bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenging assumptions of future coastal habitat development around the UK
Authors: Orford Julian D. , Pethick John
Published: October 2006

One habitat management requirement forced by 21st century relative sea‐level rise (RSLR), will be the need to re‐comprehend the dimensions of long‐term transgressive behaviour of coastal systems being forced by such RSLR. Fresh approaches to the conceptual modelling and subsequent implementation of new coastal and peri‐marine habitats will be required. There is concern that existing approaches to forecasting coastal systems development (and by implication their associated scarce coastal habitats) over the next century depend on a certain premise of orderly spatial succession of habitats. This assumption is shown to be questionable given the possible future rates of RSLR, magnitude of shoreline retreat and the lack of coastal sediment to maintain the protective morphologies to low‐energy coastal habitats. Of these issues, sediment deficiency is regarded as one of the major problem for future habitat development. Examples of contemporary behaviour of UK coasts show evidence of coastal sediment starvation resulting from relatively stable RSLR, anthropogenic sealing of coastal sources, and intercepted coastal sediment pathways, which together force segmentation of coastal systems. From these examples key principles are deduced which may prejudice the existence of future habitats: accelerated future sediment demand due to RSLR may not be met by supply and, if short‐ to medium‐term hold‐the‐line policies predominate, long‐term strategies for managed realignment and habitat enhancement may prove impossible goals. Methods of contemporary sediment husbandry may help sustain some habitats in place but otherwise, instead of integrated coastal organization, managers may need to consider coastal breakdown, segmentation and habitat reduction as the basis of 21st century coastal evolution and planning. Copyright © 2006 John Wiley & Sons, Ltd.
Bed waves at the basin scale: implications for river management and restoration
Authors: James L. Allan
Published: October 2006

An extensive literature about fluvial sediment waves, slugs or pulses has emerged in the past 20 years. The concept has been useful in many respects, but has been applied to diverse phenomena using a variety of definitions. Moreover, inferred linkages between channel‐bed changes and sediment loads are often not justifiable. This paper reviews concepts of large fluvial sediment waves at scales extending to several tens of kilometres. It points out constraints on the inferences that can be made about sediment loads based on changes in channel‐bed elevation at this scale where channel sediment interacts with storage in floodplain and terrace deposits. The type area of G. K. Gilbert's initial sediment‐wave concept is re‐examined to show that neither wave translation nor dispersion occurred in the simple manner commonly assumed. Channel aggradation and return to graded conditions provide an alternative theory explaining Gilbert's observed bed‐elevation changes. Recognizing the evidence and implications of the former passage of a large‐scale bed wave is essential to the accurate diagnosis of catchment conditions and the adoption of appropriate river restoration goals or methods. Sediment loads, water quality, channel morphologic stability and aquatic ecosystems often reflect changes in sediment storage long after the channel bed has returned to grade. Copyright © 2006 John Wiley & Sons, Ltd.
Controlled Synthesis of a Chitosan‐Based Graft Copolymer Having Polysarcosine Side Chains Using the NCA Method with a Carboxylic Acid Additive
Authors: Nakamura Rikiya , Aoi Keigo , Okada Masahiko
Published: October 2006

Summary: A novel chitosan derivative with polysarcosine side chains, i.e., chitosan‐graft‐polysarcosine [chitosan‐graft‐poly(N‐methylglycine)], was synthesized by ring‐opening polymerization of sarcosine N‐carboxyanhydride (NCA) with chitosan as a macroinitiator in the presence of carboxylic acids in dimethyl sulfoxide at 27 °C. Degree of substitution ($\overline {DS}$) for polysarcosine side chains introduced to chitosan was controlled successfully by the feed amount of the additive nicotinic acid ($\overline {DS}$ = 0.21–0.71). Independent of $\overline {DS}$ control, degree of polymerization ($\overline {DP}$) for polysarcosine side chains was controlled by adjusting feed ratios of NCA monomer to chitosan ($\overline {DP}$ = 14–43). Kinetic analysis of the propagation of sarcosine NCA was conducted by measuring CO2 evolution. Apparent kp values decreased with increased feed amounts of nicotinic acid, supporting the theory that propagation of NCA in the presence of nicotinic acid proceeds via equilibrium between active amine and dormant ammonium species.

Propagation mechanism of carboxylic acid‐mediated polymerization of sarcosine N‐carboxyanhydride.

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Propagation mechanism of carboxylic acid‐mediated polymerization of sarcosine N‐carboxyanhydride.
A High‐Content Diarylethene Photochromic Polymer for an Efficient Fluorescence Modulation
Authors: Jeong Yong‐Chul , Yang Sung Ik , Kim Eunkyoung , Ahn Kwang‐Hyun
Published: October 2006

Summary: A highly fluorescent photochromic polymer, poly‐BTFO4, was prepared. The fluorescence quantum yield of the poly‐BTFO4 was six times higher than that of BTFO4. Fatigue resistance of the polymer at its photostationary state was significantly enhanced compared with that of BTFO4. Importantly, the poly‐BTFO4 film also showed an efficient photochromism as well as strong fluorescence similar to the results in solution, which allow photoinduced fluorescence switching applicable to optical switches.

Improvement of fluorescence quantum yield and fatigue resistance.

