bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservative integration of rigid body motion by quaternion parameters with implicit constraints
Authors: Nielsen M.B. , Krenk S.
Published: July 2012

An angular momentum and energy‐conserving time integration algorithm for rigid body rotation is formulated in terms of the quaternion parameters and the corresponding four‐component conjugate momentum vector via Hamilton's equations. The introduction of an extended mass matrix leads to a symmetric set of eight state‐space equations of motion. The extra inertial parameter serves as a multiplier on the kinematic constraint, and it is demonstrated that convergence characteristics are improved by selecting this parameter somewhat larger than the inertial moments. External loads enter these equations via the set of momentum equations. Initially, the normalization of the quaternion array is introduced via a Lagrange multiplier. However, this Lagrange multiplier can be expressed explicitly in terms of the gradient of the external load potential, and elimination of the Lagrange multiplier from the final format leaves only an explicit projection applied to the external load potential gradient. An algorithm is developed by forming a finite increment of the Hamiltonian. This procedure identifies the proper selection of increments and mean values, and leads to an algorithm with conservation of momentum and energy. Implementation, conservation properties, and accuracy of the algorithm are illustrated by examples with a flying box and a spinning top. Copyright © 2012 John Wiley & Sons, Ltd.
Low interface state density and low leakage current of atomic‐layer deposited TiO2/Al2O3/sulfur‐treated GaAs
Authors: Lee Ming‐Kwei , Yen Chih‐Feng
Published: July 2012

The (NH4)2S treatment can reduce native oxides and passivate GaAs. Atomic‐layer‐deposited (ALD‐Al2O3) can further remove the residue native oxides by self‐cleaning. For the first time, native oxides can be sufficiently removed by the combination of (NH4)2S treatment and ALD‐Al2O3. Stacked with high dielectric constant TiO2 prepared by atomic‐layer deposition on a Al2O3/(NH4)2S‐treated GaAs MOS capacitor, the leakage current densities can reach 1.9 × 10−8 and 3.1 × 10−6 A/cm2 at ±2 MV/cm. The dielectric constant is 25 and the interface state density is about 2.4 × 1011 cm−2 eV−1.
Comparative ab initio calculations of SrTiO3 and CaTiO3 polar (111) surfaces
Authors: Eglitis R. I.
Published: July 2012

We present the results of calculations of SrTiO3 and CaTiO3 polar (111) surface relaxations, rumplings, energetics, optical band gaps, and charge distributions using the ab initio code CRYSTAL and a hybrid description of exchange and correlation. We have calculated the surface relaxation of the two possible terminations (Ti and SrO3 or CaO3) of the SrTiO3 and CaTiO3 (111) surfaces. According to our calculations, atoms of the first surface layer relax inwards for Ti‐, SrO3‐, and CaO3‐terminated (111) surfaces of both materials. The only exception is outward relaxation of the SrO3‐terminated SrTiO3 (111) surface upper layer Sr atom. For both Ti‐terminated SrTiO3 and CaTiO3 (111) surfaces our calculated second layer Sr and Ca metal atom inward relaxations are approximately four and two times larger than the upper layer Ti atom inward relaxation. Our calculated optical band gap for the SrO3‐ and Ti‐terminated SrTiO3, as well as for CaO3‐terminated CaTiO3 (111) surfaces, becomes smaller with respect to the bulk optical band gap. Our calculated surface energies for SrO3‐ and CaO3‐terminated SrTiO3 and CaTiO3 (111) surfaces (6.30 and 5.86 eV) are considerably larger than the surface energies for Ti‐terminated SrTiO3 and CaTiO3 (111) surfaces (4.99 and 4.18 eV). Our B3LYP calculations indicate a considerable increase of Ti–O chemical bond covalency near the SrTiO3 and CaTiO3 (111) surface (+0.098e and +0.094e) relative to the SrTiO3 and CaTiO3 bulk (+0.088e and +0.084e).
State estimation for two‐dimensional complex networks with randomly occurring nonlinearities and randomly varying sensor delays
Authors: Liang Jinling , Wang Zidong , Liu Yurong , Liu Xiaohui
Published: July 2012

This paper is concerned with the state estimation problem for two‐dimensional (2D) complex networks with randomly occurring nonlinearities and randomly varying sensor delays. To describe the fact that measurement delays may occur in a probabilistic way, the randomly varying sensor delays are introduced in the delayed sensor measurements. The randomly occurring nonlinearity, on the other hand, is included to account for the phenomenon of nonlinear disturbances appearing in a random fashion that is governed by a Bernoulli distributed white sequence with known conditional probability. The stochastic Brownian motions are also considered, which enter into not only the coupling terms of the complex networks but also the measurements of the output systems. Through available actual network measurements, a state estimator is designed to estimate the true states of the considered 2D complex networks. By utilizing an energy‐like function, the Kronecker product and some stochastic analysis techniques, several sufficient criteria are established in terms of matrix inequalities under which the 2D estimation error dynamics is globally asymptotically stable in the mean square. Furthermore, the explicit expression of the estimator gains is also characterized. Finally, a numerical example is provided to demonstrate the effectiveness of the design method proposed in this paper. Copyright © 2012 John Wiley & Sons, Ltd.
ASSESSING IMPACTS OF DAM OPERATIONS—INTERDISCIPLINARY APPROACHES FOR SUSTAINABLE REGULATED RIVER MANAGEMENT
Authors: Bruno M. C. , Siviglia A.
Published: July 2012

