bluuebunny/crossref_metadata_2025 huggingface dataset:
Solution of flat crack problems in shear mode
Authors: Chen Y. Z. , Lin X. Y.
Published: September 2005

Solution of the flat crack problems in shear mode is presented. The least potential energy principle is used to solve the problems. In the solution a family of the crack opening displacements (COD) with some undermined coefficients is assumed. The strain energy stored in body is expressed in the form of a quadratic form with some undetermined coefficients. In the formulation of the quadratic form, the differential–integral equation for the flat crack problem is used. After using the least potential energy principle, the coefficients in the family of COD can be determined and the crack opening displacements can be evaluated immediately. The stress intensity factors along the crack border can be obtained from the known crack opening displacements. A particular feature of the present method is that no singular integral is involved in computation. Several numerical examples are given with the calculated stress intensity factors along the crack border. Copyright © 2005 John Wiley & Sons, Ltd.
Efficient surface reconstruction from contours based on two‐dimensional Delaunay triangulation
Authors: Wang Desheng , Hassan Oubay , Morgan Kenneth , Weatherill Nigel
Published: September 2005

This paper introduces an efficient method for surface reconstruction from sectional contours. The surface between neighbouring sections is reconstructed based on the consistent utilization of the two‐dimensional constrained Delaunay triangulation. The triangulation is used to extract the parametric domain and to solve the problems associated with correspondence, tiling and branching in a general framework. Natural distance interpolations are performed in order to complete the mapping of the added intermediate points. Surface smoothing and remeshing are conducted to optimize the initial surface triangulations. Several examples are presented to demonstrate the effectiveness and efficiency of the proposed approach. Copyright © 2005 John Wiley & Sons, Ltd.
A high‐level programming‐language implementation of topology optimization applied to steady‐state Navier–Stokes flow
Authors: Olesen Laurits Højgaard , Okkels Fridolin , Bruus Henrik
Published: September 2005

We present a versatile high‐level programming‐language implementation of non‐linear topology optimization. Our implementation is based on the commercial software package FEMLAB, and it allows a wide range of optimization objectives to be dealt with easily. We exemplify our method by studies of steady‐state Navier–Stokes flow problems, thus extending the work by Borrvall and Petersson on topology optimization of fluids in Stokes flow (Int. J. Num. Meth. Fluids 2003; 41:77–107). We analyse the physical aspects of the solutions and how they are affected by different parameters of the optimization algorithm. A complete example of our implementation is included as FEMLAB code in an appendix. Copyright © 2005 John Wiley & Sons, Ltd.
The changing association between prenatal participation in WIC and birth outcomes in New York City
Authors: Joyce Ted , Gibson Diane , Colman Silvie
Published: September 2005

We analyze the relationship between prenatal WIC participation and birth outcomes in New York City from 1988—2001. The analysis is unique for several reasons. First, we have over 800,000 births to women on Medicaid, the largest sample ever used to analyze prenatal participation in WIC. Second, we focus on measures of fetal growth distinct from preterm birth, since there is little clinical support for a link between nutritional supplementation and premature delivery. Third, we restrict the primary analysis to women on Medicaid who have no previous live births and who initiate prenatal care within the first four months of pregnancy. Our goal is to lessen heterogeneity between WIC and non‐WIC participants by limiting the sample to highly motivated women who have no experience with WIC from a previous pregnancy. Fourth, we analyze a large sub‐sample of twin deliveries. Multifetal pregnancies increase the risk of anemia and fetal growth retardation and thus may benefit more than singletons from nutritional supplementation. We find no relationship between prenatal WIC participation and measures of fetal growth among singletons. We find a modest pattern of association between WIC and fetal growth among U.S.‐born Black twins. Our findings suggest that prenatal participation in WIC has had a minimal effect on adverse birth outcomes in New York City. © 2005 by the Association for Public Policy Analysis and Management
Poverty, food programs, and childhood obesity
Authors: Hofferth Sandra L. , Curtin Sally
Published: September 2005

Sixteen percent of children 6–11 years of age were classified as overweight in 1999–2002, four times the percentage in 1965. Although poverty has traditionally been associated with underweight as a result of poor diet, researchers have recently pointed to a paradox in the U.S., which is that low income and obesity can coexist in the same population. This paper first examines whether income is linked to overweight in school‐age children. Second, it explores whether food programs such as the Food Stamp Program, the National School Lunch Program, and the School Breakfast Program are associated with overweight among children in different income groups. The data come from the nationally representative 1997 Panel Study of Income Dynamics Child Development Supplement. No evidence either that poor children are more likely to be overweight or that food programs contribute to overweight among poor children was found. © 2005 by the Association for Public Policy Analysis and Management
Morbid obesity and the transition from welfare to work
Authors: Cawley John , Danziger Sheldon
Published: September 2005

This paper utilizes a rich longitudinal data set—the Women's Employment Study (WES)—to investigate whether obesity, which is common among women of low socioeconomic status, is a barrier to employment and earnings for current and former welfare recipients. We find that former welfare recipients who are both White and morbidly obese have been less successful in transitioning from welfare to work. These women are less likely to work at any survey wave, spend a greater percentage of months between waves receiving cash welfare, and have lower monthly earnings at each wave. The magnitude of the difference in labor market outcomes between the morbidly obese and those who are less heavy is in some cases similar in magnitude to the differences in these labor market outcomes between high school dropouts and graduates. In contrast, we find no such labor market differences associated with morbid obesity for African‐American respondents.

