bluuebunny/crossref_metadata_2025 huggingface dataset:
Smoothing with adaptive rank order filters for early processing in image segmentation
Authors: Zamperoni Piero
Published: July 2007

This paper describes two non‐linear smoothing filters based on adaptive rank order filtering. the ideal output of these filters is a grey value suitable for characterizing the grey value distribution associated with the local texture, i.e. suitable for use as a region label for image segmentation purposes. the problem is to select as output a grey value that is stable with respect to the fluctuations of the local grey value distribution inside homogeneous regions. the first proposed method aims at the estimation of the mode of the local distribution. the second selects the output rank in dependence on the local average; it is simpler and combines the edge‐sharpening advantages of ‘comparison and selection filters’ with a better mode estimation, in comparison with the median filter, in the presence of asymmetrical local grey value distributions.
Real‐time implementation of an indirect adaptive robot controller
Authors: Dessaint L.‐A. , Saad Maarouf , Hebert Bernard , Robert Sylvain
Published: July 2007

Adaptive controllers applied to high‐speed and high‐precision robot manipulators give excellent tracking performances because they take into account the full dynamics of the robot. Recent publications have shown that on‐line estimation of the dynamic constant parameters can be obtained by the joint tracking error (direct adaptive control) or by the torque prediction error (indirect adaptive control).

In direct adaptive controllers the estimation law is derived from Lyapunov stability or Popov hyperstability methods. These controllers are simple and their real‐time implementation is easy; however, the estimation is not so accurate. In indirect adaptive controllers the estimation law is based on a least squares algorithm. These controllers give accurate estimates of the manipulator parameters; however, they involve much more computation than the direct approach. Therefore no real‐time implementations of indirect adaptive tracking controllers for robots have been reported in the literature until now.

This paper describes a real‐time implementation of an indirect adaptive scheme applied to a two‐degree‐of‐freedom (2DOF) direct‐drive SCAM robot. the controller is implemented at low cost by the use of a single‐chip digital signal processor (DSP).
A robust decentralized three‐segment nonlinear sliding mode control for rigid robotic manipulators
Authors: Zhihong Man , Palaniswami M.
Published: July 2007

In this paper the design of three‐segment non‐linear sliding mode parameters is further investigated and a robust decentralized tracking control scheme using the three‐segment non‐linear sliding mode technique for non‐linear rigid robotic manipulators is developed. It is shown that some parameters of the three‐segment non‐linear sliding mode are related to the initial values of the system dynamics and should be suitably chosen in order to guarantee the stability of the system dynamics. Strong robustness and fast error convergence can be obtained for rigid robotic manipulators with large uncertain dynamics by using the three‐segment non‐linear sliding mode technique together with a few useful smctural properties of rigid robotic manipulators. A simulation example is given in support of the proposed control scheme.
Distinguishing Concepts: Lexicons of Interactive Art and Architecture
Authors: Haque Usman
Published: July 2007

Interactive design has come about as a result of the intermingling of disciplines. As a consequence, the language it uses has become blurred ‐ borrowed or stolen with little restraint from elsewhere. Though particular terms have become ubiquitous, the original concepts that lie behind them have been lost. This means that all too frequently they are no longer knowingly used. Usman Haque sorts the wheat from the chaff and brings clarity to bear on the vocabulary and thinking behind interactivity. Copyright © 2007 John Wiley & Sons, Ltd.
Food pricing, competition, and the emerging supercenter format
Authors: Stiegert Kyle W. , Sharkey Todd
Published: July 2007

Much previous research has examined the role of concentration, level of service, and entry barriers on U.S. food retailing profits and prices. Despite the rapid advancement of food supercenters, public policy research evaluating their price impacts remains quite limited. The purpose this study is to examine the price impacts from supercenter entry, growing supercenter market share, and supermarket consolidation from 1993–2003. Findings were that both the market share of supercenter food sales and the marginal impact of supercenter entry did not have a significant impact on food prices in the metropolitan statistical areas (MSAs) analyzed. These are important findings in light of claims that supercenters entry causes a procompetitive effect. Futhermore, changes in market concentration was significantly and positively related to price changes. Therefore, it appears consolidation led to higher prices and any merger‐related cost gains during this period were not passed on to consumers. [EconLit Classifications: D400, L130, L660]. © 2007 Wiley Periodicals, Inc. Agribusiness 23: 295–312, 2007.
Beef safety shocks and dynamics of vertical price adjustment: The case of BSE discovery in the U.S. beef sector
Authors: Saghaian Sayed H.
Published: July 2007

This article addresses the dynamic impact of the 2003 Bovine Spongiform Encephalopathy discovery on the U.S. beef sector. Time series analysis and historical decomposition with weekly feedlot, wholesale, and retail beef price series is used to address the dynamics of price adjustment and causality along the U.S. beef marketing channel. The results show price transmission is bidirectional, determined through interaction between the different stages, and price adjustment is asymmetric with respect to both speed and magnitude. The results reveal a differential impact of the exogenous shock on producers and retailers, which leads to widening of price margins and points to imperfect price transmission, specifically at the retail level, with consequences for the efficiency and equity of the marketing channel. [EconLit citations: Q11, Q13]. © 2007 Wiley Periodicals, Inc. Agribusiness 23: 333–348, 2007.
Nonhomogeneous products and the law of one price
Authors: Spreen Thomas H. , Kilmer Richard L. , Pitta Carlos R.
Published: July 2007