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Improvement of fluorescence quantum yield and fatigue resistance.
Stimuli‐Responsive A‐b‐(B‐co‐C) Diblock Terpolymers Bearing Polyampholyte Sequences
Authors: Gotzamanis George , Tsitsilianis Constantinos
Published: October 2006

Summary: Diblock terpolymers that consist of homopolymer and statistical copolymer (polyampholyte) building blocks are synthesized by group transfer polymerization. Two types of block tepolymers are explored in aqueous media: the amphiphilic poly{[(diethylamino)ethyl methacrylate]‐co‐(methacrylic acid)}‐block‐poly(methyl methacrylate) and the double hydrophilic poly[oligo(ethylene glycol) methacrylate]‐block‐poly{[(diethylamino)ethyl methacrylate]‐co‐(methacrylic acid)}. The first terpolymer self‐assembles in aqueous media to form responsive micelles that change their corona charge sign upon switching pH. The second terpolymer exhibits a multi‐responsive behavior. It forms neutral, positive, or negative micelles depending on a combination of different environmental conditions such as temperature, pH, and ionic strength.

P(DEAEMA‐co‐MAA)‐b‐PMMA pH‐sensitive micelles.

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P(DEAEMA‐co‐MAA)‐b‐PMMA pH‐sensitive micelles.
Single‐Line EPR Spectra from Radicals Encapsulated in Aggregates of Amphiphilic Block Copolymers with Hydrophobic Dendritic Pendants in Water
Authors: Tamano Kana , Tanaka Toshiyuki , Awaga Kunio , Imae Toyoko , Yusa Shin‐ichi , Shimada Yoshihiko
Published: October 2006

Summary: A water‐insoluble organic 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical is solubilized in aqueous solutions of aggregates of amphiphilic block copolymers with hydrophobic dendritic pendants. The number (100–200) of DPPH molecules solubilized in an aggregate, which is evaluated from UV‐visible absorption spectra, is in agreement with that of the DPPH radicals determined from electron paramagnetic resonance (EPR) spectroscopy. The DPPH radicals are stably solubilized without decomposition in the polymer aggregates. The radicals exhibit a single‐line EPR absorption, which is narrowed by the interspin interaction, and indicates the assembly formation of DPPH radicals in polymer aggregates. These results suggest the effective utilization of the DPPH radical as a spin‐probe indicator in aqueous solutions.

When DPPH is solubilized in aqueous solutions of NaAMPS‐b‐G2(n3), the polymer solutions become purple colored, which is characteristic of the DPPH radical.

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When DPPH is solubilized in aqueous solutions of NaAMPS‐b‐G2(n3), the polymer solutions become purple colored, which is characteristic of the DPPH radical.
Some probability functions in reliability and their applications
Authors: Cha Ji Hwan , Mi Jie
Published: October 2006

There has been much research on the general failure model recently. In the general failure model, when the unit fails at its age t, Type I failure (minor failure) occurs with probability 1 − p(t) and Type II failure (catastrophic failure) occurs with probability p(t). In the previous research, some specific shapes (constant, non‐decreasing, or bathtub‐shape) on the probability function p(t) are assumed. In this article, general results on some probability functions are obtained and applied to study the shapes of p(t). The results are also applied to determining the optimal inspection and allocation policies in maintenance problems. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Robust tower location for code division multiple access networks
Authors: Rosenberger Jay M. , Olinick Eli V.
Published: October 2006

Designing Code Division Multiple Access networks includes determining optimal locations of radio towers and assigning customer markets to the towers. In this paper, we describe a deterministic model for tower location and a stochastic model to optimize revenue given a set of constructed towers. We integrate these models in a stochastic integer programming problem with simple recourse that optimizes the location of towers under demand uncertainty. We develop algorithms using Benders' reformulation, and we provide computational results. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Numerical modelling of non‐linear electroelasticity
Authors: Vu D. K. , Steinmann P. , Possart G.
Published: October 2006

The numerical modelling of non‐linear electroelasticity is presented in this work. Based on well‐established basic equations of non‐linear electroelasticity a variational formulation is built and the finite element method is employed to solve the non‐linear electro‐mechanical coupling problem. Numerical examples are presented to show the accuracy of the implemented formulation. Copyright © 2006 John Wiley & Sons, Ltd.
Analysis and Interpretation of Hopper Flow Behaviour Using Electrical Capacitance Tomography
Authors: Romanowski Andrzej , Grudzien Krzysztof , Williams Richard A.
Published: October 2006

This paper presents a critical analysis of the application of electrical capacitance tomography (ECT) to exploring the behaviour of solids flow during hopper discharge. Particulate media are employed in many areas such as the food industry, civil and chemical engineering etc. This is a report of work on the measurement of parameters that determine hopper flow for several different types of particulate systems, using a hopper of adjustable geometry equipped with ECT sensors. There is a comparison of different data analysis methods including: Bayesian/MCMC spatial modelling; reconstructed measurements analysis; raw data processing and theoretical descriptions. Measurement and interpretation protocols suited to detection of particular flow phenomena are assessed and recommended.
Effect of substrate temperature and post‐deposition annealing on the properties of evaporated CdSe thin films
Authors: Bacaksiz E. , Basol B. M. , Altunbaş M. , Yılmaz S. , Tomakin M. , Abay B.
Published: October 2006

