bluuebunny/crossref_metadata_2025 huggingface dataset:
OPTICAL SIGNAL ANALYSIS AND PROCESSING OF OPTICAL IMAGING WITH STRAY LIGHT BEAMS
Authors: LIU YING , ZHOU YUANPING , WANG WEIGUO , TANG WENMING
Published: October 2010

For the optical signal analysis and processing of optical imaging with stray light beams, a new analysis method for smoothing the optical image edge and maintaining the spectrum signal well is presented in this paper. By calculating the mean gray value of the light pixel in the filter window of adaptive algorithm, we can analyze and compare the difference between the mean gray value and the current gray value with the light pixel of stray light beams, and can determine the smoothness of the optical image edge. This method can increase greatly the ability of optical image analysis and processing, and effectively reduce the false edge and the edge loss for the optical imaging with stray light beams, so that the optical image with high quality can be obtained.
ALGEBRAIC CONNECTIVITY OF WEIGHED GRAPHS UNDER SHIFTING COMPONENTS
Authors: GUAN YU , XU GUANGHUI
Published: October 2010

Integrating quadratic form of algebraic connectivity and Perron value of bottleneck matrices, we investigate how the algebraic connectivity of a connected weighted graph behaves under shifting components. Generally speaking, when shift components not containing characteristic vertex from less positive (larger negative) valuation vertices to larger positive (less negative) valuation vertices, or reduce weights of some edges, or add some new blocks, its algebraic connectivity is nonincreasing; when shift components along paths from blocks to other block closer to characteristic block (vertex), or increase weights of some edges, or delete some blocks, its algebraic connectivity is non-decreasing. Therefore, algebraic connectivity could be regarded as a measure of central tendency about blocks of a connected weighted graph with characteristic block (vertex) as its center.
APPLICATION OF VERTEX SUBSET DEGREE PRESERVING SPANNING TREES IN SENSOR NETWORKS
Authors: SANGAVAI K. , ANITHA R.
Published: October 2010

In sensor networks, it is an important task to periodically collect data from an area of interest for time-sensitive applications. The sensed data must be gathered and transmitted to a base station for further processing to meet the end-user queries. Since the network consists of low-cost nodes with limited battery power, it is a challenging task to design an efficient routing scheme that can minimize delay and offer good performance in energy efficiency, and long network lifetimes. In this paper, we propose a distance based multi-clustering in sensor networks using vertex subset degree preserving minimum spanning tree.
COMPETITIVE GROUP TESTING AND LEARNING HIDDEN VERTEX COVERS WITH MINIMUM ADAPTIVITY
Authors: DAMASCHKE PETER , MUHAMMAD AZAM SHEIKH
Published: October 2010

Suppose that we are given a set of n elements d of which have a property called defective. A group test can check for any subset, called a pool, whether it contains a defective. It is known that a nearly optimal number of O(d log (n/d)) pools in two stages (where tests within a stage are done in parallel) are sufficient, but then the searcher must know d in advance. Here we explore group testing strategies that use a nearly optimal number of pools and a few stages although d is not known beforehand. We prove a lower bound of Ω( log d/ log log d) stages and more general pools versus stages tradeoff. This is almost tight, since O( log d) stages are sufficient for a strategy with O(d log n) pools. As opposed to this negative result, we devise a randomized strategy using O(d log (n/d)) pools in three stages, with any desired success probability 1-ϵ. With some additional measures even two stages are enough. Open questions concern the optimal constant factors and practical implications. A related problem motivated by biological network analysis is to learn hidden vertex covers of a small size k in unknown graphs by edge group tests. (Does a given subset of vertices contain an edge?) We give a one-stage strategy using O(k3 log n) pools, with any parameterized algorithm for vertex cover enumeration as a decoder. During the course of this work we also provide a classification of types of randomized search strategies in general.
AVERAGE DISTANCE AND MINIMUM AVERAGE DISTANCE OF BINARY CONSTANT WEIGHT CODE AND ITS PROPERTIES
Authors: BASU MANJUSRI , PRASAD BANDHU
Published: October 2010

Let [Formula: see text] denote the average Hamming distance of a binary constant weight code C. Ai is the distance distribution of C and Bj is the transform quantity of Ai. Let β(n, M, w) denote the minimum average Hamming distance of a binary constant weight code with length n, size M, and weight w. In this paper, we have established the relation among Bj, [Formula: see text] and Ai. We also study the problem of determining β(n, M, w) and bounds of β(n, M, w) for different values of M.
MINIMUM FLOW VARIATION IN MAXIMUM FLOWS
Authors: MASOUMI M. , MOBASSERI A. M. , REZAEI A. R.
Published: October 2010

Network flows are of growing interest in both applications and theory. Given a network flow with costs and arc capacities, the classical max flow-min cost problem is to send a given amount of flow from the source vertex to the sink vertex at least cost. Among the predominant issues in this field are problems that result when the flow is going through one arc to another arc in the same direction, such as the role of compressors in gas pipeline networks or the role of transformers in electricity wide networks. Hence, in order to minimize the cost of these elements in the network, we perform applications of line-digraphs in the form of an optimization algorithm. This paper proposes a new variant of the max flow-min cost problem. Our objective is to find the smoothest max flow over a given network.
IMPROPER COLORING OF WEIGHTED GRID AND HEXAGONAL GRAPHS
Authors: BERMOND JEAN-CLAUDE , HAVET FRÉDÉRIC , HUC FLORIAN , SALES CLÁUDIA LINHARES
Published: October 2010