A special session of the European Geosciences Union General Assembly held in Vienna on 2–7 May 2010 was dedicated to the assessment of the impacts of hydropeaking, definition and implementation of environmental flows, implementation of experimental releases and flushing floods and proposal of mitigation measures, including dam removal and dam re‐operation. This special issue contributes to the understanding of consequences of dam operations, promoting interdisciplinary works in the ecohydrology field and stimulating scientific exchange between ecologists, hydrologists, geomorphologists, engineers and end‐users to develop a unified view of the problems of flow regulation below dams. Copyright © 2012 John Wiley & Sons, Ltd.
The impact of random‐effect misspecification on percentile estimation for longitudinal growth data
Authors: Cheon Kyeongmi , Albert Paul S. , Zhang Zhiwei
Published: July 2012

Identifying unusual growth‐related measurements or longitudinal patterns in growth is often the focus in fetal and pediatric medicine. For example, the goal of the ongoing National Fetal Growth Study is to develop both cross‐sectional and longitudinal reference curves for ultrasound fetal growth measurements that can be used for this purpose. Current methodology for estimating cross‐sectional and longitudinal reference curves relies mainly on the linear mixed model. The focus of this paper is on examining the robustness of percentile estimation to the assumptions with respect to the Gaussian random‐effect assumption implicitly made in the standard linear mixed model. We also examine a random‐effects distribution based on mixtures of normals and compare the two approaches under both correct and misspecified random‐effects distributions. In general, we find that the standard linear mixed model is relatively robust for cross‐sectional percentile estimation but less robust for longitudinal or ‘personalized’ reference curves based on the conditional distribution given prior ultrasound measurements. The methodology is illustrated with data from a longitudinal fetal growth study. Published 2012. This article is a US Government work and is in the public domain in the USA.
Jointly modeling the relationship between longitudinal and survival data subject to left truncation with applications to cystic fibrosis
Authors: Piccorelli Annalisa V. , Schluchter Mark D.
Published: July 2012

Numerous methods for joint analysis of longitudinal measures of a continuous outcome y and a time to event outcome T have recently been developed either to focus on the longitudinal data y while correcting for nonignorable dropout, to predict the survival outcome T using the longitudinal data y, or to examine the relationship between y and T. The motivating problem for our work is in joint modeling of the serial measurements of pulmonary function (FEV1% predicted) and survival in cystic fibrosis (CF) patients using registry data. Within the CF registry data, an additional complexity is that not all patients have been followed from birth; therefore, some patients have delayed entry into the study while others may have been missed completely, giving rise to a left truncated distribution. This paper shows in joint modeling situations where y and T are not independent, that it is necessary to account for this left truncation to obtain valid parameter estimates related to both survival and the longitudinal marker. We assume a linear random effects model for FEV1% predicted, where the random intercept and slope of FEV1% predicted, along with a specified transformation of the age at death follow a trivariate normal distribution. We develop an expectation‐maximization algorithm for maximum likelihood estimation of parameters, which takes left truncation and right censoring of survival times into account. The methods are illustrated using simulation studies and using data from CF patients in a registry followed at Rainbow Babies and Children's Hospital, Cleveland, OH. Copyright © 2012 John Wiley & Sons, Ltd.
The consequences of “school improvement”: Examining the association between two standardized assessments measuring school improvement and student science achievement
Authors: Maltese Adam V. , Hochbein Craig D.
Published: July 2012

For more than half a century concerns about the ability of American students to compete in a global workplace focused policymakers' attention on improving school performance generally, and student achievement in science, technology, engineering, and mathematics (STEM) specifically. In its most recent form—No Child Left Behind—there is evidence this focus led to a repurposing of instructional time to dedicate more attention to tested subjects. While this meant a narrowing of the curriculum to focus on English and mathematics at the elementary level, the effects on high school curricula have been less clear and generally absent from the research literature. In this study, we sought to explore the relationship between school improvement efforts and student achievement in science and thus explore the intersection of school reform and STEM policies. We used school‐level data on state standardized test scores in English and math to identify schools as either improving or declining over three consecutive years. We then compared the science achievement of students from these schools as measured by the ACT Science exams. Our findings from three consecutive cohorts, including thousands of high school students who attended 12th grade in 2008, 2009, and 2010 indicate that students attending improving schools identified by state administered standardized tests generally performed no better on a widely administered college entrance exam with tests in science, math and English. In 2010, students from schools identified as improving in English scored nearly one‐half of a point lower than their peers from declining schools on both the ACT Science and Math exams. We discuss various interpretations and implications of these results and suggest areas for future research. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 804–830, 2012
Simulating the dynamics of wind turbine blades: part I, model development and verification
Authors: Mollineaux Mark G. , Van Buren Kendra L. , Hemez François M. , Atamturktur Sezer
Published: July 2012

