bluuebunny/crossref_metadata_2025 huggingface dataset:
Corticosteroids and Outcome in Children Undergoing Congenital Heart Surgery
Authors: Pasquali Sara K. , Hall Matthew , Li Jennifer S. , Peterson Eric D. , Jaggers James , Lodge Andrew J. , Marino Bradley S. , Goodman Denise M. , Shah Samir S.
Published: November 2010

Background—

Children undergoing congenital heart surgery often receive corticosteroids with the aim of reducing the inflammatory response after cardiopulmonary bypass; however, the value of this approach is unclear.

Methods and Results—

The Pediatric Health Information Systems Database was used to evaluate outcomes associated with corticosteroids in children (0 to 18 years of age) undergoing congenital heart surgery at 38 US centers from 2003 to 2008. Propensity scores were constructed to account for potential confounders: age, sex, race, prematurity, genetic syndrome, type of surgery (Risk Adjustment in Congenital Heart Surgery [RACHS-1] category), center, and center volume. Multivariable analysis, adjusting for propensity score and individual covariates, was performed to evaluate in-hospital mortality, postoperative length of stay, duration of ventilation, infection, and use of insulin. A total of 46 730 children were included; 54% received corticosteroids. In multivariable analysis, there was no difference in mortality among corticosteroid recipients and nonrecipients (odds ratio, 1.13; 95% confidence interval, 0.98 to 1.30). Corticosteroids were associated with longer length of stay (least square mean difference, 2.18 days; 95% confidence interval, 1.62 to 2.74 days), greater infection (odds ratio, 1.27; 95% confidence interval, 1.10 to 1.46), and greater use of insulin (odds ratio, 2.45; 95% confidence interval, 2.24 to 2.67). There was no difference in duration of ventilation. In analysis stratified by RACHS-1 category, no significant benefit was seen in any group, and the association of corticosteroids with increased morbidity was most prominent in RACHS-1 categories 1 through 3.

Conclusion—

In this observational analysis of children undergoing congenital heart surgery, we were unable to demonstrate a significant benefit associated with corticosteroids and found that corticosteroids may be associated with increased morbidity, particularly in lower-risk patients.
Silent Information Regulator 1 Protects the Heart From Ischemia/Reperfusion
Authors: Hsu Chiao-Po , Zhai Peiyong , Yamamoto Takanobu , Maejima Yasuhiro , Matsushima Shouji , Hariharan Nirmala , Shao Dan , Takagi Hiromitsu , Oka Shinichi , Sadoshima Junichi
Published: November 2010

Background—

Silent information regulator 1 (Sirt1), a class III histone deacetylase, retards aging and protects the heart from oxidative stress. We here examined whether Sirt1 is protective against myocardial ischemia/reperfusion (I/R).

Methods and Results—

Protein and mRNA expression of Sirt1 is significantly reduced by I/R. Cardiac-specific Sirt1
−/−
mice exhibited a significant increase (44±5% versus 15±5%;
P
=0.01) in the size of myocardial infarction/area at risk. In transgenic mice with cardiac-specific overexpression of Sirt1, both myocardial infarction/area at risk (15±4% versus 36±8%;
P
=0.004) and terminal deoxynucleotidyl transferase dUTP nick end labeling–positive nuclei (4±3% versus 10±1%;
P
<0.003) were significantly reduced compared with nontransgenic mice. In Langendorff-perfused hearts, the functional recovery during reperfusion was significantly greater in transgenic mice with cardiac-specific overexpression of Sirt1 than in nontransgenic mice. Sirt1 positively regulates expression of prosurvival molecules, including manganese superoxide dismutase, thioredoxin-1, and Bcl-xL, whereas it negatively regulates the proapoptotic molecules Bax and cleaved caspase-3. The level of oxidative stress after I/R, as evaluated by anti-8-hydroxydeoxyguanosine staining, was negatively regulated by Sirt1. Sirt1 stimulates the transcriptional activity of FoxO1, which in turn plays an essential role in mediating Sirt1-induced upregulation of manganese superoxide dismutase and suppression of oxidative stress in cardiac myocytes. Sirt1 plays an important role in mediating I/R-induced increases in the nuclear localization of FoxO1 in vivo.

Conclusions—

These results suggest that Sirt1 protects the heart from I/R injury through upregulation of antioxidants and downregulation of proapoptotic molecules through activation of FoxO and decreases in oxidative stress.
Factors Associated With Pulseless Electric Activity Versus Ventricular Fibrillation
Authors: Teodorescu Carmen , Reinier Kyndaron , Dervan Celia , Uy-Evanado Audrey , Samara Mershed , Mariani Ronald , Gunson Karen , Jui Jonathan , Chugh Sumeet S.
Published: November 2010

Background—

Corresponding with a continuing decline in the prevalence of sudden cardiac arrest cases presenting with ventricular fibrillation (VF), there has been a significant rise in the prevalence of pulseless electrical activity (PEA). Given significantly lower survival from PEA versus VF, we comprehensively investigated PEA correlates by incorporating first-responder data with lifetime clinical history information.

