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Sample records for schenck dynamic balancer

  1. Biomechanical assessment of dynamic balance: Specificity of different balance tests.

    Science.gov (United States)

    Ringhof, Steffen; Stein, Thorsten

    2018-04-01

    Dynamic balance is vitally important for most sports and activities of daily living, so the assessment of dynamic stability has become an important issue. In consequence, a large number of balance tests have been developed. However, it is not yet known whether these tests (i) measure the same construct and (ii) can differentiate between athletes with different balance expertise. We therefore studied three common dynamic balance tests: one-leg jump landings, Posturomed perturbations and simulated forward falls. Participants were 24 healthy young females in regular training in either gymnastics (n = 12) or swimming (n = 12). In each of the tests, the participants were instructed to recover balance as quickly as possible. Dynamic stability was computed by time to stabilization and margin of stability, deduced from force plates and motion capture respectively. Pearson's correlations between the dynamic balance tests found no significant associations between the respective dynamic stability measures. Furthermore, independent t-tests indicated that only jump landings could properly distinguish between both groups of athletes. In essence, the different dynamic balance tests applied did not measure the same construct but rather task-specific skills, each of which depends on multifactorial internal and external constraints. Our study therefore contradicts the traditional view of considering balance as a general ability, and reinforces that dynamic balance measures are not interchangeable. This highlights the importance of selecting appropriate balance tests. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Dynamic Analysis of a Pendulum Dynamic Automatic Balancer

    Directory of Open Access Journals (Sweden)

    Jin-Seung Sohn

    2007-01-01

    Full Text Available The automatic dynamic balancer is a device to reduce the vibration from unbalanced mass of rotors. Instead of considering prevailing ball automatic dynamic balancer, pendulum automatic dynamic balancer is analyzed. For the analysis of dynamic stability and behavior, the nonlinear equations of motion for a system are derived with respect to polar coordinates by the Lagrange's equations. The perturbation method is applied to investigate the dynamic behavior of the system around the equilibrium position. Based on the linearized equations, the dynamic stability of the system around the equilibrium positions is investigated by the eigenvalue analysis.

  3. Effects of dynamic posturographic balance training versus conventional balance training on mobility and balance in elderly

    International Nuclear Information System (INIS)

    Saddiqi, F.A.; Masood, T.

    2017-01-01

    To determine the effects of dynamic posturographic balance training versus conventional balance training in improving mobility and balance in elderly. Methodology: Forty subjects between 50 to 80 years of age were selected via non-probability convenience sampling technique, for this randomized controlled trial. Both females and males with no major co-morbid conditions and cognitive impairments were recruited and randomized via coin toss method into two equal groups: Dynamic Posturographic balance training (DPG) group and Conventional balance training (CBT) group. The DPG training was provided via Biodex Balance System (Static and Dynamic). Both groups received interventions 3 times (35 to 45min each day) a week for 8 weeks, after which terminal assessment was done. Data were collected on demographic profile, balance via berg balance score and mobility by using Timed Up and Go Test. Independent samples t test was used to check difference between CBT group and DPG Group and repeated measures Analysis of Variance (ANOVA) was used for within-group analysis. Results: Baseline analysis of Berg balance scale and timed up and go test between two groups showed no significant difference with (p 0.805 and 0.251, respectively). After 8 weeks of intervention, there was significant difference between the groups in both variables (p 0.019 and 0.001, respectively). Conclusion: Dynamic posturographic balance training was more effective in improving dynamic balance and mobility in elderly population in comparison to conventional balance training. (author)

  4. Synthesis of Dynamically Balanced Mechanisms by Using Counter-Rotary Countermass Balanced Double Pendula

    NARCIS (Netherlands)

    van der Wijk, V.; Herder, Justus Laurens

    2009-01-01

    Complete dynamic balancing principles still cannot avoid a substantial increase in mass and inertia. In addition, the conditions for dynamic balance and inertia equations can be complicated to derive. This article shows how a double pendulum, which is fully dynamically balanced using counter-rotary

  5. High technology at 'General Turbo', DH 12/13 balance-over speed testing stand

    International Nuclear Information System (INIS)

    Nuta, Florian Nicolae; Vasiliu, Dinu; Mauna, Traian

    2005-01-01

    'General Turbo' activity started in 1970 including building the balancing and over speed stand. DH 12/13 is the latest up-to-date facility of this type, the best one of the five in Europe, and was commissioned in 2004. The facility was especially built to be used for Romanian Nuclear Power Plant rotor testing and also for thermal very big rotors. The paper underlines the main attributes and the components of the facility DH 12/13 based on the Schenck technology. (authors)

  6. Effect of Selected Balance Exercises on the Dynamic Balance of Children with Visual Impairments

    Science.gov (United States)

    Jazi, Shirin Davarpanah; Purrajabi, Fatemeh; Movahedi, Ahmadreza; Jalali, Shahin

    2012-01-01

    Introduction: Maintaining balance while walking is of utmost importance for individuals with visual impairments because deficits in dynamic balance have been associated with a high risk of falling. Thus, the primary aim of the study presented here was to determine whether balance training effects the dynamic balance of children with visual…

  7. Balance of power theory meets Al Qaeda : dynamics of non-state actor balancing in postinternational politics

    OpenAIRE

    Denk, Aytaç

    2008-01-01

    Ankara : The Department of International Relations, Bilkent University, 2008. Thesis (Master's) -- Bilkent University, 2008. Includes bibliographical references leaves 196-207. The bulk of studies on the balance of power, which constitutes balance of power theory, suggest that only states are involved in balance of power dynamics. This thesis maintains that exclusion of non-state actors (NSAs) from balance of power dynamics constitutes a significant gap in balance of power t...

  8. Immediate effects of cryotherapy on static and dynamic balance.

    Science.gov (United States)

    Douglas, Matthew; Bivens, Serena; Pesterfield, Jennifer; Clemson, Nathan; Castle, Whitney; Sole, Gisela; Wassinger, Craig A

    2013-02-01

    Cryotherapy is commonly used in physical therapy with many known benefits; however several investigations have reported decreased functional performance following therapeutic application thereof. The purpose of this study was to determine the effect of cryotherapy applied to the ankle on static and dynamic standing balance. It was hypothesized that balance would be decreased after cryotherapy application. Twenty individuals (aged 18 to 40 years) participated in this research project. Each participant was tested under two conditions: an experimental condition where subjects received ice water immersion of the foot and ankle for 15 minutes immediately before balance testing and a control condition completed at room temperature. A Biodex® Balance System was used to quantify balance using anterior/posterior (AP), medial/lateral (ML), and overall balance indices. Paired t-tests were used to compare the balance indices for the two conditions with alpha set at 0.05 a priori. Effect size was also calculated to account for the multiple comparisons made. The static balance indices did not display statistically significant differences between the post-cryotherapy and the control conditions with low effect sizes. Dynamic ML indices significantly increased following the cryotherapy application compared to the control exhibiting a moderate effect size indicating decreased balance following cryotherapy application. No differences were noted between experimental and control conditions for the dynamic AP or overall balance indices while a small effect size was noted for both. The results suggest that cryotherapy to the ankle has a negative effect on the ML component of dynamic balance following ice water immersion. Immediate return to play following cryotherapy application is cautioned given the decreased dynamic ML balance and potential for increased injury risk. 3b Case-control study.

  9. Dynamic balance during walking adaptability tasks in individuals post-stroke.

    Science.gov (United States)

    Vistamehr, Arian; Balasubramanian, Chitralakshmi K; Clark, David J; Neptune, Richard R; Fox, Emily J

    2018-04-24

    Maintaining dynamic balance during community ambulation is a major challenge post-stroke. Community ambulation requires performance of steady-state level walking as well as tasks that require walking adaptability. Prior studies on balance control post-stroke have mainly focused on steady-state walking, but walking adaptability tasks have received little attention. The purpose of this study was to quantify and compare dynamic balance requirements during common walking adaptability tasks post-stroke and in healthy adults and identify differences in underlying mechanisms used for maintaining dynamic balance. Kinematic data were collected from fifteen individuals with post-stroke hemiparesis during steady-state forward and backward walking, obstacle negotiation, and step-up tasks. In addition, data from ten healthy adults provided the basis for comparison. Dynamic balance was quantified using the peak-to-peak range of whole-body angular-momentum in each anatomical plane during the paretic, nonparetic and healthy control single-leg-stance phase of the gait cycle. To understand differences in some of the key underlying mechanisms for maintaining dynamic balance, foot placement and plantarflexor muscle activation were examined. Individuals post-stroke had significant dynamic balance deficits in the frontal plane across most tasks, particularly during the paretic single-leg-stance. Frontal plane balance deficits were associated with wider paretic foot placement, elevated body center-of-mass, and lower soleus activity. Further, the obstacle negotiation task imposed a higher balance requirement, particularly during the trailing leg single-stance. Thus, improving paretic foot placement and ankle plantarflexor activity, particularly during obstacle negotiation, may be important rehabilitation targets to enhance dynamic balance during post-stroke community ambulation. Copyright © 2018. Published by Elsevier Ltd.

  10. Modelling and Analysis of a New Piezoelectric Dynamic Balance Regulator

    Directory of Open Access Journals (Sweden)

    Mu-Xun Xu

    2012-11-01

    Full Text Available In this paper, a new piezoelectric dynamic balance regulator, which can be used in motorised spindle systems, is presented. The dynamic balancing adjustment mechanism is driven by an in-plane bending vibration from an annular piezoelectric stator excited by a high-frequency sinusoidal input voltage. This device has different construction, characteristics and operating principles than a conventional balance regulator. In this work, a dynamic model of the regulator is first developed using a detailed analytical method. Thereafter, MATLAB is employed to numerically simulate the relations between the dominant parameters and the characteristics of the regulator based on thedynamic model. Finally, experimental measurements are used to certify the validity of the dynamic model. Consequently, the mathematical model presented and analysed in this paper can be used as a tool for optimising the design of a piezoelectric dynamic balance regulator during steady state operation.

  11. Dynamic balancing of planar mechanisms using toric geometry

    OpenAIRE

    Moore, Brian; Schicho, Josef; Gosselin, Clement M.

    2007-01-01

    In this paper, a new method to determine the complete set of dynamically balanced planar four-bar mechanims is presented. Using complex variables to model the kinematics of the mechanism, the dynamic balancing constraints are written as algebraic equations over complex variables and joint angular velocities. After elimination of the joint angular velocity variables, the problem is formulated as a problem of factorization of Laurent polynomials. Using toric polynomial division, necessary and s...

  12. Virtual-reality balance training with a video-game system improves dynamic balance in chronic stroke patients.

    Science.gov (United States)

    Cho, Ki Hun; Lee, Kyoung Jin; Song, Chang Ho

    2012-09-01

    Stroke is one of the most serious healthcare problems and a major cause of impairment of cognition and physical functions. Virtual rehabilitation approaches to postural control have been used for enhancing functional recovery that may lead to a decrease in the risk of falling. In the present study, we investigated the effects of virtual reality balance training (VRBT) with a balance board game system on balance of chronic stroke patients. Participants were randomly assigned to 2 groups: VRBT group (11 subjects including 3 women, 65.26 years old) and control group (11 subjects including 5 women, 63.13 years old). Both groups participated in a standard rehabilitation program (physical and occupational therapy) for 60 min a day, 5 times a week for 6 weeks. In addition, the VRBT group participated in VRBT for 30 min a day, 3 times a week for 6 weeks. Static balance (postural sway velocity with eyes open or closed) was evaluated with the posturography. Dynamic balance was evaluated with the Berg Balance Scale (BBS) and Timed Up and Go test (TUG) that measures balance and mobility in dynamic balance. There was greater improvement on BBS (4.00 vs. 2.81 scores) and TUG (-1.33 vs. -0.52 sec) in the VRBT group compared with the control group (P < 0.05), but not on static balance in both groups. In conclusion, we demonstrate a significant improvement in dynamic balance in chronic stroke patients with VRBT. VRBT is feasible and suitable for chronic stroke patients with balance deficit in clinical settings.

  13. Microworlds of the dynamic balanced scorecard for university (DBSC-UNI)

    Science.gov (United States)

    Hawari, Nurul Nazihah; Tahar, Razman Mat

    2015-12-01

    This research focuses on the development of a Microworlds of the dynamic balanced scorecard for university in order to enhance the university strategic planning process. To develop the model, we integrated both the balanced scorecard method and the system dynamics modelling method. Contrasting the traditional university planning tools, the developed model addresses university management problems holistically and dynamically. It is found that using system dynamics modelling method, the cause-and-effect relationships among variables related to the four conventional balanced scorecard perspectives are better understand. The dynamic processes that give rise to performance differences between targeted and actual performances also could be better understood. So, it is expected that the quality of the decisions taken are improved because of being better informed. The developed Microworlds can be exploited by university management to design policies that can positively influence the future in the direction of desired goals, and will have minimal side effects. This paper integrates balanced scorecard and system dynamics modelling methods in analyzing university performance. Therefore, this paper demonstrates the effectiveness and strength of system dynamics modelling method in solving problem in strategic planning area particularly in higher education sector.

  14. Dynamic Load Balancing of Parallel Monte Carlo Transport Calculations

    International Nuclear Information System (INIS)

    O'Brien, M; Taylor, J; Procassini, R

    2004-01-01

    The performance of parallel Monte Carlo transport calculations which use both spatial and particle parallelism is increased by dynamically assigning processors to the most worked domains. Since the particle work load varies over the course of the simulation, this algorithm determines each cycle if dynamic load balancing would speed up the calculation. If load balancing is required, a small number of particle communications are initiated in order to achieve load balance. This method has decreased the parallel run time by more than a factor of three for certain criticality calculations

  15. Dynamic power balance analysis in JET

    International Nuclear Information System (INIS)

    Matthews, G F; Silburn, S A; Challis, C D; Iglesias, D; King, D; Eich, T; Sieglin, B; Contributors, JET

    2017-01-01

    The full scale realisation of nuclear fusion as an energy source requires a detailed understanding of power and energy balance in current experimental devices. In this we explore whether a global power balance model in which some of the calibration factors applied to the source or sink terms are fitted to the data can provide insight into possible causes of any discrepancies in power and energy balance seen in the JET tokamak. We show that the dynamics in the power balance can only be properly reproduced by including the changes in the thermal stored energy which therefore provides an additional opportunity to cross calibrate other terms in the power balance equation. Although the results are inconclusive with respect to the original goal of identifying the source of the discrepancies in the energy balance, we do find that with optimised parameters an extremely good prediction of the total power measured at the outer divertor target can be obtained over a wide range of pulses with time resolution up to ∼25 ms. (paper)

  16. The relationship between gait parameters and static and dynamic balance in the elderly

    Directory of Open Access Journals (Sweden)

    Razieh Tabe

    2015-02-01

    Full Text Available Background: The physiological changes and muscle problems can lead to balance disorder and increased risk of falling among the elderly. Therefore, it is necessary to evaluate the factors associated with balance in the elderly, to increase their awareness of the falling risks and to provide them with appropriate assistive devices.. Hence, this study was carried out to investigate the relationship between some gait parameters and static and dynamic balance in the elderly. Methods: In this quasi-experimental study, 44 men and women in two groups (22 per group participated as the study sample. The measured values included step length, stride length, step width, rotating angle of toes, and static and dynamic balance. The static balance was measured with Romberg test and dynamic balance with TUGTU test. Data were analysed by SPSS-15 software using t-test and Pearson correlation coefficient. Results: There was a significant relationship between step length and stride length with static and dynamic balance and between step width and dynamic balance (p0/05. But no significant relationship was reported between step width and static balance and between rotating angle of toes with static and dynamic balance among the elderly. Conclusions: the elderly balance can be improved by decreasing the step length and increasing the stride length, thereby reducing the possibility of their falling.

  17. A Dynamic and Heuristic Phase Balancing Method for LV Feeders

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    Samad Taghipour Boroujeni

    2016-01-01

    Full Text Available Due to the single-phase loads and their stochastic behavior, the current in the distribution feeders is not balanced. In addition, the single-phase loads are located in different positions along the LV feeders. So the amount of the unbalanced load and its location affect the feeder losses. An unbalanced load causes the feeder losses and the voltage drop. Because of time-varying behavior of the single-phase loads, phase balancing is a dynamic and combinatorial problem. In this research, a heuristic and dynamic solution for the phase balancing of the LV feeders is proposed. In this method, it is supposed that the loads’ tie could be connected to all phases through a three-phase switch. The aim of the proposed method is to make the feeder conditions as balanced as possible. The amount and the location of single-phase loads are considered in the proposed phase balancing method. Since the proposed method needs no communication interface or no remote controller, it is inexpensive, simple, practical, and robust. Applying this method provides a distributed and dynamic phase balancing control. In addition, the feasibility of reducing the used switches is investigated. The ability of the proposed method in the phase balancing of the LV feeders is approved by carrying out some simulations.

  18. Nonlinear dynamics modeling and simulation of two-wheeled self-balancing vehicle

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    Yunping Liu

    2016-11-01

    Full Text Available Two-wheeled self-balancing vehicle system is a kind of naturally unstable underactuated system with high-rank unstable multivariable strongly coupling complicated dynamic nonlinear property. Nonlinear dynamics modeling and simulation, as a basis of two-wheeled self-balancing vehicle dynamics research, has the guiding effect for system design of the project demonstration and design phase. Dynamics model of the two-wheeled self-balancing vehicle is established by importing a TSi ProPac package to the Mathematica software (version 8.0, which analyzes the stability and calculates the Lyapunov exponents of the system. The relationship between external force and stability of the system is analyzed by the phase trajectory. Proportional–integral–derivative control is added to the system in order to improve the stability of the two-wheeled self-balancing vehicle. From the research, Lyapunov exponent can be used to research the stability of hyperchaos system. The stability of the two-wheeled self-balancing vehicle is better by inputting the proportional–integral–derivative control. The Lyapunov exponent and phase trajectory can help us analyze the stability of a system better and lay the foundation for the analysis and control of the two-wheeled self-balancing vehicle system.

  19. Comparison of dynamic balance in collegiate field hockey and football players using star excursion balance test.

    Science.gov (United States)

    Bhat, Rashi; Moiz, Jamal Ali

    2013-09-01

    The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Field hockey players and football players did not differ in terms of dynamic balance.

  20. Dynamic balancing of mechanisms and synthesizing of parallel robots

    CERN Document Server

    Wei, Bin

    2016-01-01

    This book covers the state-of-the-art technologies in dynamic balancing of mechanisms with minimum increase of mass and inertia. The synthesis of parallel robots based on the Decomposition and Integration concept is also covered in detail. The latest advances are described, including different balancing principles, design of reactionless mechanisms with minimum increase of mass and inertia, and synthesizing parallel robots. This is an ideal book for mechanical engineering students and researchers who are interested in the dynamic balancing of mechanisms and synthesizing of parallel robots. This book also: ·       Broadens reader understanding of the synthesis of parallel robots based on the Decomposition and Integration concept ·       Reinforces basic principles with detailed coverage of different balancing principles, including input torque balancing mechanisms ·       Reviews exhaustively the key recent research into the design of reactionless mechanisms with minimum increase of mass a...

  1. Acute effects of rearfoot manipulation on dynamic standing balance in healthy individuals.

    Science.gov (United States)

    Wassinger, Craig A; Rockett, Ariel; Pitman, Lucas; Murphy, Matthew Matt; Peters, Charles

    2014-06-01

    Dynamic standing balance is essential to perform functional activities and is included in the treatment of many lower extremity injuries. Physiotherapists utilize many methods to restore standing balance including stability exercises, functional retraining, and manual therapy. The purpose of this study was to investigate the effects of a rearfoot distraction manipulation on dynamic standing balance. Twenty healthy participants (age: 24.4 ± 2.8 years; height: 162.9 ± 37.7 cm; mass: 68.0 ± 4.8 kg; right leg dominant = 20) completed this study. Following familiarization, dynamic standing balance was assessed during: (1) an experimental condition immediately following a rearfoot distraction manipulation, and (2) a control condition. Dominant leg balance was quantified using the Y-balance test which measures lower extremity reach distances. Reach distances were normalized to leg length and measured in the anterior, posteromedial and posterolateral directions. Overall balance was calculated through the summing of all normalized directions. Paired t-tests and Wilcoxon rank tests were used to compare balance scores for parametric and non-parametric data as appropriate. Significance was set at 0.05 a priori. Effect size (ES) was calculated to determine the clinical impact of the manipulation. Increased reach distances (indicating improved balance) were noted following manipulation for overall balance (p = 0.03, ES = 0.26) and in the posteromedial direction (p = 0.01, ES = 0.42). Reach distances did not differ for the anterior (p = 0.11, ES = 0.16) or posterolateral (p = 0.11, ES = 0.25) components. Dynamic standing balance improved after a rearfoot distraction manipulation in healthy participants. It is hypothesized that manual therapy applied to the foot and ankle may be beneficial to augment other therapeutic modalities when working with patients to improve dynamic standing balance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. The relationships of eccentric strength and power with dynamic balance in male footballers.

    Science.gov (United States)

    Booysen, Marc Jon; Gradidge, Philippe Jean-Luc; Watson, Estelle

    2015-01-01

    Unilateral balance is critical to kicking accuracy in football. In order to design interventions to improve dynamic balance, knowledge of the relationships between dynamic balance and specific neuromuscular factors such as eccentric strength and power is essential. Therefore, the aim was to determine the relationships of eccentric strength and power with dynamic balance in male footballers. The Y-balance test, eccentric isokinetic strength testing (knee extensors and flexors) and the countermovement jump were assessed in fifty male footballers (university (n = 27, mean age = 20.7 ± 1.84 years) and professional (n = 23, mean age = 23.0 ± 3.08 years). Spearman Rank Order correlations were used to determine the relationships of eccentric strength and power with dynamic balance. Multiple linear regression, adjusting for age, mass, stature, playing experience and competitive level was performed on significant relationships. Normalised reach score in the Y-balance test using the non-dominant leg for stance correlated with (1) eccentric strength of the non-dominant leg knee extensors in the university group (r = 0.50, P = 0.008) and (2) countermovement jump height in the university (r = 0.40, P = 0.04) and professional (r = 0.56, P = 0.006) football groups, respectively. No relationships were observed between eccentric strength (knee flexors) and normalised reach scores. Despite the addition of potential confounders, the relationship of power and dynamic balance was significant (r = 0.52, P power correlates moderately with dynamic balance on the non-dominant leg in male footballers.

  3. Comparative analysis for low-mass and low-inertia dynamic balancing of mechanisms

    NARCIS (Netherlands)

    van der Wijk, V.; Demeulenaere, B.; Gosselin, C.M.; Herder, Justus Laurens

    2012-01-01

    Dynamic balance is an important feature of high speed mechanisms and robotics that need to minimize vibrations of the base. The main disadvantage of dynamic balancing, however, is that it is accompanied with a considerable increase in mass and inertia. Aiming at low-mass and low-inertia dynamic

  4. Energy Balance Models and Planetary Dynamics

    Science.gov (United States)

    Domagal-Goldman, Shawn

    2012-01-01

    We know that planetary dynamics can have a significant affect on the climate of planets. Planetary dynamics dominate the glacial-interglacial periods on Earth, leaving a significant imprint on the geological record. They have also been demonstrated to have a driving influence on the climates of other planets in our solar system. We should therefore expect th.ere to be similar relationships on extrasolar planets. Here we describe a simple energy balance model that can predict the growth and thickness of glaciers, and their feedbacks on climate. We will also describe model changes that we have made to include planetary dynamics effects. This is the model we will use at the start of our collaboration to handle the influence of dynamics on climate.

  5. Transcribing the balanced scorecard into system dynamics

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2013-01-01

    The purpose of this paper is to show how a System Dynamics Modelling approach can be integrated into the Balanced Scorecard (BSC) for a case company with special focus on the handling of causality in a dynamic perspective. The BSC model includes five perspectives and a number of financial and non...... the cause-and-effect relationships of an integrated BSC model. Including dynamic aspects of BSCs into the discussion is only in its infancy, so the aim of our work is also to contribute to both scholars’ and practitioners’ general understanding of how such delayed dynamic effects propagate through system...

  6. Adaptive control of dynamic balance in human gait on a split-belt treadmill.

    Science.gov (United States)

    Buurke, Tom J W; Lamoth, Claudine J C; Vervoort, Danique; van der Woude, Lucas H V; den Otter, Rob

    2018-05-17

    Human bipedal gait is inherently unstable and staying upright requires adaptive control of dynamic balance. Little is known about adaptive control of dynamic balance in reaction to long-term, continuous perturbations. We examined how dynamic balance control adapts to a continuous perturbation in gait, by letting people walk faster with one leg than the other on a treadmill with two belts (i.e. split-belt walking). In addition, we assessed whether changes in mediolateral dynamic balance control coincide with changes in energy use during split-belt adaptation. In nine minutes of split-belt gait, mediolateral margins of stability and mediolateral foot roll-off changed during adaptation to the imposed gait asymmetry, especially on the fast side, and returned to baseline during washout. Interestingly, no changes in mediolateral foot placement (i.e. step width) were found during split-belt adaptation. Furthermore, the initial margin of stability and subsequent mediolateral foot roll-off were strongly coupled to maintain mediolateral dynamic balance throughout the gait cycle. Consistent with previous results net metabolic power was reduced during split-belt adaptation, but changes in mediolateral dynamic balance control were not correlated with the reduction of net metabolic power during split-belt adaptation. Overall, this study has shown that a complementary mechanism of relative foot positioning and mediolateral foot roll-off adapts to continuously imposed gait asymmetry to maintain dynamic balance in human bipedal gait. © 2018. Published by The Company of Biologists Ltd.

  7. A Dynamic Model for Load Balancing in Cloud Infrastructure

    Directory of Open Access Journals (Sweden)

    Jitendra Bhagwandas Bhatia

    2015-08-01

    Full Text Available This paper analysis various challenges faced in optimizing computing resource utilization via load balancing and presents a platform-independent model for load balancing which targets high availability of resources, low SLA (Service Level agreement violations and saves power. To achieve this, incoming requests are monitored for sudden burst, a prediction model is employed to maintain high availability and a power-aware algorithm is applied for choosing a suitable physical node for a virtual host. The proposed dynamic load balancing model provides a way to conflicting goals of saving power and maintaining high resource availability.For anyone building a private, public or hybrid IaaS cloud infrastructure, load balancing of virtual hosts on a limited number of physical nodes, becomes a crucial aspect. This paper analysis various challenges faced in optimizing computing resource utilization via load balancing and presents a platform independent model for load balancing which targets high availability of resources, low SLA (Service Level agreement violations and saves power. To achieve this, incoming requests are monitored for sudden burst, prediction model is employed to maintain high availability and power aware algorithm is applied for choosing a suitable physical node for virtual host. The proposed dynamic load balancing model provides a way to conflicting goals of saving power and maintaining high resource availability.

  8. Static and dynamic balance of children and adolescents with sensorineural hearing loss.

    Science.gov (United States)

    Melo, Renato de Souza; Marinho, Sônia Elvira Dos Santos; Freire, Maryelly Evelly Araújo; Souza, Robson Arruda; Damasceno, Hélio Anderson Melo; Raposo, Maria Cristina Falcão

    2017-01-01

    To assess the static and dynamic balance performance of students with normal hearing and with sensorineural hearing loss. A cross-sectional study assessing 96 students, 48 with normal hearing and 48 with sensorineural hearing loss of both sexes, aged 7 and 18 years. To evaluate static balance, Romberg, Romberg-Barré and Fournier tests were used; and for the dynamic balance, we applied the Unterberger test. Hearing loss students showed more changes in static and dynamic balance as compared to normal hearing, in all tests used (pRomberg, Romberg-Barré, Fournier and Unterberger test p values were, respectively, p=0.004, pRomberg, Romberg-Barré and Fournier tests were, respectively, p=0.007, pRomberg, Romberg-Barré, Fournier and Unterberger tests were p=0.002, pRomberg-Barré, Fournier and Unterberger tests were, respectively, p=0.037, p<0.001 and p=0.037. Hearing-loss students showed more changes in static and dynamic balance comparing to normal hearing of same sex and age groups.

  9. Static and Dynamic Balance in Congenital Severe to Profound Hearing-Impaired Children

    Directory of Open Access Journals (Sweden)

    Farideh HajiHeydari

    2011-09-01

    Full Text Available Background and Aim: Research conducted since the early 1900s has consistently identified differences between deaf and hearing children on performance of a wide variety of motor tasks, most notably balance. Our study was performed to test static and dynamic balance skills in congenital severe to profound hearing impaired children in comparison with normal age-matched children.Methods: This cross-sectional study was conducted on 30 severe to profound hearing impaired and 40 normal children with age 6 to 10 years old. Bruininks-Oseretsky test of motor proficiency 2, balance subset with 9 parts was used for evaluation of balance skills.Results: Hearing-impaired children showed 16.7 to 100% fail results in 7 parts of the balance subset. In normal children fail result was revealed just in 3 parts of the balance subset from 2.5 to 57.5%, and differences between two groups were significant (p<0.0001. There was a significant difference between two groups in two static balance skills of standing on one leg on a line and standing on one leg on a balance beam with eyes closed (p<0.0001.conclusion: It seems that development of static balance skills are longer than dynamic ones. Because severe to profound hearing-impaired children showed more weakness than normal children in both static and dynamic balance abilities, functional tests of balance proficiency can help to identify balance disorders in these children.

  10. Dynamic balance in elite karateka.

    Science.gov (United States)

    Zago, Matteo; Mapelli, Andrea; Shirai, Yuri Francesca; Ciprandi, Daniela; Lovecchio, Nicola; Galvani, Christel; Sforza, Chiarella

    2015-12-01

    In karate, balance control represents a key performance determinant. With the hypothesis that high-level athletes display advanced balance abilities, the purpose of the current study was to quantitatively investigate the motor strategies adopted by elite and non-elite karateka to maintain balance control in competition. The execution of traditional karate techniques (kihon) in two groups of elite Masters (n = 6, 31 ± 19 years) and non-elite Practitioners (n = 4, 25 ± 9 years) was compared assessing body center of mass (CoM) kinematics and other relevant parameters like step width and angular joint behavior. In the considered kihon sequence, normalized average CoM height was 8% lower (p < 0.05), while CoM displacement in the horizontal direction was significantly higher in Masters than in Practitioners (2.5 vs. 1.9 m, p < 0.05), as well as CoM average velocity and rms acceleration (p < 0.05). Step width was higher in Masters in more than half of the sequence steps (p < 0.05). Results suggest that elite karateka showed a refined dynamic balance control, obtained through the increase of the base of support and different maneuvers of lower limbs. The proposed method could be used to objectively detect talented karateka, to measure proficiency level and to assess training effectiveness. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. A screw-based dynamic balancing approach, applied to a 5-bar mechanism

    NARCIS (Netherlands)

    de Jong, Jan Johannes; van Dijk, Johannes; Herder, Justus Laurens; Lenarcic, Jadran; Merlet, Jean-Pierre

    2016-01-01

    Dynamic balancing aims to reduce or eliminate the shaking base reaction forces and moments of mechanisms, in order to minimize vibration and wear. The derivation of the dynamic balance conditions requires significant algebraic effort, even for simple mechanisms. In this study, a screw-based

  12. Reactor primary pumps dynamic balancing test

    International Nuclear Information System (INIS)

    Lu Qunxian

    2002-01-01

    Reactor primary Pump is the important equipment in the primary circuit, its working quality would directly influence the safety and operation of nuclear power plant. The author describes that the primary pump vibration status, vibration fault diagnosis and dynamic balancing process on site have been performed since commercial operation of DA YA BAY Nuclear Power plant

  13. Adaptive control of structural balance for complex dynamical networks based on dynamic coupling of nodes

    Science.gov (United States)

    Gao, Zilin; Wang, Yinhe; Zhang, Lili

    2018-02-01

    In the existing research results of the complex dynamical networks controlled, the controllers are mainly used to guarantee the synchronization or stabilization of the nodes’ state, and the terms coupled with connection relationships may affect the behaviors of nodes, this obviously ignores the dynamic common behavior of the connection relationships between the nodes. In fact, from the point of view of large-scale system, a complex dynamical network can be regarded to be composed of two time-varying dynamic subsystems, which can be called the nodes subsystem and the connection relationships subsystem, respectively. Similar to the synchronization or stabilization of the nodes subsystem, some characteristic phenomena can be also emerged in the connection relationships subsystem. For example, the structural balance in the social networks and the synaptic facilitation in the biological neural networks. This paper focuses on the structural balance in dynamic complex networks. Generally speaking, the state of the connection relationships subsystem is difficult to be measured accurately in practical applications, and thus it is not easy to implant the controller directly into the connection relationships subsystem. It is noted that the nodes subsystem and the relationships subsystem are mutually coupled, which implies that the state of the connection relationships subsystem can be affected by the controllable state of nodes subsystem. Inspired by this observation, by using the structural balance theory of triad, the controller with the parameter adaptive law is proposed for the nodes subsystem in this paper, which may ensure the connection relationship matrix to approximate a given structural balance matrix in the sense of the uniformly ultimately bounded (UUB). That is, the structural balance may be obtained by employing the controlling state of the nodes subsystem. Finally, the simulations are used to show the validity of the method in this paper.

  14. Relationship between maximum dynamic force of inferior members and body balance in strength training apprentices

    Directory of Open Access Journals (Sweden)

    Ariane Martins

    2010-08-01

    Full Text Available The relationship between force and balance show controversy results and has directimplications in exercise prescription practice. The objective was to investigate the relationshipbetween maximum dynamic force (MDF of inferior limbs and the static and dynamic balances.Participated in the study 60 individuals, with 18 to 24 years old, strength training apprentices.The MDF was available by mean the One Maximum Repetition (1MR in “leg press” and “kneeextension” and motor testes to available of static and dynamic balances. The correlation testsand multiple linear regression were applied. The force and balance variables showed correlationin females (p=0.038. The corporal mass and static balance showed correlation for the males(p=0.045. The explication capacity at MDF and practices time were small: 13% for staticbalance in males, 18% and 17%, respectively, for static and dynamic balance in females. Inconclusion: the MDF of inferior limbs showed low predictive capacity for performance in staticand dynamic balances, especially for males.

  15. Dynamic game balancing implementation using adaptive algorithm in mobile-based Safari Indonesia game

    Science.gov (United States)

    Yuniarti, Anny; Nata Wardanie, Novita; Kuswardayan, Imam

    2018-03-01

    In developing a game there is one method that should be applied to maintain the interest of players, namely dynamic game balancing. Dynamic game balancing is a process to match a player’s playing style with the behaviour, attributes, and game environment. This study applies dynamic game balancing using adaptive algorithm in scrolling shooter game type called Safari Indonesia which developed using Unity. The game of this type is portrayed by a fighter aircraft character trying to defend itself from insistent enemy attacks. This classic game is chosen to implement adaptive algorithms because it has quite complex attributes to be developed using dynamic game balancing. Tests conducted by distributing questionnaires to a number of players indicate that this method managed to reduce frustration and increase the pleasure factor in playing.

  16. Optimized balance rehabilitation training strategy for the elderly through an evaluation of balance characteristics in response to dynamic motions

    Science.gov (United States)

    Jung, HoHyun; Chun, Keyoung Jin; Hong, Jaesoo; Lim, Dohyung

    2015-01-01

    Balance is important in daily activities and essential for maintaining an independent lifestyle in the elderly. Recent studies have shown that balance rehabilitation training can improve the balance ability of the elderly, and diverse balance rehabilitation training equipment has been developed. However, there has been little research into optimized strategies for balance rehabilitation training. To provide an optimized strategy, we analyzed the balance characteristics of participants in response to the rotation of a base plate on multiple axes. Seven male adults with no musculoskeletal or nervous system-related diseases (age: 25.5±1.7 years; height: 173.9±6.4 cm; body mass: 71.3±6.5 kg; body mass index: 23.6±2.4 kg/m2) were selected to investigate the balance rehabilitation training using customized rehabilitation equipment. Rotation of the base plate of the equipment was controlled to induce dynamic rotation of participants in the anterior–posterior, right-diagonal, medial–lateral, and left-diagonal directions. We used a three-dimensional motion capture system employing infrared cameras and the Pedar Flexible Insoles System to characterize the major lower-extremity joint angles, center of body mass, and center of pressure. We found statistically significant differences between the changes in joint angles in the lower extremities in response to dynamic rotation of the participants (P0.05). These results indicate that optimizing rotation control of the base plate of balance rehabilitation training equipment to induce anterior–posterior and medial–lateral dynamic rotation preferentially can lead to effective balance training. Additional tests with varied speeds and ranges of angles of base plate rotation are expected to be useful as well as an analysis of the balance characteristics considering a balance index that reflects the muscle activity and cooperative characteristics. PMID:26508847

  17. Effect of smart phone using duration and gender on dynamic balance

    Directory of Open Access Journals (Sweden)

    Doaa Rafat El Azab

    2017-01-01

    Full Text Available Smart phones are constantly used for extended periods while looking at the visual display terminals this may causes musculoskeletal problems. So, the purpose of this study was to investigate effect of smart phone using duration and gender on dynamic balance. Subjects: Sixty normal subjects included in this study their age ranged from 20 years to 35 years were divided into three groups, A not using smart phone, B using smart phone less than 4 h per day, C using smart phone more than 4 h per day. Methods: Biodex Stability System was utilized to assess dynamic balance; 3 trials were performed from which the mean value was calculated. Results: there is a significant decrease in all balance directions for group B and C (using smart phone with favor reduction for group C (using smart phone more than 4 h per day and there is a significant difference between male and female subjects as dynamic balance decreased more in female subjects more than male subjects. Conclusion: Long duration of smart phone using affect negatively the balance ability especially in females, so we should develop preventive programs to alleviate its negative effects.

  18. Balancing the dynamic Stark shift in a driven Jaynes-Cummings system

    International Nuclear Information System (INIS)

    Mogilevtsev, D; Kilin, S

    2004-01-01

    In this work we discuss the possibility of balancing a dynamic Shark shift in a Jaynes-Cummings system by simultaneously driving the cavity and the atom with classical fields, of the same frequency. For a lossless Jaynes-Cummings system this can lead to unusual atomic population dynamics. For a lossy Jaynes-Cummings system such balancing can lead to complete suppression of resonance fluorescence even for leaky cavities

  19. Static and dynamic balance of children and adolescents with sensorineural hearing loss

    OpenAIRE

    Melo, Renato de Souza; Marinho, Sônia Elvira dos Santos; Freire, Maryelly Evelly Araújo; Souza, Robson Arruda; Damasceno, Hélio Anderson Melo; Raposo, Maria Cristina Falcão

    2017-01-01

    ABSTRACT Objective To assess the static and dynamic balance performance of students with normal hearing and with sensorineural hearing loss. Methods A cross-sectional study assessing 96 students, 48 with normal hearing and 48 with sensorineural hearing loss of both sexes, aged 7 and 18 years. To evaluate static balance, Romberg, Romberg-Barré and Fournier tests were used; and for the dynamic balance, we applied the Unterberger test. Results Hearing loss students showed more changes in static ...

  20. Static and dynamic balance of children and adolescents with sensorineural hearing loss

    OpenAIRE

    Melo, Renato de Souza; Marinho, Sônia Elvira dos Santos; Freire, Maryelly Evelly Araújo; Souza, Robson Arruda; Damasceno, Hélio Anderson Melo; Raposo, Maria Cristina Falcão

    2017-01-01

    ABSTRACT Objective To assess the static and dynamic balance performance of students with normal hearing and with sensorineural hearing loss. Methods A cross-sectional study assessing 96 students, 48 with normal hearing and 48 with sensorineural hearing loss of both sexes, aged 7 and 18 years. To evaluate static balance, Romberg, Romberg-Barré and Fournier tests were used; and for the dynamic balance, we applied the Unterberger test. Results Hearing loss students showed more changes in s...

  1. Dynamic Balanced Scorecard for companies in the business field of power supply; Dynamic Balanced Scorecard fuer Unternehmen im Geschaeftsfeld der dezentralen Energieversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Hollmann, M.; Roy, I. [Paderborn Univ. (Germany). Lehrstuhl fuer Nachhaltige Energiekonzepte

    2006-06-19

    Due to deregulation and liberalisation of the power market and due to the opting out of the nuclear energy, the decentralized power supply increasingly gains in importance in comparison to the classical power supply. Thus, the entrepreneur who wants to engage in the decentralized power supply needs a management tool for conversion and supervision his strategy. A pertinent means for this already is the Dynamic Balanced Scorecard. By means of an evaluation of a simple balanced scorecard, the entrepreneur realizes his vision and strategy in order to determine the success-critical factors. These success-critical factors are related together in a causal chain. By this, the entrepreneur can recognize, what has to be done in order to act successfully on the market, and in order to secure the success on a long-term basis. The modelling of the Dynamic balanced Scorecard enables the examination of the corporate strategy, before it is implemented in the enterprise. Thus, the entrepreneur saves time and minimizes the corporate risk.

  2. Dynamic Load Balancing for PIC code using Eulerian/Lagrangian partitioning

    OpenAIRE

    Sauget, Marc; Latu, Guillaume

    2017-01-01

    This document presents an analysis of different load balance strategies for a Plasma physics code that models high energy particle beams with PIC method. A comparison of different load balancing algorithms is given: static or dynamic ones. Lagrangian and Eulerian partitioning techniques have been investigated.

  3. Dynamic balance ability in young elite soccer players: implication of isometric strength.

    Science.gov (United States)

    Chtara, Moktar; Rouissi, Mehdi; Bragazzi, Nicola L; Owen, Adam L; Haddad, Monoem; Chamari, Karim

    2018-04-01

    Soccer requires maintaining unilateral balance when executing movement with the contralateral leg. Despite the fact that balance requires standing with maintaining isometric posture with the support leg, currently there is a lack of studies regarding the implication of isometric strength on dynamic balance's performance among young soccer players. Therefore, the aim of this study was to examine the relationship between the Y-Balance Test and 12 lower limbs isometric strength tests. Twenty-six right footed soccer players (mean±SD, age=16.2±1.6 years, height=175±4.2 cm, body mass=68.8±6.1 kg) performed a dynamic balance test (star excursion balance-test with dominant- (DL) and nondominant-legs (NDL). Furthermore, maximal isometric contraction tests of 12 lower limb muscle groups were assessed in DL and NDL. Correlations analysis reported a significant positive relationship between some of isometric strength tests (with DL and NDL) and the Y-Balance Test. Furthermore, stepwise multiple regression analysis showed that maximal isometric strength explained between 21.9% and 49.4% of the variance of the Y-Balance Test. Moreover, maximal isometric strength was dependent upon the reaching angle of the Y-Balance Test and the leg used to support body weight. This study showed a significant implication of maximal isometric strength of the lower limb and the Y-Balance Test. Moreover, the present investigation suggests the implementation of specific lower limb strengthening exercises depending on players' deficit in each reaching direction and leg. This result suggests that further studies should experiment if increasing lower limbs isometric strength could improve dynamic balance ability among young soccer players.

  4. Detailed Balance of Thermalization Dynamics in Rydberg-Atom Quantum Simulators.

    Science.gov (United States)

    Kim, Hyosub; Park, YeJe; Kim, Kyungtae; Sim, H-S; Ahn, Jaewook

    2018-05-04

    Dynamics of large complex systems, such as relaxation towards equilibrium in classical statistical mechanics, often obeys a master equation that captures essential information from the complexities. Here, we find that thermalization of an isolated many-body quantum state can be described by a master equation. We observe sudden quench dynamics of quantum Ising-like models implemented in our quantum simulator, defect-free single-atom tweezers in conjunction with Rydberg-atom interaction. Saturation of their local observables, a thermalization signature, obeys a master equation experimentally constructed by monitoring the occupation probabilities of prequench states and imposing the principle of the detailed balance. Our experiment agrees with theories and demonstrates the detailed balance in a thermalization dynamics that does not require coupling to baths or postulated randomness.

  5. Detailed Balance of Thermalization Dynamics in Rydberg-Atom Quantum Simulators

    Science.gov (United States)

    Kim, Hyosub; Park, YeJe; Kim, Kyungtae; Sim, H.-S.; Ahn, Jaewook

    2018-05-01

    Dynamics of large complex systems, such as relaxation towards equilibrium in classical statistical mechanics, often obeys a master equation that captures essential information from the complexities. Here, we find that thermalization of an isolated many-body quantum state can be described by a master equation. We observe sudden quench dynamics of quantum Ising-like models implemented in our quantum simulator, defect-free single-atom tweezers in conjunction with Rydberg-atom interaction. Saturation of their local observables, a thermalization signature, obeys a master equation experimentally constructed by monitoring the occupation probabilities of prequench states and imposing the principle of the detailed balance. Our experiment agrees with theories and demonstrates the detailed balance in a thermalization dynamics that does not require coupling to baths or postulated randomness.

  6. Comparison of dynamic balance ability in healthy university students according to foot shape.

    Science.gov (United States)

    Hyong, In Hyouk; Kang, Jong Ho

    2016-01-01

    [Purpose] This study aimed to compare dynamic balance ability according to foot shape, defined as normal, pronated, or supinated on the basis of the height of the medial arch. [Subjects] In this study, 14 subjects for the pronated foot group, 14 for the supinated foot group, and 14 for the normal foot group were selected from among 162 healthy university students by using the navicular drop test proposed by Brody. To measure dynamic balance ability, a star excursion balance test (SEBT) was conducted for each group, in which a cross-shaped line and lines at 45° in eight directions were drawn on the floor. In this study, only three directions were used, namely anterior, posterolateral, and posteromedial. The mean of the SEBT was calculated by measuring three times for each group, and the values were standardized using the following equation: measured value/leg length × 100. [Results] No significant differences in dynamic balance ability were found between the normal, pronated, and supinated foot groups. [Conclusion] No significant differences in dynamic balance ability according to the foot shape were found among the healthy university students with normal, pronated, and supinated feet.

  7. Improved postural control after dynamic balance training in older overweight women.

    Science.gov (United States)

    Bellafiore, Marianna; Battaglia, Giuseppe; Bianco, Antonino; Paoli, Antonio; Farina, Felicia; Palma, Antonio

    2011-01-01

    Many studies have reported a greater frequency of falls among older women than men in conditions which stress balance. Previously, we found an improvement in static balance in older women with an increased support surface area and equal load redistribution on both feet, in response to a dynamic balance training protocol. The aim of the present study was to examine whether the same training program and body composition would have effects on the postural control of older overweight women. Ten healthy women (68.67 ± 5.50 yrs; 28.17 ± 3.35 BMI) participated in a five-week physical activity program. This included dynamic balance exercises, such as heel-to-toe walking in different directions, putting their hands on their hips, eyes open (EO) or closed (EC), with a tablet on their heads, going up and down one step, and walking on a mat. Postural stability was assessed before and after training with an optoelectronic platform and a uni-pedal balance performance test. Body composition of the trunk, upper limbs and lower limbs was measured by bio-impedance analysis. The mean speed (MS), medial-lateral MS (MS-x), anterior-posterior MS (MS-y), sway path (SP) and ellipse surface area (ESA) of the pressure center was reduced after training in older women. However, only MS, MS-x, MS-y and SP significantly decreased in bipodalic conditions with EO and MS-y also with EC (punipedal static balance. Our dynamic balance training protocol appears to be feasible, safe and repeatable for older overweight women and to have positive effects in improving their lateral and anterior-posterior postural control, mainly acting on the visual and skeletal muscle components of the balance control system.

  8. Static, dynamic balance and functional performance in subjects with and without plantar fasciitis

    Directory of Open Access Journals (Sweden)

    Geiseane Aguiar Gonçalves

    Full Text Available Abstract Introduction: Plantar fasciitis (PF is characterized by non-inflammatory degeneration and pain under the heel, and is one of the most common foot complaints. The compensations and adjustments made to decrease the discomfort caused by the disease are clinical findings and can be a factor that contributes to impaired balance and decreased functional performance. Objective: To compare functional performance as well as static and dynamic balance among subjects with and without PF. Methods: The sample consisted of 124 subjects of both sexes aged 20-60 years. Participants were divided into two groups: a bilateral PF group (PFG; n = 62 and a control group (CG, n = 62. The following outcomes were analyzed: static and dynamic balance (using functional tests and functional performance (using a questionnaire. We used Student’s t test for independent samples to compare variables between the groups. The alpha error was set at 0.05. Results: Subjects with PF showed greater impairment in their overall dynamic balance performance (p < 0.001 than the control group, except for left posteromedial movement (p = 0.19. The CG showed showed better functional performance (p < 0.001 than the PF group. There was no difference between groups for the variable static balance on stable (p = 0.160 and unstable surfaces (p = 0.085. Conclusion: Subjects with PF displayed smaller reach distances in the overall Star Excursion Balance Test (SEBT, demonstrating a deficit in dynamic balance and functional performance when compared with healthy subjects.

  9. Zhong-Yong as Dynamic Balancing Between Yin-Yang Opposites

    DEFF Research Database (Denmark)

    Li, Xin

    2018-01-01

    of Zhong-Yong balancing being incorrect and incomplete, the author proposes an alternative perspective on Zhong-Yong as dynamic balancing between Yin-Yang opposites. Design/methodology/approach: The author first explain why Peter P. Li’s “asymmetry” and “superiority” arguments are flawed by referring...... to the original text of the classical book of Zhong-Yong (中庸) and a comparison between Zhong-Yong and Aristotle’s doctrine of the mean. The author then propose an alternative approach to Zhong-Yong balancing that is embedded in the original text Zhong-Yong but somehow has been neglected by many Chinese scholars...

  10. A preliminary study of static and dynamic balance in sedentary obese young adults: the relationship between BMI, posture and postural balance.

    Science.gov (United States)

    do Nascimento, J A; Silva, C C; Dos Santos, H H; de Almeida Ferreira, J J; de Andrade, P R

    2017-12-01

    The aim of this study was to evaluate the postural control of obese young adults with normal body mass index during different static (bipedic and unipedic support) and dynamic postural conditions (gait velocity and limits of stability) in order to compare the static and dynamic balance of these individuals. A cross-sectional quantitative study was carried out to evaluate static and dynamic balance in 25 sedentary individuals. The sample was divided into two groups, 10 in the normal-weight group (24.70 ± 3.89 years and 21.5 ± 1.66 kg m -2 ) and 15 in the obese group (26.80 ± 5.16 years and 35.66 ± 4.29 kg m -2 ). Postural evaluation was performed through visual inspection, and balance analyses were performed using the Timed Up & Go test (TUGT) and Balance System (Biodex). Descriptive analyses, Fisher's exact test and Mann Whitney U-tests were performed using the Statistical Package for Social Sciences (SPSS - 20.0, Armonk, NY) software. Most of the obese volunteers presented postural alterations, such as head protrusion (47.6%), hyperkyphosis (46.7%) and hyperlordosis (26.7%). Medial-lateral dynamic displacement, risk of falls and mean time to perform the limits of stability test and TUGT were higher for obese subjects (P  0.05) for static balance tests for either bipedal or unipedal tasks. The disadvantage presented by the young obese subjects occurs in dynamic activities, representing worse balance and an increase in time needed to accomplish these activities. © 2017 World Obesity Federation.

  11. Concussion History and Time Since Concussion Do not Influence Static and Dynamic Balance in Collegiate Athletes.

    Science.gov (United States)

    Merritt, Eric D; Brown, Cathleen N; Queen, Robin M; Simpson, Kathy J; Schmidt, Julianne D

    2017-11-01

    Dynamic balance deficits exist following a concussion, sometimes years after injury. However, clinicians lack practical tools for assessing dynamic balance. To determine if there are significant differences in static and dynamic balance performance between individuals with and without a history of concussion. Cross sectional. Clinical research laboratory. 45 collegiate student-athletes with a history of concussion (23 males, 22 females; age = 20.0 ± 1.4 y; height = 175.8 ± 11.6 cm; mass = 76.4 ± 19.2 kg) and 45 matched controls with no history of concussion (23 males, 22 females; age = 20.0 ± 1.3 y; height = 178.8 ± 13.2 cm; mass = 75.7 ± 18.2 kg). Participants completed a static (Balance Error Scoring System) and dynamic (Y Balance Test-Lower Quarter) balance assessment. A composite score was calculated from the mean normalized Y Balance Test-Lower Quarter reach distances. Firm, foam, and overall errors were counted during the Balance Error Scoring System by a single reliable rater. One-way ANOVAs were used to compare balance performance between groups. Pearson's correlations were performed to determine the relationship between the time since the most recent concussion and balance performance. A Bonferonni adjusted a priori α balance performance did not significantly differ between groups. No significant correlation was found between the time since the most recent concussion and balance performance. Collegiate athletes with a history of concussion do not present with static or dynamic balance deficits when measured using clinical assessments. More research is needed to determine whether the Y Balance Test-Lower Quarter is sensitive to acute balance deficits following concussion.

  12. EFFECT OF WOBBLE BOARD BALANCE TRAINING PROGRAM ON STATIC BALANCE, DYNAMIC BALANCE & TRIPLE HOP DISTANCE IN MALE COLLEGIATE BASKETBALL ATHLETE

    OpenAIRE

    Neeraj Panwar, MPT (Sports); Gaurav Kadyan, MPT (Sports); Aseem Gupta, MPT (Sports); Ravinder Narwal, MPT (Ortho,Cardiopulmonary)

    2014-01-01

    Aim & Objective: The aim of the study was to determine the effect of wobble board balance training program on static & dynamic balance & on triple hop distance in male collegiate basketball athletes. Methodology: Fifty healthy basketball players within a age group of 18-22 yrs. were randomly selected with a baseline BESS score between 6 to 14 & modified SEBT score equal to or greater than 94 (till 100) and they randomly divided into control (n-25) & training group (n-25).The training grou...

  13. Development of a clinical static and dynamic standing balance measurement tool appropriate for use in adolescents.

    Science.gov (United States)

    Emery, Carolyn A; Cassidy, J David; Klassen, Terry P; Rosychuk, Rhonda J; Rowe, Brian B

    2005-06-01

    There is a need in sports medicine for a static and dynamic standing balance measure to quantify balance ability in adolescents. The purposes of this study were to determine the test-retest reliability of timed static (eyes open) and dynamic (eyes open and eyes closed) unipedal balance measurements and to examine factors associated with balance. Adolescents (n=123) were randomly selected from 10 Calgary high schools. This study used a repeated-measures design. One rater measured unipedal standing balance, including timed eyes-closed static (ECS), eyes-open dynamic (EOD), and eyes-closed dynamic (ECD) balance at baseline and 1 week later. Dynamic balance was measured on a foam surface. Reliability was examined using both intraclass correlation coefficients (ICCs) and Bland and Altman statistical techniques. Multiple linear regressions were used to examine other potentially influencing factors. Based on ICCs, test-retest reliability was adequate for ECS, EOD, and ECD balance (ICC=.69, .59, and .46, respectively). The results of Bland and Altman methods, however, suggest that caution is required in interpreting reliability based on ICCs alone. Although both ECS balance and ECD balance appear to demonstrate adequate test-retest reliability by ICC, Bland and Altman methods of agreement demonstrate sufficient reliability for ECD balance only. Thirty percent of the subjects reached the 180-second maximum on EOD balance, suggesting that this test is not appropriate for use in this population. Balance ability (ECS and ECD) was better in adolescents with no past history of lower-extremity injury. Timed ECD balance is an appropriate and reliable clinical measurement for use in adolescents and is influenced by previous injury.

  14. Dynamic Load Balanced Clustering using Elitism based Random Immigrant Genetic Approach for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    K. Mohaideen Pitchai

    2017-07-01

    Full Text Available Wireless Sensor Network (WSN consists of a large number of small sensors with restricted energy. Prolonged network lifespan, scalability, node mobility and load balancing are important needs for several WSN applications. Clustering the sensor nodes is an efficient technique to reach these goals. WSN have the characteristics of topology dynamics because of factors like energy conservation and node movement that leads to Dynamic Load Balanced Clustering Problem (DLBCP. In this paper, Elitism based Random Immigrant Genetic Approach (ERIGA is proposed to solve DLBCP which adapts to topology dynamics. ERIGA uses the dynamic Genetic Algorithm (GA components for solving the DLBCP. The performance of load balanced clustering process is enhanced with the help of this dynamic GA. As a result, the ERIGA achieves to elect suitable cluster heads which balances the network load and increases the lifespan of the network.

  15. Dynamic load balancing algorithm for molecular dynamics based on Voronoi cells domain decompositions

    Energy Technology Data Exchange (ETDEWEB)

    Fattebert, J.-L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Richards, D.F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glosli, J.N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-12-01

    We present a new algorithm for automatic parallel load balancing in classical molecular dynamics. It assumes a spatial domain decomposition of particles into Voronoi cells. It is a gradient method which attempts to minimize a cost function by displacing Voronoi sites associated with each processor/sub-domain along steepest descent directions. Excellent load balance has been obtained for quasi-2D and 3D practical applications, with up to 440·106 particles on 65,536 MPI tasks.

  16. Using motor imagery to study the neural substrates of dynamic balance

    NARCIS (Netherlands)

    Ferraye, M.U.; Debû, B.H.G.; Heil, L.; Carpenter, M.; Bloem, B.R.; Toni, I.

    2014-01-01

    This study examines the cerebral structures involved in dynamic balance using a motor imagery (MI) protocol. We recorded cerebral activity with functional magnetic resonance imaging while subjects imagined swaying on a balance board along the sagittal plane to point a laser at target pairs of

  17. Efficient graph-based dynamic load-balancing for parallel large-scale agent-based traffic simulation

    NARCIS (Netherlands)

    Xu, Y.; Cai, W.; Aydt, H.; Lees, M.; Tolk, A.; Diallo, S.Y.; Ryzhov, I.O.; Yilmaz, L.; Buckley, S.; Miller, J.A.

    2014-01-01

    One of the issues of parallelizing large-scale agent-based traffic simulations is partitioning and load-balancing. Traffic simulations are dynamic applications where the distribution of workload in the spatial domain constantly changes. Dynamic load-balancing at run-time has shown better efficiency

  18. Examine the Relationship between Dynamic Balance and Physical Fitness Tests in Preschool Children

    OpenAIRE

    杉浦, 宏季; Sugiura, Hiroki; 杉本, 寛恵; Sugimoto, Hiroe

    2016-01-01

    This study examined the relationship between dynamic balance tests and various physical fitness tests in preschool children. The subjects were 22 preschool children (age, 5.0+0.4years; height, 107.3+5.7cm; weight, 17.9+3.4 kg). Dynamic balance was assessed by walking the length of a balance beam several times (beam height, 30cm; width, 10cm; length, 200cm) and walking a pathway (width, 10cm; length, 200cm). Physical fitness was assessed with activities such as a 25-meter run, continuous bilat...

  19. A dynamic balanced scorecard for identification internal process factor

    Directory of Open Access Journals (Sweden)

    Javad sofiyabadi

    2012-08-01

    Full Text Available We present a dynamic balanced score card (BSC to investigate the strategic internal process management factors. The proposed dynamic BSC emphasizes on internal processes aspect, and using VIKOR and Shannon Entropy, determinants the internal processes, process management and improvement and all important factors are ranked. The current study first introduces dynamic BSC and examines effective factors on the process. The proposed model focuses on internal processes perspective of BSC and determines importance degree of each factor is used using VIKOR decision-making techniques.

  20. Relationships among age, gender, anthropometric characteristics, and dynamic balance in children 5 to 12 years old.

    Science.gov (United States)

    Butz, Sarah M; Sweeney, Jane K; Roberts, Pamela L; Rauh, Mitchell J

    2015-01-01

    To examine relationships among age, gender, anthropometrics, and dynamic balance. Height, weight, and arm and foot length were measured in 160 children with typical development aged 5 to 12 years. Dynamic balance was assessed using the Timed Up and Go (TUG) test, Pediatric Reach Test (PRT), and Pediatric Balance Scale (PBS). Moderate to good positive relationships (r = 0.61 and r = 0.56) were found between increasing age and PRT and PBS scores. A fair negative relationship (r = -0.49) was observed between age and TUG test. No significant gender-by-age group difference was observed. Age had the strongest influence on TUG and PBS scores; arm length had the strongest influence on PRT scores. Dynamic balance ability is directly related to chronological age. Age and arm length have the strongest relationships with balance scores. These findings may assist pediatric therapists in selecting dynamic balance tests according to age rather than specific diagnosis.

  1. Dynamic Balance Performance and Noncontact Lower Extremity Injury in College Football Players

    OpenAIRE

    Butler, Robert J.; Lehr, Michael E.; Fink, Michael L.; Kiesel, Kyle B.; Plisky, Phillip J.

    2013-01-01

    Background: Field expedient screening tools that can identify individuals at an elevated risk for injury are needed to minimize time loss in American football players. Previous research has suggested that poor dynamic balance may be associated with an elevated risk for injury in athletes; however, this has yet to be examined in college football players. Hypothesis: To determine if dynamic balance deficits are associated with an elevated risk of injury in collegiate football players. It was hy...

  2. The Effects of Core Stability Exercise on the Dynamic Balance of Volleyball Players

    Directory of Open Access Journals (Sweden)

    Hassan Sadeghi

    2013-12-01

    Full Text Available Dynamic balance is a key component of injury prevention and rehabilitation in sports. Training the core muscles has been hypothesized as an intervention for improving balance. However, there is a lack of current scientific evidence to support this claim. The purpose of this study was to evaluate the effects of a core stability program on dynamic balance of volleyball players as measured with the Star Excursion Balance Test (SEBT. Thirty healthy participants were divided into 2 groups: control and exercise groups. All participants performed the SEBT before and after 8-week exercise time. During the 8-week time, the exercise group performed a core stability program, whereas the control group abstained from any new exercise. These results also illustrated there was significant differences in the scores for pre-test and post-test of all direction according SEBT in the experimental group. An independent sample t-test was conducted to compare experimental and control group (F=43.573, Sig=0.000. These results were a significant difference in the scores for control and experimental groups. Maximum excursion distances improved for the exercise group, compared with the control group. This result justifies the hypothesis that core strengthening can improve dynamic postural control during landing of volleyball players significantly. Keywords: Core stabilization; volleyball player; dynamic balance; SEBT

  3. The effects of smartphone multitasking on gait and dynamic balance.

    Science.gov (United States)

    Lee, Jeon Hyeong; Lee, Myoung Hee

    2018-02-01

    [Purpose] This study was performed to analyze the influence of smartphone multitasking on gait and dynamic balance. [Subjects and Methods] The subjects were 19 male and 20 female university students. There were 4 types of gait tasks: General Gait (walking without a task), Task Gait 1 (walking while writing a message), Task Gait 2 (walking while writing a message and listening to music), Task Gait 3 (walking while writing a message and having a conversation). To exclude the learning effect, the order of tasks was randomized. The Zebris FDM-T treadmill system (Zebris Medical GmbH, Germany) was used to measure left and right step length and width, and a 10 m walking test (10MWT) was conducted for gait velocity. In addition, a Timed Up and Go test (TUG) was used to measure dynamic balance. All the tasks were performed 3 times, and the mean of the measured values was analyzed. [Results] There were no statistically significant differences in step length and width. There were statistically significant differences in the 10MWT and TUG tests. [Conclusion] Using a smartphone while walking decreases a person's dynamic balance and walking ability. It is considered that accident rates are higher when using a smartphone.

  4. Measures of static postural control moderate the association of strength and power with functional dynamic balance.

    Science.gov (United States)

    Forte, Roberta; Boreham, Colin A G; De Vito, Giuseppe; Ditroilo, Massimiliano; Pesce, Caterina

    2014-12-01

    Age-related reductions in strength and power are considered to negatively impact balance control, but the existence of a direct association is still an issue of debate. This is possibly due to the fact that balance assessment is complex, reflects different underlying physiologic mechanisms and involves quantitative measurements of postural sway or timing of performance during balance tasks. The present study evaluated the moderator effect of static postural control on the association of power and strength with dynamic balance tasks. Fifty-seven healthy 65-75 year old individuals performed tests of dynamic functional balance (walking speed under different conditions) and of strength, power and static postural control. Dynamic balance performance (walking speed) was associated with lower limb strength and power, as well as postural control under conditions requiring postural adjustments (narrow surface walking r(2) = 0.31, p balance tasks. Practical implications for assessment and training are discussed.

  5. Recovery of dynamic balance after general anesthesia with sevoflurane in short-duration oral surgery.

    Science.gov (United States)

    Fujisawa, Toshiaki; Miyamoto, Eriko; Takuma, Shigeru; Shibuya, Makiko; Kurozumi, Akihiro; Kimura, Yukifumi; Kamekura, Nobuhito; Fukushima, Kazuaki

    2009-01-01

    Recovery of dynamic balance, involving adjustment of the center of gravity, is essential for safe discharge on foot after ambulatory anesthesia. The purpose of this study was to assess the recovery of dynamic balance after general anesthesia with sevoflurane, using two computerized dynamic posturographies. Nine hospitalized patients undergoing oral surgery of less than 2 h duration under general anesthesia (air-oxygensevoflurane) were studied. A dynamic balance test, assessing the ability of postural control against unpredictable perturbation stimuli (Stability System; Biodex Medical), a walking analysis test using sheets with foot pressure sensors (Walk Way-MG1000; Anima), and two simple psychomotor function tests were performed before anesthesia (baseline), and 150 and 210 min after the emergence from anesthesia. Only the double-stance phase in the walking analysis test showed a significant difference between baseline and results at 150 min. None of the other variables showed any differences among results at baseline and at 150 and 210 min. The recovery times for dynamic balance and psychomotor function seem to be within 150 min after emergence from general anesthesia with sevoflurane in patients undergoing oral surgery of less than 2-h duration.

  6. Exploring the dynamics of balance data - movement variability in terms of drift and diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Gottschall, Julia [Institute of Physics, University of Oldenburg, D-26111 Oldenburg (Germany)], E-mail: julia.gottschall@uni-oldenburg.de; Peinke, Joachim [Institute of Physics, University of Oldenburg, D-26111 Oldenburg (Germany)], E-mail: peinke@uni-oldenburg.de; Lippens, Volker [Department of Human Movement, University of Hamburg, Moller Street 10, D-20148 Hamburg (Germany)], E-mail: vlippens@uni-hamburg.de; Nagel, Volker [Department of Human Movement, University of Hamburg, Moller Street 10, D-20148 Hamburg (Germany)

    2009-02-23

    We introduce a method to analyze postural control on a balance board by reconstructing the underlying dynamics in terms of a Langevin model. Drift and diffusion coefficients are directly estimated from the data and fitted by a suitable parametrization. The governing parameters are utilized to evaluate balance performance and the impact of supra-postural tasks on it. We show that the proposed method of analysis gives not only self-consistent results but also provides a plausible model for the reconstruction of balance dynamics.

  7. Exploring the dynamics of balance data - movement variability in terms of drift and diffusion

    International Nuclear Information System (INIS)

    Gottschall, Julia; Peinke, Joachim; Lippens, Volker; Nagel, Volker

    2009-01-01

    We introduce a method to analyze postural control on a balance board by reconstructing the underlying dynamics in terms of a Langevin model. Drift and diffusion coefficients are directly estimated from the data and fitted by a suitable parametrization. The governing parameters are utilized to evaluate balance performance and the impact of supra-postural tasks on it. We show that the proposed method of analysis gives not only self-consistent results but also provides a plausible model for the reconstruction of balance dynamics

  8. Understanding balance differences in individuals with multiple sclerosis with mild disability: An investigation of differences in sensory feedback on postural and dynamic balance control

    Science.gov (United States)

    Denomme, Luke T.

    Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system (CNS) and causes a broad range of neurological symptoms. One of the most common symptoms experienced by individuals with MS is poor balance control during standing and walking. The main mechanism underlying impaired balance control in MS appears to result from slowed somatosensory conduction and impaired central integration. The current thesis assessed postural and dynamic control of balance of 'individuals with MS with mild disability' (IwMS). IwMS were compared to 'healthy age-matched individuals' (HAMI) and community-dwelling 'older adults' (OA). The purpose of this thesis was to quantify differences in postural and dynamic control of balance in IwMS to the two populations who display balance control differences across the lifespan and represent two extreme ends of the balance control continuum due to natural aging. IwMS (n = 12, x¯age: 44 +/- 9.4 years), HAMI (n = 12, x¯age: 45 +/- 9.9 years) and community-dwelling OA (n = 12, x¯ age: 68.1 +/- 4.5 years) postural and dynamic balance control were evaluated during a Romberg task as well as a dynamic steering task. The Romberg task required participants to stand with their feet together and hands by their sides for 45 seconds with either their eyes open or closed. The dynamic steering task required participants to walk and change direction along the M-L plane towards a visual goal. Results from these two tasks reveal that IwMS display differences in postural control when compared to HAMI when vision was removed as well as differences in dynamic stability margin during steering situations. During the postural control task IwMS displayed faster A-P and M-L COP velocities when vision was removed and their COP position was closer to their self-selected maximum stability limits compared to HAMI. Assessment of dynamic stability during the steering task revealed that IwMS displayed reduced walking speed and cadence during the

  9. Research on dynamic balancing simulation of rotary shaft based on ADAMS

    Science.gov (United States)

    Zheng, Weiqiang; Rui, Chengjie; Yang, Jie; Liu, Pingyi

    2018-02-01

    Due to the design and processing technology of rotary shaft, the mass center of it does not coincide with the rotating axis of the rotary shaft and there is an unbalanced mass. The unbalanced mass can have some disadvantages, such as the centrifugal force, the vibration and so on. Those disadvantages could reduce the accuracy and service life of the equipment.In this paper, the dynamic balance of the rotary shaft is analysed by the theory analysis combined with the dynamic simulation software. This method ensures that the rotary shaft meets the dynamic balancing requirements during the design stage. It effectively supports the structural design of the rotary shift, and provides a way of thinking and method for the design and development of the same type of products.

  10. A method, device and application for the dynamic balancing of a rotating component

    International Nuclear Information System (INIS)

    Voinis, P.

    1995-01-01

    The dynamic balancing method is based on the detection of the vibrations generated by an unbalance; two satellites are then displaced in order to create a counter-unbalance and their position is measured. Their position is then adjusted so as the unbalance and counter-unbalance phases and intensities differences are inferior to predetermined reference values in order to balance dynamically the rotating component. Application to superpower turbogenerator shafting systems. 4 fig

  11. The Effect of Water Exercise Program on Static and Dynamic Balance in Elderly Women

    Directory of Open Access Journals (Sweden)

    Heydar Sadeghi

    2008-01-01

    Full Text Available Objectives: Poor balance is one of risk factors of falling, a cause of injury and even death in elderly. The aim of this study was to evaluate the effect of a water exercise program on static and dynamic balance in elder women. Methods & Materials: Thirty participants aged 55-70 years completed an exercise program (60 min, 3 days and 6 weeks, in 2 groups, exercise and control, voluntarily. Static and dynamic balances were measured before and after exercise program in both groups. Postural sway parameters, including mean displacement of center of pressure and velocity of center of pressure in Medio-Lateral (ML and Anterio-Posterior (AP directions, in single stance position, as a measure of static balance and functional reach test, functional reach right test and functional reach left test, as dynamic measure of balance was considered. T test for deepened groups was used for evaluation of changes within groups, and T test for independent groups was used for between groups' changes at threshold of 0.05 After 6 weeks. Results: Significant changes were observed in results of Functional Reach Test (FRT, Functional Reach Left Test (FRLT after exercise program, also in average displacement of cop and velocity of cop in ML direction. Between groups significant differences were observed in results of average cop displacement and velocity of displacement, FRT and FRLT. Conclusion: These results suggest that challenging the physiological systems involved in balance control, in water, while on the non stable support surface, improved both static and dynamic balance and probably might decrease the risk of falling.

