bluuebunny/crossref_metadata_2025 huggingface dataset:
The creation and consequences of the social world: an interactional analysis of extraversion
Authors: Eaton Leslie G. , Funder David C.
Published: October 2003

Seventy‐six previously unacquainted, opposite‐sex pairs of undergraduate participants engaged in a 5 min videotaped interaction, then provided their mutual impressions. Research assistants coded 64 behaviours from the videotapes; these ratings were combined into behavioural factors. Participants provided self‐descriptions of personality and were described by two acquaintances. Path analyses indicated that targets extraversion was associated with their behavioural involvement, which in turn was associated with partners subsequent ratings of their personality. Targets interpersonal positive affectivity was associated with their partners extraversion. Similar patterns of behavioural associations were found in relation to self‐reported, partner‐reported, and acquaintance‐reported extraversion. These results demonstrate how extraverts may create a positive social environment through their own positivity and by creating a social press for positivity in return. Copyright © 2003 John Wiley & Sons, Ltd.
Gray's model of personality and aggregate level factor analysis
Authors: Jackson Chris J. , Levine Stephen Z. , Furnham Adrian
Published: October 2003

Previous research shows that correlations tend to increase in magnitude when individuals are aggregated across groups. This suggests that uncorrelated constellations of personality variables (such as the primary scales of Extraversion and Neuroticism) may display much higher correlations in aggregate factor analysis. We hypothesize and report that individual level factor analysis can be explained in terms of Giant Three (or Big Five) descriptions of personality, whereas aggregate level factor analysis can be explained in terms of Gray's physiological based model. Although alternative interpretations exist, aggregate level factor analysis may correctly identify the basis of an individual's personality as a result of better reliability of measures due to aggregation. We discuss the implications of this form of analysis in terms of construct validity, personality theory, and its applicability in general. Copyright © 2003 John Wiley & Sons, Ltd.
Head‐to‐head comparison of the predictive validity of personality types and dimensions
Authors: Asendorpf Jens B.
Published: October 2003

The utility of a configural type approach for predictions from personality is currently controversial. Configural types predict important personality correlates, but continuous dimensions based on the same data often fare much better in cross‐sectional head‐to‐head comparisons. However, many such comparisons can be considered unfair to the type approach, confound diverse differences between type and dimensional approaches, and rely only on cross‐sectional data. A sequence of analyses is reported that include fairer comparisons and deconfound differences due to the number of predictors, categorical versus dimensional predictors, dichotomized dimensions versus configural types, dimensional versus type criterion variables, and cross‐sectional versus longitudinal predictions. The results suggest incremental validity of configural types over dimensions only in a very few cases. Copyright © 2003 John Wiley & Sons, Ltd.
Novel N‐methylbenzothiazolium salts as hardeners for epoxy and acrylate monomers
Authors: Takahashi Eiji , Sanda Fumio , Yamamoto Takakazu , Endo Takeshi
Published: October 2003

Novel N‐methylbenzothiazolium salts [N‐methyl‐2‐benzylthiobenzothiazolium, N‐methyl‐2‐(4‐nitrobenzylthio)benzothiazolium, N‐methyl‐2‐(1‐ethoxycarbonylethylthio)benzothiazolium, and N‐methyl‐2‐methylthiobenzothiazolium hexafluoroantimonates] were synthesized by the reaction of the corresponding 2‐substituted benzothiazole with dimethylsulfate, followed by anion exchange with KSbF6. These benzothiazolium salts cationically polymerized an epoxy monomer by photoirradiation. They also polymerized an acrylate monomer via a photoradical process. The use of aromatic compounds such as 2‐ethyl‐9,10‐dimethoxyanthracene as photosensitizers was effective in enhancing the polymerization. These benzothiazolium salts also served as thermal cationic initiators. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3828–3837, 2003
Macrocycles. XXVIII. Cyclic poly(benzonitrile ether)s derived from bisphenol A
Authors: Kricheldorf Hans R. , Garaleh Mazen , Schwarz Gert
Published: October 2003

Bisphenol A was polycondensed with 2,6‐dichlorobenzonitrile, 2,6‐difluorobenzonitrile, 2,4‐difluorobenzonitrile, and 3,5‐difluorobenzonitrile in sulfolane. With 2,6‐and 2,4‐difluorobenzonitrile, quantitative conversions were achieved, and matrix‐assisted laser desorption/time‐of‐flight mass spectra revealed a nearly quantitative formation of cyclic oligoethers and polyethers. Furthermore, O,O′‐bistrimethylsilyl bisphenol A was polycondensed with the aforementioned dihalobenzonitriles in dry N‐methylpyrrolidone (promoted by potassium carbonate). Both the temperature and time were optimized. Only with 2,6‐difluorobenzonitrile were nearly quantitative conversions achieved, and this resulted in high molecular weights and high cycle contents. Size exclusion chromatography elution curves exhibited a tendency toward a bimodal character when larger fractions of cycles were present. Calibration with polystyrene standards indicated number‐average molecular weights of up to 105 Da and weight‐average molecular weights of up to 2.3 × 105 Da. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3838–3846, 2003
Synthesis and characterization of hyperbranched aromatic poly(ether imide)s with terminal amino groups
Authors: Chang Yao‐Te , Shu Ching‐Fong , Leu Chyi‐Ming , Wei Kung‐Hwa
Published: October 2003

