bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustained Off-Resonance Irradiation Collision-Induced Dissociation of Linear, Substituted and Cyclic Polyesters Using a 9.4 T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer
Authors: McDonnell Liam A. , Derrick Peter J. , Powell Brian B. , Double Philip
Published: May 2003

The fragment ions obtained from sustained off-resonance irradiation collision-induced dissociation of linear polyesters, substituted polyesters and cyclic polyesters have been characterized using a 9.4 T Fourier transform ion cyclotron resonance mass spectrometer. Charge-induced and charge-remote fragmentation channels, together with the participation of other nucleophilic groups, are proposed for the substituted polyesters. The linear polyesters were found to fragment at equivalent positions along the polymer chain whereas, under the experimental conditions employed, the cyclic polyester produced a single fragment.
Profiling of Cyclic Hexadepsipeptides Roseotoxins Synthesized In Vitro and In Vivo: A Combined Tandem Mass Spectrometry and Quantum Chemical Study
Authors: Jegorov Alexandr , Paizs Béla , Žabka Martin , Kuzma Marek , Havlíček Vladimír , Giannakopulos Anastassios E. , Derrick Peter J.
Published: May 2003

High-performance liquid chromatography and tandem mass spectrometry (HPLC/MS/MS) was used for the detection of cyclic hexadepsipeptides roseotoxins produced by Trichothecium roseum. Roseotoxins were found in both submerged standard cultivation on Czapek–Dox medium and in vivo cultivation extract obtained from an apple. Roseotoxin chromatographic profiles from these two experiments were compared. Product-ion collision-induced dissociation (CID) spectra obtained on an ion trap (electrospray ionisation, ESI) were used for the identification of natural roseotoxins A, B, C and of minor destruxins A and B. The dissociation behavior of roseotoxins is discussed in terms of a fragmentation scheme proposed for describing the dissociation pathways of cyclic peptides. This scheme involves opening of the cyclopeptide ring via formation of oxazolone derivatives and fragmentation of the resulting linear species, which have a free N-terminus and an oxazolone ring at the C-terminus. Some aspects of this fragmentation scheme are underlined by modeling the dissociation channels of roseotoxin A using quantum chemical calculations. The structures of roseotoxin A and destruxin B were verified by nuclear magnetic resonance (NMR) spectroscopy. Structures of three new minor natural roseotoxins [Val4]RosA, [MeLxx4]RosA and [MeLxx4]RosB were deduced by ion cyclotron resonance Fourier transform mass spectrometry (ICR-FT-MS) and ion trap tandem mass spectrometry by examining the pre-separated roseotoxin fraction.
The Automation of a Commercial Fourier Transform Mass Spectrometer to Provide a Quick and Robust Method for Determining Exact Mass for the Synthetic Chemist
Authors: Dykes Sarah , Fancy Sally-Ann , Perkins George L. , Pullen Frank S.
Published: May 2003

Automation of a commercially available Fourier transform ion cyclotron resonance (FTICR) mass spectrometer for the routine analysis of the synthetic products from high-speed chemistry is described. The automation includes software written by the instrument manufacturer as well as in-house-developed software that allows electronic submission of samples by the chemist and e-mailing of results back to the chemist. The use of samples of relatively high concentration (approx. 1 mg mL−1) is possible due to the protocol that has been developed, which includes dilution by the autosampler during sample injection. Though high concentrations are used for speed and convenience, the amount of sample consumed is still small at approx. 15 μg per injection. The results from this method have been shown to be both accurate (typical error range – 2.29 to 2.36 ppm, average error 1.07 ppm) and precise (standard deviation of the order of 0.3 ppm). The system is capable of analysing up to 800 samples per 24 hours. As high-speed chemistry becomes more highly utilised within Pfizer Discovery, the number of samples requiring accurate mass analysis will rise but the method we have described will prevent high-resolution mass spectrometry becoming the bottleneck in new chemical entity production. The accuracy and precision demonstrated by this method allows high confidence levels in assigned molecular formulae for expected compounds and reduces the number of possible formulae to consider when working with a compound that is not the desired product of a given reaction.
Analysis of Polypropyleneglycols Using Electrospray Ionization Mass Spectrometry. Effects of Cationizing Agents on the Mass Spectra
Authors: Okuno Shoji , Ohmoto Masayoshi , Arakawa Ryuichi
Published: May 2003

In electrospray ionization mass spectrometry (ESI-MS) of polypropyleneglycol (PPG), effects of cationizing agents were examined. When NaI was used as a cationizing agent, the distribution of multiply-charged ions in the spectra was greatly affected by the ratio of cationizing agent and PPG. However, the distribution was not affected by the use of CH3COONH4. With an increase of cone voltage, fragmentation occurred by in-source collision-induced dissociation (CID) when CH3COONH4 was used. On the contrary, no decomposition of the PPG backbone was observed with NaI. Instead, the intensity of the lower-charged ions, whose mass-to-charge ( m/z) ratios are larger, increased because of the elimination of Na+ with increase of cone voltage. Under optimum conditions for ESI-MS analysis, PPGs that have different molecular weights, different initiators or end groups were easily and accurately characterized. A tandem mass spectrometry (MS/MS) study of NH4+ adduct ions of PPG indicated that a vinyl-terminated linear structure is formed at the end group during the fragmentation.
Effects of Internal Hydrogen Bonds between Amide Groups: Protonation of Alicyclic Diamides
Authors: Witt Matthias , Kreft Dirk , Grützmacher Hans-Friedrich
Published: May 2003

