bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial and temporal variability in the concentration and speciation of metals in suspended sediment transported by the River Aire, Yorkshire, UK
Authors: Carter Julie , Walling Desmond E. , Owens Philip N. , Leeks Graham J. L.
Published: April 2006

In recent years, there has been an increasing awareness of the important role of fine sediment in the transport and storage of metals in fluvial systems. However, there has been little research on the behaviour of contaminated sediment in industrial rivers in the UK. This paper examines spatial and temporal variations in the concentration and speciation of lead, copper and chromium associated with suspended sediment in the River Aire in Yorkshire, UK. An increase in the total concentration of all three metals in sediment was identified in the lower reaches, which reflected inputs of road dust, sewage and industrial effluents. Spatial variations in the chemical speciation of the metals were also identified. The iron–manganese oxides and organic fractions were the most significant for the adsorption of metals by sediment. Both the concentrations and speciation of sediment‐associated metals exhibited substantial temporal variation. Such variation reflected the accumulation of metals and organic matter on the river‐bed during low flows, the subsequent remobilization of the sediment at high flows and the additional supply of sediment from uncontaminated and contaminated sources, including pulse inputs of road dust, sewage and industrial effluent. The findings presented have important implications for the development of effective catchment management strategies for the control of point‐ and diffuse‐source pollution. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of the force necessary for the propagation of tears in ostrich and calf pericardium
Authors: Páez José María García , Carrera Antonio , Jorge Eduardo , Millán Isabel , Cordón Angeles , Maestro María A. , Rocha Aurora , Morales S. , Castillo‐Olivares José Luis
Published: April 2006

The durability of prosthetic heart valve leaflets made of biological materials is limited. A tear in the biomaterial accelerates their early failure, but microtearing of the collagen fibers may be responsible for their medium‐term failure. We studied the force necessary to propagate tearing in two biomaterials: ostrich and calf pericardium. One hundred twenty samples of each tissue were tested in an Elmendorf pendulum capable of measuring the force required to tear a tissue in which a predefined slit had been made. The forces required to produce tears, ranging between 2.5 and 0.25 cm in length, were determined. For ostrich pericardium, this force ranged between 67.67 and 4.80 newton, while that required to tear the same lengths of calf pericardium ranged between 70.67 and 4.70 newton. The function that relates the tearing force to the length of the tear was expressed as follows: y = 20.62x + 1.77x2 (R2 = 0.923) for ostrich pericardium and y = 45.57x − 7.21x2 (R2 = 0.936) for calf pericardium, where y is the force in newton and x is the length in centimeter. Calf pericardium was found to have a greater resistance to tearing. However, these results should be interpreted with caution owing to the fact that the thickness of the majority of the samples of ostrich pericardium was significantly less than that of calf pericardium. A more careful selection and utilization of adult ostrich pericardium would probably improve these results. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Ionic liquid‐derived blood‐compatible composite membranes for kidney dialysis
Authors: Murugesan Saravanababu , Mousa Shaker , Vijayaraghavan Aravind , Ajayan Pulickel M. , Linhardt Robert J.
Published: April 2006

A novel heparin‐ and cellulose‐based biocomposite is fabricated by exploiting the enhanced dissolution of polysaccharides in room temperature ionic liquids (RTILs). This represents the first reported example of using a new class of solvents, RTILs, to fabricate blood‐compatible biomaterials. Using this approach, it is possible to fabricate the biomaterials in any form, such as films or membranes, fibers (nanometer‐ or micron‐sized), spheres (nanometer‐ or micron‐sized), or any shape using templates. In this work, we have evaluated a membrane film of this composite. Surface morphological studies on this biocomposite film showed the uniformly distributed presence of heparin throughout the cellulose matrix. Activated partial thromboplastin time and thromboelastography demonstrate that this composite is superior to other existing heparinized biomaterials in preventing clot formation in human blood plasma and in human whole blood. Membranes made of these composites allow the passage of urea while retaining albumin, representing a promising blood‐compatible biomaterial for renal dialysis, with a possibility of eliminating the systemic administration of heparin to the patients undergoing renal dialysis. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Recovery of oleate‐inhibited anaerobic digestion by addition of simple substrates
Authors: Kuang Yunhua , Pullammanappallil Pratap , Lepesteur Muriel , Ho Goen E
Published: April 2006

Four laboratory‐scale anaerobic digesters were deliberately and completely inhibited by feeding sodium oleate to such an extent that no methane was produced from the digesters. Three of them were then respectively fed glucose, cysteine or glucose and cysteine along with sodium oleate, while the remaining digester was operated as control reactor and continued to be fed with only sodium oleate. Oligonucleotide probes ARC915, EUB338, MB310, MC1109, MSMX860 and MG1200 were used to target and quantify specific groups of microbes, Archaea, Bacteria, Methanobacteriales, Methanococcales, Methanosarcinaceae, and Methanomicrobiaceae, Methanocorpusculaceae and Methanoplanaceae respectively throughout the operation of reactors. Addition of glucose and/or cysteine assisted with the recovery of methane production from oleate inhibition. The addition of glucose was more effective than cysteine, while the combination of glucose and cysteine was most effective on this recovery. The addition of these substrates also stimulated the degradation of oleate in the reactor. Daily methane production from the digesters correlated negatively with residual oleate concentration and positively with Archaea counts. Addition of glucose was more effective than cysteine on increasing the number of Archaea cells, while cysteine was more effective in increasing the number of Bacteria cells. All microbial populations recovered to pre‐inhibition levels within 40 days when glucose together with cysteine was fed. Copyright © 2006 Society of Chemical Industry
Simulating air temperature in an urban street canyon in all weather conditions using measured data at a reference meteorological station
Authors: Erell E. , Williamson T.
Published: April 2006