This paper documents the relationship between weight and labor market outcomes for the first time among the welfare population. In addition, it investigates whether the correlation for White females is due to unobserved heterogeneity. We find that after controlling for individual fixed effects, the point estimate of the correlation of morbid obesity and each of the labor market outcomes falls considerably and is no longer statistically significant. These results are consistent with unobserved heterogeneity causing the correlation between morbid obesity and labor market outcomes. Findings are similar after controlling for the respondent's mental and physical health. © 2005 by the Association for Public Policy Analysis and Management
Covenants with weak swords: ISO 14001 and facilities' environmental performance
Authors: Potoski Matthew , Prakash Aseem
Published: September 2005

Voluntary environmental programs are codes of progressive environmental conduct that firms pledge to adopt. This paper investigates whether ISO 14001, a voluntary program with a weak sword—a weak monitoring and sanctioning mechanism—can mitigate shirking and improve participants' environmental performance. Sponsored by the International Organization for Standardization (ISO), ISO 14001 is the most widely adopted voluntary environmental program in the world. Our analysis of over 3,000 facilities regulated as major sources under the U.S. Clean Air Act suggests that ISO 14001‐certified facilities reduce their pollution emissions more than non‐certified facilities. This result persists even after controlling for facilities' emission and regulatory compliance histories as well as addressing potential endogeneity issues between facilities' environmental performance and their decisions to join ISO 14001. © 2005 by the Association for Public Policy Analysis and Management
Can public policy deter smoking escalation among young adults?
Authors: Tauras John A.
Published: September 2005

In the wake of significant budget shortfalls, 37 states and the District of Columbia have recently increased cigarette excise taxes to boost revenues. This study examines the impact of increasing the price of cigarettes, which will occur as a consequence of cigarette excise tax increases, and implementing restrictions on smoking in private worksites, restaurants, government worksites, healthcare facilities, and other public places on young adult smoking progression. This paper employs nationally representative longitudinal data on young adults from the Monitoring the Future Surveys matched with information on site‐specific prices and smokefree air laws. The estimates clearly indicate that increasing the price of cigarettes would substantially decrease the number of young adults who progress into higher intensities of smoking. In addition, private worksite restrictions and restrictions on smoking in other public places are found to decrease moderate smoking uptake among young adults. © 2005 by the Association for Public Policy Analysis and Management
The effects of state R&D tax credits in stimulating private R&D expenditure: A cross‐state empirical analysis
Authors: Wu Yonghong
Published: September 2005

This is a cross‐state empirical study which examines the effects of state research and development (R&D) tax credits on private R&D expenditure in the states. Other explanatory variables include federal R&D subsidies, public services in higher education and R&D‐targeted programs as well as other control variables. The statistical result shows that the establishment of state R&D credit programs is effective in stimulating more industrial R&D expenditure. In addition, state services in higher education and R&D‐targeted programs also matter in private decision of R&D investment. This policy assessment sends a positive message to state policymakers because it shows the great potential in using R&D policy instruments to promote innovation‐based economic development. © 2005 by the Association for Public Policy Analysis and Management
Optimal compensating wages for military personnel
Authors: Carrell Scott E. , West James E.
Published: September 2005

The current U.S. military pay structure offers inequitable and inefficient wages across locations. Military personnel are paid less competitive wages in high‐cost and/or low‐amenity locations compared to low‐cost and/or high‐amenity locations. This pay system results in unequal reenlistment rates across locations, which leads to production inefficiencies caused by short‐term manning shortages in highturnover locations. Wages set according to local civilian compensating wage differentials would result in a more stabilized force (across locations) by equalizing the opportunity cost of staying in the military at each location. Additionally, more personnel would volunteer to serve in the high‐cost and/or low‐amenity locations because wages would be more commensurate with local costs and amenities. This would result in fewer non‐volunteer assignments to undesirable locations and a minimized opportunity cost for personnel serving at each location. Reenlistment simulations on first‐term Air Force personnel show that the proposed wage structure would better equalize reenlistment rates across locations. This proposal could be implemented at no cost to the government by cutting wages in low‐cost and/or high‐amenity locations. A gradual implementation in which such wages are frozen or increased slowly may be more politically palatable. © 2005 by the Association for Public Policy Analysis and Management
Interdisciplinarity and the teaching of public policy
Authors: Szostak Rick
Published: September 2005

De Leon and Steelman (2001) addressed three deficiencies in public policy programs. This paper focuses on the first of these, arguing that public policy students can and should be exposed to a comprehensive classification of types of ethical analysis. It then briefly addresses the two other deficiencies, again with recourse to recent interdisciplinary scholarship. Students can and should be exposed to the full range of types of ethical evaluation, theories, methods, and possible side effects of policies. © 2005 by the Association for Public Policy Analysis and Management
Using the Kaldor‐Hicks tableau format for cost‐benefit analysis and policy evaluation
Authors: Krutilla Kerry
Published: September 2005

