bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlates of quality of life‐related outcomes in breast cancer patients participating in the Pathfinders pilot study
Authors: Smith Sophia K. , Herndon James E. , Lyerly H. Kim , Coan April , Wheeler Jane L. , Staley Tina , Abernethy Amy P.
Published: May 2010

Objective: In a pilot study, participation in the Pathfinders program was associated with reductions in distress and despair and improvements in quality of life (QOL) among advanced breast cancer patients. This study explores the relationship between psychosocial resources invoked through the Pathfinders intervention and outcomes.

Methods: Advanced breast cancer patients were enrolled in a prospective, single‐arm, pilot study of the Pathfinders psychosocial program. Participants met at least monthly with a licensed clinical social worker who administered the Pathfinders intervention, which focused on strengthening adaptive coping skills, identifying inner strengths, and developing a self‐care plan. Longitudinal assessments over 6 months used validated instruments to assess changes in Pathfinders targets (coping, social support, self‐efficacy, spirituality, and optimism) and outcomes (distress, despair, QOL, and fatigue). Multiple linear regression models examined the joint effect of average changes in target subscales on average outcome changes, adjusted for baseline outcome scores and patient characteristics.

Results: Participants (n=44) were: mean age 51 (SD, 12), 20% non‐Caucasian, 50% college degree, and 75% married. Improvements in active coping skills, self‐efficacy, and spiritual meaning/peace significantly correlated with an improvement in despair after adjustment for demographic characteristics (all P<0.05). Improvements in social support significantly correlated with positive changes in distress (P<0.05). Gains in learned optimism independently correlated with an increase in overall QOL (P<0.01).

Conclusions: In this pilot assessment, changes in pre‐defined Pathfinders targets such as coping skills, social support, self‐efficacy, spirituality, and optimism correlated with improvements in patient‐reported outcomes. Copyright © 2010 John Wiley & Sons, Ltd.
Family‐oriented multilevel study on the psychological functioning of adolescent children having a mother with cancer
Authors: Huizinga Gea A. , Visser Annemieke , Van der Graaf Winette T. A. , Hoekstra Harald J. , Stewart Roy E. , Hoekstra‐Weebers Josette E. H. M.
Published: May 2010

Objective: This study aims to identify the predictive power of adolescents', parents', and illness characteristics on the functioning of adolescents when a mother has cancer.

Methods: Two hundred and seventy‐one adolescents, 128 mothers with cancer, and 96 spouses completed standardized questionnaires 1–5 years after diagnosis. Stress response symptoms (SRS), internalizing and externalizing problems were assessed in adolescents. Parents' SRS, trait anxiety, marital satisfaction, and parent–adolescent communication were assessed in parents. Descriptive statistics and multilevel analyses accounting for non‐independence of observations within groups were used.

Results: Descriptive analyses showed clinically elevated SRS in 20% of the sons and 30% of the daughters. Daughters experienced more internalizing problems than norm group girls. Multilevel analyses showed that adolescents' female gender and older age were associated with impaired child functioning. Higher levels of parents' trait anxiety and SRS, marital dissatisfaction, and poorer parent–adolescent communication were significant predictors also. Recurrent disease was associated with SRS and internalizing problems, and more intensive treatment with externalizing problems. Female gender and poorer parent–adolescent communication were overall the best predictors.

Conclusions: Having a mother with cancer may have far‐reaching consequences for more than a quarter of the adolescent offspring. The multilevel approach of this study identified individual‐level adolescent' risk characteristics as well as family‐level risk characteristics for mental health problems. Adolescents at risk should be referred to health‐care professionals specialized in working with families to help them to adapt to their parent's illness. Copyright © 2010 John Wiley & Sons, Ltd.
What is a psychological intervention? A metareview and practical proposal
Authors: Hodges Laura J. , Walker Jane , Kleiboer Annet M. , Ramirez Amanda J. , Richardson Alison , Velikova Galina , Sharpe Michael
Published: May 2010

Objective: What do we mean by a ‘psychological intervention’ in the context of cancer care? It is critical to know what treatments are included under this term, if data from diverse treatment trials are to be summarized in order to inform clinical practice. We, therefore, aimed to determine how the term ‘psychological intervention’ has been defined and used to group and compare interventions in reviews of cancer care.

Methods: We conducted a review of existing reviews (a metareview). These included systematic and narrative reviews and meta‐analyses of interventions that were described as ‘psychological’, with the aim of determining: (a) the definitions for ‘psychological interventions’ that were used and (b) the treatments that were included within this category.

Results: We identified 66 relevant reviews. Surprisingly, we were unable to find any explicit definition of the term ‘psychological intervention’ in these reviews. The reviews included 79 different treatments with little consistency between reviews in which treatments were included.