Law of One Price (LOP) is important in the theory of international trade. It is important in LOP studies to have data that accurately represents homogeneous products (i.e., the product in one country has the same product characteristics as the product in another country). We present a theoretical model that determines fresh grapefruit prices Free on Board (FOB) at the packinghouse. The first order conditions show that the FOB packinghouse prices are equal for products with the same product characteristics. The theoretical conditions show a difference in FOB prices when the product characteristics are different. The product characteristics that are varied include packing costs and pack‐out rates. The results from a nonlinear programming optimization routine demonstrates the importance of using data that accurately represents homogeneous products for LOP studies. Different packing costs and pack‐out percentages are shown to cause different FOB packinghouse prices for fresh grapefruit destined for domestic and export markets. [JEL Classification: Q11, Q13, F14]. © 2007 Wiley Periodicals, Inc. Agribusiness 23: 407–420, 2007.
The economic nature of network capital in B2B transactions
Authors: Wilson Paul N.
Published: July 2007

Social scientists, including numerous economists, have explored the incidence and importance of social capital embedded networks as a governance mechanism in business operations. The buyer‐seller dyads represented by 12 large‐scale dairies and 7 feed suppliers were studied to contribute to our understanding of network capital in business‐to‐business (B2B) transactions. A high incidence of institutional and personal trust was found in these buyer‐seller networks. Trust facilitates economic exchange through uncertainty management, information sharing, and time savings. [L140, Q120]. © 2007 Wiley Periodicals, Inc. Agribusiness 23: 435–448, 2007.
Job stress and other working conditions: Relationships with smoking behaviors in a representative sample of working Australians
Authors: Radi Samia , Ostry Aleck , LaMontagne Anthony D.
Published: July 2007

Objectives

To assess the relationships between current smoking status and psychosocial working conditions.

Methods

A cross‐sectional population‐based telephone survey was conducted (66% response rate, N = 1,101). Job stress was measured using the demand/control, effort/reward imbalance (ERI), and job pressure models. Multiple regression modelling was conducted for smoking status (current versus non‐smokers, and a more restricted analysis of current versus former‐smokers) and daily smoking intensity outcomes in relation to job stress measures, working hours, shift work, and other independent variables.

Results

After adjustment for age, education, martial status, and hostility, high job strain was positively associated with current smoking in men only. Employment in active jobs was associated with decreased odds of smoking among women only. High strain jobs were associated with decreased odds of current smoking compared to former smoking in women. In men, extreme and moderate job pressure were related to current smoking compared to current non‐smoking, and moderate job pressure was associated with current smoking compared with former smokers. Other working conditions associated with smoking were excessive working hours in men and physical demand in women. Daily smoking intensity in current smokers was associated with high psychological demand and with ERI in women.

Conclusions

These results suggest that job stress is related to smoking status at the population level, with different patterns in men and women. Am. J. Ind. Med. 50:584–596, 2007. © 2007 Wiley‐Liss, Inc.
Occupational risk factors for prostate cancer
Authors: Sass‐Kortsak Andrea M. , Purdham James T. , Kreiger Nancy , Darlington Gerarda , Lightfoot Nancy E.
Published: July 2007

Background

Occupational risk factors for prostate cancer have been investigated with inconsistent findings.

Methods

This was a population‐based case‐control study of men in Northeastern Ontario, Canada. Cases (n = 760) were from the Ontario Cancer Registry, 50 to 84 years old, and diagnosed with prostate cancer between 1995 and 1998. Age‐frequency matched controls (n = 1,632) were obtained from telephone listings. A questionnaire yielded information on occupational history and self‐reported exposures to a list of occupational hazards. Exposures to these hazards were assessed by an occupational hygienist.

Results

An odds ratio estimate (OR) of 1.21 (95 percent confidence interval (% CI) 1.01, 1.46) was found for employment in trades, transport and equipment operators and related occupations, possibly related to exposure to whole‐body vibration (OR = 1.38, 95% CI 1.07, 1.78). For the highest quartile of lifetime cumulative workplace physical activity an OR of 1.33 (95% CI 1.02, 1.74) was found. No statistically significant associations were found for any other occupational category or exposure.

Conclusions

This study does not provide strong evidence for significant occupational risk factors for prostate cancer. However, whole‐body vibration exposures, as well as physical activity, may be worth pursuing in future occupational studies. Am. J. Ind. Med. 50:568–576, 2007. © 2007 Wiley‐Liss, Inc.
Effects of postextrusion conditions on the morphology of foamed high‐density polyethylene/polypropylene blends
Authors: Zepeda Sahagún C. , González Núñez R. , Rodrigue D.
Published: July 2007

The effects of postextrusion conditions (i.e., the draw ratio) were studied to control the cellular structure of extruded foams based on polymer blends. High‐density polyethylene and polypropylene were foamed with azodicarbonamide as a chemical blowing agent, zinc oxide as an accelerator, and Kraton D1102 as a compatibilizer. The deformation of the cellular structure and dispersed phase particles was measured with micrographs in both longitudinal and transversal directions to obtain a full three‐dimensional picture of the foam morphology. A simple model of the cellular structure is presented to predict cell deformation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Surface nanaostructure evolution of functionalized polypropylene fibers
Authors: Wei Qufu , Wang Yingying , Wang Xueqian , Huang Fenglin , Yang Shengwei
Published: July 2007

