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Sample records for neuromuscular control mechanisms

  1. Muscle mechanics and neuromuscular control

    NARCIS (Netherlands)

    Hof, AL

    2003-01-01

    The purpose of this paper is to demonstrate that the properties of the mechanical system, especially muscle elasticity and limb mass, to a large degree determine force output and movement. This makes the control demands of the central nervous system simpler and more robust. In human triceps surae, a

  2. Altered neuromuscular control mechanisms of the trapezius muscle in fibromyalgia

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    Karlsson Stefan J

    2010-03-01

    Full Text Available Abstract Background fibromyalgia is a relatively common condition with widespread pain and pressure allodynia, but unknown aetiology. For decades, the association between motor control strategies and chronic pain has been a topic for debate. One long held functional neuromuscular control mechanism is differential activation between regions within a single muscle. The aim of this study was to investigate differences in neuromuscular control, i.e. differential activation, between myalgic trapezius in fibromyalgia patients and healthy controls. Methods 27 fibromyalgia patients and 30 healthy controls performed 3 minutes bilateral shoulder elevations with different loads (0-4 Kg with a high-density surface electromyographical (EMG grid placed above the upper trapezius. Differential activation was quantified by the power spectral median frequency of the difference in EMG amplitude between the cranial and caudal parts of the upper trapezius. The average duration of the differential activation was described by the inverse of the median frequency of the differential activations. Results the median frequency of the differential activations was significantly lower, and the average duration of the differential activations significantly longer in fibromyalgia compared with controls at the two lowest load levels (0-1 Kg (p Conclusion these findings illustrate a different neuromuscular control between fibromyalgia patients and healthy controls during a low load functional task, either sustaining or resulting from the chronic painful condition. The findings may have clinical relevance for rehabilitation strategies for fibromyalgia.

  3. NEUROMUSCULAR CONTROL IN LUMBAR DISORDERS

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    Ville Leinonen

    2004-03-01

    Full Text Available Impaired motor and sensory functions have been associated with low back pain (LBP. This includes disturbances in a wide range of sensorimotor control e.g. sensory dysfunctions, impaired postural responses and psychomotor control. However, the physiological mechanisms, clinical relevance and characteristics of these findings in different spinal pathologies require further clarification. The purposes of this study were to investigate postural control, lumbar muscle function, movement perception and associations between these findings in healthy volunteers (n=35, patients with lumbar disc herniation (n=20 and lumbar spinal stenosis (LSS, n=26. Paraspinal muscle responses for sudden upper limb loading and muscle activation during flexion-extension movement and the lumbar endurance test were measured by surface electromyography (EMG. Postural stability was measured on a force platform during two- and one-footed standing. Lumbar movement perception was assessed in a motorised trunk rotation unit in the seated position. In addition, measurements of motor-(MEP and somatosensory evoked potentials (SEP and needle EMG examination of lumbar multifidus muscles were performed in the LSS patients. Clinical and questionnaire data were also recorded. A short latency paraspinal muscle response (~50 ms for sudden upper limb loading was observed. The latency of the response was shortened by expectation (p=0.017. The response latency for unexpected loading was similar in healthy persons and disc herniation patients but the latency was not shortened by expectation in the patients (p = 0.014. Also impaired postural control (p < 0.05 and lumbar movement perception (p = 0.012 were observed in disc herniation patients. The impaired lumbar movement perception (p=0.054 and anticipatory muscle activation (p = 0.043 tended to be restored after successful surgery but postural control had still not recovered after 3 months of follow-up. The majority of LSS patients were unable

  4. [Molecular mechanisms underlying the formation of neuromuscular junction].

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    Higuchi, Osamu; Yamanashi, Yuji

    2011-07-01

    The neuromuscular junction (NMJ) is a synapse between a motor neuron and skeletal muscle. The contraction of skeletal muscle is controlled by the neurotransmitter acetylcholine (ACh), which is released from the motor nerve terminal. To achieve efficient neuromuscular transmission, acetylcholine receptors (AChRs) must be densely clustered on the muscle membrane of the NMJ. Failure of AChR clustering is associated with disorders of neuromuscular transmission such as congenital myasthenic syndromes (CMS) and myasthenia gravis (MG). Motoneuronal agrin and muscle-specific receptor tyrosine kinase (MuSK) are known to play essential roles in the formation and maintenance of NMJs in the central region of each muscle. However, it had been unclear how agrin activates MuSK. Recent studies have elucidated the roles of several key molecules, including the cytoplasmic adaptor protein Dok-7 and LDL receptor-related protein 4 (Lrp4), in agrin-induced MuSK activation. Moreover, new evidence indicates that cyclin-dependent kinase 5 (Cdk5) regulates postsynaptic differentiation. In this review, we summarize the latest developments in molecular mechanisms underlying NMJ formation in vertebrates. PMID:21747134

  5. Invasive home mechanical ventilation, mainly focused on neuromuscular disorders

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    Börger, Sandra

    2010-01-01

    Full Text Available Introduction and background: Invasive home mechanical ventilation is used for patients with chronic respiratory insufficiency. This elaborate and technology-dependent ventilation is carried out via an artificial airway (tracheal cannula to the trachea. Exact numbers about the incidence of home mechanical ventilation are not available. Patients with neuromuscular diseases represent a large portion of it. Research questions: Specific research questions are formulated and answered concerning the dimensions of medicine/nursing, economics, social, ethical and legal aspects. Beyond the technical aspect of the invasive home, mechanical ventilation, medical questions also deal with the patient’s symptoms and clinical signs as well as the frequency of complications. Economic questions pertain to the composition of costs and the differences to other ways of homecare concerning costs and quality of care. Questions regarding social aspects consider the health-related quality of life of patients and caregivers. Additionally, the ethical aspects connected to the decision of home mechanical ventilation are viewed. Finally, legal aspects of financing invasive home mechanical ventilation are discussed. Methods: Based on a systematic literature search in 2008 in a total of 31 relevant databases current literature is viewed and selected by means of fixed criteria. Randomized controlled studies, systematic reviews and HTA reports (health technology assessment, clinical studies with patient numbers above ten, health-economic evaluations, primary studies with particular cost analyses and quality-of-life studies related to the research questions are included in the analysis. Results and discussion: Invasive mechanical ventilation may improve symptoms of hypoventilation, as the analysis of the literature shows. An increase in life expectancy is likely, but for ethical reasons it is not confirmed by premium-quality studies. Complications (e. g. pneumonia are rare

  6. Neuromuscular control and rehabilitation of the unstable ankle

    OpenAIRE

    Hung, You-jou

    2015-01-01

    Lateral ankle sprain is a common orthopedic injury with a very high recurrence rate in athletes. After decades of research, it is still unclear what contributes to the high recurrence rate of ankle sprain, and what is the most effective intervention to reduce the incident of initial and recurrent injuries. In addition, clinicians often implement balance training as part of the rehabilitation protocol in hopes of enhancing the neuromuscular control and proprioception of the ankle joint. Howeve...

  7. Tai Chi and vestibular rehabilitation improve vestibulopathic gait via different neuromuscular mechanisms: Preliminary report

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    Parker Stephen W

    2005-02-01

    Full Text Available Abstract Background Vestibular rehabilitation (VR is a well-accepted exercise program intended to remedy balance impairment caused by damage to the peripheral vestibular system. Alternative therapies, such as Tai Chi (TC, have recently gained popularity as a treatment for balance impairment. Although VR and TC can benefit people with vestibulopathy, the degree to which gait improvements may be related to neuromuscular adaptations of the lower extremities for the two different therapies are unknown. Methods We examined the relationship between lower extremity neuromuscular function and trunk control in 36 older adults with vestibulopathy, randomized to 10 weeks of either VR or TC exercise. Time-distance measures (gait speed, step length, stance duration and step width, lower extremity sagittal plane mechanical energy expenditures (MEE, and trunk sagittal and frontal plane kinematics (peak and range of linear and angular velocity, were measured. Results Although gait time-distance measures were improved in both groups following treatment, no significant between-groups differences were observed for the MEE and trunk kinematic measures. Significant within groups changes, however, were observed. The TC group significantly increased ankle MEE contribution and decreased hip MEE contribution to total leg MEE, while no significant changes were found within the VR group. The TC group exhibited a positive relationship between change in leg MEE and change in trunk velocity peak and range, while the VR group exhibited a negative relationship. Conclusion Gait function improved in both groups consistent with expectations of the interventions. Differences in each group's response to therapy appear to suggest that improved gait function may be due to different neuromuscular adaptations resulting from the different interventions. The TC group's improvements were associated with reorganized lower extremity neuromuscular patterns, which appear to promote a faster

  8. Identification of the Feedback Component of the Neuromuscular System in a Pitch Control Task

    NARCIS (Netherlands)

    Damveld, H.J.; Abbink, D.A.; Mulder, M.; Mulder, Mark; Van Paassen, M.M.; Van der Helm, F.C.T.; Hosman, R.J.A.W.

    2010-01-01

    This goal of this study is to understand which parts of the the neuromuscular system contribute during a pitch control task. A novel method developed at the Delft University of Technology allows us to determine the contribution of the neuromuscular feedback system by identifying the admittance, whic

  9. Time course and dimensions of postural control changes following neuromuscular training in youth field hockey athletes

    NARCIS (Netherlands)

    Zech, Astrid; Klahn, Philipp; Hoeft, Jon; Eulenburg, Christine Zu; Steib, Simon

    2014-01-01

    Purpose Injury prevention effects of neuromuscular training have been partly attributed to postural control adaptations. Uncertainty exists regarding the magnitude of these adaptations and on how they can be adequately monitored. The objective was to determine the time course of neuromuscular traini

  10. Noninvasive Mechanical Ventilation Improves Breathing-Swallowing Interaction of Ventilator Dependent Neuromuscular Patients: A Prospective Crossover Study

    OpenAIRE

    Marine Garguilo; Michèle Lejaille; Isabelle Vaugier; David Orlikowski; Nicolas Terzi; Frédéric Lofaso; Hélène Prigent

    2016-01-01

    Background Respiratory involvement in neuromuscular disorders may contribute to impaired breathing-swallowing interactions, swallowing disorders and malnutrition. We investigated whether the use of non-invasive ventilation (NIV) controlled by the patient could improve swallowing performances in a population of neuromuscular patients requiring daytime NIV. Methods Ten neuromuscular patients with severe respiratory failure requiring extensive NIV use were studied while swallowing without and wi...

  11. Propiocepción y control neuromuscular en el fútblo infantil

    OpenAIRE

    Zarza, Cristían

    2014-01-01

    En el fútbol profesional la escasa utilización de la pierna no hábil hace que muchas situaciones de juego no se resuelvan eficazmente, además de predisponer a la aparición de lesiones. El presente estudio se concentró en determinar la influencia del entrenamiento propioceptivo y del control neuromuscular en las cualidades físicas y técnicas del miembro no hábil. Objetivo: Indagar el nivel propioceptivo y de control neuromuscular del miembro inferior no hábil en chicos que re...

  12. Mechanical and neuromuscular changes with lateral trunk lean gait modifications.

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    Robbins, Shawn M; Teoli, Anthony; Preuss, Richard A

    2016-09-01

    Lateral trunk lean (LTL) is a proposed intervention for knee osteoarthritis but increased muscular demands have not been considered. The objective was to compare lower extremity and trunk muscle activation and joint mechanics between normal and increased LTL gait in healthy adults. Participants (n=20, mean age 22 years) were examined under two gait conditions: normal and increased LTL. A motion capture system and force plates sampled at 100 and 2000Hz respectively were used to determine joint angles and external moments including LTL angle and external knee adduction moment (KAM). Surface electromyography, sampled at 2000Hz, measured activation of six trunk/hip muscles bilaterally. Peak LTL angle, peak KAM, gait speed, and mean values from electromyography waveforms were compared between normal and LTL conditions using paired t-tests or 2-way analysis of variance. There was a significant (p<0.05) increase in peak LTL angle, decrease in first but not second peak KAM, and decrease in gait speed during LTL gait. There were significant (p<0.01) increases in external oblique and iliocostalis muscle activation during LTL gait. There was no change in activation for internal oblique, rectus abdominis, longissimus, and gluteus medius. LTL gait decreased early/mid-stance KAM demonstrating its ability to decrease medial compartment knee loading. Increases in external oblique and iliocostalis activation were present but small to moderate in size and unlikely to lead to short term injury. Longitudinal studies should evaluate the effectiveness of increased LTL for knee osteoarthritis and if the increase in muscular demands leads to negative long term side effects.

  13. Hormonal and neuromuscular responses to mechanical vibration applied to upper extremity muscles.

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    Riccardo Di Giminiani

    Full Text Available OBJECTIVE: To investigate the acute residual hormonal and neuromuscular responses exhibited following a single session of mechanical vibration applied to the upper extremities among different acceleration loads. METHODS: Thirty male students were randomly assigned to a high vibration group (HVG, a low vibration group (LVG, or a control group (CG. A randomized double-blind, controlled-parallel study design was employed. The measurements and interventions were performed at the Laboratory of Biomechanics of the University of L'Aquila. The HVG and LVG participants were exposed to a series of 20 trials ×10 s of synchronous whole-body vibration (WBV with a 10-s pause between each trial and a 4-min pause after the first 10 trials. The CG participants assumed an isometric push-up position without WBV. The outcome measures were growth hormone (GH, testosterone, maximal voluntary isometric contraction during bench-press, maximal voluntary isometric contraction during handgrip, and electromyography root-mean-square (EMGrms muscle activity (pectoralis major [PM], triceps brachii [TB], anterior deltoid [DE], and flexor carpi radialis [FCR]. RESULTS: The GH increased significantly over time only in the HVG (P = 0.003. Additionally, the testosterone levels changed significantly over time in the LVG (P = 0.011 and the HVG (P = 0.001. MVC during bench press decreased significantly in the LVG (P = 0.001 and the HVG (P = 0.002. In the HVG, the EMGrms decreased significantly in the TB (P = 0.006 muscle. In the LVG, the EMGrms decreased significantly in the DE (P = 0.009 and FCR (P = 0.006 muscles. CONCLUSION: Synchronous WBV acutely increased GH and testosterone serum concentrations and decreased the MVC and their respective maximal EMGrms activities, which indicated a possible central fatigue effect. Interestingly, only the GH response was dependent on the acceleration with respect to the subjects' responsiveness.

  14. Fatiguing exercise intensity influences the relationship between parameters reflecting neuromuscular function and postural control variables.

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    Sébastien Boyas

    Full Text Available The purpose of this study was to investigate the influence of fatiguing exercise intensity on the nature and extent of fatigue-induced changes in neuromuscular function and postural stability in quiet standing. We also explored the contribution of selected neuromuscular mechanisms involved in force production to postural stability impairment observed following fatigue using an approach based on multivariate regressions. Eighteen young subjects performed 30-s postural trials on one leg with their eyes closed. Postural trials were performed before and after fatiguing exercises of different intensities: 25, 50 and 75% of maximal isometric plantarflexor torque. Fatiguing exercises consisted of sustaining a plantarflexor isometric contraction at the target intensity until task failure. Maximal isometric plantarflexor torque, electromyographic activity of plantarflexor and dorsiflexor muscles, activation level (twitch interpolation technique and twitch contractile properties of plantarflexors were used to characterize neuromuscular function. The 25% exercise was associated with greater central fatigue whereas the 50 and 75% exercises involved mostly peripheral fatigue. However, all fatiguing exercises induced similar alterations in postural stability, which was unexpected considering previous literature. Stepwise multiple regression analyses showed that fatigue-related changes in selected parameters related to neuromuscular function could explain more than half (0.51≤R(2≤0.82 of the changes in postural variables for the 25% exercise. On the other hand, regression models were less predictive (0.17≤R(2≤0.73 for the 50 and 75% exercises. This study suggests that fatiguing exercise intensity does not influence the extent of postural stability impairment, but does influence the type of fatigue induced and the neuromuscular function predictors explaining changes in postural variables.

  15. Acceleromyography and mechanomyography for establishing potency of neuromuscular blocking agents: a randomized-controlled trial

    DEFF Research Database (Denmark)

    Claudius, C; Viby-Mogensen, J; Skovgaard, Lene Theil

    2009-01-01

    BACKGROUND: Acceleromyography (AMG) is increasingly being used in neuromuscular research, including in studies establishing the potency of neuromuscular blocking and reversal agents. However, AMG is insufficiently validated for use interchangeably with the gold standard, mechanomyography (MMG) for...... this purpose. The aim of this study was to compare AMG and MMG for establishing dose-response relationship and potency, using rocuronium as an example. METHODS: We included 40 adult patients in this randomized-controlled single-dose response study. Anaesthesia was induced and maintained with propofol......-response relationships were determined for both recording methods using log (dose) against probit (maximum block). The obtained slopes of the regression lines, ED(50), ED(95) and the maximum block were compared. RESULTS: The ED(50) and ED(95) [95% confidence interval (CI)] for AMG were 185 microg/kg(167-205 microg...

  16. Unsteady locomotion: integrating muscle function with whole body dynamics and neuromuscular control.

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    Biewener, Andrew A; Daley, Monica A

    2007-09-01

    By integrating studies of muscle function with analysis of whole body and limb dynamics, broader appreciation of neuromuscular function can be achieved. Ultimately, such studies need to address non-steady locomotor behaviors relevant to animals in their natural environments. When animals move slowly they likely rely on voluntary coordination of movement involving higher brain centers. However, when moving fast, their movements depend more strongly on responses controlled at more local levels. Our focus here is on control of fast-running locomotion. A key observation emerging from studies of steady level locomotion is that simple spring-mass dynamics, which help to economize energy expenditure, also apply to stabilization of unsteady running. Spring-mass dynamics apply to conditions that involve lateral impulsive perturbations, sudden changes in terrain height, and sudden changes in substrate stiffness or damping. Experimental investigation of unsteady locomotion is challenging, however, due to the variability inherent in such behaviors. Another emerging principle is that initial conditions associated with postural changes following a perturbation define different context-dependent stabilization responses. Distinct stabilization modes following a perturbation likely result from proximo-distal differences in limb muscle architecture, function and control strategy. Proximal muscles may be less sensitive to sudden perturbations and appear to operate, in such circumstances, under feed-forward control. In contrast, multiarticular distal muscles operate, via their tendons, to distribute energy among limb joints in a manner that also depends on the initial conditions of limb contact with the ground. Intrinsic properties of these distal muscle-tendon elements, in combination with limb and body dynamics, appear to provide rapid initial stabilizing mechanisms that are often consistent with spring-mass dynamics. These intrinsic mechanisms likely help to simplify the neural

  17. Effect of jumping interval training on neuromuscular and physiological parameters: a randomized controlled study.

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    Ache-Dias, Jonathan; Dellagrana, Rodolfo A; Teixeira, Anderson S; Dal Pupo, Juliano; Moro, Antônio R P

    2016-01-01

    This study analyzed the effect of 4 weeks of jumping interval training (JIT), included in endurance training, on neuromuscular and physiological parameters. Eighteen recreational runners, randomized in control and experimental groups, performed 40 min of running at 70% of velocity at peak oxygen uptake, for 3 times per week. Additionally, the experimental group performed the JIT twice per week, which consisted of 4 to 6 bouts of continuous vertical jumps (30 s) with 5-min intervals. Three days before and after the training period, the countermovement (CMJ) and continuous jump (CJ30), isokinetic and isometric evaluation of knee extensors/flexors, progressive maximal exercise, and submaximal constant-load exercise were performed. The JIT provoked improvement in neuromuscular performance, indicated by (i) increased jump height (4.7%; effect size (ES) = 0.99) and power output (≈ 3.7%; ES ≈ 0.82) of CMJ and rate of torque development of knee extensors in isometric contraction (29.5%; ES = 1.02); (ii) anaerobic power and capacity, represented by the mean of jump height (7.4%; ES = 0.8), and peak power output (PPO) (5.6%; ES = 0.73) of the first jumps of CJ30 and the mean of jump height (10.2%, ES = 1.04) and PPO (9.5%, ES = 1.1), considering all jumps of CJ30; and (iii) aerobic power and capacity, represented by peak oxygen uptake (9.1%, ES = 1.28), velocity at peak oxygen uptake (2.7%, ES = 1.11), and velocity corresponding to the onset of blood lactate accumulation (9.7%, ES = 1.23). These results suggest that the JIT included in traditional endurance training induces moderate to large effects on neuromuscular and physiological parameters.

  18. Neuromuscular complications in cancer.

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    Grisold, W; Grisold, A; Löscher, W N

    2016-08-15

    Cancer is becoming a treatable and even often curable disease. The neuromuscular system can be affected by direct tumor invasion or metastasis, neuroendocrine, metabolic, dysimmune/inflammatory, infections and toxic as well as paraneoplastic conditions. Due to the nature of cancer treatment, which frequently is based on a DNA damaging mechanism, treatment related toxic side effects are frequent and the correct identification of the causative mechanism is necessary to initiate the proper treatment. The peripheral nervous system is conventionally divided into nerve roots, the proximal nerves and plexus, the peripheral nerves (mono- and polyneuropathies), the site of neuromuscular transmission and muscle. This review is based on the anatomic distribution of the peripheral nervous system, divided into cranial nerves (CN), motor neuron (MND), nerve roots, plexus, peripheral nerve, the neuromuscular junction and muscle. The various etiologies of neuromuscular complications - neoplastic, surgical and mechanic, toxic, metabolic, endocrine, and paraneoplastic/immune - are discussed separately for each part of the peripheral nervous system. PMID:27423586

  19. Acute effect of scapular proprioceptive neuromuscular facilitation (PNF) techniques and classic exercises in adhesive capsulitis: a randomized controlled trial.

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    Balcı, Nilay Comuk; Yuruk, Zeliha Ozlem; Zeybek, Aslican; Gulsen, Mustafa; Tekindal, Mustafa Agah

    2016-04-01

    [Purpose] The aim of our study was to compare the initial effects of scapular proprioceptive neuromuscular facilitation techniques and classic exercise interventions with physiotherapy modalities on pain, scapular dyskinesis, range of motion, and function in adhesive capsulitis. [Subjects and Methods] Fifty-three subjects were allocated to 3 groups: scapular proprioceptive neuromuscular facilitation exercies and physiotherapy modalities, classic exercise and physiotherapy modalities, and only physiotherapy modalities. The intervention was applied in a single session. The Visual Analog Scale, Lateral Scapular Slide Test, range of motion and Simple Shoulder Test were evaluated before and just after the one-hour intervention in the same session (all in one session). [Results] All of the groups showed significant differences in shoulder flexion and abduction range of motion and Simple Shoulder Test scores. There were statistically significant differences in Visual Analog Scale scores in the proprioceptive neuromuscular facilitation and control groups, and no treatment method had significant effect on the Lateral Scapular Slide Test results. There were no statistically significant differences between the groups before and after the intervention. [Conclusion] Proprioceptive neuromuscular facilitation, classic exercise, and physiotherapy modalities had immediate effects on adhesive capsulitis in our study. However, there was no additional benefit of exercises in one session over physiotherapy modalities. Also, an effective treatment regimen for shoulder rehabilitation of adhesive capsulitis patients should include scapular exercises.

  20. The Role of Musculoskeletal Dynamics and Neuromuscular Control in Stress Development in Bone

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    DeWoody, Yssa

    1996-01-01

    The role of forces produced by the musculotendon units in the stress development of the long bones during gait has not been fully analyzed. It is well known that the musculotendons act as actuators producing the joint torques which drive the body. Although the joint torques required to perform certain motor tasks can be recovered through a kinematic analysis, it remains a difficult problem to determine the actual forces produced by each muscle that resulted in these torques. As a consequence, few studies have focused on the role of individual muscles in the development of stress in the bone. This study takes a control theoretic approach to the problem. A seven-link, eight degrees of freedom model of the body is controlled by various muscle groups on each leg to simulate gait. The simulations incorporate Hill-type models of muscles with activation and contraction dynamics controlled through neural inputs. This direct approach allows one to know the exact muscle forces exerted by each musculotendon throughout the gait cycle as well the joint torques and reaction forces at the ankle and knee. Stress and strain computed by finite element analysis on skeletal members will be related to these derived loading conditions. Thus the role of musculoskeletal dynamics and neuromuscular control in the stress development of the tibia during gait can be analyzed.

  1. Sympathetic innervation controls homeostasis of neuromuscular junctions in health and disease.

    Science.gov (United States)

    Khan, Muzamil Majid; Lustrino, Danilo; Silveira, Willian A; Wild, Franziska; Straka, Tatjana; Issop, Yasmin; O'Connor, Emily; Cox, Dan; Reischl, Markus; Marquardt, Till; Labeit, Dittmar; Labeit, Siegfried; Benoit, Evelyne; Molgó, Jordi; Lochmüller, Hanns; Witzemann, Veit; Kettelhut, Isis C; Navegantes, Luiz C C; Pozzan, Tullio; Rudolf, Rüdiger

    2016-01-19

    The distribution and function of sympathetic innervation in skeletal muscle have largely remained elusive. Here we demonstrate that sympathetic neurons make close contact with neuromuscular junctions and form a network in skeletal muscle that may functionally couple different targets including blood vessels, motor neurons, and muscle fibers. Direct stimulation of sympathetic neurons led to activation of muscle postsynaptic β2-adrenoreceptor (ADRB2), cAMP production, and import of the transcriptional coactivator peroxisome proliferator-activated receptor γ-coactivator 1α (PPARGC1A) into myonuclei. Electrophysiological and morphological deficits of neuromuscular junctions upon sympathectomy and in myasthenic mice were rescued by sympathicomimetic treatment. In conclusion, this study identifies the neuromuscular junction as a target of the sympathetic nervous system and shows that sympathetic input is crucial for synapse maintenance and function. PMID:26733679

  2. Neuromuscular blockade in children Bloqueadores neuromusculares em crianças

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    João Fernando Lourenço de Almeida

    2000-06-01

    Full Text Available Neuromuscular blocking agents (NMBAs have been widely used to control patients who need to be immobilized for some kind of medical intervention, such as an invasive procedure or synchronism with mechanical ventilation. The purpose of this monograph is to review the pharmacology of the NMBAs, to compare the main differences between the neuromuscular junction in neonates, infants, toddlers and adults, and moreover to discuss their indications in critically ill pediatric patients. Continuous improvement of knowledge about NMBAs pharmacology, adverse effects, and the many other remaining unanswered questions about neuromuscular junction and neuromuscular blockade in children is essential for the correct use of these drugs. Therefore, the indication of these agents in pediatrics is determined with extreme judiciousness. Computorized (Medline 1990-2000 and active search of articles were the mechanisms used in this review.Os bloqueadores neuromusculares têm sido amplamente utilizados para controlar pacientes que necessitem imobilidade para algum tipo de intervenção médica, desde a realização de procedimentos invasivos até a obtenção de sincronismo com a ventilação mecânica. O objetivo básico desta monografia é revisar a farmacologia dos principais bloqueadores neuromusculares, analisar as diferenças existentes na junção neuromuscular de neonatos, lactentes, pré-escolares e adultos, além de discutir suas indicações em pacientes criticamente enfermos internados em unidade de terapia intensiva pediátrica. Revisão computadorizada da literatura (Medline 1990-2000 associado a busca ativa de artigos compuseram o mecanismo de busca dos dados desta revisão.

  3. Neuromuscular control of scapula muscles during a voluntary task in subjects with Subacromial Impingement Syndrome

    DEFF Research Database (Denmark)

    Larsen, C M; Søgaard, Karen; Chreiteh, S S;

    2013-01-01

    Imbalance of neuromuscular activity in the scapula stabilizers in subjects with Subacromial Impingement Syndrome (SIS) is described in restricted tasks and specific populations. Our aim was to compare the scapular muscle activity during a voluntary movement task in a general population with and w...

  4. [Mechanism of the development of neuromuscular disorders in Itsenko-Cushing disease].

    Science.gov (United States)

    Agafonov, B V; Lahutina, T S; Deianova, A F

    1982-01-01

    The results of electromyographic studies indicate that the affection of the neuromuscular system is seen in all the patients with Icenko-Cushing's disease. Changes in different indices of the electromyogram (EMG), i.e. denervation activity, a character of the summary EMG alteration, mean duration of the motor unit action potentials (MUAP), the number of polyphase action potentials, their amplitude and the MUAP synchronization in different spheres indicate a neurogenic character of this affection. It was shown that both denervation and reinnervation processes are more pronounced in the foot muscles than in the hand ones. The denervation process is seemed to be primarily developed in the foot muscles, followed by the hand musculature injury. Therefore, the changes in several EMG parameters may be seen during several stages of the disease in some muscles and not to be observed in the others. PMID:7156070

  5. Hybrid Neuroprosthesis for the Upper Limb: Combining Brain-Controlled Neuromuscular Stimulation with a Multi-Joint Arm Exoskeleton.

    Science.gov (United States)

    Grimm, Florian; Walter, Armin; Spüler, Martin; Naros, Georgios; Rosenstiel, Wolfgang; Gharabaghi, Alireza

    2016-01-01

    Brain-machine interface-controlled (BMI) neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion (ROM) and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES) is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related ROM and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton) in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. NMES was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD) and electromyography (EMG) activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e., induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p = 0.028) or EMG (p = 0.021) modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related ROM (p = 0.009) and the movement-related brain modulation (p = 0.019). Combining a hybrid BMI with neuromuscular stimulation

  6. Hybrid Neuroprosthesis for the Upper Limb: Combining Brain-Controlled Neuromuscular Stimulation with a Multi-Joint Arm Exoskeleton.

    Science.gov (United States)

    Grimm, Florian; Walter, Armin; Spüler, Martin; Naros, Georgios; Rosenstiel, Wolfgang; Gharabaghi, Alireza

    2016-01-01

    Brain-machine interface-controlled (BMI) neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion (ROM) and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES) is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related ROM and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton) in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. NMES was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD) and electromyography (EMG) activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e., induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p = 0.028) or EMG (p = 0.021) modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related ROM (p = 0.009) and the movement-related brain modulation (p = 0.019). Combining a hybrid BMI with neuromuscular stimulation

  7. Mechanisms of hydrogen sulfide (H2S) action on synaptic transmission at the mouse neuromuscular junction.

    Science.gov (United States)

    Gerasimova, E; Lebedeva, J; Yakovlev, A; Zefirov, A; Giniatullin, R; Sitdikova, G

    2015-09-10

    Hydrogen sulfide (H2S) is a widespread gasotransmitter also known as a powerful neuroprotective agent in the central nervous system. However, the action of H2S in peripheral synapses is much less studied. In the current project we studied the modulatory effects of the H2S donor sodium hydrosulfide (NaHS) on synaptic transmission in the mouse neuromuscular junction using microelectrode technique. Using focal recordings of presynaptic response and evoked transmitter release we have shown that NaHS (300 μM) increased evoked end-plate currents (EPCs) without changes of presynaptic waveforms which indicated the absence of NaHS effects on sodium and potassium currents of motor nerve endings. Using intracellular recordings it was shown that NaHS increased the frequency of miniature end-plate potentials (MEPPs) without changing their amplitudes indicating a pure presynaptic effect. Furthermore, NaHS increased the amplitude of end-plate potentials (EPPs) without influencing the resting membrane potential of muscle fibers. L-cysteine, a substrate of H2S synthesis induced, similar to NaHS, an increase of EPC amplitudes whereas inhibitors of H2S synthesis (β-cyano-L-alanine and aminooxyacetic acid) had the opposite effect. Inhibition of adenylate cyclase using MDL 12,330A hydrochloride (MDL 12,330A) or elevation of cAMP level with 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (pCPT-cAMP) completely prevented the facilitatory action of NaHS indicating involvement of the cAMP signaling cascade. The facilitatory effect of NaHS was significantly diminished when intracellular calcium (Ca(2+)) was buffered by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis acetoxymethyl ester (BAPTA-AM) and ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid acetoxymethyl ester (EGTA-AM). Activation of ryanodine receptors by caffeine or ryanodine increased acetylcholine release and prevented further action of NaHS on transmitter release, likely due to

  8. Hybrid neuroprosthesis for the upper limb: combining brain-controlled neuromuscular stimulation with a multi-joint arm exoskeleton

    Directory of Open Access Journals (Sweden)

    Florian Grimm

    2016-08-01

    Full Text Available Brain-machine interface-controlled (BMI neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related range of motion and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. Neuromuscular electrical stimulation was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD and electromyography (EMG activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e. induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p=0.028 or EMG (p=0.021 modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related range of motion (p=0.009 and the movement-related brain modulation (p=0

  9. Effects of proprioceptive neuromuscular facilitation neck pattern exercise on the ability to control the trunk and maintain balance in chronic stroke patients.

    Science.gov (United States)

    Hwangbo, Pil Neo; Don Kim, Kyoung

    2016-03-01

    [Purpose] The aim of this study was to investigate the effects of proprioceptive neuromuscular facilitation neck pattern exercise on the ability to control the trunk and balance in chronic stroke patients. [Subjects and Methods] A total of 30 study subjects were selected and randomly divided into an experimental group of 15 subjects, who received the proprioceptive neuromuscular facilitation neck pattern exercise, and a control group of 15 subjects, who received a traditional rehabilitation treatment. [Results] Statistically significant changes in all the items of the Trunk Impairment Scale, the Trunk Impairment Scale total score, and the Berg Balance Scale were observed in both the experimental group and the control group. significant between-group differences were found in all items among the subitems of the Trunk Impairment Scale except the static sitting balance. [Conclusion] Proprioceptive neuromuscular facilitation neck pattern exercise was shown to have a positive effect on increasing the ability to control the trunk and maintain balance in chronic stroke patients.

  10. Management of Ventilatory Insufficiency in Neuromuscular Patients Using Mechanical Ventilator Supported by the Korean Government.

    Science.gov (United States)

    Kang, Seong-Woong; Choi, Won Ah; Cho, Han Eol; Lee, Jang Woo; Park, Jung Hyun

    2016-06-01

    Since 2001, financial support has been provided for all patients with neuromuscular disease (NMD) who require ventilatory support due to the paralysis of respiratory muscles in Korea. The purpose of this study was to identify ventilator usage status and appropriateness in these patients. We included 992 subjects with rare and incurable NMD registered for ventilator rental fee support. From 21 February 2011 to 17 January 2013, ventilator usage information, regular follow-up observation, and symptoms of chronic hypoventilation were surveyed by phone. Home visits were conducted for patients judged by an expert medical team to require medical examination. Abnormal ventilatory status was assessed by respiratory evaluation. Chronic respiratory insufficiency symptoms were reported by 169 of 992 subjects (17%), while 565 subjects (57%) did not receive regular respiratory evaluation. Ventilatory status was abnormal in 102 of 343 home-visit subjects (29.7%). Although 556 subjects (56%) reported 24-hour ventilator use, only 458 (46%) had an oxygen saturation monitoring device, and 305 (31%) performed an airstacking exercise. A management system that integrates ventilator usage monitoring, counselling and advice, and home visits for patients who receive ventilator support could improve the efficiency of the ventilator support project.

  11. Load Dependency of Postural Control - Kinematic and Neuromuscular Changes in Response to over and under Load Conditions

    Science.gov (United States)

    Ritzmann, Ramona; Freyler, Kathrin; Weltin, Elmar; Krause, Anne; Gollhofer, Albert

    2015-01-01

    Introduction Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL) and under loading (UL) used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms. Methods Balance performance was recorded under normal loading (NL, 1g), UL (0.16g; 0.38g) and OL (1.8g) in monopedal stance. Center of pressure (COP) displacement and frequency distribution (low 0.15-0.5Hz (LF), medium 0.5-2Hz (MF), high 2-6Hz (HF)) as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios). Results Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL. Conclusion Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal

  12. Load Dependency of Postural Control--Kinematic and Neuromuscular Changes in Response to over and under Load Conditions.

    Directory of Open Access Journals (Sweden)

    Ramona Ritzmann

    Full Text Available Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL and under loading (UL used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms.Balance performance was recorded under normal loading (NL, 1 g, UL (0.16 g 0.38 g and OL (1.8 g in monopedal stance. Center of pressure (COP displacement and frequency distribution (low 0.15-0.5 Hz (LF, medium 0.5-2 Hz (MF, high 2-6 Hz (HF as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios.Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL.Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal segments to adjust the center of

  13. HYDRAULIC SERVO CONTROL MECHANISM

    Science.gov (United States)

    Hussey, R.B.; Gottsche, M.J. Jr.

    1963-09-17

    A hydraulic servo control mechanism of compact construction and low fluid requirements is described. The mechanism consists of a main hydraulic piston, comprising the drive output, which is connected mechanically for feedback purposes to a servo control piston. A control sleeve having control slots for the system encloses the servo piston, which acts to cover or uncover the slots as a means of controlling the operation of the system. This operation permits only a small amount of fluid to regulate the operation of the mechanism, which, as a result, is compact and relatively light. This mechanism is particuiarly adaptable to the drive and control of control rods in nuclear reactors. (auth)

  14. [Fatigue in neuromuscular disease].

    Science.gov (United States)

    Van Engelen, B G M; Kalkman, J S; Schillings, M L; Van Der Werf, S P; Bleijenberg, G; Zwarts, M J

    2004-07-01

    Chronic fatigue is a symptom of diseases such as cancer, multiple sclerosis, Parkinson's and cerebrovascular disease. Fatigue can also be present in people with no demonstrable somatic disease. If certain criteria are met, chronic-fatigue syndrome may be diagnosed in these cases. Fatigue is a multi-dimensional concept with physiological and psychological dimensions. The 'Short Fatigue Questionnaire' consisting of 4 questions is a tool to measure fatigue with a high degree of reliability and validity. Within the group of neuromuscular disorders, fatigue has been reported by patients with post-polio syndrome, myasthenia gravis, and Guillain-Barré syndrome. The percentage of neuromuscular patients suffering from severe fatigue (64%) is comparable with that of patients with multiple sclerosis, a disease in which fatigue is an acknowledged symptom. Now that reliable psychological and clinical neurophysiological techniques are available, a multidisciplinary approach to fatigue in patients with well-defined neuromuscular disorders may contribute towards the elucidation of the pathophysiological mechanisms of chronic fatigue, with the ultimate goal being to develop methods of treatment for fatigue in neuromuscular patients. PMID:15283024

  15. Ankles back in randomized controlled trial (ABrCt: braces versus neuromuscular exercises for the secondary prevention of ankle sprains. Design of a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Verhagen Evert ALM

    2011-09-01

    Full Text Available Abstract Background Ankle sprains are the most common sports and physical activity related injury. There is extensive evidence that there is a twofold increased risk for injury recurrence for at least one year post injury. In up to 50% of all cases recurrences result in disability and lead to chronic pain or instability, requiring prolonged medical care. Therefore ankle sprain recurrence prevention in athletes is essential. This RCT evaluates the effect of the combined use of braces and neuromuscular training (e.g. proprioceptive training/sensorimotor training/balance training against the individual use of either braces or neuromuscular training alone on ankle sprain recurrences, when applied to individual athletes after usual care. Methods/Design This study was designed as three way randomized controlled trial with one year follow-up. Healthy individuals between 12 and 70 years of age, who were actively participating in sports and who had sustained a lateral ankle sprain in the two months prior to inclusion, were eligible for inclusion. After subjects had finished ankle sprain treatment by means of usual care, they were randomised to any of the three study groups. Subjects in group 1 received an eight week neuromuscular training program, subjects in group 2 received a sports brace to be worn during all sports activities for the duration of one year, and group 3 received a combination of the neuromuscular training program and a sports brace to be worn during all sports activities for the duration of eight weeks. Outcomes were assessed at baseline and every month for 12 months therafter. The primary outcome measure was incidence of ankle sprain recurrences. Secondary outcome measures included the direct and indirect costs of recurrent injury, the severity of recurrent injury, and the residual complaints during and after the intervention. Discussion The ABrCt is the first randomized controlled trial to directly compare the secondary preventive

  16. Neuromuscular control of scapula muscles during a voluntary task in subjects with Subacromial Impingement Syndrome. A case-control study

    DEFF Research Database (Denmark)

    Larsen, Camilla Marie; Søgaard, Karen; Chreiteh, S S;

    2013-01-01

    Imbalance of neuromuscular activity in the scapula stabilizers in subjects with Subacromial Impingement Syndrome (SIS) is described in restricted tasks and specific populations. Our aim was to compare the scapular muscle activity during a voluntary movement task in a general population with and w...

  17. Brain-Controlled Neuromuscular Stimulation to Drive Neural Plasticity and Functional Recovery

    Science.gov (United States)

    Ethier, C.; Gallego, J.A.; Miller, L.E.

    2015-01-01

    There is mounting evidence that appropriately timed neuromuscular stimulation can induce neural plasticity and generate functional recovery from motor disorders. This review addresses the idea that coordinating stimulation with a patient’s voluntary effort might further enhance neurorehabilitation. Studies in cell cultures and behaving animals have delineated the rules underlying neural plasticity when single neurons are used as triggers. However, the rules governing more complex stimuli and larger networks are less well understood. We argue that functional recovery might be optimized if stimulation were modulated by a brain machine interface, to matched the details of the patient’s voluntary intent. The potential of this novel approach highlights the need for a better understanding of the complex rules underlying this form of plasticity. PMID:25827275

  18. The effects of neuromuscular exercise on medial knee joint load post-arthroscopic partial medial meniscectomy: 'SCOPEX', a randomised control trial protocol

    DEFF Research Database (Denmark)

    Hall, Michelle; Hinman, Rana S; Wrigley, Tim V;

    2012-01-01

    to reduce the risk of developing or progressing osteoarthritis. The primary purpose of this randomised, assessor-blind controlled trial is to determine the effects of a home-based, physiotherapist-supervised neuromuscular exercise program on medial knee joint load during functional tasks in people who have...

  19. THE RELAXOMETER - A COMPLETE AND COMPREHENSIVE COMPUTER-CONTROLLED NEUROMUSCULAR-TRANSMISSION MEASUREMENT SYSTEM DEVELOPED FOR CLINICAL RESEARCH ON MUSCLE-RELAXANTS

    NARCIS (Netherlands)

    ROWAAN, CJ; VANDENBROM, RHG; WIERDA, JMKH

    1993-01-01

    The Relaxometer is a computer-controlled system developed for reliable clinical experimental measurements on neuromuscular block. This system is based on an adapted personal computer (Atari 1040 ST) with a monochrome monitor (Atari SM 124), and a microcomputer-driven slave unit (stimulator). There a

  20. The effects of neuromuscular training on knee joint motor control during sidecutting in female elite soccer and handball players

    DEFF Research Database (Denmark)

    Zebis, Mette K; Bencke, Jesper; Andersen, Lars;

    2008-01-01

    and 8 female elite team handball players aged 26 +/- 3 years at the start of the study. INTERVENTION: The subjects participated in a specific neuromuscular training program previously shown to reduce non-contact ACL injury. METHODS: Neuromuscular activity at the knee joint, joint angles at the hip and...

  1. Home mechanical ventilation in childhood-onset hereditary neuromuscular diseases: 13 years' experience at a single center in Korea.

    Directory of Open Access Journals (Sweden)

    Young Joo Han

    Full Text Available Children with hereditary neuromuscular diseases (NMDs are at a high risk of morbidity and mortality related to respiratory failure. The use of home mechanical ventilation (HMV has saved the lives of many children with NMD but, due to a lack of studies, dependable guidelines are not available. We drew upon our experience to compare the various underlying NMDs and to evaluate HMV with regard to respiratory morbidity, the proper indications and timing for its use, and to develop a policy to improve the quality of home noninvasive ventilation (NIV.We retrospectively analyzed the medical records of 57 children with childhood-onset hereditary NMDs in whom HMV was initiated between January 2000 and May 2013 at Seoul National University Children's Hospital. The degree of respiratory morbidity was estimated by the frequency and duration of hospitalizations caused by respiratory distress.The most common NMD was spinal muscular atrophy (SMA, n = 33. Emergent mechanical ventilation was initiated in 44% of the patients before the confirmed diagnosis, and the indicators of pre-HMV respiratory morbidity (e.g., extubation trials, hypoxia, hospitalizations, and intensive care unit stay were greater in these patients than in others. The proportion of post-HMV hospitalizations (range, 0.00-0.52; median, 0.01 was lower than that of pre-HMV hospitalizations (0.02-1.00; 0.99 (P < 0.001. Eight patients were able to maintain home NIV. The main causes of NIV failure were air leakage and a large amount of airway secretions.The application of HMV helped reduce respiratory morbidity in children with childhood-onset hereditary NMD. Patients with SMA type I can benefit from an early diagnosis and the timely application of HMV. The choice between invasive and noninvasive HMV should be based on the patient's age and NIV trial tolerance. Systematic follow-up guidelines provided by a multidisciplinary team are needed.

  2. Nonholonomic mechanics and control

    CERN Document Server

    Murray, RM

    2015-01-01

    This book explores some of the connections between control theory and geometric mechanics; that is, control theory is linked with a geometric view of classical mechanics in both its Lagrangian and Hamiltonian formulations and in particular with the theory of mechanical systems subject to motion constraints. The synthesis of the topic is appropriate as there is a particularly rich connection between mechanics and nonlinear control theory. The book provides a unified treatment of nonlinear control theory and constrained mechanical systems and illustrates the elegant mathematics behind many simple, interesting, and useful mechanical examples. It is intended for graduate students who wish to learn this subject and researchers in the area who want to enhance their techniques. The book contains sections focusing on physical examples and elementary terms, as well as theoretical sections that use sophisticated analysis and geometry. The first four chapters offer preliminaries and background information, while the...

  3. Proactive and reactive neuromuscular control in subjects with chronic ankle instability: evidence from a pilot study on landing.

    Science.gov (United States)

    Levin, Oron; Vanwanseele, Benedicte; Thijsen, Jo R J; Helsen, Werner F; Staes, Filip F; Duysens, Jacques

    2015-01-01

    To understand why subjects with chronic ankle instability (CAI) have frequent sprains, one must study the preparation/reactions of these subjects to situations related to ankle inversion in real life. In the present pilot study, we examined whether subjects with CAI altered their neuromuscular control and reflex responses during and after ankle perturbations in landing. EMG signals were collected from the tibialis anterior (TA), peroneus longus (PL), medial gastrocnemius (MG), and gluteus medius (GLM) of both legs in 9 subjects with CAI and 9 subjects with intact ankles (control). A trapdoor was used to produce an ankle inversion of 25° with the left leg (control) or the affected leg (CAI) in 0%, 50% or 100% of the landing trials. As compared to controls, subjects with CAI had increased proactive activity in the contralateral side prior to touchdown during landing trials with 50% (PL) and 100% (PL and MG) chance of inversion (all, p proactive control on the contralateral side could be part of a strategy to smooth the impact of landing on the affected side in subjects with CAI. Following touchdown, the CAI group showed decreased ipsilateral short latency reflex (SLR) responses in all test conditions both in distal (PL and MG) and in proximal muscles (GLM) on the affected side (all, p strategies from controls while landing. PMID:25439444

  4. ALS as a distal axonopathy : molecular mechanisms affecting neuromuscular junction stability in the presymptomatic stages of the disease

    NARCIS (Netherlands)

    Moloney, Elizabeth B; de Winter, Fred; Verhaagen, J.

    2014-01-01

    Amyotrophic Lateral Sclerosis (ALS) is being redefined as a distal axonopathy, in that many molecular changes influencing motor neuron degeneration occur at the neuromuscular junction (NMJ) at very early stages of the disease prior to symptom onset. A huge variety of genetic and environmental causes

  5. A device for investigating neuromuscular control in the human masticatory system.

    Science.gov (United States)

    Türker, K S; Brinkworth, R S A; Abolfathi, P; Linke, I R; Nazeran, H

    2004-07-30

    A new apparatus has been developed to study the control of mastication in humans. The subject places his/her teeth on fixed upper and mobile lower bite plates; the device then enables opening and closing movements of the lower jaw against a controlled resistance. It is also possible to vary the number of teeth in contact with the device during an experiment from the entire dental arcade to a single tooth. The specially designed lower bite plate is dynamic and allows for both rotation and translation of the lower jaw during movement, thus, permitting the natural curvilinear trajectory of the jaw. The lower bite plate can follow chewing initiated by the subject without resisting the movement ('no force' mode) via a dedicated microprocessor controlled compensation mechanism. Another function of the device is to inject a constant predetermined load onto the lower bite plate so that the subject 'chews' against a fixed resistance simulating rapidly yielding food bolus ('fixed force' mode). The device can be programmed to increase or decrease the force during the closing or opening phase of chewing by feeding the position information into the force compensation system so both position and force change in parallel, hence, simulating a bite onto a non-yielding, or sticky, food bolus ('normal chewing' mode). By use of a jaw position compensation mechanism, the device can actively move the lower jaw, following any imposed position pattern ('position controlled' mode). The chewing simulator also has a mode that holds the position at a fixed level and allows the force to change ('position hold' mode). Furthermore, the device can inject additional rapid or slow forces or displacements onto the lower bite plate in order to elicit reflexes so that the response of jaw muscles to such stimuli can be examined at various jaw positions, force levels, phases of motion and velocities. The different modes of the apparatus can be used to study the operation and feedback control of human

  6. Changes in Balance Strategy and Neuromuscular Control during a Fatiguing Balance Task-A Study in Perturbed Unilateral Stance.

    Science.gov (United States)

    Ritzmann, Ramona; Freyler, Kathrin; Werkhausen, Amelie; Gollhofer, Albert

    2016-01-01

    Fatigue impairs sensorimotor performance, reduces spinal reflexes and affects the interaction of antagonistic muscles in complex motor tasks. Although there is literature dealing with the interference of fatigue and postural control, the interpretation is confounded by the variety of paradigms used to study it. This study aimed to evaluate the effects of postural fatigue on balance control and strategy, as well as on neuromuscular modulation, in response to postural perturbation (PERT) during a fatiguing balance task. A fatigue protocol consisting of continuous exposure to perturbations until exhaustion was executed in 24 subjects. Number of failed attempts, paths of center of pressure displacement (COP), ankle, knee, and hip joint kinematics, electromyographic activity of the soleus (SOL), tibialis anterior (TA), rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), and gluteus maximus muscles (GM) and spinal excitability of SOL at the peak of the short-latency responses (SLR) were recorded after posterior PERT. The co-contraction index (CCI) was calculated for TA_SOL, VL_BF and RF_GM. (1) The number of failed attempts significantly increased while COP amplitude and velocity, as well as angular excursion at the ankle, knee and hip joints, decreased with fatigue (P < 0.05). (2) Concomitantly, CCI of SOL_TA, VL_BF and RF_GM increased and spinal excitability in SOL declined. (3) Adaptations progressively augmented with progressing exhaustion and occurred in the distal prior to proximal segment. Distinctly deteriorated balance ability was accompanied by a modified neuromuscular control-the increase in co-contraction reflected by simultaneously activated antagonists is accompanied by smaller knee and hip joint excursions, indicating an elevated level of articular stiffness. These changes may be associated with an exaggerated postural rigidity and could have caused the delayed and reduced postural reactions that are reflected in the changes in COP

  7. Knee joint biomechanics and neuromuscular control during gait before and after total knee arthroplasty are sex-specific.

