bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal recording electrode placement in the lumbrical–interossei comparison study
Authors: Al‐Shekhlee Amer , Filho Jose A. Fernandes , Sukul Devraj , Preston David C.
Published: December 2005

The lumbrical–interossei comparison study is commonly employed in the electrodiagnosis of carpal tunnel syndrome. Placement of the recording electrodes relies on anatomic landmarks as the muscles being recorded cannot be seen or palpated. To determine the optimal active electrode location, 15 controls and 5 patients were studied using a grid of 12 electrodes placed over the lateral palm. Amplitudes, rise‐times, and latencies of the responses at each location were measured. The lowest control latency difference was located in the lateral mid‐proximal palm (mean 0 ms, upper range of 0.5 ms). This location also had the highest lumbrical amplitude and rise‐time. More distal in the palm, the mean latency difference increased to 0.5 ms with an upper range of 0.9 ms. When performing the lumbrical–interossei comparison study, it is essential to place the active recording electrode in the optimal location. Failure to do so will result in an increased number of false‐positive studies. Muscle Nerve, 2006
A branch‐and‐cut algorithm for the quay crane scheduling problem in a container terminal
Authors: Moccia Luigi , Cordeau Jean‐François , Gaudioso Manlio , Laporte Gilbert
Published: December 2005

The quay crane scheduling problem consists of determining a sequence of unloading and loading movements for cranes assigned to a vessel in order to minimize the vessel completion time as well as the crane idle times. Idle times originate from interferences between cranes since these roll on the same rails and a minimum safety distance must be maintained between them. The productivity of container terminals is often measured in terms of the time necessary to load and unload vessels by quay cranes, which are the most important and expensive equipment used in ports. We formulate the quay crane scheduling problem as a vehicle routing problem with side constraints, including precedence relationships between vertices. For small size instances our formulation can be solved by CPLEX. For larger ones we have developed a branch‐and‐cut algorithm incorporating several families of valid inequalities, which exploit the precedence constraints between vertices. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Single and multi‐interval Legendre spectral methods in time for parabolic equations
Authors: Tang Jian‐guo , Ma He‐ping
Published: December 2005

In this article, we take the parabolic equation with Dirichlet boundary conditions as a model to present the Legendre spectral methods both in spatial and in time. Error analysis for the single/multi‐interval schemes in time is given. For the single interval spectral method in time, we obtain a better error estimate in L2‐norm. For the multi‐interval spectral method in time, we obtain the L2‐optimal error estimate in spatial. By choosing approximate trial and test functions, the methods result in algebraic systems with sparse forms. A parallel algorithm is constructed for the multi‐interval scheme in time. Numerical results show the efficiency of the methods. The methods are also applied to parabolic equations with Neumann boundary conditions, Robin boundary conditions and some nonlinear PDEs. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006
Delivering long‐term follow‐up care to pediatric cancer survivors: Transitional care issues
Authors: Ginsberg Jill P. , Hobbie Wendy L. , Carlson Claire A. , Meadows Anna T.
Published: December 2005

One of the major challenges faced by young adult survivors of childhood cancer is the transition from a specialized pediatric care facility to adult‐based health care that provides appropriate follow‐up. This review summarizes the issues regarding the necessity of this transition, including a brief history of follow‐up care of childhood cancer survivors. The general principles of transition care, as well as the barriers and obstacles specific to this population are outlined with the advantages and limitations of several models of transition care that could be considered. © 2005 Wiley‐Liss, Inc.
Synthesis and characterization of mid‐ and end‐chain functional telechelics by controlled polymerization methods and coupling processes
Authors: Colak Demet , Cianga Ioan , Muftuoglu Ali Ekrem , Yagci Yusuf
Published: November 2005

Well‐defined polystyrene‐ (PSt) or poly(ε‐caprolactone) (PCL)‐based polymers containing mid‐ or end‐chain 2,5 or 3,5‐ dibromobenzene moieties were prepared by controlled polymerization methods, such as atom transfer radical polymerization (ATRP) or ring opening polymerization (ROP). 1,4‐Dibromo‐2‐(bromomethyl)benzene, 1,3‐dibromo‐5‐(bromomethyl)benzene, and 1,4‐dibromo‐2,5‐di(bromomethyl)benzene were used as initiators in ATRP of styrene (St) in conjunction with CuBr/2,2′‐bipyridine as catalyst. 2,5‐Dibromo‐1,4‐(dihydroxymethyl)benzene initiated the ROP of ε‐caprolactone (CL) in the presence of stannous octoate (Sn(Oct)2) catalyst. The reaction of these polymers with amino‐ or aldehyde‐functionalized monoboronic acids, in Suzuki‐type couplings, afforded the corresponding telechelics. Further functionalization with oxidable groups such as 2‐pyrrolyl or 1‐naphthyl was attained by condensation reactions of the amino or aldehyde groups with low molecular weight aldehydes or amines, respectively, with the formation of azomethine linkages. Preliminary attempts for the synthesis of fully conjugated poly(Schiff base) with polymeric segments as substituents, by oxidative polymerization of the macromonomers, are presented. All the starting, intermediate, or final polymers were structurally analyzed by spectral methods (1H NMR, 13C NMR, and IR). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 727–743, 2006
Crosslinked epoxy materials exhibiting thermal remendablility and removability from multifunctional maleimide and furan compounds
Authors: Liu Ying‐Ling , Hsieh Chia‐Yun
Published: December 2005