Methods and Results—

In the Portland, Ore, metropolitan area (population ≈1 million), cases of out-of-hospital sudden cardiac arrest who underwent attempted resuscitation were identified prospectively (2002–2007). Those presenting with PEA versus VF and asystole were compared with χ
2
tests, ANOVA, and logistic regression. A total of 1277 cases aged ≥18 years underwent resuscitation by first responders (mean age, 65±16 years; 67% male). Presenting arrhythmia was VF in 48%, PEA in 25%, and asystole/other in the remainder. Compared with VF cases, PEA cases were older (mean age, 68 versus 63 years;
P
=0.0002), more likely to be female (37% versus 26%;
P
=0.0008), and less likely to survive to hospital discharge (6% versus 25%;
P
<0.0001). A history of syncope was strongly associated with PEA (odds ratio, 2.6; confidence interval, 1.3 to 5.3) after adjustment for age, gender, response time, and arrest circumstances. Black race was also independently associated with PEA (odds ratio, 2.6; confidence interval, 1.3 to 5.4). Pulmonary disease and female gender were significant factors associated with PEA (
P
for interaction=0.04). In a subgroup analysis of resting ECGs (n=391), there were no differences in cardiac clinical history or prevalence of cardiac conduction system disease (PEA, 31.6% versus VF, 32.2%;
P
=0.48).

Conclusions—

PEA cases had a significantly higher prevalence of syncope in their lifetime, with other correlates, including black race, that were distinct from VF cases. Potential mechanistic links between syncope and future manifestation with PEA warrant further exploration.
GTP Cyclohydrolase I/BH4 Pathway Protects EPCs via Suppressing Oxidative Stress and Thrombospondin-1 in Salt-Sensitive Hypertension
Authors: Xie He-Hui , Zhou Shuang , Chen Dan-Dan , Channon Keith M. , Su Ding-Feng , Chen Alex F.
Published: November 2010

Endothelial progenitor cells (EPCs) are both reduced and dysfunctional in hypertension that correlates inversely with its mortality, but the mechanisms are poorly understood. Endothelial nitric oxide synthase (eNOS) critically regulates EPC mobilization and function but is uncoupled in salt-sensitive hypertension because of the reduced cofactor tetrahydrobiopterin (BH4). We tested the hypothesis that GTP cyclohydrolase I (GTPCH I), the rate-limiting enzyme of BH4 de novo synthesis, protects EPCs and its function in deoxycorticosterone acetate (DOCA)-salt mice. EPCs were isolated from peripheral blood and bone marrow of wild-type (WT), WT DOCA-salt, endothelial-specific GTPCH transgenic (Tg-GCH), GTPCH transgenic DOCA-salt, and BH4-deficient hph-1 mice. In WT DOCA-salt and hph-1 mice, EPCs were significantly decreased with impaired angiogenesis and adhesion, which were restored in Tg-GCH DOCA-salt mice. Superoxide (O
2
−
) and nitric oxide (NO) levels in EPCs were elevated and reduced, respectively, in WT DOCA-salt and hph-1 mice; both were rescued in Tg-GCH DOCA-salt mice. eNOS
−/−
/GCH
+/−
hybrid mice demonstrated that GTPCH preserved the circulating EPC number, reduced intracellular O
2
−
in EPCs, and ameliorated EPC dysfunction independent of eNOS in DOCA-salt hypertension. Secreted thrombospondin-1 (TSP-1; a potent angiogenesis inhibitor) from EPCs was elevated in WT DOCA-salt and hph-1 but not DOCA-salt Tg-GCH mice. In vitro treatment with BH4, polyethylene glycol-superoxide dismutase (PEG-SOD), or Nomega-nitro-L-arginine (L-NNA) significantly augmented NO and reduced TSP-1 and O
2
−
levels from EPCs of WT DOCA-salt mice. These results demonstrated, for the first time, that the GTPCH/BH4 pathway critically regulates EPC number and function in DOCA-salt hypertensive mice, at least in part, via suppressing TSP-1 expression and oxidative stress.
Understanding Negative Impacts of Perceived Cognitive Load on Job Learning Effectiveness: A Social Capital Solution
Authors: Lin Chieh-Peng
Published: November 2010

Objective: This study proposes a model explaining how social capital helps ease excessively required mental effort.

Background: Although organizational researchers have studied both social capital and cognitive load, no prior research has critically examined the role of social capital in improving individuals’ mental load and effort and consequently enhancing job learning effectiveness.

Method: This study surveys participants made up of professionals in Taiwan’s information technology industry. It measures the constructs with the use of 5-point Likert-type scale items modified from existing literature. The survey data were analyzed with the use of structural equation modeling.

Results: Job learning effectiveness is negatively influenced by role ambiguity and role conflict. Time pressure has a positive influence on role ambiguity and role conflict. Although the relationship between task complexity and role ambiguity is insignificant, task complexity has a positive influence on role conflict. Because the relationship between network ties and role conflict is insignificant, trust has a negative influence on role conflict. Last, shared vision has a negative influence on role ambiguity.