    Science.gov (United States)

    Astephen Wilson, Janie L; Dunbar, Michael J; Hubley-Kozey, Cheryl L

    2015-01-01

    The future of total knee arthroplasty (TKA) surgery will involve planning that incorporates more patient-specific characteristics. Despite known biological, morphological, and functional differences between men and women, there has been little investigation into knee joint biomechanical and neuromuscular differences between men and women with osteoarthritis, and none that have examined sex-specific biomechanical and neuromuscular responses to TKA surgery. The objective of this study was to examine sex-associated differences in knee kinematics, kinetics and neuromuscular patterns during gait before and after TKA. Fifty-two patients with end-stage knee OA (28 women, 24 men) underwent gait and neuromuscular analysis within the week prior to and one year after surgery. A number of sex-specific differences were identified which suggest a different manifestation of end-stage knee OA between the sexes.

  8. Influência da procainamida sobre o bloqueio neuromuscular produzido pelo rocurônio e investigação sobre o mecanismo de ação da procainamida na junção neuromuscular Influencia de la procainamida sobre el bloqueo neuromuscular producido por el rocuronio e investigación sobre el mecanismo de acción de la procainamida en la junción neuromuscular Influence of procainamide on the neuromuscular blockade caused by rocuronium and investigation on the mechanism of action of procainamide on the neuromuscular junction

    Directory of Open Access Journals (Sweden)

    Thalita Duque Martins

    2007-02-01

    : It has already been proved that procainamide potentiates the neuromuscular blockade of d-tubocurarine; however, the mechanism of this potentiation is controversial. The aim of this study was to assess the influence of procainamide on the neuromuscular blockade produced by rocuronium and investigate the mechanisms of this interaction. METHODS: Fifteen rats (250 to 300 g were used in the preparation described by Bülbring. They were divided in three groups (n = 5 each: procainamide - 20 µg.mL-1 (Group I; rocuronium - 4 µg.mL-1 (Group II; and rocuronium - 4 µg.mL-1 and procainamide - 20 µg.mL-1 (Group III. The following parameters were evaluated: 1 amplitude of muscle contractions under indirect stimulation, before and after the administration of the drugs; 2 miniature end plate potentials (MEPPs; and 3 the efficacy of 4-aminopyridine in reverting the muscular blockade. The mechanism of the interaction was studied in Biventer cervicis (n = 5 and in the denervated rat diaphragm (n = 5, observing the influence of procainamide in the response to acetylcholine. RESULTS: Procainamide alone did not change the neuromuscular responses. Group III presented a 68.6% ± 7.1% blockade, which represented a statistically significant difference (p = 0.0067 when compared with Group II (10.4% ± 4.5%, which was reverted by 4-aminopiridine. Procainamide increased the frequency of the MEPP, followed by a blockade that was reverted by 4-aminopiridine. In Biventer cervicis, procainamide increased the contraction in response to acetylcholine, which was not observed in the denervated diaphragm. CONCLUSIONS: Procainamide potentiated the blockade caused by rocuronium. The changes observed with MEPP and Biventer cervicis identified pre-synaptic action. The antagonism of 4-aminopiridine on the blockade of the MEPP suggested receptor desensitization by procainamide.

  9. Changes in Balance Strategy and Neuromuscular Control during a Fatiguing Balance Task—A Study in Perturbed Unilateral Stance

    Science.gov (United States)

    Ritzmann, Ramona; Freyler, Kathrin; Werkhausen, Amelie; Gollhofer, Albert

    2016-01-01

    Fatigue impairs sensorimotor performance, reduces spinal reflexes and affects the interaction of antagonistic muscles in complex motor tasks. Although there is literature dealing with the interference of fatigue and postural control, the interpretation is confounded by the variety of paradigms used to study it. This study aimed to evaluate the effects of postural fatigue on balance control and strategy, as well as on neuromuscular modulation, in response to postural perturbation (PERT) during a fatiguing balance task. A fatigue protocol consisting of continuous exposure to perturbations until exhaustion was executed in 24 subjects. Number of failed attempts, paths of center of pressure displacement (COP), ankle, knee, and hip joint kinematics, electromyographic activity of the soleus (SOL), tibialis anterior (TA), rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), and gluteus maximus muscles (GM) and spinal excitability of SOL at the peak of the short-latency responses (SLR) were recorded after posterior PERT. The co-contraction index (CCI) was calculated for TA_SOL, VL_BF and RF_GM. (1) The number of failed attempts significantly increased while COP amplitude and velocity, as well as angular excursion at the ankle, knee and hip joints, decreased with fatigue (P < 0.05). (2) Concomitantly, CCI of SOL_TA, VL_BF and RF_GM increased and spinal excitability in SOL declined. (3) Adaptations progressively augmented with progressing exhaustion and occurred in the distal prior to proximal segment. Distinctly deteriorated balance ability was accompanied by a modified neuromuscular control—the increase in co-contraction reflected by simultaneously activated antagonists is accompanied by smaller knee and hip joint excursions, indicating an elevated level of articular stiffness. These changes may be associated with an exaggerated postural rigidity and could have caused the delayed and reduced postural reactions that are reflected in the changes in COP

  10. Changes in Balance Strategy and Neuromuscular Control during a Fatiguing Balance Task—A Study in Perturbed Unilateral Stance

    Science.gov (United States)

    Ritzmann, Ramona; Freyler, Kathrin; Werkhausen, Amelie; Gollhofer, Albert

    2016-01-01

    Fatigue impairs sensorimotor performance, reduces spinal reflexes and affects the interaction of antagonistic muscles in complex motor tasks. Although there is literature dealing with the interference of fatigue and postural control, the interpretation is confounded by the variety of paradigms used to study it. This study aimed to evaluate the effects of postural fatigue on balance control and strategy, as well as on neuromuscular modulation, in response to postural perturbation (PERT) during a fatiguing balance task. A fatigue protocol consisting of continuous exposure to perturbations until exhaustion was executed in 24 subjects. Number of failed attempts, paths of center of pressure displacement (COP), ankle, knee, and hip joint kinematics, electromyographic activity of the soleus (SOL), tibialis anterior (TA), rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), and gluteus maximus muscles (GM) and spinal excitability of SOL at the peak of the short-latency responses (SLR) were recorded after posterior PERT. The co-contraction index (CCI) was calculated for TA_SOL, VL_BF and RF_GM. (1) The number of failed attempts significantly increased while COP amplitude and velocity, as well as angular excursion at the ankle, knee and hip joints, decreased with fatigue (P PERT. The reduction in spinal excitability may either be caused by fatigue itself or by an increase in reciprocal inhibition due to augmented TA activity. PMID:27378886

  11. The effects of neuromuscular exercise on medial knee joint load post-arthroscopic partial medial meniscectomy: ‘SCOPEX’ a randomised control trial protocol

    Directory of Open Access Journals (Sweden)

    Hall Michelle

    2012-11-01

    Full Text Available Abstract Background Meniscectomy is a risk factor for knee osteoarthritis, with increased medial joint loading a likely contributor to the development and progression of knee osteoarthritis in this group. Therefore, post-surgical rehabilitation or interventions that reduce medial knee joint loading have the potential to reduce the risk of developing or progressing osteoarthritis. The primary purpose of this randomised, assessor-blind controlled trial is to determine the effects of a home-based, physiotherapist-supervised neuromuscular exercise program on medial knee joint load during functional tasks in people who have recently undergone a partial medial meniscectomy. Methods/design 62 people aged 30–50 years who have undergone an arthroscopic partial medial meniscectomy within the previous 3 to 12 months will be recruited and randomly assigned to a neuromuscular exercise or control group using concealed allocation. The neuromuscular exercise group will attend 8 supervised exercise sessions with a physiotherapist and will perform 6 exercises at home, at least 3 times per week for 12 weeks. The control group will not receive the neuromuscular training program. Blinded assessment will be performed at baseline and immediately following the 12-week intervention. The primary outcomes are change in the peak external knee adduction moment measured by 3-dimensional analysis during normal paced walking and one-leg rise. Secondary outcomes include the change in peak external knee adduction moment during fast pace walking and one-leg hop and change in the knee adduction moment impulse during walking, one-leg rise and one-leg hop, knee and hip muscle strength, electromyographic muscle activation patterns, objective measures of physical function, as well as self-reported measures of physical function and symptoms and additional biomechanical parameters. Discussion The findings from this trial will provide evidence regarding the effect of a home

  12. Effects of repetitive work on proprioception and of stretching on sensory mechanisms : implications for work-related neuromuscular disorders

    OpenAIRE

    Björklund, Martin

    2004-01-01

    The aims of the thesis were (i) to investigate the impact of repetitive low-intensity work exposure on proprioception and (ii) to examine effects of muscle stretching (especially sensory effects and effects on muscle nociception) and to relate its application to the prevention, alleviation and/or treatment of work-related neuromuscular disorders. The effects of low-intensity repetitive work on the shoulder proprioception were tested in healthy subjects. The effect of working time on the reten...

  13. Effect of upper extremity proprioceptive neuromuscular facilitation combined with elastic resistance bands on respiratory muscle strength: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Guilherme P. T. Areas

    2013-12-01

    Full Text Available BACKGROUND: Elastic resistance bands (ERB combined with proprioceptive neuromuscular facilitation (PNF are often used in resistance muscle training programs, which have potential effects on peripheral muscle strength. However, the effects of the combination of ERB and PNF on respiratory muscle strength warrant further investigation. OBJECTIVES: The assessment of the effects of PNF combined with ERB on respiratory muscle strength. METHOD: Twenty healthy, right-handed females were included. Subjects were randomized to either the resistance training program group (TG, n=10 or the control group (CG, n=10. Maximal expiratory pressure (MEP and inspiratory pressure (MIP were measured before and after four weeks of an upper extremity resistance training program. The training protocol consisted of upper extremity PNF combined with ERB, with resistance selected from 1 repetition maximum protocol. RESULTS: PNF combined with ERB showed significant increases in MIP and MEP (p<0.05. In addition, there were significant differences between the TG and CG regarding ∆MIP (p=0.01 and ∆MEP (p=0.04. CONCLUSIONS: PNF combined with ERB can have a positive impact on respiratory muscle strength. These results may be useful with respect to cardiopulmonary chronic diseases that are associated with reduced respiratory muscle strength.

  14. Effects of shared medical appointments on quality of life and cost-effectiveness for patients with a chronic neuromuscular disease. Study protocol of a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    van der Wilt Gert-Jan

    2011-08-01

    Full Text Available Abstract Background Shared medical appointments are a series of one-to-one doctor-patient contacts, in presence of a group of 6-10 fellow patients. This group visits substitute the annual control visits of patients with the neurologist. The same items attended to in a one-to- one appointment are addressed. The possible advantages of a shared medical appointment could be an added value to the present management of neuromuscular patients. The currently problem-focused one-to-one out-patient visits often leave little time for the patient's psychosocial needs, patient education, and patient empowerment. Methods/design A randomized, prospective controlled study (RCT with a follow up of 6 months will be conducted to evaluate the clinical and cost-effectiveness of shared medical appointments compared to usual care for 300 neuromuscular patients and their partners at the Radboud University Nijmegen Medical Center. Every included patient will be randomly allocated to one of the two study arms. This study has been reviewed and approved by the medical ethics committee of the region Arnhem-Nijmegen, the Netherlands. The primary outcome measure is quality of life as measured by the EQ-5D, SF-36 and the Individualized neuromuscular Quality of Life Questionnaire. The primary analysis will be an intention-to-treat analysis on the area under the curve of the quality of life scores. A linear mixed model will be used with random factor group and fixed factors treatment, baseline score and type of neuromuscular disease. For the economic evaluation an incremental cost-effectiveness analysis will be conducted from a societal perspective, relating differences in costs to difference in health outcome. Results are expected in 2012. Discussion This study will be the first randomized controlled trial which evaluates the effect of shared medical appointments versus usual care for neuromuscular patients. This will enable to determine if there is additional value of shared

  15. Proactive and reactive neuromuscular control in subjects with chronic ankle instability: evidence from a pilot study on landing

    NARCIS (Netherlands)

    Levin, O.; Vanwanseele, B.; Thijsen, J.R.; Helsen, W.F.; Staes, F.F.; Duysens, J.E.J.

    2015-01-01

    To understand why subjects with chronic ankle instability (CAI) have frequent sprains, one must study the preparation/reactions of these subjects to situations related to ankle inversion in real life. In the present pilot study, we examined whether subjects with CAI altered their neuromuscular contr

  16. A technique for sequential segmental neuromuscular stimulation with closed loop feedback control.

    Science.gov (United States)

    Zonnevijlle, Erik D H; Abadia, Gustavo Perez; Somia, Naveen N; Kon, Moshe; Barker, John H; Koenig, Steven; Ewert, D L; Stremel, Richard W

    2002-01-01

    In dynamic myoplasty, dysfunctional muscle is assisted or replaced with skeletal muscle from a donor site. Electrical stimulation is commonly used to train and animate the skeletal muscle to perform its new task. Due to simultaneous tetanic contractions of the entire myoplasty, muscles are deprived of perfusion and fatigue rapidly, causing long-term problems such as excessive scarring and muscle ischemia. Sequential stimulation contracts part of the muscle while other parts rest, thus significantly improving blood perfusion. However, the muscle still fatigues. In this article, we report a test of the feasibility of using closed-loop control to economize the contractions of the sequentially stimulated myoplasty. A simple stimulation algorithm was developed and tested on a sequentially stimulated neo-sphincter designed from a canine gracilis muscle. Pressure generated in the lumen of the myoplasty neo-sphincter was used as feedback to regulate the stimulation signal via three control parameters, thereby optimizing the performance of the myoplasty. Additionally, we investigated and compared the efficiency of amplitude and frequency modulation techniques. Closed-loop feedback enabled us to maintain target pressures within 10% deviation using amplitude modulation and optimized control parameters (correction frequency = 4 Hz, correction threshold = 4%, and transition time = 0.3 s). The large-scale stimulation/feedback setup was unfit for chronic experimentation, but can be used as a blueprint for a small-scale version to unveil the theoretical benefits of closed-loop control in chronic experimentation. PMID:12028619

  17. Functional Neuromuscular Stimulation Controlled by Surface Electromyographic Signals Produced by Volitional Activation of the Same Muscle

    DEFF Research Database (Denmark)

    Sennels, Søren; Biering-Sørensen, Fin; Andersen, Ole Trier;

    1997-01-01

    In order to use the volitional electromyography (EMG) as a control signal for the stimulation of the same muscle, it is necessary to eliminate the stimulation artifacts and the muscle responses caused by the stimulation. The stimulation artifacts, caused by the electric field in skin and tissue g...

  18. Low vitamin D levels in healthy controls and patients with autoimmune neuromuscular disorders in Greece.

    Science.gov (United States)

    Chroni, Elisabeth; Dimisianos, Nikolaos; Punga, Anna Rostedt

    2016-03-01

    Normal autoimmune function is dependent on adequate levels of activated vitamin D, 25 hydroxy vitamin D [25(OH)D]. A recent study presented deficiency of 25(OH)D levels in Swedish MG patients. We aimed to study 25(OH)D levels in patients with MG and autoimmune polyneuropathies (PNP) at a southern latitude in Greece. Plasma levels of 25(OH)D were analyzed in Greek patients with MG (n = 19), immune-mediated PNP (N = 11) and in 30 Greek healthy age- and sex-matched controls. Ten MG patients received supplementation with vitamin D3. The MG Composite Score (MGC) and MG quality of life assessed disease severity in MG patients, whereas the INCAT Disability Scale assessed clinical features in the PNP patients. MG patients with and without vitamin D3 supplementation had higher 25(OH)D levels (mean 58.8 ± 16.3 and 62.0 ± 22.4 nmol/L, respectively) than PNP patients (mean 42.1 ± 11.5 nmol/L, p = 0.01) and healthy controls (mean 45.7 ± 13.8 nmol/L, p = 0.01). Plasma 25(OH)D levels was lower with age in all groups. There were no correlations between 25(OH)D and disease duration, MGC score, or INCAT score. Vitamin D deficiency was found in all Greek patient groups and healthy controls. Levels of 25(OH)D were higher in MG patients with as well as without vitamin D supplementation compared to healthy controls, whereas CIDP/GBS patients had levels similar to controls. PMID:26183131

  19. EEG controlled neuromuscular electrical stimulation of the upper limb for stroke patients

    Science.gov (United States)

    Tan, Hock Guan; Shee, Cheng Yap; Kong, Keng He; Guan, Cuntai; Ang, Wei Tech

    2011-03-01

    This paper describes the Brain Computer Interface (BCI) system and the experiments to allow post-acute (Aided by visual feedback, subjects then trained to regulate their mu-rhythm EEG to operate the BCI to trigger NMES of the wrist/finger. 6 post-acute stroke patients successfully completed the training, with 4 able to learn to control and use the BCI to initiate NMES. This result is consistent with the reported BCI literacy rate of healthy subjects. Thereafter, without the loss of generality, the controller of the NMES is developed and is based on a model of the upper limb muscle (biceps/triceps) groups to determine the intensity of NMES required to flex or extend the forearm by a specific angle. The muscle model is based on a phenomenological approach, with parameters that are easily measured and conveniently implemented.

  20. Comparison of neuromuscular and quadriceps strengthening exercise in the treatment of varus malaligned knees with medial knee osteoarthritis: a randomised controlled trial protocol

    Directory of Open Access Journals (Sweden)

    Bennell Kim L

    2011-12-01

    Full Text Available Abstract Background Osteoarthritis of the knee involving predominantly the medial tibiofemoral compartment is common in older people, giving rise to pain and loss of function. Many people experience progressive worsening of the disease over time, particularly those with varus malalignment and increased medial knee joint load. Therefore, interventions that can reduce excessive medial knee loading may be beneficial in reducing the risk of structural progression. Traditional quadriceps strengthening can improve pain and function in people with knee osteoarthritis but does not appear to reduce medial knee load. A neuromuscular exercise program, emphasising optimal alignment of the trunk and lower limb joints relative to one another, as well as quality of movement performance, while dynamically and functionally strengthening the lower limb muscles, may be able to reduce medial knee load. Such a program may also be superior to traditional quadriceps strengthening with respect to improved pain and physical function because of the functional and dynamic nature. This randomised controlled trial will investigate the effect of a neuromuscular exercise program on medial knee joint loading, pain and function in individuals with medial knee joint osteoarthritis. We hypothesise that the neuromuscular program will reduce medial knee load as well as pain and functional limitations to a greater extent than a traditional quadriceps strengthening program. Methods/Design 100 people with medial knee pain, radiographic medial compartment osteoarthritis and varus malalignment will be recruited and randomly allocated to one of two 12-week exercise programs: quadriceps strengthening or neuromuscular exercise. Each program will involve 14 supervised exercise sessions with a physiotherapist plus four unsupervised sessions per week at home. The primary outcomes are medial knee load during walking (the peak external knee adduction moment from 3D gait analysis, pain, and self

  1. Characteristics of Neuromuscular Control of the Scapula after Stroke: A First Exploration

    Science.gov (United States)

    De Baets, Liesbet; Jaspers, Ellen; Janssens, Luc; Van Deun, Sara

    2014-01-01

    This study aimed to characterize scapular muscle timing in stroke patients with and without shoulder pain. Muscle activity of upper trapezius, lower trapezius, serratus anterior, infraspinatus, and anterior deltoid (AD) was measured (Delsys Trigno surface EMG system, USA) in 14 healthy controls (dominant side) and 30 stroke patients (hemiplegic side) of whom 10 had impingement-like shoulder pain. Participants performed 45° and full range anteflexion, in two load conditions. The impact of group, anteflexion height, load condition, and muscle was assessed for onset and offset of the different muscles relative to the onset and offset of AD, using a 3 (group) × 2 (height) × 2 (load) × 4 (muscle) mixed model design. Recruitment patterns were additionally described. Across all load conditions and groups, serratus anterior had a significantly earlier onset and, together with lower trapezius, a significantly later offset in 45° compared to full range anteflexion tasks (p < 0.001). In stroke patients without pain, lower trapezius had furthermore a significantly earlier onset in comparison to stroke patients with shoulder pain (all tasks, p = 0.04). Serratus anterior also showed a significantly earlier offset in stroke patients with shoulder pain in comparison to controls (p = 0.01) and stroke patients without pain (p < 0.001). Analysis of muscle recruitment patterns indicated that for full range tasks, stroke patients without pain used early and prolonged activity of infraspinatus. In stroke patients with shoulder pain, recruitment patterns were characterized by delayed activation and early inactivity of serratus anterior. These timing results can serve as a reference frame for scapular muscle timing post-stroke, and when designing upper limb treatment protocols and clinical guidelines for shoulder pain after stroke. PMID:25477805

  2. Genetics and Neuromuscular Diseases

    Science.gov (United States)

    ... Dermatomyositis Inclusion-body myositis Diseases of Neuromuscular Junction Myasthenia gravis Lambert-Eaton (myasthenic) syndrome Congenital myasthenic syndromes Diseases of Peripheral Nerve Charcot-Marie- ...

  3. The Effects of Plyometric Type Neuromuscular Training on Postural Control Performance of Male Team Basketball Players.

    Science.gov (United States)

    Asadi, Abbas; Saez de Villarreal, Eduardo; Arazi, Hamid

    2015-07-01

    Anterior cruciate ligament injuries are common in basketball athletes; common preventive programs for decreasing these injures may be enhancing postural control (PC) or balance with plyometric training. This study investigated the efficiency of plyometric training program within basketball practice to improve PC performance in young basketball players. Sixteen players were recruited and assigned either to a plyometric + basketball training group (PT) or basketball training group (BT). All players trained twice per week, but the PT + BT followed a 6-week plyometric program implemented within basketball practice, whereas the BT followed regular practice. The star excursion balance test (SEBT) at 8 directions (anterior, A; anteromedial, AM; anterolateral, AL; medial, M; lateral, L; posterior, P; posteromedial, PM; and posterolateral, PL) was measured before and after the 6-week period. The PT group induced significant improvement (p ≤ 0.05) and small to moderate effect size in the SEBT (A = 0.95, AM = 0.62, AL = 0.61, M = 0.36, L = 0.47, P = 0.27, PM = 0.25, PL = 0.24). No significant improvements were found in the BT group. Also, there were significant differences between groups in all directions except PM and PL. An integrated plyometric program within the regular basketball practice can lead to significant improvements in SEBT and consequently PC. It can be recommended that strength and conditioning professionals use PT to enhance the athletes' joint awareness and PC to reduce possible future injuries in the lower extremity.

  4. Quality of residual neuromuscular control and functional deficits in patients with spinal cord injury

    Directory of Open Access Journals (Sweden)

    Alexander eOvechkin

    2013-11-01

    Full Text Available Study Design: Prospective cohort studyObjective: This study examined the relationship between motor control and clinical function outcomes after spinal cord injury (SCI.Setting: University of Louisville, Louisville, Kentucky, USA.Material: Eleven persons with SCI and 5 non-injured subjects were included in this study.Methods: The American Spinal Injury Association Impairment Scale (AIS was used to categorize injury level and severity. Multi-muscle, surface EMG (sEMG recording, was carried out using a protocol of reflex and volitional motor tasks and was analyzed using a vector-based tool that calculates index values that relate a distribution of multi-muscle activation pattern of each SCI subject to the prototype obtained from non-injured subject group and presents overall magnitude as a separate value. Functional Independence Measure (FIM motor subscale, Spinal Cord Injury Independence Measure (SCIM-III, and Walking Index for Spinal Cord Injury (WISCI scale scores were compared to neurophysiological parameters.Results: AIS category and injury level correlated significantly with the WISCI and SCIM mobility subscales. sEMG-derived parameters were significantly correlated with SCIM and WISCI scores but only for examinations carried out 48 or more days post-injury. Conclusions: These results supported the hypothesis that clinically-relevant function after SCI is related to the degree to which functional organization within the central nervous system is disrupted. Further, due likely to the constraints placed on the expression of functional ability by early post-injury immobilization and hospitalization, neurophysiological assessment of motor function may provide better sensitivity and reliability than can be obtained using the clinical function scales examined here within the early period after injury.

  5. Doenças neuromusculares Neuromuscular disorders

    OpenAIRE

    Umbertina C. Reed

    2002-01-01

    Objetivo: apresentar os dados essenciais para o diagnóstico diferencial entre as principais doenças neuromusculares, denominação genérica sob a qual agrupam-se diferentes afecções, decorrentes do acometimento primário da unidade motora (motoneurônio medular, raiz nervosa, nervo periférico, junção mioneural e músculo). Fontes dos dados: os aspectos clínicos fundamentais para estabelecer o diagnóstico diferencial entre as diferentes doenças neuromusculares, bem como entre estas e as causas de h...

  6. Feedback Control of arm movements using Neuro-Muscular Electrical Stimulation (NMES combined with a lockable, passive exoskeleton for gravity compensation

    Directory of Open Access Journals (Sweden)

    Christian eKlauer

    2014-09-01

    Full Text Available Within the European project MUNDUS, an assistive framework was developed for the support of arm and hand functions during daily life activities in severely impaired people. Potential users of this system are patients with high-level spinal cord injury and neurodegenerative neuromuscular diseases, such as amyotrophic lateral sclerosis, Friedreich ataxia, and multiple sclerosis. This contribution aims at designing a feedback control system for Neuro-Muscular Electrical Stimulation (NMES to enable reaching functions in people with no residual voluntary control of the arm due to upper motor neuron lesions after spinal cord injury. NMES is applied to the deltoids and the biceps muscles and integrated with a three degrees of freedom (DoFs passive exoskeleton, which partially compensates gravitational forces and allows to lock each DOF. The user is able to choose the target hand position and to trigger actions using an eyetracker system. The target position is selected by using the eyetracker and determined by a marker-based tracking system using Microsoft Kinect. A central controller, i.e. a finite state machine, issues a sequence of basic movement commands to the real-time arm controller. The NMES control algorithm sequentially controls each joint angle while locking the other DoFs. Daily activities, such as drinking, brushing hair, pushing an alarm button, etc., can be supported by the system. The robust and easily tunable control approach was evaluated with five healthy subjects during a drinking task. Subjects were asked to remain passive and to allow NMES to induce the movements. In all of them, the controller was able to perform the task, and a mean hand positioning error of less than five centimeters was achieved. The average total time duration for moving the hand from a rest position to a drinking cup, for moving the cup to the mouth and back, and for finally returning the arm to the rest position was 71 seconds.

  7. Influência da procainamida sobre o bloqueio neuromuscular produzido pelo rocurônio e investigação sobre o mecanismo de ação da procainamida na junção neuromuscular Influencia de la procainamida sobre el bloqueo neuromuscular producido por el rocuronio e investigación sobre el mecanismo de acción de la procainamida en la junción neuromuscular Influence of procainamide on the neuromuscular blockade caused by rocuronium and investigation on the mechanism of action of procainamide on the neuromuscular junction

    OpenAIRE

    Thalita Duque Martins; Yolanda Christina S. Loyola; Angélica de Fátima de Assunção Braga

    2007-01-01

    JUSTIFICATIVA E OBJETIVOS: A potencialização da procainamida sobre o bloqueio neuromuscular produzido pela d-tubocurarina já está comprovada, porém o mecanismo é controverso. O objetivo do estudo foi avaliar a influência da procainamida no bloqueio neuromuscular produzido pelo rocurônio e investigar os mecanismos desta interação. MÉTODO: Foram utilizados 15 ratos (250 a 300 g) em preparação descrita por Bülbring. Formaram-se os seguintes grupos (n = 5 cada): procainamida - 20 µg.mL-1 (G...

  8. Doenças neuromusculares Neuromuscular disorders

    Directory of Open Access Journals (Sweden)

    Umbertina C. Reed

    2002-08-01

    Full Text Available Objetivo: apresentar os dados essenciais para o diagnóstico diferencial entre as principais doenças neuromusculares, denominação genérica sob a qual agrupam-se diferentes afecções, decorrentes do acometimento primário da unidade motora (motoneurônio medular, raiz nervosa, nervo periférico, junção mioneural e músculo. Fontes dos dados: os aspectos clínicos fundamentais para estabelecer o diagnóstico diferencial entre as diferentes doenças neuromusculares, bem como entre estas e as causas de hipotonia muscular secundária ao comprometimento do sistema nervoso central ou a doenças sistêmicas não-neurológicas, são enfatizados, com base na experiência clínica vinda do atendimento a crianças com doenças neuromusculares durante os últimos 12 anos, no ambulatório de doenças neuromusculares do Hospital das Clínicas da Faculdade de Medicina, da Universidade de São Paulo. A revisão bibliográfica foi efetuada através do Medline e do periódico Neuromuscular Disorders, publicação oficial da World Muscle Society. Síntese dos dados: nas crianças, a maior parte destas afecções é geneticamente determinada, sendo as mais comuns a distrofia muscular progressiva ligada ao sexo, de Duchenne, a amiotrofia espinal infantil, a distrofia muscular congênita, a distrofia miotônica de Steinert, e as miopatias congênitas, estruturais e não estruturais. Polineuropatias hereditárias, síndrome miastênica congênita e miopatias metabólicas são menos comuns, porém mostram correlação geno-fenotípica cada vez mais precisa. Conclusões: na década passada, inúmeros avanços da genética molecular facilitaram imensamente o diagnóstico e o aconselhamento genético das doenças neuromusculares mais comuns das crianças, inclusive possibilitando diagnóstico fetal e, adicionalmente, vieram permitir melhor caracterização fenotípica e classificação mais objetiva.Objective: to discuss the most important aspects for performing a

  9. Bracing superior to neuromuscular training for the prevention of self-reported recurrent ankle sprains: a three-arm randomised controlled trial

    OpenAIRE

    Janssen, Kasper W.; van Mechelen, Willem; Verhagen, Evert A L M

    2014-01-01

    Background Ankle sprain is the most common sports-related injury with a high rate of recurrence and associated costs. Recent studies have emphasised the effectiveness of both neuromuscular training and bracing for the secondary prevention of ankle sprains. Aim To evaluate the effectiveness of combined bracing and neuromuscular training, or bracing alone, against the use of neuromuscular training on recurrences of ankle sprain after usual care. Methods 384 athletes, aged 18–70, who had sustain...

  10. Efeitos da estimulação elétrica neuromuscular durante a imobilização nas propriedades mecânicas do músculo esquelético Efectos de la estimulación eléctrica neuromuscular durante la inmovilización en las propiedades mecánicas del músculo esquelético Effects of neuromuscular electric stimulation during immobilization in the mechanical properties of the skeletal muscle

    Directory of Open Access Journals (Sweden)

    João Paulo Chieregato Matheus

    2007-02-01

    inmovilizadas en alongamiento y electro estimuladas (ILP + EE. Para la inmovilización, el miembro posterior derecho fue envuelto por una malla tubular y vendas de algodón en conjunto con vendas de escayola. La EENM fue utilizada con una frecuencia de 50 Hz, 10 minutos por día, totalizando 20 contracciones en cada sesión. Después de 7 días los animales fueron sometidos a eutanasia y los músculos gastrocnemios fueron retirados para la realización del ensayo mecánico de tracción en una máquina universal de ensayos (EMIC®. A partir de los gráficos carga versus alongamiento se calculó las siguientes propiedades mecánicas: alongamiento en el límite de proporcionalidad (ALP, carga en el límite de proporcionalidad (CLP y rigidez. Las inmovilizaciones SP y LP dieron reducciones significativas (p The neuromuscular electric stimulation (NMES is an important tool used in sports medicine to accelerate the recovery process. The objective of this study was to analyze the effects of NMES during immobilization of the gastrocnemius muscle, in lengthened (LP and shortened positions (SP. Sixty young female Wistar rats were distributed into six groups and followed for 7 days: control (C; electric stimulation (ES; immobilized in shortening (ISP; immobilized in lengthening (ILP; immobilized in shortening and electric stimulation (ISP + ES and immobilized in lengthening and electric stimulation (ILP + ES. For the immobilization, a tubular mesh and cotton rolls together with the plaster were wrapped around the rat's right posterior paw. NMES in a frequency of 50 Hz was used 10 minutes a day, totaling 20 contractions in each session. After 7 days the animals were sacrificed and their gastrocnemius muscles of the right paw were submitted to a mechanical test of traction in a universal test machine (EMIC®. From the load versus elongation curves the following mechanical properties were obtained: elongation in the yield limit (EPL, load in the yield limit (LPL and stiffness. The SP and LP

  11. Efeitos da estimulação elétrica neuromuscular durante a imobilização nas propriedades mecânicas do músculo esquelético Efectos de la estimulación eléctrica neuromuscular durante la inmovilización en las propiedades mecánicas del músculo esquelético Effects of neuromuscular electric stimulation during immobilization in the mechanical properties of the skeletal muscle

    OpenAIRE

    João Paulo Chieregato Matheus; Liana Barbaresco Gomide; Juliana Goulart Prata de Oliveira; José Batista Volpon; Antônio Carlos Shimano

    2007-01-01

    A estimulação elétrica neuromuscular (EENM) é um importante recurso utilizado em medicina esportiva para acelerar processos de recuperação. O objetivo deste estudo foi analisar os efeitos da EENM durante a imobilização do músculo gastrocnêmio, em posições de alongamento (LP) e encurtamento (SP). Para tanto, 60 ratas fêmeas jovens Wistar foram distribuídas em seis grupos e acompanhadas durante sete dias: controle (C), eletroestimuladas (EE), imobilizadas em encurtamento (ISP), imobilizadas em ...

  12. Scoliosis and the impact in neuromuscular disease.

    Science.gov (United States)

    Mayer, Oscar Henry

    2015-01-01

    Scoliosis can alter respiratory mechanics by changing the orientation of the muscles and joints of the respiratory system and in severe forms can put a patient at risk of severe respiratory morbidity or respiratory failure. However, perhaps the most important factor in determining the pulmonary morbidity in scoliosis is the balance between the "load" or altered respiratory mechanics and the "pump" or the respiratory muscle strength. Therefore, scoliosis in patients with neuromuscular disease will both lead to increased "load" and a weakened "pump", an exceptionally unfortunate combination. While progressive neuromuscular disease by its nature does not respond favorably to attempts to improve respiratory muscle strength, the natural approach of early proactive management of the "load" and in the case of scoliosis a variety of different strategies have been tried with variable short term and long term results. Figuring this out requires both an understanding of the underlying pathophysiology of a particular neuromuscular condition and the available options for and timing of surgical intervention.

  13. Hereditary neuromuscular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Oezsarlak, O. E-mail: ozkan.ozsarlak@uza.be; Schepens, E.; Parizel, P.M.; Goethem, J.W. van; Vanhoenacker, F.; Schepper, A.M. de; Martin, J.J

    2001-12-01

    This article presents the actual classification of neuromuscular diseases based on present expansion of our knowledge and understanding due to genetic developments. It summarizes the genetic and clinical presentations of each disorder together with CT findings, which we studied in a large group of patients with neuromuscular diseases. The muscular dystrophies as the largest and most common group of hereditary muscle diseases will be highlighted by giving detailed information about the role of CT and MRI in the differential diagnosis. The radiological features of neuromuscular diseases are atrophy, hypertrophy, pseudohypertrophy and fatty infiltration of muscles on a selective basis. Although the patterns and distribution of involvement are characteristic in some of the diseases, the definition of the type of disease based on CT scan only is not always possible.

  14. Electrodiagnosis in neuromuscular disease.

    Science.gov (United States)

    Lipa, Bethany M; Han, Jay J

    2012-08-01

    Electromyography (EMG) is an important diagnostic tool for the assessment of individuals with various neuromuscular diseases. It should be an extension of a thorough history and physical examination. Some prototypical characteristics and findings of EMG and nerve conduction studies are discussed; however, a more thorough discussion can be found in the textbooks and resources sited in the article. With an increase in molecular genetic diagnostics, EMG continues to play an important role in the diagnosis and management of patients with neuromuscular diseases and also provides a cost-effective diagnostic workup before ordering a battery of costly genetic tests. PMID:22938876

  15. Electrodiagnosis in neuromuscular disease.

    Science.gov (United States)

    Lipa, Bethany M; Han, Jay J

    2012-08-01

    Electromyography (EMG) is an important diagnostic tool for the assessment of individuals with various neuromuscular diseases. It should be an extension of a thorough history and physical examination. Some prototypical characteristics and findings of EMG and nerve conduction studies are discussed; however, a more thorough discussion can be found in the textbooks and resources sited in the article. With an increase in molecular genetic diagnostics, EMG continues to play an important role in the diagnosis and management of patients with neuromuscular diseases and also provides a cost-effective diagnostic workup before ordering a battery of costly genetic tests.

  16. Purinoceptors in neuromuscular transmission

    NARCIS (Netherlands)

    Henning, RH

    1997-01-01

    At the neuromuscular junction, P-2-purinoceptors mediate the actions of the co-transmitter ATP and P-1-purinoceptors, those of its degradation product adenosine. The classification of the subtypes of P-1- and P-2-purinoceptors and their signal transduction routes is presented. Purinoceptor mediated

  17. Optimal Control of Mechanical Systems

    Directory of Open Access Journals (Sweden)

    Vadim Azhmyakov

    2007-01-01

    Full Text Available In the present work, we consider a class of nonlinear optimal control problems, which can be called “optimal control problems in mechanics.” We deal with control systems whose dynamics can be described by a system of Euler-Lagrange or Hamilton equations. Using the variational structure of the solution of the corresponding boundary-value problems, we reduce the initial optimal control problem to an auxiliary problem of multiobjective programming. This technique makes it possible to apply some consistent numerical approximations of a multiobjective optimization problem to the initial optimal control problem. For solving the auxiliary problem, we propose an implementable numerical algorithm.

  18. Effect of a 6-week dynamic neuromuscular training programme on ankle joint function: A Case report

    LENUS (Irish Health Repository)

    O'Driscoll, Jeremiah

    2011-06-09

    Abstract Background Ankle joint sprain and the subsequent development of chronic ankle instability (CAI) are commonly encountered by clinicians involved in the treatment and rehabilitation of musculoskeletal injuries. It has recently been advocated that ankle joint post-sprain rehabilitation protocols should incorporate dynamic neuromuscular training to enhance ankle joint sensorimotor capabilities. To date no studies have reported on the effects of dynamic neuromuscular training on ankle joint positioning during landing from a jump, which has been reported as one of the primary injury mechanisms for ankle joint sprain. This case report details the effects of a 6-week dynamic neuromuscular training programme on ankle joint function in an athlete with CAI. Methods The athlete took part in a progressive 6-week dynamic neuromuscular training programme which incorporated postural stability, strengthening, plyometric, and speed\\/agility drills. The outcome measures chosen to assess for interventional efficacy were: 1 Cumberland Ankle Instability Tool (CAIT) scores, 2 Star Excursion Balance Test (SEBT) reach distances, 3 ankle joint plantar flexion during drop landing and drop vertical jumping, and 4 ground reaction forces (GRFs) during walking. Results CAIT and SEBT scores improved following participation in the programme. The angle of ankle joint plantar flexion decreased at the point of initial contact during the drop landing and drop vertical jumping tasks, indicating that the ankle joint was in a less vulnerable position upon landing following participation in the programme. Furthermore, GRFs were reduced whilst walking post-intervention. Conclusions The 6-week dynamic neuromuscular training programme improved parameters of ankle joint sensorimotor control in an athlete with CAI. Further research is now required in a larger cohort of subjects to determine the effects of neuromuscular training on ankle joint injury risk factors.

  19. Effect of a 6-week dynamic neuromuscular training programme on ankle joint function: A Case report

    Directory of Open Access Journals (Sweden)

    O'Driscoll Jeremiah

    2011-06-01

    Full Text Available Abstract Background Ankle joint sprain and the subsequent development of chronic ankle instability (CAI are commonly encountered by clinicians involved in the treatment and rehabilitation of musculoskeletal injuries. It has recently been advocated that ankle joint post-sprain rehabilitation protocols should incorporate dynamic neuromuscular training to enhance ankle joint sensorimotor capabilities. To date no studies have reported on the effects of dynamic neuromuscular training on ankle joint positioning during landing from a jump, which has been reported as one of the primary injury mechanisms for ankle joint sprain. This case report details the effects of a 6-week dynamic neuromuscular training programme on ankle joint function in an athlete with CAI. Methods The athlete took part in a progressive 6-week dynamic neuromuscular training programme which incorporated postural stability, strengthening, plyometric, and speed/agility drills. The outcome measures chosen to assess for interventional efficacy were: 1 Cumberland Ankle Instability Tool (CAIT scores, 2 Star Excursion Balance Test (SEBT reach distances, 3 ankle joint plantar flexion during drop landing and drop vertical jumping, and 4 ground reaction forces (GRFs during walking. Results CAIT and SEBT scores improved following participation in the programme. The angle of ankle joint plantar flexion decreased at the point of initial contact during the drop landing and drop vertical jumping tasks, indicating that the ankle joint was in a less vulnerable position upon landing following participation in the programme. Furthermore, GRFs were reduced whilst walking post-intervention. Conclusions The 6-week dynamic neuromuscular training programme improved parameters of ankle joint sensorimotor control in an athlete with CAI. Further research is now required in a larger cohort of subjects to determine the effects of neuromuscular training on ankle joint injury risk factors.

  20. Feedback control of arm movements using Neuro-Muscular Electrical Stimulation (NMES) combined with a lockable, passive exoskeleton for gravity compensation.

    Science.gov (United States)

    Klauer, Christian; Schauer, Thomas; Reichenfelser, Werner; Karner, Jakob; Zwicker, Sven; Gandolla, Marta; Ambrosini, Emilia; Ferrante, Simona; Hack, Marco; Jedlitschka, Andreas; Duschau-Wicke, Alexander; Gföhler, Margit; Pedrocchi, Alessandra

    2014-01-01

    Within the European project MUNDUS, an assistive framework was developed for the support of arm and hand functions during daily life activities in severely impaired people. This contribution aims at designing a feedback control system for Neuro-Muscular Electrical Stimulation (NMES) to enable reaching functions in people with no residual voluntary control of the arm and shoulder due to high level spinal cord injury. NMES is applied to the deltoids and the biceps muscles and integrated with a three degrees of freedom (DoFs) passive exoskeleton, which partially compensates gravitational forces and allows to lock each DOF. The user is able to choose the target hand position and to trigger actions using an eyetracker system. The target position is selected by using the eyetracker and determined by a marker-based tracking system using Microsoft Kinect. A central controller, i.e., a finite state machine, issues a sequence of basic movement commands to the real-time arm controller. The NMES control algorithm sequentially controls each joint angle while locking the other DoFs. Daily activities, such as drinking, brushing hair, pushing an alarm button, etc., can be supported by the system. The robust and easily tunable control approach was evaluated with five healthy subjects during a drinking task. Subjects were asked to remain passive and to allow NMES to induce the movements. In all of them, the controller was able to perform the task, and a mean hand positioning error of less than five centimeters was achieved. The average total time duration for moving the hand from a rest position to a drinking cup, for moving the cup to the mouth and back, and for finally returning the arm to the rest position was 71 s. PMID:25228853

  1. Effects of Tai Chi versus Proprioception Exercise Program on Neuromuscular Function of the Ankle in Elderly People: A Randomized Controlled Trial

    OpenAIRE

    Jing Liu; Xue-Qiang Wang; Jie-Jiao Zheng; Yu-Jian Pan; Ying-Hui Hua; Shang-Min Zhao; Li-Yan Shen; Shuai Fan; Jiu-Gen Zhong

    2012-01-01

    Background. Tai Chi is a traditional Chinese medicine exercise used for improving neuromuscular function. This study aimed to investigate the effects of Tai Chi versus proprioception exercise program on neuromuscular function of the ankle in elderly people. Methods. Sixty elderly subjects were randomly allocated into three groups of 20 subjects per group. For 16 consecutive weeks, subjects participated in Tai Chi, proprioception exercise, or no structured exercise. Primary outcome measures in...

  2. Electrodiagnosis of disorders of neuromuscular transmission.

    Science.gov (United States)

    Howard, James F

    2013-02-01

    This article reviews the use of electrodiagnostic testing in disorders of neuromuscular transmission and discusses the differences between various presynaptic and postsynaptic disorders. Attention is paid to quality control issues that influence the sensitivity of repetitive nerve stimulation and single fiber electromyography. Electrodiagnostic testing, when used as an extension of the clinician's history and physical examination, will provide appropriate direction in establishing the diagnosis.

  3. The role of multisensor data fusion in neuromuscular control of a sagittal arm with a pair of muscles using actor-critic reinforcement learning method.

    Science.gov (United States)

    Golkhou, V; Parnianpour, M; Lucas, C

    2004-01-01

    In this study, we consider the role of multisensor data fusion in neuromuscular control using an actor-critic reinforcement learning method. The model we use is a single link system actuated by a pair of muscles that are excited with alpha and gamma signals. Various physiological sensor information such as proprioception, spindle sensors, and Golgi tendon organs have been integrated to achieve an oscillatory movement with variable amplitude and frequency, while achieving a stable movement with minimum metabolic cost and coactivation. The system is highly nonlinear in all its physical and physiological attributes. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex loops. This paper proposes a reinforcement learning method with an Actor-Critic architecture instead of middle and low level of central nervous system (CNS). The Actor in this structure is a two layer feedforward neural network and the Critic is a model of the cerebellum. The Critic is trained by the State-Action-Reward-State-Action (SARSA) method. The Critic will train the Actor by supervisory learning based on previous experiences. The reinforcement signal in SARSA is evaluated based on available alternatives concerning the concept of multisensor data fusion. The effectiveness and the biological plausibility of the present model are demonstrated by several simulations. The system showed excellent tracking capability when we integrated the available sensor information. Addition of a penalty for activation of muscles resulted in much lower muscle coactivation while keeping the movement stable. PMID:15671597

  4. Neuromuscular junctional disorders.

    Science.gov (United States)

    Girija, A S; Ashraf, V V

    2008-07-01

    Neuromuscular junctional disorders (NMJ) in children are distinct entity. They may be acquired or hereditary. They pose problem in diagnosis because of the higher occurrence of sero negative Myasthenia Gravis (MG) cases in children. The identity of MusK antibody positivity in a good percentage of sero negative cases further adds to problems in diagnosis. The Congenital Myasthenic Syndrome (CMS) which are rare disorders of hereditary neuromuscular transmission (NMT) has to be differentiated because immunotherapy has no benefit in this group. Molecular genetic studies of these diseases helps to identify specific type of CMS which is important as other drugs like Fluoxetine, Quinidine are found to be effective in some. In infancy, all can manifest as floppy infant syndrome. The important key to diagnosis is by detailed electrophysiological studies including repetitive nerve stimulation at slow and high rates and its response to anticholinesterases and estimation of Acetyl choline receptor antibodies. Other causes of neuromuscular transmission defects viz. snake venom poisoning and that due to drugs are discussed. PMID:18716738

  5. Cellular mechanisms that control mistranslation

    DEFF Research Database (Denmark)

    Reynolds, Noah M; Lazazzera, Beth A; Ibba, Michael

    2010-01-01

    Mistranslation broadly encompasses the introduction of errors during any step of protein synthesis, leading to the incorporation of an amino acid that is different from the one encoded by the gene. Recent research has vastly enhanced our understanding of the mechanisms that control mistranslation...... at the molecular level and has led to the discovery that the rates of mistranslation in vivo are not fixed but instead are variable. In this Review we describe the different steps in translation quality control and their variations under different growth conditions and between species though a comparison...

  6. Patterning mechanisms controlling digit development

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Vertebrate digits are essential structures for movement,feeding and communication.Specialized regions of the developing limb bud including the zone of polarizing activity(ZPA),the apical ectodermal ridge(AER),and the non-ridge ectoderm regulate the patterning of digits.Although a series of signaling molecules have been characterized as patterning signals from the organizing centers,the delicate cellular and molecular mechanisms that interpret how these patterning signals control the detailed digit anatomy remain unclear.Recent studies from model organisms and human hand malformations provide new insights into the mechanisms regulating this process.Here,we review the current understanding of the genetic networks governing digit morphogenesis.

  7. Plyometric type neuromuscular exercise is a treatment to postural control deficits of volleyball players: A case study

    Directory of Open Access Journals (Sweden)

    A. Asadi

    2016-06-01

    Conclusions: It can be recommend that strength and conditioning professionals in the field of volleyball do not perform other type of landing exercise in plyometric training sessions because of postural control impaired and consequently the probability of lower extremity injuries will increase.

  8. Respiratory motor training and neuromuscular plasticity in patients with chronic obstructive pulmonary disease: A pilot study.

    Science.gov (United States)

    Ovechkin, Alexander V; Sayenko, Dimitry G; Ovechkina, Elena N; Aslan, Sevda C; Pitts, Teresa; Folz, Rodney J

    2016-07-15

    The objective of this study was to examine the feasibility of a full-scale investigation of the neurophysiological mechanisms of COPD-induced respiratory neuromuscular control deficits. Characterization of respiratory single- and multi-muscle activation patterns using surface electromyography (sEMG) were assessed along with functional measures at baseline and following 21±2 (mean±SD) sessions of respiratory motor training (RMT) performed during a one-month period in four patients with GOLD stage II or III COPD. Pre-training, the individuals with COPD showed significantly increased (prespiratory muscle activity and disorganized multi-muscle activation patterns in association with lowered spirometrical measures and decreased fast- and slow-twitch fiber activity as compared to healthy controls (N=4). Following RMT, functional and respiratory sEMG activation outcomes during quite breathing and forced expiratory efforts were improved suggesting that functional improvements, induced by task-specific RMT, are evidence respiratory neuromuscular networks re-organization.