In the state of the art of modeling and simulation of wind turbines, verification and validation (V&V) is a somewhat underdeveloped field. The purpose of this paper is to spotlight the process of a completely integrated V&V procedure, as it is applied to a wind turbine blade. The novelty, besides illustrating the application of V&V to blade modeling, is to challenge the conventional separation between verification and validation activities. First, simple closed‐form solutions for bending stress, torsional stress and mode shapes of a hollow cylinder are derived analytically to verify the ANSYS finite element software. Shell‐281 elements are used to approximate these closed‐form solutions and demonstrate that the software runs properly. The grid convergence index is used to quantify the degree of numerical uncertainty that results. Next, model development and verification activities are applied to the CX‐100 blade designed at the Sandia National Laboratories. A three‐dimensional model is developed based on the actual geometry of the CX‐100 blade. For simplicity, the model assumes smeared cross sections with uniform, isotropic material properties. Solution verification is performed to quantify the numerical uncertainty due to mesh discretization of the finite element model. The mesh refinement study provides evidence that the model leads to numerical solutions located in the regime of asymptotic convergence. We depart from the conventional V&V paradigm by proposing that the level of mesh discretization should be based on an assessment of experimental variability. Instead of choosing the mesh size ‘in a vacuum’, it is selected such that the overall numerical uncertainty caused by truncation effects is similar to, or smaller than, the test‐to‐test variability. This rationale guarantees that predictions are sufficiently accurate relative to the level of uncertainty with which physical tests can be replicated. Part II of this work highlights the V&V steps implemented to quantify sensitivities of the model and further quantify the prediction uncertainty caused by our imperfect knowledge of the idealized material description. Copyright © 2012 John Wiley & Sons, Ltd.
Beam-helicity and beam-charge asymmetries associated with deeply virtual Compton scattering on the unpolarised proton
Authors:   The HERMES Collaboration, Airapetian A. , Akopov N. , Akopov Z. , Aschenauer E. C. , Augustyniak W. , Avakian R. , Avetissian A. , Avetisyan E. , Blok H. P. , Borissov A. , Bowles J. , Bryzgalov V. , Burns J. , Capiluppi M. , Capitani G. P. , Cisbani E. , Ciullo G. , Contalbrigo M. , Dalpiaz P. F. , Deconinck W. , De Leo R. , De Nardo L. , De Sanctis E. , Diefenthaler M. , Di Nezza P. , Düren M. , Ehrenfried M. , Elbakian G. , Ellinghaus F. , Fabbri R. , Fantoni A. , Felawka L. , Frullani S. , Gabbert D. , Gapienko G. , Gapienko V. , Garibaldi F. , Gavrilov G. , Giordano F. , Gliske S. , Golembiovskaya M. , Hadjidakis C. , Hartig M. , Hasch D. , Hoek M. , Holler Y. , Imazu Y. , Jackson H. E. , Jo H. S. , Kaiser R. , Karyan G. , Keri T. , Kinney E. , Kisselev A. , Kobayashi N. , Korotkov V. , Kozlov V. , Kravchenko P. , Krivokhijine V. G. , Lagamba L. , Lapikás L. , Lehmann I. , Lenisa P. , Lorenzon W. , Ma B.-Q. , Mahon D. , Makins N. C. R. , Manaenkov S. I. , Manfré L. , Mao Y. , Marianski B. , de la Ossa A. Martinez , Marukyan H. , Miller C. A. , Miyachi Y. , Movsisyan A. , Muccifora V. , Murray M. , Mussgiller A. , Nappi E. , Naryshkin Y. , Nass A. , Nowak W.-D. , Pappalardo L.L. , Perez-Benito R. , Petrosyan A. , Raithel M. , Reimer P. E. , Reolon A. R. , Riedl C. , Rith K. , Rosner G. , Rostomyan A. , Rubin J. , Ryckbosch D. , Salomatin Y. , Sanftl F. , Schäfer A. , Schnell G. , Schüler K. P. , Seitz B. , Shibata T.-A. , Shutov V. , Stancari M. , Statera M. , Steffens E. , Steijger J. J. M. , Stewart J. , Taroian S. , Terkulov A. , Truty R. , Trzcinski A. , Tytgat M. , Van Haarlem Y. , Van Hulse C. , Veretennikov D. , Vikhrov V. , Vilardi I. , Wang S. , Yaschenko S. , Ye Z. , Yen S. , Yu W. , Zagrebelnyy V. , Zeiler D. , Zihlmann B. , Zupranski P.
Published: July 2012

Abstract

Beam-helicity and beam-charge asymmetries in the hard exclusive leptoproduction of real photons from an unpolarised hydrogen target by a 27.6 GeV lepton beam are extracted from the Hermes data set of 2006-2007 using a missing-mass event selection technique. The asymmetry amplitudes extracted from this data set are more precise than those extracted from the earlier data set of 1996-2005 previously analysed in the same manner by Hermes. The results from the two data sets are compatible with each other. Results from these combined data sets are extracted and constitute the most precise asymmetry amplitude measurements made in the Hermes kinematic region using a missing-mass event selection technique.
Composite octet searches with jet substructure
Authors: Bai Yang , Shelton Jessie
Published: July 2012

Abstract

Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new states for the case of QCD octet mesons, considering both two gluon and two b-jet decay modes for the pseudoscalar mesons. We develop both a simple dijet search using only the jet mass and a more sophisticated jet substructure analysis, both of which can discover the composite octets in a dijet-like signature. The reach depends on the mass hierarchy between the vector and pseudoscalar mesons. We find that for the pseudoscalar-to-vector meson mass ratio below approximately 0.2 a simple dijet analysis with only the jet mass variable provides the best discovery limit; for a ratio between 0.2 and the QCD-like value of 0.3, the full jet substructure analysis has the best discovery potential; for a ratio above approximately 0.3, the standard four-jet analysis is more suitable.
Impact-parameter dependent nuclear parton distribution functions: EPS09s and EKS98s and their applications in nuclear hard processes
Authors: Helenius Ilkka , Eskola Kari J. , Honkanen Heli , Salgado Carlos A.
Published: July 2012

Abstract

We determine the spatial (impact parameter) dependence of nuclear parton distribution functions (nPDFs) using the A-dependence of the spatially independent (averaged) global fits EPS09 and EKS98. We work under the assumption that the spatial dependence can be formulated as a power series of the nuclear thickness functions T