This note describes the Kaldor‐Hicks (KH) tableau format as a framework for distributional accounting in cost‐benefit analysis and policy evaluation. The KH tableau format can serve as a heuristic aid for teaching microeconomics‐based policy analysis, and offer insight to policy analysts and decisionmakers beyond conventional efficiency analysis. © 2005 by the Association for Public Policy Analysis and Management
Fingerprinting of Cretaceous higher plant resins by infrared spectroscopy and gas chromatography coupled to mass spectrometry
Authors: Chaler Roser , Grimalt Joan O.
Published: September 2005

Ambers from Peñacerrada (Basque Country, North Spain) have been analysed by IR spectroscopy and GC‐MS in order to study the polymeric and solvent‐soluble GC‐amenable fractions, respectively. All samples showed branched monoalkybenzenes, bicyclic sesquiterpenoids and tricyclic diterpenoids related to pimaric acids precursors, suggesting a paleobotanic origin from araucarian species. Molecules containing oxygenated polar functionalities were not found, which is in agreement with the Cretaceous origin of the samples and in good correspondence with the IR spectra and with the low oxygen content estimated from elemental composition analysis. In addition, no IR bands for exocyclic double bonds and very few GC‐amenable monounsaturated molecules were found, which provides further evidence of the loss of olefinic groups. Theses features show that the age‐dependent loss of oxygenated and olefinic functions is a general process affecting the whole amber structure, not only the solvent soluble fraction. Copyright © 2005 John Wiley & Sons, Ltd.
Accuracy and validity of using medical claims data to identify episodes of hospitalizations in patients with COPD
Authors: Monfared Amir Abbas Tahami , LeLorier Jacques
Published: September 2005

Purpose

In Quebec, MED‐ECHO database can be used to estimate inhospital length of stay (LOS) and number of hospitalizations (NOH) both accurately and reliably. However, access to MED‐ECHO database is time‐consuming. Quebec medical claims database (RAMQ) can be used as an alternative source to estimate these measures. Considering MED‐ECHO as the ‘gold standard,’ this study examined the validity of using RAMQ medical claims to estimate LOS and NOH.

Methods

We used a cohort of 3768 elderly patients with chronic obstructive pulmonary disease (COPD) between 1990 and 1996 and identified those with inhospital claims. Inhospital LOS was defined as the total number of days with inhospital claims. Various grace periods (1–15 days) between consecutive claims were considered for the estimation of LOS and NOH. RAMQ and MED‐ECHO databases were linked using unique patient identifiers. Estimates obtained from RAMQ data were compared to those from MED‐ECHO using various measures of central tendency and predictive error estimates.

Results

Overall, 32.7% of patients were hospitalized at least once during the study period based on RAMQ claims, as compared to 32.0% in MED‐ECHO ( p‐value = 0.51). The best estimates [mean (p‐value)] were found to be those obtained when using a 7‐day grace period. RAMQ versus MED‐ECHO estimates were: 12.2 versus 13.5 days (< 0.001) for LOS and 3.6 versus 3.7 times (0.36) for NOH.

Conclusions

RAMQ medical claims can be used as a reliable source to estimate LOS and NOH, particularly when time and resources are restricted. RAMQ, however, should be used with caution since slight underestimations may occur. Copyright © 2005 John Wiley & Sons, Ltd.
Predictors of recall of over‐the‐counter and prescription non‐steroidal anti‐inflammatory drug exposure
Authors: Lewis James D. , Strom Brian L. , Kimmel Stephen E. , Farrar John , Metz David C. , Brensinger Colleen , Nessel Lisa , Localio A. Russell
Published: September 2005

Purpose

Because of the difficulty in establishing a gold standard, data on accuracy of recall of over‐the‐counter (OTC) medication use are sparse.

Methods

We studied a cohort of 1889 persons living in the Philadelphia area to assess recall of non‐aspirin non‐steroidal anti‐inflammatory drug (NANSAID) use during the preceding 8 weeks. Our analyses were based on the assumption that among the group of subjects, on average, the reported usage of NANSAIDs should not vary over the previous 8 weeks. To model the effect of time on reported usage while allowing for the inherent correlation of responses within subjects over time, we employed alternating logistic regression.

Results

We documented a significant decline in reported use of OTC NANSAIDs but not prescription NANSAIDs during the 8‐week study period (p = 0.3 for frequent prescription NANSAIDs, p = 0.2 for infrequent prescription NANSAIDs, p < 0.001 for frequent OTC NANSAIDs, and p < 0.001 for infrequent OTC NANSAIDs). Reported rates of frequent and infrequent OTC NANSAID consumption declined from 6.3 to 4.6% and from 17.1 to 12.8% between the most recent week and eight weeks prior, respectively.

