bluuebunny/crossref_metadata_2025 huggingface dataset:
Elastic properties of KGd(WO4)2:Ho3+ single crystals studied by Brillouin spectroscopy
Authors: Kasprowicz D. , Mielcarek S. , Trzaskowska A. , Majchrowski A. , Michalski E. , Drozdowski M.
Published: November 2007

The analysis some of the acoustic phonons propagating in pure and Ho3+‐doped KGd(WO4)2 single crystals in the GHz frequency range by Brillouin scattering method has been presented. For investigated crystals the velocities of the longitudinal and transverse acoustic phonons [100], [010], [001], [101], [101] and [110] have been determined. Moreover, the value of elastic constants C22, C44 and C66 of pure and Ho3+‐doped KGd(WO4)2 single crystals have been estimated. It was revealed that the presence of the Ho3+‐ions in KGd(WO4)2 crystals, for the used doping concentration 1 at% and 8 at%, does not influence their elastic properties. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of 50 MeV Si ion irradiation on nonlinear optical benzimidazole single crystals
Authors: Kanagasekaran T. , Mythili P. , Srinivasan P. , Vijayan N. , Bhagavannarayana G. , Kulriya P. K. , Kanjilal D. , Gopalakrishnan R. , Ramasamy P.
Published: November 2007

The 50 MeV Si7+ ion irradiation induced modifications on structural, dielectric, optical and mechanical properties of Vertical Bridgman grown benzimidazole (BMZ) crystals were studied. The high resolution X‐ray diffraction studies show the quality of as grown BMZ and irradiated BMZ crystals. The dielectric constant and dielectric loss as a function of frequency and temperature was studied in detail. The ion induced mechanical behaviour of both as grown BMZ and irradiated BMZ crystals has been explained with the indentation effects using Vickers microhardness tester. UV‐VIS. studies reveal the decrease in bandgap values and defects on irradiation. The above results are discussed in detail. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Risk factors in V‐shaped risk associations with all‐cause mortality in type 2 diabetes—The Hong Kong Diabetes Registry
Authors: So Wing Yee , Yang Xilin , Ma Ronald C. W. , Kong Alice P. S. , Lam Christopher W. K. , Ho Chung Shun , Cockram Clive S. , Ko Gary T. C. , Chow Chun‐Chung , Wong Vivian , Tong Peter C. Y. , Chan Juliana C. N.
Published: November 2007

Background

Body mass index (BMI) is associated with death in a V‐shaped manner in general populations but it is unknown whether BMI or other risk factors also exhibit V‐shaped relationships with death in type 2 diabetic patients.

Methods

A prospective cohort of 7534 Chinese, type 2 diabetic patients enrolled since 1995 were censored on 30 July 2005. Spline Cox regression analysis with a stepwise algorithm (p < 0.05) was used to select predictors. Hazard ratio (HR) curves were used to explore the relationships, which were confirmed by standard Cox models.

Results

763 patients died during the 5.5 years of follow‐up. BMI, high‐density lipoprotein cholesterol (HDL‐C) and white blood cell (WBC) count were related to all‐cause mortality in a V‐shaped manner. The nadirs of the risk curves were at 26 kg/m2 for BMI, 1.15 mmol/L for HDL‐C and 6.25 × 109 counts/L for WBC. The multivariate hazard ratio of BMI away from 26.0 kg/m2 was 1.08; HDL‐C, 1.06 per mmol/L for values less than the nadir and 6.97 per mmol/L for greater than the nadir; and WBC, 1.16 per 109 count/L for less than 6.25 × 109 and 1.47 for greater than the nadir. Respiratory and neoplastic deaths were the major contributors to the increased death in patients with low or high BMI. Neoplastic death was the major contributor to the increased death in those with low WBC. Genitourinary death was the major contributor to the increased death in those with low and high HDL‐C.

Conclusion

BMI, HDL‐C and WBC are associated with death in a V‐shaped manner in type 2 diabetic patients. Copyright © 2007 John Wiley & Sons, Ltd.
Regulation and function of Dbx genes in the zebrafish spinal cord
Authors: Gribble Suzanna L. , Nikolaus O. Brant , Dorsky Richard I.
Published: November 2007

Dbx homeodomain proteins are important for spinal cord dorsal/ventral patterning and the production of multiple spinal cord cell types. We have examined the regulation and function of Dbx genes in the zebrafish. We report that Hedgehog signaling is not required for the induction or maintenance of these genes; in the absence of Hedgehog signaling, dbx1a/1b/2 are expanded ventrally with concomitant increases in postmitotic neurons that differentiate from this domain. Also, we find that retinoic acid signaling is not required for the induction of Dbx expression. Furthermore, we are the first to report that knockdown of Dbx1 function causes a dorsal expansion of nkx6.2, which is thought to be the cross‐repressive partner of Dbx1 in mouse. Our data confirm that the dbx1a/1b/2 domain in zebrafish spinal cord development behaves similarly to amniotes, while extending knowledge of Dbx1 function in spinal cord patterning. Developmental Dynamics 236:3472–3483, 2007. © 2007 Wiley‐Liss, Inc.
The developing embryonic cardiac outflow tract is highly sensitive to oxidant stress
Authors: Fisher Steven A.
Published: November 2007