A
. To reproduce the A-dependence over the entire x range we need terms up to [T

A
]4. As an outcome, we release two sets, EPS09s (LO, NLO, error sets) and EKS98s, of spatially dependent nPDFs for public use. We also discuss the implementation of these into the existing calculations. With our results, the centrality dependence of nuclear hard-process observables can be studied consistently with the globally fitted nPDFs for the first time. As an application, we first calculate the LO nuclear modification factor
$ R_{{AA}}^{{1{\text{jet}}}} $
for primary partonic-jet production in different centrality classes in Au+Au collisions at RHIC and Pb+Pb collisions at LHC. Also the corresponding central-to-peripheral ratios
$ R_{{CP}}^{{1{\text{jet}}}} $
are studied. We also calculate the LO and NLO nuclear modification factors for single inclusive neutral pion production,
$ R_{\text{dAu}}^{{{\pi^0}}} $
, at mid- and forward rapidities in different centrality classes in d+Au collisions at RHIC. In particular, we show that our results are compatible with the PHENIX mid-rapidity data within the overall normalization uncertainties given by the experiment. Finally, we show our predictions for the corresponding modifications
$ R_{\text{pPb}}^{{{\pi^0}}} $
in the forthcoming p+Pb collisions at LHC.
Low Rates of African American Participation in Genetic Counseling and Testing for BRCA1/2 Mutations: Racial Disparities or Just a Difference?
Authors: Halbert Chanita Hughes , Kessler Lisa , Collier Aliya , Weathers Benita , Stopfer Jill , Domchek Susan , McDonald Jasmine A.
Published: July 2012

Low rates of genetic counseling among African American women have generated concerns about disparities; however, to the extent that women's decisions to accept or decline counseling are consistent with their values, then lower participation may reflect preferences and not disparities. We evaluated the extent to which women were satisfied with their decision about participating in genetic counseling for BRCA1/2 mutations and identified variables that were associated significantly with satisfaction. Prospective study of decision satisfaction with 135 African American women who had a minimum 5% prior probability of having a BRCA1/2 mutation. Decision satisfaction was evaluated one month after women were offered participation in genetic counseling using a structured questionnaire. Women were satisfied with their participation decision; more than 80% reported that their decision was consistent with their family values. However, women who declined pre‐test counseling had significantly lower satisfaction scores. Our findings highlight the importance ensuring that racial differences that are due to preferences and values are not misclassified as disparities in order to identify and address the root causes of disparate treatment.
Quand la contraception se décline au masculin : un processus de sensibilisation et d’appropriation sous contrainte
Authors: Desjeux C.
Published: July 2012

Les représentations collectives véhiculent l’image d’hommes irresponsables dans le domaine de la contraception. Cependant, cette perception tend à occulter une partie des comportements des hommes qui prennent activement part dans la contraception. En effet, face à une demande féminine, une partie des hommes s’inscrivent dans une logique de soutien et de partage des responsabilités contraceptives. Cette position s’inscrit dans un double processus. D’une part, il est activé par une dynamique de sensibilisation qui passe par les femmes et qui permet de construire une image positive quant à la participation des hommes à la contraception. D’autre part, la mise en pratique de ce type de méthode demande une phase d’appropriation et de réflexivité. Il s’agit alors de repenser la contraception, non seulement par rapport aux femmes, mais aussi et surtout par rapport à soi. Ainsi, nous verrons que les hommes ont différents degrés d’engagement contraceptif.
Les approches épididymaires de la contraception masculine
Authors: Drevet J. -R.
Published: July 2012

L’offre en matière de moyens contraceptifs masculins est limitée et, en particulier, à ce jour il n’existe pas de contraception hormonale masculine sur le marché. L’épididyme, dans lequel les spermatozoïdes acquièrent leurs capacités fécondantes et où ils sont stockés, s’avère être un site intéressant à cibler. Cette revue vise à présenter de façon synthétique les quelques pistes prometteuses qui ont émergé ces dernières années.
Carbondioxide Gating in Silk Cocoon
Authors: Roy Manas , Meena Sunil Kumar , Kusurkar Tejas Sanjeev , Singh Sushil Kumar , Sethy Niroj Kumar , Bhargava Kalpana , Sarkar Sabyasachi , Das Mainak
Published: July 2012

Silk is the generic name given to the fibrous proteins spun by a number of arthropods. During metamorphosis, the larva of the silk producing arthropods excrete silk-fiber from its mouth and spun it around the body to form a protective structure called cocoon. An adult moth emerges out from the cocoon after the dormant phase (pupal phase) varying from 2 weeks to 9 months. It is intriguing how CO2/O2 and ambient temperature are regulated inside the cocoon during the development of the pupa. Here we show that the cocoon membrane is asymmetric, it allows preferential gating of CO2 from inside to outside and it regulates a physiological temperature inside the cocoon irrespective of the surrounding environment temperature. We demonstrate that under simulating CO2 rich external environment, the CO2 does not diffuse inside the cocoon. Whereas, when CO2 was injected inside the cocoon, it diffuses out in 20 s, indicating gating of CO2 from inside to outside the membrane. Removal of the calcium oxalate hydrate crystals which are naturally present on the outer surface of the cocoon affected the complete blockade of CO2 flow from outside to inside suggesting its role to trap most of the CO2 as hydrogen bonded bicarbonate on the surface. The weaved silk of the cocoon worked as the second barrier to prevent residual CO2 passage. Furthermore, we show that under two extreme natural temperature regime of 5 and 50 °C, a temperature of 25 and 34 °C respectively were maintained inside the cocoons. Our results demonstrate, how CO2 gating and thermoregulation helps in maintaining an ambient atmosphere inside the cocoon for the growth of pupa. Such natural architectural control of gas and temperature regulation could be helpful in developing energy saving structures and gas filters.
Roger Layton and the Early History of Marketing at the University of New South Wales
Authors: Glaser Stan
Published: July 2012