A model is proposed that adapts data from a standard meteorological station to provide realistic site‐specific air temperature in a city street exposed to the same meso‐scale environment. In addition to a rudimentary description of the two sites, the canyon air temperature (CAT) model requires only inputs measured at standard weather stations; yet it is capable of accurately predicting the evolution of air temperature in all weather conditions for extended periods. It simulates the effect of urban geometry on radiant exchange; the effect of moisture availability on latent heat flux; energy stored in the ground and in building surfaces; air flow in the street based on wind above roof height; and the sensible heat flux from individual surfaces and from the street canyon as a whole. The CAT model has been tested on field data measured in a monitoring program carried out in Adelaide, Australia, in 2000–2001. After calibrating the model, predicted air temperature correlated well with measured data in all weather conditions over extended periods. The experimental validation provides additional evidence in support of a number of parameterisation schemes incorporated in the model to account for sensible heat and storage flux. Copyright © 2006 Royal Meteorological Society
Simultaneous determination of eight biologically active thiol compounds using gradient elution‐liquid chromatography with Coul‐Array detection
Authors: Petrlova Jitka , Mikelova Radka , Stejskal Karel , Kleckerova Andrea , Zitka Ondrej , Petrek Jiri , Havel Ladislav , Zehnalek Josef , Adam Vojtech , Trnkova Libuse , Kizek Rene
Published: April 2006

The most active form of sulfur in biomolecules is the thiol group, present in a number of biologically active compounds. Here we present a comprehensive study of thiol analysis using flow injection analysis/HPLC with electrochemical detection. The effect of different potentials of working electrodes, of organic solvent contents in the mobile phase, and of isocratic and gradient elution on simultaneous determination of thiol compounds (cysteine, cystine, N‐acetylcysteine, homocysteine, reduced and oxidised glutathione, desglycinephytochelatin, and phytochelatins) are described and discussed. These thiol compounds were well separated and detected under optimised HPLC‐electrochemical detection conditions (mobile phase: 80 mM trifluoroacetic acid and methanol with a gradient profile starting at 97 : 3 (TFA : methanol), kept constant for the first 8 min, then decreasing to 85 : 15 during one minute, kept constant for 8 min, and finally increasing linearly up to 97 : 3 from 17 to 18 min; the flow rate was 0.8 mL/min, column and detector temperature 25°C, and the electrode potential 900 mV). We were able to determine tens of femtomoles (3 S/N) of the thiols per injection (5 μL), except for phytochelatin5 whose detection limit was 2.1 pmole. This technique was consequently used for simultaneous determination of compounds of interest in biological samples (maize tissue and human blood serum).
Exploring conspicuousness in the context of donation behaviour
Authors: Grace Debra , Griffin Deborah
Published: April 2006

The study of donation behaviour has been significant in recent years as charitable organisations realise the value of marketing strategies in order for growth and survival. Consequently, in recent years the growing trend, to increase awareness of charities and generate much‐needed funds, has been the sale of empathy ribbons and the like (e.g. red noses etc.). However, it is argued that the motivation behind the purchase of empathy ribbons is largely ostentatious rather than altruistic and, thus, is viewed under the broader umbrella of ‘conspicuous compassion’ (West, 2004). As such, this paper documents a conceptualization of monetary donation behaviour which we term ‘conspicuous donation behaviour’ and, in doing so, we provide a number of research propositions which pre‐empt new avenues for future research.

Copyright © 2006 John Wiley & Sons, Ltd.
An investigation into the values dimensions of branding: implications for the charity sector
Authors: Stride Helen
Published: April 2006

Branding is being adopted by charities and written about in academic and practitioner charity literature with increasing frequency. There is also growing concern, however, about the over‐commercialistion of the sector and the misappropriation of techniques developed specifically for the commercial environment. Literature supporting the claim that charities are values‐based organisations is reviewed and the proposition is made that it is in fact the non‐negotiability of charity values that differentiate them from commercial organisations. Given the significance of values in the charity sector, the paper argues that a clearer understanding of how values are conceptualised in branding is necessary in order to establish whether branding is an appropriate and effective tool in the charity context. To achieve this, the paper reviews relevant branding literature focusing in particular upon the delineation of the values dimensions identified in for‐profit branding models. To aid further understanding of these values dimensions in the non‐profit context and their applicability (or otherwise) to it, the metaphors of brand as ‘mirror’, ‘lamp’ and ‘lens’ are introduced.