We synthesized an AB2‐type monomer, 4‐{4‐[di(4‐aminophenyl)methyl]phenoxy}phthalic acid, which contained one phthalic acid group and two aminophenyl functionalities. The direct self‐polycondensation of the AB2‐type monomer in the presence of triphenylphosphite as an activator afforded a hyperbranched poly(ether imide) with a large number of terminal amino groups. This polymer was characterized with 1H NMR and IR spectroscopy. The degree of branching of the hyperbranched poly(ether imide) was approximately 56%, as determined by a combination of model compound studies and an analysis of 1H NMR spectroscopy integration data. The terminal amino groups underwent functionalization readily. The solubility and thermal properties of the resulting polymers depended on the nature of the chain end groups. In addition, the hyperbranched poly(ether imide) was grafted with polyhedral oligomeric silsesquioxane (POSS). Transmission electron microscopy analysis revealed that the grafted POSS molecules aggregated to form a nanocomposite material. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3726–3735, 2003
Synthesis and characterization of poly[phenyl(fluoroalkyloxaalkane)silanediyl]s
Authors: Zuev Vjacheslav V. , Skvortsov Nikolai K.
Published: October 2003

Monomeric fluoroalkoxyalkyl(phenyl)dichlorosilanes were synthesized with quantitative yields by hydrosilylation of allyl ethers of fluoroalcohols with phenyldichlorosilane with Pt(Ph3Sb)2Cl2 complex as a catalyst. Starting from these monomers, corresponding polysilanes with weight‐average molecular weights of 2–3 × 104 were obtained by the Wurtz reaction. Increasing the CF2 groups containing two to six monomer units caused the char yields to increase from 3 to 48% at 800 °C in air. The emission characteristics of these polysilanes in a chloroform solution were examined. They had a narrow peak at 344 nm with a small Stokes shift (≈20 nm). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3761–3767, 2003
Crosslinked poly(ester anhydride)s based on poly(ε‐caprolactone) and polylactide oligomers
Authors: Helminen Antti O. , Korhonen Harri , Seppälä Jukka V.
Published: October 2003

Resorbable poly(ester anhydride) networks based on ε‐caprolactone, L‐lactide, and D,L‐lactide oligomers were synthesized. The ring‐opening polymerization of the monomers yielded hydroxyl telechelic oligomers, which were end‐functionalized with succinic anhydride and reacted with methacrylic anhydride to yield dimethacrylated oligomers containing anhydride bonds. The degree of substitution, determined by 13C NMR, was over 85% for acid functionalization and over 90% for methacrylation. The crosslinking of the oligomers was carried out thermally with dibenzoyl peroxide at 120 °C, leading to polymer networks with glass‐transition temperatures about 10 °C higher than those of the constituent oligomers. In vitro degradation tests, in a phosphate buffer solution (pH 7.0) at 37 °C, revealed a rapid degradation of the networks. Crosslinked polymers based on lactides exhibited high water absorption and complete mass loss in 4 days. In ε‐caprolactone‐based networks, the length of the constituent oligomer determined the degradation: PCL5‐AH, formed from longer poly(ε‐caprolactone) (PCL) blocks, lost only 40% of its mass in 2 weeks, whereas PCL10‐AH, composed of shorter PCL blocks, completely degraded in 2 days. The degradation of PCL10‐AH showed characteristics of surface erosion, as the dimensions of the specimens decreased steadily and, according to Fourier transform infrared, labile anhydride bonds were still present after 90% mass loss. © 2003 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3788–3797, 2003
Dendrimers and other dendritic macromolecules: From building blocks to functional assemblies in nanoscience and nanotechnology
Authors: Fréchet Jean M. J.
Published: October 2003

Given their size, in the single‐digit nanometer range, and the versatility of their functionality, dendrimers and other dendritic macromolecules are poised to make a significant contribution to the rapidly expanding fields of nanoscience and nanotechnology. This highlight focuses on nascent applications of dendrimers that take advantage of their structural features and polyvalent character. In particular, the concept of dendritic encapsulation of function, borrowed from Nature, can be applied to the design of a varied array of energy‐harvesting, light‐emitting, or catalytic macromolecules. Similarly, the compact size and hierarchical ordering of components within dendrimers make them ideal for exploring the limits of nanolithography. Finally, the presence of differentiated functionalities and the polyvalent character of dendrons and dendrimers constitute strong assets for their use in polymer therapeutics. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3713–3725, 2003
Dispersion polymerization of styrene in carbon dioxide stabilized by copolymers of poly(propylene glycol) methacrylate and 2‐(perfluorooctyl)ethyl methacrylate
Authors: Ding Lunhan , Olesik Susan V.
Published: October 2003

The dispersion polymerization of styrene in carbon dioxide with a series of copolymers of poly(propylene glycol) methacrylate (PPGMA) and 2‐(perfluorooctyl)ethyl methacrylate (FOEMA) as the polymerization dispersants was examined. It was demonstrated that PPGMA and FOEMA copolymers and polymers containing 52–100% FOEMA could be used as effective dispersants for the polymerization, and the composition of the copolymeric dispersant had a dramatic effect on both the polymerization yield and the morphology of the resulting polystyrene. The effects of the concentrations of the copolymeric dispersants, the concentrations of the monomer, and the reaction pressure were also investigated. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3804–3815, 2003
Hyperbranched polymers as scaffolds for multifunctional reversible addition–fragmentation chain‐transfer agents: A route to polystyrene‐core‐polyesters and polystyrene‐block‐poly(butyl acrylate)‐core‐polyesters
Authors: Jesberger Martin , Barner Leonie , Stenzel Martina H. , Malmström Eva , Davis Thomas P. , Barner‐Kowollik Christopher
Published: October 2003