We study a weighted improper coloring problem motivated by a frequency allocation problem. It consists of associating to each vertex a set of p(v) (weight) distinct colors (frequencies), such that the set of vertices having a given color induces a graph of degree at most k (the case k = 0 corresponds to proper coloring). The objective is to minimize the number of colors. We propose approximation algorithms to compute such a coloring for general graphs. We apply these to obtain good approximation ratio for grid and hexagonal graphs. Furthermore we give exact results for the 2-dimensional grid and the triangular lattice when the weights are all the same.
Huffman-based code compression techniques for embedded processors
Authors: Bonny Talal , Henkel Jörg
Published: October 2010

The size of embedded software is increasing at a rapid pace. It is often challenging and time consuming to fit an amount of required software functionality within a given hardware resource budget. Code compression is a means to alleviate the problem by providing substantial savings in terms of code size. In this article we introduce a novel and efficient hardware-supported compression technique that is based on Huffman Coding. Our technique reduces the size of the generated decoding table, which takes a large portion of the memory. It combines our previous techniques, Instruction Splitting Technique and Instruction Re-encoding Technique into new one called Combined Compression Technique to improve the final compression ratio by taking advantage of both previous techniques. The instruction Splitting Technique is instruction set architecture (ISA)-independent. It splits the instructions into portions of varying size (called patterns) before Huffman coding is applied. This technique improves the final compression ratio by more than 20% compared to other known schemes based on Huffman Coding. The average compression ratios achieved using this technique are 48% and 50% for ARM and MIPS, respectively. The Instruction Re-encoding Technique is ISA-dependent. It investigates the benefits of reencoding unused bits (we call them reencodable bits) in the instruction format for a specific application to improve the compression ratio. Reencoding those bits can reduce the size of decoding tables by up to 40%. Using this technique, we improve the final compression ratios in comparison to the first technique to 46% and 45% for ARM and MIPS, respectively (including all overhead that incurs). The Combined Compression Technique improves the compression ratio to 45% and 42% for ARM and MIPS, respectively. In our compression technique, we have conducted evaluations using a representative set of applications and we have applied each technique to two major embedded processor architectures, namely ARM and MIPS.
What is parallel circuit simulation?
Authors: Li Peng
Published: October 2010

Transistor-level circuit simulation, i.e. SPICE simulation [1], is a fundamental tool for design and verification of a wide range of integrated circuits such as memories, custom digital ICs, analog, mixed-signal and RF circuits as well as digital cell library characterization. It is common for today's designers to spend days, weeks or even months of CPU time to perform expensive transistor-level circuit analysis. The simulation bottleneck significantly limits pre-silicon verification and design space exploration, contributing to long design turnaround time, suboptimal designs and even chip failures. With the advent of more complex device models and increased design complexity, high-capacity circuit simulation is strongly desirable in order to boost design productivity.
What is adaptive computing?
Authors: Henkel Joerg , Bauer Lars
Published: October 2010

Adaptive computing refers to the capability of a computing system to adapt one or more of its properties (e.g. performance) during runtime. There are diverse reasons of why it is advantageous for a computing system to adapt during runtime and there are various enabling techniques and paradigms that allow a computing system to perform such an adaptation. In the following, we limit our explanations of adaptive computing systems to the newest advances in embedded computing systems. Often, reconfigurable computing is referred to as adaptive computing. Actually, it corresponds to one of the key paradigms that along with application-specific instruction set processors enable adaptive computing. We will shortly discuss state-of-the-art in both areas.
What is DNA array?
Authors: Reda Sherief
Published: October 2010

DNA probe arrays - DNA arrays or DNA chips for short have recently emerged as one of the core genome technologies. They provide a cost-effective method for obtaining fast and accurate results in a wide range of genomic analyses, including gene expression monitoring, mutation detection, and single nucleotide polymorphism analysis (see [1] for a survey). The number of applications is growing at a high rate already covering a diversity of fields ranging from health care to environmental sciences and law enforcement.
What is stochastic computation?
Authors: Shanbhag Naresh
Published: October 2010

Stochastic computation [shan-1] is a communications-inspired [shan-2] model of computation for jointly achieving robustness and energy-efficiency in systems implemented in nanoscale processes. Emerging applications, driven by societal needs in security, health and energy [jan], tend to be media/sensory data-intensive with primary emphasis on the extraction of features/models in order to enable cognitive, detection and decision-making tasks. Stochastic computation exploits the somewhat relaxed definition of "correctness" afforded by such applications by incorporating application-awareness and statistical performance metrics (e.g., signal-to-noise ratio (SNR) and bit error-rate (BER) in communications, probability of anomaly detection in biomedical applications and others) into the design of computational platforms. Nanoscale circuit and device fabrics exhibit artifacts such as process, voltage and temperature (PVT) variations, leakage, soft errors, and noise leading to intermittent errors and hence a reliability problem. Stochastic computation matches the error statistics of the underlying circuit fabrics to the statistical performance metrics of emerging applications in order to enhance robustness by orders-of-magnitude and simultaneously achieve significant energy-efficiency. It may seem that stochastic computation may not be applicable to small class of critical applications such as those in finance/banking, flight control systems, and others whereas precise definition of correctness is mandatory. This is until one realizes that the inherent communication mechanisms in such systems are in fact stochastic in nature.
What is hardware security?
Authors: Koushanfar Farinaz , Potkonjak Miodrag
Published: October 2010