  12. Active influence in dynamical models of structural balance in social networks

    Science.gov (United States)

    Summers, Tyler H.; Shames, Iman

    2013-07-01

    We consider a nonlinear dynamical system on a signed graph, which can be interpreted as a mathematical model of social networks in which the links can have both positive and negative connotations. In accordance with a concept from social psychology called structural balance, the negative links play a key role in both the structure and dynamics of the network. Recent research has shown that in a nonlinear dynamical system modeling the time evolution of “friendliness levels” in the network, two opposing factions emerge from almost any initial condition. Here we study active external influence in this dynamical model and show that any agent in the network can achieve any desired structurally balanced state from any initial condition by perturbing its own local friendliness levels. Based on this result, we also introduce a new network centrality measure for signed networks. The results are illustrated in an international-relations network using United Nations voting record data from 1946 to 2008 to estimate friendliness levels amongst various countries.

  13. Effects of Water-Based Training on Static and Dynamic Balance of Older Women.

    Science.gov (United States)

    Bento, Paulo Cesar Barauce; Lopes, Maria de Fátima A; Cebolla, Elaine Cristine; Wolf, Renata; Rodacki, André L F

    2015-08-01

    The aim of this study was to evaluate the effects of a water-based exercise program on static and dynamic balance. Thirty-six older women were randomly assigned to a water-based training (3 days/week for 12 weeks) or control group. Water level was kept at the level of the xiphoid process and temperature at ∼28-30°C. Each session included aerobic activities and lower limb strength exercises. The medial-lateral, the anterior-posterior amplitude, and displacement of the center of pressure (CP-D) were measured in a quiet standing position (60 sec eyes opened and closed). The dynamic balance and 8-Foot Up-and-Go tests were also applied. Group comparisons were made using two-way analysis of variance (ANOVA) with repeated measures. No differences were found in the center of pressure variables; however, the WBT group showed better performance in the 8 Foot Up-and-Go Test after training (5.61±0.76 vs. 5.18±0.42; pwater-based training was effective in improving dynamic balance, but not static balance.

  14. Comparison of Various Dynamic Balancing Principles Regarding Additional Mass and Additional Inertia

    NARCIS (Netherlands)

    van der Wijk, V.; Demeulenaere, Bram; Herder, Justus Laurens

    2009-01-01

    The major disadvantage of existing dynamic balancing principles is that a considerable amount of mass and inertia is added to the system. The objectives of this article are to summarize, to compare, and to evaluate existing complete balancing principles regarding the addition of mass and the

  15. Gaze stability, dynamic balance and participation deficits in people with multiple sclerosis at fall-risk.

    Science.gov (United States)

    Garg, Hina; Dibble, Leland E; Schubert, Michael C; Sibthorp, Jim; Foreman, K Bo; Gappmaier, Eduard

    2018-05-05

    Despite the common complaints of dizziness and demyelination of afferent or efferent pathways to and from the vestibular nuclei which may adversely affect the angular Vestibulo-Ocular Reflex (aVOR) and vestibulo-spinal function in persons with Multiple Sclerosis (PwMS), few studies have examined gaze and dynamic balance function in PwMS. 1) Determine the differences in gaze stability, dynamic balance and participation measures between PwMS and controls, 2) Examine the relationships between gaze stability, dynamic balance and participation. Nineteen ambulatory PwMS at fall-risk and 14 age-matched controls were recruited. Outcomes included (a) gaze stability [angular Vestibulo-Ocular Reflex (aVOR) gain (ratio of eye to head velocity); number of Compensatory Saccades (CS) per head rotation; CS latency; gaze position error; Coefficient of Variation (CV) of aVOR gain], (b) dynamic balance [Functional Gait Assessment, FGA; four square step test], and (c) participation [dizziness handicap inventory; activities-specific balance confidence scale]. Separate independent t-tests and Pearson's correlations were calculated. PwMS were age = 53 ± 11.7yrs and had 4.2 ± 3.3 falls/yr. PwMS demonstrated significant (pbalance and participation measures compared to controls. CV of aVOR gain and CS latency were significantly correlated with FGA. Deficits and correlations across a spectrum of disability measures highlight the relevance of gaze and dynamic balance assessment in PwMS. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

  16. DNA Dynamics Studied Using the Homogeneous Balance Method

    International Nuclear Information System (INIS)

    Zayed, E. M. E.; Arnous, A. H.

    2012-01-01

    We employ the homogeneous balance method to construct the traveling waves of the nonlinear vibrational dynamics modeling of DNA. Some new explicit forms of traveling waves are given. It is shown that this method provides us with a powerful mathematical tool for solving nonlinear evolution equations in mathematical physics. Strengths and weaknesses of the proposed method are discussed. (general)

  17. Mental, Physical and Mixed Practice Effects on Elderly Static and Dynamic Balance

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Aslankhani

    2008-10-01

    Full Text Available Objectives: After age of 65, annually 10 percent of older adults> loss their independent in one or more daily task. Because of decreasing changes in neuromuscular system that is important factor in loss the balance and walking ability in this group of people. In according to these sentences, the aim of this research was to the comparison of mental, physical and mixed practices on static and dynamic balance in health older adults. Methods & Materials: The study is semi-experimental with pre and post test design and three experimental groups. Statistical sample included 60 older adults> with age range of 60-70 years from Shahre-kord, that randomly divided to three experimental groups. In this research, the Stroke stands test (standing with one leg were used to measure the static balance and Star Excursion Balance Test (SEBT test was used to measure the dynamic balance. After 8 session of training, subject of each group participated in post test that similar to pretest. The data were analyzed by one way ANOVA and Tukey post hoc and in order to detect the homogeny of variances, Leaven>s test was used in level of P balance by strength training, coaches and related affairs can use this training method in their specific programs for older adults.

  18. Breaking the excitation-inhibition balance makes the cortical network’s space-time dynamics distinguish simple visual scenes

    DEFF Research Database (Denmark)

    Roland, Per E.; Bonde, Lars H.; Forsberg, Lars E.

    2017-01-01

    Brain dynamics are often taken to be temporal dynamics of spiking and membrane potentials in a balanced network. Almost all evidence for a balanced network comes from recordings of cell bodies of few single neurons, neglecting more than 99% of the cortical network. We examined the space......-time dynamics of excitation and inhibition simultaneously in dendrites and axons over four visual areas of ferrets exposed to visual scenes with stationary and moving objects. The visual stimuli broke the tight balance between excitation and inhibition such that the network exhibited longer episodes of net...... excitation subsequently balanced by net inhibition, in contrast to a balanced network. Locally in all four areas the amount of net inhibition matched the amount of net excitation with a delay of 125 ms. The space-time dynamics of excitation-inhibition evolved to reduce the complexity of neuron interactions...

  19. Effect of progressive resistance exercise with neuromuscular joint facilitation on the dynamic balance performance of junior soccer players.

    Science.gov (United States)

    Wang, Hongzhao; Huo, Ming; Guan, Peipei; Onoda, Ko; Chen, Di; Huang, Qiuchen; Maruyama, Hitoshi

    2015-11-01

    [Purpose] The aim of this study was to investigate the change in dynamic balance performance of junior soccer players after progressive resistance treatment with neuromuscular joint facilitation (NJF). [Subjects] The subjects were 14 healthy males who were divided into two groups, namely the NJF and control groups. The NJF group consisted of 8 subjects, and the control group consisted of 6 subjects. [Methods] The participants in the NJF group received NJF progressive resistance treatment. Dynamic balance performance was measured before and after 3 weeks of exercise. [Results] Significant improvement in dynamic balance performance was observed both in the NJF and control groups. In the NJF group, dynamic balance performance was significantly increased compared with that in the control group. [Conclusion] The NJF intervention shortened movement time, which implies that NJF is effective for dynamic balance performance.

  20. Correlation of energy balance method to dynamic pipe rupture analysis

    International Nuclear Information System (INIS)

    Kuo, H.H.; Durkee, M.

    1983-01-01

    When using an energy balance approach in the design of pipe rupture restraints for nuclear power plants, the NRC specifies in its Standard Review Plan 3.6.2 that the input energy to the system must be multiplied by a factor of 1.1 unless a lower value can be justified. Since the energy balance method is already quite conservative, an across-the-board use of 1.1 to amplify the energy input appears unneccessary. The paper's purpose is to show that this 'correlation factor' could be substantially less than unity if certain design parameters are met. In this paper, result of nonlinear dynamic analyses were compared to the results of the corresponding analyses based on the energy balance method which assumes constant blowdown forces and rigid plastic material properties. The appropriate correlation factors required to match the energy balance results with the dynamic analyses results were correlated to design parameters such as restraint location from the break, yield strength of the energy absorbing component, and the restraint gap. It is shown that the correlation factor is related to a single nondimensional design parameter and can be limited to a value below unity if appropriate design parameters are chosen. It is also shown that the deformation of the restraints can be related to dimensionless system parameters. This, therefore, allows the maximum restraint deformation to be evaluated directly for design purposes. (orig.)

  1. Dynamic Balance of Excitation and Inhibition in Human and Monkey Neocortex

    Science.gov (United States)

    Dehghani, Nima; Peyrache, Adrien; Telenczuk, Bartosz; Le van Quyen, Michel; Halgren, Eric; Cash, Sydney S.; Hatsopoulos, Nicholas G.; Destexhe, Alain

    2016-03-01

    Balance of excitation and inhibition is a fundamental feature of in vivo network activity and is important for its computations. However, its presence in the neocortex of higher mammals is not well established. We investigated the dynamics of excitation and inhibition using dense multielectrode recordings in humans and monkeys. We found that in all states of the wake-sleep cycle, excitatory and inhibitory ensembles are well balanced, and co-fluctuate with slight instantaneous deviations from perfect balance, mostly in slow-wave sleep. Remarkably, these correlated fluctuations are seen for many different temporal scales. The similarity of these computational features with a network model of self-generated balanced states suggests that such balanced activity is essentially generated by recurrent activity in the local network and is not due to external inputs. Finally, we find that this balance breaks down during seizures, where the temporal correlation of excitatory and inhibitory populations is disrupted. These results show that balanced activity is a feature of normal brain activity, and break down of the balance could be an important factor to define pathological states.

  2. Overview of Ice-Sheet Mass Balance and Dynamics from ICESat Measurements

    Science.gov (United States)

    Zwally, H. Jay

    2010-01-01

    The primary purpose of the ICESat mission was to determine the present-day mass balance of the Greenland and Antarctic ice sheets, identify changes that may be occurring in the surface-mass flux and ice dynamics, and estimate their contributions to global sea-level rise. Although ICESat's three lasers were planned to make continuous measurements for 3 to 5 years, the mission was re-planned to operate in 33-day campaigns 2 to 3 times each year following failure of the first laser after 36 days. Seventeen campaigns were conducted with the last one in the Fall of 2009. Mass balance maps derived from measured ice-sheet elevation changes show that the mass loss from Greenland has increased significantly to about 170 Gt/yr for 2003 to 2007 from a state of near balance in the 1990's. Increased losses (189 Gt/yr) from melting and dynamic thinning are over seven times larger'than increased gains (25 gt/yr) from precipitation. Parts of the West Antarctic ice sheet and the Antarctic Peninsula are losing mass at an increasing rate, but other parts of West Antarctica and the East Antarctic ice sheet are gaining mass at an increasing rate. Increased losses of 35 Gt/yr in Pine Island, Thwaites-Smith, and Marie-Bryd.Coast are more than balanced by gains in base of Peninsula and ice stream C, D, & E systems. From the 1992-2002 to 2003-2007 period, the overall mass balance for Antarctica changed from a loss of about 60 Gt/yr to near balance or slightly positive.

  3. Dynamic load-balancing-extended gradient mechanism: Graphic representation

    International Nuclear Information System (INIS)

    Muniz, Francisco J.

    2017-01-01

    Load-balancing methods are quite well described in the open literature (hundreds of articles can be found about this subject). In particularly, about the Dynamic Load-balancing mechanism Extended Gradient (EG), several articles of the author are available. Even though, there are some overlap, each one of them is focused on a particular aspect of the mechanism, in a complementary way. In this article, a graphic representation of the Extended Gradient mechanism is done: this representation way had not yet been explored. However, for an in-depth knowledge of the Extended Gradient mechanism, at least, some other articles should to be read. In the CDTN, Clusters are used, mainly, in deterministic methods (CFD) and non-deterministic methods (Monte Carlo). (author)

  4. Dynamic load-balancing-extended gradient mechanism: Graphic representation

    Energy Technology Data Exchange (ETDEWEB)

    Muniz, Francisco J., E-mail: muniz@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Load-balancing methods are quite well described in the open literature (hundreds of articles can be found about this subject). In particularly, about the Dynamic Load-balancing mechanism Extended Gradient (EG), several articles of the author are available. Even though, there are some overlap, each one of them is focused on a particular aspect of the mechanism, in a complementary way. In this article, a graphic representation of the Extended Gradient mechanism is done: this representation way had not yet been explored. However, for an in-depth knowledge of the Extended Gradient mechanism, at least, some other articles should to be read. In the CDTN, Clusters are used, mainly, in deterministic methods (CFD) and non-deterministic methods (Monte Carlo). (author)

  5. Predictive coding of dynamical variables in balanced spiking networks.

    Science.gov (United States)

    Boerlin, Martin; Machens, Christian K; Denève, Sophie

    2013-01-01

    Two observations about the cortex have puzzled neuroscientists for a long time. First, neural responses are highly variable. Second, the level of excitation and inhibition received by each neuron is tightly balanced at all times. Here, we demonstrate that both properties are necessary consequences of neural networks that represent information efficiently in their spikes. We illustrate this insight with spiking networks that represent dynamical variables. Our approach is based on two assumptions: We assume that information about dynamical variables can be read out linearly from neural spike trains, and we assume that neurons only fire a spike if that improves the representation of the dynamical variables. Based on these assumptions, we derive a network of leaky integrate-and-fire neurons that is able to implement arbitrary linear dynamical systems. We show that the membrane voltage of the neurons is equivalent to a prediction error about a common population-level signal. Among other things, our approach allows us to construct an integrator network of spiking neurons that is robust against many perturbations. Most importantly, neural variability in our networks cannot be equated to noise. Despite exhibiting the same single unit properties as widely used population code models (e.g. tuning curves, Poisson distributed spike trains), balanced networks are orders of magnitudes more reliable. Our approach suggests that spikes do matter when considering how the brain computes, and that the reliability of cortical representations could have been strongly underestimated.

  6. Effect of Hydrotherapy on Static and Dynamic Balance in Older Adults: Comparison of Perturbed and Non-Perturbed Programs

    Directory of Open Access Journals (Sweden)

    Elham Azimzadeh

    2013-01-01

    Full Text Available Objectives: Falling is a main cause of mortality in elderly. Balance training exercises can help to prevent falls in older adults. According to the principle of specificity of training, the perturbation-based trainings are more similar to the real world. So these training programs can improve balance in elderly. Furthermore, exercising in an aquatic environment can reduce the limitations for balance training rather than a non-aquatic on. The aim of this study is comparing the effectiveness of perturbed and non-perturbed balance training programs in water on static and dynamic balance in aforementioned population group. Methods & Materials: 37 old women (age 80-65, were randomized to the following groups: perturbation-based training (n=12, non-perturbation-based training (n=12 and control (n=13 groups. Static and dynamic balance had been tested before and after the eight weeks of training by the postural stability test of the Biodex balance system using dynamic (level 4 and static platform. The data were analyzed by one sample paired t-test, Independent t-test and ANOVA. Results: There was a significant improvement for all indexes of static and dynamic balance in perturbation-based training (P<0.05. However, in non-perturbed group, all indexes were improved except ML (P<0.05. ANOVA showed that perturbed training was more effective than non-perturbed training on both static and dynamic balances. Conclusion: The findings confirmed the specificity principle of training. Although balance training can improve balance abilities, these kinds of trainings are not such specific for improving balance neuromuscular activities.The perturbation-based trainings can activate postural compensatory responses and reduce falling risk. According to results, we can conclude that hydrotherapy especially with perturbation-based programs will be useful for rehabilitation interventions in elderly .

  7. Testing the performance of a Dynamic Global Ecosystem Model: Water balance, carbon balance, and vegetation structure

    Science.gov (United States)

    Kucharik, Christopher J.; Foley, Jonathan A.; Delire, Christine; Fisher, Veronica A.; Coe, Michael T.; Lenters, John D.; Young-Molling, Christine; Ramankutty, Navin; Norman, John M.; Gower, Stith T.

    2000-09-01

    While a new class of Dynamic Global Ecosystem Models (DGEMs) has emerged in the past few years as an important tool for describing global biogeochemical cycles and atmosphere-biosphere interactions, these models are still largely untested. Here we analyze the behavior of a new DGEM and compare the results to global-scale observations of water balance, carbon balance, and vegetation structure. In this study, we use version 2 of the Integrated Biosphere Simulator (IBIS), which includes several major improvements and additions to the prototype model developed by Foley et al. [1996]. IBIS is designed to be a comprehensive model of the terrestrial biosphere; the model represents a wide range of processes, including land surface physics, canopy physiology, plant phenology, vegetation dynamics and competition, and carbon and nutrient cycling. The model generates global simulations of the surface water balance (e.g., runoff), the terrestrial carbon balance (e.g., net primary production, net ecosystem exchange, soil carbon, aboveground and belowground litter, and soil CO2 fluxes), and vegetation structure (e.g., biomass, leaf area index, and vegetation composition). In order to test the performance of the model, we have assembled a wide range of continental and global-scale data, including measurements of river discharge, net primary production, vegetation structure, root biomass, soil carbon, litter carbon, and soil CO2 flux. Using these field data and model results for the contemporary biosphere (1965-1994), our evaluation shows that simulated patterns of runoff, NPP, biomass, leaf area index, soil carbon, and total soil CO2 flux agree reasonably well with measurements that have been compiled from numerous ecosystems. These results also compare favorably to other global model results.

  8. Dynamic balance performance and noncontact lower extremity injury in college football players: an initial study.

    Science.gov (United States)

    Butler, Robert J; Lehr, Michael E; Fink, Michael L; Kiesel, Kyle B; Plisky, Phillip J

    2013-09-01

    Field expedient screening tools that can identify individuals at an elevated risk for injury are needed to minimize time loss in American football players. Previous research has suggested that poor dynamic balance may be associated with an elevated risk for injury in athletes; however, this has yet to be examined in college football players. To determine if dynamic balance deficits are associated with an elevated risk of injury in collegiate football players. It was hypothesized that football players with lower performance and increased asymmetry in dynamic balance would be at an elevated risk for sustaining a noncontact lower extremity injury. Prospective cohort study. Fifty-nine collegiate American football players volunteered for this study. Demographic information, injury history, and dynamic balance testing performance were collected, and noncontact lower extremity injuries were recorded over the course of the season. Receiver operator characteristic curves were calculated based on performance on the Star Excursion Balance Test (SEBT), including composite score and asymmetry, to determine the population-specific risk cut-off point. Relative risk was then calculated based on these variables, as well as previous injury. A cut-off point of 89.6% composite score on the SEBT optimized the sensitivity (100%) and specificity (71.7%). A college football player who scored below 89.6% was 3.5 times more likely to get injured. Poor performance on the SEBT may be related to an increased risk for sustaining a noncontact lower extremity injury over the course of a competitive American football season. College football players should be screened preseason using the SEBT to identify those at an elevated risk for injury based upon dynamic balance performance to implement injury mitigation strategies to this specific subgroup of athletes.

  9. Public Infrastructure Investment, Output Dynamics, and Balanced Budget Fiscal Rules

    NARCIS (Netherlands)

    Duarte Bom, P.R.; Ligthart, J.E.

    2011-01-01

    We study the dynamic output and welfare effects of public infrastructure investment under a balanced budget fiscal rule, using an overlapping generations model of a small open economy. The government finances public investment by employing distortionary labor taxes. We find a negative short-run

  10. Effect of Jaw Clenching on Balance Recovery: Dynamic Stability and Lower Extremity Joint Kinematics after Forward Loss of Balance

    Directory of Open Access Journals (Sweden)

    Steffen eRinghof

    2016-03-01

    Full Text Available Postural control is crucial for most tasks of daily living, delineating postural orientation and balance, with its main goal of fall prevention. Nevertheless, falls are common events and have been associated with deficits in muscle strength and dynamic stability. Recent studies reported on improvements in rate of force development and static postural control evoked by jaw clenching activities, potentially induced by facilitation of human motor system excitability. However, there are no studies describing the effects on dynamic stability. The present study, therefore, aimed investigated the effects of submaximum jaw clenching on recovery behavior from forward loss of balance. Participants were twelve healthy young adults, who were instructed to recover balance from a simulated forward fall by taking a single step while either biting at a submaximum force or keeping the mandible at rest. Bite forces were measured by means of hydrostatic splints, whereas a 3D motion capture system was used to analyze spatiotemporal parameters and joint angles, respectively. Additionally, dynamic stability was quantified by the extrapolated CoM concept, designed to determine postural stability in dynamic situations. Paired t-tests revealed that submaximum biting did not significantly influence recovery behavior with respect to any variable under investigation. Therefore, reductions in postural sway evoked by submaximum biting are obviously not transferable to dynamic stability. It is suggested that these contradictions are the result of different motor demands associated with the abovementioned tasks. Furthermore, floor effects and the sample size might be discussed as potential reasons for the absence of significances. Notwithstanding this, the present study also revealed that bite forces under both conditions significantly increased from subjects’ release to touchdown of the recovery limb. Clenching the jaw, hence, seems to be part of a common physiological

  11. On the balance energy and nuclear dynamics in peripheral heavy-ion collisions

    International Nuclear Information System (INIS)

    Chugh, Rajiv; Puri, Rajeev K.

    2010-01-01

    We present here the system size dependence of balance energy for semi-central and peripheral collisions using quantum molecular dynamics model. For this study, the reactions of Ne 20 +Ne 20 , Ca 40 +Ca 40 , Ni 58 + Ni 58 , Nb 93 +Nb 93 , Xe 131 +Xe 131 , and Au 197 +Au 197 are simulated at different incident energies and impact parameters. A hard equation of state along with nucleon–nucleon cross-sections between 40 and 55 mb explains the data nicely. Interestingly, balance energy follows a power law ∝A τ for the mass dependence at all colliding geometries. The power factor τ is close to –1/3 in central collisions, whereas it is –2/3 for peripheral collisions suggesting stronger system size dependence at peripheral geometries. This also suggests that in the absence of momentum dependent interactions, Coulomb's interaction plays an exceedingly significant role. These results are further analyzed for nuclear dynamics at the balance point. (author)

  12. Effects of Rigid and Soft Foot Orthoses on Dynamic Balance in Females With Flatfoot

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    Hassan Saeedi

    2007-08-01

    Full Text Available Background:Various types of foot orthoses are prescribed for people with flatfoot.It has been reported that orthoses not only improve the biomechanics of the lower limb, but also have good effects on some balance parameters in these subjects.It is hypothesized that the latter effect is dependent on the rigidity of the orthoses. The aim of this study was to evaluate and compare the effects of rigid and soft foot orthoses on dynamic balance in females with flatfoot. The Biodex Balance System was used in a clinical trial study. Methods: 20 healthy students with bilateral flatfoot were randomly assigned to two equal groups. Each participant was tested on two days with 2-week interval. On each day, dynamic stability test was performed while standing in single-leg stance on an unstable platform of the balance system in 3 conditions (barefoot, with shoe, shoe with orthosis. SPSS11.5 was used for statistical analysis. Results: A significant group-by-day-by-condition interaction was found. Both groups on day 2 testing had a decreased overall stability index while wearing orthoses. Overall stability index was significantly lower on day 2 testing. Conclusion: Foot orthoses, depending on the amount of rigidity, were associated with some improvements in dynamic balance in subjects with flatfoot.

  13. Dynamic balance and stepping versus tai chi training to improve balance and stepping in at-risk older adults.

    Science.gov (United States)

    Nnodim, Joseph O; Strasburg, Debra; Nabozny, Martina; Nyquist, Linda; Galecki, Andrzej; Chen, Shu; Alexander, Neil B

    2006-12-01

    To compare the effect of two 10-week balance training programs, Combined Balance and Step Training (CBST) versus tai chi (TC), on balance and stepping measures. Prospective intervention trial. Local senior centers and congregate housing facilities. Aged 65 and older with at least mild impairment in the ability to perform unipedal stance and tandem walk. Participants were allocated to TC (n = 107, mean age 78) or CBST, an intervention focused on improving dynamic balance and stepping (n = 106, mean age 78). At baseline and 10 weeks, participants were tested in their static balance (Unipedal Stance and Tandem Stance (TS)), stepping (Maximum Step Length, Rapid Step Test), and Timed Up and Go (TUG). Performance improved more with CBST than TC, ranging from 5% to 10% for the stepping tests (Maximum Step Length and Rapid Step Test) and 9% for TUG. The improvement in TUG represented an improvement of more than 1 second. Greater improvements were also seen in static balance ability (in TS) with CBST than TC. Of the two training programs, in which variants of each program have been proven to reduce falls, CBST results in modest improvements in balance, stepping, and functional mobility versus TC over a 10-week period. Future research should include a prospective comparison of fall rates in response to these two balance training programs.

  14. The effect of virtual reality gaming on dynamic balance in older adults.

    Science.gov (United States)

    Rendon, Abel Angel; Lohman, Everett B; Thorpe, Donna; Johnson, Eric G; Medina, Ernie; Bradley, Bruce

    2012-07-01

    physical therapy interventions that increase functional strength and balance have been shown to reduce falls in older adults. this study compared a virtual reality group (VRG) and a control group (CG). randomised controlled 6-week intervention with pre- and post-test evaluations. outpatient geriatric orthopaedic and balance physical therapy clinic. forty participants were randomised into two groups. the VRG received three different Nintendo® Wii FIT balance interventions three times per week for 6 weeks and the CG received no intervention. compared with the CG, post-intervention measurements showed significant improvements for the VRG in the 8-foot Up & Go test [median decrease of 1.0 versus -0.2 s, (P=0.038) and the Activities-specific Balance Confidence Scale (6.9 versus 1.3%) (P=0.038)]. virtual reality gaming provides clinicians with a useful tool for improving dynamic balance and balance confidence in older adults.

  15. The effects of attention capacity on dynamic balance control following concussion

    Directory of Open Access Journals (Sweden)

    Chou Li-Shan

    2011-02-01

    Full Text Available Abstract The purpose of this study was to examine how individuals modulate attention in a gait/cognition dual task during a 4-week period following a concussion. Ten individuals suffering from a grade 2 concussion and 10 matched controls performed a single task of level walking, a seated auditory Stroop task and a simultaneous auditory Stroop and walking task. Reaction time and accuracy were measured from the Stroop task. Dynamic balance control during gait was measured by the interaction (displacement and velocity between the center of mass (CoM and center of pressure (CoP in the coronal and sagittal planes. Concussed individuals shifted from conservative control of balance (shorter separation between CoM and CoP immediately after injury to normal balance control over 28 days post-injury. Immediately after injury, correlations analyses using each subject on each testing day as a data point showed that there was a spectrum of deficient performance among concussed individuals on the first testing day. Within a testing session, deficiencies in reaction time of processing involved in the Stroop task were commonly seen with reduce dynamic balance control. However, the prioritization was not always towards the same task between trials. There were no correlations in the control group. Information provided in this study would enhance our understanding of the interaction between attention and gait following concussion.

  16. The effect of time-of-day on static and dynamic balance in recreational athletes.

    Science.gov (United States)

    Heinbaugh, Erika M; Smith, Derek T; Zhu, Qin; Wilson, Margaret A; Dai, Boyi

    2015-09-01

    The purpose of this study was to investigate the effect of time-of-day (morning vs. afternoon) on static and dynamic balance in recreational athletes. A total of 34 recreational athletes completed the single-leg stance test with or without eyes open, lower quarter Y-balance test, upper quarter Y-balance test, and single-leg landing balance test in a random order in the morning (7:00-10:00 am) and afternoon (3:00-6:00 pm) for two consecutive days. Compared with the morning, participants demonstrated decreased centre of pressure (COP) sway areas (p = 0.002; Cohen's d (d) = 0.28) and sway speeds (p = 0.002; d = 0.17) during the eyes-open single-leg stance test, increased stance time (p = 0.031; d = 0.16) and decreased COP sway areas (p = 0.029; d = 0.22) during the eyes-closed single-leg stance test, and increased reaching distances (p = 0.024; d = 0.10) during the upper quarter Y-balance test in the afternoon. The between-day effect (day 1 vs. day 2) was observed for several parameters. Time-of-day had a minimal effect on dynamic balance and a noticeable effect on static balance. Time-of-day may be considered as a factor in designing balance training programmes and intervention studies for recreational athletes.

  17. Improvements in Dynamic Balance Using an Adaptive Snowboard with the Nintendo Wii.

    Science.gov (United States)

    Sullivan, Brendan; Harding, Alexandra G; Dingley, John; Gras, Laura Z

    2012-08-01

    The purpose of this case report is to see if a novel balance board could improve balance and gait of a subject with dynamic balance impairments and enjoyment of virtual rehabilitation training. A novel Adaptive Snowboard™ (developed by two of the authors, B.S. and J.D.) was used in conjunction with the Nintendo(®) (Redmond, WA) Wii™ snowboarding and wakeboarding games with a participant in a physical therapy outpatient clinic. Baseline measurements were taken for gait velocity and stride length, Four Square Step Test, Star Balance Excursion Test, Sensory Organization Test, and the Intrinsic Motivation Inventory. Two 60-90-minute sessions per week for 5 weeks included seven to nine trials of Wii snowboarding or wakeboarding games. Improvements were seen in every outcome measure. This study had comparable results to studies performed using a wobble board in that improvements in balance were made. Use of virtual snowboard simulation improved the subject's balance, gait speed, and stride length, as well as being an enjoyable activity.

  18. The influence of the external ankle support on the dynamic balance in volleyball athletes

    Directory of Open Access Journals (Sweden)

    Manuela Azevedo Correia de Lima

    2015-09-01

    Full Text Available AbstractThe purpose of this study was to assess the effect of ankle external supports on proprioception and dynamic balance in volleyball players. Seventeen female volleyball players (18.94±2.49 years; 65.45±9.49 kg; 1.71±0.05 m; BMI=22.0±2.67 kg/m² took part in this study. The dynamic balance was assessed through the Star Excursion Balance Test (SEBT. Comparisons between stabilization (no stabilizer/NS, orthosis/ORT and functional bandaging/FB modes and the SEBT grid lines and inter-limb were carried out. The SEBT assessment showed a significant difference between the groups NS x ORT and NS x FB (p < .01, and between the lines (p< .01. Significant line/limb interaction in DL and NDL (p< .01 was detected. The external supports tested herein showed similar effects on balance, restricting lower limb's reach in the SEBT execution in some of tested directions.

  19. Dissipation and energy balance in electronic dynamics of Na clusters

    Science.gov (United States)

    Vincendon, Marc; Suraud, Eric; Reinhard, Paul-Gerhard

    2017-06-01

    We investigate the impact of dissipation on the energy balance in the electron dynamics of metal clusters excited by strong electro-magnetic pulses. The dynamics is described theoretically by Time-Dependent Density-Functional Theory (TDDFT) at the level of Local Density Approximation (LDA) augmented by a self interaction correction term and a quantum collision term in Relaxation-Time Approximation (RTA). We evaluate the separate contributions to the total excitation energy, namely energy exported by electron emission, potential energy due to changing charge state, intrinsic kinetic and potential energy, and collective flow energy. The balance of these energies is studied as function of the laser parameters (frequency, intensity, pulse length) and as function of system size and charge. We also look at collisions with a highly charged ion and here at the dependence on the impact parameter (close versus distant collisions). Dissipation turns out to be small where direct electron emission prevails namely for laser frequencies above any ionization threshold and for slow electron extraction in distant collisions. Dissipation is large for fast collisions and at low laser frequencies, particularly at resonances. Contribution to the Topical Issue "Dynamics of Systems at the Nanoscale", edited by Andrey Solov'yov and Andrei Korol.

  20. Application of dynamic flux balance analysis to an industrial Escherichia coli fermentation.

    Science.gov (United States)

    Meadows, Adam L; Karnik, Rahi; Lam, Harry; Forestell, Sean; Snedecor, Brad

    2010-03-01

    We have developed a reactor-scale model of Escherichia coli metabolism and growth in a 1000 L process for the production of a recombinant therapeutic protein. The model consists of two distinct parts: (1) a dynamic, process specific portion that describes the time evolution of 37 process variables of relevance and (2) a flux balance based, 123-reaction metabolic model of E. coli metabolism. This model combines several previously reported modeling approaches including a growth rate-dependent biomass composition, maximum growth rate objective function, and dynamic flux balancing. In addition, we introduce concentration-dependent boundary conditions of transport fluxes, dynamic maintenance demands, and a state-dependent cellular objective. This formulation was able to describe specific runs with high-fidelity over process conditions including rich media, simultaneous acetate and glucose consumption, glucose minimal media, and phosphate depleted media. Furthermore, the model accurately describes the effect of process perturbations--such as glucose overbatching and insufficient aeration--on growth, metabolism, and titer. (c) 2009 Elsevier Inc. All rights reserved.

  1. EFFECT OF DYNAMIC BALANCE TRAINING ON AGILITY IN MALE BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Avi Saraswat

    2015-10-01

    Full Text Available Background: Athletes focus their training on two major goals, i.e., avoidance of the injury and increasing the performance. Balance training has been widely used in competitive sports to improve the balance and thus reduce the risk of injury, for example, ligamentous sprains, which are very common in Basketball. On the other hand, various drills are being used to improve the performance parameters such as agility. Our effort is to find out an exercise program which focuses on balance training and see whether it has any effect on agility. Methods: The study design was a Pretest-Posttest Control-Group Design. 30 healthy school level Male Basketball Players were selected from V-One Basketball Academy, Don Bosco Basketball Academy, Modern School Basketball Academy, New Delhi. They were randomly divided into two groups. Group A performed dynamic balance training 3 sessions per week for 4 weeks. Group B performed conventional exercises throughout the duration of the study. Outcome measure, i.e., T- test was measured pre and post 4 week period. Results: Data analysis was done by Independent t test and Paired t test for between group analysis and within group analysis respectively. There was a significant reduction in T-test times in the experimental group as compared to the control group (‘p’ value <0.05 while there was no significant improvement in the control group. Conclusion: Four weeks of dynamic balance training significantly improved agility as detected by T-test. Thus it can be concluded that the used protocol can be incorporated in the training regimes to reduce the risk of injury as well as improve the performance.

  2. Evaluation of static and dynamic balance in elderly women performing aquatic exercise and gymnastics

    Directory of Open Access Journals (Sweden)

    Ana Paula Almeida

    2010-01-01

    Full Text Available This study evaluated static and dynamic balance and related motor valences in elderly women who had been undergone gymnastics or aquatic exercise training for at least 6 months, three times a week. Thirty-one women performed water gymnastics (mean age: 69.32 ± 6.57 years and 28 gymnastics (65.57 ± 7.67 years. Height (cm, weight (kg and waist, hip and abdominal circumference (cm were measured and the body mass index (BMI and waist-hip ratio (WHR were calculated. Physical fitness was measured using the “sit and get up in 30 seconds” test (leg endurance and “8-foot up-and-go” test (dynamic balance, both proposed by Rikli and Jones (1999, and the “sit and reach” (flexibility and static balance tests described by Caromano (1998. Statistical analysis was performed using the Student t-test and Pearson’s correlation, with a level of significance of 0.05. No significant difference in the anthropometric measures (BMI and WHR was observed between groups. In the physical fitness tests, significant differences were only found in the “8-foot up-and-go” and “sit and get up” tests, with the gymnastics group presenting better results. No correlations within or between groups were observed regarding static and dynamic balance or motor valences. In conclusion, neither type of exercise was superior but the gymnastics group tended to show better results in terms of parameters such as agility, balance and flexibility.

  3. An age-structured population balance model for microbial dynamics

    Directory of Open Access Journals (Sweden)

    Duarte M.V.E.

    2003-01-01

    Full Text Available This work presents an age-structured population balance model (ASPBM for a bioprocess in a continuous stirred-tank fermentor. It relates the macroscopic properties and dynamic behavior of biomass to the operational parameters and microscopic properties of cells. Population dynamics is governed by two time- and age-dependent density functions for living and dead cells, accounting for the influence of substrate and dissolved oxygen concentrations on cell division, aging and death processes. The ASPBM described biomass and substrate oscillations in aerobic continuous cultures as experimentally observed. It is noteworthy that a small data set consisting of nonsegregated measurements was sufficient to adjust a complex segregated mathematical model.

  4. The research of hourglass worm dynamic balancing simulation based on SolidWorks motion

    Science.gov (United States)

    Wang, Zhuangzhuang; Yang, Jie; Liu, Pingyi; Zhao, Junpeng

    2018-02-01

    Hourglass worm is extensively used in industry due to its characteristic of heavy-load and a large reduction ratio. Varying sizes of unbalanced mass distribution appeared in the design of a single head worm. With machines developing towards higher speed and precision, the vibration and shock caused by the unbalanced mass distribution of rotating parts must be considered. Therefore, the balance grade of these parts must meet higher requirements. A method based on theoretical analysis and SolidWorks motion software simulation is presented in this paper; the virtual dynamic balance simulation test of the hourglass worm was carried out during the design of the product, so as to ensure that the hourglass worm meet the requirements of dynamic balance in the design process. This can effectively support the structural design of the hourglass worm and provide a way of thinking and designing the same type of products.

  5. Masticatory efficiency contributing to the improved dynamic postural balance: A cross-sectional study.

    Science.gov (United States)

    Hwang, Hae-Yun; Choi, Jun-Seon; Kim, Hee-Eun

    2018-05-28

    To evaluate whether masticatory efficiency is associated with dynamic postural balance. Masticatory dysfunction can cause deterioration of general health due to nutritional imbalances, thereby negatively affecting postural balance. However, few studies have investigated the association between masticatory efficiency and postural balance. The masticatory efficiency of 74 participants was evaluated by calculating mixing ability index (MAI) using a wax cube. The timed up and go test (TUGT) was used to measure dynamic balance. Participants with an MAI above or below the median value of 1.05 were defined as having high or low masticatory efficiency, respectively. An independent samples t-test was used to identify significant differences in TUGT, according to masticatory efficiency. Analysis of covariance was performed to adjust for confounding factors. Logistic regression analysis was used to assess the correlation between masticatory efficiency and postural balance. The high masticatory efficiency group could complete the TUGT exercise approximately 1.67 seconds faster while maintaining the postural balance, compared to the low masticatory efficiency group (P = .005). Furthermore, the postural imbalance odds of the group with high mastication efficiency decreased by 0.14-fold, relative to the group with low mastication efficiency (95% confidence interval: 0.04-0.46). With some reservations about statistical power, the association found between masticatory efficiency and postural balance justifies further investigations to confirm the strength of the associations, and possibly to identify causal relationships between mastication and posture in old age. © 2018 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  6. The effects of moderate fatigue on dynamic balance control and attentional demands

    Directory of Open Access Journals (Sweden)

    Teasdale Normand

    2006-09-01

    Full Text Available Abstract Background During daily activities, the active control of balance often is a task per se (for example, when standing in a moving bus. Other constraints like fatigue can add to the complexity of this balance task. In the present experiment, we examined how moderate fatigue induced by fast walking on a treadmill challenged dynamic balance control. We also examined if the attentional demands for performing the balance task varied with fatigue. Methods Subjects (n = 10 performed simultaneously a dynamic balance control task and a probe reaction time task (RT (serving as an indicator of attentional demands before and after three periods of moderate fatigue (fast walking on a treadmill. For the balance control task, the real-time displacement of the centre of pressure (CP was provided on a monitor placed in front of the subject, at eye level. Subjects were asked to keep their CP within a target (moving box moving upward and downward on the monitor. The tracking performance was measured (time spent outside the moving box and the CP behavior analyzed (mean CP speed and mean frequency of the CP velocity. Results Moderate fatigue led to an immediate decrement of the performance on the balance control task; increase of the percentage of time spent outside the box and increase of the mean CP speed. Across the three fatigue periods, subjects improved their tracking performance and reduced their mean CP speed. This was achieved by increasing their frequency of actions; mean frequency of the CP velocity were higher for the fatigue periods than for the no fatigue periods. Fatigue also induced an increase in the attentional demands suggesting that more cognitive resources had to be allocated to the balance task with than without fatigue. Conclusion Fatigue induced by fast walking had an initial negative impact on the control of balance. Nonetheless, subjects were able to compensate the effect of the moderate fatigue by increasing the frequency of

  7. Differences in dynamic balance scores in one sport versus multiple sport high school athletes.

    Science.gov (United States)

    Gorman, Paul P; Butler, Robert J; Rauh, Mitchell J; Kiesel, Kyle; Plisky, Phillip J

    2012-04-01

    Researchers have previously reported on the importance of dynamic balance in assessing an individual's risk for injury during sport. However, to date there is no research on whether multiple sport participation affects dynamic balance ability. Therefore, the purpose of this study was to determine if there was a difference in dynamic balance scores in high school athletes that competed in one sport only as compared athletes who competed in multiple sports, as tested by the Lower Quarter Y Balance Test (YBT-LQ). Ninety-two high school athletes who participated in one sport were matched, by age, gender and sport played, to athletes who participated in the same sport as well as additional sports. All individuals were assessed using the YBT-LQ to examine differences in composite reach score and reach direction asymmetry between single sport and multiple sport athletes. The greatest reach distance of three trials in each reach direction for right and left lower-extremities was normalized by limb length and used for analysis. A two-way ANOVA (gender x number of sports played) was used to statistically analyze the variables in the study. No significant interactions or main effects related to number of sports played were observed for any YBT-LQ score (p>0.05). Male athletes exhibited significantly greater normalized reach values for the posteromedial, posterolateral, and composite reach while also exhibiting a larger anterior reach difference when compared to the females. Athletes who participated in multiple sports had similar performances on the YBT-LQ when compared to athletes who participated in a single sport. The findings of this study suggest that the number of sports played by a high school athlete does not need to be controlled for when evaluating dynamic balance with the YBT-LQ.

  8. Effect of 8-Week of Selected Aerobic Exercise on Static and Dynamic Balance in Healthy Elderly Inactive Men

    Directory of Open Access Journals (Sweden)

    Masoud Mirmoezzi

    2016-04-01

    Conclusion: Our results showed that regular aerobic exercise improves dynamic balance in elderly men. We also found that jogging and walking improved dynamic balance. The improvement in balance may be due to the increase in nervous compatibility (due to exercise; increase in fitness, strength, and motion domain; improvement in aerobic status, response time and mental status; improvement in neuromuscular control, including a decrease in changing movement units; and improvement in simultaneous movement units. Furthermore, there is a positive relationship between body composition and movement with balance. Therefore, regular aerobic activities are recommended as a suitable training method for improving balance.

  9. Water balance dynamics in the Nile Basin

    Science.gov (United States)

    Senay, Gabriel B.; Asante, Kwabena; Artan, Guleid A.

    2009-01-01

    Understanding the temporal and spatial dynamics of key water balance components of the Nile River will provide important information for the management of its water resources. This study used satellite-derived rainfall and other key weather variables derived from the Global Data Assimilation System to estimate and map the distribution of rainfall, actual evapotranspiration (ETa), and runoff. Daily water balance components were modelled in a grid-cell environment at 0·1 degree (∼10 km) spatial resolution for 7 years from 2001 through 2007. Annual maps of the key water balance components and derived variables such as runoff and ETa as a percent of rainfall were produced. Generally, the spatial patterns of rainfall and ETa indicate high values in the upstream watersheds (Uganda, southern Sudan, and southwestern Ethiopia) and low values in the downstream watersheds. However, runoff as a percent of rainfall is much higher in the Ethiopian highlands around the Blue Nile subwatershed. The analysis also showed the possible impact of land degradation in the Ethiopian highlands in reducing ETa magnitudes despite the availability of sufficient rainfall. Although the model estimates require field validation for the different subwatersheds, the runoff volume estimate for the Blue Nile subwatershed is within 7·0% of a figure reported from an earlier study. Further research is required for a thorough validation of the results and their integration with ecohydrologic models for better management of water and land resources in the various Nile Basin ecosystems.

  10. Relationship Between Elderly Body Composition Indices and Static and Dynamic Balance in Relation to Their Rate of Falling

    Directory of Open Access Journals (Sweden)

    Elham Azimzadeh

    2013-01-01

    Full Text Available Objectives: The purpose of this study was to investigate relationship between body composition indices with static and dynamic balance and rate of falling in active elderly people. Methods & Materials: This research was a correlation study. Active elderly women volunteered for participation in this research (n=45. Body composition indices (body fat mass, fat free mass, body mass index, waist to hip ratio measured with the body composition analyzer. Static and dynamic balance measured by Biodex, with postural stability and fall risk tests, respectively. Also, the rate of falling in the previous 1- year asked for subjects. Statically analyses performed with the Pearson correlation test, significant level was set at P≤0.05. SPSS software was used. Results: The results of this study showed all of body composition indices have significant correlation with static and dynamic balance and rate of falling (P≤0.05. Conclusion: The finding of this research showed that all of body composition indices have significant correlation with static and dynamic balance and rate of falling in active elderly people. Therefore, it seems physical activity through improvement of body composition indices in active elderly people, causes improvement of static and dynamic balance and lowering the rate of falling.

  11. Broken detailed balance and non-equilibrium dynamics in living systems: a review

    Science.gov (United States)

    Gnesotto, F. S.; Mura, F.; Gladrow, J.; Broedersz, C. P.

    2018-06-01

    Living systems operate far from thermodynamic equilibrium. Enzymatic activity can induce broken detailed balance at the molecular scale. This molecular scale breaking of detailed balance is crucial to achieve biological functions such as high-fidelity transcription and translation, sensing, adaptation, biochemical patterning, and force generation. While biological systems such as motor enzymes violate detailed balance at the molecular scale, it remains unclear how non-equilibrium dynamics manifests at the mesoscale in systems that are driven through the collective activity of many motors. Indeed, in several cellular systems the presence of non-equilibrium dynamics is not always evident at large scales. For example, in the cytoskeleton or in chromosomes one can observe stationary stochastic processes that appear at first glance thermally driven. This raises the question how non-equilibrium fluctuations can be discerned from thermal noise. We discuss approaches that have recently been developed to address this question, including methods based on measuring the extent to which the system violates the fluctuation-dissipation theorem. We also review applications of this approach to reconstituted cytoskeletal networks, the cytoplasm of living cells, and cell membranes. Furthermore, we discuss a more recent approach to detect actively driven dynamics, which is based on inferring broken detailed balance. This constitutes a non-invasive method that uses time-lapse microscopy data, and can be applied to a broad range of systems in cells and tissue. We discuss the ideas underlying this method and its application to several examples including flagella, primary cilia, and cytoskeletal networks. Finally, we briefly discuss recent developments in stochastic thermodynamics and non-equilibrium statistical mechanics, which offer new perspectives to understand the physics of living systems.

  12. Broken detailed balance and non-equilibrium dynamics in living systems: a review.

    Science.gov (United States)

    Gnesotto, F S; Mura, F; Gladrow, J; Broedersz, C P

    2018-03-05

    Living systems operate far from thermodynamic equilibrium. Enzymatic activity can induce broken detailed balance at the molecular scale. This molecular scale breaking of detailed balance is crucial to achieve biological functions such as high-fidelity transcription and translation, sensing, adaptation, biochemical patterning, and force generation. While biological systems such as motor enzymes violate detailed balance at the molecular scale, it remains unclear how non-equilibrium dynamics manifests at the mesoscale in systems that are driven through the collective activity of many motors. Indeed, in several cellular systems the presence of non-equilibrium dynamics is not always evident at large scales. For example, in the cytoskeleton or in chromosomes one can observe stationary stochastic processes that appear at first glance thermally driven. This raises the question how non-equilibrium fluctuations can be discerned from thermal noise. We discuss approaches that have recently been developed to address this question, including methods based on measuring the extent to which the system violates the fluctuation-dissipation theorem. We also review applications of this approach to reconstituted cytoskeletal networks, the cytoplasm of living cells, and cell membranes. Furthermore, we discuss a more recent approach to detect actively driven dynamics, which is based on inferring broken detailed balance. This constitutes a non-invasive method that uses time-lapse microscopy data, and can be applied to a broad range of systems in cells and tissue. We discuss the ideas underlying this method and its application to several examples including flagella, primary cilia, and cytoskeletal networks. Finally, we briefly discuss recent developments in stochastic thermodynamics and non-equilibrium statistical mechanics, which offer new perspectives to understand the physics of living systems.

  13. Dynamic Load Balancing Based on Constrained K-D Tree Decomposition for Parallel Particle Tracing

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiang; Guo, Hanqi; Yuan, Xiaoru; Hong, Fan; Peterka, Tom

    2018-01-01

    Particle tracing is a fundamental technique in flow field data visualization. In this work, we present a novel dynamic load balancing method for parallel particle tracing. Specifically, we employ a constrained k-d tree decomposition approach to dynamically redistribute tasks among processes. Each process is initially assigned a regularly partitioned block along with duplicated ghost layer under the memory limit. During particle tracing, the k-d tree decomposition is dynamically performed by constraining the cutting planes in the overlap range of duplicated data. This ensures that each process is reassigned particles as even as possible, and on the other hand the new assigned particles for a process always locate in its block. Result shows good load balance and high efficiency of our method.

  14. Single, childless working women's construction of wellbeing: On balance, being dynamic and tensions between them.

    Science.gov (United States)

    Engler, Kim; Frohlich, Katherine; Descarries, Francine; Fernet, Mylène

    2011-01-01

    Single, childless working women (SCWW) are a notable proportion of the female workforce. The budding research on this population suggests that they have issues of wellbeing that may be tied to specific needs of both their workplaces and their personal lives, and hence, distinct work-life dynamics that require attention. This study explores how SCWW construct their wellbeing. The sample was composed of 22 SCWW aged 29 to 45. A discourse analysis of the transcripts of semi-structured interviews with these women was performed. Most women drew on an interpretative repertoire of "wellbeing as balance" (e.g., diversification and reasonable dosing of life's dimensions). It was associated with a recurrent subject position we have termed "the dynamic woman" whose intensity transfused talk of the activities in her life. Here, work becomes a "passion" and a source of appreciated challenges. However, a dilemma could arise from these constructions for positioning oneself in relation to the cadence of one's active life or rather, in articulating an unambiguous claim to balance. Balance/dosing and dynamicity/passion can be uneasy bedfellows. Our analyses raise questions about possible counter[balancing] discourses and further argue the relevance of work-life issues for SCWW.

  15. Effects of Indoor Horseback Riding and Virtual Reality Exercises on the Dynamic Balance Ability of Normal Healthy Adults

    Science.gov (United States)

    Lee, Daehee; Lee, Sangyong; Park, Jungseo

    2014-01-01

    [Purpose] The objective of this study was to determine the effect of indoor horseback riding and virtual reality exercises on the dynamic balance ability of normal adults. [Subjects] This study enrolled 24 normal adults and divided them into two groups: an indoor horseback riding exercise group (IHREG, n = 12) and a virtual reality exercise group (VREG, n = 12). [Methods] IHREG exercised on indoor horseback riding equipment and VREG exercised using the Nintendo Wii Fit three times a week for six weeks. The Biodex Balance System was used to analyze dynamic balance as measured by the overall stability index (OSI), anteroposterior stability index (APSI), and mediolateral stability index (MLSI). [Results] In the within-group comparison, IHREG and VERG both showed significant decreases in the dynamic balance indexes of OSI, APSI, and MLSI after the intervention, but no significant difference was found between the groups. [Conclusion] Both indoor horseback riding and virtual reality exercises were effective at improving the subjects’ dynamic balance ability as measured by OSI, APSI, and MLSI, and can be used as additional exercises for patients with conditions affecting postural control. PMID:25540494

  16. Effect of segmental, localized lower limb cooling on dynamic balance.

    Science.gov (United States)

    Montgomery, Roger E; Hartley, Geoffrey L; Tyler, Christopher J; Cheung, Stephen S

    2015-01-01

    This study aimed to determine the effect of cooling progressively greater portions of the lower extremities on dynamic balance and neuromuscular activation. Ten healthy males (22.8 ± 3.4 yr, 76.5 ± 9.1 kg) performed one room air temperature control (22.4°C ± 0.8°C) and three trials of cold water immersion at 12°C (lateral malleolus, ankle; lateral femoral epicondyle, knee; anterior superior iliac spine, hip) for 10 min before performing a unipedal balance test (Star Excursion Balance Test (SEBT)) with their dominant limb. Muscle activation of the vastus lateralis, biceps femoris, tibialis anterior, and lateral gastrocnemius was measured with surface EMG during the SEBT. Core temperature remained euthermic throughout all trials. Gastrocnemius temperature decreased from control (30.4°C ± 0.5°C) with knee (23.7°C ± 1.7°C) and hip immersion (22.4°C ± 1.0°C), whereas vastus lateralis temperature decreased from control (33.7°C ± 1.7°C) with hip immersion (27.3°C ± 2.0°C) (P water immersion influenced mean anterior and posterior reach distance on the SEBT in a dose-dependent fashion. Compared with those in control, mean anterior and posterior SEBT reach distances were not decreased with ankle (-1.38% and -0.74%, respectively) and knee immersion (-2.48% and -2.74%), whereas hip immersion significantly reduced SEBT by 4.73% and 4.05% (P lower extremities were cooled, with only the lateral gastrocnemius during the anterior SEBT approaching a decrease (P = 0.059). Cooling larger portions of the lower extremities progressively affect dynamic balance, and thermal protection strategies should focus on maintaining temperature in the large muscle mass of the thigh.

  17. Online Dynamic Balance Technology for High Speed Spindle Based on Gain Parameter Adaption and Scheduling Control

    Directory of Open Access Journals (Sweden)

    Shihai Zhang

    2018-06-01

    Full Text Available Unbalance vibration is one of the main vibration forms of a high speed machine tool spindle. The overlarge unbalance vibration will have some adverse effects on the working life of the spindle system and the surface quality of the work-piece. In order to reduce the unbalance of a high speed spindle system, a pneumatic online dynamic balance device and its control system are presented in the paper. To improve the balance accuracy and adaptation of the balance system, the gain parameter adaption and scheduling control method are proposed first, and then the different balance effects of the influence coefficient method and the gain scheduling control method are compared through many dynamic balance experiments of the high speed spindle. The experimental results indicate that the gain parameters can be changed timely according to the transformation of the speed and kinetic parameters of the spindle system. The balance accuracy can be improved for a high speed spindle with time-varying characteristics, based on the adaptive gain scheduling control method.

  18. Static and dynamic balance performance in patients with osteoporotic vertebral compression fracture.

    Science.gov (United States)

    Wang, Ling-Yi; Liaw, Mei-Yun; Huang, Yu-Chi; Lau, Yiu-Chung; Leong, Chau-Peng; Pong, Ya-Ping; Chen, Chia-Lin

    2013-01-01

    Patients with osteoporotic vertebral compression fracture (OVCF) have postural changes and increased risk of falling. The aim of this study is to compare balance characteristics between patients with OVCF and healthy control subjects. Patients with severe OVCF and control subjects underwent computerised dynamic posturography (CDP) in this case-control study. Forty-seven OVCF patients and 45 controls were recruited. Compared with the control group, the OVCF group had significantly decreased average stability; maximal stability under the `eye open with swayed support surface' (CDP subtest 4) and 'eye closed with swayed support surface' conditions (subtest 5); and decreased ankle strategy during subtests 4 and 5 and under the `swayed vision with swayed support surface' condition (subtest 6). The OVCF group fell more frequently during subtests 5 and 6 and had longer overall reaction time and longer reaction time when moving backward during the directional control test. OVCF patients had poorer static and dynamic balance performance compared with normal control. They had decreased postural stability and ankle strategy with increased fall frequency on a swayed surface; they also had longer reaction times overall and in the backward direction. Therefore, we suggest balance rehabilitation for patients with OVCF to prevent fall.

  19. Instrumented static and dynamic balance assessment after stroke using Wii Balance Boards: reliability and association with clinical tests.

    Science.gov (United States)

    Bower, Kelly J; McGinley, Jennifer L; Miller, Kimberly J; Clark, Ross A

    2014-01-01

    The Wii Balance Board (WBB) is a globally accessible device that shows promise as a clinically useful balance assessment tool. Although the WBB has been found to be comparable to a laboratory-grade force platform for obtaining centre of pressure data, it has not been comprehensively studied in clinical populations. The aim of this study was to investigate the measurement properties of tests utilising the WBB in people after stroke. Thirty individuals who were more than three months post-stroke and able to stand unsupported were recruited from a single outpatient rehabilitation facility. Participants performed standardised assessments incorporating the WBB and customised software (static stance with eyes open and closed, static weight-bearing asymmetry, dynamic mediolateral weight shifting and dynamic sit-to-stand) in addition to commonly employed clinical tests (10 Metre Walk Test, Timed Up and Go, Step Test and Functional Reach) on two testing occasions one week apart. Test-retest reliability and construct validity of the WBB tests were investigated. All WBB-based outcomes were found to be highly reliable between testing occasions (ICC  = 0.82 to 0.98). Correlations were poor to moderate between WBB variables and clinical tests, with the strongest associations observed between task-related activities, such as WBB mediolateral weight shifting and the Step Test. The WBB, used with customised software, is a reliable and potentially useful tool for the assessment of balance and weight-bearing asymmetry following stroke. Future research is recommended to further investigate validity and responsiveness.

  20. A Markov model for the temporal dynamics of balanced random networks of finite size

    Science.gov (United States)

    Lagzi, Fereshteh; Rotter, Stefan

    2014-01-01

    The balanced state of recurrent networks of excitatory and inhibitory spiking neurons is characterized by fluctuations of population activity about an attractive fixed point. Numerical simulations show that these dynamics are essentially nonlinear, and the intrinsic noise (self-generated fluctuations) in networks of finite size is state-dependent. Therefore, stochastic differential equations with additive noise of fixed amplitude cannot provide an adequate description of the stochastic dynamics. The noise model should, rather, result from a self-consistent description of the network dynamics. Here, we consider a two-state Markovian neuron model, where spikes correspond to transitions from the active state to the refractory state. Excitatory and inhibitory input to this neuron affects the transition rates between the two states. The corresponding nonlinear dependencies can be identified directly from numerical simulations of networks of leaky integrate-and-fire neurons, discretized at a time resolution in the sub-millisecond range. Deterministic mean-field equations, and a noise component that depends on the dynamic state of the network, are obtained from this model. The resulting stochastic model reflects the behavior observed in numerical simulations quite well, irrespective of the size of the network. In particular, a strong temporal correlation between the two populations, a hallmark of the balanced state in random recurrent networks, are well represented by our model. Numerical simulations of such networks show that a log-normal distribution of short-term spike counts is a property of balanced random networks with fixed in-degree that has not been considered before, and our model shares this statistical property. Furthermore, the reconstruction of the flow from simulated time series suggests that the mean-field dynamics of finite-size networks are essentially of Wilson-Cowan type. We expect that this novel nonlinear stochastic model of the interaction between

  1. The Influence of Mulligan Ankle Taping on Dynamic Balance in the Athletes with and without Chronic Ankle Instability

    Directory of Open Access Journals (Sweden)

    Tahereh Pourkhani

    2014-04-01

    Full Text Available Objective: The ankle joint is the most frequently injured anatomical site in athletes. Ankle instability is responsible for 25% of all time lost from sport. Clinical efficacy of the effect of taping in athletes with chronic ankle instability is unknown. So the purpose of this investigation is the study of the influence of Mulligan ankle taping on dynamic balance in the athletes with and without chronic ankle instability. Materials & Methods: 32 athletes participated in this investigation: 16 subjects with chronic ankle instability, 6 women and 10 men (age 23.5±0.3 years, height 175.4±10.3 cm, weight 73.6±14.5 kg, Foot Ankle Disability Index 74.5±8.62% and Foot Ankle Disability Index Sport 63.5±7.86% and 16 healthy subjects, 6 women and 10 men (age 22.81±7.1 years, height 173.6±12.26 cm, weight 66.4±11.4 kg, Foot Ankle Disability Index and Foot Ankle Disability Index Sport 100%. Dynamic balance was assessed with Star Excursion Balance Test in 3 reaching directions (medial, antero-medial and postero-medial before and after Mulligan ankle taping. Independent and paired t-test were used for statistical analysis. Results: Dynamic balance in healthy group significantly was better than injured group (P&le0.05. Application of taping caused significantly improvement in dynamic balance in both groups (reaching in media, antero-medial and postero-medial directions (P&le0.05 (except reaching in antero-medial direction in healthy group (P>0.05. Conclusion: So it seems that Mulligan ankle taping can improve dynamic balance in the athletes with and without chronic ankle instability.

  2. Influence of traditional dance training programs on dynamic balance of people with intellectual disability: a short review

    OpenAIRE

    Vasileios, K.

    2015-01-01

    Traditional dance is gaining popularity as an intervention choice for improving poor balance ability of people with intellectual disability (ID). Balance improvement for individuals with ID through dance provides opportunities for participation in sport activities and promotes independent living. This short review provides in brief research evidence of dynamic balance improvement as measured by means of a balance deck in duration of 30, 45, and 60 sec intervals, highlighting the need to incor...

  3. Effects of Physical Fitness Exercise, Mental Exercise and Mindfulness Exercise on Static and Dynamic Balance in Elderly Women

    Directory of Open Access Journals (Sweden)

    Latifeh Ghasempour

    2017-09-01

    Conclusion The study showed that physical exercises, mindfulness and mental training have a significant effect on the improvement of static and dynamic balance in elderly women, though the association of cognitive practices (mindfulness and mental training with motor training (physical exercises could cause a lasting impact. So, it is recommended to use physical exercises with cognitive training to improve static and dynamic balance in elderly people.

  4. A Comparison of 12 Weeks of Pilates and Aquatic Training on the Dynamic Balance of Women with Mulitple Sclerosis

    Directory of Open Access Journals (Sweden)

    Sayyed Mohammad Marandi

    2013-01-01

    Results: The adjusted mean differences of Timed Up and Go Test (TUGT scores of the experimental groups are significantly different (P<0.05. Therefore, it can be said that Pilates exercise interventions and aquatic training can significantly increase the dynamic balance of the examinees in the post-experiment stage. Conclusions: Performing the Pilate exercises and aquatic training increases dynamic balance of the MS patients. Considering the role of dynamic balance on physical fitness and enabling the person in doing is daily chores and routines, and its direct effect on the quality of life, it leads the specialists in applying these exercises as a supplementary treatment along with the medicinal treatments for MS patients.

  5. Instrumented static and dynamic balance assessment after stroke using Wii Balance Boards: reliability and association with clinical tests.

    Directory of Open Access Journals (Sweden)

    Kelly J Bower

    Full Text Available The Wii Balance Board (WBB is a globally accessible device that shows promise as a clinically useful balance assessment tool. Although the WBB has been found to be comparable to a laboratory-grade force platform for obtaining centre of pressure data, it has not been comprehensively studied in clinical populations. The aim of this study was to investigate the measurement properties of tests utilising the WBB in people after stroke.Thirty individuals who were more than three months post-stroke and able to stand unsupported were recruited from a single outpatient rehabilitation facility. Participants performed standardised assessments incorporating the WBB and customised software (static stance with eyes open and closed, static weight-bearing asymmetry, dynamic mediolateral weight shifting and dynamic sit-to-stand in addition to commonly employed clinical tests (10 Metre Walk Test, Timed Up and Go, Step Test and Functional Reach on two testing occasions one week apart. Test-retest reliability and construct validity of the WBB tests were investigated.All WBB-based outcomes were found to be highly reliable between testing occasions (ICC  = 0.82 to 0.98. Correlations were poor to moderate between WBB variables and clinical tests, with the strongest associations observed between task-related activities, such as WBB mediolateral weight shifting and the Step Test.The WBB, used with customised software, is a reliable and potentially useful tool for the assessment of balance and weight-bearing asymmetry following stroke. Future research is recommended to further investigate validity and responsiveness.

  6. Two Stage Secure Dynamic Load Balancing Architecture for SIP Server Clusters

    Directory of Open Access Journals (Sweden)

    G. Vennila

    2014-08-01

    Full Text Available Session Initiation Protocol (SIP is a signaling protocol emerged with an aim to enhance the IP network capabilities in terms of complex service provision. SIP server scalability with load balancing has a greater concern due to the dramatic increase in SIP service demand. Load balancing of session method (request/response and security measures optimizes the SIP server to regulate of network traffic in Voice over Internet Protocol (VoIP. Establishing a honeywall prior to the load balancer significantly reduces SIP traffic and drops inbound malicious load. In this paper, we propose Active Least Call in SIP Server (ALC_Server algorithm fulfills objectives like congestion avoidance, improved response times, throughput, resource utilization, reducing server faults, scalability and protection of SIP call from DoS attacks. From the test bed, the proposed two-tier architecture demonstrates that the ALC_Server method dynamically controls the overload and provides robust security, uniform load distribution for SIP servers.

  7. Predictors of chronic ankle instability: Analysis of peroneal reaction time, dynamic balance and isokinetic strength.

    Science.gov (United States)

    Sierra-Guzmán, Rafael; Jiménez, Fernando; Abián-Vicén, Javier

    2018-05-01

    Previous studies have reported the factors contributing to chronic ankle instability, which could lead to more effective treatments. However, factors such as the reflex response and ankle muscle strength have not been taken into account in previous investigations. Fifty recreational athletes with chronic ankle instability and 55 healthy controls were recruited. Peroneal reaction time in response to sudden inversion, isokinetic evertor muscle strength and dynamic balance with the Star Excursion Balance Test and the Biodex Stability System were measured. The relationship between the Cumberland Ankle Instability Tool score and performance on each test was assessed and a backward multiple linear regression analysis was conducted. Participants with chronic ankle instability showed prolonged peroneal reaction time, poor performance in the Biodex Stability System and decreased reach distance in the Star Excursion Balance Test. No significant differences were found in eversion and inversion peak torque. Moderate correlations were found between the Cumberland Ankle Instability Tool score and the peroneal reaction time and performance on the Star Excursion Balance Test. Peroneus brevis reaction time and the posteromedial and lateral directions of the Star Excursion Balance Test accounted for 36% of the variance in the Cumberland Ankle Instability Tool. Dynamic balance deficits and delayed peroneal reaction time are present in participants with chronic ankle instability. Peroneus brevis reaction time and the posteromedial and lateral directions of the Star Excursion Balance Test were the main contributing factors to the Cumberland Ankle Instability Tool score. No clear strength impairments were reported in unstable ankles. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Dynamic load balancing in a concurrent plasma PIC code on the JPL/Caltech Mark III hypercube

    International Nuclear Information System (INIS)

    Liewer, P.C.; Leaver, E.W.; Decyk, V.K.; Dawson, J.M.

    1990-01-01

    Dynamic load balancing has been implemented in a concurrent one-dimensional electromagnetic plasma particle-in-cell (PIC) simulation code using a method which adds very little overhead to the parallel code. In PIC codes, the orbits of many interacting plasma electrons and ions are followed as an initial value problem as the particles move in electromagnetic fields calculated self-consistently from the particle motions. The code was implemented using the GCPIC algorithm in which the particles are divided among processors by partitioning the spatial domain of the simulation. The problem is load-balanced by partitioning the spatial domain so that each partition has approximately the same number of particles. During the simulation, the partitions are dynamically recreated as the spatial distribution of the particles changes in order to maintain processor load balance

  9. Dynamic balance abilities of collegiate men for the bench press.

    Science.gov (United States)

    Piper, Timothy J; Radlo, Steven J; Smith, Thomas J; Woodward, Ryan W

    2012-12-01

    This study investigated the dynamic balance detection ability of college men for the bench press exercise. Thirty-five college men (mean ± SD: age = 22.4 ± 2.76 years, bench press experience = 8.3 ± 2.79 years, and estimated 1RM = 120.1 ± 21.8 kg) completed 1 repetition of the bench press repetitions for each of 3 bar loading arrangements. In a randomized fashion, subjects performed the bench press with a 20-kg barbell loaded with one of the following: a balanced load, one 20-kg plate on each side; an imbalanced asymmetrical load, one 20-kg plate on one side and a 20-kg plate plus a 1.25-kg plate on the other side; or an imbalanced asymmetrical center of mass, 20-kg plate on one side and sixteen 1.25-kg plates on the other side. Subjects were blindfolded and wore ear protection throughout all testing to decrease the ability to otherwise detect loads. Binomial data analysis indicated that subjects correctly detected the imbalance of the imbalanced asymmetrical center of mass condition (p[correct detection] = 0.89, p < 0.01) but did not correctly detect the balanced condition (p[correct detection] = 0.46, p = 0.74) or the imbalanced asymmetrical condition (p[correct detection] = 0.60, p = 0.31). Although it appears that a substantial shift in the center of mass of plates leads to the detection of barbell imbalance, minor changes of the addition of 1.25 kg (2.5 lb) to the asymmetrical condition did not result in consistent detection. Our data indicate that the establishment of a biofeedback loop capable of determining balance detection was only realized under a high degree of imbalance. Although balance detection was not present in either the even or the slightly uneven loading condition, the inclusion of balance training for upper body may be futile if exercises are unable to establish such a feedback loop and thus eliciting an improvement of balance performance.

  10. The Effect of Rope Jumping Exercise on Postural Control, Static and Dynamic Balance in Male Students with Cavus Foot

    Directory of Open Access Journals (Sweden)

    Mahdi Ghaderiyan

    2016-06-01

    Full Text Available Background and Objectives: Plantar foot is a very active part in leap activities, such as rope jumping and with its small surface playes an important role in balance control. In this research, the effect of 12 week rope jumping exercise was investigated on postural control and static and dynamic balance in 10-13 years old male students with cavus foot. Methods: This quasi-experimental study was done on 450 male students aged 13-10 years in Jarghouyeh sofla. After the initial evaluation by pedescope (qualitative and then measurement by a foot scanner (quantitative and Staheli index, 30 students were selected as samples and were divided into two groups (experimental and control, each 15 cases. To measure the postural control, a foot scanner device was used and changes in plantar center of pressure was recorded for 20 seconds. Static balance was evaluated with stork test and dynamic balance by Y balance test. The subjects of the experimental group participated in a rope jumping training protocol three 45-minute sessions per week for 12 weeks. In this period of time, the subjects of the control group did not participate in any regular physical activity program in this time. Data were analyzed using dependent and independent t-tests. The significance level was considered p<0/05. Results: A 12-week rope jumping exercise improved postural control and static and dynamic balance in patients with cavus foot, which this change was significant (p<0.001. Conclusion: According to the results of this study, rope jumping can be a useful exercise to improve static and dynamic balance and postural control in individuals with cavus foot.

