bluuebunny/crossref_metadata_2025 huggingface dataset:
MBS/FEM Co‐Simulation Approach for Lubrication Problems
Authors: Busch Martin , Schweizer Bernhard
Published: March 2011

Hydrodynamic bearings are used in many technical systems, e.g., in combustion engines, in gear boxes or in rotor systems. To model such bearings, different methods are available. Often, reduced bearing models are applied which can be incorporated into the multibody systems by analytical formulas or pre‐computed look‐up tables [1]. Such approaches are very time‐efficient but suffer from limited physical correctness. In order to improve the physical bearing model, the fluid flow and temperature field in the bearing gap have to be computed with partial differential equations which have to be solved simultaneously with the multibody system. These equations are nonlinear and have to be discretized with finite elements, for instance. In the current work, we consider a fully coupled simulation of a multibody rotor system with a finite element model for the hydrodynamic bearings. A co‐simulation interface between two commercial simulation tools is presented. For the synchronization of the solvers, three numerical coupling approaches (an explicit, an implicit and a semi‐implicit approach) are analyzed and compared. For the examined rotor/bearing system, it is shown that semi‐implicit coupling techniques may remarkably stabilize the solver coupling compared to well‐established explicit co‐simulation techniques [2]. Furthermore, a reduction method is introduced and applied in connection with the semi‐implicit coupling approach which can significantly decrease the computation time compared with the classical full‐implicit coupling approach [3]. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stabilization of sliding motion by partial stiction
Authors: Stamm Wolfgang
Published: March 2011

Rotating friction disks are utilized in many drivetrain components such as dry clutches and their actuator systems. Even the simplest pin‐on‐disk or disk‐on‐disk mechanical systems with Coulomb friction reveal a rich dynamical behavior with different types of motions.

Examining the radial dynamics of minimal friction disk models, it is a prevalent assumption to have pure sliding frictional contacts. Governed by the systems' design parameters and initial conditions, stable large amplitude motions at higher rotation speeds are possible. Using a Coulomb friction model with sticking and sliding instead, gives similar motions with alternating phases of sticking and sliding. However, the amplitude can be decreased significantly by these intermittent phases of stick and slip. It is suggested to exploit such motions with partial stiction in order to reduce amplitudes and thus stabilize the systems.

Similar effects can be observed in 3D‐multibody simulations and measurements of double clutch actuator systems. However, for these systems analytical treatment is not feasible any more due to the number of involved degrees of freedom. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metabolic Alterations of Withania somnifera (L.) Dunal Fruits at Different Developmental Stages by NMR Spectroscopy
Authors: Sidhu O. P. , Annarao Sanjay , Chatterjee Sandipan , Tuli Rakesh , Roy Raja , Khetrapal C. L.
Published: March 2011

Introduction

Withania somnifera (Ashwagandha) is a high‐value Ayurvedic medicinal plant and an important constituent of several dietary supplements. In order to substantiate the health claims, the herb has drawn considerable scientific attention.

Objective

The objective of the study was to investigate the alterations in primary and secondary metabolites of W. somnifera fruits during its maturity using NMR spectroscopy.

Methodology

Fruits at different stages of development from one week after fertilisation until maturity, classified in seven developmental stages, were analysed by a combined use of one‐ and two‐dimensional NMR experiments.

Results

Seventeen metabolites were characterised and quantified from non‐polar and polar extracts of different fruit development stages of W. somnifera. The principal component analysis of polar metabolites at different stages could be grossly classified into three metabolic phases, viz. initial phase, developmental phase and maturation phase.

Conclusion

Qualitative and quantitative analysis of metabolites in W. somnifera fruits indicated specific stages when fruits can be harvested for obtaining substantial bioactive ingredients for desirable pharmacological activity. This study potentially provides a complementary tool for quality control of herbal medicinal products when W. somnifera fruits are used. Copyright © 2011 John Wiley & Sons, Ltd.
Quality Evaluation of Potentilla discolor by High‐performance Liquid Chromatography Coupled with Diode Array Detection and Electrospray Ionisation Tandem Mass Spectrometry
Authors: Yang Jie , Wen Xiao‐dong , Jia Bei‐xi , Mao Qian , Wang Qiang , Lai Mao‐xiang
Published: March 2011

Introduction

The whole herb of Potentilla discolor has long been used for treatment of diarrhoea, malaria, haemoptysis and haematemesis in clinical applications. However, until now, there has been no literature regarding to the quality control of it.

Objective

To develop a simple and accurate HPLC‐DAD (diode array detection)–ESI/MSn (electrospray ionisation multistage mass spectrometry) method for the identification of constituents in P. discolor and simultaneous quantification of its marker compounds.

Methodology

Separations were performed on a Shimpack C18 column by gradient elution using acetonitrile:0.1% formic acid. The identification of constituents in P. discolor were achieved by HPLC‐DAD‐ESI/MSn while six flavonoids and five triterpenoids were determined by HPLC‐DAD at 360 and 210 nm, repectively.

Results

A total of 23 compounds including 13 flavonoids and 10 triterpenoids were identified or tentatively characterised. A quantitative HPLC‐DAD method allowing the simultaneously quantification of 11 marker compounds was optimised and validated for linearity, precision, accuracy, and limits of detection and quantification. The method was successfully applied to the quantification of 11 marker compounds in 10 samples of P. discolor collected from different provinces of China.

