bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceptions of Neighborhood Disorder: The Role of Individual and Neighborhood Characteristics*
Authors: Elo Irma T. , Mykyta Laryssa , Margolis Rachel , Culhane Jennifer F.
Published: October 2009

Objectives. The study of neighborhood effects on health and well‐being has regained prominence in recent years. Most authors have relied on Census data and other administrative data sources to assess neighborhood characteristics. Less commonly employed, but gaining in popularity, are measures from surveys that ask neighborhood residents about various aspects of their neighborhood environment. Such surveys are a potentially attractive alternative or augmentation to administrative data sources.

Methods. Using data from a study of neighborhood effects on pregnancy outcomes among low‐income, inner‐city women in Philadelphia, PA (N=3,988), we examined psychometric and ecometric properties of scales used to assess perceptions of crime and safety, physical disorder and social disorder, and estimated effects of individual‐ and neighborhood‐level predictors on perceptions.

Results. The three perceived neighborhood disorder scales had high internal consistency and good neighborhood‐level reliability. Several individual attributes of the women predicted perceptions of neighborhood disorder, controlling for neighborhood‐level characteristics (within Census tract, fixed‐effect estimates). In addition, our objective indicators of neighborhood crime and physical and social disorder were highly significant predictors of women's perceptions, explaining over 70 percent of the between‐neighborhood variation in perceptions.

Conclusions. When data on objective neighborhood characteristics are unavailable, the inclusion of questions about residents' perceptions of neighborhood conditions in surveys of inner‐city residents provides a useful alternative to characterize neighborhood conditions.
European Union and Health Policy: The “Chaordic” Dynamics of Integration*
Authors: Lamping Wolfram , Steffen Monika
Published: October 2009

Objective.The objective of this article is to analyze the various components of EU health policy and to propose a conceptualization of the Europeanization of different countries' health policies.

Method.Drawing on the methodology of public policy analysis, the authors identify core policies and their developments. They focus on the political processes and the stakeholders involved, and discuss future policy outcomes and their consequences.

Results.The results show a two‐sided picture: on the one hand, Europeanization in the health policy field primarily results from indirect impacts, rather than from direct treaty‐based provisions or from a clear‐cut sectoral policy; on the other hand, the EU exercises an increasingly strong influence over health policy in Member States, justified by internal market imperatives as well as public health requirements.

Conclusion.The conclusion identifies a growing European health policy compound characterized by new, complex, and often overlapping responsibilities between the national and supranational levels. It conceptualizes the Europeanization of health policy as a differential, multiple, and often accidental process, the effects of which nevertheless tend to be quite systematic.
Left Ventricular End‐Systolic Stress in Young Adults: Distribution, Risk Factors, and Relation to Cardiovascular Disease Events
Authors: Santo‐Domingo Noel E. , Orlov Michael , Wong Nathan D. , Kurosaki Tom , Reid Cheryl L. , Hsieh Ann‐Ming Andy , Gardin Julius M.
Published: October 2009

Background: We examined the relationship of left ventricular (LV) end‐systolic meridional wall stress (LVESS), a measure of LV afterload, with race, gender, other cardiovascular risk factors and LV mass in 3,994 young adults in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Methods: From transthoracic echocardiography, LVESS was derived from LV internal dimension and posterior wall thickness and systolic blood pressure (BP). Results: Adjusted LVESS was significantly greater in black men versus women (59.0 vs. 54.8 dynes/cm, P < 0.01) and in white men versus women (59.0 vs. 55.4 dynes/cm2, P < 0.01), but did not differ in comparing whites versus blacks either in men or women. In multiple regression analyses, age and LV mass were inversely (P < 0.01) and height was positively (P < 0.01) associated with LVESS. The overall variance of LVESS explained by the models in each race‐sex subgroup was low (R2 less than 0.03), suggesting that standard risk factors contribute little to determining LVESS in young adults. Over a 15‐year follow‐up period, LVESS, after the adjustment for covarieties, was not associated with the incidence of coronary heart disease (CHD) and cardiovascular disease (CVD) events. Conclusion: LVESS may not be a useful marker of cardiovascular risk in young adults; further study is needed to determine whether other echocardiographic measures may be more useful predictors.
The Marfan Syndrome: Implications for Athletes and Their Echocardiographic Assessment
Authors: Stout Martin
Published: October 2009

Sudden death of competitive athletes is rare. These deaths challenge the perception that trained athletes represent the healthiest segment of modern society. The increasing frequency of such reported deaths worldwide and the visibility of the issue is underlined by the high‐profile nature of each case. The majority of these deaths have been due to a variety of undiagnosed cardiovascular diseases. Marfan syndrome is a heritable disorder of the connective tissue that can hold life threatening consequences, especially for the athletic population. This paper will aim to review cardiovascular pathophysiology and assessment in relation to Marfan syndrome with particular reference to echocardiography and the athletic population.
Transesophageal Real Time Three‐Dimensional Echocardiography in Assessment of Partial Atrioventricular Septal Defect
Authors: Piatkowski Radoslaw , Budaj‐Fidecka Anna , Scislo Piotr , Kochanowski Janusz , Śpiewak Mateusz , Opolski Grzegorz
Published: October 2009