Polydisperse hyperbranched polyesters were modified for use as novel multifunctional reversible addition–fragmentation chain‐transfer (RAFT) agents. The polyester‐core‐based RAFT agents were subsequently employed to synthesize star polymers of n‐butyl acrylate and styrene with low polydispersity (polydispersity index < 1.3) in a living free‐radical process. Although the polyester‐core‐based RAFT agent mediated polymerization of n‐butyl acrylate displayed a linear evolution of the number‐average molecular weight (Mn) up to high monomer conversions (>70%) and molecular weights [Mn > 140,000 g mol−1, linear poly(methyl methacrylate) equivalents)], the corresponding styrene‐based system reached a maximum molecular weight at low conversions (≈30%, Mn = 45,500 g mol−1, linear polystyrene equivalents). The resulting star polymers were subsequently used as platforms for the preparation of star block copolymers of styrene and n‐butyl acrylate with a polyester core with low polydispersities (polydispersity index < 1.25). The generated polystyrene‐based star polymers were successfully cast into highly regular honeycomb‐structured microarrays. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3847–3861, 2003
Fragmentation pathways of sulphonamides under electrospray tandem mass spectrometric conditions
Authors: Klagkou Katerina , Pullen Frank , Harrison Mark , Organ Andy , Firth Alistair , Langley G. John
Published: October 2003

Sulphonamides are antibacterial compounds used extensively in farming and veterinary practice. Residues are commonly found in meat and milk. The growing concern about antibiotic resistance of bacteria led to a lowering of the legal concentration limits of sulphonamides in food. A range of analytical methods, employing tandem mass spectrometry (MS/MS) and selected reaction monitoring (SRM), have been developed to allow screening at the limit of detection (LOD) levels. Interest was drawn to the fragment ions produced by the sulphonamides, some involving complex rearrangements that have not previously been looked at. Here we report an investigation into the fragmentation pattern of sulphonamides under electrospray (ES) MS/MS conditions using ion trap and Fourier transform ion cyclotron resonance (FTICR) mass spectrometers. Structures are proposed for the main fragment ions observed for a range of sulphonamides, the effects of the functional groups in the dissociation pathway of the compounds are investigated, and the mechanisms leading to the main fragment ions are explored. Copyright © 2003 John Wiley & Sons, Ltd.
Comparing differentiation of xylene isomers by electronic ionization, chemical ionization and self‐ion/molecule reactions and the first observation of methyne addition ions for xylene isomers in self‐ion/molecule reactions for non‐nitrogenated compounds
Authors: Wu Hui‐Fen , Wu Wen‐Feng
Published: October 2003

This study presents the self‐ion/molecule reaction (SIMR) spectra of three xylene isomers, and proposes an approach to differentiating them based on observed differences in relative abundances of ions formed by SIMR in an internal source ion trap instrument. It also demonstrates the applicability of SIMR for isomer discrimination, which is better than electron ionization (EI) and dimethyl ether chemical ionization (DME CI) in an ion trap mass spectrometer (ITMS) since no CI reagent, metal ions or internal standards are required to perform SIMR. The merits of the new method for distinguishing isomers are that it is simple, rapid and economic. To date, methyne addition products ([M+13]+ ions) have been observed for several nitrogenated compounds including aza‐crown ethers, aniline and dopamine from SIMR in the ITMS. The xylene isomers are, however, the first three non‐nitrogenated compounds that have been shown to produce the methyne addition ions in SIMR. Copyright © 2003 John Wiley & Sons, Ltd.
A new deuterated alkylating agent for quantitative proteomics
Authors: Sebastiano Roberto , Citterio Attilio , Lapadula Marta , Righetti Pier Giorgio
Published: October 2003

Weakly basic molecules containing a double bond, such as 2‐ and 4‐vinylpyridine, are able to react and selectively alkylate –SH groups in proteins, thus preventing their re‐oxidation to disulphide bridges. In contrast to conventional alkylating agents such as iodoacetamide and non‐charged acrylamide derivatives, such molecules achieve 100% alkylation of all –SH residues, even in complex proteins, without reacting with other functional groups. Their use is particularly effective in proteome analysis and more generally for analyzing proteins in which the –SH groups should be blocked. Additionally, the use of vinylpyridines, partially or totally deuterated and thus with a mass difference compared with their non‐deuterated counterparts of 4–7 Da, allows studies of induction/repression of protein synthesis (quantitative proteomics). Copyright © 2003 John Wiley & Sons, Ltd.
Use of different proteases working in acidic conditions to improve sequence coverage and resolution in hydrogen/deuterium exchange of large proteins
Authors: Cravello Laetitia , Lascoux David , Forest Eric
Published: October 2003

