which describe the behaviour of a process on some run of its implementation, do form a subset for which the usual order is complete. By requiring that each CSP operator has a monotonic implementation which preserves pre-determinism, it is possible to show that all CSP operators have a least fixed point. In effect, it is the requirement that all operators have a methodical implementation.
Eliminating the substitution axiom from UNITY logic
Authors: Sanders Beverly A.
Published: July 2005

The UNITY substitution axiom, “if (x=y) is an invariant of a program, then x can be replaced by y in any property of the program”, is problematic for several reasons. In this paper, dual predicate transformers
sst
and
wst
are introduced that allow the strongest invariant of a program to be expressed, and these are used to give new definitions for the temporal operators
unless
and
ensures
. With the new definitions, the substitution
axiom
is no longer needed, and can be replaced by a derived rule of inference which is formally justified in the logic. One important advantage is that the effects of the initial conditions on the properties of a program are formally captured in a convenient way, and one can forget about substitution in formal treatments of the UNITY proof system while still having it available when desirable to use during the derivation of programs. Composibility and completeness of the modified logic are also discussed.
Fungal succession and decomposition ofCamellia japonicaleaf litter
Authors: Koide Kanade , Osono Takashi , Takeda Hiroshi
Published: July 2005

Decomposition processes ofCamellia japonicaleaf litter were investigated over an 18‐month period with reference to the role of fungal succession in the decomposition of lignin and holocellulose. Decomposition and fungal succession were studied in bleached and nonbleached portions of litter, which were precolonized by ligninolytic and cellulolytic fungi, respectively.Coccomyces nipponicumandLophodermiumsp. (Rhytismataceae), which can attack lignin selectively, caused mass loss of lignin and were responsible for bleaching during the first 4 months (stage I), whereas cellulolytic fungi caused mass loss of holocellulose in adjacent nonbleached portions. Soluble carbohydrates and polyphenols also decreased rapidly during this stage.Pestalotiopsis guepini, coelomycete sp.1, and theNigrosporastate ofKhuskia oryzaecaused mass loss of holocellulose between 4 and 14 months (stage II) andXylariasp. caused mass loss of both lignin and holocellulose from 14–18 months (stage III). In stages II and III, decomposition was more rapid in bleached portions than in nonbleached portions probably due to the prior delignification of lignified holocellulose in bleached portions. Frequencies of these fungi showed different responses among species to the pattern of changes in lignin and holocellulose contents during decomposition. Total hyphal length increased in both portions over the study period, but mycelia of basidiomycetes accounted for about 2% of total hyphal length, suggesting that their role in fungal succession and decomposition was low. Lignin and nitrogen contents were consistently lower and holocellulose content was higher in bleached portions than in nonbleached portions during decomposition. The succession of ligninolytic and cellulolytic fungi was a major driving factor that promoted decomposition and precolonization by ligninolytic fungi enhanced decomposition.
Effects of oil droplets by Pieris caterpillars against generalist and specialist carnivores
Authors: Shiojiri Kaori , Takabayashi Junji
Published: July 2005

Pieris rapae larvae secrete small oil droplets from their dorsal setae, which adhere to objects that touch them. The function of the droplets was studied in terms of both generalist and specialist predators. We tested the function of the droplets against ants under laboratory and field conditions. In the laboratory observation, Formica japonica ants that touched the larvae with their antennae initiated antennal cleaning and did not prey on the larvae. In the field, predation pressure by ants on larvae with oil droplets was significantly lower than on larvae from which oil droplets were removed. Thus, we concluded that the droplets had a defensive function. By contrast, oviposition by Cotesia glomerata, the specialist parasitic wasp of P. rapae larvae, was not affected by the presence of oil droplets. Furthermore, the wasps exhibited searching behavior and oviposition behavior towards filter paper which had been impregnated with the droplets’ substance, suggesting that the oil functions as a host‐searching cue and an oviposition stimulant for C. glomerata. According to these results, the functions of the droplets are discussed with regard to the prey–predator interaction.
Hetmanka and Mother: Representing the Virgin Mary in Modern Poland.
Authors: PORTER BRIAN
Published: July 2005