This study tested the hypothesis that the remodeling of the cardiac outflow tract (OFT) may represent a developmental window of vulnerability to reactive oxygen species (ROS). Chick embryos were exposed in ovo or ex ovo to increasing concentrations of the stable oxidant hydrogen peroxide (H2O2). As assessed by trypan blue staining, H2O2 induced cell injury in the stage 25–30 OFT at concentrations as low as 1 nM. Higher concentrations were required to induce cell injury in the ventricular and atrial myocardium. Using DCFDA as an indicator of oxidant stress, H2O2 also induced a greater fluorescent signal in the OFT myocardium. H2O2 at these low concentrations also induced Caspase activity, indicative of activation of the pathway of PCD. Interestingly, the induction of Caspase‐3 activity was predominately in the OFT cushion mesenchymal cells. Thus, the developing OFT is particularly sensitive to ROS‐mediated injury, suggesting that ROS could play a role in the development of congenital defects of the cardiac OFT. Developmental Dynamics 236:3496–3502, 2007. © 2007 Wiley‐Liss, Inc.
p38α MAP kinase‐deficient mouse embryonic stem cells can differentiate to endothelial cells, smooth muscle cells, and neurons
Authors: Guo Yan‐Lin , Ye Jianming , Huang Faqing
Published: November 2007

p38 MAP kinase α (p38α) regulates various cellular processes in adult cells, but little is known about its function in stem cells. We investigated the potential of wild type and p38α deficient mouse embryonic stem cells (ESCs) to differentiate into endothelial cells (ECs), smooth muscle cells (SMCs), and neurons. Our differentiation methods allowed simultaneous development of all these cell types. ECs formed monolayers similar to mature ECs and could assemble into vessel‐like structures. SMCs had well‐organized actin filaments with morphology similar to adult SMCs. Neurons exhibited well‐developed cell bodies and elongated axons. Deletion of the p38α gene did not significantly compromise ESC differentiation since p38α−/− cells could express cell‐specific markers and displayed similar overall morphology to the cells differentiated from p38α+/+ ESCs. Although p38α regulates various cellular activities of adult SMCs, ECs, and neurons, our data demonstrate that p38α is not essential for ESC differentiation to these cell types. Developmental Dynamics 236:3383–3392, 2007. © 2007 Wiley‐Liss, Inc.
Non‐linear seismic analysis and vulnerability evaluation of a masonry building by means of the SAP2000 V.10 code
Authors: Pasticier Laurent , Amadio Claudio , Fragiacomo Massimo
Published: November 2007

The aim of the paper is to explore the possibilities offered by SAP2000® v.10, a software package with user‐friendly interface widely used by practising engineers, for seismic analyses of masonry buildings. The reliability of the code was first investigated by carrying out static push‐over (SPO) analyses of two walls, already analysed by other researchers using advanced programs. The equivalent frame modelling was employed in all analyses carried out. The code was then used to investigate the seismic performance of an existing two‐storey building typical of the north‐east of Italy, with the walls being made of roughly squared stones. An SPO analysis was performed first on the most significant wall, followed by a number of time‐history analyses aimed to evaluate the dynamic push‐over curves. Finally, the seismic fragility curves were derived, considering the seismic input as a random variable. Copyright © 2007 John Wiley & Sons, Ltd.
Erosion rates of waterfalls in post‐volcanic fluvial systems around Aso volcano, southwestern Japan
Authors: Hayakawa Yuichi S. , Yokoyama Shozo , Matsukura Yukinori
Published: November 2007

Estimation of the recession rate of waterfalls is a crucial issue in bedrock river erosion because waterfall recession can cause a major impact on bedrock incision, especially when waterfall recession rates are high. Areas of active volcanoes are often characterized by many waterfalls in the volcanic edifice. This study examines recession rates of waterfalls in welded Aso‐1 ignimbrite from the Aso volcano in southwestern Japan using an empirical equation, which comprises a force/resistance index composed of measurable geomorphic parameters. The estimated recession rates are on the order of 0·01–0·07 m a−1. The estimated rates are then validated by examining the duration and distance of their recession. The duration of waterfall recession is derived from eruptive ages of the Aso ignimbrites, giving waterfall recession distances of approximately 10 km. Although the original locations of the waterfalls suggested by the recession distances exceed the downstream limit of the present Aso‐1 ignimbrite remnants along valley floors, features of the surrounding topography are consistent with these localities being where the waterfalls formed. The use of an equation to estimate recession rates is therefore considered to be valid and practical. The contrast between the highly dissected landforms downstream of the present waterfalls and the gentle landscapes upstream of the waterfalls suggests that the rapid recession of the waterfalls is the major cause of post‐eruptive fluvial erosion into ignimbrites. Copyright © 2007 John Wiley & Sons, Ltd.
Drag prediction, decomposition and visualization in unstructured mesh CFD solver of TAS‐code
Authors: Yamazaki Wataru , Matsushima Kisa , Nakahashi Kazuhiro
Published: November 2007