It is well‐known that fiber surface characteristics affect friction, wetting, conductivity, and other performance properties. This paper reports the evolution of the surface nanostructures of meltblown polypropylene (PP) fibers during the process of plasma treatment followed by copper (Cu) sputter coating. The effects of plasma treatment and Cu sputter coating on the surface morphology, chemistry, and properties of the fibers were characterized using scanning probe microscope (SPM), environmental scanning electron microscopy (ESEM), and electrical analysis. The atomic force mode (AFM) and lateral force mode (LFM) in the SPM were used to scan the fiber surface. AFM observations revealed the evolution of the surface morphology formed by surface treatment. The LFM images also indicated the change in surface nanomechanical behavior. A full energy dispersive X‐ray analysis (EDX) mounted on the ESEM was used to examine the change in the chemical compositions of the functional surfaces. The electrical properties of the functionalized materials were analyzed using electrical resistance test. The Cu sputter coating significantly altered the surface conductivity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Semi‐strong dynamic style analysis with time‐varying selectivity measurement: Applications to Brazilian exchange‐rate funds
Authors: Pizzinga Adrian , Vereda Luciano , Atherino Rodrigo , Fernandes Cristiano
Published: July 2007

This paper deals with restricted linear state space models for dynamic style analysis with time‐varying selectivity measurement. Implementation and interpretation of the models are pertinently discussed. Empirical contributions lie on the understanding of how managers of Brazilian US Dollar/Real exchange‐rate funds behaved
along 2001 and 2002, a period of some political turbulence especially due to the 2002 Brazilian presidential election. Copyright © 2007 John Wiley & Sons, Ltd.
A1298C polymorphism of the MTHFR gene and neural tube defects in the state of Yucatan, Mexico
Authors: Gonzalez‐Herrera Lizbeth , Castillo‐Zapata Ileana , Garcia‐Escalante Guadalupe , Pinto‐Escalante Doris
Published: July 2007

BACKGROUND:

Methylenetetrahydrofolate reductase (MTHFR) of the folate metabolism pathway is a candidate gene for neural tube defects (NTDs). Frequency of the second common polymorphism, A1298C, in the MTHFR gene is not well known in Mexico. Conflicting results exist regarding the association of A1298C‐MTHFR with NTDs. One explanation for this controversy might be that alleles are differently distributed among various populations. The aim of the study was to determine the frequency of the A1298C‐MTHFR polymorphism and its association with NTDs in a population of Yucatan, Mexico.

METHODS:

Genotyping was performed by use of polymerase chain reaction with restriction fragment length polymorphisms using MbOII endonuclease (PCR‐RFLPs MbOII). Allele and genotype frequencies were compared between cases with NTDs, their mothers and fathers with matched controls based on an association analysis using EpiInfo software.

RESULTS:

A1298C genotypes were distributed according to Hardy‐Weinberg expectations for all studied groups. Frequencies of allele C and heterozygous AC genotype were significantly higher in males (p = .006 and p = .011, respectively) in control group. Significant differences were not observed between cases and controls, except in mothers of NTD cases compared with mothers of healthy offspring for both allele C and heterozygous AC genotype (p = .009 and p = .01, respectively).

CONCLUSIONS:

The polymorphism A1298C‐MTHFR is not associated with NTDs, except for mothers, suggesting only a maternal association with having NTD‐affected offspring in the Yucatan population. The frequency of allele C in the control population was 10%, which is significantly lower than in other reported control populations worldwide (p < .01). Birth Defects Research (Part A) 2007. © 2007 Wiley‐Liss, Inc.
Acute exposure to low‐level CW and GSM‐modulated 900 MHz radiofrequency does not affect Ba2+ currents through voltage‐gated calcium channels in rat cortical neurons
Authors: Platano Daniela , Mesirca Pietro , Paffi Alessandra , Pellegrino Monica , Liberti Micaela , Apollonio Francesca , Bersani Ferdinando , Aicardi Giorgio
Published: July 2007

We have studied the non‐thermal effects of radiofrequency (RF) electromagnetic fields (EMFs) on Ba2+ currents ($I_{{\rm Ba}^{2+ } }$) through voltage‐gated calcium channels (VGCC), recorded in primary cultures of rat cortical neurons using the patch‐clamp technique. To assess whether low‐level acute RF field exposure could modify the amplitude and/or the voltage‐dependence of $I_{{\rm Ba}^{2+ } }$, Petri dishes containing cultured neurons were exposed for 1–3 periods of 90 s to 900 MHz RF‐EMF continuous wave (CW) or amplitude‐modulated according to global system mobile communication standard (GSM) during whole‐cell recording. The specific absorption rates (SARs) were 2 W/kg for CW and 2 W/kg (time average value) for GSM‐modulated signals, respectively. The results obtained indicate that single or multiple acute exposures to either CW or GSM‐modulated 900 MHz RF‐EMFs do not significantly alter the current amplitude or the current–voltage relationship of $I_{{\rm Ba}^{2+ } }$, through VGCC. Bioelectromagnetics 28:599–607, 2007. © 2007 Wiley‐Liss, Inc.
Vienna–Chicago: The cultural transformation of the model system of the un‐opposed molar
Authors: Luan Xianghong , Diekwisch Thomas G.H.
Published: July 2007

