bluuebunny/crossref_metadata_2025 huggingface dataset:
Rhodium‐Catalyzed Asymmetric Intramolecular Cyclopropanation of Substituted Allylic Cyanodiazoacetates
Authors: Lin Wei , Charette André B.
Published: October 2005

A chiral rhodium catalyst, Rh2[4S‐(4′)‐FBNAZ]4, was synthesized and was shown to catalyze the intramolecular cyclopropanation of substituted allylic cyanodiazoacetates. Alkenes bearing an electron‐deficient substituent including carbonyl and halogens are converted into the corresponding cyclopropanes in high yields with both chiral and achiral rhodium catalysts. The cyclopropane derivatives were generated with an enantioselectivity of up to 91% ee. For the asymmetric intramolecular cyclopropanation, cis‐halogen‐substituted substrates afforded cyclopropanes with higher enantioselectivities than the corresponding trans diastereomers. However, only moderate enantioselectivities were observed with alkenes bearing electron‐donating groups such as alkyls. The cyclopropanation of 3‐substituted 2‐propenyl cyanodiazoacetates was strongly influenced by steric and electronic factors arising from substituents on the alkenes. For the first time, we demonstrated that the intramolecular reaction of gem‐dihaloallylic cyanodiazoacetate afforded highly functionalized gem‐dihalocyclopropanes. This reaction is an appealing alternative to the addition of dihalocarbenes to alkenes for the formation of gem‐dihalocyclopropanes.
Continuous Chemoselective Methylation of m‐Cresol and Phenol with Supercritical Methanol over Solid Acid and Base Metal Oxide Catalysts
Authors: Oku Tomoharu , Arita Yoshitaka , Ikariya Takao
Published: October 2005

The chemoselective methylation of m‐ cresol and phenol with supercritical methanol (scCH3OH) promoted by metal oxide catalysts (MgO, ZrO2, CsPSi and FeV/SiO2) was investigated in a continuous flow fixed bed reactor. The use of scCH3OH as a carrier medium led to a significant change in the product selectivity compared to that attained in the gas phase reaction, and caused a marked suppression of the degradation of CH3OH during the reaction, resulting in an improvement in the catalyst lifetime. The chemoselective outcome of the reaction was highly influenced by the acid‐base character on the solid catalysts examined under supercritical conditions.
Practical Synthesis of (E)‐α,β‐Unsaturated Esters from Aldehydes
Authors: List Benjamin , Doehring Arno , Fonseca Maria T. Hechavarria , Wobser Kathrin , van Thienen Hendrik , Torres Ramon Rios , Galilea Pedro Llamas
Published: October 2005

Based on a modification of the Doebner–Knoevenagel reaction, a practical and highly efficient synthesis of α,β‐unsaturated esters with excellent regio‐ and stereoselectivity was developed. The reactions are catalyzed by 4‐dimethylaminopyridine in DMF at room temperature or below. Both aliphatic and aromatic aldehydes can readily be used in the process.
Catalytic Enantioselective Michael Reaction of 1,3‐Dicarbonyl Compounds via Formation of Chiral Palladium Enolate
Authors: Hamashima Yoshitaka , Hotta Daido , Umebayashi Natsuko , Tsuchiya Yasunori , Suzuki Takeyuki , Sodeoka Mikiko
Published: October 2005

An efficient catalytic enantioselective Michael reaction has been developed using chiral palladium complexes. Various substrates including β‐keto esters and 1,3‐diketones reacted with α,β‐unsaturated carbonyl compounds to give the corresponding Michael adducts in good yield with up to 99% ee, thereby affording chiral quaternary carbon centers. In these reactions, chiral palladium enolates were generated as key intermediates, which acted cooperatively with a strong protic acid to activate the Michael acceptors for promotion of the CC bond‐forming reaction.
A Modular Approach to α‐Arylated Carbonyl Compounds via Indium Tris(bistriflylamide)‐Catalyzed Regioselective Addition of β‐Ketoesters to 1,3‐Diynes
Authors: Nakamura Masaharu , Endo Kohei , Nakamura Eiichi
Published: October 2005

A modular synthesis of α‐arylated carbonyl compounds has been achieved by the combination of an indium‐catalyzed regioselective addition of β‐keto esters to conjugated diynes and a palladium‐catalyzed benzannulation reaction. Indium tris(bistriflylamide), In(NTf2)3, was found to be an efficient catalyst for the first addition reaction of β‐keto esters to diynes. The reaction proceeds with perfect regioselectivity to give conjugated enynes in high yield. The second palladium‐catalyzed benzannulation proceeds in high to excellent yield and with high regioselectivity for a variety of diynes. This two‐step α‐arylation of carbonyl compounds thus proceeds in a catalytic manner without loss of elements in the starting materials. The reaction may be performed in a single pot without isolation of the product of the first step.
Enantioselective Addition of Organozinc Reagents to Aldehydes Catalyzed by 3,3′‐Bis(diphenylphosphinoyl)‐BINOL
Authors: Hatano Manabu , Miyamoto Takashi , Ishihara Kazuaki
Published: October 2005

The enantioselective addition of organozinc reagents to aromatic and aliphatic aldehydes 1 gives secondary alcohols 2 with excellent enantioselectivities in high yields through the catalytic use of (R)‐3,3′‐bis(diphenylphosphinoyl)‐BINOL (3) or (R)‐3,3′‐bis(diphenylthiophosphinoyl)‐BINOL (4) without Ti(IV) complexes. The coordination of the O or S atom of a (thio)phosphinoyl group bearing a BINOL backbone to organozinc reagents can efficiently increase the nucleophilicity of the organozinc reagents.
Factors governing the consumption of explicit knowledge
Authors: Desouza Kevin C. , Awazu Yukika , Wan Yun
Published: October 2005