The accuracy of drag prediction in unstructured mesh CFD solver of TAS (Tohoku University Aerodynamic Simulation) code is discussed using a drag decomposition method. The drag decomposition method decomposes total drag into wave, profile, induced and spurious drag components, the latter resulting from numerical diffusion and errors. The mesh resolution analysis is conducted by the drag decomposition method. The effect of an advanced unstructured mesh scheme of U‐MUSCL reconstruction is also investigated by the drag decomposition method. The computational results show that the drag decomposition method reliably predicts drag and is capable of meaningful drag decomposition. The accuracy of drag prediction is increased by eliminating the spurious drag component from the total drag. It is also confirmed that the physical drag components are almost independent of the mesh resolution and scheme modification. Copyright © 2007 John Wiley & Sons, Ltd.
Aggregation rules for cost–benefit analysis: a health economics perspective
Authors: Borghi Josephine
Published: November 2007

Few willingness‐to‐pay (WTP) studies in the health sector have used their results within a cost–benefit analysis (CBA), an essential step to informing resource allocation decisions. This paper provides an overview of aggregation methods, reviews current evidence of practice in the health sector, and presents estimates of the total economic value of a women's group programme to improve mother and newborn health using different aggregation rules. A contingent valuation survey was conducted with 93 women's group members, 70 female non‐members and 33 husbands. Aggregation was conducted with and without the values of non‐users, and with different units of aggregation. The unadjusted mean, median and a weighted mean transfer were used to aggregate values. Equity weights were introduced to adjust WTP for income. Total WTP more than doubled when the values of husbands were added to that of women, and increased over 10‐fold when the values of women who were not members of the group were added. The inclusion of non‐use values, and the unit of aggregation, had the greatest effect on results. Researchers must reach agreement on the most acceptable method of aggregating WTP values to promote the use of WTP in resource allocation decisions in the health sector. Copyright © 2007 John Wiley & Sons, Ltd.
Social costs of robbery and the cost‐effectiveness of substance abuse treatment
Authors: Basu Anirban , Paltiel A. David , Pollack Harold A.
Published: November 2007

Reduced crime provides a key benefit associated with substance abuse treatment (SAT). Armed robbery is an especially costly and frequent crime committed by some drug‐involved offenders. Many studies employ valuation methods that understate the true costs of robbery, and thus the true social benefits of SAT‐related robbery reduction. At the same time, regression to the mean and self‐report bias may lead pre–post comparisons to overstate crime reductions associated with SAT.

Using 1992–1997 data from the National Treatment Improvement Evaluation Study (NTIES), we examined pre–post differences in self‐reported robbery among clients in five residential and outpatient SAT modalities. Fixed‐effect negative binomial regression was used to examine incidence rate reductions (IRR) in armed robbery. Published data on willingness to pay to avoid robbery were used to determine the social valuation of these effects. Differences in IRR across SAT modalities were explored to bound potential biases.

All SAT modalities were associated with large and statistically significant reductions in robbery. The average number of self‐reported robberies declined from 0.83/client/year pre‐entry to 0.12/client/year following SAT (p<0.001). Under worst‐case assumptions, monetized valuations of reductions in armed robbery associated with outpatient methadone and residential SAT exceeded economic costs of these interventions. Conventional wisdom posits the economic benefits of SAT. We find that SAT is even more beneficial than is commonly assumed. Copyright © 2007 John Wiley & Sons, Ltd.
Fuzzy‐logic‐based decision‐making system for stock allocation in a distribution supply chain
Authors: Xie Ying , Petrovic Dobrila
Published: November 2007

Stock allocation in a distribution supply chain (DSC) means that the warehouse has to determine quantities of the available stock to be delivered to each retailer. Different allocation rules have been developed with various aims. In this paper, a new fuzzy‐logic‐based decision‐making system for stock allocation (DMS_SA) is presented, and the objective is to achieve the target DSC fill rate whilst incurring an acceptable total holding cost, or to achieve the target holding cost whilst with a certain level of fill rate. It is shown how DMS_SA can be extended to be applied to a multi‐echelon DSC. Copyright © 2007 John Wiley & Sons, Ltd.
Hybrid approach with an expert system and a genetic algorithm to production management in the supply net
Authors: Ławrynowicz Anna
Published: November 2007

A new approach to solving production management problems in the supply net is proposed. An expert system designed to help companies in medium‐term and short‐term production planning is discussed. The proposed expert system considers alternative process plans for a job and outsourcing, when a bottleneck exists in the machine. The proposed hybrid system uses the output of the expert system as the input of the genetic algorithm. The output of the genetic algorithm is a near optimal schedule. The proposed method does not require any unrealistic assumptions. It can be used to solve highly complicated and non‐linear functions of a realistic problem. Copyright © 2007 John Wiley & Sons, Ltd.
Data mining for improving the solder bumping process in the semiconductor packaging industry
Authors: Chien Chen‐fu , Li Huan‐chung , Jeang Angus
Published: November 2007