It is argued that in the corporate sector the brand concept has been utilised to ‘mirror’ those values that underpin the needs and desires of consumers. In contrast to the passive mirror, when operationalised as ‘lamp’, it is claimed that the brand aims to influence both the values of the organisation and the values of its target audience. It is postulated that neither of these approaches is appropriate for values‐led organisations and that it is only as a metaphorical ‘lens’, projecting the values of the organisation itself that branding offers an applicable and effective model in the charity context.

Copyright © 2006 John Wiley & Sons, Ltd.
Maternal age‐specific fetal loss rates in Down syndrome pregnancies
Authors: Savva George M. , Morris Joan K. , Mutton David E. , Alberman Eva
Published: April 2006

Objectives

Pregnancies affected by Down syndrome (DS) have a greater risk of spontaneous fetal loss than those that are unaffected. In this article, we investigate the relationship between maternal age and the risk of spontaneous fetal loss in DS pregnancies.

Methods

Fetal loss at different maternal ages were estimated by survival analysis using follow‐up of 5177 prenatally diagnosed cases. The maternal age effect on loss rate was subsequently confirmed by a re‐analysis of published comparisons of the maternal age‐specific prevalence of DS at different gestational ages.

Results

The average fetal loss rate between the time of chorionic villus sampling (CVS) and term was 32% (95% CI: 26–38), increasing from 23% (95% CI: 16–31) for women aged 25 to 44% (33–56) for women aged 45. The average fetal loss rate between the time of amniocentesis and term was 25% (21–31), increasing from 19% (14–27) to 33% (26–45) across the same age range.

Conclusion

The fetal loss rate in DS pregnancies increases with maternal age, and this has consequences when estimating the live birth prevalence of DS in the presence of prenatal diagnosis and termination, and when assessing the performance of prenatal screening techniques. Copyright © 2006 John Wiley & Sons, Ltd.
Measurement of changes in antihypertensive drug utilisation following primary care educational interventions
Authors: Horn Fiona E. , Mandryk John A. , Mackson Judith M. , Wutzke Sonia E. , Weekes Lynn M. , Hyndman Rob J.
Published: April 2006

Purpose

To measure changes in drug utilisation following a national general practice education program aimed at improving prescribing for hypertension.

Methods

A series of nationally implemented, multifaceted educational interventions using social marketing principles focusing on prescribing for hypertension, was commenced in October 1999, and repeated in September 2001and August 2003. The target group was all primary care prescribers in Australia and interventions were both active (voluntary) and passive. Newsletter and prescribing feedback was mailed in October 1999, September 2001 (newsletter only) and August 2003. Approximately a third of general practitioners (GPs) in Australia undertook at least one active educational activity (clinical audit, educational visit or case study) during the period October 1999–April 2004. National dispensing data from 1996 to 2004 were analysed using time series methodology with a decay term for intervention effect, to assess trends in prescribing of various classes of antihypertensives. In particular, the program aimed to increase the prescribing of thiazide diuretics and beta blockers.

Results

Consistent with key intervention messages, the program achieved an increase in low‐dose thiazide and beta blocker prescribing. The rate of prescribing of low‐dose thiazides doubled from 1.1 per 1000 consultations in October 1999 to 2.4 per 1000 in October 2003. Beta‐blocker utilisation showed a more modest but significant increase over the time of the study, with the change in observed versus expected rate of prescribing increasing by 8% by April 2004. Therapeutic options for treating hypertension changed markedly in the time of the study with the advent of ACE inhibitor/Angiotensin II receptor antagonists and thiazide combination products. It is important, therefore, to interpret the results in light of these changes.

Conclusion

A national education program aimed at GPs was successful in improving prescribing for hypertension. Lessons learned will be applied in evaluation of future NPS programs and are also applicable to analysis of other interventions aimed at influencing prescribing behaviour. Copyright © 2006 John Wiley & Sons, Ltd.
Calcium borate flame retardation system for epoxy molding compounds
Authors: Ishii Toshiaki , Kokaku Hiroyoshi , Nagai Akira , Nishita Takafumi , Kakimoto Masaaki
Published: April 2006

A new flame retardation system for epoxy molding compounds was investigated for application to semiconductor packaging. By adding a small volume of calcium borate as a flame retardant, the flammability of the epoxy molding compound decreased. The flammability was not decreased proportionally with the volume of calcium borate. To further enhance flammability, an excess amount of phenolic resin was added to the epoxy molding compound. With the effects of calcium oxide and the excess phenolic resin, we developed an epoxy molding compound which has a flame‐retardant level sufficient to satisfy the V‐0 classification of the UL94 rating. We also found that calcium oxide in the calcium borate accelerates the curing reaction of epoxy compounds due to its absorption of water from the phenolic resin hardener. Calcium hydroxide formed from calcium oxide and water was also considered to contribute to the decrease in flammability by releasing water at high temperatures. The flame retardation mechanism of this developed epoxy compound is also discussed. Finally, the developed epoxy compound was proved to have suitable moldability, mechanical properties, and durability for use as semiconductor packaging. POLYM. ENG. SCI., 46:799–806, 2006. © 2006 Society of Plastics Engineers
Vapor‐induced crystallization behavior of bisphenol‐A polycarbonate
Authors: Fan Zhongyong , Shu Chang , Yu Ying , Zaporojtchenko V. , Faupel F.
Published: April 2006

The effects of exposure time and vapor pressure on the crystallization behaviors of bisphenol‐A polycarbonate (BAPC) films were investigated at 25°C by using differential scanning calorimetry (DSC). Double melting peaks were observed for various BAPC samples after vapor‐induced crystallization. The low temperature melting peak shifted to higher temperature and became sharper with increasing exposure time, and could be assigned to defective crystals with smaller crystal size. Crystallinity and average crystal dimension normal to (020) were calculated from wide‐angle X‐ray diffraction spectra. A good agreement was obtained between crystallinity values obtained from WAXD and those from DSC.