The first permanent professor of marketing at the University of New South Wales was Roger Layton. The social history of the department, as it then was, is described via sketches of the people who made up the initial cohort of academics and research students.
The complex structures of isocitrate dehydrogenase from Clostridium thermocellum and Desulfotalea psychrophila suggest a new active site locking mechanism
Authors: Leiros Hanna-Kirsti S. , Fedøy Anita-Elin , Leiros Ingar , Steen Ida Helene
Published: July 2012

Isocitrate dehydrogenase (IDH) catalyzes the oxidative NAD(P)+‐dependent decarboxylation of isocitrate into α‐ketoglutarate and CO2 and is present in organisms spanning the biological range of temperature. We have solved two crystal structures of the thermophilic Clostridium thermocellum IDH (CtIDH), a native open apo CtIDH to 2.35 Å and a quaternary complex of CtIDH with NADP+, isocitrate and Mg2+ to 2.5 Å. To compare to these a quaternary complex structure of the psychrophilic Desulfotalea psychrophila IDH (DpIDH) was also resolved to 1.93 Å. CtIDH and DpIDH showed similar global thermal stabilities with melting temperatures of 67.9 and 66.9 °C, respectively. CtIDH represents a typical thermophilic enzyme, with a large number of ionic interactions and hydrogen bonds per residue combined with stabilization of the N and C termini. CtIDH had a higher activity temperature optimum, and showed greater affinity for the substrates with an active site that was less thermolabile compared to DpIDH. The uncompensated negative surface charge and the enlarged methionine cluster in the hinge region both of which are important for cold activity in DpIDH, were absent in CtIDH. These structural comparisons revealed that prokaryotic IDHs in subfamily II have a unique locking mechanism involving Arg310, Asp251′ and Arg255 (CtIDH). These interactions lock the large domain to the small domain and direct NADP+ into the correct orientation, which together are important for NADP+ selectivity.
The clinical and electroanatomical characteristics of paroxysmal lone atrial fibrillation
Authors: Tuan Ta‐Chuan , Chang Shih‐Lin , Lin Yenn‐Jiang , Hu Yu‐Feng , Lo Li‐Wei , Chao Tze‐Fan , Chung Fa‐Po , Tai Ching‐Tai , Chen Shih‐Ann
Published: July 2012

Introduction

Lone atrial fibrillation (AF) is defined as AF occurring in the absence of any other cardiovascular disease. The prognosis of patients with lone AF varies in previous studies, and the clinical and electroanatomical characteristics of lone AF are unclear. The purpose of this study was to investigate the clinical characteristics of lone AF.

Methods

This study included 203 patients (52±13 years old, 144 males) that underwent circumferential pulmonary vein isolation (CPVI) for paroxysmal AF. The mean voltage and total activation time of the individual atria were obtained by using a NavX mapping system and were compared for patients with lone and non‐lone AF. Several parameters, including the age, gender, AF duration, and left atrial (LA) diameter were analyzed.

Results

Compared with non‐lone AF patients, lone AF patients were significantly younger (49±13 years old vs. 58±11 years old, p<0.001) and had lower body‐mass index (BMI, 24.60±2.96 vs. 26.07±3.29, p=0.02), lesser cholesterol level (169.06±31.41 vs. 183.63±31.12, p=0.014), smaller LA diameter (35.89±4.90 vs. 40.86±4.62, p<0.001), and higher LA bipolar voltage (2.10±0.50 vs. 1.83±0.73 mV, p<0.05). Furthermore, a dramatic voltage reduction was observed for 60‐year‐old patients.

Conclusion

Patients with lone AF have unique clinical and electroanatomical characteristics.
Anti‐arrhythmic device therapy has limits in improving the prognosis of patients with cardiac amyloidosis
Authors: Kojima Toshiya , Imai Yasushi , Fujiu Katsuhito , Suzuki Takeki , Sugiyama Hiroaki , Asada Kazuo , Ajiki Kohsuke , Hayami Noriyuki , Murakawa Yuji , Nagai Ryozo
Published: July 2012

Immunoglobulin light chain (AL) amyloidosis has poor long‐term prognosis. Sudden cardiac death (SCD) is a common cause of death in patients with cardiac AL amyloidosis. Prophylactic anti‐arrhythmic device therapy has been suggested as an option to reduce this risk. We address this issue by reviewing 4 cases of cardiac AL amyloidosis with anti‐arrhythmic device therapy. One patient who had an atrioventricular block underwent pacemaker implantation, and the other 3 patients received implantable cardioverter‐defibrillator (ICD) implantation for ventricular arrhythmia. All of the 3 ICD implantation cases received appropriate shock therapy for ventricular arrhythmia in the early stage. However, they soon died due to pulseless electrical activity (PEA) or severe heart failure. The median survival period for our 4 cases was as short as 12.3 months. In particular, the 3 patients who required ICD had worse prognoses. Thus, ICD implantation therapy for chemotherapy‐resistant cardiac AL amyloidosis may prevent SCD but may not prolong the patient's survival. There are no arguments against pacemaker implantation for cardiac amyloidosis with conduction disturbance; however, the clinical benefit of ICD indication for ventricular tachyarrhythmia is limited. Further extensive clinical research should be performed to definitively determine the effects of ICD implantation on cardiac AL amyloidosis.
Catheter ablation of three macroreentrant atrial tachycardias after surgical repair of Double‐Outlet Right Ventricle
Authors: Wada Tadashi , Watanabe Atsuyuki , Koide Yuji , Kagawa Kenzo , Naito Yoichiro , Tsushima Sho , Toda Hironobu , Kawada Satoshi , Terasaka Ritsuko , Nakahama Makoto , Nagase Satoshi
Published: July 2012