Crosslinked polymeric materials, which exhibit thermal remendability and removability through Diels–Alder (DA) and retro‐DA reactions, were obtained from using multifunctional maleimide and furan compounds as monomers. The synthesized monomers possess low melting points and good solubility in organo solvents to show excellent processing properties. The performance of DA and retro‐DA reactions were demonstrated with DSC and FTIR measurements. High performance of thermal remendablility and removability of the crosslinked materials were observed with SEM and solvent tests. These materials were applicable in advanced encapsulants and structural materials. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 905–913, 2006
Oxidation of poly(1,3‐cyclohexadiene): Influence of the polymer chain structure
Authors: Natori Itaru , Sato Hisaya
Published: December 2005

The influence of the microstructure on the oxidation of poly(1,3‐cyclohexadiene) (PCHD) homopolymer, obtained by anionic polymerization with alkyllithium/amine systems, was investigated for the first time. PCHD has a structure consisting of a main chain formed by 1,2‐addition (the 1,2‐CHD unit) and 1,4‐addition (the 1,4‐CHD unit). The molar ratio of 1,2‐CHD/1,4‐CHD units in the polymer chain strongly influenced the extent of oxidation of PCHD. A polymer chain with a high content of 1,4‐CHD units was easily oxidized by air and 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ). In contrast, the progress of oxidation was prevented in the case of PCHD containing 52% of 1,2‐CHD units. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 837–845, 2006
Homopolymer and block copolymer brushes on gold by living anionic surface‐initiated polymerization in a polar solvent
Authors: Sakellariou Georgios , Park Mikyoung , Advincula Rigoberto , Mays Jimmy W. , Hadjichristidis Nikos
Published: December 2005

Living anionic surface‐initiated polymerization on flat gold substrates has been conducted to create uniform homopolymer and diblock copolymer brushes. A 1,1‐diphenylethylene (DPE) self‐assembled monolayer was used as the immobilized precursor initiator. n‐BuLi was used to activate the DPE in tetrahydrofuran at –78 °C to initiate the polymerization of different monomers (styrene, isoprene, ethylene oxide, and methyl methacrylate). Poly(styrene) (PS) and poly(ethylene oxide) (PEO) in particular were first investigated as grafted homopolymers, followed by their copolymers, including poly(isoprene)‐b‐poly(methylmethacrylate) (PI‐b‐PMMA). A combined approach of spectroscopic (Fourier transform infrared spectroscopy, surface plasmon spectroscopy, ellipsometry, X‐ray photoelectron spectroscopy) and microscopic (atomic force microscopy) surface analysis was used to investigate the formation of the polymer brushes in polar solvent media. The chemical nature of the outermost layer of these brushes was studied by water contact angle measurements. The effect of the experimental conditions (solvent, temperature, initiator concentration) on the surface properties of the polymer brushes was also investigated. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 769–782, 2006
Nitroxide decomposition: Implications toward nitroxide design for applications in living free‐radical polymerization
Authors: Nilsen Aaron , Braslau Rebecca
Published: November 2005

Nitroxides bearing an α‐hydrogen decompose upon heating in a bimolecular reaction. A new mechanism is proposed for the decomposition of t‐butylisopropylphenyl nitroxide (TIPNO) involving the formation of a head‐to‐tail dimer, single electron transfer to form an oxammonium salt, epimerization to the corresponding nitrone, and elimination to form a conjugated oxime. This mechanism may provide insights into designing new nitroxides for use in controlled polymerization. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 697–717, 2006
Synthesis of a novel benzoxazine monomer‐intercalated montmorillonite and the curing kinetics of polybenzoxazine/clay hybrid nanocomposites
Authors: Yei Ding‐Ru , Fu Huei‐Kuan , Chen Wen‐Yi , Chang Feng‐Chih
Published: December 2005

Polybenzoxazine (PBZ), which has a structure similar to that of phenolic resin, is formed through the thermal self‐curing of benzoxazine, that is through a heterocyclic ring opening reaction that requires no catalyst and releases no condensation byproducts. We have used the solvent blending method to prepare PBZ/clay nanocomposites possessing various clay contents. We synthesized a monofunctional benzoxazine monomer (MBM) and then treated the clay with this intercalation agent. The results of X‐ray diffraction (XRD) analysis indicated that MBM intercalated into the galleries of the clay; the nanocomposite possessed an exfoliated structure at 3% clay content. To better understand the curing kinetics of the PBZ/clay nanocomposites, we performed dynamic and isothermal differential scanning calorimetry (DSC) measurements. We describe the thermodynamics of the curing process, using all three of the Kissinger, Ozawa, and Kamal models. The Kissinger and Ozawa methods gave fairly close results for the calculated activation energies, which decreased upon increasing the clay content. The Kamal method, based on an autocatalytic model, suggested a total reaction order of between 2.4 and 2.8. The glass transition temperature (Tg) decreased upon increasing the clay content. Thermogravimetric analysis (TGA) indicated that the nanocomposites have higher decomposition temperatures than does the pristine PBZ; this finding suggests an enhancement in their thermal stability. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 347–358, 2006
Plasticized polylactide/clay nanocomposites. II. The effect of aging on structure and properties in relation to the filler content and the nature of its organo‐modification
Authors: Pluta Miroslaw , Paul Marie‐Amélie , Alexandre Michaël , Dubois Philippe
Published: November 2005