The morphology of crystallized samples after various exposure time periods was examined by means of polarized optical microscopy. Nucleation occurred at the initial stage of vapor‐induced crystallization. Poor crystals become perfect through segment reorganization with increasing exposure time, and spherulites' growth was observed. The average diameter of spherulites increased from 2 μm for 1 h, to 7 and 16 μm after 3 and 56 h, respectively. POLYM. ENG. SCI., 46:729–734, 2006. © 2006 Society of Plastics Engineers
Proteomic analysis of the anterior cingulate cortex in the major psychiatric disorders: Evidence for disease‐associated changes
Authors: Beasley Clare L. , Pennington Kyla , Behan Aine , Wait Robin , Dunn Michael J. , Cotter David
Published: April 2006

Abnormalities of the anterior cingulate cortex have previously been described in schizophrenia, major depressive disorder and bipolar disorder. In this study 2‐DE was performed followed by mass spectrometric sequencing to identify disease‐specific protein changes within the anterior cingulate cortex in these psychiatric disorders. The 2‐DE system comprised IPGs 4–7 and 6–9 in the first, IEF dimension and SDS‐PAGE in the second dimension. Resultant protein spots were compared between control and disease groups. Statistical analysis indicated that 35 spots were differentially expressed in one or more groups. Proteins comprising 26 of these spots were identified by mass spectroscopy. These represented 19 distinct proteins; aconitate hydratase, malate dehydrogenase, fructose bisphosphate aldolase A, ATP synthase, succinyl CoA ketoacid transferase, carbonic anhydrase, α‐ and β‐tubulin, dihydropyrimidinase‐related protein‐1 and ‐2, neuronal protein 25, trypsin precursor, glutamate dehydrogenase, glutamine synthetase, sorcin, vacuolar ATPase, creatine kinase, albumin and guanine nucleotide binding protein β subunit. All but three of these proteins have previously been associated with the major psychiatric disorders. These findings provide support for the view that cytoskeletal and mitochondrial dysfunction are important components of the neuropathology of the major psychiatric disorders.
Optically induced electron transfer in an N,N,N′,N′‐tetraanisyl‐o‐phenylenediamine radical cation
Authors: Nöll Gilbert , Avola Manuele
Published: April 2006

Upon electrochemical and spectroelectrochemical investigation the radical cation of tetraanisyl‐o‐phenylenediamine turned out to be an almost delocalized system at the borderline between class II and III with an extremely low reorganization energy. Copyright © 2006 John Wiley & Sons, Ltd.
Solution properties of dendronized poly(hydroxy ethyl methacrylate) polymers
Authors: Hietala Sami , Nyström Andreas , Tenhu Heikki , Hult Anders
Published: April 2006

Four generations of dendronized polymers with a methacrylate backbone and hydroxy‐functionalized aliphatic polyester dendrons based on 2,2‐bis(methylol)propionic acid were studied in solutions by rheological measurements, dynamic light scattering, turbidimetry, and 1H NMR self‐diffusion measurements to reveal the effect of increasing hydrophilicity and molecular size on their solution properties. The studied polymers were interesting new amphiphiles with a hydrophobic main chain and a hydrophilic shell. Evidence of aggregation upon the heating of the first‐generation polymer in an aqueous solution was obtained by dynamic light scattering and turbidimetry, reflecting the effect of the hydrophobic polymer backbone, whereas the higher generation polymers did not show aggregation upon heating. Although the dimensions of the polymers were observed to increase with increasing generation, all the polymers exhibited low viscosities and Newtonian flow behavior in both aqueous and dimethyl sulfoxide solutions. The relative viscosities of the polymers in water and dimethyl sulfoxide showed that the conformation of the polymers was somewhat more open in dimethyl sulfoxide, and this led to higher viscosities than those in water, in agreement with the 1H NMR diffusion measurements, by which the dimensions were found to be larger for the polymers dissolved in dimethyl sulfoxide. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3674–3683, 2006
Preparation of novel poly(ethylene oxide‐co‐glycidol)‐graft‐poly(ε‐caprolactone) copolymers and inclusion complexation of the grafted chains with α‐cyclodextrin
Authors: Huang Juan , Li Zhongyu , Xu Xuewei , Ren Yong , Huang Junlian
Published: April 2006

