bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Approaches to Fused Phospha‐Pyrimidines.
Authors: Volochnyuk Dmitriy M. , Kovaleva Svetlana A. , Chernega Alexandr N. , Chubaruk Nataliya G. , Kostyuk Alexandr N. , Pinchuk Alexandr M. , Tolmachev Andrey A. , Schmutzler Reinhard
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Design and Evaluation of New Antipsoriatic Antedrug Candidates Having 16‐en‐22‐oxa‐Vitamin D3 Structures.
Authors: Shimizu Kazuki , et al. et al.
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Structure—Activity Relationship Studies on UK‐2A, a Novel Antifungal Antibiotic from Streptomyces sp. 517‐02. Part 5. Roles of the 9‐Membered Dilactone‐Ring Moiety in Respiratory Inhibition.
Authors: Usuki Yoshinosuke , Adachi Noriko , Fujita Ken‐Ichi , Ichimura Akio , Iio Hideo , Taniguchi Makoto
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Design, Synthesis, and Evaluation of Novel Kazusamycin A Derivatives as Potent Antitumor Agents.
Authors: Ando Ryoichi , Amano Yusaku , Nakamura Hideo , Arai Noriyoshi , Kuwajima Isao
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Alkali and Coinage Metals
Authors: Boss S. R. , Wheatley A. E. H.
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Challenges in Fullerene Chemistry
Authors: Martin Nazario
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Modified Steroids in the Androstane and Androstene Series
Authors: Stephan Elie
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Multisubstituted Olefins: Platform Synthesis and Applications to Materials Science and Pharmaceutical Chemistry
Authors: Itami Kenichiro , Yoshida Jun‐ichi
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Chemistry of Disilyne with a Genuine Si—Si Triple Bond: Synthesis, Structure, and Reactivity
Authors: Sekiguchi Akira , Ichinohe Masaaki , Kinjo Rei
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Meldrum′s Acid in Multicomponent Reactions: Applications to Combinatorial and Diversity‐Oriented Synthesis.
Authors: Gerencser Janos , Dorman Gyoergy , Darvas Ferenc
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalytic Asymmetric Fluorinations
Authors: Bobbio Carla , Gouverneur Veronique
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Fluorine‐Containing Heterocycles. Part 4. Electrochemical Fluorination of Heterocyclic Compounds
Authors: Furin Georgii G.
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Supramolecular Synthesis of 1D Chains and 2D Layers in Hydrogen Bond Networks of Ureas and 2‐Pyrimidinones
Authors: Nangia Ashwini
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
exo‐Glycal Chemistry: General Aspects and Synthetic Applications for Biochemical Use
Authors: Lin Chun‐Hung , Lin Hui‐Chang , Yang Wen‐Bin
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Use of N‐Heterocyclic Carbenes as Ligands in Palladium‐Mediated Catalysis
Authors: Viciu Mihai S. , Nolan Steven P.
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Chemistry of Phosphorus
Authors: Bryant David
Published: August 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
On the representation of linear system time‐varying half‐line maps
Authors: Sandberg Irwin W.
Published: August 2006

An expression is given for the most general continuous causal linear input–output map that takes the space of (Lebesgue) integrable functions into itself. This expression is a function‐space limit of an integral. As an application, a representation result is given for an important family of linear maps that take the space of bounded measurable functions into itself and satisfy a certain continuity condition. Some related material concerning engineering education is also given. Copyright © 2006 John Wiley & Sons, Ltd.
Performance of low density parity check coded continuous phase frequency shift keying (LDPCC‐CPFSK) over fading channels
Authors: Hekim Yesim , Odabasioglu Niyazi , Ucan Osman N.
Published: August 2006

In this paper, in order to improve bit error performance, bandwidth efficiency and reduction of complexity compared to related schemes such as turbo codes, we combine low density parity check (LDPC) codes and continuous phase frequency shift keying (CPFSK) modulation and introduce a new scheme, called ‘low density parity check coded‐continuous phase frequency shift keying (LDPCC‐CPFSK)’. Since LDPC codes have very large Euclidean distance and use iterative decoding algorithms, they have high error correcting capacity and have very close performances to Shannon limit. In all communication systems, phase discontinuities of modulated signals result extra bandwidth requirements. Continuous phase modulation (CPM) is a powerful solution for this problem. Beside CPM provides good bandwidth efficiency; it also improves bit error performance with its memory unit. In our proposed scheme, LDPC and CPFSK, which is a special type of CPM, are considered together to improve both error performance and bandwidth efficiencies. We also obtain error performance curves of LDPCC‐CPFSK via computer simulations for both regular and irregular LDPC code. Simulation results are drawn for 4‐ary CPFSK, 8‐ary CPFSK and 16‐ary CPFSK over AWGN, Rician and Rayleigh fading channels for maximum 100 iterations, while the frame size is chosen as 504. Copyright © 2006 John Wiley & Sons, Ltd.
The patient's view on quality of life and eating disorders
Authors: de la Rie Simone , Noordenbos Greta , Donker Marianne , van Furth Eric
Published: August 2006

Objective:

This study investigated the personal views of eating disorder (ED) patients on their quality of life (QOL).