Conclusions

Interviews focusing on medications used on an as needed basis should be performed as close as possible to the index date. Likewise, data on frequent use of OTC NANSAIDs may be more reliable than that on infrequent use, particularly when subjects are asked to recall more than a few weeks back in time. Copyright © 2005 John Wiley & Sons, Ltd.
Population antibiotic susceptibility for Streptococcus pneumoniae and treatment outcomes in common respiratory tract infections
Authors: Furuno Jon P. , Metlay Joshua P. , Harnett James P. , Wilson Jerome , Langenberg Patricia , McGregor Jessina C. , Zhu Jingkun , Perencevich Eli N.
Published: September 2005

Purpose

Antibiotic‐resistant Streptococcus pneumoniae potentially threatens the successful treatment of common respiratory tract infections (RTIs); however, the relationship between antibiotic resistance and treatment outcomes remains unclear. We aimed to test the hypothesis that higher in vitro penicillin and erythromycin nonsusceptibility levels among clinical isolates of S. pneumoniae are associated with higher risk of treatment failure in suppurative acute otitis media (AOM), acute sinusitis, and acute exacerbation of chronic bronchitis (AECB).

Methods

We conducted a population‐level analysis using treatment outcomes data from a national, managed‐care claims database, and antibiotic susceptibility data from a national repository of antimicrobial susceptibility results between 1997 and 2000. Treatment outcomes in patients with suppurative AOM, acute sinusitis, or AECB receiving selected macrolides or beta‐lactams were assessed. Associations between RTI‐specific treatment outcomes and antibiotic nonsusceptibility were determined using Spearman correlation coefficients with condition‐specific paired outcome and susceptibility data for each region and each year.

Results

There were 649 552 available RTI outcomes and 7252 susceptibility tests performed on S. pneumoniae isolates. There were no statistically significant trends across time for resolution proportions following treatment by either beta‐lactams or macrolides among any of the RTIs. Correlation analyses found no statistically significant association between S. pneumoniae susceptibility and RTI treatment outcomes apart from a significant positive association between of erythromycin nonsusceptibility in ear isolates and macrolide treatment resolution for suppurative AOM.

Conclusion

On the population level, in vitro S. pneumoniae nonsusceptibility to macrolide or beta‐lactam antibiotics was not associated with treatment failure in conditions of probable S. pneumoniae etiology. Copyright © 2005 John Wiley & Sons, Ltd.
Comparison of characteristics of treated and non‐treated patients with Hepatitis C infection
Authors: Hare C. Bradley , Morris Jonathan A. , Chu Alice , Gotz Vincent , Loveland Jacqueline J. , Hodes David , Klaskala Winslow
Published: September 2005

Objectives

This study compares the characteristics of treated and non‐treated patients with Hepatitis C (HCV) infection.

Methods

Information on patient demographics, clinical data, and treatment regimens were collected from a retrospective medical record review of 998 patients diagnosed with HCV, representing a diverse geographic sample of 200 U.S. physicians including 130 gastroenterologists, 50 infectious disease physicians, and 20 hepatologists. A total of 551 patients were randomly selected and 447 were provided as an augmented sample in an intent‐to‐treat analysis based on treatment decisions. Pretreatment factors examined included age, gender, race, weight, HCV genotype, HCV viral load, serum ALT levels, liver biopsy results, cirrhosis, HIV co‐infection, HBV co‐infection, IV drug use, and insurance status. Univariate analyses were performed using Chi‐squared or ANOVA tests. Factors that were significant in univariate analyses were entered into a multivariate logistic regression model with HCV treatment as the outcome variable.

Results

Of the 998 patients reviewed, 778 were treated for HCV and 220 were not treated. In univariate analyses, non‐treated patients were more likely to be African American, HBV co‐infected, HIV co‐infected, IDUs, alcoholics, Medicaid insured, and were less likely to have had biopsies. The multivariate regression analysis demonstrated that performance of a liver biopsy, treatment with psychiatric medications (antidepressants and anxiolytics), and patient weight were independently associated with treatment, while Medicaid insurance and HIV co‐infection were independently associated with a decreased likelihood of receiving HCV therapy.

Conclusion

This study suggests that it is not the clinical stage of HCV infection but the patient's demographic characteristics and co‐morbid conditions that impact the decision to initiate HCV therapy. Copyright © 2005 John Wiley & Sons, Ltd.
Frequency estimates from prescription drug datasets (revision of #04‐11‐066A)
Authors: Lin Swu‐Jane , Lambert Bruce , Tan Hiangkiat , Toh Sengwee
Published: September 2005

Purpose

Accurate information about the number of times a drug is prescribed or dispensed annually is important to marketers, pharmacoepidemiologists, and patient safety researchers. Yet there is no standard reference for prescribing frequency data. The multiple sources that do exist vary in their sampling methods, target populations, nomenclature, and methods of tallying individual medications prescribed or dispensed. These differences are likely to create ambiguity and contradictions in the scientific literature, but they are not well understood.

Methods

We conducted a descriptive study to examine the similarities and differences between five well‐known sources of prescribing frequency data: the National Ambulatory Medical Care Survey (NAMCS), the National Hospital Ambulatory Medical Care Survey (NHAMCS, emergency department and outpatient department), the IMS National Prescription Drug Audit, the Solucient outpatient dataset, and the Solucient inpatient dataset. We compared survey methods, costs, overall frequencies, number of unique names in each database, correlations between frequency estimates from different databases, the extent of overlap in the databases, and nomenclature differences between and within datasets.