The proton affinity ( PA) of cyclopentane carboxamide 1, cyclohexane carboxamide 2 and their secondary and tertiary amide derivatives S1, S2, T1 and T2, was determined by the thermokinetic method and the kinetic method [ PA(1) = 888 ± 5 kJ mol−1; PA(2) = 892 ± 5 kJ mol−1; PA(S1) = 920 ± 6 kJ mol−1; PA(S2) = 920 ± 6 kJ mol−1; PA(T1) = 938 ± 6 kJ mol−1; PA(T2) = 938 ± 6 kJ mol−1]. Special entropy effects are not observed. Additionally, the effects of protonation have been studied using an advanced kinetic method for all isomers 3–7 of cyclopentane dicarboxamides and cyclohexane dicarboxamides (with the exception of cis-cyclopentane-1,2-dicarboxamide) and their bis-tertiary derivatives T3–T7 by estimating the PA and the apparent entropy of protonation Δ(Δ Sapp). Finally, the study was extended to bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxamide 8 and its bis-tertiary derivative T8, to all stereoisomers of bicyclo[2.2.1]heptane-2,3-dicarboxamide 9, their secondary and tertiary amide derivatives S9 and T9, and to endo–endo–bicyclo[2.2.1]heptane-2,5-dicarboxamide 10 and the corresponding secondary and tertiary derivatives S10 and T10. Compared with 1 and 2, all alicyclic diamides exhibit a significant increase of the PA (ΔPA) and special entropy effects on protonation. For alicyclic diamides, which can not accommodate a conformation appropriate for building a proton bridge, the values of Δ PA and Δ(Δ Sapp) are small to moderate. This is explained by ion / dipole interactions between the protonated and neutral amide group which stabilize the protonated species but hinder the free rotation of the amide groups. If any of the conformations of the alicyclic diamide allows formation of a proton bridge, Δ PA and Δ(Δ Sapp) increase considerably. A spectacular case is cis-cyclohexane-1,4-dicarboxamide 7c which is the most basic monocyclic diamide, although generation of the proton bridge requires the unfavorable boat conformation with both amide substituents at a flagpole position. A pre-orientation of the two amide groups in such a 1,4-position in 10 results in a particularly large PA of < 1000 kJ mol−1. The observation of comparable values for Δ(Δ Sapp) for linear and monocyclic diamides indicates that a major part of the entropy effects originates from freezing the free rotation of the amide groups by formation of the proton bridge. This is corroborated by observing corresponding effects during the protonation of dicarboxamides containing the rigid bicyclo[2.2.1]heptane carbon skeleton, where the only internal movements of the molecules corresponds to rotation of the amide substituents.
Towards the Standard-Module Approach to Disulfide-Linked Polypeptide Nanostructures. I. Methodological Prerequisites and Mass Spectrometric Characterization of the Test Two-Loop Structure
Authors: Mirgorodskaya O.A. , Haselmann K.F. , Kjeldsen F. , Zubarev R.A. , Roepstorff P.
Published: May 2003

Potentially biologically-active nanostructures can be created from single chains of unmodified peptides by cross-linking different regions of the chain by disulfide bonds and cleaving the chain at specified sites to obtain the final configuration. The availability of techniques for assembly and characterization of such structures was tested on a two-loop structure created from a 21-residue linear peptide. Directed intra-molecular disulfide bond formation was performed by inserting partial sequences favoring intra-molecular S–S bond formation (“loops”) separated by partial sequences disfavoring such a process (“spacers”) into the precursor sequence. Peptide bond cleavage by partial acid hydrolysis at specific sites (GG, NP/DP) inside the loops opened them; the same process in the spacer separated the loops. Synthesis, oxidation and bond cleavage were monitored by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI ToF MS). The hydrolysis fragments of the produced nanostructures were characterized by tandem electrospray ionization Fourier transform mass spectrometry (ESI FT-MS) with collisional and electron capture dissociations. The latter technique was especially useful as it cleaves S–S bonds preferentially. The feasibility of the proposed synthesis approach and the adequacy of the analysis techniques for the test structure were demonstrated.
Review and analysis of incremental approaches to meeting the needs of the uninsured and under-insured
Authors: Rivers Patrick A.
Published: May 2003

The US healthcare delivery system, by all accounts, is the most advanced and sophisticated healthcare system in the world. Clinical advances in diagnostic and therapeutic regimens, superior performance in biomedical research, and the development and use of the latest management and medical technologies are all hallmarks of the system. While the US healthcare system has been extremely successful, concerns remain about access to care for a large segment of the population. This article examined the various approaches that have been adopted and those that are being proposed to bridge the existing gap in health insurance coverage. The underlying assumptions of the proposed strategies were examined, and the conditions necessary for the successful implementation of these strategies were also discussed.
Estimating winter evaporation in boreal forests with operational snow course data
Authors: Lundberg Angela , Koivusalo Harri
Published: May 2003