Conclusion

This developed method was validated as simple, precise and accurate, and could be used for effectively and comprehensibly evaluating the quality of P. discolor. Copyright © 2011 John Wiley & Sons, Ltd.
First trimester fetal head and trunk volume predict growth disturbance in twin pregnancy
Authors: Fajardo‐Expósito M. A. , Hervías B. , Bugatto González F. , Melero‐Jiménez V. , Quintero‐Prado R. , Facio‐Fernández M. C. , Bartha J. L.
Published: March 2011

Objective

To evaluate the usefulness of first trimester fetal head and trunk volume (FHTV) in predicting growth disturbance in twin pregnancy.

Methods

We studied 46 twin pairs from 11 and 14 weeks to delivery. There were 35 dichorionic (76%) and 11 monochorionic (24%) pregnancies. FHTV was assessed by VOCALTM. An inter‐twin discrepancy in FHTV, crown–rump length (CRL) and birthweight (BW) were defined by an inter‐twin difference greater than 15%. Growth retardation was defined as BW of at least one twin below the 10th percentile.

Results

There were 17 cases (37%) of FHTV discrepancy. BW discrepancy and growth retardation were more significantly frequent in cases with FHTV discrepancy than without [11/17 (64.7%) vs 4/29 (13.8%), P = 0.0004 and 7/17 (41.2%) vs 3/29 (10.3%), P = 0.02, respectively].

The detection of BW discordance and growth retardation were significantly higher when using FHTV discordance than CRL discrepancy in the first trimester [11/15 (73%) vs 2/15 (13.3%), P = 0.00001 and 7/10 (70%) vs 1/10 (10%), P = 0.0001, respectively].

Conclusion

FHTV discrepancy is a predictor for growth disturbance in twins. Copyright © 2011 John Wiley & Sons, Ltd.
T2 quantifications of fetal lungs at MRI‐normal ranges
Authors: Cannie M. , Jani J. , De Keyzer F. , Roebben I. , Breysem L. , Deprest J.
Published: March 2011

Objective

To prospectively determine the pattern of lung intensities and T2 values in fetuses with normally developing lungs as obtained with T2‐weighted single‐shot turbo spin echo magnetic resonance (TSE MR) imaging. This should serve as a reference to which images from fetuses with lung development disorders are compared.

Methods

In 105 fetuses with normal lung development who were assessed at 19 to 40 weeks of gestation, MR delineation of left and right lung organs was performed on the T2‐weighted images with TE of 31 ms and extrapolated to the images with echo time (TE) of 267 ms. T2 values were calculated based on the images with these two different TE. Linear regression analysis was used to assess the relationship between gestational age (GA) and T2. We compared T2 values in 11 left‐sided congenital diaphragmatic hernia (CDH) to the normative ranges using the Mann‐Whitney U test.

Results

In fetuses with normal lungs and in CDH, there was a positive correlation between GA and T2 values in both lungs. T2 values, corrected for gestation, were lower in CDH fetuses for ipsilateral lungs as compared to normal lungs. Contralateral lungs showed no difference.

Conclusions

In normally developing lungs there is a significant relation between T2 values with gestation. Ipsilateral lungs in CDH have a significant difference in intensity. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of novel proton‐conducting highly sulfonated polybenzimidazoles for PEMFC and the effect of the type of bisphenyl bridge on polymer and membrane properties
Authors: Ng Feifei , Péron Jennifer , Jones Deborah J. , Rozière Jacques
Published: March 2011

Six series of novel highly sulfonated polybenzimidazoles (sPBIs) with high molecular weight were prepared by direct polycondensation between 3,3′‐diaminobenzidine and original multisulfonated dinuclear dicarboxylic acids containing bridging ether, sulfone, and hexafluoroisopropylidene moieties. All reactions were carried out in polyphosphoric acid, which acts as both solvent and catalyst. The degree of sulfonation was modulated in the final products by varying the proportion of sulfonated to nonsulfonated dicarboxylic acids used in the synthesis. The high purity of the disulfonated and tetrasulfonated monomers allows wholly sulfonated homopolymers to be obtained. Confirmation of the chemical structure and the degree of sulfonation were derived from 1H nuclear magnetic resonance spectroscopy. Inherent viscosity was estimated as between 0.70 and 5.33 dL g−1 for sPBIs with ion exchange capacity in the range 0.87–4.68 mequiv g−1. Dynamic thermogravimetric analysis in air showed no weight loss below 350 °C (heating rate 5 °C min−1). The nature of the bisphenyl bridge has clear influence on the water uptake and proton conduction properties of the resulting sPBI membranes, with hexafluoroisopropylidene links providing materials of highest conductivity as well as favoring film‐forming characteristics. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and characterization of radiopaque poly(ether urethane) with iodine‐Containing diol as chain extender
Authors: Qu Weiqiang , Xia Weijuan , Feng Chao , Tuo Xinlin , Qiu Teng
Published: March 2011