The combination of hydrogen exchange and mass spectrometry has been widely used in structural biology, providing views on protein structure and protein dynamics. One of the constraints is to use proteases working at low pH and low temperature to limit back‐exchange during proteolysis. Although pepsin works in these conditions and is currently used in such experiments, sequence coverage is not always complete especially for large proteins, and the spatial resolution of the exchange rate is limited by the size of the resulting peptides. In this study we tried two other proteases, protease type XIII from Aspergillus saitoi and protease type XVIII from Rhizhopus species. The penicillin‐binding protein X (PBP‐2X*), a 77‐kDa protein, was selected as a model. Like pepsin, neither of these proteases is really specific, but we found very good reproducibility in the digestion pattern. Compared with using pepsin alone, combining the results of the three independent proteolyses increased the coverage for the peptide mapping, thus avoiding missing some potentially interesting regions of the protein. Furthermore, we obtained a better spatial resolution for deuterium incorporation data, specifying accurately the deuterated regions. Copyright © 2003 John Wiley & Sons, Ltd.
Atmospheric pressure photoionization mechanisms. 2. The case of benzene and toluene
Authors: Tubaro Michela , Marotta Ester , Seraglia Roberta , Traldi Pietro
Published: October 2003

Benzene and toluene have been proposed previously as dopants in atmospheric pressure photoionization (APPI) experiments on compounds exhibiting ionization energies higher than the energy of photons used for irradiation. Their low ionization energies lead to their easy photoionization and the ions so formed lead to the ionization of analytes through charge exchange. However, some measurements have shown that some protonation reactions also take place, and a series of experiments was undertaken to investigate this unexpected behavior. It was shown that, when benzene is irradiated in the APPI source, the odd‐electron molecular ions of phenol, diphenyl ether and phenoxyphenol are produced in high yield, together with protonated diphenyl ether and protonated phenoxyphenol. These results have been confirmed by deuterium labelling and MSn experiments. A possible mechanism is proposed, based on a radical attack by benzene molecular ions on oxygen molecules present inside the APPI source, analogous to that proposed in the literature for phenyl radicals. Similar results have been obtained with toluene, proving that APPI is able to activate a series of reactions leading to highly reactive species which are highly effective in promoting ionization of molecules with ionization energies higher than the photon energy. Copyright © 2003 John Wiley & Sons, Ltd.
Increasing sensitivity and decreasing spot size using an inexpensive, removable hydrophobic coating for matrix‐assisted laser desorption/ionisation plates
Authors: Owen Stacey J. , Meier Felix S. , Brombacher Stephan , Volmer Dietrich A.
Published: October 2003

Spot size reduction and increased detection sensitivity in matrix‐assisted laser desorption/ionisation (MALDI) of small molecules are accomplished by using an inexpensive and removable hydrophobic coating for MALDI targets, based on 3M Scotch Gard™ surface treatment. Several variations in sample preparation were explored, such as surface coating technique, identity of the matrix, solvent composition, and the type of metal support plate used. These were investigated on both uncoated and coated surfaces and their impact on spot size, crystal coverage, and sensitivity is presented here. Additionally, crystallisation behaviour obtained on coated plates is compared with that on uncoated plates using scanning electron microscope analysis. To demonstrate the potential of the new coating technique, erythromycin A and valinomycin are studied to determine the increase in detection sensitivity of coated plates in comparison to uncoated plates, and to reveal the suitability of the plates for application in combined high‐performance liquid chromatography/MALDI (HPLC/MALDI), where widely varying solvent compositions and droplet volumes are observed. It is shown that enhancements in detection sensitivities correlate very well with the achieved spot size reduction. The versatility of the coated plates is also exhibited by the ease of removing the surface layer, after which the plates can be rigorously cleaned without worry about damaging the hydrophobic surface, followed by a quick reapplication of new hydrophobic coating material. This makes the non‐polar coating superior to more expensive commercial hydrophobic‐coated targets, which are much more delicate to clean. Furthermore, cleaning and reapplication eliminate potential carry‐over effects and the easy application procedure also makes the fabrication of inexpensive, disposable MALDI targets readily possible. Copyright © 2003 John Wiley & Sons, Ltd.
Detection of peonidin and pelargonidin glycosides in black carrots (Daucus carota ssp. sativus var. atrorubens Alef.) by high‐performance liquid chromatography/electrospray ionization mass spectrometry
Authors: Kammerer Dietmar , Carle Reinhold , Schieber Andreas
Published: October 2003

Anthocyanins of black carrots (Daucus carota ssp. sativus var. atrorubens Alef.) were investigated by high‐performance liquid chromatography/electrospray ionization mass spectrometry. Besides the main compounds which have already been characterized in detail as cyanidin glycosides, six anthocyanins with m/z 757, 565, 595, 903, 933 and 903 were detected and unambiguously characterized as peonidin and pelargonidin glycosides, based on their fragmentation patterns. Peonidin and pelargonidin were identified after acid hydrolysis by comparison of the fragmentation patterns and retention times of the released aglycones with those of standard compounds. To the best of our knowledge this is the first report on anthocyanins in black carrots consisting of aglycones other than cyanidin. Copyright © 2003 John Wiley & Sons, Ltd.
Collection of selected reaction monitoring and full scan data on a time scale suitable for target compound quantitative analysis by liquid chromatography/tandem mass spectrometry
Authors: King Richard C. , Gundersdorf Richard , Fernández‐Metzler Carmen L.
Published: October 2003