A 54‐year‐old man with a surgically repaired double‐outlet right ventricle (DORV) presented with palpitations and worsening right heart failure. His 12‐lead ECG showed atrial tachycardia (AT) with an atrial cycle length (CL) of 300 ms and an inverted saw‐tooth F‐wave pattern in the inferior leads II, III, and aVF typical of atrial flutter. Electrophysiological study and radiofrequency catheter ablation were performed. A total of 3 sustained ATs (AT1–AT3) were induced. Using the electroanatomical mapping system, CARTO3, and conventional mapping techniques, the ATs were identified as macroreentrant tachycardias circling around an incisional line on the free wall of the right atrium (AT1), the tricuspid annulus (AT2), and low voltage area in the lateral wall including the right septum (AT3). Accuracy of CARTO3 in three‐dimensional reconstruction was sufficient to elucidate anatomical features (including catheter sites, incision, and low voltage areas) and macroreentrant circuits. However, conventional mapping techniques were also necessary to identify the mechanism of the tachycardias, and therefore to eliminate all of them successfully. This case demonstrates that the use of combined conventional and electroanatomical mapping techniques, such as CARTO3, can be helpful in identifying the critical isthmus for catheter ablation of macroreentrant AT in patients with surgically corrected congenital heart disease (CHD).
A case of an infant with bundle branch reentrant ventricular tachycardia
Authors: Fujii Satoki , Tasaka Hiroshi , Okamoto Yoji , Takahashi Katsuyuki , Kadota Kazushige , Mitsudo Kazuaki , Waki Kenji , Aragaki Yoshio
Published: July 2012

Catheter ablation of the right bundle branch was performed on an 11‐month‐old infant for the treatment of drug‐resistant bundle branch reentrant ventricular tachycardia. The occurrence of right bundle branch block could not be used as an endpoint of treatment because the patient had presented with incomplete right bundle branch block pattern during sinus rhythm. We performed ablation of the right bundle branch and utilized changes of duration and morphology of the QRS complex as indicators. Eight years have passed with no development of any atrioventricular block or tachycardia episode.
A case of thoracoscopy‐guided lead extraction with an excimer laser sheath
Authors: Ohmori Hiroya , Nitta Takashi , Sakamoto Shun‐ichiro , Haraguchi Shuji , Shimizu Kazuo , Ochi Masami
Published: July 2012

The patient was a 29‐year‐old male who had been diagnosed with transposition of the great arteries with an intact ventricular septum. At the age of 6 months, he underwent a Senning operation. At the age of 10 years, a dual‐chamber (DDD) pacemaker was implanted via the right subclavian vein for the treatment of sick sinus syndrome. At the age of 25, the generator was removed due to a lead fracture, and a new pacemaker was implanted via the left subclavian vein, leaving the previous lead in the right subclavian vein. Later, the patient developed pain in the right precordium, cramping of the major pectoral muscle, and non‐sustained ventricular tachycardia, suggesting physical stimulation of the left ventricle (functional right ventricle) by the residual leads. Therefore, lead extraction using an excimer laser sheath was planned. However, the leads adhered strongly to the vessels, and extraction was considered to involve a high risk of injury to the blood vessels, particularly the superior vena cava (SVC). We inserted a thoracoscope via the right precordial third intercostal space and observed the SVC via the thoracic cavity in order to immediately detect any complications. Using this approach, it was possible to extract the lead safely with an excimer laser sheath.
Postural change‐dependent T‐wave oversensing resulting in the administration of inappropriate shocks
Authors: Hirai Yukoh , Nakano Yukiko , Ogi Hiroshi , Kihara Yasuki
Published: July 2012

A 68‐year‐old man with dilated cardiomyopathy (left ventricular ejection fraction, 15%) and nonsustained ventricular tachycardia received an implantable cardioverter defibrillator. Even though his cardiac status had greatly improved 2 years later after β‐blocker therapy, he experienced 2 episodes of sudden shock when he was squatting in a bathroom without any preceding symptoms. His serum electrolyte and plasma glucose levels were normal. Interrogation of the device revealed that the shock was caused by sinus tachycardia and T‐wave oversensing. A number of episodes of nonsustained ventricular tachycardia due to T‐wave oversensing was also recorded. Follow‐up interrogation of the device with the patient in the supine position could not reproduce the T‐wave oversensing. We were able to elicit T‐wave oversensing only after reproduction of the patient's clinical situation using isoproterenol and postural changes (i.e., sinus tachycardia and squatting). This case suggests that sudden increases in nonsustained ventricular tachycardia events may be caused by T‐wave oversensing, and postural changes should be taken into consideration in such situations.
Current overview of the genetic background of atrial fibrillation: Possible therapeutic gene targets for the treatment of atrial fibrillation
Authors: Furukawa Tetsushi , Ebana Yusuke
Published: July 2012

Atrial fibrillation (AF) is the most common arrhythmia. Although AF is known to develop during the course of various cardiac pathological conditions, including valvular heart diseases, congestive heart failure, and hypertension, recent clinical data implicate the additional contribution of genetic factors in the pathogenesis of AF. A familial form of AF has been noted, and 8 loci and 6 responsible genes have been identified. In non‐familial AF, genetic risks were originally investigated by the candidate gene approach, and recently by genome‐wide association studies (GWASs). GWASs executed in other countries have identified 3 loci: 4q25 near Pitx2, 1q21 in KCNN3, and 16q22 in ZFHX3. Several AF‐associated SNPs in 4q25 are also associated with the recurrence rate of AF after catheter pulmonary vein isolation. This review will discuss the genetic underpinnings of AF, in both familial AF and non‐familial AF.
Smoking history and underlying lung disease are associated with poor outcome in patients developing interstitial pneumonia during low‐dose amiodarone therapy
Authors: Nozoe Masatsugu , Honda Toshihiro , Honda Mitsuko , Ichikado Kazuya , Suga Moritaka , Nakao Koichi
Published: July 2012

Background

Amiodarone is a useful antiarrhythmic drug, especially in patients with serious heart diseases, but amiodarone‐induced interstitial pneumonia (AMD‐IP) is sometimes lethal.