  9. Functional Neuromuscular Stimulation Controlled by Surface Electromyographic Signals Produced by the Volitional Activation of the Same Muscle:

    DEFF Research Database (Denmark)

    Sennels, Søren; Fin, Biering-Sørensen; Andersen, Ole Trier;

    1997-01-01

    Using the voluntary EMG as a control signal for the stimulation of the same muscle necessitates elimination of stimulus artifacts and the muscle response caused by the stimulation. The stimulus artifacts are easily eliminated by shutting down the amplifier during stimulation. The muscle response...... is relatively insensitive to amplitude variations og the muscle responses. For variations in shape and for real data, an improved filter performance can be achieved by increasing the filter length. A filter length of up to 7 stimulation periods makes it possible to reduce real muscle responses to a level...

  10. Autoregulatory mechanisms controlling the microprocessor.

    Science.gov (United States)

    Triboulet, Robinson; Gregory, Richard I

    2011-01-01

    The Microprocessor, comprising the ribonuclease Drosha and its essential cofactor, the double-stranded RNA-binding protein, DGCR8, is essential for the first step of the miRNA biogenesis pathway. It specifically cleaves double-stranded RNA within stem-loop structures of primary miRNA transcripts (pri-miRNAs) to generate precursor (pre-miRNA) intermediates. Pre-miRNAs are subsequently processed by Dicer to their mature ∼22 nt form. Thus, Microprocessor is essential for miRNA maturation, and pri-miRNA cleavage by this complex defines one end of the mature miRNA. Moreover, it is emerging that dysregulation of the Microprocessor is associated with various human diseases. It is therefore important to understand the mechanisms by which the expression of the subunits of the Microprocessor is regulated. Recent findings have uncovered a post-transcriptional mechanism that maintains the integrity of the Microprocessor. These studies revealed that the Microprocessor is involved in the processing of the messenger RNA (mRNA) that encodes DGCR8. This regulatory feedback loop, along with the reported role played by DGCR8 in the stabilization of Drosha protein, is part of a newly identified regulatory mechanism controlling Microprocessor activity.

  11. Control mechanisms for ecological-economic systems

    CERN Document Server

    Burkov, Vladimir N; Shchepkin, Alexander V

    2015-01-01

    This monograph presents and analyzes the optimization, game-theoretic and simulation models of control mechanisms for ecological-economic systems. It is devoted to integrated assessment mechanisms for total risks and losses, penalty mechanisms, risk payment mechanisms, financing and costs compensation mechanisms for risk level reduction, sales mechanisms for risk level quotas, audit mechanisms, mechanisms for expected losses reduction, economic motivation mechanisms, optimization mechanisms for regional environmental (risk level reduction) programs, and mechanisms for authorities' interests coordination. The book is aiming at undergraduate and postgraduate students, as well as at experts in mathematical modeling and control of ecological economic, socioeconomic and organizational systems.

  12. Neuromuscular complications of acromegaly.

    Science.gov (United States)

    Pickett, J B; Layzer, R B; Levin, S R; Scheider, V; Campbell, M J; Sumner, A J

    1975-07-01

    Seventeen consecutive acromegalic patients were evaluated for evidence of neuromuscular dysfunction and followed for 1 year after hypophysectomy. Before treatment, four patients had both a myopathy and the carpal tunnel syndrome, five had myopathy alone, four had carpal tunnel syndrome alone, and four had neither. The myopathy was caracterized by mild, strictly promixal weakness and flabbiness of muscles; electromyography revealed typical myopathic abnormalities, but serum enzymes and muscle biopsy usually were normal. The presence of myopathy or the carpal tunnel syndrrome could not be correlated with the magnitude of growth hormone elevation or any secondary endocrine derangement, but myopathy was associated with a longer duration of acromegaly. Carpal tunnel symptoms usually improved in the first 6 weeks after hypophysectomy, while myopathy improved more slowly and sometimes was detectable 1 year later.

  13. Neuromuscular blockade: what was, is and will be.

    Science.gov (United States)

    Schepens, Tom; Cammu, Guy

    2014-01-01

    Non-depolarizing neuromuscular blocking agents (NMBAs) produce neuromuscular blockade by competing with acetylcholine at the neuromuscular junction, whereas depolarizing NMBAs open receptor channels in a manner similar to that of acetylcholine. Problems with NMBAs include malignant hyperthermia caused by succinylcholine, anaphylaxis with the highest incidence for succinylcholine and rocuronium, and residual neuromuscular blockade. To reverse these blocks, anticholinesterases can act indirectly by increasing the amount of acetylcholine in the neuromuscular junction; sugammadex is the only selective relaxant binding agent (SRBA) in clinical use. At all levels of blockade, recovery after sugammadex is faster than after neostigmine. Sugammadex potentially also has some other advantages over neostigmine that are related to neostigmine's increase in the amount of acetylcholine and the necessity of co-administering anticholinergics. However, hypersensitivity reactions, including anaphylaxis, have occurred in some patients and healthy volunteers after sugammadex and remain an issue for the FDA. In the near future, we may see the emergence of new SRBAs and of easier-to-use technologies that can routinely monitor neuromuscular transmissions in daily practice. The nature of the effect of sugammadex on freeing nicotinic acetylcholine receptors located outside the neuromuscular junction from NMBAs is unknown. Moreover, it is uncertain whether the full removal of the competing antagonists (by SRBAs) at the neuromuscular junction impacts the efficiency of acetylcholine transmission. In a recent pilot study in healthy volunteers, we demonstrated increased electromyographic diaphragm activity after sugammadex, compared to neostigmine. Further research is needed to elucidate the role of NMBAs and their reversal agents in the central control of breathing, respiratory muscle activity, and respiratory outcomes. PMID:25622380

  14. Expecting ankle tilts and wearing an ankle brace influence joint control in an imitated ankle sprain mechanism during walking.

    Science.gov (United States)

    Gehring, Dominic; Wissler, Sabrina; Lohrer, Heinz; Nauck, Tanja; Gollhofer, Albert

    2014-03-01

    A thorough understanding of the functional aspects of ankle joint control is essential to developing effective injury prevention. It is of special interest to understand how neuromuscular control mechanisms and mechanical constraints stabilize the ankle joint. Therefore, the aim of the present study was to determine how expecting ankle tilts and the application of an ankle brace influence ankle joint control when imitating the ankle sprain mechanism during walking. Ankle kinematics and muscle activity were assessed in 17 healthy men. During gait rapid perturbations were applied using a trapdoor (tilting with 24° inversion and 15° plantarflexion). The subjects either knew that a perturbation would definitely occur (expected tilts) or there was only the possibility that a perturbation would occur (potential tilts). Both conditions were conducted with and without a semi-rigid ankle brace. Expecting perturbations led to an increased ankle eversion at foot contact, which was mediated by an altered muscle preactivation pattern. Moreover, the maximal inversion angle (-7%) and velocity (-4%), as well as the reactive muscle response were significantly reduced when the perturbation was expected. While wearing an ankle brace did not influence muscle preactivation nor the ankle kinematics before ground contact, it significantly reduced the maximal ankle inversion angle (-14%) and velocity (-11%) as well as reactive neuromuscular responses. The present findings reveal that expecting ankle inversion modifies neuromuscular joint control prior to landing. Although such motor control strategies are weaker in their magnitude compared with braces, they seem to assist ankle joint stabilization in a close-to-injury situation. PMID:24365326

  15. Mechanisms of TSC-mediated control of synapse assembly and axon guidance.

    Directory of Open Access Journals (Sweden)

    Sarah Knox

    Full Text Available Tuberous sclerosis complex is a dominant genetic disorder produced by mutations in either of two tumor suppressor genes, TSC1 and TSC2; it is characterized by hamartomatous tumors, and is associated with severe neurological and behavioral disturbances. Mutations in TSC1 or TSC2 deregulate a conserved growth control pathway that includes Ras homolog enriched in brain (Rheb and Target of Rapamycin (TOR. To understand the function of this pathway in neural development, we have examined the contributions of multiple components of this pathway in both neuromuscular junction assembly and photoreceptor axon guidance in Drosophila. Expression of Rheb in the motoneuron, but not the muscle of the larval neuromuscular junction produced synaptic overgrowth and enhanced synaptic function, while reductions in Rheb function compromised synapse development. Synapse growth produced by Rheb is insensitive to rapamycin, an inhibitor of Tor complex 1, and requires wishful thinking, a bone morphogenetic protein receptor critical for functional synapse expansion. In the visual system, loss of Tsc1 in the developing retina disrupted axon guidance independently of cellular growth. Inhibiting Tor complex 1 with rapamycin or eliminating the Tor complex 1 effector, S6 kinase (S6k, did not rescue axon guidance abnormalities of Tsc1 mosaics, while reductions in Tor function suppressed those phenotypes. These findings show that Tsc-mediated control of axon guidance and synapse assembly occurs via growth-independent signaling mechanisms, and suggest that Tor complex 2, a regulator of actin organization, is critical in these aspects of neuronal development.

  16. Control of a mechanical gripper with a fuzzy controller

    International Nuclear Information System (INIS)

    A fuzzy logic system is used to control a mechanical gripper. System is based in a NLX230 fuzzy micro controller. Control rules are programmed by a 68020 microprocessor in the micro controller memory. Stress and its derived are used as feedback signals in the control. This system can adapt its effort to the mechanical resistance of the object between the fingers. (Author)

  17. Effects of carbohydrates-BCAAs-caffeine ingestion on performance and neuromuscular function during a 2-h treadmill run: a randomized, double-blind, cross-over placebo-controlled study

    Directory of Open Access Journals (Sweden)

    Peltier Sébastien L

    2011-12-01

    Full Text Available Abstract Background Carbohydrates (CHOs, branched-chain amino acids (BCAAs and caffeine are known to improve running performance. However, no information is available on the effects of a combination of these ingredients on performance and neuromuscular function during running. Methods The present study was designed as a randomized double-blind cross-over placebo-controlled trial. Thirteen trained adult males completed two protocols, each including two conditions: placebo (PLA and Sports Drink (SPD: CHOs 68.6 g.L-1, BCAAs 4 g.L-1, caffeine 75 mg.L-1. Protocol 1 consisted of an all-out 2 h treadmill run. Total distance run and glycemia were measured. In protocol 2, subjects exercised for 2 h at 95% of their lowest average speeds recorded during protocol 1 (whatever the condition. Glycemia, blood lactate concentration and neuromuscular function were determined immediately before and after exercise. Oxygen consumption (V˙O2, heart rate (HR and rate of perceived exertion (RPE were recorded during the exercise. Total fluids ingested were 2 L whatever the protocols and conditions. Results Compared to PLA, ingestion of SPD increased running performance (p = 0.01, maintained glycemia and attenuated central fatigue (p = 0.04, an index of peripheral fatigue (p = 0.04 and RPE (p = 0.006. Maximal voluntary contraction, V˙O2, and HR did not differ between the two conditions. Conclusions This study showed that ingestion of a combination of CHOs, BCAAs and caffeine increased performance by about 2% during a 2-h treadmill run. The results of neuromuscular function were contrasted: no clear cut effects of SPD were observed. Trial registration ClinicalTrials.gov, http://www.clinicaltrials.gov, NCT00799630

  18. Neuromuscular disease classification system.

    Science.gov (United States)

    Sáez, Aurora; Acha, Begoña; Montero-Sánchez, Adoración; Rivas, Eloy; Escudero, Luis M; Serrano, Carmen

    2013-06-01

    Diagnosis of neuromuscular diseases is based on subjective visual assessment of biopsies from patients by the pathologist specialist. A system for objective analysis and classification of muscular dystrophies and neurogenic atrophies through muscle biopsy images of fluorescence microscopy is presented. The procedure starts with an accurate segmentation of the muscle fibers using mathematical morphology and a watershed transform. A feature extraction step is carried out in two parts: 24 features that pathologists take into account to diagnose the diseases and 58 structural features that the human eye cannot see, based on the assumption that the biopsy is considered as a graph, where the nodes are represented by each fiber, and two nodes are connected if two fibers are adjacent. A feature selection using sequential forward selection and sequential backward selection methods, a classification using a Fuzzy ARTMAP neural network, and a study of grading the severity are performed on these two sets of features. A database consisting of 91 images was used: 71 images for the training step and 20 as the test. A classification error of 0% was obtained. It is concluded that the addition of features undetectable by the human visual inspection improves the categorization of atrophic patterns. PMID:23804164

  19. Active zone stability:insights from fly neuromuscular junction

    Institute of Scientific and Technical Information of China (English)

    Xiaolin Tian; Chunlai Wu

    2015-01-01

    The presynaptic active zone is a dynamic structure that orchestrates regulated release of neurotrans-mitters. Developmental and aging processes, and changes in neuronal network activity can all modulate the number, size and composition of active zone and thereby synaptic efifcacy. However, very little is known about the mechanism that controls the structural stability of active zone. By study-ing a model synapse, theDrosophila neuromuscular junction, our recent work shed light on how two scaffolding proteins at the active zone regulate active zone stability by promoting a localized dephos-phorylation event at the nerve terminal. Here we discuss the major insights from our ifndings and their implications for future research.

  20. Neuromuscular activity and knee kinematics in adolescents with patellofemoral pain

    DEFF Research Database (Denmark)

    Rathleff, Michael Skovdal; Samani, Afshin; Olesen, Jens L.;

    2013-01-01

    This study aimed to investigate the neuromuscular control of the knee during stair descent among female adolescents with patellofemoral pain (PFP) and to report its association with self-reported clinical status assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS).......This study aimed to investigate the neuromuscular control of the knee during stair descent among female adolescents with patellofemoral pain (PFP) and to report its association with self-reported clinical status assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS)....

  1. Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome

    Science.gov (United States)

    Rowe, Peter C.; Fontaine, Kevin R.; Lauver, Megan; Jasion, Samantha E.; Marden, Colleen L.; Moni, Malini; Thompson, Carol B.; Violand, Richard L.

    2016-01-01

    Chronic fatigue syndrome (CFS) is a complex, multisystem disorder that can be disabling. CFS symptoms can be provoked by increased physical or cognitive activity, and by orthostatic stress. In preliminary work, we noted that CFS symptoms also could be provoked by application of longitudinal neural and soft tissue strain to the limbs and spine of affected individuals. In this study we measured the responses to a straight leg raise neuromuscular strain maneuver in individuals with CFS and healthy controls. We randomly assigned 60 individuals with CFS and 20 healthy controls to either a 15 minute period of passive supine straight leg raise (true neuromuscular strain) or a sham straight leg raise. The primary outcome measure was the symptom intensity difference between the scores during and 24 hours after the study maneuver compared to baseline. Fatigue, body pain, lightheadedness, concentration difficulties, and headache scores were measured individually on a 0–10 scale, and summed to create a composite symptom score. Compared to individuals with CFS in the sham strain group, those with CFS in the true strain group reported significantly increased body pain (P = 0.04) and concentration difficulties (P = 0.02) as well as increased composite symptom scores (all P = 0.03) during the maneuver. After 24 hours, the symptom intensity differences were significantly greater for the CFS true strain group for the individual symptom of lightheadedness (P = 0.001) and for the composite symptom score (P = 0.005). During and 24 hours after the exposure to the true strain maneuver, those with CFS had significantly higher individual and composite symptom intensity changes compared to the healthy controls. We conclude that a longitudinal strain applied to the nerves and soft tissues of the lower limb is capable of increasing symptom intensity in individuals with CFS for up to 24 hours. These findings support our preliminary observations that increased mechanical sensitivity may be a

  2. Neuromuscular ultrasound of cranial nerves.

    Science.gov (United States)

    Tawfik, Eman A; Walker, Francis O; Cartwright, Michael S

    2015-04-01

    Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed.

  3. Neuromuscular Exercise Post Partial Medial Meniscectomy

    DEFF Research Database (Denmark)

    Hall, Michelle; Hinman, Rana S; Wrigley, Tim V;

    2015-01-01

    : An assessor-blinded, randomised controlled trial including people aged 30-50 years with no to mild pain following medial arthroscopic partial meniscectomy was conducted. Participants were randomly allocated to either a 12-week neuromuscular exercise program that targeted neutral lower limb alignment...... outcomes included additional measures of knee joint load distribution, patient-reported outcomes, maximal knee and hip muscle strength, and physical function measures. RESULTS: 60 out of 62 randomized participants (97%) completed the trial. There were no significant between-group differences in the change...

  4. Comparison of the effects of hamstring stretching using proprioceptive neuromuscular facilitation with prior application of cryotherapy or ultrasound therapy.

    Science.gov (United States)

    Magalhães, Francisco Elezier Xavier; Junior, Arlindo Rodrigues de Mesquita; Meneses, Harnold's Tyson de Sousa; Moreira Dos Santos, Rayele Pricila; Rodrigues, Ezaine Costa; Gouveia, Samara Sousa Vasconcelos; Gouveia, Guilherme Pertinni de Morais; Orsini, Marco; Bastos, Victor Hugo do Vale; Machado, Dionis de Castro Dutra

    2015-05-01

    [Purpose] Stretching using proprioceptive neuromuscular facilitation involve physiological reflex mechanisms through submaximal contraction of agonists which activate Golgi organ, promoting the relaxation reflex. The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation alone and with prior application of cryotherapy and thermotherapy on hamstring stretching. [Subjects and Methods] The sample comprised of 32 young subjects with hamstring retraction of the right limb. The subjects were randomly allocated to four groups: the control, flexibility PNF, flexibility PNF associated with cryotherapy, flexibility PNF in association with ultrasound therapy. [Results] After 12 stretching sessions, experimental groups showed significant improvements compared to the control group. Moreover, we did not find any significant differences among the experimental groups indicating PNF stretching alone elicits similar results to PNF stretching with prior administration of cryotherapy or thermotherapy. [Conclusion] PNF without other therapy may be a more practical and less expensive choice for clinical care.

  5. Protein defects in neuromuscular diseases

    Directory of Open Access Journals (Sweden)

    Vainzof M.

    2003-01-01

    Full Text Available Muscular dystrophies are a heterogeneous group of genetically determined progressive disorders of the muscle with a primary or predominant involvement of the pelvic or shoulder girdle musculature. The clinical course is highly variable, ranging from severe congenital forms with rapid progression to milder forms with later onset and a slower course. In recent years, several proteins from the sarcolemmal muscle membrane (dystrophin, sarcoglycans, dysferlin, caveolin-3, from the extracellular matrix (alpha2-laminin, collagen VI, from the sarcomere (telethonin, myotilin, titin, nebulin, from the muscle cytosol (calpain 3, TRIM32, from the nucleus (emerin, lamin A/C, survival motor neuron protein, and from the glycosylation pathway (fukutin, fukutin-related protein have been identified. Mutations in their respective genes are responsible for different forms of neuromuscular diseases. Protein analysis using Western blotting or immunohistochemistry with specific antibodies is of the utmost importance for the differential diagnosis and elucidation of the physiopathology of each genetic disorder involved. Recent molecular studies have shown clinical inter- and intra-familial variability in several genetic disorders highlighting the importance of other factors in determining phenotypic expression and the role of possible modifying genes and protein interactions. Developmental studies can help elucidate the mechanism of normal muscle formation and thus muscle regeneration. In the last fifteen years, our research has focused on muscle protein expression, localization and possible interactions in patients affected by different forms of muscular dystrophies. The main objective of this review is to summarize the most recent findings in the field and our own contribution.

  6. LRP4 is critical for neuromuscular junction maintenance.

    Science.gov (United States)

    Barik, Arnab; Lu, Yisheng; Sathyamurthy, Anupama; Bowman, Andrew; Shen, Chengyong; Li, Lei; Xiong, Wen-cheng; Mei, Lin

    2014-10-15

    The neuromuscular junction (NMJ) is a synapse between motor neurons and skeletal muscle fibers, and is critical for control of muscle contraction. Its formation requires neuronal agrin that acts by binding to LRP4 to stimulate MuSK. Mutations have been identified in agrin, MuSK, and LRP4 in patients with congenital myasthenic syndrome, and patients with myasthenia gravis develop antibodies against agrin, LRP4, and MuSK. However, it remains unclear whether the agrin signaling pathway is critical for NMJ maintenance because null mutation of any of the three genes is perinatal lethal. In this study, we generated imKO mice, a mutant strain whose LRP4 gene can be deleted in muscles by doxycycline (Dox) treatment. Ablation of the LRP4 gene in adult muscle enabled studies of its role in NMJ maintenance. We demonstrate that Dox treatment of P30 mice reduced muscle strength and compound muscle action potentials. AChR clusters became fragmented with diminished junctional folds and synaptic vesicles. The amplitude and frequency of miniature endplate potentials were reduced, indicating impaired neuromuscular transmission and providing cellular mechanisms of adult LRP4 deficiency. We showed that LRP4 ablation led to the loss of synaptic agrin and the 90 kDa fragments, which occurred ahead of other prejunctional and postjunctional components, suggesting that LRP4 may regulate the stability of synaptic agrin. These observations demonstrate that LRP4 is essential for maintaining the structural and functional integrity of the NMJ and that loss of muscle LRP4 in adulthood alone is sufficient to cause myasthenic symptoms. PMID:25319686

  7. Caffeine ingestion reverses the circadian rhythm effects on neuromuscular performance in highly resistance-trained men.

    Directory of Open Access Journals (Sweden)

    Ricardo Mora-Rodríguez

    Full Text Available PURPOSE: To investigate whether caffeine ingestion counteracts the morning reduction in neuromuscular performance associated with the circadian rhythm pattern. METHODS: Twelve highly resistance-trained men underwent a battery of neuromuscular tests under three different conditions; i morning (10:00 a.m. with caffeine ingestion (i.e., 3 mg kg(-1; AM(CAFF trial; ii morning (10:00 a.m. with placebo ingestion (AM(PLAC trial; and iii afternoon (18:00 p.m. with placebo ingestion (PM(PLAC trial. A randomized, double-blind, crossover, placebo controlled experimental design was used, with all subjects serving as their own controls. The neuromuscular test battery consisted in the measurement of bar displacement velocity during free-weight full-squat (SQ and bench press (BP exercises against loads that elicit maximum strength (75% 1RM load and muscle power adaptations (1 m s(-1 load. Isometric maximum voluntary contraction (MVC(LEG and isometric electrically evoked strength of the right knee (EVOK(LEG were measured to identify caffeine's action mechanisms. Steroid hormone levels (serum testosterone, cortisol and growth hormone were evaluated at the beginning of each trial (PRE. In addition, plasma norepinephrine (NE and epinephrine were measured PRE and at the end of each trial following a standardized intense (85% 1RM 6 repetitions bout of SQ (POST. RESULTS: In the PM(PLAC trial, dynamic muscle strength and power output were significantly enhanced compared with AM(PLAC treatment (3.0%-7.5%; p≤0.05. During AM(CAFF trial, muscle strength and power output increased above AM(PLAC levels (4.6%-5.7%; p≤0.05 except for BP velocity with 1 m s(-1 load (p = 0.06. During AM(CAFF, EVOK(LEG and NE (a surrogate of maximal muscle sympathetic nerve activation were increased above AM(PLAC trial (14.6% and 96.8% respectively; p≤0.05. CONCLUSIONS: These results indicate that caffeine ingestion reverses the morning neuromuscular declines in highly resistance

  8. Neuromuscular disruption with ultrashort electrical pulses

    Science.gov (United States)

    Pakhomov, Andrei; Kolb, Juergen F.; Joshi, Ravindra P.; Schoenbach, Karl H.; Dayton, Thomas; Comeaux, James; Ashmore, John; Beason, Charles

    2006-05-01

    Experimental studies on single cells have shown that application of pulsed voltages, with submicrosecond pulse duration and an electric field on the order of 10 kV/cm, causes sudden alterations in the intracellular free calcium concentration, followed by immobilization of the cell. In order to examine electrical stimulation and incapacitation with such ultrashort pulses, experiments on anesthetized rats have been performed. The effect of single, 450 nanosecond monopolar pulses have been compared with that of single pulses with multi-microsecond duration (TASER pulses). Two conditions were explored: 1. the ability to elicit a muscle twitch, and, 2. the ability to suppress voluntary movement by using nanosecond pulses. The second condition is relevant for neuromuscular incapacitation. The preliminary results indicate that for stimulation microsecond pulses are advantageous over nanosecond pulses, whereas for incapacitation, the opposite seems to apply. The stimulation effects seem to scale with electrical charge, whereas the disruption effects don't follow a simple scaling law. The increase in intensity (time of incapacitation) for a given pulse duration, is increasing with electrical energy, but is more efficient for nanosecond than for microsecond pulses. This indicates different cellular mechanisms for incapacitation, most likely subcellular processes, which have been shown to become increasingly important when the pulse duration is shortened into the nanosecond range. If further studies can confirm these initial results, consequences of reduced pulse duration are a reduction in weight and volume of the pulse delivery system, and likely, because of the lower required energy for neuromuscular incapacitation, reduced safety risks.

  9. Mechanical engineers' handbook, design, instrumentation, and controls

    CERN Document Server

    Kutz, Myer

    2015-01-01

    Full coverage of electronics, MEMS, and instrumentation andcontrol in mechanical engineering This second volume of Mechanical Engineers' Handbookcovers electronics, MEMS, and instrumentation and control, givingyou accessible and in-depth access to the topics you'll encounterin the discipline: computer-aided design, product design formanufacturing and assembly, design optimization, total qualitymanagement in mechanical system design, reliability in themechanical design process for sustainability, life-cycle design,design for remanufacturing processes, signal processing, dataacquisition and dis

  10. Neuromuscular Dysfunction in Experimental Sepsis and Glutamine

    Science.gov (United States)

    Çankayalı, İlkin; Boyacılar, Özden; Demirağ, Kubilay; Uyar, Mehmet; Moral, Ali Reşat

    2016-01-01

    Background: Electrophysiological studies show that critical illness polyneuromyopathy appears in the early stage of sepsis before the manifestation of clinical findings. The metabolic response observed during sepsis causes glutamine to become a relative essential amino acid. Aims: We aimed to assess the changes in neuromuscular transmission in the early stage of sepsis after glutamine supplementation. Study Design: Animal experimentation. Methods: Twenty male Sprague-Dawley rats were randomized into two groups. Rats in both groups were given normal feeding for one week. In the study group, 1 g/kg/day glutamine was added to normal feeding by feeding tube for one week. Cecal ligation and perforation (CLP) surgery was performed at the end of one week. Before and 24 hours after CLP, compound muscle action potentials were recorded from the gastrocnemius muscle. Results: Latency measurements before and 24 hours after CLP were 0.68±0.05 ms and 0.80±0.09 ms in the control group and 0.69±0.07 ms and 0.73±0.07 ms in the study group (p<0.05). Conclusion: Since enteral glutamine prevented compound muscle action potentials (CMAP) latency prolongation in the early phase of sepsis, it was concluded that enteral glutamine replacement might be promising in the prevention of neuromuscular dysfunction in sepsis; however, further studies are required. PMID:27308070

  11. Neuromuscular dressing effects: a literature review

    Directory of Open Access Journals (Sweden)

    Calero PA

    2012-05-01

    Full Text Available The kinesio taping is a technique that was created in 1979 by Doctor Kenzo Kase I’m looking through it that could generate a new therapeutic option to control pain, improve athletic performance and reduce the impact of musculoskeletal disorders. From the Sydney 2000 Olympic Games, this technique as a therapeutic alternative PTO and is composed of health professionals in the field of sport and physical rehabilitation.Objetive: This article aims to identify theoretical approaches on the bandage neuromuscular. Material and methods: held today, for which conducted a literature search of databases such as como Proquest, Ovid, Cochraine, PEDro, Journal of Orthopedic and Sports Physical, Sciencedirect, Pubmed y Literatura Latinoamericana y del Caribe en Ciencias de la Salud (Lilacs.The paper proposes a scheme of contextualization of the current landscape of the use and effects of kinesio taping in the management of different pathologies of the musculo-skeletal system in sports. Conclusion: it is concluded that currently many health professionals, and take the neuromuscular bandage a good therapeutic option in the management of diseases affecting the human body is investigated and every day more about the subject, which makes these new therapeutic methods to acquire a scientific value and transcends knowledge.

  12. Tests of gastric neuromuscular function.

    Science.gov (United States)

    Parkman, Henry P; Jones, Michael P

    2009-05-01

    Tests of gastric neuromuscular function are used to evaluate patients with symptoms referable to the upper digestive tract. These symptoms can be associated with alterations in the rates of gastric emptying, impaired accommodation, heightened gastric sensation, or alterations in gastric myoelectrical function and contractility. Management of gastric neuromuscular disorders requires an understanding of pathophysiology and treatment options as well as the appropriate use and interpretation of diagnostic tests. These tests include measures of gastric emptying; contractility; electrical activity; regional gastric motility of the fundus, antrum, and pylorus; and tests of sensation and compliance. Tests are also being developed to improve our understanding of the afferent sensory pathways from the stomach to the central nervous system that mediate gastric sensation in health and gastric disorders. This article reviews tests of gastric function and provides a basic description of the tests, the methodologies behind them, descriptions of the physiology that they assess, and their clinical utility. PMID:19293005

  13. Noise control mechanisms of inside aircraft

    Science.gov (United States)

    Zverev, A. Ya.

    2016-07-01

    World trends in the development of methods and approaches to noise reduction in aircraft cabins are reviewed. The paper discusses the mechanisms of passive and active noise and vibration control, application of "smart" and innovative materials, new approaches to creating all fuselage-design elements, and other promising directions of noise control inside aircraft.

  14. Identification and Control of Mechanical Systems

    Science.gov (United States)

    Juang, Jer-Nan; Phan, Minh Q.

    2001-08-01

    The control of vibrating systems is a significant issue in the design of aircraft, spacecraft, bridges, and high-rise buildings. This book discusses the control of vibrating systems, integrating structural dynamics, vibration analysis, modern control, and system identification. By integrating these subjects engineers will need only one book, rather than several texts or courses, to solve vibration control problems. The authors cover key developments in aerospace control and identification theory, including virtual passive control, observer and state-space identification, and data-based controller synthesis. They address many practical issues and applications, and show examples of how various methods are applied to real systems. Some methods show the close integration of system identification and control theory from the state-space perspective, rather than from the traditional input-output model perspective of adaptive control. This text will be useful for advanced undergraduate and beginning graduate students in aerospace, mechanical, and civil engineering, as well as for practicing engineers.

  15. Dengue-associated neuromuscular complications

    OpenAIRE

    Ravindra Kumar Garg; Hardeep Singh Malhotra; Amita Jain; Kiran Preet Malhotra

    2015-01-01

    Dengue is associated with many neurological dysfunctions. Up to 4% of dengue patients may develop neuromuscular complications. Muscle involvement can manifest with myalgias, myositis, rhabdomyolysis and hypokalemic paralysis. Diffuse myalgia is the most characteristic neurological symptom of dengue fever. Dengue-associated myositis can be of varying severity ranging from self-limiting muscle involvement to severe dengue myositis. Dengue-associated hypokalemic paralysis often has a rapidly evo...

  16. Exercise therapy and other types of physical therapy for patients with neuromuscular diseases: a systematic review.

    NARCIS (Netherlands)

    Cup, E.H.C.; Pieterse, A.J.; Broek-Pastoor, J.M. Ten; Munneke, M.; Engelen, B.G.M. van; Hendricks, H.T.; Wilt, G.J. van der; Oostendorp, R.A.B.

    2007-01-01

    OBJECTIVE: To summarize and critically appraise the available evidence on exercise therapy and other types of physical therapies for patients with neuromuscular diseases (NMD). DATA SOURCES: Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, Medline, CINAHL,

  17. The undesirable effects of neuromuscular blocking drugs

    DEFF Research Database (Denmark)

    Claudius, C; Garvey, L H; Viby-Mogensen, J

    2009-01-01

    Neuromuscular blocking drugs are designed to bind to the nicotinic receptor at the neuromuscular junction. However, they also interact with other acetylcholine receptors in the body. Binding to these receptors causes adverse effects that vary with the specificity for the cholinergic receptor...... in question. Moreover, all neuromuscular blocking drugs may cause hypersensitivity reactions. Often the symptoms are mild and self-limiting but massive histamine release can cause systematic reactions with circulatory and respiratory symptoms and signs. At the end of anaesthesia, no residual effect...... of a neuromuscular blocking drug should be present. However, the huge variability in response to neuromuscular blocking drugs makes it impossible to predict which patient will suffer postoperative residual curarization. This article discusses the undesirable effects of the currently available neuromuscular blocking...

  18. Neuronal mechanisms of feedback postural control

    OpenAIRE

    Hsu, Li-Ju

    2015-01-01

    Different species maintain a basic body posture due to the activity of the postural control system. An efficient control of the body orientation, as well as the body configuration, is important for standing and during locomotion. A general goal of the present study was to analyze neuronal feedback mechanisms contributing to stabilization of the trunk orientation in space, as well as those controlling the body configuration. Two animal models of different complexity, the lamprey...

  19. Wrist range of motion and motion frequency during toy and game play with a joint-specific controller specially designed to provide neuromuscular therapy: A proof of concept study in typically developing children.

    Science.gov (United States)

    Crisco, Joseph J; Schwartz, Joel B; Wilcox, Bethany; Brideau, Holly; Basseches, Benjamin; Kerman, Karen

    2015-08-20

    Upper extremities affected by hemiplegic cerebral palsy (CP) and other neuromuscular disorders have been demonstrated to benefit from therapy, and the greater the duration of the therapy, the greater the benefit. A great motivator for participating in and extending the duration of therapy with children is play. Our focus is on active motion therapy of the wrist and forearm. In this study we examine the wrist motions associated with playing with two toys and three computer games controlled by a specially-designed play controller. Twenty children (ages 5-11) with no diagnosis of a muscular disorder were recruited. The play controller was fitted to the wrist and forearm of each child and used to measure and log wrist flexion and extension. Play activity and enjoyment were quantified by average wrist range of motion (ROM), motion frequency measures, and a discrete visual scale. We found significant differences in the average wrist ROM and motion frequency among the toys and games, yet there were no differences in the level of enjoyment across all toys and games, which was high. These findings indicate which toys and games may elicit the greater number of goal-directed movements, and lay the foundation for our long-term goal to develop and evaluate innovative motion-specific play controllers that are engaging rehabilitative devices for enhancing therapy and promoting neural plasticity and functional recovery in children with CP. PMID:25935686

  20. Degeneration of Neuromuscular Junction in Age and Dystrophy

    Directory of Open Access Journals (Sweden)

    Rüdiger eRudolf

    2014-05-01

    Full Text Available Functional denervation is a hallmark of aging sarcopenia as well as of muscular dystrophy. It is thought to be a major factor reducing skeletal muscle mass, particularly in the case of sarcopenia. Neuromuscular junctions serve as the interface between the nervous and skeletal muscular systems, and thus they may receive pathophysiological input of both pre- and postsynaptic origin. Consequently, neuromuscular junctions are good indicators of motor health on a systemic level. Indeed, upon sarcopenia and dystrophy, neuromuscular junctions morphologically deteriorate and exhibit altered characteristics of primary signaling molecules, such as nicotinic acetylcholine receptor and agrin. Since a remarkable reversibility of these changes can be observed by exercise, there is significant interest in understanding the molecular mechanisms underlying synaptic deterioration upon aging and dystrophy and how synapses are reset by the aforementioned treatments. Here, we review the literature that describes the phenomena observed at the neuromuscular junction in sarcopenic and dystrophic muscle as well as to how these alterations can be reversed and to what extent. In a second part, the current information about molecular machineries underlying these processes is reported.

  1. The clinical examination for neuromuscular disease.

    Science.gov (United States)

    Glass, Eric N; Kent, Marc

    2002-01-01

    Neuromuscular disease can present even the most astute clinician with a challenging diagnostic dilemma. This article focuses on the neuroanatomy and the historical, physical, and neurologic examination findings observed in many of the neuromuscular disorders affecting dogs and cats. In addition, some common laboratory tests and imaging modalities used in the diagnosis of neuromuscular disease, including routine radiography, computed tomography, and magnetic resonance imaging, are discussed. A brief discussion of sensory nerve disorders is also presented. PMID:11785724

  2. Comparison of effects of static, proprioceptive neuromuscular facilitation and Mulligan stretching on hip flexion range of motion: a randomized controlled trial.

    Science.gov (United States)

    Yıldırım, M S; Ozyurek, S; Tosun, Oç; Uzer, S; Gelecek, N

    2016-03-01

    The aim of this study was to compare the effects of static stretching, proprioceptive neuromuscular facilitation (PNF) stretching and Mulligan technique on hip flexion range of motion (ROM) in subjects with bilateral hamstring tightness. A total of 40 students (mean age: 21.5±1.3 years, mean body height: 172.8±8.2 cm, mean body mass index: 21.9±3.0 kg · m(-2)) with bilateral hamstring tightness were enrolled in this randomized trial, of whom 26 completed the study. Subjects were divided into 4 groups performing (I) typical static stretching, (II) PNF stretching, (III) Mulligan traction straight leg raise (TSLR) technique, (IV) no intervention. Hip flexion ROM was measured using a digital goniometer with the passive straight leg raise test before and after 4 weeks by two physiotherapists blinded to the groups. 52 extremities of 26 subjects were analyzed. Hip flexion ROM increased in all three intervention groups (p<0.05) but not in the no-intervention group after 4 weeks. A statistically significant change in initial-final assessment differences of hip flexion ROM was found between groups (p<0.001) in favour of PNF stretching and Mulligan TSLR technique in comparison to typical static stretching (p=0.016 and p=0.02, respectively). No significant difference was found between Mulligan TSLR technique and PNF stretching (p=0.920). The initial-final assessment difference of hip flexion ROM was similar in typical static stretching and no intervention (p=0.491). A 4-week stretching intervention is beneficial for increasing hip flexion ROM in bilateral hamstring tightness. However, PNF stretching and Mulligan TSLR technique are superior to typical static stretching. These two interventions can be alternatively used for stretching in hamstring tightness.

  3. Musculoskeletal complications of neuromuscular disease in children.

    Science.gov (United States)

    Driscoll, Sherilyn W; Skinner, Joline

    2008-02-01

    A wide variety of neuromuscular diseases affect children, including central nervous system disorders such as cerebral palsy and spinal cord injury; motor neuron disorders such as spinal muscular atrophy; peripheral nerve disorders such as Charcot-Marie-Tooth disease; neuromuscular junction disorders such as congenital myasthenia gravis; and muscle fiber disorders such as Duchenne's muscular dystrophy. Although the origins and clinical syndromes vary significantly, outcomes related to musculoskeletal complications are often shared. The most frequently encountered musculoskeletal complications of neuromuscular disorders in children are scoliosis, bony rotational deformities, and hip dysplasia. Management is often challenging to those who work with children who have neuromuscular disorders. PMID:18194756

  4. Damage-mitigating control of mechanical systems

    Science.gov (United States)

    Holmes, Michael S.

    Damage-Mitigating Control is a field of research involving the integration of two distinct disciplines: Systems Sciences and Mechanics of Materials. This dissertation presents a feedback control architecture for mechanical systems to achieve a tradeoff between dynamic performance and structural durability of critical plant components. The proposed damage-mitigating control system has a two-tier structure: (i) A lower-level linear output feedback controller for plant output tracking and stability robustness over a specified operating range; and (ii) An upper-level nonlinear feedback controller which takes advantage of the real-time information generated by a physics-based model of material damage. The advantages and disadvantages of various methods available for the design of linear tracking controllers are discussed. A robust sampled-data Hsbinfty controller is designed for a reusable rocket engine, similar to the Space Shuttle Main Engine, based on a 2-input/2-output, 20-state model. The mu-synthesis technique is used to design a robust sampled-data controller for a commercial-scale fossil-fueled power plant based on a 4-input/4-output, 27-state model. A procedure for the design of damage-mitigating linear tracking controllers is also presented. The concept of fuzzy control is used to synthesize upper-level nonlinear feedback controllers based on real-time damage information. Damage-mitigating controllers are designed for the reusable rocket engine and the fossil-fueled power plant. A major advantage of using the fuzzy method for damage-mitigating controller design is that the controller can be synthesized without directly dealing with the inherent nonlinearities of the damage model. Simulation results for the reusable rocket engine and the fossil-fueled power plant suggest that the fuzzy method of damage mitigation is a practical way to design damage controllers for mechanical systems. The damage controller parameter optimization method is presented as an

  5. Facial rehabilitation: a neuromuscular reeducation, patient-centered approach.

    Science.gov (United States)

    Vanswearingen, Jessie

    2008-05-01

    Individuals with facial paralysis and distorted facial expressions and movements secondary to a facial neuromotor disorder experience substantial physical, psychological, and social disability. Previously, facial rehabilitation has not been widely available or considered to be of much benefit. An emerging rehabilitation science of neuromuscular reeducation and evidence for the efficacy of facial neuromuscular reeducation, a process of facilitating the return of intended facial movement patterns and eliminating unwanted patterns of facial movement and expression, may provide patients with disorders of facial paralysis or facial movement control opportunity for the recovery of facial movement and function. We provide a brief overview of the scientific rationale for facial neuromuscular reeducation in the structure and function of the facial neuromotor system, the neuropsychology of facial expression, and relations among expressions, movement, and emotion. The primary purpose is to describe principles of neuromuscular reeducation, assessment and outcome measures, approach to treatment, the process, including surface-electromyographic biofeedback as an adjunct to reeducation, and the goal of enhancing the recovery of facial expression and function in a patient-centered approach to facial rehabilitation.

  6. Contribución del soporte nutricional al tratamiento de las alteraciones neuro-musculares del paciente crítico Contribution of nutritional support to treatment neuromuscular impairments of critically ill patients

    Directory of Open Access Journals (Sweden)

    J. C. Montejo González

    2006-05-01

    Full Text Available Las alteraciones neuromusculares que tienen lugar en el paciente crítico han sido atribuidas a factores como la situación séptica, la liberación de mediadores inflamatorioso el empleo de fármacos que afectan desfavorablemente a la función neuro-muscular. El papel de factores metabólicos y nutricionales en el desarrollo de esta patología ha recibido poca atención. En la actualidad, el empleo de protocolos de control intensivo de la glucemia podría tener gran interés en la prevención de las alteraciones neuro-musculares de los pacientes críticos. Los mecanismos exactos de la implicación de la hiperglucemia en esta patología son, todavía, desconocidos, aunque la evidencia de los datos procedentes de la investigación es importante. La miopatía caquectizante (atrofia muscular tiene lugar de manera habitual como consecuencia de los cambios obligados por la respuesta metabólica al estrés. El efecto del aporte de nutrientes sobre la ganancia de masa muscular es muy limitado, por lo que deben estudiarse otras acciones dirigidas a recuperar, de manera más rápida, la masa muscular perdida. Deben evitarse pautas agresivas de renutrición con objeto de prevenir el síndrome de realimentación y el consiguiente mayor deterioro de la función muscular. El aporte de substratos específicos, como la glutamina, podría tener un efecto beneficioso en la recuperación de las alteraciones neuro-musculares del paciente crítico. No obstante, no existen aún datos para justificar su empleo si el único objetivo es la recuperación de la función neuro-muscular.Neuromuscular impairments occurring in the critically ill patient have been attributed to factors such as sepsis, release of inflammatory mediators, or the use of drugs unfavorably affecting neuromuscular function. The role of metabolic and nutritional factors in the development of this condition has received little attention. Currently, the use of protocols of intensive glycemia monitoring

  7. Nonsmooth mechanics models, dynamics and control

    CERN Document Server

    Brogliato, Bernard

    2016-01-01

    Now in its third edition, this standard reference is a comprehensive treatment of nonsmooth mechanical systems refocused to give more prominence to control and modelling. It covers Lagrangian and Newton–Euler systems, detailing mathematical tools such as convex analysis and complementarity theory. The ways in which nonsmooth mechanics influence and are influenced by well-posedness analysis, numerical analysis and simulation, modelling and control are explained. Contact/impact laws, stability theory and trajectory-tracking control are given in-depth exposition connected by a framework formed from complementarity systems and measure-differential inclusions. Links are established with electrical circuits with set-valued nonsmooth elements and with other nonsmooth dynamical systems like impulsive and piecewise linear systems. Nonsmooth Mechanics (third edition) has been substantially rewritten, edited and updated to account for the significant body of results that have emerged in the twenty-first century—incl...

  8. Early rehabilitation using a passive cycle ergometer on muscle morphology in mechanically ventilated critically ill patients in the Intensive Care Unit (MoVe-ICU study): study protocol for a randomized controlled trial

    OpenAIRE

    dos Santos, Laura Jurema; de Aguiar Lemos, Fernando; Bianchi, Tanara; Sachetti, Amanda; Acqua, Ana Maria Dall’; da Silva Naue, Wagner; Dias, Alexandre Simões; Vieira, Silvia Regina Rios

    2015-01-01

    Background Patients in Intensive Care Units (ICU) are often exposed to prolonged immobilization which, in turn, plays an important role in neuromuscular complications. Exercise with a cycle ergometer is a treatment option that can be used to improve the rehabilitation of patients on mechanical ventilation (MV) in order to minimize the harmful effects of immobility. Methods/Design A single-blind randomized controlled trial (the MoVe ICU study) will be conducted to evaluate and compare the effe...

  9. Development of a Neuromuscular Junction Model on Surfaces Modified by Plasma Polymerization

    OpenAIRE

    E. Zuñiga-Aguilar; R. Godínez; O. Ramírez-Fernández; Morales, J.; R. Olayo

    2013-01-01

    The aim of this work is to implement a biological model of neuromuscular junctions to study the mechanisms involved in intra and inter cellular processes using cell co-cultures. To optimize growth and development of the neuromuscular junction, cells were seeded on plasma polymerized pyrrole which has proven suitable for other types of cell cultures. The cell lines used were motor neuron NG108-15 and skeletal muscle C2C12. Cells were evaluated according to their morphology and elect...

  10. Reactive Balance Control in Response to Perturbation in Unilateral Stance: Interaction Effects of Direction, Displacement and Velocity on Compensatory Neuromuscular and Kinematic Responses.

    Directory of Open Access Journals (Sweden)

    Kathrin Freyler

    Full Text Available Unexpected sudden perturbations challenge postural equilibrium and require reactive compensation. This study aimed to assess interaction effects of the direction, displacement and velocity of perturbations on electromyographic (EMG activity, centre of pressure (COP displacement and joint kinematics to detect neuromuscular characteristics (phasic and segmental and kinematic strategies of compensatory reactions in an unilateral balance paradigm. In 20 subjects, COP displacement and velocity, ankle, knee and hip joint excursions and EMG during short (SLR, medium (MLR and long latency response (LLR of four shank and five thigh muscles were analysed during random surface translations varying in direction (anterior-posterior (sagittal plane, medial-lateral (frontal plane, displacement (2 vs. 3 cm and velocity (0.11 vs. 0.18 m/s of perturbation when balancing on one leg on a movable platform. Phases: SLR and MLR were scaled to increased velocity (P<0.05; LLR was scaled to increased displacement (P<0.05. Segments: phasic interrelationships were accompanied by segmental distinctions: distal muscles were used for fast compensation in SLR (P<0.05 and proximal muscles to stabilise in LLR (P<0.05. Kinematics: ankle joints compensated for both increasing displacement and velocity in all directions (P<0.05, whereas knee joint deflections were particularly sensitive to increasing displacement in the sagittal (P<0.05 and hip joint deflections to increasing velocity in the frontal plane (P<0.05. COP measures increased with increasing perturbation velocity and displacement (P<0.05. Interaction effects indicate that compensatory responses are based on complex processes, including different postural strategies characterised by phasic and segmental specifications, precisely adjusted to the type of balance disturbance. To regain balance after surface translation, muscles of the distal segment govern the quick regain of equilibrium; the muscles of the proximal limb

  11. Notions of controllability for quantum mechanical systems

    CERN Document Server

    Albertini, F

    2001-01-01

    In this paper, we define four different notions of controllability of physical interest for multilevel quantum mechanical systems. These notions involve the possibility of driving the evolution operator as well as the state of the system. We establish the connections among these different notions as well as methods to verify controllability. The paper also contains results on the relation between the controllability in arbitrary small time of a system varying on a compact transformation Lie group and the corresponding system on the associated homogeneous space. As an application, we prove that, for the system of two interacting spin 1/2 particles, not every state transfer can be obtained in arbitrary small time.

  12. Electrophysiological study in neuromuscular junction disorders

    OpenAIRE

    Cherian, Ajith; Baheti, Neeraj N.; Iype, Thomas

    2013-01-01

    This review is on ultrastructure and subcellular physiology at normal and abnormal neuromuscular junctions. The clinical and electrophysiological findings in myasthenia gravis, Lambert-Eaton myasthenic syndrome (LEMS), congenital myasthenic syndromes, and botulinum intoxication are discussed. Single fiber electromyography (SFEMG) helps to explain the basis of testing neuromuscular junction function by repetitive nerve stimulation (RNS). SFEMG requires skill and patience and its availability i...

  13. Diagnostic NGS for Severe Neuromuscular Disorders

    OpenAIRE

    Radhika Dhamija; Chelsea Chambers

    2015-01-01

    Investigators from the University of Western Australia report the diagnostic yield of performing next generation sequencing (NGS; whole exome and targeted capture of 277 neuromuscular genes) in a heterogenous cohort of patients with neuromuscular disorders (NMD) presenting at or before birth.

  14. Common complications of pediatric neuromuscular disorders.

    Science.gov (United States)

    Skalsky, Andrew J; Dalal, Pritha B

    2015-02-01

    Children with pediatric neuromuscular disorders experience common complications, primarily due to immobility and weakness. Musculoskeletal complications include hip dysplasia with associated hip subluxation or dislocation, neuromuscular scoliosis, and osteoporosis and resulting fractures. Constipation, gastroesophageal reflux, and obesity and malnutrition are commonly experienced gastrointestinal complications. Disordered sleep also is frequently observed, which affects both patients and caregivers. PMID:25479776

  15. Computed tomography of skeletal muscles in neuromuscular disease

    Energy Technology Data Exchange (ETDEWEB)

    Rodiek, S.O.; Kuether, G.