A hybrid linear ion trap/triple quadrupole mass spectrometer was used to demonstrate the value of collecting full scan qualitative data during quantitative analysis of target compounds. We present examples of the additional information that can be obtained from plasma samples analyzed primarily for target compound concentrations. This information includes detection of circulating metabolites, dosing vehicle, interfering matrix components, and potential interfering drug conjugates. Additionally, the quantitative results from selected reaction monitoring (SRM) analysis and from combined full scan and SRM analysis (SRM/EMS) were compared. The quantitative data in both scan modes are acceptable in terms of sensitivity, accuracy and precision. One can conclude from this work that the hybrid linear ion trap/triple quadrupole mass analyzer can provide in a single analysis both useful qualitative data, and accurate and precise quantitative data from the samples routinely prepared and analyzed for target drug concentrations. Copyright © 2003 John Wiley & Sons, Ltd.
Sustainability development analysis of semi‐intensive shrimp farms in Sonora, México
Authors: González O. H. A. , Beltrán L. F. , Cáceres‐Martínez C. , Ramírez H. , Hernández‐Vazquez S. , Troyo‐Dieguez E. , Ortega‐Rubio A.
Published: October 2003

During the year 2000, 12 modified and five new sustainable development indicators (SDIs) were applied and a sustainable index (SI) was developed for 21 out of the 33 semi‐intensive shrimp farms in Sonora, Mexico, to measure their sustainable development. Farms 5, 7 and 19 showed the highest values in social indicators, farms 5, 7 and 19 in the economic indicators and farms 2, 3 and 4 in natural indicators. In contrast farms 9, 16 and 17 obtained the lowest values in social indicators, farms 3 and 11 in the economic indicators, and farms 9, 11 and 16 in natural indicators. In the SI, farm 9 obtained the lowest value, farm 20 the highest, and most farms values between 6 and 7. In Sonora most of the semi‐intensive shrimp farms avoided adverse impacts on the environment by constructing on salty or arid lands with no mangroves. Most of the projects are communal and benefits go directly to the population, giving Sonora, in comparison with other regions, a more sustainable development. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Greening the United Nations' Human Development Index?
Authors: Morse Stephen
Published: October 2003

The Human Development Index (HDI) introduced by the United Nations Development Programme (UNDP) in 1990 has helped facilitate widespread debate amongst development researchers, practitioners and policy makers. The HDI is an aggregate index, calculated on an annual basis by the UNDP and published in its Human Development Reports, comprising measures of three components deemed by them to be central to development: (i) income (the gross domestic product per capita), (ii) education (adult literacy rate) and (iii) health (life expectancy at birth).

The results of calculating the HDI are typically presented as country/regional league tables, and provide a quick means for policy makers and others to judge performance. Perhaps partly because of the relative simplicity of the index, the HDI has managed to achieve a level of acceptance and use amongst politicians and policy makers that has yet to emerge with any indicator of sustainability. Indeed, despite its existence for 11 years, including nine years after the Rio Earth Summit, the HDI has not even been modified to take on board wider issues of sustainability. This paper will critically examine the potential for ‘greening’ the HDI so as to include environmental and resource‐consumption dimensions. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Analysing the latency of World Wide Web applications
Authors: Ruddle Alan , Allison Colin , Nicoll R.
Published: October 2003

As the Web becomes increasingly used for routine social and economic interactions, the issue of interactive delay, as experienced by end‐users, has become an ongoing cause for concern. This paper reports on an approach of identifying and analysing the factors that contribute towards that delay. The evolution of a structured timing model is described, which forms the basis for decomposing delay into its constituent parts. The four high‐level components identified are the server, network, protocol and client. Methodologies for determining the contribution of each element are presented and their use is illustrated in a case study of the traffic associated with an operational distributed learning environment (DLE) serving six universities over a period of several months. Quality of service (QoS) is key to the success of DLEs and this includes an understanding of their relationship with the underlying networks and systems upon which they are built and deployed. Delay, as experienced by the end user, is one of the key QoS parameters for a DLE. The importance of developing an understanding of the nature of delay in a DLE is twofold: it informs decisions about where to target effort and resources in order to achieve improvements; and it provides techniques that can be used as the basis for an early‐warning and advisory system for QoS aware applications. The latter functionality is illustrated by a novel solution that modifies TCP's congestion avoidance algorithm for the benefit of interactive Web traffic. Copyright © 2003 John Wiley & Sons, Ltd.
Multi‐level modeling approach for the availability assessment of e‐business applications
Authors: Kaâniche M. , Kanoun K. , Rabah M.
Published: October 2003

This paper defines a multi‐level modeling approach for availability assessment of e‐business applications, based on two main steps: (1) hierarchical description of the system and its interactions with the users, from the functional and structural points of view, and (2) hierarchical construction and solution of the availability models based on information from the first step. Four modeling abstraction levels are considered. The highest level (user level) describes the availability of the e‐business application as perceived by the users. Intermediate levels describe the availability of functions and services provided to the users. The lowest level describes the availability of the component systems on which functions and services are implemented. The availability measures of a given level are computed based on the measures provided by the immediately lower level. Copyright © 2003 John Wiley & Sons, Ltd.
Design and implementation of Acceptance Monitor for building intrusion tolerant systems
Authors: Wang Rong , Wang Feiyi , Byrd Gregory T.
Published: October 2003