We present a practical application of real time three‐dimensional transesophageal echocardiography in a 67‐year‐old male patient with congenital heart disease.
2D and 3D Echocardiography of a Left Ventricular Diverticulum
Authors: Ruiz‐Esparza Eugenia , Roldan Francisco‐Javier , Vazquez‐Antona Clara , Romero‐Cárdenas Angel , Vargas‐Barrón Jesus
Published: October 2009

A real time transthoracic 3D study of a left ventricular diverticulum established through a narrow orifice located between the aortic and mitral valves is presented. Diverticular morphology was reconstructed and its volumes were calculated by this technique for the first time in the literature.
Evaluation of a Posterior Mitral Valve Leaflet Aneurysm by Real Time Three‐Dimensional Transesophageal Echocardiography
Authors: Hong Susie N. , Perk Gila , Skolnick Adam , Kronzon Itzhak
Published: October 2009

Posterior mitral valve (MV) leaflet aneurysms are extremely rare complications of infective endocarditis (IE). When MV aneurysms occur, they usually involve the anterior leaflet. Real time three‐dimensional transesophageal echocardiography (RT3D TEE) has been recently developed and provides views of unparalleled quality by optimizing visualization of spatial relationships. We present a rare case of a posterior MV leaflet aneurysm due to IE in a 64‐year‐old woman, best visualized by RT3D TEE.
Characterization of Rice Husk Ash and Its Recycling as Quartz Substitute for the Production of Ceramic Glazes
Authors: Bondioli Federica , Barbieri Luisa , Ferrari Anna Maria , Manfredini Tiziano
Published: October 2009

In this work a complete characterization of rice husk ash (RHA) was conducted in order to evaluate mainly the composition and the thermal reactivity in terms of crystalline phase evolution. Moreover, the screening results of the research conducted on the possibility to use RHA as silica precursor in ceramic materials, such as ceramic glazes, were reported. The selected frits were prepared in a semiindustrial furnace and the obtained glasses were investigated in comparison with the frits prepared from pure quartz. Besides, laboratory glazes were obtained and characterized following the technical rules. This work allows to confirm the possibility to use RHA as silica precursor for the development of glazes for ceramic tile. The results evidenced, however, that it is not possible for a generalized production substitution of quartz with RHA.
Integrating DSM‐IV Factors to Predict Violence in High‐Risk Psychiatric Patients
Authors: Lynch Donna M. , Noel Helen C.
Published: October 2009

Abstract:  This study incorporated Axis‐II and Axis‐IV factors in DSM‐IV to test the relationship between predicted risk for violence assessed in the psychiatric emergency room and actual violence during hospitalization. Psychiatric nurses lack an objective instrument to use during the acute psychiatric assessment. The retrospective study comprised consecutive psychiatric admissions (n = 161) in one tertiary veterans’ hospital. Statistical testing for the predictive power of risk factors, relationships between variables, and violent events included nonparametric tests, factor analysis, and logistic regression. Of the 32 patients who committed violence during hospitalization, 12 had committed violence in the psychiatric emergency room. Statistical significance was shown for violent incidents and dementia, court‐ordered admission, mood disorder, and for three or more risk factors. The 13‐item Risk of Violence Assessment (ROVA) scale suggests validity and sensitivity for rating DSM‐IV factors and psychosocial stressors to predict risk for violence during hospitalization. Replication studies are recommended to strengthen validity of the ROVA scale.
Labor–Management Relations: Understanding and Practicing Effective Negotiations
Authors: McKersie Robert , Cutcher‐Gershenfeld Joel
Published: October 2009

Periodic collective bargaining between employers and unions, combined with contract administration and workplace dispute resolution, has provided many core insights for the broad field of negotiations. Over the past twenty‐five years, this arena has advanced knowledge regarding the interdependence of integrative and distributive bargaining, the concurrent shaping of attitudes, the management of internal relations (within a party), and the roles of elected and appointed agents. Public sector negotiations have provided new insights into the dynamics of multilateral bargaining as well as a broad array of mediation and arbitration models. While the number of labor agreements negotiated each year has declined over the past half century, at least 23,000 private sector agreements are still executed each year and fundamental changes in industrial relations systems make continued attention to labor–management negotiations of increasing importance. In particular, this arena now features highly structured approaches applying interest‐based bargaining principles and presents profound challenges as power relations shift in multiple ways.
Too Bad for the Women or Does It Have to Be? Gender and Negotiation Research over the Past Twenty‐Five Years
Authors: Kolb Deborah M.
Published: October 2009

