bluuebunny/crossref_metadata_2025 huggingface dataset:
Visit-to-Visit Blood Pressure Variability, Carotid Atherosclerosis, and Cardiovascular Events in the European Lacidipine Study on Atherosclerosis
Authors: Mancia Giuseppe , Facchetti Rita , Parati Gianfranco , Zanchetti Alberto
Published: July 2012

Background—

In high-cardiovascular-risk treated hypertensive patients, the incidence of cardiovascular events has been reported to relate to visit-to-visit blood pressure (BP) variability. We investigated whether visit-to-visit BP variability is prognostically important in treated mildly to moderately hypertensive patients in whom treatment aims at avoiding events but also at preventing or delaying progression of organ damage.

Methods and Results—

We analyzed the pooled data from the European Lacidipine Study on Atherosclerosis (ELSA), a randomized, double-blind 4-year trial of the effect of lacidipine or atenolol on echographic carotid intima-media thickness. Visit-to-visit BP variability was assessed by the coefficient of variation or the SD of the mean on-treatment systolic BP (SBP) obtained at 6- (clinic BP) and 12- (24 hours BP) month intervals, respectively (1521 and 1264 patients, respectively). In a multivariable linear regression model, mean on-treatment clinic or 24-hour SBP, but not SBP coefficient of variation or SD, was associated with end-of-treatment carotid intima-media thickness. Intima-media thickness increased progressively from the lowest to highest quartile of mean on-treatment clinic or 24-hour SBP (adjusted
P
for trend=0.046 and 0.048) but not along similar quartiles of SBP coefficient of variation or SD. In a multivariable logistic regression model, mean BP, but not variability, was associated with cardiovascular outcomes.

Conclusions—

In mildly to moderately hypertensive patients, carotid intima-media thickness and cardiovascular outcomes were related to the mean clinic or ambulatory SBP achieved by treatment but not to on-treatment visit-to-visit clinic or 24-hour BP variability. Thus, when BP is modestly elevated, inconsistency of BP control between visits plays a less important prognostic role than long-term average BP levels.
Image-Guided Method in the Rat for Inducing Cortical or Striatal Infarction and for Controlling Cerebral Blood Flow Under MRI
Authors: Arnberg Fabian , Lundberg Johan , Söderman Michael , Damberg Peter , Holmin Staffan
Published: July 2012

Background and Purpose—

Experimental models are essential for research on ischemic stroke, the second most common cause of death worldwide. The failure of clinical trials on neuroprotective treatment may be due in part to poor animal models. To push the translation of new therapies, we describe a new rat model that captures key elements of human brain ischemia. The model includes imaging and neurointerventional tools that represent the near future of clinical diagnosis and treatment of stroke.

Methods—

Using Sprague-Dawley rats (n=26), we navigated a microwire with fluoroscopy and MRI guidance from the ventral tail artery to 2 different positions in the middle cerebral artery to establish local occlusion. Animals were scanned with 9.4-T MRI before occlusion, during ischemia, and after reperfusion.

Results—

We detected stroke lesions, corresponding to the level of occlusion, in all animals by diffusion-weighted and T2 images. We measured lesion volume (mm
3
±SD) on T2 scans at 24 hours to be 23.2±29.8 in the somatosensory cortex group and 107.9±80 in the striatum group.

Conclusion—

We present a new rat model for focal stroke with the possibility to cause lesions in different regions of the brain under fluoroscopic and MRI control. The model will be highly useful for extended studies on the ischemic penumbra, alterations in neural connectivity, and for investigating neurotransmitter-mediated events and biochemical changes in the hyperacute phase of brain ischemia. Also, the model uses clinical routine microcatheters facilitating superselective administration of therapeutics directly to the cerebral circulation.
Assessing the Integrity of Corticospinal Pathways From Primary and Secondary Cortical Motor Areas After Stroke
Authors: Schulz Robert , Park Chang-Hyun , Boudrias Marie-Hélène , Gerloff Christian , Hummel Friedhelm C. , Ward Nick S.
Published: July 2012

Background and Purpose—

Aside from the primary motor cortex, the corticospinal tract (CST) also receives fibers from dorsal and ventral premotor cortices and supplementary motor area, all of which might potentially contribute to motor function after stroke. We sought to quantify the microstructural integrity of CST originating from the hand representations in these 4 motor cortices separately and examined how these values related to hand motor impairment.

Methods—

Probabilistic tractography from functional MRI-defined cortical sites demonstrated continuous CST originating from hand representations within each motor area in a group of healthy subjects. Microstructural integrity for each tract was calculated using fractional anisotropy at the level of the posterior limb of the internal capsule in a group of patients with chronic stroke.

Results—

Fractional anisotropy was reduced in all 4 CSTs in the affected hemisphere. Grip strength correlated with the integrity of the CSTs originating from primary motor and dorsal premotor cortices, whereas, in a multiple regression model, the latter improved the ability of primary motor cortex CST to explain variability in grip strength.