The discussion over the roles of genes and environment on the phenotypical specification of organisms has held a central role in science philosophy since the late 19th century and has re‐emerged in today's debate over genetic determinism and developmental plasticity. In fin‐de‐siecle Vienna, this debate coincided with a philosophical debate over empiricism/materialism versus idealism/vitalism. Turn‐of‐the‐century Vienna's highly interdisciplinary environment was also the birthplace for the model system of the un‐opposed molar. The un‐opposed molar system features new tissue formation at the roots of teeth and tooth drift once opposing teeth are lost. The un‐opposed molar model system was revived by a group of Viennese scientists who left Vienna during the Nazi period to address Vienna's questions about evolution and heredity and about genes and environment in Chicago's post‐WWII scientific exile community. Here we are using the colorful history of the un‐opposed molar to investigate the role of culture and method in the scientific evolution of a model system. BioEssays 29:819–830, 2007. © 2007 Wiley Periodicals, Inc.
Gender, immunity and the regulation of longevity
Authors: May Robin C.
Published: July 2007

For humans and many other animals, gender is a fact of life. Most individuals are born either male or female and their sex will have an enormous influence on their behaviour, physiology and life history. In this review, I consider the effect gender has on lifespan. In particular, I discuss the role played by behaviour, immunity and oxidative damage in determining sex‐dependent differences in longevity. I consider existing explanations for the effect of gender on lifespan and how these explanations fit together. Finally, I expand on the recent suggestion of a key role for the insulin/IGF‐1 signalling pathway in regulating sex‐dependent differences in lifespan(1) and I highlight a number of areas for future investigation. BioEssays 29:795–802, 2007. © 2007 Wiley Periodicals, Inc.
Adult neurogenesis in non‐mammalian vertebrates
Authors: Chapouton Prisca , Jagasia Ravi , Bally‐Cuif Laure
Published: July 2007

Adult neurogenesis is an exciting and rapidly advancing field of research. It addresses basic biological questions, such as the how and why of de novo neuronal production during adulthood, as well as medically relevant issues, including the potential link between adult neural stem cells and psychiatric disorders, or how stem cell manipulation might be used as a strategy for neuronal replacement. Current research mainly focuses on rodents, but we review here recent examination of non‐mammalian vertebrates, which demonstrates that bona fide adult neural stem cells exist in these species. Importantly, especially in teleost fish, these cells can be abundant and located in various brain areas. Hence, non‐mammalian vertebrate species provide invaluable comparative material for extracting core mechanisms of adult neural stem cell maintenance and fate. BioEssays 29:745–757, 2007. © 2007 Wiley Periodicals, Inc.
Criminality and continued DUI offense: criminal typologies and recidivism among repeat offenders
Authors: LaBrie Richard A. , Kidman Rachel C. , Albanese Mark , Peller Allyson J. , Shaffer Howard J.
Published: July 2007

We examined over 20,000 arraignment records to define criminal typologies and post‐treatment driving under the influence of alcohol (DUI) convictions for a select cohort of 1,281 repeat DUI offenders who were offered and elected treatment as an alternative to incarceration; we compared this information with a similar data analysis collected 20 years previously. Analyses of 8,600 prior‐to‐treatment convictions defined four basic crime profiles: only DUI and other substance‐related offenses (60%), plus crimes against property (18%), plus crimes against people (8%), plus crimes against both property and people (13%). During the six years after inpatient treatment, 15.5% of the cohort was convicted of another DUI. The reoffense rate was significantly different across criminal types and was not related to the time post treatment years at risk. The findings show there has been no significant improvement in treatment outcome over the last 20 years. New and innovative DUI offender policies and practices are needed to better engage the heterogeneous offender population, and reduce the incidence of repeat DUI. Copyright © 2007 John Wiley & Sons, Ltd.
Determining dangerousness in sexually violent predator evaluations: cognitive–experiential self‐theory and juror judgments of expert testimony
Authors: Lieberman Joel D. , Krauss Daniel A. , Kyger, Mariel , Lehoux, Maribeth
Published: July 2007

Past research examining the effects of expert testimony on the future dangerousness of a defendant in death penalty sentencing found that jurors are more influenced by less scientific clinical expert testimony and tend to devalue scientific actuarial testimony. This study was designed to determine whether these findings extend to civil commitment trials for sexual offenders and to test a theoretical rationale for this effect. In addition, we investigated the influence of a recently developed innovation in risk assessment procedures, Guided Professional Judgment (GPJ) instruments. Consistent with a cognitive–experiential self‐theory based explanation, mock jurors motivated to process information in an experiential condition were more influenced by clinical testimony, while mock jurors in a rational mode were more influenced by actuarial testimony. Participants responded to clinical and GPJ testimony in a similar manner. However, participants' gender exerted important interactive effects on dangerousness decisions, with male jurors showing the predicted effect while females did not. The policy implications of these findings are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Ideology and power: the influence of current neo‐liberalism in society
Authors: Nafstad Hilde Eileen , Blakar Rolv Mikkel , Carlquist Erik , Phelps Joshua Marvle , Rand‐Hendriksen Kim
Published: July 2007