One overriding question that scholars have addressed over the past twenty‐five years is: are women the same or different from men when it comes to negotiating and what might explain these differences? The inquiry has shifted and has become more nuanced over time, but in its essence the issue of individual difference still dominates much of our thinking and research on the topic. The purpose of this article is to provide a structured overview of this considerable literature on gender and negotiation as it has evolved over the past twenty‐five years. In doing this, the article highlights how the social construction of gender has generally changed the discourse from essentialist concepts of differences between men and women to seeing gender as a more complex and shifting dimension of individual identity that is shaped by the contexts in which negotiation occurs. The second purpose of this article is to consider how recent feminist perspectives on gender, which have shifted from viewing gender as a property of individuals to considering the role of institutionalized social practices that sustain gender differences and inequities, can be incorporated into our understanding of gender relations in negotiation theory, practice, and research.
Five‐year follow‐up of prematurely born children with postnatally developing caudothalamic cysts
Authors: Lind A , Lapinleimu H , Korkman M , Lehtonen L , Parkkola R , Haataja L ,   the PIPARI Study Group
Published: October 2009

Aim:  To assess the long‐term developmental outcome of very low birth weight children with postnatally developing caudothalamic cysts.

Methods:  Five very low birth weight children with postnatal caudothalamic cysts were examined using cranial ultrasound and brain Magnetic Resonance Imaging as neonates, the Bayley Scales of Infant Development, 2nd edition, and the Hammersmith Infant Neurological Examination at 2 years of corrected age, and with the Wechsler Preschool and Primary Scale of Intelligence‐Revised and the standardization version of NEPSY II at 5 years of age. The Magnetic Resonance Imaging of the brain was repeated at 5 years of age. The developmental outcome at 5 years of age was compared with that of 23 very low birth weight children with normal brain structure.

Results:  A cognitive level below normal and/or neuropsychological impairments was seen in all the children with caudothalamic cysts as well as in those with normal brain structure.

Conclusion:  Very low birth weight children with postnatally developing caudothalamic cysts had cognitive and neuropsychological impairments similar to very low birth weight children without such cysts.
Prevalence of advance care directives in aged care facilities of the Northern Illawarra
Authors: Bezzina Andrew J
Published: October 2009

Objective:  To assess the prevalence of advance care directives in the residential aged care facilities within the catchment for a single ED and to assess the systems in place for development of those advance care directives with focus on documentation and communication.

Methods:  A de‐identified, paper‐based, mail‐out survey of all 30 residential aged care facilities potentially referring to the Wollongong Hospital ED.

Results:  A total of 24 of 30 surveys were returned. Thirteen facilities reported at least some proportion of their residents having documented advance care directives. The median prevalence of advance care directives was 5% of residents (interquartile range 0–10%). Discussions with residents over advance care directives were reported in 9 of 24 survey returns. Not all facilities that reported documenting advance care directives had processes for regular review or 24 h access to the documentation for carers. Ten of the survey returns reported general practitioner involvement in advance care directive development.

Conclusion:  The facilities surveyed reported that advance care directives are the exception rather than the rule. Where they were developed some facilities did not ensure regular review, dissemination of the information nor consistent involvement of the GP. This demonstrates low utilization and poor application, which has implications for care appropriate to patients' wishes and for resource use within the ED.
Malnutrition associated with increased risk of frail mechanical falls among older people presenting to an emergency department
Authors: Vivanti Angela P , McDonald Cameron K , Palmer Michelle A , Sinnott Michael
Published: October 2009

Objective:  To identify associations between malnutrition falls risk and hospital admission among older people presenting to ED.

Methods:  A prospective convenience sample of patients, aged 60 years or more, presenting to an Australian tertiary teaching hospital ED were included in this cross‐sectional study. Malnutrition Screening Tool and Subjective Global Assessment tool were administered to 126 non‐consecutive participants. Participants were categorized as non‐fallers, frail mechanical or active mechanical fallers. Self‐reported falls in past 6 months and hospital admission were documented.

Results:  Participant age and sex (median age 74, interquartile range 65–82 years; male 59%, 74/126, 95% CI 50–67%) were representative of older people presenting to the ED. Malnutrition prevalence was 15% (19/126, 95% CI 9–21%). There was an increased risk of being assessed as malnourished when a frail mechanical faller relative to: a non‐faller (relative risk [RR]: 1.5, 95% CI 1.0–2.3, P= 0.001), an active mechanical faller (RR: 3.1, 95% CI 1.0–10.9, Fisher's Exact test P= 0.02) or a non‐faller and active mechanical faller combined (RR: 1.5, 95% CI 1.0–2.1, P= 0.001). Malnourished participants had an increased risk of self‐reported falls over 6 months (RR: 1.5, 95% CI 1.0–2.5, P= 0.03). There was over five times the risk of hospital admission if malnourished than if well‐nourished (RR: 5.3, 95% CI 1.4–20.0, Fisher's exact test P= 0.001). The Malnutrition Screening Tool captured 84% (16/19, 95% CI 78–92%) of participants assessed as malnourished by Subjective Global Assessment.

Conclusions:  Older people presenting to ED should be nutritionally screened. Malnutrition prevalence of 15% was documented and was associated with an increased risk of frail mechanical falls and hospital admission. The Malnutrition Screening Tool was a simple and practical screen for ED.
Quality of Sexual Life in Hyperandrogenic Women Treated with an Oral Contraceptive Containing Chlormadinone Acetate
Authors: Caruso Salvatore , Rugolo Salvatore , Agnello Carmela , Romano Mattea , Cianci Antonio
Published: October 2009

Introduction

Hyperandrogenism produces change in quality of life of women.