Method:

The views of 146 current ED patients and 146 former ED patients on their QOL were studied using a self‐report questionnaire. Patients were requested to name the most important aspects of their life and they subsequently rated themselves on these aspects. Qualitative analysis clustered items into meaningful categories.

Results:

A sense of belonging was mentioned most often (93.0%) by the participants. Work or education, health and well‐being were also mentioned frequently. Furthermore, participants stated a sense of self, disease‐specific psychopathology, life skills, leisure activities, a sense of purpose, financial situation, living condition, and pets. Current ED patients more frequently mentioned disease‐specific psychopathology than former ED patients. Current ED patients reported poor QOL on most domains, particularly on self‐image and well‐being. Former ED patients reported better QOL than current ED patients, but ratings were just above average.

Conclusion:

The views on QOL of ED patients broadens the scope of relevant domains of QOL. The assessment of these views may be a useful adjunct to the use of standardized QOL measures. © 2006 by Wiley Periodicals, Inc. Int J Eat Disord 2006
Titanium(IV) Complexes of Hydrazones and Azines
Authors: Davidson Matthew G. , Johnson Andrew L. , Jones Matthew D. , Lunn Matthew D. , Mahon Mary F.
Published: August 2006

The coordination modes of various azines (C=N–N=C) and hydrazones (C=N–NR2) with titanium(IV) are investigated. Five ligands were studied, two hydrazones 1H–2H and three azines 3H2–5H2, and it was found that hydrazones form monomers and azines form dimers in the solid state. The hydrogen‐bonded arrays observed for the hydrazones were significantly different for the two ligands, with one forming a ribbon like structure and the other a chain. For the azines the supramolecular structures are also discussed. A pronounced twist is observed in the azine ligand upon complexation to the metal centre, which is rationalised in terms of the favourable interactions observed in the solid‐state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Norstatines from Aldehydes by Sequential Organocatalytic α‐Amination and Passerini Reaction
Authors: Umbreen Sumaira , Brockhaus Manfred , Ehrenberg Helmut , Schmidt Boris
Published: August 2006

The combination of the enantioselective, organocatalytic α‐amination of aldehydes by diazodicarboxylates and the Passerini reaction provides rapid access to norstatine‐based peptidomimetics. These intermediates were elaborated further by deprotection and cleavage of the N–N bond to provide useful building blocks for aspartic protease inhibitors. Coupling of the compounds 76–86 with the mono‐isophthalamide 91 provided moderate inhibitors of human β‐secretase (BACE) 92–102. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Why people resort to coercion: the role of utility and legitimacy
Authors: van Knippenberg Barbara , van Knippenberg Daan , De Cremer David
Published: August 2006

This study focuses on why people may resort to coercive tactics. We tested the proposition that considerations of utility and legitimacy mediate effects of a powerholder's competence and reward structure on the use of coercion. Results showed that in general coercive tactics are employed less often than softer tactics, that coercive tactics are used more by more competent individuals than by less competent individuals, and that coercive tactics are used more often when the revenues of task performance benefited the agent of power than when they benefited both agent and target or when they benefited the target solely. Results identified perceived utility and perceived legitimacy as mediators of the decision to coerce the other or not. Copyright © 2006 John Wiley & Sons, Ltd.
Ultrasensitive native fluorescence detection of proteins with miniaturized polyacrylamide gel electrophoresis by laser side‐entry excitation
Authors: Zhang Hui , Yeung Edward S.
Published: August 2006

Direct detection of separated proteins inside polyacrylamide gels has many advantages compared to staining methods. Ultrasensitive native fluorescence detection of proteins with miniaturized 1‐D and 2‐D PAGE was achieved with laser side‐entry excitation. The detection limit for R‐phycoerythrin protein spots in 1‐D SDS‐PAGE with 532 nm excitation was as low as 15 fg, which corresponds to only 40 000 molecules. The average detection limit of six standard native proteins was 5 pg per band with 275 nm excitation. The dynamic range spanned more than three orders of magnitude. By using the same detection setup, approximately 150 protein spots from 30 ng of total Escherichia coli extraction were detected on a 0.8 cm×1 cm gel in 2‐D separation. The significant improvement in sensitivity for laser side‐entry excitation comes from higher excitation power and lower background level compared with other excitation modes.
Automated integration of monolith‐based protein separation with on‐plate digestion for mass spectrometric analysis of esophageal adenocarcinoma human epithelial samples
Authors: Yoo Chul , Zhao Jia , Pal Manoj , Hersberger Katherine , Huber Christian G. , Simeone Diane M. , Beer David G. , Lubman David M.
Published: August 2006