Results

All the correlations between frequency estimates derived from different datasets were significant, but the frequency estimates differed considerably. The lowest correlation (0.17) was found between the IMS and emergency department of the NHAMCS, and the highest correlation (0.93) was between IMS and Solucient outpatient data.

Conclusions

Although there were significant correlations between frequency estimates for comparable datasets, sampling methods and nomenclature choices resulted in important differences both for individual drug products and for overall frequency statistics. Researchers need to be aware of the differences when deriving drug frequency with these datasets. Copyright © 2005 John Wiley & Sons, Ltd.
Ionic liquids in the synthesis and modification of polymers
Authors: Kubisa Przemysław
Published: September 2005

Ionic liquids are organic salts that are liquid at ambient temperatures, preferably at room temperature. They are nonvolatile, thermally and chemically stable, highly polar liquids that dissolve many organic, inorganic, and metallo‐organic compounds. Many combinations of organic cations with different counterions are already known, and the properties of ionic liquids may be adjusted by the proper selection of the cation and counterion. In the last decade, there has been increasing interest in using ionic liquids as solvents for chemical reactions. The interest is stimulated not only by their nonvolatility (green solvents) but also by their special properties, which often affect the course of a reaction. In recent years, ionic liquids have also attracted the attention of polymer chemists. Although the research on using ionic liquids in polymer systems is still in its infancy, several interesting possibilities have already emerged. Ionic liquids are used as solvents for polymerization processes, and in several systems they indeed show some advantages. In radical polymerization, the kp/kt ratio (where kp is the rate constant of propagation and kt is the rate constant of termination) is higher than in organic media, and thus better control of the process can be achieved. Ionic liquids, as electrolytes, have also attracted the attention of researchers in the fields of electrochemical polymerization and the synthesis of conducting polymers. Finally, the blending of ionic liquids with polymers may lead to the development of new materials (ionic liquids may act as plasticizers, electrolytes dispersed in polymer matrices, or even porogens). In this article, the new developments in these fields are briefly discussed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4675–4683, 2005
Force calculations in automated docking: Enzyme–substrate interactions in Fusarium oxysporum Cel7B
Authors: Mulakala Chandrika , Reilly Peter J.
Published: September 2005

AutoDock is a small‐molecule docking program that uses an energy function to score docked ligands. Here AutoDock's grid‐based method for energy evaluation was exploited to evaluate the force exerted by Fusarium oxysporum Cel7B on the atoms of docked cellooligosaccharides and a thiooligosaccharide substrate analog. Coupled with the interaction energies evaluated for each docked ligand, these forces give insight into the dynamics of the ligand in the active site, and help to elucidate the relative importance of specific enzyme–substrate interactions in stabilizing the substrate transition‐state conformation. The processive force on the docked substrate in the F. oxysporum Cel7B active site is less than half of that on the docked substrate in the Hypocrea jecorina Cel7A active site. Hydrogen bonding interactions of the enzyme with the C2 hydroxyl group of the glucosyl residue in subsite −2 and with the C3 hydroxyl group of the glucosyl residue in subsite +1 are the most significant in stabilizing the distorted1, 4B transition‐state conformation of the glucosyl residue in subsite −1. The force calculations also help to elucidate the mechanism that prevents the active site from fouling. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Superlattice ordering in SrFeO3–δ: Electron microscopy and diffraction study
Authors: Schott Stefanie , Jia Zhihong , Schaper Andreas K. , Thangadurai Venkataraman , Weppner Werner , Schmid‐Beurmann Peter
Published: September 2005

The oxygen‐deficient SrFeO2.74 phase of quenched samples is located within the miscibility gap of the SrFeO3–δ perovskite system, and exhibits a manifold vacancy ordering pattern at room temperature. We have studied the complex ordering by high‐resolution electron microscopy, and by electron and X‐ray diffraction. New principal superlattice structures have been identified by electron diffraction which can be of relevance for the electronic and magnetic properties of this respective perovskite system. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Configuration of twins in glass‐embedded silver nanoparticles of various origin
Authors: Hofmeister H. , Dubiel M. , Tan G. L. , Schicke K.‐D.
Published: September 2005

Structural characterization using high resolution electron microscopy and diffractogram analysis of silver nanoparticles embedded in glass by various routes of fabrication was aimed at revealing the characteristic features of twin faults occuring in such particles. Nearly spherical silver nanoparticles well below 10 nm size embedded in commercial soda‐lime silicate float glass have been fabricated either by silver/sodium ion exchange or by Ag+ ion implantation. Twinned nanoparticles, besides single crystalline species, have frequently been observed for both fabrication routes, mainly at sizes above 5 nm, but also at smaller sizes, even around 1 nm. The variety of particle forms comprises single crystalline particles of nearly cuboctahedron shape, particles containing single twin faults, and multiply twinned particles containing parallel twin lamellae, or cyclic twinned segments arranged around axes of fivefold symmetry. Parallel twinning is distinctly favoured by ion implantation whereas cyclic twinning preferably occurs upon ion exchange processing. Regardless of single or repeated twinning, parallel or cyclic twin arrangement, one may classify simple twin faults of regular atomic configuration and compound twin faults whose irregular configuration consists of additional planar defects like associated stacking faults or secondary twin faults. Besides, a particular superstructure composed of parallel twin lamellae of only three atomic layers thickness is observed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coordination of transition‐metals in glasses from high‐resolution electron energy‐loss spectroscopy
Authors: Höche Thomas , Heyroth Frank , Grodzicki Michael , van Aken Peter A.
Published: September 2005