Conclusion—

Handgrip critically depends on the CST originating in primary motor cortex but microstructural integrity of CST originating from premotor cortices appears to play a role in supporting motor function after stroke.
Sexual Harassment, Workplace Authority, and the Paradox of Power
Authors: McLaughlin Heather , Uggen Christopher , Blackstone Amy
Published: July 2012

Power is at the core of feminist theories of sexual harassment, although it has rarely been measured directly in terms of workplace authority. Popular characterizations portray male supervisors harassing female subordinates, but power-threat theories suggest that women in authority may be more frequent targets. This article analyzes longitudinal survey data and qualitative interviews from the Youth Development Study to test this idea and to delineate why and how supervisory authority, gender nonconformity, and workplace sex ratios affect harassment. Relative to nonsupervisors, female supervisors are more likely to report harassing behaviors and to define their experiences as sexual harassment. Sexual harassment can serve as an equalizer against women in power, motivated more by control and domination than by sexual desire. Interviews point to social isolation as a mechanism linking harassment to gender nonconformity and women’s authority, particularly in male-dominated work settings.
Cardiometabolic risk factors in people with psychotic disorders: The second Australian national survey of psychosis
Authors: Galletly Cherrie A , Foley Debra L , Waterreus Anna , Watts Gerald F , Castle David J , McGrath John J , Mackinnon Andrew , Morgan Vera A
Published: July 2012

Objective:

To determine the prevalence of cardiometabolic risk factors in Australian adults with a psychotic disorder.

Method:

Data were collected during the interview phase of the second Australian survey of psychosis, a population-based survey of Australians aged 18 to 64 years with a psychotic disorder. Body mass index, waist circumference and blood pressure were measured. Participants were asked about diagnoses of relevant medical conditions, medications, smoking and physical activity. Fasting blood samples were analysed for glucose, high-density lipoprotein cholesterol, total cholesterol and triglycerides. The prevalence of metabolic syndrome was determined using the harmonized criteria developed by the International Diabetes Federation and other bodies.

Results:

A total of 1087 men (60%) and 738 women (40%) participated. Their mean age was 38.36 (SD 11.16) years; 773 (42%) were aged 18–34 years and 1052 (58%) 35–64 years. Three-quarters were overweight or obese and 82% had abdominal obesity. Almost half were hypertensive. Two-thirds were current smokers and 81% had a lifetime history of smoking. Levels of physical activity were very low. About 30% reported a diagnosis of hypertension or high cholesterol, 20% knew they had diabetes or high blood sugar and 18% had cardiovascular disease. Half of those with self-reported hypertension were taking antihypertensive drugs, and about 40% with hypercholesterolemia or hyperglycaemia were receiving medication for these conditions. Seventy per cent ( N = 1286) of participants provided fasting blood samples. Abnormal levels of high-density lipoprotein cholesterol and triglycerides were each found in almost half of participants and almost one-third had elevated fasting glucose. More than half of participants (54.8%) met criteria for metabolic syndrome.

Conclusions:

Australians living with psychosis have high rates of cardiometabolic risk factors. There are a number of obvious targets for prevention and treatment, including obesity (especially in women), smoking (more prevalent in men), hypertension, hyperlipidaemia and sedentary lifestyle.
Problematic Preferences? A Mixed Method Examination of Principals’ Preferences for Teacher Characteristics in Chicago
Authors: Engel Mimi
Published: July 2012

Purpose: Relatively little is known about how principals make decisions about teacher hiring. This article uses mixed methods to examine what characteristics principals look for in teachers. Research Methods: Data were gathered using a mixed method approach, including in-depth interviews with a representative sample of 31 principals as well as an online survey of 368 principals in the Chicago Public Schools. Data analysis techniques included both qualitative analysis to look for patterns and themes and exploratory regression analysis of surveys to examine variation in preferences across school and principal characteristics. Findings: Results indicate that principals focus on behaviors and skills rather than qualifications. Principals report looking for teachers who care about students, have content knowledge, are willing to go beyond contractual obligations, and have classroom management skills. Principals, in general, talk extensively about caring, classroom management, and willingness to “give extra,” while most say little about content knowledge or teaching skills. Preferences vary substantially across low- and high-achieving schools. Implications: Whether the skills and behaviors that principals report focusing on during the teacher-hiring process are those that will benefit their students most is an important question, particularly because even ineffective teachers are rarely dismissed from public schools.
Mechanical behavior of carbon/flax hybrid composites for structural applications
Authors: Fiore V , Valenza A , Di Bella G
Published: July 2012