Plasticized polylactide (PLA) – layered silicate nanocomposites were obtained by melt blending PLA with polyethylene glycol as plasticizer (20 wt %) and with different montmorillonite fillers: Cloisite® 20A, Cloisite® 25A, and Cloisite® 30B (from 1 to 10 wt %). Comparative samples of melt‐blended polylactide (without filler) and plasticized PLA with 20 wt % PEG were considered as well. Samples have been aged for 1 and 4 years and their chemical and physical characteristics were compared with not aged reference ones. It was found that molecular weight of the PLA decreased upon melt‐processing and aging, particularly when the Cloisite content increased, without a clear relation to the nature of the organo‐modifier. On the contrary, the PEG plasticizer was practically undegraded upon melt processing and aging. Structural studies revealed that plasticized PLA and plasticized PLA‐based nanocomposites are unstable in time of aging and undergo deplasticization. They showed, after aging, the presence of a thin PEG crystalline layer at the surface of the samples and improved the order in the PLA matrix to a higher extent in plasticized polylactide than in plasticized nanocomposite (due to clay stabilization effect). The amount of PEG diffusing toward sample surface was correlated with aging time, molecular weight of PLA matrix, and Cloisite® type, in clear relation to the extent of intercalation with PLA and PEG. Some modifications of the viscoelastic properties of PLA matrix, induced by the presence of both the nanoparticlate filler and the plasticizer, as well as a deterioration of the mechanical properties upon aging were observed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 312–325, 2006
Crosslinking induced by in‐situ coordination in acrylonitrile butadiene rubber/poly(vinyl chloride) alloy, filled with anhydrous copper sulfate particles
Authors: Shen Fei , Li Hui , Wu Chifei
Published: December 2005

Acrylonitrile butadiene rubber (NBR)/poly(vinyl chloride) (PVC) alloy, filled with anhydrous copper sulfate (CuSO4) particles, was investigated for the first time. The material could be crosslinked in the existence of CuSO4 by heat pressing, without any other crosslink agents. The crosslinking in the material was induced by in situ coordination between nitrile groups of NBR and solid CuSO4 particles, which is thoroughly different from the traditional vulcanization of rubber materials. The coordination crosslinking is formed during heat pressing, other than in solutions, which is valuable for practical applications. The resulting material showed excellent tensile properties, and the maximum strength was close to 90 MPa. The CuSO4 particles act not only as crosslink agents, but also as reinforcing fillers in the polymer matrix. In this work, dynamic mechanical analysis, differential scanning calorimetry, Fourier transform infrared spectrum, X‐ray photoelectron spectroscopy, scanning electron microscope, energy‐dispersive X‐ray spectrum, equilibrium swelling method, and tensile test were performed for the characterization of the material. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 378–386, 2006
Process control systems in the chemical industry: Safety vs. security
Authors: Hahn Jeffrey , Guillen Donna Post , Anderson Thomas
Published: December 2005

Traditionally, the primary focus of the chemical industry has been safety and productivity. However, recent threats to our nation's critical infrastructure have prompted a tightening of security measures across many different industry sectors. Reducing control system vulnerabilities against physical and cyber attack is necessary to ensure the safety, reliability, integrity, and availability of these systems. The U.S. Department of Homeland Security has developed a strategy to secure these vulnerabilities. Crucial to this strategy is the Control Systems Security and Test Center (CSSTC) established to test and analyze control systems and their components. In addition, the CSSTC promotes a proactive, collaborative approach to increase industry's awareness of standards, products, and processes that can enhance the security of control systems. This paper outlines measures that can be taken to enhance the cybersecurity of process control systems in the chemical sector. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2006
Topological currents in ferromagnets and related systems – from the viewpoint of wave‐packet dynamics
Authors: Imura Ken‐Ichiro , Shindou Ryuichi
Published: December 2005

We reconsider the problem of the adiabatic motion of a wave packet of Bloch electrons, under a perturbation that is incommensurate with the lattice structure and varies slowly in time. Its effective dynamics is described by a set of equations of motion (EOM) with corrections due to the Berry phase. The underlying idea of our analyses is that various types of transport phenomena such as quantized, anomalous and spin Hall effects as well as specific sorts of polarization current can be best understood from the viewpoint of topological current associated with the Berry phase. Our EOM approach plays the role of bridge between the microscopic Berry phase and macroscopic topological transport. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the possibility of nonuniversal behavior in the 3D Ashkin–Teller model
Authors: Musiał Grzegorz , Rogiers Jos
Published: December 2005

The Monte Carlo simulations in the 3D Ashkin–Teller model on a cubic lattice are performed. The study is undertaken in the region where the universality class of the phase transitions has not been unambigously resolved yet. Using the finite‐size scaling relation between the magnetization, the temperature and the size of the system, the method of calculation of the critical exponent yh is proposed. Our preliminary results obtained for yh suggest a nonuniversal behavior, similarly as it was observed in the 2D case. Its value seems to change continuously in some interval approaching the Ising value near to all the tricritical points except one. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin‐polarized charge transport through ionic clusters of magnetic oxides
Authors: Gehring G. A. , Lehmann‐Szweykowska A. , Wojciechowski R. J. , Wigen P. E. , Micnas R.
Published: December 2005