Conclusions: There is confusion about what ‘psychological intervention’ means in the cancer review literature. A clearer definition is essential to summarize research findings. We propose that rather than simply grouping interventions as ‘psychological’, it would be more useful if reviews focussed on specified domains of the interventions, namely content, proposed mechanism, target outcome, and methods of delivery. This would enable greater specificity in the review question, more meaningful comparisons, and would hopefully provide clearer answers for the readers of the reviews. A checklist for the summarizing of reports of interventions for review is provided. Copyright © 2010 John Wiley & Sons, Ltd.
Barium Salts of Tetrazole Derivatives – Synthesis and Characterization
Authors: Damavarapu Reddy , Klapötke Thomas M. , Stierstorfer Jörg , Tarantik Karina R.
Published: May 2010

The compounds barium tetrazolate (6), barium 5‐aminotetrazolate tetrahydrate (7), barium 5‐nitriminotetrazolate dihydrate (8), barium bis(1H‐5‐nitriminotetrazolate) tetrahydrate (9), barium 1‐methyl‐5‐nitriminotetrazolate monohydrate (10), and barium 2‐methyl‐5‐nitriminotetrazolate dihydrate (11) were synthesized by the reactions of barium hydroxide octahydrate and 1H‐tetrazole (1), 5‐aminotetrazole (2), 1,4H‐5‐nitriminotetrazole (3), 1‐methyl‐5‐nitriminotetrazole (4), and 2‐methyl‐5‐nitraminotetrazole (5), respectively. The compounds were characterized using multi‐nuclear NMR spectroscopy, vibrational (IR and Raman) spectroscopy, elemental analysis, and differential scanning calorimetry. The solid‐state structures of 7–11 were determined using low temperature X‐ray diffraction and a comprehensive characterization is given. In addition, the sensitivities (impact, friction, electrical discharge) of 6–11 were investigated and bomb calorimetric measurements were carried out.
X‐ray crystallographic analysis of adipocyte fatty acid binding protein (aP2) modified with 4‐hydroxy‐2‐nonenal
Authors: Hellberg Kristina , Grimsrud Paul A. , Kruse Andrew C. , Banaszak Leonard J. , Ohlendorf Douglas H. , Bernlohr David A.
Published: May 2010

Fatty acid binding proteins (FABP) have been characterized as facilitating the intracellular solubilization and transport of long‐chain fatty acyl carboxylates via noncovalent interactions. More recent work has shown that the adipocyte FABP is also covalently modified in vivo on Cys117 with 4‐hydroxy‐2‐nonenal (4‐HNE), a bioactive aldehyde linked to oxidative stress and inflammation. To evaluate 4‐HNE binding and modification, the crystal structures of adipocyte FABP covalently and noncovalently bound to 4‐HNE have been solved to 1.9 Å and 2.3 Å resolution, respectively. While the 4‐HNE in the noncovalently modified protein is coordinated similarly to a carboxylate of a fatty acid, the covalent form show a novel coordination through a water molecule at the polar end of the lipid. Other defining features between the two structures with 4‐HNE and previously solved structures of the protein include a peptide flip between residues Ala36 and Lys37 and the rotation of the side chain of Phe57 into its closed conformation. Representing the first structure of an endogenous target protein covalently modified by 4‐HNE, these results define a new class of in vivo ligands for FABPs and extend their physiological substrates to include bioactive aldehydes.
Chemoprevention of prostate cancer with lycopene in the TRAMP model
Authors: Konijeti Ramdev , Henning Susanne , Moro Aune , Sheikh Ahmed , Elashoff David , Shapiro Ari , Ku Melvin , Said Jonathan W. , Heber David , Cohen Pinchas , Aronson William J.
Published: May 2010

BACKGROUND

Dietary lycopene combined with other constituents from whole tomatoes was previously found to have greater chemopreventive effects against prostate cancer as compared to pure lycopene provided in a beadlet formulation. We hypothesized that tomato paste would have greater chemopreventive effects in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice relative to equivalent lycopene doses provided from lycopene beadlets.

METHODS

Fifty‐nine TRAMP mice were randomized to a control diet or to diets providing 28 mg lycopene per kg diet from tomato paste (TP) or from lycopene beadlet (LB), and sacrificed at 20 weeks. Prostate histopathology, prostate weight and serum levels of IGF‐I and IGF binding protein‐3 were evaluated.

RESULTS

The incidence of prostate cancer was significantly decreased in the LB group relative to the control group (60% vs. 95%, respectively, P = 0.0197) whereas the difference between the TP and control groups was not statistically significant (80% vs. 95%, P = 0.34). There was no difference in prostate weights between the groups. Total lycopene levels in the serum and prostate tissue were similarly elevated in the LB and TP groups relative to the control group. The ratio of 5‐cis‐lycopene to trans‐lycopene in the serum was significantly greater in the LB group relative to the TP group (P = 0.0001). Oxidative DNA damage was significantly reduced in the livers of mice fed LB and TP diets relative to the control group.

CONCLUSIONS

This preclinical trial suggests significant chemopreventive activity with a lycopene beadlet‐enriched diet. The chemopreventive effects of lycopene from beadlets versus whole tomato products requires further testing in preclinical and clinical models of prostate cancer. Prostate 70: 1547–1554, 2010. © 2010 Wiley‐Liss, Inc.
Growth of InGaN/GaN light emitting diodes by MOCVD with a thin tapered reactor cell
Authors: Iso Kenji , Takaki Ryohei , Ishihama Yoshiyasu , Inagawa Tomokazu , Takahashi Yuzuru
Published: May 2010