Novel radiopaque iodinated poly(ether urethane) (IPEU) was prepared by using iodine‐containing diol as chain extender in a normal two‐step condensation polymerization process. This new iodine‐containing diol was synthesized by iodination of terephthalic acid and then reaction with 3‐aminopropanol. The chemical structure of the diol chain extender and IPEU was characterized, and the basic properties of IPEU were measured and compared with PEU. X‐ray images showed that 15 wt % iodine‐containing IPEUs were highly radiopaque, and radiopacity did not decrease after 6‐week oxidative degradation treatment. Experimental results showed that IPEUs possessed good thermal stability, favorable mechanical properties, and noncytotoxicity. These results reveal that it is an effective route for the synthesis of biological polyurethane with radiopacity by using iodine‐containing diol as chain extender. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Patients' perception of the usefulness of a question prompt sheet for advanced cancer patients when deciding the initial treatment: a randomized, controlled trial
Authors: Shirai Yuki , Fujimori Maiko , Ogawa Asao , Yamada Yu , Nishiwaki Yutaka , Ohtsu Atsushi , Uchitomi Yosuke
Published: March 2011

Objective: The objective of this study was to evaluate the patients' perception of the usefulness of a question prompt sheet (QPS) in facilitating the involvement of advanced cancer patients during consultation.

Methods: Advanced cancer patients attending their first consultation after diagnosis were randomly assigned to the intervention group (received QPS and a hospital introduction sheet (HIS)) or the control group (received HIS only). Analysis was conducted on an intention‐to‐treat basis. The primary outcome measure was patient rating of the usefulness of the material(s) (numerical rating scale of 0–10).

Results: Sixty‐three advanced cancer patients (72.4% response rate) were enrolled and analyzed. Nearly three‐quarters of patients in both groups read the material(s) before consultation. The rated usefulness of the material(s) for asking questions of physicians was significantly higher in the intervention group than in controls (4.4 ± 3.6 and 2.7 ± 2.8, respectively; p = 0.033). The mean score of the usefulness of the material(s) for understanding the treatment plan tended to be higher in the intervention group than in the controls (4.9 ± 3.6 and 3.3 ± 2.8; p = 0.051). The mean score of willingness to use the material(s) in the future was significantly higher in the intervention group than in the controls (5.3 ± 3.8 and 2.8 ± 2.8; p = 0.006). There were no significant differences between the groups in the average total number of questions asked by patients (median, 1.0; interquartile range in both groups, 2.0).

Conclusions: QPS provided before oncology consultation may be useful for advanced cancer patients, on the other hand, it did not directly promote patient confidence to ask questions. Copyright © 2011 John Wiley & Sons, Ltd.
The experience of caregivers of hematological cancer patients undergoing a hematopoietic stem cell transplant: a comprehensive literature review
Authors: Beattie Sara , Lebel Sophie
Published: March 2011

Objective: Hematopoietic stem cell transplant (HSCT) is a demanding procedure with associated physical and psychological sequelae that affects patients and their families. Caregivers to HSCT patients not only have to cope with the life‐threatening nature of the disease and treatment, but they also have care‐giving responsibilities. This study reviews the literature on the psychosocial impact of being a caregiver to a HSCT patient.

Methods: A critical review of the literature published before June 2010 was conducted. Databases searched included CINAHL, Medline, PsycInfo, and Academic Search Complete, as well as a comprehensive reference review. Studies that pertained to caregivers of children (under the age of 18) undergoing a HSCT or caregivers to patients with non‐hematological malignancies were excluded. Sixteen quantitative research articles and three qualitative research articles were reviewed and analyzed.

Results: Caregiver distress is highest pre‐transplant and decreases over time, and caregivers display distress levels comparable to or higher than patients' reported distress levels. Predictors of caregiver distress include female gender, elevated subjective burden, and higher patient symptom distress. Caregivers reported uncertainty, fear of the future, juggling patients' needs with their own, and difficulties adapting to role changes; however, they also reported positive aspects to care giving, such as personal growth and developing a more positive relationship with the patient.

Conclusions: There are many limitations to the current research and future directions should include both members of the dyad to evaluate the reciprocal relation between caregiver and patient variables, as well as theory‐driven research and research with direct clinical applications. Copyright © 2011 John Wiley & Sons, Ltd.
Immigrant to Canada, newcomer to childhood cancer: a qualitative study of challenges faced by immigrant parents
Authors: Klassen Anne F. , Gulati Sonia , Watt Lisa , Banerjee Ananya T. , Sung Lillian , Klaassen Robert J. , Dix David , Poureslami Iraj M. , Shaw Nicola
Published: March 2011

Background: Given the increasing numbers of immigrant families in Canada, it is imperative that healthcare providers (HCPs) understand the caregiving experiences of immigrant family caregivers. Our study aimed to explore any special challenges faced by immigrant parents of children with cancer and to identify supportive factors.

Methods: A constructivist grounded theory approach was used. Participants included 50 first generation Chinese and South Asian parents of children with cancer who were at least six months post‐diagnosis. Recruitment took place at six Canadian pediatric oncology centres. Interviews were conducted in English, Cantonese, Mandarin, Urdu, Punjabi or Hindi. Analysis involved coding and the use of the constant comparison method. Interviewing continued until no new themes emerged.

Results: While immigrant parents described many challenges faced by any parent of a child with cancer, the context of being an immigrant made certain experiences particularly challenging. Parents described challenges in the following areas: managing caregiving demand and financial strain, accessing support from others, and interfacing with the healthcare system. Parents described receiving a range of practical, emotional, social and informational support from extended family, their workplace, other cancer families, community organizations and HCPs.