Modern semiconductor manufacturing is very complex and expensive. Maintaining high quality and yield enhancement have been recognized as important factors to build core competences for semiconductor manufacturing companies. Data mining can find potentially useful information from huge databases. This paper proposes a data‐mining framework based on decision‐tree induction for improving the yield of the solder bumping process in which the various (physical and chemical) input variables that affect the bumping process exhibit highly complex interactions. We conducted an empirical study in a semiconductor fabrication facility in Taiwan to validate this approach. The results show that the proposed approach can effectively derive the causal relationships among controllable input process factors and the target class to enhance the yield. Copyright © 2007 John Wiley & Sons, Ltd.
Changing investment styles: style creep and style gaming in the hedge fund industry
Authors: Baghai‐Wadji Ramin , El‐Berry Rami , Klocker Stefan , Schwaiger Markus
Published: November 2007

Notwithstanding their common features, hedge funds remain an extremely diverse asset class. Information on fund styles is important for numerous purposes, such as portfolio construction, performance attribution and risk management. With fund self‐declaration being prone to (strategic) misclassification, return‐based taxonomies grouping funds along similarities in realized returns provide a useful alternative. We provide a consistent classification system of homogeneous groups of hedge funds based on self‐organizing maps. Whereas some fund categories such as managed futures are largely consistent in their self‐declared strategies, others, especially so‐called ‘equity hedge’ funds, display no or very limited return similarities. Furthermore, we also find evidence of fund managers performing undisclosed changes of their trading style over time. Those funds that misclassified themselves once are particularly likely to change their trading style again. Although style self‐declaration can, therefore, be quite misleading, our results indicate that hedge funds do not misdeclare their style strategically to improve their relative performance. Copyright © 2006 John Wiley & Sons, Ltd.
Assessing early warning signals of currency crises: a fuzzy clustering approach
Authors: Liu Shuhua , Lindholm Christer K.
Published: November 2007

In the period of 1990s alone, four waves of financial crises occurred around the world. The repeated occurrence of financial crises stimulated a large number of theoretical and empirical studies on the phenomena, in particular studies on the determinants of or early warning signals of financial crises. Nonetheless, the different studies of early warning systems have achieved mixed results and there remains much room for further investigation. Since, so far, the empirical studies have focused on conventional economic modelling methods such as simplified probabilistic models and regression models, in this study we examine whether new insights can be gained from the application of the fuzzy clustering method.

The theories of fuzzy sets and fuzzy logic offer us the means to deal with uncertainties inherent in a wide variety of tasks, especially when the uncertainty is not the result of randomness but the result of unknown factors and relationships that are difficult to explain. They also provide us with the instruments to treat vague and imprecise linguistic values and to model nonlinear relationships. This paper presents empirical results from analysing the Finnish currency crisis in 1992 using the fuzzy C‐means clustering method. We first provide the relevant background knowledge and introduce the fuzzy clustering method. We then show how the use of fuzzy C‐means method can help us to identify the critical levels of important economic indicators for predicting of financial crises. Copyright © 2007 John Wiley & Sons, Ltd.
Combining heterogeneous classifiers for stock selection
Authors: Albanis George , Batchelor Roy
Published: November 2007

Combining unbiased forecasts of continuous variables necessarily reduces the forecast error variance below that of a typical individual forecast. However, this does not necessarily hold for forecasts of discrete variables, or where the costs of errors are not directly related to the error variance. This paper investigates the benefits of combining forecasts of outperforming shares, based on one linear and four non‐linear statistical classification techniques, including neural network and recursive partitioning methods. All produce excess returns. Combining by simple ‘majority voting’ improves accuracy and profitability. Much greater gains come from applying the ‘unanimity principle’, whereby a share is not held in the high‐performing portfolio unless all classifiers agree. Copyright © 2007 John Wiley & Sons, Ltd.
A comparison of nearest neighbours, discriminant and logit models for auditing decisions
Authors: Gaganis Chrysovalantis , Pasiouras Fotios , Spathis Charalambos , Zopounidis Constantin
Published: November 2007

This study investigates the efficiency of k‐nearest neighbours (k‐NN) in developing models for estimating auditors' opinions, as opposed to models developed with discriminant and logit analyses. The sample consists of 5276 financial statements, out of which 980 received a qualified audit opinion, obtained from 1455 private and public UK companies operating in the manufacturing and trade sectors. We develop two industry‐specific models and a general one using data from the period 1998–2001, which are then tested over the period 2002–2003. In each case, two versions of the models are developed. The first includes only financial variables. The second includes both financial and non‐financial variables. The results indicate that the inclusion of credit rating in the models results in a considerable increase both in terms of goodness of fit and classification accuracies. The comparison of the methods reveals that the k‐NN models can be more efficient, in terms of average classification accuracy, than the discriminant and logit models. Finally, the results are mixed concerning the development of industry‐specific models, as opposed to general models. Copyright © 2007 John Wiley & Sons, Ltd.
Age‐related differences in susceptibility to toxic effects of valproic acid in rats
Authors: Espandiari Parvaneh , Zhang Jun , Schnackenberg Laura K. , Miller Terry J. , Knapton Alan , Herman Eugene H. , Beger Richard D. , Hanig Joseph P.
Published: November 2007