Historically, the dominant technological and application trends have had a direct impact on the key integrated circuits design metrics. In the 70s, the silicon area was a scarce and expensive commodity. Therefore, development of techniques such as hardware sharing and design simplification was of prime importance. In the 80s, the premier design metrics was the speed of computation while in the 90s, the quest for power and energy optimization emerged. Initially, the emphasis was on minimizing the switching power but the focus has gradually moved towards minimizing the leakage energy.
Energy Landscapes as a Tool to Integrate GPCR Structure, Dynamics, and Function
Authors: Deupi Xavier , Kobilka Brian K.
Published: October 2010

G protein-coupled receptors (GPCRs) are versatile signaling molecules that mediate the majority of physiological responses to hormones and neurotransmitters. Recent high-resolution structural insights into GPCR structure and dynamics are beginning to shed light on the molecular basis of this versatility. We use energy landscapes to conceptualize the link between structure and function.
Sorting It Out in Endosomes: An Emerging Concept in Renal Epithelial Cell Transport Regulation
Authors: Welling Paul A. , Weisz Ora A.
Published: October 2010

Ion and water transport by the kidney is continually adjusted in response to physiological cues. Selective endocytosis and endosomal trafficking of ion transporters are increasingly appreciated as mechanisms to acutely modulate renal function. Here, we discuss emerging paradigms in this new area of investigation.
System Integration and Its Influence on the Quality of Life of Children with Complex Needs
Authors: Thurston Sandy , Paul Louise , Ye Chenglin , Loney Patricia , Browne Dillon , Browne Gina , Wong Maria , Thabane Lehana , Rosenbaum Peter
Published: October 2010

Purpose. To explore the interactions between child and parents psychosocial factors and team integration variables that may explain improvements in physical dimensions of the PEDS QL quality of life of children with complex needs after 2 years.Methods. In this 2-year study, parents were identified by the Children's Treatment Network. Families were eligible if the child was aged 0–19 years, had physical limitations, resided in either Simcoe County or the Region of York, Ontario, and there were multiple other family needs. Regression analysis used to explore associations and interactions;n=110.Results. A child's physical quality of life was affected by interacting factors including child's behavior, parenting, and integrated care. Statistically significant interactions between team integration, processes of care, and child/parent variables highlight the complexity of the rehabilitation approach in real-life situations.Conclusions. Rehabilitation providers working with children with complex needs and their families should also address child and parent problematic behaviors. When this was the case in high integrated teams, the child's physical quality of life improved after two years.
Feedback Controller Stabilizing Vibrations of a Flexible Cable Related to an Overhead Crane
Authors: Elharfi Abdelhadi
Published: October 2010

The problem of stabilizing vibrations of flexible cable related to an overhead crane is considered. The cable vibrations are described by a hyperbolic partial differential equation (HPDE) with an update boundary condition. We provide in this paper a systematic way to derive a boundary feedback law which restores in a closed form the cable vibrations to the desired zero equilibrium. Such a control law is explicitly constructed in terms of the solution of an appropriate kernel PDE. The pursued approach combines the “backstepping method” and “semigroup theory”.
A 10-Month Physical Activity Intervention Improves Body Composition in Young Black Boys
Authors: Howe Cheryl A. , Harris Ryan A. , Gutin Bernard
Published: October 2010

Objective. To determine if a 10-month after-school physical activity (PA) intervention could prevent deleterious changes in body composition and cardiovascular (CV) fitness in young black boys.Methods. Following baseline measures, 106 boys (8–12 yrs) were randomized to either a control group or an intervention group, further divided into attenders (ATT) and nonattenders (NATT), participating in ≥60% or <60% of the intervention, respectively. The daily intervention consisted of skills development (25 min), vigorous PA (VPA, 35 min), and strengthening/stretching (20 min) components. Body composition was measured by dual-energy X-ray absorptiometry.Results. Following the intervention, the ATT exhibited an increase in moderate-to-vigorous PA and a significant reduction in BMI, fat mass, and %BF compared to the control group. A significant association among the intervention energy expenditure and changes in body composition and CV fitness was observed only in the ATT group.Conclusion. An after-school PA program of sufficient length and intensity can promote healthy changes in body composition and fitness levels in black boys who attend at least 3 days/week.
Dark Matter Halos: The Dynamical Basis of Effective Empirical Models
Authors: Lapi Andrea , Cavaliere Alfonso
Published: October 2010

We investigate the dynamical basis of the classic empirical models (specifically, Sérsic-Einasto and generalized NFW) that are widely used to describe the distributions of collisionless matter in galaxies. We submit that such a basis is provided by ourα-profiles, shown to constitute solutions of the Jeans dynamical equilibrium with physical boundary conditions. We show how to set the parameters of the empirical in terms of the dynamical models; we find the empirical models, and specifically Sérsic-Einasto, to constitute a simple and close approximation to the dynamical models. Finally, we discuss how these provide a useful baseline for assessing the impact of the small-scale dynamics that may modulate the density slope in the central galaxy regions.
Asia-Pacific Thrombosis Advisory Board consensus paper on prevention of venous thromboembolism after major orthopaedic surgery
Authors: Cohen Alexander ,   the Asia-Pacific Thrombosis Advisory Board
Published: October 2010