Conclusion: This study provides an example of how social capital can be applied as a useful remedy to ease the negative impact of perceived cognitive load on job learning effectiveness.

Application: The negative relationship between shared vision and role ambiguity suggests that a shared vision helps in disseminating organizationally common goals and directions among employees to alleviate individuals’ mental efforts in dealing with the ambiguity of their job roles. A firm’s management team should take actions to decrease role conflict by strengthening trust among employees.
In Vivo Measurement of Humeral Elevation Angles and Exposure Using a Triaxial Accelerometer
Authors: Amasay Tal , Latteri Michael , Karduna Andrew R.
Published: November 2010

Objective: The aim of this study was to measure the capability of a triaxial accelerometer (Virtual Corset) to collect humeral elevation angles and exposure parameters in a simulated occupational environment.

Background: There is a need for an economical ambulatory device to estimate elevation angles and exposure parameters in occupational groups.

Method: A magnetic tracking device was used to assess the ability of the Virtual Corset to evaluate humeral elevation angles and identify exposure parameters with in vivo dynamic conditions for 16 female dental hygienists.

Results: Significant differences were found for the reaching task with the Virtual Corset, underestimating the means of the average humeral elevation angle by 10° and the means for the range of the humeral elevation by 4°. Furthermore, significant differences were found for the exposure parameters with the Virtual Corset, overestimating the jerk by 4% and underestimating the percentage time above 40° and 60° by 9% and 4%, respectively. However, the Virtual Corset was able to identify similar kinematics patterns and exposure data when compared with a magnetic tracking device.

Conclusion: The outcomes of the study suggest that the Virtual Corset may be useful for data collection during a dental hygienist workday. Professions that have similar patterns of angular velocity and acceleration and humeral range of elevation as the dental hygienist flossing technique may benefit from the use of the Virtual Corset.

Application: This study provides evidence that the Virtual Corset can be used to reconstruct humeral elevation angles and identify exposure parameters in some tasks of dental hygienists.
The male state
Authors: Saha Jonathan
Published: November 2010

At the turn of the twentieth century British colonial officials imagined women in Burma to be distinctly more liberated than their sisters in other quarters of British India, but this posed a set of specific problems. The perceived influence women held over their husbands in official positions led to fears that they caused corruption. Women represented private interests infiltrating public duties. Thus the desired, normative subordinate colonial official was assertively masculine and in a position of authority over their female spouse. In this colonial desire there was a curious parallel with the everyday acts of misconduct committed by subordinate officials that was most apparent in rape investigations. Indigenous women faced great difficulties, even dangers, when seeking redress for crimes of gendered violence due to the machinations of subordinate state employees. High-ranking British officials demonstrated at best indifference, at worst suspicion, concerning women’s accusations. These everyday acts of subordinate officials were more important in gendering the colonial state than has been previously recognised.
Numerical analysis of displacement and stress fields of off-axis composites in three-point flexure
Authors: Romera J.M. , Adarraga I. , Cantera M.A. , Mujika F.
Published: November 2010

Three-point flexure test for unidirectional off-axis composites has been analyzed by the finite element method. The main difficulty of modeling three-point flexure test of this kind of material is due to the bending-twisting coupling that induces the lift-off of the specimen at the fixture supports. In the present work, the contact between the load and support rollers and the specimen has been modeled with linear gap elements. The type of element and refinement of the mesh have been analyzed in order to minimize numerical error. After having selected those parameters, a complete model with discretization of load and support rollers has been developed to simulate different test conditions. The numerical displacement field has been compared with analytical and experimental results obtained previously. Furthermore, the length and location of the contact between specimen and rollers has been numerically predicted in some configurations.
FGF-2 Stimulates Periodontal Regeneration
Authors: Kitamura M. , Akamatsu M. , Machigashira M. , Hara Y. , Sakagami R. , Hirofuji T. , Hamachi T. , Maeda K. , Yokota M. , Kido J. , Nagata T. , Kurihara H. , Takashiba S. , Sibutani T. , Fukuda M. , Noguchi T. , Yamazaki K. , Yoshie H. , Ioroi K. , Arai T. , Nakagawa T. , Ito K. , Oda S. , Izumi Y. , Ogata Y. , Yamada S. , Shimauchi H. , Kunimatsu K. , Kawanami M. , Fujii T. , Furuichi Y. , Furuuchi T. , Sasano T. , Imai E. , Omae M. , Yamada S. , Watanuki M. , Murakami S.
Published: November 2010

The efficacy of the local application of recombinant human fibroblast growth factor-2 (FGF-2) in periodontal regeneration has been investigated. In this study, a randomized, double-blind, placebo-controlled clinical trial was conducted in 253 adult patients with periodontitis. Modified Widman periodontal surgery was performed, during which 200 µL of the investigational formulation containing 0% (vehicle alone), 0.2%, 0.3%, or 0.4% FGF-2 was administered to 2- or 3-walled vertical bone defects. Each dose of FGF-2 showed significant superiority over vehicle alone (p < 0.01) for the percentage of bone fill at 36 wks after administration, and the percentage peaked in the 0.3% FGF-2 group. No significant differences among groups were observed in clinical attachment regained, scoring approximately 2 mm. No clinical safety problems, including an abnormal increase in alveolar bone or ankylosis, were identified. These results strongly suggest that topical application of FGF-2 can be efficacious in the regeneration of human periodontal tissue that has been destroyed by periodontitis.
A Modest Festschrift and Insider Perspective on Beatrice Wright’s Contributions to Rehabilitation Theory and Practice
Authors: McCarthy Henry
Published: November 2010