Aim

To prespectively determine the changes of the sexual behaviour of hyperandrogenic women using an oral contraceptive containing 30 µg ethinylestradiol and 2 mg chlormadinone acetate (EE/CMA).

Methods

Seventy-two volunteer women (age range, 18–32 years), with moderate to severe hirsutim and acne were treated with EE/CMA for 9 cycles.

Main Outcomes Measure(s)

To assess hirsutism, the Ferriman-Gallwey (F-G) scoring system was used. Serum FSH, LH, estradiol, total and free testosterone, DHEAS, androstenedione, and SHBG levels were measured at baseline and at the 9th cycle of pill intake. The Short Personal Experience Questionnaire (SPEQ), the Short Form-36 (SF-36), and a visual analog scales questionnaires were used to assess the QoL, at baseline and after 3, 6 and 9 cycles of pill use.

Result(s)

A reduction of 65% and 81% in the total mean F-G score was observed after the 6th cycle and the 9th cycle, respectively. The serum Androstenedione, and total and free testosterone levels decreased, and SHBG levels increased after the 9th cycle (p < 0.05). The SF-36 score was higher after 6 (p < 0.05) 9 cycles (p < 0.001) with respect to baseline. Frequency of sexual intercourse and of orgasm by intercourse increased, and the frequency of masturbation decreased during the 6th (p < 0.05) and the 9th cycle (p < 0.001).

Conclusion(s)

The EE/CMA pill has anti-androgenic properties reducing the anti-aesthetic effect of hyperandrogenism and improving female sexual and social self-esteem.
Food Commodity Prices in the Long Run: The Crucial Role of Agricultural Research and Productivity  Les prix à long terme des produits alimentaires primaires : le rôle décisif de la recherche et de la productivité agricoles  Langfristige Preisentwicklung von Nahrungsmitteln: Die entscheidende Rolle der Agrarforschung und landwirtschaftlicher Produktivität
Authors: Alston Julian M. , Beddow Jason M. , Pardey Philip G.
Published: October 2009

Food Commodity Prices in the Long Run: The Crucial Role of Agricultural Research and Productivity

Over the past 50 years and longer, the supply of food commodities has grown faster than the effective market demand, in spite of increasing population and per capita incomes. Consequently, the real (deflated) prices of food commodities have steadily trended down. The past increases in agricultural productivity and production, and the resulting real price trends, are attributable in large part to technological changes enabled by investments in agricultural R&D. A range of evidence indicates a slowdown in the long‐term path of agricultural productivity growth. A slowdown in the long‐term rate of growth can be difficult to discern in the context of myriad other secular and random changes, and even more difficult to attribute among potential causes. It seems likely that at least some of the recent slowdown in productivity growth is attributable to shifts in agricultural R&D spending: a progressive slowing down in the growth rate of total spending on agricultural R&D and a redirection of the funds away from farm productivity that began 20–30 years ago. The effects of a productivity slowdown are cumulative and enduring with potentially serious consequences. Regardless of what caused the slowdown in productivity, a restoration of past growth rates is likely to require an acceleration of spending on farm‐productivity‐oriented R&D.
Thyroid hormone receptor α can control action potential duration in mouse ventricular myocytes through the KCNE1 ion channel subunit
Authors: Mansén A. , Tiselius C. , Sand P. , Fauconnier J. , Westerblad H. , Rydqvist B. , Vennström B.
Published: October 2009

Aims:  The reduced heart rate and prolonged QTend duration in mice deficient in thyroid hormone receptor (TR) α1 may involve aberrant expression of the K+ channel α‐subunit KCNQ1 and its regulatory β‐subunit KCNE1. Here we focus on KCNE1 and study whether increased KCNE1 expression can explain changes in cardiac function observed in TRα1‐deficient mice.

Methods:  TR‐deficient, KCNE1‐overexpressing and their respective wildtype (wt) mice were used. mRNA and protein expression were assessed with Northern and Western blot respectively. Telemetry was used to record electrocardiogram and temperature in freely moving mice. Patch‐clamp was used to measure action potentials (APs) in isolated cardiomyocytes and ion currents in Chinese hamster ovary (CHO) cells.

Results:  KCNE1 was four to 10‐fold overexpressed in mice deficient in TRα1. Overexpression of KCNE1 with a heart‐specific promoter in transgenic mice resulted in a cardiac phenotype similar to that in TRα1‐deficient mice, including a lower heart rate and prolonged QTend time. Cardiomyocytes from KCNE1‐overexpressing mice displayed increased AP duration. CHO cells transfected with expression plasmids for KCNQ1 and KCNE1 showed an outward rectifying current that was maximal at equimolar plasmids for KCNQ1‐KCNE1 and decreased at higher KCNE1 levels.