Methods and results

We retrospectively analyzed the clinical characteristics of 280 patients who were treated with daily oral amiodarone. Among the patients, 29 (10.2%) developed AMD‐IP during the follow‐up period of 66.0±38.2 months. The average dose of amiodarone in the AMD‐IP group (173±10 mg) was significantly higher than that in the non‐AMD‐IP group (150±3 mg). The prevalence of smoking history (AMD‐IP group: 70.0%; non‐AMD‐IP group: 42.2%; P<0.01) and underlying lung disease (AMD‐IP group: 17.2%; non‐AMD‐IP group: 5.6%; P<0.05) was significantly higher in the AMD‐IP group than in the non‐AMD‐IP group. Furthermore, multiple stepwise logistic regression analysis demonstrated that smoking history was an independent predictor of AMD‐IP (OR, 3.56; 95% CI, 1.08–10.23; P<0.001). Among patients who developed AMD‐IP, those with chronic obstructive pulmonary disease (COPD) had a higher relapse rate and a worse prognosis.

Conclusions

During the mean follow‐up period of >5 years, 10.2% of patients receiving low‐dose amiodarone therapy developed AMD‐IP. Higher maintenance doses, smoking history, and preexisting lung disease were related to the development of AMD‐IP. The AMD‐IP patients with COPD had a poor prognosis.
New therapeutic target for the non‐electrophysiological signaling in atrial fibrosis and fibrillation such as inflammation
Authors: Takahashi Naohiko , Kume Osamu , Wakisaka Osamu , Teshima Yasushi , Hara Masahide , Saikawa Tetsunori
Published: July 2012

We have experimentally established appropriate models of atrial fibrillation (AF) with atrial interstitial fibrosis. Two approaches were adopted. Firstly, left atrial fibrosis was induced by continuous infusion of angiotensin II (AII). In an electrophysiological study using isolated perfused heart, AF was easily induced following AII treatment. Repeated whole‐body hyperthermia led to the induction of heat‐shock protein 72, which resulted in attenuation of AII‐induced left atrial fibrosis and suppression of AF inducibility. Secondly, atrial fibrosis was induced by pressure overload by abdominal aortic constriction (AAC). AAC enhanced left atrial expression of monocyte chemoattractant protein‐1 and activity of matrix metalloproteinase‐9. Treatment with pioglitazone, a peroxisome proliferator‐activated receptor‐γ agonist, resulted in attenuation of pressure overload‐induced left atrial fibrosis and suppression of AF inducibility. In the same AAC model, the effects of candesartan on gap junction remodeling were investigated. Connexin 43 (Cx43) of the left atria was firmly located in the intercalated disks in control rats. A progressive redistribution of Cx43 from the intercalated disk to the lateral surface (lateralization) was observed in AAC rats. Candesartan prevented left Cx43 lateralization. Thus, heat‐shock proteins, pioglitazone, and candesartan could be novel therapeutic approaches to prevent atrial fibrosis and AF.
Outcomes after stepwise ablation for persistent atrial fibrillation in patients with heart failure
Authors: Takahashi Yoshihide , Takahashi Atsushi , Kuwahara Taishi , Okubo Kenji , Takagi Katsumasa , Watari Yuji , Takigawa Masateru , Nakashima Emiko , Kawaguchi Naohiko , Yamao Kazuya , Hirao Kenzo , Isobe Mitsuaki
Published: July 2012

Background

There is limited data regarding the outcomes after stepwise ablation for persistent atrial fibrillation (AF) in patients with heart failure (HF).

Methods and results

Patients without structural heart disease undergoing stepwise ablation for persistent AF (continuous AF≤1 year) were studied (n=108; age, 61±10 years) and 32 patients had a history of HF. The HF patients were further grouped on the basis of left ventricular ejection fraction (LVEF)≤45% (n=15) and >45% (n=17). During a median follow‐up period of 2.2 years, repeated ablations were necessary in 65 patients. The proportion of patients that were arrhythmia free 1 year after the last ablation was 67% in patients with LVEF≤45%, 86% in LVEF>45%, and 91% in no HF (p=0.0009). In patients with LVEF≤45%, the AF burden was reduced to less than one paroxysmal episode per month, and patients with and without recurrences both showed significant increases in LVEF over the follow‐up period (38±7% to 60±10% and 37±6% to 53±10%, respectively).