A unique approach of automating the integration of monolithic capillary HPLC‐based protein separation and on‐plate digestion for subsequent MALDI‐MS analysis has been developed. All liquid‐handling procedures were performed using a robotic module. This automated high‐throughput method minimizes the amount of time and extensive labor required for traditional in‐solution digestion followed by exhaustive sample cleanup and analysis. Also, precise positioning of the droplet from the capillary HPLC separation onto the MALDI plate allows for preconcentration effects of analytes for improved sensitivity. Proteins from primary esophageal Barrett's adenocarcinoma tissue were prefractionated by chromatofocusing and analyzed successfully by this automated configuration, obtaining rapid protein identifications through PMF and sequencing analyses with high sequence coverage. Additionally, intact protein molecular weight values were obtained as a means to further confirm protein identification and also to identify potential sequence modifications of proteins. This simple and rapid method is a highly versatile and robust approach for the analysis of complex proteomes.
Surface structures and tiered topography
Authors: Myers Wayne L.
Published: August 2006

The use of contemporary spatial analysis systems for environmental monitoring tends to promote an emphasis on high versus low areas in surface data. However, locally elevated areas as summits or domes may be important even if higher levels are found elsewhere. Also, trends on the periphery of elevated areas can be informative. Some elevated areas drop precipitously on the edges, others drop gradually, and still others have proximate reversals of decline leading up again to other areas that are elevated in greater or lesser degree. The reversals of downward trend may be small and subtle or sustained as major features of the surface. Small reversals having high spatial frequency can be considered as a type of noise engendering local uncertainty for which suppression may be advantageous. Mapping and characterizing these transitional areas leads to major opportunities for etiology since these are zones in which causal factors are also varying and thus relatively amenable to study. Echelon analysis and dome domains enable systematic investigation of spatial trends that would otherwise be difficult. Biodiversity of fish species richness and topographic analysis in Pennsylvania provide contexts for consideration and generalization. Copyright © 2006 John Wiley & Sons, Ltd.
Optimal network design for spatial prediction, covariance parameter estimation, and empirical prediction
Authors: Zimmerman Dale L.
Published: August 2006

Inferences for spatial data are affected substantially by the spatial configuration of the network of sites where measurements are taken. In this article, criteria for network design that emphasize the utility of the network for prediction (kriging) of unobserved responses assuming known spatial covariance parameters are contrasted with criteria that emphasize the estimation of the covariance parameters themselves. It is shown, via a series of related examples, that these two main design objectives are largely antithetical and thus lead to quite different “optimal” designs. Furthermore, a hybrid design criterion that accounts for the effect that the sampling variation of spatial covariance parameter estimates has on prediction is described and illustrated. Situations in which the hybrid optimal design resembles designs that are optimal with respect to each of the other two criteria are identified. An application to the optimal augmentation of an acid deposition monitoring network in the eastern US is presented. Copyright © 2006 John Wiley & Sons, Ltd.
Iterated confirmatory factor analysis for pollution source apportionment
Authors: Christensen William F. , Schauer James J. , Lingwall Jeff W.
Published: August 2006

Many approaches for pollution source apportionment have been considered in the literature, most of which are based on the chemical mass balance equations. The simplest approaches for identifying the pollution source contributions require that the pollution source profiles are known. When little or nothing is known about the nature of the pollution sources, exploratory factor analysis, confirmatory factor analysis, and other multivariate approaches have been employed. In recent years, there has been increased interest in more flexible approaches, which assume little knowledge about the nature of the pollution source profiles, but are still able to produce nonnegative and physically realistic estimates of pollution source contributions. Confirmatory factor analysis can yield a physically interpretable and uniquely estimable solution, but requires that at least some of the rows of the source profile matrix be known. In the present discussion, we discuss the iterated confirmatory factor analysis (ICFA) approach. ICFA can take on aspects of chemical mass balance analysis, exploratory factor analysis, and confirmatory factor analysis by assigning varying degrees of constraint to the elements of the source profile matrix when iteratively adapting the hypothesized profiles to conform to the data. ICFA is illustrated using PM2.5 data from Washington D.C., and a simulation study illustrates the relative strengths of ICFA, chemical mass balance approaches, and positive matrix factorization (PMF). Copyright © 2006 John Wiley & Sons, Ltd.
Suicidal behaviour, risky eating behaviours and psychosocial correlates in Mexican female students
Authors: Unikel Claudia , Gómez‐Peresmitré Gilda , González‐Forteza Catalina
Published: August 2006

Objective

To determine the frequency of suicidal behaviour and its characteristics, and its association to different variables such as: depressive symptomatology, risky eating behaviours, suicidal ideation, experience of sexual abuse and the relationship with mother and father, as well as to identify the protective and risk factors.

Method

Cross‐sectional study of a sample of high school and college female students (N = 405 with a mean age of 18.5 years, SD = 3).