Conclusion:  The bradycardia and prolonged QTend time in hypothyroid states can be explained by altered K+ channel function due to decreased TRα1‐dependent repression of KCNE1 expression.
Folate: A Functional Food Constituent
Authors: Iyer Ramya , Tomar S.K.
Published: October 2009

ABSTRACT:  Folate, a water‐soluble vitamin, includes naturally occurring food folate and synthetic folic acid in supplements and fortified foods. Mammalian cells cannot synthesize folate and its deficiency has been implicated in a wide variety of disorders. A number of reviews have dwelt up on the health benefits associated with increased folate intakes and many countries possess mandatory folate enrichment programs. Lately, a number of studies have shown that high intakes of folic acid, the chemically synthesized form, but not natural folates, can cause adverse effects in some individuals such as the masking of the hematological manifestations of vitamin B12 deficiency, leukemia, arthritis, bowel cancer, and ectopic pregnancies. As fermented milk products are reported to contain even higher amounts of folate produced by the food‐grade bacteria, primarily lactic acid bacteria (LAB), the focus has primarily shifted toward the natural folate, that is, folate produced by LAB and levels of folate present in foods fermented by/or containing these valuable microorganisms. The proper selection and use of folate‐producing microorganisms is an interesting strategy to increase “natural” folate levels in foods. An attempt has been made through this review to share information available in the literature on wide ranging aspects of folate, namely, bioavailability, analysis, deficiency, dietary requirements, and health effects of synthetic and natural folate, dairy and nondairy products as a potential source of folate, microorganisms with special reference to Streptococcus thermophilus as prolific folate producer, and recent insight on modulation of folate production levels in LAB by metabolic engineering.
Evidence‐based transfusion: young versus old blood as a case study
Authors: Benjamin R. J.
Published: October 2009

Background Evidence‐based medicine incorporates critical appraisal of the literature, individual clinical expertise, patient values, clinical circumstances and societies’ expectations into medical decision‐making. This approach is increasingly utilized to formulate individual transfusion decisions and to set national transfusion policies.

Aims To describe the process of evidence‐based decision‐making and its application to transfusion medicine through the analysis of a test case.

Methods Critical appraisal of the literature and evidence‐based medicine techniques are described and applied to the issue of the duration of red cell storage and the incidence of complications after transfusion, as raised by the report of Kochet al.(N Engl J Med358:12, 1229–39). This report compared the outcomes of patients transfused with blood after ≤ 14 or > 14 days of storage during and after cardiac surgery.

Results The methods and logic of literature appraisal and evidence‐based medicine are reviewed, and applied to the paper by Kochet al(N Engl J Med358:12, 1229–39).This report describes a case‐controlled, retrospective observational study with Level 3‐4 evidence to support the use of younger blood (≤14 days old) in cardiac surgery patients. Issues are raised concerning the equivalence of the prestudy prognosis of the test and control groups and the use of non‐risk adjusted statistics in comparing data. After risk adjustment, the association of an older blood transfusion with a poorly defined composite index of adverse outcomes has only marginal significance (OR: 1·16, 95% CI: 1·01–1·33). Reports of systematic review of the literature reveals 19 publications: 14 studies are retrospective observational studies and many suggest an association of older blood with various adverse outcomes. Five prospective studies fail to show an adverse relationship, however, these are small and underpowered. Society values emphasize the availability of blood products, which at this time requires inventory management practices that prevent the transfusion of blood < 14 days storage on a routine basis for all patients.

Conclusions Evidence‐based decision‐making provides a formal process to evaluate the information supporting individual clinical and national policy decisions in transfusion medicine. Application to the specific problem of whether to limit the use of older blood suggests that the level of available evidence does not yet justify changing clinical practice. Adequately powered randomized controlled trials are necessary to determine the relative safety of older blood compared with younger blood in transfusion practice.
Advanced General Dentistry program directors’ attitudes on physician involvement in pediatric oral health care
Authors: Raybould Ted P. , Wrightson A. Stevens , Massey Christi Sporl , Smith Tim A. , Skelton Judith
Published: October 2009

Childhood oral disease is a significant health problem, particularly for vulnerable populations. Since a major focus of General Dentistry Program directors is the management of vulnerable populations, we wanted to assess their attitudes regarding the inclusion of physicians in the prevention, assessment, and treatment of childhood oral disease. A survey was mailed to all General Practice Residency and Advanced Education in General Dentistry program directors (accessed through the ADA website) to gather data. Spearman's rho was used to determine correlation among variables due to nonnormal distributions. Overall, Advanced General Dentistry directors were supportive of physicians’ involvement in basic aspects of oral health care for children, with the exception of applying fluoride varnish. The large majority of directors agreed with physicians’ assessing children's oral health and counseling patients on the prevention of dental problems. Directors who treated larger numbers of children from vulnerable populations tended to strongly support physician assistance with early assessment and preventive counseling.
Design of Adaptive and Controllable Compliant Systems With Embedded Actuators and Sensors
Authors: Trease Brian , Kota Sridhar
Published: October 2009