Knowledge management as a field continues to receive resounding interest from scholars. While we have made progress in many areas of knowledge management, we are yet to understand what factors contribute to employee usage of knowledge artifacts. A field study of 175 employees in a software engineering organization was conducted to understand factors that govern consumption of explicit knowledge. We assert that the decision to consume knowledge can be framed as a problem of risk evaluation. Specifically, there are two sources of risk a consumer must evaluate prior to knowledge consumption—risk from the knowledge producer and risk from the knowledge product. We find support for the factors of perceived complexity, perceived relative advantage, and perceived risk as they relate to intentions to consuming knowledge.
Hierarchical phylogenetics as a quantitative analytical framework for evolutionary developmental biology
Authors: Serb Jeanne M. , Oakley Todd H.
Published: October 2005

Phylogenetics has inherent utility in evolutionary developmental biology (EDB) as it is an established methodology for estimating evolutionary relationships and for making comparisons between levels of biological organization. However, explicit phylogenetic methods generally have been limited to two levels of organization in EDB—the species and the gene. We demonstrate that phylogenetic methods can be applied broadly to other organizational levels, such as morphological structures or cell types, to identify evolutionary patterns. We present examples at and between different hierarchical levels of organization to address questions central to EDB. We argue that this application of “hierarchical phylogenetics” can be a unifying analytical approach to the field of EDB. BioEssays 27:1158–1166, 2005. © 2005 Wiley Periodicals, Inc.
Microbial experiments on adaptive landscapes
Authors: Colegrave Nick , Buckling Angus
Published: October 2005

The adaptive landscape is one of the most widely used metaphors in evolutionary biology. It is created by plotting fitness against phenotypes or genotypes in a given environment. The shape of the landscape is crucial in predicting the outcome of evolution: whether evolution will result in populations reaching predictable end points, or whether multiple evolutionary outcomes are more likely. In a more applied sense, the landscape will determine whether organisms will evolve to lose ‘costly’ resistance to antibiotics, herbicides or pesticides when the use of the control agent is stopped. Laboratory populations of microbes allow evolution to be observed in real time and, as such, provide key insights into the topology of adaptive landscapes. BioEssays 27:1167–1173, 2005. © 2005 Wiley Periodicals, Inc.
Did internal transport, rather than directed locomotion, favor the evolution of bilateral symmetry in animals?
Authors: Finnerty John R.
Published: October 2005

The standard explanation for the origin of bilateral symmetry is that it conferred an advantage over radial symmetry for directed locomotion. However, recent developmental and phylogenetic studies suggest that bilateral symmetry may have evolved in a sessile benthic animal, predating the origin of directed locomotion. An evolutionarily feasible alternative explanation is that bilateral symmetry evolved to improve the efficiency of internal circulation by affecting the compartmentalization of the gut and the location of major ciliary tracts. This functional design principle is illustrated best by the phylum Cnidaria where symmetry varies from radial to tetraradial, biradial and bilateral. In the Cnidaria, bilateral symmetry is manifest most strongly in the internal anatomy and the disposition of ciliary tracts. Furthermore, the bilaterally symmetrical Cnidaria are typically sessile and, in those bilaterally symmetrical cnidarians that undergo directed locomotion, the secondary body axis does not bear a consistent orientation to the direction of locomotion as it typically does in Bilateria. Within the Cnidaria, the hypothesized advantage of bilateral symmetry for internal circulation can be tested by experimental analysis and computer modeling of fluid mechanics. The developmental evolution of symmetry within the Cnidaria can be further explored through comparative gene expression studies among species whose symmetry varies. BioEssays 27:1174–1180, 2005. © 2005 Wiley Periodicals, Inc.
The synaptic muscle‐specific kinase (MuSK) complex: New partners, new functions
Authors: Strochlic Laure , Cartaud Annie , Cartaud Jean
Published: October 2005

The muscle‐specific kinase MuSK is part of an agrin receptor complex that stimulates tyrosine phosphorylation and drives clustering of acetylcholine receptors (AChRs) in the postsynaptic membrane at the vertebrate neuromuscular junction (NMJ). MuSK also regulates synaptic gene transcription in subsynaptic nuclei. Over the past few years, decisive progress has been made in the identification of MuSK effectors, helping to understand its function in the formation of the NMJ. Similarly to AChR, MuSK and several of its partners are the target of mutations responsible for diseases of the NMJ, such as congenital myasthenic syndromes. This minireview will focus on the multiple MuSK effectors so far identified that place MuSK at the center of a multifunctional signaling complex involved in the organization of the NMJ and associated disorders. BioEssays 27:1129–1135, 2005. © 2005 Wiley Periodicals, Inc.
Jekyll and Hyde: Evolving perspectives on the function and potential of the adult liver progenitor (oval) cell
Authors: Knight Belinda , Matthews Vance B. , Olynyk John K. , Yeoh George C.
Published: October 2005