Two fresnoitic glasses (2BaO–TiO2–2GeO2 and 2SrO–TiO2–2SiO2) are studied by high‐resolution electron energy‐loss spectroscopy in the transmission electron microscope. It is shown that coordination fingerprinting using the electron energy‐loss near‐edge structure (being widely used in crystalline compounds bearing transition metals) can also be applied to amorphous matter. In particular, respective ratios of fourfold, fivefold, and sixfold co‐ordinated Ti4+ are verified for both glasses in comparison to earlier X‐ray photoemission measurements. The results demonstrate that – sufficiently high spectral resolution given – electron energy‐loss spectroscopy in the transmission electron microscope is an extremely promising and powerful technique for atomistic‐structure studies of amorphous materials. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiple‐textured gallium nitride prepared by ion beam assisted molecular beam epitaxy
Authors: Gerlach Jürgen W. , Höche Thomas
Published: September 2005

A gallium nitride bilayer was deposited on Al2O3(0001) by low‐energy nitrogen ion beam assisted molecular beam epitaxy using two different ion energies. First, the ion energy was chosen such that a thin film consisting of a mixture of wurtzitic and zincblende polytypes of GaN could be deposited. For the covering second layer, the ion energy was lowered to obtain optimum growth conditions for single‐polytype wurtzitic GaN. The resulting bilayer was investigated by X‐ray diffraction and transmission electron microscopy and found to contain no less than nine differently oriented types of crystallites possessing well‐defined orientation relationships. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nitrogen substitutions in GaAs(001) surfaces: Density‐functional supercell calculations of the surface stability
Authors: Jenichen Arndt , Engler Cornelia , Leibiger Gunnar , Gottschalch Volker
Published: September 2005

The structures and energies of various probable reconstruction patterns of the GaAs(001) surface with restricted nitrogen substitution on arsenic positions are calculated using periodic supercells and the density‐functional method. In dependence on chemical potentials of arsenic and nitrogen the most stable structures and compositions of the surface are obtained: Under extreme As‐rich conditions the N‐free c(4 × 4) reconstruction is the preferred arrangement. Under Ga‐rich conditions the ζ(4 × 2) reconstruction builds in variously high N‐substituted structures (especially parallel coupled (GaN)n chains), which can lead to a GaN phase (phase separation). In the transition region between the Ga‐ and As‐rich limits the α2(2 × 4) but also the β2(2 × 4) reconstruction form structures with restricted nitrogen substitution. The high stability of restricted substitutions predestinates the region between the Ga‐ and As‐rich conditions for the growth of GaAsN alloys. The blueshift of the band gap during the annealing of the grown bulk can be explained by the transformation of the grown (GaN)n chains, which are also formed in this region (in the β(2 × 4) reconstruction), to the thermodynamically most stable bulk structures. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Proton stopping data from experiment and theory
Authors: Kalbitzer S.
Published: September 2005

Proton stopping cross‐sections in several solid and gaseous targets have been calculated by applying the Bethe–Bloch formalism to each electron shell. In addition, binary collision kinetics for both proton and electron in motion have been taken into account. The calculations closely match experimental data on C and Si by us and on He and Ne by TRIM. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phonon polariton modes in porous III–V semiconductors
Authors: Wilson K. S. Joseph , Navaneethakrishnan K.
Published: September 2005

The phonon polariton modes in the bulk porous III–V semiconductor materials like GaP and GaAs are investigated for different porosity values. Their behavior under an external hydrostatic pressure is also studied. The frequencies of the various modes shift to higher values. The model has been extended to the case of self assembled GaP quantum dots (QDOTs) in GaAs matrix. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chromium ions in alkali lead borotellurite glasses – An EPR and optical study
Authors: Sreekanth Chakradhar R. P. , Lakshmana Rao J. , Sivaramaiah G. , Gopal N. O.
Published: September 2005

Chromium ions doped 90 Na2B4O7 + (9 – x)PbO + 1TeO2 and 90 K2B4O7 + (9 – x)PbO + 1TeO2 (x = 3, 4, 5, 6, 7 and 8 mol%) glasses have been studied by using Electron Paramagnetic Resonance (EPR) and optical absorption techniques. The EPR spectra exhibit a broad resonance signal at g = 4.65 and a narrow resonance signal at g = 1.97. The resonance at g = 4.65 can be attributed to isolated Cr3+ ions in rhombic symmetry subjected to strong crystal field effects and the resonance at g = 1.97 is due to Cr5+ ions. The EPR spectra have also been studied at different temperatures (153–393 K). The number of spins (N) participating in the resonance is measured as a function of temperature and the activation energy is calculated. The exchange coupling constant J between chromium ions is calculated. The optical absorption spectrum exhibits bands characteristic of Cr3+ ions in an octahedral symmetry. The optical band gap (Eopt) and Urbach energies (ΔE) have been calculated for all the glass samples and it is observed that Eopt decreases and ΔE increases with increase of chromium content. This has been explained as due to the creation of additional localized states with chromium doping, which overlap and extend in the mobility gap of the glass matrix. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Self‐consistent calculation for energy band profiles and energy levels of cubic quantum dots
Authors: Lee Johnson , Spector Harold N. , Chou Wu Ching
Published: September 2005