The incidence of postoperative venous thromboembolism (VTE) in Asian populations is generally thought to be lower than in Western populations, and the use of thromboprophylaxis after surgery is not routine. This paper is authored by the Asia-Pacific Thrombosis Advisory Board. To provide guidance on the most effective postoperative thrombo prophylaxis management, this paper reviews the available data on the incidence of VTE in Asian populations, considers current clinical guidelines for the prevention of VTE to determine whether these guidelines are applicable to Asian populations, and evaluates the potential of new thromboprophylactic agents. Based on the available evidence, it was agreed that VTE represents a genuine problem in Asian patients, although the exact incidence in local populations requires confirmation in large, well-designed clinical trials. Furthermore, there was consensus that current guideline recommendations for the routine use of postoperative thromboprophylaxis should be implemented in Asia, and that new oral agents now available represent an effective and potentially more convenient therapeutic option. In conclusion, we call for recognition that VTE is an issue in Asian patients, and that effective thromboprophylaxis is the most important strategy.
Impact of concomitant treatment with proton pump inhibitors and clopidogrel on clinical outcome in patients after coronary stent implantation
Authors: Jarai Rudolf , Farhan Serdar , Brozovic Ivan , Smetana Peter , Geppert Alexander , Wojta Johann , Siller-Matula Jolanta , Huber Kurt , Tentzeris Ioannis
Published: October 2010

The aim of the study was to evaluate the effect of the concomitant treatment with proton-pump inhibitors (PPIs) and clopidogrel on the incidence of stent thrombosis, acute coronary syndrome (ACS) and death in patients who underwent percutaneous coronary intervention (PCI) and stent implantation. In total, 1,210 patients under dual anti-platelet therapy, who underwent PCI and stent implantation, were included in a prospective registry from January 2003 until December 2006. The patients were divided retrospectively into those with or without long-term PPI treatment (for the duration of dual antiplatelet therapy). All-cause mortality, cardiovascular death, re-hospitalisation for reACS, stent thrombosis, as well as the combined endpoint all-cause death, re-ACS or stent thrombosis were evaluated over a mean follow-up period of 7.8 (± 3.63) months (range 1–12 months). Propensity score analysis was performed to reduce potential selection bias and exhibited no significant difference between the two study groups with respect to all-cause mortality, cardiovascular death, re-ACS, stent thrombosis and the combined endpoint. In pre-specified subgroup analyses performed in patients presenting with ACS and referred for acute PCI or for stable patients referred for elective PCI, receiving drug-eluting stents or bare metal stents, in diabetics or non-diabetics, in males or females, and in patients older than 75 years or ≤75 years of age use of PPIs had no significant impact on clinical outcome. Our data suggest that a combined use of clopidogrel as part of dual antiplatelet therapy (DAPT) after coronary stenting and PPIs does not significantly influence the clinical outcome.
Apixaban decreases coagulation activity in patients with acute deep-vein thrombosis
Authors: Wang Jessie , Knabb Robert , Mohan Puneet , Barrett Yu Chen
Published: October 2010

In patients with acute deep-vein thrombosis (DVT), apixaban, a direct oral factor Xa inhibitor, showed efficacy and safety similar to low-molecular-weight heparin followed by vitamin K antagonist (LMWH/VKA). We evaluated biomarkers of coagulation activity in relation to treatment dose, duration and clinical outcome. Patients (N = 520) with symptomatic DVT were randomised to receive apixaban (5 mg bid, 10 mg bid or 20 mg qd) or LMWH/VKA for 12 weeks. Plasma D-dimer, prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin complex (TAT) levels were measured at baseline, and weeks 3 and 12 after treatment. Median plasma levels of D-dimer, F1+2 and TAT were elevated at baseline. At weeks 3 and 12, biomarker levels were normalised in most patients in all treatment groups, consistent with the low rate of venous thromboembolism (VTE) observed. Median reduction in D-dimer was similar in all treatment groups; percentage of patients with D-dimer above upper limit of normal decreased from 95% to 24–40% at week 12. F1+2 decline was greater with LMWH/VKA than apixaban. F1+2 in the apixaban groups changed to a similar extent (>84% of patients had F1+2 within reference range at week 12). Magnitude of TAT reduction was not quantifiable. In conclusion, levels of coagulation biomarkers decreased over 12 weeks of treatment with apixaban or LMWH/VKA in most patients with acute VTE. Baseline D-dimer and F1+2 were higher in patients with recurrent symptomatic VTE than in those without. Plasma levels of coagulation biomarkers did not appear to correlate with total bleeding events.
Mode of action of P2Y12 antagonists as inhibitors of platelet function
Authors: Glenn Jackie , White Ann , Fox Sue , van Giezen Hans , Nylander Sven , Heptinstall Stan , Iyú David
Published: October 2010