Results

Ten per cent of the women in the sample displayed suicidal behaviour at some point in their lives. The statistical analysis showed significant differences between students with and without suicidal behaviours in all variables measured except for father's support. A positive association was found between the father's emotional mistreatment, suicidal ideation and risky eating behaviours, as well as a negative association with the mother's affect. Copyright © 2006 John Wiley & Sons, Ltd and Eating Disorders Association.
Investigation of a model of weight restricting behaviour amongst adolescent girls
Authors: Donovan Caroline L. , Spence Susan H. , Sheffield Jeanie K.
Published: August 2006

Objective

This study examined the validity of a model predicting weight restricting behaviour both cross‐sectionally and longitudinally.

Method

Participants comprised 1207 girls aged from 12 to 14 years. The girls completed self‐report questionnaires at three time points over 1‐year intervals.

Results

The cross‐sectional results suggested that weight preoccupation and body dissatisfaction directly predicted weight restricting behaviour. In addition, upset induced by teasing, depressive symptoms, BMI and negative attributional style demonstrated indirect effects on weight restricting behaviour through their effects on body dissatisfaction and/or weight preoccupation. Longitudinally however, only weight restricting behaviour and body dissatisfaction were significant in the prediction of weight restricting behaviour.

Discussion

The implications of the results are discussed, together with suggestions for future research. Copyright © 2006 John Wiley & Sons, Ltd and Eating Disorders Association.
A node‐centred finite volume formulation for the solution of two‐phase flows in non‐homogeneous porous media
Authors: de Carvalho D. K. E. , Willmersdorf R. B. , Lyra P. R. M.
Published: August 2006

The simulation of two‐phase flow of oil and water in inhomogeneous porous media represents a great challenge because rock properties such as porosity and permeability can change abruptly throughout the reservoir. This fact can produce velocities which vary several orders of magnitude within very short distances. The presence of complex geometrical features such as faults and deviated wells is quite common in reservoir modelling, and unstructured mesh procedures, such as finite elements (FE) and finite volume (FV) methods can offer advantages relative to standard finite differences (FD) due to their ability to deal with complex geometries and the easiness of incorporating mesh adaptation procedures. In fluid flow problems FV formulations are particularly attractive as they are naturally conservative in a local basis. In this paper, we present an unstructured edge‐based finite volume formulation which is used to solve the partial differential equations resulting from the modelling of the immiscible displacement of oil by water in inhomogeneous porous media. This FV formulation is similar to the edge‐based finite element formulation when linear triangular elements are employed. Flow equations are modelled using a fractional flux approach in a segregated manner through an IMplicit Pressure‐Explicit Saturation (IMPES) procedure. The elliptic pressure equation is solved using a two‐step approach and the hyperbolic saturation equation is approximated through an artificial diffusion method adapted for use on unstructured meshes. Some representative examples are shown in order to illustrate the potential of the method to solve fluid flows in porous media with highly discontinuous properties. Copyright © 2006 John Wiley & Sons, Ltd.
Numerical simulation of flows around two circular cylinders by mesh‐free least square‐based finite difference methods
Authors: Ding H. , Shu C. , Yeo K. S. , Xu D.
Published: August 2006

In this paper, the mesh‐free least square‐based finite difference (MLSFD) method is applied to numerically study the flow field around two circular cylinders arranged in side‐by‐side and tandem configurations. For each configuration, various geometrical arrangements are considered, in order to reveal the different flow regimes characterized by the gap between the two cylinders. In this work, the flow simulations are carried out in the low Reynolds number range, that is, Re=100 and 200. Instantaneous vorticity contours and streamlines around the two cylinders are used as the visualization aids. Some flow parameters such as Strouhal number, drag and lift coefficients calculated from the solution are provided and quantitatively compared with those provided by other researchers. Copyright © 2006 John Wiley & Sons, Ltd.
Hierarchical distributed metamodel‐assisted evolutionary algorithms in shape optimization
Authors: Karakasis Marios K. , Koubogiannis Dimitrios G. , Giannakoglou Kyriakos C.
Published: August 2006

In aerodynamic shape optimization, the availability of multiple evaluation models of different precision and hence computational cost can be efficiently exploited in a hierarchical evolutionary algorithm. Thus, in this work the demes of a distributed evolutionary algorithm are ordered in levels, with each level employing a different flow analysis method, giving rise to a hierarchical distributed scheme. The arduous task of exploring the design space is undertaken by demes consisting the lower hierarchy level, which use a low‐cost flow analysis tool, namely a viscous–inviscid flow interaction method. Promising solutions are directed towards the higher level, where these are further evolved based on a high precision/cost evaluation tool, viz. a Navier–Stokes equations solver. The final, optimal solution is obtained from the highest hierarchy level. At each level, metamodels, trained on‐line on the outcome of evaluations with the level's analysis tool, are used. The role of metamodels is to allow a parsimonious use of computational resources by filtering the poorly performing individuals in each deme. The entire algorithm has been implemented so as to take advantage of a parallel computing system. The efficiency and effectiveness of the proposed hierarchical distributed evolutionary algorithm have been assessed in the design of a transonic isolated airfoil and a compressor cascade. Remarkable superiority over the conventional evolutionary algorithms has been monitored. Copyright © 2006 John Wiley & Sons, Ltd.
Stability of convective flows in cavities: solution of benchmark problems by a low‐order finite volume method
Authors: Gelfgat Alexander Yu.
Published: August 2006