Marian devotion has long been a central component of Catholic spirituality, in part because the image of the Virgin has been accommodated effectively within so many diverse cultural contexts. In modern Poland, Marianism gained much of its power from the way it linked seemingly contradictory models of femininity together within a national (or even nationalist) worldview. Mary, the Queen of Poland, has been offered to the faithful as a model for conceptualising the feminine within the nation, a model which is flexible enough to endure because it rests on a basic dichotomy: on the one hand, Mary is a powerful, sometimes militant, protector of Poland; on the other, she is an exemplar of feminine domesticity. She provides an image of authority and power which ultimately (perhaps paradoxically) poses little challenge to traditional norms of femininity – indeed, she is frequently called upon to fortify those norms. Marianism thus provides some of the glue that helps hold together two otherwise distinct strains of Polish national thought, one focused on maintaining conservative gender relations and the other on attaining victory in the international realm.
European Empire and the Making of the Modern World: Recent Books and Old Arguments
Authors: FINALDI GIUSEPPE
Published: July 2005

Robert Aldrich, Colonialism and Homosexuality (London: Routledge, 2003), 436 pp., £18.99 (pb), ISBN 0415196167.

L. J. Butler, Britain and Empire. Adjusting to a Post-imperial World (London: Tauris, 2000), 249 pp., £14.99 (pb), ISBN 186064449X.

Tony Chafer and Amanda Sackur, eds., Promoting the Colonial Idea: Propaganda and Visions of Empire in France (Basingstoke: Palgrave, 2002), 248 pp., £55.00 (hb), ISBN 0333791800.

Nicola Labanca, Oltremare (Bologna: Il Mulino, 2002), 569 pp., pb, €20.00, ISBN 8815089594.

Patrizia Palumbo, ed., A Place in the Sun (Berkeley: University of California Press, 2003), 332 pp., $60.00 (hb), ISBN 0521386632.

Emanuelle Sibeud, Une Science Impériale pour l'Afrique? (Paris: EHESS, 2002), 356 pp., €32.00, ISBN 2713217849.

Mary Sutphen and Bridie Andrews, eds., Medicine and Colonial Identity (London: Routledge, 2003), 160 pp., £58.00 (hb), ISBN 0415288800.
The rate of return of pay-as-you-go pension systems: a more exact consumption-loan model of interest
Authors: SETTERGREN OLE , MIKULA BOGUSLAW D.
Published: July 2005

The article presents a method for calculating the cross-section internal rate of return on contributions to pension systems financed according to the pay-as-you-go principle. The method entails a procedure for valuing the contribution flow of pay-as-you-go financing, and identifies the complete set of factors that determine the cross-section internal rate of return. The procedure makes it possible to apply the algorithm of double-entry bookkeeping in analyzing and presenting the financial position and development of pay-as-you-go pension systems.
Infrasound monitoring of volcanoes to probe high‐altitude winds
Authors: Le Pichon A. , Blanc E. , Drob D. , Lambotte S. , Dessa J. X. , Lardy M. , Bani P. , Vergniolle S.
Published: July 2005

Active volcanoes in the Vanuatu archipelago permanently generate infrasonic waves. Their monitoring over 1 year exhibits clear seasonal trends in the direction of arrival of the detected signals. From summer to winter the azimuth variation reaches 15°. This deviation is essentially due to the reversibility of the zonal stratospheric wind with season which strongly affects the deflection of the ray direction. A three‐dimensional (3‐D) ray‐tracing modeling roughly explains the observed seasonal trend in the azimuth variation but underestimates its amplitude. The discrepancy between the measurements and the results of simulation is explained by undervalued wind speeds in the upper atmosphere. Infrasonic observations are used as input of an inversion scheme for adjusting the vertical structure of the wind in the upper stratosphere and mesosphere. It is shown that the mesospheric zonal winds are underestimated by at least 20 m/s throughout the year with differences reaching 50 m/s.
Numerical simulations of grass fires using a coupled atmosphere–fire model: Basic fire behavior and dependence on wind speed
Authors: Linn Rodman R. , Cunningham Philip
Published: July 2005