We analyze the spin‐controlled charge transfer through a heterostructure consisting of one octahedral and one tetrahedral iron–oxygen ionic clusters, which are site‐coupled, sharing an oxygen ion. A number of charge carriers can be manipulated by valence‐uncompensated doping. The electron‐energy structure of the clusters and that of the heterostructure are found on the basis of the Anderson model. Current–voltage (I–V ) characteristics, derived from the Landauer‐like formula, turn out to be highly sensitive to the position of the Fermi level. We also calculated the magnetoresistance for the heterostructure with different orientations of the magnetic field. The result confirmed the empirical data for Ca:YIG, which indicate strong anisotropy of the magnetoresistance. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the symmetry of a Preisach map
Authors: Gutowski Marek W.
Published: December 2005

At the very heart of the successful phenomenological model of magnetic hysteresis there is the so called Preisach distribution. In the existing literature it is implicitly assumed, that this distribution has a mirror symmetry. We show, by simple and convincing example, that this common assumption is plainly wrong. Dropping it, we gain the ability to model not only the usual hysteresis loops (major and minor) more accurately than ever before, but also those displaying the exchange bias effect, what is impossible within the framework of the symmetrical Preisach model. It is hoped, that our observation paves the way towards the unified description of all hysteretic systems, including, but not necessarily limited to, superconductors, (multi)layered structures, nanocrystalline materials, patterned media, and – perhaps – the other non‐magnetic hysteretic phenomena. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin‐dependent transport through double‐island single‐electron devices
Authors: Weymann I. , Barnaś J.
Published: December 2005

Spin‐dependent electronic transport through a double‐island device with Coulomb blockade is considered theoretically in the sequential tunneling regime. The analysis is based on the master equation method, with the corresponding tunneling rates calculated from the Fermi golden rule. Electric current and the resulting tunnel magnetoresistance are analyzed as a function of bias and gate voltages for different collinear magnetic configurations of the device. Furthermore, the nonequilibrium spin accumulation on the islands is calculated self‐consistently from the appropriate spin balance conditions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transfer‐matrix study of critical properties of the Ising model following from the three‐cluster MFRG approach
Authors: Kamieniarz Grzegorz , Tomecka Daria M.
Published: December 2005

Using a transfer matrix technique and the Ising model, the predictions of the MFRG concept for clusters with linear size up to 21 have been tested for the three‐cluster MFRG approach. Even for small sizes of the clusters, the three‐cluster estimates of critical couplings and bulk critical exponents give the accuracy level equal to that of two‐cluster renormalization for much greater sizes. Performing the asymptotic analysis for the new data, the convergence of the surface critical exponent yhs towards the exact value is illustrated for the first time. Our improved method has enabled us to obtain the results for clusters with substantially greater sizes, to accelerate the calculations and also to confirm the reliability of the MFRG approach for the Ising model. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal time‐points in clinical trials with linearly divergent treatment effects
Authors: Winkens Bjorn , Schouten Hubert J. A. , van Breukelen Gerard J. P. , Berger Martijn P. F.
Published: November 2005

In repeated measures studies, equidistant time‐points do not always yield efficient treatment effect estimators. In the present paper, the optimal allocation of time‐points is calculated for a small number of repeated measures, different covariance structures and linearly divergent treatment effects. The gain in efficiency of the treatment effect estimator by using optimally allocated time‐points instead of equidistant time‐points or by adding optimally spaced measures (at the expense of patients) is then computed. The assumed covariance structure is crucial for the results. For a compound symmetric covariance structure, a large gain in efficiency is obtained by adding repeated measures at the end of the study. For a first‐order auto‐regressive covariance structure, highly efficient treatment effect estimators are obtained with only two repeated measures, i.e. at the start and at the end of the study. For a first‐order auto‐regressive covariance structure including measurement error, the gain in efficiency by adding optimally spaced measures depends on the covariance parameter values. The gain in efficiency is similar with or without a random intercept. For a fixed study budget, the commonly used design with more than two equally spaced measures was never optimal for the linear cost function and covariance structures that were used. If the covariance structure is unknown, the optimal design based on a first‐order auto‐regressive covariance structure with measurement error is preferable in terms of robustness against misspecification of the covariance structure. The numerical results are illustrated by two examples. Copyright © 2005 John Wiley & Sons, Ltd.
Anatomical and functional significance of urogenital hiatus in primary urodynamic stress incontinence
Authors: Huang W.‐C. , Yang S.‐H. , Yang J.‐M.
Published: December 2005

Objectives

To explore the correlations of anatomical and functional sonographic parameters of urogenital hiatus in primary urodynamic stress incontinence.

Methods

We reviewed retrospectively our urodynamic database from July 1996 to June 2003 and identified subjects with primary urodynamic stress incontinence who had had anatomical assessment of the lower urinary tract and the central part of the pelvic floor by ultrasound. The morphological changes that had occurred in the central pelvic floor were determined by the measurement of genitohiatal angle, genitohiatal distance and anorectal angle.