  11. Dynamic workload balancing of parallel applications with user-level scheduling on the Grid

    CERN Document Server

    Korkhov, Vladimir V; Krzhizhanovskaya, Valeria V

    2009-01-01

    This paper suggests a hybrid resource management approach for efficient parallel distributed computing on the Grid. It operates on both application and system levels, combining user-level job scheduling with dynamic workload balancing algorithm that automatically adapts a parallel application to the heterogeneous resources, based on the actual resource parameters and estimated requirements of the application. The hybrid environment and the algorithm for automated load balancing are described, the influence of resource heterogeneity level is measured, and the speedup achieved with this technique is demonstrated for different types of applications and resources.

  12. The effects of Pilates exercise training on static and dynamic balance in chronic stroke patients: a randomized controlled trial

    Science.gov (United States)

    Lim, Hee Sung; Kim, You Lim; Lee, Suk Min

    2016-01-01

    [Purpose] The purpose of this study was to analyze the effects of Pilates exercise on static and dynamic balance in chronic stroke patients. [Subjects and Methods] Nineteen individuals with unilateral chronic hemiparetic stroke (age, 64.7 ± 6.9 years; height, 161.7 ± 7.9 cm; weight, 67.0 ± 11.1 kg) were randomly allocated to either a Pilates exercise group (PG, n=10) or a control group (CG, n=9). The PG attended 24 exercise sessions conducted over an 8-week period (3 sessions/week). Center of pressure (COP) sway and COP velocity were measured one week before and after the exercise program and compared to assess training effects. [Results] Pilates exercise positively affected both static and dynamic balance in patients with chronic stroke. For static balance, COP sway and velocity in the medial-lateral (M-L) and anterior-posterior (A-P) directions were significantly decreased in the PG after training while no significant differences were found in the CG. For dynamic balance, measured during treadmill walking, the PG showed significantly reduced COP sway and velocity in the M-L and A-P directions for both the paretic and non-paretic leg. [Conclusions] The findings provide initial evidence that Pilates exercise can enhance static and dynamic balance in patients with chronic stroke. PMID:27390424

  13. The effect of six week mixed exercise (power & plyometric of dynamic balance in Takhti school physical education students in Babol city

    Directory of Open Access Journals (Sweden)

    Mohammadbagher Forghani

    2015-09-01

    Full Text Available The purpose of this research was the considering of the effect of six week mixed exercise (power & plyometric of dynamic balance in Takhti school physical education students in Babol city. 60 male athlete students (physical education, without record of injury in lower organs, head & auricle disorders voluntarily participated in this research and randomly divided into two 15 individual groups (first group: power exercise; second group: plyometric exercise; third group: mixed exercise (power and plyometric and forth group: control group. The day before the performing of the six weeks exercise program, dynamic balance of examined students measured by Star Excursion Balance test (SEBT. During the six weeks that exercise group did their special exercises, the control group was asked to keep their daily body exercises and their own exercise. The day after the exercise period finished, the dynamic balance of examined students measured. Descriptive statistics one variable variance analyzes and perspective Tukey test in meaning level α≤0/05 used for statistical analyze. The results showed that power exercise, plyometric and mixed, caused meaningful increasing of examined students success distance in all eight aspects of SEBT. According to the results of the research, the   use of mixed exercise, plyometric and power (specially mixed exercises is suggested in order to decrease the probability of injury and the improvement of athlete’s dynamic balance.  . Keywords: Power Exercise, Plyometric Exercise, Mixed Exercise, Dynamic Balance

  14. Snow cover dynamics and water balance in complex high alpine terrain

    Science.gov (United States)

    Warscher, Michael; Kraller, Gabriele; Kunstmann, Harald; Strasser, Ulrich; Franz, Helmut

    2010-05-01

    The water balance in high alpine regions in its full complexity is so far insufficiently understood. High altitudinal gradients, a strong variability of meteorological variables in time and space, complex hydrogeological situations, unquantified lateral snow transport processes and heterogenous snow cover dynamics result in high uncertainties in the quantification of the water balance. To achieve interpretable modeling results we have complemented the deterministic hydrological model WaSiM-ETH with the high-alpine specific snow model AMUNDSEN. The integration of the new snow module was done to improve the modeling of water fluxes influenced by the dynamics of the snow cover, which greatly affect the water cycle in high alpine regions. To enhance the reproduction of snow deposition and ablation processes, the new approach calculates the energy balance of the snow cover considering the terrain-dependent radiation fluxes, the interaction between tree canopy and snow cover as well as lateral snow transport processes. The test site for our study is the Berchtesgaden National Park which is characterized by an extreme topography with mountain ranges covering an altitude from 607 to 2713 m.a.s.l. About one quarter of the investigated catchment area, which comprises 433 km² in total, is terrain steeper than 35°. Due to water soluble limestone being predominant in the region, a high number of subsurface water pathways (karst) exist. The results of several tracer experiments and extensive data of spring observations provide additional information to meet the challenge of modeling the unknown subsurface pathways and the complex groundwater system of the region. The validation of the new snow module is based on a dense network of meteorological stations which have been adapted to measure physical properties of the snow cover like snow water equivalent and liquid water content. We will present first results which show that the integration of the new snow module generates a

  15. The Balanced Scorecard and the Strategic Learning Process: A System Dynamics Modeling Approach

    Directory of Open Access Journals (Sweden)

    Steen Nielsen

    2015-01-01

    Full Text Available The main purpose of this paper is to improve on the conceptual as well as the methodological aspects of BSC as a quantitative model by combining elements from traditional balanced scorecard (BSC thinking with the Systems Thinking. This is done by combining short and long term aspects of measurements. The result is then used to build and construct a balanced scorecard model for strategic learning with the specific aim to maintain satisfied customers and motivated employees. Strategic planning, operational execution, feedback, and learning are some of the most important key features of any performance measurement model. This paper aims to address not only the conceptual domain related to BSC, that is, learning and system dynamics causality and feedback, but also the methodological domain concept of precision solved by differential equations. Our results show how a potential move from a static strategic vision map to a linked and dynamic understanding may be not fully realistic but very useful for learning purposes. The new knowledge obtained from the learning feedbacks fertilizes both decision discussion and decision-making and what may be required in order to move to the next level of BSC and system dynamics integration.

  16. The Effects of Short-Term Ski Trainings on Dynamic Balance Performance and Vertical Jump in Adolescents

    Science.gov (United States)

    Camliguney, Asiye Filiz

    2013-01-01

    Skiing is a sport where balance and strength are critical and which can be practiced actively especially from early years to old age. The purpose of this study is to examine the effect of a 5-day training of skiing skills on dynamic balance performance and development of vertical jump strength in adolescents. Sixteen adolescent volunteers who do…

  17. Motor intensive anti-gravity training improves performance in dynamic balance related tasks in persons with Parkinson's disease

    DEFF Research Database (Denmark)

    Malling, Anne Sofie Bøgh; Jensen, Bente Rona

    2016-01-01

    , the aim was to study the effect of motor intensive training performed in a safe anti-gravity environment using lower-body positive pressure (LBPP) technology on performance during dynamic balance related tasks. Thirteen male PDP went through an 8-week control period followed by 8 weeks of motor intensive...... antigravity training. Seventeen healthy males constituted a control group (CON). Performance during a five repetition sit-to-stand test (STS; sagittal plane) and a dynamic postural balance test (DPB; transversal plane) was evaluated. Effect measures were completion time, functional rates of force development...

  18. Effect of Jaw Clenching on Balance Recovery: Dynamic Stability and Lower Extremity Joint Kinematics after Forward Loss of Balance

    OpenAIRE

    Ringhof, Steffen; Stein, Thorsten; Hellmann, Daniel; Schindler, Hans J.; Potthast, Wolfgang

    2016-01-01

    Postural control is crucial for most tasks of daily living, delineating postural orientation and balance, with its main goal of fall prevention. Nevertheless, falls are common events, and have been associated with deficits in muscle strength and dynamic postural stability. Recent studies reported on improvements in rate of force development and static postural control evoked by jaw clenching activities, potentially induced by facilitation of human ...

  19. Research Paper: Effect of Lower Leg Cold Immersion on Dynamic Balance of Athletes and Nonathlete

    Directory of Open Access Journals (Sweden)

    Ruhollah Salehi

    2016-07-01

    Conclusion The results of this study suggest that cryotherapy through immersion of foot and ankle does not have a negative effect on the overall and anteroposterior indices of dynamic balance of athletes and nonathletes following an 8-min ice water immersion. It seems that the immersion process affected only the surface receptors of the skin and did not affect the deeper joint receptors that have a key role in balance.

  20. Statically vs dynamically balanced gait: Analysis of a robotic exoskeleton compared with a human.

    Science.gov (United States)

    Barbareschi, Giulia; Richards, Rosie; Thornton, Matt; Carlson, Tom; Holloway, Catherine

    2015-01-01

    In recent years exoskeletons able to replicate human gait have begun to attract growing popularity for both assistive and rehabilitative purposes. Although wearable robots often need the use of external support in order to maintain stability, the REX exoskeleton by REX Bionics is able to self-balance through the whole cycle. However this statically balanced gait presents important differences with the dynamically balanced gait of human subjects. This paper will examine kinematic and kinetic differences between the gait analysis performed on a subject wearing the REX exoskeleton and human gait analysis data as presented in literature. We will also provide an insight on the impact that these differences can have for both rehabilitative and assistive applications.

  1. The Effect of Two Kinds of Aerobic Exercise on the Static and Dynamic Balance of Old Men

    Directory of Open Access Journals (Sweden)

    Mojtaba Kashefi

    2014-07-01

    Full Text Available Objectives: The aim of present study is to determine the effect of two methods of aerobic training on static and dynamic balance in old men.  Methods & Materials: 37 aged people over 60 years old who were physically healthy divided into three groups after randomly carrying out pretest: 1 walking or running aerobic exercise group (n=12, 2 cycling aerobic exercise group (n=13 and 3 control group (n=12. Then groups 1 and 2, participated in running or walking exercise and cycling aerobic exercise as well with 60 percent of maximum heartbeat intensity. These two groups who were considered experimental groups of research appeared on exam site for 8 weeks, each week 3 sessions and each session 45 minutes. They rested one day between every two sessions of exercise. During the project group 3 (control continued its daily activities and had no especial exercise. After the training period, all subjects participated in the posttest session. In order to measure the static and dynamic balance Sharpend Romberg test and balancing timber test were used. The covariance analysis test (ANCOVA was also applied to examine the effect of exercise on the dependent variables and to study differences between group.  Results: The findings showed that exercise training programs in both experimental groups in research compared with control group significantly improved static and dynamic balance of subjects. It was also showed that the development of the first group (walking or running exercise group in both static and dynamic balance test was significantly higher than Group 2 (bike exercise group.  Conclusion: According to the results, it is recommended that trainers, organizations and institutions that deal with the elderly, use the cycling and walking exercises, especially walking and jogging to reduce the risk of further problem in these people.

  2. A comparison of 12 weeks of pilates and aquatic training on the dynamic balance of women with mulitple sclerosis.

    Science.gov (United States)

    Marandi, Sayyed Mohammad; Nejad, Vahid Shayegan; Shanazari, Zohreh; Zolaktaf, Vahid

    2013-04-01

    Multiple Sclerosis (MS) is a disabling chronic disease of the nervous system in which the myelin system of the central nervous system is deteriorated. The objective of this study is to understand the effect of Pilates exercises and aquatic training for a 12 week period on the dynamic balance of MS patients. The research method is semi-experimental. As a result, among the female patients visiting the MS clinic of Kashani hospital in Esfahan, 57 patients with disease intensity levels between 0 and 4.5 were taken as samples. The average length of the disease was 8 ± 2 years, 20;40 years old, and they were randomly divided into three groups of Pilates exercise group, aquatic training group, and the control group. The exercise schedule for the experiment groups consisted of 12 weeks, three sessions per week, and 1 hour for each session. The dynamic balance of the patients, before and after the exercises was measured by Six Spot Step Test. The adjusted mean differences of Timed Up and Go Test (TUGT) scores of the experimental groups are significantly different (PPilates exercise interventions and aquatic training can significantly increase the dynamic balance of the examinees in the post-experiment stage. Performing the Pilate exercises and aquatic training increases dynamic balance of the MS patients. Considering the role of dynamic balance on physical fitness and enabling the person in doing is daily chores and routines, and its direct effect on the quality of life, it leads the specialists in applying these exercises as a supplementary treatment along with the medicinal treatments for MS patients.

  3. Comparison of Static and Dynamic Balance at Different Levels of Sport Competition in Professional and Junior Elite Soccer Players.

    Science.gov (United States)

    Jadczak, Łukasz; Grygorowicz, Monika; Dzudziński, Witold; Śliwowski, Robert

    2018-04-12

    Jadczak, Ł, Grygorowicz, M, Dzudziński, W, and Śliwowski, R. Comparison of static and dynamic balance at different levels of sport competition in professional and junior elite soccer players. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this study was to compare body balance control and balance recovery strategies of professional football players, representing various sports levels in static (eyes open, eyes closed) and dynamic conditions, both on the dominant and nondominant leg. Three groups of professional and junior elite soccer players were investigated: a PRO group (n = 52), a U-21 group (n = 55), and a U-19 group (n = 47). The study of body balance control was performed using a Delos Postural Proprioceptive System measurement tool. The analysis of the results showed an effect of group (p balance on both legs, which allows for a comprehensive comparison of body balance control and the balance recovery strategy depending on the represented sport level. Our study indicates that the higher the sport level of football players (the PRO group), the better their balance, which may indirectly contribute to the prevention of injuries and more effective performance of any actions directly related to the game.

  4. Static and dynamic load-balancing strategies for parallel reservoir simulation

    International Nuclear Information System (INIS)

    Anguille, L.; Killough, J.E.; Li, T.M.C.; Toepfer, J.L.

    1995-01-01

    Accurate simulation of the complex phenomena that occur in flow in porous media can tax even the most powerful serial computers. Emergence of new parallel computer architectures as a future efficient tool in reservoir simulation may overcome this difficulty. Unfortunately, major problems remain to be solved before using parallel computers commercially: production serial programs must be rewritten to be efficient in parallel environments and load balancing methods must be explored to evenly distribute the workload on each processor during the simulation. This study implements both a static load-balancing algorithm and a receiver-initiated dynamic load-sharing algorithm to achieve high parallel efficiencies on both the IBM SP2 and Intel IPSC/860 parallel computers. Significant speedup improvement was recorded for both methods. Further optimization of these algorithms yielded a technique with efficiencies as high as 90% and 70% on 8 and 32 nodes, respectively. The increased performance was the result of the minimization of message-passing overhead

  5. Intra- and interrater reliability and agreement of the Danish version of the Dynamic Gait Index in older people with balance impairments

    DEFF Research Database (Denmark)

    Jønsson, Line R; Kristensen, Morten; Tibaek, Sigrid

    2011-01-01

    To examine the intrarater and interrater reliability and agreement of the Danish version of the Dynamic Gait Index (DGI) in hospitalized and community-dwelling older people with balance impairments.......To examine the intrarater and interrater reliability and agreement of the Danish version of the Dynamic Gait Index (DGI) in hospitalized and community-dwelling older people with balance impairments....

  6. Static and dynamic balance ability, lumbo-pelvic movement control and injury incidence in cricket pace bowlers.

    Science.gov (United States)

    Olivier, B; Stewart, A V; Olorunju, S A S; McKinon, W

    2015-01-01

    This study aimed to establish the difference in lumbo-pelvic movement control, static and dynamic balance at the start and at the end of a cricket season in pace bowlers who sustained an injury during the season and those who did not. This is a longitudinal, observational study. Thirty-two, healthy, injury free, male premier league fast, fast-medium and medium pace bowlers between the ages of 18 and 26 years (mean age 21.8 years, standard deviation 1.8 years) participated in the study. The main outcome measures were injury incidence, lumbo-pelvic movement control, static and dynamic balance ability. Fifty-three percent of the bowlers (n=17) sustained injuries during the reviewed cricket season. Lumbo-pelvic movement control tests could not discriminate between bowlers who sustained an injury during the cricket season and bowlers who did not. However, performance in the single leg balance test (p=0.03; confidence interval 4.74-29.24) and the star excursion balance test (p=0.02; confidence interval 1.28-11.93) as measured at the start of the season was better in bowlers who did not sustain an injury during the season. The improvement in the lumbo-pelvic movement control and balance tests suggests that the intensity and type of physical conditioning that happens throughout the season may have been responsible for this improvement. Poor performance in the single leg balance test and the star excursion balance test at the start of the cricket season may be an indication that a bowler is at heightened risk of injury. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  7. Dual-task functional exercises as an effective way to improve dynamic balance in persons with intellectual disability – continuation of the project

    Directory of Open Access Journals (Sweden)

    Edyta Mikołajczyk

    2017-06-01

    Full Text Available Introduction: Balance disorders are common in people with intellectual disability (ID. Aim of the research: The continuation of the project is aimed at finding out whether extension of the unstable surface dual-task functional exercises programme by another 12 weeks affects the level of dynamic balance in adolescents with ID and what those changes are like after the 8-week summer holidays. Material and methods: A total of 17 adolescents with ID aged 14–16 years (E performed functional exercises for another 12 weeks on unstable surfaces, and a group of 17 individuals with ID were the controls. Dynamic balance was assessed three times: after the first stage of the programme (test 2, after another 12 weeks (test 3, after the 8-week holiday (test 4. ALFA AC An International East stabilometric platform was used for measurements. Results : No statistical differences were discovered in group E, in dynamic balance assessment between test 2 and 3; however, the mean scores in group E, in test 3, were slightly better than in test 2, and notably better than in group C. No significant differences between test 3 and 4 were found in group E either. Conclusions : Extension of the intervention program helped to maintain improved dynamic balance. Discontinuation of the program for the period of 8 weeks resulted in decreased level of balance; however, it was still higher than at the beginning of the project. Dual-task functional exercises based on activities of daily living (ADLs and stimulation of righting reactions may enhance dynamic balance in individuals with ID, but it should be constantly stimulated.

  8. Wii Fit balance training or progressive balance training in patients with chronic stroke: a randomised controlled trial

    Science.gov (United States)

    Yatar, Gozde Iyigun; Yildirim, Sibel Aksu

    2015-01-01

    [Purpose] The aim of this study was to compare the effects of Wii Fit balance training (WBT) and progressive balance training (PBT) approaches on balance functions, balance confidence, and activities of daily living in chronic stroke patients. [Subjects] A total of 30 patients were randomized into the WBT (n=15) and PBT (n=15) groups. [Methods] All of the subjects received exercise training based on a neurodevelopemental approach in addition to either Wii Fit or progressive balance training for total of 1 hour a day, 3 days per week for 4 weeks. Primary measurements were static balance function measured with a Wii Balance Board and dynamic balance function assessed with the Berg Balance Scale, Timed Up and Go test, Dynamic Gait Index, and Functional Reach Test. Secondary measures were balance confidence assessed with the Activities-specific Balance Confidence scale and activities of daily living evaluated with the Frenchay Activity Index. [Results] There was not remarkable difference between the two treatments in dynamic balance functions, balance confidence, and activities of daily living. [Conclusion] Although both of the approaches were found to be effective in improving the balance functions, balance confidence, and activities of daily living, neither of them were more preferable than the other for the treatment of balance in patients with chronic stroke. PMID:25995576

  9. Wii Fit balance training or progressive balance training in patients with chronic stroke: a randomised controlled trial.

    Science.gov (United States)

    Yatar, Gozde Iyigun; Yildirim, Sibel Aksu

    2015-04-01

    [Purpose] The aim of this study was to compare the effects of Wii Fit balance training (WBT) and progressive balance training (PBT) approaches on balance functions, balance confidence, and activities of daily living in chronic stroke patients. [Subjects] A total of 30 patients were randomized into the WBT (n=15) and PBT (n=15) groups. [Methods] All of the subjects received exercise training based on a neurodevelopemental approach in addition to either Wii Fit or progressive balance training for total of 1 hour a day, 3 days per week for 4 weeks. Primary measurements were static balance function measured with a Wii Balance Board and dynamic balance function assessed with the Berg Balance Scale, Timed Up and Go test, Dynamic Gait Index, and Functional Reach Test. Secondary measures were balance confidence assessed with the Activities-specific Balance Confidence scale and activities of daily living evaluated with the Frenchay Activity Index. [Results] There was not remarkable difference between the two treatments in dynamic balance functions, balance confidence, and activities of daily living. [Conclusion] Although both of the approaches were found to be effective in improving the balance functions, balance confidence, and activities of daily living, neither of them were more preferable than the other for the treatment of balance in patients with chronic stroke.

  10. Trunk motion visual feedback during walking improves dynamic balance in older adults: Assessor blinded randomized controlled trial.

    Science.gov (United States)

    Anson, Eric; Ma, Lei; Meetam, Tippawan; Thompson, Elizabeth; Rathore, Roshita; Dean, Victoria; Jeka, John

    2018-05-01

    Virtual reality and augmented feedback have become more prevalent as training methods to improve balance. Few reports exist on the benefits of providing trunk motion visual feedback (VFB) during treadmill walking, and most of those reports only describe within session changes. To determine whether trunk motion VFB treadmill walking would improve over-ground balance for older adults with self-reported balance problems. 40 adults (75.8 years (SD 6.5)) with self-reported balance difficulties or a history of falling were randomized to a control or experimental group. Everyone walked on a treadmill at a comfortable speed 3×/week for 4 weeks in 2 min bouts separated by a seated rest. The control group was instructed to look at a stationary bulls-eye target while the experimental group also saw a moving cursor superimposed on the stationary bulls-eye that represented VFB of their walking trunk motion. The experimental group was instructed to keep the cursor in the center of the bulls-eye. Somatosensory (monofilaments and joint position testing) and vestibular function (canal specific clinical head impulses) was evaluated prior to intervention. Balance and mobility were tested before and after the intervention using Berg Balance Test, BESTest, mini-BESTest, and Six Minute Walk. There were no significant differences between groups before the intervention. The experimental group significantly improved on the BESTest (p = 0.031) and the mini-BEST (p = 0.019). The control group did not improve significantly on any measure. Individuals with more profound sensory impairments had a larger improvement on dynamic balance subtests of the BESTest. Older adults with self-reported balance problems improve their dynamic balance after training using trunk motion VFB treadmill walking. Individuals with worse sensory function may benefit more from trunk motion VFB during walking than individuals with intact sensory function. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Dynamic calibration and validation of an accelerometer force balance for hypersonic lifting models.

    Science.gov (United States)

    Singh, Prakash; Trivedi, Sharad; Menezes, Viren; Hosseini, Hamid

    2014-01-01

    An accelerometer-based force balance was designed and developed for the measurement of drag, lift, and rolling moment on a blunt-nosed, flapped delta wing in a short-duration hypersonic shock tunnel. Calibration and validation of the balance were carried out by a convolution technique using hammer pulse test and surface pressure measurements. In the hammer pulse test, a known impulse was applied to the model in the appropriate direction using an impulse hammer, and the corresponding output of the balance (acceleration) was recorded. Fast Fourier Transform (FFT) was operated on the output of the balance to generate a system response function, relating the signal output to the corresponding load input. Impulse response functions for three components of the balance, namely, axial, normal, and angular, were obtained for a range of input load. The angular system response function was corresponding to rolling of the model. The impulse response functions thus obtained, through dynamic calibration, were operated on the output (signals) of the balance under hypersonic aerodynamic loading conditions in the tunnel to get the time history of the unknown aerodynamic forces and moments acting on the model. Surface pressure measurements were carried out on the model using high frequency pressure transducers, and forces and moments were deduced thereon. Tests were carried out at model angles of incidence of 0, 5, 10, and 15 degrees. A good agreement was observed among the results of different experimental methods. The balance developed is a comprehensive force/moment measurement device that can be used on complex, lifting, aerodynamic geometries in ground-based hypersonic test facilities.

  12. Effects of plyometric and pneumatic explosive strength training on neuromuscular function and dynamic balance control in 60-70year old males.

    Science.gov (United States)

    Piirainen, Jarmo M; Cronin, Neil J; Avela, Janne; Linnamo, Vesa

    2014-04-01

    The present study compared neuromuscular adaptations to 12weeks of plyometric (PLY) or pneumatic (PNE) power training and their effects on dynamic balance control. Twenty-two older adults aged 60-70 (PLY n=9, PNE n=11) participated in the study. Measurements were conducted at Pre, 4, 8 and 12weeks. Dynamic balance was assessed as anterior-posterior center of pressure (COP) displacement in response to sudden perturbations. Explosive isometric knee extension and plantar flexion maximal voluntary contractions (MVCs) were performed. Maximal drop jump performance from optimal dropping height was measured in a sledge ergometer. Increases in knee extensor and ankle plantar flexor torque and muscle activity were higher and occurred sooner in PNE, whereas in drop jumping, PLY showed a clearer increase in optimal drop height (24%, pmuscle activity after 12weeks of training. In spite of these training mode specific adaptations, both groups showed similar improvements in dynamic balance control after 4weeks of training (PLY 38%, p<0.001; PNE 31%, p<0.001) and no change thereafter. These results show that although power and plyometric training may involve different neural adaptation mechanisms, both training modes can produce similar improvements in dynamic balance control in older individuals. As COP displacement was negatively correlated with rapid knee extension torque in both groups (PLY r=-0.775, p<0.05; PNE r=-0.734, p<0.05) after training, the results also highlight the importance of targeting rapid force production when training older adults to improve dynamic balance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. INFLUENCE OF TRADITIONAL DANCE TRAINING PROGRAMS ON DYNAMIC BALANCE OF PEOPLE WITH INTELLECTUAL DISABILITY: A SHORT REVIEW

    Directory of Open Access Journals (Sweden)

    K. Tsimaras Vasileios

    2015-05-01

    Full Text Available Traditional dance is gaining popularity as an intervention choice for improving poor balance ability of people with intellectual disability (ID. Balance improvement for individuals with ID through dance provides opportunities for participation in sport activities and promotes independent living. This short review provides in brief research evidence of dynamic balance improvement as measured by means of a balance deck in duration of 30, 45, and 60 sec intervals, highlighting the need to incorporate traditional dance programs in Physical Education (PE lessons applied on participants with ID. Overall, traditional dances provide emotional and cognitive interaction that has a direct positive effect on quality of life and successful motor performance of individuals with ID.

  14. INFLUENCE OF TRADITIONAL DANCE TRAINING PROGRAMS ON DYNAMIC BALANCE OF PEOPLE WITH INTELLECTUAL DISABILITY: A SHORT REVIEW

    Directory of Open Access Journals (Sweden)

    Vasileios K. Tsimaras

    2015-04-01

    Full Text Available Traditional dance is gaining popularity as an intervention choice for improving poor balance ability of people with intellectual disability (ID. Balance improvement for individuals with ID through dance provides opportunities for participation in sport activities and promotes independent living. This short review provides in brief research evidence of dynamic balance improvement as measured by means of a balance deck in duration of 30, 45, and 60 sec intervals, highlighting the need to incorporate traditional dance programs in Physical Education (PE lessons applied on participants with ID. Overall, traditional dances provide emotional and cognitive interaction that has a direct positive effect on quality of life and successful motor performance of individuals with ID.

  15. Lineage dynamics and mutation-selection balance in non-adapting asexual populations

    Science.gov (United States)

    Pénisson, Sophie; Sniegowski, Paul D.; Colato, Alexandre; Gerrish, Philip J.

    2013-02-01

    In classical population genetics, mutation-selection balance refers to the equilibrium frequency of a deleterious allele established and maintained under two opposing forces: recurrent mutation, which tends to increase the frequency of the allele; and selection, which tends to decrease its frequency. In a haploid population, if μ denotes the per capita rate of production of the deleterious allele by mutation and s denotes the selective disadvantage of carrying the allele, then the classical mutation-selection balance frequency of the allele is approximated by μ/s. This calculation assumes that lineages carrying the mutant allele in question—the ‘focal allele’—do not accumulate deleterious mutations linked to the focal allele. In principle, indirect selection against the focal allele caused by such additional mutations can decrease the frequency of the focal allele below the classical mutation-selection balance. This effect of indirect selection will be strongest in an asexual population, in which the entire genome is in linkage. Here, we use an approach based on a multitype branching process to investigate this effect, analyzing lineage dynamics under mutation, direct selection, and indirect selection in a non-adapting asexual population. We find that the equilibrium balance between recurrent mutation to the focal allele and the forces of direct and indirect selection against the focal allele is closely approximated by γμ/(s + U) (s = 0 if the focal allele is neutral), where γ ≈ eθθ-(ω+θ)(ω + θ)(Γ(ω + θ) - Γ(ω + θ,θ)), \\theta =U/\\tilde {s}, and \\omega =s/\\tilde {s}; U denotes the genomic deleterious mutation rate and \\tilde {s} denotes the geometric mean selective disadvantage of deleterious mutations elsewhere on the genome. This mutation-selection balance for asexual populations can remain surprisingly invariant over wide ranges of the mutation rate.

  16. More symmetrical gait after split-belt treadmill walking does not modify dynamic and postural balance in individuals post-stroke.

    Science.gov (United States)

    Miéville, Carole; Lauzière, Séléna; Betschart, Martina; Nadeau, Sylvie; Duclos, Cyril

    2018-04-24

    Spontaneous gait is often asymmetrical in individuals post-stroke, despite their ability to walk more symmetrically on demand. Given the sensorimotor deficits in the paretic limb, this asymmetrical gait may facilitate balance maintenance. We used a split-belt walking protocol to alter gait asymmetry and determine the effects on dynamic and postural balance. Twenty individuals post-stroke walked on a split-belt treadmill. In two separate periods, the effects of walking with the non-paretic leg, and then the paretic one, on the faster belt on spatio-temporal symmetry and balance were compared before and after these perturbation periods. Kinematic and kinetic data were collected using a motion analysis system and an instrumented treadmill to determine symmetry ratios of spatiotemporal parameters and dynamic and postural balance. Balance, quantified by the concepts of stabilizing and destabilizing forces, was compared before and after split-belt walking for subgroups of participants who improved and worsened their symmetry. The side on the slow belt during split-belt walking, but not the changes in asymmetry, affected balance. Difficulty in maintaining balance was higher during stance phase of the leg that was on the slow belt and lower on the contralateral side after split-belt walking, mostly because the center of pressure was closer (higher difficulty) or further (lower difficulty) from the limit of the base of support, respectively. Changes in spatiotemporal parameters may be sought without additional alteration of balance during gait post-stroke. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Effects of a dynamic balance training protocol on podalic support in older women. Pilot Study.

    Science.gov (United States)

    Battaglia, Giuseppe; Bellafiore, Marianna; Bianco, Antonino; Paoli, Antonio; Palma, Antonio

    2010-01-01

    The foot provides the only direct contact with supporting surfaces and therefore plays an important role in all postural tasks. Changes in the musculoskeletal and neurological characteristics of the foot with advancing age can alter plantar loading patterns and postural balance. Several studies have reported that exercise training improves postural performance in elderly individuals. The aim of our study was to investigate the effectiveness of a dynamic balance training protocol performed for 5 weeks on the support surface, percentage distribution of load in both feet, and body balance performance in healthy elderly women. Ten subjects (68.67±5.50 yrs old; 28.17±3.35 BMI) were evaluated with a monopodalic performance test and baropodometric analyses before and after the training period. We found a significant improvement in balance unipedal performance times on left and right foot by 20.18% and 26.23% respectively (p0.05). The increased support surface and equal redistribution of body weight on both feet obtained in response to our training protocol may be postural adaptations sufficient to improve static balance in elderly women.

  18. Elevation Change, Mass Balance, Dynamics, and Surging of Langjökull, Iceland from 1997 to 2007

    OpenAIRE

    Pope, Allen; Willis, Ian Craig; Pálsson, Finnur; Arnold, Neil Stuart; Rees, William Gareth; Björnsson, Helgi; Grey, Lauren

    2016-01-01

    Glaciers and ice caps around the world are changing quickly, with surge-type behaviour superimposed upon climatic forcing. Here, we study Iceland’s second largest ice cap, Langjökull, which has both surge- and non-surge-type outlets. By differencing elevation change with surface mass balance, we estimate the contribution of ice dynamics to elevation change. We use DEMs, in situ stake measurements, regional reanalyses, and a mass balance model to calculate the vertical ice velocity. Thus,...

  19. Social inequality in dynamic balance performance in an early old age Spanish population: The role of health and life style associated factors

    DEFF Research Database (Denmark)

    Rodriguez Lopez, Santiago; Nilsson, Charlotte Juul; Lund, Rikke

    2012-01-01

    of poor balance, also after adjustment for age, gender, obesity and physical activity. In addition, obesity and sedentary physical activity were related to poor dynamic balance. The findings suggest an independent effect of both SES and behavioral factors on poor balance performance in the older Spanish...

  20. Dynamic balance in children with attention-deficit hyperactivity disorder and its relationship with cognitive functions and cerebellum

    Directory of Open Access Journals (Sweden)

    Goetz M

    2017-03-01

    Full Text Available Michal Goetz,1 Jaroslava Paulasova Schwabova,2 Zdenek Hlavka,3 Radek Ptacek,4 Craig BH Surman5 1Department of Child Psychiatry, Second Faculty of Medicine, Motol University Hospital, 2Department of Neurology, 3Department of Statistics, 4Department of Psychiatry, Charles University, Prague, Czech Republic; 5Department of Psychiatry, Harvard Medical School, Boston, MA, USA Background: Attention-deficit hyperactivity disorder (ADHD is linked to the presence of motor deficiencies, including balance deficits. The cerebellum serves as an integrative structure for balance control and is also involved in cognition, including timing and anticipatory regulation. Cerebellar development may be delayed in children and adolescents with ADHD, and inconsistent reaction time is commonly seen in ADHD. We hypothesized that dynamic balance deficits would be present in children with ADHD and they would correlate with attention and cerebellar functions. Methods: Sixty-two children with ADHD and no other neurological conditions and 62 typically developing (TD children were examined with five trials of the Phyaction Balance Board, an electronic balancing platform. Cerebellar clinical symptoms were evaluated using an international ataxia rating scale. Conners’ Continuous Performance Test was used to evaluate patterns of reaction. Results: Children with ADHD had poorer performance on balancing tasks, compared to TD children (P<0.001. They exhibited significantly greater sway amplitudes than TD children (P<0.001 in all of the five balancing trials. The effect size of the difference between the groups increased continuously from the first to the last trial. Balance score in both groups was related to the variation in the reaction time, including reaction time standard error (r =0.25; P=0.0409, respectively, r =0.31; P=0.0131 and Variability of Standard Error (r =0.28; P=0.0252, respectively, r =0.41; P<0.001. The burden of cerebellar symptoms was strongly related to

  1. Measuring and modeling the temporal dynamics of nitrogen balance in an experimental-scale paddy field

    Science.gov (United States)

    Tseng, C.; Lin, Y.

    2013-12-01

    Nitrogen balance involves many mechanisms and plays an important role to maintain the function of nature. Fertilizer application in agriculture activity is usually seen as a common and significant nitrogen input to environment. Improper fertilizer application on paddy field can result in great amount of various types of nitrogen losses. Hence, it is essential to understand and quantify the nitrogen dynamics in paddy field for fertilizer management and pollution control. In this study, we develop a model which considers major transformation processes of nitrogen (e.g. volatilization, nitrification, denitrification and plant uptake). In addition, we measured different types of nitrogen in plants, soil and water at plant growth stages in an experimental-scale paddy field in Taiwan. The measurement includes total nitrogen in plants and soil, and ammonium-N (NH4+-N), nitrate-N (NO3--N) and organic nitrogen in water. The measured data were used to calibrate the model parameters and validate the model for nitrogen balance simulation. The results showed that the model can accurately estimate the temporal dynamics of nitrogen balance in paddy field during the whole growth stage. This model might be helpful and useful for future fertilizer management and pollution control in paddy field.

  2. Mizan: A system for dynamic load balancing in large-scale graph processing

    KAUST Repository

    Khayyat, Zuhair

    2013-01-01

    Pregel [23] was recently introduced as a scalable graph mining system that can provide significant performance improvements over traditional MapReduce implementations. Existing implementations focus primarily on graph partitioning as a preprocessing step to balance computation across compute nodes. In this paper, we examine the runtime characteristics of a Pregel system. We show that graph partitioning alone is insufficient for minimizing end-to-end computation. Especially where data is very large or the runtime behavior of the algorithm is unknown, an adaptive approach is needed. To this end, we introduce Mizan, a Pregel system that achieves efficient load balancing to better adapt to changes in computing needs. Unlike known implementations of Pregel, Mizan does not assume any a priori knowledge of the structure of the graph or behavior of the algorithm. Instead, it monitors the runtime characteristics of the system. Mizan then performs efficient fine-grained vertex migration to balance computation and communication. We have fully implemented Mizan; using extensive evaluation we show that - especially for highly-dynamic workloads - Mizan provides up to 84% improvement over techniques leveraging static graph pre-partitioning. © 2013 ACM.

  3. The Association of Flexibility, Balance, and Lumbar Strength with Balance Ability: Risk of Falls in Older Adults

    Directory of Open Access Journals (Sweden)

    Emilio J. Martínez-López Emilio

    2014-06-01

    Full Text Available The purpose of the present study was to determine the effects of a proprioceptive training program on older adults, as well as to analyze the association between flexibility, balance and lumbar strength (physical fitness test with balance ability and fall risk (functional balance tests. This study was a controlled, longitudinal trial with a 12-week follow-up period. Subjects from a population of older adults were allocated to the intervention group (n = 28 or to the usual care (control group (n = 26. Subjects performed proprioceptive training twice weekly (6 specific exercises with Swiss ball and BOSU. Each session included 50 minutes (10 minutes of warm-up with slow walk, 10 minutes of mobility and stretching exercises, 30 minutes of proprioceptive exercises. The outcome variables were physical fitness (lower-body flexibility, hip-joint mobility, dynamic balance, static balance, and lumbar strength and functional balance (Berg scale and Tinetti test. The experimental group obtained significantly higher values than the control group in lower-body flexibility, dynamic balance, and lumbar strength (p = 0.019, p < 0.001, and p = 0.034 respectively. Hip-joint mobility, dynamic balance, and lumbar strength were positively associated with balance ability (p < 0.001, p < 0.001, and p = 0.014, respectively and the prevention of falls (p = 0.001, p < 0.001, and p = 0.017 respectively. These findings suggest that a 12-week proprioception program intervention (twice a week significantly improves flexibility, balance, and lumbar strength in older adults. Hip-joint mobility, dynamic balance and lumbar strength are positively associated to balance ability and the risk of falls in older adults. This proprioceptive training does not show a significant improvement in hip-joint mobility or static balance.

  4. Investigating the effects of maximal anaerobic fatigue on dynamic postural control using the Y-Balance Test.

    Science.gov (United States)

    Johnston, William; Dolan, Kara; Reid, Niamh; Coughlan, Garrett F; Caulfield, Brian

    2018-01-01

    The Y Balance Test is one of the most commonly used dynamic balance assessments, providing an insight into the integration of the sensorimotor subsystems. In recent times, there has been an increase in interest surrounding it's use in various clinical populations demonstrating alterations in motor function. Therefore, it is important to examine the effect physiological influences such as fatigue play in dynamic postural control, and establish a timeframe for its recovery. Descriptive laboratory study. Twenty male and female (age 23.75±4.79years, height 174.12±8.45cm, mass 69.32±8.76kg) partaking in competitive sport, completed the Y Balance Test protocol at 0, 10 and 20min, prior to a modified 60s Wingate fatiguing protocol. Post-fatigue assessments were then completed at 0, 10 and 20 min post-fatiguing intervention. Intraclass correlation coefficients demonstrated excellent intra-session reliability (0.976-0.982) across the three pre-fatigue YBT tests. Post-hoc paired sample t-tests demonstrated that all three reach directions demonstrated statistically significant differences between pre-fatigue and the first post-fatigue measurement (anterior; p=0.019, posteromedial; p=0.019 & posterolateral; p=0.003). The anterior reach direction returned to pre-fatigue levels within 10min (p=0.632). The posteromedial reach direction returned to pre-fatigue levels within 20min (p=0.236), while the posterolateral direction maintained a statistically significant difference at 20min (p=0.023). Maximal anaerobic fatigue has a negative effect on normalised Y balance test scores in all three directions. Following the fatiguing protocol, dynamic postural control returns to pre-fatigue levels for the anterior (20min). Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  5. Management of postural sensory conflict and dynamic balance control in late-stage Parkinson's disease.

    Science.gov (United States)

    Colnat-Coulbois, S; Gauchard, G C; Maillard, L; Barroche, G; Vespignani, H; Auque, J; Perrin, P P

    2011-10-13

    Parkinson's disease (PD) is known to affect postural control, especially in situations needing a change in balance strategy or when a concurrent task is simultaneously performed. However, few studies assessing postural control in patients with PD included homogeneous population in late stage of the disease. Thus, this study aimed to analyse postural control and strategies in a homogeneous population of patients with idiopathic advanced (late-stage) PD, and to determine the contribution of peripheral inputs in simple and more complex postural tasks, such as sensory conflicting and dynamic tasks. Twenty-four subjects with advanced PD (duration: median (M)=11.0 years, interquartile range (IQR)=4.3 years; Unified Parkinson's Disease Rating Scale (UPDRS): M "on-dopa"=13.5, IQR=7.8; UPDRS: M "off-dopa"=48.5, IQR=16.8; Hoehn and Yahr stage IV in all patients) and 48 age-matched healthy controls underwent static (SPT) and dynamic posturographic (DPT) tests and a sensory organization test (SOT). In SPT, patients with PD showed reduced postural control precision with increased oscillations in both anterior-posterior and medial-lateral planes. In SOT, patients with PD displayed reduced postural performances especially in situations in which visual and vestibular cues became predominant to organize balance control, as was the ability to manage balance in situations for which visual or proprioceptive inputs are disrupted. In DPT, postural restabilization strategies were often inefficient to maintain equilibrium resulting in falls. Postural strategies were often precarious, postural regulation involving more hip joint than ankle joint in patients with advanced PD than in controls. Difficulties in managing complex postural situations, such as sensory conflicting and dynamic situations might reflect an inadequate sensory organization suggesting impairment in central information processing. Copyright © 2011. Published by Elsevier Ltd.

  6. Inverse Force Determination on a Small Scale Launch Vehicle Model Using a Dynamic Balance

    Science.gov (United States)

    Ngo, Christina L.; Powell, Jessica M.; Ross, James C.

    2017-01-01

    A launch vehicle can experience large unsteady aerodynamic forces in the transonic regime that, while usually only lasting for tens of seconds during launch, could be devastating if structural components and electronic hardware are not designed to account for them. These aerodynamic loads are difficult to experimentally measure and even harder to computationally estimate. The current method for estimating buffet loads is through the use of a few hundred unsteady pressure transducers and wind tunnel test. Even with a large number of point measurements, the computed integrated load is not an accurate enough representation of the total load caused by buffeting. This paper discusses an attempt at using a dynamic balance to experimentally determine buffet loads on a generic scale hammer head launch vehicle model tested at NASA Ames Research Center's 11' x 11' transonic wind tunnel. To use a dynamic balance, the structural characteristics of the model needed to be identified so that the natural modal response could be and removed from the aerodynamic forces. A finite element model was created on a simplified version of the model to evaluate the natural modes of the balance flexures, assist in model design, and to compare to experimental data. Several modal tests were conducted on the model in two different configurations to check for non-linearity, and to estimate the dynamic characteristics of the model. The experimental results were used in an inverse force determination technique with a psuedo inverse frequency response function. Due to the non linearity, the model not being axisymmetric, and inconsistent data between the two shake tests from different mounting configuration, it was difficult to create a frequency response matrix that satisfied all input and output conditions for wind tunnel configuration to accurately predict unsteady aerodynamic loads.

  7. Improved determination of dynamic balance using the centre of mass and centre of pressure inclination variables in a complete golf swing cycle.

    Science.gov (United States)

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2016-01-01

    Golf requires proper dynamic balance to accurately control the club head through a harmonious coordination of each human segment and joint. In this study, we evaluated the ability for dynamic balance during a golf swing by using the centre of mass (COM)-centre of pressure (COP) inclination variables. Twelve professional, 13 amateur and 10 novice golfers participated in this study. Six infrared cameras, two force platforms and SB-Clinic software were used to measure the net COM and COP trajectories. In order to evaluate dynamic balance ability, the COM-COP inclination angle, COM-COP inclination angular velocity and normalised COM-COP inclination angular jerk were used. Professional golfer group revealed a smaller COM-COP inclination angle and angular velocity than novice golfer group in the lead/trail direction (P golf injuries.

  8. A Force Balanced Fragmentation Method for ab Initio Molecular Dynamic Simulation of Protein

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    Mingyuan Xu

    2018-05-01

    Full Text Available A force balanced generalized molecular fractionation with conjugate caps (FB-GMFCC method is proposed for ab initio molecular dynamic simulation of proteins. In this approach, the energy of the protein is computed by a linear combination of the QM energies of individual residues and molecular fragments that account for the two-body interaction of hydrogen bond between backbone peptides. The atomic forces on the caped H atoms were corrected to conserve the total force of the protein. Using this approach, ab initio molecular dynamic simulation of an Ace-(ALA9-NME linear peptide showed the conservation of the total energy of the system throughout the simulation. Further a more robust 110 ps ab initio molecular dynamic simulation was performed for a protein with 56 residues and 862 atoms in explicit water. Compared with the classical force field, the ab initio molecular dynamic simulations gave better description of the geometry of peptide bonds. Although further development is still needed, the current approach is highly efficient, trivially parallel, and can be applied to ab initio molecular dynamic simulation study of large proteins.

  9. The Effects of the Disturbance of the Vestibular System on the Dynamic Balance of Idiopathic Scoliotic Subjects with and Without Exercise Therapy Compared to Healthy Subjects

    Directory of Open Access Journals (Sweden)

    N. Farahpour

    2004-01-01

    Full Text Available The mechanism of the neuromuscular system’s disorders in Adolescent Idiopathic Scoliosis (AIS are not well known. The objectives of this study were to assess the dynamic balance of the AIS patients and the influence of exercise therapy on patients' dynamic balance. Eleven teenager scoliotic subjects after three months exercise therapy, nine similar patients without therapy and 13 healthy age matched subjects as control group were studied. Using dynamic stability platform, the deviation of COG of subjects in different positions, including up right standing, standing with head flexion and standing with head hyper extension were measured. The tests were repeated in both lose and stable condition of the foot platform. Results showed that the stability of the foot platform resulted in COG's deviation by 1.13 0.08 in all subjects. Dynamic balance of scoliotic patients without treatment was similar to that of the normal subjects. While, exercised patients had less COG deviation than the other groups. The change in head position increased the COG deviation by 2.5 times in control and non-exercised patients and 1.5 times in exercised patients. The dynamic balance in scoliosis was not affected. Exercise improved the dynamic balance in scoliotic subjects. Exercise therapy is recommended to improve the proprioceptives function.

  10. Changes in dynamic balance control over time in children with and without Developmental Coodination Disorder

    NARCIS (Netherlands)

    Jelsma, L.D.; Smits-Engelsman, B.C.M.; Geuze, R.H.

    2015-01-01

    Changes in dynamic balance control over time in children with and without Developmental Coordination Disorder L.D. Jelsma1, B.C.M. Smits-Engelsman2 & R.H. Geuze1 1Clinical and Developmental Neuropsychology, University of Groningen, Grote Kruisstraat 2-1, 9712 TS Groningen, the Netherlands.

  11. The effects of core stabilization exercise on dynamic balance and gait function in stroke patients.

    Science.gov (United States)

    Chung, Eun-Jung; Kim, Jung-Hee; Lee, Byoung-Hee

    2013-07-01

    [Purpose] The purpose of this study was to determine the effects of core stabilization exercise on dynamic balance and gait function in stroke patients. [Subjects] The subjects were 16 stroke patients, who were randomly divided into two groups: a core stabilization exercise group of eight subjects and control group of eight subjects. [Methods] Subjects in both groups received general training five times per week. Subjects in the core stabilization exercise group practiced an additional core stabilization exercise program, which was performed for 30 minutes, three times per week, during a period of four weeks. All subjects were evaluated for dynamic balance (Timed Up and Go test, TUG) and gait parameters (velocity, cadence, step length, and stride length). [Results] Following intervention, the core exercise group showed a significant change in TUG, velocity, and cadence. The only significant difference observed between the core group and control group was in velocity. [Conclusion] The results of this study suggest the feasibility and suitability of core stabilization exercise for stroke patients.

  12. Can segmental model reductions quantify whole-body balance accurately during dynamic activities?

    Science.gov (United States)

    Jamkrajang, Parunchaya; Robinson, Mark A; Limroongreungrat, Weerawat; Vanrenterghem, Jos

    2017-07-01

    When investigating whole-body balance in dynamic tasks, adequately tracking the whole-body centre of mass (CoM) or derivatives such as the extrapolated centre of mass (XCoM) can be crucial but add considerable measurement efforts. The aim of this study was to investigate whether reduced kinematic models can still provide adequate CoM and XCoM representations during dynamic sporting tasks. Seventeen healthy recreationally active subjects (14 males and 3 females; age, 24.9±3.2years; height, 177.3±6.9cm; body mass 72.6±7.0kg) participated in this study. Participants completed three dynamic movements, jumping, kicking, and overarm throwing. Marker-based kinematic data were collected with 10 optoelectronic cameras at 250Hz (Oqus Qualisys, Gothenburg, Sweden). The differences between (X)CoM from a full-body model (gold standard) and (X)CoM representations based on six selected model reductions were evaluated using a Bland-Altman approach. A threshold difference was set at ±2cm to help the reader interpret which model can still provide an acceptable (X)CoM representation. Antero-posterior and medio-lateral displacement profiles of the CoM representation based on lower limbs, trunk and upper limbs showed strong agreement, slightly reduced for lower limbs and trunk only. Representations based on lower limbs only showed less strong agreement, particularly for XCoM in kicking. Overall, our results provide justification of the use of certain model reductions for specific needs, saving measurement effort whilst limiting the error of tracking (X)CoM trajectories in the context of whole-body balance investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Mini-trampoline exercise related to mechanisms of dynamic stability improves the ability to regain balance in elderly.

    Science.gov (United States)

    Aragão, Fernando Amâncio; Karamanidis, Kiros; Vaz, Marco Aurélio; Arampatzis, Adamantios

    2011-06-01

    Falls have been described by several studies as the major cause of hip and femur fractures among the elderly. Therefore, interventions to reduce fall risks, improve dynamic stability and the falling recovery strategies in the elderly population are highly relevant. This study aimed at investigating the effects of a 14-week mini-trampoline exercise intervention regarding the mechanisms of dynamic stability on elderly balance ability during sudden forward falls. Twenty-two elderly subjects participated on mini-trampoline training and 12 subjects were taken as controls. The subjects of the experimental group were evaluated before and after the 14-week trampoline training (exercised group), whereas control subjects were evaluated twice in the forward fall task with a three-month interval. The applied exercise intervention increased the plantarflexors muscle strength (∼10%) as well as the ability to regain balance during the forward falls (∼35%). The 14-week mini-trampoline training intervention increased elderly abilities to recover balance during forward falls; the improvement was attributed to the higher rate of hip moment generation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. An efficient dynamic load balancing algorithm

    Science.gov (United States)

    Lagaros, Nikos D.

    2014-01-01

    In engineering problems, randomness and uncertainties are inherent. Robust design procedures, formulated in the framework of multi-objective optimization, have been proposed in order to take into account sources of randomness and uncertainty. These design procedures require orders of magnitude more computational effort than conventional analysis or optimum design processes since a very large number of finite element analyses is required to be dealt. It is therefore an imperative need to exploit the capabilities of computing resources in order to deal with this kind of problems. In particular, parallel computing can be implemented at the level of metaheuristic optimization, by exploiting the physical parallelization feature of the nondominated sorting evolution strategies method, as well as at the level of repeated structural analyses required for assessing the behavioural constraints and for calculating the objective functions. In this study an efficient dynamic load balancing algorithm for optimum exploitation of available computing resources is proposed and, without loss of generality, is applied for computing the desired Pareto front. In such problems the computation of the complete Pareto front with feasible designs only, constitutes a very challenging task. The proposed algorithm achieves linear speedup factors and almost 100% speedup factor values with reference to the sequential procedure.

  15. The Effects of Patellar Taping on Dynamic Balance and Reduction of Pain in Athletic Women with Patellofemoral Pain Syndrome(PFPS

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    N Khoshraftare Yazdi

    2012-08-01

    Full Text Available Introduction: Patellofemoral pain syndrome(PFPS is the most common overuse syndrome in athletes. It is one of the causes of anterior knee pain in athletic population who attend to the sport medical clinics. Patellofemoral is more common among female athletes especially adolescents and young adults. Patellar taping provides an effective treatment in alleviating the symptoms of a high proportion of subjects who suffer from PFPS, though the mechanisms of pain reduction have not completely been established following its application. The purpose of this study was to investigate the effects of taping on dynamic balance and reduction of pain in athletic women with patellofemoral pain syndrome. Methods: Fifteen female athletes with patellofemoral pain syndrome participated in the study. Therefore, dynamic balance was assessed using a SEBT(Star Excursion Balance Test before and after application of patellar taping. The severity of pain was measured by VAS(Visual Analog Scale. Results: The results of variance analysis by VAS(p<0/008 in repeated measure indicated a statistically significant improvement in pain and in knee function in anterior, anteromedial, medial, posteromedial and anterolateral directions(p<0/05. Conclusion: The study results confirmed a significant improvement in reducing pain and increasing function (dynamic balance of female athletes with patellofemoral pain syndrome after patellar taping.

  16. Effect of manual therapy versus proprioceptive neuromuscular facilitation in dynamic balance, mobility and flexibility in field hockey players. A randomized controlled trial.

    Science.gov (United States)

    Espí-López, Gemma V; López-Martínez, Susana; Inglés, Marta; Serra-Añó, Pilar; Aguilar-Rodríguez, Marta

    2018-04-22

    To compare the effectiveness of a specific Manual Therapy (MT) protocol applied to field hockey players (FHP), versus a Proprioceptive Neuromuscular Facilitation (PNF) protocol, in the improvement of dynamic balance, active range of movement and lumbar flexibility one-week and four-weeks after the treatment. Randomized controlled trial. Participants were assigned to 2 groups: MT and PNF. 30 min' sessions were performed once a week for three weeks. Three evaluations were performed: basal, one-week and four-weeks post-treatment. University of Valencia (Spain). 22 in MT group and 20 in PNF group. Dynamic Balance, measured with Star Excursion Balance Test; Active Range of Motion (ROM), using a manual goniometer and Lumbar Flexibility, assessed with Fingertip-to-floor test. Both groups significantly improved in lateral and medial dynamic balance one-week post-treatment (p < 0.05); but the improvement in the MT group lasted until the fourth-week after treatment in both reaches (lateral and medial) (p < 0.05). MT group also obtained significant improvements in dorsal flexion of the ankle in the fourth-week post-treatment (p < 0.05) and in lumbar flexibility one-week post-treatment (p < 0.05). MT and PNF improve dynamic balance one-week post-treatment; however, the improvement obtained through MT is maintained four-weeks later. Only MT improves dorsal flexion of the ankle four-weeks post-treatment and lumbar flexibility one-week post-treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Portable Parallel Programming for the Dynamic Load Balancing of Unstructured Grid Applications

    Science.gov (United States)

    Biswas, Rupak; Das, Sajal K.; Harvey, Daniel; Oliker, Leonid

    1999-01-01

    The ability to dynamically adapt an unstructured -rid (or mesh) is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult, particularly from the view point of portability on various multiprocessor platforms We address this problem by developing PLUM, tin automatic anti architecture-independent framework for adaptive numerical computations in a message-passing environment. Portability is demonstrated by comparing performance on an SP2, an Origin2000, and a T3E, without any code modifications. We also present a general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication pattern, with a goal to providing a global view of system loads across processors. Experiments on, an SP2 and an Origin2000 demonstrate the portability of our approach which achieves superb load balance at the cost of minimal extra overhead.

  18. Wii Fit exer-game training improves sensory weighting and dynamic balance in healthy young adults.

    Science.gov (United States)

    Cone, Brian L; Levy, Susan S; Goble, Daniel J

    2015-02-01

    The Nintendo Wii Fit is a balance training tool that is growing in popularity due to its ease of access and cost-effectiveness. While considerable evidence now exists demonstrating the efficacy of the Wii Fit, no study to date has determined the specific mechanism underlying Wii Fit balance improvement. This paucity of knowledge was addressed in the present study using the NeuroCom Balance Manager's Sensory Organization Test (SOT) and Limits of Stability (LOS) test. These well-recognized posturography assessments, respectively, measure sensory weighting and dynamic stability mechanisms of balance. Forty healthy, young participants were recruited into two groups: Wii Fit Balance Intervention (WFBI) (n=20) and Control (CON) (n=20). Balance training consisted of seven Wii Fit exer-games played over the course of six consecutive weeks (2-4×/week, 30-45min/day). The WFBI group performed Neurocom testing before and after the intervention, while the CON group was tested along a similar timeline with no intervention. Mixed-design ANOVAs found significant interactions for testing time point and condition 5 of the SOT (peffects were such that greater improvements were seen for the WFBI group following Wii Fit training. These findings suggest that individuals with known issues regarding the processing of multiple sources of sensory information and/or who have limited functional bases of support may benefit most from Wii Fit balance training. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Investigation of Balance Function Using Dynamic Posturography under Electrical-Acoustic Stimulation in Cochlear Implant Recipients

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    B. Schwab

    2010-01-01

    Full Text Available Introduction. The purpose of the present study is to investigate the effect of electrical-acoustic stimulation on vestibular function in CI patients by using the EquiTest and to help answer the question of whether electrically stimulating the inner ear using a cochlear implant influences the balance system in any way. Material and Methods. A test population (=50 was selected at random from among the cochlear implant recipients. Dynamic posturography (using the EquiTest was performed with the device switched off an switched on. Results. In summary, it can be said that an activated cochlear implant affects the function of the vestibular system and may, to an extent, even lead to a stabilization of balance function under the static conditions of dynamic posturography, but nevertheless also to a significant destabilization. Significant improvements in vestibular function were seen mainly in equilibrium scores under conditions 4 and 5, the composite equilibrium score, and the vestibular components as revealed by sensory analysis. Conclusions. Only under the static conditions are significantly poorer scores achieved when stimulation is applied. It may be that the explanation for any symptoms of dizziness lies precisely in the fact that they occur in supposedly noncritical situations, since, when the cochlear implant makes increased demands on the balance system, induced disturbances can be centrally suppressed.

  20. The effect of activity history and current activity on static and dynamic postural balance in older adults.

    Science.gov (United States)

    Bulbulian, R; Hargan, M L

    2000-01-01

    The purpose of this study was to investigate the effects of former athleticism and current activity status on static and dynamic postural balance in older adults. Fifty-six subjects participated in four study groups including former athletes, currently active (AA; n = 15; 69.1+/-4.4 years.; 77.8+/-9.8 kg), former athletes, currently inactive (AI; n = 12; 66.7 years.; 87.2+/-15.1 kg), controls currently active (CA; n = 14; 68.6 +/- 4.5 years.; 73.9+/-15 kg), and controls currently inactive (CI; n = 15; 72.8+/-4.8 years; 81.1+/-14.8). All subjects were tested for height, weight, flexibility, thigh circumference, and static (sharpened Romberg/unipedal stance), and dynamic (step length and width) balance tests. The sharpened Romberg (eyes open) test showed that AA (60.0+/-0 s) and CA (59.4+/- 0.5 s) balanced significantly longer than AI (41.5+/-7.2 s), and CI (41.8+/-6.1 s) (punipedal (eyes open) test balance scores for AA, CA, AI, and CI were respectively 40.0+/-4.5, 55.1+/- 3.4, 33.0+/-7.1, and 27.5+/-6.1 s, with CA significantly better than CI (ptest results for relative group comparisons were similar. Overall, two-way analysis of variance showed a significant activity main effect for all dependent variables measured (p<0.05). The results indicated that current activity status plays a key role on balance performance in older adults. Furthermore, former athletic activity history provides no protection for the age related onset of postural imbalance.

  1. Fungos micorrízicos arbusculares em bananeiras cultivadas no Vale do Submédio São Francisco Arbuscular mycorrhizal fungi associated with roots of banana cultivated in the Submédio São Francisco Valley

    Directory of Open Access Journals (Sweden)

    Adriana Mayumi Yano de Melo

    1997-12-01

    Full Text Available Na região do Vale do São Francisco, onde a exploração da agricultura irrigada é a principal responsável pela alta produção de frutas para exportação, a banana é uma das culturas que mais tem se expandido em área cultivada. Com o objetivo de registrar os fungos micorrízicos arbusculares associados a essa cultura, foram coletadas, sob a parte aérea da bananeira, amostras de solo da rizosfera, em quatro áreas com diferentes características de solo, sendo identificadas as espécies: Acaulospora longula Spain & Schenck, A. morrowiae Spain & Schenck, A. rehmii Sieverding & Toro, A. scrobiculata Trappe, A. spinosa Walker & Trappe, A. tuberculata Janos & Trappe, Entrophospora infrequens (Hall Ames & Schneider, Gigaspora ramisporophora Spain, Sieverding & Schenck, Glomus diaphanum Morton & Walker, G. etunicatum Becker & Gerd., G. intraradices Schenck & Smith, G. macrocarpum Tui. & Tui., G. mosseae (Nicol. & Gerd. Gerd. & Trappe, G. occultum Walker e Scutellospora sp. A percentagem de colonização das raízes de bananeiras nas diferentes áreas foi em média 55%.In the region of the São Francisco Valley, where irrigated agriculture is responsable for high production of fruits for exportation, banana is one of the most expanded crops in cultivated areas. In order to know the arbuscular mycorrhizal fungi associated with this crop, samples from the rhizosphere of banana plants were collected in four areas with different soil characteristics, being identified the species: Acaulospora longula Spain & Schenck, A. morrowiae Spain & Schenck, A. rehmii Sieverding & Toro, A. scrobiculata Trappe, A. spinosa Walker & Trappe, A. tuberculata Janos & Trappe, Entrophospora infrequens (Hall Ames & Schneider, Gigaspora ramisporophora Spain, Sieverding & Schenck, Glomus diaphanum Morton & Walker, G. etunicatum Becker & Gerd., G. intraradices Schenck & Smith, G. macrocarpum Tui. & Tui., G. mosseae (Nicol. & Gerd. Gerd. & Trappe, G. occultum Walker and

  2. Understanding decision making about balancing two stocks: the faculty gender balancing task

    NARCIS (Netherlands)

    Bleijenbergh, I.L.; Vennix, J.A.M.; Jacobs, H.A.G.M.; Engen, M.L. van; Engen, M. van

    2016-01-01

    This paper contributes to the understanding of dynamic decision making. Using the faculty gender balancing task, we experimentally test the extent to which participants correctly estimate the inflow needed to balance two unbalanced stocks and how they substantiate their decision. The results show

  3. Fungos micorrízicos arbusculares (Glomales, Zygomycota na Ilha dos Eucaliptos, Represa do Guarapiranga, São Paulo, SP Arbuscular mycorrhizal fungi (Glomales, Zygomycota from "Ilha dos Eucaliptos", Guarapiranga Reservoir, São Paulo, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Simone de Paula Gomes

    1998-01-01

    Full Text Available Com o objetivo de se conhecer a micota de fungos micorrízicos arbusculares (FMA, Glomales, Zygomycota, coletou-se amostras de solo rizosférico de plantas instaladas em três áreas (plantio de eucaliptos, mata e transição entre ambas em três épocas (março/1996, época chuvosa e final de verão; junho/1996, época de inverno; janeiro/1997, início das chuvas e do verão na Ilha dos Eucaliptos (cerca de 323.500m², na Represa do Guarapiranga, São Paulo, SP. O solo foi processado para a separação dos esporos de FMA segundo a técnica do peneiramento e decantação em via úmida, seguindo-se centrifugação em solução de sacarose 50% (V:V. Os esporos isolados foram preparados em lâminas permanentes com resina PVL. Foram constatados 21 táxons de FMA: Acaulospora excávala Ingleby, Walker & Mason, Acaulospora foveata Trappe & Janos, Acaulospora longula Spain & Schenck, Acaulospora mellea Spain & Schenck, Acaulospora morrowiae Spain & Schenck, Acaulospora spinosa Walker & Trappe, Acaulospora sp. 1, Acaulospora sp. 2, Acaulospora sp. 3, Acaulospora sp. 4, Entrophospora colombiana Spain & Schenck, Gigaspora gigantea Nicol. & Gerd., Gigaspora ramisporopfwra Spain, Sieverding & Schenck, Glomus aggregatum (Schenck & Smith Koske, Glomus etunicatum Becker & Gerd., Glomus geosporum (Nicol. & Gerd. Walker, Glomus invennayum Hall, Glomus macrocarpum Tul. & Tui., Glomus multisubstensum Mukerjii, Bhattacharjee & Tewari, Scutellospora aff. biornata Spain, Sieverding & Toro e Scutellospora erythropa Koske & Walker. A aplicação do índice de similaridade de Sõrensen entre populações de FMA nas diferentes áreas e as épocas de coletas mostrou valores de 64 a 90%, sugerindo não haver seleção dos FMA mediada por esses fatores.With the aim of verifying the occurence of arbuscular mycorrhizal fungi AMF, Glomales, Zygomycota, rhizosphere soil samples were collected in three areas (eucaliptus reforestation, forest and intersection and on three

  4. Association of balance, strength, and power measures in young adults.

    Science.gov (United States)

    Muehlbauer, Thomas; Gollhofer, Albert; Granacher, Urs

    2013-03-01

    The purpose of this study was to investigate the relationship between variables of static/dynamic balance, isometric strength, and power. Twenty-seven young healthy adults (mean age: 23 ± 4 years) performed measurements of static (unperturbed)/dynamic (perturbed) balance, isometric strength (i.e., maximal isometric torque [MIT]; rate of torque development [RTD] of the plantar flexor), and power (i.e., countermovement jump [CMJ] height and power). No significant associations were found between variables of static and dynamic balance (r = -0.090 to +0.329, p > 0.05) and between measures of static/dynamic balance and isometric strength (r = +0.041 to +0.387, p > 0.05) and static/dynamic balance and power (r = -0.076 to +0.218, p > 0.05). Significant positive correlations (r) were detected between variables of power and isometric strength ranging from +0.458 to +0.689 (p balance measures and between static/dynamic balance, isometric strength, and power variables implies that these capacities may be independent of each other and may have to be tested and trained complementarily.

  5. Balance Performance Is Task Specific in Older Adults

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    Ayelet Dunsky

    2017-01-01

    Full Text Available Balance ability among the elderly is a key component in the activities of daily living and is divided into two types: static and dynamic. For clinicians who wish to assess the risk of falling among their elderly patients, it is unclear if more than one type of balance test can be used to measure their balance impairment. In this study, we examined the association between static balance measures and two dynamic balance field tests. One hundred and twelve community-dwelling older adults (mean age 74.6 participated in the study. They underwent the Tetrax static postural assessment and then performed the Timed Up and Go (TUG and the Functional Reach (FR Test as dynamic balance tests. In general, low-moderate correlations were found between the two types of balance tests. For women, age and static balance parameters explained 28.1–40.4% of the variance of TUG scores and 14.6–24% of the variance of FR scores. For men, age and static balance parameters explained 9.5–31.2% of the variance of TUG scores and 23.9–41.7% of the variance of FR scores. Based on our findings, it is suggested that a combination of both static and dynamic tests be used for assessing postural balance ability.

  6. Balancing low mass and low inertia addition

    NARCIS (Netherlands)

    van der Wijk, V.

    2009-01-01

    To increase the accuracy as well the production speed of industrial machines, dynamic balance is becoming a key issue. Instead of applying complicated control strategies to reduce machine vibrations, and damping systems to suppress vibrations, in dynamic balancing the mechanism parts are considered

  7. Modifying a dynamic global vegetation model for simulating large spatial scale land surface water balance

    Science.gov (United States)

    Tang, G.; Bartlein, P. J.

    2012-01-01

    Water balance models of simple structure are easier to grasp and more clearly connect cause and effect than models of complex structure. Such models are essential for studying large spatial scale land surface water balance in the context of climate and land cover change, both natural and anthropogenic. This study aims to (i) develop a large spatial scale water balance model by modifying a dynamic global vegetation model (DGVM), and (ii) test the model's performance in simulating actual evapotranspiration (ET), soil moisture and surface runoff for the coterminous United States (US). Toward these ends, we first introduced development of the "LPJ-Hydrology" (LH) model by incorporating satellite-based land covers into the Lund-Potsdam-Jena (LPJ) DGVM instead of dynamically simulating them. We then ran LH using historical (1982-2006) climate data and satellite-based land covers at 2.5 arc-min grid cells. The simulated ET, soil moisture and surface runoff were compared to existing sets of observed or simulated data for the US. The results indicated that LH captures well the variation of monthly actual ET (R2 = 0.61, p 0.46, p 0.52) with observed values over the years 1982-2006, respectively. The modeled spatial patterns of annual ET and surface runoff are in accordance with previously published data. Compared to its predecessor, LH simulates better monthly stream flow in winter and early spring by incorporating effects of solar radiation on snowmelt. Overall, this study proves the feasibility of incorporating satellite-based land-covers into a DGVM for simulating large spatial scale land surface water balance. LH developed in this study should be a useful tool for studying effects of climate and land cover change on land surface hydrology at large spatial scales.

  8. Collective circular motion in synchronized and balanced formations with second-order rotational dynamics

    Science.gov (United States)

    Jain, Anoop; Ghose, Debasish

    2018-01-01

    This paper considers collective circular motion of multi-agent systems in which all the agents are required to traverse different circles or a common circle at a prescribed angular velocity. It is required to achieve these collective motions with the heading angles of the agents synchronized or balanced. In synchronization, the agents and their centroid have a common velocity direction, while in balancing, the movement of agents causes the location of the centroid to become stationary. The agents are initially considered to move at unit speed around individual circles at different angular velocities. It is assumed that the agents are subjected to limited communication constraints, and exchange relative information according to a time-invariant undirected graph. We present suitable feedback control laws for each of these motion coordination tasks by considering a second-order rotational dynamics of the agent. Simulations are given to illustrate the theoretical findings.

  9. Modelling system dynamics and phytoplankton diversity at Ranchi lake using the carbon and nutrient mass balance equations.