The structural, morphological and optical properties of vacuum‐evaporated CdSe thin films were investigated as a function of the substrate temperature and the post‐deposition annealing conditions. It was observed that the grain sizes and morphologies of as‐deposited layers were similar for substrate temperatures of 100 and 200 K. However, CdSe films produced at a substrate temperature of 300 K had substantially different surface morphology. Annealing at 473–673 K in air did not cause any appreciable grain growth in any of the films irrespective of their growth temperature. However, annealing at 673 K initiated intergrain coalescence and altered surface morphology by reducing faceting. X‐ray diffraction studies showed that the crystallinity of the CdSe films was improved upon annealing. The optical band gap energy values were obtained and two direct transitions were observed. This may be attributed to spin orbit splitting of the valence band. Resistivity measurements indicated that annealing at 673 K in air forms a highly resistive compensated CdSe film. The results showed that although the substrate temperature during growth plays the major role in determining the properties of deposited films, post‐deposition annealing at temperatures of at least 673 K may lead to further changes in these properties. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strain sensing with carbon nanotube devices
Authors: Sickert D. , Taeger S. , Kühne I. , Mertig M. , Pompe W. , Eckstein G.
Published: October 2006

Carbon nanotubes have been demonstrated to behave piezoresistively, i.e. to change resistance dramatically upon elastic deformation. This effect can be utilized for strain sensing, pressure sensing and for nano electromechanical transducers in microsystems. Here we report on a bottom‐up method for integrating carbon nanotube bundles into such microsystems based on ac‐dielectrophoresis. In contrast to previous publications there are many carbon nanotubes contacted at once. At the cost of sensitivity of the sensing element the manufacturing is simplified. We demonstrate the functionality of our approach with a macroscopic strain gauge. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resistivity measurements of Mo6S3I6 nanowire networks
Authors: Berčič B. , Pirnat U. , Kusar P. , Dvorsek D. , Vengust D. , Mihailovic D.
Published: October 2006

We present measurements of resistivity on Mo6S3I6 nanowire networks as a function of temperature, moisture and high‐temperature processing conditions. The room‐temperature conductivity of as‐grown material is s 300 K ∼ 0.04 S/m with a linear I –V characteristic. The temperature dependence of conductivity of pristine samples closely follows the expression s = s 0 exp (–T 0/T)b , where b = 1/4. Removal of interstitial iodine from the network by annealing in vacuum gives rise to a cross‐over to b = 1/2 and an increase in conductivity. Different scenarios for observed cross‐over are discussed. The introduction of water vapour leads to a decrease in conductivity and reveals that the resistivity of the network is sensitive to interstitial water molecules, which is interesting for potential chemical sensor applications. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magneto‐optical spectroscopy of excitons in carbon nanotubes
Authors: Shaver J. , Kono J. , Portugall O. , Krstić V. , Rikken G. L. J. A. , Miyauchi Y. , Maruyama S. , Perebeinos V.
Published: October 2006

We describe recent results of optical experiments on single‐walled carbon nanotubes in high magnetic fields, probing the influence of a tube‐threading magnetic flux on their band structure and excitonic states. The magnetic flux breaks the time‐reversal symmetry and thus lifts the K –K ′ valley degeneracy, and the amount of state splitting is determined by the Aharonov–Bohm phase. We show experimental evidence that this field‐induced symmetry breaking overcomes the Coulomb‐induced exciton splitting which is predicted to make the lowest singlet exciton state optically inactive (or “dark”). Thus, a magnetic field applied parallel to the tube axis “brightens” the dark exciton, resulting in a drastic increase in photoluminescence intensity with magnetic field. We also find that the amount of brightening increases with decreasing temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of stable dispersions containing up to 70% individual carbon nanotubes in a common organic solvent
Authors: Giordani S. , Bergin S. , Nicolosi V. , Lebedkin S. , Blau W. J. , Coleman J. N.
Published: October 2006

Applications of single‐wall carbon nanotubes (SWNT) are severely restricted, as they exist in rope‐like bundles. Many methods have been suggested to de‐bundle SWNTs, including both covalent and non‐covalent funtionalisation with surfactants, acids, polymers and macromolecules. However, these strategies are unsatisfactory because they result in either the chemical modification of the nanotube or the presence of residual dispersion agents. What is required is the demonstration of stable, exfoliated SWNT dispersions in common solvents. In this work we have demonstrated debundling of single‐wall nanotubes by diluting nanotubes dispersions in the solvent N‐methyl‐2‐pyrrolidinone (NMP). Atomic‐force‐microscopy measurements show a steady decrease in bundle diameter distribution as the concentration is decreased. Photoluminescence and Raman spectroscopy confirmed the presence of individual nanotubes in NMP dispersion. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin interactions in InAs quantum dots and molecules
Authors: Doty M. F. , Ware M. E. , Stinaff E. A. , Scheibner M. , Bracker A. S. , Ponomarev I. V. , Badescu S. C. , Korenev V. L. , Reinecke T. L. , Gammon D.
Published: October 2006

Spin interactions between particles in quantum dots or quantum dot molecules appear as fine structure in the photoluminescence spectra. Using the understanding of exchange interactions that has been developed from single dot spectra, we analyze the spin signatures of coupled quantum dots separated by a wide barrier such that inter‐dot interactions are negligible. We find that electron–hole exchange splitting is directly evident. In dots charged with an excess hole, an effective hole–hole interaction can be turned on through tunnel coupling. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Removing spin blockade by photon‐assisted tunneling in double quantum dots
Authors: Sánchez Rafael , Platero Gloria , Aguado Ramón , Cota Ernesto
Published: October 2006