Snow course measurements from 11 sites located in eastern and northern Finland were used to estimate the total interception evaporation of a winter season for different forest categories. We categorized the sites based on forest density and tree species. Results showed that interception loss from gross precipitation increased with forest density and approached 30% for a forest with the highest density class. Interception loss for the most common forest density class was 11%. Interception losses were slightly larger in spruce forests than in pine, deciduous, or mixed forests. We provide suggestions as to how to design snow surveys to estimate wintertime interception evaporation better. Rough terrain and transition zones between forest and open areas should be avoided. Since evaporation fraction was strongly dependent on tree crown characteristics, snow course data should include direct estimates of canopy closure. Qualitative observations made by different observers should be given a reference frame to ensure comparability of records from different sites. Copyright © 2003 John Wiley & Sons, Ltd.
The effects of controlled drainage on subsurface outflow from level agricultural fields
Authors: Wesström Ingrid , Ekbohm Gunnar , Linnér Harry , Messing Ingmar
Published: May 2003

Daily outflow frequencies and recession curves were used to identify differences in storage–outflow relationships between two different drainage systems, conventional and controlled drainage. A three‐year (1996–1999) field drainage experiment was carried out on a loamy sand soil in southern Sweden. Plots with an area of 0·2 hectares were drained by conventional subsurface drainage (CD) or by controlled drainage (CWT1 and CWT2). The controlled drainage system allowed the groundwater level in the soil to be varied during the year. It was kept at least 70 cm below the soil surface during the growing season but allowed to rise to a maximum of 20 cm below the soil surface during the rest of the year. Measurements were performed to record precipitation, drain outflow and groundwater levels. Daily values of outflow were divided into 10 categories, based on the size of outflow. Recession curves of hourly measurement of outflow were selected. They behaved like single reservoirs and a linear storage–outflow model was applied. Least squares estimates of the parameters initial outflow, initial storage volume and retention constant were calculated.

Controlled drainage had a significant effect on total drain outflow and outflow pattern during the three years of measurement. The total drain outflow was 70% to 90% smaller in CWT than in CD. The analysis revealed that the initial outflows were higher, the retention constant and the temporary storage lower in CWT. The hydrological impacts of the reduction in temporary storage were higher peak flow, shorter lag time and shorter recession time and these effects increased with an increased groundwater level. Copyright © 2003 John Wiley & Sons, Ltd.
Evaluation and forecasting of daily groundwater outflow in a small chalky watershed
Authors: Lallahem S. , Mania J.
Published: May 2003

The purpose of this research is to include expert knowledge as one part of the modelling system and therefore offer the chance to create a productive interaction system between expert, mathematical model (MMO8) and artificial neural networks (ANNs). In the present project, the first objective is to determine some parameters by the MMO8 model, introduced as ANN input parameters to forecast spring outflow. The second objective is first to investigate the effect of temporal information by taking current and past data sets and then to forecast spring outflow. The good results obtained reveal the merit of the ANNs–MMO8 combination, and specifically multilayer perceptron (MLP) models. This methodology, for a network with lower, lag and number hidden layer, consistently produced better performance. Copyright © 2003 John Wiley & Sons, Ltd.
Hysteresis‐based analysis of overland metal transport
Authors: Mishra Surendra Kumar , Sansalone J. J. , Singh Vijay P.
Published: May 2003

Introducing a concept of equivalent mass depth of flow, this study describes the phenomenon of non‐point source pollutant (metal) transport for pavement (or overland) flow in analogy with wave propagation in wide open channels. Hysteretic and normal mass rating curves are developed for runoff rate and mass of 12 dissolved and particulate‐bound metal elements (pollutants) using the rainfall‐runoff and water quality data of the 15 × 20 m2 instrumented pavement in Cincinnati, USA. Normal mass rating curves developed for easy computation of pollutant load are found to be of a form similar to Manning's, which is valid for open channel flows. Based on the hysteresis analysis, wave types for dissolution and mixing of particulate‐bound metals are identified. The analysis finds that the second‐order partial‐differential equation normally used for metal transport does not have the efficacy to describe fully the strong non‐linear phenomena such as is described for various metal elements by dynamic waves. In addition, the proportionality concept of the popular SCS‐CN concept is extended for determining the potential maximum metal mass Mp of all the 12 elements transported by a rain storm and related to the antecedent dry period (ADP). For the primary metal zinc element, Mp is found to increase with the ADP and vice versa. Copyright © 2003 John Wiley & Sons, Ltd.
Distinctive features in the sex ratio of Japan's interprefectural migrants: an explanation based on the family system and spatial economy of Japan
Authors: Liaw Kao‐Lee
Published: May 2003