The liver progenitor cell (LPC) has enormous potential for use in cell therapy to treat liver disease. Since liver regenerates readily from pre‐existing hepatocytes, a role for LPCs and, indeed, their existence have been questioned. Research during the last decade has established that LPCs are an important alternative source of cells for liver regeneration. Their utility for cell therapy lies in their ability to generate both hepatocytes and cholangiocytes. However, they are observed in liver diseases that often lead to cancer and there is experimental evidence that implicates LPCs as the source of tumours. This article provides a brief history of the studies that established the functional importance of LPCs in liver disease. It focuses on mouse models that have led to the identification of factors that regulate LPC growth and differentiation and discusses LPCs derived from different sources. Recent promising results from both in vitro and vivo studies suggest that LPCs could be useful for cell therapy. In the context of liver disease, LPCs may indeed be the cell of the future and understandably “our favourite cell”. BioEssays 27:1192–1202, 2005. © 2005 Wiley Periodicals, Inc.
Notch signaling in hematopoiesis and lymphopoiesis: Lessons from Drosophila
Authors: Radtke Freddy , Wilson Anne , MacDonald H. Robson
Published: October 2005

The evolutionarily conserved Notch signaling pathway regulates a broad spectrum of cell fate decisions and differentiation processes during fetal and postnatal life. It is involved in embryonic organogenesis as well as in the maintenance of homeostasis of self‐renewing systems. In this article, we review the role of Notch signaling in the hematopoietic system with particular emphasis on lymphocyte development and highlight the similarities in Notch function between Drosophila and mammalian differentiation processes. Recent studies indicating that aberrant NOTCH signaling is frequently linked to the induction of T leukemia in humans will also be discussed. BioEssays 27:1117–1128, 2005. © 2005 Wiley Periodicals, Inc.
The business case for sustainability? An examination of small firms in the UK's construction and restaurant sectors
Authors: Revell Andrea , Blackburn Robert
Published: October 2005

Studies show that despite a concerted attempt by UK policy‐makers to portray ‘eco‐efficiency’ measures as cost reducing, most owner‐managers of small firms view environmental measures as expensive to undertake. As a result, owner‐managers tend to be highly resistant to voluntarily improving their environmental performance. Given that SMEs are such a vast sector of the economy, this perceived discord between profits and environmental protection is clearly a major barrier to the ‘greening’ of industry. This ESRC‐funded study has sought to unearth the underlying motivations for why SME owner‐managers in the UK resist or accept the idea that there are business benefits for improving their environmental performance. The findings from 40 in‐depth interviews with SME owners in the UK's construction and restaurant sectors and 12 ‘key informants’ from industry and government are presented, followed by a discussion of SME perspectives on the ‘business case’ for sustainability and its implications for policy‐makers. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Sustainability, performance and organizational strategy: an empirical analysis of public organizations
Authors: Enticott Gareth , Walker Richard M.
Published: October 2005

This paper presents a first time empirical analysis of sustainable management and performance in public organizations. Prior evidence from private firms on the relationship between sustainable management and performance indicates that the benefits of adopting social responsibility practices accrue across a number of dimensions of performance. Empirical analysis of English local government suggests that sustainable management is related to sustainability performance but not to other measures of organizational performance. These conclusions raise questions about the nature of sustainable management in public agencies and the measurement of performance. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Corporate greening through prosocial extrarole behaviours – a conceptual framework for employee motivation
Authors: Ramus Catherine A. , Killmer Annette B. C.
Published: October 2005

Scholars in environmental management have called for better grounding of research on corporate greening within established organizational theories. We propose a conceptual framework (including suggestions for operationalizing it) that embeds empirical research within behavioural intent models and the concept of value‐creating prosocial behaviours. We argue that conceiving of corporate greening as a prosocial behaviour in this manner provides an improved understanding of the dominant factors that motivate employees to engage in ecoinitiatives. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Collaborating to create: The Internet as a platform for customer engagement in product innovation
Authors: Sawhney Mohanbir , Verona Gianmario , Prandelli Emanuela
Published: October 2005

In the networked world, firms are recognizing the power of the Internet as a platform for co-creating value with customers. We focus on how the Internet has impacted the process of collaborative innovation—a key process in value co-creation. We outline the distinctive capabilities of the Internet as a platform for customer engagement, including interactivity, enhanced reach, persistence, speed, and flexibility, and suggest that firms can use these capabilities to engage customers in collaborative product innovation through a variety of Internet-based mechanisms. We discuss how these mechanisms can facilitate collaborative innovation at different stages of the New Product Development process (back end vs. front end stages) and for differing levels of customer involvement (high reach vs. high richness). We present two detailed exploratory case studies to illustrate the integrated and systematic usage of Internet-based collaborative innovation mechanisms—Ducati from the motorbike industry and Eli Lilly from the pharmaceutical industry. We derive implications for managerial practice and academic research on collaborative innovation.
Processing of animation in online banner advertising: The roles of cognitive and emotional responses
Authors: Yun Yoo Chan , Kim Kihan
Published: October 2005

Marketers often compete to incorporate fast-moving images in their online banner ads to break through the ad clutter, in the hope for a positive perception of the ads. However, the findings of this study suggest that this strategy may not work. An experiment was designed to explore the effects of the degree of animation on memory and attitudes toward ads. The results showed inverted U-shaped relationships between the level of animation and both recognition rates and A ad, suggesting the existence of unintended negative effects of highly animated online banner ads. Under high-animation conditions, subjects experienced negatively valenced thoughts and unpleasant feelings, which negatively influenced A ad. Also, subjects were highly aroused, as indicated by the increased level of emotional intensity; this arousal inhibited subjects’ ad recognition performance. These findings show different processing mechanisms under different animation levels, and suggest that marketers should exercise caution when using animation in their ads.
Pre-sale vs. Post-sale e-satisfaction: Impact on repurchase intention and overall satisfaction
Authors: Posselt Thorsten , Gerstner Eitan
Published: October 2005