Results

A total of 396 women with a mean age of 48.8 ± 10.7 (range, 26–82) years were included in the study. One hundred and eighteen subjects (29.8%) were postmenopausal. Stage I pelvic organ prolapse was found in 345 (87.1%) of the women, stage II in 19 (4.8%) and stage III in 32 (8.1%). The genitohiatal angle and genitohiatal distance were significantly and positively associated with resting and straining bladder neck angles. The genitohiatal angle was associated with bladder neck funneling and dependent cystocele during stress (r = 0.144, P = 0.016 and r = 0.140, P = 0.02, respectively), and it was negatively associated with functional profile length (r = −0.157, P = 0.012). The genitohiatal distance was negatively associated with functional profile length and maximum urethral closure pressure (r = −0.148, P = 0.018 and r = −0.227, P = 0.009, respectively). Increased genitohiatal distance was also related to a low Valsalva leak‐point pressure (r = −0.199, P = 0.02). Multivariate analysis revealed that resting bladder neck angle was the independent factor for genitohiatal angle and genitohiatal distance.

Conclusions

In primary urodynamic stress incontinence, an increased resting genitohiatal distance or genitohiatal angle on sonographic imaging implies anterior vaginal wall prolapse. In addition, an increased genitohiatal distance is associated with functional impairment of urethral closure. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Überwachung von Plasmaprozessen durch OES. Monitoring of plasma processes by OES
Authors: Schmachtenberg Ernst , Hegenbart Andreas
Published: November 2005

Bei der industriellen Anwendung von Plasmaprozessen fehlt es häufig an einer Online‐Prozessüberwachung zur Prozessprotokollierung und Qualitätssicherung. Die Optische Emissionsspektroskopie (OES) bietet eine relativ einfache Möglichkeit, dieses Problem in vielen Fällen zu lösen. Das Verfahren beeinflusst die Prozesse selbst nicht, ist äußerst robust und preiswert. Die OES wurde für verschiedene Anwendungen beim Einsatz Mikrowellen‐angeregter Plasmen, zur gezielten Funktionalisierung (Behandlung und Beschichtung) von Kunststoffbauteilen, untersucht. Es konnte gezeigt werden, dass die OES zur Überwachung der Qualität von Sauerstoff‐Plasmaprozessen, z. B. bei der Aktivierung von Kunststoffbauteilen, eingesetzt werden kann. Darüber hinaus eignet sich die OES zur Online‐Qualitätssicherung bei der Erzeugung glasartiger Plasmapolymerschichten mit Hilfe der Mikrowellen‐angeregten Plasmapolymerisation, unter Verwendung eines Prozessgasgemisches aus HMDSO und Sauerstoff. Es gibt klare Zusammenhänge zwischen der chemischen Zusammensetzung, der Oberflächenspannung sowie der Rauigkeit der erzeugten Schichten und der Emission bestimmter chemischer Spezies im Plasma.
Evaluating hypotheses about dispersal in a vulnerable butterfly
Authors: Casula Paolo
Published: December 2005

Sound management of species requires reliable estimates of dispersal. Indeed, dispersal of individuals among local populations is a key factor in the biology and persistence of local populations and metapopulations. Here, the small‐scale dispersal pattern of a vulnerable species, the endemic Sardinian chalk hill blue butterfly, was studied by applying capture–recapture multistate models and a model selection based on AIC values. Model parameters were survival, capture and movement probabilities. The model selection showed that (a) survival probability of individuals varied between sexes, (b) capture probability varied between sexes and among patches, and (c) movement probability varied with direction. The probability of movement among adjacent local populations was generally low and ranged from 0.009 to 0.212. Movement probabilities were subsequently modeled using data on interpatch distance and donor patch population size or area. The ultrastructural “biology‐based” models turned out to be the most appropriate models for inference, showing that dispersal decreases with increasing interpatch distance and increasing donor patch population size or area, and suggesting that butterfly dispersal is affected by patch geometry and the presence of conspecifics. The application of multistate models, the model selection approach, and ultrastructural modeling allowed testing the validity of some general hypotheses related to dispersal in metapopulations and helped elucidate the butterfly small‐scale dispersal pattern.
Similarity of rocky intertidal assemblages along the Pacific coast of Japan: effects of spatial scales and geographic distance
Authors: Nakaoka Masahiro , Ito Norihiko , Yamamoto Tomoko , Okuda Takehiro , Noda Takashi
Published: December 2005