A well‐defined comblike copolymer of poly(ethylene oxide‐co‐glycidol) [(poly(EO‐co‐Gly)] as the main chain and poly(ε‐caprolactone) (PCL) as the side chain was successfully prepared by the combination of anionic polymerization and ring‐opening polymerization. The glycidol was protected by ethyl vinyl ether to form 2,3‐epoxypropyl‐1‐ethoxyethyl ether (EPEE) first, and then ethylene oxide was copolymerized with EPEE by an anionic mechanism. The EPEE segments of the copolymer were deprotected by formic acid, and the glycidol segments of the copolymers were recovered after saponification. Poly(EO‐co‐Gly) with multihydroxyls was used further to initiate the ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate. When the grafted copolymer was mixed with α‐cyclodextrin, crystalline inclusion complexes (ICs) were formed, and the intermediate and final products, poly(ethylene oxide‐co‐glycidol)‐graft‐poly(ε‐caprolactone) and ICs, were characterized with gel permeation chromatography, NMR, differential scanning calorimetry, X‐ray diffraction, and thermogravimetric analysis in detail. The obtained ICs had a channel‐type crystalline structure, and the ratio of ε‐caprolactone units to α‐cyclodextrin for the ICs was higher than 1:1. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3684–3691, 2006
Gender differences in caregiving stress among caregivers of cancer survivors
Authors: Kim Youngmee , Loscalzo Matthew J. , Wellisch David K. , Spillers Rachel L.
Published: April 2006

Despite a growing body of research on male caregivers, limited information is available on male caregivers of cancer survivors. Furthermore, few studies have examined the unique contribution of caregiver esteem as well as care‐recipient's functional status as potential mediators of the link between gender and caregiving stress. Thus, the present study examines how the caregiver's perception of providing care to a spouse with cancer differs by gender. The proposed mediators, caregiver's esteem and care‐recipient's psychosocial and physical functioning, were tested simultaneously, utilizing structural equation modeling. Results revealed that both caregiver's esteem and care‐recipient's psychosocial functioning were significant mediators, but in different directions. Specifically, husband caregivers reported higher caregiver's esteem, which resulted in reporting less stress from providing care to their wife with cancer. On the other hand, when husband caregivers provided care to their wife with poorer psychosocial functioning, they reported greater stress from caregiving. Husband caregivers will benefit from programs designed to educate them to effectively assist their wife's psychosocial adjustment to cancer by reducing their stress from providing care. Copyright © 2006 John Wiley & Sons, Ltd.
Comprehensive view on ultrafast dynamics of ferromagnetic films
Authors: Djordjevic M. , Lüttich M. , Moschkau P. , Guderian P. , Kampfrath T. , Ulbrich R. G. , Münzenberg M. , Felsch W. , Moodera J. S.
Published: April 2006

The relaxation mechanisms in magnetic thin films studied in all‐optical pump probe experiments involve electrons, spin and lattice as well as the different couplings in between those. With this technique, the evolution of the electron and spin dynamics can be studied directly in real time from 100 fs to ns timescale. We give a comprehensive view of the current understanding of the processes involved. The details of the spin relaxation‐mechanisms on the ultrafast and Landau‐Lifshitz‐Gilbert time scales are still unknown. Time‐resolved reflectivity measurements on ferromagnetic transition metal films give an insight into the specific electronic and lattice relaxation processes. The time‐resolved Kerr rotation measurements address the demagnetization and relaxation of the spin system. The demagnetization of the spin system observed in general is strongly coupled to the relaxation mechanism of the electrons, thus follows almost instantaneously the dynamics of the electron system. On the longer time scale, coherent magnetization dynamics is described by the Landau‐Lifshitz‐Gilbert equation and results in a precession with periods of 50 to 200 ps typical for ferromagnets. The full understanding of the mechanisms will be only accessible by a complete analysis of the interaction between electrons, lattice and spin system. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantification of clopidogrel in human plasma by sensitive liquid chromatography/tandem mass spectrometry
Authors: Nirogi Ramakrishna V. S. , Kandikere Vishwottam N. , Shukla Manoj , Mudigonda Koteshwara , Maurya Santosh , Boosi Ravikumar
Published: April 2006

A simple, sensitive and rapid high‐performance liquid chromatography/positive electrospray ionization tandem mass spectrometry method was developed and validated for the assay of clopidogrel in human plasma. Following liquid‐liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed‐phase column and analyzed by mass spectrometry in the multiple reaction monitoring mode using the respective [M+H]+ions,m/z322/212 for clopidogrel andm/z264/154 for the internal standard. The assay exhibited a linear dynamic range of 5–6000 pg/mL for clopidogrel in human plasma. The lower limit of quantification was 5 pg/mL with a relative standard deviation of less than 8%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. A run time of 2.5 min for each sample made it possible to analyze more than 400 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies. Copyright © 2006 John Wiley & Sons, Ltd.
A cooperative perception system for multiple UAVs: Application to automatic detection of forest fires
Authors: Merino Luis , Caballero Fernando , Martínez‐de Dios J.R. , Ferruz Joaquín , Ollero Aníbal
Published: April 2006