A problem of stability of steady convective flows in rectangular cavities is revisited and studied by a second‐order finite volume method. The study is motivated by further applications of the finite volume‐based stability solver to more complicated applied problems, which needs an estimate of convergence of critical parameters. It is shown that for low‐order methods the quantitatively correct stability results for the problems considered can be obtained only on grids having more than 100 nodes in the shortest direction, and that the results of calculations using uniform grids can be significantly improved by the Richardson's extrapolation. It is shown also that grid stretching can significantly improve the convergence, however sometimes can lead to its slowdown. It is argued that due to the sparseness of the Jacobian matrix and its large dimension it can be effective to combine Arnoldi iteration with direct sparse solvers instead of traditional Krylov‐subspace‐based iteration techniques. The same replacement in the Newton steady‐state solver also yields a robust numerical process, however, it cannot be as effective as modern preconditioned Krylov‐subspace‐based iterative solvers. Copyright © 2006 John Wiley & Sons, Ltd.
Dynamics of large solid particles in bioconvective sedimentation
Authors: Geng P. , Kuznetsov A. V.
Published: August 2006

Settling of one or two large solid particles in a bioconvection flow induced by gyrotactic motile microorganisms is investigated using a 2D numerical model. The results of varying the initial positions of large particles on the bioconvection flow pattern are investigated. The Chimera method is utilized to generate subgrids around the moving particles. It is demonstrated that the introduction of a single large particle displaces bioconvection plume and changes its shape. The introduction of two particles on the same side of the bioconvection plume further displaces the plume while the introduction of two particles on opposite sides reduces this displacement. The influence of the bioconvection plume on the particles' settling paths and particles' settling velocities is investigated. Copyright © 2006 John Wiley & Sons, Ltd.
Optimization of heat‐transfer rate into time‐periodic two‐dimensional Stokes flows
Authors: Mota J. P. B. , Rodrigo A. J. S. , Saatdjian E.
Published: August 2006

The periodic boundary displacement protocol leading to the optimum wall‐to‐fluid heat‐transfer rate, or to the most efficient mixing rate, in 2‐D annular Stokes flows is determined by calculating the steady periodic velocity and temperature fields. To obtain the steady periodic state one usually solves the dynamical system obtained after the spatial coordinates have been discretized. Here, we calculate the steady periodic state using an implicit method based on the discretization of the time coordinate over a period and the asymptotic regime is enforced by the periodicity condition in the computed temperature field. The obtained system of equations is solved using a Newton‐type iterative algorithm with invariant Jacobian. At each iteration step, the sparse linearized system is solved using a multi‐grid algebraic technique of rapid convergence. From a computational point of view and for the problem considered here, this method is an order of magnitude faster than the one based on a spatial discretization. Copyright © 2006 John Wiley & Sons, Ltd.
Topographical recognition memory sensitive to amnestic mild cognitive impairment but not to depression
Authors: Ritter Emilie , Després Olivier , Monsch Andreas U. , Manning Lilianne
Published: August 2006

Objective

Amnestic mild cognitive impairment (aMCI) involves episodic memory. The person who presents aMCI has a high risk of developing Alzheimer's disease (AD). However, prediction of deterioration to dementia in cases of aMCI can be confounded with depression due to lack of specificity on selective memory tests. Finding a test sensitive to aMCI but not to depression would be potentially most useful to subsequent longitudinal studies researching the neuropsychological markers of preclinical AD. We hypothesized that the performance on a topographical memory task would be sensitive to the aMCI condition, while depression would not influence such a performance.

Participants and Methods

A group of 137 community‐dwelling French‐speaking subjects between 55 and 70 years old was administered a topographical recognition memory task. Based on aMCI and depression criteria, 45 subjects were selected and divided into four groups: 11 patients with aMCI without depression, nine depressive patients with aMCI, ten depressive patients without cognitive impairment and 15 control subjects. The remaining non‐selected participants did not belong to any of the previous interest groups.

Results

The ‘aMCI’ factor had a significant effect on the topographical recognition memory task scores, while the ‘depression’ factor did not. The aMCI patients performed worse than the non‐aMCI.