E-tailers deliver services in two phases: before the sale takes place, and after the sale is over. Previous research in behavioral science has suggested that the time sequence of service delivery may affect customer evaluation of service and therefore it may also affect e-satisfaction. To determine how much to invest in pre-sale services relative to post-sale services, e-tailers should examine the impacts of customer satisfaction with services delivered in each phase on repurchase intention and overall service rating. In this paper, we measure these impacts and find that post-sale service has a much stronger impact on customer repurchase intention and overall service ratings compared to service delivered pre-sale. Because of this recency effect (buyers give more weight to e-service they receive late than to e-service received earlier), e-tailers are advised to put a strong emphasis on post-sale service.
Mutation in the δ‐subunit of the nAChR suppresses the muscle defects caused by lack of Dystrophin
Authors: Etard Christelle , Behra Martine , Ertzer Raymond , Fischer Nadine , Jesuthasan Suresh , Blader Patrick , Geisler Robert , Strähle Uwe
Published: October 2005

Normal motility of the zebrafish embryo requires a large number of gene loci, many of which have human orthologues implicated in myasthenias and other myopathies. We have identified a mutation in the zebrafish that abolishes body motility. Embryos have narrower myofibrils and lack clusters of nicotinic acetylcholine receptors (nAChRs) on the surface of the somitic muscle. We mapped the mutation to the δ‐subunit of the nAChR, showing this mutant to be a new allele of the previously namedsofa potato(sop). The mutant allele carries a missense mutation in the extracellular domain altering the cysteine at position 150 to an arginine. The δ‐subunit is expressed in all striated muscles in embryonic and early larval stages together with the α1, β1, ϵ, and γ‐subunits of nAChR. In contrast to mammals that show switching from the γ embryonic to the adult ϵ‐subunit, the two subunits are coexpressed in zebrafish embryos. We, furthermore, demonstrated that thesop/δ‐nAChRmutation is a suppressor of the myopathy caused by lack of Dystrophin. The myofiber detachment phenotype of Dystroglycan‐deficient embryos was not suppressed, suggesting that Dystrophin and Dystroglycan play distinct roles in muscle formation and maintenance of muscle integrity. Developmental Dynamics 234:1016–1025, 2005. © 2005 Wiley‐Liss, Inc.
DPATJ plays a role in retinal morphogenesis and protects against light‐dependent degeneration of photoreceptor cells in the Drosophila eye
Authors: Richard Mélisande , Grawe Ferdi , Knust Elisabeth
Published: October 2005

The establishment of apicobasal polarity in epithelial cells is a prerequisite for their function. Drosophila photoreceptor cells derive from epithelial cells, and their apical membranes undergo elaborate differentiation during pupal development, forming photosensitive rhabdomeres and associated stalk membranes. Crumbs (Crb), a transmembrane protein involved in the maintenance of epithelial polarity in the embryo, defines the stalk as a subdomain of the apical membrane. Crb organizes a complex composed of several PDZ domain‐containing proteins, including DPATJ (formerly known as Discs lost). Taking advantage of a DPATJ mutant line in which only a truncated form of the protein is synthesized, we demonstrate that DPATJ is necessary for the stability of the Crb complex at the stalk membrane and is crucial for stalk membrane development and rhabdomere maintenance during late pupal stages. Moreover, DPATJ protects against light‐induced photoreceptor degeneration. Developmental Dynamics 235:895–907, 2006. © 2005 Wiley‐Liss, Inc.
Synthesis and Structures of Fullerene Bromides and Chlorides
Authors: Troyanov Sergey I. , Kemnitz Erhard
Published: October 2005

Halogenated fullerenes have been subjects of intensive investigations since the discovery of fullerene, because of their possible further derivatization. This paper reviews the synthesis and molecular structures of fullerene bromides and chlorides, covering earlier work in this field and progress in synthetic methods developed by the authors. The use of inorganic chlorides and oxychlorides for the chlorination of fullerenes allowed the preparation of new compounds that have been fully characterized by single‐crystal X‐ray diffraction and IR spectroscopy and confirmed by theoretical calculations. Comparison between fullerene bromides, chlorides, and fluorides has revealed that the maximum degrees of halogenation and compound stability increase from the bromides to the fluorides. The larger Cl and Br atoms and the lower C–Hal energies also engender significant differences in addition patterns of the C60Haln and C70Halm molecules in relation to those of the fluorides. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
The Abnormal Behavior of an Atropisomer: 3,3′‐Dibromo‐1,1′‐difluoro‐2,2′‐binaphthyl Reacting with Alkyllithium Compounds
Authors: Leroux Frédéric , Mangano Giuseppe , Schlosser Manfred
Published: October 2005

1‐Fluoro‐2‐(triethylsilyl)naphthalene (1) and other 1‐fluoronaphthalenes bearing a metalation‐resistant substituent at the 2‐position proved to be totally inert toward base attack. 3‐Bromo‐1‐fluoronaphthalene (6), readily prepared from the 2‐bromo isomer 5 by deprotonation‐triggered heavy halogen migration, was converted into 3,3′‐dibromo‐1,1′‐difluoro‐2,2′‐binaphthyl (8) by consecutive treatment with lithium diisopropylamide, copper(II) bromide and nitrobenzene. The dilithiated intermediate generated from the atropisomer 8 by treatment with 2 equiv. of butyllithium reacted with a variety of electrophiles to afford products such as the diacid 12 or the bis(phosphanes) 14 and 15 in high yields. The latter compound was also obtained in a straightforward manner from (4‐fluoro‐2‐naphthyl)diphenylphosphane oxide (16). Unexpectedly, neither the 3,3′‐dibromobinaphthyl 8 nor its 3,3′‐diiodo analogue 18 were amenable to a unilateral but only to a double‐sided halogen/metal permutation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Cyclopentathiadiazines, Cyclohepta‐ and Cyclopentadithiazoles: New Materials and a Rich Heterocyclic Chemistry of Cyclic Enaminonitriles
Authors: Gómez Teresa , Macho Sonia , Miguel Daniel , Neo Ana G. , Rodríguez Teresa , Torroba Tomás
Published: October 2005