This paper presents a cooperative perception system for multiple heterogeneous unmanned aerial vehicles (UAVs). It considers different kind of sensors: infrared and visual cameras and fire detectors. The system is based on a set of multipurpose low‐level image‐processing functions including segmentation, stabilization of sequences of images, and geo‐referencing, and it also involves data fusion algorithms for cooperative perception. It has been tested in field experiments that pursued autonomous multi‐UAV cooperative detection, monitoring, and measurement of forest fires. This paper presents the overall architecture of the perception system, describes some of the implemented cooperative perception techniques, and shows experimental results on automatic forest fire detection and localization with cooperating UAVs. © 2006 Wiley Periodicals, Inc.
Project AURORA: Infrastructure and flight control experiments for a robotic airship
Authors: de Paiva Ely Carneiro , Azinheira José Raul , Ramos Jr. Josué G. , Moutinho Alexandra , Bueno Samuel Siqueira
Published: April 2006

Project AURORA aims at the development of unmanned robotic airships capable of autonomous flight over user‐defined locations for aerial inspection and environmental monitoring missions. In this article, the authors report a successful control and navigation scheme for a robotic airship flight path following. First, the AURORA airship, software environment, onboard system, and ground station infrastructures are described. Then, two main approaches for the automatic control and navigation system of the airship are presented. The first one shows the design of dedicated controllers based on the linearized dynamics of the vehicle. Following this methodology, experimental results for the airship flight path following through a set of predefined points in latitude/longitude, along with automatic altitude control are presented. A second approach considers the design of a single global nonlinear control scheme, covering all of the aerodynamic operational range in a sole formulation. Nonlinear control solutions under investigation for the AURORA airship are briefly described, along with some preliminary simulation results. © 2006 Wiley Periodicals, Inc.
Visual servoing of an autonomous helicopter in urban areas using feature tracking
Authors: Mejías Luis , Saripalli Srikanth , Campoy Pascual , Sukhatme Gaurav S.
Published: April 2006

We present the design and implementation of a vision‐based feature tracking system for an autonomous helicopter. Visual sensing is used for estimating the position and velocity of features in the image plane (urban features like windows) in order to generate velocity references for the flight control. These visual‐based references are then combined with GPS‐positioning references to navigate towards these features and then track them. We present results from experimental flight trials, performed in two UAV systems and under different conditions, that show the feasibility and robustness of our approach. © 2006 Wiley Periodicals, Inc.
Synthesis, characterization and self‐assemblies of magnetite nanoparticles
Authors: Yang Tianzhong , Shen Chengmin , Yang Haitao , Xiao Congwen , Xu Zhichuan , Chen Shutang , Shi Dongxia , Gao Hongjun
Published: April 2006

Monodisperse Fe3O4 nanoparticles (NPs) with a narrow size distribution were synthesized by a high‐temperature solution‐phase method. The diameter of magnetic NPs was tuned from 2 to 13 nm by varying the reaction conditions, and the monolayer and multilayer self‐assemblies of the NPs were obtained. A few kinds of the assemblies are presented and the reasons that drive the particles to form the superlattices are discussed. The physical‐property‐measurement system (PPMS) results showed that the as‐synthesized NPs are ferrimagnetic at low temperatures (5 K) while they are superparamagnetic at room temperature (300 K). In addition, the particles were transformed into hydrophilic ones by an exchange reaction. Copyright © 2006 John Wiley & Sons, Ltd.
On the phenomenological nature of the work function as determined from electron field–emission experiments on nanotubes and nanowires
Authors: Peng Lian‐Mao , Wang Mingshen , Wang Jingyun
Published: April 2006

Electron field–emission current was measured from clean tips of individual carbon nanotubes (CNT) inside the transmission electron microscope (TEM) and analyzed by the Fowler–Nordheim (F–N) theory. The F–N theory was critically examined, and various factors leading to the deviation from the ideal F–N field emission model were discussed. It was concluded that parameters obtained by fitting F–N plot with a straight line, such as the field‐enhancement factor and work function of the one‐dimensional nanomaterials, should be regarded only as phenomenological parameters, and assignment of these parameters with any physical significance should be made with caution. Copyright © 2006 John Wiley & Sons, Ltd.
Why inter‐country loans will not help sumatra's elephants
Authors: Hedges Simon , Tyson Martin J. , Sitompul Arnold F. , Hammatt Hank
Published: April 2006

Asian elephants (Elephas maximus) in western zoos are likely to become extinct unless elephants are regrouped into breeding units or additional elephants are imported from range States. There have been proposals for the export of elephants from elephant camps in Sumatra, Indonesia. In exchange, zoos would be expected to provide funds or support ‘in kind’ for the camps or for the conservation of wild elephants. Most of the elephants in the Sumatran camps were captured because of crop‐raiding problems around protected areas or because elephant habitat has been and continues to be lost to development schemes and illegal conversion of protected areas to agriculture. Capture‐related mortality rates are high and conditions in the camps are poor, with low standards of veterinary care and husbandry. This is partly due to over‐crowding and inadequate budgets. It might seem, therefore, that the loan of elephants to western zoos would improve the lot of these elephants and reduce the pressures on the camps. However, we show that both total and annual demand for Asian elephants, and particularly Sumatran elephants (E. m. sumatranus), by western zoos are low, and consequently the resources generated by any loan scheme would be limited. Elephant loan schemes are unlikely to have significant beneficial impact on either the conservation or welfare of elephants in Sumatra. More importantly, a credible loan scheme would require a permanent moratorium on the capture of wild elephants in Sumatra. Such a moratorium is needed to prevent illicit captures for sale or loan. At present, wild elephants are caught to replace those that die at the camps or are moved to other facilities. Without a moratorium, the loan of elephants to overseas zoos would contribute directly to reductions in wild elephant populations in Sumatra. However, a moratorium is likely to prove impossible to enforce, and this alone should call into question the desirability of any loan scheme. Zoo Biol 25:235–246, 2006. © 2006 Wiley‐Liss, Inc.
The meaning of stigma: identity construction in two old-age institutions
Authors: GAMLIEL TOVA , HAZAN HAIM
Published: April 2006