Understanding power requires analysis of the intra‐personal, interpersonal, inter‐group as well as the ideological levels. The present study demonstrates the importance of the ideological level. A longitudinal analysis (1984–2005) of media language in Norwegian public discourse demonstrates how the current globalised capitalist market ideology has increasingly permeated this long‐established Scandinavian welfare state; individualism increasing at the cost of communal values. The current hegemonic shift is reflected in that the usage of the Norwegian equivalents of ‘I’/‘me’ has increased considerably whereas ‘we’/‘us’ has been stable. Usage of words such as ‘solidarity’, ‘common/communal/shared’, ‘welfare society’, ‘duty/obligation’ and ‘equality’ has decreased, whereas ‘right/entitlement’, ‘optional’ and ‘freedom to choose’ has increased. Copyright © 2007 John Wiley & Sons, Ltd.
Youth, community belonging, planning and power
Authors: Arcidiacono Caterina , Procentese Fortuna , Di Napoli Immacolata
Published: July 2007

In order to explain people's action in the community to which they feel they belong (Arcidiacono,2006; Brodsky,2006; De Piccoli & Tartaglia,2006), this study investigates the power perception in relation to the local community, based on two studies of Neapolitan youths. Both research projects, one with 101 participants and the other with 600 participants, looked at youth community belonging, respectively focusing on problems connected to youth unemployment, on related resources (Arcidiacono, Sommantico, & Procentese,2001), and finally on youth planning of future actions in the community (Arcidiacono, Di Napoli, & Sarnacchiaro, submitted). A reinterpretation of the categories emerging from these studies was carried out, by first adopting the grounded theory methodology and subsequently the Prilleltensky (in press) approach of a greater conceptualization within the power frame. The classification undertaken suggests that the perception of a lack of youth power is closely linked to their expectations for the local community. A lack of individual and social power, rage and hopelessness is the core evidence among our interviewees. Powerlessness firstly denies empowerment, thus it is as if young people distance themselves from the context. The assumption of this perspective opens new paths through which promoting empowerment processes. Copyright © 2007 John Wiley & Sons, Ltd.
A randomised controlled study comparing conventional and magnetic guidewires in a two‐dimensional branching tortuous phantom simulating angulated coronary vessels
Authors: Ramcharitar Steve , Patterson Mark S. , van Geuns Robert J. , van der Ent Martin , Sianos Georgios , Welten Gijs M.J.M. , van Domburg Ron T. , Serruys Patrick W.
Published: July 2007

Objectives:

To directly compare the magnetic navigation system (MNS) guidewires with conventional guidewires in branching tortuous phantoms with operators of varying MNS and percutaneous coronary intervention experience.

Background:

Vessel tortuosity, angulation, and side branches remain limiting factors in coronary interventions. The MNS addresses these limitations by precisely directing the tip of a magnetised guidewire in vivo aided by two permanent adjustable external magnets.

Methods:

Crossing and fluoroscopy times of six operators were evaluated in five tortuous Perspex® phantom vessels in three consecutive attempts. Standard guidewire (SG) usage was unrestricted. Two 2nd generation magnetic guidewires (MG) were used. Failure was noted if the cross was unsuccessful within 5 min.

Results:

The magnetic navigation was vastly superior to SG techniques with increasingly tortuous phantoms. It dramatically decreased both the crossing and fluoroscopy times with maximal reduction from 201.7 ± 111 to 36.4 ± 13 sec, P < 0.001 and 204.7 ± 24 to 47.2 ± 19 sec, P < 0.001, respectively. The MNS had a 98.8% procedural success rate compared to 68% with SG techniques. Moreover it considerably limited the amount of wire usage from 5.5 to 1.3. Operators with prior MG experience performed significantly better than those without, except in the simplest phantom where the difference was nonsignificant (33.8 ± 13 sec vs. 41.7 ± 17 sec, P = 0.2).

Conclusion:

MNS significantly reduces both the crossing and fluoroscopy times in tortuous coronary phantom models achieving excellent success rates with dramatic reductions in guidewire usage. Operators with prior MNS experience had an advantage over the inexperienced. © 2007 Wiley‐Liss, Inc.
Comparison of myocardial perfusion by distal protection before and after primary stenting for acute myocardial infarction: Angiographic and clinical results of a randomized controlled trial
Authors: Muramatsu Toshiya , Kozuma Ken , Tsukahara Reiko , Ito Yoshiaki , Fujita Naoya , Suwa Satoru , Koyama Shiho , Saitoh Masahiko , Kamiya Haruo , Nakamura Masato
Published: July 2007

Objectives:

To assess the myocardium‐reperfusing effect of a distal protection device, GuardWire Plus™ (GuardWire Plus), in patients with acute myocardial infarction (AMI).

Background:

Distal embolization may result in reduced myocardial perfusion, increasing the risk of non‐Q‐wave myocardial infarction and death. Distal protection devices may protect the microcirculation from embolic debris, improving short‐ and long‐term clinical outcomes.

Methods:

From February 2002 to July 2003, a total of 341 AMI patients at 22 institutions in Japan were enrolled in the present, multicenter, prospective, randomized trial. Patients experiencing AMI within 12 hr of symptom onset, who were considered treatable by stenting and who met the inclusion criteria, were eligible for randomization. Stenting with and without GuardWire Plus was conducted to examine whether the device provides faster and more complete ST‐segment resolution, smaller infarct size, and improved myocardial blush score.

Results:

The rates of slow flow and no‐reflow immediately after PCI were 5.3 and 11.4% in the GuardWire Plus and control groups, respectively (P = 0.05). Blush score 3 acquisition rates immediately after PCI were 25.2 and 20.3% in the GuardWire Plus and control groups, respectively (P = 0.26), and the rates at 30 days after PCI were 42.9 and 30.4%, respectively (P = 0.035).