In this work, the influence of an unidirectional carbon fabric layer on the mechanical performances of bidirectional flax fabric/epoxy composites used for structural applications was studied. Two different bidirectional flax fabrics were used to produce flax fabric reinforced plastic (FFRP) laminates by a vacuum bagging process: one is normally used to make curtains; the other, heavier and more expensive than the previous one, is usually used as reinforcement in composite structures. In order to realize hybrid structures starting from FFRP, an unidirectional UHM carbon fabric was used to replace a bidirectional flax fabric. Tensile and three-point bending tests were performed to evaluate the mechanical properties of the laminates investigated (both FFRP and hybrids). Furthermore, the mechanical behavior of the different bidirectional flax fabrics was analyzed by carrying out tensile tests. The experimental tests showed that the structures reinforced with flax fabrics, normally used to make curtains, present better flexural properties than that of others while, in tensile configuration, these last show higher modulus and strength. Moreover, both FFRP laminates show low mechanical properties, which do not allow their use in structural applications while the presence of one external layer of unidirectional carbon involves remarkable increase in their properties. According to this study, the hybrid composites realized could be used in several structural applications (i.e., nautical and automotive).
Similitude study on bending stiffness and behavior of composite tubes
Authors: Derisi Bijan , Hoa Suong , Hojjati Mehdi
Published: July 2012

A procedure to design a composite tube that matches the flexural stiffness, load-carrying capacity, and energy absorption of an aluminum tube while subjected to bending load is of interest. The large deformation and energy absorption requirements are fulfilled through the progressive failure of the plies of suitable fiber orientations across the thickness of the tube. The layer wise nature of the composite tubes and cylindrical anisotropy, however, has impeded obtaining a simple closed-form solution for calculating the flexural stiffness. Available analytical solutions are mainly a complex set of equations, which should be solved simultaneously. In addition, the boundary and interface conditions between the adjacent plies must be satisfied. This article presents a straightforward simulation technique for this purpose. First, the tube is correlated to a corresponding composite sandwich panel, the flexural stiffness of which is obtained by the classical laminate theory. Then an analogous aluminum sandwich panel is designed and is correlated to a so-called ‘equivalent’ aluminum tube. The bending stiffness of the composite tube is shown to be the same as that of its equivalent aluminum tube. As a result, a complex problem of cylindrical anisotropy is mapped into a Cartesian coordinate system and solved via the classical laminate theory. The accuracy of the technique is verified by experimental work and analytical solutions. The agreement between the three methods is shown.
Adaptive insecure attachment and resource control strategies during middle childhood
Authors: Chen Bin-Bin , Chang Lei
Published: July 2012

By integrating the life history theory of attachment with resource control theory, the current study examines the hypothesis that insecure attachment styles reorganized in middle childhood are alternative adaptive strategies used to prepare for upcoming competition with the peer group. A sample of 654 children in the second through seventh grades in Shanghai, China, participated in this study. The children reported attachment relationships with their mother and the use of resource control strategies in the peer group. Boys had higher avoidant attachment scores than girls, whereas girls had higher ambivalent attachment scores than boys. Moreover, avoidant attachment was positively associated with the use of coercive strategies to control resources. Ambivalent attachment was associated with the use of both coercive and prosocial strategies to control resources. A number of other gender and developmental differences were also observed. The implications for the adaptiveness of insecure attachment in middle childhood are discussed.
Sustained attention at age 5 predicts attention-related problems at age 9
Authors: Martin Anne , Razza Rachel A. , Brooks-Gunn Jeanne
Published: July 2012

This study tested whether two aspects of sustained attention (focused attention and lack of impulsivity) measured at child age 5 predicted attention problems reported by mothers and teachers at age 9. Because lack of impulsivity reflects the executive control network, and ADHD is commonly characterized as a deficit in executive function, it was expected to have more predictive power than focused attention. Data were drawn from the Fragile Families and Child Wellbeing Study. Focused attention and lack of impulsivity, measured in a laboratory task at age 5, were equally predictive of attention problems at age 9, including the mother’s report of whether the child had been diagnosed with ADHD. However, age 9 teacher-reported hyperactivity was not predicted by focused attention, and only marginally predicted by lack of impulsivity. Results complement an earlier study by Razza, Martin, and Brooks-Gunn showing that both focused attention and lack of impulsivity at age 5 predicted children’s approaches to learning at age 9.
Does political theology entail decisionism?
Authors: Espejo Paulina Ochoa
Published: July 2012

The thesis of political theology holds that all justificatory theories of the state rely on metaphysical assumptions, rather than just empirical facts and accepted political conventions. For this reason, the thesis challenges liberal theories that justify the state on the basis of individual autonomy and popular will. The thesis is controversial because many theorists believe that metaphysical assumptions introduce decisionism – the view that a state depends on the unrestrained personal decision of a ruler – to the theory of the state. But, does political theology entail decisionism? This article argues that decisionism does not follow necessarily from political theology because an omnipotent deciding sovereign is only one of many possible metaphysical assumptions in theology. It illustrates this claim with examples from the philosophy of Nicholas Cusanus and process philosophy. This conclusion challenges two different entrenched views: first, that the modern state is a continuation of theistic beliefs; and second, that metaphysical discussions have no place in contemporary normative political theory.
Revisiting the Palliative Performance Scale: Change in scores during disease trajectory predicts survival
Authors: Chan Ee-Yuee , Wu Huei-Yaw , Chan Yiong-Huak
Published: July 2012

Background:

The Palliative Performance Scale (PPS) on admission is a predictor of survival. However, it is not highly discriminating for mid-range scores. ‘PPS Change’ between two time points considers the disease trajectory, and may improve the scale’s utility.