Intrusion detection research has so far concentrated on techniques that effectively identify the malicious behaviors. No assurance can be assumed once the system is compromised. Intrusion tolerance, however, focuses on providing minimal level of services, even when some components have been partially compromised. The challenges here are how to take advantage of fault tolerant techniques in the intrusion tolerant system context and how to deal with possible unknown attacks and compromised components so as to continue providing the service. This paper presents our work on applying one important fault tolerance technique, acceptance testing, for building scalable intrusion tolerant systems. First, we propose a general methodology for designing acceptance testing. An Acceptance Monitor architecture is proposed to apply various tests for detecting the compromises based on the impact of the attacks. Second, we make a comprehensive vulnerability analysis on typical commercial‐off‐the‐shelf (COTS) Web servers. Various acceptance testing modules are implemented to show the effectiveness of the proposed approach. By utilizing the fault tolerance techniques on intrusion tolerance system, we provide a mechanism for building reliable distributed services that are more resistant to both known and unknown attacks. Copyright © 2003 John Wiley & Sons, Ltd.
LYS2 gene and its mutation in Kluyveromyces lactis
Authors: Alberti Adriana , Ferrero Iliana , Lodi Tiziana
Published: October 2003

The KlLYS2 gene, encoding the α‐aminoadipate reductase of Kluyveromyces lactis, was isolated by complementation of a lysA1 mutant. The deduced amino acid sequence shared an identity of 73% with the LYS2 product of Saccharomyces cerevisiae. Despite the high sequence homology of the α‐aminoadipate reductase genes, the two yeast species differently responded to the presence of α‐aminoadipate in the medium. Wild‐type S. cerevisiae is known to be sensitive to α‐aminoadipate, but becomes resistant when mutated to lys2. In contrast, K. lactis strains were found to be naturally resistant to α‐aminoadipate. Therefore, the positive selection procedure for the isolation of lys2 mutants on α‐aminoadipate, as practised in S. cerevisiae, cannot be applied to K. lactis. A possible reason of this difference may be that the catalytic rate of the α‐aminoadipate reductase differs in the two yeasts. The EMBL/Genbank Accession No. for the KlLYS2 gene is AJ504405. Copyright © 2003 John Wiley & Sons, Ltd.
Negative regulation of phospholipid biosynthesis in Saccharomyces cerevisiae by a Candida albicans orthologue of OPI1
Authors: Heyken Willm‐Thomas , Wagner Christian , Wittmann Jürgen , Albrecht Antje , Schüller Hans‐Joachim
Published: October 2003

Structural genes of phospholipid biosynthesis in the yeast Saccharomyces cerevisiae are coordinately regulated by a UAS element, designated ICRE (inositol/choline‐responsive element). Opi1 is a negative regulator responsible for repression of ICRE‐dependent genes in the presence of an excess of inositol and choline. Gene regulation by phospholipid precursors has been also reported for the pathogenic yeast Candida albicans. Screening of a data base containing raw sequences of the C. albicans genome project allowed us to identify an open reading frame exhibiting weak similarity to Opi1. Expression of the putative CaOPI1 in an opi1 mutant of S. cerevisiae could restore repression of an ICRE‐dependent reporter gene. Similar to OPI1, overexpression of CaOPI1 strongly inhibited derepression of ICRE‐driven genes leading to inositol‐requiring transformants. Previous work has shown that Opi1 mediates gene repression by interaction with the pleiotropic repressor Sin3. The genome of C. albicans also encodes a protein similar to Sin3 (CaSin3). By two‐hybrid analyses and in vitro studies for protein–protein interaction we were able to show that CaOpi1 binds to ScSin3. ScOpi1 could also interact with CaSin3, while CaOpi1 failed to bind to CaSin3. Despite of some conservation of regulatory mechanisms between both yeasts, these results suggest that repression of phospholipid biosynthetic genes in C. albicans is mediated by a mechanism which does not involve recruitment of CaSin3 by CaOpi1. Copyright © 2003 John Wiley & Sons, Ltd.
Screening for new yeast mutants affected in mannosylphosphorylation of cell wall mannoproteins
Authors: Conde Raúl , Pablo Guadalupe , Cueva Rosario , Larriba Germán
Published: October 2003

We have carried out a screen of 622 deletion strains generated during the EUROFAN B0 project to identify non‐essential genes related to the mannosylphosphate content of the cell wall. By examining the affinity of the deletants for the cationic dye alcian blue and the ion exchanger QAE‐Sephadex, we have selected 50 strains. On the basis on their reactivity (blue colour intensity) in the alcian blue assay, mutants with a lower phosphate content than wild‐type cells were then arranged in groups defined by previously characterized mutants, as follows: group I (mnn6), group II (between mnn6 and mnn9) and group III (mnn9). Similarly, strains that behaved like mnn1 (i.e. a blue colour deeper than wild‐type) were included in group VI. To confirm the association between the phenotype and a specific mutation, strains were complemented with clones or subjected to tetrad analysis. Selected strains were further tested for extracellular invertase and exoglucanase. Within groups I, II and III, we found some genes known to be involved in oligosaccharide biosynthesis (ALG9, ALG12, HOC1), secretion (BRE5, COD4/COG5, VPS53), transcription (YOL072w/THP1, ELP2, STB1, SNF11), cell polarity (SEP7, RDG1), mitochondrial function (YFH1), cell metabolism, as well as orphan genes. Within group VI, we found genes involved in environmentally regulated transduction pathways (PAL2 and RIM20) as well as others with miscellaneous or unknown functions. We conclude that mannosylphosphorylation is severely impaired in some deletants deficient in specific glycosylation/secretion processes, but many other different pathways may also modulate the amount of mannosylphosphate in the cell wall. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of the genetic variability in the species of theSaccharomyces sensu strictocomplex
Authors: Teresa Fernández‐Espinar M. , Barrio Eladio , Querol Amparo
Published: October 2003