A multi‐age rat model was evaluated as a means to identify a potential age‐related difference in liver injury following exposure to valproic acid (VPA), a known pediatric hepatotoxic agent. Different age groups of Sprague‐Dawley (SD) rats (10‐, 25‐, 40‐, 80‐day‐old) were administered VPA at doses of 160, 320, 500 or 650 mg kg−1 (i.p.) for 4 days. Animals from all age groups developed toxicity after treatment with VPA; however, the patterns of toxicity were dissimilar within each age group. The high dose of VPA caused significant lethality in 10‐ and 25‐day‐old rats. All doses of VPA caused decrease in the platelet counts (10‐, 25‐day‐old rats) and the rate of growth (40‐day‐old rats) and increases in the urine creatine concentration (high dose, 80‐day‐old rats). VPA induced hepatic and splenic alterations in all age groups. The most severe lesions were found mostly in 10‐ and 80‐day‐old rats. Significant changes in blood urea nitrogen, alanine aminotransferase and alkaline phosphatase were observed in 10‐day‐old pups after treatment with low doses of VPA. The highest VPA dose caused significant decreases in the levels of serum total protein (40‐ and 80‐day‐old rats). Principal component analysis of spectra derived from terminal urine samples of all age groups showed that each age group clusters separately. In conclusion, this study showed that the vulnerability profile of each age group was different indicating that a multi‐age pediatric animal model is appropriate to assess more completely age‐dependent changes in drug toxicity. Published in 2007 by John Wiley & Sons, Ltd.
Transformation of nacre coatings into apatite coatings in phosphate buffer solution at low temperature
Authors: Guo Yaping , Zhou Yu
Published: November 2007

Nacre coatings were deposited on Ti6Al4V substrates by electrophoretic technique, and subsequently converted into apatite coatings with hierarchical porous structures by treatment with a phosphate buffer solution. The samples were characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma optical emission spectroscopy, X‐ray photoelectron spectroscopy (XPS), and N2 adsorption–desorption isotherms. The results show that the nacre coatings are converted into the plate‐like apatite coatings via a dissolution–precipitation reaction, while the organic components of the nacre are reserved. The mesopores with pore size of ˜4.4 nm are formed within the plate‐like structure, and the macropores are formed among the plate‐like structure. Simulated body fluid (SBF) immersion tests reveal that the apatite coatings have a good in vitro bioactivity. Bone‐like apatite crystals are formed on the surfaces of the apatite coatings after soaking in SBF for 12 h, and fill up the macropores on the coatings with increasing the soaking time. In addition, XPS indicates that a TiOx layer and PO43− ions appear on the substrate surfaces by pretreatment with a H3PO4/HF solution. The TiOx layer and PO43− ions can induce the formation of apatite crystals, resulting in a composition gradient from the oxide layer to the external apatite layer. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
1,25‐Dihydroxyvitamin D3 stimulates bone neovascularization by enhancing the interactions of osteoblasts‐like cells and endothelial cells
Authors: Li Tao , Yu Yao‐Ting , Wang Jing , Tang Tian‐Si
Published: November 2007

The current work investigated whether 1,25‐dihydroxyvitamin D3(1,25‐(OH)2D3) can promote the neovascularization of tissue‐engineered bone. Human osteoblast‐like cells (HOB) and endothelial cells (EC) were isolated and cultured. HOB and EC were inoculated at the ratio of 2:1 onto the coral‐derived hydroxyapatite (CHA) scaffolds coated with and without 1,25‐(OH)2D3. Tissue‐engineered bones were cultured for 3 days before implantation into the backs of nude mice. Four and 8 weeks after the operation, the retrieved scaffolds and cells were examined histologically and by scanning electron microscope, and the vascular area was measured. The immature bone grew into the pores of CHA scaffolds in both groups. At each time interval, there was a conspicuous neovascularization in the 1,25‐(OH)2D3 treatment group, with a larger amount of new capillaries accompanying immature bone. In the 1,25‐(OH)2D3 group, scanning electron microscopy revealed luminal sprouting from the larger vessels. Maturation of the new bone was paralleled by the occurrence of the new capillaries. The vascular areas were 28.74% ± 7.81% and 19.52% ± 4.57% at 4‐week intervals (p < 0.05) and 24.66% ± 7.38% and 17.84% ± 5.22% at 8‐week intervals (p < 0.05) in test and control groups, respectively. These results imply that 1,25‐dihydroxyvitamin D3 may be useful as a cytokine for tissue engineering bone for neovascularization. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
In vitro fibroblast response to polyurethane organosilicate nanocomposites
Authors: Styan K. E. , Martin D. J. , Poole‐Warren L. A.
Published: November 2007

The term nanocomposite refers to organic:inorganic composites where one phase, typically the inorganic phase, has dimensions on the nanoscale. Several authors have noted the potential benefit of biomedical application of nanocomposite technology, and have suggested using quaternary ammonium compounds (QAC) as an organic modification to enhance dispersion of nanoparticles within polymer matrices. This study aimed to examine fibroblast responses in vitro to a range of nanocomposites using different organic modifiers. Composite materials were prepared from a polyether urethane (PEU) and various unmodified and organically modified montmorillonite (MMT) nanoparticles. QAC and amino undecanoic acid (AUA) modified‐MMT were added to PEU at loadings ranging from ∼1 to 15 wt %. Composites with organically modified QAC and AUA particles displayed partially exfoliated and intercalated silicate morphology, respectively. Nanocomposites showed increases in ultimate tensile properties for materials with lower QACMMT loadings. However QAC was shown to significantly inhibit cell growth following release from PEU‐QACMMT under extraction conditions mimicking those of the physiological environment. Materials containing silicate modified using AUA were cytocompatible. The results of this study suggest that QAC may be unsuitable as organic modifiers for nanoparticles destined for biomedical use. Alternative modifiers based on AUA confer equivalent dispersion and are of low toxicity. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Cigarette smoke and dopaminergic system
Authors: Miller Leah R. , Mukherjee Shyamali , Ansah Twum A. , Das Salil K.
Published: November 2007