    Science.gov (United States)

    Mukherjee, B; Nivedita, M; Mukherjee, D

    2014-05-01

    Modelling system dynamics in a hyper-eutrophic lake is quite complex especially with a constant influx of detergents and sewage material which continually changes the state variables and interferes with the assessment of the chemical rhythm occurring in polluted conditions as compared to unpolluted systems. In this paper, a carbon and nutrient mass balance model for predicting system dynamics in a complex environment was studied. Studies were conducted at Ranchi lake to understand the altered environmental dynamics in hyper-eutrophic conditions, and its impact on the plankton community. The lake was monitored regularly for five years (2007 - 2011) and the data collected on the carbon flux, nitrates, phosphates and silicates was used to design a mass balance model for evaluating and predicting the system. The model was then used to correlate the chemical rhythm with that of the phytoplankton dynamics and diversity. Nitrates and phosphates were not limiting (mean nitrate and phosphate concentrations were 1.74 and 0.83 mgl⁻¹ respectively). Free carbon dioxide was found to control the system and, interacting with other parameters determined the diversity and dynamics of the plankton community. N/P ratio determined which group of phytoplankton dominated the community, above 5 it favoured the growth of chlorophyceae while below 5 cyanobacteria dominates. TOC/TIC ratio determined the abundance. The overall system was controlled by the availability of free carbon dioxide which served as a limiting factor.

  10. Wii Fit Balance Board Playing Improves Balance and Gait in Parkinson Disease

    Science.gov (United States)

    Mhatre, Priya V.; Vilares, Iris; Stibb, Stacy M.; Albert, Mark V.; Pickering, Laura; Marciniak, Christina M.; Kording, Konrad; Toledo, Santiago

    2014-01-01

    Objective To assess the effect of exercise training by using the Nintendo Wii Fit video game and balance board system on balance and gait in adults with Parkinson disease (PD). Design A prospective interventional cohort study. Setting An outpatient group exercise class. Participants Ten subjects with PD, Hoehn and Yahr stages 2.5 or 3, with a mean age of 67.1 years; 4 men, 6 women. Interventions The subjects participated in supervised group exercise sessions 3 times per week for 8 weeks by practicing 3 different Wii balance board games (marble tracking, skiing, and bubble rafting) adjusted for their individualized function level. The subjects trained for 10 minutes per game, a total of 30 minutes training per session. Main Outcome Measurements Pre-and postexercise training, a physical therapist evaluated subjects’ function by using the Berg Balance Scale, Dynamic Gait Index, and Sharpened Romberg with eyes open and closed. Postural sway was assessed at rest and with tracking tasks by using the Wii balance board. The subjects rated their confidence in balance by using the Activities-specific Balance Confidence scale and depression on the Geriatric Depression Scale. Results Balance as measured by the Berg Balance Scale improved significantly, with an increase of 3.3 points (P = .016). The Dynamic Gait Index improved as well (mean increase, 2.8; P = .004), as did postural sway measured with the balance board (decreased variance in stance with eyes open by 31%; P = .049). Although the Sharpened Romberg with eyes closed increased by 6.85 points and with eyes opened by 3.3 points, improvements neared significance only for eyes closed (P = .07 versus P = .188). There were no significant changes on patient ratings for the Activities-specific Balance Confidence (mean decrease, −1%; P = .922) or the Geriatric Depression Scale (mean increase, 2.2; P = .188). Conclusions An 8-week exercise training class by using the Wii Fit balance board improved selective measures of

  11. Specific balance training included in an endurance-resistance exercise program improves postural balance in elderly patients undergoing haemodialysis.

    Science.gov (United States)

    Frih, Bechir; Mkacher, Wajdi; Jaafar, Hamdi; Frih, Ameur; Ben Salah, Zohra; El May, Mezry; Hammami, Mohamed

    2018-04-01

    The purpose of this study was to evaluate the effects of 6 months of specific balance training included in endurance-resistance program on postural balance in haemodialysis (HD) patients. Forty-nine male patients undergoing HD were randomly assigned to an intervention group (balance training included in an endurance-resistance training, n = 26) or a control group (resistance-endurance training only, n = 23). Postural control was assessed using six clinical tests; Timed Up and Go test, Tinetti Mobility Test, Berg Balance Scale, Unipodal Stance test, Mini-Balance Evaluation Systems Test and Activities Balance Confidence scale. All balance measures increased significantly after the period of rehabilitation training in the intervention group. Only the Timed Up and Go, Berg Balance Scale, Mini-Balance Evaluation Systems Test and Activities Balance Confidence scores were improved in the control group. The ranges of change in these tests were greater in the balance training group. In HD patients, specific balance training included in a usual endurance-resistance training program improves static and dynamic balance better than endurance-resistance training only. Implications for rehabilitation Rehabilitation using exercise in haemodialysis patients improved global mobility and functional abilities. Specific balance training included in usual endurance resistance training program could lead to improved static and dynamic balance.

  12. Dynamic Energy Balance: An Integrated Framework for Discussing Diet and Physical Activity in Obesity Prevention-Is it More than Eating Less and Exercising More?

    Science.gov (United States)

    Manore, Melinda M; Larson-Meyer, D Enette; Lindsay, Anne R; Hongu, Nobuko; Houtkooper, Linda

    2017-08-19

    Understanding the dynamic nature of energy balance, and the interrelated and synergistic roles of diet and physical activity (PA) on body weight, will enable nutrition educators to be more effective in implementing obesity prevention education. Although most educators recognize that diet and PA are important for weight management, they may not fully understand their impact on energy flux and how diet alters energy expenditure and energy expenditure alters diet. Many nutrition educators have little training in exercise science; thus, they may not have the knowledge essential to understanding the benefits of PA for health or weight management beyond burning calories. This paper highlights the importance of advancing nutrition educators' understanding about PA, and its synergistic role with diet, and the value of incorporating a dynamic energy balance approach into obesity-prevention programs. Five key points are highlighted: (1) the concept of dynamic vs. static energy balance; (2) the role of PA in weight management; (3) the role of PA in appetite regulation; (4) the concept of energy flux; and (5) the integration of dynamic energy balance into obesity prevention programs. The rationale for the importance of understanding the physiological relationship between PA and diet for effective obesity prevention programming is also reviewed.

  13. The Effect of Teeth Clenching on Dynamic Balance at Jump-Landing: A Pilot Study.

    Science.gov (United States)

    Nakamura, Tomomasa; Yoshida, Yuriko; Churei, Hiroshi; Aizawa, Junya; Hirohata, Kenji; Ohmi, Takehiro; Ohji, Shunsuke; Takahashi, Toshiyuki; Enomoto, Mitsuhiro; Ueno, Toshiaki; Yagishita, Kazuyoshi

    2017-07-01

    The aim of this study was to analyze the effect of teeth clenching on dynamic balance at jump landing. Twenty-five healthy subjects performed jump-landing tasks with or without teeth clenching. The first 3 trials were performed with no instruction; subsequently, subjects were ordered to clench at the time of landing in the following 3 trials. We collected the data of masseter muscle activity by electromyogram, the maximum vertical ground reaction force (vGRFmax) and center of pressure (CoP) parameters by force plate during jump-landing. According to the clenching status of control jump-landing, all participants were categorized into a spontaneous clenching group and no clenching group, and the CoP data were compared. The masseter muscle activity was correlated with vGRFmax during anterior jump-landing, while it was not correlated with CoP. In comparisons between the spontaneous clenching and the no clenching group during anterior jump-landing, the spontaneous clenching group showed harder landing and the CoP area became larger than the no clenching group. There were no significant differences between pre- and postintervention in both spontaneous clenching and no clenching groups. The effect of teeth clenching on dynamic balance during jump-landing was limited.

  14. The effect of shoe type on static and dynamic balance during treadmill walking in young healthy women.

    Science.gov (United States)

    Kim, Mi-Kyoung; Kong, Byung-Sun; Yoo, Kyung-Tae

    2017-09-01

    [Purpose] The purpose of this study was to analyze the effect of various shoes on the static and dynamic balance of young women in their 20s. [Subjects and Methods] The subjects of the study were 15 healthy young women and repeated measured design. The subjects walked on the treadmill at a speed of 4 km/h for 30 minutes wearing three types of shoes: sneaker, rain boots, and combat boots. Balance was measured by a Romberg test and a limits of stability test. One-way ANOVA was used for statistical analysis. [Results] As the results of the Romberg test, the main effect of time was shown in the EO-COG area, EO-COG length, and EO-COG velocity. As the results of the limits of stability test, the main effects of time in LT, RT, FW, and total. There were significant differences in the LT in the sneaker group, the rain boots group, and the LT and RT in the combat boots group between the pre- and post-test. [Conclusion] The characteristics of shoes such as the materials, hardness, and thickness of the soles, the coefficient of friction of the outsoles, and the collar height affected the static and dynamic balance.

  15. Influence of visual control, conduction, and central integration on static and dynamic balance in healthy older adults.

    Science.gov (United States)

    Perrin, P P; Jeandel, C; Perrin, C A; Béné, M C

    1997-01-01

    Aging is associated with decreased balance abilities, resulting in an increased risk of fall. In order to appreciate the visual, somatosensory, and central signals involved in balance control, sophisticated methods of posturography assessment have been developed, using static and dynamic tests, eventually associated with electromyographic measurements. We applied such methods to a population of healthy older adults in order to appreciate the respective importance of each of these sensorial inputs in aging individuals. Posture control parameters were recorded on a force-measuring platform in 41 healthy young (age 28.5 +/- 5.9 years) and 50 older (age 69.8 +/- 5.9 years) adults, using a static test and two dynamic tests performed by all individuals first with eyes open, then with eyes closed. The distance covered by the center of foot pressure, sway area, and anteroposterior oscillations were significantly higher, with eyes open or closed, in older people than in young subjects. Significant differences were noted in dynamic tests with longer latency responses in the group of old people. Dynamic recordings in a sinusoidal test had a more regular pattern when performed eyes open in both groups and evidenced significantly greater instability in old people. These data suggest that vision remains important in maintaining postural control while conduction and central integration become less efficient with age.

  16. Computerized dynamic posturography in the objective assessment of balance in patients with intermittent claudication.

    Science.gov (United States)

    Mockford, Katherine A; Mazari, Fayyaz A K; Jordan, Alastair R; Vanicek, Natalie; Chetter, Ian C; Coughlin, Patrick A

    2011-02-01

    One-third of all elderly patients fall each year and impaired balance has been recognized as a specific risk factor. Intermittent claudication is common among the elderly population, affecting approximately 5% of the population over the age of 50. The aim of this proof-of-concept study was to assess the prevalence of impaired balance among elderly claudicants and to assess each patient's insight into their own risk of falling. A total of 58 claudicants (45 men), median age of 70 (interquartile range = 65-73) years, underwent objective balance assessment by using computerized dynamic posturography. As compared with 195 (5%) historic controls, 24 (41%) of the claudicants demonstrated abnormal balance when the Sensory Organization Test (SOT) was used. Vestibular dysfunction occurred in 52% of the claudicants. Abnormalities including somatosensory (22%), visual function (17%), and preferential reliance on inaccurate visual cues (17%) occurred less often. Prolonged Motor Control Test latency times were uncommon (n = 13) and were in most cases evenly distributed between those with normal (n = 7) and abnormal (n = 6) composite SOT scores. There was a significant difference in history of falling between claudicants with abnormal and normal SOT scores (p = 0.003), with a higher number of patients with abnormal SOT having experienced falling in the past year. However, no correlation between fear of falling and composite SOT score was found (Spearman rank correlation, r = 0.124; p = 0.381). Impaired balance, particularly secondary to vestibular problems, is very common among claudicants and may predispose to a high incidence of falls. Claudicants with abnormal balance are more likely to have a history of falls but not a fear of falling, thus potentially rendering these patients to be at a greater risk. Copyright © 2011. Published by Elsevier Inc.

  17. DYMAC digital electronic balance

    International Nuclear Information System (INIS)

    Stephens, M.M.

    1980-06-01

    The Dynamic Materials Accountability (DYMAC) System at LASL integrates nondestructive assay (NDA) instruments with interactive data-processing equipment to provide near-real-time accountability of the nuclear material in the LASL Plutonium Processing Facility. The most widely used NDA instrument in the system is the DYMAC digital electronic balance. The DYMAC balance is a commercial instrument that has been modified at LASL for weighing material in gloveboxes and for transmitting the weight data directly to a central computer. This manual describes the balance components, details the LASL modifications, reviews a DYMAC measurement control program that monitors balance performance, and provides instructions for balance operation and maintenance

  18. Effect of 8-Week of Selected Aerobic Exercise on Static and Dynamic Balance in Healthy Elderly Inactive Men

    OpenAIRE

    Masoud Mirmoezzi; Mojtaba Amini; Asghar Khaledan; Davood Khorshidi

    2016-01-01

    Objectives: Old age refers to years near or passed the middle age and therefore, near to the end of life cycle. Old-aged people have limited reviving capability and are more at risk of catching diseases, syndromes, and ailments. Falling is one of the most common problems in the elderly that occur due to their inability to maintain balance. This study aimed to examine the effect of aerobic exercises on static and dynamic balance in healthy elderly inactive men. Methods &...

  19. Dynamic modelling of balance of plant systems for a pulsed DEMO power plant

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, C., E-mail: Chris.Harrington@ccfe.ac.uk

    2015-10-15

    Highlights: • A fully dynamic model of the balance of plant systems for pulsed DEMO is presented. • An operating strategy for handling pulse/dwell transitions has been devised. • Operation of a water-cooled system without energy storage appears feasible. • Steam turbine cycling can be minimised if rotation speed is maintained. - Abstract: The current baseline concept for a European DEMO defines a pulsed reactor producing power for periods of 2–4 h at a time, interrupted by dwell periods of approximately half an hour, potentially leading to cyclic fatigue of the heat transfer system and power generation equipment. Thermal energy storage systems could mitigate pulsing issues; however, the requirements for such a system cannot be defined without first understanding the challenges for pulsed operation, while any system will simultaneously increase the cost and complexity of the balance of plant. This work therefore presents a dynamic model of the primary heat transfer system and associated steam plant for a water-cooled DEMO, without energy storage, capable of simulating pulsed plant operation. An operating regime is defined such that the primary coolant flows continuously throughout the dwell period while the secondary steam flow is reduced. Simulation results show minimised thermal and pressure transients in the primary circuit, and small thermally induced stresses on the steam turbine rotor. If the turbine can be kept spinning to also minimise mechanical cycling, pulsed operation of a water-cooled DEMO without thermal energy storage may be feasible.

  20. Wii Fit balance board playing improves balance and gait in Parkinson disease.

    Science.gov (United States)

    Mhatre, Priya V; Vilares, Iris; Stibb, Stacy M; Albert, Mark V; Pickering, Laura; Marciniak, Christina M; Kording, Konrad; Toledo, Santiago

    2013-09-01

    To assess the effect of exercise training by using the Nintendo Wii Fit video game and balance board system on balance and gait in adults with Parkinson disease (PD). A prospective interventional cohort study. An outpatient group exercise class. Ten subjects with PD, Hoehn and Yahr stages 2.5 or 3, with a mean age of 67.1 years; 4 men, 6 women. The subjects participated in supervised group exercise sessions 3 times per week for 8 weeks by practicing 3 different Wii balance board games (marble tracking, skiing, and bubble rafting) adjusted for their individualized function level. The subjects trained for 10 minutes per game, a total of 30 minutes training per session. Pre-and postexercise training, a physical therapist evaluated subjects' function by using the Berg Balance Scale, Dynamic Gait Index, and Sharpened Romberg with eyes open and closed. Postural sway was assessed at rest and with tracking tasks by using the Wii balance board. The subjects rated their confidence in balance by using the Activities-specific Balance Confidence scale and depression on the Geriatric Depression Scale. Balance as measured by the Berg Balance Scale improved significantly, with an increase of 3.3 points (P = .016). The Dynamic Gait Index improved as well (mean increase, 2.8; P = .004), as did postural sway measured with the balance board (decreased variance in stance with eyes open by 31%; P = .049). Although the Sharpened Romberg with eyes closed increased by 6.85 points and with eyes opened by 3.3 points, improvements neared significance only for eyes closed (P = .07 versus P = .188). There were no significant changes on patient ratings for the Activities-specific Balance Confidence (mean decrease, -1%; P = .922) or the Geriatric Depression Scale (mean increase, 2.2; P = .188). An 8-week exercise training class by using the Wii Fit balance board improved selective measures of balance and gait in adults with PD. However, no significant changes were seen in mood or

  1. Complexity and dynamics of switched human balance control during quiet standing.

    Science.gov (United States)

    Nema, Salam; Kowalczyk, Piotr; Loram, Ian

    2015-10-01

    In this paper, we use a combination of numerical simulations, time series analysis, and complexity measures to investigate the dynamics of switched systems with noise, which are often used as models of human balance control during quiet standing. We link the results with complexity measures found in experimental data of human sway motion during quiet standing. The control model ensuring balance, which we use, is based on an act-and-wait control concept, that is, a human controller is switched on when a certain sway angle is reached. Otherwise, there is no active control present. Given a time series data, we determine how does it look a typical pattern of control strategy in our model system. We detect the switched nonlinearity in the system using a frequency analysis method in the absence of noise. We also analyse the effect of time delay on the existence of limit cycles in the system in the absence of noise. We perform the entropy and detrended fluctuation analyses in view of linking the switchings (and the dead zone) with the occurrences of complexity in the model system in the presence of noise. Finally, we perform the entropy and detrended fluctuation analyses on experimental data and link the results with numerical findings in our model example.

  2. Effect of the Power Balance® hologram on balance, flexibility, strength and speed-coordination among university students

    Directory of Open Access Journals (Sweden)

    Rafael Merino Marban, Daniel Mayorga Vega, Emilio Fernández Rodríguez, Francisco José Santana Pérez, Oscar Romero Ramos

    2011-01-01

    Full Text Available Based on the body’s energy field, the inventors of Power Balance® have created a hologram that theoretically runs through frequencies that are in our natural environment. Its creators say that people may experience improve balance, strength, flexibility, endurance, concentration, coordination and recovery time, among others. The purpose of this research is to evaluate the effect of Power Balance® hologram on balance, flexibility, strength and speed-coordination in university students. A sample of 105 young volunteers’ physical education students (age 20.91 ± 3.36 years, mass 69.69 ± 11.35 kg, height 171.70 ± 8.07 cm was used. A between-group experimental design with double-blind control group was used to evaluate the possible effects of the Power Balance ® on the dynamic balance, flexibility, abdominal strength, endurance and speed-coordination measured with the Dynamic Balance Test, Sit and Reach, Sit-ups in 30 seconds and Race 10 x 5 m, respectively. A t of Student for independent and dependent samples was used to assess the potential effects between-group and intra-group, respectively. Power Balance®’s hologram produces no significant effects on the balance, flexibility, strength and speed-coordination among university students

  3. Zhong-Yong as Dynamic Balancing Between Yin-Yang Opposites

    DEFF Research Database (Denmark)

    Li, Xin

    2017-01-01

    Purpose The purpose of this paper is to comment on Peter Ping Li’s understanding of Zhong-Yong balancing, presented in his article titled “Global implications of the indigenous epistemological system from the East: How to apply Yin-Yang balancing to paradox management.” Seeing his understanding....... Originality/value This commentary contributes to the “West meets East” discourse by debunking Peter P. Li’s assertion that Yin-Yang balancing is superior as a solution to paradox management and his prescription that balancing between Yin-Yang opposites must be asymmetric. It also contributes to the Chinese...

  4. Effect of core strength training on dynamic balance and agility in adolescent badminton players.

    Science.gov (United States)

    Ozmen, Tarik; Aydogmus, Mert

    2016-07-01

    The aim of the present study was to investigate effect of core strength training (CST) on core endurance, dynamic balance and agility in adolescent badminton players. Twenty adolescent (age = 10.8 ± 0.3 years; height = 140.6 ± 4.4 cm, weight = 33.9 ± 5.8 kg) badminton players were randomly divided into two groups as training group (TG) and control (CG) group. All subjects were evaluated with Star Excursion Balance Test (SEBT), Illinois Agility Test, and the core endurance tests. The TG completed CST twice a week, for 6 weeks. There were significant increases in (p  0.05). The CST resulted in significant gains in directions of the SEBT and core endurances in adolescent badminton players, but not in agility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Effects of training and detraining on the static and dynamic balance in elderly fallers and non-fallers: a pilot study.

    Science.gov (United States)

    Toulotte, Claire; Thevenon, Andre; Fabre, Claudine

    2006-01-30

    The aim of this study was to evaluate the effects of training based on static and dynamic balance in single and dual task conditions in order to analyse the effects of detraining on static and dynamic balance in healthy elderly fallers and non-fallers. A group of 16 subjects were trained: eight fallers aged 71.1 +/- 5.0 years and eight non-fallers aged 68.4 +/- 4.5 years. The subjects were evaluated 3 months before the training period, 2 days before the training period, 2 days after the end of the training period and 3 months after the training period. All subjects performed a unipedal test with eyes open and eyes closed. Gait parameters were analysed under single-task and dual motor-task conditions. This study demonstrated a loss of physical capacities over 3 months for stride time, single support time for fallers in both conditions. Physical training significantly improves static and dynamic balance under single and dual task conditions. Lastly, after 3 months of detraining, a loss of the physical training effects were measured for fallers and non-fallers on the different walking parameters in the two conditions and on the unipedal tests. The absence of stimulation before the trained period shows a negative effect of ageing on walking and falls whereas training permits an improvement in static balance and the pattern of walking under single and dual task conditions, which could be due to an increase in muscular strength and a better division of attention. On the other hand, 3 months of detraining inhibited the effects of training, which showed the speed of the decline caused by 'natural' ageing.

  6. Analysis of static and dynamic balance in healthy elderly practitioners of Tai Chi Chuan versus ballroom dancing

    Directory of Open Access Journals (Sweden)

    Miguel Antônio Rahal

    2015-03-01

    Full Text Available OBJECTIVE: To determine whether Tai Chi Chuan or ballroom dancing promotes better performance with respect to postural balance, gait, and postural transfer among elderly people. METHODS: We evaluated 76 elderly individuals who were divided into two groups: the Tai Chi Chuan Group and the Dance Group. The subjects were tested using the NeuroCom Balance Master¯ force platform system with the following protocols: static balance tests (the Modified Clinical Tests of Sensory Interaction on Balance and Unilateral Stance and dynamic balance tests (the Walk Across Test and Sit-to-stand Transfer Test. RESULTS: In the Modified Clinical Test of Sensory Interaction on Balance, the Tai Chi Chuan Group presented a lower sway velocity on a firm surface with open and closed eyes, as well as on a foam surface with closed eyes. In the Modified Clinical Test of Sensory Interaction on Unilateral Stance, the Tai Chi Chuan Group presented a lower sway velocity with open eyes, whereas the Dance Group presented a lower sway velocity with closed eyes. In the Walk Across Test, the Tai Chi Chuan Group presented faster walking speeds than those of the Dance Group. In the Sit-to-stand Transfer Test, the Tai Chi Chuan Group presented shorter transfer times from the sitting to the standing position, with less sway in the final standing position. CONCLUSION: The elderly individuals who practiced Tai Chi Chuan had better bilateral balance with eyes open on both types of surfaces compared with the Dance Group. The Dance Group had better unilateral postural balance with eyes closed. The Tai Chi Chuan Group had faster walking speeds, shorter transfer times, and better postural balance in the final standing position during the Sit-to-stand Test.

  7. Effect of somatosensory and neurofeedback training on balance in older healthy adults: a preliminary investigation.

    Science.gov (United States)

    Azarpaikan, Atefeh; Taheri Torbati, Hamidreza

    2017-10-23

    The aim of this study was to assess the effectiveness of balance training with somatosensory and neurofeedback training on dynamic and static balance in healthy, elderly adults. The sample group consisted of 45 healthy adults randomly assigned to one of the three test groups: somatosensory, neurofeedback, and a control. Individualization of the balance program started with pre-tests for static and dynamic balances. Each group had 15- and 30-min training sessions. All groups were tested for static (postural stability) and dynamic balances (Berg Balance Scale) in acquisition and transfer tests (fall risk of stability and timed up and go). Improvements in static and dynamic balances were assessed by somatosensory and neurofeedback groups and then compared with the control group. Results indicated significant improvements in static and dynamic balances in both test groups in the acquisition test. Results revealed a significant improvement in the transfer test in the neurofeedback and somatosensory groups, in static and dynamic conditions, respectively. The findings suggest that these methods of balance training had a significant influence on balance. Both the methods are appropriate to prevent falling in adults. Neurofeedback training helped the participants to learn static balance, while somatosensory training was effective on dynamic balance learning. Further research is needed to assess the effects of longer and discontinuous stimulation with somatosensory and neurofeedback training on balance in elderly adults.

  8. Electrical Power Grid Delivery Dynamic Analysis: Using Prime Mover Engines to Balance Dynamic Wind Turbine Output

    Energy Technology Data Exchange (ETDEWEB)

    Diana K. Grauer; Michael E. Reed

    2011-11-01

    This paper presents an investigation into integrated wind + combustion engine high penetration electrical generation systems. Renewable generation systems are now a reality of electrical transmission. Unfortunately, many of these renewable energy supplies are stochastic and highly dynamic. Conversely, the existing national grid has been designed for steady state operation. The research team has developed an algorithm to investigate the feasibility and relative capability of a reciprocating internal combustion engine to directly integrate with wind generation in a tightly coupled Hybrid Energy System. Utilizing the Idaho National Laboratory developed Phoenix Model Integration Platform, the research team has coupled demand data with wind turbine generation data and the Aspen Custom Modeler reciprocating engine electrical generator model to investigate the capability of reciprocating engine electrical generation to balance stochastic renewable energy.

  9. The NIST Step Class Library (Step Into the Future)

    Science.gov (United States)

    1990-09-01

    Figure 6. Excerpt from a STEP exclange file based on the Geometry model 1be NIST STEP Class Libary Page 13 An issue of concern in this...Scheifler, R., Gettys, J., and Newman, P., X Window System: C Library and Protocol Reference. Digital Press, Bedford, Mass, 1988. [Schenck90] Schenck, D

  10. Balancing High-Speed Rotors at Low Speed

    Science.gov (United States)

    Giordano, J.; Zorzi, E.

    1986-01-01

    Flexible balancing reduces vibrations at operating speeds. Highspeed rotors in turbomachines dynamically balanced at fraction of operating rotor speed. New method takes into account rotor flexible rather than rigid.

  11. Detailed balance method for chemical potential determination in Monte Carlo and molecular dynamics simulations

    International Nuclear Information System (INIS)

    Fay, P.J.; Ray, J.R.; Wolf, R.J.

    1994-01-01

    We present a new, nondestructive, method for determining chemical potentials in Monte Carlo and molecular dynamics simulations. The method estimates a value for the chemical potential such that one has a balance between fictitious successful creation and destruction trials in which the Monte Carlo method is used to determine success or failure of the creation/destruction attempts; we thus call the method a detailed balance method. The method allows one to obtain estimates of the chemical potential for a given species in any closed ensemble simulation; the closed ensemble is paired with a ''natural'' open ensemble for the purpose of obtaining creation and destruction probabilities. We present results for the Lennard-Jones system and also for an embedded atom model of liquid palladium, and compare to previous results in the literature for these two systems. We are able to obtain an accurate estimate of the chemical potential for the Lennard-Jones system at higher densities than reported in the literature

  12. Effects of zonal flows on correlation between energy balance and energy conservation associated with nonlinear nonviscous atmospheric dynamics in a thin rotating spherical shell

    Science.gov (United States)

    Ibragimov, Ranis N.

    2018-03-01

    The nonlinear Euler equations are used to model two-dimensional atmosphere dynamics in a thin rotating spherical shell. The energy balance is deduced on the basis of two classes of functorially independent invariant solutions associated with the model. It it shown that the energy balance is exactly the conservation law for one class of the solutions whereas the second class of invariant solutions provides and asymptotic convergence of the energy balance to the conservation law.

  13. Subtle balance of tropoelastin molecular shape and flexibility regulates dynamics and hierarchical assembly.

    Science.gov (United States)

    Yeo, Giselle C; Tarakanova, Anna; Baldock, Clair; Wise, Steven G; Buehler, Markus J; Weiss, Anthony S

    2016-02-01

    The assembly of the tropoelastin monomer into elastin is vital for conferring elasticity on blood vessels, skin, and lungs. Tropoelastin has dual needs for flexibility and structure in self-assembly. We explore the structure-dynamics-function interplay, consider the duality of molecular order and disorder, and identify equally significant functional contributions by local and global structures. To study these organizational stratifications, we perturb a key hinge region by expressing an exon that is universally spliced out in human tropoelastins. We find a herniated nanostructure with a displaced C terminus and explain by molecular modeling that flexible helices are replaced with substantial β sheets. We see atypical higher-order cross-linking and inefficient assembly into discontinuous, thick elastic fibers. We explain this dysfunction by correlating local and global structural effects with changes in the molecule's assembly dynamics. This work has general implications for our understanding of elastomeric proteins, which balance disordered regions with defined structural modules at multiple scales for functional assembly.

  14. The Effects of Core Stabilization Exercise on Dynamic Balance and Gait Function in Stroke Patients

    OpenAIRE

    Chung, Eun-Jung; Kim, Jung-Hee; Lee, Byoung-Hee

    2013-01-01

    [Purpose] The purpose of this study was to determine the effects of core stabilization exercise on dynamic balance and gait function in stroke patients. [Subjects] The subjects were 16 stroke patients, who were randomly divided into two groups: a core stabilization exercise group of eight subjects and control group of eight subjects. [Methods] Subjects in both groups received general training five times per week. Subjects in the core stabilization exercise group practiced an additional core s...

  15. Nonlinear dynamics analysis of the human balance control subjected to physical and sensory perturbations.

    Science.gov (United States)

    Ashtiani, Mohammed N; Mahmood-Reza, Azghani

    2017-01-01

    Postural control after applying perturbation involves neural and muscular efforts to limit the center of mass (CoM) motion. Linear dynamical approaches may not unveil all complexities of body efforts. This study was aimed at determining two nonlinear dynamics parameters (fractal dimension (FD) and largest Lyapunov exponent (LLE)) in addition to the linear standing metrics of balance in perturbed stance. Sixteen healthy young males were subjected to sudden rotations of the standing platform. The vision and cognition during the standing were also interfered. Motion capturing was used to measure the lower limb joints and the CoM displacements. The CoM path length as a linear parameter was increased by elimination of vision (pnonlinear metric FD was decreased due to the cognitive loads (pnonlinear metrics of the perturbed stance showed that a combination of them may properly represent the body behavior.

  16. Soil Water Balance and Vegetation Dynamics in two Water-limited Mediterranean Ecosystem on Sardinia under past and future climate change

    Science.gov (United States)

    Corona, R.; Montaldo, N.; Albertson, J. D.

    2016-12-01

    Water limited conditions strongly impacts soil and vegetation dynamics in Mediterranean regions, which are commonly heterogeneous ecosystems, characterized by inter-annual rainfall variability, topography variability and contrasting plant functional types (PFTs) competing for water use. Historical human influences (e.g., deforestation, urbanization) further altered these ecosystems. Sardinia island is a representative region of Mediterranean ecosystems. It is low urbanized except some plan areas close to the main cities where main agricultural activities are concentrated. Two contrasting case study sites are within the Flumendosa river basin (1700 km2). The first site is a typical grassland on an alluvial plan valley (soil depth > 2m) while the second is a patchy mixture of Mediterranean vegetation species (mainly wild olive trees and C3 herbaceous) that grow in a soil bounded from below by a rocky layer of basalt, partially fractured (soil depth 15 - 40 cm). In both sites land-surface fluxes and CO2 fluxes are estimated by the eddy correlation technique while soil moisture was continuously estimated with water content reflectometers, and periodically leaf area index (LAI) was estimated. The following objectives are addressed:1) pointing out the dynamics of land surface fluxes, soil moisture, CO2 and vegetation cover for two contrasting water-limited ecosystems; 2) assess the impact of the soil depth and type on the CO2 and water balance dynamics; 3) evaluate the impact of past and future climate change scenarios on the two contrasting ecosystems. For reaching the objectives an ecohydrologic model that couples a vegetation dynamic model (VDM), and a 3-component (bare soil, grass and woody vegetation) land surface model (LSM) has been used. Historical meteorological data are available from 1922 and hydro-meteorological scenarios are then generated using a weather generator. The VDM-LSM model predict soil water balance and vegetation dynamics for the generated

  17. Long-term follow-up of a randomized controlled trial on additional core stability exercises training for improving dynamic sitting balance and trunk control in stroke patients.

    Science.gov (United States)

    Cabanas-Valdés, Rosa; Bagur-Calafat, Caritat; Girabent-Farrés, Montserrat; Caballero-Gómez, Fernanda Mª; du Port de Pontcharra-Serra, Helena; German-Romero, Ana; Urrútia, Gerard

    2017-11-01

    Analyse the effect of core stability exercises in addition to conventional physiotherapy training three months after the intervention ended. A randomized controlled trial. Outpatient services. Seventy-nine stroke survivors. In the intervention period, both groups underwent conventional physiotherapy performed five days/week for five weeks, and in addition the experimental group performed core stability exercises for 15 minutes/day. Afterwards, during a three-month follow-up period, both groups underwent usual care that could eventually include conventional physiotherapy or physical exercise but not in a controlled condition. Primary outcome was trunk control and dynamic sitting balance assessed by the Spanish-Version of Trunk Impairment Scale 2.0 and Function in Sitting Test. Secondary outcomes were standing balance and gait evaluated by the Berg Balance Scale, Tinetti Test, Brunel Balance Assessment, Spanish-Version of Postural Assessment Scale for Stroke and activities of daily living using the Barthel Index. A total of 68 subjects out of 79 completed the three-month follow-up period. The mean difference (SD) between groups was 0.78 (1.51) points ( p = 0.003) for total score on the Spanish-Version of Trunk Impairment Scale 2.0, 2.52 (6.46) points ( p = 0.009) for Function in Sitting Test, dynamic standing balance was 3.30 (9.21) points ( p= 0.009) on the Berg Balance Scale, gait was 0.82 (1.88) points ( p = 0.002) by Brunel Balance Assessment (stepping), and 1.11 (2.94) points ( p = 0.044) by Tinetti Test (gait), all in favour of core stability exercises. Core stability exercises plus conventional physiotherapy have a positive long-term effect on improving dynamic sitting and standing balance and gait in post-stroke patients.

  18. Effect of arbuscular mycorrhizal fungal inoculation on growth, and ...

    African Journals Online (AJOL)

    The aim of our work was to assess the effect of inoculation with three arbuscular mycorrhizal fungi (AMF) (Rhizoglomus aggregatum (N.C. Schenck and G.S. Sm.) Sieverd., G.A. Silva and Oeh., Funneliformis mosseae (T.H. Nicolson and Gerd.) C. Walker and A. Schüssler. and Rhizoglomus intraradices (N.C. Schenck and ...

  19. The effect of 6 weeks of Tai chi training on cognitive status, dynamic balance and quality of life in women with stroke

    Directory of Open Access Journals (Sweden)

    Manijeh Norouzian

    2017-03-01

    Full Text Available Background and Objectives: Stroke can lead to permanent disabilities, including motor and cognitive impairments. The aim of this study was to determine the effect of Tai Chi training on cognitive status, dynamic balance, and quality of life in women with stroke. Methods: In this quasi-experimental study, 20 women with stroke (mean age, 65.8±3.5 years; weight, 68.4±14kg; and body mass index, 26.3±5.1kg/m2 in Qom city, were selected voluntarily and randomly divided into experimental (N=10 and control (N=10 groups. Cognitive status, dynamic balance, and quality of life were assessed by Mini-Mental State Examination (MMSE and SF-36 quality of life questionnaires and Timed Up and Go test. Tai Chi group trained for 6 weeks, three 60-minute sessions per week (a 10-minute warm-up period, a 40-minute simplified Tai Chi exercise, and a 10-minute cool-down period. Data were analyzed using dependent and independent t-tests and (p0.05. Conclusion: According to de results of the study, it can be said that Tai Chi training as a low-intensity and simple training improves dynamic balance and quality of life in women with stroke.

  20. Tai Chi and balance control.

    Science.gov (United States)

    Wong, Alice M K; Lan, Ching

    2008-01-01

    Balance function begins to decline from middle age on, and poor balance function increases the risk of fall and injury. Suitable exercise training may improve balance function and prevent accidental falls. The coordination of visual, proprioceptive, vestibular and musculoskeletal system is important to maintain balance. Balance function can be evaluated by functional balance testing and sensory organization testing. Tai Chi Chuan (TC) is a popular conditioning exercise in the Chinese community, and recent studies substantiate that TC is effective in balance function enhancement and falls prevention. In studies utilizing functional balance testing, TC may increase the duration of one-leg standing and the distance of functional reach. In studies utilizing sensory organization testing, TC improves static and dynamic balance, especially in more challenging sensory perturbed condition. Therefore, TC may be prescribed as an alternative exercise program for elderly subjects or balance-impaired patients. Participants can choose to perform a complete set of TC or selected movements according to their needs. In conclusion, TC may improve balance function and is appropriate for implementation in the community.

  1. Load Balancing of Parallel Monte Carlo Transport Calculations

    International Nuclear Information System (INIS)

    Procassini, R J; O'Brien, M J; Taylor, J M

    2005-01-01

    The performance of parallel Monte Carlo transport calculations which use both spatial and particle parallelism is increased by dynamically assigning processors to the most worked domains. Since he particle work load varies over the course of the simulation, this algorithm determines each cycle if dynamic load balancing would speed up the calculation. If load balancing is required, a small number of particle communications are initiated in order to achieve load balance. This method has decreased the parallel run time by more than a factor of three for certain criticality calculations

  2. Effects of core instability strength training on trunk muscle strength, spinal mobility, dynamic balance and functional mobility in older adults.

    Science.gov (United States)

    Granacher, Urs; Lacroix, Andre; Muehlbauer, Thomas; Roettger, Katrin; Gollhofer, Albert

    2013-01-01

    Age-related postural misalignment, balance deficits and strength/power losses are associated with impaired functional mobility and an increased risk of falling in seniors. Core instability strength training (CIT) involves exercises that are challenging for both trunk muscles and postural control and may thus have the potential to induce benefits in trunk muscle strength, spinal mobility and balance performance. The objective was to investigate the effects of CIT on measures of trunk muscle strength, spinal mobility, dynamic balance and functional mobility in seniors. Thirty-two older adults were randomly assigned to an intervention group (INT; n = 16, aged 70.8 ± 4.1 years) that conducted a 9-week progressive CIT or to a control group (n = 16, aged 70.2 ± 4.5 years). Maximal isometric strength of the trunk flexors/extensors/lateral flexors (right, left)/rotators (right, left) as well as of spinal mobility in the sagittal and the coronal plane was measured before and after the intervention program. Dynamic balance (i.e. walking 10 m on an optoelectric walkway, the Functional Reach test) and functional mobility (Timed Up and Go test) were additionally tested. Program compliance was excellent with participants of the INT group completing 92% of the training sessions. Significant group × test interactions were found for the maximal isometric strength of the trunk flexors (34%, p training-related improvements were found for spinal mobility in the sagittal (11%, p velocity (9%, p velocity (31%, p training regimen could be used as an adjunct or even alternative to traditional balance and/or resistance training. Copyright © 2012 S. Karger AG, Basel.

  3. Influence of neural mobilization of lower limbs on the functional performance and dynamic balance in asymptomatic individuals: a cross-over randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Nunes Guilherme S.

    2017-12-01

    Full Text Available Purpose. To verify the influence of neural mobilization (NM applied to the lower limbs on functional performance and dynamic balance in asymptomatic individuals. Methods. The total of 30 asymptomatic participants (15 women and 15 men; age, 30.1 ± 6.7 years; height, 1.70 ± 0.1 m; body mass, 73.1 ± 13.4 kg were enrolled in this cross-over randomized controlled trial. The participants received NM of the femoral, sciatic, and tibial nerves, as well as static stretching (SS of the following muscles: hamstring, lumbar, piriformis, hip adductors, hip flexors, quadriceps, and triceps surae. The order of applying NM and SS was randomly decided and the interventions were performed at least 48 hours apart. Functional performance was measured by performance in vertical jump (VJ and dynamic balance was measured with the Star Excursion Balance Test (SEBT. Results. There were no differences between NM and SS for height (cm in VJ (p = 0.16 or in the distance reached (% in the SEBT, normalized by lower limb length (dominant limb: anterior, p = 0.35; posterolateral, p = 0.69; posteromedial, p = 0.50 / non-dominant limb: anterior, p = 0.68; posterolateral, p = 1.00; posteromedial, p = 0.77. Conclusions. NM did not exert any influence on functional performance or dynamic balance. Thereby, having no positive or negative impact on performance, NM can be used at any time of treatment.

  4. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, Søren

    This paper focuses on the leadership challenge of balancing trust and control. The relation between trust and control has for a long time been a puzzling issue for management researchers. In the paper I first show that there has been a dramatic change in the way the relation between trust...... and control has been conceptualized in trust research. While the relation between trust and control earlier was conceptualized as a more or less stable balance between trust and control, more recent research conceptualizes the relation between trust and control more as a dynamical process that involves...... an ongoing process of balancing the relation between trust and control. Second, taking the departure in the recent conceptualization of the balance between trust and control as an interactive process I discuss the challenges for management in handling this more subtle balancing of trust and control...

  5. Dynamic Analysis of Electrical Power Grid Delivery: Using Prime Mover Engines to Balance Dynamic Wind Turbine Output

    Energy Technology Data Exchange (ETDEWEB)

    Diana K. Grauer

    2011-10-01

    This paper presents an investigation into integrated wind + combustion engine high penetration electrical generation systems. Renewable generation systems are now a reality of electrical transmission. Unfortunately, many of these renewable energy supplies are stochastic and highly dynamic. Conversely, the existing national grid has been designed for steady state operation. The research team has developed an algorithm to investigate the feasibility and relative capability of a reciprocating internal combustion engine to directly integrate with wind generation in a tightly coupled Hybrid Energy System. Utilizing the Idaho National Laboratory developed Phoenix Model Integration Platform, the research team has coupled demand data with wind turbine generation data and the Aspen Custom Modeler reciprocating engine electrical generator model to investigate the capability of reciprocating engine electrical generation to balance stochastic renewable energy.

  6. 基于LabVIEW的现场动平衡测试系统的开发%Development of field dynamic balance testing system based on LabVIEW

    Institute of Scientific and Technical Information of China (English)

    粱召华; 李智

    2014-01-01

    In order to adapt to the needs of the rotor field dynamic balance and improve the testing accuracy,the field dy-namic balance testing system based on virtual instrument technology was developed,which uses correlation method to extract the amplitude and phase of the vibration signal accurately , and adopts single-side dynamic balance and double-side dynamic balance method based on influence coefficient method to do the dynamic balance experiment. Many rotor dynamic balance experi-ments on the multi-function rotor testing bench show that the unbalance vibration has been effectively suppressed and the vibra-tion amplitude has been reduced obviously after adding appropriate testing weight on the rotor. This has important significance for reducing machine noise and the bearing wear,and improving the performance and life of the machine. It is also helpful to im-prove the machine's work efficiency and to ensure the safety of machining operators.%为了适应转子现场动平衡的需要,提高测试精度,开发了基于虚拟仪器技术的现场动平衡测试系统,它利用相关法准确提取出振动信号的幅值和相位,采用基于影响系数法的单面动平衡和双面动平衡的方法进行动平衡实验。通过在多功能转子试验台上做了多次转子动平衡试验,实验结果表明:转子在加适当的试重后不平衡振动得到了有效的抑制,振动幅度明显减小。这对于减小机器噪声和轴承磨损,提高机器的性能和寿命有着重要意义,同时也有助于提高机器的工作效率和保障机械加工操作者的安全。

  7. Mass balance gradients and climatic change

    NARCIS (Netherlands)

    Oerlemans, J.; Hoogendoorn, N.C.

    1989-01-01

    It is generally assumed that the mass-balance gradient on glaciers is more or less conserved under climatic change. In studies of the dynamic response of glaciers to climatic change, one of the following assumptions is normally made: (i) the mass-balance perturbation is independent of altitude

  8. Linking Economic Value Added, Direct Costing, and the Lean Thinking to the Balanced Scorecard in a System Dynamics Modelling Approach

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    Review, July-August, 2007], provide evidence that companies fail to see the possible benefits of combining and integrating several accounting practices into a single framework. Design/methodology/approach - We use a System Dynamics Modelling approach to the BSC-thinking. The BSC model includes the five...... Purpose - To show how three practices normally applied separately can be linked to support the strategy evaluation and the performance measurement in the balanced scorecard. Recent studies, e.g. Kaplan and Norton [Using the Balanced Scorecard as a Strategic Management System, Harvard Business...

  9. Engineering redox balance through cofactor systems.

    Science.gov (United States)

    Chen, Xiulai; Li, Shubo; Liu, Liming

    2014-06-01

    Redox balance plays an important role in the production of enzymes, pharmaceuticals, and chemicals. To meet the demands of industrial production, it is desirable that microbes maintain a maximal carbon flux towards target metabolites with no fluctuations in redox. This requires functional cofactor systems that support dynamic homeostasis between different redox states or functional stability in a given redox state. Redox balance can be achieved by improving the self-balance of a cofactor system, regulating the substrate balance of a cofactor system, and engineering the synthetic balance of a cofactor system. This review summarizes how cofactor systems can be manipulated to improve redox balance in microbes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Expanding a dynamic flux balance model of yeast fermentation to genome-scale

    Science.gov (United States)

    2011-01-01

    Background Yeast is considered to be a workhorse of the biotechnology industry for the production of many value-added chemicals, alcoholic beverages and biofuels. Optimization of the fermentation is a challenging task that greatly benefits from dynamic models able to accurately describe and predict the fermentation profile and resulting products under different genetic and environmental conditions. In this article, we developed and validated a genome-scale dynamic flux balance model, using experimentally determined kinetic constraints. Results Appropriate equations for maintenance, biomass composition, anaerobic metabolism and nutrient uptake are key to improve model performance, especially for predicting glycerol and ethanol synthesis. Prediction profiles of synthesis and consumption of the main metabolites involved in alcoholic fermentation closely agreed with experimental data obtained from numerous lab and industrial fermentations under different environmental conditions. Finally, fermentation simulations of genetically engineered yeasts closely reproduced previously reported experimental results regarding final concentrations of the main fermentation products such as ethanol and glycerol. Conclusion A useful tool to describe, understand and predict metabolite production in batch yeast cultures was developed. The resulting model, if used wisely, could help to search for new metabolic engineering strategies to manage ethanol content in batch fermentations. PMID:21595919

  11. Heider balance in human networks

    Science.gov (United States)

    Gawroński, P.; Kułakowski, K.

    2005-07-01

    Recently, a continuous dynamics was proposed to simulate dynamics of interpersonal relations in a society represented by a fully connected graph. The final state of such a society was found to be identical with the so-called Heider balance (HB), where the society is divided into two mutually hostile groups. In the continuous model, a polarization of opinions was found in HB. Here we demonstrate that the polarization occurs also in Barabási-Albert networks, where the Heider balance is not necessarily present. In the second part of this work we demonstrate the results of our formalism, when applied to reference examples: the Southern women and the Zachary club.

  12. The The Effects of Cold Water Immersion on Anaerobic Power, Dynamic Balance and Muscle Activation After a karate kumite fighting in Female Karateka

    Directory of Open Access Journals (Sweden)

    Taher Afshar Nezhad

    2017-10-01

    Full Text Available Many athletes are using specific techniques to minimize fatigue and accelerate recovery processes. Cold water immersion (CWI is one of the most popular interventions used by athletes to potentially return to their pre-fatigue performance level. the purpose of this study was to investigate the effects of CWI on anaerobic performance, balance and muscle activation of female karateka after a simulated match. 15 young female karateka (age: 18.7±1.7 years, body mass: 55.5±6.3 kg, height:165±5.1 cm with at least three years' experience in karate kumite fighting were included in the study. After three round 3-minute competition, participants were grouped into a CWI group (20 min at 12±1°C and a control group (CTL. Anaerobic power (30 s Wingate test, and dynamic balance (Star-Excursion test were measured before the competition and 24 h after intervention. Surface electromyography (EMG was sampled from quadriceps femoris muscles. Peak normalized muscle activation levels and force were identified during maximal isometric test. A significant decrease in the anaerobic performance after the competition was observed for both groups (p<0.05. CWI were effective in enhancing the anaerobic performance after competition compared with the CTL. Dynamic balance decreased for two groups, although CWI resulted in the smallest reduction in balance. There was a significant difference in peak and mean RMS values of the EMG in Rectus Femoris but not Vastus muscles after the CWI intervention when compared to CTL (p<0.05. CWI improve recovery related to dynamic balance and anaerobic performance of karate kumite fighter. It can be concluded that CWI appears to promote muscle activation and reduce fatigue that is related to better performance in 24 hours post intervention.

  13. A new approach of the Star Excursion Balance Test to assess dynamic postural control in people complaining from chronic ankle instability.

    Science.gov (United States)

    Pionnier, Raphaël; Découfour, Nicolas; Barbier, Franck; Popineau, Christophe; Simoneau-Buessinger, Emilie

    2016-03-01

    The purpose of this study was to quantitatively and qualitatively assess dynamic balance with accuracy in individuals with chronic ankle instability (CAI). To this aim, a motion capture system was used while participants performed the Star Excursion Balance Test (SEBT). Reached distances for the 8 points of the star were automatically computed, thereby excluding any dependence to the experimenter. In addition, new relevant variables were also computed, such as absolute time needed to reach each distance, lower limb ranges of motion during unipodal stance, as well as absolute error of pointing. Velocity of the center of pressure and range of variation of ground reaction forces have also been assessed during the unipodal phase of the SEBT thanks to force plates. CAI group exhibited smaller reached distances and greater absolute error of pointing than the control group (p<0.05). Moreover, the ranges of motion of lower limbs joints, the velocity of the center of pressure and the range of variation of the ground reaction forces were all significantly smaller in the CAI group (p<0.05). These reduced quantitative and qualitative performances highlighted a lower dynamic postural control. The limited body movements and accelerations during the unipodal stance in the CAI group could highlight a protective strategy. The present findings could help clinicians to better understand the motor strategies used by CAI patients during dynamic balance and may guide the rehabilitation process. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. A Review of Postural Balance and its Related Factors in the Elderly

    Directory of Open Access Journals (Sweden)

    Masoumi Nasrin

    2015-01-01

    Full Text Available Objective: The slowing down of the nervous system function and changes in the musculoskeletal system (including joint changes and instability during old age have resulted in imbalance and lack of postural control becoming common problems during this age period. Using balancing tests and identifying those at risk can be an important step in the prevention of falls and its consequences in the elderly. The purpose of this study was to investigate the balance status of the elderly according to some demographic characteristics. Materials and Methods: In this descriptive cross-sectional study, 194 elderly retired from public institutions were selected using systematic random sampling method and studied. To gather information, tinetti gait and balance evaluation tests were performed which included 16 items in 2 sections of dynamic balance and static balance. After collecting the data, they were analyzed using SPSS software, and Kruskal-Wallis test, Mann-Whitney U test, and Spearman's rank correlation coefficient. Results: Results showed that regarding static balance, 82% of participants had natural balance and 18% had abnormal balance. Regarding dynamic balance, 95.4% of participants had natural balance and 4.6% had abnormal balance. Among the demographic characteristics (age, gender, and disease, age had a significant relationship with balance (dynamic and static. Moreover, a significant relationship was observed between dynamic balance and disease. Therefore, the possibility of imbalance in the elderly increased with age and history of a disease. Conclusion: Imbalance has been introduced as one of the most common risk factors for falls in the elderly. Therefore, using balance tests and identifying elderly with balance disorders, and using multilateral interventions (including balance rehabilitation programs, regular exercise programs, suitable living environment (safer furniture, installing rails and handles, and showers with no tub, and specialist

  15. Evaluation of static and dynamic balance in elderly women performing aquatic exercise and gymnastics DOI:10.5007/1980-0037.2010v12n1p55

    Directory of Open Access Journals (Sweden)

    Ana Paula Almeida

    2010-12-01

    Full Text Available This study evaluated static and dynamic balance and related motor valences in elderly women who had been undergone gymnastics or aquatic exercise training for at least 6 months, three times a week. Thirty-one women performed water gymnastics (mean age: 69.32 ± 6.57 years and 28 gymnastics (65.57 ± 7.67 years. Height (cm, weight (kg and waist, hip and abdominal circumference (cm were measured and the body mass index (BMI and waist-hip ratio (WHR were calculated. Physical fitness was measured using the “sit and get up in 30 seconds” test (leg endurance and “8-foot up-and-go” test (dynamic balance, both proposed by Rikli and Jones (1999, and the “sit and reach” (flexibility and static balance tests described by Caromano (1998. Statistical analysis was performed using the Student t-test and Pearson’s correlation, with a level of significance of 0.05. No significant difference in the anthropometric measures (BMI and WHR was observed between groups. In the physical fitness tests, significant differences were only found in the “8-foot up-and-go” and “sit and get up” tests, with the gymnastics group presenting better results. No correlations within or between groups were observed regarding static and dynamic balance or motor valences. In conclusion, neither type of exercise was superior but the gymnastics group tended to show better results in terms of parameters such as agility, balance and flexibility.

  16. Effects of virtual reality programs on balance in functional ankle instability.

    Science.gov (United States)

    Kim, Ki-Jong; Heo, Myoung

    2015-10-01

    [Purpose] The aim of present study was to identify the impact that recent virtual reality training programs used in a variety of fields have had on the ankle's static and dynamic senses of balance among subjects with functional ankle instability. [Subjects and Methods] This study randomly divided research subjects into two groups, a strengthening exercise group (Group I) and a balance exercise group (Group II), with each group consisting of 10 people. A virtual reality program was performed three times a week for four weeks. Exercises from the Nintendo Wii Fit Plus program were applied to each group for twenty minutes along with ten minutes of warming up and wrap-up exercises. [Results] Group II showed a significant decrease of post-intervention static and dynamic balance overall in the anterior-posterior, and mediolateral directions, compared with the pre-intervention test results. In comparison of post-intervention static and dynamic balance between Group I and Group II, a significant decrease was observed overall. [Conclusion] Virtual reality programs improved the static balance and dynamic balance of subjects with functional ankle instability. Virtual reality programs can be used more safely and efficiently if they are implemented under appropriate monitoring by a physiotherapist.

  17. Modeling the monthly mean soil-water balance with a statistical-dynamical ecohydrology model as coupled to a two-component canopy model

    Directory of Open Access Journals (Sweden)

    J. P. Kochendorfer

    2010-10-01

    Full Text Available The statistical-dynamical annual water balance model of Eagleson (1978 is a pioneering work in the analysis of climate, soil and vegetation interactions. This paper describes several enhancements and modifications to the model that improve its physical realism at the expense of its mathematical elegance and analytical tractability. In particular, the analytical solutions for the root zone fluxes are re-derived using separate potential rates of transpiration and bare-soil evaporation. Those potential rates, along with the rate of evaporation from canopy interception, are calculated using the two-component Shuttleworth-Wallace (1985 canopy model. In addition, the soil column is divided into two layers, with the upper layer representing the dynamic root zone. The resulting ability to account for changes in root-zone water storage allows for implementation at the monthly timescale. This new version of the Eagleson model is coined the Statistical-Dynamical Ecohydrology Model (SDEM. The ability of the SDEM to capture the seasonal dynamics of the local-scale soil-water balance is demonstrated for two grassland sites in the US Great Plains. Sensitivity of the results to variations in peak green leaf area index (LAI suggests that the mean peak green LAI is determined by some minimum in root zone soil moisture during the growing season. That minimum appears to be close to the soil matric potential at which the dominant grass species begins to experience water stress and well above the wilting point, thereby suggesting an ecological optimality hypothesis in which the need to avoid water-stress-induced leaf abscission is balanced by the maximization of carbon assimilation (and associated transpiration. Finally, analysis of the sensitivity of model-determined peak green LAI to soil texture shows that the coupled model is able to reproduce the so-called "inverse texture effect", which consists of the observation that natural vegetation in dry climates tends

  18. A dynamic human water and electrolyte balance model for verification and optimization of life support systems in space flight applications

    Science.gov (United States)

    Hager, P.; Czupalla, M.; Walter, U.

    2010-11-01

    In this paper we report on the development of a dynamic MATLAB SIMULINK® model for the water and electrolyte balance inside the human body. This model is part of an environmentally sensitive dynamic human model for the optimization and verification of environmental control and life support systems (ECLSS) in space flight applications. An ECLSS provides all vital supplies for supporting human life on board a spacecraft. As human space flight today focuses on medium- to long-term missions, the strategy in ECLSS is shifting to closed loop systems. For these systems the dynamic stability and function over long duration are essential. However, the only evaluation and rating methods for ECLSS up to now are either expensive trial and error breadboarding strategies or static and semi-dynamic simulations. In order to overcome this mismatch the Exploration Group at Technische Universität München (TUM) is developing a dynamic environmental simulation, the "Virtual Habitat" (V-HAB). The central element of this simulation is the dynamic and environmentally sensitive human model. The water subsystem simulation of the human model discussed in this paper is of vital importance for the efficiency of possible ECLSS optimizations, as an over- or under-scaled water subsystem would have an adverse effect on the overall mass budget. On the other hand water has a pivotal role in the human organism. Water accounts for about 60% of the total body mass and is educt and product of numerous metabolic reactions. It is a transport medium for solutes and, due to its high evaporation enthalpy, provides the most potent medium for heat load dissipation. In a system engineering approach the human water balance was worked out by simulating the human body's subsystems and their interactions. The body fluids were assumed to reside in three compartments: blood plasma, interstitial fluid and intracellular fluid. In addition, the active and passive transport of water and solutes between those

  19. Impact of different disassembly line balancing algorithms on the performance of dynamic kanban system for disassembly line

    Science.gov (United States)

    Kizilkaya, Elif A.; Gupta, Surendra M.

    2005-11-01

    In this paper, we compare the impact of different disassembly line balancing (DLB) algorithms on the performance of our recently introduced Dynamic Kanban System for Disassembly Line (DKSDL) to accommodate the vagaries of uncertainties associated with disassembly and remanufacturing processing. We consider a case study to illustrate the impact of various DLB algorithms on the DKSDL. The approach to the solution, scenario settings, results and the discussions of the results are included.

  20. A parallel 3D particle-in-cell code with dynamic load balancing

    International Nuclear Information System (INIS)

    Wolfheimer, Felix; Gjonaj, Erion; Weiland, Thomas

    2006-01-01

    A parallel 3D electrostatic Particle-In-Cell (PIC) code including an algorithm for modelling Space Charge Limited (SCL) emission [E. Gjonaj, T. Weiland, 3D-modeling of space-charge-limited electron emission. A charge conserving algorithm, Proceedings of the 11th Biennial IEEE Conference on Electromagnetic Field Computation, 2004] is presented. A domain decomposition technique based on orthogonal recursive bisection is used to parallelize the computation on a distributed memory environment of clustered workstations. For problems with a highly nonuniform and time dependent distribution of particles, e.g., bunch dynamics, a dynamic load balancing between the processes is needed to preserve the parallel performance. The algorithm for the detection of a load imbalance and the redistribution of the tasks among the processes is based on a weight function criterion, where the weight of a cell measures the computational load associated with it. The algorithm is studied with two examples. In the first example, multiple electron bunches as occurring in the S-DALINAC [A. Richter, Operational experience at the S-DALINAC, Proceedings of the Fifth European Particle Accelerator Conference, 1996] accelerator are simulated in the absence of space charge fields. In the second example, the SCL emission and electron trajectories in an electron gun are simulated

  1. A parallel 3D particle-in-cell code with dynamic load balancing

    Energy Technology Data Exchange (ETDEWEB)

    Wolfheimer, Felix [Technische Universitaet Darmstadt, Institut fuer Theorie Elektromagnetischer Felder, Schlossgartenstr.8, 64283 Darmstadt (Germany)]. E-mail: wolfheimer@temf.de; Gjonaj, Erion [Technische Universitaet Darmstadt, Institut fuer Theorie Elektromagnetischer Felder, Schlossgartenstr.8, 64283 Darmstadt (Germany); Weiland, Thomas [Technische Universitaet Darmstadt, Institut fuer Theorie Elektromagnetischer Felder, Schlossgartenstr.8, 64283 Darmstadt (Germany)

    2006-03-01

    A parallel 3D electrostatic Particle-In-Cell (PIC) code including an algorithm for modelling Space Charge Limited (SCL) emission [E. Gjonaj, T. Weiland, 3D-modeling of space-charge-limited electron emission. A charge conserving algorithm, Proceedings of the 11th Biennial IEEE Conference on Electromagnetic Field Computation, 2004] is presented. A domain decomposition technique based on orthogonal recursive bisection is used to parallelize the computation on a distributed memory environment of clustered workstations. For problems with a highly nonuniform and time dependent distribution of particles, e.g., bunch dynamics, a dynamic load balancing between the processes is needed to preserve the parallel performance. The algorithm for the detection of a load imbalance and the redistribution of the tasks among the processes is based on a weight function criterion, where the weight of a cell measures the computational load associated with it. The algorithm is studied with two examples. In the first example, multiple electron bunches as occurring in the S-DALINAC [A. Richter, Operational experience at the S-DALINAC, Proceedings of the Fifth European Particle Accelerator Conference, 1996] accelerator are simulated in the absence of space charge fields. In the second example, the SCL emission and electron trajectories in an electron gun are simulated.

  2. Balance, Proprioception, and Gross Motor Development of Chinese Children Aged 3 to 6 Years.

    Science.gov (United States)

    Jiang, Gui-Ping; Jiao, Xi-Bian; Wu, Sheng-Kou; Ji, Zhong-Qiu; Liu, Wei-Tong; Chen, Xi; Wang, Hui-Hui

    2018-01-01

    The authors' aim was to find the features of balance, proprioception, and gross motor development of Chinese children 3-6 years old and their correlations, provide theoretical support for promoting children's motor development, and enrich the world theoretical system of motor development. This study used a Tekscan foot pressure measurement instrument (Tekscan, Inc., Boston, MA), walking on a balance beam, Xsens 3-dimensional positional measuring system (Xsens Technologies, Enschede, the Netherlands), and Test of Gross Motor Development-2 to assess static balance, dynamic balance, knee proprioception, and levels of gross motor development (GMD) of 3- to 6-year-old children (n = 60) in Beijing. The results are as follows: children had significant age differences in static balance, dynamic balance, proprioception, and levels of GMD; children had significant gender differences in static balance, proprioception, and levels of GMD; children's static balance, dynamic balance, and proprioception had a very significant positive correlation with GMD (p < .01), but no significant correlation with body mass index.

  3. Mandibular position influence on pilots' postural balance analyzed under dynamic conditions.

    Science.gov (United States)

    Baldini, Alberto; Nota, Alessandro; Cioffi, Clementina; Ballanti, Fabiana; Tecco, Simona

    2017-11-01

    The aim of this study is to evaluate the influence of the mandibular position on the postural stability in a sample of civilian and military pilots. Twenty military pilots (males, mean age 35.15 ± 3.14 years) and 17 civilian pilots (males, mean 34.91 ± 2.15 years) were enrolled in this study and underwent a Sensory Organization Test (SOT) using the EquiTest® (NeuroCom International Inc., Clackamas, OR, USA) computerized dynamic posturography. The composite parameter was recorded and analyzed. The equilibrium score (ES) recorded in centric occlusion is slightly higher than the ES recorded in mandibular rest position; civilian pilots showed ESs slightly higher than military pilots. The two-way ANOVA analysis shows these differences are not statistically significant. The findings of this study seem to suggest that the composite parameter of the SOT is not sensitive in analyzing the influence of the stomatognathic system on the postural balance of civilian and military pilots.

  4. Ocorrência de Fungos Micorrízicos Arbusculares em resíduo da mineração de bauxita revegetado com espécies arbóreas Arbuscular mycorrhizal fungi occurrence in bauxite mining residue planted to tree species

    Directory of Open Access Journals (Sweden)

    Ana Lucy Caproni

    2007-03-01

    Full Text Available Avaliou-se a ocorrência de fungos micorrízicos arbusculares (FMAs em tanques contendo resíduo da mineração de bauxita cultivados com espécies arbóreas inoculadas com Glomus clarum Nicol. & Schenck e Gigaspora margarita Becker & Hall na fase de viveiro. Acacia holosericea A. Cunn. ex G. Don juntamente com Sesbania virgata (Cav. Pers. ou uma mistura de várias espécies foram transplantadas em tanques contendo resíduo de bauxita. Coletaram-se amostras de resíduos em agosto/1998 (estação seca e abril/1999 (estação chuvosa, extraíram e identificaram-se os esporos de FMAs. Determinaram-se a densidade dos esporos de FMAs, a densidade relativa, a freqüência de ocorrência de cada espécie por período de amostragem e o índice de abundância e freqüência (IAF. A densidade dos esporos e a diversidade das espécies de FMAs foram baixas sob ambas as coberturas. Um maior número de esporos de Glomus clarum, e alto IAF, foram detectados no substrato cultivado com Acacia holosericea e Sesbania virgata na época seca. Isto também ocorreu em ambas as áreas na época chuvosa. Não foram encontrados esporos de Gigaspora margarita em ambas as áreas, nas duas épocas. Independentemente da inoculação, verificaram-se esporos de Archeospora leptoticha (Schenck & Smith Morton & Redecker, Entrophospora colombiana Spain & Schenck, Acaulospora mellea Spain & Schenck e Glomus macrocarpum Tulasne & Tulasne em abundância.The establishment of arbuscular mycorrhizal fungi (AMF was evaluated in two areas of bauxite mining residue planted to tree species inoculated with Glomus clarum Nicol. & Schenck and Gigaspora margarita Becker & Hall in the nursery phase. Acacia holosericea A. Cunn. ex G. Don and Sesbania virgata (Cav. Pers. and a mixture of several tree species were transplanted to deposits of containing bauxite mining residue. In August, 1998 (dry season and April, 1999 (rainy season residue samples were collected and AMF spores extracted and

  5. Dynamic balancing of super-critical rotating structures using slow-speed data via parametric excitation

    Science.gov (United States)

    Tresser, Shachar; Dolev, Amit; Bucher, Izhak

    2018-02-01

    High-speed machinery is often designed to pass several "critical speeds", where vibration levels can be very high. To reduce vibrations, rotors usually undergo a mass balancing process, where the machine is rotated at its full speed range, during which the dynamic response near critical speeds can be measured. High sensitivity, which is required for a successful balancing process, is achieved near the critical speeds, where a single deflection mode shape becomes dominant, and is excited by the projection of the imbalance on it. The requirement to rotate the machine at high speeds is an obstacle in many cases, where it is impossible to perform measurements at high speeds, due to harsh conditions such as high temperatures and inaccessibility (e.g., jet engines). This paper proposes a novel balancing method of flexible rotors, which does not require the machine to be rotated at high speeds. With this method, the rotor is spun at low speeds, while subjecting it to a set of externally controlled forces. The external forces comprise a set of tuned, response dependent, parametric excitations, and nonlinear stiffness terms. The parametric excitation can isolate any desired mode, while keeping the response directly linked to the imbalance. A software controlled nonlinear stiffness term limits the response, hence preventing the rotor to become unstable. These forces warrant sufficient sensitivity required to detect the projection of the imbalance on any desired mode without rotating the machine at high speeds. Analytical, numerical and experimental results are shown to validate and demonstrate the method.

  6. Investigating ice cliff evolution and contribution to glacier mass-balance using a physically-based dynamic model

    Science.gov (United States)

    Buri, Pascal; Miles, Evan; Ragettli, Silvan; Brun, Fanny; Steiner, Jakob; Pellicciotti, Francesca

    2016-04-01

    Supraglacial cliffs are a surface feature typical of debris-covered glaciers, affecting surface evolution, glacier downwasting and mass balance by providing a direct ice-atmosphere interface. As a result, melt rates can be very high and ice cliffs may account for a significant portion of the total glacier mass loss. However, their contribution to glacier mass balance has rarely been quantified through physically-based models. Most cliff energy balance models are point scale models which calculate energy fluxes at individual cliff locations. Results from the only grid based model to date accurately reflect energy fluxes and cliff melt, but modelled backwasting patterns are in some cases unrealistic, as the distribution of melt rates would lead to progressive shallowing and disappearance of cliffs. Based on a unique multitemporal dataset of cliff topography and backwasting obtained from high-resolution terrestrial and aerial Structure-from-Motion analysis on Lirung Glacier in Nepal, it is apparent that cliffs exhibit a range of behaviours but most do not rapidly disappear. The patterns of evolution cannot be explained satisfactorily by atmospheric melt alone, and are moderated by the presence of supraglacial ponds at the base of cliffs and by cliff reburial with debris. Here, we document the distinct patterns of evolution including disappearance, growth and stability. We then use these observations to improve the grid-based energy balance model, implementing periodic updates of the cliff geometry resulting from modelled melt perpendicular to the ice surface. Based on a slope threshold, pixels can be reburied by debris or become debris-free. The effect of ponds are taken into account through enhanced melt rates in horizontal direction on pixels selected based on an algorithm considering distance to the water surface, slope and lake level. We use the dynamic model to first study the evolution of selected cliffs for which accurate, high resolution DEMs are available

  7. Developing a balanced scorecard with System Dynamics

    NARCIS (Netherlands)

    Akkermans, H.A.; Oorschot, van K.E.

    2002-01-01

    The Balanced Scorecard (BSC) is a popular concept for performance measurement, because it focuses attention of management on just a few measures and bridges different functional areas (both financial and non-financial measures are included in the BSC). But, the BSC has also received some criticism.

  8. Balance Systems and the Variational Bicomplex

    Directory of Open Access Journals (Sweden)

    Serge Preston

    2011-07-01

    Full Text Available In this work we show that the systems of balance equations (balance systems of continuum thermodynamics occupy a natural place in the variational bicomplex formalism. We apply the vertical homotopy decomposition to get a local splitting (in a convenient domain of a general balance system as the sum of a Lagrangian part and a complemental ''pure non-Lagrangian'' balance system. In the case when derivatives of the dynamical fields do not enter the constitutive relations of the balance system, the ''pure non-Lagrangian'' systems coincide with the systems introduced by S. Godunov [Soviet Math. Dokl. 2 (1961, 947-948] and, later, asserted as the canonical hyperbolic form of balance systems in [Müller I., Ruggeri T., Rational extended thermodynamics, 2nd ed., Springer Tracts in Natural Philosophy, Vol. 37, Springer-Verlag, New York, 1998].