InGaN/GaN‐based light emitting diodes (LEDs) can be grown by using metal organic chemical vapor deposition (MOCVD) to make eight, 3‐inch diameter wafers with a thin, tapered reactor cell at atmospheric pressure. The reactor configuration was optimized for the purpose of improving the GaN growth rate and its in‐plane distribution. The growth rate and the layer uniformity of GaN were improved when the reactor cell was narrowed down and tapered. The on‐wafer deviation of the electroluminescence (EL) peak wavelength and power were 5 nm and within 4%, respectively, except at the edge. The full width at half maximum (FWHM) of EL spectrum for an LED grown at atmospheric pressure was consistently smaller than that of one grown at reduced pressure over the entire wavelength range.
GaN/AlN quantum disc single‐nanowire photodetectors
Authors: Rigutti L. , Tchernycheva M. , Bugallo A. De Luna , Jacopin G. , Julien F. H. , Songmuang R. , Monroy E. , Chou S. T. , Lin Y. T. , Tseng P. H. , Tu L. W. , Fortuna F. , Zagonel L. , Kociak M. , Stephan O.
Published: May 2010

We demonstrate single‐nanowire photodetectors based on nanowires containing GaN/AlN quantum disc heterostructures. The structural and electronic properties are investigated by photocurrent and microphotoluminescence spectroscopy, as well as scanning transmission electron microscopy. Single‐nanowire photodetectors are visible‐blind with photoresponse in the ultraviolet spectral range arising from interband absorption in the multi‐quantum disc GaN/AlN heterostructure. The photoconductive gain as high as 104 is measured.
Optical polarization anisotropy of nonpolar InN epilayers
Authors: Wang K. , Yamaguchi T. , Takeda A. , Kimura T. , Kawashima K. , Araki T. , Nanishi Y.
Published: May 2010

Photoluminescence (PL) intensity of both a‐plane and m‐plane InN epilayers has been observed to strongly depend on polarization angle. The PL intensity for polarization perpendicular to c‐axis (E⟂c) is up to four times as that of polarization parallel to c‐axis (E//c) for a‐plane InN, and this ratio is up to seven times for m‐plane InN. The absorption edges of a‐plane samples for the two polarizations are separated by 19 meV, with (E//c) at higher energy side. The PL detected from sample edge also shows such anisotropy. X‐ray diffraction experiments for a series of a‐plane samples, taking orthorhombic distortion of lattice into account, have shown some samples are compressively strained along growth direction and others have negligible strain. With measured strain, the polarization anisotropy has been analyzed by comparing the experimental results with calculated transition energies and relative oscillator strengths including anisotropic in‐plane strain.
AlGaN/GaN HFETs on Fe‐doped GaN substrates
Authors: Oshimura Yoshinori , Takeda Kenichiro , Sugiyama Takayuki , Iwaya Motoaki , Kamiyama Satoshi , Amano Hiroshi , Akasaki Isamu , Bandoh Akira , Udagawa Takashi
Published: May 2010

AlGaN/GaN HFETs with different undoped GaN thicknesses were grown on Fe‐doped freestanding GaN substrates by conventional MOVPE. To realize a high drain current, thick undoped GaN is found to be necessary. SIMS measurement shows that Fe is redistributed into the epilayer, by which the scattering center is generated at the channel when the thickness of the undoped GaN is insufficient. We also observed a similar Fe profile in the GaN/sapphire template placed on the side of the Fe‐doped GaN substrate during growth. Therefore, Fe in the Fe‐doped GaN substrate is redistributed not only through a solid but also through vapor. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of growth temperature on the optical properties of InN nanostructures grown by MOCVD
Authors: Sun Yuanping , Cho Yong‐Hoon , Wang Hui , Wang Lili , Zhang Shuming , Yang Hui
Published: May 2010

The non‐intentionally doped InN nanostructures with different sizes were grown by metal‐organic chemical vapor deposition at different temperatures. Atomic force microscope images show that the structure of InN nanostructures sample is hexagonal with a height of 33.6, 52.5 and 132.6 nm for sample A to C, which corresponding to the growth temperature of 475, 500 and 525 °C, respectively. The height of wetting layers decided by the air‐bearing surface (ABS) analysis is 3.8, 5.8 and 16.0 nm for sample A to C, respectively. The main emission peak at 12 K for sample A to C is 0.806, 0.760 and 0.755 eV, respectively, which is related to the height of wetting layer and size of nanostructures. By the best theoretical fitting of the main emission peaks, an almost same band‐gap value of 0.712 eV with an error 0.001 eV is obtained. The difference of main emission energy and the band gap energy was caused by the recombination of degenerate electrons with photo‐holes near the top of the valence band (Burstein‐Moss effect) together with the quantum confinement effect. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In situ SiN passivation of AlInN/GaN heterostructures by MOVPE
Authors: Behmenburg H. , Khoshroo L. Rahimzadeh , Mauder C. , Ketteniss N. , Lee K. H. , Eickelkamp M. , Brast M. , Fahle D. , Woitok J. F. , Vescan A. , Kalisch H. , Heuken M. , Jansen R. H.
Published: May 2010

AlInN is being considered to replace AlGaN as barrier material in high‐electron mobility transistors (HEMT) mainly due to the possibility to downscale the barrier layer thickness at coexistent higher drain current density. However, the stability of surface conditions which can strongly influence the electrical properties of the device has to be assured. In situ deposition of a SiN passivation layer by metal‐organic vapour phase epitaxy (MOVPE) is therefore a promising candidate to improve the device structure. In this paper, heterostructures with thin AlInN barrier passivated by in situ deposition of SiN layers of different thicknesses are presented. As expected, deterioration of the sheet resistance (RSh) was observed for the reference sample without SiN passivation layer by continuously performed RSh mappings of the investigated wafer. This change is noticeably reduced for samples with in situ SiN passivation layer. A comparison of two wafers, stored either with or without air exposure, reveals oxidation as presumable reason for the deterioration. Further, results from RSh measurements on processed wafers indicate an enhanced RSh stability during process for SiN‐capped samples. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scaling behavior of plasmon coupling in Au and ReO3 nanoparticles incorporated in polymer matrices
Authors: Maitra Urmimala , Ghosh Sandeep , Biswas Kanishka , Rao C. N. R.
Published: May 2010