We present a framework for the design of a compliant system, i.e., the concurrent design of a compliant mechanism with embedded actuators and sensors. Our methods simultaneously synthesize optimal structural topology and component placement for maximum energy efficiency and adaptive performance, while satisfying various weight and performance constraints. The goal of this research is to lay an algorithmic framework for distributed actuation and sensing within a compliant active structure. Key features of the methodology include (1) the simultaneous optimization of the location, orientation, and size of actuators (and sensors) concurrent with the compliant transmission topology, and (2) the implementation of controllability and observability concepts (both arising from consideration of control) in compliant systems design. The methods used include genetic algorithms, graph searches for connectivity, and multiple load cases implemented with linear finite element analysis. Actuators, modeled as both force generators and structural compliant elements, are included as topology variables in the optimization. The results from the controllability problem are used to motivate and describe the analogous extension to observability for sensing. Results are provided for several studies, including (1) concurrent actuator placement and topology design for a compliant amplifier, (2) a shape-morphing aircraft wing demonstration with three controlled output nodes, and (3) a load-distribution sensing wing structure with internal sensors. Central to this method is the concept of structure/component orthogonality, which refers to the unique system response for each component (actuator or sensor) it contains.
Continuum Modeling of Biological Tissue Growth by Cell Division, and Alteration of Intracellular Osmolytes and Extracellular Fixed Charge Density
Authors: Ateshian Gerard A. , Costa Kevin D. , Azeloglu Evren U. , Morrison Barclay , Hung Clark T.
Published: October 2009

A framework is formulated within the theory of mixtures for continuum modeling of biological tissue growth that explicitly addresses cell division, using a homogenized representation of cells and their extracellular matrix (ECM). The model relies on the description of the cell as containing a solution of water and osmolytes, and having a porous solid matrix. The division of a cell into two nearly identical daughter cells is modeled as the doubling of the cell solid matrix and osmolyte content, producing an increase in water uptake via osmotic effects. This framework is also generalized to account for the growth of ECM-bound molecular species that impart a fixed charge density (FCD) to the tissue, such as proteoglycans. This FCD similarly induces osmotic effects, resulting in extracellular water uptake and osmotic pressurization of the ECM interstitial fluid, with concomitant swelling of its solid matrix. Applications of this growth model are illustrated in several examples.
Coupling the Hemodynamic Environment to the Evolution of Cerebral Aneurysms: Computational Framework and Numerical Examples
Authors: Watton Paul N. , Raberger Nikolaus B. , Holzapfel Gerhard A. , Ventikos Yiannis
Published: October 2009

The physiological mechanisms that give rise to the inception and development of a cerebral aneurysm are accepted to involve the interplay between the local mechanical forces acting on the arterial wall and the biological processes occurring at the cellular level. In fact, the wall shear stresses (WSSs) that act on the endothelial cells are thought to play a pivotal role. A computational framework is proposed to explore the link between the evolution of a cerebral aneurysm and the influence of hemodynamic stimuli that act on the endothelial cells. An aneurysm evolution model, which utilizes a realistic microstructural model of the arterial wall, is combined with detailed 3D hemodynamic solutions. The evolution of the blood flow within the developing aneurysm determines the distributions of the WSS and the spatial WSS gradient (WSSG) that act on the endothelial cell layer of the tissue. Two illustrative examples are considered: Degradation of the elastinous constituents is driven by deviations of WSS or the WSSG from normotensive values. This model provides the basis to further explore the etiology of aneurysmal disease.
A Structure-Based Model of Arterial Remodeling in Response to Sustained Hypertension
Authors: Tsamis Alkiviadis , Stergiopulos Nikos , Rachev Alexander
Published: October 2009

A novel structure-based mathematical model of arterial remodeling in response to a sustained increase in pressure is proposed. The model includes two major aspects of remodeling in a healthy matured vessel. First, the deviation of the wall stress and flow-induced shear stress from their normal physiological values drives the changes in the arterial geometry. Second, the new mass that is produced during remodeling results from an increase in the mass of smooth muscle cells and collagen fibers. The model additionally accounts for the effect of the average pulsatile strain on the recruitment of collagen fibers in load bearing. The model was used to simulate remodeling of a human thoracic aorta, and the results are in good agreement with previously published model predictions and experimental data. The model predicts that the total arterial volume rapidly increases during the early stages of remodeling and remains virtually constant thereafter, despite the continuing stress-driven geometrical remodeling. Moreover, the effects of a perfect or incomplete restoration of the arterial compliance on the remodeling outputs were analyzed. For instance, the model predicts that the pattern of the time course of the opening angle depends on the extent to which the average pulsatile strain is restored at the end of the remodeling process. Future experimental studies on the time course of compliance, opening angle, and mass fractions of collagen, elastin, and smooth muscle cells can validate and improve the introduced hypotheses of the model.
Parameter Sensitivity Study of a Constrained Mixture Model of Arterial Growth and Remodeling
Authors: Valentín A. , Humphrey J. D.
Published: October 2009