Conclusions:

A significant difference was found between the GuardWire Plus and control groups with respect to the total incidence of distal embolization, indicating that GuardWire Plus angiographically improved myocardial perfusion without demonstrating the preventive effect of myocardial damage. © 2007 Wiley‐Liss, Inc.
Traumatic aortic dissection and coronary fistula treated with transcatheter management
Authors: Williams Paul D. , Mahadevan Vaikom S. , Clarke Bernard
Published: July 2007

An adolescent male presented with a dissection of the thoracic aorta and a left anterior descending coronary artery to right ventricular fistula following a road traffic accident. Authors report the management of this patient using a transcatheter approach for both these arterial issues, with stenting to the thoracic aorta and coil embolization of the coronary artery to right ventricular fistula as a staged procedure, along with a brief review of the literature on traumatic arterial injuries. © 2007 Wiley‐Liss, Inc.
Results of percutaneous coronary interventions in patients ≥90 years of age
Authors: Teplitsky Igal , Assali Abid , Lev Eli , Brosh David , Vaknin‐Assa Hana , Kornowski Ran
Published: July 2007

Background:

There are few data about percutaneous coronary interventions (PCI) in nonagenarians (patients aged ≥90 years). This study aimed to assess acute and intermediate term clinical outcomes among nonagenarian patients undergoing PCI.

Methods:

The study included 65 consecutive patients, age ≥90 years undergoing PCI between January 2001 and August 2006. Fourteen patients were admitted with acute ST elevation acute myocardial infarction (STEAMI), one had cardiogenic shock, 39 patients sustained non‐STEAMI, and 12 patients were with severe stable angina pectoris. Procedural data, in‐hospital, and six‐month clinical outcomes were obtained and adjudicated for all patients.

Results:

Coronary angiography documented multivessel disease in 86% of patients with relatively complex lesions (type B or C) in 94% treated using stent deployment in 92% of patients. In 7% of cases IABP was needed. Immediate procedural success was achieved in 92% patients. Cumulative mortality at hospital discharge and by 30‐days was14% and increased to 18% at 6‐months follow‐up. Total major adverse cardiac events (MACE: death, AMI, TVR, stroke) was 17% at hospital discharge and increased to 21% by 6‐months. Stroke was documented in one patient (1.5%) at hospital discharge. Cumulative mortality at 6 month was 0% in patients with stable angina and 23% in emergent PCI scenario (AMI or NSTEAMI or ACS). Univariate analysis revealed that emergent PCI, systolic blood pressure, left ventricular ejection fraction, diabetes mellitus, renal failure, TIMI flow at baseline, and procedural success, are all correlative with 6‐months mortality.

Conclusion:

We conclude that clinically stable nonagenarian patients with coronary artery disease undergoing PCI have excellent PCI related prognosis while clinically unstable patients have a worse outcome. Thus, careful attention to background medical history and clinical presentation should dictate the prognosis and/or management among nonagenarian patients. © 2007 Wiley‐Liss, Inc.
Efficacy of reduced‐dose sirolimus‐eluting stents in the human coronary artery: Serial IVUS analysis of neointimal hyperplasia and luminal dimension
Authors: Nakamura Mamoo , Abizaid Alexandre , Hirohata Atsushi , Honda Yasuhiro , Sousa J. Edward , Fitzgerald Peter J.
Published: July 2007

Study Objective:

Using serial intravascular ultrasound (IVUS), the efficacy of reduced‐dose sirolimus‐eluting stents (SESs) in the prevention of neointimal hyperplasia (NH) and maintenance of luminal patency in human coronary arteries was evaluated.

Background:

In the animal model, a broad therapeutic window regarding sirolimus doses in suppressing NH has been reported.

Methods:

Serial cross‐sectional and volumetric IVUS analyses were performed in 44 patients treated with SES that contained lower sirolimus doses (either 45% or 70%) than standard SES. For cross‐sectional analysis, minimum lumen area (MLA) was measured. Percent (%) NH volumetric obstruction was calculated as 100 × NH volume/stent volume.

Results:

IVUS measurements were similar between the two drug‐dose groups. At 12 months follow‐up, only one case developed late incomplete stent apposition. Between 4 and 12 months, a slight increase of in‐stent % area loss and % NH obstruction was noted (3.5% ± 10.4% to 6.7% ± 10.7% and 1.9% ± 5.0% to 4.4% ± 8.0%, respectively). The majority of studied cases, however, sustained less than a 10% volumetric (93% of studied cases) and area loss (75% of studied cases) in the stented segment up to 12 months. At 12 months, % area loss within the stented segments and 5‐mm reference segments were comparable (7.0% ± 19.6% versus 6.7% ± 10.7%).