Factors and processes affecting community structures operate at various spatial and temporal scales. We analyzed how similarities of rocky intertidal assemblages vary at different spatial scales using a nested, hierarchical sampling design. Intertidal assemblages consisting of algae, sessile animals, and mobile animals were censused on five rock walls at each of five shores chosen within each of six regions along the Pacific coast of Japan, encompassing 1,800 km of coastlines. Based on this sampling design, similarities in assemblages were calculated using both qualitative (presence/absence) and quantitative (percent cover and density) data, and compared at three spatial levels: (1) rock level (the finest spatial scale, encompassing several to hundreds of meters), (2) shore level (the intermediate spatial scale, encompassing several to tens of kilometers), and (3) region level (the broadest spatial scale, encompassing hundreds to thousands of kilometers). Cluster analysis showed that assemblages were categorized into distinct regional groups except for the two southern regions, but they did not separate clearly from each shore. A nested analysis of similarities revealed significant variation in similarities among regions and among shores within each region, with the former showing greater variation. Similarity was negatively correlated with geographic distance at the regional level but not at the shore or the rock levels. At the regional level, similarity decreased more rapidly with distance for mobile animals than sessile organisms. The analyses highlighted the importance of broad‐scale abiotic/biotic factors such as oceanic current conditions and biogeographic factors in determining observed patterns in similarity of rocky intertidal assemblages.
Late Pleistocene highstand and recession of a small, high-altitude pluvial lake, Jakes Valley, central Great Basin, USA
Authors: García Antonio Francisco , Stokes Martin
Published: November 2005

Models of factors controlling late Pleistocene pluvial lake-level fluctuations in the Great Basin are evaluated by dating lake levels in Jakes Valley. “Jakes Lake” rose to a highstand at 13,870 ± 50 14C Yr B.P., receded to a stillstand at 12,440 ± 50 14C yr B.P., and receded steadily to desiccation thereafter. The Jakes Lake highstand is roughly coincident with highstands of lakes Bonneville, Lahontan and Russell. The rise to highstand and recession of Jakes Lake were most likely controlled by a storm track steered by the polar jet stream. The final stillstand of Jakes Lake helps constrain timing of northward retreat of the polar jet stream during the Pleistocene–Holocene transition.
Duration of untreated psychosis and ethnicity in the ÆSOP first-onset psychosis study
Authors: MORGAN CRAIG , FEARON PAUL , HUTCHINSON GERARD , McKENZIE KWAME , LAPPIN JULIA M. , ABDUL-AL RUDWAN , MORGAN KEVIN , DAZZAN PAOLA , BOYDELL JANE , HARRISON GLYNN , CRAIG TOM , LEFF JULIAN , JONES PETER , MURRAY ROBIN
Published: December 2005

Background. There is a common assumption that Black patients with a psychotic mental illness experience longer treatment delays during a first episode. We sought to investigate this issue in a large cohort of patients with a first episode of psychosis.

Method. All patients with a first episode of psychosis presenting to secondary mental health services within tightly defined catchment areas in south-east London and Nottingham over a 2-year period were included in the study. Data relating to duration of untreated psychosis (DUP) and clinical and sociodemographic characteristics were collected from patients, relatives and case-notes.

Results. There was no evidence that African-Caribbean or Black African patients experienced longer periods of untreated psychosis than White British patients prior to first contact with services. There was evidence that Black African patients experienced shorter periods of untreated psychosis than White British patients.

Conclusions. Contrary to what is commonly assumed, our study suggests that Black patients with a psychotic mental illness do not experience longer treatment delays prior to first contact with services than White British patients. This suggests that strategies to reduce treatment delays targeted specifically at Black patients will be of limited value.
A survey of interestingness measures for knowledge discovery
Authors: MCGARRY KEN
Published: December 2005

It is a well-known fact that the data mining process can generate many hundreds and often thousands of patterns from data. The task for the data miner then becomes one of determining the most useful patterns from those that are trivial or are already well known to the organization. It is therefore necessary to filter out those patterns through the use of some measure of the patterns actual worth. This article presents a review of the available literature on the various measures devised for evaluating and ranking the discovered patterns produced by the data mining process. These so-called interestingness measures are generally divided into two categories: objective measures based on the statistical strengths or properties of the discovered patterns and subjective measures that are derived from the user's beliefs or expectations of their particular problem domain. We evaluate the strengths and weaknesses of the various interestingness measures with respect to the level of user integration within the discovery process.
Exercise-based transportation reduces oil dependence, carbon emissions and obesity
Authors: HIGGINS PAUL A.T.
Published: December 2005

Societal dependence on oil leads to increasingly negative social consequences throughout the world, including climate change, air pollution, political and economic instability, and habitat degradation. Reliance on the automobile for transportation also contributes to a sedentary lifestyle, an obesity epidemic and poor health. These problems are particularly pronounced in the USA, which currently consumes c. 27% of global oil production and produces c. 25% of global carbon emissions, and where c. 65% of adults are overweight or obese. Other countries throughout the world that replicate or hope to replicate the automobile-based lifestyle of the USA face similar problems now or in the near future. This paper develops and applies calculations relating the distances that could be travelled through recommended daily walking or cycling with weight loss, oil consumption and carbon emissions. These straightforward calculations demonstrate that widespread substitution of driving with distances travelled during recommended daily exercise could reduce the USA's oil consumption by up to 38%. This saving far exceeds the amount of oil recoverable from the Arctic National Wildlife Refuge, suggesting that exercise can reduce foreign oil dependence and provide an alternative to oil extraction from environmentally sensitive habitat. At the same time, an average individual who substitutes this amount of exercise for transportation would burn respectively c. 12.2 and 26.0 kg of fat per year for walking and cycling. This is sufficient to eliminate obese and overweight conditions in a few years without dangerous or draconian diet plans. Furthermore, a reduction in carbon dioxide emissions of c. 35% is possible if the revenue saved through decreased health care spending on obesity is redirected toward carbon abatement. As a result, exercise-based transportation may constitute a favourable alternative to the energy and diet plans that are currently being implemented in the USA and may offer better development choices for developing countries.
Infections associated with cantaloupe consumption: a public health concern
Authors: BOWEN A. , FRY A. , RICHARDS G. , BEAUCHAT L.
Published: December 2005