Computational models of arterial growth and remodeling promise to increase our understanding of basic biological processes, such as development, tissue maintenance, and aging, the biomechanics of functional adaptation, the progression and treatment of disease, responses to injuries, and even the design of improved replacement vessels and implanted medical devices. Ensuring reliability of and confidence in such models requires appropriate attention to verification and validation, including parameter sensitivity studies. In this paper, we classify different types of parameters within a constrained mixture model of arterial growth and remodeling; we then evaluate the sensitivity of model predictions to parameter values that are not known directly from experiments for cases of modest sustained alterations in blood flow and pressure as well as increased axial extension. Particular attention is directed toward complementary roles of smooth muscle vasoactivity and matrix turnover, with an emphasis on mechanosensitive changes in the rates of turnover of intramural fibrillar collagen and smooth muscle in maturity. It is shown that vasoactive changes influence the rapid change in caliber that is needed to maintain wall shear stress near its homeostatic level and the longer term changes in wall thickness that are needed to maintain circumferential wall stress near its homeostatic target. Moreover, it is shown that competing effects of intramural and wall shear stress-regulated rates of turnover can develop complex coupled responses. Finally, results demonstrate that the sensitivity to parameter values depends upon the type of perturbation from normalcy, with changes in axial stretch being most sensitive consistent with empirical reports.
A Systems Approach to Tissue Remodeling
Authors: Kassab Ghassan S.
Published: October 2009

Remodeling of tissue in response to physical stress is a very complex process. The changes in the stimulus (cause) and response (effect) must be measured and the results must be organized into mathematical forms that are suitable for predictions and applications. An experiment where the stimulus (pressure, flow, shear stress, etc.) can be changed approximately as a step function (a step plus a perturbation) and the response (structure, material properties, function, etc.), which can be measured over time, can be simulated by indicial response functions (IRFs). The IRF is a mathematical expression of the ratio of the change in a particular feature of the system in response to a unit step change in stimulus. The IRF approach provides a quantitative description of the remodeling process, simplifies the interpretation of data, and greatly increases the potential of using the experimental data for prediction of the outcome for future experiments. The objective of this review is to provide an overview of the IRF approach including some exemplary systems. The goal is to illustrate how the indicial expressions make it possible to integrate biological complexity by convolution. The time courses of stimuli represent half of the convolution while the time course of changes in response represents the second half of the convolution. The IRF approach provides an understanding of the physiological problems with mathematical accuracy and may be conducive to new findings.
Microstructurally Motivated Constitutive Modeling of Mouse Arteries Cultured Under Altered Axial Stretch
Authors: Hansen Laura , Wan William , Gleason Rudolph L.
Published: October 2009

Good predictions of the local mechanical environment of the tissue with known geometry and applied loads are fundamental to quantifying the biological response of tissues to mechanical stimuli. Whereas mean stresses in cylindrical sections of blood vessels may be calculated directly from measured loads and vessel geometry (e.g., Laplace’s law), predicting how these stresses are distributed across the wall requires knowledge of the constitutive behavior of the tissue. Previously, we reported biaxial biomechanical data for mouse carotid arteries before and after exposure to altered axial extension in organ culture. Here we considered phenomenological and microstructurally motivated constitutive models and identified material parameters for each via nonlinear regression. Specifically, we considered the model of Chuong and Fung, a four fiber-family model, and several new variants of a rule-of-mixtures model; in the latter, we modeled the artery as a mixture of collagen, elastin, muscle, and water. We found that the four fiber-family model fitted data significantly better than the model of Chuong and Fung. When identifying parameters for the rule-of-mixtures models, we imposed penalties that required each constituent to be structurally significant; e.g., elastin contributing significantly to the overall response over low loads and collagen dominating the response over high loads. Such constraints ascribe additional microstructural “meaning” to the constitutive model. Although imposing such penalties necessarily reduces the goodness of fit of model predictions to experimental data compared to regression without such penalties, the modest reduction in the goodness of fit observed in our results was off-set by the improved structural interpretation such models provide. Such microstructurally motivated models will be useful in characterizing vascular growth and remodeling in terms of the evolution of microstructural metrics that may be quantified experimentally.
Perturbation Theory Based Robust Design Under Model Uncertainty
Authors: Lu XinJiang , Li Han-Xiong
Published: October 2009

In real-world applications, a nominal model is usually used to approximate the practical system for design and control. This approximation may make the traditional robust design less effective because the model uncertainty still affects the system performance. In this paper, a novel robust design approach is proposed to improve the system robustness to the variations in design variables as well as the model uncertainty. The proposed robust design consists of two separate optimizations. One is to minimize the variation effects of the design variables to the performance based on the nominal model just as what the traditional deterministic robust design methods do. The other is to minimize the effect of the model uncertainty using the matrix perturbation theory. Through solving a multi-objective optimization problem, the proposed design can improve the system robustness to the uncertainty. Simulation examples have demonstrated the effectiveness of the proposed design method.
Bayesian Reliability Analysis With Evolving, Insufficient, and Subjective Data Sets
Authors: Wang Pingfeng , Youn Byeng D. , Xi Zhimin , Kloess Artemis
Published: October 2009