Assessing the influence of Beatrice Wright, a groundbreaking rehabilitation psychologist, is the purpose of this article. She is best known for her books (1960, 1983) in which she elaborated numerous original concepts that describe, explain, and aim to improve outsiders’ perception and insiders’ experience of life with a disability. A panel of 15 respected academics familiar with her publications answered an e-mailed questionnaire to delineate and critique the impact of Wright’s work on rehabilitation education, research, and practice. These findings were anonymously shared with Dr. Wright, and her thoughtful responses are reported as supplementary data. Numerous specific recommendations for research and practice are provided in the responses by Wright and the panel of experts. The latter’s judgments substantiate that Wright enjoys an outstanding reputation as an author of seminal ideas that have been more successfully applied as professional guidelines for providing meaningful and sensitive services than used as variables for research and instrument development.
Transport of Aromatic Hydrocarbons through EPDM/NBR Blends
Authors: Manoj K.C. , Kumari Prajitha , Rajesh C. , Unnikrishnan G.
Published: November 2010

The effect of blend ratio on the cure and transport characteristics of EPDM/NBR blends has been investigated. Cure studies showed that the maximum torque values increased with increase of the percentage of NBR in the blend system. As the percentage of NBR in the blends increased, the penetrant transport has been found to be decreased. The experimental observations have been correlated with the morphology of the blends; attested by SEM photographs. The equilibrium sorption with respect to the nature of penetrant has been observed to follow the order: benzene > toluene > xylene for a given blend ratio. A minor deviation from Fickian trend has been observed for the mechanism of transport. The experimental observations have been compared with the existing theoretical models.
‘Climate Protection’ as Empty Signifier: A Discourse Theoretical Perspective on Climate Mainstreaming in World Politics
Authors: Methmann Chris Paul
Published: November 2010

More and more international organisations are starting to incorporate climate protection as an important policy goal. Strikingly, most institutions only rephrase existing activities in the terms of climate protection instead of changing them, although there are tensions and contradictions between short-term economic and long-term environmental goals. The aim of this article is to explore the logic of climate mainstreaming and explain the paradoxical result of such a consistent inconsistency. It employs a poststructuralist approach that combines elements of governmentality and discourse theory. Analysing discourses of the WTO, IMF, World Bank and OECD, it argues that the global governmentality of climate protection is built on four discursive pillars — globalism, scientism, an ethics of growth and efficiency — that make climate protection function as an empty signifier; that is, they make it possible to integrate climate protection into the global hegemonic order without changing the basic social structures of the world economy. International organisations can claim to be in favour of climate protection and stick to business as usual at the same time. This claim is backed up by an interpretive discourse analysis of 31 texts of the respective organisations.
George W. Bush, the Supreme Court, and the Pursuit of “Big Government Conservatism” in Federal Personnel Management
Authors: Rosenbloom David H.
Published: November 2010

Ironically, by the end of the first year of the Obama administration, President George W. Bush appears to have gained an indirect impact on public personnel policy through his appointments of Chief Justice John Roberts and Justice Samuel Alito. In cases involving public personnel issues, both jurists have supported Bush’s preferences with respect to strict construction, executive power, and the use of racial and ethnic preferences. With one Obama appointee on the Supreme Court and another nominated, the prospects for the durability of that legacy in pursuit of “big government conservatism” are unclear. Nevertheless, this article’s analysis of Bush’s appointment “power in use” comports with findings regarding judicial appointee loyalty to presidential agendas that have emerged in recent years. It also suggests that further research on presidential appointments of federal judges and justices is needed and may demonstrate that the appointment power is an important determinant of public sector personnel policy in the United States.
Providing Competency Training to Clinical Supervisors Through an Interactional Supervision Approach
Authors: Kraemer Tebes Jacob , Matlin Samantha L. , Migdole Scott J. , Farkas Melanie S. , Money Roy W. , Shulman Lawrence , Hoge Michael A.
Published: November 2010

Training in supervisory competencies is essential to effective clinical practice and helps address the current national crisis in the behavioral health workforce. Interactional supervision, the approach used in the current study, is well established in clinical social work and focuses the task of the supervisee on the interpersonal exchanges encountered in clinical practice. This study examines the feasibility of supervisory competency training and associated gains in competencies among 81 clinical supervisors. Three types of competencies are assessed before and after training and at a 3-month follow-up—managing supervisory relationships, managing job performance, and promoting professional development. The results show that competency training is a feasible and potentially effective approach and is associated with supervisor satisfaction and stress management. The training employed is compatible with skills-based and intervention-specific supervisor training common among evidence-based treatments and is appropriate for use with clinical social workers, counseling and clinical psychologists, and psychiatric nurses.
A dynamic model and a robust controller for a fully-actuated marine surface vessel
Authors: Khaled N. , Chalhoub NG
Published: November 2010