Polymer nanocomposites containing different concentrations of Au nanoparticles have been investigated by small angle X‐ray scattering and electronic absorption spectroscopy. The variation in the surface plasmon resonance (SPR) band of Au nanoparticles with concentration is described by a scaling law. The variation in the plasmon band of ReO3 nanoparticles embedded in polymers also follows a similar scaling law.

magnified image

Distance dependence of plasmon coupling in polymer composites of metal nanoparticles.

(© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Using age and usage for prediction of reliability of an arbitrary system from a finite population
Authors: Lu Lu , Anderson‐Cook Christine M.
Published: May 2010

For single‐use non‐repairable systems, reliability is commonly estimated as a function of age and usage. For the effective management of individual systems or populations of systems, it is frequently important and necessary to predict the reliability in the future for age and usage values not yet observed. When predicting future system reliability, the age of the future system is easily predicted whereas future usage values will typically be unknown. In this paper we present the methodology for how to estimate both individual and population reliability summaries based on the currently known age and usage values. Projected usage values for future points in time can be obtained based on observed usage patterns or user‐specified patterns of usage rates. Individual system summaries can be used to answer the questions ‘For a given system of age A and usage U, what is its reliability with associated uncertainty?’ or ‘For a given system with known current age A and usage U, but unknown usage in the future, what is its reliability with associated uncertainty?’ The population summary of interest predicts the probability that a system randomly selected from the population of systems works. This summary takes into consideration the estimation of future usage, the estimated probability of individual systems working at their given ages and usage values, and the life cycle demographics of the population of interest. In this paper we discuss these questions for a given application. Published in 2010 by John Wiley & Sons, Ltd.
A simple control scheme for the manipulation of a particle by means of optical tweezers
Authors: Aguilar‐Ibañez Carlos , Suarez‐Castanon Miguel S. , Rosas‐Soriano Luis I.
Published: May 2010

We present a simple control scheme for changing the position of a microscopic particle immersed in a viscous medium and trapped by optical tweezers. We derive a simple feedback controller under the consideration that the particle mass is so small that it can be discarded from the motion equations. This approximation is well justified in practice, since the inertial force produced by the motion of a micron‐scaled trapped particle is completely dominated by the medium viscous drag force. Finally, we formally prove that the obtained controller is able to globally asymptotically stabilize the system when the particle mass is considered, if some suitable values of some control parameter are used. The stability analysis of the controlled system was carried out by using the standard Lyapunov stability theory. Also, by means of numerical simulations, we show that the obtained closed‐loop system is robust when random thermal noise is presented. Copyright © 2010 John Wiley & Sons, Ltd.
Vision‐based autonomous convoying with constant time delay
Authors: Goi Hien K. , Giesbrecht Jared L. , Barfoot Timothy D. , Francis Bruce A.
Published: May 2010

This paper describes the design and experimental validation of a vision‐based vehicle‐following system that uses only onboard sensors to enable a convoy of follower vehicles to autonomously track the trajectory of a manually driven lead vehicle. The tracking is done using the concept of a constant time delay, in which a follower tracks the delayed trajectory of its leader. This constant‐time‐delay approach allows for new techniques to be used to estimate the speed and heading of the leader. Experiments were conducted with full‐sized military vehicles on a 1.3‐km test track. Successful field trials with one follower for 10 laps and with two followers for 13.5 laps, totaling over 30 km, are presented. © 2010 Government of Canada. Exclusive worldwide publication rights in the article have been transferred to Wiley Periodicals, Inc., AWiley Company.
1‐Point RANSAC for extended Kalman filtering: Application to real‐time structure from motion and visual odometry
Authors: Civera Javier , Grasa Oscar G. , Davison Andrew J. , Montiel J. M. M.
Published: May 2010

Random sample consensus (RANSAC) has become one of the most successful techniques for robust estimation from a data set that may contain outliers. It works by constructing model hypotheses from random minimal data subsets and evaluating their validity from the support of the whole data. In this paper we present a novel combination of RANSAC plus extended Kalman filter (EKF) that uses the available prior probabilistic information from the EKF in the RANSAC model hypothesize stage. This allows the minimal sample size to be reduced to one, resulting in large computational savings without the loss of discriminative power. 1‐Point RANSAC is shown to outperform both in accuracy and computational cost the joint compatibility branch and bound (JCBB) algorithm, a gold‐standard technique for spurious rejection within the EKF framework. Two visual estimation scenarios are used in the experiments: first, six‐degree‐of‐freedom (DOF) motion estimation from a monocular sequence (structure from motion). Here, a new method for benchmarking six‐DOF visual estimation algorithms based on the use of high‐resolution images is presented, validated, and used to show the superiority of 1‐point RANSAC. Second, we demonstrate long‐term robot trajectory estimation combining monocular vision and wheel odometry (visual odometry). Here, a comparison against global positioning system shows an accuracy comparable to state‐of‐the‐art visual odometry methods. © 2010 Wiley Periodicals, Inc.
The maximal probability that k‐wise independent bits are all 1
Authors: Peled Ron , Yadin Ariel , Yehudayoff Amir
Published: May 2010