Conclusion

Although these results were found with relatively small groups, deficits in topographical recognition memory were observed in aMCI patients and did not seem to be sensitive to depression. Further longitudinal studies are needed to examine whether deficits in topographical recognition memory are a neuropsychological marker of preclinical AD. Copyright © 2006 John Wiley & Sons, Ltd.
Investigating the quitting decision of nurses: panel data evidence from the british national health service
Authors: Frijters Paul , Shields Michael A. , Price Stephen Wheatley
Published: August 2006

In this paper, we provide a detailed investigation into the quitting behaviour of nurses in the British National Health Service (NHS), using a recently constructed longitudinal survey. We fit both single and competing risks duration models that enable us to establish the characteristics of those nurses who leave the public sector, distinguish the importance of pay in this decision and document the destinations that nurses move to. Contrary to expectations, we find that the hourly wage received by nurses outside of the NHS is around 20% lower than in the NHS, and that hours of work are about the same. However, while the effect of wages is found to be statistically significant, the predicted impact of an increase in nurses' pay on retention rates is small. The current nurse retention problem in the NHS is therefore unlikely to be eliminated through substantially increased pay. Copyright © 2006 John Wiley & Sons, Ltd.
Origin and type of rainfall for recharge of a karstic aquifer in the western Mediterranean: a case study from the Sierra de Gador–Campo de Dalias (southeast Spain)
Authors: Frot Elisabeth , van Wesemael Bas , Vandenschrick Grégoire , Souchez Roland , Solé Benet Albert
Published: August 2006

Isotope signatures in precipitation from the Global Network for Isotopes in Precipitation around the Mediterranean basin and literature data are compared with isotopic data from a large karstic aquifer in southeast Spain to explain the origin and type of the precipitation events dominating recharge. Analysis of the deuterium excess d at the scale of the Mediterranean basin and at the regional scale allows us to understand the isotopic context of the study area: Campo de Dalias and the Sierra de Gador (Almería province). The origin of precipitation can be determined from its d value. The d value changes as a function of the initial evaporation condition. It depends on the relative humidity and temperature during the evaporation producing the water vapour of the clouds. The water vapour, which dominates the study area, is generated in two areas: the Atlantic Ocean (d = 10‰) and the western Mediterranean basin (d = 15‰). With increasing precipitation volume, the western Mediterranean character dominates. These heavier storms contribute mainly to recharge, as illustrated by the d value of 13·6‰ in deep groundwater of the Campo de Dalias. Weighted d values increase with the volume of precipitation, giving a significant relationship for the southern and eastern coasts of the Iberian Peninsula. This selectivity of d to monthly precipitation was used to estimate the return period of precipitation leading to aquifer recharge at 0·9–4·9 years. Moderate rainfall, which occurs more frequently, still represents ∼60–90% of the total precipitation. One of the challenges to meet ever‐growing water demands is to increase recharge from moderate events yielding intermediate quantities per event, but forming the bulk of the annual precipitation. Copyright © 2006 John Wiley & Sons, Ltd.
Climatic and topographic limits to the abundance of bog pools
Authors: Belyea Lisa R.
Published: August 2006

On patterned peatlands, open water pools develop within a matrix of terrestrial vegetation (‘ridges’). Regional patterns in the distribution of ridge–pool complexes suggest that the relative cover of these two surface types is controlled in part by climate wetness, but landscape topography must also be an important controlling factor. In this paper, a functional model that relates relative cover of ridges and pools to climate and surface gradient was developed and tested. The model was formulated in terms of a water budget, based on the differential effects of ridges and pools on losses by evapotranspiration and subsurface flow. It predicts a positive relationship between surface gradient and ridge proportion, with a linear effect related to water supply and ridge hydraulic conductivity, modified at high ridge proportion by differences in evapotranspiration between ridges and pools. The limit to patterned peatland distribution occurs where the surface is completely covered by ridges. The model may be sensitive or insensitive to climate differences between localities, depending on whether hydraulic characteristics of ridge peat co‐vary with water supply. To distinguish between these alternative hypotheses, surface gradient and ridge proportion were surveyed along 20 transects in each of three localities in Scotland that differ threefold in net precipitation to pools. The results of the field survey served to reject the climate‐sensitive hypothesis, but were consistent with the climate‐insensitive hypothesis. Analysis of the residuals suggested that variation within localities was related more to topographic control of water supply than to ridge hydraulic conductivity or developmental stage. Hence, within this maritime climate region, the distribution of ridge–pool complexes and the relative abundance of pools are controlled mainly by topographic variables. Field surveys across both maritime and continental regions are required to confirm a subtle climatic effect that allows pools to occur on higher gradients in drier climates than in wetter climates. Further development and testing of the functional model will provide a stronger basis for assessing potential feedback between climate change, peatland surface structure and methane emission from pools. Copyright © 2006 John Wiley & Sons, Ltd.
Studies on groundwater recharge characteristics at a reclaimed land site with an equatorial climate using time‐series and spectral analyses
Authors: Tan Stephen Boon Kean , Shuy Eng Ban , Chua Lloyd Hock Chye , Yee Woon Kang
Published: August 2006