Conclusions: Our study addresses an important gap in the research literature by providing practical insight into the experiences of immigrant family caregivers. Our findings may help to inform the development of pediatric oncology policies and programs in ways that respond to the unique needs and challenges of culturally and linguistically diverse families. Copyright © 2011 John Wiley & Sons, Ltd.
Amplitudes and ultraviolet behavior of N = 8 supergravity
Authors: Bern Z. , Carrasco J.J. , Dixon L.J. , Johansson H. , Roiban R.
Published: March 2011

In this contribution we describe computational tools that permit the evaluation of multi‐loop scattering amplitudes in 𝒩 = 8 supergravity, in terms of amplitudes in 𝒩 = 4 super‐Yang‐Mills theory. We also discuss the remarkable ultraviolet behavior of 𝒩 = 8 supergravity, which follows from these amplitudes, and is as good as that of 𝒩 = 4 super‐Yang‐Mills theory through at least four loops.
The change of PSA doubling time and its association with disease progression in patients with biochemically relapsed prostate cancer treated with intermittent androgen Deprivation
Authors: Keizman Daniel , Huang Peng , Antonarakis Emmanuel S. , Sinibaldi Victoria , Carducci Michael A. , Denmeade Samuel , Kim Jenny J. , Walczak Janet , Eisenberger Mario A.
Published: March 2011

BACKGROUND

We sought to determine the change of PSA doubling time (PSADT) and its association with disease progression during intermittent androgen deprivation (IAD) therapy for prostate cancer.

METHODS

Data were retrospectively analyzed in 96 patients with biochemically relapsed prostate cancer (BRPC) treated with IAD since 1995. IAD consisted of LHRH‐agonists ± antiandrogen given usually at PSA threshold (ng/ml) of 10–20, for 6–9 months. Cycles were repeated until the development of castration resistance. Mixed effects model was used to study PSADT change over cycles. Multivariate cox regression model was used to identify outcome‐associated variables.

RESULTS

Patients received a mean of 2.8 treatment cycles over a mean follow‐up time of 71 months. Fifty‐seven (59%) remain on treatment and 39 (41%) developed PSA refractoriness (n = 8) or positive scans (n = 31). First off treatment interval PSADT (median 2.3 months) was significantly shorter than the baseline (median 7.34) but remained stable in subsequent cycles. Off treatment interval PSADT adjusted for testosterone recovery (median 3.7) was significantly longer than that based on all PSA determinations (median 2). Factors associated with disease progression were pre‐treatment PSADT (≥6 vs. <6), first off treatment interval PSADT (≥3 vs. <3), and PSA nadir during the first treatment interval (<0.1 vs. ≥0.1).

CONCLUSIONS

During IAD for BRPC, PSADT becomes shorter, and is associated with testosterone recovery. PSADT before treatment and during the first off treatment interval is associated with disease progression. If prospectively validated these data may guide treatment with IAD and clinical trial design. Prostate 71:1608–1615, 2011. © 2011 Wiley‐Liss, Inc.
PC3 is a cell line characteristic of prostatic small cell carcinoma
Authors: Tai Sheng , Sun Yin , Squires Jill M. , Zhang Hong , Oh William K. , Liang Chao‐Zhao , Huang Jiaoti
Published: March 2011

BACKGROUND

The majority of the prostatic cancers are adenocarcinomas characterized by glandular formation and the expression of luminal differentiation markers androgen receptor (AR) and prostate‐specific antigen (PSA). Most adenocarcinomas are indolent and androgen‐dependent. Hormonal therapy that inhibits AR signaling produces symptomatic relief in patients with advanced and metastatic adenocarcinomas. Prostatic small cell neuroendocrine carcinoma (SCNC) is a variant form of prostate cancer (PC). In contrast to adenocarcinoma, the tumor cells of SCNC do not form glands and are negative for AR and PSA. SCNC is extremely aggressive and does not respond to hormonal therapy. The purpose of this study was to compare the important and relevant features of two most commonly used PC cell lines, LNCaP and PC3, with prostatic adenocarcinoma and SCNC.

METHODS

Xenograft tumors of LNCaP and PC3 were prepared and compared with human prostatic adenocarcinoma and SCNC for the expression of key signaling molecules by immunohistochemistry and Western blot analysis.

RESULTS

LNCaP cells express AR and PSA and their growth is inhibited by androgen withdrawal, similar to human prostatic adenocarcinoma. PC3 cells do not express AR and PSA and their proliferation is independent of androgen, similar to SCNC. Adenocarcinoma cells and LNCaP cells are negative for neuroendocrine markers and stem cell‐associated marker CD44 while SCNC and PC3 cells are positive. LNCaP cells have identical cytokeratin profiles to adenocarcinoma while PC3 cells have cytokeratin profiles similar to SCNC.