Aim:

The aim of this study is to determine if a change in PPS scores between two significant time points predicts survival.

Design:

This prospective cohort study examined ‘Change on Admission’, ‘Change at Week 1’, and ‘Change at Week 2’. We followed patients until death or 6 months, whichever was earlier. Cox regressions were used to determine if the Change scores were predictors of survival, adjusting for age, sex, diagnosis category, Charlson Index, and Do-Not-Resuscitate order.

Setting/Participants:

The sample consisted of patients referred to the palliative care service.

Results:

All three Change scores were independent predictors of survival. The greater the change, the poorer the prognosis. At week 1, when compared to ‘PPS Change ≤ 10%’, ‘Change 11% –30%’ and ‘Change > 30%’ increased the hazard ratios by 1.70 (95% CI 1.10–2.63) and 3.14 (95% CI 1.77–5.59), respectively. At week 2, when compared to ‘PPS Change ≤ 10%’, ‘Change 11% –30%’ and ‘Change > 30%’ increased the hazard ratios by almost 3- and 8-fold, respectively. The same magnitude of Change scores also has higher hazard ratios as patients’ hospitalization progressed.

Conclusions:

The magnitude of change in PPS score during the disease trajectory is associated with one’s survival and is a potentially useful prognostication tool. Further research is needed to extend on our work.
Where a Hollow State Casts No Shadow
Authors: Tao Jill L. , McCabe Barbara C.
Published: July 2012

Outsourcing public service provision to the private and nonprofit sectors has been well-documented and studied for over two decades as manifestations of the hollow state, but there is a relatively new phenomenon at local levels of government that has until recently eluded the attention of researchers in public administration and policy: private governments. Increasingly, U.S. citizens are far more likely to reside in a development operated by a homeowner’s association, rather than (or in addition to) a city government. Services are provided by these private entities, funded by association dues, and governed by covenants, conditions and restrictions, drafted largely by developers. As administrative units, how do these developments interact with local governments? Using data from the first national survey of large homeowner associations, we present evidence that their perceptions of local government are significantly influenced by the degree to which they set themselves apart in private enclaves, and we offer some recommendations for further research of the implications that these perceptions pose.
Russia’s “Pure Spirit”
Authors: Kravets Olga
Published: July 2012

This article examines the interplay of vodka branding and politics in post-Soviet Russia. The trajectory of vodka branding over the past three decades reflects shifts in politics and articulates changes in ideology, while setting the environment in which certain sociopolitical ideas unfold and become naturalized. The analysis suggests that the political economy and historical dynamics of a market system, and the societal standing of the commodity being branded, define and frame the potentialities of marketing meanings and their ideological inflections.
Failure filtrations for fenced sensor networks
Authors: Munch Elizabeth , Shapiro Michael , Harer John
Published: July 2012

In this paper we consider the question of sensor network coverage for a two-dimensional domain. We seek to compute the probability that a set of sensors fails to cover given only non-metric, local (who is talking to whom) information and a probability distribution of failure of each node. This builds on the work of de Silva and Ghrist who analyzed this problem in the deterministic situation. We first show that it is part of a slightly larger class of problems which is #P-hard, and thus fast algorithms likely do not exist unless P = NP. The question of whether the specific problem is, in fact, #P-hard remains open. We then give a deterministic algorithm which is feasible in the case of a small set of sensors, and give a dynamic algorithm for an arbitrary set of sensors failing over time which utilizes a new criterion for coverage to give an early warning of potential failure. These algorithms build on the theory of topological persistence.
Capturability-based analysis and control of legged locomotion, Part 1: Theory and application to three simple gait models
Authors: Koolen Twan , de Boer Tomas , Rebula John , Goswami Ambarish , Pratt Jerry
Published: July 2012

This two-part paper discusses the analysis and control of legged locomotion in terms of N-step capturability: the ability of a legged system to come to a stop without falling by taking N or fewer steps. We consider this ability to be crucial to legged locomotion and a useful, yet not overly restrictive criterion for stability. In this part (Part 1), we introduce a theoretical framework for assessing N-step capturability. This framework is used to analyze three simple models of legged locomotion. All three models are based on the 3D Linear Inverted Pendulum Model. The first model relies solely on a point foot step location to maintain balance, the second model adds a finite-sized foot, and the third model enables the use of centroidal angular momentum by adding a reaction mass. We analyze how these mechanisms influence N-step capturability, for any N > 0. Part 2 will show that these results can be used to control a humanoid robot.
Functional Magnetic Resonance Imaging Reveals Changes in Language Localization in Children With Benign Childhood Epilepsy With Centrotemporal Spikes
Authors: Vannest Jennifer , Szaflarski Jerzy P. , Eaton Kenneth P. , Henkel David M. , Morita Diego , Glauser Tracy A. , Byars Anna W. , Patel Krishna , Holland Scott K.
Published: July 2012