A nonlinear six degree-of-freedom dynamic model is presented for a marine surface vessel. The formulation closely follows the current literature on ship modeling. It considers the effects of inertial forces, wave excitations, retardation forces, nonlinear restoring forces, wind and current loads along with linear viscous damping terms. The capability of the model is shown through its prediction of the ship response during a turning-circle maneuver. The ship model is used herein as a test bed to assess the performance of the proposed controller. The present study assumes that the ship is fully actuated and all state variables of the system are available through measurements. A nonlinear robust controller, based on the sliding mode methodology, has been designed based on a reduced-order version of the ship model. The latter accounts only for the surge, sway and yaw motions of the ship. The initial simulation results, generated based on the reduced-order model of the marine vessel, demonstrate robust performance and good tracking characteristics of the controller in the presence of structured uncertainties and external disturbances. Furthermore, they illustrate the adverse effects of the physical limitations of the propulsion system on the controlled response of the ship. Next, the same controller is implemented on the six degree-of-freedom model of the ship. The simulation results reveal tracking characteristics of the controller that are similar to those observed in the initial results, in spite of significantly larger modeling uncertainties.
Convergence of an iterative method for solving Sylvester matrix equations over reflexive matrices
Authors: Dehghan Mehdi , Hajarian Masoud
Published: November 2010

This note proposes an iterative method to solve the Sylvester matrix equation AY + YB = C over a reflexive matrix Y which has wide applications in many systems and control applications. Analysis of convergence shows that the proposed iterative method converges to the reflexive solution for any initial reflexive matrix. Finally, a numerical example confirms the theoretical results and shows that the method works reliably.
Measurement and identification of dynamic properties of flexible polyurethane foam
Authors: Lanzhu Zhang  , Dupuis Raphael
Published: November 2010

Experimental techniques and identification of dynamic properties of flexible polyurethane foam used in automotive seats are described here. In the experimental fixture a rigid block is mounted on a 3 inch cube of foam material, which serves as the only flexible component. The dynamic system is modeled as a single degree-of -freedom system. The experimental fixture is excited by a small impulse at the top of the block and by a shaker on the basement. For the first situation the foam is simplified as a linear viscoelastic material. By exciting with the shaker the nonlinear and viscoelastic properties of foam materials are considered. For these two different cases not only the model response and the impact of model parameters are analyzed but also the corresponding system parameters are identified during the experimental data.
Delay-dependent control design for a time-delay supercavitating vehicle model
Authors: Xiaofeng Mao  , Qian Wang
Published: November 2010

By extending a widely cited benchmark model on the pitch-plane dynamics of a supercavitating vehicle, recent literature has proposed new models that include the memory effect in characterizing the interaction of the supercavitating vehicle and the cavity. Based on this time-delay supercavitating vehicle model, this paper develops delay-dependent control designs that explicitly address the cavity memory effect in the supercavitating vehicle dynamics. We first reformulate the pitch-plane dynamics of the supercavitating vehicle as a time-delay Quasi-Linear-Parameter-Varying system, and then develop delay-dependent H∞ controllers. Simulations have been conducted for both initial and tracking responses to evaluate the performance and robustness of the proposed delay-dependent controllers.
Model, tests and application design for viscoelastic dampers
Authors: Xu Zhao-Dong , Wang Deng-Xiang , Shi Chun-Fang
Published: November 2010

Many kinds of dampers are invented to reduce the dynamic responses due to earthquake or strong wind. Viscoelastic damper is a kind of commonly used passive control device for vibration mitigation of structures. Its energy dissipation characteristics are affected by environmental temperature and excitation frequency. In order to describe the complex characteristics of viscoelastic dampers changing with temperature and frequency, a new model — the equivalent standard solid model, which is based on the standard linear solid model and temperature-frequency equivalent theory, is proposed. The comparison results between experimental and numerical data of viscoelastic dampers show that the equivalent standard solid model can precisely describe energy dissipation behavior of viscoelastic dampers under different temperatures and frequencies. At the same time, 52 viscoelastic dampers are applied for seismic retrofit design on Xi’an Petrol Hotel, and the finite analysis for structures with and without dampers are carried out under frequent-earthquake and infrequent-earthquake excitations. The dynamic responses of structures with and without dampers are compared. Analytical results show that viscoelastic dampers can reduce the earthquake responses effectively, and they are high-performance energy dissipation devices.
Bending vibration and buckling of non-uniform plate with time-dependent boundary conditions
Authors: Saeidifar M. , Ohadi AR
Published: November 2010