CONCLUSION

LNCaP cells share common features with adenocarcinoma while PC3 cells are characteristic of SCNC. Prostate 71:1668–1679, 2011. © 2011 Wiley‐Liss, Inc.
Free‐energy function for discriminating the native fold of a protein from misfolded decoys
Authors: Yasuda Satoshi , Yoshidome Takashi , Harano Yuichi , Roth Roland , Oshima Hiraku , Oda Koji , Sugita Yuji , Ikeguchi Mitsunori , Kinoshita Masahiro
Published: March 2011

In this study, free‐energy function (FEF) for discriminating the native fold of a protein from misfolded decoys was investigated. It is a physics‐based function using an all‐atom model, which comprises the hydration entropy (HE) and the total dehydration penalty (TDP). The HE is calculated using a hybrid of a statistical–mechanical theory applied to a molecular model for water and the morphometric approach. The energetic component is suitably taken into account in a simple manner as the TDP. On the basis of the results from a careful test of the FEF, which have been performed for 118 proteins in representative decoy sets, we show that its performance is distinctly superior to that of any other function. The FEF varies largely from model to model for the candidate models for the native structure (NS) obtained from nuclear magnetic resonance experiments, but we can find models or a model for which the FEF becomes lower than for any of the decoy structures. A decoy set is not suited to the test of a free‐energy or potential function in cases where a protein isolated from a protein complex is considered and the structure in the complex is used as the model NS of the isolated protein without any change or where portions of the terminus sides of a protein are removed and the percentage of the secondary structures lost due to the removal is significantly high. As these findings are made possible, we can assume that our FEF precisely captures the features of the true NS. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Quaternion‐based definition of protein secondary structure straightness and its relationship to Ramachandran angles
Authors: Hanson Robert M. , Kohler Daniel , Braun Steven G.
Published: March 2011

We describe here definitions of “local helical axis” and “straightness” that are developed using a simple quaternion‐based analysis of protein structure without resort to least‐squares fitting. As part of this analysis, it is shown how quaternion differences can be visualized to depict accurately the local helical axis relating any two adjacent amino acid residues in standard, nonidealized proteins. Three different options for the definition of amino acid residue orientation in terms of quaternion frames are described. Two of these, the “Cα frame” and the “P frame,” are shown to be correlated strongly with a simple approximate measure derived solely from Ramachandran angles. The relationship between quaternion‐based straightness and recognized DSSP‐derived secondary structure motifs is discussed. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Climate change: a crop protection challenge for the twenty‐first century
Authors: Gustafson David I
Published: March 2011

Convincing data now show that temperatures are increasing, and that changing precipitation patterns are already affecting agriculture. Predicted future impacts vary by region, but all are projected to suffer productivity declines by the late twenty‐first century unless successful mitigation measures are implemented soon. Exacerbating the climate change challenge, doubling of overall crop productivity will be required by mid‐century. Clearly, crop protection will become increasingly difficult as higher‐yielding varieties present a larger and more tempting target to all pests, and the pests themselves extend their ranges poleward and into other new geographies owing to reduced winter kill and longer growing seasons. Fortunately, good progress on enhancing crop protection technology to meet these challenges is already being made, but the scope of this climatic provocation is such that complacency is not an option. Increased investment into new technologies and adoption of new agricultural practices with improved adaptive and mitigation potential are both essential. Copyright © 2011 Society of Chemical Industry
Pyrethroid resistance in the tomato red spider mite, Tetranychus evansi, is associated with mutation of the para‐type sodium channel
Authors: Nyoni Benjamin N , Gorman Kevin , Mzilahowa Themba , Williamson Martin S , Navajas Maria , Field Linda M , Bass Chris
Published: March 2011

BACKGROUND: The tomato red spider mite, Tetranychus evansi (Baker and Pritchard), is a serious pest of solanaceous crops in many African countries. In this study an investigation has been conducted to establish whether mutation of the para‐type sodium channel underlies pyrethroid resistance in T. evansi strains collected in Southern Malawi.

RESULTS: Two T. evansi strains from Malawi showed tolerance to the organophosphate chlorpyrifos and resistance (20–40‐fold) to the pyrethroid bifenthrin, but were susceptible to two contemporary acaricides (abamectin and fenpyroximate) in insecticide bioassays. Cloning of a 3.1 kb fragment (domains IIS5 to IVS5) of the T. evansi para gene from pyrethroid‐resistant and pyrethroid‐susceptible strains revealed a single non‐synonymous mutation in the resistant strains that results in an amino acid substitution (M918T) within the domain II region of the channel. Although novel to mites, this mutation confers high levels of resistance to pyrethroids in several insect species where it has always been associated with another mutation (L1014F). This is the first report of the M918T mutation in the absence of L1014F in any arthropod species. Diagnostic tools were developed that allow sensitive detection of this mutation in individual mites.

CONCLUSION: This is the first study of pyrethroid resistance in T. evansi and provides contemporary information for resistance management of this pest in Southern Malawi. Copyright © 2011 Society of Chemical Industry
Migration, Risk, and Uncertainty: Theoretical Perspectives
Authors: Williams Allan M. , Baláž Vladimir
Published: March 2011

Risk shapes, and is shaped by, migration: although widely acknowledged, this is unevenly, and mostly only implicitly, theorised and analysed. Starting from the distinction between risk and uncertainty, the paper contrasts the different approaches of economics and sociology to theorising risk, in terms of scale, social constructionism, and being informed by risk as opposed to being at risk. It reviews the extent to which six theoretical approaches have been, and could be, applied to migration, risk, and uncertainty: human capital, risk tolerance, new economics of migration, risk and culture, risk society, and governmentality. Copyright © 2011 John Wiley & Sons, Ltd.
Nanometer‐scale cathodoluminescence analysis of GaAs and its application to the assessment of laser diode
Authors: Hosokawa Teppei , Fujimura Shinya , Yabuuchi Yasufumi , Tsukamoto Yoshiaki , Porporati Alessandro Alan , Zhu Wenliang , Pezzotti Giuseppe
Published: March 2011