Pauli exclusion principle can lead to a supression of transport through double quantum dots, even if both quantum dots are connected by a resonant driving ac field. In this work, we study how this effect, known as spin blockade, can be removed by means of the influence of the driving field on the contacts to the leads. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two time scales of the electron–hole spin relaxation in InAs/GaAs quantum dots
Authors: Testelin C. , Aubry E. , Chaouache M. , Maaref M. , Bernardot F. , Chamarro M. , Gérard J.‐M.
Published: October 2006

We have performed time‐resolved differential transmission on an ensemble of InAs/GaAs self‐assembled quantum dots. We have calculated the polarization rate decay, on which two time scales in the electron–hole spin relaxation dynamics are observed. A study versus the energy of the interband transition reveals that the fast spin relaxation becomes important when excited and mixed states are involved. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Special issue: Electronic Properties of Novel Nanostructures
Authors: Kuzmany Hans , Dinse Peter , Roth Siegmar , Thomsen Christian
Published: October 2006

This special issue of physica status solidi (b) contains contributions presented at the International Winterschool/Euroconference on Electronic Properties of Novel Materials (IWEPNM 2006). The twentieth anniversary meeting was held in March 2006 in Kirchberg, Austria.

The articles in this issue provide essential information on a wide spectrum of topics, including mechanical and electronic properties of carbon nanotubes, graphene, fullerenes and fulleroides, ab initio calculations for molecular nanostructures, single molecule experiments, scanning electron microscopy of molecular nanostructures, applications, composites and chemistry of molecular nanostructures, molecular machines and molecular motors, and template grown molecular nanomaterials.

As in previous years, the meeting was attended by many outstanding researchers from around the world and from a wide spectrum of scientific disciplines. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron transport with mobility above 10–3 cm2/Vs in amorphous film of co‐planar bipyridyl‐substituted oxadiazole
Authors: Ichikawa Musubu , Hiramatsu Nobuyasu , Yokoyama Norimasa , Miki Tetsuzo , Narita Susumu , Koyama Toshiki , Taniguchi Yoshio
Published: October 2006

We demonstrate that a bipyridyl substituted oxadiazole (Bpy‐OXD) shows high electron mobility that reached above 10–3 cm2/Vs. We believe that the high mobility results from both the hybrid molecular structure of the two electron‐accepting units: bipyridyl and oxadiazole, and the planar molecular structure based on its lack of sterically hindered bulky substituent. The computational analysis elucidates that the amorphous nature of Bpy‐OXD in thin‐film state probably results from the polymorphic effect in isolated state and the volume effect in solid state. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Climate‐induced changes in the vegetation pattern of China in the 21st century
Authors: Yu Li , Cao Mingkui , Li Kerang
Published: October 2006

Quantifying climate‐induced changes in vegetation patterns is essential to understanding land–climate interactions and ecosystem changes. In the present study, we estimated various distributional changes of vegetation under different climate‐change scenarios in the 21st century. Both hypothetical scenarios and Hedley RCM scenarios show that the transitional vegetation types, such as shrubland and grassland, have higher sensitivity to climatic change compared to vegetation under extreme climatic conditions, such as the evergreen broadleaf forest or desert, barren lands. Mainly, the sensitive areas in China lie in the Tibetan Plateau, Yunnan‐Guizhou Plateau, northeastern plain of China and eco‐zones between different vegetations. As the temperature increases, mixed forests and deciduous broadleaf forests will shift towards northern China. Grassland, shrubland and wooded grassland will extend to southeastern China. The RCM‐project climate changes generally have caused positive vegetation changes; vegetation cover will probably improve 19% relative to baseline, and the forest will expand to 8% relative to baseline, while the desert and bare ground will reduce by about 13%.
Monitoring wild greenfinch (Carduelis chloris) for Salmonella enterica typhimurium
Authors: Grant David , Todd Peter A. , Pennycott Tom
Published: October 2006

The identification and monitoring of emerging infectious diseases in free living wild birds is a challenge to wildlife biologists. In this study, a non‐invasive methodology for identifying salmonellosis in wild garden birds was developed. We focussed on greenfinch, Carduelis chloris, which were found to have a seasonal pattern in the occurrence of Salmonella Typhimurium DT 56(v). Principal components analysis of biometric data indicated that low fat and low weight could be useful indicators of Salmonella positive greenfinch. A combination of biometrics taken from live birds, faecal analysis, and behavioural observations provide an effective and efficient system for identifying the presence of salmonellosis within greenfinch.
Wave dynamics of an electrojet: generalized Farley–Buneman instability
Authors: McKENZIE JAMES F.
Published: October 2006

In this paper we generalize the classical Farley–Buneman (FB) instability to include space-charge effects and finite electron inertia. The former effect makes the ion-acoustic wave dispersive with the usual resonance appearing at the ion plasma frequency, but other than that the structure of the FB instability remains intact. However, the inclusion of the latter, finite electron inertia, gives rise to the propagating electron-cyclotron mode, albeit modified by collisions. In the presence of differential electron streaming relative to the ions, the interaction between this mode, attempting to propagate against the stream, but convected forward by the stream, and a forward propagating ion-acoustic mode, gives rise to a new instability distinct from the FB instability. The process may be thought of in terms of the coupling between negative energy waves (electron-cyclotron waves attempting to propagate against the stream) and positive energy waves (forward propagating ion-acoustic waves). In principle, the instability simply requires super-ion acoustic streaming electrons and the corresponding growth rates are of the order of one half of the lower hybrid frequency, which are faster than the corresponding FB growth rates. For conditions appropriate to the middle day-side E-region this instability excites a narrow band of frequencies just below the ion plasma frequency. Its role in the generation of electrojet irregularities may be as important as the classical FB instability.
Context for the ESA ExoMars rover: the Panoramic Camera (PanCam) instrument
Authors: Griffiths Andrew D. , Coates Andrew J. , Jaumann Ralf , Michaelis Harald , Paar Gerhard , Barnes David , Josset Jean-Luc
Published: October 2006