In the context of the general trends towards gender equality in major socioeconomic factors in Japan and other industrialised countries, this paper highlights and explains three distinctive features in the temporal pattern of the sex ratio of Japan's interprefectural migrants since the 1950s: a high level, an upward trend, and systematic fluctuations around the trend. The high level is explained by the ‘base camp’ nature and the ‘motherly principle’ of the Japanese family system, as well as the properties of the tightly‐knit groups that have been the basic functioning units of Japanese society. The upward trend is explained by a weakening of the Confucian superstructure and a strengthening of the motherly principle in the Japanese family system. The systematic fluctuations are explained by the major changes in Japan's spatial economy. Drawing upon the insights of major Japanese social thinkers, Hayao Kawai and Chie Nakane, this research infers that, relative to the females in Canada and probably other Western industrialised countries, women in Japan are more prone to forsake long‐distance migration as a means to achieve economic and career goals, so that they can enjoy closeness to their mothers and avoid the potentially negative consequences for their children of the whole family's long‐distance relocation. Copyright © 2003 John Wiley & Sons, Ltd.
International student migration and the European ‘Year Abroad’: effects on European identity and subsequent migration behaviour
Authors: King Russell , Ruiz‐Gelices Enric
Published: May 2003

This paper first draws attention to the scant literature in population geography on international student migration, or ISM. Yet students comprise an important element in global and European population mobility, especially of highly skilled movements. This study is set within the context of intra‐European ISM and looks specifically at the ‘Year Abroad experience’ which has been subsidised over the past 15 years by the Erasmus and Socrates programmes. Empirical data come from questionnaire surveys to three groups of University of Sussex students, surveyed during 2000–01. The main survey was a large postal survey to graduates who had spent a year abroad (YA) in another European country as part of their Sussex degree. This questionnaire was designed to test two sets of hypotheses: firstly that the YA had given students/graduates a more ‘European’ identity or consciousness, and a greater insight into European issues; and secondly that YA graduates would be more likely to pursue their subsequent career/migration paths in continental Europe. These hypotheses were tested against a control sample of Sussex graduates who had not been on a YA, matched by degree type and time of graduation. A third sample was undertaken with second‐year undergraduate students about to embark on their YA, in order to test pre‐ and post‐YA perspectives. The results broadly confirm the research hypotheses, although with a variety of nuances and outcomes. Copyright © 2003 John Wiley & Sons, Ltd.
Raman spectra of putrescine, spermidine and spermine polyamines and their N‐deuterated and N‐ionized derivatives
Authors: Amorim da Costa A. M. , Marques M. P. M. , Batista de Carvalho L. A. E.
Published: May 2003

The experimental and calculated Raman spectra of the N‐hydrogenated and N‐deuterated biogenic polyamines putrescine, spermidine and spermine and of their N‐hydrogenated and N‐deuterated hydrochloride salts in the 2000–3400 cm−1 spectral region (at distinct temperatures) are reported and analysed. A complete assignment of the N–H, C–H and N–D stretching modes is carried out, in the light of both steric and hydrogen‐bonding interactions on the conformational behaviour of these systems. Copyright © 2003 John Wiley & Sons, Ltd.
Surface adsorption of 4,4′‐dithiodipyridine and 2,2′‐dithiodipyridine on silver nanoparticles
Authors: Nogueira Helena I. S. , Cruz Sandra M. G. , Soares‐Santos Paula C. R. , Ribeiro‐Claro Paulo J. A. , Trindade Tito
Published: May 2003

A detailed vibrational study on the isomers 2,2′‐dithiodipyridine and 4,4′‐dithiodipyridine was carried out. These organic ligands are of great interest as possible linkers in the fabrication of nanostructures, and therefore a study on the adsorption modes of both ligands at silver surfaces is presented. Orientational information on the 2,2′‐dithiodipyridine and 4,4′‐dithiodipyridine molecules adsorbed on silver colloids was collected based on the SERS spectra and supported by ab initio calculations. There is evidence that both organic ligands adsorb on the silver surface through the sulfur atoms, with the aromatic rings in a tilted position. Copyright © 2003 John Wiley & Sons, Ltd.
Raman scattering investigation of cesium plumbochloride, CsPbCl3, phase transitions
Authors: Carabatos‐Nédelec C. , Oussaïd M. , Nitsch K.
Published: May 2003

We report a Raman scattering investigation of CsPbCl3 as a function of temperature in four different scattering configurations allowing us to obtain the various irreducible representations of the appropriate symmetry groups describing the substance in its successive phase transitions: cubic, tetragonal, orthorhombic and monoclinic or orthorhombic. We identify the correct ‘parentage’ of the observed modes with respect to infrared reflectivity data reported in the literature in accord with the Lyddane–Sachs–Teller relation, which was not fulfilled in previous assignments. We demonstrate the presence of strong correlation chains, which maintain the compound in a pseudo‐cubic state as far as x‐ray, infrared and Raman spectroscopy are concerned. The intensity of the related central peak was analysed on the basis of a Debye‐type relaxation as a function of temperature; the results show perfect correspondence of its variations and the temperatures of the phase transitions. In addition, an order–disorder phase transition is evidenced at low temperature, 193 K (−80 °C). Copyright © 2003 John Wiley & Sons, Ltd.
Raman spectroscopy with simultaneous measurement of two orthogonally polarized Raman spectra
Authors: Thomson G. A. , Baldwin K. J. , Batchelder D. N.
Published: May 2003