3‐Amino‐1H‐indene‐2‐carbonitrile and 2‐amino‐3H‐indene‐1‐carbonitrile reacted with SCl2, iBu3N and NCS to give benzocyclopenta[1,2,6]thiadiazines, and whilst 2‐aminocyclopent‐1‐enecarbonitrile gave, under the same conditions, a cyclopenta[1,2,6]thiadiazine, its reaction with mixtures of S2Cl2, SCl2 and iBu3N under different conditions gave, selectively, an isothiazolo[3,4‐d]cyclopenta[1,2,3]dithiazole and new cyclopenta[1,2,3]dithiazole derivatives. Similarly, 2‐aminocyclohept‐1‐enecarbonitrile reacted with SCl2, iBu3N and NCS to give a formally antiaromatic cyclohepta[1,2,3]dithiazole. Some of the compounds obtained showed characteristics useful as new materials, for example, as liquid crystals and near‐infrared dyes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Solvent‐Dependent Pseudopolymorphism of Tripyridoxycalix[4]arene: cone versus partial‐cone Conformation
Authors: Dyker Gerald , Mastalerz Michael , Müller Iris M. , Merz Klaus , Koppe Karsten
Published: October 2005

The preferred conformation of the tripyridoxycalixarene 1 in the crystalline state strongly depends on the applied solvents: The interaction with the clathrated solvent molecules influences the equilibrium between intra‐ and intermolecular hydrogen bonds and therefore the conformation of 1. The paco‐1 molecules form methanol‐containing channels; cone‐1 crystallizes as a clathrate with ethyl acetate fixed in the lattice voids. The conformations and their interconversion were studied by X‐ray crystal structure analysis and DSC measurements. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Response Behavior of Poly(vinyl chloride)‐ and Polyurethane‐Based Ca2+‐Selective Membrane Electrodes with Polypyrrole‐ and Poly(3‐octylthiophene)‐Mediated Internal Solid Contact
Authors: Sutter Jolanda , Pretsch Ernö
Published: October 2005

The potentiometric response behavior of Ca2+‐selective poly(vinyl chloride) (PVC) and polyurethane (PU) membranes with different inner contacts has been compared. Evidence for the formation of a water film between membrane and internal contact and, hence, a less than optimal lower detection limit have been found for membranes directly in contact with bare Au or with polypyrrole generated by electropolymerization in the presence of KCl. A significantly better behavior is shown by membranes with polypyrrole prepared in the presence of potassium hexacyanoferrate. Best performances have been obtained with solvent‐cast poly(3‐octylthiophene) as the internal contacting layer. As compared with the PVC membranes, those with PU had a significantly worse performance throughout.
Mass spectrometric investigation of protein alkylation by the RNA footprinting probe kethoxal
Authors: Akinsiku Olusimidele T. , Yu Eizadora T. , Fabris Daniele
Published: October 2005

The reactivity of the RNA footprinting reagent kethoxal (KT) toward proteins was investigated by electrospray ionization‐Fourier transform mass spectrometry. Using standard peptides, KT was shown to selectively modify the guanidino group of arginine side chains at neutral pH, while primary amino groups of lysine and N‐terminus were found to be unreactive under these conditions. Gas‐phase fragmentation of KT adducts provided evidence for a cyclic 1,2‐diol structure. Esterification of the 1,2‐diol product was obtained in borate buffer, and its structure was also investigated by tandem mass spectrometry. When model proteins were probed with this RNA footprinting reagent, the adducts proved to be sufficiently stable to allow for the application of different peptide‐mapping procedures to identify the location of modified arginines. Probing of proteins under native folding conditions provided modification patterns that very closely matched the structural context of arginines in the global protein structure. A strong correlation was demonstrated between the susceptibility to modification and residue accessibility calculated from the known 3D structure. When the complexes formed by HIV‐1 nucleocapsid (NC) protein and RNA stemloops SL2 and SL3 were investigated, KT footprinting provided accurate information regarding the involvement of individual arginines in binding RNA and showed different reactivity according to their mode of interaction. Copyright © 2005 John Wiley & Sons, Ltd.
Development of a hydrometeorological forcing data set for global soil moisture estimation
Authors: Berg A. A , Famiglietti J. S. , Rodell M. , Reichle R. H. , Jambor U. , Holl S. L. , Houser P. R.
Published: October 2005