P2Y12 receptor antagonists are antithrombotic agents that inhibit platelet function by blocking the effects of adenosine diphosphate (ADP) at P2Y12 receptors. However, some P2Y12 receptor antagonists may affect platelet function through additional mechanisms. It was the objective of this study to investigate the possibility that P2Y12 antagonists inhibit platelet function through interaction with G-protein-coupled receptors other than P2Y12 receptors. We compared the effects of cangrelor, ticagrelor and the prasugrel active metabolite on platelet aggregation and on phosphorylation of vasodilator-stimulated phosphoprotein (VASP). We compared their effects with those of selective IP, EP4 and A2A agonists, which act at Gs-coupled receptors. All three P2Y12 antagonists were strong inhibitors of ADP-induced platelet aggregation but only partial inhibitors of aggregation induced by thrombin receptor activating peptide (TRAP) or the thromboxane A2 mimetic U46619. Further, after removing ADP and its metabolites using apyrase and adenosine deaminase, the P2Y12 antagonists produced only minor additional inhibition of TRAP or U46619-induced aggregation. Conversely, the Gs-coupled receptor agonists always produced strong inhibition of aggregation irrespective of whether ADP was removed. Other experiments using selective receptor agonists and antagonists provided no evidence of any of the P2Y12 antagonists acting through PAR1, TP, IP, EP4, A2A or EP3 receptors. All three P2Y12 antagonists enhanced VASPphosphorylation to a small and equal extent but the effects were much smaller than those of the IP, EP4 and A2A agonists. The effects of cangrelor, ticagrelor and prasugrel on platelet function are mediated mainly through P2Y12 receptors and not through another G-protein-coupled receptor.
Population genetics of venous thromboembolism
Authors: Grandone Elvira , Margaglione Maurizio
Published: October 2010

Results from epidemological studies are consistent with the hypothesis that disparities in venous thromboembolism (VTE) burden are attributable to differences in genetic structure among populations from different genetic backgrounds. To that end, recent genetic studies have demonstrated not only potential associations between certain alleles and VTE but also clear differences in the distribution of these alleles in patients stratified by ancestry. There are a number of notable clinical and pathophysiological questions that arise from these findings. First at all is defining the precise variant(s) that alter disease susceptibility. The comparatively lower rates of VTE recorded among Asians would imply that risk profile is devoid of many risk factors on comparison to Caucasian or African counterparts or that a putative protective factor is advocated in the former population. Identification of these variants provided specific insight into VTE disease in selected populations and also shed lights on the biology of the disease. The association observed between ancestry and VTE is likely to be multifactorial, possibly reflecting, in addition to genetic variation, also socioeconomic differences. Acknowledgment of this may provide useful information in biomedical contexts and help to identify individual risk factors for VTE.
Unravelling the mechanism and significance of thrombin binding to platelet glycoprotein Ib
Authors: Zarpellon Alessandro , Roberts James , Mc Clintock Richard , Jing Hua , Mendolicchio G. Loredana , Ruggeri Zaverio
Published: October 2010

The main question concerning the mechanism of α-thrombin binding to platelet membrane glycoprotein (GP)Ib is whether it involves both thrombin exosite I and exosite II. The solution of two independent crystal structures suggests alternative explanations that may actually reflect different modes of binding with distinct pathophysiological significance. With respect to function, it is still unclear whether thrombin binding to GPIb promotes procoagulant and prothrombotic pathways of re-sponse to vascular injury or limits such responses by sequestering, at least temporarily, the active enzyme. We review here published information on these topics and touch upon ongoing studies aimed at finding definitive answers to outstanding questions relevant for a better understanding of thrombosis and haemostasis.
Fibrillatory Conduction in the Atrial Free Walls of Goats in Persistent and Permanent Atrial Fibrillation
Authors: Verheule Sander , Tuyls Els , van Hunnik Arne , Kuiper Marion , Schotten Ulrich , Allessie Maurits
Published: October 2010

Background—

Over a time course of months, the stability of atrial fibrillation (AF) gradually increases and the efficacy of pharmacological cardioversion declines both in humans and in animal models. Changes in fibrillatory conduction over this period largely are unexplored.

Methods and Result—

Goats were instrumented with an atrial endocardial pacemaker lead and a burst pacemaker. AF was maintained for 3 weeks (short-term AF [ST], n=10) or 6 months (long-term AF [LT], n=7). AF could be cardioverted pharmacologically at the early time point (persistent AF), but not at the later time point (permanent AF). At follow-up, a high-resolution mapping electrode was used to record epicardial conduction patterns in the free walls of the right atrium (RA) and left atrium (LA). A new method for mapping of fibrillation waves was used to describe AF conduction patterns.

Wavefronts propagated uniformly during slow pacing in both groups, although conduction velocity was significantly lower in the LT group (LA, 93±14 versus 72±10 cm/s; RA, 94±8 versus 78±8 cm/s). Median AF cycle length (AFCL) was not significantly different between the groups. However, the LT group showed highly complex activation patterns during AF, with an increased number of simultaneously propagating waves (LT group RA, 8.4±3.0 waves/AFCL; LA, 12.8±2.4 waves/AFCL; versus ST group RA, 4.3±2.2 waves/AFCL; LA, 4.5±2.5 waves/AFCL). Fibrillation waves in the LT group showed pronounced dissociation with large activation time differences. The incidence of waves newly appearing within the recording area also was increased in both atria. These alterations in conduction were accompanied by myocyte hypertrophy and increased endomysial fibrosis.