Current work presents an exact solution for investigating the buckling, free vibration and dynamic response of plates with variable parameters in one direction. The plate has two opposite simply-supported edges subjected to in-plane loads with desired functions, whereas other edges may have various general time-dependent boundary conditions. The solution procedure is obtained by developing and generalizing Mindlin-Goodman and Frobenius methods. First, by introducing a general change of dependent variable with shifting functions, the original system with four nonhomogeneous boundary conditions is transformed into a system composed of a time-independent governing differential equation and a system with four homogeneous boundary conditions. Then, assuming that the transverse displacement varies as a sinusoidal function, the governing partial differential equation of the plate is reduced to an ordinary differential equation in terms of y with variable coefficients. An exact solution is obtained as a power series to solve the resulting equation. Applying boundary conditions of two other edges yields the problem of finding eigenvalues of a fourth order characteristic determinant. Some examples are illustrated for validation with previous studies and the finite element method. Eventually, in other examples, the effect of some parameters on vibration behavior of the system is investigated.
Vibration properties of beams using frequency-domain system identification methods
Authors: Urgessa Girum S
Published: November 2010

The application of system identification methods to a number of civil engineering structures is increasing in order to improve the understanding of actual structural behaviors and augment traditional analytical assessments. The identification methods are typically used to determine structural dynamics properties (frequencies, damping ratios and mode shapes) and detection of local structural damages and deterioration. This paper presents two frequency domain system identification methods for determining structural vibration properties: eigensystem realization algorithm and the McKelvey frequency domain subspace algorithm. The methods were used in order to formulate a mathematical model that closely matches the frequency response function obtained from a vibration experiment conducted on an uncontrolled cantilever plate. Natural frequencies and damping ratios were determined using the system identification methods and the results are compared with a finite element analysis. A pulse response for a step input is simulated based on the state-space model system matrices obtained from the identification.
Impact oscillations with multiple modes between a pantograph and an overhead rigid conductor line in a railway current collection system
Authors: Yamashita Kiyotaka , Kitajo Kotaro , Wada Shou , Sugiura Toshihiko , Yabuno Hiroshi
Published: November 2010

A theoretical and experimental investigation was conducted into impact oscillations between a pantograph and an overhead rigid conductor line in a railway current system. The contact problem was modeled as impact oscillations of an intermediate spring-supported beam excited by an oscillating plate. First, the impact oscillations of a beam with a sinusoidal vibrating plate were theoretically examined. The impact relations are derived considering the effects of multiple vibration modes. Using some of the concepts behind periodic oscillations, qualitatively distinct impact oscillations of the beam with multiple modes are clarified. The interactions between the lowest two modes during the impacts are also discussed. Moreover, we conducted an experiment using a similar model based on the analytical model. Qualitative agreement was demonstrated between the experimental and theoretical results. Some experimental results reveal specific impact oscillations which correspond to the theoretical results considering the interactions between the lowest two vibration modes.
On the control design and robustness analysis for high-density microcantilever arrays
Authors: Sarwar Azeem , Voulgaris Petros G , Salapaka Srinivasa M
Published: November 2010

In this paper we present a basic model and control design of an array of electrostatically actuated microcantilevers. Part of the main focus of this paper is to study the feasibility and compare the performance of the centralized, decentralized and distributed schemes on a microcantilever array system. Since the implementation of a centralized controller for such systems is impractical, we consider the following two control schemes with localized architecture: (a) a H∞ decentralized controller that completely ignores the dynamics contributed by the neighbors hence treating them as an external disturbance; and (b) a H∞ distributed controller that makes use of information only from its immediate neighbors. In order to have some benchmark performance index, we first design a H ∞ centralized controller for an array of eight microcantilevers. The performance of these controllers are tested via simulations on a finite nonlinear model of the system, and compared with the benchmark performance delivered by the centralized controller. It is seen that the performance delivered by a distributed controller is quite comparable to the performance delivered by the benchmark scheme of a centralized controller. In comparison, the performance of the decentralized controller degrades by more than 100% in terms of resolution. Another main contribution of this paper is the robustness analysis with respect to the modeling uncertainties. This is important, especially in the view of the fabrication errors which result in deviation of actual dynamics of each microcantilever from its model, as well as since the control designs are derived from a linearized model of the cantilever array. In this direction, analysis and simulations of control implementations on perturbed linear as well as nonlinear models of system with finite microcantilever arrays are presented.
Theoretical and experimental study for identification of crack in cantilever beam by measurement of natural frequencies
Authors: Sayyad FB , Kumar Bimlesh
Published: November 2010