Fresh produce is an important part of a healthy diet and is consumed in greater quantity in the United States than ever before. Consumption of cantaloupe has recently been associated with several large outbreaks of infections in North America, highlighting the need for a better understanding of practices and processes that may contribute to contamination. We reviewed all cantaloupe-associated outbreaks that were reported to the Centers for Disease Control and Prevention (CDC) and published in the literature. Twenty-three outbreaks occurred between 1984 and 2002; 1434 people became ill, 42 were hospitalized, and two died in these outbreaks. Aetiological agents in the outbreaks included five serotypes of Salmonella enterica, Campylobacter jejuni, Escherichia coli O157:H7, and norovirus. We reviewed processes contributing to cantaloupe contamination, conditions affecting survival and growth of bacterial pathogens on melons, and potential methods for sanitization. For maximum safety, industry, federal, and international partners must collaborate to ensure that appropriate interventions are in place to minimize the risk of contamination and prevent the growth of pathogens during cantaloupe production, processing, storage, and preparation.
Purinergic receptors activating rapid intracellular Ca2+ increases in microglia
Authors: LIGHT ALAN R. , WU YING , HUGHEN RONALD W. , GUTHRIE PETER B.
Published: December 2005

We provide both molecular and pharmacological evidence that the metabotropic, purinergic, P2Y6, P2Y12 and P2Y13 receptors and the ionotropic P2X4 receptor contribute strongly to the rapid calcium response caused by ATP and its analogues in mouse microglia. Real-time PCR demonstrates that the most prevalent P2 receptor in microglia is P2Y6 followed, in order, by P2X4, P2Y12, and P2X7 = P2Y13. Only very small quantities of mRNA for P2Y1, P2Y2, P2Y4, P2Y14, P2X3 and P2X5 were found. Dose-response curves of the rapid calcium response gave a potency order of: 2MeSADP>ADP=UDP=IDP=UTP>ATP>BzATP, whereas A2P4 had little effect. Pertussis toxin partially blocked responses to 2MeSADP, ADP and UDP. The P2X4 antagonist suramin, but not PPADS, significantly blocked responses to ATP. These data indicate that P2Y6, P2Y12, P2Y13 and P2X receptors mediate much of the rapid calcium responses and shape changes in microglia to low concentrations of ATP, presumably at least partly because ATP is rapidly hydrolyzed to ADP. Expression of P2Y6, P2Y12 and P2Y13 receptors appears to be largely glial in the brain, so that peripheral immune cells and CNS microglia share these receptors. Thus, purinergic, metabotropic, P2Y6, P2Y12, P2Y13 and P2X4 receptors might share a role in the activation and recruitment of microglia in the brain and spinal cord by widely varying stimuli that cause the release of ATP, including infection, injury and degeneration in the CNS, and peripheral tissue injury and inflammation which is signaled via nerve signaling to the spinal cord.
Chemical and physical characterization by EELS of strontium hexanoate reverse micelles and strontium carbonate nanophase produced during tribological experiments
Authors: Mansot J. L. , Golabkan V. , Romana L. , Césaire T.
Published: December 2005

Electron energy‐loss spectroscopy (EELS) in the analytical electron microscope has been used to characterize nanometre‐scale phases of overbased strontium 3,5‐dimethylhexanoate reverse micelles and the tribological film obtained during a friction test when the phases are used as lubricant additives. Accurate chemical, molecular and structural information on these materials are deduced by interpreting the EELS near‐edge structure. This approach allows confirmation of the composite structure of the micelles, which contain a mineral core and amorphous strontium carbonate surrounded by an organic shell. It also allows identification of the chemical composition and physical structure of the tribological film as an assembly of pure strontium carbonate microcrystals, i.e. strontianite, distributed in an amorphous intergranular phase.
Subcellular localization of boron in cultured melanoma cells by electron energy‐loss spectroscopy of freeze‐dried cryosections
Authors: Michel J. , Sauerwein W. , Wittig A. , Balossier G. , Zierold K.
Published: December 2005

Boron neutron capture therapy (BNCT) is based on the ability of the non‐radioactive isotope 10B to capture thermal neutrons and to disintegrate instantaneously. This reaction opens a way to selectively destroy tumour cells after specific uptake of 10B. In this paper, a method based on electron energy‐loss spectroscopy is presented for detecting and quantifying boron in freeze‐dried cryosections of human melanoma cells. A practical detection limit of around 6 mmol kg−1 in 0.1‐µm2 areas is estimated using specimens prepared from standard boron solutions. Preliminary results of boron mapping in the spectrum‐imaging acquisition mode reveal boron penetration and probably spot‐like accumulation within melanoma cells when exposed to culture medium containing sodium borocaptate.
Electron energy‐loss spectroscopy study of thin film hafnium aluminates for novel gate dielectrics
Authors: Stemmer S. , Chen Z. Q. , Zhu W. J. , Ma T. P.
Published: December 2005