RandomamplifiedpolymorphicDNA–polymerasechainreaction (RAPD–PCR) analysis was applied to differentiate the sibling speciesSaccharomyces bayanus, S. cerevisiae, S. paradoxusandS. pastorianus,which constitute the most common strains of theSaccharomyces sensu strictocomplex. Six decamer primers of arbitrary sequences were used to amplify the DNA of 58 strains. Species‐specific (diagnostic) bands were obtained for each species. Two phylogenetic trees constructed by the neighbour‐joining and maximum parsimony methods clearly showed that the delimitation of these related yeast species is possible by using RAPD analysis. Four groups of strains, corresponding to the speciesS. bayanus, S. cerevisiae, S. paradoxusandS. pastorianus, were obtained. Within theS. bayanustaxon, two groups of strains were observed. One includes the former type strain ofS. uvarum, CECT1969T, and closely related wine strains (S. bayanusvar.uvarum), whilst the other containsS. bayanustype strain CECT1941Tand strains CECT1991 and 10513 (S. bayanusvar.bayanus). The heterogeneousS. paradoxusgroup was divided into three lineages, corresponding to different geographic origin, American, Japanese and European populations. In addition, due to the multilocus nature of the RAPD–PCR marker, this method is both useful and appropriate for the identification of the hybrid origin ofS. pastorianus. The hybrid nature was deduced from the analysis of the fraction of bands shared by each hybrid strain and the parental species. Among the 58 strains analysed, sixS. pastorianusstrains were hybrids, although the fraction of genome coming from each parent varied depending on the strain. Copyright © 2003 John Wiley & Sons, Ltd.
Axillary Dissection over the Years: Where To from Here?
Authors: Keshtgar M.R.S. , Baum M.
Published: October 2003

Management of the axilla in breast cancer patients has been a subject of intense debate and controversy. Axillary lymph node status is still considered to be the single most important prognostic indicator in breast cancer patients. Despite a tendency toward a conservative approach for the surgery of primary breast carcinoma, axillary lymph node dissection (ALND) has remained an integral part of breast cancer management for more than a century. Among patients with T1/T2 tumors, up to 70% have a negative axillary dissection, and more than 50% of these node‐negative patients develop morbidity related to ALND. It is ironic that the extent, morbidity, and cost of a staging procedure (ALND) is more than that of the surgical treatment of the primary tumor. We must readdress the question of axillary management in breast carcinoma in the light of information gained from the sentinel node biopsy trials around the world. We review the historical milestones and various modalities used for axillary management, discuss the concept of sentinel node biopsy for breast carcinoma, and propose a management plan.
Predicting Axillary Nodal Positivity in 2282 Patients with Breast Carcinoma
Authors: Silverstein Melvin J. , Skinner Kristin A. , Lomis Thomas J.
Published: October 2003

Asbtract

Axillary lymph node status continues to be the single most important prognostic variable for breast cancer survival despite significant progress in the molecular and genetic characterization of breast malignancies. All patients with invasive breast cancer who underwent axillary lymph node dissection as part of their treatment were evaluated by 11 clinical and pathologic factors, including the primary lesion’s T category (TNM staging system), whether the lesion was clinically palpable, the presence of lymphatic or vascular invasion, nuclear grade, estrogen and progesterone receptors, S‐phase, age, HER2/neu overexpression, histology (infiltrating lobular or ductal), and ploidy. A total of 2282 axillary dissections were performed: 391 in patients with ductal carcinoma in situ (DCIS) [3 of which (0.8%) contained metastases] and 1891 in patients with invasive breast cancer [680 of which (36%) contained metastases]. Multivariate analysis of patients with invasive cancer identified four factors as independent predictors of axillary lymph node metastases: lymph/vascular invasion, tumor size, nuclear grade, tumor palpability. Among a group of 189 patients with nonpalpable, non‐highgrade invasive lesions 15 mm or smaller without lymph/vascular invasion, only 6 (3%) had metastases to lymph nodes. If any three of the favorable factors were present, lymph node positivity was 6% or less. Clinical and pathologic feature of the primary lesions can be used to estimate the risk of axillary lymph node metastases. Such risk assessment can be used for the treatment decision‐making process.
Is Lymphatic Mapping in Breast Cancer Adequate and Safe?
Authors: Nieweg Omgo E. , Rutgers Emiel J.T. , Jansen Liesbeth , Valdes Olmos Renato A. , Peterse Johannes L. , Hoefnagel Kees A. , Kroon Bin B.R.
Published: October 2003