In children with benign childhood epilepsy with centrotemporal spikes, centrotemporal spikes may cause language dysfunction via disruption of underlying functional neuroanatomy. Fifteen patients with benign childhood epilepsy with centrotemporal spikes and 15 healthy controls completed 3 functional magnetic resonance imaging (MRI) language paradigms; standardized cognitive and language assessments were also performed. For all paradigms, children with benign childhood epilepsy with centrotemporal spikes showed specific regional differences in activation compared to controls. Children with benign childhood epilepsy with centrotemporal spikes also differed from controls on neuropsychological testing. They did not differ in general intelligence, but children with benign childhood epilepsy with centrotemporal spikes scored significantly lower than controls on tests of language, visuomotor integration, and processing speed. These results extend previous findings of lower language and cognitive skills in patients with benign childhood epilepsy with centrotemporal spikes, and suggest epilepsy-related remodeling of language networks that may underlie these observed differences.
Confounding Diagnoses in the Neurodevelopmental Disabilities Population
Authors: Lance Eboni I. , Shapiro Bruce K.
Published: July 2012

We report the case of a school-age child with a history of hearing loss presenting with staring spells. Electroencephalography (EEG) revealed a pattern consistent with absence epilepsy, and the patient was started on antiepileptic medication with decreased frequency of staring spells but he then continued to have behavioral issues. The patient was diagnosed subsequently with combined-type attention-deficit hyperactivity disorder (ADHD) and started on stimulant medication with subsequent improvement in attention and school performance. Multiple confounding diagnoses are common in children with neurodevelopmental disabilities, and comprehensive evaluation is required for appropriate management.
Did the Work Opportunity Tax Credit Cause Subsidized Worker Substitution?
Authors: Ajilore Olugbenga
Published: July 2012

This article questions whether the implementation of the Work Opportunity Tax Credit (WOTC) created an incentive for employers to substitute subsidized workers for incumbent workers. To see if this substitution occurs, the author uses a differences-in-differences methodology to test whether the implementation of the WOTC caused both an increase in employment from a representative target group and a decrease in employment of a group that is a close substitute for members of the target group. The author finds no evidence that subsidized worker substitution occurred in the period after the WOTC was implemented. There is evidence that the WOTC is effective in increasing the employment rates of long-term welfare recipients.
Investigation on tooling geometrical effects of micro tools and the associated micro milling performance
Authors: Wu Tao , Cheng Kai , Rakowski Richard
Published: July 2012

In micro scale cutting, tooling geometry plays a significant role in determining machining quality and tool life, and the knowledge of tooling geometrical effects on process performance potentially benefits engineers on improving tool designs and selecting optimum cutting conditions. This research aims to comprehensively investigate tooling geometrical effects on the process performance in micro milling using a finite element method supported with well-designed cutting trials. In the study, a benchmark three-dimensional tooling model, incorporating rake angle, relief angle, helix angle, diameter and cutting edge radius is initially developed for simulating the micro milling process under large deformations. The simulation is then experimentally validated and the predicted micro chip formation and cutting forces are in reasonable agreement with measured results in cutting trials. Furthermore, finite element-based simulations are performed under different helix angles, rake angles and cutting edge radius, and comparisons of cutting forces, tool stresses, tool temperatures, chip formation and temperatures are presented and discussed. It is found that the cutting edge radius is the most influential factor on the tool’s process performance, followed by helix angle, and rake angle has less effect.
A probabilistic modelling scheme for analysis of long-term failure of cemented femoral joint replacements
Authors: Galibarov Pavel E , Prendergast Patrick J , Lennon Alexander B
Published: July 2012

Reliable prediction of long-term medical device performance using computer simulation requires consideration of variability in surgical procedure, as well as patient-specific factors. However, even deterministic simulation of long-term failure processes for such devices is time and resource consuming so that including variability can lead to excessive time to achieve useful predictions. This study investigates the use of an accelerated probabilistic framework for predicting the likely performance envelope of a device and applies it to femoral prosthesis loosening in cemented hip arthroplasty.

A creep and fatigue damage failure model for bone cement, in conjunction with an interfacial fatigue model for the implant–cement interface, was used to simulate loosening of a prosthesis within a cement mantle. A deterministic set of trial simulations was used to account for variability of a set of surgical and patient factors, and a response surface method was used to perform and accelerate a Monte Carlo simulation to achieve an estimate of the likely range of prosthesis loosening. The proposed framework was used to conceptually investigate the influence of prosthesis selection and surgical placement on prosthesis migration.