Conclusions—

Long-term AF in goats leads to dissociated conduction in the atrial free walls that may contribute to increased AF stability.
Remote Magnetic Navigation With Irrigated Tip Catheter for Ablation of Paroxysmal Atrial Fibrillation
Authors: Miyazaki Shinsuke , Shah Ashok J. , Xhaët Olivier , Derval Nicolas , Matsuo Seiichiro , Wright Matthew , Nault Isabelle , Forclaz Andrei , Jadidi Amir S. , Knecht Sébastien , Rivard Lena , Liu Xingpeng , Linton Nick , Sacher Frédéric , Hocini Mélèze , Jaïs Pierre , Haïssaguerre Michel
Published: October 2010

Background—

The remote magnetic navigation system (MNS) has been used with a nonirrigated magnetic catheter for atrial fibrillation (AF) ablation. The objective of this study was to evaluate the feasibility and efficiency of the newly available irrigated tip magnetic catheter for index pulmonary vein isolation (PVI) in patients with paroxysmal AF (PAF).

Methods and Results—

Between January 2008 and June 2009, 30 consecutive patients with drug-resistant PAF underwent circular mapping catheter-guided PVI with MNS (MNS group). The outcomes were compared retrospectively with those of a conventional hand-controlled ablation technique during the same period in 44 consecutive patients (manual group). All 4 pulmonary veins were successfully isolated in both groups except in 4 patients in the MNS group. Radiofrequency and procedure duration were higher in the MNS group (60±27 versus 43±16 minutes;
P
=0.0019) than in the manual group (246±50 versus 153±51 minutes;
P
<0.0001). In the patients who underwent only PVI, total fluoroscopic time also was longer in the MNS group than in the manual group (58±24 versus 40±14 minutes;
P
=0.0002). At 12-month follow-up after a single procedure, 69.0% of the patients in MNS group and 61.8% of patients in manual group were free of atrial tachyarrhythmia without antiarrhythmic drugs. There was no significant difference in the atrial tachyarrhythmia-free survival between the 2 groups (
P
=0.961). Cardiac tamponade occurred in 1 patient in the manual group.

Conclusions—

In patients with PAF, MNS-guided PVI with the newly available irrigated tip magnetic catheter backed up with manual ablation whenever required is feasible. However, it requires longer ablation, fluoroscopy, and procedural times than the conventional approach in the early experience stage.
Noninvasive Diagnosis of Electroanatomic Abnormalities in Arrhythmogenic Right Ventricular Cardiomyopathy
Authors: Santangeli Pasquale , Pieroni Maurizio , Dello Russo Antonio , Casella Michela , Pelargonio Gemma , Macchione Andrea , Camporeale Antonia , Smaldone Costantino , Bartoletti Stefano , Di Biase Luigi , Bellocci Fulvio , Natale Andrea
Published: October 2010

Background—

The diagnostic reliability and pathophysiologic relevance of different noninvasive diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) are undefined. We tested the association between noninvasive diagnostic criteria for ARVC and the presence of low-voltage areas (LVAs) detected at electroanatomic voltage mapping (EAM).

Methods and Results—

Noninvasive diagnostic criteria, including ECG, signal-averaged ECG (SAECG), and cardiac magnetic resonance (CMR) criteria, were compared with the presence and location of LVAs detected at right ventricular (RV) EAM in 17 patients (9 men) aged 50±16 years with biopsy specimen-proven ARVC. LVAs were found in 15 (88%) patients. Patients with surface ECG abnormalities showed a higher degree of RV involvement than those without ECG abnormalities (number of LVAs, 1.8±0.5 versus 0.9±0.6, respectively;
P
<0.01). A significant association was found between SAECG abnormalities and LVAs in the RV outflow tract (
P
=0.03) but not between SAECG parameters and LVAs in other RV regions. Among CMR findings, RV delayed enhancement was more significantly associated with the distribution of LVAs (free wall,
P
<0.01; outflow tract,
P
<0.01; posteroinferior wall,
P
=0.02). Regional RV dysfunction also showed a good correlation with LVAs, with the most significant association being found with the free wall (
P
=0.01), whereas RV fat infiltration at CMR was not correlated with LVAs.

Conclusion—

In patients with ARVC, SAECG abnormalities correlate with the presence of LVAs selectively in the RV outflow tract, whereas surface ECG abnormalities are associated with a more diffuse RV involvement. Myocardial delayed enhancement is the CMR finding more strongly associated with LVAs, thus supporting the appropriateness of its inclusion among diagnostic criteria for ARVC.
Health Status After Treatment for Coronary Artery Disease and Type 2 Diabetes Mellitus in the Bypass Angioplasty Revascularization Investigation 2 Diabetes Trial
Authors: Brooks Maria Mori , Chung Sheng-Chia , Helmy Tarek , Hillegass William B. , Escobedo Jorge , Melsop Kathryn A. , Massaro Elaine M. , McBane Robert D. , Hyde Pamela , Hlatky Mark A. ,   the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) Study Group
Published: October 2010

Background—

Health status is a key outcome for comparing treatments, particularly when mortality does not differ significantly.