Off‐line land surface modeling simulations require accurate meteorological forcing with consistent spatial and temporal resolutions. Although reanalysis products present an attractive data source for these types of applications, bias to many of the reanalysis fields limits their use for hydrological modeling. In this study, we develop a global 0.5° forcing data sets for the time period 1979–1993 on a 6‐hourly time step through application of a bias correction scheme to reanalysis products. We then use this forcing data to drive a land surface model for global estimation of soil moisture and other hydrological states and fluxes. The simulated soil moisture estimates are compared toin situmeasurements, satellite observations and to a modeled data set of root zone soil moisture produced within a separate land surface model, using a different data set of hydrometeorological forcing. In general, there is good agreement between anomalies in modeled and observed (in situ) root zone soil moisture. Similarly, for the surface soil wetness state, modeled estimates and satellite observations are in general statistical agreement; however, correlations decline with increasing vegetation amount. Comparisons to a modeled data set of soil moisture also demonstrates that both simulations present estimates that are well correlated for the soil moisture in the anomaly time series, despite being derived from different land surface models, using different data sources for meteorological forcing, and with different specifications of the land surfaces properties. Copyright © 2005 Royal Meteorological Society
Sensitivity of frost occurrence to temperature variability in the European Alps
Authors: Auer Ingeborg , Matulla Christoph , Böhm Reinhard , Ungersböck Markus , Maugeri Maurizio , Nanni Teresa , Pastorelli Rossella
Published: October 2005

In this study, we set out to investigate the linkage of frost frequency to monthly mean temperature and its sensitivity to temperature changes. According to other related studies, the linkage between frost frequency and monthly mean temperature is approximated month per month via hyperbolic tangent functions. These models are validated using three validation experiments including split sample tests and temporal cross‐validation. As there are quality‐checked station data in Austria, whose temporal resolution and length allow for such a validation procedure, the validation experiments are conducted there.

After the performance of the empirical models is evaluated and found adequate, the hyperbolic tangent approach is applied to about 500 stations within the so called Greater Alpine region (GAR), which extends from about 4 °E to 18 °E and from 44 °N to 49 °N. Using these models, it is possible to derive the sensitivity of frost frequency for any location for which the annual temperature cycle is known. This strategy is explicitly demonstrated for the Po Plain, where vertical temperature profiles on a monthly base are on hand as well as in Austria, where spatially high resolved maps of monthly mean temperature are available. Moreover, at stations for which long‐term homogenised series of monthly mean temperature are available, reconstructions of frost frequency via the empirical models are done, returning to historical periods where no measurements of minimum temperature exist.

On the basis of these findings, the impact of a possible future warming can be assessed, which is essential with regard to glaciers, permafrost and avalanches. Reduction in frost might bring positive economic aspects for agriculture, but negative consequences for low level skiing areas. Copyright © 2005 Royal Meteorological Society.
Retracted: Temperature affects flavour intensity and quality of aroma in fresh basil (Ocimum basilicum L.) leaves
Authors: Chang Xianmin , Alderson Peter G , Hollowood Tracey A , Hewson Louise , Wright Charles J
Published: October 2005

Retraction: The following article from the Journal of the Science of Food and Agriculture, ‘Temperature affects flavour intensity and quality of aroma in fresh basil (Ocimum basilicum L.) leaves’ by Xianmin Chang, Peter G Alderson, Tracey A Hollowood, Louise Hewson, and Charles J Wright, published online on 19 October 2005 in Wiley InterScience (www.interscience.wiley.com), has been retracted by agreement between the authors, the journal Editor in Chief, David S. Reid and John Wiley & Sons, Ltd. The retraction has been agreed due to overlap between this article and the following article published in the The Journal of Horticultural Science & Biotechnology; ‘Effect of temperature integration on the growth and volatile oil content of Basil (Ocimum basilicum L.)’ by Xianmin Chang, Peter G Alderson and Charles J Wright. Volume 80 Issue 5, 2005, pages 593 – 598
Intraoperative photodynamic therapy of the chest cavity in malignant pleural mesothelioma bearing rats
Authors: Krueger Thorsten , Pan Youmin , Tran Nam , Altermatt Hans‐Joerg , Opitz Isabelle , Ris Hans‐Beat
Published: October 2005

Background and Objective

Experimental assessment of anticancer effect, normal tissue damage, and toxicity of intrathoracic mTHPC‐mediated photodynamic therapy (PDT) combined to surgery in malignant pleural mesothelioma (MPM) bearing rats.

Study Design/Materials and Methods

Six days after implantation of syngenic malignant mesothelioma cells in the left chest cavity of Fischer rats (n = 21) and 4 days after sensitization (0.1 mg/kg mTHPC), a left‐sided pneumonectomy was performed, followed by intraoperative light delivery (652 nm, fluence 20 J/cm2), either by spherical illumination of the chest cavity (fluence rate 15 mW/cm2) or by focal illumination of a tumor area (fluence rate 150 mW/cm2). Controls comprised tumor‐bearing untreated animals, tumor‐bearing animals undergoing pneumonectomy, and tumor‐bearing animals undergoing pneumonectomy and light delivery without sensitization or sensitization without light delivery. No thoracocentesis was performed during follow‐up.

Results

An invasively growing sarcomatous type of mesothelioma was found in all animals at day 10, without tumor necrosis in control animals. PDT resulted in 0.5–1 mm deep inhomogeneous tumor necrosis after spherical, and in a 1–2 mm deep tumor necrosis after focal illumination. No injury to mediastinal organs was observed, neither after PDT with spherical nor with focal light delivery except focal interstitial lung fibrosis at the mediastinal area of the opposite lung. All animals with pneumonectomy followed by spherical PDT of the entire tumor‐bearing chest cavity died within 72 hours whereas all other animals survived. All animals that died presented massive pleural effusion.