We studied steep gradients of both chemical composition and residual stress in a Si‐doped GaAs blocking layer of a laser diode by means of spectrally and spatially resolved cathodoluminescence (CL) spectroscopy. Using a low‐energy electron beam as an excitation source for the CL emission, a spatial resolution in the sub‐micron scale could be achieved. The knowledge of local doping concentration, local stress state, and their distribution on the nanometer scale is crucial in diode design since lasing characteristics and near‐field width. Emphasis was placed in making quantitative the CL spectroscopic assessments in GaAs by means of a set of preliminary calibrations, regarding both probe size and material composition. These procedures enabled extracting from the CL spectra and quantitatively mapping values of both carrier concentration and residual stress in the diode device. The visualization of those parameters into highly spatially resolved maps (i.e., recorded with nanometer‐scale resolution) required the implementation of a spectroscopic algorithm that was purposely built up in this study and preliminarily validated according to the shown sets of calibration procedures.
An np‐control chart for inspection errors and repeated classifications
Authors: Ho Linda Lee , Quinino Roberto da Costa , Trindade Anderson Laécio Galindo
Published: March 2011

The np‐control chart has been used to monitor the conforming fraction in process production, and it is assumed that no classification errors occur during the inspection process. Increases in the sample size and/or the number of repeated classifications of the inspected items can reduce the impact of the classification errors. In this paper, an np‐control chart is proposed, and the monitored statistics are based on the results of independent repeated classifications with classification errors during the inspection process. The aim of the proposed control chart is to have the same performance as a control chart without classification errors. Numerical examples illustrate the proposal. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of the origin of conformational and tautomeric preferences inN‐formylformamide – A quantum chemical study
Authors: Nowroozi A. , Mohammadzadeh Jahani P. , Asli N. , Hajiabadi H. , Dahmardeh S. , Raissi H.
Published: March 2011

Quantum chemical study ofN‐formylformamide (NFF) was carried out at various theoretical levels and the determinate equilibrium conformations were recomputed at the high level ab initio methods such as G2MP2, G2, G3, and complete basis set (CBS)‐QB3. The computational results reveal that the amide resonance and intramolecular hydrogen bonding are two superior factors in determining the most stable conformation of diamide (DA) and amide–imidic (AI) acid tautomers, respectively. The evaluation of hydrogen bond energies predicts that the hydrogen bond (HB( strength of NFF is weaker than the malonaldehyde (MA). But the results of atoms in molecules (AIM(, natural bond orbital (NBO), and geometrical parameters are given a different order, EHB(NFF) > EHB(MA). Although the bond average energies of tautomerization process emphasized on more stability of AI tautomer, but our theoretical calculations reveal that the DA conformers are more stable than the AI ones. The population analyses of equilibrium conformations by NBO method also predict that the origin of tautomeric preference is mainly because of the electron delocalization of amide functional group, especially LP(N)→ π*COcharge transfer. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
A comparative study of the dimers of selected hydroxybenzenes
Authors: Kabanda Mwadham M. , Mammino Liliana
Published: March 2011

Hydroxybenzenes are the parent compounds of large classes of derivatives, many of which exhibit biological activities. This work presents the results of a comparative study of the dimers of selected hydroxybenzenes, considering all the possible mutual geometrical arrangements of the two monomers and comparing their relative stabilities and interaction energies. The OH···OH hydrogen bond between the two monomers is the dominant stabilizing factor, with frequent preference for mutual perpendicularity of the two aromatic rings. CH···O unconventional H‐bonds, OH···π unconventional H‐bonds, H···π interactions and π··π interactions also may play significant roles. The factors stabilizing individual hydroxybenzenes (presence of intramolecular hydrogen bonds; number, positioning and orientation of the OH groups; symmetry features) have greater influence on the dimers' relative energy than on the interaction energy between monomers. While results from different calculations methods (HF, MP2, and DFT/B3LYP) show consistency for all the features just‐mentioned, they show some relevant differences in the way they take into account different types of interactions between monomers, resulting in some differences in the geometry arrangements of the monomers in the lowest energy dimers and in differences in the relative preferences among higher‐energy dimer geometries. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Combined experimental and computational modeling studies on 3,5‐dimethyl‐pyrazole‐1‐carbodithioic acid benzyl ester
Authors: Shi Zhiqiang , Ji Ningning , Zhao Rengao , Li Zhifeng
Published: March 2011

The title compound, 3,5‐Dimethyl‐pyrazole‐1‐carbodithioic acid benzyl ester, has been synthesized and structurally characterized by X‐ray single crystal diffraction, elemental analysis, IR spectra, and UV‐Vis spectrum. The crystal belongs to orthorhombic, space group P212121, with a = 5.3829(15), b = 11.193(3), c = 21.824(6) Å, V = 1315.0(6) Å3, and Z = 4. The molecules are connected via intermolecular C–H···N hydrogen bonds into 1D infinite chains. The crystal structure is consolidated by the intramolecular C–H···S hydrogen bonds. Furthermore, Density functional theory (DFT) calculations of the structure, stabilities, orbital energies, composition characteristics of some frontier molecular orbitals and Mulliken charge distributions of the title compound were performed by means of Gaussian 03W package and taking B3LYP/6‐31G(d) basis set. The time‐dependent DFT (TD‐DFT) calculations have been employed to calculate the electronic spectrum of the title compound, and the UV‐Vis spectra has been discussed on this basis. The results show that DFT method at B3LYP/6‐31G(d) level can well reproduce the structure of the title compound. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Transition metals compounds: Outstanding challenges for multiconfigurational methods
Authors: Pierloot K.
Published: March 2011