Numerical simulations using a fire model, FIRETEC, coupled to an atmospheric dynamics model, HIGRAD, are examined to investigate several fundamental aspects of fire behavior in grasslands, and specifically the dependence of this behavior on the ambient atmospheric winds and on the initial length of the fire line. The FIRETEC model is based on a multi‐phase transport approach, and incorporates representations of the physical processes that govern wildfires, such as combustion and radiative and convective heat exchange. Results from the coupled model show that the forward spread of the simulated fires increases with increasing ambient wind speed, and the spread rates are consistent with those observed in field experiments of grass fires; however, the forward spread also depends significantly on the initial length of the fire line, and for a given ambient wind speed the spread rate for long (100 m) lines is greater than that for short (16 m) lines. The spread of the simulated fires in the lateral direction also depends on the ambient wind speed and the length of the fire line, and a possible explanation for this effect is given. For weak ambient winds, the shape of the fire perimeter is dramatically different from that seen with higher wind speeds. The shape of the fire perimeter is also shown to depend on the initial length of the fire line. These differences in fire behavior are attributed to the differences in the nature of the coupled atmosphere–fire interactions among these cases, and are described in terms of the complex interplay between radiative and convective heat transfer.
Flood frequency censoring errors associated with daily‐read flood observations
Authors: Micevski Tom , Kuczera George , Franks Stewart W.
Published: July 2005

The effects of daily‐read discharges, discharges derived from a single daily observation (say at 9 AM), are examined in the context of flood frequency analysis. These discharges underestimate the true peak discharge because the actual peak is unlikely to occur at the single observation time. The resultant error in discharge estimates can be quite large, up to a factor of 10. Several maximum likelihood methods are proposed to deal with these daily‐read, or censored, discharges. Three methods are evaluated: censored as gauged (CAG), which treats daily‐read discharges as the true peak, binomial censoring (BC), which uses binomial censoring, and random dependent censoring (RDC), which incorporates the dependence between the the daily‐read and true peak discharges. The performance of the methods is evaluated using a Monte Carlo study. The RDC method is found preferable to the CAG method because it provides better performance (in terms of root mean squared error and bias) and is theoretically sound. The BC method performs very poorly and is not recommended.
Rosiglitazone ameliorates abnormal expression and activity of protein tyrosine phosphatase 1B in the skeletal muscle of fat‐fed, streptozotocin‐treated diabetic rats
Authors: Wu Yong , Ouyang Jing Ping , Wu Ke , Wang Shi Shun , Wen Chong Yuan , Xia Zheng Yuan
Published: July 2005

Protein tyrosine phosphatase 1B (PTP1B) acts as a physiological negative regulator of insulin signaling by dephosphorylating the activated insulin receptor (IR). Here we examine the role of PTP1B in the insulin‐sensitizing action of rosiglitazone (RSG) in skeletal muscle and liver.

Fat‐fed, streptozotocin‐treated rats (10‐week‐old), an animal model of type II diabetes, and age‐matched, nondiabetic controls were treated with RSG (10 μmol kg−1 day−1) for 2 weeks.

After RSG treatment, the diabetic rats showed a significant decrease in blood glucose and improved insulin sensitivity. Diabetic rats showed significantly increased levels and activities of PTP1B in the skeletal muscle (1.6‐ and 2‐fold, respectively) and liver (1.7‐ and 1.8‐fold, respectively), thus diminishing insulin signaling in the target tissues.

We found that the decreases in insulin‐stimulated glucose uptake (55%), tyrosine phosphorylation of IRβ‐subunits (48%), and IR substrate‐1 (IRS‐1) (39%) in muscles of diabetic rats were normalized after RSG treatment. These effects were associated with 34 and 30% decreases in increased PTP1B levels and activities, respectively, in skeletal muscles of diabetic rats. In contrast, RSG did not affect the increased PTP1B levels and activities or the already reduced insulin‐stimulated glycogen synthesis and tyrosine phosphorylation of IRβ‐subunits and IRS‐2 in livers of diabetic rats.

RSG treatment in normal rats did not significantly change PTP1B activities and levels or protein levels of IRβ, IRS‐1, and ‐2 in diabetic rats.

These data suggest that RSG enhances insulin activity in skeletal muscle of diabetic rats possibly by ameliorating abnormal levels and activities of PTP1B.