A k‐wise independent distribution on n bits is a joint distribution of the bits such that each k of them are independent. In this paper we consider k‐wise independent distributions with identical marginals, each bit has probability p to be 1. We address the following question: how high can the probability that all the bits are 1 be, for such a distribution? For a wide range of the parameters n,k, and p we find an explicit lower bound for this probability which matches an upper bound given by Benjamini et al., up to multiplicative factors of lower order. In particular, for fixed k, we obtain the sharp asymptotic behavior. The question we investigate can be viewed as a relaxation of a major open problem in error‐correcting codes theory, namely, how large can a linear error‐correcting code with given parameters be?

The question is a type of discrete moment problem, and our approach is based on showing that bounds obtained from the theory of the classical moment problem provide good approximations for it. The main tool we use is a bound controlling the change in the expectation of a polynomial after small perturbation of its zeros. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 38, 502–525, 2011
Policy analysis for online game addiction problems
Authors: Park Bong‐Won , Ahn Jae‐Hyeon
Published: May 2010

With the worldwide popularity of online games, game addiction is a serious social issue. To address online game addiction problems and pursue the steady growth of the online gaming industry, we propose and evaluate two policies using a system dynamics approach: a self‐regulation policy and a tax and rebate policy. Through our analysis, we demonstrate that the tax and rebate policy can be a very effective policy measure. Contrary to the concern of most game companies, by implementing the tax and rebate policy while the total revenue of the online gaming industry increases slightly, the social image of gaming improves and the number of addicted game users decreases. This clearly demonstrates that restricting excessive use of games actually benefits online game companies as well as society in general, and that the system can be more efficiently implemented by the tax and rebate policy. Copyright © 2010 John Wiley & Sons, Ltd.
Economic transition management in a commodity market: the case of the Iranian cement industry
Authors: Ghaffarzadegan Navid , Tajrishi Amir T.
Published: May 2010

Economic transition management is an important issue in countries that have not completely adjusted to the market economy style, as well in countries that temporarily implement price controls. The common concern is to manage the transition in a way that lessens the socio‐economic side effects of the process. This paper presents policy recommendations for the Iranian cement industry, which will undergo such a transition. Building on the commodity model literature and supported by interviews with different stakeholders in the industry, we develop a cement price model and calibrate it for Iran's economy. In the base run, we predict a large overshoot in price before it reaches its long‐term equilibrium state. Experimenting with the model, we suggest a specific transition policy which starts from drastic rise(s) in price before leaving the price up to the market. In addition, this paper gives some insights into analyzing similar economic policy problems. Copyright © 2010 John Wiley & Sons, Ltd.
Generic structure to simulate acceptance dynamics
Authors: Ulli‐Beer Silvia , Gassmann Fritz , Bosshardt Mathias , Wokaun Alexander
Published: May 2010

Social behaviour patterns and social equilibrium states are often guided by stable values such as social norms. However, changing environmental conditions (e.g. climate warming, resource scarcity) may require behavioural change and the acceptance of new technologies. Antecedents of aggregate behavioural change are value changes that predetermine when new behaviour patterns emerge and a new social equilibrium state can be reached. The paper addresses these phenomena. First, based on a waste recycling model, we explain these phenomena and develop a simple, generic mathematical model describing the basic traits of acceptance–rejection dynamics. Second, we propose a generic model structure for the simulation of acceptance–rejection behaviour that represents the dynamical characteristics of paradigm change processes. We show that a fourth‐order potential function is a sine qua non for an adequate representation of a paradigm change. Third, we also explain why the well‐known Bass model is unable to capture acceptance and rejection dynamics. Copyright © 2010 John Wiley & Sons, Ltd.
A provably secure threshold signature scheme based on DDH assumption
Authors: Lin Xiaodong
Published: May 2010

Threshold signature is an important cryptographic primitive, which was introduced by Desmedt and Frankel in 1991. In a (t, n) threshold signature scheme, a group secret key is distributed among n parties. Later, any t or more parties can use their shares of secret key to generate valid signatures on behalf of the group, while any t−1 or less parties cannot. Over the past years, many excellent threshold signature schemes have been proposed, but few of them provide the provable security proof. Therefore, in this paper, based on Decisional Diffie–Hellman (DDH) assumption, we present a new (t, n) threshold signature scheme and use the techniques from provable security to analyze its security. Copyright © 2010 John Wiley & Sons, Ltd.
Depth‐profiling analysis of MOCVD‐grown triple junction solar cells by SIMS
Authors: Téllez Helena , Vadillo José M. , Messmer Egbert Rodríguez , Miguel‐Sánchez Javier , Laserna J. Javier
Published: May 2010

Dynamic secondary ion mass spectrometry (d‐SIMS) has been applied to the analysis of the multilayered structure of GaInP/Ga(In)As/Ge concentration photovoltaic devices fabricated by metal organic chemical vapour deposition (MOCVD). Within the arsenal of techniques required to characterize such devices, SIMS represents the most powerful one due to the complete atomic/molecular information provided, its excellent sensitivity and reproducibility. Under Ar+ sputtering, the sample oxidation state is preserved, allowing for the location of interlayer oxides that may appear during the fabrication. Copyright © 2010 John Wiley & Sons, Ltd.
Comparison of MeV monomer ion and keV cluster ToF‐SIMS
Authors: Jones Brian N. , Matsuo Jiro , Nakata Yoshihiko , Yamada Hideaki , Watts John , Hinder Steven , Palitsin Vladimir , Webb Roger
Published: May 2010