    1985-06-01

    CT-documentation of skeletal muscular lesions caused by neuromuscular diseases implies an essential contribution to conventional techniques in the macroscopic field. Size, distribution and degree of lesions as well as compensatory mechanisms are proved thereby. We report about the different effects on muscle appearance referring to 106 patients of our own experience in amyotrophic lateral sclerosis, spinal muscular atrophy, poliomyelitis, polyradiculitis, polyneuropathy as well as peripheral traumatic nerve lesions.

  16. Intravenous immunoglobulin in the treatment of autoimmune neuromuscular diseases: present status and practical therapeutic guidelines.

    Science.gov (United States)

    Dalakas, M C

    1999-11-01

    This review summarizes the current status of intravenous immunoglobulin (IVIg) in the treatment of autoimmune neuromuscular disorders and the possible mechanisms of action of the drug based on work in vivo, in vitro, and in animal models. Supply of idiotypic antibodies, suppression of antibody production, or acceleration of catabolism of immunoglobulin G (IgG) are relevant in explaining the efficacy of IVIg in myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), and antibody-mediated neuropathies. Suppression of pathogenic cytokines has putative relevance in inflammatory myopathies and demyelinating neuropathies. Inhibition of complement binding and prevention of membranolytic attack complex (MAC) formation are relevant in dermatomyositis (DM), Guillain-Barré syndrome (GBS), and MG. Modulation of Fc receptors or T-cell function is relevant in chronic inflammatory demyelinating polyneuropathy (CIDP), GBS, and inflammatory myopathies. The clinical efficacy of IVIg, based on controlled clinical trials conducted in patients with GBS, CIDP, multifocal motor neuropathy (MMN), DM, MG, LEMS, paraproteinemic IgM anti-myelin-associated glycoprotein (anti-MAG) demyelinating polyneuropathies, and inclusion body myositis is summarized and practical issues related to each disorder are addressed. The present role of IVIg therapy in other disorders based on small controlled or uncontrolled trials is also summarized. Finally, safety issues, risk factors, adverse reactions, spurious results or serological tests, and practical guidelines associated with the administration of IVIg in the treatment of neuromuscular disorders are presented.

  17. Respiratory motor training and neuromuscular plasticity in patients with chronic obstructive pulmonary disease: A pilot study.

    Science.gov (United States)

    Ovechkin, Alexander V; Sayenko, Dimitry G; Ovechkina, Elena N; Aslan, Sevda C; Pitts, Teresa; Folz, Rodney J

    2016-07-15

    The objective of this study was to examine the feasibility of a full-scale investigation of the neurophysiological mechanisms of COPD-induced respiratory neuromuscular control deficits. Characterization of respiratory single- and multi-muscle activation patterns using surface electromyography (sEMG) were assessed along with functional measures at baseline and following 21±2 (mean±SD) sessions of respiratory motor training (RMT) performed during a one-month period in four patients with GOLD stage II or III COPD. Pre-training, the individuals with COPD showed significantly increased (p<0.05) overall respiratory muscle activity and disorganized multi-muscle activation patterns in association with lowered spirometrical measures and decreased fast- and slow-twitch fiber activity as compared to healthy controls (N=4). Following RMT, functional and respiratory sEMG activation outcomes during quite breathing and forced expiratory efforts were improved suggesting that functional improvements, induced by task-specific RMT, are evidence respiratory neuromuscular networks re-organization. PMID:27137413

  18. Fully Mechanically Controlled Automated Electron Microscopic Tomography

    Science.gov (United States)

    Liu, Jinxin; Li, Hongchang; Zhang, Lei; Rames, Matthew; Zhang, Meng; Yu, Yadong; Peng, Bo; Celis, César Díaz; Xu, April; Zou, Qin; Yang, Xu; Chen, Xuefeng; Ren, Gang

    2016-07-01

    Knowledge of three-dimensional (3D) structures of each individual particles of asymmetric and flexible proteins is essential in understanding those proteins’ functions; but their structures are difficult to determine. Electron tomography (ET) provides a tool for imaging a single and unique biological object from a series of tilted angles, but it is challenging to image a single protein for three-dimensional (3D) reconstruction due to the imperfect mechanical control capability of the specimen goniometer under both a medium to high magnification (approximately 50,000–160,000×) and an optimized beam coherence condition. Here, we report a fully mechanical control method for automating ET data acquisition without using beam tilt/shift processes. This method could reduce the accumulation of beam tilt/shift that used to compensate the error from the mechanical control, but downgraded the beam coherence. Our method was developed by minimizing the error of the target object center during the tilting process through a closed-loop proportional-integral (PI) control algorithm. The validations by both negative staining (NS) and cryo-electron microscopy (cryo-EM) suggest that this method has a comparable capability to other ET methods in tracking target proteins while maintaining optimized beam coherence conditions for imaging.

  19. Electrochemical biofilm control: mechanism of action

    OpenAIRE

    Istanbullu, Ozlem; Babauta, Jerome; Nguyen, Hung Duc; Beyenal, Haluk

    2012-01-01

    Although it has been previously demonstrated that an electrical current can be used to control biofilm growth on metal surfaces, the literature results are conflicting and there is no accepted mechanism of action. One of the suggested mechanisms is the production of hydrogen peroxide (H2O2) on metal surfaces. However, there are literature studies in which H2O2 could not be detected in the bulk solution. This is most likely because H2O2 was produced at a low concentration near the surface and ...

  20. PICU EXTUBATION FAILURE: THE ROLE OF NEUROMUSCULAR DISORDERS

    Directory of Open Access Journals (Sweden)

    N. Billan MD

    2009-01-01

    Full Text Available ObjectiveNeuromuscular disorders (diseases of the motor unit, can cause respiratory problems such as impaired cough reflex, chest deformity, recurrent pneumonia and acute respiratory failure; these are the worst most common complications of these diseases and the leading cause of death in such patients (1, 2. Their management hence, very often, entails admission to the Pediatric Intensive Care Unit (PICU (3,4 and during this phase, endotracheal intubation is almost always necessary, to maintain the patency of airways and to apply Positive Pressure Ventilation (PPV. However, endotracheal intubation is always temporary, and its success or failure depends on the timely decision of its termination to restore the normal respiration or to avoid the risk of recurring respiratory failure (5, 6. We designed this study to evaluate the role of neuromuscular disorders in causing extubation failure as compared to that of other risk factors.Materials & MethodsIn an analytical cross-sectional study, the risk factors of reintubation and duration of mechanical ventilation in two groups of 30 patients each, was compared, the first successful extubation and the second with extubation failure.ResultsNeuromuscular disorders (including Spinal Muscular Atrophy, Guillain- Barre' Syndrome, Congenital Myopathies and Muscular Dystrophies were the main underlying diseases in extubation-failure group (P= 0.0002. Hypercapnia (PaCO2>50mmHg was shown to be the most common cause of both the first intubation (P=0.001 and reintubation (P=0.004 in the group of patients who failed extubation. The mean duration of intubation and mechanical ventilation was longer in patients with neuromuscular disorders who had extubation failure (P= 0.01.ConclusionThis study showed that, as underlying problems, neuromuscular disorders are the most common causes of prolonged intubation which defeat weaning from the ventilator and result in reintubation by inducing hypercapnia. Therefore the weaning

  1. Control mechanisms for Nordic ship emissions

    Energy Technology Data Exchange (ETDEWEB)

    Martinsen, K. [DNV, Oslo (Norway); Torvanger, A. [Cicero, Oslo (Norway)

    2013-04-15

    Shipping today operates under a complex set of international and domestic regulations. However, the environmental regulations have lagged behind those of other industries. This situation is now changing quite dramatically. The increased focus on environmental issues, combined with the growing realisation of the actual pollution burden imposed by shipping, has led to an upsurge in both international and national regulations. Some are ready and will enter into force in the near future, while others are still being developed. On behalf of the Nordic Council of Ministers DNV has carried out a study on possible control mechanisms for Nordic ship emission. The aim is to assess the baseline shipping emissions and reduction potential and the possible controlling mechanisms (both incentives and regulations) available for reducing the emissions to air from shipping within the Nordic region. (Author)

  2. LRP4 Is Critical for Neuromuscular Junction Maintenance

    OpenAIRE

    Barik, Arnab; Lu, Yisheng; Sathyamurthy, Anupama; Bowman, Andrew; Shen, Chengyong; Li, Lei(Beijing Institute of Petrochemical Technology, Beijing, 102617, People's Republic of China); Xiong, Wen-Cheng; Mei, Lin

    2014-01-01

    The neuromuscular junction (NMJ) is a synapse between motor neurons and skeletal muscle fibers, and is critical for control of muscle contraction. Its formation requires neuronal agrin that acts by binding to LRP4 to stimulate MuSK. Mutations have been identified in agrin, MuSK, and LRP4 in patients with congenital myasthenic syndrome, and patients with myasthenia gravis develop antibodies against agrin, LRP4, and MuSK. However, it remains unclear whether the agrin signaling pathway is critic...

  3. Control mechanisms for assuring better IS quality:

    OpenAIRE

    Pivka, Marjan

    1998-01-01

    The software domain is faced with a number of quality assurance and process improvement models. Business managers are under pressure from many different kinds of assessments for their operations, products and services. Accounting departments are audited by financial auditors. What about information systems? Do we have a universal model on how to achieve required IS quality? This paper deals with the definition of IS quality and the influence of different control mechanisms on IS. The results ...

  4. Concurrency Control Mechanism of Complex Objects

    Institute of Scientific and Technical Information of China (English)

    徐庆云; 王能斌

    1992-01-01

    A complex object is an abstraction and description of a complex entity of the real world.Many applications in such domains as CIMS,CAD and OA define and manipulate a complex object as a single unit.In this paper,a definition of the model of complex objects is given,and the concurrency control mechanism of complex objects in WHYMX object-oriented database system is described.

  5. Early appearance and possible roles of non-neuromuscular cholinesterases.

    Directory of Open Access Journals (Sweden)

    Carla eFalugi

    2012-04-01

    Full Text Available The biological function of the cholinesterase (ChE enzymes is well known and has been studied since the beginning of the XXth century; in particular, acetylcholinesterase (AChE, E.C. 3.1.1.7 is an enzyme playing a key role in the modulation of neuromuscular impulse transmission. However, in the past decades, there has been increasing interest concerning its role in regulating non-neuromuscular cell-to-cell interactions mediated by intracellular ion concentration changes, like the ones occurring during gamete interaction and embryonic development. An understanding of the mechanisms of the cholinergic regulation of these events can help us foresee the possible impact on environmental and human health, including gamete efficiency and possible teratogenic effects on different models, and help elucidate the extent to which exposure to ChE inhibitors may affect human health.

  6. New Interference Mechanism Controls Ultracold Chemistry

    Science.gov (United States)

    Kendrick, Brian K.; Hazra, Jisha; Balakrishnan, N.

    2016-05-01

    A newly discovered interference mechanism has been shown to control the outcome of ultracold chemical reactions. The mechanism originates from the unique properties associated with ultracold collisions, namely: (1) isotropic (s-wave) scattering and (2) an effective quantization of the scattering phase shift (which originates from the bound state structure of the molecule). These two properties can lead to maximum constructive or destructive interference between two interfering reaction pathways (such as exchange and non-exchange in systems with two or more identical nuclei). If the molecular system exhibits a conical intersection, then the associated geometric phase is shown to act as a ``quantum switch'' which can turn the reactivity on or off. Reaction rate coefficients for the O + OH --> H + O2 and H + H2, reactions are presented which explicitly demonstrate the effect. Experimentalists might exploit this new mechanism to control ultracold reactions by the application of external electric or magnetic fields or by the selection of a particular nuclear spin state. This work was supported in part by the LDRD program (Grant No. 20140309ER) at LANL (B.K.) and by NSF Grant PHY-1505557 (N.B.) and ARO MURI Grant No. W911NF-12-1-0476 (N.B.).

  7. Theory of multichannel magnetic stimulation: toward functional neuromuscular rehabilitation.

    Science.gov (United States)

    Ruohonen, J; Ravazzani, P; Grandori, F; Ilmoniemi, R J

    1999-06-01

    Human excitable cells can be stimulated noninvasively with externally applied time-varying electromagnetic fields. The stimulation can be achieved either by directly driving current into the tissue (electrical stimulation) or by means of electro-magnetic induction (magnetic stimulation). While the electrical stimulation of the peripheral neuromuscular system has many beneficial applications, peripheral magnetic stimulation has so far only a few. This paper analyzes theoretically the use of multiple magnetic stimulation coils to better control the excitation and also to eventually mimic electrical stimulation. Multiple coils allow electronic spatial adjustment of the shape and location of the stimulus without moving the coils. The new properties may enable unforeseen uses for peripheral magnetic stimulation, e.g., in rehabilitation of patients with neuromuscular impairment. PMID:10356871

  8. Bayesian analysis of the kinetics of quantal transmitter secretion at the neuromuscular junction.

    Science.gov (United States)

    Saveliev, Anatoly; Khuzakhmetova, Venera; Samigullin, Dmitry; Skorinkin, Andrey; Kovyazina, Irina; Nikolsky, Eugeny; Bukharaeva, Ellya

    2015-10-01

    The timing of transmitter release from nerve endings is considered nowadays as one of the factors determining the plasticity and efficacy of synaptic transmission. In the neuromuscular junction, the moments of release of individual acetylcholine quanta are related to the synaptic delays of uniquantal endplate currents recorded under conditions of lowered extracellular calcium. Using Bayesian modelling, we performed a statistical analysis of synaptic delays in mouse neuromuscular junction with different patterns of rhythmic nerve stimulation and when the entry of calcium ions into the nerve terminal was modified. We have obtained a statistical model of the release timing which is represented as the summation of two independent statistical distributions. The first of these is the exponentially modified Gaussian distribution. The mixture of normal and exponential components in this distribution can be interpreted as a two-stage mechanism of early and late periods of phasic synchronous secretion. The parameters of this distribution depend on both the stimulation frequency of the motor nerve and the calcium ions' entry conditions. The second distribution was modelled as quasi-uniform, with parameters independent of nerve stimulation frequency and calcium entry. Two different probability density functions for the distribution of synaptic delays suggest at least two independent processes controlling the time course of secretion, one of them potentially involving two stages. The relative contribution of these processes to the total number of mediator quanta released depends differently on the motor nerve stimulation pattern and on calcium ion entry into nerve endings. PMID:26129670

  9. Control mechanisms in mitochondrial oxidative phosphorylation

    Institute of Scientific and Technical Information of China (English)

    Jana Hroudová; Zdeněk Fi(s)ar

    2013-01-01

    Distribution and activity of mitochondria are key factors in neuronal development, synaptic plasticity and axogenesis. The majority of energy sources, necessary for cellular functions, originate from oxidative phosphorylation located in the inner mitochondrial membrane. The adenosine-5'- triphosphate production is regulated by many control mechanism–firstly by oxygen, substrate level, adenosine-5'-diphosphate level, mitochondrial membrane potential, and rate of coupling and proton leak. Recently, these mechanisms have been implemented by "second control mechanisms," such as reversible phosphorylation of the tricarboxylic acid cycle enzymes and electron transport chain complexes, allosteric inhibition of cytochrome c oxidase, thyroid hormones, effects of fatty acids and uncoupling proteins. Impaired function of mitochondria is implicated in many diseases ranging from mitochondrial myopathies to bipolar disorder and schizophrenia. Mitochondrial dysfunctions are usually related to the ability of mitochondria to generate adenosine-5'-triphosphate in response to energy demands. Large amounts of reactive oxygen species are released by defective mitochondria, similarly, decline of antioxidative enzyme activities (e.g. in the elderly) enhances reactive oxygen species production. We reviewed data concerning neuroplasticity, physiology, and control of mitochondrial oxidative phosphorylation and reactive oxygen species production.

  10. Evaluation of neuromuscular activity in patients with obstructive sleep apnea using chin surface electromyography of polysomnography

    Institute of Scientific and Technical Information of China (English)

    YIN Guo-ping; YE Jing-ying; HAN De-min; WANG Xiao-yi; ZHANG Yu-huan; LI Yan-ru

    2013-01-01

    Background It is believed that defects in upper airway neuromuscular control play a role in sleep apnea pathogenesis.Currently,there is no simple and non-invasive method for evaluating neuromuscular activity for the purpose of screening in patients with obstructive sleep apnea.This study was designed to assess the validity of chin surface electromyography of routine polysomnography in evaluating the neuromuscular activity of obstructive sleep apnea subjects and probe the neuromuscular contribution in the pathogenesis of the condition.Methods The chin surface electromyography of routine polysomnography during normal breathing and obstructive apnea were quantified in 36 male patients with obstructive sleep apnea.The change of chin surface electromyography from normal breathing to obstructive apnea was expressed as the percent compensated electromyography value,where the percent compensated electromyography value =(normal breath surface electromyography-apnea surface electromyography)/normal breath surface electromyography,and the percent compensated electromyography values among subjects were compared.The relationship between sleep apnea related parameters and the percent compensated electromyography value was examined.Results The percent compensated electromyography value of the subjects varied from 1% to 90% and had a significant positive correlation with apnea hypopnea index (R2=0.382,P <0.001).Conclusions Recording and analyzing chin surface electromyography by routine polysomnography is a valid way of screening the neuromuscular activity in patients with obstructive sleep apnea.The neuromuscular contribution is different among subjects with obstructive sleep apnea.

  11. Stance control knee mechanism for lower-limb support in hybrid neuroprosthesis

    Directory of Open Access Journals (Sweden)

    Curtis S. To, PhD

    2011-08-01

    Full Text Available A hydraulic stance control knee mechanism (SCKM was developed to fully support the knee against flexion during stance and allow uninhibited motion during swing for individuals with paraplegia using functional neuromuscular stimulation (FNS for gait assistance. The SCKM was optimized for maximum locking torque for body-weight support and minimum resistance when allowing for free knee motion. Ipsilateral and contralateral position and force feedback were used to control the SCKM. Through bench and nondisabled testing, the SCKM was shown to be capable of supporting up to 70 N-m, require no more than 13% of the torque achievable with FNS to facilitate free motion, and responsively and repeatedly unlock under an applied flexion knee torque of up to 49 N-m. Preliminary tests of the SCKM with an individual with paraplegia demonstrated that it could support the body and maintain knee extension during stance without the stimulation of the knee extensor muscles. This was achieved without adversely affecting gait, and knee stability was comparable to gait assisted by knee extensor stimulation during stance.

  12. Electrophysiology of autonomic neuromuscular transmission involving ATP.

    Science.gov (United States)

    Sneddon, P

    2000-07-01

    Electrophysiological investigations of autonomic neuromuscular transmission have provided great insights into the role of ATP as a neurotransmitter. Burnstock and Holman made the first recordings of excitatory junction potentials (e.j.p.s) produced by sympathetic nerves innervating the smooth muscle of the guinea-pig vas deferens. This led to the identification of ATP as the mediator of e.j.p.s in this tissue, where ATP acts as a cotransmitter with noradrenaline. The e.j.p.s are mediated solely by ATP acting on P2X(1) receptors leading to action potentials and a rapid phasic contraction, whilst noradrenaline mediates a slower, tonic contraction which is not dependent on membrane depolarisation. Subsequent electrophysiological studies of the autonomic innervation of smooth muscles of the urogenital, gastrointestinal and cardiovascular systems have revealed a similar pattern of response, where ATP mediates a fast electrical and mechanical response, whilst another transmitter such as noradrenaline, acetylcholine, nitric oxide or a peptide mediates a slower response. The modulation of junction potentials by a variety of pre-junctional receptors and the mechanism of inactivation of ATP as a neurotransmitter will also be described.

  13. Pneumatic, PLC Controlled, Automotive Gear Shifting Mechanism

    Directory of Open Access Journals (Sweden)

    Muntaser Momani

    2010-05-01

    Full Text Available In this study, a gear shifting mechanism was designed and applied to make the shifting process faster and less destructible for the driver. The new device must be reliable, has a small dimensions, low construction and maintenance cost. This paper aims to improve gear shifting process using devices as: a manual four speed gear box, four pneumatic double acting cylinders, four pneumatic two position five ways directional control valves, Programmable Logic Controller (PLC LOGO unit, an electrical motor, an electrical clutch, a belt, two pulleys, limit switches, push buttons, bulbs, a table (holder and power supply. According to suggested gear_ shifting method the driver can select the transmission gear ratio without moving his hands from the steering wheel by putting the gear shifting push buttons on the steering wheel. Using this method leaves to the driver the excitement of choosing the shifting moment.

  14. Smartphone app design for the wireless control of a neuromuscular electrical stimulator device with integrated randomization allocation process for RCT applications.

    Science.gov (United States)

    Sweeney, Dean; Quinlan, Leo R; OLaighin, Gearoid

    2015-08-01

    The use of NMES has evolved over the last five decades. Technological advancements have transformed these once complex systems into user-friendly devices with enhanced control functions, leading to new applications of NMES being investigated. The use of Randomized Control Trial (RCT) methodology in evaluating the effectiveness of new and existing applications of NMES is a demanding process adding time and cost to a translation into clinical practice. Poor quality trials may result in poor evidence of NMES effectiveness. In this paper some of the key challenges encountered in NMES clinical trials are identified with the aim of purposing a solution to address these challenges through the adoption of Smartphone technology. The design and evaluation of a smartphone application to provide automatic blind randomization control and facilitating the wireless temporal control of a portable Bluetooth enabled NMES is presented.

  15. Defective membrane remodeling in neuromuscular diseases: insights from animal models.

    Directory of Open Access Journals (Sweden)

    Belinda S Cowling

    Full Text Available Proteins involved in membrane remodeling play an essential role in a plethora of cell functions including endocytosis and intracellular transport. Defects in several of them lead to human diseases. Myotubularins, amphiphysins, and dynamins are all proteins implicated in membrane trafficking and/or remodeling. Mutations in myotubularin, amphiphysin 2 (BIN1, and dynamin 2 lead to different forms of centronuclear myopathy, while mutations in myotubularin-related proteins cause Charcot-Marie-Tooth neuropathies. In addition to centronuclear myopathy, dynamin 2 is also mutated in a dominant form of Charcot-Marie-Tooth neuropathy. While several proteins from these different families are implicated in similar diseases, mutations in close homologues or in the same protein in the case of dynamin 2 lead to diseases affecting different tissues. This suggests (1 a common molecular pathway underlying these different neuromuscular diseases, and (2 tissue-specific regulation of these proteins. This review discusses the pathophysiology of the related neuromuscular diseases on the basis of animal models developed for proteins of the myotubularin, amphiphysin, and dynamin families. A better understanding of the common mechanisms between these neuromuscular disorders will lead to more specific health care and therapeutic approaches.

  16. Gain control mechanisms in spinal motoneurons

    Directory of Open Access Journals (Sweden)

    Michael David Johnson

    2014-07-01

    Full Text Available Motoneurons provide the only conduit for motor commands to reach muscles. For many years, motoneurons were in fact considered to be little more than passive wires. Systematic studies in the past 25 years however have clearly demonstrated that the intrinsic electrical properties of motoneurons are under strong neuromodulatory control via multiple sources. The discovery of potent neuromodulation from the brainstem and its ability to change the gain of motoneurons shows that the passive view of the motor output stage is no longer tenable. A mechanism for gain control at the motor output stage makes good functional sense considering our capability of generating an enormous range of forces, from very delicate (e.g. putting in a contact lens to highly forceful (emergency reactions. Just as sensory systems need gain control to deal with a wide dynamic range of inputs, so to might motor output need gain control to deal with the wide dynamic range of the normal movement repertoire. Two problems emerge from the potential use of the brainstem monoaminergic projection to motoneurons for gain control. First, the projection is highly diffuse anatomically, so that independent control of the gains of different motor pools is not feasible. In fact, the system is so diffuse that gain for all the motor pools in a limb likely increases in concert. Second, if there is a system that increases gain, probably a system to reduce gain is also needed. In this review, we summarize recent studies that show local inhibitory circuits within the spinal cord, especially reciprocal and recurrent inhibition, have the potential to solve both of these problems as well as constitute another source of gain modulation.

  17. Tracheal intubation without neuromuscular block in children

    OpenAIRE

    Shaikh, Safiya I; Bellagali, Vijayalaxmi P

    2010-01-01

    Endotracheal intubation has been performed during the administration of Propofol anaesthesia without neuromuscular blockade. In the study, we have assessed tracheal intubating conditions and haemodynamic responses in children aged 4 to12 years by using combination of either Fentanyl and Propofol; or Propofol and a neuromuscular blocker, suxamethonium. Intubating conditions were assessed on a 1-4 scale based on ease of laryngoscopy, position of vocal cords, degree of coughing and jaw relaxatio...

  18. Pelvic fixation for neuromuscular scoliosis deformity correction

    OpenAIRE

    Dayer, Romain; Ouellet, Jean Albert; Saran, Neil

    2012-01-01

    Pelvic fixation is most frequently indicated in the pediatric population for the treatment of neuromuscular scoliosis with significant pelvic obliquity. Neuromuscular scoliosis surgery is associated with a high risk of complications, and this is further increased by extension of fusion to the sacrum. Numerous techniques have been described for pelvic fixation associated with a long spine fusion each with its own set of specific benefits and risks. This article reviews the contemporary surgica...

  19. Dynamic congestion control mechanisms for MPLS networks

    Science.gov (United States)

    Holness, Felicia; Phillips, Chris I.

    2001-02-01

    Considerable interest has arisen in congestion control through traffic engineering from the knowledge that although sensible provisioning of the network infrastructure is needed, together with sufficient underlying capacity, these are not sufficient to deliver the Quality of Service required for new applications. This is due to dynamic variations in load. In operational Internet Protocol (IP) networks, it has been difficult to incorporate effective traffic engineering due to the limited capabilities of the IP technology. In principle, Multiprotocol Label Switching (MPLS), which is a connection-oriented label swapping technology, offers new possibilities in addressing the limitations by allowing the operator to use sophisticated traffic control mechanisms. This paper presents a novel scheme to dynamically manage traffic flows through the network by re-balancing streams during periods of congestion. It proposes management-based algorithms that will allow label switched routers within the network to utilize mechanisms within MPLS to indicate when flows are starting to experience frame/packet loss and then to react accordingly. Based upon knowledge of the customer's Service Level Agreement, together with instantaneous flow information, the label edge routers can then instigate changes to the LSP route and circumvent congestion that would hitherto violate the customer contacts.

  20. Sugammadex: A Review of Neuromuscular Blockade Reversal.

    Science.gov (United States)

    Keating, Gillian M

    2016-07-01

    Sugammadex (Bridion(®)) is a modified γ-cyclodextrin that reverses the effect of the steroidal nondepolarizing neuromuscular blocking agents rocuronium and vecuronium. Intravenous sugammadex resulted in rapid, predictable recovery from moderate and deep neuromuscular blockade in patients undergoing surgery who received rocuronium or vecuronium. Recovery from moderate neuromuscular blockade was significantly faster with sugammadex 2 mg/kg than with neostigmine, and recovery from deep neuromuscular blockade was significantly faster with sugammadex 4 mg/kg than with neostigmine or spontaneous recovery. In addition, recovery from neuromuscular blockade was significantly faster when sugammadex 16 mg/kg was administered 3 min after rocuronium than when patients spontaneously recovered from succinylcholine. Sugammadex also demonstrated efficacy in various special patient populations, including patients with pulmonary disease, cardiac disease, hepatic dysfunction or myasthenia gravis and morbidly obese patients. Intravenous sugammadex was generally well tolerated. In conclusion, sugammadex is an important option for the rapid reversal of rocuronium- or vecuronium-induced neuromuscular blockade. PMID:27324403

  1. Effects of shared medical appointments on quality of life and cost-effectiveness for patients with a chronic neuromuscular disease. Study protocol of a randomized controlled trial

    NARCIS (Netherlands)

    Seesing, F.M.; Drost, G.; Wilt, G.J. van der; Engelen, B.G.M. van

    2011-01-01

    BACKGROUND: Shared medical appointments are a series of one-to-one doctor-patient contacts, in presence of a group of 6-10 fellow patients. This group visits substitute the annual control visits of patients with the neurologist. The same items attended to in a one-to-one appointment are addressed. T

  2. PICU EXTUBATION FAILURE: THE ROLE OF NEUROMUSCULAR DISORDERS

    Directory of Open Access Journals (Sweden)

    N. Billan MD,

    2007-02-01

    Full Text Available ObjectiveNeuromuscular disorders (diseases of the motor unit, can cause respiratory problems such as impaired cough reflex, chest deformity, recurrent pneumonia and acute respiratory failure; these are the worst most common complications of these diseases and the leading cause of death in such patients (1, 2. Their management hence, very often, entails admission to the Pediatric Intensive Care Unit (PICU (3,4 and during this phase, endotracheal intubation is almost always necessary, to maintain the patency of airways and to apply Positive Pressure Ventilation (PPV. However, endotracheal intubation is always temporary, and its success or failure depends on the timely decision of its termination to restore the normal respiration or to avoid the risk of recurring respiratory failure (5, 6. We designed this study to evaluate the role of neuromuscular disorders in causing extubation failure as compared to that of other risk factors.Materials & MethodsIn an analytical cross-sectional study, the risk factors of reintubation and duration of mechanical ventilation in two groups of 30 patients each, was compared, the first successful extubation and the second with extubation failure.ResultsNeuromuscular disorders (including Spinal Muscular Atrophy, Guillain- Barre' Syndrome, Congenital Myopathies and Muscular Dystrophies were the main underlying diseases in extubation-failure group (P= 0.0002. Hypercapnia (PaCO2>50mmHg was shown to be the most common cause of both the first intubation (P=0.001 and reintubation (P=0.004 in the group of patients who failed extubation. The mean duration of intubation and mechanical ventilation was longer in patients with neuromuscular disorders who had extubation failure (P= 0.01.ConclusionThis study showed that, as underlying problems, neuromuscular disorders are the most common causes of prolonged intubation which defeat weaning from the ventilator and result in reintubation by inducing hypercapnia. Therefore the weaning

  3. Effect of exercise therapy on neuromuscular activity and knee strength in female adolescents with patellofemoral pain

    DEFF Research Database (Denmark)

    Rathleff, Michael S.; Samani, Afshin; Olesen, Jens L.;

    2016-01-01

    BACKGROUND: Female adolescents with patellofemoral pain are characterized by altered neuromuscular knee control and reduced maximal quadriceps torque. The purpose of this study is to investigate whether exercise therapy and patient education are associated with larger improvements in neuromuscular...... knee control and maximal quadriceps torque compared with patient education alone. METHODS: This is an ancillary analysis of a cluster randomized controlled trial investigating the effect of patient education and exercise therapy on self-reported recovery in 121 adolescents with patellofemoral pain...... flexion/extension kinematics and maximal quadriceps torque. FINDINGS: There was an 8-15% greater decrease in the complexity of surface electromyography suggesting an improvement in neuromuscular knee control among those randomized to exercise therapy (0.08

  4. Assembly, plasticity and selective vulnerability to disease of mouse neuromuscular junctions.

    Science.gov (United States)

    Santos, Alexandre Ferrão; Caroni, Pico

    2003-01-01

    Although physiological differences among neuromuscular junctions (NMJs) have long been known, NMJs have usually been considered as one type of synapse, restricting their potential value as model systems to investigate mechanisms controlling synapse assembly and plasticity. Here we discuss recent evidence that skeletal muscles in the mouse can be subdivided into two previously unrecognized subtypes, designated FaSyn and DeSyn muscles. These muscles differ in the pattern of neuromuscular synaptogenesis during embryonic development. Differences between classes are intrinsic to the muscles, and manifest in the absence of innervation or agrin. The distinct rates of synaptogenesis in the periphery may influence processes of circuit maturation through retrograde signals. While NMJs on FaSyn and DeSyn muscles exhibit a comparable anatomical organization in postnatal mice, treatments that challenge synaptic stability result in nerve sprouting, NMJ remodeling, and ectopic synaptogenesis selectively on DeSyn muscles. This anatomical plasticity of NMJs diminishes greatly between 2 and 6 months postnatally. NMJs lacking this plasticity are lost selectively and very early on in mouse models of motoneuron disease, suggesting that disease-associated motoneuron dysfunction may fail to initiate maintenance processes at "non-plastic" NMJs. Transgenic mice overexpressing growth-promoting proteins in motoneurons exhibit greatly enhanced stimulus-induced sprouting restricted to DeSyn muscles, supporting the notion that anatomical plasticity at the NMJ is primarily controlled by processes in the postsynaptic muscle. The discovery that entire muscles in the mouse differ substantially in the anatomical plasticity of their synapses establishes NMJs as a uniquely advantageous experimental system to investigate mechanisms controlling synaptic rearrangements at defined synapses in vivo.

  5. Cambios en el control neuromuscular de seis músculos de miembro inferior durante CMJ máximos realizados con fatiga

    Directory of Open Access Journals (Sweden)

    Gabriel Fábrica

    2013-06-01

    Full Text Available Hay diferentes opiniones respecto a si existen cambios en el control muscular cuando saltos con contramovimiento (CMJ son realizados en condición de fatiga. Este trabajo evalúa si la actividad y la secuencia temporal de activación de seis músculos de miembro inferior durante CMJ cambian por causa de la fatiga. El nivel de actividad varió principalmente en los músculos biarticulares. Los tiempos de los picos de actividad eléctrica sugieren la existencia de grupos de acción muscular, si bien ocurren cambios en la secuencia de activación dentro de cada grupo. Fue posible establecer que existe un patrón general de control muscular durante el apoyo en los CMJ, con ajustes del nivel y tiempo de activación que dependen del periodo temporal analizado y el músculo considerado.

  6. Diagnostic Certified Assay: Neuromuscular and Cardiac Assessments

    Directory of Open Access Journals (Sweden)

    Rea Valaperta

    2013-01-01

    Full Text Available The expansion of the specific trinucleotide sequence, [CTG], is the molecular pathological mechanism responsible for the clinical manifestations of DM1. Many studies have described different molecular genetic techniques to detect DM1, but as yet there is no data on the analytical performances of techniques used so far in this disease. We therefore developed and validated a molecular method, “Myotonic Dystrophy SB kit,” to better characterize our DM1 population. 113 patients were examined: 20 DM1-positive, 11 DM1/DM2-negative, and13 DM1-negative/DM2-positive, who had a previous molecular diagnosis, while 69 were new cases. This assay correctly identified 113/113 patients, and all were confirmed by different homemade assays. Comparative analysis revealed that the sensitivity and the specificity of the new kit were very high (>99%. Same results were obtained using several extraction procedures and different concentrations of DNA. The distribution of pathologic alleles showed a prevalence of the “classical” form, while of the 96 nonexpanded alleles 19 different allelic types were observed. Cardiac and neuromuscular parameters were used to clinically characterize our patients and support the new genetic analysis. Our findings suggest that this assay appears to be a very robust and reliable molecular test, showing high reproducibility and giving an unambiguous interpretation of results.

  7. Urgencias en patología neuromuscular Emergencies in neuromuscular pathology

    Directory of Open Access Journals (Sweden)

    T. Ayuso

    2008-01-01

    . Within the broad group of neuromuscular diseases, those that most frequently provoke AMW and respiratory failure are Guillain-Barré syndrome (GBS and myasthenia gravis (MG. GBS is the most frequent cause of acute flaccid paralysis; it can cause respiratory failure in a third of cases, making mechanical ventilation necessary. Accurate diagnosis of this syndrome enables immunomodulatory treatment to be started, which has been shown to modify the course of the disease. Besides, clinical evaluation of the patients and knowledge of the simple tests of neurophysiology and respiratory function will guide the decision on mechanical ventilation, avoiding emergency intubation. The most frequent emergency caused by MG is myasthenic crisis, defined by the deterioration in the bulbar function with acute respiratory insufficiency and risk of respiratory stoppage. This occurs in 15-20% of myasthenic patients and can be triggered by numerous factors. Besides early identification of the crisis, it is important to suppress the triggering factors and to provide measure of ventilatory support. Amongst the pharmacological measures, the most useful instruments at present are plasmapheresis and intravenous immunoglobulins; these treatments do not cancel the need for intensive vigilance and of checking for imminent signs of respiratory failure that will involve invasive or non-invasive ventilatory support.

  8. Discrete Mechanics and Optimal Control: an Analysis

    CERN Document Server

    Ober-Bloebaum, S; Marsden, J E

    2008-01-01

    The optimal control of a mechanical system is of crucial importance in many realms. Typical examples are the determination of a time-minimal path in vehicle dynamics, a minimal energy trajectory in space mission design, or optimal motion sequences in robotics and biomechanics. In most cases, some sort of discretization of the original, infinite-dimensional optimization problem has to be performed in order to make the problem amenable to computations. The approach proposed in this paper is to directly discretize the variational description of the system's motion. The resulting optimization algorithm lets the discrete solution directly inherit characteristic structural properties from the continuous one like symmetries and integrals of the motion. We show that the DMOC approach is equivalent to a finite difference discretization of Hamilton's equations by a symplectic partitioned Runge-Kutta scheme and employ this fact in order to give a proof of convergence. The numerical performance of DMOC and its relationsh...

  9. Spatial constancy mechanisms in motor control.

    Science.gov (United States)

    Medendorp, W Pieter

    2011-02-27

    The success of the human species in interacting with the environment depends on the ability to maintain spatial stability despite the continuous changes in sensory and motor inputs owing to movements of eyes, head and body. In this paper, I will review recent advances in the understanding of how the brain deals with the dynamic flow of sensory and motor information in order to maintain spatial constancy of movement goals. The first part summarizes studies in the saccadic system, showing that spatial constancy is governed by a dynamic feed-forward process, by gaze-centred remapping of target representations in anticipation of and across eye movements. The subsequent sections relate to other oculomotor behaviour, such as eye-head gaze shifts, smooth pursuit and vergence eye movements, and their implications for feed-forward mechanisms for spatial constancy. Work that studied the geometric complexities in spatial constancy and saccadic guidance across head and body movements, distinguishing between self-generated and passively induced motion, indicates that both feed-forward and sensory feedback processing play a role in spatial updating of movement goals. The paper ends with a discussion of the behavioural mechanisms of spatial constancy for arm motor control and their physiological implications for the brain. Taken together, the emerging picture is that the brain computes an evolving representation of three-dimensional action space, whose internal metric is updated in a nonlinear way, by optimally integrating noisy and ambiguous afferent and efferent signals. PMID:21242137

  10. Neuromuscular Adaptations to Reduced Use

    Science.gov (United States)

    Ploutz-Snyder, Lori

    2009-01-01

    This viewgraph presentation reviews the studies done to reduce neuromuscular strength loss during unilateral lower limb suspension (ULLS). Since there are animals that undergo fairly long periods of muscular disuse without any or minimal muscular atrophy, there is an answer to that might be applicable to human in situations that require no muscular use to diminish the effects of muscular atrophy. Three sets of ULLS studies were reviewed indicated that muscle strength decreased more than the muscle mass. The study reviewed exercise countermeasures to combat the atrophy, including: ischemia maintained during Compound muscle action potential (CMAP), ischemia and low load exercise, Japanese kaatsu, and the potential for rehabilitation or situations where heavy loading is undesirable. Two forms of countermeasures to unloading have been successful, (1) high-load resistance training has maintained muscle mass and strength, and low load resistance training with blood flow restriction (LL(sub BFR)). The LL(sub BFR) has been shown to increase muscle mass and strength. There has been significant interest in Tourniquet training. An increase in Growth Hormone(GH) has been noted for LL(sub BFR) exercise. An experimental study with 16 subjects 8 of whom performed ULLS, and 8 of whom performed ULLS and LL(sub BFR) exercise three times per week during the ULLS. Charts show the results of the two groups, showing that performing LL(sub BFR) exercise during 30 days of ULLS can maintain muscle size and strength and even improve muscular endurance.

  11. Splicing therapy for neuromuscular disease.

    Science.gov (United States)

    Douglas, Andrew G L; Wood, Matthew J A

    2013-09-01

    Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) are two of the most common inherited neuromuscular diseases in humans. Both conditions are fatal and no clinically available treatments are able to significantly alter disease course in either case. However, by manipulation of pre-mRNA splicing using antisense oligonucleotides, defective transcripts from the DMD gene and from the SMN2 gene in SMA can be modified to once again produce protein and restore function. A large number of in vitro and in vivo studies have validated the applicability of this approach and an increasing number of preliminary clinical trials have either been completed or are under way. Several different oligonucleotide chemistries can be used for this purpose and various strategies are being developed to facilitate increased delivery efficiency and prolonged therapeutic effect. As these novel therapeutic compounds start to enter the clinical arena, attention must also be drawn to the question of how best to facilitate the clinical development of such personalised genetic therapies and how best to implement their provision. PMID:23631896

  12. Neuromuscular Risk Factors for Knee and Ankle Ligament Injuries in Male Youth Soccer Players.

    Science.gov (United States)

    Read, Paul J; Oliver, Jon L; De Ste Croix, Mark B A; Myer, Gregory D; Lloyd, Rhodri S

    2016-08-01

    Injuries reported in male youth soccer players most commonly occur in the lower extremities, and include a high proportion of ligament sprains at the ankle and knee with a lower proportion of overuse injuries. There is currently a paucity of available literature that examines age- and sex-specific injury risk factors for such injuries within youth soccer players. Epidemiological data have reported movements that lead to non-contact ligament injury include running, twisting and turning, over-reaching and landing. Altered neuromuscular control during these actions has been suggested as a key mechanism in females and adult populations; however, data available in male soccer players is sparse. The focus of this article is to review the available literature and elucidate prevalent risk factors pertaining to male youth soccer players which may contribute to their relative risk of injury. PMID:26856339

  13. Mechanism and control of lake eutrophication

    Institute of Scientific and Technical Information of China (English)

    QIN Boqiang; YANG Liuyan; CHEN Feizhou; ZHU Guangwei; ZHANG Lu; CHEN Yiyu

    2006-01-01

    A review about lake naturally eutrophi- cating, the internal loading of nutrients from lake sediment as well as the mechanism of algal blooms and the control practices was made, especially the eutrophication problem of shallow lakes since sev- enty percent of fresh water lakes in China are shallow lakes. It was found that shallow lakes are apt toward eutrophication than deep lakes. Without any influ- ences of human activity, shallow lakes in the middle and lower reaches of Yangtze River are still easily eutrophicated, which may be owing to the effects of flood in this area. In shallow lakes, sediments are frequently disturbed by wind-wave and resuspended, which result in huge nutrients release to overlying water. This may be the major reason for higher in- ternal loading of nutrients in shallow lakes than in deep lakes. Algal bloom is an extreme response of lake ecosystem to the eutrophication. Appearance of algal blooms is related to physical condition of lakes, such as underwater radiation (or transparency), temperature, and hydrodynamic conditions, or related to geochemical conditions of lakes, like concentra- tions of nutrients and ratio of nitrogen to phosphorus, as well as the physiological advantage of cyanobac- teria such as vacuole for moving towards the radiant energy-rich zone and the mycosporine-like amino acids (MAAs) for resisting the harm of ultraviolet ra- diation. In shallow lakes, these advantages of cyanobacteria are favorable in the competition than in deep lakes. Also being the shallowness, it is more difficult to reduce nutrient loading and to control algae blooms in shallow lakes. For the control of eutrophi- cation, people should follow the sequence from pollution sources control, ecological restoration to catchment management. To control the internal nu- trient release, physical, chemical, biological tech- niques, and even bionic techniques could be selected. The idea of ecological restoration for a eutrophic lake is to shift the ecosystem

  14. Neuromuscular control of the point to point and oscillatory movements of a sagittal arm with the actor-critic reinforcement learning method.

    Science.gov (United States)

    Golkhou, Vahid; Parnianpour, Mohamad; Lucas, Caro

    2005-04-01

    In this study, we have used a single link system with a pair of muscles that are excited with alpha and gamma signals to achieve both point to point and oscillatory movements with variable amplitude and frequency.The system is highly nonlinear in all its physical and physiological attributes. The major physiological characteristics of this system are simultaneous activation of a pair of nonlinear muscle-like-actuators for control purposes, existence of nonlinear spindle-like sensors and Golgi tendon organ-like sensor, actions of gravity and external loading. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex loops.A reinforcement learning method with an actor-critic (AC) architecture instead of middle and low level of central nervous system (CNS), is used to track a desired trajectory. The actor in this structure is a two layer feedforward neural network and the critic is a model of the cerebellum. The critic is trained by state-action-reward-state-action (SARSA) method. The critic will train the actor by supervisory learning based on the prior experiences. Simulation studies of oscillatory movements based on the proposed algorithm demonstrate excellent tracking capability and after 280 epochs the RMS error for position and velocity profiles were 0.02, 0.04 rad and rad/s, respectively. PMID:16154874

  15. Control mechanisms for a nonlinear model of international relations

    Energy Technology Data Exchange (ETDEWEB)

    Pentek, A.; Kadtke, J. [Univ. of California, San Diego, La Jolla, CA (United States). Inst. for Pure and Applied Physical Sciences; Lenhart, S. [Univ. of Tennessee, Knoxville, TN (United States). Mathematics Dept.; Protopopescu, V. [Oak Ridge National Lab., TN (United States). Computer Science and Mathematics Div.

    1997-07-15

    Some issues of control in complex dynamical systems are considered. The authors discuss two control mechanisms, namely: a short range, reactive control based on the chaos control idea and a long-term strategic control based on an optimal control algorithm. They apply these control ideas to simple examples in a discrete nonlinear model of a multi-nation arms race.

  16. Effect of early progressive exercises on neuromuscular function recovery of mechanically ventilated patients in intensive care unit%早期渐进性活动训练促进重症监护病房机械通气患者神经肌肉功能恢复的效果观察

    Institute of Scientific and Technical Information of China (English)

    胡细玲; 陈妙霞; 凌聪; 蔡有弟; 郭晓迪

    2012-01-01

    目的 探讨早期渐进性活动训练促进重症监护病房(intensive care unit,ICU)机械通气患者神经肌肉功能恢复的效果.方法 将98例ICU机械通气患者随机分为实验组和对照组,每组各49例,实验组患者在镇静中断后每天实施两次早期渐进性活动训练;对照组患者每天两次接受床上被动或主动全范围关节活动.采用功能独立性评分表(functional independence measure,FIM)对两组患者分别在拔除气管插管时、转出ICU时和出院时进行评定,并比较两组患者住院期间并发症发生情况.结果 实验组患者在拔除气管插管时FIM总分及自理能力、括约肌控制、转移方面得分明显高于对照组,两组比较,均P<0.05,差异具有统计学意义;实验组患者在转出ICU时和出院时在FIM总分及5个方面得分明显高于对照组,两组比较,均P<0.05,差异具有统计学意义.实验组患者呼吸机相关性肺炎(ventilator associated pneumonia,VAP)、下肢深静脉栓塞(deep vein thrombosis,DVT)的发生率明显低于对照组,两组比较,均P<0.05,差异具有统计学意义.结论 早期渐进性活动训练能促进ICU机械通气患者神经肌肉功能恢复,并可降低相关并发症的发生率.%Objective To study the effect of early progressive exercises on neuromuscular function recovery of mechanically ventilated patients in intensive care unit. Methods 98 mechanically ventilated patients in the ICU were randomly divided into the experiment group and the control group, 49 patients in each group. Patients in the experiment group were implemented the training program of early progressive exercise twice a day once the sedation was cut off. Patients in the control group were implemented early passive or active training of joint activities in a full range on bed twice a day. The two groups were assessed in terms of complications using the Functional Independence Measures at the time of extubation, shifting out of ICU

  17. Effects of neuromuscular electrostimulation in patients with heart failure admitted to ward

    Directory of Open Access Journals (Sweden)

    de Araújo Carlos José Soares

    2012-11-01

    Full Text Available Abstract Background Neuromuscular electrostimulation has become a promising issue in cardiovascular rehabilitation. However there are few articles published in the literature regarding neuromuscular electrostimulation in patients with heart failure during hospital stay. Methods This is a randomized controlled pilot trial that aimed to investigate the effect of neuromuscular electrostimulation in the walked distance by the six-minute walking test in 30 patients admitted to ward for heart failure treatment in a tertiary cardiology hospital. Patients in the intervention group performed a conventional rehabilitation and neuromuscular electrostimulation. Patients underwent 60 minutes of electrostimulation (wave frequency was 20 Hz, pulse duration of 20 us two times a day for consecutive days until hospital discharge. Results The walked distance in the six-minute walking test improved 75% in the electrostimulation group (from 379.7 ± 43.5 to 372.9 ± 46.9 meters to controls and from 372.9 ± 62.4 to 500 ± 68 meters to electrostimulation, p Conclusion The neuromuscular electrostimulation group showed greater improvement in the walked distance in the six-minute walking test in patients admitted to ward for compensation of heart failure.

  18. Employment profiles in neuromuscular diseases.

    Science.gov (United States)

    Fowler, W M; Abresch, R T; Koch, T R; Brewer, M L; Bowden, R K; Wanlass, R L

    1997-01-01

    Consumer and rehabilitation provider factors that might limit employment opportunities for 154 individuals with six slowly progressive neuromuscular diseases (NMD) were investigated. The NMDs were spinal muscular atrophy (SMA), hereditary motor sensory neuropathy (HMSN), Becker's muscular dystrophy (BMD), facioscapulohumeral muscular dystrophy (FSHD), myotonic muscular dystrophy (MMD), and limb-girdle syndrome (LGS). Forty percent were employed in the competitive labor market at the time of the study, 50% had been employed in the past, and 10% had never been employed. The major consumer barrier to employment was education. Other important factors were type of occupation, intellectual capacity, psychosocial adjustment, and the belief by most individuals that their physical disability was the only or major barrier to obtaining a job. Psychological characteristics were associated with level of unemployment. However, physical impairment and disability were not associated with level of unemployment. There also were differences among the types of NMDs. Compared with the SMA, HMSN, BMD, and FSHD groups, the MMD and LGS groups had significantly higher levels of unemployment, lower educational levels, and fewer employed professional, management, and technical workers. Nonphysical impairment factors such as a low percentage of college graduates, impaired intellectual function in some individuals, and poor psychological adjustment were correlated with higher unemployment levels in the MMD group. Unemployment in the LGS group was correlated with a failure to complete high school. Major provider barriers to employment were the low level of referrals to Department of Rehabilitation by physicians and the low percentage of acceptance into the State Department of Rehabilitation. The low rate of acceptance was primarily attributable to the low number of referrals compounded by a lack of counselor experience with individuals with NMD. Both consumer and provider barriers may

  19. Tracheal intubation without neuromuscular block in children

    Directory of Open Access Journals (Sweden)

    Safiya I Shaikh

    2010-01-01

    Full Text Available Endotracheal intubation has been performed during the administration of Propofol anaesthesia without neuromuscular blockade. In the study, we have assessed tracheal intubating conditions and haemodynamic responses in children aged 4 to12 years by using combination of either Fentanyl and Propofol; or Propofol and a neuromuscular blocker, suxamethonium. Intubating conditions were assessed on a 1-4 scale based on ease of laryngoscopy, position of vocal cords, degree of coughing and jaw relaxation. Tracheal intubation was successful in 95% of patients receiving Fentanyl-Propofol and 100% of patients receiving Propofol-suxamethonium. Fentanyl-Propofol provided better haemodynamic stability than Propofol-suxamethonium. We conclude that Propofol-Fentanyl combination could be a useful alternative technique for tracheal intubation when neuromuscular blocking drugs are contraindicated or need to be avoided.