People in advanced old age with frailties and those who are resident in old-age institutions manage their identities within the constraints of stigmatised settings. This paper compares the processes of identity construction in an old-age home and in a sheltered housing project for older people in Israel. Applying a symbolic-interactionist perspective that sees old-age institutions as social arenas for the reconstruction of identity, the paper first distinguishes the residents' constructions of stigma and deviance. While the old-age home residents collectively turned their stigma into a source of positive labelling, the sheltered housing residents drew advantages from their previous roles and statuses. Gossip is shown to play a critical role in reproducing stigma, particularly in the old-age home. These findings are used to demonstrate the variability and potential for adaptation among the residents – who are often stereotyped as homogeneous and passive. The paper concludes with a discussion of the literal and metaphorical languages used by older people, and of stigma as a positive instrument that can introduce content into the definition of the self.
Suicide to Harass Others
Authors: Preti Antonio
Published: April 2006

Suicide by revenge, the Samsonic suicide, and the suicide by devotio, all described in classical mythology and also reported in the ethnographic literature, belong to the same class of suicidal behaviors as kamikaze suicide and the suicide bombing attack: suicide to harass and burden others or suicide with a hostile intent. The lack of a social dimension to share in a positive manner may lead an individual to integrate him/herself in another social structure, e.g., a military organization, which allows the individual to express his/her desires and personal identity only by destroying others and themselves. The dynamics of these forms of suicide are also likely to work in other displays of life-threatening behavior, such as family annihilation, mass murder, and spree killing. A more thorough investigation of the dynamics operating in suicide bombing attacks could, therefore, contribute to preventative strategies against violence at large.
Recombinant P‐selectin glycoprotein‐ligand‐1 delays thrombin‐induced platelet aggregation: a new role for P‐selectin in early aggregation
Authors: Théorêt Jean‐François , Chahrour Wissam , Yacoub Daniel , Merhi Yahye
Published: April 2006

P‐selectin is involved, with P‐selectin glycoprotein (GP)‐ligand‐1 (PSGL‐1), in platelet/leukocyte interactions during thrombo‐inflammatory reactions; it also stabilizes platelet aggregates. Its antagonism accelerates thrombolysis and enhances the anti‐aggregatory effects of GPIIb–IIIa inhibitors. This study was designed to investigate the mechanisms of P‐selectin‐mediated platelet aggregation.

In freshly isolated human platelets, P‐selectin translocation after thrombin stimulation increased rapidly to 48, 72, and 86% positive platelets after 60, 120, and 300 s, respectively. Platelet aggregation at 60 s post‐stimulation averaged 46.7±1.9% and its extent followed closely the kinetics of P‐selectin translocation.

Pre‐treatment of platelets with P‐selectin antagonists, a recombinant PSGL‐1 (rPSGL‐Ig) or a blocking monoclonal antibody, significantly delayed platelet aggregation in a dose‐dependent manner. At 100 μg ml−1of rPSGL‐Ig, platelet aggregation was completely inhibited up to 60 s post‐stimulation and increased thereafter to reach maximal aggregation at 5 min. The second phase of platelet aggregation, in the presence of rPSGL‐Ig, was completely prevented by the addition of a GPIIb–IIIa antagonist (Reopro) at 60 s, whereas its addition in the absence of rPSGL‐Ig was without any significant effect.

Combination of rPSGL‐Ig with Reopro or with an inhibitor of Pi3K (LY294002), which reduces GPIIb–IIIa activation, showed to be more effective in inhibiting platelet aggregation, in comparison to the effects observed individually.

rPSGL‐Ig blocks P‐selectin, whereas Reopro and LY294002 block GPIIb–IIIa and its activation, respectively, without a major effect on the percentage of platelets expressing P‐selectin.

In summary, platelet P‐selectin participates with GPIIb–IIIa in the initiation of platelet aggregation. Its inhibition, with rPSGL‐Ig, delays the aggregation process and increases the anti‐aggregatory potency of Reopro. Thus, combination of P‐selectin and GPIIb–IIIa antagonism may constitute a promising therapeutic option in the management of thrombotic disorders.