British Journal of Pharmacology (2005) 146, 234–243. doi:10.1038/sj.bjp.0706306
Pharmacological characterization of nucleotide P2Y receptors on endothelial cells of the mouse aorta
Authors: Guns Pieter‐Jan D F , Korda András , Crauwels Herta M , Van Assche Tim , Robaye Bernard , Boeynaems Jean‐Marie , Bult Hidde
Published: July 2005

Nucleotides regulate various effects including vascular tone. This study was aimed to characterize P2Y receptors on endothelial cells of the aorta of C57BL6 mice. Five adjacent segments (width 2 mm) of the thoracic aorta were mounted in organ baths to measure isometric force development.

Nucleotides evoked complete (adenosine 5′ triphosphate (ATP), uridine 5′ triphosphate (UTP), uridine 5′ diphosphate (UDP); >90%) or partial (adenosine 5′ diphosphate (ADP)) relaxation of phenylephrine precontracted thoracic aortic rings of C57BL6 mice. Relaxation was abolished by removal of the endothelium and was strongly suppressed (>90%) by inhibitors of nitric oxide synthesis.

The rank order of potency was: UDP∼UTP∼ADP>adenosine 5′‐[γ‐thio] triphosphate (ATPγS)>ATP, with respective pD2 values of 6.31, 6.24, 6.22, 5.82 and 5.40. These results are compatible with the presence of P2Y1 (ADP>ATP), P2Y2 or P2Y4 (ATP and UTP) and P2Y6 (UDP) receptors.

P2Y4 receptors were not involved, since P2Y4‐deficient mice displayed unaltered responses to ATP and UTP.

The purinergic receptor antagonist suramin exerted surmountable antagonism for all agonists. Its apparent pKb for ATP (4.53±0.07) was compatible with literature, but the pKb for UTP (5.19±0.03) was significantly higher. This discrepancy suggests that UTP activates supplementary non‐P2Y2 receptor subtype(s).

Further, pyridoxal‐phosphate‐6‐azophenyl‐2′‐4′‐disulphonic acid (PPADS) showed surmountable (UTP, UDP), nonsurmountable (ADP) or no antagonism (ATP).

Finally, 2′‐deoxy‐N6‐methyladenosine3′,5′‐bisphosphate (MRS2179) inhibited ADP‐evoked relaxation only.

Taken together, these results point to the presence of functional P2Y1 (ADP), P2Y2 (ATP, UTP) and P2Y6 (UDP) receptors on murine aorta endothelial cells. The identity of the receptor(s) mediating the action of UTP is not fully clear and other P2Y subtypes might be involved in UTP‐evoked vasodilatation.

British Journal of Pharmacology (2005) 146, 288–295. doi:10.1038/sj.bjp.0706326
Photoinduced molecular reorientation dynamics in confined domains of Langmuir monolayers
Authors: Crusats Joaquim , Albalat Rosa , Claret Josep , Ignés-Mullol Jordi , Reigada Ramon , Sagués Francesc
Published: July 2005

In a photoresponsive Langmuir monolayer comprised of smectic-C-like domains of mesogenic trans-azobenzene derivative embedded within an isotropic matrix of its cis isomer counterpart, several structurally differing circular droplets were irradiated with linearly polarized light. This report describes the structural rearrangements that occurred in these droplets upon illumination followed by Brewster angle microscopy analysis. Starting from initial well-characterized and symmetric states, final photoaligned situations were reached in which the azimuth angles of the rod-shaped elongated molecules were found to be perpendicular to the electric component of the excitation light. The dynamical aspects of the photoalignments, including their transient patterns, are captured by a theoretical model that couples a relaxational principle incorporating long-range elastic forces with a kinetic formalism presenting an anisotropic rate law.
Interaction between benzenedithiolate and gold: Classical force field for chemical bonding
Authors: Leng Yongsheng , Krstić Predrag S. , Wells Jack C. , Cummings Peter T. , Dean David J.
Published: July 2005