A Raman microscope was modified to allow the independent acquisition of two orthogonally polarized components of a Raman spectrum in a single measurement. Preliminary performance was demonstrated by simultaneously measuring the intensity of both polarized components of the silicon Raman band at 520 cm−1 as a silicon wafer was rotated through 360° under a polarized laser Raman probe. Polarization‐resolved Raman spectra of a complex molecular crystal are also presented, illustrating the increase in spectral information available with the modified system. Copyright © 2003 John Wiley & Sons, Ltd.
α‐Aminoxy acids as building blocks for the oxime and hydroxylamine pseudopeptide links. Application to the synthesis of human elastase inhibitors
Authors: Vanderesse Regis , Thevenet Laurent , Marraud Michel , Boggetto Nicole , Reboud Michele , Corbier Catherine
Published: May 2003

The aminoxy acids NH2O–C–αHRCO–2H are much more easily obtained in the enantiomerically pure form than the analogous hydrazino acids NH2NH–C–αHRCO–2H, and it has been shown that the isosteric amidoxy ψ[CO–NH–O] and hydrazide ψ[CO–NH–NH] amide surrogates induce two quite similar γ‐like folded structures. An aminoxy acid can also be N‐coupled to a peptide aldehyde to give the aldoxime ψ[CHNO–O] link or to a peptide ketone to form the ketoxime ψ[CRN O] link. The former can be further reduced into the hydroxylamine ψ[CH2NH–O] link which gives rise to reduced amidoxy peptides. The structural properties induced by these amide surrogates were studied, using IR and NMR spectroscopy, paying particular attention to the Z/E‐isomerism of the oxime link. In order to investigate their inhibitory potency, the three amide surrogates were introduced in the Pro3‐Val4 and Val4‐Ala5 position of Z‐Ala1‐Ala2‐Pro3‐Val4‐Ala5‐Ala6‐NHiPr, a substrate which is cleaved in the Val4‐Ala5 position by human leukocyte elastase (HLE). The [Val4ψ[CONH–O–]Ala5] analogue was still a substrate, while the [Pro3ψ[CONH–O–]Val4] and [Val4ψ[CHNO–]Ala5] pseudopeptides acted as HLE competitive inhibitors. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Dissecting the role of peptides in the immune response: theory, practice and the application to vaccine design
Authors: Purcell Anthony W. , Zeng Weiguang , Mifsud Nicole A. , Ely Lauren K. , Macdonald Whitney A. , Jackson David C.
Published: May 2003

Analytical biochemistry and synthetic peptide based chemistry have helped to reveal the pivotal role that peptides play in determining the specificity, magnitude and quality of both humoral (antibody) and cellular (cytotoxic and helper T cell) immune responses. In addition, peptide based technologies are now at the forefront of vaccine design and medical diagnostics. The chemical technologies used to assemble peptides into immunogenic structures have made great strides over the past decade and assembly of highly pure peptides which can be incorporated into high molecular weight species, multimeric and even branched structures together with non‐peptidic material is now routine. These structures have a wide range of applications in designer vaccines and diagnostic reagents. Thus the tools of the peptide chemist are exquisitely placed to answer questions about immune recognition and along the way to provide us with new and improved vaccines and diagnostics. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Efficient protocols for the synthesis of enantiopure γ‐amino acids with proteinogenic side chains
Authors: Loukas Vassilios , Noula Caterina , Kokotos George
Published: May 2003

The synthesis of enantiopure γ‐substituted γ‐amino acids with proteinogenic side chains, starting from the corresponding natural α‐amino acids, was studied. N‐Protected amino aldehydes containing various protective groups were prepared from the corresponding amino alcohols by oxidation with NaOCl in the presence of AcNH‐TEMPO and directly reacted with methyl, benzyl and tert‐butyl phosphoranylidene acetate to produce α, β‐unsaturated γ‐amino esters. Simultaneous hydrogenation of the double bond and removal of either the benzyl or benzyloxycarbonyl group led to N‐ or C‐protected γ‐amino acids in high yield. The enantiomeric purity was studied by 1H NMR analysis of Mosher amides and chiral HPLC analysis. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Motivic cohomology and unramified cohomology of quadrics
Authors: Kahn Bruno , Sujatha Ramdorai
Published: May 2003

Abstract. This is the last of a series of three papers where we compute the unramified cohomology of quadrics in degree up to 4. Complete results were obtained in the two previous papers for quadrics of dimension h4 and S11. Here we deal with the remaining dimensions between 5 and 10. We also prove that the unramified cohomology of Pfister quadrics with divisible coefficients always comes from the ground field, and that the same holds for their unramified Witt rings. We apply these results to real quadrics. For most of the paper we have to assume that the ground field has characteristic 0, because we use Voevodsky's motivic cohomology.
A new proof of Fréchet differentiability of Lipschitz functions
Authors: Lindenstrauss Joram , Preiss David
Published: May 2003