  9. Validation of a robotic balance system for investigations in the control of human standing balance.

    Science.gov (United States)

    Luu, Billy L; Huryn, Thomas P; Van der Loos, H F Machiel; Croft, Elizabeth A; Blouin, Jean-Sébastien

    2011-08-01

    Previous studies have shown that human body sway during standing approximates the mechanics of an inverted pendulum pivoted at the ankle joints. In this study, a robotic balance system incorporating a Stewart platform base was developed to provide a new technique to investigate the neural mechanisms involved in standing balance. The robotic system, programmed with the mechanics of an inverted pendulum, controlled the motion of the body in response to a change in applied ankle torque. The ability of the robotic system to replicate the load properties of standing was validated by comparing the load stiffness generated when subjects balanced their own body to the robot's mechanical load programmed with a low (concentrated-mass model) or high (distributed-mass model) inertia. The results show that static load stiffness was not significantly (p > 0.05) different for standing and the robotic system. Dynamic load stiffness for the robotic system increased with the frequency of sway, as predicted by the mechanics of an inverted pendulum, with the higher inertia being accurately matched to the load properties of the human body. This robotic balance system accurately replicated the physical model of standing and represents a useful tool to simulate the dynamics of a standing person. © 2011 IEEE

  10. A stochastic approach for the description of the water balance dynamics in a river basin

    Directory of Open Access Journals (Sweden)

    S. Manfreda

    2008-09-01

    Full Text Available The present paper introduces an analytical approach for the description of the soil water balance dynamics over a schematic river basin. The model is based on a stochastic differential equation where the rainfall forcing is interpreted as an additive noise in the soil water balance. This equation can be solved assuming known the spatial distribution of the soil moisture over the basin transforming the two-dimensional problem in space in a one dimensional one. This assumption is particularly true in the case of humid and semihumid environments, where spatial redistribution becomes dominant producing a well defined soil moisture pattern. The model allowed to derive the probability density function of the saturated portion of a basin and of its relative saturation. This theory is based on the assumption that the soil water storage capacity varies across the basin following a parabolic distribution and the basin has homogeneous soil texture and vegetation cover. The methodology outlined the role played by the soil water storage capacity distribution of the basin on soil water balance. In particular, the resulting probability density functions of the relative basin saturation were found to be strongly controlled by the maximum water storage capacity of the basin, while the probability density functions of the relative saturated portion of the basin are strongly influenced by the spatial heterogeneity of the soil water storage capacity. Moreover, the saturated areas reach their maximum variability when the mean rainfall rate is almost equal to the soil water loss coefficient given by the sum of the maximum rate of evapotranspiration and leakage loss in the soil water balance. The model was tested using the results of a continuous numerical simulation performed with a semi-distributed model in order to validate the proposed theoretical distributions.

  11. The dose-response relationship of balance training in physically active older adults.

    Science.gov (United States)

    Maughan, Kristen K; Lowry, Kristin A; Franke, Warren D; Smiley-Oyen, Ann L

    2012-10-01

    A 6-wk group balance-training program was conducted with physically active older adults (based on American College of Sports Medicine requirements) to investigate the effect of dose-related static and dynamic balance-specific training. All participants, age 60-87 yr, continued their regular exercise program while adding balance training in 1 of 3 doses: three 20-min sessions/wk (n = 20), one 20-min session/wk (n = 21), or no balance training (n = 19). Static balance (single-leg-stance, tandem), dynamic balance (alternate stepping, limits of stability), and balance confidence (ABC) were assessed pre- and posttraining. Significant interactions were observed for time in single-leg stance, excursion in limits of stability, and balance confidence, with the greatest increase observed in the group that completed 3 training sessions/wk. The results demonstrate a dose-response relationship indicating that those who are already physically active can improve balance performance with the addition of balance-specific training.

  12. Balance Assessment Practices and Use of Standardized Balance Measures Among Ontario Physical Therapists

    Science.gov (United States)

    Sibley, Kathryn M.; Straus, Sharon E.; Inness, Elizabeth L.; Salbach, Nancy M.

    2011-01-01

    Background Balance impairment is a significant problem for older adults, as it can influence daily functioning. Treating balance impairment in this population is a major focus of physical therapist practice. Objective The purpose of this study was to document current practices in clinical balance assessment and compare components of balance assessed and measures used across practice areas among physical therapists. Design This was a cross-sectional study. Methods A survey questionnaire was mailed to 1,000 practicing physical therapists in Ontario, Canada. Results Three hundred sixty-nine individuals completed the survey questionnaire. More than 80% of respondents reported that they regularly (more than 60% of the time) assessed postural alignment, static and dynamic stability, functional balance, and underlying motor systems. Underlying sensory systems, cognitive contributions to balance, and reactive control were regularly assessed by 59.6%, 55.0%, and 41.2% of the respondents, respectively. The standardized measures regularly used by the most respondents were the single-leg stance test (79.1%), the Berg Balance Scale (45.0%), and the Timed “Up & Go” Test (27.6%). There was considerable variation in the components of balance assessed and measures used by respondents treating individuals in the orthopedic, neurologic, geriatric, and general rehabilitation populations. Limitations The survey provides quantitative data about what is done to assess balance, but does not explain the factors influencing current practice. Conclusions Many important components of balance and standardized measures are regularly used by physical therapists to assess balance. Further research, however, is needed to understand the factors contributing to the relatively lower rates of assessing reactive control, the component of balance most directly responsible for avoiding a fall. PMID:21868613

  13. Variations in annual water-energy balance and their correlations with vegetation and soil moisture dynamics: A case study in the Wei River Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shengzhi; Huang, Qiang; Leng, Guoyong; Zhao, Menglong; Meng, Erhao

    2017-03-01

    It is of importance to investigate watershed water-energy balance variations and to explore their correlations with vegetation and soil moisture dynamics, which helps better understand the interplays between underlying surface dynamics and the terrestrial water cycle. The heuristic segmentation method was adopted to identify change points in the parameter to series in Fu's equation belonging to the Budyko framework in the Wei River Basin (WRB) and its sub-basins aiming to examine the validity of stationary assumptions. Additionally, the cross wavelet analysis was applied to explore the correlations between vegetation and soil moisture dynamics and to variations. Results indicated that (1) the omega variations in the WRB are significant, with some change points identified except for the sub-basin above Zhangjiashan, implying that the stationarity of omega series in the WRB is invalid except for the sub-basin above Zhangjiashan; (2) the correlations between soil moisture series and to series are weaker than those between Normalized Difference Vegetation Index (NDVI) series and omega series; (3) vegetation dynamics show significantly negative correlations with omega variations in 1983-2003 with a 4-8 year signal in the whole WRB, and both vegetation and soil moisture dynamics exert strong impacts on the parameter omega changes. This study helps understanding the interactions between underlying land surface dynamics and watershed water-energy balance. (C) 2017 Elsevier B.V. All rights reserved.

  14. Ankle Taping Does Not Impair Performance in Jump or Balance Tests

    OpenAIRE

    Abián-Vicén, Javier; Alegre, Luis M.; Fernández-Rodríguez, J. Manuel; Lara, Amador J.; Meana, Marta; Aguado, Xavier

    2008-01-01

    This study aimed to investigate the influence of prophylactic ankle taping on two balance tests (static and dynamic balance) and one jump test, in the push off and the landing phase. Fifteen active young subjects (age: 21.0 ± 4.4 years) without previous ankle injuries volunteered for the study. Each participant performed three tests in two different situations: with taping and without taping. The tests were a counter movement jump, static balance, and a dynamic posturography test. The tests a...

  15. System Dynamics Modelling for a Balanced Scorecard

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2008-01-01

    /methodology/approach - We use a case study model to develop time or dynamic dimensions by using a System Dynamics modelling (SDM) approach. The model includes five perspectives and a number of financial and non-financial measures. All indicators are defined and related to a coherent number of different cause...... have a major influence on other indicators and profit and may be impossible to predict without using a dynamic model. Practical implications - The model may be used as the first step in quantifying the cause-and-effect relationships of an integrated BSC model. Using the System Dynamics model provides......Purpose - To construct a dynamic model/framework inspired by a case study based on an international company. As described by the theory, one of the main difficulties of BSC is to foresee the time lag dimension of different types of indicators and their combined dynamic effects. Design...

  16. Scalable and balanced dynamic hybrid data assimilation

    Science.gov (United States)

    Kauranne, Tuomo; Amour, Idrissa; Gunia, Martin; Kallio, Kari; Lepistö, Ahti; Koponen, Sampsa

    2017-04-01

    Scalability of complex weather forecasting suites is dependent on the technical tools available for implementing highly parallel computational kernels, but to an equally large extent also on the dependence patterns between various components of the suite, such as observation processing, data assimilation and the forecast model. Scalability is a particular challenge for 4D variational assimilation methods that necessarily couple the forecast model into the assimilation process and subject this combination to an inherently serial quasi-Newton minimization process. Ensemble based assimilation methods are naturally more parallel, but large models force ensemble sizes to be small and that results in poor assimilation accuracy, somewhat akin to shooting with a shotgun in a million-dimensional space. The Variational Ensemble Kalman Filter (VEnKF) is an ensemble method that can attain the accuracy of 4D variational data assimilation with a small ensemble size. It achieves this by processing a Gaussian approximation of the current error covariance distribution, instead of a set of ensemble members, analogously to the Extended Kalman Filter EKF. Ensemble members are re-sampled every time a new set of observations is processed from a new approximation of that Gaussian distribution which makes VEnKF a dynamic assimilation method. After this a smoothing step is applied that turns VEnKF into a dynamic Variational Ensemble Kalman Smoother VEnKS. In this smoothing step, the same process is iterated with frequent re-sampling of the ensemble but now using past iterations as surrogate observations until the end result is a smooth and balanced model trajectory. In principle, VEnKF could suffer from similar scalability issues as 4D-Var. However, this can be avoided by isolating the forecast model completely from the minimization process by implementing the latter as a wrapper code whose only link to the model is calling for many parallel and totally independent model runs, all of them

  17. Dynamic balance in persons with multiple sclerosis who have a falls history is altered compared to non-fallers and to healthy controls.

    Science.gov (United States)

    Peebles, Alexander T; Bruetsch, Adam P; Lynch, Sharon G; Huisinga, Jessie M

    2017-10-03

    Around 60% of persons with multiple sclerosis (MS) experience falls, however the dynamic balance differences between those who fall and those who don't are not well understood. The purpose of this study is to identify distinct biomechanical features of dynamic balance during gait that are different between fallers with MS, non-fallers with MS, and healthy controls. 27 recurrent fallers with MS, 28 persons with MS with no falls history, and 27 healthy controls walked on a treadmill at their preferred speed for 3min. The variability of trunk accelerations and the average and variability of minimum toe clearance, spatiotemporal parameters, and margin of stability were compared between groups. Fallers with MS exhibited a slower cautious gait compared to non-fallers and healthy controls, but had decreased anterior-posterior margin of stability and minimum toe clearance. Fallers walked with less locally stable and predictable trunk accelerations, and increased variability of step length, stride time, and both anterior-posterior and mediolateral margin of stability compared to non-fallers and healthy controls. The present work provides evidence that within a group of persons with MS, there are gait differences that are influenced by falls history. These differences indicate that in persons with MS who fall, the center of mass is poorly controlled through base of support placement and the foot is closer to the ground during swing phase relative to the non-fallers. These identified biomechanical differences could be used to evaluate dynamic balance in persons with MS and to help improve fall prevention strategies. Copyright © 2017. Published by Elsevier Ltd.

  18. Balance of Payment Dynamic in Indonesia and the Structure of Economy

    Directory of Open Access Journals (Sweden)

    Telisa Falianty

    2018-03-01

    Full Text Available This paper will assess in aggregate and detail the trend of BOP and its component in Indonesia. Stationarity test will be employed to each component of Indonesian BOP to assess the persistency. This study will calculate the balance of payment constrained growth (BOPC using Kalman Filter technique (state space model. The BOP, secondary income, and financial account are found to be stationer which means that the data are mean reverting. On the other hand, current account balance, trade balance, service balance, primary income, and capital account balance are unit root. This paper found the evidence of the importance of commodity price to Indonesian current account and export. Indonesian dependency on commodity-based export need to be restructured. Indonesia should also consider the side effect of FDI as a source of financing for current account deficit, without ignoring the positive effect of FDI and the volatility of portfolio investment. The persistency of primary income deficit should also become Indonesian future policy agenda.

  19. Clinical balance tests, proprioceptive system and adolescent idiopathic scoliosis.

    Science.gov (United States)

    Le Berre, Morgane; Guyot, Marc-Alexandre; Agnani, Olivier; Bourdeauducq, Isabelle; Versyp, Marie-Christine; Donze, Cécile; Thévenon, André; Catanzariti, Jean-Francois

    2017-06-01

    Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spinal column of unknown etiology. Multiple factors could be involved, including neurosensory pathways and, potentially, an elective disorder of dynamic proprioception. The purpose of this study was to determine whether routine balance tests could be used to demonstrate an elective alteration of dynamic proprioception in AIS. This was a multicentre case-control study based on prospectively collected clinical data, in three hospitals pediatric, with spine consultation, from January 2013 through April 2015. From an original population of 547 adolescents, inclusion and non-inclusion criteria indentified 114 adolescents with right thoracic AIS (mean age 14.5 ± 1.9 years, Cobb angle 35.7 ± 15.3°) and 81 matched adolescents without scoliosis (mean age 14.1 ± 1.9 years). Participants performed three routine clinical balance tests to assess the static and dynamic proprioception: the Fukuda-Utenberger stepping test (angle of rotation in degrees and distance of displacement in cm) to assess dynamic balance; the sharpened Romberg test and the unipedal stance test (eyes closed) to assess static balance. There was no significant difference between AIS subjects and controls for the static tests, but there was a significant difference for the dynamic test for both measures: distance of displacement (p tests can be performed in routine practice. Their validity as a biomarker for screening and monitoring purposes should be assessed.

  20. Kin Selection - Mutation Balance

    DEFF Research Database (Denmark)

    Dyken, J. David Van; Linksvayer, Timothy Arnold; Wade, Michael J.

    2011-01-01

    selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamilton´s rule is satisfied, selection is never strong enough to eliminate recurrent cheater mutants from a population, but cheater...

  1. The effect of single-task and dual-task balance exercise programs on balance performance in adults with osteoporosis: a randomized controlled preliminary trial.

    Science.gov (United States)

    Konak, H E; Kibar, S; Ergin, E S

    2016-11-01

    Osteoporosis is a serious disease characterized by muscle weakness in the lower extremities, shortened length of trunk, and increased dorsal kyphosis leading to poor balance performance. Although balance impairment increases in adults with osteoporosis, falls and fall-related injuries have been shown to occur mainly during the dual-task performance. Several studies have shown that dual-task performance was improved with specific repetitive dual-task exercises. The aims of this study were to compare the effect of single- and dual-task balance exercise programs on static balance, dynamic balance, and activity-specific balance confidence in adults with osteoporosis and to assess the effectiveness of dual-task balance training on gait speed under dual-task conditions. Older adults (N = 42) (age range, 45-88 years) with osteoporosis were randomly assigned into two groups. Single-task balance training group was given single-task balance exercises for 4 weeks, whereas dual-task balance training group received dual-task balance exercises. Participants received 45-min individualized training session, three times a week. Static balance was evaluated by one-leg stance (OLS) and a kinesthetic ability trainer (KAT) device. Dynamic balance was measured by the Berg Balance Scale (BBS), Time Up and Go (TUG) test, and gait speed. Self-confidence was assessed with the Activities-specific Balance Confidence (ABC-6) scale. Assessments were performed at baseline and after the 4-week program. At the end of the treatment periods, KAT score, BBS score, time in OLS and TUG, gait speeds under single- and dual-task conditions, and ABC-6 scale scores improved significantly in all patients (p gait speeds under single- and dual-task conditions showed significantly greater improvement in the dual-task balance training group than in the single-task balance training group (p gait speeds showed greater improvement following the application of a specific type of dual-task exercise programs

  2. Dynamics of Competition between Subnetworks of Spiking Neuronal Networks in the Balanced State

    Science.gov (United States)

    Lagzi, Fereshteh; Rotter, Stefan

    2015-01-01

    We explore and analyze the nonlinear switching dynamics of neuronal networks with non-homogeneous connectivity. The general significance of such transient dynamics for brain function is unclear; however, for instance decision-making processes in perception and cognition have been implicated with it. The network under study here is comprised of three subnetworks of either excitatory or inhibitory leaky integrate-and-fire neurons, of which two are of the same type. The synaptic weights are arranged to establish and maintain a balance between excitation and inhibition in case of a constant external drive. Each subnetwork is randomly connected, where all neurons belonging to a particular population have the same in-degree and the same out-degree. Neurons in different subnetworks are also randomly connected with the same probability; however, depending on the type of the pre-synaptic neuron, the synaptic weight is scaled by a factor. We observed that for a certain range of the “within” versus “between” connection weights (bifurcation parameter), the network activation spontaneously switches between the two sub-networks of the same type. This kind of dynamics has been termed “winnerless competition”, which also has a random component here. In our model, this phenomenon is well described by a set of coupled stochastic differential equations of Lotka-Volterra type that imply a competition between the subnetworks. The associated mean-field model shows the same dynamical behavior as observed in simulations of large networks comprising thousands of spiking neurons. The deterministic phase portrait is characterized by two attractors and a saddle node, its stochastic component is essentially given by the multiplicative inherent noise of the system. We find that the dwell time distribution of the active states is exponential, indicating that the noise drives the system randomly from one attractor to the other. A similar model for a larger number of populations might

  3. Dynamics of Competition between Subnetworks of Spiking Neuronal Networks in the Balanced State.

    Science.gov (United States)

    Lagzi, Fereshteh; Rotter, Stefan

    2015-01-01

    We explore and analyze the nonlinear switching dynamics of neuronal networks with non-homogeneous connectivity. The general significance of such transient dynamics for brain function is unclear; however, for instance decision-making processes in perception and cognition have been implicated with it. The network under study here is comprised of three subnetworks of either excitatory or inhibitory leaky integrate-and-fire neurons, of which two are of the same type. The synaptic weights are arranged to establish and maintain a balance between excitation and inhibition in case of a constant external drive. Each subnetwork is randomly connected, where all neurons belonging to a particular population have the same in-degree and the same out-degree. Neurons in different subnetworks are also randomly connected with the same probability; however, depending on the type of the pre-synaptic neuron, the synaptic weight is scaled by a factor. We observed that for a certain range of the "within" versus "between" connection weights (bifurcation parameter), the network activation spontaneously switches between the two sub-networks of the same type. This kind of dynamics has been termed "winnerless competition", which also has a random component here. In our model, this phenomenon is well described by a set of coupled stochastic differential equations of Lotka-Volterra type that imply a competition between the subnetworks. The associated mean-field model shows the same dynamical behavior as observed in simulations of large networks comprising thousands of spiking neurons. The deterministic phase portrait is characterized by two attractors and a saddle node, its stochastic component is essentially given by the multiplicative inherent noise of the system. We find that the dwell time distribution of the active states is exponential, indicating that the noise drives the system randomly from one attractor to the other. A similar model for a larger number of populations might suggest a

  4. Load Balancing Scientific Applications

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, Olga Tkachyshyn [Texas A & M Univ., College Station, TX (United States)

    2014-12-01

    The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.

  5. Crescimento de mudas de maracujazeiro-doce (Passiflora alata Curtis) associadas a fungos micorrízicos arbusculares (Glomeromycota)

    OpenAIRE

    Silva,Maryluce Albuquerque da; Cavalcante,Uided Maaze Tibúrcio; Silva,Fábio Sérgio Barbosa da; Soares,Sueli Aparecida Gomes; Maia,Leonor Costa

    2004-01-01

    Para determinar o efeito de fungos micorrízicos arbusculares sobre o crescimento de mudas de maracujazeiro-doce foi conduzido, em casa de vegetação, experimento com delineamento inteiramente casualizado usando cinco tratamentos de inoculação (200 esporos/planta de Acaulospora longula Spain & Schenck, Gigaspora albida Schenck & Smith, Glomus etunicatum Becker & Gerd., Scutellospora heterogama (Nicol. & Gerd.) Walker & Sanders e controle não inoculado), com sete repetições. ...

  6. Use of the Microsoft Kinect system to characterize balance ability during balance training.

    Science.gov (United States)

    Lim, Dohyung; Kim, ChoongYeon; Jung, HoHyun; Jung, Dukyoung; Chun, Keyoung Jin

    2015-01-01

    The risk of falling increases significantly in the elderly because of deterioration of the neural musculature regulatory mechanisms. Several studies have investigated methods of preventing falling using real-time systems to evaluate balance; however, it is difficult to monitor the results of such characterizations in real time. Herein, we describe the use of Microsoft's Kinect depth sensor system to evaluate balance in real time. Six healthy male adults (25.5±1.8 years, 173.9±6.4 cm, 71.4±6.5 kg, and 23.6±2.4 kg/m(2)), with normal balance abilities and with no musculoskeletal disorders, were selected to participate in the experiment. Movements of the participants were induced by controlling the base plane of the balance training equipment in various directions. The dynamic motion of the subjects was measured using two Kinect depth sensor systems and a three-dimensional motion capture system with eight infrared cameras. The two systems yielded similar results for changes in the center of body mass (P>0.05) with a large Pearson's correlation coefficient of γ>0.60. The results for the two systems showed similarity in the mean lower-limb joint angle with flexion-extension movements, and these values were highly correlated (hip joint: within approximately 4.6°; knee joint: within approximately 8.4°) (0.400.05). Large differences with a low correlation were, however, observed for the lower-limb joint angle in relation to abduction-adduction and internal-external rotation motion (γ<0.40) (P<0.05). These findings show that clinical and dynamic accuracy can be achieved using the Kinect system in balance training by measuring changes in the center of body mass and flexion-extension movements of the lower limbs, but not abduction-adduction and internal-external rotation.

  7. Balance of Payment Dynamic in Indonesia and the Structure of Economy

    OpenAIRE

    Telisa Falianty

    2018-01-01

    This paper will assess in aggregate and detail the trend of BOP and its component in Indonesia. Stationarity test will be employed to each component of Indonesian BOP to assess the persistency. This study will calculate the balance of payment constrained growth (BOPC) using Kalman Filter technique (state space model). The BOP, secondary income, and financial account are found to be stationer which means that the data are mean reverting. On the other hand, current account balance, trade balanc...

  8. T700 power turbine rotor multiplane/multispeed balancing demonstration

    Science.gov (United States)

    Burgess, G.; Rio, R.

    1979-01-01

    Research was conducted to demonstrate the ability of influence coefficient based multispeed balancing to control rotor vibration through bending criticals. Rotor dynamic analyses were conducted of the General Electric T700 power turbine rotor. The information was used to generate expected rotor behavior for optimal considerations in designing a balance rig and a balance technique. The rotor was successfully balanced 9500 rpm. Uncontrollable coupling behavior prevented observations through the 16,000 rpm service speed. The balance technique is practical and with additional refinement it can meet production standards.

  9. EFFECT OF DYNAMIC BALANCE TRAINING ON AGILITY IN MALE BASKETBALL PLAYERS

    OpenAIRE

    Avi Saraswat; Deepak Malhotra; C. Sivaram

    2015-01-01

    Background: Athletes focus their training on two major goals, i.e., avoidance of the injury and increasing the performance. Balance training has been widely used in competitive sports to improve the balance and thus reduce the risk of injury, for example, ligamentous sprains, which are very common in Basketball. On the other hand, various drills are being used to improve the performance parameters such as agility. Our effort is to find out an exercise program which focuses on balance training...

  10. Balance Devices Train Golfers for a Consistent Swing

    Science.gov (United States)

    2015-01-01

    As part of the effort to understand the effects of spaceflight on astronauts, NASA funded research that resulted in a commercial product to treat balance disorders. West Palm Beach, Florida-based Sports Therapy Inc. worked with the inventor to modify the technology, creating the Dynamic Balance System (DBS) for sports applications. DBS is now used by Professional Golfers' Association-owned facilities and golf academies to help players achieve an effective, balanced swing.

  11. A Dynamic Consensus Algorithm to Adjust Virtual Impedance Loops for Discharge Rate Balancing of AC Microgrid Energy Storage Units

    DEFF Research Database (Denmark)

    Guan, Yajuan; Meng, Lexuan; Li, Chendan

    2018-01-01

    A dynamic consensus algorithm (DCA)-based coordinated secondary control with an autonomous current-sharing control strategy is proposed in this paper for balancing the discharge rate of energy storage systems (ESSs) in an islanded AC microgrid. The DCA is applied for information sharing between......, the proposed approach can provide higher system reliability, expandability, and flexibility due to its distributed control architecture. The proposed controller can effectively prevent operation failure caused by over-current and unintentional outage of DGs by means of balanced discharge rate control. It can...... also provide fast response and accurate current sharing performance. A generalizable linearized state-space model for n-DG network in the z-domain is also derived and proposed in this paper; the model includes electrical, controller, and communication parts. The system stability and parameter...

  12. [Soil moisture dynamics and water balance of Salix psammophila shrubs in south edge of Mu Us Sandy Land].

    Science.gov (United States)

    An, Hui; An, Yu

    2011-09-01

    Taking the artificial sand-fixing Salix psammophila shrubs with different plant density (0.2, 0.6, and 0.8 plants x m(-2)) in Mu Us Sandy Land as test objects, this paper studied the soil moisture dynamics and evapotranspiration during growth season. There existed obvious differences in the soil moisture dynamics and evapotranspiration among the shrubs. The soil moisture content changed in single-hump-shape with the increase of plant density, and in "S" shape during growth season, being closely correlated with precipitation. The evapotranspiration was the highest (114.5 mm) in the shrubs with a density 0.8 plants x m(-1), accounting for 90.8% of the total precipitation during growth season, and the lowest (109.7 mm) in the shrubs with a density 0.6 plants x m(-2) Based on the soil moisture dynamics and water balance characteristics, the appropriate planting density of S. psammophila shrubs in Mu Us Sandy Land could be 0.6 plants x m(-2).

  13. Comparative impacts of Tai Chi, balance training, and a specially-designed yoga program on balance in older fallers.

    Science.gov (United States)

    Ni, Meng; Mooney, Kiersten; Richards, Luca; Balachandran, Anoop; Sun, Mingwei; Harriell, Kysha; Potiaumpai, Melanie; Signorile, Joseph F

    2014-09-01

    To compare the effect of a custom-designed yoga program with 2 other balance training programs. Randomized controlled trial. Research laboratory. A group of older adults (N=39; mean age, 74.15 ± 6.99 y) with a history of falling. Three different exercise interventions (Tai Chi, standard balance training, yoga) were given for 12 weeks. Balance performance was examined during pre- and posttest using field tests, including the 8-foot up-and-go test, 1-leg stance, functional reach, and usual and maximal walking speed. The static and dynamic balances were also assessed by postural sway and dynamic posturography, respectively. Training produced significant improvements in all field tests (Ptime × group interaction were not detected. For postural sway, significant decreases in the area of the center of pressure with eyes open (P=.001) and eyes closed (P=.002) were detected after training. For eyes open, maximum medial-lateral velocity significantly decreased for the sample (P=.013). For eyes closed, medial-lateral displacement decreased for Tai Chi (Ptime on the test (P=.006), and 2 linear measures in lateral (P=.001) and anterior-posterior (P<.001) directions were seen for the sample. Yoga was as effective as Tai Chi and standard balance training for improving postural stability and may offer an alternative to more traditional programs. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  14. Home-based balance training programme using Wii Fit with balance board for Parkinsons's disease: a pilot study.

    Science.gov (United States)

    Esculier, Jean-Francois; Vaudrin, Joanie; Bériault, Patrick; Gagnon, Karine; Tremblay, Louis E

    2012-02-01

    To evaluate the effects of a home-based balance training programme using visual feedback (Nintendo Wii Fit game with balance board) on balance and functional abilities in subjects with Parkinson's disease, and to compare the effects with a group of paired healthy subjects. Ten subjects with moderate Parkinson's disease and 8 healthy elderly subjects. Subjects participated in a 6-week home-based balance training programme using Nintendo Wii Fit and balance board. Baseline measures were taken before training for the Sit-to-Stand test (STST), Timed-Up-and-Go (TUG), Tinetti Performance Oriented Mobility Assessment (POMA), 10-m walk test, Community Balance and Mobility assessment (CBM), Activities-specific Balance and Confidence scale (ABC), unipodal stance duration, and a force platform. All measurements were taken again after 3 and 6 weeks of training. The Parkinson's disease group significantly improved their results in TUG, STST, unipodal stance, 10-m walk test, CBM, POMA and force platform at the end of the 6-week training programme. The healthy subjects group significantly improved in TUG, STST, unipodal stance and CBM. This pilot study suggests that a home-based balance programme using Wii Fit with balance board could improve static and dynamic balance, mobility and functional abilities of people affected by Parkinson's disease.

  15. Medical Devices Assess, Treat Balance Disorders

    Science.gov (United States)

    2009-01-01

    You may have heard the phrase as difficult as walking and chewing gum as a joking way of referring to something that is not difficult at all. Just walking, however, is not all that simple physiologically speaking. Even standing upright is an undertaking requiring the complex cooperation of multiple motor and sensory systems including vision, the inner ear, somatosensation (sensation from the skin), and proprioception (the sense of the body s parts in relation to each other). The compromised performance of any of these elements can lead to a balance disorder, which in some form affects nearly half of Americans at least once in their lifetimes, from the elderly, to those with neurological or vestibular (inner ear) dysfunction, to athletes with musculoskeletal injuries, to astronauts returning from space. Readjusting to Earth s gravity has a significant impact on an astronaut s ability to balance, a result of the brain switching to a different "model" for interpreting sensory input in normal gravity versus weightlessness. While acclimating, astronauts can experience headaches, motion sickness, and problems with perception. To help ease the transition and study the effects of weightlessness on the body, NASA has conducted many investigations into post-flight balance control, realizing this research can help treat patients with balance disorders on Earth as well. In the 1960s, the NASA-sponsored Man Vehicle Laboratory at the Massachusetts Institute of Technology (MIT) studied the effects of prolonged space flight on astronauts. The lab s work intrigued MIT doctoral candidate Lewis Nashner, who began conducting NASA-funded research on human movement and balance under the supervision of Dr. Larry Young in the MIT Department of Aeronautics and Astronautics. In 1982, Nashner s work resulted in a noninvasive clinical technique for assessing the cooperative systems that allow the body to balance, commonly referred to as computerized dynamic posturography (CDP). CDP employs a

  16. Growth of seedlings of sweet-passion fruit (Passiflora alata Curtis) associated to arbuscular mycorrhizal fungi (Glomeromycota)

    OpenAIRE

    Silva, Maryluce Albuquerque da; Cavalcante, Uided Maaze Tibúrcio; Silva, Fábio Sérgio Barbosa da; Soares, Sueli Aparecida Gomes; Maia, Leonor Costa

    2004-01-01

    Para determinar o efeito de fungos micorrízicos arbusculares sobre o crescimento de mudas de maracujazeiro-doce foi conduzido, em casa de vegetação, experimento com delineamento inteiramente casualizado usando cinco tratamentos de inoculação (200 esporos/planta de Acaulospora longula Spain & Schenck, Gigaspora albida Schenck & Smith, Glomus etunicatum Becker & Gerd., Scutellospora heterogama (Nicol. & Gerd.) Walker & Sanders e controle não inoculado), com sete repetições. A cada 20 dias foram...

  17. Firm Investment and Balance-Sheet Problems in Japan

    OpenAIRE

    Toshitaka Sekine

    1999-01-01

    This paper investigates whether balance-sheet conditions of firms and their main banks matter for firm investment behavior using dynamic corporate panel data in Japan for the period 1985-95. It finds that smaller non-bond issuing firms were facing liquidity constraints; these firms’ balance-sheet conditions (the debt asset ratios) affected their investment from the midst of the bubble era by influencing main banks’ lending to them; and the deterioration of their main banks’ balance-sheet cond...

  18. Validation of the Balance Board for Clinical Evaluation of Balance During Serious Gaming Rehabilitation Exercises.

    Science.gov (United States)

    Bonnechère, Bruno; Jansen, Bart; Omelina, Lubos; Sholukha, Victor; Van Sint Jan, Serge

    2016-09-01

    Balance and posture can be affected in various conditions or become decreased with aging. A diminution of balance control induces an increase of fall's risk. The Nintendo Wii Balance Board™ (WBB) is used in rehabilitation to perform balance exercises (using commercial video games). The WBB has also been validated to assess balance and posture in static conditions. However, there is currently no study investigating the use of WBB to assess balance during the realization of balance exercises using this device. The aim of this study was to validate the use of WBB, coupled with specially developed serious games, to assess dynamic balance during rehabilitation exercises. Thirty five subjects participated in this study. Subjects were asked to play two specially developed serious games. Center of pressure (CP) displacements were simultaneously recorded with a WBB and a gold standard force plate (FP). Nine parameters were derived from CP displacement. Bland and Altman plots, paired-sample t tests, intraclass correlation coefficient's, and Pearson's coefficient correlations were computed. Excellent correlation between both devices was found for each parameter for the two games (R = 0.95 and 0.96). Unlike previous work on the WBB, these excellent results were obtained without using any calibration procedure. Despite this, results were highly correlated between the WBB and the FP. The WBB could be used in clinics to assess balance during rehabilitation exercises and, thus, allows a more regular patient follow-up.

  19. Heavy-metal balances of agro-ecosystems in the Netherlands.

    NARCIS (Netherlands)

    Moolenaar, S.W.; Lexmond, Th.M.

    1998-01-01

    Heavy-metal flows (Cd, Cu, Pb, and Zn) of arable, dairy and mixed farming systems in the Netherlands were studied, and farm-gate and field-scale balances calculated. On the field-scale, static and dynamic balances were distinguished. By determining the characteristic metal flows, it became possible

  20. Linear versus Nonlinear Filtering with Scale-Selective Corrections for Balanced Dynamics in a Simple Atmospheric Model

    KAUST Repository

    Subramanian, Aneesh C.

    2012-11-01

    This paper investigates the role of the linear analysis step of the ensemble Kalman filters (EnKF) in disrupting the balanced dynamics in a simple atmospheric model and compares it to a fully nonlinear particle-based filter (PF). The filters have a very similar forecast step but the analysis step of the PF solves the full Bayesian filtering problem while the EnKF analysis only applies to Gaussian distributions. The EnKF is compared to two flavors of the particle filter with different sampling strategies, the sequential importance resampling filter (SIRF) and the sequential kernel resampling filter (SKRF). The model admits a chaotic vortical mode coupled to a comparatively fast gravity wave mode. It can also be configured either to evolve on a so-called slow manifold, where the fast motion is suppressed, or such that the fast-varying variables are diagnosed from the slow-varying variables as slaved modes. Identical twin experiments show that EnKF and PF capture the variables on the slow manifold well as the dynamics is very stable. PFs, especially the SKRF, capture slaved modes better than the EnKF, implying that a full Bayesian analysis estimates the nonlinear model variables better. The PFs perform significantly better in the fully coupled nonlinear model where fast and slow variables modulate each other. This suggests that the analysis step in the PFs maintains the balance in both variables much better than the EnKF. It is also shown that increasing the ensemble size generally improves the performance of the PFs but has less impact on the EnKF after a sufficient number of members have been used.

  1. Linear versus Nonlinear Filtering with Scale-Selective Corrections for Balanced Dynamics in a Simple Atmospheric Model

    KAUST Repository

    Subramanian, Aneesh C.; Hoteit, Ibrahim; Cornuelle, Bruce; Miller, Arthur J.; Song, Hajoon

    2012-01-01

    This paper investigates the role of the linear analysis step of the ensemble Kalman filters (EnKF) in disrupting the balanced dynamics in a simple atmospheric model and compares it to a fully nonlinear particle-based filter (PF). The filters have a very similar forecast step but the analysis step of the PF solves the full Bayesian filtering problem while the EnKF analysis only applies to Gaussian distributions. The EnKF is compared to two flavors of the particle filter with different sampling strategies, the sequential importance resampling filter (SIRF) and the sequential kernel resampling filter (SKRF). The model admits a chaotic vortical mode coupled to a comparatively fast gravity wave mode. It can also be configured either to evolve on a so-called slow manifold, where the fast motion is suppressed, or such that the fast-varying variables are diagnosed from the slow-varying variables as slaved modes. Identical twin experiments show that EnKF and PF capture the variables on the slow manifold well as the dynamics is very stable. PFs, especially the SKRF, capture slaved modes better than the EnKF, implying that a full Bayesian analysis estimates the nonlinear model variables better. The PFs perform significantly better in the fully coupled nonlinear model where fast and slow variables modulate each other. This suggests that the analysis step in the PFs maintains the balance in both variables much better than the EnKF. It is also shown that increasing the ensemble size generally improves the performance of the PFs but has less impact on the EnKF after a sufficient number of members have been used.

  2. Task oriented training improves the balance outcome & reducing fall risk in diabetic population.

    Science.gov (United States)

    Ghazal, Javeria; Malik, Arshad Nawaz; Amjad, Imran

    2016-01-01

    The objective was to determine the balance impairments and to compare task oriented versus traditional balance training in fall reduction among diabetic patients. The randomized control trial with descriptive survey and 196 diabetic patients were recruited to assess balance impairments through purposive sampling technique. Eighteen patients were randomly allocated into two groups; task oriented balance training group TOB (n=8) and traditional balance training group TBT (n=10). The inclusion criteria were 30-50 years age bracket and diagnosed cases of Diabetes Mellitus with neuropathy. The demographics were taken through standardized & valid assessment tools include Berg Balance Scale and Functional Reach Test. The measurements were obtained at baseline, after 04 and 08 weeks of training. The mean age of the participants was 49 ±6.79. The result shows that 165(84%) were at moderate risk of fall and 31(15%) were at mild risk of fall among total 196 diabetic patients. There was significant improvement (p balance training group for dynamic balance, anticipatory balance and reactive balance after 8 weeks of training as compare to traditional balance training. Task oriented balance training is effective in improving the dynamic, anticipator and reactive balance. The task oriented training reduces the risk of falling through enhancing balance outcome.

  3. A Stochastic Water Balance Framework for Lowland Watersheds

    Science.gov (United States)

    Thompson, Sally; MacVean, Lissa; Sivapalan, Murugesu

    2017-11-01

    The water balance dynamics in lowland watersheds are influenced not only by local hydroclimatic controls on energy and water availability, but also by imports of water from the upstream watershed. These imports result in a stochastic extent of inundation in lowland watersheds that is determined by the local flood regime, watershed topography, and the rate of loss processes such as drainage and evaporation. Thus, lowland watershed water balances depend on two stochastic processes—rainfall and local inundation dynamics. Lowlands are high productivity environments that are disproportionately associated with urbanization, high productivity agriculture, biodiversity, and flood risk. Consequently, they are being rapidly altered by human development—generally with clear economic and social motivation—but also with significant trade-offs in ecosystem services provision, directly related to changes in the components and variability of the lowland water balance. We present a stochastic framework to assess the lowland water balance and its sensitivity to two common human interventions—replacement of native vegetation with alternative land uses, and construction of local flood protection levees. By providing analytical solutions for the mean and PDF of the water balance components, the proposed framework provides a mechanism to connect human interventions to hydrologic outcomes, and, in conjunction with ecosystem service production estimates, to evaluate trade-offs associated with lowland watershed development.

  4. The Effect of Selective Hata Yoga Training on Balance of Elderly Women

    Directory of Open Access Journals (Sweden)

    Sepideh Jannati

    2011-01-01

    Full Text Available Objectives: The aim of current study was to determine the effects of Hata yoga training on dynamic and static balances of elderly women in Mashhad. Methods and Materials: The present study enjoys the semi-experimental design. The statistical population of the study, which has been carried out in 2009, were elderly women of Mashhad who were voluntarily invited to participate in the research. 29 healthy elderly women aged 56-72 years old have been selected who haven’t had any disease history during the last one year such as: advanced osteoporosis, hip replacement, glaucoma, Parkinson’s disease, common occurrences of dizziness, or any surgery. Before and after doing the Hata yoga training program which was performed in 3- sessions of 1- hour during 8 weeks Dynamic and static balances were evaluated by fall risk test and postural stability test respectively by Biodex Balance System. Finally data were analyzed by using Variance analysis (GLM-repeated measures and Dependent T-test and the significance of results was α=0.05. Results: The effects of 24 sessions of Hata yoga training were significant on static balance: overall (P=0.001, anterior-posterior (P=0.002, medial-lateral (P=0.006 and dynamic balance of elderly women (P=0.00. Conclusion: Considering the positive influence of Hata yoga training on dynamic and static balances, it is concluded that Hata yoga training has led to the improvement muscle strength among elderly women particularly endurance and strength of muscles in lower extremity and may increase the efficiency of neuro- motor system and improve somatosensory of muscles and joints by ameliorating the existed balance and decreasing fall risk in elderly women.

  5. Use of the Microsoft Kinect system to characterize balance ability during balance training

    Directory of Open Access Journals (Sweden)

    Lim DH

    2015-06-01

    Full Text Available Dohyung Lim,1 ChoongYeon Kim,2 HoHyun Jung,1 Dukyoung Jung,3 Keyoung Jin Chun21Department of Mechanical Engineering, Sejong University, Seoul, Republic of Korea; 2Advanced Biomedical Engineering Lab, Korea Institute of Industrial Technology, Cheonan, Republic of Korea; 3R&D Team, Senior Products Industrial Center, Busan, Republic of KoreaAbstract: The risk of falling increases significantly in the elderly because of deterioration of the neural musculature regulatory mechanisms. Several studies have investigated methods of preventing falling using real-time systems to evaluate balance; however, it is difficult to monitor the results of such characterizations in real time. Herein, we describe the use of Microsoft’s Kinect depth sensor system to evaluate balance in real time. Six healthy male adults (25.5±1.8 years, 173.9±6.4 cm, 71.4±6.5 kg, and 23.6±2.4 kg/m2, with normal balance abilities and with no musculoskeletal disorders, were selected to participate in the experiment. Movements of the participants were induced by controlling the base plane of the balance training equipment in various directions. The dynamic motion of the subjects was measured using two Kinect depth sensor systems and a three-dimensional motion capture system with eight infrared cameras. The two systems yielded similar results for changes in the center of body mass (P>0.05 with a large Pearson’s correlation coefficient of γ>0.60. The results for the two systems showed similarity in the mean lower-limb joint angle with flexion–extension movements, and these values were highly correlated (hip joint: within approximately 4.6°; knee joint: within approximately 8.4° (0.40<γ<0.74 (P>0.05. Large differences with a low correlation were, however, observed for the lower-limb joint angle in relation to abduction–adduction and internal–external rotation motion (γ<0.40 (P<0.05. These findings show that clinical and dynamic accuracy can be achieved using the Kinect

  6. The effect of viewing a virtual environment through a head-mounted display on balance.

    Science.gov (United States)

    Robert, Maxime T; Ballaz, Laurent; Lemay, Martin

    2016-07-01

    In the next few years, several head-mounted displays (HMD) will be publicly released making virtual reality more accessible. HMD are expected to be widely popular at home for gaming but also in clinical settings, notably for training and rehabilitation. HMD can be used in both seated and standing positions; however, presently, the impact of HMD on balance remains largely unknown. It is therefore crucial to examine the impact of viewing a virtual environment through a HMD on standing balance. To compare static and dynamic balance in a virtual environment perceived through a HMD and the physical environment. The visual representation of the virtual environment was based on filmed image of the physical environment and was therefore highly similar. This is an observational study in healthy adults. No significant difference was observed between the two environments for static balance. However, dynamic balance was more perturbed in the virtual environment when compared to that of the physical environment. HMD should be used with caution because of its detrimental impact on dynamic balance. Sensorimotor conflict possibly explains the impact of HMD on balance. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Postural Balance in Women with Osteoporosis and Effective Factors

    OpenAIRE

    Duygu Ünlüsoy; Ece Aydoğ; İhsan Ünlüsoy

    2011-01-01

    Introduction: The most common cause of mortality and morbidity among osteoporotic individuals is bone fracture which in many cases is a direct result of falls. Individual factors contributing to the risk of fall are poor postural balance and lack of muscle strength. Our aims were to assess postural dynamic balance in osteoporotic women and to describe the effective factors on the balance performance. Methods: Twenty osteoporotic women with kyphosis, 50 osteoporotic women without kyph...

  8. Global Particle Balance Measurements in DIII-D H-mode Discharges

    International Nuclear Information System (INIS)

    Unterberg, Ezekial A.; Allen, S.L.; Brooks, N.; Evans, T.E.; Leonard, A.W.; McLean, A.; Watkins, J.G.; Whyte, D.G.

    2011-01-01

    Experiments are performed on the DIII-D tokamak to determine the retention rate in an all graphite first-wall tokamak. A time-dependent particle balance analysis shows a majority of the fuel retention occurs during the initial Ohmic and L-mode phase of discharges, with peak fuel retention rates typically similar to 2 x 10(21) D/s. The retention rate can be zero within the experimental uncertainties (<3 x 10(20) D/s) during the later stationary phase of the discharge. In general, the retention inventory can decrease in the stationary phase by similar to 20-30% from the initial start-up phase of the discharge. Particle inventories determined as a function of time in the discharge, using a 'dynamic' particle balance analysis, agree with more accurate particle inventories directly measured after the discharge, termed 'static' particle balance. Similarly, low stationary retention rates are found in discharges with heating from neutral-beams, which injects particles, and from electron cyclotron waves, which does not inject particles. Detailed analysis of the static and dynamic balance methods provide an estimate of the DIII-D global co-deposition rate of <= 0.6-1.2 x 10(20) D/s. Dynamic particle balance is also performed on discharges with resonant magnetic perturbation ELM suppression and shows no additional retention during the ELM-suppressed phase of the discharge.

  9. Evaluating water conservation and reuse policies using a dynamic water balance model.

    Science.gov (United States)

    Qaiser, Kamal; Ahmad, Sajjad; Johnson, Walter; Batista, Jacimaria R

    2013-02-01

    A dynamic water balance model is created to examine the effects of different water conservation policies and recycled water use on water demand and supply in a region faced with water shortages and significant population growth, the Las Vegas Valley (LVV). The model, developed using system dynamics approach, includes an unusual component of the water system, return flow credits, where credits are accrued for returning treated wastewater to the water supply source. In LVV, Lake Mead serves as, both the drinking water source and the receiving body for treated wastewater. LVV has a consumptive use allocation from Lake Mead but return flow credits allow the water agency to pull out additional water equal to the amount returned as treated wastewater. This backdrop results in a scenario in which conservation may cause a decline in the available water supply. Current water use in LVV is 945 lpcd (250 gpcd), which the water agency aims to reduce to 752 lpcd (199 gpcd) by 2035, mainly through water conservation. Different conservation policies focused on indoor and outdoor water use, along with different population growth scenarios, are modeled for their effects on the water demand and supply. Major contribution of this study is in highlighting the importance of outdoor water conservation and the effectiveness of reducing population growth rate in addressing the future water shortages. The water agency target to decrease consumption, if met completely through outdoor conservation, coupled with lower population growth rate, can potentially satisfy the Valley's water demands through 2035.

  10. Evaluating Water Conservation and Reuse Policies Using a Dynamic Water Balance Model

    Science.gov (United States)

    Qaiser, Kamal; Ahmad, Sajjad; Johnson, Walter; Batista, Jacimaria R.

    2013-02-01

    A dynamic water balance model is created to examine the effects of different water conservation policies and recycled water use on water demand and supply in a region faced with water shortages and significant population growth, the Las Vegas Valley (LVV). The model, developed using system dynamics approach, includes an unusual component of the water system, return flow credits, where credits are accrued for returning treated wastewater to the water supply source. In LVV, Lake Mead serves as, both the drinking water source and the receiving body for treated wastewater. LVV has a consumptive use allocation from Lake Mead but return flow credits allow the water agency to pull out additional water equal to the amount returned as treated wastewater. This backdrop results in a scenario in which conservation may cause a decline in the available water supply. Current water use in LVV is 945 lpcd (250 gpcd), which the water agency aims to reduce to 752 lpcd (199 gpcd) by 2035, mainly through water conservation. Different conservation policies focused on indoor and outdoor water use, along with different population growth scenarios, are modeled for their effects on the water demand and supply. Major contribution of this study is in highlighting the importance of outdoor water conservation and the effectiveness of reducing population growth rate in addressing the future water shortages. The water agency target to decrease consumption, if met completely through outdoor conservation, coupled with lower population growth rate, can potentially satisfy the Valley's water demands through 2035.

  11. A Comparison of 12 Weeks of Pilates and Aquatic Training on the Dynamic Balance of Women with Mulitple Sclerosis

    OpenAIRE

    Marandi, Sayyed Mohammad; Nejad, Vahid Shayegan; Shanazari, Zohreh; Zolaktaf, Vahid

    2013-01-01

    Background: Multiple Sclerosis (MS) is a disabling chronic disease of the nervous system in which the myelin system of the central nervous system is deteriorated. The objective of this study is to understand the effect of Pilates exercises and aquatic training for a 12 week period on the dynamic balance of MS patients. Methods: The research method is semi-experimental. As a result, among the female patients visiting the MS clinic of Kashani hospital in Esfahan, 57 patients with disease in...

  12. A Network-Based Data Envelope Analysis Model in a Dynamic Balanced Score Card

    Directory of Open Access Journals (Sweden)

    Mojtaba Akbarian

    2015-01-01

    Full Text Available Performance assessment during the time and along with strategies is the most important requirements of top managers. To assess the performance, a balanced score card (BSC along with strategic goals and a data envelopment analysis (DEA are used as powerful qualitative and quantitative tools, respectively. By integrating these two models, their strengths are used and their weaknesses are removed. In this paper, an integrated framework of the BSC and DEA models is proposed for measuring the efficiency during the time and along with strategies based on the time delay of the lag key performance indicators (KPIs of the BSC model. The causal relationships during the time among perspectives of the BSC model are drawn as dynamic BSC at first. Then, after identifying the network-DEA structure, a new objective function for measuring the efficiency of nine subsidiary refineries of the National Iranian Oil Refining and Distribution Company (NIORDC during the time and along with strategies is developed.

  13. Effects of picture amount on preference, balance, and dynamic feel of Web pages.

    Science.gov (United States)

    Chiang, Shu-Ying; Chen, Chien-Hsiung

    2012-04-01

    This study investigates the effects of picture amount on subjective evaluation. The experiment herein adopted two variables to define picture amount: column ratio and picture size. Six column ratios were employed: 7:93,15:85, 24:76, 33:67, 41:59, and 50:50. Five picture sizes were examined: 140 x 81, 220 x 127, 300 x 173, 380 x 219, and 460 x 266 pixels. The experiment implemented a within-subject design; 104 participants were asked to evaluate 30 web page layouts. Repeated measurements revealed that the column ratio and picture size have significant effects on preference, balance, and dynamic feel. The results indicated the most appropriate picture amount for display: column ratios of 15:85 and 24:76, and picture sizes of 220 x 127, 300 x 173, and 380 x 219. The research findings can serve as the basis for the application of design guidelines for future web page interface design.

  14. A dynamic force balance model for colloidal expansion and its DLVO-based application.

    Science.gov (United States)

    Liu, Longcheng; Moreno, Luis; Neretnieks, Ivars

    2009-01-20

    A force balance model that describes the dynamic expansion of colloidal bentonite gels/sols is presented. The colloidal particles are assumed to consist of one or several thin sheets with the other dimensions much larger than their thickness. The forces considered include van der Waals force, diffuse double layer force, thermal force giving rise to Brownian motion, gravity, as well as friction force. The model results in an expression resembling the instationary diffusion equation but with an immensely variable diffusivity. This diffusivity is strongly influenced by the concentration of counterions as well as by the particle concentration in the colloid gel/sol. The properties of the model are explored and discussed, exemplified by the upward expansion of an originally highly compacted bentonite tablet in a test tube. Examples are presented for a number of cases with ionic concentrations varying between very dilute waters up to several molar of counterions. The volume fraction of particles ranges from 40% to very dilute sols.

  15. Comparative analysis of hourly and dynamic power balancing models for validating future energy scenarios

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan R.; Heussen, Kai; Østergaard, Poul Alberg

    2011-01-01

    Energy system analyses on the basis of fast and simple tools have proven particularly useful for interdisciplinary planning projects with frequent iterations and re-evaluation of alternative scenarios. As such, the tool “EnergyPLAN” is used for hourly balanced and spatially aggregate annual......, the model is verified on the basis of the existing energy mix on Bornholm as an islanded energy system. Future energy scenarios for the year 2030 are analysed to study a feasible technology mix for a higher share of wind power. Finally, the results of the hourly simulations are compared to dynamic frequency...... simulations incorporating the Vehicle-to-grid technology. The results indicate how the EnergyPLAN model may be improved in terms of intra-hour variability, stability and ancillary services to achieve a better reflection of energy and power capacity requirements....

  16. Strategic Balanced Scorecard Simulation

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2012-01-01

    The purpose of this article is to show how a System Dynamics Modelling approach can be integrated into the Balanced Scorecard (BSC) for a case company with special focus on the handling of causality in a dynamic perspective. The case company’s BSC model includes five perspectives and a number...... of financial and non-financial measures. The overall idea of BSC is to make the strategy operational, as proposed by Kaplan and Norton (1992; 1996; 2007) and to use the strategy for simulation. Our results indicate that a company may gain great learning insight from such simulation studies. The whole article...

  17. K-means clustering for optimal partitioning and dynamic load balancing of parallel hierarchical N-body simulations

    International Nuclear Information System (INIS)

    Marzouk, Youssef M.; Ghoniem, Ahmed F.

    2005-01-01

    A number of complex physical problems can be approached through N-body simulation, from fluid flow at high Reynolds number to gravitational astrophysics and molecular dynamics. In all these applications, direct summation is prohibitively expensive for large N and thus hierarchical methods are employed for fast summation. This work introduces new algorithms, based on k-means clustering, for partitioning parallel hierarchical N-body interactions. We demonstrate that the number of particle-cluster interactions and the order at which they are performed are directly affected by partition geometry. Weighted k-means partitions minimize the sum of clusters' second moments and create well-localized domains, and thus reduce the computational cost of N-body approximations by enabling the use of lower-order approximations and fewer cells. We also introduce compatible techniques for dynamic load balancing, including adaptive scaling of cluster volumes and adaptive redistribution of cluster centroids. We demonstrate the performance of these algorithms by constructing a parallel treecode for vortex particle simulations, based on the serial variable-order Cartesian code developed by Lindsay and Krasny [Journal of Computational Physics 172 (2) (2001) 879-907]. The method is applied to vortex simulations of a transverse jet. Results show outstanding parallel efficiencies even at high concurrencies, with velocity evaluation errors maintained at or below their serial values; on a realistic distribution of 1.2 million vortex particles, we observe a parallel efficiency of 98% on 1024 processors. Excellent load balance is achieved even in the face of several obstacles, such as an irregular, time-evolving particle distribution containing a range of length scales and the continual introduction of new vortex particles throughout the domain. Moreover, results suggest that k-means yields a more efficient partition of the domain than a global oct-tree

  18. The Effects of Hippotherapy and a Horse Riding Simulator on the Balance of Children with Cerebral Palsy

    Science.gov (United States)

    Lee, Chae-Woo; Kim, Seong Gil; Na, Sang Su

    2014-01-01

    [Purpose] We with respect to their effects on the compared hippotherapy with a horseback riding simulator (JOBA, Panasonic Inc. JP) static and dynamic balance of children with cerebral palsy (CP). [Subjects and Methods] Twenty-six children were randomly divided into two groups: a hippotherapy group that included 13 children, and a horseback riding simulator (JOBA, Panasonic Inc., Japan) group, which was also composed of 13 children. The two groups participated in 1 hour of exercise per day, 3 times a week, for 12 weeks. The subjects’ static balance ability was measured using BPM (software 5.3, SMS Healthcare Inc., UK) as the center of pressure sway length while standing for 30 seconds with their eyes open and looking to the front. Dynamic balance ability was measured using the PBS (Pediatric Balance Scale). [Results] Both groups showed significant improvements in static and dynamic balance but significant differences between the two groups were not found. [Conclusion] The horseback riding simulator could be a useful alternative to hippotherapy for the improvement of static and dynamic balance of children with CP. PMID:24707098

  19. Charge balancing fill rate monitor

    International Nuclear Information System (INIS)

    Rothman, J.L.; Blum, E.B.

    1995-01-01

    A fill rate monitor has been developed for the NSLS storage rings to allow machine tuning over a very large dynamic range of beam current. Synchrotron light, focused on a photodiode, produces a signal proportional to the beam current. A charge balancing circuit processes the diode current, creating an output signal proportional to the current injected into the ring. The unit operates linearly over a dynamic range of 120 dB and can resolve pulses of injected beam as small as 1 μA

  20. An artificial neural network estimation of gait balance control in the elderly using clinical evaluations.

    Directory of Open Access Journals (Sweden)

    Vipul Lugade

    Full Text Available The use of motion analysis to assess balance is essential for determining the underlying mechanisms of falls during dynamic activities. Clinicians evaluate patients using clinical examinations of static balance control, gait performance, cognition, and neuromuscular ability. Mapping these data to measures of dynamic balance control, and the subsequent categorization and identification of community dwelling elderly fallers at risk of falls in a quick and inexpensive manner is needed. The purpose of this study was to demonstrate that given clinical measures, an artificial neural network (ANN could determine dynamic balance control, as defined by the interaction of the center of mass (CoM with the base of support (BoS, during gait. Fifty-six elderly adults were included in this study. Using a feed-forward neural network with back propagation, combinations of five functional domains, the number of hidden layers and error goals were evaluated to determine the best parameters to assess dynamic balance control. Functional domain input parameters included subject characteristics, clinical examinations, cognitive performance, muscle strength, and clinical balance performance. The use of these functional domains demonstrated the ability to quickly converge to a solution, with the network learning the mapping within 5 epochs, when using up to 30 hidden nodes and an error goal of 0.001. The ability to correctly identify the interaction of the CoM with BoS demonstrated correlation values up to 0.89 (P<.001. On average, using all clinical measures, the ANN was able to estimate the dynamic CoM to BoS distance to within 1 cm and BoS area to within 75 cm2. Our results demonstrated that an ANN could be trained to map clinical variables to biomechanical measures of gait balance control. A neural network could provide physicians and patients with a cost effective means to identify dynamic balance issues and possible risk of falls from routinely collected clinical

  1. Exploring diversity of crop and soil management within smallholder African farms: A dynamic model for simulation of N balances and use efficiencies at field scale

    NARCIS (Netherlands)

    Tittonell, P.A.; Leffelaar, P.A.; Vanlauwe, B.; Wijk, van M.T.; Giller, K.E.

    2006-01-01

    Adding a dynamic, temporal dimension to the calculation of nitrogen balances is proposed as an alternative approach to assessing the impact of crop and soil management decisions on the establishment of farmer-induced soil fertility gradients within smallholder African farms. A simulation model that

  2. Effects of functional level on balance in children with Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Alkan, Halil; Mutlu, Akmer; Fırat, Tüzün; Bulut, Numan; Karaduman, Aynur Ayşe; Yılmaz, Öznur Tunca

    2017-07-01

    This study was planned to compare the static and dynamic balance in children with Duchenne Muscular Dystrophy (DMD) at different functional levels with each other and with healthy peers. Sixty nine children between the ages of 6 and 11 were included in this study where 52 of them were diagnosed with DMD in Level I (18 patients), Level II (17 patients), and Level III (17 patients) according to Brooke Functional Classification Scale and 17 of them healthy peers were included. In order to assess static and dynamic balance pediatric functional reach test (PFRT) and timed up and go test (TUGT) were used. When compared in terms of the TUGT, differences were found between all groups, i.e. Level 1 and 2, Level 2 and 3, Level 1 and 3, Healthy peers and Level 1, Healthy peers and Level 2, and Healthy peers and Level 3 (p level 3 and healthy peers (p level in DMD to affect the dynamic and static balance parameters in this study. The dynamic balance of a child with DMD at Level 3 is decreased to a third of a healthy peer. Copyright © 2017 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  3. Energy balance at a crossroads: translating the science into action.

    Science.gov (United States)

    Manore, Melinda M; Brown, Katie; Houtkooper, Linda; Jakicic, John; Peters, John C; Smith Edge, Marianne; Steiber, Alison; Going, Scott; Gable, Lisa Guillermin; Krautheim, Ann Marie

    2014-07-01

    One of the major challenges facing the United States is the high number of overweight and obese adults and the growing number of overweight and unfit children and youth. To improve the nation's health, young people must move into adulthood without the burden of obesity and its associated chronic diseases. To address these issues, the American College of Sports Medicine, the Academy of Nutrition and Dietetics, and the US Department of Agriculture/Agriculture Research Service convened an expert panel meeting in October 2012 titled "Energy Balance at a Crossroads: Translating the Science into Action." Experts in the fields of nutrition and exercise science came together to identify the biological, lifestyle, and environmental changes that will most successfully help children and families attain and manage energy balance and tip the scale toward healthier weights. Two goals were addressed: 1) professional training and 2) consumer/community education. The training goal focused on developing a comprehensive strategy to facilitate the integration of nutrition and physical activity (PA) using a dynamic energy balance approach for regulating weight into the training of undergraduate and graduate students in dietetics/nutrition science, exercise science/PA, and pre-K-12 teacher preparation programs and in training existing cooperative extension faculty. The education goal focused on developing strategies for integrating dynamic energy balance into nutrition and PA educational programs for the public, especially programs funded by federal/state agencies. The meeting expert presenters and participants addressed three key areas: 1) biological and lifestyle factors that affect energy balance, 2) undergraduate/graduate educational and training issues, and 3) best practices associated with educating the public about dynamic energy balance. Specific consensus recommendations were developed for each goal.

  4. Response variability in balanced cortical networks

    DEFF Research Database (Denmark)

    Lerchner, Alexander; Ursta, C.; Hertz, J.

    2006-01-01

    We study the spike statistics of neurons in a network with dynamically balanced excitation and inhibition. Our model, intended to represent a generic cortical column, comprises randomly connected excitatory and inhibitory leaky integrate-and-fire neurons, driven by excitatory input from an external...

  5. High-resolution DEMs for High-mountain Asia: A systematic, region-wide assessment of geodetic glacier mass balance and dynamics

    Science.gov (United States)

    Shean, D. E.; Arendt, A. A.; Osmanoglu, B.; Montesano, P.

    2017-12-01

    High Mountain Asia (HMA) constitutes the largest glacierized region outside of the Earth's polar regions. Although available observations are limited, long-term records indicate sustained regional glacier mass loss since 1850, with increased loss in recent decades. Recent satellite data (e.g., GRACE, ICESat-1) show spatially variable glacier mass balance, with significant mass loss in the Himalaya and Hindu Kush and slight mass gain in the Karakoram. We generated 4000 high-resolution digital elevation models (DEMs) from sub-meter commercial stereo imagery (DigitalGlobe WorldView/GeoEye) acquired over glaciers in High-mountain Asia from 2002-present (mostly 2013-present). We produced a regional 8-m DEM mosaic for 2015 and estimated 15-year geodetic mass balance for 40000 glaciers larger than 0.1 km2. We are combining with other regional DEM sources to systematically document the spatiotemporal evolution of glacier mass balance for the entire HMA region. We also generated monthly to interannual DEM and velocity time series for high-priority sites distributed across the region, with >15-20 DEMs available for some locations from 2010-present. These records document glacier dynamics, seasonal snow accumulation/redistribution, and processes that affect glacier mass balance (e.g., ice-cliff retreat, debris cover evolution). These efforts will provide basin-scale assessments of snow/ice melt runoff contributions for model cal/val and downstream water resources applications. We will continue processing all archived and newly available commercial stereo imagery for HMA, and will release all DEMs through the HiMAT DAAC.

  6. Balancing reserves within a decarbonized European electricity system in 2050. From market developments to model insights

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Casimir [German Institute for Economic Research (DIW Berlin), Berlin (Germany). Dept. of Energy, Transportation, Environment; Univ. of Technology, Berlin (Germany). Workgroup for Infrastructure Policy (WIP)

    2017-03-30

    This paper expands the discussion about future balancing reserve provision to the long-term perspective of 2050. Most pathways for a transformation towards a decarbonized electricity sector rely on very high shares of fluctuating renewables. This can be a challenge for the provision of balancing reserves, although their influence on the balancing cost is unclear. Apart from the transformation of the generation portfolio, various technical and regulatory developments within the balancing framework might further influence balancing costs: i) dynamic dimensioning of balancing reserves, ii) provision by fluctuating renewables or new (battery) storage technologies, and iii) exchange of balancing reserves between balancing zones. The first part of this paper discusses and transforms these developments into quantitative scenario definitions. The second part applies these scenarios to dynELMOD (dynamic Electricity Model), an investment model of the European electricity system that is extended to include balancing reserve provision. In contrast to other models applied in most papers on balancing reserves, this model is capable of evaluating the interdependencies between developments in balancing reserve provision and high shares of fluctuating renewables jointly. The results show that balancing reserve cost can be kept at current levels for a renewable electricity system until 2050, when using a dynamic reserve sizing horizon. Apart from the sizing horizon, storage capacity withholding duration and additional balancing demand from RES are the main driver of balancing costs. Renewables participation in balancing provision is mainly important for negative reserves, while storages play an important role for the provision of positive reserves. However, only on very few occasions, additional storage investments are required for balancing reserve provision, as most of the time sufficient storage capacities are available in the electricity system.

  7. Balancing reserves within a decarbonized European electricity system in 2050. From market developments to model insights

    International Nuclear Information System (INIS)

    Lorenz, Casimir

    2017-01-01

    This paper expands the discussion about future balancing reserve provision to the long-term perspective of 2050. Most pathways for a transformation towards a decarbonized electricity sector rely on very high shares of fluctuating renewables. This can be a challenge for the provision of balancing reserves, although their influence on the balancing cost is unclear. Apart from the transformation of the generation portfolio, various technical and regulatory developments within the balancing framework might further influence balancing costs: i) dynamic dimensioning of balancing reserves, ii) provision by fluctuating renewables or new (battery) storage technologies, and iii) exchange of balancing reserves between balancing zones. The first part of this paper discusses and transforms these developments into quantitative scenario definitions. The second part applies these scenarios to dynELMOD (dynamic Electricity Model), an investment model of the European electricity system that is extended to include balancing reserve provision. In contrast to other models applied in most papers on balancing reserves, this model is capable of evaluating the interdependencies between developments in balancing reserve provision and high shares of fluctuating renewables jointly. The results show that balancing reserve cost can be kept at current levels for a renewable electricity system until 2050, when using a dynamic reserve sizing horizon. Apart from the sizing horizon, storage capacity withholding duration and additional balancing demand from RES are the main driver of balancing costs. Renewables participation in balancing provision is mainly important for negative reserves, while storages play an important role for the provision of positive reserves. However, only on very few occasions, additional storage investments are required for balancing reserve provision, as most of the time sufficient storage capacities are available in the electricity system.

  8. Adaptive control of two-wheeled mobile balance robot capable to adapt different surfaces using a novel artificial neural network–based real-time switching dynamic controller

    Directory of Open Access Journals (Sweden)

    Ali Unluturk

    2017-03-01

    Full Text Available In this article, a novel real-time artificial neural network–based adaptable switching dynamic controller is developed and practically implemented. It will be used for real-time control of two-wheeled balance robot which can balance itself upright position on different surfaces. In order to examine the efficiency of the proposed controller, a two-wheeled mobile balance robot is designed and a test platform for experimental setup is made for balance problem on different surfaces. In a developed adaptive controller algorithm which is capable to adapt different surfaces, mean absolute target angle deviation error, mean absolute target displacement deviation error and mean absolute controller output data are employed for surface estimation by using artificial neural network. In a designed two-wheeled mobile balance robot system, robot tilt angle is estimated via Kalman filter from accelerometer and gyroscope sensor signals. Furthermore, a visual robot control interface is developed in C++ software development environment so that robot controller parameters can be changed as desired. In addition, robot balance angle, linear displacement and controller output can be observed online on personal computer. According to the real-time experimental results, the proposed novel type controller gives more effective results than the classic ones.

  9. Strength and Power Training Effects on Lower Limb Force, Functional Capacity, and Static and Dynamic Balance in Older Female Adults.

    Science.gov (United States)

    Lopes, Paula Born; Pereira, Gleber; Lodovico, Angélica; Bento, Paulo C B; Rodacki, André L F

    2016-03-03

    It has been proposed that muscle power is more effective to prevent falls than muscle force production capacity, as rapid reactions are required to allow the postural control. This study aimed to compare the effects of strength and power training on lower limb force, functional capacity, and static and dynamic balance in older female adults. Thirty-seven volunteered healthy women had been allocated into the strength-training group (n = 14; 69 ± 7.3 years, 155 ± 5.6 cm, 72 ± 9.7 kg), the power-training group (n = 12; 67 ± 7.4 years, 153 ± 5.5 cm, 67.2 ± 7 kg), and control group (n = 11; 65 ± 3.1 years, 154 ± 5.6 cm, 70.9 ± 3 kg). After 12 weeks of training, the strength-training and power-training groups increased significantly maximum dynamic strength (29% and 27%), isometric strength (26% and 37%), and step total time (13% and 14%, dynamic balance), respectively. However, only the power-training group increased the rate of torque development (55%) and the functional capacity in 30-second chair stand (22%) and in time up and go tests (-10%). Empirically, power training may reduce the risk of injuries due to lower loads compared to strength training, and consequently, the physical effort demand during the training session is lower. Therefore, power training should be recommended as attractive training stimuli to improve lower limb force, functional capacity, and postural control of older female adults.

  10. The impact of Wii Fit intervention on dynamic balance control in children with probable Developmental Coordination Disorder and balance problems

    NARCIS (Netherlands)

    Jelsma, Dorothee; Geuze, Reint H; Mombarg, Remo; Smits-Engelsman, Bouwien C.M.

    The aim of this study was to examine differences in the performance of children with probable Developmental Coordination Disorder (p-DCD) and balance problems (BP) and typical developing children (TD) on a Wii Fit task and to measure the effect on balance skills after a Wii Fit intervention.

  11. Exergaming: Interactive balance training in healthy community-dwelling older adults

    NARCIS (Netherlands)

    Kosse, Nienke M.; Caljouw, Simone R.; Vuijk, Pieter-Jelle; Lamoth, Claudine J.C.

    2011-01-01

    Exergaming is a term used for videogame exercise. The aim of this study was to examine the training effect of an exergame that relies on the movements of a dynamic balance board. Nine healthy elderly subjects participated in a six-week intervention in which they played balance games three times a

  12. Dynamic flux balancing elucidates NAD(P)H production as limiting response to furfural inhibition in Saccharomyces cerevisiae.