  20. Bonfils Fiberscope: Intubating Conditions and Hemodynamic Changes without Neuromuscular Blockade

    Directory of Open Access Journals (Sweden)

    Atabak Najafi

    2011-04-01

    Full Text Available To compare intubating conditions and hemodynamic changes between Bonfils Intubation Fiberscope and Macintosh laryngoscopy without administering neuromuscular blocking drugs (NMBDs. METHODS: In this randomized controlled trial,80 male and female patients, scheduled for elective surgery, aged 15 to 60 years, ASA class II or I, non-obese, non smokers, without anticipated difficult intubation; were randomly allocated into two groups of 40: Bonfils and Macintosh. Following adequate hydration and preoxygenation, midazolam 0.03 mg.kg-1 was administered, followed by intravenous alfentanil 20 µg.kg-1, lidocaine 1.0 mg.kg-1, and propofol 2 mg.kg-1 sequentially. Trachea was then intubated using Bonfils Intubation Fiberscope in the Bonfils group and conventional Macintosh laryngoscopy in the Macintosh group. Intubating condition, mean arterial blood pressure, heart rate, pulse oximetry, and success rate were measured. RESULTS: Clinically acceptable intubating condition scores did not differ significantly between the groups (P=0.465. Compared to the baseline values, heart rate rose significantly after intubation only in the Macintosh group (P<0.001. Although mean arterial blood pressure increased immediately after intubation in the Macintosh group (P=0.022, its post-intubation values were significantly less than baseline in both groups (P<0.001. Intubation time took much longer in the Bonfils group (40 s than the Macintosh group (11 s, P<0.001. In the absence of NMBDs, Bonfils Intubation Fiberscope compares well with Macintosh laryngoscopy in terms of success rate and intubating conditions, but with less mechanical stress and hemodynamic compromise and longer intubation time.

  1. Spin-controlled mechanics in nanoelectromechanical systems

    International Nuclear Information System (INIS)

    We consider a dc-electronic tunneling transport through a carbon nanotube suspended between normal-metal source and arbitrarily spin-polarized drain lead in the presence of an external magnetic field. We show that magnetomotive coupling between electrical current through the nanotube and its mechanical vibrations may lead to an electromechanical instability and give an onset of self-excited mechanical vibrations depending on spin polarization of the drain lead and frequency of vibrations. The self-excitation mechanism is based on correlation between the occupancy of quantized Zeeman-split electronic states in the nanotube and the direction of velocity of its mechanical motion. It is an effective gating effect by the presence of electron in the spin state which, through the Coulomb blockade, permits tunneling of electron to the drain predominantly only during a particular phase of mechanical vibration thus coherently changing mechanical momentum and leading into instability if mechanical damping is overcome

  2. Research highlights of partial neuromuscular disorders

    Directory of Open Access Journals (Sweden)

    Cheng ZHANG

    2014-05-01

    Full Text Available In order to understand the latest progression on neuromuscular disorders for clinicians, this review screened and systemized the papers on neuromuscular disorders which were collected by PubMed from January 2013 to February 2014. This review also introduced the clinical diagnosis and treatment hightlights on glycogen storage disease type Ⅱ (GSD Ⅱ, Duchenne muscular dystrophy (DMD, amyotrophic lateral sclerosis (ALS and spinal muscular atrophy (SMA. The important references will be useful for clinicians. doi: 10.3969/j.issn.1672-6731.2014.05.004

  3. Naturally occurring plant polyphenols as potential therapies for inherited neuromuscular diseases.

    Science.gov (United States)

    Fuller, Heidi R; Humphrey, Emma L; Morris, Glenn E

    2013-11-01

    There are several lines of laboratory-based evidence emerging to suggest that purified polyphenol compounds such as resveratrol, found naturally in red grapes, epigallocatechin galate from green tea and curcumin from turmeric, might be useful for the treatment of various inherited neuromuscular diseases, including spinal muscular atrophy, Duchenne muscular dystrophy and Charcot-Marie-Tooth disease. Here, we critically examine the scientific evidence related to the known molecular effects that these polyphenols have on different models of inherited neuromuscular disease, with particular attention to problems with the validity of in vitro evidence. We also present proteomic evidence that polyphenols have in vitro effects on cells related to metal ion chelation in cell-culture media. Although their precise mechanisms of action remain somewhat elusive, polyphenols could be an attractive approach to therapy for inherited neuromuscular disease, especially since they may be safer to use on young children, compared with some of the other drug candidates.

  4. Selective activation of neuromuscular compartments within the human trapezius muscle

    DEFF Research Database (Denmark)

    Holtermann, A; Roeleveld, K; Mork, P J;

    2009-01-01

    Task-dependent differences in relative activity between "functional" subdivisions within human muscles are well documented. Contrary, independent voluntary control of anatomical subdivisions, termed neuromuscular compartments is not observed in human muscles. Therefore, the main aim of this study...... was to investigate whether subdivisions within the human trapezius can be independently activated by voluntary command using biofeedback guidance. Bipolar electromyographical electrodes were situated on four subdivisions of the trapezius muscle. The threshold for "active" and "rest" for each subdivision was set...... to >12% and subdivisions, 11 of 15 subjects learned selective activation of at least one of the four anatomical subdivisions of the trapezius...

  5. Neuromuscular function in patients with Subacromial Impingement Syndrome and clinical assessment of scapular kinematics

    DEFF Research Database (Denmark)

    Larsen, Camilla Marie; Lund, Hans; Juul-Kristensen, Birgit;

    2014-01-01

    a voluntary arm movement task and 2) selective activation tasks during sessions with and without on-line biofeedback, in a general population consisting of 16 SIS patients and 15 controls (No-SIS). Furthermore, 3) a systematic review was conducted of all available clinical scapular assessment methods...... in neuromuscular activity of scapular stabilising muscles were observed, 2) and when provided with visual EMG feedback, the SIS group performed equally well as the No-SIS group, However, when assessing the neuromuscular function with and without the use of biofeedback, the findings show that without biofeedback...

  6. A neuromuscular monitoring system based on a personal computer.

    Science.gov (United States)

    White, D A; Hull, M

    1992-07-01

    We have developed a computerized neuromuscular monitoring system (NMMS) using commercially available subsystems, i.e., computer equipment, clinical nerve stimulator, force transducer, and strip-chart recorder. This NMMS was developed for acquisition and analysis of data for research and teaching purposes. Computer analysis of the muscle response to stimulation allows graphic and numeric presentation of the twitch response and calculated ratios. Since the system can store and recall data, research data can be accessed for analysis and graphic presentation. An IBM PC/AT computer is used as the central controller and data processor. The computer controls timing of the nerve stimulator output, initiates data acquisition, and adjusts the paper speed of the strip chart recorder. The data processing functions include establishing control response values (when no neuromuscular blockade is present), displaying force versus time and calculated data graphically and numerically, and storing these data for further analysis. The general purpose nature of the computer and strip chart recording equipment allow modification of the system primarily by changes in software. For example, new patterns of nerve stimulation, such as the posttetanic count, can be programmed into the computer system along with appropriate data display and analysis routines. The NMMS has functioned well in the operating room environment. We have had no episodes of electrocautery interference with the computer functions. The automated features have enhanced the utility of the NMMS.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1322977

  7. Controlled Unusual Stiffness of Mechanical Metamaterials

    Science.gov (United States)

    Lee, Wooju; Kang, Da-Young; Song, Jihwan; Moon, Jun Hyuk; Kim, Dongchoul

    2016-02-01

    Mechanical metamaterials that are engineered with sub-unit structures present unusual mechanical properties depending on the loading direction. Although they show promise, their practical utility has so far been somewhat limited because, to the best of our knowledge, no study about the potential of mechanical metamaterials made from sophisticatedly tailored sub-unit structures has been made. Here, we present a mechanical metamaterial whose mechanical properties can be systematically designed without changing its chemical composition or weight. We study the mechanical properties of triply periodic bicontinuous structures whose detailed sub-unit structure can be precisely fabricated using various sub-micron fabrication methods. Simulation results show that the effective wave velocity of the structures along with different directions can be designed to introduce the anisotropy of stiffness by changing a volume fraction and aspect ratio. The ratio of Young’s modulus to shear modulus can be increased by up to at least 100, which is a 3500% increase over that of isotropic material (2.8, acrylonitrile butadiene styrene). Furthermore, Poisson’s ratio of the constituent material changes the ratio while Young’s modulus does not influence it. This study presents the promising potential of mechanical metamaterials for versatile industrial and biomedical applications.

  8. Controlled Unusual Stiffness of Mechanical Metamaterials.

    Science.gov (United States)

    Lee, Wooju; Kang, Da-Young; Song, Jihwan; Moon, Jun Hyuk; Kim, Dongchoul

    2016-02-03

    Mechanical metamaterials that are engineered with sub-unit structures present unusual mechanical properties depending on the loading direction. Although they show promise, their practical utility has so far been somewhat limited because, to the best of our knowledge, no study about the potential of mechanical metamaterials made from sophisticatedly tailored sub-unit structures has been made. Here, we present a mechanical metamaterial whose mechanical properties can be systematically designed without changing its chemical composition or weight. We study the mechanical properties of triply periodic bicontinuous structures whose detailed sub-unit structure can be precisely fabricated using various sub-micron fabrication methods. Simulation results show that the effective wave velocity of the structures along with different directions can be designed to introduce the anisotropy of stiffness by changing a volume fraction and aspect ratio. The ratio of Young's modulus to shear modulus can be increased by up to at least 100, which is a 3500% increase over that of isotropic material (2.8, acrylonitrile butadiene styrene). Furthermore, Poisson's ratio of the constituent material changes the ratio while Young's modulus does not influence it. This study presents the promising potential of mechanical metamaterials for versatile industrial and biomedical applications.

  9. Neuromuscular hamartoma arising in the brachial plexus

    Energy Technology Data Exchange (ETDEWEB)

    Lai, P.H.; Chen, C.; Yeh, L.R.; Pan, H.B. [Department of Radiology, Veterans General Hospital-Kaohsiung, 386 Ta-Chung First Rd, 813, Kaohsiung (Taiwan); Ho, J.T.; Hsu, S.S. [Department of Neurosurgery, Veterans General Hospital-Kaohsiung, 386 Ta-Chung First Rd, 813, Kaosiung (Taiwan); Lin, S.L. [Department of Pathology, Veterans General Hospital-Kaohsiung, 386 Ta-Chung First Rd, 813, Kaohsiung (Taiwan)

    2004-03-01

    We report a case brachial plexus neuromuscular hamartoma (choristoma) in a 28-year-old man who complained of numbness of the left hand and forearm for several years. MRI revealed a circumscribed, rounded mass in the left brachial plexus. The patient is well 2 years after surgery, with no neurological deficit. (orig.)

  10. Pregnancy and Childbirth with Neuromuscular Disease

    Science.gov (United States)

    ... to get a little bit Teamwork makes the difference weaker during Coordination and communication Having a neuromuscular disease can pose special anesthesia-related risks. the pregnancy and, unfortu- among the pregnant woman, her neurologist and a team experienced — local anesthesia. ( ...

  11. Analysis and control of underactuated mechanical systems

    CERN Document Server

    Choukchou-Braham, Amal; Djemaï, Mohamed; Busawon, Krishna

    2014-01-01

    This monograph provides readers with tools for the analysis, and control of systems with fewer control inputs than degrees of freedom to be controlled, i.e., underactuated systems. The text deals with the consequences of a lack of a general theory that would allow methodical treatment of such systems and the ad hoc approach to control design that often results, imposing a level of organization whenever the latter is lacking. The authors take as their starting point the construction of a graphical characterization or control flow diagram reflecting the transmission of generalized forces through the degrees of freedom. Underactuated systems are classified according to the three main structures by which this is found to happen—chain, tree, and isolated vertex—and control design procedures proposed. The procedure is applied to several well-known examples of underactuated systems: acrobot; pendubot; Tora system; ball and beam; inertia wheel; and robotic arm with elastic joint. The text is illustrated with MATL...

  12. Poisson Theory and Inverse Problem in a Controllable Mechanical System

    Institute of Scientific and Technical Information of China (English)

    夏丽莉

    2011-01-01

    The Poisson theory and inverse problem are studied in a controllable mechanical system. Equations of motion of the controllable mechanical system in phase space are given. Poisson's integral theory of the system is established. The potential force field is constructed by solving the inverse problem in a controllable mechanical system. Finally, an example is given to illustrate the application of the results.%The Poisson theory and inverse problem are studied in a controllable mechanical system.Equations of motion of the controllable mechanical system in phase space are given.Poisson's integral theory of the system is established.The potential force field is constructed by solving the inverse problem in a controllable mechanical system.Finally,an example is given to illustrate the application of the results.

  13. Neuromuscular function in different stages of sarcopenia.

    Science.gov (United States)

    Morat, Tobias; Gilmore, Kevin J; Rice, Charles L

    2016-08-01

    This study applied the screening tool developed by the European Working Group on Sarcopenia in Older People (EWGSOP) on seniors aged over 65years and concurrently tested various laboratory-based indices of neuromuscular function. Twenty-four healthy and independent living older adults (9 men, 15 women) with a mean age of 79.1±5.8years participated. Based on gait speed, handgrip strength and muscle mass all subjects were categorized into one of the three conceptual sarcopenia stages (pre-sarcopenia, sarcopenia, severe sarcopenia). Maximal strength of dorsiflexors in the left leg was measured and voluntary activation was assessed by the interpolated twitch technique. In addition, isometric evoked contractile properties were recorded. Skeletal muscle mass was assessed by ultrasound from nine sites. There were roughly equal number of subjects in each sarcopenic category, and age was not different among the 3 groups. There were no differences in handgrip strength and skeletal muscle mass index among the 3 groups. Gait speed was significantly slower (psarcopenia group, and 51% slower (p=0.03) compared with the pre-sarcopenia group, but when normalized to peak torques there were no statistical differences. The laboratory tests found neuromuscular differences among the 3 groups which generally supported the classification scheme and helped to illustrate some key factors that could explain differences in functional capacities. These initial findings support the assumption that this categorization is relevant for identifying older adults with different neuromuscular properties. However, further studies are needed to provide more insight into the specific neuromuscular changes in the three sarcopenia stages, and how these changes relate to functional capacity. Such studies could ultimately contribute to identifying optimal interventions to improve neuromuscular functioning. PMID:27108183

  14. Clinical use of creatine in neuromuscular and neurometabolic disorders.

    Science.gov (United States)

    Tarnopolsky, Mark A

    2007-01-01

    Many of the neuromuscular (e.g., muscular dystrophy) and neurometabolic (e.g., mitochondrial cytopathies) disorders share similar final common pathways of cellular dysfunction that may be favorably influenced by creatine monohydrate (CrM) supplementation. Studies using the mdx model of Duchenne muscular dystrophy have found evidence of enhanced mitochondrial function, reduced intra-cellular calcium and improved performance with CrM supplementation. Clinical trials in patients with Duchenne and Becker's muscular dystrophy have shown improved function, fat-free mass, and some evidence of improved bone health with CrM supplementation. In contrast, the improvements in function in myotonic dystrophy and inherited neuropathies (e.g., Charcot-Marie-Tooth) have not been significant. Some studies in patients with mitochondrial cytopathies have shown improved muscle endurance and body composition, yet other studies did not find significant improvements in patients with mitochondrial cytopathy. Lower-dose CrM supplementation in patients with McArdle's disease (myophosphorylase deficiency) improved exercise capacity, yet higher doses actually showed some indication of worsened function. Based upon known cellular pathologies, there are potential benefits from CrM supplementation in patients with steroid myopathy, inflammatory myopathy, myoadenylate deaminase deficiency, and fatty acid oxidation defects. Larger randomized control trials (RCT) using homogeneous patient groups and objective and clinically relevant outcome variables are needed to determine whether creatine supplementation will be of therapeutic benefit to patients with neuromuscular or neurometabolic disorders. Given the relatively low prevalence of some of the neuromuscular and neurometabolic disorders, it will be necessary to use surrogate markers of potential clinical efficacy including markers of oxidative stress, cellular energy charge, and gene expression patterns. PMID:18652078

  15. Towards a Unified Representation of Mechanisms for Robotic Control Software

    Directory of Open Access Journals (Sweden)

    Antonio Diaz-Calderon

    2008-11-01

    Full Text Available This article gives an overview of the Mechanism Model paradigm. The mechanism model paradigm provides a framework to modeling mechanisms for robotic control. The emphasis is on the unification of mathematical models of kinematics/dynamics, geometric information and control system parameters for a variety of robotic systems (including serial manipulators, wheeled and legged locomotors, with algorithms that are needed for typical robot control applications.

  16. O uso de bloqueadores neuromusculares no Brasil El uso de bloqueadores neuromusculares en Brasil Neuromuscular blockers in Brazil

    Directory of Open Access Journals (Sweden)

    Maria Cristina Simões de Almeida

    2004-12-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Dados estatísticos referentes ao uso de bloqueadores neuromusculares no Brasil são desconhecidos. Este trabalho se propõe a análise estatística desse tópico. MÉTODO: Foram compiladas 831 respostas de um questionário preenchido em parte por anestesiologistas presentes ao 48º Congresso Brasileiro de Anestesiologia em Recife, 2001 e em parte via Internet, por anestesiologistas cujos endereços eletrônicos constam na página da Sociedade Brasileira de Anestesiologia (www.sba.com.br. Foram analisados os seguintes dados: tempo de contato com a especialidade, região onde atuam os anestesiologistas, uso de bloqueadores neuromusculares (BNM em ordem de preferência, indicações do uso de succinilcolina, uso do monitor da transmissão neuromuscular, critérios para se considerar o paciente descurarizado, uso de neostigmina, forma de administração dos BNM e descrição de complicações observadas. RESULTADOS: A maioria dos anestesiologistas em questão exerce a profissão há mais de 11 anos e o maior número de respostas foi proveniente da região sudeste do Brasil. O BNM mais empregado é o atracúrio, seguido de pancurônio e succinilcolina. A succinilcolina é mais empregada na indução rápida e em crianças (80% e 25% respectivamente. Monitores da transmissão neuromuscular, 53% dos anestesiologistas nunca usam, e como critério de recuperação, 92% consideram o paciente descurarizado mediante sinais clínicos. Em 45% das vezes os profissionais empregam a neostigmina de forma rotineira, e 94% administra os BNM sob forma de bolus. Cerca de 30% registra ter havido complicação decorrente do uso de BNM. As complicações mais apontadas foram o bloqueio prolongado, o broncoespasmo grave e a curarização residual. CONCLUSÕES: O atracúrio é o bloqueador neuromuscular mais empregado no Brasil, há percentual alto de uso da succinilcolina em situações não emergenciais, o uso de monitores da transmiss

  17. Computer aided control of a mechanical arm

    Science.gov (United States)

    Derocher, W. L., Jr.; Zermuehlen, r. O.

    1979-01-01

    A method for computer-aided remote control of a six-degree-of-freedom manipulator arm involved in the on-orbit servicing of a spacecraft is presented. The control configuration features a supervisory type of control in which each of the segments of a module exchange trajectory is controlled automatically under human supervision, with manual commands to proceed to the next step and in the event of a failure or undesirable outcome. The implementation of the supervisory system is discussed in terms of necessary onboard and ground- or Orbiter-based hardware and software, and a one-g demonstration system built to allow further investigation of system operation is described. Possible applications of the system include the construction of satellite solar power systems, environmental testing and the control of heliostat solar power stations.

  18. Critical length scale controls adhesive wear mechanisms

    Science.gov (United States)

    Aghababaei, Ramin; Warner, Derek H.; Molinari, Jean-Francois

    2016-06-01

    The adhesive wear process remains one of the least understood areas of mechanics. While it has long been established that adhesive wear is a direct result of contacting surface asperities, an agreed upon understanding of how contacting asperities lead to wear debris particle has remained elusive. This has restricted adhesive wear prediction to empirical models with limited transferability. Here we show that discrepant observations and predictions of two distinct adhesive wear mechanisms can be reconciled into a unified framework. Using atomistic simulations with model interatomic potentials, we reveal a transition in the asperity wear mechanism when contact junctions fall below a critical length scale. A simple analytic model is formulated to predict the transition in both the simulation results and experiments. This new understanding may help expand use of computer modelling to explore adhesive wear processes and to advance physics-based wear laws without empirical coefficients.

  19. Nonsmooth Mechanics. Models, Dynamics and Control : Erratum/Addendum

    OpenAIRE

    Brogliato, Bernard

    2016-01-01

    This is the first version of the Erratum/Addendum of the 3rd edition of the monograph entitled Nonsmooth Mechanics, Models, Dynamics and Control, Springer, Communications and Control Engineering, ISSN 0178-5354, 2016.

  20. Mechanical design and control of a new myoelectric hand prosthesis

    OpenAIRE

    Peerdeman, B.; Stramigioli, S.; Hekman, E.; Brouwer, D.M.; Misra, S

    2011-01-01

    The development of modern, myoelectrically controlled hand prostheses can be difficult, due to the many requirements its mechanical design and control system need to fulfill [1]. The hand should be controllable with few input signals, while being able to perform a wide range of motions. It should be lightweight and slim, but be able to actuate all fingers separately. To accomplish this, new control and mechanical design techniques are implemented in a modern hand prosthesis prototype.

  1. Man-machine interface system for neuromuscular training and evaluation based on EMG and MMG signals.

    Science.gov (United States)

    de la Rosa, Ramon; Alonso, Alonso; Carrera, Albano; Durán, Ramon; Fernández, Patricia

    2010-01-01

    This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System), a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES) and, as a novelty, the myomechanic signals (MMS). In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals.

  2. Man-Machine Interface System for Neuromuscular Training and Evaluation Based on EMG and MMG Signals

    Directory of Open Access Journals (Sweden)

    Patricia Fernández

    2010-12-01

    Full Text Available This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System, a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES and, as a novelty, the myomechanic signals (MMS. In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals.

  3. Cutaneous mechanisms of isometric ankle force control.

    Science.gov (United States)

    Choi, Julia T; Lundbye-Jensen, Jesper; Leukel, Christian; Nielsen, Jens Bo

    2013-07-01

    The sense of force is critical in the control of movement and posture. Multiple factors influence our perception of exerted force, including inputs from cutaneous afferents, muscle afferents and central commands. Here, we studied the influence of cutaneous feedback on the control of ankle force output. We used repetitive electrical stimulation of the superficial peroneal (foot dorsum) and medial plantar nerves (foot sole) to disrupt cutaneous afferent input in 8 healthy subjects. We measured the effects of repetitive nerve stimulation on (1) tactile thresholds, (2) performance in an ankle force-matching and (3) an ankle position-matching task. Additional force-matching experiments were done to compare the effects of transient versus continuous stimulation in 6 subjects and to determine the effects of foot anesthesia using lidocaine in another 6 subjects. The results showed that stimulation decreased cutaneous sensory function as evidenced by increased touch threshold. Absolute dorsiflexion force error increased without visual feedback during peroneal nerve stimulation. This was not a general effect of stimulation because force error did not increase during plantar nerve stimulation. The effects of transient stimulation on force error were greater when compared to continuous stimulation and lidocaine injection. Position-matching performance was unaffected by peroneal nerve or plantar nerve stimulation. Our results show that cutaneous feedback plays a role in the control of force output at the ankle joint. Understanding how the nervous system normally uses cutaneous feedback in motor control will help us identify which functional aspects are impaired in aging and neurological diseases.

  4. High Precision Motion Control of Hybrid Five-Bar Mechanism with an Intelligent Control

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ke; WANG Sheng-ze

    2009-01-01

    Hybrid mechanism is a new type of planar controllable mechanism. Position control accuracy of system determines the output acctracy of the mechanism In order to achieve the desired high accuracy, nonlinear factors as friction must be accurately compensated in the real-time servo control algarithm. In this paper, the model of a hybrid flve-bar mechanism is introduced In terms of the characteristics of the hybrid mechanism, a hybrid intelligent control algorithm based on proportional-integral-derivative(PID) control and cerebellar model articulation control techniques was presented and used to perform control of hybrid five-bar mechanism for the first time. The simulation results show that the hybrid control method can improve the control effect remarkably, compared with the traditional PID control strategy.

  5. Mechanisms and Control of Silk-based Electrospinning

    OpenAIRE

    Zhang, Feng; Zuo, Baoqi; Fan, Zhihai; Xie, Zonggang; Lu, Qiang; Zhang, Xueguang; Kaplan, David L.

    2012-01-01

    Silk fibroin (SF) nanofibers, formed through electrospinning, have attractive utility in regenerative medicine due to the biocompatibility, mechanical properties and tailorable degradability. The mechanism of SF electrospun nanofiber formation was studied to gain new insight into the formation and control of nanofibers. SF electrospinning solutions with different nanostructures (nanospheres or nanofilaments) were prepared by controlling the drying process during the preparation of regenerated...

  6. Improving Control Mechanism at Routers in TCP/IP Network

    Directory of Open Access Journals (Sweden)

    Nguyen Kim Quoc

    2014-09-01

    Full Text Available The existing control mechanisms at the network nodes have a good active and very effective at each local router, but they do not still strong enough to control nonlinear and dynamical behaviour of the network. Therefore, the control system requirements must be designed to be flexible to fully grasp the important status information of the variation and intelligent control methods to control network congestion in nonlinear network. To solve this problem, we propose a solution combined fuzzy reasoning with neural network control put on active queue management mechanisms at the network nodes.

  7. Cutaneous mechanisms of isometric ankle force control

    DEFF Research Database (Denmark)

    Choi, Julia T; Jensen, Jesper Lundbye; Leukel, Christian;

    2013-01-01

    The sense of force is critical in the control of movement and posture. Multiple factors influence our perception of exerted force, including inputs from cutaneous afferents, muscle afferents and central commands. Here, we studied the influence of cutaneous feedback on the control of ankle force...... output. We used repetitive electrical stimulation of the superficial peroneal (foot dorsum) and medial plantar nerves (foot sole) to disrupt cutaneous afferent input in 8 healthy subjects. We measured the effects of repetitive nerve stimulation on (1) tactile thresholds, (2) performance in an ankle force......-matching and (3) an ankle position-matching task. Additional force-matching experiments were done to compare the effects of transient versus continuous stimulation in 6 subjects and to determine the effects of foot anesthesia using lidocaine in another 6 subjects. The results showed that stimulation decreased...

  8. Two Mechanisms to Avoid Control Conflicts Resulting from Uncoordinated Intent

    Science.gov (United States)

    Mishkin, Andrew H.; Dvorak, Daniel L.; Wagner, David A.; Bennett, Matthew B.

    2013-01-01

    This software implements a real-time access control protocol that is intended to make all connected users aware of the presence of other connected users, and which of them is currently in control of the system. Here, "in control" means that a single user is authorized and enabled to issue instructions to the system. The software The software also implements a goal scheduling mechanism that can detect situations where plans for the operation of a target system proposed by different users overlap and interact in conflicting ways. In such situations, the system can either simply report the conflict (rejecting one goal or the entire plan), or reschedule the goals in a way that does not conflict. The access control mechanism (and associated control protocol) is unique. Other access control mechanisms are generally intended to authenticate users, or exclude unauthorized access. This software does neither, and would likely depend on having some other mechanism to support those requirements.

  9. Desarrollo neuromuscular en la atrofia muscular espinal

    OpenAIRE

    Martínez Hernàndez, Rebeca

    2012-01-01

    BACKGROUND: Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by degeneration and loss of spinal cord motor neurons leading to denervation and muscular atrophy. It is caused by defects in the Survival Motor Neuron 1 gene (SMN1) and it is classified by age of onset and motor milestones into three main types which strongly correlate with the copy number of its homologous gene, SMN2. SMN2 expresses markedly less full‐length protein than SMN1, provoking disease manifestations...

  10. Splicing therapy for neuromuscular disease ☆

    OpenAIRE

    Andrew G. L. Douglas; Wood, Matthew J. A.

    2013-01-01

    Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) are two of the most common inherited neuromuscular diseases in humans. Both conditions are fatal and no clinically available treatments are able to significantly alter disease course in either case. However, by manipulation of pre-mRNA splicing using antisense oligonucleotides, defective transcripts from the DMD gene and from the SMN2 gene in SMA can be modified to once again produce protein and restore function. A large numb...

  11. The emerging diversity of neuromuscular junction disorders

    OpenAIRE

    Newsom-Davis, J

    2007-01-01

    Research advances over the last 30 years have shown that key transmembrane proteins at the neuromuscular junction are vulnerable to antibody-mediated autoimmune attack These targets are acetylcholine receptors (AChRs) and muscle specific kinase (MuSK) in myasthenia gravis, voltage-gated calcium channels (VGCCs) in the Lambert-Eaton myasthenic syndrome (LEMS), and voltage-gated potassium channels (VGKCs) in neuromyotonia. In parallel with these immunological advances, mutations identified in g...

  12. Acute neuromuscular responses to car racing

    OpenAIRE

    Backman, Jani

    2005-01-01

    Purpose: The primary purpose of this study was to determine racing car drivers’ acute neuromuscular responses to race driving. The secondary purpose was to compare the cardiovascular loading of driving to that of maximal rowing action. Methods: The subjects of the present cross-sectional study (n = 9) were international level karting drivers. The study was performed in two parts; the laboratory tests and driving test. All subjects took part to the laboratory tests and five of the subjects per...

  13. Novel Mechanism Control Algorithm for Wired Network

    Directory of Open Access Journals (Sweden)

    V. B. Kirubanand

    2011-01-01

    Full Text Available Problem statement: A critical issue in wireless network where the data can hack by the person and we add a novel encryption mechanism to protect the data transfer from client to server and vice versa. Approach: We present a queuing model of a client and server that uses for bulk arrival service. The arrival of data requests is assumed to Markov Poisson Distributed Process (MPDP and the events are considered in the server for process sharing. We obtained the parameter of service rate, arrival rate, expected waiting time and expected busy period. We also derive the expression for the data value of threshold. Results: The total number of packets request processed, there was no time limit to arrivals, while compared to m/m/1 model. Our model m/m (1,b/1 was more efficient to find response and request time in between client and server. Conclusions: Our proposed simulation model validated through Java programming.

  14. Control of Drop Motion by Mechanical Vibrations

    Science.gov (United States)

    Bestehorn, Michael

    2014-11-01

    Since the first experimental observations of Michael Faraday in 1831 it is known that a vibrating liquid may show an instability of its flat free surface with respect to oscillating regular surface patterns. We study thin liquid films on a horizontal substrate in the long wave approximation. The films are parametrically excited by mechanical horizontal or inclined oscillations. Inertia effects are taken into account and the standard thin film formulation is extended by a second equation for the vertically averaged mass flux. The films can be additionally unstable by Van der Waals forces on a partially wetting substrate, leading to the formation of drops. These drops can be manipulated by the vibrations to move in a desired direction. Linear results based on a damped complex valued Mathieu equation as well as fully nonlinear results using a reduced model will be presented, for more details see.

  15. Transcription Factors in Muscle Atrophy Caused by Blocked Neuromuscular Transmission and Muscle Unloading In Rats

    OpenAIRE

    Nordquist, Jenny; Höglund, Anna-Stina; Norman, Holly; Tang, Xiaorui; Dworkin, Barry; Larsson, Lars

    2007-01-01

    The muscle wasting associated with long-term intensive care unit (ICU) treatment has a negative effect on muscle function resulting in prolonged periods of rehabilitation and a decreased quality of life. To identify mechanisms behind this form of muscle wasting, we have used a rat model designed to mimic the conditions in an ICU. Rats were pharmacologically paralyzed with a postsynaptic blocker of neuromuscular transmission, and mechanically ventilated for one to two weeks, thereby unloading ...

  16. Modeling and control of vibration in mechanical structures

    OpenAIRE

    Nauclér, Peter

    2005-01-01

    All mechanical systems exhibit vibrational response when exposed to external disturbances. In many engineering applications vibrations are undesirable and may even have harmful effects. Therefore, control of mechanical vibration is an important topic and extensive research has been going on in the field over the years. In active control of vibration, the ability to actuate the system in a controlled manner is incorporated into the structure. Sensors are used to measure the vibrations and seco...

  17. Control of a mechanical gripper with a fuzzy controller; Control de una garra robotizada mediante un controlador borroso

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, J.; Barcala, J.M.; Gamero, E.; Navarrete, J.J.

    1995-07-01

    A fuzzy logic system is used to control a mechanical gripper. System is based in a NLX230 fuzzy micro controller. Control rules are programmed by a 68020 microprocessor in the micro controller memory. Stress and its derived are used as feedback signals in the control. This system can adapt its effort to the mechanical resistance of the object between the fingers. (Author)

  18. Control of a mechanical gripper with a fuzzy controller; Control de una garra robotizada mediante un controlador borroso

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, J.; Barcala, J.M.; Gamero, E.; Navarrete, J.J.

    1995-07-01

    A fuzzy logic system is used to control a mechanical gripper. System is based in a NLX230 fuzzy micro controller. Control rules are programmed by a 68020 microprocessor in the micro controller memory. Stress and its derived are used as feedback signals in the control. This system can adapt its effort to the mechanical resistance of the object between the fingers.

  19. Urgent epidemic control mechanism for aviation networks

    KAUST Repository

    Peng, Chengbin

    2011-01-01

    In the current century, the highly developed transportation system can not only boost the economy, but also greatly accelerate the spreading of epidemics. While some epidemic diseases may infect quite a number of people ahead of our awareness, the health care resources such as vaccines and the medical staff are usually locally or even globally insufficient. In this research, with the network of major aviation routes as an example, we present a method to determine the optimal locations to allocate the medical service in order to minimize the impact of the infectious disease with limited resources. Specifically, we demonstrate that when the medical resources are insufficient, we should concentrate our efforts on the travelers with the objective of effectively controlling the spreading rate of the epidemic diseases. © 2011 Springer-Verlag Berlin Heidelberg.

  20. Mechanisms controlling radionuclide mobility in forest soils

    International Nuclear Information System (INIS)

    Soil processes strongly influence the radionuclide mobility in soils. The mobility of radionuclides in forest soils is governed by several processes involving both abiotic and biotic factors. The sorption-desorption process chiefly governs the activity of radionuclides in the soil solution, hence thereby their mobility and biological availability. Radiocaesium exhibits a very low mobility in mineral soils. Both mobility and bioavailability however increase as the thickness of organic layers and their content in organic matter increases. Clay minerals of micaceous origin strongly act as slinks for radiocaesium in forest soils. The magnitude of cesium mineral fixation in topsoils is expected to be the highest in mineral soils of Eutric cambisol type, and, to a lesser extent, of type of Distric cambisol and Podzoluvisol. A low mobility of radiocaesium in the surface horizons of forest soils may also be partially explained by a biological mobilization: fungi absorb radiocaesium and transport it to upper layers, thereby contributing to constantly recycle the radioelement in the organic horizons. This mechanism is probably important in soils with thick organic layers (Podsol, Histosol, and, to a lesser extent, Distric cambisol and Podzoluvisol). Radionuclides can be associated with soluble organic anions in the soil solution of forest acid soils. Such associations are highly mobile: they are stable in conditions of poor biological activity (low temperatures, acid soil infertility, water excess, etc.). Their magnitude is expected to be the highest in thick acid organic layers (soils of type Podzol and Histosol)

  1. Synaptic defects in the spinal and neuromuscular circuitry in a mouse model of spinal muscular atrophy.

    Directory of Open Access Journals (Sweden)

    Karen K Y Ling

    Full Text Available Spinal muscular atrophy (SMA is a major genetic cause of death in childhood characterized by marked muscle weakness. To investigate mechanisms underlying motor impairment in SMA, we examined the spinal and neuromuscular circuitry governing hindlimb ambulatory behavior in SMA model mice (SMNΔ7. In the neuromuscular circuitry, we found that nearly all neuromuscular junctions (NMJs in hindlimb muscles of SMNΔ7 mice remained fully innervated at the disease end stage and were capable of eliciting muscle contraction, despite a modest reduction in quantal content. In the spinal circuitry, we observed a ∼28% loss of synapses onto spinal motoneurons in the lateral column of lumbar segments 3-5, and a significant reduction in proprioceptive sensory neurons, which may contribute to the 50% reduction in vesicular glutamate transporter 1(VGLUT1-positive synapses onto SMNΔ7 motoneurons. In addition, there was an increase in the association of activated microglia with SMNΔ7 motoneurons. Together, our results present a novel concept that synaptic defects occur at multiple levels of the spinal and neuromuscular circuitry in SMNΔ7 mice, and that proprioceptive spinal synapses could be a potential target for SMA therapy.

  2. Physical damping in IDA-PBC controlled underactuated mechanical systems

    NARCIS (Netherlands)

    Gomez-Estern, F.; Schaft, van der A.J.

    2004-01-01

    Energy shaping and passivity-based control designs have proven to be effective in solving control problems for tinderactttated mechanical systems. In recent works, interconnection and damping assignment passivity-based control (IDA-PEC) has been successfully applied to open-loop conservative models,

  3. Fuzzy control of electro-mechanical gearbox actuator

    Institute of Scientific and Technical Information of China (English)

    G Iordanidis; P H Mellor; D Holliday; P M Churn

    2003-01-01

    In this paper, a prototype direct-drive electro-mechanical actuator is proposed to select gears in a high performance gearbox. Because of the nonlinear behavior of the actuator, a fuzzy logic controller is adopted. The result of simulation has proved that the dynamic response obtained using the fuzzy controller is much faster than that obtained using traditional PD controller.

  4. Chemical and mechanical weed control in soybean (Glycine max

    Directory of Open Access Journals (Sweden)

    Weber, Jonas Felix

    2016-02-01

    Full Text Available In this study we investigated the possibility of chemical and mechanical weed control strategies in soybean. Soybean field experiments were carried out in 2013 and 2014 in Southern Germany. Five treatments including common herbicide mixtures and four mechanical weed control treatments, implementing a harrow and a hoe, were tested at different locations. In the herbicide experiments two treatments were applied by PRE emergence herbicides (metribuzin, clomazone, dimethenamid and metribuzin, flufenacet, clomazone and another two treatments were sprayed with a combination of PRE + POST emergence herbicides (metribuzin, flufenacet, thifensulfuron and pendimethalin, thifensulfuron, bentazone, cycloxydim. Furthermore, a POST herbicide treatment was implemented (thifensulfuron, bentazone, thifensulfuron and fluazifop-P-butyl. In the mechanical weed control experiments, treatments were: three times hoeing, PRE emergence harrowing plus three times hoeing, hoeing and harrowing in rotation or three times harrowing. In both experiments an untreated control was included. A 90% weed control efficacy and 23% yield increase was observed in the POST herbicide treatment. PRE + POST treatments resulted in 92% to 99% weed control efficiency and 15% yield increase compared to the untreated control. In the mechanical weed control experiments the combination of PRE emergence harrowing and POST emergence hoeing resulted in 82% weed control efficiency and 34% higher yield compared to the untreated control. Less weed control efficiency (72% was observed in the harrow treatment, leading to 20% higher yield compared to the control. The suitability of both strategies for implementation in “Integrated Weed Management” has been investigated.

  5. Mechanisms of using mutations in pest control

    International Nuclear Information System (INIS)

    Traditional chemically based methods for insect control have been shown to have serious limitations, and many alternative approaches have been developed and evaluated, including those based on the use of different types of mutation. The mutagenic action of ionizing radiation was well known in the field of genetics long before it was realized by entomologists that it might be used to induce dominant lethal mutations in insects, which, when released, could sterilize wild female insects. The use of radiation to induce dominant lethal mutations in the sterile insect technique is now a major component of many large and successful programs for pest suppression and eradication. Specific types of mutations can also be used to make improvements to the sterile insect technique, especially for the development of strains for the production of only male insects for sterilization and release. These strains utilize male translocations and a variety of selectable mutations, either conditional or visible, so that at some stages of development, the males can be separated from the females. (author)

  6. Influence of intense neuromuscular blockade on surgical conditions during laparotomy

    DEFF Research Database (Denmark)

    Madsen, Matias Vested; Donatsky, Anders Meller; Jensen, Bente Rona;

    2015-01-01

    neuromuscular block on surgical conditions with a subjective rating scale, force needed to close the fascia, incidences of abdominal contractions while suctioning the lungs, width of the wound diastase and operating time as outcome parameters. RESULTS: In all six pigs no abdominal contractions occurred while...... neuromuscular block suctioning the lungs elicited brief periods of abdominal EMG activity. No difference was found in the force needed to close the fascia when comparing no neuromuscular block with intense neuromuscular block. Furthermore, no significant differences were found in the width of the diastase...... not influence the force needed to close the fascia....

  7. Robust vibration control of flexible linkage mechanisms using piezoelectric films

    Science.gov (United States)

    Liao, Wen-Hwei; Chou, Jyh-Horng; Horng, Ing-Rong

    1997-08-01

    Based on the state space model of the flexible linkage mechanism equipped with piezoelectric films, a robust control methodology for suppressing elastodynamic responses of the high-speed flexible linkage mechanism with linear time-varying parameter perturbations by employing an observer-based feedback controller is presented. The instability caused by the linear time-varying parameter perturbations and the instability caused by the combined effect of control and observation spillover are investigated and carefully prevented by two robust stability criteria proposed in this paper. Numerical simulation of a slider - crank mechanism example is performed to evaluate the improvement of the elastodynamic responses.

  8. Neuromuscular stimulation therapy after incomplete spinal cord injury promotes recovery of interlimb coordination during locomotion

    Science.gov (United States)

    Jung, R.; Belanger, A.; Kanchiku, T.; Fairchild, M.; Abbas, J. J.

    2009-10-01

    The mechanisms underlying the effects of neuromuscular electrical stimulation (NMES) induced repetitive limb movement therapy after incomplete spinal cord injury (iSCI) are unknown. This study establishes the capability of using therapeutic NMES in rodents with iSCI and evaluates its ability to promote recovery of interlimb control during locomotion. Ten adult female Long Evans rats received thoracic spinal contusion injuries (T9; 156 ± 9.52 Kdyne). 7 days post-recovery, 6/10 animals received NMES therapy for 15 min/day for 5 days, via electrodes implanted bilaterally into hip flexors and extensors. Six intact animals served as controls. Motor function was evaluated using the BBB locomotor scale for the first 6 days and on 14th day post-injury. 3D kinematic analysis of treadmill walking was performed on day 14 post-injury. Rodents receiving NMES therapy exhibited improved interlimb coordination in control of the hip joint, which was the specific NMES target. Symmetry indices improved significantly in the therapy group. Additionally, injured rodents receiving therapy more consistently displayed a high percentage of 1:1 coordinated steps, and more consistently achieved proper hindlimb touchdown timing. These results suggest that NMES techniques could provide an effective therapeutic tool for neuromotor treatment following iSCI.

  9. Neuromuscular stimulation therapy after incomplete spinal cord injury promotes recovery of interlimb coordination during locomotion

    Science.gov (United States)

    Jung, R; Belanger, A; Kanchiku, T; Fairchild, M; Abbas, J J

    2016-01-01

    The mechanisms underlying the effects of neuromuscular electrical stimulation (NMES) induced repetitive limb movement therapy after incomplete spinal cord injury (iSCI) are unknown. This study establishes the capability of using therapeutic NMES in rodents with iSCI and evaluates its ability to promote recovery of interlimb control during locomotion. Ten adult female Long Evans rats received thoracic spinal contusion injuries (T9; 156 ± 9.52 Kdyne). 7 days post-recovery, 6/10 animals received NMES therapy for 15 min/day for 5 days, via electrodes implanted bilaterally into hip flexors and extensors. Six intact animals served as controls. Motor function was evaluated using the BBB locomotor scale for the first 6 days and on 14th day post-injury. 3D kinematic analysis of treadmill walking was performed on day 14 post-injury. Rodents receiving NMES therapy exhibited improved interlimb coordination in control of the hip joint, which was the specific NMES target. Symmetry indices improved significantly in the therapy group. Additionally, injured rodents receiving therapy more consistently displayed a high percentage of 1:1 coordinated steps, and more consistently achieved proper hindlimb touchdown timing. These results suggest that NMES techniques could provide an effective therapeutic tool for neuromotor treatment following iSCI. PMID:19721184

  10. Mechanical systems a unified approach to vibrations and controls

    CERN Document Server

    Gans, Roger F

    2015-01-01

    This essential textbook covers analysis and control of engineering mechanisms, which include almost any apparatus with moving parts used in daily life, from musical instruments to robots. The text  presents both vibrations and controls with considerable breadth and depth using a unified notation. It strikes a nice balance between the analytical and the practical.  This text contains enough material for a two semester sequence, but it can also be used in a single semester course combining the two topics. Mechanical Systems: A Unified Approach to Vibrations and Controls presents a common notation and approach to these closely related areas. Examples from the both vibrations and controls components are integrated throughout this text. This book also: ·         Presents a unified approach to vibrations and controls, including an excellent diagram that simultaneously discusses embedding classical vibrations (mechanical systems) in a discussion of models, inverse models, and open and closed loop control ...

  11. Diverticular Disease of the Colon: Neuromuscular Function Abnormalities.

    Science.gov (United States)

    Bassotti, Gabrio; Villanacci, Vincenzo; Bernardini, Nunzia; Dore, Maria P

    2016-10-01

    Colonic diverticular disease is a frequent finding in daily clinical practice. However, its pathophysiological mechanisms are largely unknown. This condition is likely the result of several concomitant factors occurring together to cause anatomic and functional abnormalities, leading as a result to the outpouching of the colonic mucosa. A pivotal role seems to be played by an abnormal colonic neuromuscular function, as shown repeatedly in these patients, and by an altered visceral perception. There is recent evidence that these abnormalities might be related to the derangement of the enteric innervation, to an abnormal distribution of mucosal neuropeptides, and to low-grade mucosal inflammation. The latter might be responsible for the development of visceral hypersensitivity, often causing abdominal pain in a subset of these patients. PMID:27622368

  12. Modeling and Adaptive Control of a Planar Parallel Mechanism

    Institute of Scientific and Technical Information of China (English)

    敖银辉; 陈新

    2004-01-01

    Dynamic model and control strategy of parallel mechanism have always been a problem in robotics research. In this paper,different dynamics formulation methods are discussed first, A model of redundant driven parallel mechanism with a planar parallel manipulator is then constructed as an example. A nonlinear adaptive control method is introduced. Matrix pseudo-inversion is used to get a desired actuator torque from a desired end-effector coordinate while the feedback torque is directly calculated in the actuator space. This treatment avoids forward kinematics computation that is very difficult in a parallel mechanism. Experiments with PID together with the descibed adaptive control strategy were carried out for a planar parallel mechanism. The results show that the proposed adaptive controller outperforms conventional PID methods in tracking desired input at a high speed,

  13. O uso de bloqueadores neuromusculares no Brasil El uso de bloqueadores neuromusculares en Brasil Neuromuscular blockers in Brazil

    OpenAIRE

    Maria Cristina Simões de Almeida

    2004-01-01

    JUSTIFICATIVA E OBJETIVOS: Dados estatísticos referentes ao uso de bloqueadores neuromusculares no Brasil são desconhecidos. Este trabalho se propõe a análise estatística desse tópico. MÉTODO: Foram compiladas 831 respostas de um questionário preenchido em parte por anestesiologistas presentes ao 48º Congresso Brasileiro de Anestesiologia em Recife, 2001 e em parte via Internet, por anestesiologistas cujos endereços eletrônicos constam na página da Sociedade Brasileira de Anestesiologia (www....

  14. The Integrated Control-Mechanism in ATM-Based Networks

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Survivability is one of the important issues in ATM-based networks since even a single network element failure may cause a serious data loss. This paper introduces a new restoration mechanism based on multi-layer ATM survivable network management architecture. This mechanism integrates the general control and restoration control by establishing the Working VPs logical network, Backup VPs logical network and spare logical network in order to optimally utilize the network resources while maintaining the restoration requirements.

  15. The Design of Wheelchair Lifting Mechanism and Control System

    Institute of Scientific and Technical Information of China (English)

    ZHAO Cong; WANG Zheng-xing; JIANG Shi-hong; ZHANG Li; LIU Zheng-yu

    2014-01-01

    In order to achieve a wheelchair lift function, this paper designs a tri-scissors mechanism. Through the so-called H-type transmission and L-type swing rod, the three scissors mechanisms lift in the same rate with only one liner motor while ensuring the stability of the lift. Finite element analysis in ANSYS is performed to verify the material strength. The control system with Sunplus SCM achieves the voice control of wheelchair walking and lifting.

  16. Neuromuscular induced phonation in a human ex vivo perfused larynx preparation

    OpenAIRE

    Berke, Gerald; Mendelsohn, Abie H; Scott Howard, Nelson; Zhang, Zhaoyan

    2013-01-01

    Considering differences in laryngeal anatomy, degree of control, and range of voice qualities between animals and humans, investigations of the neuromuscular process of voice control are better conducted using a living human larynx in which parametric stimulation of individual laryngeal muscles is possible. Due to difficulties in access and monitoring of laryngeal muscle activities, such investigations are impossible in living human subject experiments. This study reports the recent success i...