The present contribution provides a “perspective” on the work on transition metal (TM) bonding and spectroscopy by Björn O. Roos, performed by means of the CASPT2 method in the period 1992–2010. After giving a short overview of important nondynamic correlation effects appearing in TM atoms and molecules, ample attention is given to the work on the Cr2 molecule and to Björn's fascination for multiple bonds in inorganic molecules containing TM. A short description is also given of his contributions to bioinorganic chemistry, with emphasis on the blue copper proteins. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 111:3291–3301, 2011
Siroheme‐containing sulfite reductase: A density functional investigation of the mechanism
Authors: Silaghi‐Dumitrescu Radu , Makarov Sergei V.
Published: March 2011

Siroheme‐containing sulfite reductases (SiR) catalyze the six‐electron reduction of sulfite to sulfide via a mechanism involving sulfite binding at the heme iron. The exact sequence in which the required electrons and protons are delivered to the heme‐bound sulfite has received little attention to date. Here, a detailed account is given of these steps, based on density functional theory, thus providing data for the first attempt to draw a detailed picture of sulfite reduction in SiR by theoretical methods. Parallels are shown with reduction of other small molecules at heme centers: dioxygen (including generation of sulfide high‐valent iron centers akin to hemoproteins Compounds I and II), nitrite (including linkage isomerism akin to the nitro/nitrito known for nitrite reducing proteins), or nitric oxide. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
An adaptive confirmatory trial with interim treatment selection: Practical experiences and unbalanced randomization
Authors: Heritier Stephane , Lô Serigne N. , Morgan Caroline C.
Published: March 2011

This article has been motivated by an ongoing international adaptive confirmatory trial. At the interim analysis of this two‐stage trial, none, one or two active treatment regimens are selected for further study in the second stage. A combination test approach is used in this practical setting with an extension of the theory to unbalanced randomization. We show that a combination test with suitable weights can still preserve the overall Type I error rate provided that the test statistic is chosen appropriately and the unpooledZ‐test for proportions is not used. The accuracy of stagewisep‐values is also discussed in a more general framework. Monte Carlo simulations confirm the validity of the approach retained and evaluate the necessary sample size. Additional issues addressed during the design of the trial are also examined such as multiplicity due to testing hypotheses on key secondary endpoints, a non‐inferiority comparison to an active treatment and covariate adjusted analyses for various types of outcome. Copyright © 2011 John Wiley & Sons, Ltd.
Bias in causal estimates from Mendelian randomization studies with weak instruments
Authors: Burgess Stephen , Thompson Simon G.
Published: March 2011

Mendelian randomization studies using genetic instrumental variables (IVs) are now being commonly used to estimate the causal association of a phenotype on an outcome. Even when the necessary underlying assumptions are valid, estimates from analyses using IVs are biased in finite samples. The source and nature of this bias appear poorly understood in the epidemiological field. We explain why the bias is in the direction of the confounded observational association, with magnitude relating to the statistical strength of association between the instrument and phenotype. We comment on the size of the bias, from simulated data, showing that when multiple instruments are used, although the variance of the IV estimator decreases, the bias increases. We discuss ways to analyse Mendelian randomization studies to alleviate the problem of weak instrument bias. Copyright © 2011 John Wiley & Sons, Ltd.
Combining multiple continuous tests for the diagnosis of kidney impairment in the absence of a gold standard
Authors: Yu Binbing , Zhou Chuan , Bandinelli Stefania
Published: March 2011

Receiver operating characteristic (ROC) curves are commonly used to summarize the classification accuracy of diagnostic tests. It is not uncommon in medical practice that multiple diagnostic tests are routinely performed or multiple disease markers are available for the same individuals. When the true disease status is verified by a gold standard (GS) test, a variety of methods have been proposed to combine such potential correlated tests to increase the accuracy of disease diagnosis. In this article, we propose a method of combining multiple diagnostic tests in the absence of a GS. We assume that the test values and their classification accuracies are dependent on covariates. Simulation studies are performed to examine the performance of the combination method. The proposed method is applied to data from a population‐based aging study to compare the accuracy of three screening tests for kidney function and to estimate the prevalence of moderate kidney impairment. Copyright © 2011 John Wiley & Sons, Ltd.
Reducing false alarms in syndromic surveillance
Authors: Peter William , Najmi Amir H. , Burkom Howard S.
Published: March 2011