Methods and Results—

Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) randomized 2368 patients with type 2 diabetes mellitus and stable ischemic heart disease to (1) prompt revascularization versus medical therapy and (2) insulin sensitization versus insulin provision. Randomization was stratified by the intended method of revascularization, coronary artery bypass graft surgery or percutaneous coronary intervention. The Duke Activity Status Index and RAND Energy, Health Distress, and Self-Rated Health scales were assessed at study entry and annually thereafter; linear mixed models were used to evaluate the effect of randomized treatment on these measures. Health status improved significantly from baseline to 1 year (
P
<0.001) in each randomized treatment group. Compared with medical therapy, prompt revascularization was associated with significantly greater improvements in Duke Activity Status Index (1.32 points;
P
<0.001), Energy (1.36 points;
P
=0.02), and Self-rated Health (1.77 points;
P
=0.007) but not Health Distress (−0.47;
P
=0.46). These treatment effects were largely maintained over 4 years of follow-up. The effect of revascularization on the Duke Activity Status Index was significantly larger in the subgroup of patients intended for coronary artery bypass graft surgery compared with the subgroup intended for percutaneous coronary intervention. Health status did not differ significantly on any of the 4 measures between the insulin provision and insulin sensitization strategies.

Conclusions—

Prompt coronary revascularization was associated with small yet statistically significant improvements in health status compared with initial medical therapy among patients with diabetes mellitus and stable ischemic heart disease.

Clinical Trial Registration—

http://www.clinicaltrials.gov
. Unique identifier: NCT00006305.
Lasofoxifene and Cardiovascular Events in Postmenopausal Women With Osteoporosis
Authors: Ensrud Kristine , LaCroix Andrea , Thompson John R. , Thompson David D. , Eastell Richard , Reid David M. , Vukicevic Slobodan , Cauley Jane , Barrett-Connor Elizabeth , Armstrong Roisin , Welty Francine , Cummings Steven
Published: October 2010

Background—

In the Postmenopausal Evaluation and Risk Reduction With Lasofoxifene (PEARL) trial, women assigned to lasofoxifene 0.5 mg/d had a lower risk of major coronary heart disease (CHD) events and stroke, whereas women assigned to lasofoxifene 0.25 mg/d had a lower risk of stroke. Both doses of lasofoxifene increased the risk of venous thromboembolic events. In this report, we provide comprehensive cardiovascular end-point data, including component events comprising the composite end point of major CHD events, and evaluate whether the effect of lasofoxifene 0.5 mg/d is consistent across different categories of CHD risk.

Methods and Results—

In this study, 8556 women 59 to 80 years of age with osteoporosis received lasofoxifene 0.25 mg/d, lasofoxifene 0.5 mg/d, or placebo for 5 years. Cardiovascular events, including major CHD events, were prespecified secondary end points. Compared with placebo, lasofoxifene 0.5 mg/d reduced the risk of major CHD events 32% (hazard ratio, 0.68; 95% confidence interval, 0.50 to 0.93), including the risk of coronary revascularization (hazard ratio, 0.56, 95% confidence interval, 0.32 to 0.98). Reductions in risk of hospitalization for unstable angina (hazard ratio, 0.55; 95% confidence interval, 0.29 to 1.04) and diagnosis of new ischemic heart disease (hazard ratio, 0.52; 95% confidence interval, 0.26 to 1.04) nearly reached significance (
P
=0.06 for both comparisons). Although both hazard ratios were <1.0, no significant effect of lasofoxifene at 0.5 mg/d was demonstrated for coronary death or nonfatal myocardial infarction. The reduction in CHD events with lasofoxifene 0.25 mg/d was not significant (hazard ratio, 0.76; 95% confidence interval, 0.56 to 1.03;
P
=0.08). The effectiveness of lasofoxifene 0.5 mg/d in reducing CHD events was similar across strata of major cardiovascular risk factors.

Conclusions—

In postmenopausal women with osteoporosis, lasofoxifene 0.5 mg/d for 5 years reduced the risk of CHD events, regardless of the presence or absence of risk factors for cardiovascular disease. The significant reduction in risk of CHD events with lasofoxifene 0.5 mg/d was due primarily to lower risks of coronary revascularization procedures, hospitalization for unstable angina, and diagnosis of new ischemic heart disease.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00141323.
Multimarker Approach for the Prediction of Heart Failure Incidence in the Community
Authors: Velagaleti Raghava S. , Gona Philimon , Larson Martin G. , Wang Thomas J. , Levy Daniel , Benjamin Emelia J. , Selhub Jacob , Jacques Paul F. , Meigs James B. , Tofler Geoffrey H. , Vasan Ramachandran S.
Published: October 2010

Background—

Several biological pathways are activated in ventricular remodeling and in overt heart failure (HF). There are no data, however, on the incremental utility of a parsimonious set of biomarkers (reflecting pathways implicated in HF) for predicting HF risk in the community.

Methods and Results—

We related a multibiomarker panel to the incidence of a first HF event in 2754 Framingham Heart Study participants (mean age, 58 years; 54 women) who were free of HF and underwent routine assays for 6 biomarkers (C-reactive protein, plasminogen activator inhibitor-1, homocysteine, aldosterone-to-renin ratio, B-type natriuretic peptide, and urinary albumin-to-creatinine ratio). We estimated model c statistic, calibration, and net reclassification improvement to assess the incremental predictive usefulness of biomarkers. We also related biomarkers to the incidence of nonischemic HF in participants without prevalent coronary heart disease. On follow-up (mean, 9.4 years), 95 first HF events occurred (54 in men). In multivariable-adjusted models, the biomarker panel was significantly related to HF risk (
P
=0.00005). On backward elimination, B-type natriuretic peptide and urinary albumin-to-creatinine ratio emerged as key biomarkers predicting HF risk; hazards ratios per 1-SD increment in log marker were 1.52 (95 confidence interval, 1.24 to 1.87) and 1.35 (95 confidence interval, 1.11 to 1.66), respectively. B-type natriuretic peptide and urinary albumin-to-creatinine ratio significantly improved the model c statistic from 0.84 (95 confidence interval, 0.80 to 0.88) in standard models to 0.86 (95 confidence interval, 0.83 to 0.90), enhanced risk reclassification (net reclassification improvement=0.13;
P
=0.002), and were independently associated with nonischemic HF risk.