This paper presents a new paradigm of system reliability prediction that enables the use of evolving, insufficient, and subjective data sets. The data sets can be acquired from expert knowledge, customer survey, inspection and testing, and field data throughout a product life-cycle. In order to handle such data sets, this research integrates probability encoding methods to a Bayesian updating mechanism. The integrated tool is called Bayesian Information Toolkit. Subsequently, Bayesian Reliability Toolkit is presented by incorporating reliability analysis to the Bayesian updating mechanism. A generic definition of Bayesian reliability is introduced as a function of a predefined confidence level. This paper also finds that there is no data-sequence effect on the updating results. It is demonstrated that the proposed Bayesian reliability analysis can predict the reliability of door closing performance in a vehicle body-door subsystem, where available data sets are insufficient, subjective, and evolving.
Dry-etching properties of TiN for metal/high-k gate stack using BCl3-based inductively coupled plasma
Authors: Kim Dong-Pyo , Yang Xue , Woo Jong-Chang , Um Doo-Seung , Kim Chang-Il
Published: October 2009

The etch rate of TiN film and the selectivities of TiN∕SiO2 and TiN∕HfO2 were systematically investigated in Cl2∕BCl3∕Ar plasmas as functions of Cl2 flow rate, radio-frequency (rf) power, and direct-current (dc) bias voltage under different substrate temperatures of 10 and 80°C. The etch rate of TiN films increased with increasing Cl2 flow rate, rf power, and dc-bias voltage at a fixed substrate temperature. In addition, the etch rate of TiN films at 80°C were higher than that at 10°C when other plasma parameters were fixed. However, the selectivities of TiN∕SiO2 and TiN∕HfO2 showed different tendencies compared with etch-rate behavior as a function of rf power and dc bias voltage. The relative-volume densities of Ar (750.0nm), Cl (725.2nm), and Cl+ (386.6nm) were monitored with an optical-emission spectroscopy. When rf power increased, the relative-volume densities of all studied particles were increased. X-ray photoelectron spectroscopy was carried out to detect nonvolatile etch by-products from the surface, and nonvolatile peaks (TiClx bonds) in Ti 2p and Cl 2p were observed due to their high melting points. Based on the experimental results, we can conclude that the TiN etch is dependent on the substrate temperature when other plasma parameters are fixed. This can be explained by the enhanced chemical pathway with the assistance of ion bombardment.
Arrhythmia in Heart and Brain: KCNQ1 Mutations Link Epilepsy and Sudden Unexplained Death
Authors: Goldman A. M. , Glasscock E. , Yoo J. , Chen T. T. , Klassen T. L. , Noebels J. L.
Published: October 2009

Mice engineered to carry a human mutation that causes heart problems also have epilepsy, suggesting a cause of SUDEP, sudden unexplained death in epilepsy.
A CHARACTERIZATION OF THE INVERSE MONOID OF BI-CONGRUENCES OF CERTAIN ALGEBRAS
Authors: KAARLI KALLE , MÁRKI LÁSZLÓ
Published: October 2009

This paper provides an abstract characterization of the inverse monoids that appear as monoids of bi-congruences of finite minimal algebras generating arithmetical varieties. As a tool, a matrix construction is introduced which might be of independent interest in inverse semigroup theory. Using this construction as well as Ramsey's theorem, we embed a certain kind of inverse monoid into a factorizable monoid of the same kind. As noticed by M. Lawson, this embedding entails that the embedded finite monoids have finite F-unitary cover.
HOW CAN PRODUCT SEMANTICS BE EMBEDDED IN PRODUCT TECHNOLOGIES? THE CASE OF THE ITALIAN WINE INDUSTRY
Authors: DELL'ERA CLAUDIO , BELLINI EMILIO
Published: October 2009

Since the beginning of the 1990s, innovation management literature has attempted to overcome some oversimplified dichotomies coming from well-established theories (e.g., open vs. closed, external vs. internal, cooperation vs. competition, knowledge vs. learning). The design-push approach to the study of new product development has demonstrated that technology-push and market-pull are not divorced, since each successful new product is based on improvements in both technological performance and semantic features, which together sustain the new products to act as text that helps people generate new meanings in their daily sense-making activities. In this explorative study, we try to verify the extension of the design-push approach from science-based and specialised supplier industries (e.g., optical instruments, electronics, furniture) to more traditional, supplier-dominated industries (in this case, the wine industry), where its use could be counterintuitive. We then explain new product development, moving from the integration of technological and semantic dimensions of new products. We present the results of eleven case studies of successful new product development processes developed by companies located in Italy, known as one of the most innovative wine-producing areas in Europe. We assume that product innovation in traditional industry is only incremental, since technologies, operations and marketing processes are expected to be stable and predictable. Nevertheless, the empirical results show that the new product development process in the wine industry offers empirical insights that lead to a better understanding of the design-push approach; designing a new wine means not only to achieve new technical features but also to generate new product meanings. Through the identification of practices enabling a coherent innovation of product functions and meanings, this empirical research allows the enrichment of the design driven model. The coherence between the technology, function, language and message of a new wine can be obtained with different practices and development paths: the integrated approach, the semantic-oriented approach and the function-oriented approach. Additionally, the network of actors that wine companies access changes according to the innovation approach they adopt.