Conclusions

HF patients with LVEF≤45% had lower chances to remain free from arrhythmias after stepwise ablation for persistent AF than those with LVEF>45%. Nevertheless, LVEF also improved in patients with recurrences, reflecting the observed reduction in AF burden and emphasizing the benefits of ablation.
Catheter ablation of atrial fibrillation guided by complex fractionated atrial electrogram mapping with or without pulmonary vein isolation
Authors: Oketani Naoya , Ichiki Hitoshi , Iriki Yasuhisa , Okui Hideki , Ryuichi Maenosono , Fuminori Namino , Ninomiya Yuichi , Ishida Sanemasa , Hamasaki Shuichi , Tei Chuwa
Published: July 2012

Pulmonary vein isolation (PVI) was the main strategy for catheter ablation of atrial fibrillation (AF) until a remarkable report was published by Nademanee et al. in 2004. The ablation targeting complex fractionated atrial electrograms (CFAE) achieved not only a high rate of AF termination but also excellent outcomes in both paroxysmal and persistent AF without isolating pulmonary veins. AF is thought to be caused by random or spiral reentry, as the fixed circuit to maintain AF may not exist, although the CFAE‐guided ablation strategy is based on the theory that AF is not entirely random. CFAEs play an important role in identifying AF substrates, and have temporal and spatial stability, thus representing desirable targets for AF ablation; however, CFAE‐guided ablation has not been fully replicated by others. In reports showing that CFAE ablation did not yield a good outcome either alone or combined with PVI, the AF termination rates were extremely low. Although AF termination is not mandatory in CFAE‐ablation, terminating AF in the majority of patients appears to be necessary to yield good outcomes; therefore, this review will discuss AF ablation guided by CFAE with or without PVI, with particular emphasis given to practical aspects of achieving AF termination.
Waist circumference, body mass index, serum uric acid, blood sugar, and triglyceride levels are important risk factors for abnormal liver function tests in the Taiwanese population
Authors: Hsieh Meng‐Hsuan , Lin Wen‐Yi , Chien Hsu‐Han , Chien Li‐Ho , Huang Chao‐Kuan , Yang Jeng‐Fu , Chang Ning‐Chia , Huang Chung‐Feng , Wang Chao‐Ling , Chuang Wan‐Long , Yu Ming‐Lung , Dai Chia‐Yen , Ho Chi‐Kung
Published: July 2012

Several studies have found that metabolic syndrome and uric acid level are related to abnormal liver function test results. The aim of this study was to explore the associations of risk factors [including blood pressure, blood sugar, total cholesterol, triglyceride, uric acid, waist circumference and body mass index (BMI) measurements] with abnormal liver function in the Taiwanese population.In total, 11,411 Taiwanese adults were enrolled in this study. Blood pressure was assessed according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure criteria, fasting blood sugar level according to the Bureau of Health Promotion, Department of Health, R.O.C., criteria, total cholesterol and triglyceride levels according to the Third Report of the National Cholesterol Education Program Adult Treatment Panel III criteria, BMI according to the Asia‐Pacific criteria, and waist circumference according to the Revised Diagnostic Criteria of Metabolic Syndrome in Taiwan. The prevalence of a past history of hypertension and diabetes mellitus was 17.7% and 6.5%, respectively, and the rates of abnormal measurements of blood pressure, BMI, waist circumference, fasting blood sugar, triglyceride, total cholesterol, uric acid (male/female), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were 76.2%, 67.6%, 40.0%, 28.6%, 30.6%, 57.3%, 37.9%/21.9%, 14.6% and 21.3%, respectively. Multivariate analysis showed that waist circumference, BMI, serum uric acid, blood sugar, and triglyceride levels were related to abnormal AST and ALT (p < 0.05), but the odds ratio for waist circumference was larger than that for BMI. In conclusion, waist circumference, BMI, serum uric acid, blood sugar, and triglyceride levels are important risk factors for abnormal AST and ALT readings in Taiwanese adults. Waist circumference might be a better indicator of risk of abnormal liver function than BMI.
Prescriptions for angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers and monitoring of serum creatinine and potassium in patients with chronic kidney disease
Authors: Wang Pei‐Tzu , Huang Yaw‐Bin , Lin Ming‐Yen , Chuang Pei‐Fen , Hwang Shang‐Jyh
Published: July 2012

Angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs) are commonly used in patients with chronic kidney disease (CKD). We studied the status of ACEI/ARB prescriptions and serum creatinine (Scr) and potassium monitoring in CKD patients. A retrospective observational study was conducted on patients who had at least two sets of Scr data at outpatient visit. Estimated glomerular filtration rate (eGFR) based on the second Scr value was calculated using the Modification of Diet in Renal Disease four‐variable equation. CKD was defined and staged according to the National Kidney Foundation Disease Outcomes Quality Initiative Guideline. Patients with diabetes and/or hypertension with an eGFR over 60 mL/min/1.73 m2 and without proteinuria were defined as the CKD‐at‐risk group. The percentages and factors associated with ACEI/ARB prescription and Scr and potassium monitoring were calculated and analyzed by logistic regression. Among the 5714 subjects included, ACEIs/ARBs were prescribed to over 50% of patients in the CKD‐at‐risk group and in CKD stages 1–5. After adjusting for age, sex, potassium level, eGFR, and co‐morbidities, the odds ratios for prescriptions of ACEIs/ARBs were 1.66 [95% confidence interval (CI) 1.44–1.91, p < 0.001) and 2.80 (95% CI 2.12–3.70, p < 0.001) in CKD stage 3, and stages 4 and 5, respectively, compared with the reference group (eGFR≥60 mL/min/1.73 m2). During the year of ACEI/ARB treatment, Scr was monitored in 91.6% of ACEI/ARB‐treated patients, while potassium was monitored in only 38.1%. Renal function status was the independent factor for monitoring of Scr and potassium. In conclusion, prescription of ACEIs/ARBs was common in all stages of CKD. Most patients underwent Scr monitoring, but potassium monitoring was less frequent, and this should be improved in clinical practice.