Results demonstrate that the response surface method is capable of dramatically reducing the time to achieve convergence in mean and variance of predicted response variables. A critical requirement for realistic predictions is the size and quality of the initial training dataset used to generate the response surface and further work is required to determine the recommendations for a minimum number of initial trials. Results of this conceptual application predicted that loosening was sensitive to the implant size and femoral width. Furthermore, different rankings of implant performance were predicted when only individual simulations (e.g. an average condition) were used to rank implants, compared with when stochastic simulations were used. In conclusion, the proposed framework provides a viable approach to predicting realistic ranges of loosening behaviour for orthopaedic implants in reduced timeframes compared with conventional Monte Carlo simulations.
Standardising the clinical assessment of coronal knee laxity
Authors: Clarke Jon V , Wilson William T , Wearing Scott C , Picard Frederic , Riches Philip E , Deakin Angela H
Published: July 2012

Clinical laxity tests are used for assessing knee ligament injuries and for soft tissue balancing in total knee arthroplasty. This study reports the development and validation of a quantitative technique of assessing collateral knee laxity through accurate measurement of potential variables during routine clinical examination. The hypothesis was that standardisation of a clinical stress test would result in a repeatable range of laxity measurements.

Non-invasive infrared tracking technology with kinematic registration of joint centres gave real-time measurement of both coronal and sagittal mechanical tibiofemoral alignment. Knee flexion, moment arm and magnitude of the applied force were all measured and standardised. Three clinicians then performed six knee laxity examinations on a single volunteer using a target moment of 18 Nm.

Standardised laxity measurements had small standard deviations (within 1.1°) for each clinician and similar mean values between clinicians, with the valgus laxity assessment (mean of 3°) being slightly more consistent than varus (means of 4° or 5°).

The manual technique of coronal knee laxity assessment was successfully quantified and standardised, leading to a narrow range of measurements (within the accuracy of the measurement system). Minimising the subjective variables of clinical examination could improve current knowledge of soft tissue knee behaviour.
Iterative design and testing of a modular anterior plate for lumbar spine fixation applications
Authors: Demir Teyfik
Published: July 2012

In this study, a modular anterior lumbar plate is designed and tested in an iterative fashion. The study starts with a basic design that is built by combining same-sized modules; an approach that allow inventory costs to be decreased. The basic design is iteratively improved guided by the results of biomechanical tests performed on each new design. At the end of three iterations of improvements, the design is complete and the plate is of sufficient quality for it to be used in anterior surgical operations. Using these plates creates the advantage of being able to increase the size and slot count during surgical operations, even when some of the modules are already fixed to vertebrae. The designed modular plate is shown to be as safe for use as a rigid plate in terms of its static and fatigue biomechanical performances.
Evaluation of direct and indirect additive manufacture of maxillofacial prostheses
Authors: Eggbeer Dominic , Bibb Richard , Evans Peter , Ji Lu
Published: July 2012

The efficacy of computer-aided technologies in the design and manufacture of maxillofacial prostheses has not been fully proven. This paper presents research into the evaluation of direct and indirect additive manufacture of a maxillofacial prosthesis against conventional laboratory-based techniques. An implant/magnet-retained nasal prosthesis case from a UK maxillofacial unit was selected as a case study. A benchmark prosthesis was fabricated using conventional laboratory-based techniques for comparison against additive manufactured prostheses. For the computer-aided workflow, photogrammetry, computer-aided design and additive manufacture (AM) methods were evaluated in direct prosthesis body fabrication and indirect production using an additively manufactured mould. Qualitative analysis of position, shape, colour and edge quality was undertaken. Mechanical testing to ISO standards was also used to compare the silicone rubber used in the conventional prosthesis with the AM material. Critical evaluation has shown that utilising a computer-aided workflow can produce a prosthesis body that is comparable to that produced using existing best practice. Technical limitations currently prevent the direct fabrication method demonstrated in this paper from being clinically viable. This research helps prosthesis providers understand the application of a computer-aided approach and guides technology developers and researchers to address the limitations identified.
Alcohol and Group Formation
Authors: Sayette Michael A. , Creswell Kasey G. , Dimoff John D. , Fairbairn Catharine E. , Cohn Jeffrey F. , Heckman Bryan W. , Kirchner Thomas R. , Levine John M. , Moreland Richard L.
Published: July 2012

We integrated research on emotion and on small groups to address a fundamental and enduring question facing alcohol researchers: What are the specific mechanisms that underlie the reinforcing effects of drinking? In one of the largest alcohol-administration studies yet conducted, we employed a novel group-formation paradigm to evaluate the socioemotional effects of alcohol. Seven hundred twenty social drinkers (360 male, 360 female) were assembled into groups of 3 unacquainted persons each and given a moderate dose of an alcoholic, placebo, or control beverage, which they consumed over 36 min. These groups’ social interactions were video recorded, and the duration and sequence of interaction partners’ facial and speech behaviors were systematically coded (e.g., using the Facial Action Coding System). Alcohol consumption enhanced individual- and group-level behaviors associated with positive affect, reduced individual-level behaviors associated with negative affect, and elevated self-reported bonding. Our results indicate that alcohol facilitates bonding during group formation. Assessing nonverbal responses in social contexts offers new directions for evaluating the effects of alcohol.
Helping Parents to Motivate Adolescents in Mathematics and Science
Authors: Harackiewicz Judith M. , Rozek Christopher S. , Hulleman Chris S. , Hyde Janet S.
Published: July 2012