The recently approved ExoMars rover is the first element of the ESA Aurora programme and is scheduled to deliver the Pasteur exobiology payload to Mars by 2015. The 0.7 kg Panoramic Camera will provide multi-spectral stereo images with 65 ° field-of-view (1.1 mrad/pixel) and high-resolution (85 μrad/pixel) monoscopic ‘zoom’ images with 5 ° field-of-view. The stereo wide-angle cameras (WAC) are based on the Beagle 2 Stereo Camera System heritage (Griffiths et al. (2005). Planet. Space Sci. 53, 1466–1488). The Panoramic Camera instrument is designed to fulfil the digital terrain mapping requirements of the mission as well as to provide multi-spectral geological imaging, colour and stereo panoramic images, water vapour abundance and dust optical depth measurements. It can also be used for high-resolution imaging of inaccessible locations on crater walls and to observe retrieved subsurface samples before ingestion into the rest of the Pasteur payload.
The anti‐amnesic and neuroprotective effects of donepezil against amyloid β25‐35peptide‐induced toxicity in mice involve an interaction with theσ1receptor
Authors: Meunier J , Ieni J , Maurice T
Published: October 2006

Background and purpose:

The acetylcholinesterase inhibitor, donepezil, is also a high affinity σ1receptor agonist. We examined the involvement of σ1receptors in its anti‐amnesic and neuroprotective properties against amyloid β25‐35peptide‐induced toxicity in mice.

Experimental approach:

Mice were given an intracerebroventricular (i.c.v.) injection of Aβ25‐35peptide (9 nmol) 7‐9 days before being tested for spontaneous alternation and passive avoidance. Hippocampal lipid peroxidation was measured 7 days after Aβ25‐35injection to evaluate oxidative stress. Donepezil, the σ1agonist PRE‐084 or the cholinesterase (ChE) inhibitors tacrine, rivastigmine and galantamine were administered either 20 min before behavioural sessions to check their anti‐amnesic effects, or 20 min before Aβ25‐35injection, or 24 h after Aβ25‐35injection and then once daily before behavioural sessions, to check their pre‐ and post‐i.c.v. neuroprotective activity, respectively.

Key results:

All the drugs tested were anti‐amnesic, but only the effects of PRE‐084 and donepezil were prevented by the σ1antagonist BD1047. Only PRE‐084 and donepezil showed neuroprotection when administered pre i.c.v.; they blocked lipid peroxidation and learning deficits, effects inhibited by BD1047. Post i.c.v., PRE‐084 and donepezil showed complete neuroprotection whereas the other ChE inhibitors showed partial effects. BD1047 blocked these effects of PRE‐084, attenuated those of donepezil, but did not affect the partial effects of the other ChE inhibitors.

Conclusions and implications.

The potent anti‐amnesic and neuroprotective effects of donepezil against Aβ25‐35‐induced toxicity involve both its cholinergic and σ1agonistic properties. This dual action may explain its sustained activity compared to other ChE inhibitors.

British Journal of Pharmacology(2006)149, 998–1012. doi:10.1038/sj.bjp.0706927
Isoflurane Produces Delayed Preconditioning against Spinal Cord Ischemic Injury via Release of Free Radicals in Rabbits
Authors: Sang Hanfei , Cao Lin , Qiu Pengxin , Xiong Lize , Wang Rongrong , Yan Guangmei
Published: October 2006

Background

Whether isoflurane preconditioning produces delayed neuroprotection in the spinal cord is unclear. The authors tested the hypothesis that isoflurane produces delayed preconditioning against spinal cord ischemic injury and, further, that the beneficial effect is dependent on free radicals.

Methods

In experiment 1, 63 rabbits were randomly assigned to seven groups (n = 9 each): Animals in the control group only underwent spinal cord ischemia without pretreatment; animals in the Iso24h, Iso48h, and Iso72h groups received 40 min of 1.0 minimum alveolar concentration isoflurane in 100% oxygen each day for 5 consecutive days, with the last pretreatment at 24, 48, and 72 h, respectively, before spinal cord ischemia; animals in the O2 24h, O2 48h, and O2 72h groups received 40 min of 100% oxygen each day for 5 consecutive days, with the last pretreatment at 24, 48, and 72 h, respectively, before spinal cord ischemia. In experiment 2, 48 rabbits were randomly assigned into four groups (n = 12 each): Animals in the O2 and Iso groups received 3 ml/kg saline intraperitoneally 1 h before each session of oxygen pretreatment and isoflurane pretreatment, respectively. In the DMTU+Iso and DMTU+O2 groups, 10% dimethylthiourea (DMTU, a potent free radical scavenger) dissolved in saline (3 ml/kg) was administered at the same time point. Twenty-four hours after the last pretreatment, animals were subjected to spinal cord ischemia. Spinal cord ischemia was induced by an infrarenal aorta clamping for 20 min. Forty-eight hours after reperfusion, neurologic function and histopathology of the spinal cord were examined.