Abstract. We give a relatively simple (self-contained) proof that every real-valued Lipschitz function on Ê2 (or more generally on an Asplund space) has points of Fréchet differentiability. Somewhat more generally, we show that a real-valued Lipschitz function on a separable Banach space has points of Fréchet differentiability provided that the w* closure of the set of its points of Gâteaux differentiability is norm separable.
On a stratification of the moduli of K3 surfaces
Authors: van der Geer Gerard , Katsura Toshiyuki
Published: May 2003

In this paper we give a characterization of the height of K3 surfaces in characteristic

p>0

. This enables us to calculate the cycle classes in families of K3 surfaces of the loci where the height is at least

h

. The formulas for such loci can be seen as generalizations of the famous formula of Deuring for the number of supersingular elliptic curves in characteristic

p

. In order to describe the tangent spaces to these loci we study the first cohomology of higher closed forms.
Homogenization of a boundary condition for the heat equation
Authors: Filo Ján , Luckhaus Stephan
Published: May 2003

Abstract. An asymptotic analysis is given for the heat equation with mixed boundary conditions rapidly oscillating between Dirichlet and Neumann type. We try to present a general framework where deterministic homogenization methods can be applied to calculate the second term in the asymptotic expansion with respect to the small parameter characterizing the oscillations.
Some examples of 5 and 7 descent for elliptic curves over Q
Authors: Fisher Tom
Published: May 2003

We perform descent calculations for the families of elliptic curves over Q with a rational point of order n = 5 or 7. These calculations give an estimate for the Mordell-Weil rank which we relate to the parity conjecture. We exhibit explicit elements of the Tate-Shafarevich group of order 5 and 7, and show that the 5-torsion of the Tate-Shafarevich group of an elliptic curve over Q may become arbitrarily large.
Gaussian model selection
Authors: Birgé Lucien , Massart Pascal
Published: May 2003

Our purpose in this paper is to provide a general approach to model selection via penalization for Gaussian regression and to develop our point of view about this subject. The advantage and importance of model selection come from the fact that it provides a suitable approach to many different types of problems, starting from model selection per se (among a family of parametric models, which one is more suitable for the data at hand), which includes for instance variable selection in regression models, to nonparametric estimation, for which it provides a very powerful tool that allows adaptation under quite general circumstances. Our approach to model selection also provides a natural connection between the parametric and nonparametric points of view and copes naturally with the fact that a model is not necessarily true. The method is based on the penalization of a least squares criterion which can be viewed as a generalization of Mallows'

C_p

. A large part of our efforts will be put on choosing properly the list of models and the penalty function for various estimation problems like classical variable selection or adaptive estimation for various types of

l_p

-bodies.
Pruning theory and Thurston's classification of surface homeomorphisms
Authors: de Carvalho André , Hall Toby
Published: May 2003

Two dynamical deformation theories are presented - one for surface homeomorphisms, called pruning, and another for graph endomorphisms, called kneading - both giving conditions under which all of the dynamics in an open set can be destroyed, while leaving the dynamics unchanged elsewhere. The theories are related to each other and to Thurston's classification of surface homeomorphisms up to isotopy.
Group therapy for somatization disorders in primary care: maintenance of treatment goals of short cognitive‐behavioural treatment one‐and‐a‐half‐year follow‐up
Authors: Lidbeck J.
Published: May 2003

Objective:  The objective of this study was to evaluate the maintenance of treatment goals of a short cognitive‐behavioural group treatment programme for the management of somatization disorders in primary care.

Method:  In a previous controlled 6‐month follow‐up study, patients with somatization disorders (n=32) improved with respect to illness and somatic preoccupation, hypochondriasis, and medication usage. In the present report the same group of patients were also investigated one‐and‐a‐half year after initial treatment.

Results:  The long‐term follow‐up manifested maintained improvement with respect to hypochondriasis. There was additional reduction of anxiety and psychosocial preoccupation, whereas somatization and depression‐anxiety scores improved progressively.

Conclusion:  A short cognitive‐behavioural group treatment of psychosomatic patients can be useful in primary care and may manifest maintained or progressive beneficial outcome.
User involvement in the planning and delivery of mental health services: a cross‐sectional survey of service users and providers
Authors: Crawford M. J. , Aldridge T. , Bhui K. , Rutter D. , Manley C. , Weaver T. , Tyrer P. , Fulop N.
Published: May 2003

Objective: To identify methods for involving service users in the planning and delivery of psychiatric services and factors which may assist and impede this process.

Method: A cross‐sectional postal survey of user groups and providers of psychiatric services throughout Greater London (UK).

Results: Seventeen (94%) service providers and 29 (48%) user groups responded to the survey. Service providers employed a wide variety of different methods for involving users but none met national standards for user involvement (UI). Service providers stated that the main obstacle to UI was that users who took part were not representative of local patients. User groups highlighted staff resistance as a major obstacle and 80% stated that they were not satisfied with current arrangements for UI.