The pipeline toward careers in science, technology, engineering, and mathematics (STEM) begins to leak in high school, when some students choose not to take advanced mathematics and science courses. We conducted a field experiment testing whether a theory-based intervention that was designed to help parents convey the importance of mathematics and science courses to their high school–aged children would lead them to take more mathematics and science courses in high school. The three-part intervention consisted of two brochures mailed to parents and a Web site, all highlighting the usefulness of STEM courses. This relatively simple intervention led students whose parents were in the experimental group to take, on average, nearly one semester more of science and mathematics in the last 2 years of high school, compared with the control group. Parents are an untapped resource for increasing STEM motivation in adolescents, and the results demonstrate that motivational theory can be applied to this important pipeline problem.
Investing in Karma
Authors: Converse Benjamin A. , Risen Jane L. , Carter Travis J.
Published: July 2012

People often face outcomes of important events that are beyond their personal control, such as when they wait for an acceptance letter, job offer, or medical test results. We suggest that when wanting and uncertainty are high and personal control is lacking, people may be more likely to help others, as if they can encourage fate’s favor by doing good deeds proactively. Four experiments support this karmic-investment hypothesis. When people want an outcome over which they have little control, their donations of time and money increase (Experiments 1 and 2), but their participation in other rewarding activities does not (Experiment 1b). In addition, at a job fair, job seekers who feel the process is outside (vs. within) their control make more generous pledges to charities (Experiment 3). Finally, karmic investments increase optimism about a desired outcome (Experiment 4). We conclude by discussing the role of personal control and magical beliefs in this phenomenon.
Simultaneous Control of Attention by Multiple Working Memory Representations
Authors: Beck Valerie M. , Hollingworth Andrew , Luck Steven J.
Published: July 2012

Working memory representations play a key role in controlling attention by making it possible to shift attention to task-relevant objects. Visual working memory has a capacity of three to four objects, but recent studies suggest that only one representation can guide attention at a given moment. We directly tested this proposal by monitoring eye movements while observers performed a visual search task in which they attempted to limit attention to objects drawn in two colors. When the observers were motivated to attend to one color at a time, they searched many consecutive items of one color (long run lengths) and exhibited a delay prior to switching gaze from one color to the other (switch cost). In contrast, when they were motivated to attend to both colors simultaneously, observers’ gaze switched back and forth between the two colors frequently (short run lengths), with no switch cost. Thus, multiple working memory representations can concurrently guide attention.
Cognitive Load Disrupts Implicit Theory-of-Mind Processing
Authors: Schneider Dana , Lam Rebecca , Bayliss Andrew P. , Dux Paul E.
Published: July 2012

Eye movements in Sally-Anne false-belief tasks appear to reflect the ability to implicitly monitor the mental states of other individuals (theory of mind, or ToM). It has recently been proposed that an early-developing, efficient, and automatically operating ToM system subserves this ability. Surprisingly absent from the literature, however, is an empirical test of the influence of domain-general executive processing resources on this implicit ToM system. In the study reported here, a dual-task method was employed to investigate the impact of executive load on eye movements in an implicit Sally-Anne false-belief task. Under no-load conditions, adult participants displayed eye movement behavior consistent with implicit belief processing, whereas evidence for belief processing was absent for participants under cognitive load. These findings indicate that the cognitive system responsible for implicitly tracking beliefs draws at least minimally on executive processing resources. Thus, even the most low-level processing of beliefs appears to reflect a capacity-limited operation.
Investigation of backface cavity sealing flow in deeply scalloped radial turbines
Authors: He Ping , Sun Zhi Gang , Chen Hai Sheng , Tan Chun Qing
Published: July 2012

The backface cavity sealing flow in deeply scalloped radial turbines is numerically investigated in this article. Both the time-averaged and unsteady results are shown, and three cavity sealing geometry models are analyzed. It is found that the the sealing flow strengthens the backface casing scraping flow in the lower radial region of backface clearance, cools the root of the blade backface and prevents hot gas ingestion. With the same disk radius ratio, the model with a radial clearance shows a better performance on cooling and sealing effectiveness than that with an axial clearance. The model with a radial clearance and a larger disk radius ratio has a higher isentropic efficiency. However, the axial thrust increases drastically and the cooling effectiveness is very low. Furthermore, the sealing effectiveness for the model decreases sharply because of the larger circumferential pressure difference near the disk rim and the higher rotational Reynolds number. In transient state, the amplitude of pressure and temperature increases significantly near the disk rim. And an unsteady flow pattern with high pressure and ingestion zones rotating at twice the rotational speed in the counter rotating direction, is found on the disk backface surface.
Fault detection for a class of nonhomogeneous Markov jump systems based on delta operator approach
Authors: Long Yue , Yang Guang-Hong
Published: July 2012