Results

In experiment 1, the neurologic and histopathologic outcomes in the Iso24h and Iso48h groups were better than those in the control group (P < 0.005 for each comparison); the neurologic and histopathologic outcomes in the control group showed no significant differences in comparison with the O2 24h, O2 48h, O2 72h, and Iso72h groups (P > 0.05 for each comparison). In experiment 2, the neurologic and histopathologic outcomes in the Iso group were better than those in the DMTU+Iso, O2, and DMTU+O2 groups (P < 0.01 for each comparison); there were no significant differences in the neurologic and histopathologic outcomes among the DMTU+Iso, O2, and DMTU+O2 groups (P > 0.05 for each comparison).

Conclusions

Isoflurane produces delayed preconditioning against spinal cord ischemic injury, and the beneficial effect may be dependent on the release of free radicals.
Acute Late Sepsis Attenuates Effects of a Nondepolarizing Neuromuscular Blocker, Rocuronium, by Facilitation of Endplate Potential and Enhancement of Membrane Excitability In Vitro
Authors: Niiya Tomohisa , Narimatsu Eichi , Namiki Akiyoshi
Published: October 2006

Background

Sepsis attenuates the muscle-relaxing effects of nondepolarizing neuromuscular blockers. The authors investigated the effects of acute late sepsis on neuromuscular transmission and neuromuscular actions of rocuronium to clarify the mechanisms by which sepsis attenuates the effects of nondepolarizing neuromuscular blockers.

Methods

Sepsis was induced by cecal ligation and puncture operation. Endplate potentials, acetylcholine potentials, and electrotonic potentials were recorded from the motor endplates of isolated diaphragms from acute late septic and nonseptic rats.

Results

(1) Sepsis did not influence the effect of rocuronium to decrease endplate potential amplitude, which was increased by sepsis itself; (2) sepsis facilitated the effect of rocuronium to decrease quantal acetylcholine release, which was increased by sepsis itself; (3) sepsis did not influence the effect of rocuronium to decrease acetylcholine sensitivity, which was decreased by sepsis itself; (4) sepsis decreased critical depolarization, and rocuronium did not influence critical depolarization.

Conclusions

These results indicate that acute late sepsis facilitates endplate potentials and enhances excitability of the muscle membrane, indicated by a decrease of critical depolarization. It is thought that these elicit the sepsis-induced attenuation of the muscle-relaxing effects of rocuronium.
A Randomized Study of the Effects of Gabapentin on Postamputation Pain
Authors: Nikolajsen Lone , Finnerup Nanna B. , Kramp Steffen , Vimtrup Anne-Sofie , Keller Johnny , Jensen Troels S.
Published: October 2006

Background

Pain after amputation is common but difficult to treat. Therefore, the authors examined whether postoperative treatment with gabapentin could reduce postamputation stump and phantom pain.

Methods

Forty-six patients scheduled to undergo lower limb amputation were randomly assigned to receive oral gabapentin or placebo. Treatment was started on the first postoperative day and continued for 30 days. The daily dose of gabapentin or placebo was gradually increased to 2,400 mg/day. The intensity of stump and phantom pain was recorded every day on a numeric rating scale (0-10) during the 30-day treatment period. Five interviews were performed after 7, 14, and 30 days and after 3 and 6 months.

Results

Results from 41 patients were included in the data analysis. The risk of phantom pain (gabapentin vs. placebo) was 55.0% versus 52.6% (risk difference, 2.4%; 95% confidence interval, -28.9 to 33.7%; P = 0.88; 30 days) and 58.8% versus 50.0% (risk difference, 8.8%; 95% confidence interval, -23.3 to 40.9%; P = 0.59; 6 months). The median intensity of phantom pain (gabapentin vs. placebo) was 1.5 (range, 0-9.0) versus 1.2 (range, 0-6.6) (P = 0.60; 30 days) and 1.0 (range, 0-6.0) versus 0.5 (range, 0-5.0) (P = 0.77; 6 months). The median intensity of stump pain was 0.85 (range, 0-8.2) versus 1.0 (range, 0-5.4) (P = 0.68; 30 days) and 0 (range, 0-8.0) versus 0 (range, 0-5.0) (P = 0.58; 6 months).

Conclusion

Gabapentin administered in the first 30 postoperative days after amputation does not reduce the incidence or intensity of postamputation pain.
Experimental heart muscle damage in alcohol feeding is associated with increased amounts of reduced‐ and unreduced‐acetaldehyde and malondialdehyde–acetaldehyde protein adducts
Authors: Worrall Simon , Richardson Peter J. , Preedy Victor R.
Published: October 2006