  17. Mechanics and model-based control of advanced engineering systems

    CERN Document Server

    Irschik, Hans; Krommer, Michael

    2014-01-01

    Mechanics and Model-Based Control of Advanced Engineering Systems collects 32 contributions presented at the International Workshop on Advanced Dynamics and Model Based Control of Structures and Machines, which took place in St. Petersburg, Russia in July 2012. The workshop continued a series of international workshops, which started with a Japan-Austria Joint Workshop on Mechanics and Model Based Control of Smart Materials and Structures and a Russia-Austria Joint Workshop on Advanced Dynamics and Model Based Control of Structures and Machines. In the present volume, 10 full-length papers based on presentations from Russia, 9 from Austria, 8 from Japan, 3 from Italy, one from Germany and one from Taiwan are included, which represent the state of the art in the field of mechanics and model based control, with particular emphasis on the application of advanced structures and machines.

  18. Single-atom quantum control of macroscopic mechanical oscillators

    Science.gov (United States)

    Bariani, F.; Otterbach, J.; Tan, Huatang; Meystre, P.

    2014-01-01

    We investigate a hybrid electromechanical system consisting of a pair of charged macroscopic mechanical oscillators coupled to a small ensemble of Rydberg atoms. The resonant dipole-dipole coupling between an internal atomic Rydberg transition and the mechanics allows cooling to its motional ground state with a single atom despite the considerable mass imbalance between the two subsystems. We show that the rich electronic spectrum of Rydberg atoms, combined with their high degree of optical control, paves the way towards implementing various quantum-control protocols for the mechanical oscillators.

  19. Biomechanical and neuromuscular characteristics of male athletes: implications for the development of anterior cruciate ligament injury prevention programs.

    Science.gov (United States)

    Sugimoto, Dai; Alentorn-Geli, Eduard; Mendiguchía, Jurdan; Samuelsson, Kristian; Karlsson, Jon; Myer, Gregory D

    2015-06-01

    Prevention of anterior cruciate ligament (ACL) injury is likely the most effective strategy to reduce undesired health consequences including reconstruction surgery, long-term rehabilitation, and pre-mature osteoarthritis occurrence. A thorough understanding of mechanisms and risk factors of ACL injury is crucial to develop effective prevention programs, especially for biomechanical and neuromuscular modifiable risk factors. Historically, the available evidence regarding ACL risk factors has mainly involved female athletes or has compared male and female athletes without an intra-group comparison for male athletes. Therefore, the principal purpose of this article was to review existing evidence regarding the investigation of biomechanical and neuromuscular characteristics that may imply aberrant knee kinematics and kinetics that would place the male athlete at risk of ACL injury. Biomechanical evidence related to knee kinematics and kinetics was reviewed by different planes (sagittal and frontal/coronal), tasks (single-leg landing and cutting), situation (anticipated and unanticipated), foot positioning, playing surface, and fatigued status. Neuromuscular evidence potentially related to ACL injury was reviewed. Recommendations for prevention programs for ACL injuries in male athletes were developed based on the synthesis of the biomechanical and neuromuscular characteristics. The recommendations suggest performing exercises with multi-plane biomechanical components including single-leg maneuvers in dynamic movements, reaction to and decision making in unexpected situations, appropriate foot positioning, and consideration of playing surface condition, as well as enhancing neuromuscular aspects such as fatigue, proprioception, muscle activation, and inter-joint coordination.

  20. What Is the Evidence for Harm of Neuromuscular Blockade and Corticosteroid Use in the Intensive Care Unit?

    Science.gov (United States)

    Annane, Djillali

    2016-02-01

    Neuromuscular blocking agents and corticosteroids are widely used in medicine and in particular in the intensive care unit (ICU). Neuromuscular blockade is commonly used to ease tracheal intubation, to optimize mechanical ventilation and oxygenation in acute respiratory disorders such as status asthmaticus and acute respiratory distress syndrome (ARDS), to prevent shivering during therapeutic hypothermia, and also in patients with elevated intracranial pressure. In the ICU, patients with sepsis, ARDS, community-acquired pneumonia, exacerbation of chronic obstructive pulmonary disease, severe asthma, or trauma may receive corticosteroids. It is not rare that ICU patients receive concomitantly neuromuscular blocking drugs and corticosteroids. Among the various serious adverse reactions to these drugs, secondary infection and ICU-acquired weakness may place a burden to the health-care system by resulting in substantial cost and long-term morbidity. Both superinfections and ICU-acquired paresis are more likely when high doses of fluorinated corticosteroids are combined with prolonged treatment with a long-acting non-depolarizing neuromuscular blocker. Modern ICU practices favor lower dose of corticosteroids and very short course of short-acting curare for the management of sepsis or ARDS. Recent trials provided no evidence for increased risk of secondary infections or critical illness neuromyopathy in patients with sepsis or ARDS with the use of corticosteroids or neuromuscular blockers. PMID:26820274

  1. 21 CFR 882.5810 - External functional neuromuscular stimulator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External functional neuromuscular stimulator. 882.5810 Section 882.5810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External functional neuromuscular stimulator. (a) Identification. An external functional...

  2. Motoneuron and sensory neuron plasticity to varying neuromuscular activity levels

    Science.gov (United States)

    Ishihara, Akihiko; Roy, Roland R.; Ohira, Yoshinobu; Edgerton, V. Reggie

    2002-01-01

    The size and phenotypic properties of the neural and muscular elements of the neuromuscular unit are matched under normal conditions. When subjected to chronic decreases or increases in neuromuscular activity, however, the adaptations in these properties are much more limited in the neural compared with the muscular elements.

  3. Stress in Families of Children With Neuromuscular Disease.

    Science.gov (United States)

    Holroyd, Jean; Guthrie, Donald

    1979-01-01

    This study compared parents of children with neuromuscular diseases to parents of children with psychiatric diagnoses, using the Questionnaire on Resources and Stress. The groups showed different patterns of stress relating to child care. Within the neuromuscular group, parental stress increased with the severity of the child's illness.…

  4. Recent achievements in restorative neurology: Progressive neuromuscular diseases

    International Nuclear Information System (INIS)

    This book contains 27 chapters. Some of the chapter titles are: Computed Tomography of Muscles in Neuromuscular Disease; Mapping the Genes for Muscular Dystrophy; Trophic Factors and Motor Neuron Development; Size of Motor Units and Firing Rate in Muscular Dystrophy; Restorative Possibilities in Relation to the Pathology of Progressive Neuromuscular Disease; and An Approach to the Pathogenesis of some Congenital Myopathies

  5. Improving Network Performance by Ameliorating TCP Congestion Control Mechanism

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the rapid growth of rate-based services and wireless applications,improving Transmission Control Protocol (TCP) congestion control has been becoming more important in the network research field. This paper first briefly introduces the Additive-Increase Multiplicative-Decrease (AIMD) (a,b) algorithm,and then presents an improved TCP congestion control mechanism (D-AIMD) whose principles and simulation results are discussed in detail. This mechanism can be easily implemented with lower additional overheads and can efficiently improve network performance.

  6. Soft Time-Suboptimal Controlling Structure for Mechanical Systems

    DEFF Research Database (Denmark)

    Kulczycki, Piotr; Wisniewski, Rafal; Kowalski, Piotr;

    2004-01-01

    The paper presents conception of a soft control structure based on the time-optimal approach. Its parameters are selected in accordance with the rules of the statistical decision theory and additionally it allows to eliminate rapid changes in control values. The object is a basic mechanical system......, with uncertain (also non-stationary) mass treated as a stochastic process. The methodology proposed here is of a universal nature and may easily be applied with respect to other uncertainty elements of timeoptimal controlled mechanical systems....

  7. Long Term Follow-up of Ventilated Patients with Thoracic Restriction and Neuromuscular Disease

    Directory of Open Access Journals (Sweden)

    Dina Brooks

    2002-01-01

    Full Text Available OBJECTIVE: To evaluate the long term effects of home mechanical ventilation (HMV on pulmonary function, nighttime gas exchange, daytime arterial blood gases, sleep architecture and functional exercise capacity (6 min walk. Patients with respiratory failure attributable to thoracic restrictive disease (TRD (kyphoscoliosis or neuromuscular disease (NMD were assessed, ventilated, trained and followed in a dedicated unit for the care of patients requiring long term ventilation.

  8. Haemodynamic performance of neuromuscular electrical stimulation (NMES) during recovery from total hip arthroplasty

    OpenAIRE

    Broderick, Barry J.; Breathnach, Oisin; Condon, Finbarr; Masterson, Eric; ÓLaighin, Gearóid

    2013-01-01

    Background Patients post total hip arthroplasty (THA) remain at high risk of developing Deep Vein Thrombosis (DVT) during the recovery period following surgery despite the availability of effective pharmacological and mechanical prophylactic methods. The use of calf muscle neuromuscular electrical stimulation (NMES) during the hospitalised recovery period on this patient group may be effective at preventing DVT. However, the haemodynamic effectiveness and comfort characteristics of NMES in po...

  9. GA-Binding Protein Is Dispensable for Neuromuscular Synapse Formation and Synapse-Specific Gene Expression▿

    OpenAIRE

    Jaworski, Alexander; Smith, Cynthia L.; Burden, Steven J.

    2007-01-01

    The mRNAs encoding postsynaptic components at the neuromuscular junction are concentrated in the synaptic region of muscle fibers. Accumulation of these RNAs in the synaptic region is mediated, at least in part, by selective transcription of the corresponding genes in synaptic myofiber nuclei. The transcriptional mechanisms that are responsible for synapse-specific gene expression are largely unknown, but an Ets site in the promoter regions of acetylcholine receptor (AChR) subunit genes and o...

  10. Integrated design of cam mechanisms and servo-control systems

    Institute of Scientific and Technical Information of China (English)

    姚燕安[1; 颜鸿森[2; 张策[3; 邹慧君[4

    2000-01-01

    Traditionally, in a cam mechanism, the cam is driven by an actuator at a constant speed. The motion characteristics of the follower are determined once the cam profile is designed. This paper presents a novel theory named "integrated design of cam mechanisms and servo-control systems" whose basic idea is varying the input speed trajectory of the cam by a microcomputer-controlled servomotor to improve kinematic and dynamic characteristics of the follower system. The philosophy of the theory is developing superior machines by taking advantage of the flexibility of servo-control systems to compensate for disadvantages of rigid cam mechanisms. The systematic design criteria of the cam-servo-integrated system are developed and an approach based on optimal-control theory is presented for to select suitable cam speed functions, hence the basis of the theory is formed.

  11. Noninvasive Assessment of Neuromuscular Disease in Dogs: Use of the 6‐minute Walk Test to Assess Submaximal Exercise Tolerance in Dogs with Centronuclear Myopathy

    OpenAIRE

    Cerda‐Gonzalez, S.; Talarico, L.; Todhunter, R

    2016-01-01

    Background Noninvasive methods of quantitating exercise tolerance in dogs with neuromuscular disease are needed both for clinical and research use. The 6‐minute walk test (6MWT) has been validated as a reliable test of exercise tolerance in dogs with pulmonary and cardiac disease, but not in dogs with neuromuscular disease. Hypothesis/Objectives Distance walked and number of steps taken during 6MWT will differ between Labrador retriever dogs with centronuclear myopathy (CNM) and control (ie, ...

  12. Synthesis of dissipative output feedback controllers. Application to mechanical systems

    Energy Technology Data Exchange (ETDEWEB)

    Johannessen, Erling Aarsand

    1997-12-31

    This thesis presents new results on the synthesis of linear controllers with passivity, or more general, dissipativity properties. These methods may be applied to obtain more accurate control over mechanical systems and in the control of chemical processes that involve dissipative subsystems. The thesis presents two different approaches for synthesis of dissipative controllers: (1) A method that exploits the Riccati equation solution to the state space formulation of the H{sub {infinity}} control problem is investigated, illustrated by synthesising a controller for damping of flexible modes in a beam. (2) A more general method for dissipative control synthesis is developed that retains the well-known techniques of loop-shaping and frequency weighting in H{sub {infinity}}. A method is also presented for controller synthesis directly from frequency response data. 82 refs., 34 figs., 3 tabs.

  13. Electrophysiological study in neuromuscular junction disorders

    Directory of Open Access Journals (Sweden)

    Ajith Cherian

    2013-01-01

    Full Text Available This review is on ultrastructure and subcellular physiology at normal and abnormal neuromuscular junctions. The clinical and electrophysiological findings in myasthenia gravis, Lambert-Eaton myasthenic syndrome (LEMS, congenital myasthenic syndromes, and botulinum intoxication are discussed. Single fiber electromyography (SFEMG helps to explain the basis of testing neuromuscular junction function by repetitive nerve stimulation (RNS. SFEMG requires skill and patience and its availability is limited to a few centers. For RNS supramaximal stimulation is essential and so is display of the whole waveform of each muscle response at maximum amplitude. The amplitudes of the negative phase of the first and fourth responses are measured from baseline to negative peak, and the percent change of the fourth response compared with the first represents the decrement or increment. A decrement greater than 10% is accepted as abnormal and smooth progression of response amplitude train and reproducibility form the crux. In suspected LEMS the effect of fast rates of stimulation should be determined after RNS response to slow rates of stimulation. Caution is required to avoid misinterpretation of potentiation and pseudofacilitation.

  14. Electrophysiological study in neuromuscular junction disorders.

    Science.gov (United States)

    Cherian, Ajith; Baheti, Neeraj N; Iype, Thomas

    2013-01-01

    This review is on ultrastructure and subcellular physiology at normal and abnormal neuromuscular junctions. The clinical and electrophysiological findings in myasthenia gravis, Lambert-Eaton myasthenic syndrome (LEMS), congenital myasthenic syndromes, and botulinum intoxication are discussed. Single fiber electromyography (SFEMG) helps to explain the basis of testing neuromuscular junction function by repetitive nerve stimulation (RNS). SFEMG requires skill and patience and its availability is limited to a few centers. For RNS supramaximal stimulation is essential and so is display of the whole waveform of each muscle response at maximum amplitude. The amplitudes of the negative phase of the first and fourth responses are measured from baseline to negative peak, and the percent change of the fourth response compared with the first represents the decrement or increment. A decrement greater than 10% is accepted as abnormal and smooth progression of response amplitude train and reproducibility form the crux. In suspected LEMS the effect of fast rates of stimulation should be determined after RNS response to slow rates of stimulation. Caution is required to avoid misinterpretation of potentiation and pseudofacilitation. PMID:23661960

  15. Prevalence of complications in neuromuscular scoliosis surgery

    DEFF Research Database (Denmark)

    Sharma, Shallu; Wu, Chunsen; Andersen, Thomas;

    2013-01-01

    PURPOSE: Our objectives were primarily to review the published literature on complications in neuromuscular scoliosis (NMS) surgery and secondarily, by means of a meta-analysis, to determine the overall pooled rates (PR) of various complications associated with NMS surgery. METHODS: PubMed and Em......PURPOSE: Our objectives were primarily to review the published literature on complications in neuromuscular scoliosis (NMS) surgery and secondarily, by means of a meta-analysis, to determine the overall pooled rates (PR) of various complications associated with NMS surgery. METHODS: Pub......Med and Embase databases were searched for studies reporting the outcomes and complications of NMS surgery, published from 1997 to May 2011. We focused on NMS as defined by the Scoliosis Research Society's classification. We measured the pooled estimate of the overall complication rates (PR) using a random....... In regard to surgical complications affiliated with various surgical techniques in NMS, the level of evidence of published literature ranges between 2+ to 2-; the subsequent recommendations are level C. CONCLUSION: NMS patients have diverse and high complication rates after scoliosis surgery. High PRs...

  16. Molecular mechanism of size control in development and human diseases

    Institute of Scientific and Technical Information of China (English)

    Xiaolong Yang; Tian Xu

    2011-01-01

    How multicellular organisms control their size is a fundamental question that fascinated generations of biologists.In the past 10 years, tremendous progress has been made toward our understanding of the molecular mechanism underlying size control. Original studies from Drosophila showed that in addition to extrinsic nutritional and hormonal cues, intrinsic mechanisms also play important roles in the control of organ size during development. Several novel signaling pathways such as insulin and Hippo-LATS signaling pathways have been identified that control organ size by regulating cell size and/or cell number through modulation of cell growth, cell division, and cell death. Later studies using mammalian cell and mouse models also demonstrated that the signaling pathways identified in flies are also conserved in mammals. Significantly, recent studies showed that dysregulation of size control plays important roles in the development of many human diseases sucha as cancer,diabetes,and hypertrophy.

  17. Contribución del soporte nutricional al tratamiento de las alteraciones neuro-musculares del paciente crítico Contribution of nutritional support to treatment neuromuscular impairments of critically ill patients

    OpenAIRE

    J. C. Montejo González

    2006-01-01

    Las alteraciones neuromusculares que tienen lugar en el paciente crítico han sido atribuidas a factores como la situación séptica, la liberación de mediadores inflamatorioso el empleo de fármacos que afectan desfavorablemente a la función neuro-muscular. El papel de factores metabólicos y nutricionales en el desarrollo de esta patología ha recibido poca atención. En la actualidad, el empleo de protocolos de control intensivo de la glucemia podría tener gran interés en la prevención de las alt...

  18. Rock mechanics. Superplastic nanofibrous slip zones control seismogenic fault friction.

    Science.gov (United States)

    Verberne, Berend A; Plümper, Oliver; de Winter, D A Matthijs; Spiers, Christopher J

    2014-12-12

    Understanding the internal mechanisms controlling fault friction is crucial for understanding seismogenic slip on active faults. Displacement in such fault zones is frequently localized on highly reflective (mirrorlike) slip surfaces, coated with thin films of nanogranular fault rock. We show that mirror-slip surfaces developed in experimentally simulated calcite faults consist of aligned nanogranular chains or fibers that are ductile at room conditions. These microstructures and associated frictional data suggest a fault-slip mechanism resembling classical Ashby-Verrall superplasticity, capable of producing unstable fault slip. Diffusive mass transfer in nanocrystalline calcite gouge is shown to be fast enough for this mechanism to control seismogenesis in limestone terrains. With nanogranular fault surfaces becoming increasingly recognized in crustal faults, the proposed mechanism may be generally relevant to crustal seismogenesis. PMID:25504714

  19. Controlling disease spread on networks with feedback mechanism

    Institute of Scientific and Technical Information of China (English)

    Wang Li; Yan Jia-Ren; Zhang Jian-Guo; Liu Zi-Ran

    2007-01-01

    Many real-world networks have the ability to adapt themselves in response to the state of their nodes. This paper studies controlling disease spread on network with feedback mechanism, where the susceptible nodes are able to avoid contact with the infected ones by cutting their connections with probability when the density of infected nodes reaches a certain value in the network. Such feedback mechanism considers the networks' own adaptivity and the cost of immunization. The dynamical equations about immunization with feedback mechanism are solved and theoretical predictions are in agreement with the results of large scale simulations. It shows that when the lethality α increases,the prevalence decreases more greatly with the same immunization g. That is, with the same cost, a better controlling result can be obtained. This approach offers an effective and practical policy to control disease spread, and also may be relevant to other similar networks.

  20. Does perioperative tactile evaluation of the train-of-four response influence the frequency of postoperative residual neuromuscular blockade?

    DEFF Research Database (Denmark)

    Pedersen, T; Viby-Mogensen, J; Bang, U;

    1990-01-01

    The authors conducted a randomized controlled clinical trial to evaluate the usefulness of perioperative manual evaluation of the response to train-of-four (TOF) nerve stimulation. A total of 80 patients were divided into four groups of 20 each. For two groups (one given vecuronium and one...... pancuronium), the anesthetists assessed the degree of neuromuscular blockade during operation and during recovery from neuromuscular blockade by manual evaluation of the response to TOF nerve stimulation. In the other two groups, one of which received vecuronium and the other pancuronium, the anesthetists...

  1. EFFECT OF TRAINING WITH NEUROMUSCULAR ELECTRICAL STIMULATION ON ELBOW FLEXION STRENGTH

    OpenAIRE

    Holcomb, William R.

    2006-01-01

    Neuromuscular electrical stimulation (NMES) may be used to prevent strength loss associated with post-surgical immobilization. Most studies testing the effectiveness of NMES have trained the knee extensors. The purpose of this investigation was to test the effectiveness of NMES when training the elbow flexors. Twenty-four students were randomly assigned to one of three groups: NMES training, isometric training or control. Testing and training were completed using a Biodex™ dynamometer. After ...

  2. Neuromuscular function and fatigue resistance of the plantar flexors following short-term cycling endurance training

    OpenAIRE

    BEHRENS, Martin; Weippert, Matthias; Wassermann, Franziska; Bader, Rainer; Bruhn, Sven; Mau-Moeller, Anett

    2015-01-01

    Previously published studies on the effect of short-term endurance training on neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC) and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals ...

  3. The Effects on the Pulmonary Function of Normal Adults Proprioceptive Neuromuscular Facilitation Respiration Pattern Exercise

    OpenAIRE

    Seo, KyoChul; Cho, Misuk

    2014-01-01

    [Purpose] The purpose of this study was to determine whether proprioceptive neuromuscular facilitation (PNF) respiration exercise increases the pulmonary function of normal adults. [Subjects and Methods] Twenty-eight normal adults in their 20s were randomly assigned to an experimental group (n=14) or control group (n=14). Over the course of four weeks, the experimental group participated in PNF respiration pattern exercises for 30 minutes three times per week. Subjects were assessed pre-test ...

  4. The Role of MuSK in Synapse Formation and Neuromuscular Disease

    OpenAIRE

    Burden, Steven J.; Yumoto, Norihiro; Zhang, Wei

    2013-01-01

    Muscle-specific kinase (MuSK) is essential for each step in neuromuscular synapse formation. Before innervation, MuSK initiates postsynaptic differentiation, priming the muscle for synapse formation. Approaching motor axons recognize the primed, or prepatterned, region of muscle, causing motor axons to stop growing and differentiate into specialized nerve terminals. MuSK controls presynaptic differentiation by causing the clustering of Lrp4, which functions as a direct retrograde signal for p...

  5. Prolonged mental exertion does not alter neuromuscular function of the knee extensors

    OpenAIRE

    Pageaux, Benjamin; Marcora, Samuele; Lepers, Romuald

    2013-01-01

    International audience; Purpose: The aim of this study was to test the hypotheses that prolonged mental exertion i) reduces maximal muscle activation and ii) increases the extent of central fatigue induced by subsequent endurance exercise. Methods: Neuromuscular function of the knee extensor muscles was assessed in 10 male subjects in two different conditions: i) before and after prolonged mental exertion leading to mental fatigue; ii) before and after an easy cognitive task (control). Both c...

  6. Neuromuscular adaptations to 4 weeks of intensive drop jump training in well-trained athletes

    DEFF Research Database (Denmark)

    Alkjær, Tine; Meyland, Jacob; Raffalt, Peter C;

    2013-01-01

    This study examined the effects of 4 weeks of intensive drop jump training in well-trained athletes on jumping performance and underlying changes in biomechanics and neuromuscular adaptations. Nine well-trained athletes at high national competition level within sprinting and jumping disciplines...... performance also in well-trained athletes without concomitant changes in muscle strength. It is suggested that the behavioral improvement is primarily due to neural factors regulating the activation pattern controlling the drop jump movement....

  7. Mechanical Response of DNA–Nanoparticle Crystals to Controlled Deformation

    Science.gov (United States)

    2016-01-01

    The self-assembly of DNA-conjugated nanoparticles represents a promising avenue toward the design of engineered hierarchical materials. By using DNA to encode nanoscale interactions, macroscale crystals can be formed with mechanical properties that can, at least in principle, be tuned. Here we present in silico evidence that the mechanical response of these assemblies can indeed be controlled, and that subtle modifications of the linking DNA sequences can change the Young’s modulus from 97 kPa to 2.1 MPa. We rely on a detailed molecular model to quantify the energetics of DNA–nanoparticle assembly and demonstrate that the mechanical response is governed by entropic, rather than enthalpic, contributions and that the response of the entire network can be estimated from the elastic properties of an individual nanoparticle. The results here provide a first step toward the mechanical characterization of DNA–nanoparticle assemblies, and suggest the possibility of mechanical metamaterials constructed using DNA. PMID:27725959

  8. Engagement and control of synchroniser mechanisms in dual clutch transmissions

    Science.gov (United States)

    Walker, Paul D.; Zhang, Nong

    2012-01-01

    The study of synchroniser engagements in dual clutch transmissions is undertaken in this paper, identifying limitations to the repeatability of actuation, demonstrating one popular solution for positive synchroniser control and offering an alternate engagement tool. Principally, high wet clutch drag and the synchroniser design have lead to detrimental alignments conditions, where indexing chamfers on sleeve and target gear delay engagement of the mechanism and lead to potential sleeve block out. This paper focuses on the investigation of different control methods for overcoming these detrimental alignment conditions. The application of a closed loop control method to overcome block out related engagements is studied, and, for comparison, a novel engagement tool for overriding all chamfer alignment conditions is introduced and evaluated. Results have demonstrated that both techniques have some limitations, with the novel tool being capable of providing direct control of all chamfer engagements with limited extension of the duration of synchroniser engagements; however, some tuning of mechanism parameters is required for different engagement conditions.

  9. Output feedback control of a mechanical system using magnetic levitation.

    Science.gov (United States)

    Beltran-Carbajal, F; Valderrabano-Gonzalez, A; Rosas-Caro, J C; Favela-Contreras, A

    2015-07-01

    This paper presents an application of a nonlinear magnetic levitation system to the problem of efficient active control of mass-spring-damper mechanical systems. An output feedback control scheme is proposed for reference position trajectory tracking tasks on the flexible mechanical system. The electromagnetically actuated system is shown to be a differentially flat nonlinear system. An extended state estimation approach is also proposed to obtain estimates of velocity, acceleration and disturbance signals. The differential flatness structural property of the system is then employed for the synthesis of the controller and the signal estimation approach presented in this work. Some experimental and simulation results are included to show the efficient performance of the control approach and the effective estimation of the unknown signals. PMID:25707718

  10. Sex alters impact of repeated bouts of sprint exercise on neuromuscular activity in trained athletes.

    Science.gov (United States)

    Billaut, François; Smith, Kurt

    2009-08-01

    This study characterized the effect of sex on neuromuscular activity during repeated bouts of sprint exercise. Thirty-three healthy male and female athletes performed twenty 5-s cycle sprints separated by 25 s of rest. Mechanical work and integrated electromyograhs (iEMG) of 4 muscles of the dominant lower limb were calculated in every sprint. The iEMG signals from individual muscles were summed to represent overall electrical activity of these muscles (sum-iEMG). Neuromuscular efficiency (NME) was calculated as the ratio of mechanical work and sum-iEMG for every sprint. Arterial oxygen saturation was estimated (SpO2) with pulse oximetry throughout the protocol. The sprint-induced work decrement (18.9% vs. 29.6%; p women than for the men. However, the sprints decreased NME (10.1%; p men, R2 = 0.87; women, R2 = 0.91; all p sprint exercise is not likely to be explained by a difference in muscle contractility impairment in men and women, but may be due to a sex difference in muscle recruitment strategy. We speculate that women would be less sensitive to arterial O2 desaturation than men, which may trigger lower neuromuscular adjustments to exhaustive exercise.

  11. Neuromuscular blockade in cardiac surgery: An update for clinicians

    Directory of Open Access Journals (Sweden)

    Hemmerling Thomas

    2008-01-01

    Full Text Available There have been great advancements in cardiac surgery over the last two decades; the widespread use of off-pump aortocoronary bypass surgery, minimally invasive cardiac surgery, and robotic surgery have also changed the face of cardiac anaesthesia. The concept of "Fast-track anaesthesia" demands the use of nondepolarising neuromuscular blocking drugs with short duration of action, combining the ability to provide (if necessary sufficiently profound neuromuscular blockade during surgery and immediate re-establishment of normal neuromuscular transmission at the end of surgery. Postoperative residual muscle paralysis is one of the major hurdles for immediate or early extubation after cardiac surgery. Nondepolarising neuromuscular blocking drugs for cardiac surgery should therefore be easy to titrate, of rapid onset and short duration of action with a pathway of elimination independent from hepatic or renal dysfunction, and should equally not affect haemodynamic stability. The difference between repetitive bolus application and continuous infusion is outlined in this review, with the pharmacodynamic and pharmacokinetic characteristics of vecuronium, pancuronium, rocuronium, and cisatracurium. Kinemyography and acceleromyography are the most important currently used neuromuscular monitoring methods. Whereas monitoring at the adductor pollicis muscle is appropriate at the end of surgery, monitoring of the corrugator supercilii muscle better reflects neuromuscular blockade at more central, profound muscles, such as the diaphragm, larynx, or thoraco-abdominal muscles. In conclusion, cisatracurium or rocuronium is recommended for neuromuscular blockade in modern cardiac surgery.

  12. Quality control of injection moulded micro mechanical parts

    DEFF Research Database (Denmark)

    Gasparin, Stefania; Tosello, Guido; Hansen, Hans Nørgaard;

    2009-01-01

    Quality control of micro components is an increasing challenge. Smaller mechanical parts are characterized by smaller tolerance to be verified. This paper focuses on the dimensional verification of micro injection moulded components selected from an industrial application. These parts are measured...... using an Optical Coordinate Measuring Machine (OCMM), which guarantees fast surface scans suitable for in line quality control. The uncertainty assessment of the measurements is calculated following the substitution method. To investigate the influence parameters in optical coordinate metrology two...

  13. Control of a perturbed under-actuated mechanical system

    KAUST Repository

    Zayane, Chadia

    2015-11-05

    In this work, the trajectory tracking problem for an under-actuated mechanical system in presence of unknown input disturbances is addressed. The studied inertia wheel inverted pendulum falls in the class of non minimum phase systems. The proposed high order sliding mode control architecture including a controller and differentiator allows to track accurately the predefined trajectory and to stabilize the internal dynamics. The robustness of the proposed approach is illustrated through different perturbation and output noise configurations.

  14. Flexible neural mechanisms of cognitive control within human prefrontal cortex

    OpenAIRE

    Braver, Todd S.; Paxton, Jessica L.; Locke, Hannah S.; Barch, Deanna M

    2009-01-01

    A major challenge in research on executive control is to reveal its functional decomposition into underlying neural mechanisms. A typical assumption is that this decomposition occurs solely through anatomically based dissociations. Here we tested an alternative hypothesis that different cognitive control processes may be implemented within the same brain regions, with fractionation and dissociation occurring on the basis of temporal dynamics. Regions within lateral prefrontal cortex (PFC) wer...

  15. A Markov computer simulation model of the economics of neuromuscular blockade in patients with acute respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    Chow John L

    2006-03-01

    Full Text Available Abstract Background Management of acute respiratory distress syndrome (ARDS in the intensive care unit (ICU is clinically challenging and costly. Neuromuscular blocking agents may facilitate mechanical ventilation and improve oxygenation, but may result in prolonged recovery of neuromuscular function and acute quadriplegic myopathy syndrome (AQMS. The goal of this study was to address a hypothetical question via computer modeling: Would a reduction in intubation time of 6 hours and/or a reduction in the incidence of AQMS from 25% to 21%, provide enough benefit to justify a drug with an additional expenditure of $267 (the difference in acquisition cost between a generic and brand name neuromuscular blocker? Methods The base case was a 55 year-old man in the ICU with ARDS who receives neuromuscular blockade for 3.5 days. A Markov model was designed with hypothetical patients in 1 of 6 mutually exclusive health states: ICU-intubated, ICU-extubated, hospital ward, long-term care, home, or death, over a period of 6 months. The net monetary benefit was computed. Results Our computer simulation modeling predicted the mean cost for ARDS patients receiving standard care for 6 months to be $62,238 (5% – 95% percentiles $42,259 – $83,766, with an overall 6-month mortality of 39%. Assuming a ceiling ratio of $35,000, even if a drug (that cost $267 more hypothetically reduced AQMS from 25% to 21% and decreased intubation time by 6 hours, the net monetary benefit would only equal $137. Conclusion ARDS patients receiving a neuromuscular blocker have a high mortality, and unpredictable outcome, which results in large variability in costs per case. If a patient dies, there is no benefit to any drug that reduces ventilation time or AQMS incidence. A prospective, randomized pharmacoeconomic study of neuromuscular blockers in the ICU to asses AQMS or intubation times is impractical because of the highly variable clinical course of patients with ARDS.

  16. Predictive mechanisms in the control of contour following

    NARCIS (Netherlands)

    Tramper, J.J.; Flanders, M.

    2013-01-01

    In haptic exploration, when running a fingertip along a surface, the control system may attempt to anticipate upcoming changes in curvature in order to maintain a consistent level of contact force. Such predictive mechanisms are well known in the visual system, but have yet to be studied in the soma

  17. Improvement Research of Control Rod Drive Mechanism in CARR

    Institute of Scientific and Technical Information of China (English)

    ZHU; Xue-wei; ZHEN; Jian-xiao; LUO; Zhong; YANG; Kun; WANG; Yi-shi; JIA; Yue-guang

    2013-01-01

    We take an improvement research of synchronization in process of control rod drive mechanism(CRDM)inversion.An experimental prototype is designed based on the structure and function of the CRDM,we take some experiments on this experimental prototype,such as maximum loading force experiment,coil temperature rise experiment and stiffness experiment,achieve important magnetic

  18. Context-Based E-Health System Access Control Mechanism

    Science.gov (United States)

    Al-Neyadi, Fahed; Abawajy, Jemal H.

    E-Health systems logically demand a sufficiently fine-grained authorization policy for access control. The access to medical information should not be just role-based but should also include the contextual condition of the role to access data. In this paper, we present a mechanism to extend the standard role-based access control to incorporate contextual information for making access control decisions in e-health application. We present an architecture consisting of authorisation and context infrastructure that work cooperatively to grant access rights based on context-aware authorization policies and context information.

  19. Anormalidades neuromuscular no desuso, senilidade e caquexia

    OpenAIRE

    João Aris Kouyoumdjian

    1993-01-01

    É feita revisão de literatura sobre as principais alterações do sistema neuromuscular no desuso, senilidade e caquexia no ser humano e em modelos animais. A diminuição do diâmetro das fibras musculares após período de inatividade/imobilidade (desuso) deve-se à perda de miofibrilas periféricas não ocorrendo formação de core-targetóides ou diminuição da atividade da miofosforilase, próprias da desnervação; mantêm-se a liberação espontânea de acetilcolina e fatores tróficos na junção mio-neural;...

  20. Neuromuscular synaptogenesis: coordinating partners with multiple functions.

    Science.gov (United States)

    Darabid, Houssam; Perez-Gonzalez, Anna P; Robitaille, Richard

    2014-11-01

    The formation of highly efficient and reliable synapses at the neuromuscular junction (NMJ) relies on dynamic molecular interactions. Studies of the development and maturation of the NMJ have focused on events that are dependent on synaptic activity and that require the coordinated actions of nerve- and muscle-derived molecules with different targets and effects. More recently, perisynaptic Schwann cells--the glial cells at NMJs--have become an important focus of research. These glia concomitantly contribute to pre- and postsynaptic maturation while undergoing maturation themselves. Thus, an intricate 'danse à trois’'regulates the maturation of the NMJ to form a highly efficient communication unit, in which fine glial processes lie in close proximity to a highly concentrated population of postsynaptic receptors and perfectly aligned presynaptic release sites. PMID:25493308

  1. Spinal mechanisms may provide a combination of intermittent and continuous control of human posture: predictions from a biologically based neuromusculoskeletal model.

    Directory of Open Access Journals (Sweden)

    Leonardo Abdala Elias

    2014-11-01

    Full Text Available Several models have been employed to study human postural control during upright quiet stance. Most have adopted an inverted pendulum approximation to the standing human and theoretical models to account for the neural feedback necessary to keep balance. The present study adds to the previous efforts in focusing more closely on modelling the physiological mechanisms of important elements associated with the control of human posture. This paper studies neuromuscular mechanisms behind upright stance control by means of a biologically based large-scale neuromusculoskeletal (NMS model. It encompasses: i conductance-based spinal neuron models (motor neurons and interneurons; ii muscle proprioceptor models (spindle and Golgi tendon organ providing sensory afferent feedback; iii Hill-type muscle models of the leg plantar and dorsiflexors; and iv an inverted pendulum model for the body biomechanics during upright stance. The motor neuron pools are driven by stochastic spike trains. Simulation results showed that the neuromechanical outputs generated by the NMS model resemble experimental data from subjects standing on a stable surface. Interesting findings were that: i an intermittent pattern of muscle activation emerged from this posture control model for two of the leg muscles (Medial and Lateral Gastrocnemius; and ii the Soleus muscle was mostly activated in a continuous manner. These results suggest that the spinal cord anatomy and neurophysiology (e.g., motor unit types, synaptic connectivities, ordered recruitment, along with the modulation of afferent activity, may account for the mixture of intermittent and continuous control that has been a subject of debate in recent studies on postural control. Another finding was the occurrence of the so-called "paradoxical" behaviour of muscle fibre lengths as a function of postural sway. The simulations confirmed previous conjectures that reciprocal inhibition is possibly contributing to this effect, but

  2. Visual and tactile assessment of neuromuscular fade.

    Science.gov (United States)

    Brull, S J; Silverman, D G

    1993-08-01

    The accuracy of visual and tactile assessment of the neuromuscular fade in response to train-of-four (TOF) and double-burst stimulation (DBS) were compared to assess their relative utility in the clinical setting. For each of 74 data sets with a mechanographic TOF ratio less than 0.70, an observer (blinded to the presence or degree of fade) performed visual and tactile assessments of fade in response to TOF, DBS3,3, and DBS3,2 stimuli at low current (20 and 30 mA) and high current (50 and 60 mA). For the range of mechanographic TOF ratios between 0.41 and 0.70, visual assessment failed to identify TOF, DBS3,3, and DBS3,2 fade in 46%, 18%, and 14% of cases at high current and in 23%, 5%, and 0% of cases at low current, respectively. Tactile assessments failed to identify fade in 55%, 23%, and 14% of cases at high current and in 23%, 14%, and 14% of cases at low current. Overall, the ability to detect fade was comparable for visual and tactile assessments regardless of the method of neurostimulation (P = NS with paired t-test). However, the degree of overestimation of the fade ratio (i.e., quantitative assessment) tended to be less when using tactile means; the difference achieved significance for TOF at low current and DBS3,3 at both low and high currents. We conclude that the differences between the visual and tactile means of assessment are relatively small compared to the differences among the TOF and DBS patterns of neurostimulation. Both subjective techniques are often inadequate in settings in which assurance of full recovery of neuromuscular function is critical.

  3. Enhancement of neuromuscular activity by natural specimens and cultured mycelia of Cordyceps Sinensis in mice

    Directory of Open Access Journals (Sweden)

    K P Singh

    2014-01-01

    Full Text Available The present study was aimed to evaluate the effect of natural specimen and laboratory cultured mycelia of Cordyceps sinensis on neuromuscular activity in mice. The powder of natural specimen and laboratory cultured Cordyceps sinensis was orally administered at the dose rate of 100, 300 and 500 mg/kg for 30 days. Natural specimen and in vitro propagated Cordyceps sinensis showed significant (P<0.05 enhancement in neuromuscular endurance and antidepressant activity at 300 and 500 mg/kg as compared to the control group. However, the fungus did not proved to be as effective as fluoxetine in exhibiting antidepressant action. Muscular endurance was determined on a Rota rod apparatus while antidepressant (mood elevating activity was measured on a photoactometer in Swiss albino mice. The effects produced by both natural specimens and laboratory cultured Cordyceps sinensis were comparable and showed almost equal potency.

  4. A New Lyapunov Based Robust Control for Uncertain Mechanical Systems

    Institute of Scientific and Technical Information of China (English)

    ZHEN Sheng-Chao; ZHAO Han; CHEN Ye-Hwa; HUANG Kang

    2014-01-01

    We design a new robust controller for uncertain mechanical systems. The inertia matrix0s singularity and upper bound property are first analyzed. It is shown that the inertia matrix may be positive semi-definite due to over-simplified model. Further-more, the inertia matrix0s being uniformly bounded above is also limited. A robust controller is proposed to suppress the effect of uncertainty in mechanical systems with the assumption of uniform positive definiteness and upper bound of the inertia matrix. We theoretically prove that the robust control renders uniform boundedness and uniform ultimate boundedness. The size of the ultimate boundedness ball can be made arbitrarily small by the designer. Simulation results are presented and discussed.

  5. A new method for sudden mechanical perturbation with axial load, to assess postural control in sitting and standing.

    Science.gov (United States)

    Claus, Andrew P; Verrel, Julius; Pounds, Paul E I; Shaw, Renee C; Brady, Niamh; Chew, Min T; Dekkers, Thomas A; Hodges, Paul W

    2016-05-01

    Sudden application of load along a sagittal or coronal axis has been used to study trunk stiffness, but not axial (vertical) load. This study introduces a new method for sudden-release axial load perturbation. Prima facie validity was supported by comparison with standard mechanical systems. We report the response of the human body to axial perturbation in sitting and standing and within-day repeatability of measures. Load of 20% of body weight was released from light contact onto the shoulders of 22 healthy participants (10 males). Force input was measured via force transducers at shoulders, output via a force plate below the participant, and kinematics via 3-D motion capture. System identification was used to fit data from the time of load release to time of peak load-displacement, fitting with a 2nd-order mass-spring-damper system with a delay term. At peak load-displacement, the mean (SD) effective stiffness measured with this device for participants in sitting was 12.0(3.4)N/mm, and in standing was 13.3(4.2)N/mm. Peak force output exceeded input by 44.8 (10.0)% in sitting and by 30.4(7.9)% in standing. Intra-class correlation coefficients for within-day repeatability of axial stiffness were 0.58 (CI: -0.03 to 0.83) in sitting and 0.82(0.57-0.93) in standing. Despite greater degrees of freedom in standing than sitting, standing involved lesser time, downward displacement, peak output force and was more repeatable in defending upright postural control against the same axial loads. This method provides a foundation for future studies of neuromuscular control with axial perturbation. PMID:26968087

  6. An examination of neuromuscular and metabolic fatigue thresholds

    International Nuclear Information System (INIS)

    This study examined the relationships among the physical working capacity at the fatigue threshold (PWCFT), the power outputs associated with the gas exchange threshold (PGET) and the respiratory compensation point (PRCP), and critical power (CP) to identify possible physiological mechanisms underlying the onset of neuromuscular fatigue. Ten participants (mean ± SD age: 20 ± 1 years) performed a maximal incremental cycle ergometer test to determine the PWCFT, PGET, and PRCP. CP was determined from the 3 min all-out test. The PWCFT (197 ± 55 W), PRCP (212 ± 50 W), and CP (208 ± 63 W) were significantly greater than the PGET (168 ± 40 W), but there were no significant differences among the PWCFT, PRCP, and CP. All thresholds were significantly inter-4 (r = 0.794–0.958). The 17% greater estimates for the PWCFT than PGET were likely related to differences in the physiological mechanisms that underlie these fatigue thresholds, while the non-significant difference and high correlation between the PWCFT and the PRCP suggested that hyperkalemia may underlie both thresholds. Furthermore, it is possible that the 5% lower estimate of the PWCFT than CP could more accurately reflect the demarcation of the heavy from severe exercise intensity domains. (paper)

  7. The Mechanics and Trajectory Control in Locust Jumping

    Institute of Scientific and Technical Information of China (English)

    Longbao Han; Zhouyi Wang; Aihong Ji; Zhendong Dai

    2013-01-01

    Locusts (Locusta migratoria manilensis) are characterised by their flying ability and abiding jump ability.Research on the jumping mechanics and behavior of locusts plays an important role in elucidating the mechanism of hexapod locomotion.The jump gestures of locusts were observed using high-speed video camera at 250 fps.The reaction forces of the hindlegs were measured using two three-dimensional sensors,in case the two hindlegs attached on separated sensor plates.The jump gestures and reaction forces were used to illustrate the locust jumping mechanism.Results show that the trajectory control is achieved by rapid rolling and yawing movements of the locust body,caused by the forelegs,midlegs and hindlegs in different jumping phases.The final jump trajectory was not determined until hind tarsi left platform.The horizontal co-impulse between two hindlegs might play a key role in jump stability and accuracy.Besides,the angle between two hindlegs affects the control of jump trajectory but has a little effect on the elevation angle of a jump,which is controlled mechanically by the initial position of the hindlegs.This research lays the groundwork for the probable design and development of biomimetic robotics.

  8. Adaptive mechanism-based congestion control for networked systems

    Science.gov (United States)

    Liu, Zhi; Zhang, Yun; Chen, C. L. Philip

    2013-03-01

    In order to assure the communication quality in network systems with heavy traffic and limited bandwidth, a new ATRED (adaptive thresholds random early detection) congestion control algorithm is proposed for the congestion avoidance and resource management of network systems. Different to the traditional AQM (active queue management) algorithms, the control parameters of ATRED are not configured statically, but dynamically adjusted by the adaptive mechanism. By integrating with the adaptive strategy, ATRED alleviates the tuning difficulty of RED (random early detection) and shows a better control on the queue management, and achieve a more robust performance than RED under varying network conditions. Furthermore, a dynamic transmission control protocol-AQM control system using ATRED controller is introduced for the systematic analysis. It is proved that the stability of the network system can be guaranteed when the adaptive mechanism is finely designed. Simulation studies show the proposed ATRED algorithm achieves a good performance in varying network environments, which is superior to the RED and Gentle-RED algorithm, and providing more reliable service under varying network conditions.

  9. The potential of disease management for neuromuscular hereditary disorders.

    Science.gov (United States)

    Chouinard, Maud-Christine; Gagnon, Cynthia; Laberge, Luc; Tremblay, Carmen; Côté, Charlotte; Leclerc, Nadine; Mathieu, Jean

    2009-01-01

    Neuromuscular hereditary disorders require long-term multidisciplinary rehabilitation management. Although the need for coordinated healthcare management has long been recognized, most neuromuscular disorders are still lacking clinical guidelines about their long-term management and structured evaluation plan with associated services. One of the most prevalent adult-onset neuromuscular disorders, myotonic dystrophy type 1, generally presents several comorbidities and a variable clinical picture, making management a constant challenge. This article presents a healthcare follow-up plan and proposes a nursing case management within a disease management program as an innovative and promising approach. This disease management program and model consists of eight components including population identification processes, evidence-based practice guidelines, collaborative practice, patient self-management education, and process outcomes evaluation (Disease Management Association of America, 2004). It is believed to have the potential to significantly improve healthcare management for neuromuscular hereditary disorders and will prove useful to nurses delivering and organizing services for this population.

  10. Genetics of Pediatric-Onset Motor Neuron and Neuromuscular Diseases

    Science.gov (United States)

    2015-08-24

    Spinal Muscular Atrophy; Charcot-Marie-Tooth Disease; Muscular Dystrophy; Spinal Muscular Atrophy With Respiratory Distress 1; Amyotrophic Lateral Sclerosis; Motor Neuron Disease; Neuromuscular Disease; Peroneal Muscular Atrophy; Fragile X Syndrome

  11. Effect of nimodipine and flunarizine on neuromuscular function in mice

    Directory of Open Access Journals (Sweden)

    Swapnil B. Kaikade

    2016-08-01

    Conclusions: Nimodipine has significant dose dependent depressant action on neuromuscular function while flunarizine has no effect on the above mentioned parameter. [Int J Basic Clin Pharmacol 2016; 5(4.000: 1524-1527

  12. Effects of sugammadex on incidence of postoperative residual neuromuscular blockade

    DEFF Research Database (Denmark)

    Brueckmann, B; Sasaki, N; Grobara, P;

    2015-01-01

    BACKGROUND: This study aimed to investigate whether reversal of rocuronium-induced neuromuscular blockade with sugammadex reduced the incidence of residual blockade and facilitated operating room discharge readiness. METHODS: Adult patients undergoing abdominal surgery received rocuronium, follow...

  13. Nonmuscle Myosin II helps regulate synaptic vesicle mobility at the Drosophila neuromuscular junction

    Directory of Open Access Journals (Sweden)

    Qiu Xinping

    2010-03-01

    Full Text Available Abstract Background Although the mechanistic details of the vesicle transport process from the cell body to the nerve terminal are well described, the mechanisms underlying vesicle traffic within nerve terminal boutons is relatively unknown. The actin cytoskeleton has been implicated but exactly how actin or actin-binding proteins participate in vesicle movement is not clear. Results In the present study we have identified Nonmuscle Myosin II as a candidate molecule important for synaptic vesicle traffic within Drosophila larval neuromuscular boutons. Nonmuscle Myosin II was found to be localized at the Drosophila larval neuromuscular junction; genetics and pharmacology combined with the time-lapse imaging technique FRAP were used to reveal a contribution of Nonmuscle Myosin II to synaptic vesicle movement. FRAP analysis showed that vesicle dynamics were highly dependent on the expression level of Nonmuscle Myosin II. Conclusion Our results provide evidence that Nonmuscle Myosin II is present presynaptically, is important for synaptic vesicle mobility and suggests a role for Nonmuscle Myosin II in shuttling vesicles at the Drosophila neuromuscular junction. This work begins to reveal the process by which synaptic vesicles traverse within the bouton.

  14. Neuromuscular blockade in cardiac surgery: An update for clinicians

    OpenAIRE

    Hemmerling Thomas; Russo Gianluca; Bracco David

    2008-01-01

    There have been great advancements in cardiac surgery over the last two decades; the widespread use of off-pump aortocoronary bypass surgery, minimally invasive cardiac surgery, and robotic surgery have also changed the face of cardiac anaesthesia. The concept of "Fast-track anaesthesia" demands the use of nondepolarising neuromuscular blocking drugs with short duration of action, combining the ability to provide (if necessary) sufficiently profound neuromuscular blockade during surgery and i...

  15. Degeneration of Neuromuscular Junction in Age and Dystrophy

    OpenAIRE

    Rüdiger eRudolf; Muzamil Majid Khan; Siegfried eLabeit; Deschenes, Michael R.