The problem of fault detection for a class of nonhomogeneous Markov jump system is addressed in this article based on a delta operator approach. The system under consideration contains mode-dependent delays, nonlinearities, as well as nonhomogeneous Markov switching. Also, the delta operator provides a theoretically unified formulation of continuous-time and discrete-time systems. In addition to the stochastic H∞ performance, a new definition of stochastic H− index is introduced from the signal’s point of view, which gives a measurement of sensitivity from the residuals to the faults. Then, the fault detection scheme is proposed in which the effect of the disturbances on the residuals is minimized; meanwhile, the effect of the faults on the residuals is maximized. Subsequently, novel sufficient conditions are derived to treat this multiobjective optimization problem in a potentially less conservative framework. Especially for the sensitivity performance, a new convex condition, which includes some existing results, is obtained in terms of linear matrix inequalities. Finally, an aircraft application is given to demonstrate the effectiveness of the proposed method.
Robust control for a direct-driven permanent magnetic synchronous generator without mechanical sensors based on model reference adaptive backstepping control method
Authors: Zu Hui , Zhang Guobao , Fei Shumin , Gao Qian
Published: July 2012

This article is concerned with the robust control issues of direct-driven permanent magnetic synchronous generator without mechanical sensors. In this study, a novel nonlinear model reference adaptive backstepping control method is proposed. Extended electromotive force estimation-based rotor position and rotational velocity estimation methods are adopted, in which the stator parameters are identified online. Since the identified parameters are merely used in extended electromotive force estimator, the mathematically controlled plant cannot reflect the actual model, which decreases the robustness of the control. To provide a high-performance robust controller against uncertainties in stator parameters and mechanical torque fluctuation, a torque observer is adopted, and an adaptation law is derived with the identified parameters and estimated mechanical torque, in the sense of the Lyapunov theory. Meanwhile, the feasibility of the substitution of the actual stator parameters and state vector with estimated values is mathematically demonstrated based on the Lyapunov theory. Simulation experiments have been carried out both in surface permanent magnetic synchronous generator and interior permanent magnetic synchronous generator, and the results show that compared to the conventional process-interaction decoupling controller, the proposed controller has better disturbance rejection performance against wind speed perpetuation and parameter uncertainties.
Energy optimal trajectory planning of an underwater robot using a genetic algorithm
Authors: Bende Vikrant , Pathak Pushparaj M , Dixit Kedar S , Harsha SP
Published: July 2012

This paper presents optimal trajectory planning for an autonomous underwater robot. The optimization parameter is taken as the energy consumed by the robot to traverse its arm tip from a predefined initial point to a final point. The bond graph technique is used for modeling the robot and a genetic algorithm is used as an optimization tool. A polynomial trajectory is considered so that the tip movement is smooth. SYMBOLS Shakti¯ is used as bond graph modeling software and its special feature of generation of CPP code containing the robot model’s expressions is used. The genetic algorithm is implemented on the generated CPP code. Simulation and results for an energy efficient trajectory are presented.
An investigation on semi-active suspension damper and control strategies for vehicle ride comfort and road holding
Authors: BalaMurugan Loganathan , Jancirani Jeyaraj
Published: July 2012

The real “golden age” of electronic suspension can be probably located in the 1980s; during that decade the exceptional potential of replacing a traditional spring-damper system with a fully fledged electronically controllable fast-reacting hydraulic actuator was demonstrated. High costs, significant power absorption, bulky and unreliable hydraulic systems, and uncertain management of the safety issues: the fatal attraction for fully active electronic suspensions lasted only a few years. In the second half of the 1990s, a new trend emerged: it became increasingly clear that the best compromise of cost (component cost, weight, electronics and sensors, power consumption, etc.) and performance (comfort, handling, safety) was to be found in the technology of electronically controllable suspensions: the variable-damping suspension or, in brief, the semi-active suspension. After a decade this technology is still highly promising and attractive: it has been introduced in the mass-market production of cars; it is entering the motorcycle market; a lot of special vehicles or niche applications are considering this technology; many new variable-damping technologies are being developed. Semi-active suspensions are expected to play an even more important role in the emerging trend of electric vehicles with in-wheel motors: in such a vehicle architecture the role of suspension damping is more crucial, and semi-active suspensions can significantly contribute to reduce the negative effects of the large unsprung mass. As in many other electronically controlled systems, the actuator is not “smart itself”: it simply inherits the smartness (or dumbness) of its control algorithm designer. The key of semi-active suspensions is in the algorithm. For the discussed reasons, this paper briefly reviews the basic theoretical concepts for variable-damping shock absorber technologies and the available control algorithms.