    Science.gov (United States)

    Pornkamol, Unrean; Franzen, Carl J

    2015-08-01

    Achieving efficient and economical lignocellulose-based bioprocess requires a robust organism tolerant to furfural, a major inhibitory compound present in lignocellulosic hydrolysate. The aim of this study was to develop a model that could generate quantitative descriptions of cell metabolism for elucidating the cell's adaptive response to furfural. Such a modelling tool could provide strategies for the design of more robust cells. A dynamic flux balance (dFBA) model of Saccharomyces cerevisiae was created by coupling a kinetic fermentation model with a previously published genome-scale stoichiometric model. The dFBA model was used for studying intracellular and extracellular flux responses to furfural perturbations under steady state and dynamic conditions. The predicted effects of furfural on dynamic flux profiles agreed well with previously published experimental results. The model showed that the yeast cell adjusts its metabolism in response to furfural challenge by increasing fluxes through the pentose phosphate pathway, TCA cycle, and proline and serine biosynthesis in order to meet the high demand of NAD(P)H cofactors. The model described here can be used to aid in systematic optimization of the yeast, as well as of the fermentation process, for efficient lignocellulosic ethanol production. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Power distribution in complex environmental negotiations: Does balance matter?

    Science.gov (United States)

    Burkardt, N.; Lamb, B.L.; Taylor, J.G.

    1997-01-01

    We studied six interagency negotiations covering Federal Energy Regulatory Commission (FERC) hydroelectric power licenses. Negotiations occurred between state and federal resource agencies and developers over project operations and natural resource mitigation. We postulated that a balance of power among parties was necessary for successful negotiations. We found a complex relationship between balanced power and success and conclude that a balance of power was associated with success in these negotiations. Power played a dynamic role in the bargaining and illuminates important considerations for regulatory design.

  14. Harmonic and power balance tools for tapping-mode atomic force microscope

    International Nuclear Information System (INIS)

    Sebastian, A.; Salapaka, M. V.; Chen, D. J.; Cleveland, J. P.

    2001-01-01

    The atomic force microscope (AFM) is a powerful tool for investigating surfaces at atomic scales. Harmonic balance and power balance techniques are introduced to analyze the tapping-mode dynamics of the atomic force microscope. The harmonic balance perspective explains observations hitherto unexplained in the AFM literature. A nonconservative model for the cantilever - sample interaction is developed. The energy dissipation in the sample is studied and the resulting power balance equations combined with the harmonic balance equations are used to estimate the model parameters. Experimental results confirm that the harmonic and power balance tools can be used effectively to predict the behavior of the tapping cantilever. [copyright] 2001 American Institute of Physics

  15. The Role of Stream Water Carbon Dynamics and Export in the Carbon Balance of a Tropical Seasonal Rainforest, Southwest China

    Science.gov (United States)

    Zhou, Wen-Jun; Zhang, Yi-Ping; Schaefer, Douglas A.; Sha, Li-Qing; Deng, Yun; Deng, Xiao-Bao; Dai, Kai-Jie

    2013-01-01

    A two-year study (2009 ∼ 2010) was carried out to investigate the dynamics of different carbon (C) forms, and the role of stream export in the C balance of a 23.4-ha headwater catchment in a tropical seasonal rainforest at Xishuangbanna (XSBN), southwest China. The seasonal volumetric weighted mean (VWM) concentrations of total inorganic C (TIC) and dissolved inorganic C (DIC) were higher, and particulate inorganic C (PIC) and organic C (POC) were lower, in the dry season than the rainy season, while the VWM concentrations of total organic C (TOC) and dissolved organic C (DOC) were similar between seasons. With increased monthly stream discharge and stream water temperature (SWT), only TIC and DIC concentrations decreased significantly. The most important C form in stream export was DIC, accounting for 51.8% of the total C (TC) export; DOC, POC, and PIC accounted for 21.8%, 14.9%, and 11.5% of the TC export, respectively. Dynamics of C flux were closely related to stream discharge, with the greatest export during the rainy season. C export in the headwater stream was 47.1 kg C ha−1 yr−1, about 2.85% of the annual net ecosystem exchange. This finding indicates that stream export represented a minor contribution to the C balance in this tropical seasonal rainforest. PMID:23437195

  16. The role of stream water carbon dynamics and export in the carbon balance of a tropical seasonal rainforest, southwest China.

    Directory of Open Access Journals (Sweden)

    Wen-Jun Zhou

    Full Text Available A two-year study (2009 ~ 2010 was carried out to investigate the dynamics of different carbon (C forms, and the role of stream export in the C balance of a 23.4-ha headwater catchment in a tropical seasonal rainforest at Xishuangbanna (XSBN, southwest China. The seasonal volumetric weighted mean (VWM concentrations of total inorganic C (TIC and dissolved inorganic C (DIC were higher, and particulate inorganic C (PIC and organic C (POC were lower, in the dry season than the rainy season, while the VWM concentrations of total organic C (TOC and dissolved organic C (DOC were similar between seasons. With increased monthly stream discharge and stream water temperature (SWT, only TIC and DIC concentrations decreased significantly. The most important C form in stream export was DIC, accounting for 51.8% of the total C (TC export; DOC, POC, and PIC accounted for 21.8%, 14.9%, and 11.5% of the TC export, respectively. Dynamics of C flux were closely related to stream discharge, with the greatest export during the rainy season. C export in the headwater stream was 47.1 kg C ha(-1 yr(-1, about 2.85% of the annual net ecosystem exchange. This finding indicates that stream export represented a minor contribution to the C balance in this tropical seasonal rainforest.

  17. Coastal estuaries and lagoons: The delicate balance at the edge of the sea

    Science.gov (United States)

    Conrads, Paul A.; Rodgers, Kirk D.; Passeri, Davina L.; Prinos, Scott T.; Smith, Christopher; Swarzenski, Christopher M.; Middleton, Beth A.

    2018-04-19

    Coastal communities are increasingly concerned about the dynamic balance between freshwater and saltwater because of its implications for societal, economic, and ecological resources. While the mixing of freshwater and saltwater sources defines coastal estuaries and lagoons, sudden changes in this balance can have a large effect on critical ecosystems and infrastructure. Any change to the delivery of water from either source has the potential to affect the health of both humans and natural biota and also to damage coastal infrastructure. This fact sheet discusses the potential of major shifts in the dynamic freshwater-saltwater balance to alter the environment and coastal stability.

  18. Relationships among the Y balance test, Berg Balance Scale, and lower limb strength in middle-aged and older females

    Directory of Open Access Journals (Sweden)

    Dong-Kyu Lee

    2015-06-01

    Full Text Available Background: Older females have less dynamic postural control and muscle strength than do middle-aged females. Aging-related strength losses may limit balancing performance. Objective: The purpose of this study was to investigate the ability of the Y Balance Test (YBT and lower limb strength to discriminate between females in 2 age groups, the relationship between YBT distance and the Berg Balance Scale (BBS, and the degree to which performance on YBT distance is related to lower limb strength in middle-aged and older females. Method: The 40 healthy, independently active females were divided into 2 groups: older and middle-aged. The participants underwent measurements of YBT distance using the YBT, maximal muscular strength of the lower limbs using a handheld dynamometer, and the BBS. Results: The YBT distance in 3 directions and lower limb muscle strength for both lower limbs were significantly lower in the older adults than in the middle-aged group. A moderate correlation but insignificant correlation was found between the YBT composite distance and the BBS score. In the older females, YBT distance was significantly positively correlated with strength of the knee flexor and hip abductor. In the middle-aged group, YBT distance was significantly positively correlated with strength of the knee flexor and hip extensor. Conclusions: Performance on the YBT was influenced by the strength of lower limb. We suggested that YBT can be used to alternative as a measurement of dynamic balance. Proper training programs for older people could include not only strengthening exercises but also YBT performance to improve balance.

  19. Effects of balance Vestibular Rehabilitation Therapy in elderly with Benign Paroxysmal Positional Vertigo: a randomized controlled trial.

    Science.gov (United States)

    Ribeiro, Karyna Myrelly Oliveira Bezerra de Figueiredo; Freitas, Raysa Vanessa de Medeiros; Ferreira, Lidiane Maria de Brito Macedo; Deshpande, Nandini; Guerra, Ricardo Oliveira

    2017-06-01

    To evaluate short-term effects of balance Vestibular Rehabilitation Therapy (VRT) on balance, dizziness symptoms and quality of life of the elderly with chronic Benign Paroxysmal Positional Vertigo (BPPV). In this randomized, single-blind and controlled trial, older adults with chronic BPPV were randomized into two groups, the experimental group (n = 7, age: 69 (65-78) years) and the control group (n = 7, age: 73 (65-76) years). Patients in the experimental group underwent balance VRT (50 min per session, two times a week) and Canalith Repositioning Maneuver (CRM) as required, for 13 weeks. The control group was treated using only CRM as required. Standing and dynamic balance, dizziness symptoms and quality of life were measured at the baseline, and at one, five, nine and thirteen weeks. There were no between-group differences in dizziness, quality of life and standing balance over the 13 weeks. Significant differences were observed in dynamic balance measures between groups (p CRM. Implications for Rehabilitation The findings that balance VRT in addition to CRM improves dynamic balance in elderly people with BPPV should be useful in guiding rehabilitation professionals' clinical decision making to design interventions for seniors suffering from BPPV; Improvements in tests of dynamic balance suggest that the risk of adverse consequences of BPPV in the elderly such as falls and fractures can be potentially reduced through implementation of CRM in conjunction with balance VRT; Lack of additional improvement in Visual Analogue Scale of dizziness and Dizziness Handicap Index suggests that addition of balance VRT does not influence dizziness symptomatology, per se, and CRM alone is effective to ameliorate vertiginous symptoms and potentially improve quality of life.

  20. Workload Balancing on Heterogeneous Systems: A Case Study of Sparse Grid Interpolation

    KAUST Repository

    Muraraşu, Alin; Weidendorfer, Josef; Bode, Arndt

    2012-01-01

    load balancing is essential. This paper proposes static and dynamic solutions for load balancing in the context of an application for visualizing high-dimensional simulation data. The application relies on the sparse grid technique for data compression

  1. The Effects of Shoulder Slings on Balance in Patients With Hemiplegic Stroke

    Science.gov (United States)

    Sohn, Min Kyun; Jee, Sung Ju; Hwang, Pyoungsik; Jeon, Yumi

    2015-01-01

    Objective To investigate the effects of a shoulder sling on balance in patients with hemiplegia. Methods Twenty-seven hemiplegic stroke patients (right 13, left 14) were enrolled in this study. The subjects' movement in their centers of gravity (COGs) during their static and dynamic balance tests was measured with their eyes open in each sling condition-without a sling, with Bobath's axillary support (Bobath sling), and with a simple arm sling. The percent times in quadrant, overall, anterior/posterior, and medial/lateral stability indexes were measured using a posturography platform (Biodex Balance System SD). Functional balance was evaluated using the Berg Balance Scale and the Trunk Impairment Scale. All balance tests were performed with each sling in random order. Results The COGs of right hemiplegic stroke patients and all hemiplegic stroke patients shifted to, respectively, the right and posterior quadrants during the static balance test without a sling (pBobath or the simple arm sling. There was no significant improvement in any stability index during either the static or the dynamic balance tests in any sling condition. Conclusion The right and posterior deviations of the hemiplegic stroke patients' COGs were maintained during the application of the shoulder slings, and there were no significant effects of the shoulder slings on the patients' balance in the standing still position. PMID:26798614

  2. INTRA-RATER RELIABILITY OF WII BALANCE BOARD (WBB IN ASSESSING STANDING BALANCE IN OLDER ADULTS

    Directory of Open Access Journals (Sweden)

    Shilpa Dugani Burji

    2014-06-01

    Full Text Available Background: WII Balance Board (WBB being one of the latest, advanced technologies of high sensitivity in monitoring change in balance over time and owing to, ease of use, and portability, it is being used in physical therapy clinics as a popular substitute for the expensive and complicated force plates to improve dynamic strength and balance. Despite its growing popularity, the WBB’s reliability as an intervention and assessment tool for balance is still being investigated. So this study aims in finding the accuracy of WBB. The objectives of the study are to find the Intraclass Correlation Coefficient and Standard Error Measurement on both day 1 and day 2 with eyes closed and eyes open in older adults. Method: 30 subjects over the age of 65 years were assessed for balance using WBB. Subjects were measured in double limb stance with eyes open and closed with feet comfortably distant apart on the board. The same procedure was repeated after 24 hours. Results: The study showed to be statistically significant for eyes open on day 1 and day 2, but was not statistically significant for eyes closed on day 1 and day 2. Conclusion: The study suggested that the WBB was reliable for eyes open and not reliable with eyes closed.

  3. Time-interval for integration of stabilizing haptic and visual information in subjects balancing under static and dynamic conditions

    Directory of Open Access Journals (Sweden)

    Jean-Louis eHoneine

    2014-10-01

    Full Text Available Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a subtract or integrate sensory inputs, (b move from allocentric to egocentric reference or vice versa, and (c adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1-2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training

  4. Time-interval for integration of stabilizing haptic and visual information in subjects balancing under static and dynamic conditions

    Science.gov (United States)

    Honeine, Jean-Louis; Schieppati, Marco

    2014-01-01

    Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system (CNS) continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a) subtract or integrate sensory inputs; (b) move from allocentric to egocentric reference or vice versa; and (c) adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1–2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift) in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training devices

  5. Basins of attraction in human balance

    Science.gov (United States)

    Smith, Victoria A.; Lockhart, Thurmon E.; Spano, Mark L.

    2017-12-01

    Falls are a recognized risk factor for unintentional injuries among older adults, accounting for a large proportion of fractures, emergency department visits, and urgent hospitalizations. Human balance and gait research traditionally uses linear or qualitative tests to assess and describe human motion; however, human motion is neither a simple nor a linear process. The objective of this research is to identify and to learn more about what factors affect balance using nonlinear dynamical techniques, such as basin boundaries. Human balance data was collected using dual force plates for leans using only ankle movements as well as for unrestricted leans. Algorithms to describe the basin boundary were created and compared based on how well each method encloses the experimental data points as well as captures the differences between the two leaning conditions.

  6. Dynamic modelling of nuclear steam generators

    International Nuclear Information System (INIS)

    Kerlin, T.W.; Katz, E.M.; Freels, J.; Thakkar, J.

    1980-01-01

    Moving boundary, nodal models with dynamic energy balances, dynamic mass balances, quasi-static momentum balances, and an equivalent single channel approach have been developed for steam generators used in nuclear power plants. The model for the U-tube recirculation type steam generator is described and comparisons are made of responses from models of different complexity; non-linear versus linear, high-order versus low order, detailed modeling of the control system versus a simple control assumption. The results of dynamic tests on nuclear power systems show that when this steam generator model is included in a system simulation there is good agreement with actual plant performance. (author)

  7. Wii-habilitation as balance therapy for children with acquired brain injury.

    Science.gov (United States)

    Tatla, Sandy K; Radomski, Anna; Cheung, Jessica; Maron, Melissa; Jarus, Tal

    2014-02-01

    To evaluate the effectiveness of the Nintendo Wii compared to traditional balance therapy in improving balance, motivation, and functional ability in children undergoing acute rehabilitation after brain injury. A non-concurrent, randomized multiple baseline single-subject research design was used with three participants. Data were analyzed by visual inspection of trend lines. Daily Wii balance training was equally motivating to traditional balance therapy for two participants and more motivating for one participant. While improvements in dynamic balance were observed, the results for static balance remain inconclusive. All participants demonstrated improvements in functional ability. Wii balance therapy is a safe, feasible, and motivating intervention for children undergoing acute rehabilitation after an acquired brain injury. Further research to examine the effectiveness of Wii balance therapy in this population is warranted.

  8. Assessing and training standing balance in older adults: a novel approach using the 'Nintendo Wii' Balance Board.

    Science.gov (United States)

    Young, William; Ferguson, Stuart; Brault, Sébastien; Craig, Cathy

    2011-02-01

    Older adults, deemed to be at a high risk of falling, are often unable to participate in dynamic exercises due to physical constraints and/or a fear of falling. Using the Nintendo 'Wii Balance Board' (WBB) (Nintendo, Kyoto, Japan), we have developed an interface that allows a user to accurately calculate a participant's centre of pressure (COP) and incorporate it into a virtual environment to create bespoke diagnostic or training programmes that exploit real-time visual feedback of current COP position. This platform allows researchers to design, control and validate tasks that both train and test balance function. This technology provides a safe, adaptable and low-cost balance training/testing solution for older adults, particularly those at high-risk of falling. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Comparative Effects of Different Balance-Training-Progression Styles on Postural Control and Ankle Force Production: A Randomized Controlled Trial.

    Science.gov (United States)

    Cuğ, Mutlu; Duncan, Ashley; Wikstrom, Erik

    2016-02-01

    Despite the effectiveness of balance training, the exact parameters needed to maximize the benefits of such programs remain unknown. One such factor is how individuals should progress to higher levels of task difficulty within a balance-training program. Yet no investigators have directly compared different balance-training-progression styles. To compare an error-based progression (ie, advance when proficient at a task) with a repetition-based progression (ie, advance after a set amount of repetitions) style during a balance-training program in healthy individuals. Randomized controlled trial. Research laboratory. A total of 28 (16 women, 12 men) physically healthy young adults (age = 21.57 ± 3.95 years, height = 171.60 ± 11.03 cm, weight = 72.96 ± 16.18 kg, body mass index = 24.53 ± 3.7). All participants completed 12 supervised balance-training sessions over 4 weeks. Each session consisted of a combination of dynamic unstable-surface tasks that incorporated a BOSU ball and lasted about 30 minutes. Static balance from an instrumented force plate, dynamic balance as measured via the Star Excursion Balance Test, and ankle force production in all 4 cardinal planes of motion as measured with a handheld dynamometer before and after the intervention. Selected static postural-control outcomes, dynamic postural control, and ankle force production in all planes of motion improved (P .05) for any of the outcome measures. A 4-week balance-training program consisting of dynamic unstable-surface exercises on a BOSU ball improved dynamic postural control and ankle force production in healthy young adults. These results suggest that an error-based balance-training program is comparable with but not superior to a repetition-based balance-training program in improving postural control and ankle force production in healthy young adults.

  10. EFFECTS OF CIRCADIAN RHYTHM ON BALANCE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Karagul Osman

    2017-09-01

    Full Text Available Introduction. The aim of the study was to examine the effect of circadian rhythm on dynamic balance performance and to determine the role of physical activity level, body temperature, chronotype, and gender in this possible effect. Material and

  11. Multi-agent grid system Agent-GRID with dynamic load balancing of cluster nodes

    Science.gov (United States)

    Satymbekov, M. N.; Pak, I. T.; Naizabayeva, L.; Nurzhanov, Ch. A.

    2017-12-01

    In this study the work presents the system designed for automated load balancing of the contributor by analysing the load of compute nodes and the subsequent migration of virtual machines from loaded nodes to less loaded ones. This system increases the performance of cluster nodes and helps in the timely processing of data. A grid system balances the work of cluster nodes the relevance of the system is the award of multi-agent balancing for the solution of such problems.

  12. Visual feedback training using WII Fit improves balance in Parkinson's disease.

    Science.gov (United States)

    Zalecki, Tomasz; Gorecka-Mazur, Agnieszka; Pietraszko, Wojciech; Surowka, Artur D; Novak, Pawel; Moskala, Marek; Krygowska-Wajs, Anna

    2013-01-01

    Postural instability including imbalance is the most disabling long term problem in Parkinson's disease (PD) that does not respond to pharmacotherapy. This study aimed at investigating the effectiveness of a novel visual-feedback training method, using Wii Fit balance board in improving balance in patients with PD. Twenty four patients with moderate PD were included in the study which comprised of a 6-week home-based balance training program using Nintendo Wii Fit and balance board. The PD patients significantly improved their results in Berg Balance Scale, Tinnet's Performance-Oriented Mobility Assessment, Timed Up-and-Go, Sit-to-stand test, 10-Meter Walk test and Activities-specific Balance Confidence scale at the end of the programme. This study suggests that visual feedback training using Wii-Fit with balance board could improve dynamic and functional balance as well as motor disability in PD patients.

  13. Analysis of agility, reaction time and balance variables at badminton players aged 9-14 years

    Directory of Open Access Journals (Sweden)

    Seydi Ahmet Ağaoğlu

    2017-12-01

    Full Text Available Aim: The aim of this study was investigated agility, static and dynamic balance and reaction time variables of badminton players aged between 9-14 and relate with among variables. Material and Methods: In Samsun, 19 males (sport age, 3.42±1.64 years and 12 females (3.00±1.28 years active badminton players were voluntarily participated in who are in 9-14 ages range. Agility was measured by “T” test, CSMI-Tecnobody Pk-252 isokinetic balance system measuring instrument was used to test static balance and dynamic balance and Mozart Lafayette reaction measuring instrument was used to test visual and auditory reaction times of players. Spearman correlation analysis was applied so as to correlation analysis. The level of significance was taken as p<0.05. Results: For female athletes, a positive relation was determined between the agility and the perimeter (mm used (r=0.727; p<0.01 through the static balance measure double foot and eyes are open. For male athletes, a positive relation was determined between the visual reaction time and the perimeter (mm used (r=0.725; p<0.01 through the static balance measure dominant foot and eyes are open. For male and female athletes were not found any correlation between reaction time and dynamic balance. Conclusion: It was determined that audio (ears and visual (eyes reaction time was effective on balance. While badminton players are closed eyes, audio sensors are more influence on balance test through measure dominant foot.

  14. GENETIC ALGORITHM BASED CONCEPT DESIGN TO OPTIMIZE NETWORK LOAD BALANCE

    Directory of Open Access Journals (Sweden)

    Ashish Jain

    2012-07-01

    Full Text Available Multiconstraints optimal network load balancing is an NP-hard problem and it is an important part of traffic engineering. In this research we balance the network load using classical method (brute force approach and dynamic programming is used but result shows the limitation of this method but at a certain level we recognized that the optimization of balanced network load with increased number of nodes and demands is intractable using the classical method because the solution set increases exponentially. In such case the optimization techniques like evolutionary techniques can employ for optimizing network load balance. In this paper we analyzed proposed classical algorithm and evolutionary based genetic approach is devise as well as proposed in this paper for optimizing the balance network load.

  15. TauG-guidance of dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia.

    Science.gov (United States)

    Rasouli, Omid; Stensdotter, Ann-Katrin; Van der Meer, Audrey L H

    2016-08-01

    Impaired postural control has been reported in static conditions in chronic fatigue syndrome and fibromyalgia, but postural control in dynamic tasks have not yet been investigated. Thus, we investigated measurements from a force plate to evaluate dynamic balance control during gait initiation in patients with chronic fatigue syndrome and fibromyalgia compared to matched healthy controls. Thirty female participants (10 per group) performed five trials of gait initiation. Center of pressure (CoP) trajectory of the initial weight shift onto the supporting foot in the mediolateral direction (CoPX) was analyzed using General Tau Theory. We investigated the hypothesis that tau of the CoPX motion-gap (τCoPx) is coupled onto an intrinsic tauG-guide (τG) by keeping the relation τCoPx=KτG, where K is a scaling factor that determines the relevant kinematics of a movement. Mean K values were 0.57, 0.55, and 0.50 in fibromyalgia, chronic fatigue syndrome, and healthy controls, respectively. Both patient groups showed K values significantly higher than 0.50 (P0.5). The findings revealed a lower level of dynamic postural control in both fibromyalgia and chronic fatigue syndrome compared to controls. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Den haemostatiske balance under behandling med nyere p-pillepraeparater

    DEFF Research Database (Denmark)

    Petersen, K R; Skouby, S O; Sidelmann, Johannes Jakobsen

    1994-01-01

    and concentration of tissue plasminogen activator inhibitor. The ratio between thrombin-antithrombin-III-complexes and fibrin degradation products were unchanged signifying no effect of hormonal intake on the balance between thrombin formation and fibrin resolution. In conclusion, the dynamic balance between...... generation and resolution of fibrin was undisturbed during treatment with both hormonal compounds and our findings do not provide evidence for increased risk of thrombosis in normal women....

  17. Striking a balance between types of organisational citizenship ...

    African Journals Online (AJOL)

    kirstam

    8An increasing number of studies suggest that organisational citizenship behaviours ... (OCB-O) and of the balanced aspects on employee innovative work .... 1Based on a dynamic combination of the thermodynamic theory of entropy, Laffer's.

  18. Effects of an 8-Week Body-Weight Neuromuscular Training on Dynamic Balance and Vertical Jump Performances in Elite Junior Skiing Athletes: A Randomized Controlled Trial.

    Science.gov (United States)

    Vitale, Jacopo A; La Torre, Antonio; Banfi, Giuseppe; Bonato, Matteo

    2018-04-01

    Vitale, JA, La Torre, A, Banfi, G, and Bonato, M. Effects of an 8-week body-weight neuromuscular training on dynamic balance and vertical jump performances in elite junior skiing athletes: a randomized controlled trial. J Strength Cond Res 32(4): 911-920, 2018-The aim of the present randomized controlled trial was to evaluate the effects of an 8-week neuromuscular training program focused on core stability, plyometric, and body-weight strengthening exercises on dynamic postural control and vertical jump performance in elite junior skiers. Twenty-four Italian elite junior male skiers were recruited and randomized to either an experimental group (EG), performing neuromuscular warm-up exercises, (EG; n = 12; age 18 ± 1 years; body mass 66 ± 21 kg; height 1.70 ± 0.1 m) or a control group (CG) involved in a standard warm-up (CG; n = 12; age 18 ± 1 years; body mass 62 ± 14 kg; height 1.73 ± 0.1 m). lower quarter Y-Balance Test (YBT), countermovement jump (CMJ), and drop jump (DJ) at baseline (PRE) and at the end (POST) of the experimental procedures were performed. No significant differences between EG and CG were observed at baseline. Results showed that EG achieved positive effects from PRE to POST measures in the anterior, posteromedial, posterolateral directions, and composite score of YBT for both lower limbs, whereas no significant differences were detected for CG. Furthermore, 2-way analysis of variance with Bonferroni's multiple comparisons test did not reveal any significant differences in CMJ and DJ for both EG and CG. The inclusion of an 8-week neuromuscular warm-up program led to positive effects in dynamic balance ability but not in vertical jump performance in elite junior skiers. Neuromuscular training may be an effective intervention to specifically increase lower limb joint awareness and postural control.

  19. The effect of modified trampoline training on balance, gait, and falls efficacy of stroke patients.

    Science.gov (United States)

    Hahn, Joohee; Shin, Seonhae; Lee, Wanhee

    2015-11-01

    [Purpose] This research was conducted to investigate the effects of modified trampoline training on the balance, gait, and falls efficacy of stroke patients. [Subjects] Twenty-four stroke patients participated in this study. The subjects were randomly allocated to one of two groups: the trampoline group (n=12) or the control group (n=12). [Methods] Both groups participated in conventional physical therapy for thirty minutes per day, three times a week for six weeks. The trampoline group also took part in trampoline training for thirty minutes per day, three times a week for six weeks. We evaluated balance (Berg balance scale, timed up and go test), gait (dynamic gait index), and falls efficacy (falls efficacy scale-K) to confirm the effects of the intervention. [Results] Both the trampoline and the control group showed significant improvements in balance, gait, and falls efficacy compared to before the intervention, and the improvements were significantly greater in the trampoline group than in the control group. [Conclusion] Modified trampoline training resulted in significantly improved balance, dynamic gait, and falls efficacy of stroke patients compared to the control group. These results suggest that modified trampoline training is feasible and effective at improving balance, dynamic gait, and falls efficacy after stroke.

  20. On delay adjustment for dynamic load balancing in distributed virtual environments.

    Science.gov (United States)

    Deng, Yunhua; Lau, Rynson W H

    2012-04-01

    Distributed virtual environments (DVEs) are becoming very popular in recent years, due to the rapid growing of applications, such as massive multiplayer online games (MMOGs). As the number of concurrent users increases, scalability becomes one of the major challenges in designing an interactive DVE system. One solution to address this scalability problem is to adopt a multi-server architecture. While some methods focus on the quality of partitioning the load among the servers, others focus on the efficiency of the partitioning process itself. However, all these methods neglect the effect of network delay among the servers on the accuracy of the load balancing solutions. As we show in this paper, the change in the load of the servers due to network delay would affect the performance of the load balancing algorithm. In this work, we conduct a formal analysis of this problem and discuss two efficient delay adjustment schemes to address the problem. Our experimental results show that our proposed schemes can significantly improve the performance of the load balancing algorithm with neglectable computation overhead.

  1. Pilot study comparing changes in postural control after training using a video game balance board program and 2 standard activity-based balance intervention programs.

    Science.gov (United States)

    Pluchino, Alessandra; Lee, Sae Yong; Asfour, Shihab; Roos, Bernard A; Signorile, Joseph F

    2012-07-01

    To compare the impacts of Tai Chi, a standard balance exercise program, and a video game balance board program on postural control and perceived falls risk. Randomized controlled trial. Research laboratory. Independent seniors (N=40; 72.5±8.40) began the training, 27 completed. Tai Chi, a standard balance exercise program, and a video game balance board program. The following were used as measures: Timed Up & Go, One-Leg Stance, functional reach, Tinetti Performance Oriented Mobility Assessment, force plate center of pressure (COP) and time to boundary, dynamic posturography (DP), Falls Risk for Older People-Community Setting, and Falls Efficacy Scale. No significant differences were seen between groups for any outcome measures at baseline, nor were significant time or group × time differences for any field test or questionnaire. No group × time differences were seen for any COP measures; however, significant time differences were seen for total COP, 3 of 4 anterior/posterior displacement and both velocity, and 1 displacement and 1 velocity medial/lateral measure across time for the entire sample. For DP, significant improvements in the overall score (dynamic movement analysis score), and in 2 of the 3 linear and angular measures were seen for the sample. The video game balance board program, which can be performed at home, was as effective as Tai Chi and the standard balance exercise program in improving postural control and balance dictated by the force plate postural sway and DP measures. This finding may have implications for exercise adherence because the at-home nature of the intervention eliminates many obstacles to exercise training. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  2. ANKLE TAPING DOES NOT IMPAIR PERFORMANCE IN JUMP OR BALANCE TESTS

    Directory of Open Access Journals (Sweden)

    Javier Abián-Vicén

    2008-09-01

    Full Text Available This study aimed to investigate the influence of prophylactic ankle taping on two balance tests (static and dynamic balance and one jump test, in the push off and the landing phase. Fifteen active young subjects (age: 21.0 ± 4.4 years without previous ankle injuries volunteered for the study. Each participant performed three tests in two different situations: with taping and without taping. The tests were a counter movement jump, static balance, and a dynamic posturography test. The tests and conditions were randomly performed. The path of the center of pressures was measured in the balance tests, and the vertical ground reaction forces were recorded during the push-off and landing phases of the counter movement jump. Ankle taping had no influence on balance performance or in the push off phase of the jump. However, the second peak vertical force value during the landing phase of the jump was 12% greater with ankle taping (0.66 BW, 95% CI -0.64 to 1.96. The use of prophylactic ankle taping had no influence on the balance or jump performance of healthy young subjects. In contrast, the taped ankle increased the second peak vertical force value, which could be related to a greater risk of injury produced by the accumulation of repeated impacts in sports where jumps are frequently performed

  3. Reliability and number of trials of Y Balance Test in adolescent athletes.

    Science.gov (United States)

    Linek, Pawel; Sikora, Damian; Wolny, Tomasz; Saulicz, Edward

    2017-10-01

    The Star Excursion Balance Test (SEBT) is commonly used to evaluate dynamic equilibrium. The Y Balance Test (Y-BT) is a shortened version of the SEBT where a Y- Balance Kit is commonly used. To date, research concerning the protocol and reliability of the SEBT and Y-BT has been conducted only for adults. The aim of the study was to assess the protocol (the necessary number of trials to stabilize the results) and reliability of the Y-BT in adolescent athletes. One-way repeated-measures analysis of variance (ANOVA) and reliability study. The sample of 38 athletes (mean age: 15.6 years) was selected from a football club. A Y-Balance test kit was applied for the evaluation of dynamic balance. The analysis used the values normalized to the relative length of the lower limbs. After six attempts, three consecutive ones achieved stability for all directions and both extremities (p > 0.05). The intraclass correlation coefficient (ICC 3,1 ), standard error of measurement and minimal detectable change values for the three attempts ranged from 0.57 to 0.82, from 3 to less than 6% and from 7.68 to 13.7%, respectively. In the study of adolescent dynamic equilibrium using the Y-BT, it is recommended to perform nine attempts (including six trial attempts and three measurements). In order to increase reliability it is recommended that the average of the three measured attempts is analysed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Comparative Effects of Different Balance-Training–Progression Styles on Postural Control and Ankle Force Production: A Randomized Controlled Trial

    Science.gov (United States)

    Cuğ, Mutlu; Duncan, Ashley; Wikstrom, Erik

    2016-01-01

    Context:  Despite the effectiveness of balance training, the exact parameters needed to maximize the benefits of such programs remain unknown. One such factor is how individuals should progress to higher levels of task difficulty within a balance-training program. Yet no investigators have directly compared different balance-training–progression styles. Objective:  To compare an error-based progression (ie, advance when proficient at a task) with a repetition-based progression (ie, advance after a set amount of repetitions) style during a balance-training program in healthy individuals. Design:  Randomized controlled trial. Setting:  Research laboratory. Patients or Other Participants:  A total of 28 (16 women, 12 men) physically healthy young adults (age = 21.57 ± 3.95 years, height = 171.60 ± 11.03 cm, weight = 72.96 ± 16.18 kg, body mass index = 24.53 ± 3.7). Intervention(s):  All participants completed 12 supervised balance-training sessions over 4 weeks. Each session consisted of a combination of dynamic unstable-surface tasks that incorporated a BOSU ball and lasted about 30 minutes. Main Outcome Measure(s):  Static balance from an instrumented force plate, dynamic balance as measured via the Star Excursion Balance Test, and ankle force production in all 4 cardinal planes of motion as measured with a handheld dynamometer before and after the intervention. Results:  Selected static postural-control outcomes, dynamic postural control, and ankle force production in all planes of motion improved (P .05) for any of the outcome measures. Conclusions:  A 4-week balance-training program consisting of dynamic unstable-surface exercises on a BOSU ball improved dynamic postural control and ankle force production in healthy young adults. These results suggest that an error-based balance-training program is comparable with but not superior to a repetition-based balance-training program in improving postural control and ankle force production in

  5. The Mammalian Cortex as a Self-Organizing Complex System: Multi-Scale Homeostatic Approaches to Criticality via Dynamical Balance of Inhibition against Excitation

    Science.gov (United States)

    Ng, Tony T.

    The mammalian cortex is a highly structured network of densely packed neurons that interact strongly with each other in very specific ways. Loosely speaking, neurons are cells that fire clicks at each other as a means of communication. Common sites of communication, known as synapses, are enabled by transmitter molecules released from presynaptic sender cells, which bind to receptors on postsynaptic receiver cells. There are two major classes of neurons - excitatory ones that prompt their downstream neighbors to fire spikes through depolarization, and inhibitory ones that suppress spike activity of their postsynaptic partners via hyperpolarization. Depolarization and hyperpolarization make membrane potential of a cell more positive and more negative, respectively. A sufficiently depolarized neuron fires a spike, which technically is called an action potential. In this thesis, we focus on the interplay between three of the cortex's most ubiquitous features and examine some of the consequences that their interactions have on cortical dynamics. One of the features, widespread projections between clusters of excitatory neurons, is topological. The two remaining features, homeostasis and balance between the amount of excitatory and inhibitory activity are dynamical. Here, homeostasis refers to the regulatory mechanism of individual cells or collections of cells that maintains constant levels of spike activity over time. Simply by varying the average homeostatic firing rate in clusters of excitatory neurons or by tuning the common homoeostatic rate of individual inhibitory neurons, we show via simulation that cluster-based activity bursts can exhibit critical dynamics and display power-law distributions with exponents that are consistent with those found in in vivo experiments of awake animals. Criticality is an idea that originated in statistical physics. At the critical point, activity levels of sites across an entire system, such as those of different cortical regions

  6. System Dynamics Modeling as a Supporting Tool in order to Uncover Relevant KPI’s as well as Their Main Relations in the Process of Constructing a Balanced Scorecard

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn; Bjoern Pedersen, Lars

    This paper focuses on how system dynamics modelling can contribute to an increased understanding of business, which is necessarily to identify those variables that are strongest in relation to supporting the company's strategy execution through the use of the Balanced Scorecard. Strategic plannin...

  7. Balance and risk of fall in individuals with bilateral mild and moderate knee osteoarthritis.

    Science.gov (United States)

    Khalaj, Nafiseh; Abu Osman, Noor Azuan; Mokhtar, Abdul Halim; Mehdikhani, Mahboobeh; Wan Abas, Wan Abu Bakar

    2014-01-01

    Balance is essential for mobility and performing activities of daily living. People with knee osteoarthritis display impairment in knee joint proprioception. Thus, the aim of this study was to evaluate balance and risk of fall in individuals with bilateral mild and moderate knee osteoarthritis. Sixty subjects aged between 50 and 70 years volunteered in this study. They were categorized into three groups which were healthy (n = 20), mild (n = 20) and moderate (n = 20) bilateral knee osteoarthritis groups. Dynamic and static balance and risk of fall were assessed using Biodex Stability System. In addition, Timed Up and Go test was used as a clinical test for balance. Results of this study illustrated that there were significant differences in balance (dynamic and static) and risk of fall between three groups. In addition, the main (most significant) difference was found to be between healthy group and moderate group. Furthermore, on clinical scoring of balance, the "Timed Up and Go" test, all three groups showed significant difference. In conclusion, bilateral knee osteoarthritis impaired the balance and increased the risk of fall, particularly in people with moderate knee osteoarthritis.

  8. Clinical measures of balance in people with type two diabetes: A systematic literature review.

    Science.gov (United States)

    Dixon, C J; Knight, T; Binns, E; Ihaka, B; O'Brien, D

    2017-10-01

    Approximately 422 million people have diabetes mellitus worldwide, with the majority diagnosed with type 2 diabetes mellitus (T2DM). The complications of diabetes mellitus include diabetic peripheral neuropathy (DPN) and retinopathy, both of which can lead to balance impairments. Balance assessment is therefore an integral component of the clinical assessment of a person with T2DM. Although there are a variety of balance measures available, it is uncertain which measures are the most appropriate for this population. Therefore, the aim of this study was to conduct a systematic review on clinical balance measures used with people with T2DM and DPN. Databases searched included: CINAHL plus, MEDLINE, SPORTDiscus, Dentistry and Oral Sciences source, and SCOPUS. Key terms, inclusion and exclusion criteria were used to identify appropriate studies. Identified studies were critiqued using the Downs and Black appraisal tool. Eight studies were included, these studies incorporated a total of ten different clinical balance measures. The balance measures identified included the Dynamic Balance Test, balance walk, tandem and unipedal stance, Functional Reach Test, Clinical Test of Sensory Interaction and Balance, Berg Balance Scale, Tinetti Performance-Oriented Mobility Assessment, Activity-Specific Balance Confidence Scale, Timed Up and Go test, and the Dynamic Gait Index. Numerous clinical balance measures were used for people with T2DM. However, the identified balance measures did not assess all of the systems of balance, and most had not been validated in a T2DM population. Therefore, future research is needed to identify the validity of a balance measure that assesses these systems in people with T2DM. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Load Balancing As A Service In Openstack-Liberty

    Directory of Open Access Journals (Sweden)

    Rashmi T V

    2015-08-01

    Full Text Available Cloud computing is a technology which provides computing resource on demand over the internet as a service. To meet this many opensource cloud operating system are provided for the tenants in order to get useful services from the cloud. There are many opensource cloud OS like AWS Open Shift HP OpenStack etc. Out of all these OpenStack comes with free of cost and it has got a huge community. It can be installed and deploy in private institution or company with free of cost. This paper provides a model and techniques for the dynamic load balancing in OpenStack for managing the trafficloads among the Virtual Machines. The main purpose is to increase the utilization of computing resources and minimize the traffic. Load Balancing as a Service is one of the main service in OpenStack Networking. OpenStack is an opensource platform which provides Infrastructure as a Service. It allows userstenants tocreate their own private clouds and to deploy Virtual Machines which manages different workloads. In this paper we provide an architecture of openstack LBaaS for dynamic load balancing in open stack cloud deployment.

  10. Does Kinesiology tape counter exercise-related impairments of balance in the elderly?

    Science.gov (United States)

    Hosp, Simona; Csapo, Robert; Heinrich, Dieter; Hasler, Michael; Nachbauer, Werner

    2018-05-01

    Maintaining balance is an essential requirement for the performance of daily tasks and sporting activities, particularly in older adults to prevent falls and associated injuries. Kinesiology tape has gained great popularity in sports and is frequently used as a tool for performance enhancement. However, there is little research investigating its influence on balance. The purpose of this study was to evaluate the effect of Kinesiology tape on dynamic balance, postural stability and knee proprioception after physical activity in healthy, older adults. Twelve physically active, healthy men aged 63-77 years performed the test on two separate days, with and without Kinesiology tape at the knee joint (prospective intervention with cross-over design). Dynamic balance during an obstacle-crossing task, postural stability in a single-leg stance test, and knee joint position sense as a measure of proprioception were examined before and after 30 min of downhill walking on a treadmill. The influences of taping condition and physical activity on all parameters were statistically tested using factorial ANOVAs. Factorial ANOVA revealed significant time × taping condition interaction effects on all performance parameters (p postural stability and knee proprioception differed between the two taping conditions. The deterioration of performance was always greater when no tape was used. This study demonstrated that physical exercise significantly deteriorated dynamic balance, postural stability and knee proprioception in older men. These effects can be attenuated through the usage of Kinesiology tape. By preventing exercise-related impairments of balance, Kinesiology tape might help reduce the risk of sports-associated falls and associated injuries. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Relationships Between Simple Toe Elevation Angle in the Standing Position and Dynamic Balance and Fall Risk Among Community-Dwelling Older Adults.

    Science.gov (United States)

    Takatori, Katsuhiko; Matsumoto, Daisuke

    2015-10-01

    To investigate the relationships between toe elevation ability in the standing position and dynamic balance and fall risk among community-dwelling older adults. Cross-sectional survey. General community. Community-dwelling older adults (N = 287). Toe elevation angles in the standing position. Intra-rater and inter-rater reliability of measurements of the toe elevation angle was high (internal coefficient of correlation [ICC] (1,2) = 0.94 for the former and ICC (2,1) = 0.90 for the latter). Significant correlations were found between the toe elevation angle and age (r = -0.20, P fall in the previous 6 months had a significantly lower toe elevation angle compared with subjects who did not experience a fall (t = 2.19, P balance ability and appears to be a simple screening test for fall risk in community-dwelling older adults. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  12. Hormone Replacement and Strength Training Positively Influence Balance During Gait in Post-Menopausal Females: A Pilot Study

    Science.gov (United States)

    Perry, Stephen D.; Bombardier, Eric; Radtke, Alison; Tiidus, Peter M.

    2005-01-01

    This study examined the effects of hormone replacement combined with strength training on improving dynamic balance control in post-menopausal women. Thirty one participating post-menopausal women were divided into three groups (hormone replacement (HR), non-hormone replacement (NR) and control (CR) group). HR and NR groups were tested for muscle strength and balance control during gait, prior to training and following a six week lower body strength training program. Quadriceps muscle strength was evaluated as isokinetic peak torque (60°·sec-1) using a CYBEX NORM and balance control was evaluated by center of mass - base of support relationships and ground reaction forces during gait perturbations. Only the HR group showed significantly (p < 0.05) improved balance control during the initial phase of unexpected gait termination and single stance periods while walking across uneven terrain following training. The strength gains in the HR group tended to be greater than in the NR group over the six week training program, although neither group showed statistically significant increases. The CR group showed no significant differences between testing times. HR in post-menopausal females may enhance dynamic balance control when combined with a strength training program, even if no statistically significant gains in strength are achieved. Key Points This study provides evidence that even a short modest strength training program can enhance dynamic balance control in older adult females taking hormone replacement. If potential benefits of hormone replacement therapy extend to enhancing muscle strength then this would be important in designing optimal interventions for both strength and balance for this cohort. Future work should explore the influence of hormone replacement therapy on other dynamic balance or functional tasks. PMID:24501551

  13. Analysis of Dynamical Characteristic of Piecewise-Nonlinear Asymmetric Hysteretic System Based on Incremental Harmonic Balance Method

    Directory of Open Access Journals (Sweden)

    H. R. Liu

    2015-01-01

    Full Text Available Considering a sort of elastic mass with asymmetric hysteresis characteristic which widespread existing in engineering field, a piecewise-nonlinear dynamical equation, which contains asymmetric hysteretic loop, is established. By using the method of Incremental Harmonic Balance (IHB, the analytic linearized algebraic equation of the system is obtained. On the basis of this algebraic equation, the coefficients of the algebraic expression are figured out by the incremental procedure and the iterative process of the regulated variable. Through the emulation, the amplitude frequency response curve and the relation between the value of the harmonic component and the external excitation are researched; the bistable regions of the bifurcation diagram of the system under the variation of the excitation amplitude are studied. The above results can be used to guide the research of the asymmetric hysteretic system with polynomial expression.

  14. The Effects of a Postural Balance Training Program on Balance, Gait and Health-Related Quality of Life in Patients with Essential Tremor

    Directory of Open Access Journals (Sweden)

    Bilge Kara

    2018-03-01

    Full Text Available Objective: Although the effectiveness of postural balance training on balance and gait impairment has been proven as an effective treatment approach in several patient and healthy populations, its effectiveness in patients with essential tremor (ET is yet unknown. The aim was to examine the effects of postural balance training program on balance and gait performance, and health-related quality of life in patients with ET. Materials and Methods: This uncontrolled clinical study included patients with ET. The outcome measures were the Postural Stability Test, Limits of Stability Test, Fall Risk Test, Activities-Specific Balance Confidence scale, Dynamic Gait Index, and Short Form-36. The assessments were performed before and after the training program. The participants underwent an 8-week balance training designed to improve their ability to integrate multisensory inputs and postural control using a computerized balance assessment and training device. Results: In total, 24 patients with ET participated in the study. The compliance rate was 87.5%. There were significant improvements in all outcome measures of balance and gait performance, balance confidence, fall risk, and health-related quality of life (except the mental component, p>0.05 between baseline and 8 weeks (p<0.05. Conclusion: Our results suggest that the balance training program is a feasible method that may have positive effects on balance performance and confidence, gait performance, and health-related quality of life in patients with ET

  15. Single- and Dual-Task Balance Training Are Equally Effective in Youth.

    Science.gov (United States)

    Lüder, Benjamin; Kiss, Rainer; Granacher, Urs

    2018-01-01

    Due to maturation of the postural control system and secular declines in motor performance, adolescents experience deficits in postural control during standing and walking while concurrently performing cognitive interference tasks. Thus, adequately designed balance training programs may help to counteract these deficits. While the general effectiveness of youth balance training is well-documented, there is hardly any information available on the specific effects of single-task (ST) versus dual-task (DT) balance training. Therefore, the objectives of this study were (i) to examine static/dynamic balance performance under ST and DT conditions in adolescents and (ii) to study the effects of ST versus DT balance training on static/dynamic balance under ST and DT conditions in adolescents. Twenty-eight healthy girls and boys aged 12-13 years were randomly assigned to either 8 weeks of ST or DT balance training. Before and after training, postural sway and spatio-temporal gait parameters were registered under ST (standing/walking only) and DT conditions (standing/walking while concurrently performing an arithmetic task). At baseline, significantly slower gait speed ( p 0.05, d = 0-0.1) in DT costs for all parameters of secondary task performance during standing and walking. Training produced significant pre-post increases ( p = 0.001; d = 1.47) in secondary task performance while sitting. The observed increase was significantly greater for the ST training group ( p = 0.04; d = 0.81). For standing, no significant changes were found over time irrespective of the experimental group. We conclude that adolescents showed impaired DT compared to ST walking but not standing. ST and DT balance training resulted in significant and similar changes in DT costs during walking. Thus, there appears to be no preference for either ST or DT balance training in adolescents.

  16. Elevated atmospheric CO2 in a semi-natural grassland: Root dynamics, decomposition and soil C balances

    International Nuclear Information System (INIS)

    Sindhoej, Erik

    2001-01-01

    This thesis focuses on how elevated atmospheric CO 2 affects a semi-natural grassland, with emphasis on root growth, decomposition and the subsequent long-term effects on soil C balances. Parts of a semi-natural grassland in Central Sweden were enclosed in open-top chambers and exposed to ambient and elevated levels of CO 2 (+350 μmol mol -1 ) from 1995 to 2000, while chamberless rings were used for controls. Root dynamics were observed with minirhizotrons while root biomass and production were studied with soil cores and ingrowth cores. Roots collected from ingrowth cores were incubated under controlled conditions for 160 days to measure root decomposition rates. Treatment-induced differences in microclimate, C input and root decomposability were entered into the ICBM soil C balance model for 30-year projections of soil C balances for the three treatments. Elevated CO 2 chambers had higher biomass production both above and below ground compared to ambient, however the root response increased over the years while the shoot response decreased. Plants grown under elevated CO 2 had greater water-use efficiency compared to ambient, which was shown in higher soil moisture and greater biomass production during slightly dry years. Elevated CO 2 chambers showed higher root appearance rates in spring and higher disappearance rates during autumn and winter. Roots from plants grown under elevated CO 2 decomposed more rapidly. The decreased input and the drier conditions in the ambient chambers were projected to lead to a 1.7% decrease in soil C over 30 years. Under elevated CO 2 , however, the increased input compensated for the higher root decomposability and moister soil conditions and lead only to a projected 1.3% decrease in soil C. This work shows that six years of elevated CO 2 exposure had extensive effects on this semi-natural grassland. The CO 2 response of the grassland was dependent on weather conditions and production increased most when under slight water stress

  17. Balance outcomes following a tap dance program for a child with congenital myotonic muscular dystrophy.

    Science.gov (United States)

    Biricocchi, Charlanne; Drake, JaimeLynn; Svien, Lana

    2014-01-01

    This case report describes the effects of a 6-week progressive tap dance program on static and dynamic balance for a child with type 1 congenital myotonic muscular dystrophy (congenital MMD1). A 6-year-old girl with congenital MMD1 participated in a 1-hour progressive tap dance program. Classes were held once a week for 6 consecutive weeks and included 3 children with adaptive needs and 1 peer with typical development. The Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2) balance subsection and the Pediatric Balance Scale were completed at the beginning of the first class and the sixth class. The participant's BOT-2 score improved from 3 to 14. Her Pediatric Balance Scale score did not change. Participation in a progressive tap dance class by a child with congenital MMD1 may facilitate improvements in static and dynamic balance.

  18. Balance Training Enhances Motor Coordination During a Perturbed Sidestep Cutting Task.

    Science.gov (United States)

    Oliveira, Anderson Souza; Silva, Priscila Brito; Lund, Morten Enemark; Farina, Dario; Kersting, Uwe Gustav

    2017-11-01

    Study Design Controlled laboratory study. Background Balance training may improve motor coordination. However, little is known about the changes in motor coordination during unexpected perturbations to postural control following balance training. Objectives To study the effects of balance training on motor coordination and knee mechanics during perturbed sidestep cutting maneuvers in healthy adults. Methods Twenty-six healthy men were randomly assigned to a training group or a control group. Before balance training, subjects performed unperturbed, 90° sidestep cutting maneuvers and 1 unexpected perturbed cut (10-cm translation of a movable platform). Participants in the training group participated in a 6-week balance training program, while those in the control group followed their regular activity schedule. Both groups were retested after a 6-week period. Surface electromyography was recorded from 16 muscles of the supporting limb and trunk, as well as kinematics and ground reaction forces. Motor modules were extracted from electromyography by nonnegative matrix factorization. External knee abduction moments were calculated using inverse dynamics equations. Results Balance training reduced the external knee abduction moment (33% ± 25%, PBalance training also increased burst duration for the motor module related to landing early in the perturbation phase (23% ± 11%, PBalance training resulted in altered motor coordination and a reduction in knee abduction moment during an unexpected perturbation. The previously reported reduction in injury incidence following balance training may be linked to changes in dynamic postural stability and modular neuromuscular control. J Orthop Sports Phys Ther 2017;47(11):853-862. Epub 23 Sep 2017. doi:10.2519/jospt.2017.6980.

  19. Ankle taping does not impair performance in jump or balance tests.

    Science.gov (United States)

    Abián-Vicén, Javier; Alegre, Luis M; Fernández-Rodríguez, J Manuel; Lara, Amador J; Meana, Marta; Aguado, Xavier

    2008-01-01

    This study aimed to investigate the influence of prophylactic ankle taping on two balance tests (static and dynamic balance) and one jump test, in the push off and the landing phase. Fifteen active young subjects (age: 21.0 ± 4.4 years) without previous ankle injuries volunteered for the study. Each participant performed three tests in two different situations: with taping and without taping. The tests were a counter movement jump, static balance, and a dynamic posturography test. The tests and conditions were randomly performed. The path of the center of pressures was measured in the balance tests, and the vertical ground reaction forces were recorded during the push-off and landing phases of the counter movement jump. Ankle taping had no influence on balance performance or in the push off phase of the jump. However, the second peak vertical force value during the landing phase of the jump was 12% greater with ankle taping (0.66 BW, 95% CI -0.64 to 1.96). The use of prophylactic ankle taping had no influence on the balance or jump performance of healthy young subjects. In contrast, the taped ankle increased the second peak vertical force value, which could be related to a greater risk of injury produced by the accumulation of repeated impacts in sports where jumps are frequently performed. Key pointsAnkle taping has no influence on balance performance.Ankle taping does not impair performance during the push-off phase of the jump.Ankle taping could increase the risk of injury during landings by increasing peak forces.

  20. Balanced Flow Meters without Moving Parts

    Science.gov (United States)

    Kelley, Anthony R.; VanBuskirk, Paul

    2008-01-01

    Balanced flow meters are recent additions to an established class of simple, rugged flow meters that contain no moving parts in contact with flow and are based on measurement of pressure drops across objects placed in flow paths. These flow meters are highly accurate, minimally intrusive, easily manufacturable, and reliable. A balanced flow meter can be easily mounted in a flow path by bolting it between conventional pipe flanges. A balanced flow meter can be used to measure the flow of any of a variety of liquids or gases, provided that it has been properly calibrated. Relative to the standard orifice-plate flow meter, the balanced flow meter introduces less turbulence and two times less permanent pressure loss and is therefore capable of offering 10 times greater accuracy and repeatability with less dissipation of energy. A secondary benefit of the reduction of turbulence is the reduction of vibration and up to 15 times less acoustic noise generation. Both the balanced flow meter and the standard orifice-plate flow meter are basically disks that contain holes and are instrumented with pressure transducers on their upstream and downstream faces. The most obvious difference between them is that the standard orifice plate contains a single, central hole while the balanced flow meter contains multiple holes. The term 'balanced' signifies that in designing the meter, the sizes and locations of the holes are determined in an optimization procedure that involves balancing of numerous factors, including volumetric flow, mass flow, dynamic pressure, kinetic energy, all in an effort to minimize such undesired effects as turbulence, pressure loss, dissipation of kinetic energy, and non-repeatability and nonlinearity of response over the anticipated range of flow conditions. Due to proper balancing of these factors, recent testing demonstrated that the balanced flow-meter performance was similar to a Venturi tube in both accuracy and pressure recovery, but featured reduced

  1. Analysis of Human Standing Balance by Largest Lyapunov Exponent

    Directory of Open Access Journals (Sweden)

    Kun Liu

    2015-01-01

    Full Text Available The purpose of this research is to analyse the relationship between nonlinear dynamic character and individuals’ standing balance by the largest Lyapunov exponent, which is regarded as a metric for assessing standing balance. According to previous study, the largest Lyapunov exponent from centre of pressure time series could not well quantify the human balance ability. In this research, two improvements were made. Firstly, an external stimulus was applied to feet in the form of continuous horizontal sinusoidal motion by a moving platform. Secondly, a multiaccelerometer subsystem was adopted. Twenty healthy volunteers participated in this experiment. A new metric, coordinated largest Lyapunov exponent was proposed, which reflected the relationship of body segments by integrating multidimensional largest Lyapunov exponent values. By using this metric in actual standing performance under sinusoidal stimulus, an obvious relationship between the new metric and the actual balance ability was found in the majority of the subjects. These results show that the sinusoidal stimulus can make human balance characteristics more obvious, which is beneficial to assess balance, and balance is determined by the ability of coordinating all body segments.

  2. Insensitive versus efficient dynamic load balancing in networks without blocking

    NARCIS (Netherlands)

    Jonckheere, M.

    2006-01-01

    So-called Whittle networks have recently been shown to give tight approximations for the performance of non-locally balanced networks with blocking, including practical routing policies such as joining the shortest queue. In the present paper, we turn the attention to networks without blocking. To

  3. Effectiveness of a Wii balance board-based system (eBaViR for balance rehabilitation: a pilot randomized clinical trial in patients with acquired brain injury

    Directory of Open Access Journals (Sweden)

    Alcañiz Mariano

    2011-05-01

    Full Text Available Abstract Background Acquired brain injury (ABI is the main cause of death and disability among young adults. In most cases, survivors can experience balance instability, resulting in functional impairments that are associated with diminished health-related quality of life. Traditional rehabilitation therapy may be tedious. This can reduce motivation and adherence to the treatment and thus provide a limited benefit to patients with balance disorders. We present eBaViR (easy Balance Virtual Rehabilitation, a system based on the Nintendo® Wii Balance Board® (WBB, which has been designed by clinical therapists to improve standing balance in patients with ABI through motivational and adaptative exercises. We hypothesize that eBaViR, is feasible, safe and potentially effective in enhancing standing balance. Methods In this contribution, we present a randomized and controlled single blinded study to assess the influence of a WBB-based virtual rehabilitation system on balance rehabilitation with ABI hemiparetic patients. This study describes the eBaViR system and evaluates its effectiveness considering 20 one-hour-sessions of virtual reality rehabilitation (n = 9 versus standard rehabilitation (n = 8. Effectiveness was evaluated by means of traditional static and dynamic balance scales. Results The final sample consisted of 11 men and 6 women. Mean ± SD age was 47.3 ± 17.8 and mean ± SD chronicity was 570.9 ± 313.2 days. Patients using eBaViR had a significant improvement in static balance (p = 0.011 in Berg Balance Scale and p = 0.011 in Anterior Reaches Test compared to patients who underwent traditional therapy. Regarding dynamic balance, the results showed significant improvement over time in all these measures, but no significant group effect or group-by-time interaction was detected for any of them, which suggests that both groups improved in the same way. There were no serious adverse events during treatment in either group. Conclusions The

  4. Effectiveness of a Wii balance board-based system (eBaViR) for balance rehabilitation: a pilot randomized clinical trial in patients with acquired brain injury.

    Science.gov (United States)

    Gil-Gómez, José-Antonio; Lloréns, Roberto; Alcañiz, Mariano; Colomer, Carolina

    2011-05-23

    Acquired brain injury (ABI) is the main cause of death and disability among young adults. In most cases, survivors can experience balance instability, resulting in functional impairments that are associated with diminished health-related quality of life. Traditional rehabilitation therapy may be tedious. This can reduce motivation and adherence to the treatment and thus provide a limited benefit to patients with balance disorders. We present eBaViR (easy Balance Virtual Rehabilitation), a system based on the Nintendo® Wii Balance Board® (WBB), which has been designed by clinical therapists to improve standing balance in patients with ABI through motivational and adaptative exercises. We hypothesize that eBaViR, is feasible, safe and potentially effective in enhancing standing balance. In this contribution, we present a randomized and controlled single blinded study to assess the influence of a WBB-based virtual rehabilitation system on balance rehabilitation with ABI hemiparetic patients. This study describes the eBaViR system and evaluates its effectiveness considering 20 one-hour-sessions of virtual reality rehabilitation (n = 9) versus standard rehabilitation (n = 8). Effectiveness was evaluated by means of traditional static and dynamic balance scales. The final sample consisted of 11 men and 6 women. Mean ± SD age was 47.3 ± 17.8 and mean ± SD chronicity was 570.9 ± 313.2 days. Patients using eBaViR had a significant improvement in static balance (p = 0.011 in Berg Balance Scale and p = 0.011 in Anterior Reaches Test) compared to patients who underwent traditional therapy. Regarding dynamic balance, the results showed significant improvement over time in all these measures, but no significant group effect or group-by-time interaction was detected for any of them, which suggests that both groups improved in the same way. There were no serious adverse events during treatment in either group. The results suggest that eBaViR represents a safe and effective

  5. Dynamic response of high speed centrifuge for reprocessing plant

    International Nuclear Information System (INIS)

    Rajput, Gaurav; Satish Kumar, V.; Selvaraj, T.; Ananda Rao, S.M.; Ravisankar, A.

    2012-01-01

    The standard for balancing the rotating bowl describes only the details about the selection of balance quality grade and the permissible residual unbalance for different operating speeds. This paper presents the effects of unbalance on the rotating bowl of high speed centrifuge used in reprocessing of spent nuclear fuel. In this study, the residual unbalance is evaluated for different recommended balancing grades in accordance with the ISO 1940. This unbalance mass generates dynamic force which acts on the rotor. The dynamic response of the rotor like displacements and stresses under this dynamic force are studied by numerical simulation. Finally, the effect of residual unbalance on the rotating bowl performance for different balancing grades is discussed. The experimental measurements are also carried out for the case of G 1.0 grade balanced rotating bowl to validate the resonance frequency as well as vibration amplitudes. (author)

  6. Effect of Playful Balancing Training - A Pilot Randomized Controlled Trial

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Jessen, Jari Due

    2013-01-01

    We used the modular playware in the form of modular interactive tiles for playful training of community-dwelling elderly with balancing problem. During short-term play on the modular interactive tiles, the elderly were playing physical, interactive games that were challenging their dynamic balance...... increase in balancing performance (DGI score: 21.3) after short-term playful training with the modular interactive tiles, whereas the control group remained with a score indicating balancing problems and risk of falling (DGI score: 16.6). The small pilot randomized controlled trial suggests...... that the playful interaction with the modular interactive tiles has a significant effect even after a very short time of play. The average total training time to obtain the statistical significant effect amounted to just 2h45m....

  7. COMPARATIVE STUDY OF 4 WEEKS OF DYNAMIC B ALANCE TRAINING PROGRAM IN COLLEGIATE FOOTBALL PLAYERS: RANDOMIZED CLINICAL TRIAL

    Directory of Open Access Journals (Sweden)

    Nisha

    2015-03-01

    Full Text Available BACKGROUND: Balance is highly integrative dynamic process involving coordination of multiple neurological pathways that allows for the maintenance of the COG over BOS . Football players often perform lower extremity passing , shooting , twisting , cutting and dribbling skills while wearing shoes , these actions require body to be in the equilibrium position to perform the task . This leads to t he conclusion of the great importance of the ability of balance in football . AIMS: 1 . To study the effect of 4 week multidirectional balance board training on dynamic balance in football players . 2 . To study the effect of 4 week Both Sides Up ball training on dynamic balance in football players . 3 . To compare the effect of multidirectional balance board training program and BOSU ball training program on dynamic balance in football players . STUDY DESIGN: Randomized Clinical trial . METHODS: Total of 60 competitive badminton players with age group between18 - 25 were recruited in this study . The participants were allocated into 2 groups viz ., Group A (multidirectional balance board training and Group B (BOSU ball Training for a period of 4 we eks . Participants were test for SEBT and vertical jump test on first day and after 4 weeks of balance training . STATISTICAL ANALYSIS: Student t test , Chi - Square Test . RESULTS: The data analysis and statistical inference showed that , after 4 weeks of balanc e training there was improvement in dynamic balance in both the groups but there was no significant difference in dynamic balance between two groups . As seen by difference in the SEBT and VJT scores pre and post training with p<0 . 001 . CONCLUSION: 4 weeks balance training using BOSU and multidirectional balance board is effective in improving dynamic balance and vertical jump performance in football players and also can be used as a component of multifaceted training to improve dynamic balance and game skills

  8. DNS load balancing in the CERN cloud

    Science.gov (United States)

    Reguero Naredo, Ignacio; Lobato Pardavila, Lorena

    2017-10-01

    Load Balancing is one of the technologies enabling deployment of large-scale applications on cloud resources. A DNS Load Balancer Daemon (LBD) has been developed at CERN as a cost-effective way to balance applications accepting DNS timing dynamics and not requiring persistence. It currently serves over 450 load-balanced aliases with two small VMs acting as master and slave. The aliases are mapped to DNS subdomains. These subdomains are managed with DDNS according to a load metric, which is collected from the alias member nodes with SNMP. During the last years, several improvements were brought to the software, for instance: support for IPv6, parallelization of the status requests, implementing the client in Python to allow for multiple aliases with differentiated states on the same machine or support for application state. The configuration of the Load Balancer is currently managed by a Puppet type. It discovers the alias member nodes and gets the alias definitions from the Ermis REST service. The Aiermis self-service GUI for the management of the LB aliases has been produced and is based on the Ermis service above that implements a form of Load Balancing as a Service (LBaaS). The Ermis REST API has authorisation based in Foreman hostgroups. The CERN DNS LBD is Open Software with Apache 2 license.

  9. Discrete event dynamic system (DES)-based modeling for dynamic material flow in the pyroprocess

    International Nuclear Information System (INIS)

    Lee, Hyo Jik; Kim, Kiho; Kim, Ho Dong; Lee, Han Soo

    2011-01-01

    A modeling and simulation methodology was proposed in order to implement the dynamic material flow of the pyroprocess. Since the static mass balance provides the limited information on the material flow, it is hard to predict dynamic behavior according to event. Therefore, a discrete event system (DES)-based model named, PyroFlow, was developed at the Korea Atomic Energy Research Institute (KAERI). PyroFlow is able to calculate dynamic mass balance and also show various dynamic operational results in real time. By using PyroFlow, it is easy to rapidly predict unforeseeable results, such as throughput in unit process, accumulated product in buffer and operation status. As preliminary simulations, bottleneck analyses in the pyroprocess were carried out and consequently it was presented that operation strategy had influence on the productivity of the pyroprocess.

  10. Impaired osteoblast function in osteoporosis: comparison between calcium balance and dynamic histomorphometry.

    Science.gov (United States)

    Arlot, M; Edouard, C; Meunier, P J; Neer, R M; Reeve, J

    1984-09-01

    Osteoblast function was investigated in 27 patients with idiopathic osteoporosis. Transiliac bone biopsy specimens were taken after double labelling with tetracycline, and metabolic calcium balance was studied almost simultaneously. Many of the patients showed poor double labelling of their otherwise unremarkable trabecular osteoid, suggesting impaired formation of bone at many of these surfaces. This phenomenon was not accompanied by increased width of osteoid seams (as seen in osteomalacia), indicating that formation of the matrix and its mineralisation were in equilibrium. For the first time, highly significant positive correlations (p less than 0.01) were found between indices of bone formation, determined by labelling with tetracycline, and calcium balance. Thus some patients with osteoporosis who are rapidly losing bone have low rates of formation of trabecular bone both by individual osteoblasts and in relation to available bone surfaces. As histological indices of bone resorption also independently correlated strongly and inversely (p less than 0.01) with calcium balance the rate of initiation of new basic multicellular units by osteoclastic resorption of trabecular surfaces (or the depth of resorption at these surfaces) also appears to be an important determinant of mineral balance. The mechanisms that regulate the effective life span of mature osteoblasts require further investigation, particularly as some promising treatments that can increase trabecular bone volume in osteoporosis, such as parathyroid peptide hPTH (1-34) and sodium fluoride, must work through a reversal of osteoblastic depression.

  11. Emerging of Stochastic Dynamical Equalities and Steady State Thermodynamics from Darwinian Dynamics

    International Nuclear Information System (INIS)

    Ao, P.

    2008-01-01

    The evolutionary dynamics first conceived by Darwin and Wallace, referring to as Darwinian dynamics in the present paper, has been found to be universally valid in biology. The statistical mechanics and thermodynamics, while enormous successful in physics, have been in an awkward situation of wanting a consistent dynamical understanding. Here we present from a formal point of view an exploration of the connection between thermodynamics and Darwinian dynamics and a few related topics. We first show that the stochasticity in Darwinian dynamics implies the existence temperature, hence the canonical distribution of Boltzmann-Gibbs type. In term of relative entropy the Second Law of thermodynamics is dynamically demonstrated without detailed balance condition, and is valid regardless of size of the system. In particular, the dynamical component responsible for breaking detailed balance condition does not contribute to the change of the relative entropy. Two types of stochastic dynamical equalities of current interest are explicitly discussed in the present approach: One is based on Feynman-Kac formula and another is a generalization of Einstein relation. Both are directly accessible to experimental tests. Our demonstration indicates that Darwinian dynamics represents logically a simple and straightforward starting point for statistical mechanics and thermodynamics and is complementary to and consistent with conservative dynamics that dominates the physical sciences. Present exploration suggests the existence of a unified stochastic dynamical framework both near and far from equilibrium

  12. The effects of mobilization with movement on dorsiflexion range of motion, dynamic balance, and self-reported function in individuals with chronic ankle instability.

    Science.gov (United States)

    Gilbreath, Julie P; Gaven, Stacey L; Van Lunen, L; Hoch, Matthew C

    2014-04-01

    Previous studies have examined the effectiveness of a manual therapy intervention known as Mobilization with Movement (MWM) to increase dorsiflexion range of motion (ROM) in individuals with chronic ankle instability (CAI). While a single talocrural MWM treatment has increased dorsiflexion ROM in these individuals, examining the effects of multiple treatments on dorsiflexion ROM, dynamic balance, and self-reported function would enhance the clinical application of this intervention. This study sought to determine if three treatment sessions of talocrural MWM would improve dorsiflexion ROM, Star Excursion Balance Test (SEBT) reach distances, and self-reported function using the Foot and Ankle Ability Measure (FAAM) in individuals with CAI. Eleven participants with CAI (5 Males, 6 Females, age: 21.5 ± 2.2 years, weight: 83.9 ± 15.6 kg, height: 177.7 ± 10.9 cm, Cumberland Ankle Instability Tool: 17.5 ± 4.2) volunteered in this repeated-measures study. Subjects received three MWM treatments over one week. Weight-bearing dorsiflexion ROM (cm), normalized SEBT reach distances (%), and self-reported function (%) were assessed one week before the intervention (baseline), prior to the first MWM treatment (pre-intervention), and 24–48 h following the final treatment (post-intervention). No significant changes were identified in dorsiflexion ROM, SEBT reach distances, or the FAAM-Activities of Daily Living scale (p > 0.05). Significant changes were identified on the FAAM-Sport (p = 0.01). FAAM-Sport scores were significantly greater post-intervention (86.82 ± 9.18%) compared to baseline (77.27 ± 11.09%; p = 0.01) and pre-intervention (79.82 ± 13.45%; p = 0.04). These results indicate the MWM intervention did not improve dorsiflexion ROM, dynamic balance, or patient-centered measures of activities of daily living. However, MWM did improve patient-centered measures of sport-related activities in individuals with CAI.

  13. Dynamic balance deficits in individuals with chronic ankle instability compared to ankle sprain copers 1 year after a first-time lateral ankle sprain injury.

