980 research outputs found

    Design and Analysis of Nanotube-Based Memory Cells

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    In this paper, we proposed a nanoelectromechanical design as memory cells. A simple design contains a double-walled nanotube-based oscillator. Atomistic materials are deposed on the outer nanotube as electrodes. Once the WRITE voltages are applied on electrodes, the induced electromagnetic force can overcome the interlayer friction between the inner and outer tubes so that the oscillator can provide stable oscillations. The READ voltages are employed to indicate logic 0/1 states based on the position of the inner tube. A new continuum modeling is developed in this paper to analyze large models of the proposed nanoelectromechanical design. Our simulations demonstrate the mechanisms of the proposed design as both static and dynamic random memory cells

    The Precursors and Products of Justice Climates: Group Leader Antecedents and Employee Attitudinal Consequences

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    Drawing on the organizational justice, organizational climate, leadership and personality, and social comparison theory literatures, we develop hypotheses about the effects of leader personality on the development of three types of justice climates (e.g., procedural, interpersonal, and informational), and the moderating effects of these climates on individual level justice- attitude relationships. Largely consistent with the theoretically-derived hypotheses, the results showed that leader (a) agreeableness was positively related to procedural, interpersonal and informational justice climates, (b) conscientiousness was positively related to a procedural justice climate, and (c) neuroticism was negatively related to all three types of justice climates. Further, consistent with social comparison theory, multilevel data analyses revealed that the relationship between individual justice perceptions and job attitudes (e.g., job satisfaction, commitment) was moderated by justice climate such that the relationships were stronger when justice climate was high

    Effectiveness of automated locomotor training in patients with acute incomplete spinal cord injury: A randomized controlled multicenter trial

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    <p>Abstract</p> <p>Background</p> <p>A large proportion of patients with spinal cord injury (SCI) regain ambulatory function. However, during the first 3 months most of the patients are not able to walk unsupported. To enable ambulatory training at such an early stage the body weight is partially relieved and the leg movements are assisted by two therapists. A more recent approach is the application of robotic based assistance which allows for longer training duration. From motor learning science and studies including patients with stroke, it is known that training effects depend on the duration of the training. Longer trainings result in a better walking function. The aim of the present study is to evaluate if prolonged robot assisted walking training leads to a better walking outcome in patients with incomplete SCI and whether such training is feasible or has undesirable effects.</p> <p>Methods/Design</p> <p>Patients from multiple sites with a subacute incomplete SCI and who are not able to walk independently will be randomized to either standard training (3-5 sessions per week, session duration maximum 25 minutes) or an intensive training (3-5 sessions per week, session duration minimum 50 minutes). After 8 weeks of training and 4 months later the walking ability, the occurrence of adverse events and the perceived rate of exertion as well as the patients' impression of change will be compared between groups.</p> <p>Trial registration</p> <p>This study is registered at clinicaltrials.gov, identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01147185">NCT01147185</a>.</p

    Treatment of uterine prolapse stage 2 or higher: a randomized multicenter trial comparing sacrospinous fixation with vaginal hysterectomy (SAVE U trial)

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    Contains fulltext : 97471.pdf (publisher's version ) (Open Access)BACKGROUND: Pelvic organ prolapse is a common health problem, affecting up to 40% of parous women over 50 years old, with significant negative influence on quality of life. Vaginal hysterectomy is currently the leading treatment method for patients with symptomatic uterine prolapse. Several studies have shown that sacrospinous fixation in case of uterine prolapse is a safe and effective alternative to vaginal hysterectomy. However, no large randomized trials with long-term follow-up have been performed to compare efficacy and quality of life between both techniques.The SAVE U trial is designed to compare sacrospinous fixation with vaginal hysterectomy in the treatment of uterine prolapse stage 2 or higher in terms of prolapse recurrence, quality of life, complications, hospital stay, post-operative recovery and sexual functioning. METHODS/DESIGN: The SAVE U trial is a randomized controlled multi-center non-inferiority trial. The study compares sacrospinous fixation with vaginal hysterectomy in women with uterine prolapse stage 2 or higher. The primary outcome measure is recurrence of uterine prolapse defined as: uterine descent stage 2 or more assessed by pelvic organ prolapse quantification examination and prolapse complaints and/or redo surgery at 12 months follow-up. Secondary outcomes are subjective improvement in quality of life measured by generic (Short Form 36 and Euroqol 5D) and disease-specific (Urogenital Distress Inventory, Defecatory Distress Inventory and Incontinence Impact Questionnaire) quality of life instruments, complications following surgery, hospital stay, post-operative recovery and sexual functioning (Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire). Analysis will be performed according to the intention to treat principle. Based on comparable recurrence rates of 3% and considering an upper-limit of 7% to be non-inferior (beta 0.2 and one sided alpha 0.025), 104 patients are needed per group. DISCUSSION: The SAVE U trial is a randomized multicenter trial that will provide evidence whether the efficacy of sacrospinous fixation is similar to vaginal hysterectomy in women with uterine prolapse stage 2 or higher. TRIAL REGISTRATION: Netherlands Trial Register (NTR): NTR1866