Most of the rotating machines used in process industries or in manufacturing plant need maintenance and repair. However, failure of just one of these machines can disturb an entire process with losses in terms of production, manpower, and equipment repair or replacement. Also failure of a single machine component in process industries like petrochemicals or power stations can result in the loss of millions of rupees per down time hour. These facts together with higher costs for new equipment have placed increased demand on plant maintenance to keep existing equipment operating efficiently with higher availability. A number of non-destructive crack detection techniques have been developed, such as ultrasonic testing, X-ray technique, magnetic particle method etc. Every method has some advantages and disadvantages. In recent years, ultrasonic testing has gained greater attention for monitoring the cracks in structures and machine components. Most of these methods are very laborious and time consuming, in the case of larger components like bridges, long pipe lines, railway tracks etc. These inconveniences can be avoided by the use of vibration monitoring technique such as model analysis. Therefore the development of vibration monitoring techniques has received increasing attention in recent years. Damage in structure alters its dynamic characteristics. The change is characterized by a change in model parameters i.e. model frequencies, model damping values and mode shapes associated with each model frequencies. Changes also occur in some of the structural parameters like mass, damping, stiffness and flexibility matrices of structure. Thus a vibration technique can be suitably used as a nondestructive test for crack detection of components to be tested. In this paper, theoretical and experimental analysis of a vibrating cantilever beam with a crack is carried out. This method is used to address the inverse problem of assessing the crack location and crack size in various beam structure. The method is based on measurement of natural frequencies, which are global parameter and can be easily measured from any point on the structure. In theoretical analysis the crack is simulated by an equivalent spring, connecting the two segments of the beam. Analysis of this approximate model results in algebraic equation, which relates the natural frequencies of the beam, and crack location. Also the relationship between the natural frequencies, crack location and crack size has also been developed. For identification of crack location and crack size, it was shown that data on the variation of the first two natural frequencies are sufficient. The computation of natural frequencies of uncracked and cracked beam is facilitated by a finite element method package. This database is to be utilized in an analytical method to address the inverse problem to identify the crack location and crack size.
Creating confident, motivated teachers of physical education in primary schools
Authors: Petrie Kirsten
Published: November 2010

This paper analyses the impact of a nationwide one-year physical education (PE) professional development (PD) programme on 25 generalist classroom teachers from 10 primary schools in New Zealand. This research specifically explores how a year-long PD programme, focused predominantly on general pedagogical strategies, supported in-service generalist teachers to use of pedagogies previously reserved to the classroom to enhance their PE practice, reconceptualise the place and purpose of PE, and shifted their perceptions of themselves as teachers of PE. Interviews, questionnaires, lesson observations and document analysis were used to investigate the impact a PD programme had on teachers’ knowledge and practices in PE. This research specifically explores how a year-long PD programme, focused predominantly on general pedagogical strategies, supported in-service generalist teachers to explore how the use of pedagogies previously reserved to the classroom support them to enhance their PE practice; to reconceptualize the place and purpose of PE, and shifted their perceptions of themselves as teachers of PE. It is concluded that generalist teachers benefit from PD opportunities that allow for the transfer of pedagogical strategies and skills from the classroom to the PE context. However, these learning opportunities should be balanced and connected with opportunities to develop content knowledge associated with PE.
‘‘Healthism’’ and looking good: Body ideals and body practices in Norway
Authors: Rysst Mari
Published: November 2010

Aims: This article explores judgemental and disciplining attitudes and ‘‘gazes’’ found in magazines and among Norwegian men and women concerning body ideals and body practices. The analysis is informed by Michel Foucault’s argument on governmentality and Nikolas Rose’s on governing the soul. Methods: The data consist of 20 qualitative interviews and four selected Norwegian magazines. Results: The analysis shows a corresponding relationship of how magazines depict ideal bodies and how the informants describe good-looking bodies. The interviews also indicate that people who train (ie work out) give more detailed and clear descriptions of good-looking bodies than those who do not train. Body dissatisfaction is present among both men and women, but seems more widespread among women. Body dissatisfaction is understood as a public health issue. Conclusions: The analysis suggests that the Norwegian men and women in the study are governed by ‘‘healthism’’ and dominant body ideals depicted in media discourses concerning description of ideal bodies and their own body practices. In addition, the material shows widespread body dissatisfaction particularly among women, and suggests that this is a health issue and an indication of new forms of patriarchal power governing the thoughts of women and to an increasing degree also men. Having a free choice concerning body practices is thus suggested to be an illusion.
The STORK Groruddalen research programme: A population-based cohort study of gestational diabetes, physical activity, and obesity in pregnancy in a multiethnic population. Rationale, methods, study population, and participation rates
Authors: Jenum Anne K. , Sletner Line , Voldner Nanna , Vangen Siri , Mørkrid Kjersti , Andersen Lene F. , Nakstad Britt , Skrivarhaug Torild , Rognerud-Jensen Odd-Harald , Roald Borghild , Birkeland Kåre I.
Published: November 2010