    2014-01-01

    Functional denervation is a hallmark of aging sarcopenia as well as of muscular dystrophy. It is thought to be a major factor reducing skeletal muscle mass, particularly in the case of sarcopenia. Neuromuscular junctions serve as the interface between the nervous and skeletal muscular systems, and thus they may receive pathophysiological input of both pre- and postsynaptic origin. Consequently, neuromuscular junctions are good indicators of motor health on a systemic level. Indeed, upon sarco...

  16. Comparative Study on New AQM Mechanisms for Congestion Control

    Directory of Open Access Journals (Sweden)

    Ramakrishna B B

    2013-09-01

    Full Text Available As usage of network goes increasing day by day, managing network traffic becomes a very difficult task. It is important to avoid high packet loss rates in the Internet. Congestion is the one of the major issue in the present networks. Congestion Control is one of the solutions adopted to solve the congestion issue and to control it. Numbers of queue management algorithms are proposed for congestion control and to reduce high packet loss rates. Active Queue Management (AQM is one such mechanism which provides better control over congestion. In this paper a study is made on recent load based AQM techniques that are proposed and its merits and shortfall is presented.

  17. Controlling chaos based on an adaptive nonlinear compensator mechanism

    Institute of Scientific and Technical Information of China (English)

    Tian Ling-Ling; Li Dong-Hai; Sun Xian-Fang

    2008-01-01

    The control problems of chaotic systems are investigated in the presence of parametric uncertainty and persistent external disturbances based on nonlinear control theory.By using a designed nonlinear compensator mechanism,the system deterministic nonlinearity,parametric uncertainty and disturbance effect can be compensated effectively.The renowned chaotic Lorenz system subjected to parametric variations and external disturbances is studied as an illustrative example.From the Lyapunov stability theory,sufficient conditions for choosing control parameters to guarantee chaos control are derived.Several experiments are carried out,including parameter change experiments,set-point change experiments and disturbance experiments.Simulation results indicate that the chaotic motion can be regulated not only to steady states but also to any desired periodic orbits with great immunity to parametric variations and external disturbances.

  18. Biomimetic Control of Mechanical Systems Equipped with Musculotendon Actuators

    Institute of Scientific and Technical Information of China (English)

    Javier Moreno-Valenzuela; Adriana Salinas-Avila

    2011-01-01

    This paper addresses the problem of modelling, control, and simulation of a mechanical system actuated by an agonist-antagonist musculotendon subsystem. Contraction dynamics is given by case I of Zajac's model. Saturated semi positive proportional-derivative-type controllers with switching as neural excitation inputs are proposed. Stability theory of switched system and SOSTOOLS, which is a sum of squares optimization toolbox of Matlab, are used to determine the stability of the obtained closed-loop system. To corroborate the obtained theoretical results numerical simulations are carried out. As additional contribution, the discussed ideas are applied to the biomimetic control of a DC motor, i.e., the position control is addressed assuming the presence of musculotendon actuators. Real-experiments corroborate the expected results.

  19. Mechanisms of abscisic acid-mediated control of stomatal aperture.

    Science.gov (United States)

    Munemasa, Shintaro; Hauser, Felix; Park, Jiyoung; Waadt, Rainer; Brandt, Benjamin; Schroeder, Julian I

    2015-12-01

    Drought stress triggers an increase in the level of the plant hormone abscisic acid (ABA), which initiates a signaling cascade to close stomata and reduce water loss. Recent studies have revealed that guard cells control cytosolic ABA concentration through the concerted actions of biosynthesis, catabolism as well as transport across membranes. Substantial progress has been made at understanding the molecular mechanisms of how the ABA signaling core module controls the activity of anion channels and thereby stomatal aperture. In this review, we focus on our current mechanistic understanding of ABA signaling in guard cells including the role of the second messenger Ca(2+) as well as crosstalk with biotic stress responses. PMID:26599955

  20. Antenna mechanism of length control of actin cables

    CERN Document Server

    Mohapatra, Lishibanya; Kondev, Jane

    2014-01-01

    Actin cables are linear cytoskeletal structures that serve as tracks for myosin-based intracellular transport of vesicles and organelles in both yeast and mammalian cells. In a yeast cell undergoing budding, cables are in constant dynamic turnover yet some cables grow from the bud neck toward the back of the mother cell until their length roughly equals the diameter of the mother cell. This raises the question: how is the length of these cables controlled? Here we describe a novel molecular mechanism for cable length control inspired by recent experimental observations in cells. This antenna mechanism involves three key proteins: formins, which polymerize actin, Smy1 proteins, which bind formins and inhibit actin polymerization, and myosin motors, which deliver Smy1 to formins, leading to a length-dependent actin polymerization rate. We compute the probability distribution of cable lengths as a function of several experimentally tuneable parameters such as the formin-binding affinity of Smy1 and the concentra...

  1. Mechanization and Control Concepts for Biologically Inspired Micro Aerial Vehicles

    Science.gov (United States)

    Raney, David L.; Slominski, Eric C.

    2003-01-01

    It is possible that MAV designs of the future will exploit flapping flight in order to perform missions that require extreme agility, such as rapid flight beneath a forest canopy or within the confines of a building. Many of nature's most agile flyers generate flapping motions through resonant excitation of an aeroelastically tailored structure: muscle tissue is used to excite a vibratory mode of their flexible wing structure that creates propulsion and lift. A number of MAV concepts have been proposed that would operate in a similar fashion. This paper describes an ongoing research activity in which mechanization and control concepts with application to resonant flapping MAVs are being explored. Structural approaches, mechanical design, sensing and wingbeat control concepts inspired by hummingbirds, bats and insects are examined. Experimental results from a testbed capable of generating vibratory wingbeat patterns that approximately match those exhibited by hummingbirds in hover, cruise, and reverse flight are presented.

  2. A Dynamic Adaptive Layered Multicast Congestion Control Mechanism

    Institute of Scientific and Technical Information of China (English)

    REN Liyong; LU Xianliang; WEI Qingsong; ZHOU Xu

    2003-01-01

    To solve the problem that most of existing layered multicast protocols cannot adapt to dynamic network conditions because their layers are coarsely granulated and static, a new congestion control mechanism for dynamic adaptive layered multicast(DALM) is presented. In this mechanism, a novel feedback aggregating algorithm is put forward, which can dynamically determine the number of layers and the rate of each layer, and can efficiently improve network bandwidth utilization ratio.Additionally, because all layers is transmitted in only one group, the intricate and time-consuming internet group management protocol(IGMP) operations, caused by receiver joining a new layer or leaving the topmost subscribed layer, are thoroughly eliminated. And this mechanism also avoids other problems resulted from multiple groups. Simulation results show that DALM is adaptive and TCP friendly.

  3. Invasive mechanism and control strategy of Ageratina adenophora (Sprengel)

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to ascertain the invasive mechanism and control strategy of the invasive Crofton weed, Ageratina adenophora, its ecological adaptability and population differentiation,the formation of single dominant population, displacement of native plants and sustainable management strategies were investigated. The present results helped to clarify and explain such issues as the adaptability post invasion,interaction and competition between inter-and intra-species and community resistance, thereby providing important references to researches on other invasive alien species.

  4. Multi-finger prehension: control of a redundant mechanical system.

    Science.gov (United States)

    Latash, Mark L; Zatsiorsky, Vladimir M

    2009-01-01

    The human hand has been a fascinating object of study for researchers in both biomechanics and motor control. Studies of human prehension have contributed significantly to the progress in addressing the famous problem of motor redundancy. After a brief review of the hand mechanics, we present results of recent studies that support a general view that the apparently redundant design of the hand is not a source of computational problems but a rich apparatus that allows performing a variety of tasks in a reliable and flexible way (the principle of abundance). Multi-digit synergies have been analyzed at two levels of a hypothetical hierarchy involved in the control of prehensile actions. At the upper level, forces and moments produced by the thumb and virtual finger (an imagined finger with a mechanical action equal to the combined mechanical action of all four fingers of the hand) co-vary to stabilize the gripping action and the orientation of the hand-held object. These results support the principle of superposition suggested earlier in robotics with respect to the control of artificial grippers. At the lower level of the hierarchy, forces and moments produced by individual fingers co-vary to stabilize the magnitude and direction of the force vector and the moment of force produced by the virtual finger. Adjustments to changes in task constraints (such as, for example, friction under individual digits) may be local and synergic. The latter reflect multi-digit prehension synergies and may be analyzed with the so-called chain effects: Sequences of relatively straightforward cause-effect links directly related to mechanical constraints leading to non-trivial strong co-variation between pairs of elemental variables. Analysis of grip force adjustments during motion of hand-held objects suggests that the central nervous system adjusts to gravitational and inertial loads differently. The human hand is a gold mine for researchers interested in the control of natural human

  5. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    OpenAIRE

    2014-01-01

    Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of...

  6. PRIVATE AND PUBLIC FOOD SAFETY CONTROL MECHANISMS: INTERDEPENDENCE AND EFFECTIVENESS

    OpenAIRE

    Mojduszka, Eliza M.

    2004-01-01

    In this paper, we propose new research methods and approaches in the area of food safety economics that would improve the allocation and effectiveness of private and public resources and efforts in ensuring food safety. The focus is on approaches that would build a comprehensive understanding of the interdependence between private and public food safety control mechanisms, including direct regulation by process and performance safety standards, traceability requirements, product liability, an...

  7. CONFIGURATION CONTROLLABILITY FOR NON-ZERO POTENTIAL MECHANICAL CONTROL SYSTEMS WITH DISSIPATION

    Institute of Scientific and Technical Information of China (English)

    KANG Jian-ling; WANG Hong; YE Hua-wen

    2005-01-01

    Within the affine connection framework of Lagrangian control systems, based on the results of Sussmann on controllability of general affine control systems defined on a finite-dimensional manifold, a computable sufficient condition of configuration controllability for the simple mechanical control systems was extended to the case of systems with strictly dissipative energy terms of linear isotropic nature, and a sufficient condition of equilibrium controllability for the systems was also given, where Lagrangian is kinetic energy minus potential energy. Lie bracketting of vector fields in controllable Lie algebra, and the symmetric product associated with Levi-Civita connection show virtues in the discussion. Liouville vector field simplified the computation of controllable Lie algebra for the systems, although the terms of potential energy complicated the study of configuration controllability.

  8. Model Predictive Vibration Control Efficient Constrained MPC Vibration Control for Lightly Damped Mechanical Structures

    CERN Document Server

    Takács, Gergely

    2012-01-01

    Real-time model predictive controller (MPC) implementation in active vibration control (AVC) is often rendered difficult by fast sampling speeds and extensive actuator-deformation asymmetry. If the control of lightly damped mechanical structures is assumed, the region of attraction containing the set of allowable initial conditions requires a large prediction horizon, making the already computationally demanding on-line process even more complex. Model Predictive Vibration Control provides insight into the predictive control of lightly damped vibrating structures by exploring computationally efficient algorithms which are capable of low frequency vibration control with guaranteed stability and constraint feasibility. In addition to a theoretical primer on active vibration damping and model predictive control, Model Predictive Vibration Control provides a guide through the necessary steps in understanding the founding ideas of predictive control applied in AVC such as: ·         the implementation of ...

  9. Cable control and take-up mechanisms and x-ray scanning apparatus incorporating such mechanisms

    International Nuclear Information System (INIS)

    In this patent, an invention for cable control and take-up mechanisms for elongated, flexible cables is described. Such cables are used in X-ray scanner apparatus to provide power, electronic signals and fluids. A detailed design and description is given of the cable harness, control and take-up mechanism that would be used in conjunction with an X-ray scanner. As a result of this invention, the cables are prevented from becoming prematurely worn or entangled in the X-ray apparatus during the rotational and translational movements necessary in tomographic examinations. This invention is also applicable to other types of apparatus and environments where a number of different positions is required and where it is necessary to control the take-up of elongated, flexible, cable-like members. (U.K.)

  10. Safe neuromuscular electrical stimulator designed for the elderly.

    Science.gov (United States)

    Krenn, Matthias; Haller, Michael; Bijak, Manfred; Unger, Ewald; Hofer, Christian; Kern, Helmut; Mayr, Winfried

    2011-03-01

    A stimulator for neuromuscular electrical stimulation (NMES) was designed, especially suiting the requirements of elderly people with reduced cognitive abilities and diminished fine motor skills. The aging of skeletal muscle is characterized by a progressive decline in muscle mass, force, and condition. Muscle training with NMES reduces the degradation process. The discussed system is intended for evoked muscle training of the anterior and posterior thigh. The core of the stimulator is based on a microcontroller with two modular output stages. The system has two charge-balanced biphasic voltage-controlled stimulation channels. Additionally, the evoked myoelectric signal (M-wave) and the myokinematic signal (surface acceleration) are measured. A central controller unit allows using the stimulator as a stand-alone device. To set up the training sequences and to evaluate the compliance data, a personal computer is connected to the stimulator via a universal serial bus. To help elderly people handle the stimulator by themselves, the user interface is kept very simple. For safety reasons, the electrode impedance is monitored during stimulation. A comprehensive compliance management with included measurements of muscle activity and stimulation intensity enables a scientific use of the stimulator in clinical trials.

  11. Mechanical design and optimal control of humanoid robot (TPinokio

    Directory of Open Access Journals (Sweden)

    Teck Chew Wee

    2014-04-01

    Full Text Available The mechanical structure and the control of the locomotion of bipedal humanoid is an important and challenging domain of research in bipedal robots. Accurate models of the kinematics and dynamics of the robot are essential to achieve bipedal locomotion. Toe-foot walking produces a more natural and faster walking speed and it is even possible to perform stretch knee walking. This study presents the mechanical design of a toe-feet bipedal, TPinokio and the implementation of some optimal walking gait generation methods. The optimality in the gait trajectory is achieved by applying augmented model predictive control method and the pole-zero cancellation method, taken into consideration of a trade-off between walking speed and stability. The mechanism of the TPinokio robot is designed in modular form, so that its kinematics can be modelled accurately into a multiple point-mass system, its dynamics is modelled using the single and double mass inverted pendulum model and zero-moment-point concept. The effectiveness of the design and control technique is validated by simulation testing with the robot walking on flat surface and climbing stairs.

  12. Antenna Mechanism of Length Control of Actin Cables.

    Directory of Open Access Journals (Sweden)

    Lishibanya Mohapatra

    2015-06-01

    Full Text Available Actin cables are linear cytoskeletal structures that serve as tracks for myosin-based intracellular transport of vesicles and organelles in both yeast and mammalian cells. In a yeast cell undergoing budding, cables are in constant dynamic turnover yet some cables grow from the bud neck toward the back of the mother cell until their length roughly equals the diameter of the mother cell. This raises the question: how is the length of these cables controlled? Here we describe a novel molecular mechanism for cable length control inspired by recent experimental observations in cells. This "antenna mechanism" involves three key proteins: formins, which polymerize actin, Smy1 proteins, which bind formins and inhibit actin polymerization, and myosin motors, which deliver Smy1 to formins, leading to a length-dependent actin polymerization rate. We compute the probability distribution of cable lengths as a function of several experimentally tuneable parameters such as the formin-binding affinity of Smy1 and the concentration of myosin motors delivering Smy1. These results provide testable predictions of the antenna mechanism of actin-cable length control.

  13. Animal models for genetic neuromuscular diseases.

    Science.gov (United States)

    Vainzof, Mariz; Ayub-Guerrieri, Danielle; Onofre, Paula C G; Martins, Poliana C M; Lopes, Vanessa F; Zilberztajn, Dinorah; Maia, Lucas S; Sell, Karen; Yamamoto, Lydia U

    2008-03-01

    The neuromuscular disorders are a heterogeneous group of genetic diseases, caused by mutations in genes coding sarcolemmal, sarcomeric, and citosolic muscle proteins. Deficiencies or loss of function of these proteins leads to variable degree of progressive loss of motor ability. Several animal models, manifesting phenotypes observed in neuromuscular diseases, have been identified in nature or generated in laboratory. These models generally present physiological alterations observed in human patients and can be used as important tools for genetic, clinic, and histopathological studies. The mdx mouse is the most widely used animal model for Duchenne muscular dystrophy (DMD). Although it is a good genetic and biochemical model, presenting total deficiency of the protein dystrophin in the muscle, this mouse is not useful for clinical trials because of its very mild phenotype. The canine golden retriever MD model represents a more clinically similar model of DMD due to its larger size and significant muscle weakness. Autosomal recessive limb-girdle MD forms models include the SJL/J mice, which develop a spontaneous myopathy resulting from a mutation in the Dysferlin gene, being a model for LGMD2B. For the human sarcoglycanopahties (SG), the BIO14.6 hamster is the spontaneous animal model for delta-SG deficiency, whereas some canine models with deficiency of SG proteins have also been identified. More recently, using the homologous recombination technique in embryonic stem cell, several mouse models have been developed with null mutations in each one of the four SG genes. All sarcoglycan-null animals display a progressive muscular dystrophy of variable severity and share the property of a significant secondary reduction in the expression of the other members of the sarcoglycan subcomplex and other components of the Dystrophin-glycoprotein complex. Mouse models for congenital MD include the dy/dy (dystrophia-muscularis) mouse and the allelic mutant dy(2J)/dy(2J) mouse

  14. The Role of Chest Physiotherapy in Prevention of Postextubation Atelectasis in Pediatric Patients with Neuromuscular Diseases

    Directory of Open Access Journals (Sweden)

    Nemat BILAN

    2013-02-01

    Full Text Available How to Cite This Article: Bilan N, Poorshiri B.The Role of Chest Physiotherapy in Prevention of Postextubation Atelectasis in Pediatric Patients with Neuromuscular Diseases. Iran J Child Neurol. 2013 Winter; 7 (1:21-24. ObjectiveThere are controversial findings in the literature on the effects of chest physiotherapy on postextubation lung collapse in pediatric age group. Therefore, we aimed to investigate the efficacy of chest physiotherapy in prevention of postextubation atelectasis in pediatric patients. Materials & Methods In a case-control study from March 2007 to March 2011, two groups of patients (35 patients in each group susceptible to lung collapse were enrolled in the study. The studied patients had neuromuscular diseases such as spinal muscular atrophy, Guillain-Barre syndrome, critical illness polyneuropathy/myopathy, and cerebral palsy. The patients were randomly divided into two groups (case and control; The case group underwent daily chest physiotherapy through vibrator and chest percussion and the control group was under supervision. In the latter group, the underlying disease was treated and the lung collapse was managed, if occurred. Results The frequency of atelectasis was lower in the case group who received prophylactic chest physiotherapy compared to the control group (16.6% vs. 40%. Conclusion Chest physiotherapy as well as appropriate and regular change of position can considerably reduce the rate of pulmonary collapse in pediatric patients.References Jorgensen J, Wei JL, Sykes KJ, Klem SA, Weatherly RA, Bruegger DE, Latz AD, Nicklaus PJ. Incidence of and risk factors for airway complications following endotracheal intubation for bronchiolitis. Otolaryngol Head Neck Surg 2007;137(3:394-9.Flenady VJ, Gray PH. Chest physiotherapy for preventing morbidity in babies being extubated from mechanical ventilation. Cochrane Database Syst Rev 2002;(2:CD000283.Odita JC, Kayyali M, Ammari A. Post-extubation atelectasis in ventilated

  15. Bio-Inspired Controller for a Robot Cheetah with a Neural Mechanism Controlling Leg Muscles

    Institute of Scientific and Technical Information of China (English)

    Xin Wang; Mantian Li; Pengfei Wang; Wei Guo; Lining Sun

    2012-01-01

    The realization of a high-speed running robot is one of the most challenging problems in developing legged robots.The excellent performance of cheetahs provides inspiration for the control and mechanical design of such robots.This paper presents a three-dimensional model of a cheetah that predicts the locomotory behaviors of a running cheetah.Applying biological knowledge of the neural mechanism,we control the muscle flexion and extension during the stance phase,and control the positions of the joints in the flight phase via a PD controller to minimize complexity.The proposed control strategy is shown to achieve similar locomotion of a real cheetah.The simulation realizes good biological properties,such as the leg retraction,ground reaction force,and spring-like leg behavior.The stable bounding results show the promise of the controller in high-speed locomotion.The model can reach 2.7 m·s- 1 as the highest speed,and can accelerate from 0 to 1.5 m·s -1 in one stride cycle.A mechanical structure based on this simulation is designed to demonstrate the control approach,and the most recently developed hindlimb controlled by the proposed controller is presented in swinging-leg experiments and jump-force experiments.

  16. Dynamics and control of mechanical systems in offshore engineering

    CERN Document Server

    He, Wei; How, Bernard Voon Ee; Choo, Yoo Sang

    2014-01-01

    Dynamics and Control of Mechanical Systems in Offshore Engineering is a comprehensive treatment of marine mechanical systems (MMS) involved in processes of great importance such as oil drilling and mineral recovery. Ranging from nonlinear dynamic modeling and stability analysis of flexible riser systems, through advanced control design for an installation system with a single rigid payload attached by thrusters, to robust adaptive control for mooring systems, it is an authoritative reference on the dynamics and control of MMS. Readers will gain not only a complete picture of MMS at the system level, but also a better understanding of the technical considerations involved and solutions to problems that commonly arise from dealing with them. The text provides:                                                                                                                                 ...

  17. Applications of Shape Memory Alloys for Neurology and Neuromuscular Rehabilitation

    Directory of Open Access Journals (Sweden)

    Simone Pittaccio

    2015-05-01

    Full Text Available Shape memory alloys (SMAs are a very promising class of metallic materials that display interesting nonlinear properties, such as pseudoelasticity (PE, shape memory effect (SME and damping capacity, due to high mechanical hysteresis and internal friction. Our group has applied SMA in the field of neuromuscular rehabilitation, designing some new devices based on the mentioned SMA properties: in particular, a new type of orthosis for spastic limb repositioning, which allows residual voluntary movement of the impaired limb and has no predetermined final target position, but follows and supports muscular elongation in a dynamic and compliant way. Considering patients in the sub-acute phase after a neurological lesion, and possibly bedridden, the paper presents a mobiliser for the ankle joint, which is designed exploiting the SME to provide passive exercise to the paretic lower limb. Two different SMA-based applications in the field of neuroscience are then presented, a guide and a limb mobiliser specially designed to be compatible with diagnostic instrumentations that impose rigid constraints in terms of electromagnetic compatibility and noise distortion. Finally, the paper discusses possible uses of these materials in the treatment of movement disorders, such as dystonia or hyperkinesia, where their dynamic characteristics can be advantageous.

  18. Neuromuscular disorders: genes, genetic counseling and therapeutic trials.

    Science.gov (United States)

    Zatz, Mayana; Passos-Bueno, Maria Rita; Vainzof, Mariz

    2016-01-01

    Neuromuscular disorders (NMD) are a heterogeneous group of genetic conditions, with autosomal dominant, recessive, or X-linked inheritance. They are characterized by progressive muscle degeneration and weakness. Here, we are presenting our major contributions to the field during the past 30 years. We have mapped and identified several novel genes responsible for NMD. Genotype-phenotype correlations studies enhanced our comprehension on the effect of gene mutations on related proteins and their impact on clinical findings. The search for modifier factors allowed the identification of a novel "protective"; variant which may have important implication on therapeutic developments. Molecular diagnosis was introduced in the 1980s and new technologies have been incorporated since then. Next generation sequencing greatly improved our capacity to identify disease-causing mutations with important benefits for research and prevention through genetic counseling of patients' families. Stem cells researches, from and for patients, have been used as tools to study human genetic diseases mechanisms and for therapies development. The clinical effect of preclinical trials in mice and canine models for muscular dystrophies are under investigation. Finally, the integration of our researches and genetic services with our post-graduation program resulted in a significant output of new geneticists, spreading out this expertise to our large country. PMID:27575431

  19. Degeneration of neuromuscular junction in age and dystrophy.

    Science.gov (United States)

    Rudolf, Rüdiger; Khan, Muzamil Majid; Labeit, Siegfried; Deschenes, Michael R

    2014-01-01

    Functional denervation is a hallmark of aging sarcopenia as well as of muscular dystrophy. It is thought to be a major factor reducing skeletal muscle mass, particularly in the case of sarcopenia. Neuromuscular junctions (NMJs) serve as the interface between the nervous and skeletal muscular systems, and thus they may receive pathophysiological input of both pre- and post-synaptic origin. Consequently, NMJs are good indicators of motor health on a systemic level. Indeed, upon sarcopenia and dystrophy, NMJs morphologically deteriorate and exhibit altered characteristics of primary signaling molecules, such as nicotinic acetylcholine receptor and agrin. Since a remarkable reversibility of these changes can be observed by exercise, there is significant interest in understanding the molecular mechanisms underlying synaptic deterioration upon aging and dystrophy and how synapses are reset by the aforementioned treatments. Here, we review the literature that describes the phenomena observed at the NMJ in sarcopenic and dystrophic muscle as well as to how these alterations can be reversed and to what extent. In a second part, the current information about molecular machineries underlying these processes is reported. PMID:24904412

  20. Flexible neural mechanisms of cognitive control within human prefrontal cortex.

    Science.gov (United States)

    Braver, Todd S; Paxton, Jessica L; Locke, Hannah S; Barch, Deanna M

    2009-05-01

    A major challenge in research on executive control is to reveal its functional decomposition into underlying neural mechanisms. A typical assumption is that this decomposition occurs solely through anatomically based dissociations. Here we tested an alternative hypothesis that different cognitive control processes may be implemented within the same brain regions, with fractionation and dissociation occurring on the basis of temporal dynamics. Regions within lateral prefrontal cortex (PFC) were examined that, in a prior study, exhibited contrasting temporal dynamics between older and younger adults during performance of the AX-CPT cognitive control task. The temporal dynamics in younger adults fit a proactive control pattern (primarily cue-based activation), whereas in older adults a reactive control pattern was found (primarily probe-based activation). In the current study, we found that following a period of task-strategy training, these older adults exhibited a proactive shift within a subset of the PFC regions, normalizing their activity dynamics toward young adult patterns. Conversely, under conditions of penalty-based monetary incentives, the younger adults exhibited a reactive shift some of the same regions, altering their temporal dynamics toward the older adult baseline pattern. These experimentally induced crossover patterns of temporal dynamics provide strong support for dual modes of cognitive control that can be flexibly shifted within PFC regions, via modulation of neural responses to changing task conditions or behavioral goals. PMID:19380750

  1. Neuromuscular Fatigue During 200 M Breaststroke

    Directory of Open Access Journals (Sweden)

    Ana Conceição

    2014-03-01

    Full Text Available The aims of this study were: i to analyze activation patterns of four upper limb muscles (duration of the active and non-active phase in each lap of 200m breaststroke, ii quantify neuromuscular fatigue, with kinematics and physiologic assessment. Surface electromyogram was collected for the biceps brachii, deltoid anterior, pectoralis major and triceps brachii of nine male swimmers performing a maximal 200m breaststroke trial. Swimming speed, SL, SR, SI decreased from the 1st to the 3rd lap. SR increased on the 4th lap (35.91 ± 2.99 stroke·min-1. Peak blood lactate was 13.02 ± 1.72 mmol·l-1 three minutes after the maximal trial. The EMG average rectified value (ARV increased at the end of the race for all selected muscles, but the deltoid anterior and pectoralis major in the 1st lap and for biceps brachii, deltoid anterior and triceps brachii in the 4th lap. The mean frequency of the power spectral density (MNF decreased at the 4th lap for all muscles. These findings suggest the occurrence of fatigue at the beginning of the 2nd lap in the 200m breaststroke trial, characterized by changes in kinematic parameters and selective changes in upper limb muscle action. There was a trend towards a non-linear fatigue state.

  2. Neuromuscular disorders in chronic alcohol intoxication

    Directory of Open Access Journals (Sweden)

    A. Yu. Emelyanova

    2015-01-01

    Full Text Available The paper reviews the present-day Russian and foreign literature on neuromuscular disorders in chronic alcohol intoxication. The most common manifestations of alcohol disease include alcoholic polyneuropathy (PNP and alcohol-induced skeletal muscle injury. The clinical polymorphism of alcoholic PNP is discussed. The paper considers a chronic sensory automatic form due to the direct toxic effects of ethanol and its metabolites during long-term alcohol intoxication, as well as acute/subacute sensorimotor neuropathy, the basis for the pathogenesis of which is B group vitamins, predominantly thiamine, deficiency that develops in the presence of drinking bouts concurrent with malnutrition and/or alcohol-related gastrointestinal tract diseases. In addition to nonuse of alcohol and a properly balanced diet, antioxidant therapy with alphalipoic acid and neurotropic B group vitamins is considered to be pathogenetic therapy for neuropathy. The most common and least studied clinicalform of alcohol-induced musculoskeletal injury is chronic alcoholic myopathy (AM, the diagnostic standard for which is morphometricand immunohistochemical examination of a muscle biopsy specimen. The morphological base for this form of myopathy is predominantly type 2 muscle fiber atrophy caused by impaired protein synthesis and a decreased regenerative potential of muscle fiber. The efficacy of antioxidants and leucine-containing amino acid mixtures in the treatment of chronic AM is discussed.

  3. Muscle dystroglycan organizes the postsynapse and regulates presynaptic neurotransmitter release at the Drosophila neuromuscular junction.

    Directory of Open Access Journals (Sweden)

    Laurent Bogdanik

    Full Text Available BACKGROUND: The Dystrophin-glycoprotein complex (DGC comprises dystrophin, dystroglycan, sarcoglycan, dystrobrevin and syntrophin subunits. In muscle fibers, it is thought to provide an essential mechanical link between the intracellular cytoskeleton and the extracellular matrix and to protect the sarcolemma during muscle contraction. Mutations affecting the DGC cause muscular dystrophies. Most members of the DGC are also concentrated at the neuromuscular junction (NMJ, where their deficiency is often associated with NMJ structural defects. Hence, synaptic dysfunction may also intervene in the pathology of dystrophic muscles. Dystroglycan is a central component of the DGC because it establishes a link between the extracellular matrix and Dystrophin. In this study, we focused on the synaptic role of Dystroglycan (Dg in Drosophila. METHODOLOGY/PRINCIPAL FINDINGS: We show that Dg was concentrated postsynaptically at the glutamatergic NMJ, where, like in vertebrates, it controls the concentration of synaptic Laminin and Dystrophin homologues. We also found that synaptic Dg controlled the amount of postsynaptic 4.1 protein Coracle and alpha-Spectrin, as well as the relative subunit composition of glutamate receptors. In addition, both Dystrophin and Coracle were required for normal Dg concentration at the synapse. In electrophysiological recordings, loss of postsynaptic Dg did not affect postsynaptic response, but, surprisingly, led to a decrease in glutamate release from the presynaptic site. CONCLUSION/SIGNIFICANCE: Altogether, our study illustrates a conservation of DGC composition and interactions between Drosophila and vertebrates at the synapse, highlights new proteins associated with this complex and suggests an unsuspected trans-synaptic function of Dg.

  4. Patient Machine Interface for the Control of Mechanical Ventilation Devices

    Directory of Open Access Journals (Sweden)

    Rolando Grave de Peralta

    2013-11-01

    Full Text Available The potential of Brain Computer Interfaces (BCIs to translate brain activity into commands to control external devices during mechanical ventilation (MV remains largely unexplored. This is surprising since the amount of patients that might benefit from such assistance is considerably larger than the number of patients requiring BCI for motor control. Given the transient nature of MV (i.e., used mainly over night or during acute clinical conditions, precluding the use of invasive methods, and inspired by current research on BCIs, we argue that scalp recorded EEG (electroencephalography signals can provide a non-invasive direct communication pathway between the brain and the ventilator. In this paper we propose a Patient Ventilator Interface (PVI to control a ventilator during variable conscious states (i.e., wake, sleep, etc.. After a brief introduction on the neural control of breathing and the clinical conditions requiring the use of MV we discuss the conventional techniques used during MV. The schema of the PVI is presented followed by a description of the neural signals that can be used for the on-line control. To illustrate the full approach, we present data from a healthy subject, where the inspiration and expiration periods during voluntary breathing were discriminated with a 92% accuracy (10-fold cross-validation from the scalp EEG data. The paper ends with a discussion on the advantages and obstacles that can be forecasted in this novel application of the concept of BCI.

  5. Design and Control of Nonlinear Mechanical Systems for Minimum Time

    Directory of Open Access Journals (Sweden)

    J.B. Cardoso

    2008-01-01

    Full Text Available This paper presents an integrated methodology for optimal design and control of nonlinear flexible mechanical systems, including minimum time problems. This formulation is implemented in an optimum design code and it is applied to the nonlinear behavior dynamic response. Damping and stiffness characteristics plus control driven forces are considered as decision variables. A conceptual separation between time variant and time invariant design parameters is presented, this way including the design space into the control space and considering the design variables as control variables not depending on time. By using time integrals through all the derivations, design and control problems are unified. In the optimization process we can use both types of variables simultaneously or by interdependent levels. For treating minimum time problems, a unit time interval is mapped onto the original time interval, then treating equally time variant and time invariant problems. The dynamic response and its sensitivity are discretized via space-time finite elements, and may be integrated either by at-once integration or step-by-step. Adjoint system approach is used to calculate the sensitivities.

  6. The involvement of P2Y12 receptors, NADPH oxidase, and lipid rafts in the action of extracellular ATP on synaptic transmission at the frog neuromuscular junction.

    Science.gov (United States)

    Giniatullin, A; Petrov, A; Giniatullin, R

    2015-01-29

    Adenosine 5'-triphosphate (ATP) is the main co-transmitter accompanying the release of acetylcholine from motor nerve terminals. Previously, we revealed the direct inhibitory action of extracellular ATP on transmitter release via redox-dependent mechanism. However, the receptor mechanism of ATP action and ATP-induced sources of reactive oxygen sources (ROS) remained not fully understood. In the current study, using microelectrode recordings of synaptic currents from the frog neuromuscular junction, we analyzed the receptor subtype involved in synaptic action of ATP, receptor coupling to NADPH oxidase and potential location of ATP receptors within the lipid rafts. Using subtype-specific antagonists, we found that the P2Y13 blocker 2-[(2-chloro-5-nitrophenyl)azo]-5-hydroxy-6-methyl-3-[(phosphonooxy)methyl]-4-pyridinecarboxaldehyde did not prevent the depressant action of ATP. In contrast, the P2Y12 antagonist 2-methylthioadenosine 5'-monophosphate abolished the inhibitory action of ATP, suggesting the key role of P2Y12 receptors in ATP action. As the action of ATP is redox-dependent, we also tested potential involvement of the NADPH oxidase, known as a common inducer of ROS. The depressant action of extracellular ATP was significantly reduced by diphenyleneiodonium chloride and 4-(2-aminoethyl)-benzenesulfonyl fluoride hydrochloride, two structurally different inhibitors of NADPH oxidase, indicating that this enzyme indeed mediates the action of ATP. Since the location and activity of various receptors are often associated with lipid rafts, we next tested whether ATP-driven inhibition depends on lipid rafts. We found that the disruption of lipid rafts with methyl-beta-cyclodextrin reduced and largely delayed the action of ATP. Taken together, these data revealed key steps in the purinergic control of synaptic transmission via P2Y12 receptors associated with lipid rafts, and identified NADPH oxidase as the main source of ATP-induced inhibitory ROS at the neuromuscular

  7. Modeling Human Error Mechanism for Soft Control in Advanced Control Rooms (ACRs)

    Energy Technology Data Exchange (ETDEWEB)

    Aljneibi, Hanan Salah Ali [Khalifa Univ., Abu Dhabi (United Arab Emirates); Ha, Jun Su; Kang, Seongkeun; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    To achieve the switch from conventional analog-based design to digital design in ACRs, a large number of manual operating controls and switches have to be replaced by a few common multi-function devices which is called soft control system. The soft controls in APR-1400 ACRs are classified into safety-grade and non-safety-grade soft controls; each was designed using different and independent input devices in ACRs. The operations using soft controls require operators to perform new tasks which were not necessary in conventional controls such as navigating computerized displays to monitor plant information and control devices. These kinds of computerized displays and soft controls may make operations more convenient but they might cause new types of human error. In this study the human error mechanism during the soft controls is studied and modeled to be used for analysis and enhancement of human performance (or human errors) during NPP operation. The developed model would contribute to a lot of applications to improve human performance (or reduce human errors), HMI designs, and operators' training program in ACRs. The developed model of human error mechanism for the soft control is based on assumptions that a human operator has certain amount of capacity in cognitive resources and if resources required by operating tasks are greater than resources invested by the operator, human error (or poor human performance) is likely to occur (especially in 'slip'); good HMI (Human-machine Interface) design decreases the required resources; operator's skillfulness decreases the required resources; and high vigilance increases the invested resources. In this study the human error mechanism during the soft controls is studied and modeled to be used for analysis and enhancement of human performance (or reduction of human errors) during NPP operation.

  8. Tratamiento farmacológico de las alteraciones neuromusculares en el paciente crítico Pharmacological treatment neuromuscular impairments in critically ill patients

    Directory of Open Access Journals (Sweden)

    C. Ortiz Leyba

    2006-05-01

    Full Text Available El empleo de fármacos para tratamiento de las alteraciones neuromusculares que se presentan en el enfermo ingresado en una Unidad de Cuidados Intensivos es prácticamente inexistente. El empleo de inmunoglobulinas por vía venosa para el tratamiento de la polineuropatía del paciente crítico (PPC no aporta ninguna evidencia para su uso. Más importancia tiene el tratamiento profiláctico, como es el caso de la administración de una perfusión de insulina para prevenir la hiperglucemias que seasocian a un mayor desarrollo de la PPC. Nuevos datos inducen a pensar que el mecanismo protector de esta perfusión, normalizando los niveles de glucosa se hacen modulando una disfunción endotelial y a unos menores niveles de dimetilarginina asimétrica (ADMA. Con respecto a la miopatía del paciente crítico o a los cuadros de bloqueo neuromuscular prolongado, el tratamiento consiste en evitar el empleo de diversos fármacos que se sabe se asocian al desarrollo de estas entidades como son los corticoides, los relajantes musculares y los aminoglucósidos. Por lo que respecta a la parálisis aguda flácida -infección por el virus del oeste del nilo se han comunicado casos anecdóticos de mejoría con el empleo de corticoides o de interferón, pero su tratamiento rutinario queda aún por establecer.The use of drugs for treating neuromuscular impairments that present in the patient admitted to the Intensive Care Unit is virtually inexistent. The use of intravenous immunoglobulins for managing polyneuropathy of the critically ill patient (PCIP is supported by no evidence. More important is prophylactic therapy, as is the administration of insulin perfusion to prevent hyperglycemia that is associated to increased development of PCIP. New data suggest that the protective mechanism of this perfusion, which normalizes glucose levels, is achieved through the modulation of endothelial dysfunction and lowering levels of asymmetrical di-methyl arginine (ADMA. As

  9. Control of forced vibrations of mechanical structures by an electromagnetic controller with a permanent magnet

    DEFF Research Database (Denmark)

    Stein, George Juraj; Darula, Radoslav; Sorokin, Sergey

    2012-01-01

    A theoretical analysis of an electromagnetic vibration controller is presented. The analyzed device consists of a pot-type iron core with a coil and a permanent magnet as a source of constant magnetic flux. The magnetic circuit is closed by a yoke, excited by an external harmonic mechanical force....... Due to the hysteretic effects in the magnetic material the internal losses influence the overall system’s performance. A mathematical model of the force balance in the oscillatory system is derived in a simplified, linearised form. The electric as well as mechanical system is modelled using lumped......-parameter approach and the actuating principle for control of forced vibration is investigated....

  10. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    Directory of Open Access Journals (Sweden)

    Yan Shi

    2014-01-01

    Full Text Available Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of ventilator on the dynamics of the ventilated respiratory system are carried out. This study can be helpful in the VCV ventilation treatment and respiratory diagnostics.

  11. Control and Virtual Reality Simulation of Tendon Driven Mechanisms

    International Nuclear Information System (INIS)

    In this paper the authors present a control strategy for tendon driven mechanisms. The aim of the control system is to find the correct torques which the motors have to exert to make the end effector describe a specific trajectory. In robotic assemblies this problem is often solved with closed loop algorithm, but here a simpler method, based on a open loop strategy, is developed. The difficulties in the actuation are in keeping the belt tight during all working conditions. So an innovative solution of this problem is presented here. This methodology can be easily applied in real time monitoring or very fast operations. For this reason several virtual reality simulations, developed using codes written in Virtual Reality Markup Language, are also presented. This approach is very efficient because it requires a very low cpu computation time, small size files, and the manipulator can be easily put into different simulated scenarios

  12. Tracking control mechanisms for positioning automatic CRD exchanger

    International Nuclear Information System (INIS)

    Purpose: To enable completely automatic positioning for the automatic CRD (control rod drives) exchanger, as well as shorten the time for the exchanging operation and save the operator's labour. Constitution: Images of a target attached to the lower flange face of CRD are picked up by a fiber scope mounted to a mounting head. The images are converted through I.T.V. into electrical signals, passed through a cable and then sent to a pattern recognition mechanism. The position for the images of the target is calculated and the calculated position is sent to a drive control section, where the position for the images of the target is compared with a reference position for the images (exactly aligned position) and the moving amount of the mounting head is calculated to move the driving section and thereby complete the positioning. (Kawakami, Y.)

  13. Heralded Control of Mechanical Motion by Single Spins

    Science.gov (United States)

    Rao, D. D. Bhaktavatsala; Momenzadeh, S. Ali; Wrachtrup, Jörg

    2016-08-01

    We propose a method to achieve a high degree of control of nanomechanical oscillators by coupling their mechanical motion to single spins. Manipulating the spin alone and measuring its quantum state heralds the cooling or squeezing of the oscillator even for weak spin-oscillator couplings. We analytically show that the asymptotic behavior of the oscillator is determined by a spin-induced thermal filter function whose overlap with the initial thermal distribution of the oscillator determines its cooling, heating, or squeezing. Counterintuitively, the rate of cooling dependence on the instantaneous thermal occupancy of the oscillator renders robust cooling or squeezing even for high initial temperatures and damping rates. We further estimate how the proposed scheme can be used to control the motion of a thin diamond cantilever by coupling it to its defect centers at low temperature.

  14. Control of mechanical systems with rolling constraints: Application to dynamic control of mobile robots

    Science.gov (United States)

    Sarkar, Nilanjan; Yun, Xiaoping; Kumar, Vijay

    1994-01-01

    There are many examples of mechanical systems that require rolling contacts between two or more rigid bodies. Rolling contacts engender nonholonomic constraints in an otherwise holonomic system. In this article, we develop a unified approach to the control of mechanical systems subject to both holonomic and nonholonomic constraints. We first present a state space realization of a constrained system. We then discuss the input-output linearization and zero dynamics of the system. This approach is applied to the dynamic control of mobile robots. Two types of control algorithms for mobile robots are investigated: trajectory tracking and path following. In each case, a smooth nonlinear feedback is obtained to achieve asymptotic input-output stability and Lagrange stability of the overall system. Simulation results are presented to demonstrate the effectiveness of the control algorithms and to compare the performane of trajectory-tracking and path-following algorithms.

  15. Uranium dioxide sintering Kinetics and mechanisms under controlled oxygen potentials

    International Nuclear Information System (INIS)

    The initial, intermediate, and final sintering stages of uranium dioxide were investigated as a function of stoichiometry and temperature by following the kinetics of the sintering reaction. Stoichiometry was controlled by means of the oxygen potential of the sintering atmosphere, which was measured continuously by solid-state oxygen sensors. Included in the kinetic study were microspheres originated from UO2 gels and UO2 pellets produced by isostatic pressing ceramic grade powders. The microspheres sintering behavior was examined using hot-stage microscopy and a specially designed high-temperature, controlled atmosphere furnace. This same furnace was employed as part of an optical dilatometer, which was utilized in the UO2 pellet sintering investigations. For controlling the deviations from stoichiometry during heat treatment, the oxygen partial pressure in the sintering atmosphere was varied by passing the gas through a Cu-Ti-Cu oxygen trap. The trap temperature determined the oxygen partial pressure of the outflowing mixture. Dry hydrogen was also used in some of the UO sub(2+x) sintering experiments. The determination of diametrial shrinkages and sintering indices was made utilizing high-speed microcinematography and ultra-microbalance techniques. It was observed that the oxygen potential has a substantial influence on the kinetics of the three sintering stages. The control of the sintering atmosphere oxygen partial pressure led to very fast densification of UO sub(2+x). Values in the interval 95.0 to 99.5% of theoretical density were reached in less than one minute. Uranium volume diffusion is the dominant mechanism in the initial and intermediate sintering stages. For the final stage, uranium grain boundary diffusion was found to be the main sintering mechanism. (Author)

  16. Lumbopelvic flexibility modulates neuromuscular responses during trunk flexion-extension.

    Science.gov (United States)

    Sánchez-Zuriaga, Daniel; Artacho-Pérez, Carla; Biviá-Roig, Gemma

    2016-06-01

    Various stimuli such as the flexibility of lumbopelvic structures influence the neuromuscular responses of the trunk musculature, leading to different load sharing strategies and reflex muscle responses from the afferents of lumbopelvic mechanoreceptors. This link between flexibility and neuromuscular response has been poorly studied. The aim of this study was to investigate the relationship between lumbopelvic flexibility and neuromuscular responses of the erector spinae, hamstring and abdominal muscles during trunk flexion-extension. Lumbopelvic movement patterns were measured in 29 healthy women, who were separated into two groups according to their flexibility during trunk flexion-extension. The electromyographic responses of erector spinae, rectus abdominis and biceps femoris were also recorded. Subjects with greater lumbar flexibility had significantly less pelvic flexibility and vice versa. Subjects with greater pelvic flexibility had a higher rate of relaxation and lower levels of hamstring activation during maximal trunk flexion. The neuromuscular response patterns of the hamstrings seem partially modulated by pelvic flexibility. Not so with the lumbar erector spinae and lumbar flexibility, despite the assertions of some previous studies. The results of this study improve our knowledge of the relationships between trunk joint flexibility and neuromuscular responses, a relationship which may play a role in low back pain. PMID:27155332

  17. Using mouse cranial muscles to investigate neuromuscular pathology in vivo.

    Science.gov (United States)

    Murray, L M; Gillingwater, T H; Parson, S H

    2010-11-01

    Neuromuscular pathology is a classic hallmark of many diseases such as muscular dystrophy, myasthenia gravis, amyotrophic lateral sclerosis and spinal muscular atrophy. It is also a feature of many congenital and acquired myopathies and neuropathies such as diabetic neuropathy and toxin-exposure. The availability of experimentally accessible nerve-muscle preparations from rodent models in which pathological events can be studied in nerve and muscle, as well as at the neuromuscular junction, is therefore of fundamental importance for investigating neuromuscular disease. The group of small cranial muscles, which move the ear in the mouse provide ideal experimental preparations for the study of neuromuscular disease in vivo, but information regarding their anatomical and functional characteristics is currently lacking. Here, we provide a detailed description of the levator auris longus, auricularis superior, abductor auris longus and interscutularis muscles. In addition, we briefly review their differential fibre type and developmental characteristics, which can be exploited to aid our understanding of neuromuscular vulnerability and to provide preferable alternatives to more traditional muscle preparations such as gastrocnemius, soleus and diaphragm. PMID:20637618

  18. Preventing Ischial Pressure Ulcers: III. Clinical Pilot Study of Chronic Neuromuscular Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Hilton M. Kaplan

    2011-01-01

    Full Text Available Objective: BIONs™ (BIOnic Neurons are injectable, wireless microstimulators that make chronic BION Active Seating (BAS possible for pressure ulcer prevention (PUP. Neuromuscular electrical stimulation (NMES produces skeletal motion and activates trophic factors, counteracting three major etiological mechanisms leading to pressure ulcers (PUs: immobility, soft-tissue atrophy, and ischemia. Companion papers I and II reviewed prior experience with NMES for PUP, and analyzed the biomechanical considerations, respectively. This paper presents a treatment strategy derived from this analysis, and the clinical results of the first three cases.

  19. Neuromuscular function and fatigue resistance of the plantar flexors following short-term cycling endurance training.

    Science.gov (United States)

    Behrens, Martin; Weippert, Matthias; Wassermann, Franziska; Bader, Rainer; Bruhn, Sven; Mau-Moeller, Anett

    2015-01-01

    Previously published studies on the effect of short-term endurance training on neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC) and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals without the endurance training stimulus. Therefore, this randomized controlled study was directed to investigate the neuromuscular function of the plantar flexors at rest and during iMVC before and after 8 weeks of cycling endurance training. Twenty-two young adults were randomly assigned to an intervention group and a control group. During neuromuscular testing, rate of torque development, isometric maximum voluntary torque and muscle activation were measured. Triceps surae muscle activation and tibialis anterior muscle co-activation were assessed by normalized root mean square of the EMG signal during the initial phase of contraction (0-100, 100-200 ms) and iMVC of the plantar flexors. Furthermore, evoked spinal reflex responses of the soleus muscle (H-reflex evoked at rest and during iMVC, V-wave), peak twitch torques induced by electrical stimulation of the posterior tibial nerve at rest and fatigue resistance were evaluated. The results indicate that cycling endurance training did not lead to a significant change in any variable of interest. Data of the present study conflict with the outcome of previously published studies that have found an increase in H-reflex excitability after endurance training. However, these studies had not included a control group in their study design as was the case here. It is concluded that short-term cycling endurance training does not necessarily enhance H-reflex responses and fatigue resistance. PMID:26029114

  20. Neuromuscular function and fatigue resistance of the plantar flexors following short-term cycling endurance training

    Directory of Open Access Journals (Sweden)

    Martin eBehrens

    2015-05-01

    Full Text Available Previously published studies on the effect of short-term endurance training on the neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals without the endurance training stimulus. Therefore, this randomized controlled study was directed to investigate the neuromuscular function of the plantar flexors at rest and during iMVC before and after eight weeks of cycling endurance training. Twenty-two young adults were randomly assigned to an intervention group and a control group. During neuromuscular testing, rate of torque development, isometric maximum voluntary torque and muscle activation were measured. Triceps surae muscle activation and tibialis anterior muscle co-activation were assessed by normalized root mean square of the EMG signal during the initial phase of contraction (0-100, 100-200 ms and isometric maximum voluntary contraction of the plantar flexors. Furthermore, evoked spinal reflex responses of the soleus muscle (H-reflex evoked at rest and during iMVC, V-wave, peak twitch torques induced by electrical stimulation of the posterior tibial nerve at rest and fatigue resistance were evaluated. The results indicate that the endurance training did not lead to a significant change in any variable of interest. Data of the present study conflict with the outcome of previously published studies that have found an increase in H-reflex excitability after endurance training. However, these studies had not included a control group in their study design as was the case here. It is concluded that short-term cycling endurance training does not necessarily enhance H-reflex responses and fatigue

  1. Central chemoreceptors and neural mechanisms of cardiorespiratory control

    Directory of Open Access Journals (Sweden)

    T.S. Moreira

    2011-09-01

    Full Text Available The arterial partial pressure (P CO2 of carbon dioxide is virtually constant because of the close match between the metabolic production of this gas and its excretion via breathing. Blood gas homeostasis does not rely solely on changes in lung ventilation, but also to a considerable extent on circulatory adjustments that regulate the transport of CO2 from its sites of production to the lungs. The neural mechanisms that coordinate circulatory and ventilatory changes to achieve blood gas homeostasis are the subject of this review. Emphasis will be placed on the control of sympathetic outflow by central chemoreceptors. High levels of CO2 exert an excitatory effect on sympathetic outflow that is mediated by specialized chemoreceptors such as the neurons located in the retrotrapezoid region. In addition, high CO2 causes an aversive awareness in conscious animals, activating wake-promoting pathways such as the noradrenergic neurons. These neuronal groups, which may also be directly activated by brain acidification, have projections that contribute to the CO2-induced rise in breathing and sympathetic outflow. However, since the level of activity of the retrotrapezoid nucleus is regulated by converging inputs from wake-promoting systems, behavior-specific inputs from higher centers and by chemical drive, the main focus of the present manuscript is to review the contribution of central chemoreceptors to the control of autonomic and respiratory mechanisms.