    Climate change adaptation in European river basins

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    This paper contains an assessment and standardized comparative analysis of the current water management regimes in four case-studies in three European river basins: the Hungarian part of the Upper Tisza, the Ukrainian part of the Upper Tisza (also called Zacarpathian Tisza), Alentejo Region (including the Alqueva Reservoir) in the Lower Guadiana in Portugal, and Rivierenland in the Netherlands. The analysis comprises several regime elements considered to be important in adaptive and integrated water management: agency, awareness raising and education, type of governance and cooperation structures, information management and—exchange, policy development and—implementation, risk management, and finances and cost recovery. This comparative analysis has an explorative character intended to identify general patterns in adaptive and integrated water management and to determine its role in coping with the impacts of climate change on floods and droughts. The results show that there is a strong interdependence of the elements within a water management regime, and as such this interdependence is a stabilizing factor in current management regimes. For example, this research provides evidence that a lack of joint/participative knowledge is an important obstacle for cooperation, or vice versa. We argue that there is a two-way relationship between information management and collaboration. Moreover, this research suggests that bottom-up governance is not a straightforward solution to water management problems in large-scale, complex, multiple-use systems, such as river basins. Instead, all the regimes being analyzed are in a process of finding a balance between bottom-up and top–down governance. Finally, this research shows that in a basin where one type of extreme is dominant—like droughts in the Alentejo (Portugal) and floods in Rivierenland (Netherlands)—the potential impacts of other extremes are somehow ignored or not perceived with the urgency they might deserv

    Triceps Surae Short Latency Stretch Reflexes Contribute to Ankle Stiffness Regulation during Human Running

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    During human running, short latency stretch reflexes (SLRs) are elicited in the triceps surae muscles, but the function of these responses is still a matter of controversy. As the SLR is primarily mediated by Ia afferent nerve fibres, various methods have been used to examine SLR function by selectively blocking the Ia pathway in seated, standing and walking paradigms, but stretch reflex function has not been examined in detail during running. The purpose of this study was to examine triceps surae SLR function at different running speeds using Achilles tendon vibration to modify SLR size. Ten healthy participants ran on an instrumented treadmill at speeds between 7 and 15 km/h under 2 Achilles tendon vibration conditions: no vibration and 90 Hz vibration. Surface EMG from the triceps surae and tibialis anterior muscles, and 3D lower limb kinematics and ground reaction forces were simultaneously collected. In response to vibration, the SLR was depressed in the triceps surae muscles at all speeds. This coincided with short-lasting yielding at the ankle joint at speeds between 7 and 12 km/h, suggesting that the SLR contributes to muscle stiffness regulation by minimising ankle yielding during the early contact phase of running. Furthermore, at the fastest speed of 15 km/h, the SLR was still depressed by vibration in all muscles but yielding was no longer evident. This finding suggests that the SLR has greater functional importance at slow to intermediate running speeds than at faster speeds