We have used conventional high‐resolution transmission electron microscopy and electron energy‐loss spectroscopy (EELS) in scanning transmission electron microscopy to investigate the microstructure and electronic structure of hafnia‐based thin films doped with small amounts (6.8 at.%) of Al grown on (001) Si. The as‐deposited film is amorphous with a very thin (∼0.5 nm) interfacial SiOx layer. The film partially crystallizes after annealing at 700 °C and the interfacial SiO2‐like layer increases in thickness by oxygen diffusion through the Hf‐aluminate layer and oxidation of the silicon substrate. Oxygen K‐edge EELS fine‐structures are analysed for both films and interpreted in the context of the films’ microstructure. We also discuss valence electron energy‐loss spectra of these ultrathin films.
Study of changes in L32 EELS ionization edges upon formation of Ni‐based intermetallic compounds
Authors: Potapov P. L. , Kulkova S. E. , Schryvers D.
Published: December 2005

EELS L32 ionization edges in several Ni‐based intermetallic compounds have been studied and interpreted in terms of the distribution of electrons in the valence d‐bands. It is demonstrated that the integral EELS cross‐sections change only slightly upon the formation of intermetallic compounds and therefore the charge transfer between atoms is negligible. On the other hand, the changes in the fine energy‐loss near‐edge structure (ELNES) of the Ni L3 edge can be readily detected indicating an important redistribution of d‐electrons at the Ni site with alloying. These features are well reproduced by ab‐initio calculations with a FLAPW method in its WIEN97 implementation. In contrast to the drastic effect of chemical environment, structural transformations in the investigated intermetallics result in smaller ELNES changes, which can be detected by only exceptional instruments with a higher energy resolution.
EELS investigation of FeCo/SiO2 nanocomposites
Authors: Falqui A. , Serin V. , Calmels L. , Snoeck E. , Corrias A. , Ennas G.
Published: December 2005

The factors that determine the local magnetic properties of FeCo/SiO2 nanocomposite powders and films have been analysed by electron energy‐loss spectroscopy (EELS) and transmission electron microscopy (TEM). Attention has been given to the chemical composition, the local electronic structure and the atomic arrangement. The results show that the nanoparticles from sol‐gel prepared powders are generally Fe‐rich, whereas they are Co‐rich in sol‐gel prepared films. In addition, a subnanometre oxide layer at the surface of the FeCo nanoparticles has been clearly observed in the powder sample. It is found that the magnetic moment should be partly governed by alloying effects. Numerical values of the near‐surface magnetic moment have been obtained using the ab‐initio layer‐KKR method. These values should be helpful in understanding the layer‐by‐layer changes of the white line ratio close to the surface of the nanoparticles.
N‐K ELNES study of anisotropy effects in hexagonal AlN
Authors: Radtke G. , Epicier T. , Bayle‐Guillemaud P. , Le Bossé J. C.
Published: December 2005

Anisotropic effects in hexagonal aluminium nitride have been studied by electron energy‐loss spectroscopy (EELS) in the N‐K energy loss near edge structure (ELNES). Experimental data acquired with different collection angles and with a nearly parallel incident electron beam aligned along the c‐axis have been compared to simulations based on ab initio calculations. The extraction of intrinsic parallel I‖ (with momentum transfer q ‖ c axis) and perpendicular I⊥ (with momentum transfer q ⊥ c axis) components has been performed directly from the experimental spectra. This has been done according to their description as linear combinations of I‖ and I⊥, with adequate weights deduced from a geometrical model of anisotropic behaviour.
Endothelin‐1 stimulates the translocation and upregulation of both glucose transporter and hexokinase in astrocytes: relationship with gap junctional communication
Authors: Sánchez‐Alvarez Rosa , Tabernero Arantxa , Medina José M.
Published: December 2005

We have previously shown that endothelin‐1 increases glucose uptake in astrocytes. In the present work we investigate the mechanism through which endothelin‐1 (ET‐1) increases glucose uptake. Our results show that ET‐1 activates a short‐term and a long‐term mechanism. Thus, ET‐1 induced a rapid change in the localization of both GLUT‐1 and type I hexokinase. These changes are probably aimed at rapidly increasing the entry and phosphorylation of glucose. In addition, ET‐1 upregulated GLUT‐1 and type I hexokinase and induced the expression of isoforms not normally expressed in astrocytes, such as GLUT‐3 and type II hexokinase. These changes provide astrocytes with the machinery required to sustain a high rate of glucose uptake for a longer period of time. Our previous work had suggested that the effect of ET‐1 on glucose uptake was associated with the inhibition of gap junctions. In this work, we compare the effect of ET‐1 with that of carbenoxolone, a classical inhibitor of gap junction communication. Carbenoxolone increased glucose uptake to the same extent as ET‐1 following the same mechanisms. Thus, carbenoxolone induced a rapid change in the localization of both GLUT‐1 and type I hexokinase, upregulated GLUT‐1 and type I hexokinase and induced the expression of GLUT‐3 and type II hexokinase. When the inhibition of gap junction was prevented by tolbutamide, neither ET‐1 nor carbenoxolone were able to increase the levels of GLUT‐1, GLUT‐3, type I hexokinase or type II hexokinase, indicating that these events are closely related to gap junctions.