Algorithms for identifying public health threats or disease outbreaks are vulnerable to false alarms arising from sudden shifts in health‐care utilization or data participation. This paper describes a method of reducing false alerts in automated public health surveillance algorithms, and in particular, automated syndromic surveillance algorithms, that rely on health‐care utilization data. The technique is based on monitoring syndromic counts with reference to a suitable background, or reference, series of counts. The suitability of the background time series in decreasing the false‐alarm rate will be shown to be related mathematically to the so‐called mutual information that exists between the random variables representing the syndromic and background time series of counts. The method can be understood as a noise cancellation filter technique in which one noisy (reference) channel is used to cancel the background noise of the monitored (measured) channel. The issues discussed here may also be relevant to the appropriate use of rates in epidemiology and biostatistics. Copyright © 2011 John Wiley & Sons, Ltd.
How a new stratified adaptive phase II design could improve targeting population
Authors: Tournoux‐Facon, Caroline , De Rycke Yann , Tubert‐Bitter Pascale
Published: March 2011

Phase II clinical trials in oncology are used for initial evaluation of the therapeutic efficacy of a new treatment regimen. Simon's two‐stage or Fleming designs are commonly used for such trials. Treatment effect dilution may be observed because of heterogeneity of the population leading to negative conclusion on the whole population and termination of drug development while patients with particular characteristics may have benefit. Several authors have proposed alternative strategies based on Simon's design, including stratification on the patients' characteristics. In this paper, the authors develop a new stratified phase II design, allowing early stop of the trial for efficacy as it is an extension of Fleming's design. An example based on real data is given and the results from exact binomial calculations are developed to explore several assumptions on response rates, prevalence of each population and errors. Copyright © 2011 John Wiley & Sons, Ltd.
A Bayesian response‐adaptive covariate‐balanced randomization design with application to a leukemia clinical trial
Authors: Yuan Ying , Huang Xuelin , Liu Suyu
Published: March 2011

We propose a Bayesian response‐adaptive covariate‐balanced (RC) randomization design for multiple‐arm comparative clinical trials. The goal of the design is to skew the allocation probability to more efficacious treatment arms, while also balancing the distribution of the covariates across the arms. In particular, we first propose a new covariate‐adaptive randomization (CA) method based on a prognostic score that naturally accommodates continuous and categorical prognostic factors and automatically assigns imbalance weights to covariates according to their importance in response prediction. We then incorporate this CA design into a group sequential response‐adaptive randomization (RA) scheme. The resulting RC randomization design combines the advantages of both CA and RA randomizations and meets the design goal. We illustrate the proposed design through its application to a phase II leukemia clinical trial, and evaluate its operating characteristics through simulation studies. Copyright © 2011 John Wiley & Sons, Ltd.
Die Sondertragwerke der “Mansueto Library” in Chicago – vom Entwurf zum Bau
Authors: Sobek Werner , Blandini Lucio , Krtscha Annette
Published: March 2011

Die Bibliothek der Universität Chicago wird momentan durch einen Anbau, die sogenannte Mansueto Library, erweitert. Dieser vom Chicagoer Architekten Helmut Jahn entworfene Anbau wird durch eine weitspannende Stahlgitterschale überdacht, die eine natürliche Belichtung des gesamten Innenraums ermöglicht. Der Erweiterungsbau besteht aus einem ebenerdigen Lesesaal und einem unterirdischen Archivraum. Die gesamte Bibliothek soll bis zu 3 Mio. Bücher beherbergen und wird nach der Eröffnung im Jahr 2011 zu den größten “on‐campus”‐Bibliotheken der Welt zählen. Am Standort des Bibliotheksanbaus gelang übrigens im Dezember 1942 die weltweit erste “self‐sustaining” nukleare Kettenreaktion.

Die 36,5 m breite und 73 m lange Translationsschale über dem neuen Lesesaal ist mit bedrucktem Isolierglas eingedeckt, das auf einer minimierten Aluminium‐Unterkonstruktion aufliegt, welche ihrerseits über Abstandhalter auf das Primärtragwerk, eine Gitterschale aus Stahlrohren, aufgeständert ist. Die von Helmut Jahn in enger Zusammenarbeit mit Werner Sobek entworfene transparente Gitterschale kontrastiert eindrucksvoll mit der massiven, gänzlich geschlossenen Hülle der bereits bestehenden Universitätsbibliothek. Der Entwurf besticht durch die Klarheit seiner Formensprache und durch seine große Detailqualität (Bild 1).

Im Innern des Neubaus befindet sich eine Reihe von Studienräumen, die als Ganzglaskonstruktion konzipiert wurden. Durch den Einsatz von Glas als statisch tragendem Element kann maximale Transparenz erreicht werden. Eine weitere interessante Sonderkonstruktion, die im Rahmen der Bibliothekserweiterung entsteht, ist die 20 m lange, verglaste Brückenkonstruktion, die den Neubau mit dem Bestandsgebäude verbindet. Der Aufsatz gibt einen Überblick über Entwurf und Bau der Gitterschale und der weiteren Sonderkonstruktionen.

The special structures for the Mansueto Library in Chicago. From design to construction. The library of the University of Chicago is currently extended by means of a building directly adjacent to the existing library. The extension building called Mansueto Library – designed by Chicago‐based architect Helmut Jahn – is covered by an all but dematerialized glazed steel grid shell spanning over the reading room. The translational shell is 36.5 m wide and 73 m long. It is clad with fritted insulated glass units lying on minimized aluminium extrusions. The building includes further special structures, such as a 20 m long glazed steel bridge; this bridge connects the new library with the existing building. Another interesting special structure is the row of glazed study rooms: the walls of these rooms are fully transparent due to the use of glass as a loadbearing element. The present article gives an overview of the design and construction of the grid shell and the other special structures.