Background: Gestational diabetes mellitus (GDM) and obesity may cause adverse pregnancy outcomes for mothers and offspring. We have set up a research programme to identify predictors for GDM and fetal growth in a multiethnic population in Oslo to improve the identification of high risk pregnancies and reduce adverse short and long-term outcomes for mothers and offspring. Aims: To present the rationale, methods, study population and participation rates. Methods: Population-based cohort study of pregnant women attending the Child Health Clinics (CHC) in Groruddalen, Oslo, and their offspring. Questionnaire data, blood pressure, anthropometric measurements, and fasting blood and urine samples are collected (gestational weeks 8—20 and 28, and 12 weeks postpartum) and an oral glucose tolerance test (28 weeks). Physical activity is measured, three ultrasound measurements are performed and paternal questionnaire data collected. Routine hospital data are available for all mothers and offspring. Umbilical venous blood and placentas are collected, sampled, and stored and neonatal anthropometric measurements performed. Ethnicity is self-reported country of birth. Results: 823 women were included, 59% of non-Western origin. The participation rate was 74% (64—83% in main ethnic groups), mean age 29.8 years (95% CI 29.5—30.1) and median parity 1 (inter-quartile range 1). The cohort is representative for women attending the CHC with respect to ethnicity and age. A slight selection towards lower parity (South Asians) and age (Africans) was found. Few were lost to follow-up. Conclusions: Unique information is collected from a representative group of multiethnic women to address important public health problems and mechanisms of disease. Participation rates are high in all ethnic groups.
Youth Empowerment Solutions for Peaceful Communities: Combining Theory and Practice in a Community-Level Violence Prevention Curriculum
Authors: Zimmerman Marc A. , Stewart Sarah E. , Morrel-Samuels Susan , Franzen Susan , Reischl Thomas M.
Published: November 2010

This article describes the development and evaluation of an after-school curriculum designed to prepare adolescents to prevent violence through community change. This curriculum, part of the Youth Empowerment Solutions for Peaceful Communities (YES) program, is guided by empowerment and ecological theories within a positive youth development context. YES is designed to enhance the capacity of adolescents and adults to work together to plan and implement community change projects. The youth curriculum is organized around six themed units: (a) Youth as Leaders, (b) Learning about Our Community, (c) Improving Our Community, (d) Building Intergenerational Partnerships, (e) Planning for Change, and (f) Action and Reflection. The curriculum was developed through an iterative process. Initially, program staff members documented their activities with youth. These outlines were formalized as curriculum sessions. Each session was reviewed by the program and research staff and revised based on underlying theory and practical application. The curriculum process evaluation includes staff and youth feedback. This theoretically based, field-tested curriculum is designed to be easily adapted and implemented in a diverse range of communities.
Personal Landmarks as Recall Aids in Survey Interviews
Authors: van der Vaart Wander , Glasner Tina
Published: November 2010

Personal landmarks are a central element of calendar survey methods. These data collection methods use a graphical time frame in which specific landmark events can be described next to the respondents’ life history. The theoretical ideas in this article suggest that landmarks are most effective as a recall aid if they are important, domain-related, and personal events. The data originate from a calendar method that was embedded in a telephone survey in the Netherlands. The outcomes showed that respondents used a great variety of landmark events, that the number and types of landmarks are related to sociodemographic factors, and that the landmark distribution shows recency and heaping patterns. Weak positive effects of landmarks on recall accuracy were also found. The results suggest that a standardization of the landmark procedure might add to the effectiveness of its aided recall function.
Selective Embolization of Thyroid Arteries for Preresection or Palliative Treatment of Large Cervicomediastinal Goiters
Authors: Tartaglia Francesco , Salvatori Filippo Maria , Russo Giulia , Blasi Sara , Sgueglia Monica , Tromba Luciana , Berni Alberto
Published: November 2010

Background: The authors have applied the selective embolization of thyroid arteries in the treatment of voluminous cervicomediastinal goiters, especially in patients at high surgical risk or reluctant to undergo surgical intervention and radioiodine therapy. Method: Selective arteriography was used to embolize the thyroid arteries in 2 patients with voluminous hyperfunctioning cervicomediastinal goiters and mediastinal compressive symptoms. The first patient had already undergone unsuccessful radioiodine metabolic therapy and had severe left ventricular insufficiency contraindicating surgery. The second patient, despite having no contraindications, declined surgery and radioiodine metabolic therapy. Results: Radiological embolization markedly reduced the goiters in volume, resolved the compressive symptoms, and also normalized thyroid hyperfunction. The second patient needed a second embolization procedure because the embolized arterial branches had partly recanalized. Conclusion: Selective embolization of thyroid arteries can be successfully used to treat selected patients as a preoperative procedure and as an alternative to thyroid resection. Embolization can be repeated to achieve the required therapeutic aims.
Unlicensed applications of licensed psychotropic drugs in an intellectual disability clinical service: retrospective case-note study
Authors: Ghosh Soumya , Arulrajan Arum E. , Baldwin David
Published: November 2010

Prescribing of psychotropic drugs for unlicensed indications is common in inpatients with intellectual disability, but the frequency in the community is uncertain. This study examined the medical records of all patients undergoing review within a single service led by a consultant psychiatrist. The notes of 114 individuals with varying degrees of disability and independence were available. In 78 percent of individuals the cause of disability was uncertain; 72, 69 and 78 percent had mental health problems, physical ill-health and behavioural challenges respectively; and 66 percent received licensed drugs for unlicensed applications, principally for aggression, risperidone being the drug most prescribed. There were no significant differences between groups with mild, moderate or severe disability in the proportion receiving licensed and unlicensed prescriptions. Unlicensed prescribing was similarly common for patients living in different settings. Prescribing for unlicensed applications in patients with intellectual disability is common, regardless of degree of disability or place of residence.