We have performed a self‐consistent calculation for the energy band profiles and energy levels of cubic quantum dots, solving both the Schrödinger and Poisson's equations. In particular, we examined the effect of doping on these levels both in the presence and absence of a positive test charge. We found that the number of levels the cubic dot supported depended on the size of the dot, and that the energy of the levels decreased in the presence of a positive test charge. Moreover, we found that the energy levels of both the singlet and triplet states in the dot increased with the doping density. The quasi‐Fermi level was found to be lower in the presence of a positive test charge than in its absence, and the quasi‐Fermi level increased sharply with increasing doping density both in the absence and presence of the test charge. With very high doping the Fermi level is located in the barrier while with low doping the Fermi level is located down below the ground state energy which implies that the probability of finding an electron in a dot is very small. We also find that at high doping levels the lowest energy states are no longer confined in the dot. The potential energy profile was found to be dramatically affected by both the doping and the presence of a positive test charge. The profile was found to become asymmetric when the test charge was displaced from the center of the dot. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and characterization of aluminum–polyaniline thin films and membranes
Authors: Liu Yan , O'Keefe Matthew J. , Beyaz Ayse , Schuman Thomas P.
Published: September 2005

Polyaniline (PAni) films of different intrinsic oxidation states, including emeraldine salt, emeraldine base and leucoemeraldine base, were synthesized. Free‐standing membranes and thin film bilayers of aluminum–polyaniline were fabricated by magnetron sputter deposition of aluminum onto polyaniline films. Aluminum–polyaniline samples were analyzed by transmission electron microscopy (TEM) to investigate the microstructures of specimens, including cross‐sectional TEM micrographs of the metal‐polyaniline interfacial structure not previously reported in the literature. Auger electron spectroscopy (AES) and X‐ray photoelectron spectroscopy (XPS) were employed to study the chemical bonding and interaction between deposited aluminum and polyaniline at the interface. Results indicated that the intrinsic oxidation state of the polyaniline influenced the chemistry of the aluminum–polyaniline interface. Distinct interaction between aluminum and polyaniline in the emeraldine salt‐form was observed. However, there was no evidence of direct interactions of the aluminum with emeraldine base and leucoemeraldine base polyaniline. Copyright © 2005 John Wiley & Sons, Ltd.
Retracted: Nanobubbles influence on BSA adsorption on mica surface
Authors: Wu Zhihua , Zhang Xuehua , Zhang Xiaodong , Li Gang , Sun Jielin , Zhang Yi , Li Minqian , Hu Jun
Published: September 2005

Retraction: The following article from the Surface and Interface Anlysis, 'Nanobubbles influence on BSA adsorption on mica surface' by Wu ZH, Zhang XH, Zhang XD, Li G, Sun J, Zhang Y, Li M and Hu J, published online on 1 September 2005 in Wiley InterScience (www.interscience.com) and in print Volume 37 Issue 10 pages 797‐801, 2005, has been retracted by agreement between the authors, the journal's Editor‐in‐Chief Professor John F. Watts and John Wiley & Sons, Ltd. The retraction has been agreed due to the article being subsequently published in Volume 38 Issue 6, pages 990‐995 of the journal as part of a Special Issue entitled 'Chinese‐German Forum on Fundamentals and Technological Perspectives of Nanoscience 26‐30 September 2004, Beijing, China.'
Bayesian neural networks for bivariate binary data: an application to prostate cancer study
Authors: Chakraborty Sounak , Ghosh Malay , Maiti Tapabrata , Tewari Ashutosh
Published: September 2005

Prostate cancer is one of the most common cancers in American men. The cancer could either be locally confined, or it could spread outside the organ. When locally confined, there are several options for treating and curing this disease. Otherwise, surgery is the only option, and in extreme cases of outside spread, it could very easily recur within a short time even after surgery and subsequent radiation therapy. Hence, it is important to know, based on pre‐surgery biopsy results how likely the cancer is organ‐confined or not.

The paper considers a hierarchical Bayesian neural network approach for posterior prediction probabilities of certain features indicative of non‐organ confined prostate cancer. In particular, we find such probabilities for margin positivity (MP) and seminal vesicle (SV) positivity jointly. The available training set consists of bivariate binary outcomes indicating the presence or absence of the two. In addition, we have certain covariates such as prostate specific antigen (PSA), gleason score and the indicator for the cancer to be unilateral or bilateral (i.e. spread on one or both sides) in one data set and gene expression microarrays in another data set. We take a hierarchical Bayesian neural network approach to find the posterior prediction probabilities for a test and validation set, and compare these with the actual outcomes for the first data set. In case of the microarray data we use leave one out cross‐validation to access the accuracy of our method. We also demonstrate the superiority of our method to the other competing methods through a simulation study. The Bayesian procedure is implemented by an application of the Markov chain Monte Carlo numerical integration technique. For the problem at hand, our Bayesian bivariate neural network procedure is shown to be superior to the classical neural network, Radford Neal's Bayesian neural network as well as bivariate logistic models to predict jointly the MP and SV in a patient in both the data sets as well as in the simulation study. Copyright © 2005 John Wiley & Sons, Ltd.
Inferences on the within‐subject coefficient of variation
Authors: Tian Lili
Published: September 2005