Chronic and excessive alcohol consumption induces defined myocardial lesions characterized by impaired structural, mechanical and biochemical features. The pathogenic mechanisms are unknown, although it is possible that protein adduct formation by reactive metabolites of ethanol may be a contributory process. Hitherto, this has only been tested with respect to antibodies against reduced‐acetaldehyde protein adducts in clinical studies, despite the fact that during alcohol toxicity the formation of reduced‐acetaldehyde, unreducedacetaldehyde, malondialdehyde, malondialdehyde‐acetaldehyde and hydroxyethyl protein adducts have been reported in non‐cardiac tissues. It was our hypothesis that the heart is particularly sensitive to the formation of protein adducts in alcohol toxicity.Totest this hypothesis, we analysed hearts from rats fed nutritionally complete liquid diets containing ethanol as 35% of total calories for 6 weeks, using the Lieber‐DeCarli pair‐feeding protocol. Control rats were treated identically and fed the same diet in which ethanol was replaced by isocaloric glucose. At the end of the feeding period, the hearts were dissected and ventricular muscle analysed. After 6 weeks' ethanol feeding, ELISA analysis showed increased amounts of reduced‐acetaldehyde protein adducts (p < 0.01) unreduced‐acetaldehyde (p < 0.01) and malondialdehyde‐acetaldehyde (p= 0.01) protein adducts. However, malondialdehyde and α‐hydroxyethyl‐protein adducts were not significantly increased in hearts of ethanol‐fed rats compared to pair‐fed control (p > 0.1 in both instances). This is the first report of acetaldehyde adduct formation in alcoholic cardiomyopathy. This suggests that either immune process may develop or functional impairment of affected proteins may occur.
Changes in cigarette smoking among alcohol and drug misusers during inpatient detoxification
Authors: Harris Jennifer , Best David , Man Lan‐Ho , Welch Sarah , Gossop Michael , Strang John
Published: October 2006

Smoking prevalence and changes during inpatient detoxification were examined among 135 admissions to an inpatient alcohol and drug detoxification unit, of whom 83 (61.5%) were re‐interviewed one week later. Ninety‐two per cent of the initial sample were currently smokers; 87% of alcohol misusers, 97% of drug misusers and 100% of drug/alcohol misusers. Smokers consumed a daily mean of 27 cigarettes before admission. Those classified as heavy smokers (smoking 40 or more cigarettes prior to admission) decreased their smoking levels by an average of 10.5 cigarettes during detoxification. Light smokers (1–19 cigarettes per day) increased by a daily average of 8.6 cigarettes and intermediate smokers (20–39 cigarettes) by 4.9 cigarettes. The findings suggest a dose‐dependent relationship between cigarette smoking and inpatient detoxification that requires further study. Over three‐quarters of the sample expressed a desire to change their smoking behaviour, many of whom felt they would like help to tackle this change. Given the high smoking prevalence and reported interest in smoking cessation/reduction, there is an opportunity to address the smoking behaviour of drug and alcohol misusers entering inpatient care, whether during or after their detoxification.
CLINICAL STUDY: Quantification of breath carbon disulphide and acetone following a single dose of disulfiram (Antabuse) using selected ion flow tube mass spectrometry (SIFT‐MS)
Authors: Bloor Roger N. , Španěl Patrick , Smith David
Published: October 2006

Selected ion flow tube mass spectrometry (SIFT‐MS) has been used to measure simultaneously the concentrations of both carbon disulphide and acetone in exhaled breath following the ingestion of a single dose of disulfiram (Antabuse). Carbon disulphide is a product of the metabolism of disulfiram and is excreted mainly through the lungs. Acetone is a product of normal metabolism and appears in the breath of all individuals. These breath analyses were performed in single exhalations and the results were available in real time. The levels of breath acetone and carbon disulphide were compared with levels obtained from a control subject who had not ingested disulfiram. Breath carbon disulphide was seen to increase from 15 p.p.b. to 618 p.p.b. over a 28‐hour period, in the single individual tested, following ingestion of disulfiram, while acetone levels increased from 300 p.p.b. (normal) to over 4000 p.p.b. (greatly elevated). No such increases were seen in the breath of the control subject over the same period. An obvious positive correlation between breath carbon disulphide and acetone concentrations following disulfiram ingestion is seen and discussed.
REVIEW: The genetics of alcoholism: identifying specific genes through family studies
Authors: Edenberg Howard J. , Foroud Tatiana
Published: October 2006

Alcoholism is a complex disorder with both genetic and environmental risk factors. Studies in humans have begun to elucidate the genetic underpinnings of the risk for alcoholism. Here we briefly review strategies for identifying individual genes in which variations affect the risk for alcoholism and related phenotypes, in the context of one large study that has successfully identified such genes. The Collaborative Study on the Genetics of Alcoholism (COGA) is a family‐based study that has collected detailed phenotypic data on individuals in families with multiple alcoholic members. A genome‐wide linkage approach led to the identification of chromosomal regions containing genes that influenced alcoholism risk and related phenotypes. Subsequently, single nucleotide polymorphisms (SNPs) were genotyped in positional candidate genes located within the linked chromosomal regions, and analyzed for association with these phenotypes. Using this sequential approach, COGA has detected association withGABRA2,CHRM2andADH4; these associations have all been replicated by other researchers. COGA has detected association to additional genes includingGABRG3,TAS2R16,SNCA,OPRK1andPDYN, results that are awaiting confirmation. These successes demonstrate that genes contributing to the risk for alcoholism can be reliably identified using human subjects.
REVIEW: The alcohol‐preferring AA and alcohol‐avoiding ANA rats: neurobiology of the regulation of alcohol drinking
Authors: Sommer Wolfgang , Hyytiä Petri , Kiianmaa Kalervo
Published: October 2006