Conclusions:

Although slight increases of NH were noted, SESs, delivering two reduced drug doses, appeared to be effective for maintaining luminal patency during 12 months follow‐up. © 2007 Wiley‐Liss, Inc.
NMR quantum toys
Authors: Lee Jae‐Seung , Khitrin Anatoly K.
Published: July 2007

Clusters of dipolar‐coupled nuclear spins are excellent model systems for implementing various quantum experiments. The presented examples demonstrate recent techniques of coherent control for spin systems, as well as quantum dynamic schemes, like amplified quantum detection and measurement, state purification, adiabatic transfer of coherences, or projective measurement with NMR. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part A 30A: 194–217, 2007.
Magnetostatic simulation for accurate design of low field MRI phased‐array coils
Authors: Giovannetti Giulio , Viti Vittorio , Positano Vincenzo , Santarelli Maria Filomena , Landini Luigi , Benassi Antonio
Published: July 2007

Radiofrequency receiver phased‐array coils in magnetic resonance imaging systems are used to pick up the signals emitted by the nuclei with high signal‐to‐noise ratio and a large region of sensitivity. The quality of obtained images strongly depends upon the correct choice of the coils geometry and typology. In this work, we propose a fast coil simulation method, which permits to design phased‐array coils with great accuracy. The developed algorithm exploits magnetostatic analysis to obtain accurate calculation of the mutual inductances between the array coils and the magnetic field pattern. Using the simulator, we designed a novel phased‐array coil composed of a couple of rectangular butterfly elements. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 140–146, 2007
Role of radiologic imaging at the time of initial diagnosis of stage T1b‐T3b melanoma
Authors: Yancovitz Molly , Finelt Nika , Warycha Melanie A. , Christos Paul J. , Mazumdar Madhu , Shapiro Richard L. , Pavlick Anna C. , Osman Iman , Polsky David , Berman Russell S.
Published: July 2007

BACKGROUND.

In patients with T1b‐T3b cutaneous melanoma the utility of radiologic imaging at the time of diagnosis is unclear. Whether initial imaging led to a change in stage or treatment plan was investigated.

METHODS.

The melanoma database was searched for patients with T1b‐T3b primary lesions, clinically N0, and asymptomatic for metastatic disease. Radiologic studies conducted before wide local excision ± sentinel lymph node biopsy as well as all further imaging and investigations were analyzed. Outcome measures included upstaging, change in initial surgical management, true‐positive, false‐positive, true‐negative, and false‐negative rates of each imaging modality.

RESULTS.

In all, 344 preoperative imaging studies (chest x‐ray [CXR], computed tomography [CT], positron emission tomography [PET]/CT) were performed on 158 patients, resulting in 49 findings suspicious for metastatic melanoma and 134 findings suggestive of nonmelanoma pathology. Only 1 of 344 (0.3%) studies, a PET/CT, correlated with confirmed metastatic melanoma. The false‐positive rates were CXR 5 of 7 (71.4%), chest CT 21 of 24 (87.5%), abdomen/pelvis CT 10 of 11 (90.9%), head CT 2 of 2 (100.0%), PET/CT 3 of 5 (60.0%). No patient was upstaged or had a change in initial surgical management based on preoperative imaging. The cost of all initial imaging and imaging to follow‐up abnormal findings was estimated as $555,308 for the 158 patients studied.

CONCLUSIONS.

Imaging at the time of initial diagnosis of T1b‐T3b, clinically N0, M0 melanoma was of low yield with a high false‐positive rate, and did not lead to upstaging or change in initial surgical management. These findings suggest that imaging of asymptomatic patients at the time of diagnosis may not be warranted. Cancer 2007. © 2007 American Cancer Society.
Neural development of the zebrafish (Danio rerio) pectoral fin
Authors: Thorsen Dean H. , Hale Melina E.
Published: July 2007

The innervation and actuation of limbs have been major areas of research in motor control. Here we describe the innervation of the pectoral fins of the larval zebrafish (Danio rerio) and its ontogeny. Imaging and genetic tools available in this species provide opportunities to add new perspectives to the growing body of work on limbs. We used immunocytological and gross histological techniques with confocal microscopy to characterize the pattern of pectoral fin nerves. We retrogradely labeled fin neurons to describe the distributions of the pectoral fin motor pool in the spinal cord. At 5 days postfertilization, four nerves innervate the pectoral fins. We found that the rostral three nerves enter the fin from the dorsal side of the fin base and service the dorsal and middle fin regions. The fourth nerve enters the fin from the ventral fin base and innervates the ventral region. We found no mediolateral spatial segregation between adductor and abductor cell bodies in the spinal cord. During the larval stage pectoral fins have one adductor and one abductor muscle with an endoskeletal disc between them. As the skeleton and muscles expand and differentiate through postlarval development, there are major changes in fin innervation including extensive elaboration to the developing muscles and concentration of innervation to specific nerves and fin regions. The pattern of larval fin innervation recorded is associated with later muscle subdivision, suggesting that fin muscles may be functionally subdivided before they are morphologically subdivided. J. Comp. Neurol. 504:168–184, 2007. © 2007 Wiley‐Liss, Inc.
Why do Barlow points not coincide with the reduced Gauss quadrature points for higher‐order finite elements?
Authors: Zhang Xiaosong
Published: July 2007

This paper presents the reason why Barlow points do not coincide with the reduced Gauss quadrature points for higher‐order finite elements. Based on the numerical implementation for one‐dimensional bar by finite elements, it is found that the reason for noncoincidence of Barlow points and the reduced Gauss quadrature points for higher‐order elements is due to the mismatch of nodal displacements by FEM with the exact solution. Copyright © 2007 John Wiley & Sons, Ltd.
Prisoner's dilemma and clusters on small‐world networks
Authors: Thibert‐Plante Xavier , Parrott Lael
Published: July 2007