It has been reported that there is an ameliorative effect of cigarette smoking on certain neurological responses and neurodegenerative disorders. The purpose of this study was to examine the neurochemical and neurobehavioral response of cigarette smoke (CS) in the adult male guinea pig brain. Both acute and chronic CS exposure enhanced locomotor behavior and caused a decrease in midbrain dopamine (DA) levels and corresponding increase in 3,4‐dihydroxyphenylacetic acid (DOPAC) levels. In addition, CS caused a significant increase in the protein levels of the dopamine D1 and D2 receptors. CS caused a significant increase in the binding capacity of the D1 receptor and a significant decrease in the binding capacity of D2. Furthermore, CS caused a significant increase in the binding capacity of the dopamine transporter (DAT). The mechanism by which cigarette smoke exposure increases locomotor activity remains to be elucidated but may include modulation of dopamine neuron activity that emerges after repeated direct smoke exposure. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:325–335, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20197
Cardioprotective effect of α‐mangostin, a xanthone derivative from mangosteen on tissue defense system against isoproterenol‐induced myocardial infarction in rats
Authors: Devi Sampath Pandima , Vijayaraghavan Kannan
Published: November 2007

Increased oxidative stress and antioxidant deficit have been suggested to play a major role in isoproterenol‐induced myocardial infarction. The present study was designed to evaluate the effect of α‐mangostin on the antioxidant defense system and lipid peroxidation against isoproterenol‐induced myocardial infarction in rats. Induction of rats with ISO (150 mg/kg body weight, ip) for 2 days resulted in a marked elevation in lipid peroxidation, serum marker enzymes (LDH, CPK, GOT, and GPT) and a significant decrease in the activities of endogenous antioxidants (SOD, CAT, GPx, GST, and GSH). Pre‐treatment with α‐mangostin (200 mg/kg of body weight per day) orally for 6 days prior to the ISO administration and 2 days along with ISO administration significantly attenuated these changes when compared to the individual treatment groups. These findings indicate the protective effect of α‐mangostin on lipid peroxidation and antioxidant tissue defense system during ISO‐induced myocardial infarction in rats. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:336–339, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20199
Mechanism of inhibition of purified leaping mullet (liza saliens) NADPH‐cytochrome P450 reductase by toxic metals: Aluminum and thallium
Authors: Bozcaarmutlu Azra
Published: November 2007

Aluminum and thallium may reach life‐threatening levels in aquatic systems in the near future because of their extensive use in various industrial fields. It is therefore important to study the mechanism of toxicity of aluminum and thallium on fish enzymes. To this aim, the effects of aluminum and thallium on the activity of purified leaping mullet (Liza saliens) cytochrome P450 reductase, an essential component of the important cytochrome P450 system, have been studied. Results indicated that both metal ions strongly inhibited the NADPH‐cytochrome P450 reductase. The IC50 values of AlCl3 and TlCl3 were estimated to be 34 μM and 3 μM, respectively. The Lineweaver–Burk plot and Dixon plot revealed that both metal ions noncompetitively inhibited the purified mullet cytochrome P450 reductase. The Ki values of Al3+ and Tl3+ were calculated from Dixon plots as 8.9 and 5.6 μM, respectively. The inhibitory effects of Al3+ and Tl3+ on purified cytochrome P450 reductase were partially recovered by 1 mM EDTA. Additionally, tin and magnesium were shown to have no apparent effect on purified mullet cytochrome P450 reductase. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:340–3347, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20200
Benzene‐1,2‐, 1,3‐, and 1,4‐di‐N‐substituted carbamates as conformationally constrained inhibitors of acetylcholinesterase
Authors: Lin Ming‐Cheng , Hwang Mei‐Ting , Chang Han‐Ging , Lin Chung‐Sheng , Lin Gialih
Published: November 2007

Benzene‐1,2‐, 1,3‐, and 1,4‐di‐N‐substituted carbamates (1–15) are synthesized as the conformationally constrained inhibitors of acetylcholinesterase and mimic gauche, eclipsed, and anti‐conformations of acetylcholine, respectively. All carbamates 1–15 are characterized as the pseudo substrate inhibitors of acetylcholinesterase. For a series of geometric isomers, the inhibitory potencies are as follows: benzene‐1,4‐di‐N‐substituted carbamate (para compound) > benzene‐1,3‐di‐N‐substituted carbamate (meta compound) > benzene‐1,2‐di‐N‐substituted carbamate (ortho compound). Therefore, benzene‐1,4‐di‐N‐substituted carbamates (para compounds), with the angle of 180° between two C(benzene)–O bonds, mimic the preferable anti C–O/C–N conformers of acetylcholine for the choline ethylene backbone in the acetylcholinesterase catalysis. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:348–353, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20202
Adaptive correction technique for 3D reconstruction of fluorescence microscopy images
Authors: Guan Y.Q. , Cai Y.Y. , Zhang X. , Lee Y.T. , Opas M.
Published: November 2007