Recent results1 show the potential of using monomer primary ions accelerated to several MeV with a tandem accelerator to achieve the necessary secondary ion yields to image large (above 1 kDa) molecules with submicron lateral resolutions. The Surrey ion Beam Centre (Surrey IBC) has designed a time‐of‐flight secondary ion mass spectrometer (ToF‐SIMS) combined with a 2 MV Tandem accelerator to investigate the characteristics of the desorption of secondary ions by the impact of fast, heavy, primary ions. The application of this MeV‐ToF‐SIMS technique is intended to eventually image biomolecules in the subcellular regime without the need for matrix application associated with other mass spectromery techniques, such as Matrix Assisted Laser Desorption ionisation (MALDI). A discussion is given to point out the merits of using a combination of Particle‐Induced X‐ray Emission Spectrometry (PIXE) and Rutherford Backscattering (RBS) with the MeV‐ToF‐SIMS measurement to improve quantification and sensitivity of this surface analysis technique. We also present data from highly focused MeV primary ions to directly compare results obtained using keV cluster‐SIMS to measure various biological materials using ToF‐SIMS through sputtering in both the nuclear and electronic stopping regimes. Our findings show that the mass spectra obtained with MeV ions in the electronic stopping regime show similarities to those acquired with more conventional keV ion beams (e.g. Bi+, Bi3+, Bi5+ and C60+). MeV‐ToF‐SIMS has the potential for becoming a widely used quantitative surface analysis technique in the many ion beam analysis facilities already conducting‐high energy ion beam analyses. Copyright © 2010 John Wiley & Sons, Ltd.
Investigation of fullerene depth distribution in PMMA‐C60 blends using dual beam ToF‐SIMS
Authors: Py M. , Barnes J. P. , Charbonneau M. , Tiron R. , Buckley J.
Published: May 2010

Nanocomposites, and in particular, Polymer–Fullerene blends, have recently drawn strong attention owing to their properties and their numerous applications in new‐generation electronic and optoelectronic devices. The fullerene concentration in the material is critical since it dictates its electrical behavior. In this context, precise knowledge of the fullerene depth distribution in the blends is needed. Here, we investigate the capability of the ToF‐SIMS technique to provide quantitative information on PMMA‐C60 blends with extremely small C60 concentrations. Smooth PMMA layers of ∼130 nm thickness ranging from 0 to 0.04 wt% C60 were deposited on Si wafers. Samples were analyzed with an ION‐TOF TOF SIMS V instrument in negative mode. Using low‐energy Cs+ sputtering (250 eV) and Bi3+ as the analysis ion allowed monitoring of C60 characteristic secondary ions, namely C60− and its isotopes at m = 720,721,722,723,724,725 u. Operating the beams in noninterlaced mode enabled successful depth profiling of samples with very little signal decay. Improvement of depth resolution was achieved by cooling the sample while profiling; AFM study of crater bottoms showed reduced roughness at low temperature, justifying the improvement. Segregation in depth of C60 against PMMA was not observed, in agreement with surface free energy values determined by a contact angle method. Point‐by‐point normalization of C60 signal (C60−, m = 720 u) to PMMA monomer signal (C5H9O2−, m = 101 u) was found to give a linear function of C60 concentration with excellent regression coefficient. Copyright © 2010 John Wiley & Sons, Ltd.
C60 molecular depth profiling of bilayered polymer films using ToF‐SIMS
Authors: Mouhib T. , Delcorte A. , Poleunis C. , Bertrand P.
Published: May 2010

Dual‐beam time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) (sputter ion, 15 keV C60+; analysis ion, 15 keV Ga+) was used to depth profile two types of spin cast bilayered films, Poly(vinyl pyrrolidone) (PVP)/poly(methyl methacrylate) (PMMA) and poly(4‐vinyl pyridine) (P4VP)/PMMA on silicon substrates. Positive and negative ion molecular depth profiles were obtained and compared on the basis of the stability of the characteristic secondary ion intensities, the sputter rates of the polymers, and the interface widths between the polymer layers and at the silicon substrate. The sputter rates of the top polymer in the bilayered films were typically the same as for the corresponding single‐layer films. However, the presence of a P4VP top layer significantly decreased the sputter rate of the underlying PMMA films. Typical interface widths between adjacent polymer layers were less than the polymer‐silicon interface widths. Additionally, the bilayered films with the P4VP on the outermost surface had higher interface widths. Copyright © 2010 John Wiley & Sons, Ltd.
A robust weighted Kaplan–Meier approach for data with dependent censoring using linear combinations of prognostic covariates
Authors: Hsu Chiu‐Hsieh , Taylor Jeremy M. G.
Published: May 2010