Conclusion—

Using a multimarker strategy, we identified B-type natriuretic peptide and urinary albumin-to-creatinine ratio as key risk factors for new-onset HF with incremental predictive utility over standard risk factors.
Influence of Indian Summer Monsoon on Aerosol Loading in East Asia
Authors: Liu Xiaodong , Yan Libin , Yang Ping , Yin Zhi-Yong , North Gerald R.
Published: October 2010

The spatial and temporal variations of aerosol loading over eastern Asia specified in terms of the aerosol optical depth (AOD) at the 550-nm wavelength during July are examined in conjunction with the intensity of the Indian summer monsoon. AOD derived from Moderate Resolution Imaging Spectroradiometer (MODIS) observations, gridded reanalyses, and ground-based measurements are used in the analysis. Two contrasting years, 2002 and 2003, which represent weak and active Indian summer monsoon events, respectively, are selected for the study, with a focus on an eastern Asian southern subregion (SR; 23°–32°N, 105°–120°E) and an eastern Asian northern subregion (NR; 35°–44°N, 115°–130°E). It is shown that the interannual variation of July mean wind intensity is a major factor in regulating the midsummer spatial pattern of aerosols over eastern Asia when the Indian monsoon index is anomalously large. The AOD anomalies in the NR and SR are positive and negative, respectively, during an active monsoon year, whereas the opposite is observed during a weak monsoon year. The variation patterns of less cloudy-day visibility, observed at four meteorological stations in the SR and NR subregions, also show spatial–temporal aerosol variability evident in the MODIS AOD data. Relative to the case of a weak monsoon year, meridional winds and convection are stronger and more clouds and precipitation are observed in the NR subregion during the active monsoon year. The opposite pattern is observed in the SR subregion. The spatial–temporal variation pattern of aerosols over eastern Asia illustrates the nonnegligible role of transport and dispersal mechanisms associated with the Indian summer monsoon in the region.
Statistical Prediction of the Storm Surge Associated with Cool-Weather Storms at the Battery, New York
Authors: Salmun H. , Molod A. , Wisniewska K. , Buonaiuto F. S.
Published: October 2010

The winter and early spring weather in the New York City metropolitan region is highly influenced by extratropical storm systems, and the storm surge associated with these systems is one of the main factors contributing to inundation of coastal areas. This study demonstrates the predictive capability of an established statistical relationship between the “storm maximum” storm surge associated with an extratropical storm system and the “average maximum” significant wave height during that storm. Data from publicly available retrospective forecasts of sea level pressure and wave heights, along with a regression equation for storm surge, were used to predict the storm-maximum storm surge for 41 storms in the New York metropolitan region during the period from February 2005 to December 2008. The statistical storm-surge estimates were compared with the surge values predicted by NOAA’s extratropical storm-surge model and NOAA’s operational surge forecast, which includes an error correction, and with water gauge observations taken at the Battery, located at the southern tip of Manhattan Island, New York. The mean difference between the statistical surge prediction and the observed values is shown to be smaller than the difference between NOAA’s deterministic surge prediction and the observed surge at the 95% significance level and to be statistically indistinguishable from the difference between NOAA’s operational surge forecast and the observed values of surge. These statistical estimates can be used as part of a system for predicting coastal flooding.
Teleconnection Pattern Influence on Sea-Wave Climate in the Bay of Biscay
Authors: Le Cozannet Gonéri , Lecacheux Sophie , Delvallee Etienne , Desramaut Nicolas , Oliveros Carlos , Pedreros Rodrigo
Published: October 2010

The potential modification of hydrodynamic factors, such as waves, is a source of concern for many coastal communities because of its potential effect on shoreline evolution. In the northern Atlantic, swell is created by storm winds that cross the Atlantic following west–east tracks. These tracks are shifted more southward or northward depending on the season and on recurring large-scale atmospheric pressure anomalies, also called teleconnection patterns. This study investigates the trends of sea-wave patterns in the Bay of Biscay and relates their interannual variability to teleconnection patterns.

Sea-wave parameter time series from the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) show a satisfying correlation with an in situ buoy of Météo-France during the period they overlap. Using a k-means algorithm, data from this 44-yr-long time series were clustered into a few sea-state modes, each of them corresponding to an observable sea state associated with an averaged value for wave height, period, and direction.

This analysis shows that most of the increase in annual mean sea-wave height since the 1970s has occurred because the relative frequency of occurrence of persistent observable sea states is evolving over time: from 1970 to 2001, the data indicate that energetic northwest swell becomes more frequent than low-energy intermediate sea states. Moreover, anomalies of the relative frequency of occurrence of observable sea states are related to large-scale recurring pressure anomalies: principally, the Northern Atlantic Oscillation (NAO) but also (during winters) the east Atlantic (EA) pattern, as well other teleconnection patterns of the Northern Hemisphere (NOAA data).