    Science.gov (United States)

    Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Delahunt, Eamonn

    2016-04-01

    To quantify the dynamic balance deficits that characterise a group with chronic ankle instability compared to lateral ankle sprain copers and non-injured controls using kinematic and kinetic outcomes. Forty-two participants with chronic ankle instability and twenty-eight lateral ankle sprain copers were initially recruited within 2 weeks of sustaining a first-time, acute lateral ankle sprain and required to attend our laboratory 1 year later to complete the current study protocol. An additional group of non-injured individuals were also recruited to act as a control group. All participants completed the anterior, posterior-lateral and posterior-medial reach directions of the star excursion balance test. Sagittal plane kinematics of the lower extremity and associated fractal dimension of the centre of pressure path were also acquired. Participants with chronic ankle instability displayed poorer performance in the anterior, posterior-medial and posterior-lateral reach directions compared with controls bilaterally, and in the posterior-lateral direction compared with lateral ankle sprain copers on their 'involved' limb only. These performance deficits in the posterior-lateral and posterior-medial directions were associated with reduced flexion and dorsiflexion displacements at the hip, knee and ankle at the point of maximum reach, and coincided with reduced complexity of the centre of pressure path. In comparison with lateral ankle sprain copers and controls, participants with chronic ankle instability were characterised by dynamic balance deficits as measured using the SEBT. This was attested to reduced sagittal plane motions at the hip, knee and ankle joints, and reduced capacity of the stance limb to avail of its supporting base. III.

  14. The role of work-family enrichment in work-life balance & career success

    OpenAIRE

    Shah, Shalaka Sharad

    2014-01-01

    The issue of work-life balance is becoming increasingly important for employers and employees globally. The clearer becomes our understanding about this issue; the better it will be for an effective and positive integration of these dynamic domains of our lives. Work-family enrichment is a positive way of integrating work and family and it helps to achieve work-life balance. In this Indo-German study, work-life balance, work-family enrichment, work-family culture and career success are analys...

  15. Emotional intelligence and job performance: The mediating role of work-family balance.

    Science.gov (United States)

    Weinzimmer, Laurence G; Baumann, Heidi M; Gullifor, Daniel P; Koubova, Veronika

    2017-01-01

    In this study, we examine the dynamics between emotional intelligence, work-family balance, and job performance. A review of the literature to date has shown distinct relationships between emotional intelligence to job performance and work-family balance to job performance. We utilize a sample of 233 respondents to empirically test our set of hypotheses that contend work-family balance mediates the relationship between emotional intelligence and job performance. Our results support these hypotheses. Practical implications and directions for future research are discussed.

  16. Effects of a resistance training program on balance and fatigue perception in patients with Parkinson's disease: A randomized controlled trial.

    Science.gov (United States)

    Ortiz-Rubio, Araceli; Cabrera-Martos, Irene; Torres-Sánchez, Irene; Casilda-López, Jesús; López-López, Laura; Valenza, Marie Carmen

    2017-11-22

    Fatigue and balance impairment leads to a loss of independence and are important to adequately manage. The objective of this study was to examine the effects of a resistance training program on dynamic balance and fatigue in patients with Parkinson's disease (PD). Randomized controlled trial. Forty-six patients with PD were randomly allocated to an intervention group receiving a 8-week resistance training program focused on lower limbs or to a control group. Balance was assessed using the Mini-BESTest and fatigue was assessed by the Piper Fatigue Scale. Patients in the intervention group improved significantly (p<0.05) on dynamic balance (reactive postural control and total values) and perceived fatigue. An 8-week resistance training program was found to be effective at improving dynamic balance and fatigue in patients with PD. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  17. Static balancing of a spatial six-degree-of-freedom decoupling parallel mechanism

    International Nuclear Information System (INIS)

    Gao, Taoran Liu; Zhao, Xianchao; Qi, Chenkun

    2014-01-01

    The static balancing of a spatial 6-degree-of-freedom (6-DoF) decoupling parallel mechanism is discussed in this paper. Two traditional approaches (using counterweights and the springs) are used to statically balance the mechanism. Due to the existence of their shortcomings, a hybrid approach is proposed based on the static balancing of the mechanism. The main feature of this mechanism is that the 3-DoF rotating part can be static balancing itself, which means that its mass has no effect on the gravity balancing of the system, for any configuration of the mechanism, so the rotating part can be considered as a whole and the calculation is simplified. Finally, examples and dynamic analysis corresponding to the three balancing methods are given to illustrate the results.

  18. The Effects of Local Vibration on Balance, Power, and Self-Reported Pain After Exercise.

    Science.gov (United States)

    Custer, Lisa; Peer, Kimberly S; Miller, Lauren

    2017-05-01

    Muscle fatigue and acute muscle soreness occur after exercise. Application of a local vibration intervention may reduce the consequences of fatigue and soreness. To examine the effects of a local vibration intervention after a bout of exercise on balance, power, and self-reported pain. Single-blind crossover study. Laboratory. 19 healthy, moderately active subjects. After a 30-min bout of full-body exercise, subjects received either an active or a sham vibration intervention. The active vibration intervention was performed bilaterally over the muscle bellies of the triceps surae, quadriceps, hamstrings, and gluteals. At least 1 wk later, subjects repeated the bout, receiving the other vibration intervention. Static balance, dynamic balance, power, and self-reported pain were measured at baseline, after the vibration intervention, and 24 h postexercise. After the bout of exercise, subjects had reduced static and dynamic balance and increased self-reported pain regardless of vibration intervention. There were no differences between outcome measures between the active and sham vibration conditions. The local vibration intervention did not affect balance, power, or self-reported pain.

  19. Effects of physical training on age-related balance and postural control.

    Science.gov (United States)

    Lelard, T; Ahmaidi, S

    2015-11-01

    In this paper, we review the effects of physical activity on balance performance in the elderly. The increase in the incidence of falls with age reflects the disorders of balance-related to aging. We are particularly interested in age-related changes in the balance control system as reflected in different static and dynamic balance tests. We report the results of studies demonstrating the beneficial effects of physical activity on postural balance. By comparing groups of practitioners of different physical activities, it appears that these effects on postural control depend on the type of activity and the time of practice. Thus, we have focused in the present review on "proprioceptive" and "strength" activities. Training programs offering a combination of several activities have demonstrated beneficial effects on the incidence of falls, and we present and compare the effects of these two types of training activities. It emerges that there are differential effects of programs of activities: while all activities improve participants' confidence in their ability, the "proprioceptive" activities rather improve performance in static tasks, while "strength" activities tend to improve performance in dynamic tasks. These effects depend on the targeted population and will have a greater impact on the frailest subjects. The use of new technologies in the form of "exergames" may also be proposed in home-based exercises. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. The "balance of nature"-evolution of a Panchreston.

    Directory of Open Access Journals (Sweden)

    Daniel Simberloff

    2014-10-01

    Full Text Available The earliest concept of a balance of nature in Western thought saw it as being provided by gods but requiring human aid or encouragement for its maintenance. With the rise of Greek natural philosophy, emphasis shifted to traits gods endowed species with at the outset, rather than human actions, as key to maintaining the balance. The dominance of a constantly intervening God in the Middle Ages lessened interest in the inherent features of nature that would contribute to balance, but the Reformation led to renewed focus on such features, particularly traits of species that would maintain all of them but permit none to dominate nature. Darwin conceived of nature in balance, and his emphasis on competition and frequent tales of felicitous species interactions supported the idea of a balance of nature. But Darwin radically changed its underlying basis, from God to natural selection. Wallace was perhaps the first to challenge the very notion of a balance of nature as an undefined entity whose accuracy could not be tested. His skepticism was taken up again in the 20th century, culminating in a widespread rejection of the idea of a balance of nature by academic ecologists, who focus rather on a dynamic, often chaotic nature buffeted by constant disturbances. The balance-of-nature metaphor, however, lives on in large segments of the public, representing a fragile aspect of nature and biodiversity that it is our duty to protect.

  1. The "balance of nature"-evolution of a Panchreston.

    Science.gov (United States)

    Simberloff, Daniel

    2014-10-01

    The earliest concept of a balance of nature in Western thought saw it as being provided by gods but requiring human aid or encouragement for its maintenance. With the rise of Greek natural philosophy, emphasis shifted to traits gods endowed species with at the outset, rather than human actions, as key to maintaining the balance. The dominance of a constantly intervening God in the Middle Ages lessened interest in the inherent features of nature that would contribute to balance, but the Reformation led to renewed focus on such features, particularly traits of species that would maintain all of them but permit none to dominate nature. Darwin conceived of nature in balance, and his emphasis on competition and frequent tales of felicitous species interactions supported the idea of a balance of nature. But Darwin radically changed its underlying basis, from God to natural selection. Wallace was perhaps the first to challenge the very notion of a balance of nature as an undefined entity whose accuracy could not be tested. His skepticism was taken up again in the 20th century, culminating in a widespread rejection of the idea of a balance of nature by academic ecologists, who focus rather on a dynamic, often chaotic nature buffeted by constant disturbances. The balance-of-nature metaphor, however, lives on in large segments of the public, representing a fragile aspect of nature and biodiversity that it is our duty to protect.

  2. Sustained Improvements in Dynamic Balance and Landing Mechanics After a 6-Week Neuromuscular Training Program in College Women's Basketball Players.

    Science.gov (United States)

    Pfile, Kate R; Gribble, Phillip A; Buskirk, Gretchen E; Meserth, Sara M; Pietrosimone, Brian G

    2016-08-01

    Epidemiological data demonstrate the need for lower-extremity injury-prevention training. Neuromuscular-control (NMC) programs are immediately effective at minimizing lower-extremity injury risk and improving sport-related performance measures. Research investigating lasting effects after an injury-prevention program is limited. To determine whether dynamic balance, landing mechanics, and hamstring and quadriceps strength could be improved after a 6-wk NMC intervention and maintained for a season. Prospective case series. Controlled laboratory. 11 Division I women's basketball players (age 19.40 ± 1.35 y, height 178.05 ± 7.52 cm, mass 72.86 ± 10.70 kg). Subjects underwent testing 3 times, completing the Star Excursion Balance Test (SEBT), Landing Error Scoring System (LESS), and isometric strength testing for the hamstrings and quadriceps muscles. Pretest and posttest 1 occurred immediately before and after the intervention, respectively, and posttest 2 at the end of the competitive season, 9 mo after posttest 1. Subjects participated in eighteen 30-min plyometric and NMC-training sessions over a 6-wk period. The normalized SEBT composite score, normalized peak isometric hamstrings:quadriceps (H:Q) ratio, and the LESS total score. The mean composite reach significantly improved over time (F2,10 = 6.96, P = .005) where both posttest scores were significantly higher than pretest (70.41% ± 4.08%) (posttest 1 73.48% ± 4.19%, t10 = -3.11, P = .011) and posttest 2 (74.2% ± 4.77%, t10 = -3.78, P = .004). LESS scores significantly improved over time (F2,10 = 6.29, P = .009). The pretest LESS score (7.30 ± 3.40) was higher than posttest 1 (4.9 ± 1.20, t10 = 2.71, P = .024) and posttest 2 (5.44 ± 1.83, t10 = 2.58, P = .030). There were no statistically significant differences (P > .05) over time for the H:Q ratio when averaging both legs (F2,10 = 0.83, P = .45). A 6-wk NMC program improved landing mechanics and dynamic balance over a 9-mo period in women

  3. Numerical Estimation of Balanced and Falling States for Constrained Legged Systems

    Science.gov (United States)

    Mummolo, Carlotta; Mangialardi, Luigi; Kim, Joo H.

    2017-08-01

    Instability and risk of fall during standing and walking are common challenges for biped robots. While existing criteria from state-space dynamical systems approach or ground reference points are useful in some applications, complete system models and constraints have not been taken into account for prediction and indication of fall for general legged robots. In this study, a general numerical framework that estimates the balanced and falling states of legged systems is introduced. The overall approach is based on the integration of joint-space and Cartesian-space dynamics of a legged system model. The full-body constrained joint-space dynamics includes the contact forces and moments term due to current foot (or feet) support and another term due to altered contact configuration. According to the refined notions of balanced, falling, and fallen, the system parameters, physical constraints, and initial/final/boundary conditions for balancing are incorporated into constrained nonlinear optimization problems to solve for the velocity extrema (representing the maximum perturbation allowed to maintain balance without changing contacts) in the Cartesian space at each center-of-mass (COM) position within its workspace. The iterative algorithm constructs the stability boundary as a COM state-space partition between balanced and falling states. Inclusion in the resulting six-dimensional manifold is a necessary condition for a state of the given system to be balanced under the given contact configuration, while exclusion is a sufficient condition for falling. The framework is used to analyze the balance stability of example systems with various degrees of complexities. The manifold for a 1-degree-of-freedom (DOF) legged system is consistent with the experimental and simulation results in the existing studies for specific controller designs. The results for a 2-DOF system demonstrate the dependency of the COM state-space partition upon joint-space configuration (elbow-up vs

  4. Balance laws and centro velocity in dissipative systems

    NARCIS (Netherlands)

    van Groesen, Embrecht W.C.; Mainardi, F.

    1990-01-01

    Starting with a density that is conserved for a dynamical system when dissipation is ignored, a local conservation law is derived for which the total flux (integrated over the spatial domain) is unique. When dissipation is incorporated, the conservation law becomes a balance law. The contribution

  5. SU(8) family unification with boson-fermion balance

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    Grand unification has been intensively investigated for over forty years, and many different approaches have been tried. In this talk I propose a model that involves three ingredients that do not appear in the usual constructions: (1) boson--fermion balance without full supersymmetry, (2) canceling the spin 1/2 fermion gauge anomalies against the anomaly from a gauged spin 3/2 gravitino, and (3) using a scalar field representation with non-zero U(1) generator to break the SU(8) gauge symmetry through a ground state which, before dynamical symmetry breaking, has a periodic U(1) generator structure. The model has a number of promising features: (1) natural incorporation of three families, (2) incorporation of the experimentally viable flipped SU(5) model, (3) a symmetry breaking pathway to the standard model using the scalar field required by boson-fermion balance, together with a stage of most attractive channel dynamical symmetry breaking, without postulating additional Higgs fields, (4) vanishing of bare Yuk...

  6. BALANCE

    Science.gov (United States)

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  7. Online dynamic equalization adjustment of high-power lithium-ion battery packs based on the state of balance estimation

    International Nuclear Information System (INIS)

    Wang, Shunli; Shang, Liping; Li, Zhanfeng; Deng, Hu; Li, Jianchao

    2016-01-01

    Highlights: • A novel concept (SOB, State of Balance) is proposed for the LIB pack equalization. • Core parameter detection and filtering is analyzed to identify the LIB pack behavior. • The electrical UKF model is adopted for the online dynamic estimation. • The equalization target model is built based on the optimum preference. • Comprehensive imbalance state calculation is implemented for the adjustment. - Abstract: A novel concept named as state of balance (SOB) is proposed and its online dynamic estimation method is presented for the high-power lithium-ion battery (LIB) packs, based on which the online dynamic equalization adjustment is realized aiming to protect the operation safety of its power supply application. The core parameter detection method based on the specific moving average algorithm is studied because of their identical varying characteristics on the individual cells due to the manufacturing variability and other factors, affecting the performance of the high-power LIB pack. The SOB estimation method is realized with the detailed deduction, in which a dual filter consisting of the Unscented Kalman filter (UKF), equivalent circuit model (ECM) and open circuit voltage (OCV) is used in order to predict the SOB state. It is beneficial for the energy operation and the energy performance state can be evaluated online prior to the adjustment method based on the terminal voltage consistency. The energy equalization is realized that is based on the credibility reasoning together with the equalization model building process. The experiments including the core parameter detection, SOB estimation and equalization adjustment are done and the experimental results are analyzed. The experiment results show that the numerical Coulomb efficiency is bigger than 95%. The cell voltage measurement error is less than 5 mV and the terminal voltage measurement error of the LIB pack is less than 1% FS. The measurement error of the battery discharge and charge

  8. A versatile computer package for mechanism analysis, part 2: Dynamics and balance

    Science.gov (United States)

    Davies, T.

    The algorithms required for the shaking force components, the shaking moment about the crankshaft axis, and the input torque and bearing load components are discussed using the textile machine as a focus for the discussion. The example is also used to provide illustrations of the output for options on the hodograph of the shaking force vector. This provides estimates of the optimum contrarotating masses and their locations for a generalized primary Lanchester balancer. The suitability of generalized Lanchester balancers particularly for textile machinery, and the overall strategy used during the development of the package are outlined.

  9. Reliability and sensitivity to change of the timed standing balance test in children with down syndrome

    Directory of Open Access Journals (Sweden)

    Vencita Priyanka Aranha

    2016-01-01

    Full Text Available Objective: To estimate the reliability and sensitivity to change of the timed standing balance test in children with Down syndrome (DS. Methods: It was a nonblinded, comparison study with a convenience sample of subjects consisting of children with DS (n = 9 aged 8–17 years. The main outcome measure was standing balance which was assessed using timed standing balance test, the time required to maintain in four conditions, eyes open static, eyes closed static, eyes open dynamic, and eyes closed dynamic. Results: Relative reliability was excellent for all four conditions with an Interclass Correlation Coefficient (ICC ranging from 0.91 to 0.93. The variation between repeated measurements for each condition was minimal with standard error of measurement (SEM of 0.21–0.59 s, suggestive of excellent absolute reliability. The sensitivity to change as measured by smallest real change (SRC was 1.27 s for eyes open static, 1.63 s for eyes closed static, 0.58 s for eyes open dynamic, and 0.61 s for eyes closed static. Conclusions: Timed standing balance test is an easy to administer test and sensitive to change with strong absolute and relative reliabilities, an important first step in establishing its utility as a clinical balance measure in children with DS.

  10. A balance and proprioception intervention programme to enhance combat performance in military personnel.

    Science.gov (United States)

    Funk, Shany; Jacob, T; Ben-Dov, D; Yanovich, E; Tirosh, O; Steinberg, N

    2018-02-01

    Optimal functioning of the lower extremities under repeated movements on unstable surfaces is essential for military effectiveness. Intervention training to promote proprioceptive ability should be considered in order to limit the risk for musculoskeletal injuries. The aim of this study was to assess the effect of a proprioceptive intervention programme on static and dynamic postural balance among Israel Defense Forces combat soldiers. Twenty-seven male soldiers, aged 18-20 years, from a physical fitness instructor's course, were randomly divided into two groups matched by age and army unit. The intervention group (INT) underwent 4 weeks of proprioceptive exercises for 10 min daily; the control group underwent 4 weeks of upper body stretching exercises for 10 min daily. All participants were tested pre and postintervention for both static and dynamic postural balance. Significant interaction (condition*pre-post-test*group) was found for static postural balance, indicating that for the INT group, in condition 3 (on an unstable surface-BOSU), the post-test result was significantly better compared with the pretest result (pbalance on unstable surfaces, and improved the correlation between static postural balance in the eyes closed condition and dynamic postural balance following fatigue. Further longitudinal studies are needed to verify the relationship between proprioception programmes, additional weight bearing and the reduction of subsequent injuries in combat soldiers. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. The effects of hippotherapy on postural balance and functional ability in children with cerebral palsy.

    Science.gov (United States)

    Moraes, Andréa Gomes; Copetti, Fernando; Angelo, Vera Regina; Chiavoloni, Luana Leonardo; David, Ana Cristina

    2016-08-01

    [Purpose] This study evaluated the effects of hippotherapy on seated postural balance, dynamic balance, and functional performance in children with cerebral palsy and compared the effects of 12 and 24 sessions on seated postural balance. [Subjects and Methods] This study included 15 children with cerebral palsy aged between 5 and 10 years. A hippotherapy protocol was performed for 30 minutes, twice a week, for 12 weeks. Postural balance in a sitting position was measured using an AMTI AccuSway Plus force platform 1 week before initiating the hippotherapy program and after 12 and 24 weeks. The Berg Balance Scale (BBS) and Pediatric Evaluation of Disability Inventory (PEDI) were used before and after 24 sessions. [Results] Significant differences were observed for center of pressure (COP) variables, including medio-lateral (COPml), anteroposterior displacement (COPap), and velocity of displacement (VelCOP), particularly after 24 sessions. There were also significant differences in BBS scores and PEDI score increases associated with functional skills (self-care, social function, and mobility), caregiver assistance (self-care), social function, and mobility. [Conclusion] Hippotherapy resulted in improvement in postural balance in the sitting position, dynamic balance, and functionality in children with cerebral palsy, an effect particularly significant after 24 hippotherapy sessions.

  12. Effects of aquatic physiotherapy on the improvement of balance and corporal symmetry in stroke survivors.

    Science.gov (United States)

    Montagna, Jéssica Cristine; Santos, Bárbara C; Battistuzzo, Camila R; Loureiro, Ana Paula C

    2014-01-01

    One of the main problems associate with hemiparesis after stroke is the decrease in balance during static and dynamic postures which can highly affect daily life activities. To assess the effects of aquatic physiotherapy on the balance and quality of life (SS-QoL) of people with pos stroke. Chronic stroke participants received at total 18 individual sessions of aquatic physiotherapy using the principle of Halliwick (2x of 40 minutes per week). The outcomes measured were: Berg Balance scale, Timed up & go test (TUG), Stroke Specific Quality of Life Scale (SS-QoL) and baropodometric analysis. These assessment were performed before and one week after intervention. Fifteen participants were included in this study. The mean age was 58.5 and 54% was male. After intervention, participants had a significant improvement on their static balance measured by Berg Balance scale and TUG. Dynamic balance had a significant trend of improvement in mediolateral domain with eyes closed and during sit-to-stand. The mobility domain of the SS-QoL questionnaire was significant higher after intervention. Our results suggest that aquatic physiotherapy using the method of Halliwick can be a useful tool during stroke rehabilitation to improve balance. However, this improvement may not have significant impact of their quality of life.

  13. The complexity of role balance: support for the Model of Juggling Occupations.

    Science.gov (United States)

    Evans, Kiah L; Millsteed, Jeannine; Richmond, Janet E; Falkmer, Marita; Falkmer, Torbjorn; Girdler, Sonya J

    2014-09-01

    This pilot study aimed to establish the appropriateness of the Model of Juggling Occupations in exploring the complex experience of role balance amongst working women with family responsibilities living in Perth, Australia. In meeting this aim, an evaluation was conducted of a case study design, where data were collected through a questionnaire, time diary, and interview. Overall role balance varied over time and across participants. Positive indicators of role balance occurred frequently in the questionnaires and time diaries, despite the interviews revealing a predominance of negative evaluations of role balance. Between-role balance was achieved through compatible role overlap, buffering, and renewal. An exploration of within-role balance factors demonstrated that occupational participation, values, interests, personal causation, and habits were related to role balance. This pilot study concluded that the Model of Juggling Occupations is an appropriate conceptual framework to explore the complex and dynamic experience of role balance amongst working women with family responsibilities. It was also confirmed that the case study design, including the questionnaire, time diary, and interview methods, is suitable for researching role balance from this perspective.

  14. Balance Improvement Effects of Biofeedback Systems with State-of-the-Art Wearable Sensors: A Systematic Review

    Science.gov (United States)

    Ma, Christina Zong-Hao; Wong, Duo Wai-Chi; Lam, Wing Kai; Wan, Anson Hong-Ping; Lee, Winson Chiu-Chun

    2016-01-01

    Falls and fall-induced injuries are major global public health problems. Balance and gait disorders have been the second leading cause of falls. Inertial motion sensors and force sensors have been widely used to monitor both static and dynamic balance performance. Based on the detected performance, instant visual, auditory, electrotactile and vibrotactile biofeedback could be provided to augment the somatosensory input and enhance balance control. This review aims to synthesize the research examining the effect of biofeedback systems, with wearable inertial motion sensors and force sensors, on balance performance. Randomized and non-randomized clinical trials were included in this review. All studies were evaluated based on the methodological quality. Sample characteristics, device design and study characteristics were summarized. Most previous studies suggested that biofeedback devices were effective in enhancing static and dynamic balance in healthy young and older adults, and patients with balance and gait disorders. Attention should be paid to the choice of appropriate types of sensors and biofeedback for different intended purposes. Maximizing the computing capacity of the micro-processer, while minimizing the size of the electronic components, appears to be the future direction of optimizing the devices. Wearable balance-improving devices have their potential of serving as balance aids in daily life, which can be used indoors and outdoors. PMID:27023558

  15. Balance Improvement Effects of Biofeedback Systems with State-of-the-Art Wearable Sensors: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Christina Zong-Hao Ma

    2016-03-01

    Full Text Available Falls and fall-induced injuries are major global public health problems. Balance and gait disorders have been the second leading cause of falls. Inertial motion sensors and force sensors have been widely used to monitor both static and dynamic balance performance. Based on the detected performance, instant visual, auditory, electrotactile and vibrotactile biofeedback could be provided to augment the somatosensory input and enhance balance control. This review aims to synthesize the research examining the effect of biofeedback systems, with wearable inertial motion sensors and force sensors, on balance performance. Randomized and non-randomized clinical trials were included in this review. All studies were evaluated based on the methodological quality. Sample characteristics, device design and study characteristics were summarized. Most previous studies suggested that biofeedback devices were effective in enhancing static and dynamic balance in healthy young and older adults, and patients with balance and gait disorders. Attention should be paid to the choice of appropriate types of sensors and biofeedback for different intended purposes. Maximizing the computing capacity of the micro-processer, while minimizing the size of the electronic components, appears to be the future direction of optimizing the devices. Wearable balance-improving devices have their potential of serving as balance aids in daily life, which can be used indoors and outdoors.

  16. Balance Improvement Effects of Biofeedback Systems with State-of-the-Art Wearable Sensors: A Systematic Review.

    Science.gov (United States)

    Ma, Christina Zong-Hao; Wong, Duo Wai-Chi; Lam, Wing Kai; Wan, Anson Hong-Ping; Lee, Winson Chiu-Chun

    2016-03-25

    Falls and fall-induced injuries are major global public health problems. Balance and gait disorders have been the second leading cause of falls. Inertial motion sensors and force sensors have been widely used to monitor both static and dynamic balance performance. Based on the detected performance, instant visual, auditory, electrotactile and vibrotactile biofeedback could be provided to augment the somatosensory input and enhance balance control. This review aims to synthesize the research examining the effect of biofeedback systems, with wearable inertial motion sensors and force sensors, on balance performance. Randomized and non-randomized clinical trials were included in this review. All studies were evaluated based on the methodological quality. Sample characteristics, device design and study characteristics were summarized. Most previous studies suggested that biofeedback devices were effective in enhancing static and dynamic balance in healthy young and older adults, and patients with balance and gait disorders. Attention should be paid to the choice of appropriate types of sensors and biofeedback for different intended purposes. Maximizing the computing capacity of the micro-processer, while minimizing the size of the electronic components, appears to be the future direction of optimizing the devices. Wearable balance-improving devices have their potential of serving as balance aids in daily life, which can be used indoors and outdoors.

  17. A small chance of paradise —Equivalence of balanced states

    Science.gov (United States)

    Krawczyk, M. J.; Kaluzny, S.; Kulakowski, K.

    2017-06-01

    A social network is modeled by a complete graph of N nodes, with interpersonal relations represented by links. In the framework of the Heider balance theory, we prove numerically that the probability of each balanced state is the same. This means in particular, that the probability of the paradise state, where all relations are positive, is 21-N . The proof is performed within two models. In the first, relations are changing continuously in time, and the proof is performed only for N = 3 with the methods of nonlinear dynamics. The second model is the Constrained Triad Dynamics, as introduced by Antal, Krapivsky and Redner in 2005. In the latter case, the proof makes use of the symmetries of the network of system states and it is completed for 3≤ N≤ 7 .

  18. Adaptive Equilibrium Regulation: A Balancing Act in Two Timescales

    Science.gov (United States)

    Boker, Steven M.

    2015-01-01

    An equilibrium involves a balancing of forces. Just as one maintains upright posture in standing or walking, many self-regulatory and interpersonal behaviors can be framed as a balancing act between an ever changing environment and within-person processes. The emerging balance between person and environment, the equilibria, are dynamic and adaptive in response to development and learning. A distinction is made between equilibrium achieved solely due to a short timescale balancing of forces and a longer timescale preferred equilibrium which we define as a state towards which the system slowly adapts. Together, these are developed into a framework that this article calls Adaptive Equilibrium Regulation (ÆR), which separates a regulatory process into two timescales: a faster regulation that automatically balances forces and a slower timescale adaptation process that reconfigures the fast regulation so as to move the system towards its preferred equilibrium when an environmental force persists over the longer timescale. This way of thinking leads to novel models for the interplay between multiple timescales of behavior, learning, and development. PMID:27066197

  19. Hybrid Bee Ant Colony Algorithm for Effective Load Balancing And ...

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    Ant Colony algorithm is used in this hybrid Bee Ant Colony algorithm to solve load balancing issues ... Genetic Algorithm (MO-GA) for dynamic job scheduling that .... Information Networking and Applications Workshops. [7]. M. Dorigo & T.

  20. Dynamic load balance scheme for the DSMC algorithm

    International Nuclear Information System (INIS)

    Li, Jin; Geng, Xiangren; Jiang, Dingwu; Chen, Jianqiang

    2014-01-01

    The direct simulation Monte Carlo (DSMC) algorithm, devised by Bird, has been used over a wide range of various rarified flow problems in the past 40 years. While the DSMC is suitable for the parallel implementation on powerful multi-processor architecture, it also introduces a large load imbalance across the processor array, even for small examples. The load imposed on a processor by a DSMC calculation is determined to a large extent by the total of simulator particles upon it. Since most flows are impulsively started with initial distribution of particles which is surely quite different from the steady state, the total of simulator particles will change dramatically. The load balance based upon an initial distribution of particles will break down as the steady state of flow is reached. The load imbalance and huge computational cost of DSMC has limited its application to rarefied or simple transitional flows. In this paper, by taking advantage of METIS, a software for partitioning unstructured graphs, and taking the total of simulator particles in each cell as a weight information, the repartitioning based upon the principle that each processor handles approximately the equal total of simulator particles has been achieved. The computation must pause several times to renew the total of simulator particles in each processor and repartition the whole domain again. Thus the load balance across the processors array holds in the duration of computation. The parallel efficiency can be improved effectively. The benchmark solution of a cylinder submerged in hypersonic flow has been simulated numerically. Besides, hypersonic flow past around a complex wing-body configuration has also been simulated. The results have displayed that, for both of cases, the computational time can be reduced by about 50%

  1. THE EFFECTIVENESS OF SPORTS SPECIFIC BALANCE TRAINING PROGRAM IN REDUCING RISK OF ANKLE SPRAIN IN BASKETBALL

    Directory of Open Access Journals (Sweden)

    Ai Choo LEE

    2016-12-01

    Full Text Available Background: To investigate the effectiveness of four weeks sports specific balance training program to improve balance, thus reducing the risk of ankle sprain among Sultan Idris Education University basketball players. Method: There were 20 males basketball players (aged 19-24 years volunteered in this study. After screening process, there were14 male players met the inclusion criteria. They were randomized into two groups i.e experimental group (EG: n=7 and control group (CG: n=7. The EG undergone the four weeks sports specific balance training program three times per week while the CG followed their normal standard basketball training program. Balance Error Scoring System (BESS was used to assess static balance while Star Excursion Balance Test (SEBT is utilized to examine the dynamic balance. Pretest and posttest of balance measures were recorded using BESS and SEBT for both EG and CG. The data were analyzed using independent sample t-test (p=0.05. Results: The study findings indicated that there were significant differences between EG and CG for the static balance on firm surface (t=-4.642, p=0.001 and on foam surface (t=-8.590, P=0.000 as well as dynamic balance on left leg stance (t=2.350, P=0.037 and on right leg stance (t=3.145, P=0.008. Conclusion: The study findings indicated that the four weeks sports specific balance training program could improve balance ability in male basketball players, thus may reducing the risk of ankle sprain.

  2. Dirac-bracket aproach to nearly-geostrophic Hamiltonian balanced models

    NARCIS (Netherlands)

    Vanneste, J.; Bokhove, Onno

    2002-01-01

    Dirac’s theory of constrained Hamiltonian systems is applied to derive the Poisson structure of a class of balanced models describing the slow dynamics of geophysical flows. Working with the Poisson structure, instead of the canonical Hamiltonian structure previously considered in this context,

  3. Exergaming as a Viable Therapeutic Tool to Improve Static and Dynamic Balance among Older Adults and People with Idiopathic Parkinson's Disease: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Harris, Dale M; Rantalainen, Timo; Muthalib, Makii; Johnson, Liam; Teo, Wei-Peng

    2015-01-01

    The use of virtual reality games (known as "exergaming") as a neurorehabilitation tool is gaining interest. Therefore, we aim to collate evidence for the effects of exergaming on the balance and postural control of older adults and people with idiopathic Parkinson's disease (IPD). Six electronic databases were searched, from inception to April 2015, to identify relevant studies. Standardized mean differences (SMDs) and 95% confidence intervals (CI) were used to calculate effect sizes between experimental and control groups. I (2) statistics were used to determine levels of heterogeneity. 325 older adults and 56 people with IPD who were assessed across 11 -studies. The results showed that exergaming improved static balance (SMD 1.069, 95% CI 0.563-1.576), postural control (SMD 0.826, 95% CI 0.481-1.170), and dynamic balance (SMD -0.808, 95% CI -1.192 to -0.424) in healthy older adults. Two IPD studies showed an improvement in static balance (SMD 0.124, 95% CI -0.581 to 0.828) and postural control (SMD 2.576, 95% CI 1.534-3.599). Our findings suggest that exergaming might be an appropriate therapeutic tool for improving balance and postural control in older adults, but more -large-scale trials are needed to determine if the same is true for people with IPD.

  4. Apparatus and method for optimal phase balancing using dynamic programming with spatial consideration

    Science.gov (United States)

    Robertazzi, Thomas G.; Skiena, Steven; Wang, Kai

    2017-08-08

    Provided are an apparatus and method for load-balancing of a three-phase electric power distribution system having a multi-phase feeder, including obtaining topology information of the feeder identifying supply points for customer loads and feeder sections between the supply points, obtaining customer information that includes peak customer load at each of the points between each of the feeder sections, performing a phase balancing analysis, and recommending phase assignment at the customer load supply points.

  5. Effect of Cardiac Rehabilitation on Strength and Balance in Patients after Coronary Artery Bypass Graft

    Directory of Open Access Journals (Sweden)

    Nahid Nazari

    2014-01-01

    Full Text Available Background: The most common method for improving the quality of life especially in chronic heart disease is rehabilitation. For increasing the level of knowledge about effect of rehabilitation and its' impression on improving the quality of life in patients. This study evaluates effect of one month cardiac rehabilitation on lower limb strength and the static and dynamic balance of CABG patients. Materials and Methods: This study is based on clinical trial before and after rehabilitation. the exercise protocol lasted for one month, three times per week, each session lasting 1 hour, on 30 male patients in two groups in control (N=15 and experimental group (N=15 after CABG in the centre of rehabilitation in Javad-Alaeme Heart Hospital, Mashhad. The strength of lower limb by chair standing test, the static balance by standing on one leg and dynamic balance by time up and go (TUG test, was evaluated before and after 1 month rehabilitation in training group and detraining in control group. Data were analyzed with SPSS-16 and used t-test analysis (p≤0.054T. Results: The strength of lower limb (p=0.001, static balance (p=0.023 and dynamic balance (p=0.037 increased significantly after one month of cardiac rehabilitation4T. Conclusion: The result of this study indicates that cardiac rehabilitation after coronary artery bypass surgery causes significant increase in strength of lower limb and balance in patients, the more muscle strength is associated with an increase in ability of performing daily activities and so it causes improved quality of life4T.

  6. Effect of Cardiac Rehabilitation on Strength and Balance in Patients after Coronary Artery Bypass Graft

    Directory of Open Access Journals (Sweden)

    Nahid Nazari

    Full Text Available Background: The most common method for improving the quality of life especially in chronic heart disease is rehabilitation. For increasing the level of knowledge about effect of rehabilitation and its' impression on improving the quality of life in patients. This study evaluates effect of one month cardiac rehabilitation on lower limb strength and the static and dynamic balance of CABG patients. Materials and Methods: This study is based on clinical trial before and after rehabilitation. the exercise protocol lasted for one month, three times per week, each session lasting 1 hour, on 30 male patients in two groups in control (N=15 and experimental group (N=15 after CABG in the centre of rehabilitation in Javad-Alaeme Heart Hospital, Mashhad. The strength of lower limb by chair standing test, the static balance by standing on one leg and dynamic balance by time up and go (TUG test, was evaluated before and after 1 month rehabilitation in training group and detraining in control group. Data were analyzed with SPSS-16 and used t-test analysis (p≤0.05.Results: The strength of lower limb (p=0.001, static balance (p=0.023 and dynamic balance (p=0.037 increased significantly after one month of cardiac rehabilitation.Conclusion: The result of this study indicates that cardiac rehabilitation after coronary artery bypass surgery causes significant increase in strength of lower limb and balance in patients, the more muscle strength is associated with an increase in ability of performing daily activities and so it causes improved quality of life.

  7. Comprehensive, blinded assessment of balance in orthostatic tremor.

    Science.gov (United States)

    Bhatti, Danish; Thompson, Rebecca; Xia, Yiwen; Hellman, Amy; Schmaderer, Lorene; Suing, Katie; McKune, Jennifer; Penke, Cynthia; Iske, Regan; Roeder, Bobbi Jo; Siu, Ka-Chun; Bertoni, John M; Torres-Russotto, Diego

    2018-02-01

    Orthostatic Tremor (OT) is a movement disorder characterized by a sensation of unsteadiness and tremors in the 13-18 Hz range present upon standing. The pathophysiology of OT is not well understood but there is a relationship between the sensation of instability and leg tremors. Despite the sensation of unsteadiness, OT patients do not fall often and balance in OT has not been formally assessed. We present a prospective blinded study comparing balance assessment in patients with OT versus healthy controls. We prospectively enrolled 34 surface Electromyography (EMG)-confirmed primary OT subjects and 21 healthy controls. Participants underwent evaluations of balance by blinded physical therapists (PT) with standardized, validated, commonly used balance scales and tasks. OT subjects were mostly female (30/34, 88%) and controls were majority males (13/20, 65%). The average age of OT subjects was 68.5 years (range 54-87) and for controls was 69.4 (range 32-86). The average duration of OT symptoms was 18 years. OT subjects did significantly worse on all the balance scales and on most balance tasks including Berg Balance Scale, Functional Gait Assessment, Dynamic Gait Index, Unipedal Stance Test, Functional Reach Test and pull test. Gait speed and five times sit to stand were normal in OT. Common validated balance scales are significantly abnormal in primary OT. Despite the objective finding of impaired balance, OT patients do not commonly have falls. The reported sensation of unsteadiness in this patient population seems to be out of proportion to the number of actual falls. Further studies are needed to determine which components of commonly used balance scales are affected by a sensation of unsteadiness and fear of falling. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Offshore wind energy : balancing risk and reward

    International Nuclear Information System (INIS)

    Nerland, C.

    2010-01-01

    Offshore wind energy developments are expected to increase as the demand for renewable energy sources grows. This poster presentation described a method of balancing risk and reward in offshore wind energy projects. The method was based on risk assessment strategies used by the oil and gas industry. The dedicated framework considered schedules; budgets; performance; and operating and maintenance costs. A value chain assessment method was used to optimize the balance between risk and reward by evaluating uncertainties and risk related to each project element and its relationship to other elements within an integrated dynamic model designed to determine the net present value of a project. The decision-making criteria included the RISKEX risk expenditure strategy designed to consider the balance between risk exposure, capital expenditures, and operational expenditures in relation to the statistical cost of unplanned repairs, and lost production capacity. A case study of a large offshore wind farm was used to demonstrate the method. tabs., figs.

  9. The Rigour–Relevance Balance for Engaged Scholarship

    DEFF Research Database (Denmark)

    Li, Peter Ping

    2011-01-01

    and positioning JTR, my editorial has five parts. First, I present the key information about JTR. Second, I discuss the major challenges to scholarship in general and rigourrelevance balance in particular. Third, I propose a new frame of thinking capable of addressing those key challenges. Fourth, I introduce...... the four articles in the inaugural issue of JTR. Finally, I discuss the agenda for future trust research. The central theme of this editorial is that we must commit to engaged scholarship through the rigourrelevance balance, which is made possible by adopting a new frame of thinking with its holistic......, dynamic and duality tenets in academic research in general and trust research in particular....

  10. The Relationship with Balance, Foot Posture, and Foot Size in School of Physical Education and Sports Students

    Science.gov (United States)

    Irez, Gonul Babayigit

    2014-01-01

    The aim of this study is to investigate the relationship of foot posture and foot size with balance. A hundred and thirteen healthy volunteers were recruited from undergraduate students (Male = 74, Female = 37, age range 18-22). The Foot Posture Index (FPI-6), anthropometric measurements, dynamic balance and static balance measurements were done…

  11. Immunomodulation Mechanism of Antidepressants: Interactions between Serotonin/Norepinephrine Balance and Th1/Th2 Balance

    Science.gov (United States)

    Martino, Matteo; Rocchi, Giulio; Escelsior, Andrea; Fornaro, Michele

    2012-01-01

    Neurotransmitters and hormones regulate major immune functions, including the selection of T helper (Th)1 or Th2 cytokine responses, related to cell-mediated and humoral immunity, respectively. A role of imbalance and dynamic switching of Th1/Th2 system has been proposed, with relative displacement of the immune reserve in relation to complex interaction between Th1/Th2 and neuro-hormonal balance fluctuations, in the pathogenesis of various chronic human diseases, probably also including psychiatric disorders. Components of the stress system such as norepinephrine (NE) and glucocorticoids appear to mediate a Th2 shift, while serotonin (5-HT) and melatonin might mediate a Th1 shift. Some antidepressants would occur affecting these systems, acting on neurotransmitter balance (especially the 5-HT/NE balance) and expression levels of receptor subtypes, which in turn affect cytokine production and relative Th1/Th2 balance. It could be therefore hypothesized that the antidepressant-related increase in NE tone enhances the Th2 response, while the decrease in NE tone or the increase in 5-HT tone enhances the Th1 response. However, the neurotransmitter and Th1/Th2 balance modulation could be relative, aiming to restore physiological levels a previous imbalance in receptor sensitivity and cytokine production. The considerations on neuro-immunomodulation could represent an additional aid in the study of pathophysiology of psychiatric disorders and in the choice of specific antidepressants in specific clusters of symptoms, especially in comorbidity with internal pathologies. Furthermore limited data, reviewed here, have shown the effectiveness of some antidepressants as pure immunomodulators. However, these considerations are tentative and require experimental confirmation or refutation by future studies. PMID:23204981

  12. Multi-stable perception balances stability and sensitivity

    Directory of Open Access Journals (Sweden)

    Alexander ePastukhov

    2013-03-01

    Full Text Available We report that multi-stable perception operates in a consistent, dynamical regime, balancing the conflicting goals of stability and sensitivity. When a multi-stable visual display is viewed continuously, its phenomenal appearance reverses spontaneously at irregular intervals. We characterized the perceptual dynamics of individual observers in terms of four statistical measures: the distribution of dominance times (mean and variance and the novel, subtle dependence on prior history (correlation and time-constant.The dynamics of multi-stable perception is known to reflect several stabilizing and destabilizing factors. Phenomenologically, its main aspects are captured by a simplistic computational model with competition, adaptation, and noise. We identified small parameter volumes (~3% of the possible volume in which the model reproduced both dominance distribution and history-dependence of each observer. For 21 of 24 data sets, the identified volumes clustered tightly (~15% of the possible volume, revealing a consistent `operating regime' of multi-stable perception. The `operating regime' turned out to be marginally stable or, equivalently, near the brink of an oscillatory instability. The chance probability of the observed clustering was <0.02.To understand the functional significance of this empirical `operating regime', we compared it to the theoretical `sweet spot' of the model. We computed this `sweet spot' as the intersection of the parameter volumes in which the model produced stable perceptual outcomes and in which it was sensitive to input modulations. Remarkably, the empirical `operating regime' proved to be largely coextensive with the theoretical `sweet spot'. This demonstrated that perceptual dynamics was not merely consistent but also functionally optimized (in that it balances stability with sensitivity. Our results imply that multi-stable perception is not a laboratory curiosity, but reflects a functional optimization of perceptual

  13. An Efficient SDN Load Balancing Scheme Based on Variance Analysis for Massive Mobile Users

    Directory of Open Access Journals (Sweden)

    Hong Zhong

    2015-01-01

    Full Text Available In a traditional network, server load balancing is used to satisfy the demand for high data volumes. The technique requires large capital investment while offering poor scalability and flexibility, which difficultly supports highly dynamic workload demands from massive mobile users. To solve these problems, this paper analyses the principle of software-defined networking (SDN and presents a new probabilistic method of load balancing based on variance analysis. The method can be used to dynamically manage traffic flows for supporting massive mobile users in SDN networks. The paper proposes a solution using the OpenFlow virtual switching technology instead of the traditional hardware switching technology. A SDN controller monitors data traffic of each port by means of variance analysis and provides a probability-based selection algorithm to redirect traffic dynamically with the OpenFlow technology. Compared with the existing load balancing methods which were designed to support traditional networks, this solution has lower cost, higher reliability, and greater scalability which satisfy the needs of mobile users.

  14. Arbuscular mycorrhizal fungi associated with psammophilic vegetation in Mediterranean coastal sand dunes

    Energy Technology Data Exchange (ETDEWEB)

    Camprubi, A.; Calvet, C.; Cabot, P.; Pitet, M.; Estaun, V.

    2010-07-01

    This study was conducted in order to characterize the natural albacore's mycorrhizal (AM) biodiversity from Mediterranean sand dune ecosystems and to protect in a collection this biodiversity. The occurrence of AM fungi associated with sand dune plant species in three Mediterranean locations on the north-eastern coast of Spain was examined in one well preserved coastal sand dune and in two embrionary dunes recently protected from public access. Traditional taxonomy and molecular techniques were used to identify the AM fungal species present in these ecosystems. The species identified and isolated were: Scutellospora persica (Kiosk and Walker) Walker and Sanders, Glomus ambisporum Smith and Schenck, Glomus diaphanum Morton and Walker, Glomus clarum Nicolson and Schenck, Glomus intraradices Schenck and Smith, Glomus microaggregatum Koske, Gemma and Olexia and Gigaspora margarita Becker and Hall. Spores of Glomus were the most abundant in the direct soil extraction samples. The molecular analysis indicates that the most abundant fungi forming AM in the roots belonged to the Gigasporaceae group followed by fungi of Glomus group A and Glomus group B. The highest diversity of fungi and abundance of the AM fungal spores was found in the well preserved and undisturbed dune systems. (Author) 26 refs.

  15. [The modern approaches to the restoration of postural balance in the patients suffering from the consequences of an acute cerebrovascular accident (CVA)].

    Science.gov (United States)

    Volovets, S A; Sergeenko, E Y; Darinskaya, L Y; Polyaev, B A; Yashinina, Y A; Isaeva, M A; Zhitareva, I V; Lobov, A N; Panova, T I

    2018-05-21

    the most frequent and severe consequences of an acute cerebrovascular accident (CVA) are locomotor and coordination disorders which significantly increase the risk of falling in a static position and when walking. The methods used for the rehabilitation of the affected patients are designed in the first place to enable the patients to acquire the skills necessary for maintaining the static balance. The modern equipment allows to carry out coordination training in the static position and also during walking. The objective of the present study was to evaluate, based on the results of our original research, the feasibility and effectiveness of the application of the «Balance tutor» system developed for the restoration of static and dynamic balance in the framework of the combined rehabilitation treatment of the patients suffering from impaired postural balance as a consequence of acute cerebrovascular accident (CVA). A total of 56 patients presenting with impaired postural balance following CVA were available for the examination. All of them underwent functional testing to assess the static and dynamic balance, walking abilities, and the risk of falling down including the study with the use of computer-assisted stabilometry. The study has demonstrated that the inclusion of the «Balance tutor» system for the restoration of the static and dynamic balance in the combined rehabilitative treatment of the patients having postural balance disorders after the CVA reduces the risk of fall for a walking patient, improves his (her) static and dynamic balance, increases the patient's ability to move without exterior help. The patients comprising the main study group were found to experience a decrease of statokinesiogram space in the «eyes are open» position (p = 0.0576, the Mann-Whitney U test) as well as a reliable decrease of the statokinesiogram space in the «eyes are closed» position (p=0.0063, the Mann-Whitney U test). Similar changes occurred in speed of pressure

  16. Increased fall risk is associated with elevated co-contraction about the ankle during static balance challenges in older adults.

    Science.gov (United States)

    Nelson-Wong, Erika; Appell, Ryan; McKay, Mike; Nawaz, Hannah; Roth, Joanna; Sigler, Robert; Third, Jacqueline; Walker, Mark

    2012-04-01

    Falls are a leading contributor to disability in older adults. Increased muscle co-contraction in the lower extremities during static and dynamic balance challenges has been associated with aging, and also with a history of falling. Co-contraction during static balance challenges has not been previously linked with performance on clinical tests designed to ascertain fall risk. The purpose of this study was to investigate the relationship between co-contraction about the ankle during static balance challenges with fall risk on a commonly used dynamic balance assessment, the Four Square Step Test (FSST). Twenty-three volunteers (mean age 73 years) performed a series of five static balance challenges (Romberg eyes open/closed, Sharpened Romberg eyes open/closed, and Single Leg Standing) with continuous electromyography (EMG) of bilateral tibialis anterior and gastrocnemius muscles. Participants then completed the FSST and were categorized as 'at-risk' or 'not-at-risk' to fall based on a cutoff time of 12 s. Co-contraction was quantified with co-contraction index (CCI). CCI during narrow base conditions was positively correlated with time to complete FSST. High CCIs during all static balance challenges with the exception of Romberg stance with eyes closed were predictive of being at-risk to fall based on FSST time, odds ratio 19.3. The authors conclude that co-contraction about the ankle during static balance challenges can be predictive of performance on a dynamic balance test.

  17. A novel grooming algorithm with the adaptive weight and load balancing for dynamic holding-time-aware traffic in optical networks

    Science.gov (United States)

    Xu, Zhanqi; Huang, Jiangjiang; Zhou, Zhiqiang; Ding, Zhe; Ma, Tao; Wang, Junping

    2013-10-01

    To maximize the resource utilization of optical networks, the dynamic traffic grooming, which could efficiently multiplex many low-speed services arriving dynamically onto high-capacity optical channels, has been studied extensively and used widely. However, the link weights in the existing research works can be improved since they do not adapt to the network status and load well. By exploiting the information on the holding times of the preexisting and new lightpaths, and the requested bandwidth of a user service, this paper proposes a grooming algorithm using Adaptively Weighted Links for Holding-Time-Aware (HTA) (abbreviated as AWL-HTA) traffic, especially in the setup process of new lightpath(s). Therefore, the proposed algorithm can not only establish a lightpath that uses network resource efficiently, but also achieve load balancing. In this paper, the key issues on the link weight assignment and procedure within the AWL-HTA are addressed in detail. Comprehensive simulation and experimental results show that the proposed algorithm has a much lower blocking ratio and latency than other existing algorithms.

  18. Effect of Virtual Reality on Postural and Balance Control in Patients with Stroke: A Systematic Literature Review.

    Science.gov (United States)

    Chen, Ling; Lo, Wai Leung Ambrose; Mao, Yu Rong; Ding, Ming Hui; Lin, Qiang; Li, Hai; Zhao, Jiang Li; Xu, Zhi Qin; Bian, Rui Hao; Huang, Dong Feng

    2016-01-01

    Objective . To critically evaluate the studies that were conducted over the past 10 years and to assess the impact of virtual reality on static and dynamic balance control in the stroke population. Method . A systematic review of randomized controlled trials published between January 2006 and December 2015 was conducted. Databases searched were PubMed, Scopus, and Web of Science. Studies must have involved adult patients with stroke during acute, subacute, or chronic phase. All included studies must have assessed the impact of virtual reality programme on either static or dynamic balance ability and compared it with a control group. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality of the included studies. Results . Nine studies were included in this systematic review. The PEDro scores ranged from 4 to 9 points. All studies, except one, showed significant improvement in static or dynamic balance outcomes group. Conclusions . This review provided moderate evidence to support the fact that virtual reality training is an effective adjunct to standard rehabilitation programme to improve balance for patients with chronic stroke. The effect of VR training in balance recovery is less clear in patients with acute or subacute stroke. Further research is required to investigate the optimum training intensity and frequency to achieve the desired outcome.

  19. Computational fluid dynamics and population balance modelling of nucleate boiling of cryogenic liquids: Theoretical developments

    Directory of Open Access Journals (Sweden)

    Guan Heng Yeoh

    2016-12-01

    Full Text Available The main focus in the analysis of pool or flow boiling in saturated or subcooled conditions is the basic understanding of the phase change process through the heat transfer and wall heat flux partitioning at the heated wall and the two-phase bubble behaviours in the bulk liquid as they migrate away from the heated wall. This paper reviews the work in this rapid developing area with special reference to modelling nucleate boiling of cryogenic liquids in the context of computational fluid dynamics and associated theoretical developments. The partitioning of the wall heat flux at the heated wall into three components – single-phase convection, transient conduction and evaporation – remains the most popular mechanistic approach in predicting the heat transfer process during boiling. Nevertheless, the respective wall heat flux components generally require the determination of the active nucleation site density, bubble departure diameter and nucleation frequency, which are crucial to the proper prediction of the heat transfer process. Numerous empirical correlations presented in this paper have been developed to ascertain these three important parameters with some degree of success. Albeit the simplicity of empirical correlations, they remain applicable to only a narrow range of flow conditions. In order to extend the wall heat flux partitioning approach to a wider range of flow conditions, the fractal model proposed for the active nucleation site density, force balance model for bubble departing from the cavity and bubble lifting off from the heated wall and evaluation of nucleation frequency based on fundamental theory depict the many enhancements that can improve the mechanistic model predictions. The macroscopic consideration of the two-phase boiling in the bulk liquid via the two-fluid model represents the most effective continuum approach in predicting the volume fraction and velocity distributions of each phase. Nevertheless, the

  20. The Relationship Between Hip Strength and the Y-Balance Test.

    Science.gov (United States)

    Wilson, Benjamin R; Robertson, Kaley E; Burnham, Jeremy M; Yonz, Michael C; Ireland, Mary Lloyd; Noehren, Brian

    2017-07-17

    The Y-Balance Test was developed as a test of dynamic postural control and has been shown to be predictive of lower extremity injury. However, the relationship between hip strength and performance on the Y-Balance Test has not been fully elucidated. The goal of this study was to identify the relationship between components of isometric hip strength and the Y-Balance Test, to provide clinicians better guidance as to specific areas of muscle performance to address in the event of poor performance on the Y-Balance Test. Laboratory Study. Biomechanics Laboratory. Seventy-three healthy participants, 40 males and 33 females, volunteered for this study. None. Participants completed the Y-Balance Test on the right leg. We then measured peak isometric torque in hip external rotation, abduction, and extension. Correlations were calculated between torque measurements, normalized for mass, and Y-Balance Test performance. Significant relationships were used in linear regression models to determine which variables were predictive of the Y-Balance Test performance. We found significant positive correlations between Y-Balance Test performance and hip abduction strength. We also found correlations between the Y-Balance Test and hip extension and external rotation strengths. Linear regression analysis showed hip abduction to be the only significant predictor of Y- Balance performance. We found the strongest association between the Y-Balance Test and hip abduction strength. We also showed smaller but significant associations with hip extension and external rotation strength. When entered into a linear regression analysis, hip abduction strength was the only significant predictor of Y-Balance performance. Using this information, practitioners should look to hip abduction strength when patients exhibit deficits in the Y-Balance Test.

  1. Dynamic Demand-Capacity Balancing for Air Traffic Management Using Constraint-Based Local Search: First Results

    Directory of Open Access Journals (Sweden)

    Farshid Hassani Bijarbooneh

    2009-10-01

    Full Text Available Using constraint-based local search, we effectively model and efficiently solve the problem of balancing the traffic demands on portions of the European airspace while ensuring that their capacity constraints are satisfied. The traffic demand of a portion of airspace is the hourly number of flights planned to enter it, and its capacity is the upper bound on this number under which air-traffic controllers can work. Currently, the only form of demand-capacity balancing we allow is ground holding, that is the changing of the take-off times of not yet airborne flights. Experiments with projected European flight plans of the year 2030 show that already this first form of demand-capacity balancing is feasible without incurring too much total delay and that it can lead to a significantly better demand-capacity balance.

  2. How does external technology search become balanced? A three-dimensional approach

    DEFF Research Database (Denmark)

    Li-Ying, Jason; Wang, Yuandi

    2015-01-01

    Firms need to search for external knowledge in a balanced way as over-search entails too much risks and uncertainty and local-search does not promise novel opportunities, as the literature has suggested. We conceptually position firms? search behavior within a three-dimensional knowledge search...... space, including cognitive, temporal, and geographic dimensions. We suggest that the balance is no longer a matter of finding optimal search distance along a single dimension. Instead, it becomes an art to maintain balance in a dynamic manner across three dimensions. Using empirical evidence from...... Chinese licensee firms, we show that such a three-dimension balance does exist among firms? practice. The findings in this respect provide promising opportunities for future research, which will significantly contribute to our understanding of how firms search for external knowledge and the implications...

  3. Effect of a balance-training programme on postural balance, aerobic capacity and frequency of falls in women with osteoporosis: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Ibolya Miko

    2018-05-01

    Full Text Available Objective: To investigate the effect of a 12-month complex balance-training programme on static and dynamic postural balance, aerobic capacity and frequency of falls in women with established osteoporosis. Design: Randomized controlled trial in which the intervention group was assigned a 12-month exercise programme (3 times a week for 30 min and the control group had no intervention. Subjects: A total of 100 osteoporotic women with at least one previous fracture. Methods: Performance-based Timed Up and Go (TUG, Berg Balance Scale (BBS and stabilometric platform tests were used to evaluate balance. Aerobic capacity was measured by bicycle ergometry. Frequency of falls was assessed using a falls diary. Results: After 1 year, there was a statistically significant difference between the improvement achieved in the intervention and control groups on the performance-based TUG, BBS and stabilometric platform tests (p < 0.05. Mean metabolic equivalent (MET value decreased in the intervention group, from 4.91 to 3.82 (a significant difference from the change achieved in the control group; p = 0.05. Relative risk of falls was 0.534 at 1 year (p = 0.17. Conclusion: The 12-month balance-training programme significantly improved postural balance and increased aerobic capacity in women with established osteoporosis.

  4. Athletic footwear affects balance in men.

    Science.gov (United States)

    Robbins, S; Waked, E; Gouw, G J; McClaran, J

    1994-06-01

    Stable equilibrium during locomotion is required for both superior performance of sports and prevention of injuries from falls. A recent report indicated that currently available athletic footwear impairs stability in older men. Since this discovery, if confirmed, seems important to both competitive athletes and the physically active general public, we performed an experiment using similar methods on a younger population. We tested the hypothesis that midsole thickness is negatively, and hardness positively related to dynamic equilibrium, in 17 healthy adult men (mean(s.d.) age 33(11.13) years) via a balance beam method. Subjects walked along a 9-m long beam at 0.5 m s-1 once barefoot and six times wearing identical pairs of experimental shoes which differed only in midsole hardness and thickness which spanned the respective ranges currently available in footwear. Falls from the beam (balance failures) were quantified. Balance failures varied significantly in relation to midsole hardness and thickness, and there was a strong trend toward interaction of these variables (P = 0.09). Midsole hardness was positively related to stability, and midsole thickness was negatively related, which confirms the previous report. Hence, shoes with thick-soft soles, similar to modern athletic footwear and 'walking shoes', destabilize men, and shoes with thin-hard soles provide superior stability. The pair with the poorest stability (A 15-thick; 12.34 balance failures per 100 m) produced 217% more balance failures than those associated with the best stability (A 50-thin; 3.89 balance failures per 100 m). Since most types of athletic footwear and many other shoes incorporate midsoles with hardness and thickness associated with poor stability, we conclude that both athletic performance and public safety could be enhanced through stability optimized footwear.

  5. Exergaming as a viable therapeutic tool to improve static and dynamic balance among older adults and people with idiopathic Parkinson’s disease: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Dale Michael Harris

    2015-09-01

    Full Text Available The use of virtual reality games (known as ‘exergaming’ as a neurorehabilitation tool is gaining interest. Therefore, we aim to collate evidence for the effects of exergaming on the balance and postural control of older adults and people with idiopathic Parkinson’s disease (IPD. Six electronic databases were searched, from inception to April 2015, to identify relevant studies. Standardised mean differences (SMD and 95% confidence intervals (CI were used to calculate effect sizes between experimental and control groups. I2 statistics were used to determine levels of heterogeneity. 309 older adults and 74 people with IPD were assessed across eleven studies. The results showed that exergaming improved static balance (SMD 1.069, 95% CI 0.563 to 1.576, postural control (SMD 0.826, 95% CI 0.481 to 1.170 and dynamic balance (SMD -0.808, 95% CI -1.192 to -0.424 in healthy older adults. Two PD studies showed an improvement in static balance (SMD 0.124, 95% CI -0.581 to 0.828 and postural control (SMD 2.576, 95% CI 1.534 to 3.599. Our findings suggest that exergaming might be an appropriate therapeutic tool for improving balance and postural control in older adults, but more large-scale trials are needed to determine if the same is true for people with IPD.

  6. Exergaming as a Viable Therapeutic Tool to Improve Static and Dynamic Balance among Older Adults and People with Idiopathic Parkinson’s Disease: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Harris, Dale M.; Rantalainen, Timo; Muthalib, Makii; Johnson, Liam; Teo, Wei-Peng

    2015-01-01

    The use of virtual reality games (known as “exergaming”) as a neurorehabilitation tool is gaining interest. Therefore, we aim to collate evidence for the effects of exergaming on the balance and postural control of older adults and people with idiopathic Parkinson’s disease (IPD). Six electronic databases were searched, from inception to April 2015, to identify relevant studies. Standardized mean differences (SMDs) and 95% confidence intervals (CI) were used to calculate effect sizes between experimental and control groups. I2 statistics were used to determine levels of heterogeneity. 325 older adults and 56 people with IPD who were assessed across 11 ­studies. The results showed that exergaming improved static balance (SMD 1.069, 95% CI 0.563–1.576), postural control (SMD 0.826, 95% CI 0.481–1.170), and dynamic balance (SMD −0.808, 95% CI −1.192 to −0.424) in healthy older adults. Two IPD studies showed an improvement in static balance (SMD 0.124, 95% CI −0.581 to 0.828) and postural control (SMD 2.576, 95% CI 1.534–3.599). Our findings suggest that exergaming might be an appropriate therapeutic tool for improving balance and postural control in older adults, but more ­large-scale trials are needed to determine if the same is true for people with IPD. PMID:26441634

  7. Implications of multiplane-multispeed balancing for future turbine engine design and cost

    Science.gov (United States)

    Badgley, R. H.

    1974-01-01

    This paper describes several alternative approaches, provided by multiplane-multispeed balancing, to traditional gas turbine engine manufacture and assembly procedures. These alternatives, which range from addition of trim-balancing at the end of the traditional assembly process to modular design of the rotating system for assembly and balancing external to the engine, require attention by the engine designer as an integral part of the design process. Since multiplane-multispeed balancing may be incorporated at one or more of several points during manufacture-assembly, its deliberate use is expected to provide significant cost and performance (reduced vibration) benefits. Moreover, its availability provides the designer with a firm base from which he may advance, with reasonable assurance of success, into the flexible rotor dynamic regime.

  8. A Dynamic Balancing Approach for a Quadruped Robot Supported by Diagonal Legs

    Directory of Open Access Journals (Sweden)

    Jian Meng

    2015-10-01

    Full Text Available For legged robots, the most important task is to keep balance. This paper proposes a new balance control approach. To simplify the control complexity, first, LQR (linear quadratic regulator control was used to obtain stable state feedback for the model. Then, the 6-DOF model was stabilized by dividing the whole robot into three separate parts. After that, VMC (virtual model control was used to change the configuration of the joints. The simulation results showed that the proposed method allowed the quadruped robot to walk stably, even when certain types of disturbance were exerted on the models. In the simulation model, to mimic real conditions, noise was added to the sensors; the algorithm was then verified as still suitable for the quadruped robot.

  9. Performance Management through a Balanced Scorecard - A SystemsDynamics Modelling Approach

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    The object of this paper is to show how - normally separate practices - can be linked together to support the performance management system in a balanced scorecard framework. The monitor and learn of the strategy evaluation and the feedback process is important for the company to be on track...

  10. Well-balanced Arbitrary-Lagrangian-Eulerian finite volume schemes on moving nonconforming meshes for the Euler equations of gas dynamics with gravity

    Science.gov (United States)

    Gaburro, Elena; Castro, Manuel J.; Dumbser, Michael

    2018-06-01

    In this work, we present a novel second-order accurate well-balanced arbitrary Lagrangian-Eulerian (ALE) finite volume scheme on moving nonconforming meshes for the Euler equations of compressible gas dynamics with gravity in cylindrical coordinates. The main feature of the proposed algorithm is the capability of preserving many of the physical properties of the system exactly also on the discrete level: besides being conservative for mass, momentum and total energy, also any known steady equilibrium between pressure gradient, centrifugal force, and gravity force can be exactly maintained up to machine precision. Perturbations around such equilibrium solutions are resolved with high accuracy and with minimal dissipation on moving contact discontinuities even for very long computational times. This is achieved by the novel combination of well-balanced path-conservative finite volume schemes, which are expressly designed to deal with source terms written via non-conservative products, with ALE schemes on moving grids, which exhibit only very little numerical dissipation on moving contact waves. In particular, we have formulated a new HLL-type and a novel Osher-type flux that are both able to guarantee the well balancing in a gas cloud rotating around a central object. Moreover, to maintain a high level of quality of the moving mesh, we have adopted a nonconforming treatment of the sliding interfaces that appear due to the differential rotation. A large set of numerical tests has been carried out in order to check the accuracy of the method close and far away from the equilibrium, both, in one- and two-space dimensions.

  11. The contribution of postural balance analysis in older adult fallers: A narrative review.

    Science.gov (United States)

    Pizzigalli, L; Micheletti Cremasco, M; Mulasso, A; Rainoldi, A

    2016-04-01

    Falls are a serious health problem for older adults. Several studies have identified the decline of postural balance as one of the main risk factors for falls. Contrary to what may be believed, the capability of force platform measurements to predict falls remains uncertain. The focus of this narrative review is the identification of postural characteristics of older adults at risk of falling using both static and dynamic postural balance assessments. The literature analysis was conducted on Medline/PubMed. The search ended in May 2015. Centre of pressure (CoP) path length, CoP velocity and sway in medial lateral and anterior-posterior are the variables that distinguish older adult fallers from non-fallers. Recommendations to medical personnel on how to provide efficient balance training for older adults are offered, discussing the relevance and limitations of postural stability on static and dynamic board in falling risk prevention. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Balancing Energy Processes in Turbine Engines

    Directory of Open Access Journals (Sweden)

    Balicki Włodzimierz

    2015-01-01

    Full Text Available The article discusses the issue of balancing energy processes in turbine engines in operation in aeronautic and marine propulsion systems with the aim to analyse and evaluate basic operating parameters. The first part presents the problem of enormous amounts of energy needed for driving fans and compressors of the largest contemporary turbofan engines commonly used in long-distance aviation. The amounts of the transmitted power and the effect of flow parameters and constructional properties of the engines on their performance and real efficiency are evaluated. The second part of the article, devoted to marine applications of turbine engines, presents the energy balance of the kinetic system of torque transmission from main engine turbines to screw propellers in the combined system of COGAG type. The physical model of energy conversion processes executed in this system is presented, along with the physical model of gasodynamic processes taking place in a separate driving turbine of a reversing engine. These models have made the basis for formulating balance equations, which then were used for analysing static and dynamic properties of the analysed type of propulsion, in particular in the aspect of mechanical loss evaluation in its kinematic system.

  13. Typical balance exercises or exergames for balance improvement?

    Science.gov (United States)

    Gioftsidou, Asimenia; Vernadakis, Nikolaos; Malliou, Paraskevi; Batzios, Stavros; Sofokleous, Polina; Antoniou, Panagiotis; Kouli, Olga; Tsapralis, Kyriakos; Godolias, George

    2013-01-01

    Balance training is an effective intervention to improve static postural sway and balance. The purpose of the present study was to investigate the effectiveness of the Nintendo Wii Fit Plus exercises for improving balance ability in healthy collegiate students in comparison with a typical balance training program. Forty students were randomly divided into two groups, a traditional (T group) and a Nintendo Wii group (W group) performed an 8 week balance program. The "W group" used the interactive games as a training method, while the "T group" used an exercise program with mini trampoline and inflatable discs (BOSU). Pre and Post-training participants completed balance assessments. Two-way repeated measures analyses of variance (ANOVAs) were conducted to determine the effect of training program. Analysis of the data illustrated that both training program groups demonstrated an improvement in Total, Anterior-posterior and Medial Lateral Stability Index scores for both limbs. Only at the test performed in the balance board with anterior-posterior motion, the improvement in balance ability was greater in the "T group" than the "W group", when the assessment was performed post-training (p=0.023). Findings support the effectiveness of using the Nintendo Wii gaming console as a balance training intervention tool.

  14. Postural Balance in Women with Osteoporosis and Effective Factors

    Directory of Open Access Journals (Sweden)

    Duygu Ünlüsoy

    2011-08-01

    Full Text Available Introduction: The most common cause of mortality and morbidity among osteoporotic individuals is bone fracture which in many cases is a direct result of falls. Individual factors contributing to the risk of fall are poor postural balance and lack of muscle strength. Our aims were to assess postural dynamic balance in osteoporotic women and to describe the effective factors on the balance performance. Methods: Twenty osteoporotic women with kyphosis, 50 osteoporotic women without kyphosis, and 30 healthy women were included in the study. Anterior/Posterior (AP, Medial/Lateral (ML and Overall (OA stability indices were obtained using Biodex Stability System (Biodex Medical System, Shirley, NY. Subjects were tested both with eyes open and eyes closed. Quadriceps-hamstring muscles’ strength were measured with isokinetic system at angular speeds of 60-180-300°/sec. Results: OA, AP, ML stability indices in the group with osteoporosis were found to be statistically significantly higher in the open-eyed balance test. When a correlation analysis was performed on all osteoporotic patients, a negative correlation was detected between balance stability indices and knee flexion-extension strength at 60°/sec and knee flexion strength at 300°/sec. Multivariable regression analysis revealed knee extension strength at 60°/sec to be the most effective factor contributing to balance in osteoporotic patients. Conclusion: Postural balance in osteoporotic women presenting is significantly worse than in the healthy women and the factor exerting the greatest influence on balance is quadriceps muscle strength. Therefore, particular importance must be given to balance and quadriceps strengthening exercises in order to prevent falls in osteoporotic patients. (Turkish Journal of Osteoporosis 2011;17:37-43

  15. Cache-aware data structure model for parallelism and dynamic load balancing

    International Nuclear Information System (INIS)

    Sridi, Marwa

    2016-01-01

    for parallel processing where groups are distributed on available cores and a group size ensuring the complete filling of the private cache memories (i.e. L2 level). The strategy logically suggests the experimentation of a two levels parallel solution for nodes composed of several multi-core processors: one group is thus attached to one processor and an inner parallel loop is used inside the group based on the internal cores of the processor. This latter approach still requires consolidation to avoid contention upon the internal processor memory due to coherency enforcement between the different private cache memories. It is noticeable that the best performances are obtained through load balancing based on a dynamic scheduling approach with work stealing, achieved via the XKAAPI library (INRIA). (author) [fr

  16. Delta Dynamics

    DEFF Research Database (Denmark)

    Bendixen, Mette

    . The warming air temperature affects the soil temperature and permafrost thaws and destabilizes the material in the coastal zone. In Greenland, the warming temperature lowers the surface mass balance of the Greenland Ice Sheet and more material is transported to the coastal zone. The sea ice extent is thinning...... of a fjord and the second type is a wider fan-shaped open delta. Most deltas are directly coupled to the Greenland Ice Sheet or local icecaps and are highly influenced by the dynamics in the catchments. It is demonstrated how a modern changing climate directly affects delta dynamics, and that Greenlandic...... deltas are prograding, contrary to the global trend showing eroding Arctic coasts. Moreover, it is revealed that the increasing proglacial freshwater runoff, caused by a lowering of the surface mass balance of the Greenland Ice Sheet is the main determining agent in delta progradation. The final part...