The within‐subject coefficient of variation (WCV) is widely used as a measure of precision and reproducibility of data in medical and biological science. In this paper, generalized confidence intervals and tests for a single WCV is developed using the concept of generalized pivots under the assumption of one‐way random effect model. This approach is further extended to two‐sample cases. The resulting procedures are easy to compute and have good properties in term of coverage probabilities and type‐I error control at small sample sizes. The proposed methods are illustrated by a real life example. Copyright © 2005 John Wiley & Sons, Ltd.
A New Knot Technique for Vessel Ligatures
Authors: Botet Xavier , Surinyach Santiago , Molinas Joan
Published: September 2005

A new technique for ligating vessels and similar structures that offers more security is described. The aim of the study was to test whether this hypothesis was correct. Six different types of knots, including the one described in this article were compared by a strength‐testing study. The knots were tied on a silicon tube through which a constant air flow of 795.10 mmHg of pressure circulated. Tension of 2 kg was then applied to both loose ends of the suture filament (polyglyconate n°1 gauge) for 25 seconds. Then, 15 seconds after the tension was released an overpressure of 2250.31 mmHg was applied to the system. Two computerized pressure sensors were applied to both ends of the tube.

The newly described knot reached the highest strangulating force (997.63 mmHg) and had the highest resistance to slippage.

From these results, we conclude that the new knot is far more secure for vessel and duct ligature and that it represents a new and useful tool for surgeons in both open and laparoscopic surgery.
Nerve‐sparing Axillary Dissection Using the da Vinci Surgical System
Authors: Lim Susan M.L. , Kum Cheng K. , Lam Foong L.
Published: September 2005

This is an initial report of a new method of axillary dissection via a periareolar incision and an 8 mm incision in the axilla with the da Vinci Surgical System. The 10× magnification and three‐dimensional image, together with the versatility and precision of the robotic telemanipulators, has enabled us to perform nerve‐sparing axillary dissection in four patients with invasive ductal carcinoma of the breast undergoing segmental (conservative) excision and level II axillary dissection. The time for the robotic axillary dissection ranged from 30 to 105 minutes (average 70.5 minutes). The average number of lymph nodes retrieved was 13 (11, 11, 13, and 17, respectively). Postoperatively all four patients recovered well and were discharged the next day. The robotic system can enhance the surgeon’s ability by providing a high‐definition, magnified, three‐dimensional view of the operative field, intuitively controlled articulating instruments, and elimination of tremors; and it has potential benefits for the patient.
Do Antimicrobial Susceptibility Patterns of Colonic Isolates of Bacteroides Species Change after Antibiotic Prophylaxis with Cefoxitine during Elective Abdominal Surgery?
Authors: (Toprak) Nurver Ülger , Güllüoğlu Bahadır M. , Çakıcı Özlem , Akin M. Levhi , Demirkalem Pakize , Çelenk Tuncay , Söyletir Güner
Published: September 2005

The objectives of the study were to investigate and compare the susceptibility profiles of preoperative and postoperative intestinal Bacteroides fragilis and Bacteroides thetaiotaomicron strains against antimicrobials to evaluate their resistance development patterns due to prophylactic antibiotic administration. Preoperative and postoperative stool samples were obtained from patients undergoing elective abdominal surgery with a “clean‐contaminated” wound categorization. All patients received cefoxitin 2 g as prophylaxis. Isolates of Bacteroides species were identified. Susceptibility tests against ampicillin, piperacillin, cefoxitin, clindamycin, chloramphenicol, metronidazole, imipenem, and amoxicillin‐clavulanate were performed. Stool samples were collected from 40 patients at two settings: before and after the operation. Most of the patients (53%) were operated on because of colorectal carcinoma and underwent surgery that included colectomy or anterior resection. Bacteroidesfragilis and Bacteroides thetaiotaomicron were isolated in both samples obtained from 22 and 34 patients, respectively. In the present study 95% to 100%, 50% to 74%, 46% to 64%, and 18% to 35% of preoperatively isolated Bacteroides species were resistant to ampicillin, cefoxitin, clindamycin, and piperacillin, respectively. Although there were no statistically significant difference, postoperative strains were more resistant than preoperative isolates, and the resistance rates were found to be 95% to 100%, 55% to 82%, 46% to 86%, and 37% to 41%, respectively. Both Bacteroides species isolated from all specimens before and after the surgery were uniformly susceptible to amoxicillin‐clavulanate, imipenem, metronidazol, and chloramphenicol.Our data revealed that Bacteroides strains revealed high resistance to ampicillin, cefoxitin, piperacillin, and clindamycin. Metronidazole, imipenem, and amoxicillin‐clavulanate seem highly effective against both Bacteroides species. Cefoxitin prophylaxis did not significantly increase the resistance patterns against antimicrobial agents.