Conclusion: While users and providers of mental health services were able to identify changes resulting from UI the responsiveness of staff and the representativeness of service users may be impeding this process.
Integrated care in schizophrenia: a 2‐year randomized controlled study of two community‐based treatment programs
Authors: Malm U. , Ivarsson B. , Allebeck P. , Falloon I. R. H.
Published: May 2003

Objective:  To evaluate the efficacy of two community‐based programs that combined antipsychotic medication, family interventions and social skills training.

Method:  A randomized controlled trial with 2 years follow‐up. The study included 84 patients with schizophrenic disorders, continuously managed in terms of care and treatment, and regularly assessed. Analysis was by intention‐to‐treat.

Results:  Between‐program comparisons showed significantly improved social function and consumer satisfaction in favour of the program ‘Integrated Care’ (IC) at the 2‐year follow‐up. The main clinically important differences between the two treatment programs studied were the procedures for shared decision making and patient empowerment in IC.

Conclusion:  The implementation of IC in clinical practice can improve social recovery and increase consumer satisfaction for patients with schizophrenic disorders. We identified specific procedures that might be added to improve the effectiveness of any program for severely mental ill people.
Does co‐morbid personality disorder increase the risk of suicidal behaviour in psychosis?
Authors: Moran P. , Walsh E. , Tyrer P. , Burns T. , Creed F. , Fahy T.
Published: May 2003

Objective: To examine the association between co‐morbid personality disorder (PD) and suicidal behaviour over a 2‐year period in a sample of patients with psychosis.

Method: A total of 670 patients with established psychotic illness were interviewed using a battery of instruments including a screen for co‐morbid PD. The prevalence of attempted and completed suicide was measured over the next 2 years using multiple data sources. Logistic regression was used to examine whether those with co‐morbid PD were at greater risk of suicidal behaviour compared with others.

Results: One hundred and eighty six patients (28%) were rated as having a co‐morbid PD. After adjusting for all covariates, patients with co‐morbid PD were significantly more likely to attempt or complete suicide over the 2‐year period (adjusted odds ratio: 1.87; 95% CI: 1.02–3.42).

Conclusion: Co‐morbid PD is independently associated with an increased risk of suicidal behaviour in psychosis. Early assessment of personality status should be part of the routine assessment of all psychiatric patients.
Suicide attempts among patients with psychosis in a Chinese rural community
Authors: Ran Mao‐Sheng , Lai‐Wan Chan Cecilia , Xiang Meng‐Ze , Wu Qiu‐Hua
Published: May 2003

Objective:  To explore the characteristics of psychotic patients with suicide attempts in a Chinese rural community.

Method:  An epidemiological investigation of psychotic patients with suicide attempts among 123 572 population (over 15 years of age) was conducted in Xinjin County, Chengdu.

Results:  The rate of suicide attempts was found to be 8.17% among all the psychotic patients (906 cases). Patients with affective psychosis showed a significantly higher rate of suicidal attempts (15.3%) than those with schizophrenia (7.5%) (P < 0.005). Suicide attempts were significantly associated with depression and hopelessness in both schizophrenia and affective psychosis (P < 0.001). Patients with suicide attempts were younger and had an earlier age of onset than those without suicide attempts (P < 0.05). Patients with schizophrenia and affective disorders were the major patients with suicide attempts.

Conclusion:  The rate of suicide attempts in psychotic patients may be largely influenced by the illness itself. Community‐based services should be necessary for these patients.
A systematic review of powered vs. manual toothbrushes in periodontal cause‐related therapy
Authors: Sicilia A. , Arregui I. , Gallego M. , Cabezas B. , Cuesta S.
Published: May 2003

Background:  Power‐driven toothbrushes (PDT) have been designed to improve the efficacy of oral hygiene. It is not clear how they compare in efficacy with manual toothbrushes in cause‐related periodontal therapy.

Objectives:  To evaluate the effectiveness of the use of a PDT as compared with a manual toothbrush (MT), in terms of gingival bleeding or inflammation resolution, in cause‐related periodontal therapy.

Material and methods:  An electronic (MEDLINE and Cochrane Oral Health Group Specialised Trials Register) and a manual search were made to detect studies which permitted the evaluation of the efficacy of PDT in the reduction of gingival bleeding or inflammation, and their effect on other secondary variables. Only randomized studies in adults, published in English up to June 2001, which compared a PDT with an MT, and evaluated the evolution of gingival bleeding or inflammation were included. The selection of articles, extraction of data and assessment of validity were made independently by several reviewers.

Results:  Twenty‐one studies were finally selected. The heterogeneity of the data prevented a quantitative analysis. A higher efficacy in the reduction of gingival bleeding or inflammation in the PDT patients was detected in 10 studies. This effect appears to be related to the capacity to reduce plaque, and is more evident in counter‐rotational and oscillating‐rotating brushes. No solid evidence was found for a higher efficacy of sonic brushes. In short‐term studies with prophylaxis after initial examination, independently of the type of PDT tested, no significant differences were found.