  17. Dynamic Selective Exposure during Decision-Making.

    Science.gov (United States)

    Phillips, James G; Hoon, Teressa; Landon, Jason

    2016-01-01

    To understand dynamic changes in the likelihood that people would access and selectively expose themselves to information online, the present study examined the checking of account balances during simulated gambling. Sixteen participants played 120 hands of computer Blackjack for points, at higher or lower levels of risk (different point multipliers), and after each win or loss the computer recorded if participants checked their account balances. There were individual differences in checking rates. Participants who were more likely to check balances exhibited a selectivity of exposure to decision consonant information after a win at low risk. Although it was expected that people would seek to maintain positive mood, data were better explained in terms of Cognitive Dissonance. The effects of Cognitive Dissonance are liable to extend beyond single static decisions into dynamic online environments.

  18. The development of hoof balance and landing preference in the post-natal period.

    Science.gov (United States)

    Gorissen, B M C; Serra Bragança, F M; Wolschrijn, C F; Back, W; van Weeren, P R

    2018-04-20

    Foals can follow the herd within hours of birth, but it has been shown that kinetic gait parameters and static balance still have to mature. However, development of dynamic balance has not been investigated. To objectively quantify landing and pressure pattern dynamics under the hoof during the first half year of life. Prospective, cohort study performed at a single stud farm. Pressure plate measurements at walk and trot from ten Dutch warmblood foals during the first 24 weeks of life were used to quantify toe-heel and medial-lateral hoof balance asymmetry indexes and to determine preferred landing strategy. Concurrently, radiographs of the tarsocrural and femoropatellar joints were taken at 4-6 weeks and after 6 months to check for osteochondrosis. A linear mixed model was used to determine the effects of time point, limb pair (front/hind), side (left/right) and osteochondrosis status of every foal. At 25% of stance duration at walk, front limbs were more loaded in the heel region in weeks 6-20 (P≤0.04), the medial-lateral balance was more to the lateral side from week 6 onwards at both walk and trot (P≤0.04). Landing preference gradually changed in the same directions. Variability in pressure distribution decreased over time. (Subclinical) osteochondrosis did not influence any of the measured parameters. This study is limited by the relatively small sample size only containing one breed from a single stud farm. Dynamic hoof balance in new-born foals is more variable and less oriented towards the lateral side of the hoof and to the heel than in mature horses. This pattern changes gradually during the first weeks of life. Knowledge of this process is essential for the clinician when considering interventions in this area in early life. © 2018 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.

  19. Effect of Virtual Reality on Postural and Balance Control in Patients with Stroke: A Systematic Literature Review

    Directory of Open Access Journals (Sweden)

    Ling Chen

    2016-01-01

    Full Text Available Objective. To critically evaluate the studies that were conducted over the past 10 years and to assess the impact of virtual reality on static and dynamic balance control in the stroke population. Method. A systematic review of randomized controlled trials published between January 2006 and December 2015 was conducted. Databases searched were PubMed, Scopus, and Web of Science. Studies must have involved adult patients with stroke during acute, subacute, or chronic phase. All included studies must have assessed the impact of virtual reality programme on either static or dynamic balance ability and compared it with a control group. The Physiotherapy Evidence Database (PEDro scale was used to assess the methodological quality of the included studies. Results. Nine studies were included in this systematic review. The PEDro scores ranged from 4 to 9 points. All studies, except one, showed significant improvement in static or dynamic balance outcomes group. Conclusions. This review provided moderate evidence to support the fact that virtual reality training is an effective adjunct to standard rehabilitation programme to improve balance for patients with chronic stroke. The effect of VR training in balance recovery is less clear in patients with acute or subacute stroke. Further research is required to investigate the optimum training intensity and frequency to achieve the desired outcome.

  20. A Tool for Balance Control Training Using Muscle Synergies and Multimodal Interfaces

    Directory of Open Access Journals (Sweden)

    D. Galeano

    2014-01-01

    Full Text Available Balance control plays a key role in neuromotor rehabilitation after stroke or spinal cord injuries. Computerized dynamic posturography (CDP is a classic technological tool to assess the status of balance control and to identify potential disorders. Despite the more accurate diagnosis generated by these tools, the current strategies to promote rehabilitation are still limited and do not take full advantage of the technologies available. This paper presents a novel balance training platform which combines a CDP device made from low-cost interfaces, such as the Nintendo Wii Balance Board and the Microsoft Kinect. In addition, it integrates a custom electrical stimulator that uses the concept of muscle synergies to promote natural interaction. The aim of the platform is to support the exploration of innovative multimodal therapies. Results include the technical validation of the platform using mediolateral and anteroposterior sways as basic balance training therapies.

  1. Annals of African Surgery July 2011 07.12.2011.indd

    African Journals Online (AJOL)

    andrew

    Orth), Schenck R2, MD, FACS Affiliation: 1-Department of Orthopaedics, Makerere University, Kampala,. Uganda /Orthopaedic Surgeon, Orthopaedic Rehabilitation Unit, PCEA Kikuyu Hospital, Kikuyu Kenya 2- Department of Plastic Surgery, ...

  2. Abnormal sensory integration affects balance control in hemiparetic patients within the first year after stroke

    Directory of Open Access Journals (Sweden)

    Clarissa B. Oliveira

    2011-01-01

    Full Text Available OBJECTIVE: Impairments in balance can be a consequence of changes in the motor, sensory, and integrative aspects of motor control. Abnormal sensory reweighting, i.e., the ability to select the most appropriate sensory information to achieve postural stability, may contribute to balance impairment. The Sensory Organization Test is a component of Computerized Dynamic Posturography that evaluates the impact of visual, vestibular, and somatosensory inputs, as well as sensory reweighting, under conditions of sensory conflict. The aim of this study is to compare balance control in hemiparetic patients during the first year post-stroke and in age-matched neurologically normal subjects using the Berg Balance Scale and Computerized Dynamic Posturography. METHODS: We compared the Berg Balance Scale and Sensory Organization Test scores in 21 patients with hemiparesis after first-ever ischemic stroke and in 21 age-matched, neurologically normal subjects. An equilibrium score was defined for each Sensory Organization Test condition. RESULTS: Berg Balance Scale scores were significantly lower in the patients than in the neurologically normal subjects. Equilibrium scores were significantly lower in the patients than in the neurologically normal subjects for those Sensory Organization Test conditions that did not provide appropriate somatosensory information and under conditions of sensory conflict. A history of falls was more frequent in patients with lower equilibrium scores. CONCLUSION: During the first year after a stroke, defective sensory reweighting significantly impacts balance control in hemiparetic patients. These results are important for the planning of effective rehabilitation interventions.

  3. Static Load Balancing Algorithms In Cloud Computing Challenges amp Solutions

    Directory of Open Access Journals (Sweden)

    Nadeem Shah

    2015-08-01

    Full Text Available Abstract Cloud computing provides on-demand hosted computing resources and services over the Internet on a pay-per-use basis. It is currently becoming the favored method of communication and computation over scalable networks due to numerous attractive attributes such as high availability scalability fault tolerance simplicity of management and low cost of ownership. Due to the huge demand of cloud computing efficient load balancing becomes critical to ensure that computational tasks are evenly distributed across servers to prevent bottlenecks. The aim of this review paper is to understand the current challenges in cloud computing primarily in cloud load balancing using static algorithms and finding gaps to bridge for more efficient static cloud load balancing in the future. We believe the ideas suggested as new solution will allow researchers to redesign better algorithms for better functionalities and improved user experiences in simple cloud systems. This could assist small businesses that cannot afford infrastructure that supports complex amp dynamic load balancing algorithms.

  4. The climatic water balance in an ecological context

    Science.gov (United States)

    Stephenson, N. L.

    2011-12-01

    Because the climatic water balance describes the seasonal interactions of energy (heat and solar radiation) and water in biologically meaningful ways, it provides a powerful tool for understanding and predicting the effects of climatic changes on the terrestrial biosphere. I begin with a brief overview of the definitions and interpretations of the biologically most important water balance parameters -- actual evapotranspiration (AET) and climatic water deficit (Deficit) -- and how the particular approach used to calculate these parameters depends both on the goals of the study and on the available climatic data. Some authors have attempted to represent aspects of the climatic water balance with indices based on annual potential evapotranspiration (PET) and precipitation (P), such at P/PET or PET - P. However, these and related indices do not reflect soil water dynamics, snow dynamics, or the seasonal interactions of energy and water, and therefore have no biological interpretation. Consequently, such indices are more poorly correlated with ecological patterns and processes than AET and Deficit. Of critical importance, the effects of changing energy and water supplies on the climatic water balance are nearly orthogonal. For example, a plant community growing on shallow soils on a shaded slope and one growing on deep soils on a sunward slope often may have the same amount of measured soil moisture available to them. However, the dynamics of energy and water that resulted in the identical soil moistures were fundamentally different (decreased evaporative demand on the shaded slope versus increased water supply on the deep soils); the associated differences in AET and Deficit will therefore result in different plant communities occupying the sites, in spite of identical soil moistures. In the context of climatic change, the orthogonal effects of energy and water mean that increasing precipitation cannot be expected to counteract the effects of increasing temperature

  5. EFFECTS OF BALLATES, STEP AEROBICS, AND WALKING ON BALANCE IN WOMEN AGED 50-75 YEARS

    Directory of Open Access Journals (Sweden)

    Sarah Clary

    2006-09-01

    Full Text Available This study examined the effectiveness of Ballates training (strengthening of the central core musculature by the inception of balance techniques compared to more traditional exercise programs, such as step aerobics and walking, on balance in women aged 50- 75 years. Participants were randomly assigned to one of three supervised training groups (1 hour/day, 3 days/week, 13 weeks, Ballates (n = 12, step aerobics (n = 17, or walking (n =15. Balance was measured by four different methods (modified Clinical Test for the Sensory Interaction on Balance - mCTSIB; Unilateral Stance with Eyes Open - US-EO or Eyes Closed - US-EC; Tandem Walk - TW; Step Quick Turn - SQT using the NeuroCom Balance Master. A 2-way (Group and Trial repeated measures ANOVA and post-hoc Bonferroni Pair-wise Comparisons were used to evaluate changes in the dependent variables used to describe stability and balance (sway velocity, turn sway, speed, and turn time. Measures of static postural stability and dynamic balance were similar for the three groups prior to training. Following the different exercise interventions, sway velocity on firm and foam surfaces (mCTSIB with eyes closed (p < 0.05 increased for the Ballates group while the other two exercise groups either maintained or decreased their sway velocity following the training, therefore suggesting that these two groups either maintained or improved their balance. There were significant improvements in speed during the TW test (p < 0.01, and turn time (p < 0.01 and sway (p < 0.05 during the SQT test for each of the three groups. In general, all three training programs improved dynamic balance, however, step aerobics and walking programs resulted in be better improvements in postural stability or static balance when compared to the Ballates program

  6. Balance Problems

    Science.gov (United States)

    ... fully trust your sense of balance. Loss of balance also raises the risk of falls. This is a serious and even life-threatening ... 65. Balance disorders are serious because of the risk of falls. But occasionally balance problems may warn of another health condition, such ...

  7. Internet-based home training is capable to improve balance in multiple sclerosis: a randomized controlled trial.

    Science.gov (United States)

    Frevel, D; Mäurer, M

    2015-02-01

    Balance disorders are common in multiple sclerosis. Aim of the study is to investigate the effectiveness of an Internet-based home training program (e-Training) to improve balance in patients with multiple sclerosis. A randomized, controlled study. Academic teaching hospital in cooperation with the therapeutic riding center Gut Üttingshof, Bad Mergentheim. Eighteen multiple sclerosis patients (mean EDSS 3,5) took part in the trial. Outcome of patients using e-Training (N.=9) was compared to the outcome of patients receiving hippotherapy (N.=9), which can be considered as an advanced concept for the improvement of balance and postural control in multiple sclerosis. After simple random allocation patients received hippotherapy or Internet-based home training (balance, postural control and strength training) twice a week for 12 weeks. Assessments were done before and after the intervention and included static and dynamic balance (primary outcome). Isometric muscle strength of the knee and trunk extension/flexion (dynamometer), walking capacity, fatigue and quality of life served as secondary outcome parameters. Both intervention groups showed comparable and highly significant improvement in static and dynamic balance capacity, no difference was seen between the both intervention groups. However looking at fatigue and quality of life only the group receiving hippotherapy improved significantly. Since e-Training shows even comparable effects to hippotherapy to improve balance, we believe that the established Internet-based home training program, specialized on balance and postural control training, is feasible for a balance and strength training in persons with multiple sclerosis. We demonstrated that Internet-based home training is possible in patients with multiple sclerosis.

  8. Dynamic balance between master transcription factors determines the fates and functions of CD4 T cell and innate lymphoid cell subsets

    Science.gov (United States)

    2017-01-01

    CD4 T cells, including T regulatory cells (Treg cells) and effector T helper cells (Th cells), and recently identified innate lymphoid cells (ILCs) play important roles in host defense and inflammation. Both CD4 T cells and ILCs can be classified into distinct lineages based on their functions and the expression of lineage-specific genes, including those encoding effector cytokines, cell surface markers, and key transcription factors. It was first recognized that each lineage expresses a specific master transcription factor and the expression of these factors is mutually exclusive because of cross-regulation among these factors. However, recent studies indicate that the master regulators are often coexpressed. Furthermore, the expression of master regulators can be dynamic and quantitative. In this review, we will first discuss similarities and differences between the development and functions of CD4 T cell and ILC subsets and then summarize recent literature on quantitative, dynamic, and cell type–specific balance between the master transcription factors in determining heterogeneity and plasticity of these subsets. PMID:28630089

  9. Well balanced finite volume methods for nearly hydrostatic flows

    International Nuclear Information System (INIS)

    Botta, N.; Klein, R.; Langenberg, S.; Luetzenkirchen, S.

    2004-01-01

    In numerical approximations of nearly hydrostatic flows, a proper representation of the dominant hydrostatic balance is of crucial importance: unbalanced truncation errors can induce unacceptable spurious motions, e.g., in dynamical cores of models for numerical weather prediction (NWP) in particular near steep topography. In this paper we develop a new strategy for the construction of discretizations that are 'well-balanced' with respect to dominant hydrostatics. The classical idea of formulating the momentum balance in terms of deviations of pressure from a balanced background distribution is realized here through local, time dependent hydrostatic reconstructions. Balanced discretizations of the pressure gradient and of the gravitation source term are achieved through a 'discrete Archimedes' buoyancy principle'. This strategy is applied to extend an explicit standard finite volume Godunov-type scheme for compressible flows with minimal modifications. The resulting method has the following features: (i) It inherits its conservation properties from the underlying base scheme. (ii) It is exactly balanced, even on curvilinear grids, for a large class of near-hydrostatic flows. (iii) It solves the full compressible flow equations without reference to a background state that is defined for an entire vertical column of air. (iv) It is robust with respect to details of the implementation, such as the choice of slope limiting functions, or the particularities of boundary condition discretizations

  10. Long term mass balance of the Helheim and Kangerdlugssuaq glaciers in

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Fitzner, Antje; Kjær, Kurt

    2013-01-01

    Observations over the past decade show huge ice loss associated with speeding up of glaciers in southeast Greenland in 2003, followed by a deceleration in 2006. These short-term episodic dynamic perturbations have a major impact on the mass balance at decadal scale. However, to improve the projec......Observations over the past decade show huge ice loss associated with speeding up of glaciers in southeast Greenland in 2003, followed by a deceleration in 2006. These short-term episodic dynamic perturbations have a major impact on the mass balance at decadal scale. However, to improve...... the projection of future sea level rise, a long-term data record that reveals the mass balance between episodic events is required. Here, we extend the observational record of marginal thinning of Helheim glacier (HG) and Kangerdlugssuaq glacier (KG) from 7 to 30 years. Our measurements reveal that, although...... in air temperature suggest that both outlet glaciers respond immediately to small fluctuations in both the SST and air temperature. Furthermore, we compare our observations of ice flow speed and elevation changes with predictions based on the The Parallel Ice Sheet Model (PISM) software....

  11. Toward a dynamic balanced scorecard model for humanitarian relief organizations’ performance management

    NARCIS (Netherlands)

    Anjomshoae, Ali; Hassan, Adnan; Kunz, Nathan; Wong, Kuan Yew; de Leeuw, S.L.J.M.

    2017-01-01

    Purpose – In recent years, the balanced scorecard (BSC) has received considerable interest among practitioners for managing their organization’s performance. Unfortunately existing BSC frameworks, particularly for humanitarian supply chains, lack causal relationships among performance indicators,

  12. Workload Balancing on Heterogeneous Systems: A Case Study of Sparse Grid Interpolation

    KAUST Repository

    Muraraşu, Alin

    2012-01-01

    Multi-core parallelism and accelerators are becoming common features of today’s computer systems, as they allow for computational power without sacrificing energy efficiency. Due to heterogeneity, tuning for each type of compute unit and adequate load balancing is essential. This paper proposes static and dynamic solutions for load balancing in the context of an application for visualizing high-dimensional simulation data. The application relies on the sparse grid technique for data compression. Its performance critical part is the interpolation routine used for decompression. Results show that our load balancing scheme allows for an efficient acceleration of interpolation on heterogeneous systems containing multi-core CPUs and GPUs.

  13. Social balance as a satisfiability problem of computer science.

    Science.gov (United States)

    Radicchi, Filippo; Vilone, Daniele; Yoon, Sooeyon; Meyer-Ortmanns, Hildegard

    2007-02-01

    Reduction of frustration was the driving force in an approach to social balance as it was recently considered by Antal [T. Antal, P. L. Krapivsky, and S. Redner, Phys. Rev. E 72, 036121 (2005)]. We generalize their triad dynamics to k-cycle dynamics for arbitrary integer k. We derive the phase structure, determine the stationary solutions, and calculate the time it takes to reach a frozen state. The main difference in the phase structure as a function of k is related to k being even or odd. As a second generalization we dilute the all-to-all coupling as considered by Antal to a random network with connection probability wcomputer science. The phase of social balance in our original interpretation then becomes the phase of satisfaction of all logical clauses in the satisfiability problem. In common to the cases we study, the ideal solution without any frustration always exists, but the question actually is as to whether this solution can be found by means of a local stochastic algorithm within a finite time. The answer depends on the choice of parameters. After establishing the mapping between the two classes of models, we generalize the social-balance problem to a diluted network topology for which the satisfiability problem is usually studied. On the other hand, in connection with the satisfiability problem we generalize the random local algorithm to a p-random local algorithm, including a parameter p that corresponds to the propensity parameter in the social balance problem. The qualitative effect of the inclusion of this parameter is a bias towards the optimal solution and a reduction of the needed simulation time.

  14. Taekwondo training improves balance in volunteers over forty.

    Directory of Open Access Journals (Sweden)

    Gaby ePons Van Dijk

    2013-03-01

    Full Text Available AbstractBalance deteriorates with age, and may eventually lead to falling accidents which may threaten independent living. As Taekwondo contains various highly dynamic movement patterns, taekwondo practice may sustain or improve balance. Therefore, in 24 middle-aged healthy volunteers (40-71 year we investigated effects of age-adapted taekwondo training of one hour a week during one year on various balance parameters, such as: motor orientation ability (primary outcome measure, postural and static balance test, single leg stance, one leg hop test, and a questionnaire.Motor orientation ability significantly increased in favor of the antero-posterior direction with a difference of 0.62 degrees towards anterior compared to pre-training measurement, when participants corrected the tilted platform rather towards the posterior direction; female gender being an independent outcome predictor. On postural balance measurements sway path improved in all 19 participants, with a median of 9.3 mm/sec (range 0.71-45.86, and sway area in 15 participants with 4.2 mm²/sec (range 17.39-1.22. Static balance improved with an average of 5.34 seconds for the right leg, and with almost 4 seconds for the left. Median single leg stance duration increased in 17 participants with 5 seconds (range 1-16, and in 13 participants with 8 seconds (range 1-18. The average one leg hop test distance increased (not statistically significant with 9.5 cm. The questionnaire reported a better ‘ability to maintain balance’ in sixteen.In conclusion, our data suggest that age-adapted Taekwondo training improves various aspects of balance control in healthy people over the age of forty.

  15. The “Balance of Nature”—Evolution of a Panchreston

    Science.gov (United States)

    Simberloff, Daniel

    2014-01-01

    The earliest concept of a balance of nature in Western thought saw it as being provided by gods but requiring human aid or encouragement for its maintenance. With the rise of Greek natural philosophy, emphasis shifted to traits gods endowed species with at the outset, rather than human actions, as key to maintaining the balance. The dominance of a constantly intervening God in the Middle Ages lessened interest in the inherent features of nature that would contribute to balance, but the Reformation led to renewed focus on such features, particularly traits of species that would maintain all of them but permit none to dominate nature. Darwin conceived of nature in balance, and his emphasis on competition and frequent tales of felicitous species interactions supported the idea of a balance of nature. But Darwin radically changed its underlying basis, from God to natural selection. Wallace was perhaps the first to challenge the very notion of a balance of nature as an undefined entity whose accuracy could not be tested. His skepticism was taken up again in the 20th century, culminating in a widespread rejection of the idea of a balance of nature by academic ecologists, who focus rather on a dynamic, often chaotic nature buffeted by constant disturbances. The balance-of-nature metaphor, however, lives on in large segments of the public, representing a fragile aspect of nature and biodiversity that it is our duty to protect. PMID:25290954

  16. Balancing Automatic-Controlled Behaviors and Emotional-Salience States: A Dynamic Executive Functioning Hypothesis.

    Science.gov (United States)

    Kluwe-Schiavon, Bruno; Viola, Thiago W; Sanvicente-Vieira, Breno; Malloy-Diniz, Leandro F; Grassi-Oliveira, Rodrigo

    2016-01-01

    Recently, there has been growing interest in understanding how executive functions are conceptualized in psychopathology. Since several models have been proposed, the major issue lies within the definition of executive functioning itself. Theoretical discussions have emerged, narrowing the boundaries between "hot" and "cold" executive functions or between self-regulation and cognitive control. Nevertheless, the definition of executive functions is far from a consensual proposition and it has been suggested that these models might be outdated. Current efforts indicate that human behavior and cognition are by-products of many brain systems operating and interacting at different levels, and therefore, it is very simplistic to assume a dualistic perspective of information processing. Based upon an adaptive perspective, we discuss how executive functions could emerge from the ability to solve immediate problems and to generalize successful strategies, as well as from the ability to synthesize and to classify environmental information in order to predict context and future. We present an executive functioning perspective that emerges from the dynamic balance between automatic-controlled behaviors and an emotional-salience state. According to our perspective, the adaptive role of executive functioning is to automatize efficient solutions simultaneously with cognitive demand, enabling individuals to engage such processes with increasingly complex problems. Understanding executive functioning as a mediator of stress and cognitive engagement not only fosters discussions concerning individual differences, but also offers an important paradigm to understand executive functioning as a continuum process rather than a categorical and multicomponent structure.

  17. Strand Tension Control in Anchor Span for Suspension Bridge Using Dynamic Balance Theory

    Directory of Open Access Journals (Sweden)

    Da Wang

    Full Text Available Abstract Strand tension control is essential in suspension bridge safety. However, few quantitative studies have examined the bending rigidity and boundary condition behavior of strands in the anchor span of suspension bridges because of their special structure and complex configuration. In this paper, a new calculation method for strand tension is explored by using dynamic balance theory to determine the effect of bending rigidity and boundary conditions. The accuracy and effectiveness of the proposed method are tested and confirmed with verification examples and application on Nanxi Yangtze Suspension Bridge in China. The results indicated that only low-order frequency calculation could be used to calculate the strand tension without considering the effect of bending rigidity to ensure control accuracy. The influence of bending rigidity on the control precision is related to the tension and the length of the strands, which is significantly determined by the specific value between the stress rigidity and the bending rigidity. The uncertain boundary conditions of the anchor span cable, which are fixed between consolidated and hinged, also have a major effect on the control accuracy. To improve the accuracy of strand tension control, the least squares method is proposed during the tension construction control of the anchor span. This approach can significantly improve the accuracy of the tension control of the main cable strand. Some recommendations for future bridge analysis are provided based on the results of this study.

  18. Generalized dynamics of moving dislocations in quasicrystals

    International Nuclear Information System (INIS)

    Agiasofitou, Eleni; Lazar, Markus; Kirchner, Helmut

    2010-01-01

    A theoretical framework for dislocation dynamics in quasicrystals is provided according to the continuum theory of dislocations. Firstly, we present the fundamental theory for moving dislocations in quasicrystals giving the dislocation density tensors and introducing the dislocation current tensors for the phonon and phason fields, including the Bianchi identities. Next, we give the equations of motion for the incompatible elastodynamics as well as for the incompatible elasto-hydrodynamics of quasicrystals. We continue with the derivation of the balance law of pseudomomentum thereby obtaining the generalized forms of the Eshelby stress tensor, the pseudomomentum vector, the dynamical Peach-Koehler force density and the Cherepanov force density for quasicrystals. The form of the dynamical Peach-Koehler force for a straight dislocation is obtained as well. Moreover, we deduce the balance law of energy that gives rise to the generalized forms of the field intensity vector and the elastic power density of quasicrystals. The above balance laws are produced for both models. The differences between the two models and their consequences are revealed. The influences of the phason fields as well as of the dynamical terms are also discussed.

  19. Effect of a new physical therapy concept on dynamic balance in ...

    African Journals Online (AJOL)

    Hatem Abdel Mohsen Abdel Hamid Emara

    2014-09-30

    Sep 30, 2014 ... Aim of the study: This study aims to evaluate the effect of gait training using AGT on standing balance of the spastic diplegic cerebral palsy (SDCP) children. Subjects and ... of cerebral palsy has significantly risen to 2.0 per 1000 life. * Address: ..... based on our pilot work and the work of others and the fact.

  20. Interchangeability of the Wii Balance Board for Bipedal Balance Assessment.

    Science.gov (United States)

    Bonnechère, Bruno; Jansen, Bart; Omelina, Lubos; Rooze, Marcel; Van Sint Jan, Serge

    2015-08-27

    Since 2010, an increasing interest in more portable and flexible hardware for balance and posture assessment led to previously published studies determining whether or not the Wii Balance Board could be used to assess balance and posture, both scientifically and clinically. However, no previous studies aimed at comparing results from different Wii Balance Boards for clinical balance evaluation exist. The objective of this crossover study is to assess the interchangeability of the Wii Balance Board. A total of 6 subjects participated in the study and their balance was assessed using 4 different Wii Balance Boards. Trials were recorded simultaneously with Wii Balance Boards and with a laboratory force plate. Nine relevant clinical parameters were derived from center of pressure displacement data obtained from Wii Balance Board and force plate systems. Intraclass correlation coefficients (ICC), F tests, and Friedman tests were computed to assess the agreement between trials and to compare the Wii Balance Board and force plate results. Excellent correlations were found between the Wii Balance Board and force plate (mean ρ =.83). With the exception of 2 parameters, strong to excellent agreements were found for the 7 remaining parameters (ICC=.96). No significant differences were found between trials recorded with different Wii Balance Boards. Our results indicate that for most of the parameters analyzed, balance and posture assessed with one Wii Balance Board were statistically similar to results obtained from another. Furthermore, the good correlation between the Wii Balance Board and force plate results shows that Wii Balance Boards can be reliably used for scientific assessment using most of the parameters analyzed in this study. These results also suggest that the Wii Balance Board could be used in multicenter studies and therefore, would allow for the creation of larger populations for clinical studies. Ethical Committee of the Erasme Hospital (CCB B406201215142

  1. Chance for balance: Chance for balance

    OpenAIRE

    Sævild, Katariina; Skov Sørensen, Katrine; Kildahl Lauritsen, Louise; Fuglsang, Sofie Olivia; Arnbjerg, Stine Høegh

    2015-01-01

    This project investigates how (im) balance between family and career influences Danish women's desire to have children. In order to answer this question, we have chosen to use qualitative method and our analysis is based on two semi-structured research interviews with two chosen women. Thus these women’s definition of balance and their view on children define the project. We have chosen to use of work-life balance theories, Thomas Hoejrup’s lifeform-analysis and Anthony Giddens’ theories of s...

  2. A balanced water layer concept for subglacial hydrology in large-scale ice sheet models

    Directory of Open Access Journals (Sweden)

    S. Goeller

    2013-07-01

    Full Text Available There is currently no doubt about the existence of a widespread hydrological network under the Antarctic Ice Sheet, which lubricates the ice base and thus leads to increased ice velocities. Consequently, ice models should incorporate basal hydrology to obtain meaningful results for future ice dynamics and their contribution to global sea level rise. Here, we introduce the balanced water layer concept, covering two prominent subglacial hydrological features for ice sheet modeling on a continental scale: the evolution of subglacial lakes and balance water fluxes. We couple it to the thermomechanical ice-flow model RIMBAY and apply it to a synthetic model domain. In our experiments we demonstrate the dynamic generation of subglacial lakes and their impact on the velocity field of the overlaying ice sheet, resulting in a negative ice mass balance. Furthermore, we introduce an elementary parametrization of the water flux–basal sliding coupling and reveal the predominance of the ice loss through the resulting ice streams against the stabilizing influence of less hydrologically active areas. We point out that established balance flux schemes quantify these effects only partially as their ability to store subglacial water is lacking.

  3. A balanced water layer concept for subglacial hydrology in large scale ice sheet models

    Science.gov (United States)

    Goeller, S.; Thoma, M.; Grosfeld, K.; Miller, H.

    2012-12-01

    There is currently no doubt about the existence of a wide-spread hydrological network under the Antarctic ice sheet, which lubricates the ice base and thus leads to increased ice velocities. Consequently, ice models should incorporate basal hydrology to obtain meaningful results for future ice dynamics and their contribution to global sea level rise. Here, we introduce the balanced water layer concept, covering two prominent subglacial hydrological features for ice sheet modeling on a continental scale: the evolution of subglacial lakes and balance water fluxes. We couple it to the thermomechanical ice-flow model RIMBAY and apply it to a synthetic model domain inspired by the Gamburtsev Mountains, Antarctica. In our experiments we demonstrate the dynamic generation of subglacial lakes and their impact on the velocity field of the overlaying ice sheet, resulting in a negative ice mass balance. Furthermore, we introduce an elementary parametrization of the water flux-basal sliding coupling and reveal the predominance of the ice loss through the resulting ice streams against the stabilizing influence of less hydrologically active areas. We point out, that established balance flux schemes quantify these effects only partially as their ability to store subglacial water is lacking.

  4. A new approach to estimate ice dynamic rates using satellite observations in East Antarctica

    Directory of Open Access Journals (Sweden)

    B. Kallenberg

    2017-05-01

    Full Text Available Mass balance changes of the Antarctic ice sheet are of significant interest due to its sensitivity to climatic changes and its contribution to changes in global sea level. While regional climate models successfully estimate mass input due to snowfall, it remains difficult to estimate the amount of mass loss due to ice dynamic processes. It has often been assumed that changes in ice dynamic rates only need to be considered when assessing long-term ice sheet mass balance; however, 2 decades of satellite altimetry observations reveal that the Antarctic ice sheet changes unexpectedly and much more dynamically than previously expected. Despite available estimates on ice dynamic rates obtained from radar altimetry, information about ice sheet changes due to changes in the ice dynamics are still limited, especially in East Antarctica. Without understanding ice dynamic rates, it is not possible to properly assess changes in ice sheet mass balance and surface elevation or to develop ice sheet models. In this study we investigate the possibility of estimating ice sheet changes due to ice dynamic rates by removing modelled rates of surface mass balance, firn compaction, and bedrock uplift from satellite altimetry and gravity observations. With similar rates of ice discharge acquired from two different satellite missions we show that it is possible to obtain an approximation of the rate of change due to ice dynamics by combining altimetry and gravity observations. Thus, surface elevation changes due to surface mass balance, firn compaction, and ice dynamic rates can be modelled and correlated with observed elevation changes from satellite altimetry.

  5. [Effects of training on static and dynamic balance in elderly subjects who have had a fall or not].

    Science.gov (United States)

    Toulotte, C; Thévenon, A; Fabre, C

    2004-11-01

    To evaluate the effects of a physical training program on static and dynamic balance during single and dual task conditions in elderly subjects who have had a fall or not. Two groups, comprising a total of 33 elderly subjects, were trained: 16 who had a fall were 69.2 +/- 5.0 years old and 17 who had not had a fall were 67.3 +/- 3.8 years. All subjects underwent an unipedal test with eyes open and eyes closed, followed by gait assessment during single and dual motor task conditions, before and after a physical training program. All subjects showed a significant decrease, by six times for subjects who had fallen and four times by those who had not, in the number of touch-downs in the unipedal test with eyes open (P < 0.05), and by 2.5 and 2 times, respectively, with eyes closed (P < 0.05) after the training program. All subjects showed a significant increase in speed (P < 0.05), cadence (P < 0.05) and stride length (P < 0.05) and a significant decrease in the single support time (P < 0.05) and stride time (P < 0.05) in gait assessment during single and dual task conditions after the training program. During the training program, no subjects fell. The physical training program improved static balance and quality of gait in elderly subjects who had had a fall and those who had not, which could contribute to minimizing and/or retarding the effects of aging and maintaining physical independence.

  6. Development of a new index of balance in adults with intellectual and developmental disabilities.

    Directory of Open Access Journals (Sweden)

    Antonio Cuesta-Vargas

    Full Text Available PURPOSES: The first objective was to propose a new model representing the balance level of adults with intellectual and developmental disabilities (IDD using Principal Components Analysis (PCA; and the second objective was to use the results from the PCA recorded by regression method to construct and validate summative scales of the standardized values of the index, which may be useful to facilitate a balance assessment in adults with IDD. METHODS: A total of 801 individuals with IDD (509 males mean 33.1 ± 8.5 years old, were recruited from Special Olympic Games in Spain 2009 to 2012. The participants performed the following tests: the timed-stand test, the single leg stance test with open and closed eyes, the Functional Reach Test, the Expanded Timed-Get-up-and-Go Test. Data was analyzed using principal components analysis (PCA with Oblimin rotation and Kaiser normalization. We examined the construct validity of our proposed two-factor model underlying balance for adults with IDD. The scores from PCA were recorded by regression method and were standardized. RESULTS: The Component Plot and Rotated Space indicated that a two-factor solution (Dynamic and Static Balance components was optimal. The PCA with direct Oblimin rotation revealed a satisfactory percentage of total variance explained by the two factors: 51.6 and 21.4%, respectively. The median score standardized for component dynamic and static of the balance index for adults with IDD is shown how references values. CONCLUSIONS: Our study may lead to improvements in the understanding and assessment of balance in adults with IDD. First, it confirms that a two-factor model may underlie the balance construct, and second, it provides an index that may be useful for identifying the balance level for adults with IDD.

  7. Adaptive Spindle Balancing Using Magnetically Levitated Bearings

    International Nuclear Information System (INIS)

    BARNEY, PATRICK S.; LAUFFER, JAMES P.; PETTEYS, REBECCA; REDMOND, JAMES M.; SULLIVAN, WILLIAM N.

    1999-01-01

    A technological break through for supporting rotating shafts is the active magnetic bearing (AMB). Active magnetic bearings offer some important advantages over conventional ball, roller or journal bearings such as reduced frictional drag, no physical contact in the bearing, no need for lubricants, compatibility with high vacuum and ultra-clean environments, and ability to control shaft position within the bearing. The disadvantages of the AMB system are the increased cost and complexity, reduced bearing stiffness and the need for a controller. Still, there are certain applications, such as high speed machining, biomedical devices, and gyroscopes, where the additional cost of an AMB system can be justified. The inherent actuator capabilities of the AMB offer the potential for active balancing of spindles and micro-shaping capabilities for machine tools, The work presented in this paper concentrates on an AMB test program that utilizes the actuator capability to dynamically balance a spindle. In this study, an unbalanced AMB spindle system was enhanced with an LMS (Least Mean Squares) algorithm combined with an existing PID (proportional, integral, differential) control. This enhanced controller significantly improved the concentricity of an intentionally unbalanced shaft. The study included dynamic system analysis, test validation, control design and simulation, as well as experimental implementation using a digital LMS controller

  8. REPRODUCIBILITY OF THE MODIFIED STAR EXCURSION BALANCE TEST COMPOSITE AND SPECIFIC REACH DIRECTION SCORES.

    Science.gov (United States)

    van Lieshout, Remko; Reijneveld, Elja A E; van den Berg, Sandra M; Haerkens, Gijs M; Koenders, Niek H; de Leeuw, Arina J; van Oorsouw, Roel G; Paap, Davy; Scheffer, Else; Weterings, Stijn; Stukstette, Mirelle J

    2016-06-01

    The mSEBT is a screening tool used to evaluate dynamic balance. Most research investigating measurement properties focused on intrarater reliability and was done in small samples. To know whether the mSEBT is useful to discriminate dynamic balance between persons and to evaluate changes in dynamic balance, more research into intra- and interrater reliability and smallest detectable change (synonymous with minimal detectable change) is needed. To estimate intra- and interrater reliability and smallest detectable change of the mSEBT in adults at risk for ankle sprain. Cross-sectional, test-retest design. Fifty-five healthy young adults participating in sports at risk for ankle sprain participated (mean ± SD age, 24.0 ± 2.9 years). Each participant performed three test sessions within one hour and was rated by two physical therapists (session 1, rater 1; session 2, rater 2; session 3, rater 1). Participants and raters were blinded for previous measurements. Normalized composite and reach direction scores for the right and left leg were collected. Analysis of variance was used to calculate intraclass correlation coefficient values for intra- and interrater reliability. Smallest detectable change values were calculated based on the standard error of measurement. Intra- and interrater reliability for both legs was good to excellent (intraclass correlation coefficient ranging from 0.87 to 0.94). The intrarater smallest detectable change for the composite score of the right leg was 7.2% and for the left 6.2%. The interrater smallest detectable change for the composite score of the right leg was 6.9% and for the left 5.0%. The mSEBT is a reliable measurement instrument to discriminate dynamic balance between persons. Most smallest detectable change values of the mSEBT appear to be large. More research is needed to investigate if the mSEBT is usable for evaluative purposes. Level 2.

  9. Effects of functional training on pain, leg strength, and balance in women with fibromyalgia.

    Science.gov (United States)

    Latorre Román, Pedro Ángel; Santos E Campos, María Aparecida; García-Pinillos, Felipe

    2015-01-01

    The aim of this study was to analyze the effect of 18-week functional training (FT) program consisting in two sessions a week of in-water exercise and one of on-land exercise on pain, strength, and balance in women with fibromyalgia. A sample consisting of 36 fibromyalgia patients was included in the study. The patients were allocated randomly into the experimental group (EG, n = 20), and control group (CG, n = 16). Standardized field-based fitness tests were used to assess muscle strength (30-s chair stand and handgrip strength) and agility/dynamic balance and static balance. Fibromyalgia impact and pain were analyzed by Fibromyalgia Impact Questionnaire (FIQ), tender points (TPs), visual analog scale (VAS). We observed a significant reduction in the FIQ (p = 0.042), the algometer scale of TP (p = 0.008), TP (p < 0.001), and VAS (p < 0.001) in the EG. The EG shows better results in leg strength (p < 0.001), handgrip strength (p = 0.025), agility/dynamic balance (p = 0.032) and balance (p = 0.006). An 18-week intervention consisting in two sessions of in-water exercise and one session of on-land exercise of FT reduces pain and improves functional capacity in FM patients. These results suggested that FT could play an important role in maintaining an independent lifestyle in patients with FM.

  10. Relevance assumed: a case study of balanced scorecard development using system dynamics

    NARCIS (Netherlands)

    Akkermans, H.A.; Oorschot, van K.E.

    2005-01-01

    The balanced scorecard (BSC) has become a popular concept for performance measurement. It focuses attention of management on only a few performance measures and bridges different functional areas as it includes both financial and non-financial measures. However, doubts frequently arise regarding the

  11. BALANCE ABILITIES OF WORKERS IN PHYSICALLY DEMANDING JOBS: WITH SPECIAL REFERENCE TO FIREFIGHTERS OF DIFFERENT AGES

    Directory of Open Access Journals (Sweden)

    Anne Punakallio

    2005-05-01

    Full Text Available The objectives of the present study were to investigate the associations between balance abilities and age, occupation and the use of fire-protective equipment (FPE in different visual conditions, and the associations of slip and fall risk with balance abilities among workers in physically demanding jobs, especially among workers in fire and rescue work. The reliability and predictive values of balance tests in respect to perceived work ability were also studied. The professional firefighters aged 30 to 56-years (n = 29-135, construction workers (n = 52, home care workers (n = 66 and nursing workers (n = 51 aged 23 to 61 years participated in this study. The data were obtained with balance tests with the use of a force platform, functional balance tests, slipping tests and questionnaires. In one study the balance tests were carried out with and without FPE. The slipping tests with FPE were carried out on a straight 8-m long path that had one area covered by water and detergent or glycerol. Perceived work ability at baseline and after a 3-year follow-up was determined with the use of the work ability index (WAI. In the reliability study, the dynamic balance tests were repeated six times in two testing periods at an interval of 2 months. The results indicated that the balance abilities of firefighters over 49 years of age were significantly poorer than those of firefighters in the age groups of <40 and 40-49 years. The decline of balance abilities among construction, home care and nursing workers was not as consistent. Postural balance was also more harmfully affected among the older firefighters (43-56 years than among the younger ones (33-38 years by the use of FPE without visual input. Self-contained breathing apparatus was the most significant single piece of FPE to impair balance in both groups. Furthermore, fast and controlled performance in the dynamic stability test based on visual feedback was related to smaller slip and fall risk with

  12. Leg strength or velocity of movement: which is more influential on the balance of mobility limited elders?

    Science.gov (United States)

    Mayson, Douglas J; Kiely, Dan K; LaRose, Sharon I; Bean, Jonathan F

    2008-12-01

    To determine which component of leg power (maximal limb strength or limb velocity) is more influential on balance performance in mobility limited elders. In this cross-sectional analysis we evaluated 138 community-dwelling older adults with mobility limitation. Balance was measured using the Unipedal Stance Test, the Berg Balance Test (BERG), the Dynamic Gait Index, and the performance-oriented mobility assessment. We measured one repetition maximum strength and power at 40% one repetition maximum strength, from which velocity was calculated. The associations between maximal estimated leg strength and velocity with balance performance were examined using separate multivariate logistic regression models. Strength was found to be associated [odds ratio of 1.06 (95% confidence interval, 1.01-1.11)] with performance on the Unipedal Stance Test, whereas velocity showed no statistically significant association. In contrast, velocity was consistently associated with performance on all composite measures of balance (BERG 14.23 [1.84-109.72], performance-oriented mobility assessment 33.92 [3.69-312.03], and Dynamic Gait Index 35.80 [4.77-268.71]). Strength was only associated with the BERG 1.08 (1.01-1.14). Higher leg press velocity is associated with better performance on the BERG, performance-oriented mobility assessment, and Dynamic Gait Index, whereas greater leg strength is associated with better performance on the Unipedal Stance Test and the BERG. These findings are likely related to the intrinsic qualities of each test and emphasize the relevance of limb velocity.

  13. Balance control during gait initiation: State-of-the-art and research perspectives.

    Science.gov (United States)

    Yiou, Eric; Caderby, Teddy; Delafontaine, Arnaud; Fourcade, Paul; Honeine, Jean-Louis

    2017-11-18

    It is well known that balance control is affected by aging, neurological and orthopedic conditions. Poor balance control during gait and postural maintenance are associated with disability, falls and increased mortality. Gait initiation - the transient period between the quiet standing posture and steady state walking - is a functional task that is classically used in the literature to investigate how the central nervous system (CNS) controls balance during a whole-body movement involving change in the base of support dimensions and center of mass progression. Understanding how the CNS in able-bodied subjects exerts this control during such a challenging task is a pre-requisite to identifying motor disorders in populations with specific impairments of the postural system. It may also provide clinicians with objective measures to assess the efficiency of rehabilitation programs and better target interventions according to individual impairments. The present review thus proposes a state-of-the-art analysis on: (1) the balance control mechanisms in play during gait initiation in able bodied subjects and in the case of some frail populations; and (2) the biomechanical parameters used in the literature to quantify dynamic stability during gait initiation. Balance control mechanisms reviewed in this article included anticipatory postural adjustments, stance leg stiffness, foot placement, lateral ankle strategy, swing foot strike pattern and vertical center of mass braking. Based on this review, the following viewpoints were put forward: (1) dynamic stability during gait initiation may share a principle of homeostatic regulation similar to most physiological variables, where separate mechanisms need to be coordinated to ensure stabilization of vital variables, and consequently; and (2) rehabilitation interventions which focus on separate or isolated components of posture, balance, or gait may limit the effectiveness of current clinical practices.

  14. A Systematic Review of Aquatic Exercise Programs on Balance Measures in Older Adults

    OpenAIRE

    Foster, Shayla Diane

    2015-01-01

    There are a variety of studies performed using aquatic exercise programs to evaluate balance measures using a case-control or pretest-posttest method on healthy young populations (Geytenbeek, 2002). Balance can be defined as either static; maintenance of an upright posture and stance or dynamic; posture adaption and maintenance control of movements and stability (Rose & Clark, 2000). An aquatic exercise program will henceforth be defined as any acute or chronic exercises performed in water wi...

  15. A network dynamics approach to chemical reaction networks

    NARCIS (Netherlands)

    van der Schaft, Abraham; Rao, S.; Jayawardhana, B.

    2016-01-01

    A treatment of chemical reaction network theory is given from the perspective of nonlinear network dynamics, in particular of consensus dynamics. By starting from the complex-balanced assumption the reaction dynamics governed by mass action kinetics can be rewritten into a form which allows for a

  16. The relevance of clinical balance assessment tools to differentiate balance deficits

    OpenAIRE

    Mancini, Martina; Horak, Fay B

    2010-01-01

    Control of balance is complex and involves maintaining postures, facilitating movement, and recovering equilibrium. Balance control consists of controlling the body center of mass over its limits of stability. Clinical balance assessment can help assess fall risk and/or determine the underlying reasons for balance disorders. Most functional balance assessment scales assess fall risk and the need for balance rehabilitation but do not differentiate types of balance deficits. A system approach t...

  17. Uncertainty evaluation for ordinary least-square fitting with arbitrary order polynomial in joule balance method

    International Nuclear Information System (INIS)

    You, Qiang; Xu, JinXin; Wang, Gang; Zhang, Zhonghua

    2016-01-01

    The ordinary least-square fitting with polynomial is used in both the dynamic phase of the watt balance method and the weighting phase of joule balance method but few researches have been conducted to evaluate the uncertainty of the fitting data in the electrical balance methods. In this paper, a matrix-calculation method for evaluating the uncertainty of the polynomial fitting data is derived and the properties of this method are studied by simulation. Based on this, another two derived methods are proposed. One is used to find the optimal fitting order for the watt or joule balance methods. Accuracy and effective factors of this method are experimented with simulations. The other is used to evaluate the uncertainty of the integral of the fitting data for joule balance, which is demonstrated with an experiment from the NIM-1 joule balance. (paper)

  18. Dynamic optimization and adaptive controller design

    Science.gov (United States)

    Inamdar, S. R.

    2010-10-01

    In this work I present a new type of controller which is an adaptive tracking controller which employs dynamic optimization for optimizing current value of controller action for the temperature control of nonisothermal continuously stirred tank reactor (CSTR). We begin with a two-state model of nonisothermal CSTR which are mass and heat balance equations and then add cooling system dynamics to eliminate input multiplicity. The initial design value is obtained using local stability of steady states where approach temperature for cooling action is specified as a steady state and a design specification. Later we make a correction in the dynamics where material balance is manipulated to use feed concentration as a system parameter as an adaptive control measure in order to avoid actuator saturation for the main control loop. The analysis leading to design of dynamic optimization based parameter adaptive controller is presented. The important component of this mathematical framework is reference trajectory generation to form an adaptive control measure.

  19. Balance in children born prematurely currently aged 6–7

    Directory of Open Access Journals (Sweden)

    Dziuba Ewa

    2017-12-01

    Full Text Available Study aim: Premature birth is one of the major problems of obstetrics, leading to numerous complications that are associated with prematurity, for instance balance disorders. The aim of the study was to assess the impact of premature birth on the ability to maintain balance in children commencing their school education. Material and methods: The study included children aged 6-7 years. The study group consisted of 59 children (31 girls and 28 boys, mean age 6.38 ± SD 0.73 born prematurely between 24 and 35 weeks of gestation. The control group consisted of 61 children (28 girls and 33 boys, mean age 6.42 ± 0.58 born at term. The research utilized standardized test tools - one-leg open-eyed and closed-eyed standing test, one-leg jumping test - and an original questionnaire survey. Results: The children born at term achieved better results in the majority of tests. The comparison of girls and boys born pre­maturely and at term showed no statistically significant difference between them in terms of dynamic balance, static balance or total balance control. The comparison of the tests performed on the right and left lower limb in prematurely born children showed no statistically significant differences. Conclusion: Premature birth affects the ability to maintain body balance. The results of the study indicate the need to develop coordination skills that shape body balance in prematurely born children.

  20. The effects of pilates on balance, mobility and strength in patients with multiple sclerosis.

    Science.gov (United States)

    Guclu-Gunduz, Arzu; Citaker, Seyit; Irkec, Ceyla; Nazliel, Bijen; Batur-Caglayan, Hale Zeynep

    2014-01-01

    Although there are evidences as to Pilates developing dynamic balance, muscle strength and flexibility in healthy people, evidences related to its effects on Multiple Sclerosis patients are insufficient. The aims of this study were to investigate the effects of Pilates on balance, mobility, and strength in ambulatory patients with Multiple Sclerosis. Twenty six patients were divided into two groups as experimental (n = 18) and control (n = 8) groups for an 8-week treatment program. The experimental group underwent Pilates and the control group did abdominal breathing and active extremity exercises at home. Balance and mobility were measured with Berg Balance Scale and Timed up and go test, upper and lower muscle strength with hand-held dynamometer. Confidence in balance skills while performing daily activities was evaluated with Activities Specific Balance Confidence Scale. Improvements were observed in balance, mobility, and upper and lower extremity muscle strength in the Pilates group (p 0.05). Due to its structure which is made up of balance and strengthening exercises, Pilates training may develop balance, mobility and muscle strength of MS patients. For this reason, we think that, Pilates exercises which are appropriate for the disability level of the patient may be suggested.

  1. Balance Problems

    Science.gov (United States)

    ... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may ... related injuries, such as a hip fracture. Some balance problems are due to problems in the inner ...

  2. Dynamic Response of Inextensible Beams by Improved Energy Balance Method

    DEFF Research Database (Denmark)

    Sfahani, M. G.; Barari, Amin; Omidvar, M.

    2011-01-01

    An improved He's energy balance method (EBM) for solving non-linear oscillatory differential equation using a new trial function is presented. The problem considered represents the governing equations of the non-linear, large-amplitude free vibrations of a slender cantilever beam...... with a rotationally flexible root and carrying a lumped mass at an intermediate position along its span. Based on the simple EBM, the variational integral of the non-linear conservative system is established, and the Fourier series expansion is employed to address the governing algebraic equations. An alternate...

  3. Population balance models: a useful complementary modelling framework for future WWTP modelling

    DEFF Research Database (Denmark)

    Nopens, Ingmar; Torfs, Elena; Ducoste, Joel

    2015-01-01

    Population balance models (PBMs) represent a powerful modelling framework for the description of the dynamics of properties that are characterised by distributions. This distribution of properties under transient conditions has been demonstrated in many chemical engineering applications. Modelling...

  4. Impulse Force Balance for Ultrashort Duration Hypersonic Test Facilities

    Directory of Open Access Journals (Sweden)

    P. Singh

    2015-01-01

    Full Text Available This paper presents the measurement of side force, pitching, and yawing moments on a model, using an accelerometer force balance, in a short duration hypersonic shock tunnel. The test model is a blunt-nosed, flapped delta wing, mounted on a support sting through a force balance. The flexible rubber bushes constituting the balance allow the model to float freely on the sting during the test. The accelerometers were located in the model to record accelerations in the directions of interest. The model was tested in shock tunnel at Mach 8 at different angles of incidence with the freestream. Dynamic calibration of the test assembly was carried out for the acquisition of impulse response functions for the above components of force and moments, using an impulse hammer. The convolution technique was applied to derive the impulse response functions. The accelerometer outputs from the model in the hypersonic freestream were processed using the respective impulse response functions to derive the unknown aerodynamic force and moments. The newly adopted convolution technique has been found very effective for data reduction from accelerometer force balances developed for shock tunnel applications.

  5. Static and dynamic postural control in low-vision and normal-vision adults.

    Science.gov (United States)

    Tomomitsu, Mônica S V; Alonso, Angelica Castilho; Morimoto, Eurica; Bobbio, Tatiana G; Greve, Julia M D

    2013-04-01

    This study aimed to evaluate the influence of reduced visual information on postural control by comparing low-vision and normal-vision adults in static and dynamic conditions. Twenty-five low-vision subjects and twenty-five normal sighted adults were evaluated for static and dynamic balance using four protocols: 1) the Modified Clinical Test of Sensory Interaction on Balance on firm and foam surfaces with eyes opened and closed; 2) Unilateral Stance with eyes opened and closed; 3) Tandem Walk; and 4) Step Up/Over. The results showed that the low-vision group presented greater body sway compared with the normal vision during balance on a foam surface (p≤0.001), the Unilateral Stance test for both limbs (p≤0.001), and the Tandem Walk test. The low-vision group showed greater step width (p≤0.001) and slower gait speed (p≤0.004). In the Step Up/Over task, low-vision participants were more cautious in stepping up (right p≤0.005 and left p≤0.009) and in executing the movement (p≤0.001). These findings suggest that visual feedback is crucial for determining balance, especially for dynamic tasks and on foam surfaces. Low-vision individuals had worse postural stability than normal-vision adults in terms of dynamic tests and balance on foam surfaces.

  6. Energy Efficient Cooperative Spectrum Sensing in Cognitive Radio Networks Using Distributed Dynamic Load Balanced Clustering Scheme

    Directory of Open Access Journals (Sweden)

    Muthukkumar R.

    2017-04-01

    Full Text Available Cognitive Radio (CR is a promising and potential technique to enable secondary users (SUs or unlicenced users to exploit the unused spectrum resources effectively possessed by primary users (PUs or licenced users. The proven clustering approach is used to organize nodes in the network into the logical groups to attain energy efficiency, network scalability, and stability for improving the sensing accuracy in CR through cooperative spectrum sensing (CSS. In this paper, a distributed dynamic load balanced clustering (DDLBC algorithm is proposed. In this algorithm, each member in the cluster is to calculate the cooperative gain, residual energy, distance, and sensing cost from the neighboring clusters to perform the optimal decision. Each member in a cluster participates in selecting a cluster head (CH through cooperative gain, and residual energy that minimises network energy consumption and enhances the channel sensing. First, we form the number of clusters using the Markov decision process (MDP model to reduce the energy consumption in a network. In this algorithm, CR users effectively utilize the PUs reporting time slots of unavailability. The simulation results reveal that the clusters convergence, energy efficiency, and accuracy of channel sensing increased considerably by using the proposed algorithm.

  7. Energy Efficient Cooperative Spectrum Sensing in Cognitive Radio Networks Using Distributed Dynamic Load Balanced Clustering Scheme

    Directory of Open Access Journals (Sweden)

    Muthukkumar R.

    2016-07-01

    Full Text Available Cognitive Radio (CR is a promising and potential technique to enable secondary users (SUs or unlicenced users to exploit the unused spectrum resources effectively possessed by primary users (PUs or licenced users. The proven clustering approach is used to organize nodes in the network into the logical groups to attain energy efficiency, network scalability, and stability for improving the sensing accuracy in CR through cooperative spectrum sensing (CSS. In this paper, a distributed dynamic load balanced clustering (DDLBC algorithm is proposed. In this algorithm, each member in the cluster is to calculate the cooperative gain, residual energy, distance, and sensing cost from the neighboring clusters to perform the optimal decision. Each member in a cluster participates in selecting a cluster head (CH through cooperative gain, and residual energy that minimises network energy consumption and enhances the channel sensing. First, we form the number of clusters using the Markov decision process (MDP model to reduce the energy consumption in a network. In this algorithm, CR users effectively utilize the PUs reporting time slots of unavailability. The simulation results reveal that the clusters convergence, energy efficiency, and accuracy of channel sensing increased considerably by using the proposed algorithm.

  8. Balance and postural skills in normal-weight and overweight prepubertal boys.

    Science.gov (United States)

    Deforche, Benedicte I; Hills, Andrew P; Worringham, Charles J; Davies, Peter S W; Murphy, Alexia J; Bouckaert, Jacques J; De Bourdeaudhuij, Ilse M

    2009-01-01

    This study investigated differences in balance and postural skills in normal-weight versus overweight prepubertal boys. Fifty-seven 8-10-year-old boys were categorized overweight (N = 25) or normal-weight (N = 32) according to the International Obesity Task Force cut-off points for overweight in children. The Balance Master, a computerized pressure plate system, was used to objectively measure six balance skills: sit-to-stand, walk, step up/over, tandem walk (walking on a line), unilateral stance and limits of stability. In addition, three standardized field tests were employed: standing on one leg on a balance beam, walking heel-to-toe along the beam and the multiple sit-to-stand test. Overweight boys showed poorer performances on several items assessed on the Balance Master. Overweight boys had slower weight transfer (p test, greater step width while walking (p walking on a line (p test, the unilateral stance and the limits of stability were comparable between both groups. On the balance beam, overweight boys could not hold their balance on one leg as long (p test (p < 0.001) than normal-weight boys. Finally, overweight boys were slower in standing up and sitting down five times in the multiple sit-to-stand task (p < 0.01). This study demonstrates that when categorised by body mass index (BMI) level, overweight prepubertal boys displayed lower capacity on several static and dynamic balance and postural skills.

  9. A Fault Detection Filtering for Networked Control Systems Based on Balanced Reduced-Order

    Directory of Open Access Journals (Sweden)

    Da-Meng Dai

    2015-01-01

    Full Text Available Due to the probability of the packet dropout in the networked control systems, a balanced reduced-order fault detection filter is proposed. In this paper, we first analyze the packet dropout effects in the networked control systems. Then, in order to obtain a robust fault detector for the packet dropout, we use the balanced structure to construct a reduced-order model for residual dynamics. Simulation results are provided to testify the proposed method.

  10. Interchangeability of the Wii Balance Board for Bipedal Balance Assessment

    OpenAIRE

    Bonnech?re, Bruno; Jansen, Bart; Omelina, Lubos; Rooze, Marcel; Van Sint Jan, Serge

    2015-01-01

    Background Since 2010, an increasing interest in more portable and flexible hardware for balance and posture assessment led to previously published studies determining whether or not the Wii Balance Board could be used to assess balance and posture, both scientifically and clinically. However, no previous studies aimed at comparing results from different Wii Balance Boards for clinical balance evaluation exist. Objective The objective of this crossover study is to assess the interchangeabilit...

  11. Genome-scale consequences of cofactor balancing in engineered pentose utilization pathways in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Amit Ghosh

    Full Text Available Biofuels derived from lignocellulosic biomass offer promising alternative renewable energy sources for transportation fuels. Significant effort has been made to engineer Saccharomyces cerevisiae to efficiently ferment pentose sugars such as D-xylose and L-arabinose into biofuels such as ethanol through heterologous expression of the fungal D-xylose and L-arabinose pathways. However, one of the major bottlenecks in these fungal pathways is that the cofactors are not balanced, which contributes to inefficient utilization of pentose sugars. We utilized a genome-scale model of S. cerevisiae to predict the maximal achievable growth rate for cofactor balanced and imbalanced D-xylose and L-arabinose utilization pathways. Dynamic flux balance analysis (DFBA was used to simulate batch fermentation of glucose, D-xylose, and L-arabinose. The dynamic models and experimental results are in good agreement for the wild type and for the engineered D-xylose utilization pathway. Cofactor balancing the engineered D-xylose and L-arabinose utilization pathways simulated an increase in ethanol batch production of 24.7% while simultaneously reducing the predicted substrate utilization time by 70%. Furthermore, the effects of cofactor balancing the engineered pentose utilization pathways were evaluated throughout the genome-scale metabolic network. This work not only provides new insights to the global network effects of cofactor balancing but also provides useful guidelines for engineering a recombinant yeast strain with cofactor balanced engineered pathways that efficiently co-utilizes pentose and hexose sugars for biofuels production. Experimental switching of cofactor usage in enzymes has been demonstrated, but is a time-consuming effort. Therefore, systems biology models that can predict the likely outcome of such strain engineering efforts are highly useful for motivating which efforts are likely to be worth the significant time investment.

  12. Recovery of standing balance in postacute stroke patients: a rehabilitation cohort study

    NARCIS (Netherlands)

    de Haart, Mirjam; Geurts, Alexander C.; Huidekoper, Steven C.; Fasotti, Luciano; van Limbeek, Jacques

    2004-01-01

    OBJECTIVE: To identify and interrelate static and dynamic characteristics of the restoration of quiet standing balance in a representative sample of stroke survivors in the Netherlands during their inpatient rehabilitation. DESIGN: Exploratory study using an inception cohort with findings related to

  13. Population Balance Models: A useful complementary modelling framework for future WWTP modelling

    DEFF Research Database (Denmark)

    Nopens, Ingmar; Torfs, Elena; Ducoste, Joel

    2014-01-01

    Population Balance Models (PBMs) represent a powerful modelling framework for the description of the dynamics of properties that are characterised by statistical distributions. This has been demonstrated in many chemical engineering applications. Modelling efforts of several current and future unit...

  14. Future climate warming increases Greenland ice sheet surface mass balance variability

    NARCIS (Netherlands)

    Fyke, J.G.; Vizcaino, M.; Lipscomb, W.; Price, S.

    2014-01-01

    The integrated surface mass balance (SMB) of the Greenland ice sheet (GrIS) has large interannual variability. Long-term future changes to this variability will affect GrIS dynamics, freshwater fluxes, regional oceanography, and detection of changes in ice volume trends. Here we analyze a simulated

  15. Management of the water balance and quality in mining areas

    Science.gov (United States)

    Pasanen, Antti; Krogerus, Kirsti; Mroueh, Ulla-Maija; Turunen, Kaisa; Backnäs, Soile; Vento, Tiia; Veijalainen, Noora; Hentinen, Kimmo; Korkealaakso, Juhani

    2015-04-01

    Although mining companies have long been conscious of water related risks they still face environmental management problems. These problems mainly emerge because mine sites' water balances have not been adequately assessed in the stage of the planning of mines. More consistent approach is required to help mining companies identify risks and opportunities related to the management of water resources in all stages of mining. This approach requires that the water cycle of a mine site is interconnected with the general hydrologic water cycle. In addition to knowledge on hydrological conditions, the control of the water balance in the mining processes require knowledge of mining processes, the ability to adjust process parameters to variable hydrological conditions, adaptation of suitable water management tools and systems, systematic monitoring of amounts and quality of water, adequate capacity in water management infrastructure to handle the variable water flows, best practices to assess the dispersion, mixing and dilution of mine water and pollutant loading to receiving water bodies, and dewatering and separation of water from tailing and precipitates. WaterSmart project aims to improve the awareness of actual quantities of water, and water balances in mine areas to improve the forecasting and the management of the water volumes. The study is executed through hydrogeological and hydrological surveys and online monitoring procedures. One of the aims is to exploit on-line water quantity and quality monitoring for the better management of the water balances. The target is to develop a practical and end-user-specific on-line input and output procedures. The second objective is to develop mathematical models to calculate combined water balances including the surface, ground and process waters. WSFS, the Hydrological Modeling and Forecasting System of SYKE is being modified for mining areas. New modelling tools are developed on spreadsheet and system dynamics platforms to

  16. Functional-Strengthening: A Pilot Study on Balance Control Improvement in Community-Dwelling Older Adults

    Directory of Open Access Journals (Sweden)

    Micah D. Josephson

    2017-09-01

    Full Text Available Adults over the age of 65 have a 1 in 3 chance of falling; in 2012, more than $30 billion was spent on medical costs due to these falls. The division of resistance training and neuromotor training balance improvement interventions has shown to yield low to moderate results. Athletes combine both resistance training and skill development (function training to improve skilled performance. Older adults may not be performing high-level sports activities, but still require strength, power, and functional fitness levels to perform relatively high-level skills. The purpose of this study was to determine the effects of combining resistance and functional training into functional-strength training on dynamic balance control in moderately active older adults. Eighteen healthy older adults were divided into three groups; functional resistance, standard resistance, and control. All groups met for their intervention twice a week for six weeks. Dynamic balance was assessed using the Fullerton Advanced Balance Scale (0-40. Results of individual paired T-tests showed a significant improvement in balance control in the functional resistance group (t(5 =-3.492, p=.017 and a very large effect size (d=1.33 whereas neither the standard resistance nor control group had a significant reduction in the risk of falls. Manipulating multidimensional, neuromotor function during resistance training exercises is an effective method of applying the overload principle in order to reduce falls risk in moderately active seniors.

  17. Foot Placement Indicator for Balance of Planar Bipeds with Point Feet

    Directory of Open Access Journals (Sweden)

    Pieter van Zutven

    2013-05-01

    Full Text Available Abstract If humanoid robots are to be used in society, they should be able to maintain their balance. Knowing where to step is crucially important. In this paper we contribute an algorithm that can compute the foot step location such that bipedal balance is maintained for planar bipeds with point feet and an arbitrary number of non-massless links on a horizontal and flat ground. The algorithm is called the foot placement indicator (FPI and it extends the foot placement estimator (FPE. The FPE uses an inverted pendulum model to capture the dynamics of a humanoid robot, whereas the FPI deals with multi-body models with distributed masses. This paper analyses equilibrium sets and the stability of planar bipeds with point feet. The algorithm uses conservation of energy throughout the step, taking into account the instantaneous impact dynamics at foot strike. A simulation case study on a five-link planar biped shows the effectiveness of the FPI.

  18. Leg Strength or Velocity of Movement Which Is More Influential on the Balance of Mobility Limited Elders?

    Science.gov (United States)

    Mayson, Douglas J.; Kiely, Dan K.; LaRose, Sharon I.; Bean, Jonathan F.

    2009-01-01

    Objective To determine which component of leg power (maximal limb strength or limb velocity) is more influential on balance performance in mobility limited elders. Design In this cross-sectional analysis we evaluated 138 community-dwelling older adults with mobility limitation. Balance was measured using the Unipedal Stance Test, the Berg Balance Test (BERG), the Dynamic Gait Index, and the performance-oriented mobility assessment. We measured one repetition maximum strength and power at 40% one repetition maximum strength, from which velocity was calculated. The associations between maximal estimated leg strength and velocity with balance performance were examined using separate multivariate logistic regression models. Results Strength was found to be associated [odds ratio of 1.06 (95% confidence interval, 1.01–1.11)] with performance on the Unipedal Stance Test, whereas velocity showed no statistically significant association. In contrast, velocity was consistently associated with performance on all composite measures of balance [BERG 14.23 (1.84–109.72), performance-oriented mobility assessment 33.92 (3.69–312.03), and Dynamic Gait Index 35.80 (4.77–268.71))]. Strength was only associated with the BERG 1.08 (1.01–1.14). Conclusions Higher leg press velocity is associated with better performance on the BERG, performance-oriented mobility assessment, and Dynamic Gait Index, whereas greater leg strength is associated with better performance on the Unipedal Stance Test and the BERG. These findings are likely related to the intrinsic qualities of each test and emphasize the relevance of limb velocity. PMID:19033758

  19. An ecologically-controlled exoskeleton can improve balance recovery after slippage

    Science.gov (United States)

    Monaco, V.; Tropea, P.; Aprigliano, F.; Martelli, D.; Parri, A.; Cortese, M.; Molino-Lova, R.; Vitiello, N.; Micera, S.

    2017-05-01

    The evolution to bipedalism forced humans to develop suitable strategies for dynamically controlling their balance, ensuring stability, and preventing falling. The natural aging process and traumatic events such as lower-limb loss can alter the human ability to control stability significantly increasing the risk of fall and reducing the overall autonomy. Accordingly, there is an urgent need, from both end-users and society, for novel solutions that can counteract the lack of balance, thus preventing falls among older and fragile citizens. In this study, we show a novel ecological approach relying on a wearable robotic device (the Active Pelvis Orthosis, APO) aimed at facilitating balance recovery after unexpected slippages. Specifically, if the APO detects signs of balance loss, then it supplies counteracting torques at the hips to assist balance recovery. Experimental tests conducted on eight elderly persons and two transfemoral amputees revealed that stability against falls improved due to the “assisting when needed” behavior of the APO. Interestingly, our approach required a very limited personalization for each subject, and this makes it promising for real-life applications. Our findings demonstrate the potential of closed-loop controlled wearable robots to assist elderly and disabled subjects and to improve their quality of life.

  20. Do budget balance rules anchor budget balance expectations? -- Some international evidence

    OpenAIRE

    Rülke, Jan-Christoph; Frenkel, Michael; Lis, Eliza

    2013-01-01

    This is the first study that analyzes whether budget balance expectations are anchored and whether budget balance rules effectively anchor expectations. To this end, we use a unique data set which covers budget balance expectations in 17 countries that implemented a budget balance rules. While our results are mixed concerning the general impact of budget balance rules on anchoring expectations, we do find that specific features of budget balance rules are important to successfully anchor budg...