Groundwater recharge studies are essential for investigating the feasibility of using the reclaimed lands in Singapore for subsurface storage and recovery of water. Through time‐series and spectral analyses, net recharge percentages and stress‐filtering characteristics at the reclaimed land were found to depend strongly on the stress transfer velocity, which was a combined function of rainfall pattern and vadose zone thickness. Based on stress transfer velocity, a theory was established to provide logical explanations for the rainfall–recharge relationship, the observed stress‐filtering characteristics and the recharge percentage characteristics at the unconfined sandy aquifer. Although the reclaimed land site has a lithollogically homogeneous soil profile, a non‐uniform recharge pattern was observed to be influenced pronouncedly by the uneven density distribution of bush grasses. Under a bare soil condition, significantly lower recharge percentages were observed for areas under the influence of offshore tides. The unconfined sandy aquifer appears to dampen out the wave propagation of offshore tides rapidly within a short distance from the tidal source, though it has a fairly straight shoreline and is created from highly compacted sand fills. Copyright © 2006 John Wiley & Sons, Ltd.
Impact of cyclins E, neutrophil elastase and proteinase 3 expression levels on clinical outcome in primary breast cancer patients
Authors: Desmedt Christine , Ouriaghli Frank El , Durbecq Virginie , Soree Anne , Colozza Maria Antonetta , Azambuja Evandro , Paesmans Marianne , Larsimont Denis , Buyse Marc , Harris Adrian , Piccart Martine , Martiat Philippe , Sotiriou Christos
Published: August 2006

Uncontrolled cell proliferation is one of the hallmarks of cancer and the transition from the G1 to S phase is the most commonly reported cell cycle abnormality in tumors. It has been shown that the oncogenic activity of G1 cyclin E (CCNE) can be amplified by generating hyperactive low molecular weight forms (LMW) through elastase‐mediated proteolytic processing. Neutrophil elastase (NE) and proteinase 3 (PR3) are 2 proteases that are aberrantly expressed in breast cancer cells and seem to be involved in cell proliferation. In this study, we evaluated the effect of the expression of these 2 proteases in addition to 2 potential intracellular targets of NE (CCNE1 and CCNE2) on clinical outcome in a population of 205 primary breast cancer patients. By univariate analysis, CCNE1, CCNE2, estrogen receptor and grade significantly predicted relapse free interval (RFI). NE and PR3 did not achieve statistical significance. In a multivariate analysis, elevated CCNE2 [hazard ratio (HR) 2.10, p = 0.008] predicted shorter RFI. In subgroup analyses of the tamoxifen‐only treated patients, high CCNE1 levels predicted treatment resistance, while high levels of CCNE2 were associated with poor RFI in untreated patients. Investigation of the relationship between CCNE1, CCNE2 and NE did not show any impact on RFI. To conclude, this study was the first to evaluate these markers at the mRNA level by RT‐PCR in a series of primary breast cancer patients, and our results confirmed the impact of high CCNE levels on clinical outcome in systemically untreated and of CCNE1 in tamoxifen‐only treated early breast cancer patients. © 2006 Wiley‐Liss, Inc.
Cancer mortality rates among first and second generation migrants in the Netherlands: Convergence toward the rates of the native Dutch population
Authors: Stirbu Irina , Kunst Anton E. , Vlems Femke A. , Visser Otto , Bos Vivian , Deville Walter , Nijhuis Haarry G.J. , Coebergh Jan W.
Published: August 2006

This study investigates the difference in cancer mortality rates between migrant groups and the native Dutch population, and determines the extent of convergence of cancer mortality rates according to migrants' generation, age at migration and duration of residence. Data were obtained from the national cause of death and population registries in the period 1995–2000. We used Poisson regression to compare the cancer mortality rates of migrants originating from Turkey, Morocco, Surinam, Netherlands Antilles and Aruba to the rates for the native Dutch. All‐cancer mortality among all migrant groups combined was significantly lower when compared to that of the native Dutch population (RR = 0.55, CI: 0.52–0.58). For a large number of cancers, migrants had more than 50% lower risk of death, while elevated risks were found for stomach and liver cancers. Mortality rates for all cancers combined were higher among second generation migrants, among those with younger age at migration, and those with longer duration of residence. This effect was particularly pronounced in lung cancer and colorectal cancer. For most cancers, mortality among second generation migrants remained lower compared to the native Dutch population. Surinamese migrants showed the most consistent pattern of convergence of cancer mortality. The generally low cancer mortality rates among migrants showed some degree of convergence but did not yet reach the levels of the native Dutch population. This convergence implies that current levels of cancer mortality among migrants will gradually increase in future years if no specific preventive measurements are taken. © 2006 Wiley‐Liss, Inc.
The thymidylate synthase tandem repeat promoter polymorphism: A predictor for tumor‐related survival in neoadjuvant treated locally advanced gastric cancer
Authors: Ott Katja , Vogelsang Holger , Marton Noemi , Becker Karen , Lordick Florian , Kobl Michael , Schuhmacher Christoph , Novotny Alexander , Mueller James , Fink Ulrich , Ulm Kurt , Siewert Jörg Rüdiger , Höfler Heinz , Keller Gisela
Published: August 2006