British Journal of Pharmacology(2006)148, 299–305. doi:10.1038/sj.bjp.0706734
Integrated all-optical switch in a cross-waveguide geometry
Authors: Moll N. , Harbers R. , Mahrt R. F. , Bona G.-L.
Published: April 2006

An all-optical switch for future computer optical interconnect systems based on an optical cavity with a high quality factor and a nonlinear material is computionally investigated in two dimensional with a finite-difference time domain method. The signal and control bus are perpendicular to each other and can couple into a high-Q cavity consisting of a nonlinear material. It is designed in such a way that the control bus switches the signal bus on and off. Owing to the nonlinearity in the cavity, the resonance is shifted in frequency when increasing the power in the control bus so that the signal can pass through the resonator. The high Q of the cavity maximizes the interaction with the nonlinear material, and the symmetry of the cavity mode is designed in such a way that the cross talk between the signal bus and the control bus is minimized.
Transnational Development Networks
Authors: Bebbington Anthony , Kothari Uma
Published: April 2006

Development is embedded in networks that extend across space and time. These networks—maintained, reworked, and given meaning through the practices of the actors who constitute them—bring together assemblages of institutions, knowledges, and commitments that make possible and shape the ways in which development is done through them. The authors explore the usefulness of concepts of network and assemblage for conceptualizing development, elaborating their ideas through two case studies. In the first they discuss colonial officers' experiences of living and working outside the United Kingdom, the ideas and practices that informed this mode of being, and their influence on the development work they did both in colonial and in postcolonial contexts. In the second they discuss the embeddedness of nongovernmental aid networks in religious, political, and other institutions, and the ways in which these institutions fashion the flows of such aid and the types of intervention linked to it. Though distinct, the two cases each show the ways in which social networks sustain particular intersections between institution, practice, and knowledge in informing development. They also suggest different methodological tactics for exploring these intersections. The nature of these tactics and their implications for producing knowledge about development networks are explored.
Success or Failure: Selectivity and Reasons of Return Migration in Sichuan and Anhui, China
Authors: Wang Wenfei Winnie , Fan C Cindy
Published: April 2006

In this paper we examine urban–rural return migration in China. We argue that the traditional success–failure dichotomy approach used for analyzing return migration is inadequate and that it must be expanded to address better the institutional context of the transitional economy. Using an empirical study of Sichuan and Anhui provinces, we analyze the selectivity of return migrants and their reasons for return, focusing not only on how returnees compare with continuing migrants, but also on their decisionmaking. The analysis indicates that returnees are negatively selected among migrants and suggests that failure migrants are more prevalent than are typically portrayed in the literature. The results also highlight family demand as an important reason for return. These findings suggest that migrants' institutional and social inferiority in the city undermines their likelihood to succeed in the destination and reinforces their desire to return when family needs arise. Our analysis raises questions about the optimism of existing studies about the contribution of return migrants in China's countryside.
Activity of TSC2 is inhibited by AKT-mediated phosphorylation and membrane partitioning
Authors: Cai Sheng-Li , Tee Andrew R. , Short John D. , Bergeron Judith M. , Kim Jinhee , Shen Jianjun , Guo Ruifeng , Johnson Charles L. , Kiguchi Kaoru , Walker Cheryl Lyn
Published: April 2006

Loss of tuberin, the product of TSC2 gene, increases mammalian target of rapamycin (mTOR) signaling, promoting cell growth and tumor development. However, in cells expressing tuberin, it is not known how repression of mTOR signaling is relieved to activate this pathway in response to growth factors and how hamartin participates in this process. We show that hamartin colocalizes with hypophosphorylated tuberin at the membrane, where tuberin exerts its GTPase-activating protein (GAP) activity to repress Rheb signaling. In response to growth signals, tuberin is phosphorylated by AKT and translocates to the cytosol, relieving Rheb repression. Phosphorylation of tuberin at serines 939 and 981 does not alter its intrinsic GAP activity toward Rheb but partitions tuberin to the cytosol, where it is bound by 14-3-3 proteins. Thus, tuberin bound by 14-3-3 in response to AKT phosphorylation is sequestered away from its membrane-bound activation partner (hamartin) and its target GTPase (Rheb) to relieve the growth inhibitory effects of this tumor suppressor.
Ovol1 regulates the growth arrest of embryonic epidermal progenitor cells and represses c-myc transcription
Authors: Nair Mahalakshmi , Teng Andy , Bilanchone Virginia , Agrawal Anshu , Li Baoan , Dai Xing
Published: April 2006

Transcriptional control plays a key role in regulating epidermal proliferation and differentiation. Although ample information has been obtained on how epidermal homeostasis is controlled in adult skin, less is known about the control of proliferation/differentiation of epidermal stem/progenitor cells in the developing embryo. Ovol1, encoding a zinc finger protein homologous to Drosophila melanogaster Ovo, is expressed in embryonic epidermal progenitor cells that are transiting from proliferation to terminal differentiation. In this study, we demonstrate a function for Ovol1 in interfollicular epidermal development. In its absence, developing epidermis fails to properly restrict the proliferative potential of progenitor cells, and cultured keratinocytes fail to efficiently undergo growth arrest in response to extrinsic growth-inhibitory signals. We present molecular evidence that c-myc expression is up-regulated in Ovol1-deficient suprabasal cells and that Ovol1 represses c-myc transcription by directly binding to its promoter. Collectively, our findings indicate that Ovol1 is required for proliferation exit of committed epidermal progenitor cells and identify c-myc as an Ovol1 target.