Recent advances in high‐resolution imaging have provided valuable novel insights into structural relationships within cells and tissues both in vitro and in vivo. An analysis of this kind is regularly done by optical sectioning using either confocal or deconvolution microscopy. However, the reconstruction of 3D images suffers from light scattering and absorption with increasing depth by finite transparency of the used media. Photobleaching of fluorochromes has been especially troublesome and often the only remedy for loss of signal during optical sectioning is to reduce the number of sections. This causes disparities in the x–y and z dimensions of voxels, which lead to vertical distortion of the original stack of images and necessitates interpolation. Interpolation is necessary to fill up the gaps between consecutive sections in the original image stack to obtain cubic voxels. The present manuscript describes a novel method for adaptive compensation of attenuation of light intensity in stacks of fluorescence microscopy images that is based on a physical model of light attenuation. First, we use a fast interpolation technique to generate a cubic voxel‐based volume stack with the aid of a contribution look up table. With the contribution look up table, multiple calculations are avoided, which substantially reduces the computational time without compromising the accuracy of the restoration procedure. Second, each section within the resulting volume is processed to rectify its intensity values that have been altered due to photobleaching and scattering and absorption. The method allows to define the last good section in the stack and the correction is then done automatically. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Notes on the geometry of the space of polynomials
Authors: Lee Han Ju
Published: November 2007

We show that the symmetric injective tensor product space is not complex strictly convex if E is a complex Banach space of dim E ≥ 2 and if n ≥ 2 holds. It is also reproved that ℓ∞ is finitely represented in if E is infinite‐dimensional and if n ≥ 2 holds, which was proved in the other way in [3]. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quadratic transformations of the sixth Painlevé equation with application to algebraic solutions
Authors: Vidunas Raimundas , Kitaev Alexander V.
Published: November 2007

In 1991, one of the authors showed the existence of quadratic transformations between the Painlevé VI equations with local monodromy differences (1/2, a, b, ±1/2) and (a, a, b, b). In the present paper we give concise forms of these transformations. They are related to the quadratic transformations obtained by Manin and Ramani–Grammaticos–Tamizhmani via Okamoto transformations. To avoid cumbersome expressions with differentiation, we use contiguous relations instead of the Okamoto transformations. The 1991 transformation is particularly important as it can be realized as a quadratic‐pull back transformation of isomonodromic Fuchsian equations. The new formulas are illustrated by derivation of explicit expressions for several complicated algebraic Painlevé VI functions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Function spaces of varying smoothness I
Authors: Schneider Jan
Published: November 2007

This paper deals with function spaces of varying smoothness. It is a modified version of corresponding parts of [8]. Corresponding spaces of positive smoothness s (x) will be considered in part II. We define the spaces Bp (ℝn ), where the function 𝕊: x ↦ s (x) is negative and determines the smoothness pointwise. First we prove basic properties and then we use different wavelet decompositions to get information about the local smoothness behavior. The main results are characterizations of the spaces Bp (ℝn ) by weighted sequence space norms of the wavelet coefficients. These assertions are used to prove an interesting connection to the so‐called two‐microlocal spaces Cs,s ′ (x0). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The natural history of Unverricht‐Lundborg disease: A report of eight genetically proven cases
Authors: Chew Nee K. , Mir Pablo , Edwards Mark J. , Cordivari Carla , Martino Davide , Schneider Susanne A. , Kim Hee‐Tae , Quinn Niall P. , Bhatia Kailash P.
Published: November 2007

We report eight cases of genetically proven ULD, with the aim of reassessing the clinical characteristics and natural history of ULD in genetically characterized patients. The eight patients had their first symptoms at mean age of 10.6 years (range: 6–14 years). The main clinical features were action myoclonus, cerebellar ataxia, seizures, and mild intellectual dysfunction. We report three new clinical features of ULD; ocular motor apraxia, dystonia, and rapidly progressive dementia. All patients needed a combination of at least four antimyoclonic drugs, but despite this, all patients were severely disabled by their action myoclonus. After a mean duration of disease of 29.9 years (range: 21–37 years), four patients were walking with aids while another four were wheelchair bound. The clinical phenotypes associated with ULD are more diverse than previously recognized and even though the long term functional outcome and survival have improved, the overall efficacy of antimyoclonic drugs remains unsatisfactory. © 2007 Movement Disorder Society
Transplantation of adult myoblasts or adipose tissue precursor cells by high‐density injection failed to improve reinnervated skeletal muscles
Authors: César Matthieu , Roussanne‐Domergue Sophie , Coulet Bertrand , Gay Stéphanie , Micallef Jean‐Paul , Chammas Michel , Reyne Yves , Bacou Francis
Published: November 2007