We have constructed a group of classical potentials based on ab initio density-functional theory (DFT) calculations to describe the chemical bonding between benzenedithiolate (BDT) molecule and gold atoms, including bond stretching, bond angle bending, and dihedral angle torsion involved at the interface between the molecule and gold clusters. Three DFT functionals, local-density approximation (LDA), PBE0, and X3LYP, have been implemented to calculate single point energies (SPE) for a large number of molecular configurations of BDT–1, 2 Au complexes. The three DFT methods yield similar bonding curves. The variations of atomic charges from Mulliken population analysis within the molecule/metal complex versus different molecular configurations have been investigated in detail. We found that, except for bonded atoms in BDT–1, 2 Au complexes, the Mulliken partial charges of other atoms in BDT are quite stable, which significantly reduces the uncertainty in partial charge selections in classical molecular simulations. Molecular-dynamics (MD) simulations are performed to investigate the structure of BDT self-assembled monolayer (SAM) and the adsorption geometry of S adatoms on Au (111) surface. We found that the bond-stretching potential is the most dominant part in chemical bonding. Whereas the local bonding geometry of BDT molecular configuration may depend on the DFT functional used, the global packing structure of BDT SAM is quite independent of DFT functional, even though the uncertainty of some force-field parameters for chemical bonding can be as large as ∼100%. This indicates that the intermolecular interactions play a dominant role in determining the BDT SAMs global packing structure.
Spherical tensor analysis of nuclear magnetic resonance signals
Authors: van Beek Jacco D. , Carravetta Marina , Antonioli Gian Carlo , Levitt Malcolm H.
Published: July 2005

In a nuclear magnetic-resonance (NMR) experiment, the spin density operator may be regarded as a superposition of irreducible spherical tensor operators. Each of these spin operators evolves during the NMR experiment and may give rise to an NMR signal at a later time. The NMR signal at the end of a pulse sequence may, therefore, be regarded as a superposition of spherical components, each derived from a different spherical tensor operator. We describe an experimental method, called spherical tensor analysis (STA), which allows the complete resolution of the NMR signal into its individual spherical components. The method is demonstrated on a powder of a C13-labeled amino acid, exposed to a pulse sequence generating a double-quantum effective Hamiltonian. The propagation of spin order through the space of spherical tensor operators is revealed by the STA procedure, both in static and rotating solids. Possible applications of STA to the NMR of liquids, liquid crystals, and solids are discussed.
Effect of phase transformations on laser forming of Ti–6Al–4V alloy
Authors: Fan Y. , Cheng P. , Yao Y. L. , Yang Z. , Egland K.
Published: July 2005

In laser forming, phase transformations in the heat-affected zone take place under steep thermal cycles, and have a significant effect on the flow behavior of Ti–6Al–4V alloy and the laser-forming process. The flow-stress data of a material are generally provided as only dependent on strain, strain rate, and temperature, while phase transformations are determined by both temperature and temperature history. Therefore, effect of phase transformations on the flow behavior of materials in thermomechanical processing is not given necessary considerations. In the present work, both the α→β transformation during heating and the decomposition of β phase, producing martensite α′ or lamellae α dependent on cooling rate, are numerically investigated. The spatial distribution of volume fractions of phases is obtained by coupling thermal and phase transformation kinetic modeling. Consequently, the flow stress of Ti–6Al–4V alloy is calculated by the rule of mixtures based on the phase ratio and the flow stress of each single phase, which is also a function of temperature, strain, and strain rate. According to the obtained flow-stress data, the laser-forming process of Ti–6Al–4V alloy is modeled by finite element method, and the deformation is predicted. A series of carefully controlled experiments are conducted to validate the theoretically predicted results.
High-resolution study of photoinduced modification in fused silica produced by a tightly focused femtosecond laser beam in the presence of aberrations
Authors: Hnatovsky C. , Taylor R. S. , Simova E. , Bhardwaj V. R. , Rayner D. M. , Corkum P. B.
Published: July 2005

An ultrahigh-resolution (20nm) technique of selective chemical etching and atomic force microscopy has been used to study the photoinduced modification in fused silica produced at various depths by tightly focused femtosecond laser radiation affected by spherical aberration. We demonstrate that shapes of the irradiated zones near the threshold for modification can be predicted by taking proper account of spherical aberration caused by the refractive index mismatched air–silica interface. We establish a depth dependence of the pulse energy required to initiate modification and characterize the relationship between numerical aperture of the writing lens and practically achievable writing depth. We also show that spatial characteristics of the laser-modified zones can be controlled by a specially designed focusing system which allows correction for a variable amount of spherical aberration.