Lymphatic mapping with selective lymphadenectomy requires a concerted effort from the nuclear medicine physician, surgeon, and pathologist. Application of preoperative lymphoscintigraphy, and intraoperative use of both a gamma detection probe and a vital dye are recommended. This combined approach increases the likelihood of finding all sentinel nodes without removing nonsentinel nodes. A literature review of current experience reveals that the sentinel node can be found in more than 90% of the patients. When confirmatory lymphadenectomy follows, the false‐negative rate can be kept down to about 5% after a certain learning phase. The sensitivity of this novel approach to detect lymphatic dissemination is currently overestimated because lymph node metastases in patients with a tumor‐free sentinel node are probably overlooked. This shortcoming will be compensated by the more accurate pathologic evaluation of a sentinel node and the finding of sentinel nodes outside the axilla. Therefore the procedure is probably adequate and safe in patients at low risk of having disseminated disease. Lymphatic mapping with sentinel node biopsy is rapidly becoming the standard of care.
Lymphatic Mapping of the Breast: Locating the Sentinel Lymph Nodes
Authors: Uren Roger F. , Howman‐Giles Robert , Renwick Stuart B. , Gillett David
Published: October 2003

When the concept of sentinel lymph node biopsy was described in patients with melanoma, researchers quickly started to use lymphatic mapping techniques in breast cancer patients in an attempt to locate the sentinel node in the axilla. We have been performing mammary lymphoscintigraphy in this role for 6 years and have now studied 159 patients. Like others, we have found that most breast cancers (93%) have lymphatic drainage that includes the axilla, and we have found an average of 1.4 axillary sentinel nodes in these patients. Surgical biopsy of the axillary sentinel nodes accurately staged the node field in 96% of patients. We have also found, however, that the pattern of lymphatic drainage from the cancer site is unpredictable; and in 49% of patients lymphatic drainage occurred across the center line of the breast to axillary or internal mammary sentinel nodes. In more than half of our patients (56%) lymphatic drainage occurred to lymph nodes outside the axilla including the internal mammary (45%), supraclavicular (13%), and interpectoral and intramammary interval nodes (12%). These nodes are also sentinel nodes, and their presence indicates that a sentinel node biopsy procedure that stages only the status of the axillary lymph nodes has the potential to understage about half the patients with breast cancer. High quality lymphoscintigraphy allows accurate mapping of peritumoral lymphatic drainage in most patients with breast cancer. It is possible that in the future accurate nodal staging in each individual will involve biopsy of all sentinel lymph nodes, regardless of their location.
Extensive Frozen Section Examination of Axillary Sentinel Nodes to Determine Selective Axillary Dissection
Authors: Veronesi Umberto , Zurrida Stefano , Mazzarol Giovanni , Viale Giuseppe
Published: October 2003

As experience accumulates on the use of sentinel node biopsy in breast cancer, it is becoming clear that the method can reliably predict the state of the axilla and thus be used to decide whether to perform complete axillary dissection. Ongoing controlled trials will soon provide definitive evidence on the latter point. The key issue regarding sentinel node biopsy is pathologic evaluation of the biopsied node, which should be done intraoperatively whenever possible. In our initial experience with a conventional intraoperative frozen section method, the false‐negative rate was 19% compared to examination of permanent sections of the biopsied node. We therefore devised a new intraoperative method in which pairs of sections are obtained every 50 mm for the first 15 sections and every 100 mm for any remaining node, which essentially samples the entire node; the method takes about 40 minutes. Sentinel node metastases were found in 119 of 295 (40%) of T1N0 breast cancer patients examined by this new method. This high rate of positivity indicates that the new method is reliable. In all cases, metastases were identified on hematoxylin‐eosin (HE)‐stained sections, although in 4% of positive cases the HE sections were doubtful, and cytokeratin immunostaining on the adjacent section was useful for confirming malignancy. Of 295 patients, 8 (2.7%) had a negative sentinel node but another axillary node metastasis. In conclusion, we found that extensive intraoperative frozen section examination of sentinel nodes correctly predicts a metastasis‐free sentinel node in 95.4% of cases (negative predictive value), it is therefore suitable for identifying patients in whom axillary dissection might be avoided. Immunocytochemical staining for cytokeratins or other epithelial markers may be helpful for reducing the risk of missing micrometastatic foci.
Is There a Role for Selective Axillary Dissection in Breast Cancer?
Authors: Gemignani Mary L. , Borgen Patrick I.
Published: October 2003

Surgery is the most effective therapeutic intervention available for the treatment of breast cancer. It has been responsible for obtaining local control and long‐term disease‐free intervals in more patients over the past century than any other treatment modality. Trends toward earlier stage at diagnosis are likely to increase the importance of surgery and to secure its central role in the treatment of this disease. Unfortunately, during the 1990s the value of excellent local control of breast cancer has been minimized as the disease has come to be considered systemic from inception and as the results of adjuvant‐therapy trials in patients with early‐stage breast cancer have revealed survival advantages in patients receiving systemic therapy. Only rarely is it acknowledged that surgery alone achieves long‐term disease‐free states in 70% to 80% of all patients. At the core of this paradigmatic controversy is management of the axilla. The status of the axilla remains the most powerful predictor of outcome in patients with invasive carcinoma of the breast, and it is likely that a small but identifiable subset of patients obtains a survival benefit from the removal of disease‐containing nodes. It is believed that no benefit is derived from the removal of negative nodes, and indeed there are even patients in whom complete elimination of the exploration of the axilla may be considered—all of which underscores the need to investigate the axilla selectively. Lymphatic mapping and sentinel lymph node (SLN) biopsy represents the most exciting development to date toward this end. The challenge today, as we move closer to a selective approach to the axilla, is to ensure that patients with positive nodes have those nodes identified and removed and patients with negative nodes experience minimal disturbance of their axilla.