Conclusions

PDT following pneumonectomy in mesothelioma bearing rats was technically feasible and allowed to study its effect on tumor and normal tissues. PDT‐related tumor necrosis was observed after spherical and focal light delivery, however, pneumonectomy followed by PDT with spherical light delivery to the tumor‐bearing chest cavity resulted in fatal complications. Lasers Surg. Med. 37:271–277, 2005. © 2005 Wiley‐Liss, Inc.
Fluorene‐Based Conjugated Poly(azomethine)s: Synthesis, Photophysical Properties, and Theoretical Electronic Structures
Authors: Liu Cheng‐Liang , Chen Wen‐Chang
Published: October 2005

Summary: Soluble conjugated poly(azomethine)s, PFI and PFCI, were synthesized from 2,7‐diformyl‐9,9′‐dioctylfluorene (DFOF) with diamines. The replacement of the fluorene (PFI) by carbazole (PFCI) reduces the ionization potential but enhances the band gap (Eg) due to the kink disorder introduced by the 3,6‐carbazole. The optical absorption or photoluminescence of the synthesized PFI or PFCI is sensitive to good/poor solvent ratio, acid environment, or metal ions. The variation of the planarity on the polymer backbone and intermolecular charge transfer explain the above spectral tuning by chemical species. The theoretical results based on the density functional theory (DFT) suggest that the PFI and PFCI show a non‐coplanar conformation due to steric repulsion force between the adjacent hydrogen atoms. It could be resolved by replacing the fluorene or carbazole ring by thiophene (PFTI) or 3,4‐ethylenedioxythiophene (PFEI). The coplanar geometry and possible intramolecular charge transfer lead to the Eg of 2.17 and 2.03 eV for the PFTI and PFEI, respectively. The smaller effective mass of the PFTI or PFEI also indicates that both polymers could be p‐type semiconductors for organic electronics.

Chemical structures of fluorene‐based conjugated poly(azomethine)s.

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Chemical structures of fluorene‐based conjugated poly(azomethine)s.
Polystyrene End‐Labeled with 2,7‐Dibromofluorene Synthesized Using an Adaptation of Reverse Atom Transfer Radical Polymerization
Authors: Ludwig Bellamarie , Tillman Eric S.
Published: October 2005

Summary: Polystyrene with high amounts of end‐labeling was synthesized using initiating systems comprised of conventional radical initiators and 2,7‐dibromofluorene or other fluorene derivatives in an adaptation of reverse atom transfer radical polymerization (RATRP). Benzoyl peroxide (BPO) or 2,2′‐azoisobutyronitrile (AIBN) were decomposed and allowed to react with 2,7‐dibromofluorene, 2‐bromofluorene, or fluorene in the presence of ligand‐bound CuX2 allowing for abstraction of the 9‐H from the fluorenyl species and the establishment of an equilibrium between the subsequent active radical and the dormant alkyl halide. Gel permeation chromatography (GPC) traces indicated CuCl2‐catalyzed reactions produced polymers possessing narrow polydispersity index (PDI) values <1.3 with AIBN and 2,7‐dibromofluorene systems, while analogous reactions catalyzed using CuBr2 were less controlled (PDI > 1.7). Analysis of the polymers using UV‐vis spectroscopy and UV‐GPC demonstrated competition between initiation from both the conventional radical initiator and fluorenyl species generating polymers end‐labeled with both the 2,7‐dibromofluorene and isobutyronitrile groups. Fluorene or 2‐bromofluorene as co‐initiators led to lowered amounts of end‐labeling, but the polymers generally possessed lower PDI values compared to 2,7‐dibromofluorene systems.

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Effect of a mixture of iprobenfos and malathion on the development of malathion resistance in the mosquito Culex pipiens pallens Coq
Authors: Tao Li‐Ming , Yang Jian‐Zhong , Zhuang Pei‐Jun , Tang Zhen‐Hua
Published: October 2005

A malathion‐resistant (RM) strain of Culex pipiens pallens Coq was obtained by successively selecting a field population with malathion in the laboratory. The synergistic effect of iprobenfos on malathion toxicity and α‐naphthyl acetate (α‐NA) esterase assay revealed that malathion resistance in the RM strain was associated with increased α‐NA esterase activity and the synergism was mainly due to the inhibition by iprobenfos of this activity. There was no difference in α‐NA esterase activity between the larvae and female adults in the susceptible (S) strain, but the activity in the adults was 13‐fold higher than in the larvae of the RM strain. To understand the effect of the application of a mixture of iprobenfos and malathion on the evolution of malathion resistance, an artificial strain (Syn) was generated by mixing the RM and S strains with 0.1 frequency of the malathion‐resistant individuals. The offspring of the Syn strain were divided into two sub‐strains, Rm and Rm+ibp, which were successively treated with, respectively, malathion alone and malathion + iprobenfos (1:2) at LC70. In the mixture, the fungicide iprobenfos acted as a synergist of malathion. After treatment for 10 generations, the resistance level to malathion was 317.4‐fold for the Rm sub‐strain, whereas for the Rm+ibp sub‐strain it was only 38.9‐fold, compared with the Syn strain. Similar results were obtained by measurement of α‐NA esterase activity from both larvae and female adults. The α‐NA esterase activities in larvae and female adults at F10 generation were 2.6‐ and 10.9‐fold from the Rm+ibp sub‐strain and 5.7‐ and 98.5‐fold from the Rm sub‐strain, respectively, compared with the Syn strain. The above results suggested that iprobenfos, although it cannot completely stop or prevent the onset of malathion resistance, could dramatically delay its evolution. Copyright © 2005 Society of Chemical Industry
Effect of pretreatment with piperonyl butoxide on pyrethroid efficacy against insecticide‐resistant Helicoverpa armigera (Lepidoptera: Noctuidae) and Bemisia tabaci (Sternorrhyncha: Aleyrodidae)
Authors: Young Susan J , Gunning Robin V , Moores Graham D
Published: October 2005