The AA (alko, alcohol) and ANA (alko, non‐alcohol) rat lines were among the earliest rodent lines produced by bidirectional selection for ethanol preference. The purpose of this review is to highlight the strategies for understanding the neurobiological factors underlying differential alcohol‐drinking behavior in these lines. Most early work evaluated functioning of the major neurotransmitter systems implicated in drug reward in the lines. No consistent line differences were found in the dopaminergic system either under baseline conditions or after ethanol challenges. However, increased opioidergic tone in the ventral striatum and a deficiency in endocannabinoid signaling in the prefrontal cortex of AA rats may comprise mechanisms leading to increased ethanol consumption. Because complex behaviors, such as ethanol drinking, are not likely to be controlled by single factors, system‐oriented molecular‐profiling strategies have been used recently. Microarray based expression analysis of AA and ANA brains and novel data‐mining strategies provide a system biological view that allows us to formulate a hypothesis on the mechanism underlying selection for ethanol preference. Two main factors appear active in the selection: a recruitment of signal transduction networks, including mitogen‐activated protein kinases and calcium pathways and involving transcription factors such as Creb, Myc and Max, to mediate ethanol reinforcement and plasticity. The second factor acts on the mitochondrion and most likely provides metabolic flexibility for alternative substrate utilization in the presence of low amounts of ethanol.
Symmetry of post‐movement beta‐ERS and motor recovery from stroke: a low‐resolution EEG pilot study
Authors: Eder C. F. , Sokić D. , Čovičković‐Šternić N. , Mijajlović M. , Savić M. , Sinkjær T. , Popović D. B.
Published: October 2006

The inter‐hemispheric symmetry of electroencephalographic (EEG) post‐movement beta‐event‐related synchronization (PMBS) after movements on a drawing board was studied in eight acute stroke subjects with mild hemiparesis and eight normal subjects. A follow‐up testing was conducted 3 months after the initial recordings with a twofold purpose: (1) to validate the reproducibility of the experimental protocol in normal subjects; and (2) to study changes of inter‐hemispheric PMBS‐symmetry as a response to recovery of motor function. PMBS values were calculated and their topographic distributions illustrated at various time instances following movement offset. Significant PMBS patterns were present in all normal subjects, with only minor differences within consecutive recordings. The side of hemiparesis in acute stroke subjects could be distinguished (P = 0.04) on the basis of the signed symmetry index, a quantitative measure of lateralization. The follow‐up testing on three recovered stroke subjects revealed a trend of changes in the lateralization towards the contralateral side of movement, an indication that the cortical organization of movement following recovery turned out as reported for normal subjects. Further clinical investigations need to be carried out to evaluate the relationship between recovery and PMBS symmetry on a large number of subjects, using the method presented here.
Subinsular vascular lesions: an analysis of 119 consecutive autopsied brains
Authors: Tomimoto H. , Lin J. , Ihara M. , Ohtani R. , Matsuo A. , Miki Y.
Published: October 2006

The insula of Reil constitutes a functionally intriguing complex of the brain related to multifunctional activities. We examined the subinsular region in 119 consecutively autopsied patients, as T2 hyperintense lesions are frequently observed in magnetic resonance diagnosis of this region. The patients were admitted in neurology wards and were diagnosed as having cerebrovascular disease in 55 patients (46%), other neurological diseases in 57 patients (48%) and non‐neurological diseases in seven patients (6%). Demyelination of the white matter was semi‐quantified as a fiber density score (percent stained area/total area) with computer‐assisted image analysis on Klüver–Barrera‐stained sections. Astrogliosis was assessed by immunohistochemistry for glial fibrillary acidic protein.

The lesion analysis showed a dilated perivascular space in 29 patients (24%), demyelination (fiber density score less than the mean − 1 SD) in 27 patients (23%), slit‐shaped lesion in six patients (5%), lacunar infarction in one patient (1%) and cerebral hemorrhage in one patient (1%). A histologic–radiologic comparison in two patients with subcortical ischemic vascular dementia showed correspondence between subinsular hyperintensities, and demyelination, gliosis and a dilated perivascular space. These results indicate that subinsular lesions rarely signifies focal vascular lesions, and are consisted of demyelination, gliosis and a dilated perivascular space.
Association of A313 G polymorphism (GSTP1*B) in the glutathione‐S‐transferase P1 gene with sporadic Parkinson's disease
Authors: Vilar R. , Coelho H. , Rodrigues E. , Gama M. J. , Rivera I. , Taioli E. , Lechner M. C.
Published: October 2006

Genetic predisposition, environmental toxins and aging contribute to Parkinson's disease (PD) multifactorial etiology. Weak environmental neurotoxic factors may accumulate over time increasing the disease risk in genetically predisposed subjects. Polymorphic genes encoding drug‐metabolizing‐enzymes (DMEs) are considered to account for PD susceptibility by determining individual toxic response variability. In this work, the allelic distributions and genotype associations of three major brain‐expressed DMEs were characterized, in sporadic PD cases and controls. No significant association was found between CYP2D6 genotype and PD, but subjects with extensive metabolizer (EM) CYP2D6 phenotype, and the variant GSTP1*B genotype were at significantly higher PD risk than the corresponding poor or intermediary metabolizers (CYP2D6 poor metabolizer phenotype+intermediary metabolizers). A significant association was observed between the GSTP1*B allele and zygosity with PD (GSTP1*A/*B– 51.58%/34.37%, odds ratio (OR) = 2.29; 95% confidence interval (95% CI) = 1.25–4.18; *B/*B– 6.32%/1.05%, OR = 10.67; 95% CI = 1.19–94.79). This association was particularly strong in the elder patients group (≥69 year) who showed double PD risk for GSTP1*B heterozygous, whilst GSTP1*B/*B homozygous were exclusively found amongst patients. An interaction between GSTM1 and GSTP1 was observed in this late onset PD group. The present results suggest that native GSTP1 encoding the fully active transferase variant should play a relevant role in dopaminergic neuroprotection.