We previously showed that transfer of adult myoblasts (MB) into cardiotoxin‐damaged muscle improved the properties of reinnervated tibialis anterior muscle of rabbits. However, this cell therapy protocol cannot be applied to humans because of the hazardous effects of the myotoxin. To circumvent this approach, we used the recently developed high‐density injection technique to autotransplant cultured cells 1 mm from each other into the tibialis anterior muscle without previous cardiotoxin‐induced damage. Two months after transection and immediate suture of the common peroneal nerve, we transferred by this technique two types of precursor cells, MB or cells isolated from the adipose tissue stromal vascular fraction. In contrast to our previous results, muscles studied at 4 months showed no benefits in terms of function or morphology, whatever the transferred cells. These results, together with the results of earlier studies, emphasize the importance of delivery methods and the muscle environment in supporting cell integration into host tissues. Muscle Nerve, 2007
Dynamic routing of prioritized warranty repairs
Authors: Chen Feng , Kulkarni Vidyadhar G.
Published: November 2007

Recent years have seen a strong trend toward outsourcing warranty repair services to outside vendors. In this article we consider the problem of dynamically routing warranty repairs to service vendors when warranties have priority levels. Each time an item under warranty fails, it is sent to one of the vendors for repair. Items covered by higher priority warranty receive higher priority in repair service. The manufacturer pays a fixed fee per repair and incurs a linear holding cost while an item is undergoing or waiting for repair. The objective is to minimize the manufacturer's long‐run average cost. Because of the complexity of the problem, it is very unlikely that there exist tractable ways to find the optimal routing strategies. Therefore, we propose five heuristic routing procedures that are applicable to real‐life problems. We evaluate the heuristics using simulation. The simulation results show that the index‐based “generalized join the shortest queue” policy, which applies a single policy improvement step to an initial state‐independent policy, performs the best among all five heuristics. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008
On finite‐strain damage of viscoelastic‐fibred materials. Application to soft biological tissues
Authors: Peña E. , Calvo B. , Martínez M. A. , Doblaré M.
Published: November 2007

The aim of this paper is to introduce a fully three‐dimensional finite‐strain damage model for visco‐hyperelastic fibrous soft tissue. The structural model is formulated using the concept of internal variables that provide a very general description of materials involving irreversible effects. Continuum damage mechanics is used to describe the softening behaviour of soft tissues under large deformation. Modelling of the viscoelastic behaviour is based on a local additive decomposition of the stress tensor into initial and non‐equilibrium parts as resulted from the assumed structure of an uncoupled free energy density function. A local multiplicative decomposition of the deformation gradient into volume‐preserving and dilatational parts is used which permits one to model the incompressible properties of soft biological tissues. The presented formulation and the associated algorithmic discretization were efficiently implemented into a finite element code.

In order to show the performance of the constitutive model and it's algorithmic counterpart, some simple examples are included. A more complex three‐dimensional numerical application to ligament mechanics is also presented. Results show that the model is able to capture the typical stress–strain behaviour observed in fibrous soft tissues and seems to confirm the soundness of the proposed formulation. Copyright © 2007 John Wiley & Sons, Ltd.
Isoparametric spline finite strip method for the bending of perforated plates
Authors: Eccher G. , Rasmussen K. J. R. , Zandonini R.
Published: November 2007

The isoparametric spline finite strip method was recently applied by the authors to the linear elastic in‐plane stress analysis of perforated thin‐walled structures. In this paper, the application of the method is extended to the bending of perforated plates. The paper describes the theory of the isoparametric spline finite strip method in the context of Mindlin plate bending theory. It sets out the strain–displacement and stress–strain relationships and derives expressions for the local and global stiffness matrices. The reliability of the method is demonstrated by comparisons with finely meshed finite element analysis results. Square plates in bending containing openings of different shapes are analysed. Copyright © 2007 John Wiley & Sons, Ltd.
The guiding nature of the kawa (river) model in Ireland: creating both opportunities and challenges for occupational therapists
Authors: Carmody Sarah , Nolan Riona , Ni Chonchuir Niamhh , Curry Maria , Halligan Catherine , Robinson Katie
Published: November 2007

The kawa (kawa is Japanese for ‘river’) model of occupational therapy has recently emerged in response to the needs for culturally sensitive conceptual models of practice that adequately address clients' diverse cultures and belief systems (Iwama, 2006a). The present article reports two case studies in which the kawa model was used to guide occupational therapy intervention with two individuals with multiple sclerosis in Ireland, with the aim of exploring the effectiveness of the recently emerged kawa model. A qualitative grounded theory approach using case‐study methodology was undertaken. Semi‐structured interviews based on the kawa model were completed with two participants with multiple sclerosis before and after occupational therapy intervention. The authors also documented their experience of using the model in reflective diaries. Analysis revealed a core category of the guiding nature of the kawa model creating both opportunities and challenges. Opportunities afforded by the model included enablement of the occupational therapy process and facilitation of occupation‐based practice. Challenges created by the use of the kawa model included participant uncertainty and the influence of therapist preconceptions.

Limitations and recommendations for future research are discussed in terms of generalizability. Further research with greater numbers and more diversity of study participants is required to validate the tentative theory proposed. Copyright © 2007 John Wiley & Sons, Ltd.