The structure of interaction plays an important role in the outcome of evolutionary games. This study investigates the evolution of stochastic strategies of the prisoner's dilemma played on structures ranging from lattices to small world networks. Strategies and payoffs are analyzed as a function of the network characteristics of the node they are playing on. Nodes with lattice‐like neighborhoods tend to perform better than the nodes modified during the rewiring process of the construction of the small‐world network. © 2007 Wiley Periodicals, Inc. Complexity 12:22–36, 2006
Electrostatic Probe Measurements in the Glow Discharge Plasma of a D. C. Magnetron Sputtering System
Authors: Petrov I. , Orlinov V. , Ivanov I. , Kourtev J.
Published: July 2007

The characteristics of the plasma surrounding the substrates in a planar magnetron sputtering system with a graphite target have been investigated by electrostatic probe measurements. The behaviour of the ion density ni and the electron temperature Te, determining the ion flux that can be extracted by the substrate, with the variation of the basic system parameters, has been studied.
Fluid Models for a Tokamak Scrape‐Off Plasma
Authors: Petravic M. , Kuo‐Petravic G. , Arzt T.
Published: July 2007

A fluid model which includes ion drifts has been applied to the SOL of a tokamak with a poloidal divertor. Large parallel velocities and steep gradients in the pressure and electrostatic potential are found near the X‐point, in contrast with the solutions of the standard model.
Magnetogravitational Stability of Resistive Plasma through Porous Medium with Thermal Conduction and FLR Corrections
Authors: Vaghela D. S. , Chhajlani R. K.
Published: July 2007

The problem of stability of self gravitating magnetized plasma in porous medium is studied incorporating electrical resistivity, thermal conduction and FLR corrections. Normal mode analysis is applied to derive the dispersion relation. Wave propagation is discussed for parallel and perpendicular directions to the magnetic field. Applying Routh Hurwitz Criterion the stability of the medium is discussed and it is found that Jeans' criterion determines the stability of the medium. Magnetic field, porosity and resistivity of the medium have no effect on Jeans' Criterion in longitudinal direction. For perpendicular direction, in case of resistive medium Jeans' expression remains unaffected by magnetic field but for perfectly conducting medium magnetic field modifies the Jeans' expression to show the stabilizing effect. Thermal conducitivity affects the sonic mode by making the process isothermal instead of adiabatic. Porosity of the medium is effective only in case of perpendicular direction to magnetic field for perfectly conducting plasma as it reduces the stabilizing effect of magnetic field. For longitudinal wave propagation, though FLR corrections have no effect on sonic mode but it changes the growth rate for Alfvén mode. For transverse wave propagation FLR corrections and porosity affect the Jeans' expression in case of nonviscous medium but viscosity of the medium removes the effect of FLR and porosity on Jeans' condition.
Modelling of the Positive Column in an Argon‐Hexamethyl‐disiloxane dc Glow Discharge
Authors: Schmidt M. , Maass M.
Published: July 2007

A model is presented of the positive column of a dc glow discharge in argon with small admixtures of hexamethyldisiloxane (HMDS). The axial electric field, the ion production rates for direct‐, stepwise‐, pair‐, and Penning ionization, the densities of metastable Ar atoms and of electrons, and the wall current of HMDS ions are calculated in dependence on HMDS admixture and discharge current density. For the calculations particle balance equations were used for a diffusion determined plasma in a mixture of two gaseous components. The reaction rates for the electron collision processes were determined applying the electron distribution function calculated for pure argon. Taking into account PENNING ionization of HMDS molecules by metastable argon atoms the decrease of electric field for increasing HMDS admixtures is according to the experimen‐tally measured values. Also ion wall currents and electron densities are compared with experimen‐tal values for thin film formation rate and results of probe measurements.
Analysis of the Near‐Anode Processes Characters in Argon Arc Discharges of High Pressure
Authors: Nazarenko I. P. , Panevin I. G.
Published: July 2007

In this paper the anode layer model including two zones is considered. It is suggested that in the collisionalless zone (the sheath) the potential drop is negative. For the collisional part of the anode layer the equation system is considered. This system takes into account the ionization non‐equilibrium in this layer. Here side by side with the electrical field the complementary diffusion mechanism of the current transfer is examined. This mechanism is stipulated by the existence of the electron gas pressure gradients in the anode layer. It is shown that the potential drop in the collisional part of the anode layer is also negative because of the action of the diffusion mechanism of the current transfer. In this way the full potential drop in the anode layer of the discharge burning in argon by atmospere pressure is turned out to be negative. The character of the change of the energy and impulse equations terms is discussed.
Theory of Weak Modified Electron Acoustic Double Layers and Solitary Waves in Presence of Negative Ions
Authors: Dey M. , Goswami K. S. , Bujarbarua S.
Published: July 2007

We have studied the analytic solutions for modified electron acoustic double layers and solitary waves in a four component plasma system viz. two electrons and two ions, one positive and the other negative. It has been shown that DL solution does not exist when the temperatures of the free and the trapped particles are considered to be same for all the free species. On the other hand, DL solutions are found to exist when the effects of the reflected electrons (hot) are considered. The velocity and thickness of the DL have been valculated.
Theory of Optogalvanic Signals Originating from Metastable States in Hollow Cathode Neon Discharges
Authors: Sofonea V. , Popescu I. I.
Published: July 2007

A previous theoretical model is enlarged to elucidate some features of the optogalvanic signals originating from the metastable states in hollow cathode neon discharges. Numerical experiments were performed on the basis of this model to obtain the time evolution of the optogalvanic signals in pulsed and chopped cw experiments at 588.2 nm for different discharge currents and different laser intensities. The predictions of the numerical experiments were found to be in qualitative agreement with real experimental results.