The weighted Kaplan–Meier (WKM) estimator is often used to incorporate prognostic covariates into survival analysis to improve efficiency and correct for potential bias. In this paper, we generalize the WKM estimator to handle a situation with multiple prognostic covariates and potential‐dependent censoring through the use of prognostic covariates. We propose to combine multiple prognostic covariates into two risk scores derived from two working proportional hazards models. One model is for the event times. The other model is for the censoring times. These two risk scores are then categorized to define the risk groups needed for the WKM estimator. A method of defining categories based on principal components is proposed. We show that the WKM estimator is robust to misspecification of either one of the two working models. In simulation studies, we show that the robust WKM approach can reduce bias due to dependent censoring and improve efficiency. We apply the robust WKM approach to a prostate cancer data set. Copyright 2010 John Wiley & Sons, Ltd.
Effects of acute cocaine or dopamine receptor agonists on AMPA receptor distribution in the rat nucleus accumbens
Authors: Ferrario Carrie R. , Li Xuan , Wolf Marina E.
Published: May 2010

Changes in α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionate receptor (AMPAR) surface expression in the rodent nucleus accumbens (NAc) are produced by cocaine exposure and implicated in addiction‐related behaviors. The direction of change depends on the animal's prior drug history. However, little is known about the effect of a single exposure to cocaine on AMPAR distribution in the NAc of untreated rats. This is essential information for interpreting the literature on AMPAR trafficking after repeated cocaine exposure. In this study, we used a protein crosslinking assay to determine the effect of a single cocaine injection on surface and intracellular AMPAR subunit levels in the rat NAc. We found increased AMPAR surface expression in the NAc 24 h, but not 30 min or 2 h, after cocaine injection. A major effect of cocaine is to increase extracellular dopamine (DA) levels, leading to DA receptor activation. Therefore, we also evaluated the effects of directly acting DA receptor agonists. In contrast to the effects of cocaine, AMPAR surface expression was significantly decreased 24 h after injection of the D2‐class agonist quinpirole, whereas no significant effects were produced by the D1‐class agonist SKF 81297 or the mixed DA agonist apomorphine. Our results show that the effects of a single cocaine exposure in drug‐ and injection‐naïve rats are distinct from those previously reported after repeated cocaine administration. They further suggest that cocaine exerts these effects by influencing neuronal circuits rather than simply stimulating NAc DA transmission. Synapse 65:54–63, 2011. © 2010 Wiley‐Liss, Inc.
siRNA‐mediated GABABreceptor at early fetal rat brain upon acute and chronic ethanol exposure: Down regulation of PKA and p‐CREB expression
Authors: Naseer M.I. , Lee H.Y. , Ullah N. , Ullah I. , Park M.S. , Kim M.O.
Published: May 2010

To observe the modulatory role of GABAB1R upon ethanol's effect during early brain development, we studied the effects of chronic maternal (10% ethanol during pregnancy) and acute (in vitro) ethanol exposure on the neuronal protein kinase A (PKA‐α) and phosphorylation of cAMP‐response element binding protein (p‐CREB), using a system where GABAB1R were specifically knocked down in the primary cells cultured at gestational day (GD) 12.5. The results showed that upon acute and chronic ethanol treatment the GABAB1R expression was decreased and further decreased when GABAB1R was transfection with siRNA, while increased upon exposure of baclofen, and baclofen plus phaclofen treatment. PKA expression was also decreased with acute and chronic ethanol treatment, whereas it showed increase upon exposure of baclofen and baclofen with phaclofen. Furthermore, intracellular Ca2+concentration was increased upon ethanol, baclofen, phaclofen exposure but showed decrease in GABAB1R siRNA group. Finally, these effects could lead to changes of p‐CREB expression, which showed same expression pattern as PKA. We speculate that GABABR activity upon ethanol exposure could modulate intracellular calcium homeostasis and the expressional changes of PKA and p‐CREB, which cause various negative effects on fetal brain development and modulation of GABABR upon ethanol exposure may underlying cause of ethanol's effects. Synapse, 2011. © 2010 Wiley‐Liss, Inc.
Lessons from a transplantation of zebra mussels into a small urban river: An integrated ecotoxicological assessment
Authors: Bourgeault A. , Gourlay‐Francé C. , Vincent‐Hubert F. , Palais F. , Geffard A. , Biagianti‐Risbourg S. , Pain‐Devin S. , Tusseau‐Vuillemin M.‐H.
Published: May 2010

It is often difficult to evaluate the level of contamination in small urban rivers because pollution is mainly diffuse, with low levels of numerous substances. The use of a coupled approach using both chemical and biological measurements may provide an integrated evaluation of the impact of micro‐pollution on the river. Zebra mussels were transplanted along a metal and organic pollution gradient in spring 2008. For two months, mussels and water samples were collected from two sites every two weeks and analyzed for metal and PAH content as well as water physicochemical parameters. Diffusive gradients in thin film (DGT) were also used to assess levels of labile metals. Exposure of mussels to contaminants and potential impact were evaluated using physiological indices and various biomarkers including condition index (CI), defense mechanisms (glutathione‐S‐transferase: GST), digestive enzymes (amylase and cellulase) and genotoxicity (micronucleus test: MN and comet assay: CA). For most contaminants, the water contamination was significantly higher downstream. Bioaccumulation in zebra mussels was related to water contamination in the framework of the biodynamic model, which allowed us to take into account the biological dilution that was caused by the growth of soft tissue downstream. Thus, metal influxes were on average two times higher downstream than upstream in particular for Zn, Cr, Cu and Cd. Significant differences in condition index were observed (final CI was 0.42 ± 0.03 downstream and 0.31 ± 0.03 upstream) reflecting a better food availability downstream. Moreover a significant decrease of GST activity and digestive enzymes activity in the cristalline style was observed downstream. Interpreting this decrease requires considering not only micro‐pollution but also the trophic status related to the water's physicochemistry. The MN test and the CA on gill cells highlighted genotoxicity in mussels transplanted downstream compared to upstream. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.
Impact of Fe and Ag nanoparticles on seed germination and differences in bioavailability during exposure in aqueous suspension and soil
Authors: El‐Temsah Yehia Sayed , Joner Erik J.
Published: May 2010