Conclusion:  The use of PDT, especially counter‐rotational and oscillating‐rotating brushes, can be beneficial in reducing the levels of gingival bleeding or inflammation. There is a need for methodological homogeneity in future studies in this field to enable quantitative analysis of their results.
A systematic review on the use of residual probing depth, bleeding on probing and furcation status following initial periodontal therapy to predict further attachment and tooth loss
Authors: Renvert S. , Persson G. R.
Published: May 2003

Background:  Chronic periodontitis affects many adults. Initial cause related therapy (ICRT) is aimed at elimination of factors causing disease progression.

Objectives:  To use a systematic review process of peer reviewed publications to assess the predictive value of residual probing depths (PD), bleeding on probing (BOP) and furcation involvement (FI) in determining further loss of attachment and tooth loss following ICRT.

Material and Methods:  An electronic search of the Cochrane Oral Health Group specialized register, MEDLINE and EMBASE, was performed using specific search terms to identify studies assessing the predictive value of residual probing depths (PD), bleeding on probing (BOP) and furcation involvement (FI) in determining further loss of attachment and tooth loss following ICRT.

Results:  The searches resulted in 941 uniquely identified studies. Titles and abstracts were then independently screened by two reviewers (S.R. and G.R.P.) to identify publications that met specific inclusion criteria. The agreement between the reviewers was assessed and statistical analysis failed to demonstrate a difference between the two reviewers (κ‐value: 0.94, P = 0.003). Detailed review of 47 included publications resulted in acceptance of one publication which utilized data based on patient as unit of observation. This study included 16 subjects over 42 months demonstrating that residual probing depths are predictive of further disease progression whereas persisting bleeding on probing are not.

Conclusions:  Data based on one study suggest that residual probing depths are predictive of further disease progression. The implications for carefully designed multicentre randomized clinical control trials are many.
A systematic review of the prevalence of root sensitivity following periodontal therapy
Authors: Von Troil Birgitta , Needleman Ian , Sanz Mariano
Published: May 2003

Objectives:  To systematically review the evidence on the prevalence of root sensitivity following periodontal therapy.

Material and Methods:  Cross‐sectional and longitudinal clinical studies were searched for in electronic databases, hand searched journals and through contact with authors directly. The screening and data extraction were conducted by several reviewers independently. The main outcome measure was prevalence of root sensitivity following periodontal therapy.

Results:  The prevalence of root sensitivity was 9–23% before and 54–55% after periodontal therapy. An increase in the intensity of root sensitivity occurred 1–3 weeks following therapy, after which it decreased.

Conclusions:  It is concluded that there are insufficient randomized controlled trials to adequately address the stipulated question. However, based on the scarce evidence from only two studies, root sensitivity occurs in approximately half of the patients following subgingival scaling and root planing. The intensity of root sensitivity increases for a few weeks after therapy, after which it decreases. In clinical practice, it may be recommended that patients should be made aware of the potential for root sensitivity prior to treatment. In research, it may be recommended to conduct randomized controlled and prospective studies with both short and long follow‐up periods. Furthermore, to investigate the effects and the relationship of root instrumentation with the aetiology of root sensitivity, the efficacy of preventive and therapeutic regimes for root sensitivity, and the incidence and severity of root sensitivity by subjective patient‐reporting, and the response to different modes of stimuli. Protocols should follow the criteria used in dentine hypersensitivity studies.
Periodontal plastic surgery for treatment of localized gingival recessions: a systematic review
Authors: Roccuzzo Mario , Bunino Marco , Needleman Ian , Sanz Mariano
Published: May 2003

Background:  The evidence for the efficacy of periodontal plastic surgery (PPS) in the treatment of recession defects has not yet been systematically evaluated. The objective of this review was to systematically review the efficacy of PPS in achieving root coverage in the treatment of localized gingival recession. The following surgical procedures have been considered in this review: guided tissue regeneration (GTR), free gingival graft (FGG), connective tissue graft (CTG), and coronally advanced flap (CAF).

Methods:  Randomized and controlled trials, as well as case series of at least 6 months' follow‐up, were searched. Data sources included electronic databases and hand‐searched journals. Screening, data abstraction and quality assessment were conducted independently and in duplicate.

Results:  Regarding recession reduction, a limited but statistically significant greater benefit was found for CTG compared with GTR (weighted mean difference: 0.43 mm, 95% CI: 0.62–0.23). No differences were found comparing either GTR with CAF or resorbable versus non‐resorbable GTR barriers. Gain in attachment was also similar for each of the three comparisons. Analysis of single arms of trials and case series demonstrated that PPS can have a marked improvement on clinical parameters but heterogeneity was often high and only partly explained by initial defect depth.

Conclusions:  Overall, PPS was effective in reducing gingival recessions with a concomitant improvement in attachment levels. Even though no single treatment can be considered superior to all the others, CTG was statistically significantly more effective than GTR in recession reduction. Further research is needed to identify the factors most associated with successful outcomes.