We evaluated DNA polymorphisms in the thymidylate synthase (TS) and 5,10‐methylene‐tetrahydrofolate reductase (MTHFR) genes for an association with response and survival in locally advanced gastric cancer treated with 5‐FU based preoperative chemotherapy (CTx). DNA of 238 patients (CTx‐group: total n = 135, completely resected (R0) n = 102; without CTx: R0 n = 103) was isolated from blood or from nontumorous tissues. In the CTx‐group, genotyping of the tandem repeat and the G/C polymorphism in the triple repeat in the promoter region of the TS gene and of the C677T polymorphism of the MTHFR gene was performed. None of the TS or MTHFR genotypes were associated with histopathological response and only the TS tandem repeat polymorphism was significantly related to survival (all patients n = 135, p = 0.002; R0 resected patients n = 102, p = 0.007; log‐rank test). Multivariate analysis revealed ypN (p < 0.001) and the TS tandem repeat polymorphism as independent prognostic factors in the CTx‐R0‐group (p = 0.003). Analyzing the prognostic significance of the TS polymorphisms in the R0‐group without CTx, TS genotypes were not significantly associated with survival. Comparing survival between R0 patients with and without CTx in the respective TS genotype groups of the tandem repeat polymorphism, a significant survival benefit for the patients with CTx was found for the 2rpt/2rpt (n = 49; p = 0.002) and 2rpt/3rpt genotypes (n = 99; p = 0.004), but not for the 3rpt/3rpt genotype (n = 57; p = 0.93). Patients' survival after CTx was associated with the TS tandem repeat polymorphism. CTx did not improve survival of patients with the 3rpt/3rpt genotype. Thus, a different therapy might be more appropriate for these patients. © 2006 Wiley‐Liss, Inc.
Covalently crosslinked chitosan hydrogel formed at neutral pH and body temperature
Authors: Hong Yi , Mao Zhengwei , Wang Hualin , Gao Changyou , Shen Jiacong
Published: August 2006

Water‐soluble chitosan having double bonds (CS–MA–LA) was synthesized by sequential grafting of methacrylic acid (MA) and lactic acid (LA) via the reaction between amino groups and carboxyl groups under the catalysis of carbodiimide. Its molecular structure was verified by FTIR and 1H NMR characterizations. Elemental analysis measured grafting ratios of 19% and 10.33% for MA and LA, respectively. CS–MA–LA was readily soluble in pure water and did not precipitate till pH 9. Gelation of the CS–MA–LA was realized by thermal treatment at body temperature under the initiation of a redox system, ammonium persulfate (APS)/N, N,N′,N′‐tetramethylethylenediamine (TEMED). The gelation time could be mediated in a wide range, e.g. from 6 to 20 min, by reaction temperature and/or initiator's concentration. 3T3 fibroblast culture showed that the cytotoxicity of the hydrogel extractant was dependent on the cell seeding number and the initiator's concentration. With enough number of cells (>2.5 × 104) and low initiator's concentration (5 mM), the cytotoxicity introduced by the initiator is very minimal and negligible. Although the hydrogel could cause acute inflammation and foreign body reaction, no tissue necrosis and malignant infection were evidenced in vivo, demonstrating that the material has better histocompatibility. These features have endowed the chitosan with great opportunity as injectable biomaterials, which may find wide applications in the rapidly developed fields such as tissue engineering and orthopedics. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Controlled release of bioactive doxorubicin from microspheres embedded within gelatin scaffolds
Authors: DeFail Alicia J. , Edington Howard D. , Matthews Stacey , Lee Wen‐Chi C. , Marra Kacey G.
Published: August 2006

We have encapsulated the chemotherapeutic agent doxorubicin into biodegradable polymer microspheres, and incorporated these microspheres into gelatin scaffolds, resulting in a controlled delivery system. Doxorubicin was encapsulated in poly(D,L‐lactide‐co‐glycolide) (PLGA) using a double emulsion/solvent extraction method. Characterization of the microspheres including diameter, surface morphology, and in vitro drug release was determined. The release of doxorubicin up to 30 days in phosphate buffered solution was assessed by measuring the absorbance of the releasate solution. Gelatin scaffolds were crosslinked using glutaraldehyde and microspheres were added to gelatin during gelation. The murine mammary mouse tumor cell line, 4T1, was treated with various doses of doxorubicin. A propidium iodide assay was utilized to visualize dead cells. Using a Transwell basket assay, PLGA microspheres and gelatin constructs were suspended above 4T1 cells for 48 h. Viable cells were determined using the CyQUANT cell proliferation assay. Results indicate that the release was controlled by the incorporation of PLGA microspheres into gelatin constructs. A significant difference was seen in the cumulative release over days 5–16 (p < 0.05). The bioactivity of doxorubicin released from the microspheres and scaffolds was maintained as proven by significant reduction in viable cells after treatment with PLGA microspheres as well as with the gelatin constructs (p < 0.001). The drug‐polymer conjugate can be used as a controlled drug delivery system in a biocompatible scaffold that could potentially promote preservation of soft tissue contour. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006