The potential environmental toxicity of zero‐valent iron nanoparticles (nZVI) and three types of nanosilver differing in average particle size from 1 to 20 nm was evaluated using seed germination tests with ryegrass, barley, and flax exposed to 0–5000 mg L−1 nZVI or 0–100 mg L−1 Ag. For nZVI, germination tests were conducted both in water and in two contrasting soils to test the impact of assumed differences in bioavailability of nanoparticles. Inhibitory effects were observed in aqueous suspensions at 250 mg L−1 for nZVI and 10 mg L−1 for Ag. Reduction in shoot growth was a more sensitive endpoint than germination percentage. Complete inhibition of germination was observed at 1000–2000 mg L−1 for nZVI. For Ag, complete inhibition was not achieved. The presence of soil had a modest influence on toxicity, and inhibitory effects were observed at 300 mg nZVI L−1 water in soil (equivalent to 1000 mg nZVI kg−1 soil). Complete inhibition was observed at 750 and 1500 mg L−1 in sandy soil for flax and ryegrass, respectively, while for barley 13% germination still occurred at 1500 mg L−1. In clay soil, inhibition was less pronounced. Our results indicate that nZVI at low concentrations can be used without detrimental effects on plants and thus be suitable for combined remediation where plants are involved. Silver nanoparticles inhibited seed germination at lower concentrations, but showed no clear size‐dependant effects, and never completely impeded germination. Thus, seed germination tests seem less suited for estimation of environmental impact of Ag. © 2010 Wiley Periodicals, Inc. Environ Toxicol 2012.
Urethral mobility and urinary incontinence
Authors: Pirpiris A. , Shek K. L. , Dietz H. P.
Published: May 2010

Objective

Urethral mobility is considered an important factor in female urinary incontinence. We therefore undertook a study to correlate segmental urethral mobility, as described by the urethral motion profile (UMP), with symptoms and urodynamic findings. Our null hypothesis was that there would be no statistically significant relationship between female urinary incontinence and segmental urethral mobility.

Methods

We performed a retrospective study in 198 women who had undergone multichannel urodynamic testing and four‐dimensional translabial ultrasound for symptoms of lower urinary tract dysfunction or prolapse. Segmental urethral mobility was described by vectors of movement from rest to maximum Valsalva, relative to the posteroinferior pubosymphyseal margin. We described the mobility of six equidistant points located along the length of the urethra from the bladder neck to the external urethral meatus. The results were tested against symptoms and urodynamic findings.

Results

Stress urinary incontinence (SUI) and urodynamic stress incontinence (USI), but not urge incontinence, detrusor overactivity or voiding dysfunction, were strongly associated with mobility of the mid‐urethra.

Conclusion

Impairment of mid‐urethral fixation, rather than bladder neck fixation, seems important in the pathophysiology of SUI and USI. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Abnormal antenatal Doppler velocimetry and cognitive outcome in very‐low‐birth‐weight infants at 2 years of age
Authors: Leppänen M. , Ekholm E. , Palo P. , Maunu J. , Munck P. , Parkkola R. , Matomäki J. , Lapinleimu H. , Haataja L. , Lehtonen L. , Rautava P.
Published: May 2010

Objective

To study neurodevelopmental outcome at 2 years of corrected age in very‐low‐birth‐weight (VLBW) (⩽ 1500 g) preterm infants with abnormal fetoplacental flow.

Methods

A total of 258 VLBW infants were born at Turku University Hospital between 2001 and 2006. Of these, 99 had undergone, within 1 week of delivery, antenatal Doppler assessment of blood flow in the umbilical artery (UA), fetal middle cerebral artery (MCA), descending aorta (DAo), aortic isthmus and ductus venosus and were eligible for inclusion in the study. Postnatally brain pathology was assessed by serial ultrasound and magnetic resonance imaging in 86 of the neonates and brain volume was measured in 80. Cognitive development was evaluated at 2 years of corrected age in 83 infants using the Bayley Scales of Infant Development‐II. Motor development was assessed using the Hammersmith Infant Neurological Examination.

Results

On univariate analysis, abnormal pulsatility index (PI) in the UA and an abnormal UA‐PI/MCA‐PI ratio (P = 0.04 and P = 0.003, respectively) as well as increases in both the DAo‐PI and in the DAo‐PI/MCA‐PI ratio (P = 0.03 and P = 0.02, respectively), were associated with adverse cognitive outcome at 2 years of age. However, when controlling for cerebral volume using multivariate analysis, the association between abnormal antenatal Doppler characteristics and cognitive outcome became statistically non‐significant, which indicated the determinant role of the volume reduction. Motor development was not associated with antenatal Doppler indices.

Conclusion

Abnormal antenatal Doppler indices are associated with adverse cognitive outcome at 2 years in VLBW infants. Our findings suggest that this association may be mediated through brain volume. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.