    ARPES: A probe of electronic correlations

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    Angle-resolved photoemission spectroscopy (ARPES) is one of the most direct methods of studying the electronic structure of solids. By measuring the kinetic energy and angular distribution of the electrons photoemitted from a sample illuminated with sufficiently high-energy radiation, one can gain information on both the energy and momentum of the electrons propagating inside a material. This is of vital importance in elucidating the connection between electronic, magnetic, and chemical structure of solids, in particular for those complex systems which cannot be appropriately described within the independent-particle picture. Among the various classes of complex systems, of great interest are the transition metal oxides, which have been at the center stage in condensed matter physics for the last four decades. Following a general introduction to the topic, we will lay the theoretical basis needed to understand the pivotal role of ARPES in the study of such systems. After a brief overview on the state-of-the-art capabilities of the technique, we will review some of the most interesting and relevant case studies of the novel physics revealed by ARPES in 3d-, 4d- and 5d-based oxides.Comment: Chapter to appear in "Strongly Correlated Systems: Experimental Techniques", edited by A. Avella and F. Mancini, Springer Series in Solid-State Sciences (2013). A high-resolution version can be found at: http://www.phas.ubc.ca/~quantmat/ARPES/PUBLICATIONS/Reviews/ARPES_Springer.pdf. arXiv admin note: text overlap with arXiv:cond-mat/0307085, arXiv:cond-mat/020850

    Foot function during gait and parental perceived outcome in older children with symptomatic club foot deformity

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    Aims To assess if older symptomatic children with club foot deformity differ in perceived disability and foot function during gait, depending on initial treatment with Ponseti or surgery, compared to a control group. Second aim was to investigate correlations between foot function during gait and perceived disability in this population. Methods In all, 73 children with idiopathic club foot were included: 31 children treated with the Ponseti method (mean age 8.3 years; 24 male; 20 bilaterally affected, 13 left and 18 right sides analyzed), and 42 treated with primary surgical correction (mean age 11.6 years; 28 male; 23 bilaterally affected, 18 left and 24 right sides analyzed). Foot function data was collected during walking gait and included Oxford Foot Model kinematics (Foot Profile Score and the range of movement and average position of each part of the foot) and plantar pressure (peak pressure in five areas of the foot). Oxford Ankle Foot Questionnaire, Disease Specific Index for club foot, Paediatric Quality of Life Inventory 4.0 were also collected. The gait data were compared between the two club foot groups and compared to control data. The gait data were also correlated with the data extracted from the questionnaires. Results Our findings suggest that symptomatic children with club foot deformity present with similar degrees of gait deviations and perceived disability regardless of whether they had previously been treated with the Ponseti Method or surgery. The presence of sagittal and coronal plane hindfoot deformity and coronal plane forefoot deformity were associated with higher levels of perceived disability, regardless of their initial treatment. Conclusion This is the first paper to compare outcomes between Ponseti and surgery in a symptomatic older club foot population seeking further treatment. It is also the first paper to correlate foot function during gait and perceived disability to establish a link between deformity and subjective outcomes.</p

    EuraHS: the development of an international online platform for registration and outcome measurement of ventral abdominal wall hernia repair

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    Background Although the repair of ventral abdominal wall hernias is one of the most commonly performed operations, many aspects of their treatment are still under debate or poorly studied. In addition, there is a lack of good definitions and classifications that make the evaluation of studies and meta-analyses in this field of surgery difficult. Materials and methods Under the auspices of the board of the European Hernia Society and following the previously published classifications on inguinal and on ventral hernias, a working group was formed to create an online platform for registration and outcome measurement of operations for ventral abdominal wall hernias. Development of such a registry involved reaching agreement about clear definitions and classifications on patient variables, surgical procedures and mesh materials used, as well as outcome parameters. The EuraHS working group (European registry for abdominal wall hernias) comprised of a multinational European expert panel with specific interest in abdominal wall hernias. Over five working group meetings, consensus was reached on definitions for the data to be recorded in the registry. Results A set of well-described definitions was made. The previously reported EHS classifications of hernias will be used. Risk factors for recurrences and co-morbidities of patients were listed. A new severity of comorbidity score was defined. Post-operative complications were classified according to existing classifications as described for other fields of surgery. A new 3-dimensional numerical quality-of-life score, EuraHS-QoL score, was defined. An online platform is created based on the definitions and classifications, which can be used by individual surgeons, surgical teams or for multicentre studies. A EuraHS website is constructed with easy access to all the definitions, classifications and results from the database. Conclusion An online platform for registration and outcome measurement of abdominal wall hernia repairs with clear definitions and classifications is offered to the surgical community. It is hoped that this registry could lead to better evidence-based guidelines for treatment of abdominal wall hernias based on hernia variables, patient variables, available hernia repair materials and techniques
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