Pyrethroid resistance in B‐type Bemisia tabaci Gennadius and Australian Helicoverpa armigera Hübner field populations is primarily conferred by esterase isoenzymes which metabolise and sequester pyrethroid insecticides. It has been shown previously that pyrethroid resistance‐associated esterases in H. armigera are inhibited by the insecticide synergist piperonyl butoxide (PBO) over a 22‐h period. It is demonstrated here that similar inhibition can be obtained against B‐type B. tabaci. Small‐scale field trials showed excellent levels of pyrethroid control when insects were pretreated with PBO and then dosed with pyrethroid during the time of maximum esterase inhibition. These results demonstrate that PBO can restore pyrethroid efficacy in the field against both B‐type B. tabaci and resistant H. armigera. Copyright © 2005 Society of Chemical Industry
Comparative biological activities of a plaque‐purified variant and a Turkish native isolate of SpliNPV‐B against Spodoptera littoralis (Lepidoptera: Noctuidae)
Authors: Toprak Umut , Bayram Şerife , Gürkan Oktay M
Published: October 2005

The noctuid moth Spodoptera littoralis (Boisduval) is an important pest of many cultivated plants worldwide and five different geographical Nucleopolyhedrovirus (NPV) strains of this pest have been isolated to date. Two of these, a plaque‐purified variant of the S. littoralis NPV from Morocco (SpliNPV‐M2) and a SpliNPV isolated from field‐infected S. littoralis larvae found in Turkey (SpliNPV‐TR1), were compared biologically in terms of infectiveness (median lethal dose, LD50) for third instars and in terms of virulence (median lethal time, LT50) for neonates and third‐instar S. littoralis larvae. The LD50 values of SpliNPV‐TR1 and SpliNPV‐M2 were 20.73 and 185.21 occlusion bodies (OBs)/larva, respectively, with non‐overlapping confidence limits indicating they were significantly different. Thus, SpliNPV‐M2 was found to be significantly less infective (about nine times higher LD50) than SpliNPV‐TR1. The LT50 values of neonates for SpliNPV‐M2 and SpliNPV‐TR1 were 37 and 43.9 h at a concentration of 106 OBs ml−1, respectively. For these same isolates, the LT50 values at a concentration of 3 × 106 OBs ml−1 were calculated as 35.6 and 41.7 h, respectively. The LT50 values of third instars for SpliNPV‐M2 and SpliNPV‐TR1 were 147.4 and 160.5 h, respectively, at a dose of 3000 OBs/larva and 145.4 and 152.4 h, respectively, for the same isolates at a dose of 20 000 OBs/larva. On the other hand, Helicoverpa armigera (Hübner) and Agrotis ipsilon (Hufnagel) revealed a lack of lethality of the SpliNPV‐TR1 isolate. Copyright © 2005 Society of Chemical Industry
Comparative study of dielectric functions of complex organic heterostructures
Authors: Gordan O. D. , Hermann S. , Friedrich M. , Zahn D. R. T.
Published: October 2005

Organic/organic heterostructures and mixed layers were prepared by organic molecular beam deposition (OMBD) in high vacuum (HV) on hydrogen passivated (111) oriented silicon. The substrates were kept at room temperature during the deposition. The organic superstructures consisting in alternative layers of tris‐(8‐hydroxyquinoline)‐aluminum(III) (Alq3)/N,N′‐Di‐[(1‐naphthyl)‐N,N′‐diphenyl]‐(1,1′‐biphenyl)‐4,4′‐diamine (α‐NPD) and 3,4,9,10‐perylenetetracarboxylic dianhydride (PTCDA)/copper phthalocyanine (CuPc) were investigated by means of spectroscopic ellipsometry in the 0.73–5 eV spectral range. Additionally reflection infra‐red (IR) measurements were performed using p‐ and s‐polarisation.

Taking into account the dielectric function of the single layers the optical response of the Alq3/α‐NPD superstructure can be modeled assuming sharp interfaces. However, for the PTCDA/CuPc superstructure the optical response requires a more sophisticated approach than simply superimposing the responses of the individual layers. The deviation between simulated and experimental data is assigned to the molecular interaction at the interfaces between PTCDA and CuPc. This can affect the molecular orientation and the optical properties. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic ellipsometry and reflectance anisotropy spectroscopy of biomolecular layers on silicon surfaces
Authors: Zahn Dietrich R. T. , Silaghi Simona D. , Cobet Christoph , Friedrich Marion , Esser Norbert
Published: October 2005

The optical properties of the DNA bases deposited on flat and vicinal, hydrogen passivated Si(111) substrates are studied using spectroscopic ellipsometry (SE) up to 9.5 eV photon energy employing synchrotron radiation and reflectance anisotropy spectroscopy (RAS). The results for the dielectric function reveal strong optical anisotropy for adenine and guanine while the other two molecules form layers with isotropic properties. The experimentally derived dielectric functions are compared to density functional theory calculations of the optical response. Particularly interesting is the RAS response of the DNA bases as a function of thickness when deposited on vicinal Si surfaces. Ordering in the layers is induced by the step and terrace structure of the vicinal Si substrates. Even though the molecular structure is not dramatically different the RAS response is very distinct and allows an unambiguous identification of the bases. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)