  2. Thermal and mechanical controls on magma supply and volcanic deformation

    Science.gov (United States)

    Hickey, James; Gottsmann, Jo; Nakamichi, Haruhisa; Iguchi, Masato

    2016-04-01

    Ground deformation often precedes volcanic eruptions, and results from complex interactions between source processes and the thermomechanical behaviour of surrounding rock. Geodetic models aimed at constraining source processes consequently require the implementation of realistic mechanical and thermal rock properties. However, most generic models ignore this requirement and employ oversimplified mechanical assumptions without regard for thermal effects. Here we show how spatio-temporal deformation and magma reservoir evolution are fundamentally controlled by three-dimensional thermomechanical heterogeneity. Using the example of continued inflation at Aira caldera, Japan, we demonstrate that despite on-going eruptions magma is accumulating faster than it can be ejected, and the current uplift is approaching the level inferred prior to the 1914 Plinian eruption. Our results from inverse and forward numerical models are consistent with petrological constraints and highlight how the location, volume, and rate of magma supply, 0.014 km3/yr, are thermomechanically controlled. Magma storage conditions coincide with estimates for the caldera-forming reservoir ˜29,000 years ago, and the inferred magma supply rate indicates a ˜130-year timeframe to amass enough magma to feed a future 1914-sized eruption. These new inferences are important for eruption forecasting and risk mitigation, and have significant implications for the interpretations of volcanic deformation worldwide.

  3. Neural mechanisms of attentional control in mindfulness meditation

    Directory of Open Access Journals (Sweden)

    Peter eMalinowski

    2013-02-01

    Full Text Available The scientific interest in meditation and mindfulness practice has recently seen an unprecedented surge. After an initial phase of presenting beneficial effects of mindfulness practice in various domains, research is now seeking to unravel the underlying psychological and neurophysiological mechanisms. Advances in understanding these processes are required for improving and fine-tuning mindfulness-based interventions that target specific conditions such as eating disorders or attention deficit hyperactivity disorders. This review presents a theoretical framework that emphasizes the central role of attentional control mechanisms in the development of mindfulness skills. It discusses the phenomenological level of experience during meditation, the different attentional functions that are involved, and relates these to the brain networks that subserve these functions. On the basis of currently available empirical evidence specific processes as to how attention exerts its positive influence are considered and it is concluded that meditation practice appears to positively impact attentional functions by improving resource allocation processes. As a result, attentional resources are allocated more fully during early processing phases which subsequently enhance further processing. Neural changes resulting from a pure form of mindfulness practice that is central to most mindfulness programs are considered from the perspective that they constitute a useful reference point for future research. Furthermore, possible interrelations between the improvement of attentional control and emotion regulation skills are discussed.

  4. Mechanism of controlled release kinetics from medical devices

    Directory of Open Access Journals (Sweden)

    A. Raval

    2010-06-01

    Full Text Available Utilization of biodegradable polymers for controlled drug delivery has gained immense attention in the pharmaceutical and medical device industry to administer various drugs, proteins and other bio-molecules both systematically and locally to cure several diseases. The efficacy and toxicity of this local therapeutics depends upon drug release kinetics, which will further decide drug deposition, distribution, and retention at the target site. Drug Eluting Stent (DES presently possesses clinical importance as an alternative to Coronary Artery Bypass Grafting due to the ease of the procedure and comparable safety and efficacy. Many models have been developed to describe the drug delivery from polymeric carriers based on the different mechanisms which control the release phenomenon from DES. Advanced characterization techniques facilitate an understanding of the complexities behind design and related drug release behavior of drug eluting stents, which aids in the development of improved future drug eluting systems. This review discusses different drug release mechanisms, engineering principles, mathematical models and current trends that are proposed for drug-polymer coated medical devices such as cardiovascular stents and different analytical methods currently utilized to probe diverse characteristics of drug eluting devices.

  5. Emergent patterns of growth controlled by multicellular form and mechanics

    Science.gov (United States)

    Nelson, Celeste M.; Jean, Ronald P.; Tan, John L.; Liu, Wendy F.; Sniadecki, Nathan J.; Spector, Alexander A.; Chen, Christopher S.

    2005-01-01

    Spatial patterns of cellular growth generate mechanical stresses that help to push, fold, expand, and deform tissues into their specific forms. Genetic factors are thought to specify patterns of growth and other behaviors to drive morphogenesis. Here, we show that tissue form itself can feed back to regulate patterns of proliferation. Using microfabrication to control the organization of sheets of cells, we demonstrated the emergence of stable patterns of proliferative foci. Regions of concentrated growth corresponded to regions of high tractional stress generated within the sheet, as predicted by a finite-element model of multicellular mechanics and measured directly by using a micromechanical force sensor array. Inhibiting actomyosin-based tension or cadherin-mediated connections between cells disrupted the spatial pattern of proliferation. These findings demonstrate the existence of patterns of mechanical forces that originate from the contraction of cells, emerge from their multicellular organization, and result in patterns of growth. Thus, tissue form is not only a consequence but also an active regulator of tissue growth. PMID:16049098

  6. Auction Mechanism to Allocate Air Traffic Control Slots

    Science.gov (United States)

    Raffarin, Marianne

    2003-01-01

    This article deals with an auction mechanism for airspace slots, as a means of solving the European airspace congestion problem. A disequilibrium, between Air Traffic Control (ATC) services supply and ATC services demand are at the origin of almost one fourth of delays in the air transport industry in Europe. In order to tackle this congestion problem, we suggest modifying both pricing and allocation of ATC services, by setting up an auction mechanism. Objects of the auction will be the right for airlines to cross a part of the airspace, and then to benefit from ATC services over a period corresponding to the necessary time for the crossing. Allocation and payment rules have to be defined according to the objectives of this auction. The auctioneer is the public authority in charge of ATC services, whose aim is to obtain an efficient allocation. Therefore, the social value will be maximized. Another objective is to internalize congestion costs. To that end, we apply the principle of Clarke-Groves mechanism auction: each winner has to pay the externalities imposed on other bidders. The complex context of ATC leads to a specific design for this auction.

  7. Muscle Decline in Aging and Neuromuscular Disorders - Mechanisms and Countermeasures

    OpenAIRE

    Baba, Alfonc; Esser, Karyn A.; Dyar, Kenneth A.; Ciciliot, Stefano; Tagliazucchi, Guidantonio Malagoli; Pallafacchina, Giorgia; Tothova, Jana; Argentini, Carla; Agatea, Lisa; Abraham, Reimar; Ahdesmäki, Miika; Forcato, Mattia; Bicciato, Silvio; Schiaffino, Stefano; Blaauw, Bert

    2016-01-01

    Physical exercise is known to have beneficial effects on muscle trophism and force production modulating signaling pathways involved in fiber type plasticity, muscle growth and mitochondria respiratory efficiency. 1 It has been shown that the decrease of muscle mass and strength observed in aging is linked to intracellular and extracellular abnormalities, that is, sarcoplasmic reticulum-to-mitochondria malfunctions and extracellular matrix metabolism, respectively. Lifelong, high-level physic...

  8. Outcome measures in neuromuscular disease: is the world still flat?

    Science.gov (United States)

    Lunn, Michael P; Van den Bergh, Peter Y K

    2015-09-01

    Valid, responsive, and meaningful outcome measures for the measurement of the impairment, activity limitations, and quality of life in patients with neuromuscular disease are crucial to identify the natural history of disease and benefits of therapy in clinical practice and trials. Although understanding of many aspects of neuromuscular diseases has advanced dramatically, the development of outcome measures has received less attention. The scales developed from Rasch theory by the PeriNomS Group represent the biggest significant shift in thought in neuromuscular outcome measures for decades. There remain problems with many of them, and further developments are required. However, incorporating them into our outcome sets for daily use and in clinical trials will lead to the more efficient capture of meaningful change and will result in better assessment of individuals and groups of patients in both clinical trials and neurological practice. PMID:26114965

  9. Neuromuscular exercise as treatment of degenerative knee disease

    DEFF Research Database (Denmark)

    Ageberg, Eva; Roos, Ewa M.

    2015-01-01

    Exercise is recommended as first-line treatment of degenerative knee disease. Our hypothesis is that neuromuscular exercise is feasible and at least as effective as tradionally used strength or aerobic training, but aims to more closely target the sensorimotor deficiencies and functional instabil......Exercise is recommended as first-line treatment of degenerative knee disease. Our hypothesis is that neuromuscular exercise is feasible and at least as effective as tradionally used strength or aerobic training, but aims to more closely target the sensorimotor deficiencies and functional...... instability associated with the degenerative knee disease than traditionally used training methods.SUMMARY FOR TABLE OF CONTENTS PAGECurrent data suggests that the effect from neuromuscular exercise on pain and function is comparable to the effects seen from other forms of exercise....

  10. Effects of Seated Whole-Body Vibration on Spinal Stability Control

    OpenAIRE

    Slota, Gregory P.

    2008-01-01

    Low back disorders and their prevention is of great importance for companies and their employees. Whole-body vibration is a risk factor for low back disorders, but the neuromuscular, biomechanical, and/or physiological mechanisms responsible for this increased risk are unclear. These studies investigated changes in the biomechanics and control of the trunk in order to further the understanding of the mechanisms responsible for this increased risk. The purpose of the first study was to...

  11. Chemo-mechanical control of neural stem cell differentiation

    Science.gov (United States)

    Geishecker, Emily R.

    Cellular processes such as adhesion, proliferation, and differentiation are controlled in part by cell interactions with the microenvironment. Cells can sense and respond to a variety of stimuli, including soluble and insoluble factors (such as proteins and small molecules) and externally applied mechanical stresses. Mechanical properties of the environment, such as substrate stiffness, have also been suggested to play an important role in cell processes. The roles of both biochemical and mechanical signaling in fate modification of stem cells have been explored independently. However, very few studies have been performed to study well-controlled chemo-mechanotransduction. The objective of this work is to design, synthesize, and characterize a chemo-mechanical substrate to encourage neuronal differentiation of C17.2 neural stem cells. In Chapter 2, Polyacrylamide (PA) gels of varying stiffnesses are functionalized with differing amounts of whole collagen to investigate the role of protein concentration in combination with substrate stiffness. As expected, neurons on the softest substrate were more in number and neuronal morphology than those on stiffer substrates. Neurons appeared locally aligned with an expansive network of neurites. Additional experiments would allow for statistical analysis to determine if and how collagen density impacts C17.2 differentiation in combination with substrate stiffness. Due to difficulties associated with whole protein approaches, a similar platform was developed using mixed adhesive peptides, derived from fibronectin and laminin, and is presented in Chapter 3. The matrix elasticity and peptide concentration can be individually modulated to systematically probe the effects of chemo-mechanical signaling on differentiation of C17.2 cells. Polyacrylamide gel stiffness was confirmed using rheological techniques and found to support values published by Yeung et al. [1]. Cellular growth and differentiation were assessed by cell counts

  12. Neuromuscular Junction Protection for the Potential Treatment of Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Dan Krakora

    2012-01-01

    Full Text Available Amyotrophic lateral sclerosis (ALS is a neuromuscular disease characterized by the progressive degeneration of upper and lower motor neurons (MNs, leading to muscular atrophy and eventual respiratory failure. ALS research has primarily focused on mechanisms regarding MN cell death; however, degenerative processes in the skeletal muscle, particularly involving neuromuscular junctions (NMJs, are observed in the early stages of and throughout disease progression. According to the “dying-back” hypothesis, NMJ degeneration may not only precede, but actively cause upper and lower MN loss. The importance of NMJ pathology has relatively received little attention in ALS, possibly because compensatory mechanisms mask NMJ loss for prolonged periods. Many mechanisms explaining NMJ degeneration have been proposed such as the disruption of anterograde/retrograde axonal transport, irregular cellular metabolism, and changes in muscle gene and protein expression. Neurotrophic factors, which are known to have neuroprotective and regenerative properties, have been intensely investigated for their therapeutic potential in both the preclinical and clinical setting. Additional research should focus on the potential of preserving NMJs in order to delay or prevent disease progression

  13. Train-of-four fade during onset of neuromuscular block with nondepolarising neuromuscular blocking agents.

    Science.gov (United States)

    Gibson, F M; Mirakhur, R K

    1989-04-01

    Fade in the train-of-four (TOF) responses during onset of neuromuscular block was studied following administration of atracurium (225 or 450 micrograms/kg), vecuronium (40 or 80 micrograms/kg), pancuronium (60 or 120 micrograms/kg) and tubocurarine (450 micrograms/kg). TOF ratios were measured at approximate heights of T1 (first response in the TOF) of 75, 50 and 25%. Fade in TOF increased as the height of T1 decreased, with maximum fade being observed at T1 of 25%. The greatest difference between relaxants was observed at T1 of 25%, vecuronium showing the least fade and pancuronium, atracurium and tubocurarine showing increasing fade, in that order. The difference between atracurium and tubocurarine or between vecuronium and pancuronium was not significant, but the degree of TOF fade was significantly greater with atracurium and tubocurarine in comparison to vecuronium or pancuronium.

  14. Anormalidades neuromuscular no desuso, senilidade e caquexia Neuromuscular abnormalities in disuse, cachexia and ageing

    OpenAIRE

    João Aris Kouyoumdjian

    1993-01-01

    É feita revisão de literatura sobre as principais alterações do sistema neuromuscular no desuso, senilidade e caquexia no ser humano e em modelos animais. A diminuição do diâmetro das fibras musculares após período de inatividade/imobilidade (desuso) deve-se à perda de miofibrilas periféricas não ocorrendo formação de core-targetóides ou diminuição da atividade da miofosforilase, próprias da desnervação; mantêm-se a liberação espontânea de acetilcolina e fatores tróficos na junção mio-neural;...

  15. New techniques in the tissue diagnosis of gastrointestinal neuromuscular diseases

    Institute of Scientific and Technical Information of China (English)

    Charles H Knowles; Joanne E Martin

    2009-01-01

    Gastrointestinal neuromuscular diseases are a clinically heterogeneous group of disorders of children and adults in which symptoms are presumed or proven to arise as a result of neuromuscular (including interstitial cell of Cajal) dysfunction. Common to most of these diseases are symptoms of impaired motor activity which manifest as slowed or obstructed transit with or without evidence of transient or persistent radiological visceral dilatation. A variety of histopathological techniques and allied investigations are being increasingly applied to tissue biopsies from such patients. This review outlines some of the more recent advances in this field, particularly in the most contentious area of small bowel disease manifesting as intestinal pseudo-obstruction.

  16. The effectiveness of neuromuscular warm-up strategies, that require no additional equipment, for preventing lower limb injuries during sports participation: a systematic review

    Directory of Open Access Journals (Sweden)

    Herman Katherine

    2012-07-01

    Full Text Available Abstract Background Lower limb injuries in sport are increasingly prevalent and responsible for large economic as well as personal burdens. In this review we seek to determine which easily implemented functional neuromuscular warm-up strategies are effective in preventing lower limb injuries during sports participation and in which sporting groups they are effective. Methods Seven electronic databases were searched from inception to January 2012 for studies investigating neuromuscular warm-up strategies and injury prevention. The quality of each included study was evaluated using a modified version of the van Tulder scale. Data were extracted from each study and used to calculate the risk of injury following application of each evaluated strategy. Results Nine studies were identified including six randomized controlled trials (RCT and three controlled clinical trials (CCT. Heterogeneity in study design and warm-up strategies prevented pooling of results. Two studies investigated male and female participants, while the remaining seven investigated women only. Risk Ratio (RR statistics indicated 'The 11+' prevention strategy significantly reduces overall (RR 0.67, confidence interval (CI 0.54 to 0.84 and overuse (RR 0.45, CI 0.28 to 0.71 lower limb injuries as well as knee (RR 0.48, CI 0.32 to 0.72 injuries among young amateur female footballers. The 'Knee Injury Prevention Program' (KIPP significantly reduced the risk of noncontact lower limb (RR 0.5, CI 0.33 to 0.76 and overuse (RR 0.44, CI 0.22 to 0.86 injuries in young amateur female football and basketball players. The 'Prevent Injury and Enhance Performance' (PEP strategy reduces the incidence of anterior cruciate ligament (ACL injuries (RR 0.18, CI 0.08 to 0.42. The 'HarmoKnee' programme reduces the risk of knee injuries (RR 0.22, CI 0.06 to 0.76 in teenage female footballers. The 'Anterior Knee Pain Prevention Training Programme' (AKP PTP significantly reduces the incidence of anterior

  17. Altered knee joint neuromuscular control during landing from a jump in 10-15year old children with Generalised Joint Hypermobility. A substudy of the CHAMPS-study Denmark

    DEFF Research Database (Denmark)

    Junge, Tina; Wedderkopp, Niels; Thorlund, Jonas Bloch;

    2015-01-01

    -Leg-Hop-for-Distance test (SLHD) in 25 children with GJH compared to 29 children without GJH (controls), all 10-15years. Inclusion criteria for GJH: Beighton score⩾5/9 and minimum one hypermobile knee. EMG was recorded from the quadriceps, the hamstring and the calf muscles, presented relative to Maximum Voluntary...... Electrical activity (MVE). There was no difference in jump length between groups. Before landing, GJH had 33% lower Semitendinosus, but 32% higher Gastrocnemius Medialis activity and 39% higher co contraction of the lateral knee muscles, than controls. After landing, GJH had 36% lower Semitendinosus activity...

  18. Line-tension controlled mechanism for influenza fusion.

    Directory of Open Access Journals (Sweden)

    Herre Jelger Risselada

    Full Text Available Our molecular simulations reveal that wild-type influenza fusion peptides are able to stabilize a highly fusogenic pre-fusion structure, i.e. a peptide bundle formed by four or more trans-membrane arranged fusion peptides. We rationalize that the lipid rim around such bundle has a non-vanishing rim energy (line-tension, which is essential to (i stabilize the initial contact point between the fusing bilayers, i.e. the stalk, and (ii drive its subsequent evolution. Such line-tension controlled fusion event does not proceed along the hypothesized standard stalk-hemifusion pathway. In modeled influenza fusion, single point mutations in the influenza fusion peptide either completely inhibit fusion (mutants G1V and W14A or, intriguingly, specifically arrest fusion at a hemifusion state (mutant G1S. Our simulations demonstrate that, within a line-tension controlled fusion mechanism, these known point mutations either completely inhibit fusion by impairing the peptide's ability to stabilize the required peptide bundle (G1V and W14A or stabilize a persistent bundle that leads to a kinetically trapped hemifusion state (G1S. In addition, our results further suggest that the recently discovered leaky fusion mutant G13A, which is known to facilitate a pronounced leakage of the target membrane prior to lipid mixing, reduces the membrane integrity by forming a 'super' bundle. Our simulations offer a new interpretation for a number of experimentally observed features of the fusion reaction mediated by the prototypical fusion protein, influenza hemagglutinin, and might bring new insights into mechanisms of other viral fusion reactions.

  19. Anormalidades neuromuscular no desuso, senilidade e caquexia

    Directory of Open Access Journals (Sweden)

    João Aris Kouyoumdjian

    1993-09-01

    Full Text Available É feita revisão de literatura sobre as principais alterações do sistema neuromuscular no desuso, senilidade e caquexia no ser humano e em modelos animais. A diminuição do diâmetro das fibras musculares após período de inatividade/imobilidade (desuso deve-se à perda de miofibrilas periféricas não ocorrendo formação de core-targetóides ou diminuição da atividade da miofosforilase, próprias da desnervação; mantêm-se a liberação espontânea de acetilcolina e fatores tróficos na junção mio-neural; em geral são afetadas preferencialmente fibras II, que podem assumir forma angular. Existe um processo contínuo intrínseco de envelhecimento de nervos e músculos, com desnervação e reinervação lenta e progressiva; o número de unidades motoras se reduz após 60 anos, sem ocorrência de atividade elétrica desnervatória; a quantidade de acetilcolina liberada nos neurônios terminais e a capacidade máxima de utilização de oxigênio estão diminuídas; a redução da capacidade oxidativa mitocondrial pode explicar o aumento de fibras I, mantendo-se o equilíbrio energético. Após poucas semanas de caquexia as fibras musculares podem ter o diâmetro reduzido em 30%, essa redução ocorre em ordem decrescente nos músculos dos membros inferiores, superiores e tronco; existe atrofia II preferencial com fibras angulares ocasionais, redução de RNA/síntese proteica, mantendo-se DNA normal.

  20. An Effective Feedback Control Mechanism for DiffServ Architecture

    Institute of Scientific and Technical Information of China (English)

    王重钢; 隆克平; 杨健; 程时端

    2002-01-01

    As a scalable QoS (Quality of Service) architecture, DiffServ (Differentiated Service) mainly consists of two components: traffic conditioning at the edge of the DiffServ domain and simple packet forwarding inside the DiffServ domain. DiffServ has many advantages such as flexibility, scalability and simplicity. But when providing AF (Assured Forwarding)services, DiffServ has some problems such as unfairness among aggregated flows or among microflows belonging to an aggregated flow. In this paper, a feedback mechanism for AF aggregated flows is proposed to solve this problem. Simulation results show that this mechanism does improve the performance of DiffServ. First, it can improve the fairness among aggregated flows and make DiffServ more friendly toward TCP (Transmission Control Protocol) flows. Second,it can decrease the buffer requirements at the congested router and thus obtain lower delay and packet loss rate. Third, it also keeps almost the same link utility as in normal DiffServ.Finally, it is simple and easy to be implemented.

  1. Mechanisms controlling the distribution of two invasive Bromus species

    Directory of Open Access Journals (Sweden)

    Olga Bykova

    2014-03-01

    Full Text Available In order to predict future range shifts for invasive species it is important to explore their ability to acclimate to the new environment and understand physiological and reproductive constraints controlling their distribution. My dissertation studied mechanisms by which temperature may affect the distribution of two aggressive plant invaders in North America, Bromus tectorum and Bromus rubens. I first evaluated winter freezing tolerance of Bromus species and demonstrated that the mechanism explaining their distinct northern range limits is different acquisition time of freezing tolerance. While B. rubens has a slower rate of freezing acclimation that leads to intolerance of sudden, late-autumn drops in temperature below -12°C, B. tectorum rapidly hardens and so is not impacted by the sudden onset of severe late-autumn cold. In addition, the analysis of male reproductive development and seed production showed that neither species produces seed at or above 36°C, due to complete pollen sterility, which might trigger climate-mediated range contractions at B. tectorum and B. rubens southern margins. Finally, a detailed gas-exchange analysis combined with biochemical modelling demonstrated that both species acclimate to a broad range of temperatures and photosynthetic response to temperature does not explain their current range separation.

  2. Cellular and Humoral Mechanisms Involved in the Control of Tuberculosis

    Directory of Open Access Journals (Sweden)

    Joaquin Zuñiga

    2012-01-01

    Full Text Available Mycobacterium tuberculosis (Mtb infection is a major international public health problem. One-third of the world's population is thought to have latent tuberculosis, a condition where individuals are infected by the intracellular bacteria without active disease but are at risk for reactivation, if their immune system fails. Here, we discuss the role of nonspecific inflammatory responses mediated by cytokines and chemokines induced by interaction of innate receptors expressed in macrophages and dendritic cells (DCs. We also review current information regarding the importance of several cytokines including IL-17/IL-23 in the development of protective cellular and antibody-mediated protective responses against Mtb and their influence in containment of the infection. Finally, in this paper, emphasis is placed on the mechanisms of failure of Mtb control, including the immune dysregulation induced by the treatment with biological drugs in different autoimmune diseases. Further functional studies, focused on the mechanisms involved in the early host-Mtb interactions and the interplay between host innate and acquired immunity against Mtb, may be helpful to improve the understanding of protective responses in the lung and in the development of novel therapeutic and prophylactic tools in TB.

  3. Passive Flow Separation Control Mechanism Inspired by Shark Skin

    Science.gov (United States)

    Oakley, India; Lang, Amy

    2015-11-01

    The following experimental work seeks to examine shark scales as passive flow-actuated separation control mechanisms. It is hypothesized that the actuation of these scales can in fact reduce pressure drag by inhibiting flow reversal and thereby prevent flow separation. In order to examine this mechanism at a fundamental level, three-dimensional sharkskin scales were simplified and modeled as two-dimensional flaps. To further simplify the experiment, the flaps were observed within a laminar boundary layer. The laminar boundary layer was grown over a long flat plate that was placed inside a water tunnel. A rotating cylinder was also used to induce an unsteady, increasing adverse pressure gradient, which generated a reversing flow. In order to visualize the potential actuation of the two-dimensional flaps DPIV (digital particle image velocimetry) was utilized. Three main objectives for this work included, the actuation of the two-dimensional flaps, the resistance to a reversed flow as a result of flap actuation and the prevention of flow separation. However once the experiment was conducted the flaps did not perform as previously hypothesized. The adverse pressure gradient induced by the rotating cylinder did not produce a reversing flow powerful enough to actuate the flaps. NSF REU Site Award 1358991.

  4. Altered knee joint neuromuscular control during landing from a jump in 10-15 year old children with generalised joint hypermobility. A substudy of the CHAMPS-study Denmark

    DEFF Research Database (Denmark)

    Junge, Tina; Juul-Kristensen, B; Bloch Thorlund, Jonas;

    2015-01-01

    Electrical activity (MVE). There was no difference in jump length between groups. Before landing, GJH had 33% lower Semitendinosus, but 32% higher Gastrocnemius Medialis activity and 39% higher co-contraction of the lateral knee muscles, than controls. After landing, GJH had 36% lower Semitendinosus activity...

  5. Metallurgical Mechanisms Controlling Mechanical Properties of Aluminum Alloy 2219 Produced by Electron Beam Freeform Fabrication

    Science.gov (United States)

    Domack, Marcia S.; Tainger, Karen M.

    2006-01-01

    The electron beam freeform fabrication (EBF3) layer-additive manufacturing process has been developed to directly fabricate complex geometry components. EBF3 introduces metal wire into a molten pool created on the surface of a substrate by a focused electron beam. Part geometry is achieved by translating the substrate with respect to the beam to build the part one layer at a time. Tensile properties demonstrated for electron beam deposited aluminum and titanium alloys are comparable to wrought products, although the microstructures of the deposits exhibit cast features. Understanding the metallurgical mechanisms controlling mechanical properties is essential to maximizing application of the EBF3 process. Tensile mechanical properties and microstructures were examined for aluminum alloy 2219 fabricated over a range of EBF3 process variables. Unique microstructures were observed within the deposited layers and at interlayer boundaries, which varied within the deposit height due to microstructural evolution associated with the complex thermal history experienced during subsequent layer deposition. Microstructures exhibited irregularly shaped grains with interior dendritic structures, described based on overall grain size, morphology, distribution, and dendrite spacing, and were correlated with deposition parameters. Fracture features were compared with microstructural elements to define fracture paths and aid in definition of basic processing-microstructure-property correlations.

  6. Neuromuscular strain as a contributor to cognitive and other symptoms in chronic fatigue syndrome: hypothesis and conceptual model.

    Science.gov (United States)

    Rowe, Peter C; Fontaine, Kevin R; Violand, Richard L

    2013-01-01

    Individuals with chronic fatigue syndrome (CFS) have heightened sensitivity and increased symptoms following various physiologic challenges, such as orthostatic stress, physical exercise, and cognitive challenges. Similar heightened sensitivity to the same stressors in fibromyalgia (FM) has led investigators to propose that these findings reflect a state of central sensitivity. A large body of evidence supports the concept of central sensitivity in FM. A more modest literature provides partial support for this model in CFS, particularly with regard to pain. Nonetheless, fatigue and cognitive dysfunction have not been explained by the central sensitivity data thus far. Peripheral factors have attracted attention recently as contributors to central sensitivity. Work by Brieg, Sunderland, and others has emphasized the ability of the nervous system to undergo accommodative changes in length in response to the range of limb and trunk movements carried out during daily activity. If that ability to elongate is impaired-due to movement restrictions in tissues adjacent to nerves, or due to swelling or adhesions within the nerve itself-the result is an increase in mechanical tension within the nerve. This adverse neural tension, also termed neurodynamic dysfunction, is thought to contribute to pain and other symptoms through a variety of mechanisms. These include mechanical sensitization and altered nociceptive signaling, altered proprioception, adverse patterns of muscle recruitment and force of muscle contraction, reduced intra-neural blood flow, and release of inflammatory neuropeptides. Because it is not possible to differentiate completely between adverse neural tension and strain in muscles, fascia, and other soft tissues, we use the more general term "neuromuscular strain." In our clinical work, we have found that neuromuscular restrictions are common in CFS, and that many symptoms of CFS can be reproduced by selectively adding neuromuscular strain during the

  7. Radon mitigation with pressure-controlled mechanical ventilation

    International Nuclear Information System (INIS)

    Effective ventilation and positive or low negative pressure indoors are suggested to achieve low indoor radon levels. The aim of this study was to develop and to test equipment which makes it possible to achieve simultaneously effective ventilation and minimum indoor-outdoor pressure difference. The unit included mechanical supply and exhaust air fans, a heat-exchanger and a pressure control unit in direct digital control (DDC), which continuously adjusted air flows based on the pressure difference transmitter information. Indoor radon level decreased from 501 ± 95 Bq/m3 to 202 ± 54 Bq/m3 after two weeks of the equipment's installation during winter conditions. The arithmetic week average of indoor radon level was 135 Bq/m3 from May to August. When the set value of pressure difference adjustment was slightly positive (0.2 Pa) and in-out temperature difference was small in August, the minimum level (38 ± 28 Bq/m3) was obtained. (author)

  8. Shark Skin Bristling as a Passive Mechanism for Separation Control

    Science.gov (United States)

    Wheelus, Jennifer; Lang, Amy; Jones, Emily

    2011-11-01

    The skin of fast-swimming sharks is proposed to have mechanisms to reduce drag and delay flow separation. The skin of fast-swimming and agile sharks is covered with small teeth-like denticles on the order of 0.2 mm. The shortfin mako is one of the fastest and most agile ocean predators creating the need to minimize its pressure drag by controlling flow separation. Biological studies of the shortfin mako skin have shown the passive bristling angle of their denticles to exceed 50 degrees in areas on the flank corresponding to the locations likely to experience separation first. It is proposed that reversing flow, as occurs at the onset of separation in a turbulent boundary layer, would activate denticle bristling and hinder local separation from leading to global separation over the shark. This study focuses on the denticle reaction to various reversed flow conditions using a pulsating jet. Mako shark skin was subjected to numerous reversed flow velocities to determine the bristling onset velocity. Digital Particle Image Velocimetry (DPIV) and digital video were used to determine the flow conditions and denticle behavior. The effect of reversed flow velocity on denticle bristling and its relation to separation control will be discussed. Research funded by NSF (award 0932352).

  9. Genetic and evolutionary analysis of the Drosophila larval neuromuscular junction

    Science.gov (United States)

    Campbell, Megan

    Although evolution of brains and behaviors is of fundamental biological importance, we lack comprehensive understanding of the general principles governing these processes or the specific mechanisms and molecules through which the evolutionary changes are effected. Because synapses are the basic structural and functional units of nervous systems, one way to address these problems is to dissect the genetic and molecular pathways responsible for morphological evolution of a defined synapse. I have undertaken such an analysis by examining morphology of the larval neuromuscular junction (NMJ) in wild caught D. melanogaster as well as in over 20 other species of Drosophila. Whereas variation in NMJ morphology within a species is limited, I discovered a surprisingly extensive variation among different species. Compared with evolution of other morphological traits, NMJ morphology appears to be evolving very rapidly. Moreover, my data indicate that natural selection rather than genetic drift is primarily responsible for evolution of NMJ morphology. To dissect underlying molecular mechanisms that may govern NMJ growth and evolutionary divergence, I focused on a naturally occurring variant in D. melanogaster that causes NMJ overgrowth. I discovered that the variant mapped to Mob2, a gene encoding a kinase adapter protein originally described in yeast as a member of the Mitotic Exit Network (MEN). I have subsequently examined mutations in the Drosophila orthologs of all the core components of the yeast MEN and found that all of them function as part of a common pathway that acts presynaptically to negatively regulate NMJ growth. As in the regulation of yeast cytokinesis, these components of the MEN appear to act ultimately by regulating actin dynamics during the process of bouton growth and division. These studies have thus led to the discovery of an entirely new role for the MEN---regulation of synaptic growth---that is separate from its function in cell division. This work

  10. Cell shape, cytoskeletal mechanics, and cell cycle control in angiogenesis

    Science.gov (United States)

    Ingber, D. E.; Prusty, D.; Sun, Z.; Betensky, H.; Wang, N.

    1995-01-01

    Capillary endothelial cells can be switched between growth and differentiation by altering cell-extracellular matrix interactions and thereby, modulating cell shape. Studies were carried out to determine when cell shape exerts its growth-regulatory influence during cell cycle progression and to explore the role of cytoskeletal structure and mechanics in this control mechanism. When G0-synchronized cells were cultured in basic fibroblast growth factor (FGF)-containing defined medium on dishes coated with increasing densities of fibronectin or a synthetic integrin ligand (RGD-containing peptide), cell spreading, nuclear extension, and DNA synthesis all increased in parallel. To determine the minimum time cells must be adherent and spread on extracellular matrix (ECM) to gain entry into S phase, cells were removed with trypsin or induced to retract using cytochalasin D at different times after plating. Both approaches revealed that cells must remain extended for approximately 12-15 h and hence, most of G1, in order to enter S phase. After this restriction point was passed, normally 'anchorage-dependent' endothelial cells turned on DNA synthesis even when round and in suspension. The importance of actin-containing microfilaments in shape-dependent growth control was confirmed by culturing cells in the presence of cytochalasin D (25-1000 ng ml-1): dose-dependent inhibition of cell spreading, nuclear extension, and DNA synthesis resulted. In contrast, induction of microtubule disassembly using nocodazole had little effect on cell or nuclear spreading and only partially inhibited DNA synthesis. Interestingly, combination of nocodazole with a suboptimal dose of cytochalasin D (100 ng ml-1) resulted in potent inhibition of both spreading and growth, suggesting that microtubules are redundant structural elements which can provide critical load-bearing functions when microfilaments are partially compromised. Similar synergism between nocodazole and cytochalasin D was observed

  11. Diaphragm Unloading via Controlled Mechanical Ventilation Alters the Gene Expression Profile

    OpenAIRE

    DeRuisseau, Keith C.; Shanely, R Andrew; Akunuri, Nagabhavani; Hamilton, Marc T.; Van Gammeren, Darin; Zergeroglu, A. Murat; McKenzie, Michael; Powers, Scott K.

    2005-01-01

    Rationale: Prolonged controlled mechanical ventilation results in diaphragmatic inactivity and promotes oxidative injury, atrophy, and contractile dysfunction in this important inspiratory muscle. However, the impact of controlled mechanical ventilation on global mRNA alterations in the diaphragm remains unknown.

  12. Distinct neural and neuromuscular strategies underlie independent evolution of simplified advertisement calls.

    Science.gov (United States)

    Leininger, Elizabeth C; Kelley, Darcy B

    2013-04-01

    Independent or convergent evolution can underlie phenotypic similarity of derived behavioural characters. Determining the underlying neural and neuromuscular mechanisms sheds light on how these characters arose. One example of evolutionarily derived characters is a temporally simple advertisement call of male African clawed frogs (Xenopus) that arose at least twice independently from a more complex ancestral pattern. How did simplification occur in the vocal circuit? To distinguish shared from divergent mechanisms, we examined activity from the calling brain and vocal organ (larynx) in two species that independently evolved simplified calls. We find that each species uses distinct neural and neuromuscular strategies to produce the simplified calls. Isolated Xenopus borealis brains produce fictive vocal patterns that match temporal patterns of actual male calls; the larynx converts nerve activity faithfully into muscle contractions and single clicks. In contrast, fictive patterns from isolated Xenopus boumbaensis brains are short bursts of nerve activity; the isolated larynx requires stimulus bursts to produce a single click of sound. Thus, unlike X. borealis, the output of the X. boumbaensis hindbrain vocal pattern generator is an ancestral burst-type pattern, transformed by the larynx into single clicks. Temporally simple advertisement calls in genetically distant species of Xenopus have thus arisen independently via reconfigurations of central and peripheral vocal neuroeffectors. PMID:23407829

  13. Mainstreaming Children with a Neuromuscular Disease: A Map of Concerns.

    Science.gov (United States)

    Strong, Kristine; Sandoval, Jonathan

    1999-01-01

    Four focus groups (n=21) were conducted to gather information about coping issues and teacher attitudes related to the education of children with a neuromuscular disease. Results indicate a need for better home/school communication, a need to establish children's sense of competence, and a need for improved peer relationships. (Author/CR)

  14. Exercise Therapy in Spinobulbar Muscular Atrophy and Other Neuromuscular Disorders

    DEFF Research Database (Denmark)

    Dahlqvist, Julia Rebecka; Vissing, John

    2016-01-01

    with muscle wasting due to neuromuscular conditions, however, a common belief has been that physical activity could accelerate degeneration of the diseased muscle and a careful approach to training has therefore been suggested. In this review, we describe the current knowledge about physical training...

  15. Get Ready to Wnt: Prepatterning in Neuromuscular Junction Formation

    OpenAIRE

    Zhang, Bin; Xiong, Wen C.; Mei, Lin

    2009-01-01

    Clustering of acetylcholine receptors (AChR) in muscle fibers prior to innervation by motor neurons is thought to be involved in neuromuscular junction formation. Jing et al. now report in Neuron that this prepatterning of AChRs, via a novel MuSK-dependent Wnt pathway, may guide motor axons to the central region of muscle fibers for synapse formation in zebrafish.

  16. Volume of the effect compartment in simulations of neuromuscular block

    NARCIS (Netherlands)

    Nigrovic, Vladimir; Proost, Johannes H.; Amann, Anton; Bhatt, Shashi B.

    2005-01-01

    Background: The study examines the role of the volume of the effect compartment in simulations of neuromuscular block (NMB) produced by nondepolarizing muscle relaxants. Methods: The molar amount of the postsynaptic receptors at the motor end plates in muscle was assumed constant; the apparent recep

  17. Altered knee joint neuromuscular control during landing from a jump in 10-15year old children with Generalised Joint Hypermobility. A substudy of the CHAMPS-study Denmark

    DEFF Research Database (Denmark)

    Junge, Tina; Wedderkopp, Niels; Thorlund, Jonas Bloch;

    2015-01-01

    -Leg-Hop-for-Distance test (SLHD) in 25 children with GJH compared to 29 children without GJH (controls), all 10-15years. Inclusion criteria for GJH: Beighton score⩾5/9 and minimum one hypermobile knee. EMG was recorded from the quadriceps, the hamstring and the calf muscles, presented relative to Maximum Voluntary......, but with no compensatory Gastrocnemius Medialis activity. Reduced pre and post-activation of the Semitendinosus may present a risk factor for traumatic knee injuries as ACL ruptures in GJH with knee hypermobility....

  18. Antimicrobial agents used in the control of periodontal biofilms: effective adjuncts to mechanical plaque control?

    Directory of Open Access Journals (Sweden)

    Ricardo Palmier Teles

    2009-06-01

    Full Text Available The control of biofilm accumulation on teeth has been the cornerstone of periodontal disease prevention for decades. However, the widespread prevalence of gingivitis suggests the inefficiency of self-performed mechanical plaque control in preventing gingival inflammation. This is particularly relevant in light of recent evidence suggesting that long standing gingivitis increases the risk of loss of attachment and that prevention of gingival inflammation might reduce the prevalence of mild to moderate periodontitis. Several antimicrobials have been tested as adjuncts to mechanical plaque control in order to improve the results obtained with oral home care. Recent studies, including meta-analyses, have indicated that home care products containing chemical antimicrobials can provide gingivitis reduction beyond what can be accomplished with brushing and flossing. Particularly, formulations containing chlorhexidine, mouthrinses containing essential oils and triclosan/copolymer dentifrices have well documented clinical antiplaque and antigingivitis effects. In vivo microbiological tests have demonstrated the ability of these antimicrobial agents to penetrate the biofilm mass and to kill bacteria growing within biofilms. In addition, chemical antimicrobials can reach difficult-to-clean areas such as interproximal surfaces and can also impact the growth of biofilms on soft tissue. These agents have a positive track record of safety and their use does not seem to increase the levels of resistant species. Further, no study has been able to establish a correlation between mouthrinses containing alcohol and oral cancer. In summary, the adjunct use of chemical plaque control should be recommended to subjects with well documented difficulties in achieving proper biofilm control using only mechanical means.

  19. Catalytic Synthesis of Oxygenates: Mechanisms, Catalysts and Controlling Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Klier, Kamil; Herman, Richard G

    2005-11-30

    This research focused on catalytic synthesis of unsymmetrical ethers as a part of a larger program involving oxygenated products in general, including alcohols, ethers, esters, carboxylic acids and their derivatives that link together environmentally compliant fuels, monomers, and high-value chemicals. The catalysts studied here were solid acids possessing strong Brnsted acid functionalities. The design of these catalysts involved anchoring the acid groups onto inorganic oxides, e.g. surface-grafted acid groups on zirconia, and a new class of mesoporous solid acids, i.e. propylsulfonic acid-derivatized SBA-15. The former catalysts consisted of a high surface concentration of sulfate groups on stable zirconia catalysts. The latter catalyst consists of high surface area, large pore propylsulfonic acid-derivatized silicas, specifically SBA-15. In both cases, the catalyst design and synthesis yielded high concentrations of acid sites in close proximity to one another. These materials have been well-characterization in terms of physical and chemical properties, as well as in regard to surface and bulk characteristics. Both types of catalysts were shown to exhibit high catalytic performance with respect to both activity and selectivity for the bifunctional coupling of alcohols to form ethers, which proceeds via an efficient SN2 reaction mechanism on the proximal acid sites. This commonality of the dual-site SN2 reaction mechanism over acid catalysts provides for maximum reaction rates and control of selectivity by reaction conditions, i.e. pressure, temperature, and reactant concentrations. This research provides the scientific groundwork for synthesis of ethers for energy applications. The synthesized environmentally acceptable ethers, in part derived from natural gas via alcohol intermediates, exhibit high cetane properties, e.g. methylisobutylether with cetane No. of 53 and dimethylether with cetane No. of 55-60, or high octane properties, e.g. diisopropylether with

  20. Repetetive hindlimb movement using intermittent adaptive neuromuscular electrical stimulation in an incomplete spinal cord injury rodent model.

    Science.gov (United States)

    Fairchild, Mallika D; Kim, Seung-Jae; Iarkov, Alex; Abbas, James J; Jung, Ranu

    2010-06-01

    The long-term objective of this work is to understand the mechanisms by which electrical stimulation based movement therapies may harness neural plasticity to accelerate and enhance sensorimotor recovery after incomplete spinal cord injury (iSCI). An adaptive neuromuscular electrical stimulation (aNMES) paradigm was implemented in adult Long Evans rats with thoracic contusion injury (T8 vertebral level, 155+/-2 Kdyne). In lengthy sessions with lightly anesthetized animals, hip flexor and extensor muscles were stimulated using an aNMES control system in order to generate desired hip movements. The aNMES control system, which used a pattern generator/pattern shaper structure, adjusted pulse amplitude to modulate muscle force in order to control hip movement. An intermittent stimulation paradigm was used (5-cycles/set; 20-second rest between sets; 100 sets). In each cycle, hip rotation caused the foot plantar surface to contact a stationary brush for appropriately timed cutaneous input. Sessions were repeated over several days while the animals recovered from injury. Results indicated that aNMES automatically and reliably tracked the desired hip trajectory with low error and maintained range of motion with only gradual increase in stimulation during the long sessions. Intermittent aNMES thus accounted for the numerous factors that can influence the response to NMES: electrode stability, excitability of spinal neural circuitry, non-linear muscle recruitment, fatigue, spinal reflexes due to cutaneous input, and the endogenous recovery of the animals. This novel aNMES application in the iSCI rodent model can thus be used in chronic stimulation studies to investigate the mechanisms of neuroplasticity targeted by NMES-based repetitive movement therapy. PMID:20206164

  1. Assessment of ventilatory neuromuscular drive in patients with obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    L.R.A. Bittencourt

    1998-04-01

    Full Text Available The presence of abnormalities of the respiratory center in obstructive sleep apnea (OSA patients and their correlation with polysomnographic data are still a matter of controversy. Moderately obese, sleep-deprived OSA patients presenting daytime hypersomnolence, with normocapnia and no clinical or spirometric evidence of pulmonary disease, were selected. We assessed the ventilatory control and correlated it with polysomnographic data. Ventilatory neuromuscular drive was evaluated in these patients by measuring the ventilatory response (VE, the inspiratory occlusion pressure (P.1 and the ventilatory pattern (VT/TI, TI/TTOT at rest and during submaximal exercise, breathing room air. These analyses were also performed after inhalation of a hypercapnic mixture of CO2 (DP.1/DPETCO2, DVE/DPETCO2. Average rest and exercise ventilatory response (VE: 12.2 and 32.6 l/min, respectively, inspiratory occlusion pressure (P.1: 1.5 and 4.7 cmH2O, respectively, and ventilatory pattern (VT/TI: 0.42 and 1.09 l/s; TI/TTOT: 0.47 and 0.46 l/s, respectively were within the normal range. In response to hypercapnia, the values of ventilatory response (DVE/DPETCO2: 1.51 l min-1 mmHg-1 and inspiratory occlusion pressure (DP.1/DPETCO2: 0.22 cmH2O were normal or slightly reduced in the normocapnic OSA patients. No association or correlation between ventilatory neuromuscular drive and ventilatory pattern, hypersomnolence score and polysomnographic data was found; however a significant positive correlation was observed between P.1 and weight. Our results indicate the existence of a group of normocapnic OSA patients who have a normal awake neuromuscular ventilatory drive at rest or during exercise that is partially influenced by obesity

  2. Direct and indirect measurement of neuromuscular fatigue in Canadian football players.

    Science.gov (United States)

    Clarke, Nick; Farthing, Jonathan P; Lanovaz, Joel L; Krentz, Joel R

    2015-05-01

    This study assessed the effects of a fatiguing game simulation (G-Sim) on the balance of collegiate Canadian football players. The purpose of the study was to evaluate postural control as a potential tool for monitoring neuromuscular fatigue (NMF) in collision-based team sports. Fifteen male Canadian football players were recruited (mean±SD: age 21.8±1.6 years, weight 97.6±14.7 kg). Indirect NMF measures (postural sway and countermovement jump (CMJ)) were performed 24 h before (TBase), immediately before (TPre) and after (TPost), and 24 h (T24) and 48 h after (T48) a Canadian football G-Sim. Peak isometric knee extensor torque of a maximal voluntary contraction (MVC) and electrically evoked tetani at 20 Hz (P20) and 80 Hz (P80) were also recorded as direct NMF measures at TBase, TPre, TPost, and T48. At TPost, we observed significant declines in MVC, P20, and the MVC/P80 ratio (-15.3%, -15.7%, and -12.1%, respectively; n=12) along with reductions in CMJ takeoff velocity and peak power (-6.9% and -6.5%, respectively; n=12) and larger area of the center of pressure trajectory (95.2%; n=10) during a 60-s postural sway task. All variables were no longer different than baseline by T48. Acute neuromuscular impairment in this cohort is likely attributable to alterations in excitation-contraction coupling due to structural damage and central activation failure. Congruency between the direct and indirect measures of NMF suggests monitoring postural sway has the potential to identify both neuromuscular and somatosensory alterations induced by acute game-induced fatigue in collision-based team sports players.

  3. Growth differentiation factor 6 as a putative risk factor in neuromuscular degeneration.

    Directory of Open Access Journals (Sweden)

    Michèle G DuVal

    Full Text Available Mutation of Glass bottom boat, the Drosophila homologue of the bone morphogenetic protein or growth/differentiation factor (BMP/GDF family of genes in vertebrates, has been shown to disrupt development of neuromuscular junctions (NMJ. Here we tested whether this same conclusion can be broadened to vertebrate BMP/GDF genes. This analysis was also extended to consider whether such genes are required for NMJ maintenance in post-larval stages, as this would argue that BMP genes are viable candidates for analysis in progressive neuromuscular disease. Zebrafish mutants harboring homozygous null mutations in the BMP-family gene gdf6a were raised to adulthood and assessed for neuromuscular deficits. Fish lacking gdf6a exhibited decreased endurance (∼ 50%, p = 0.005 compared to wild type, and this deficit progressively worsened with age. These fish also presented with significantly disrupted NMJ morphology (p = 0.009, and a lower abundance of spinal motor neurons (∼ 50%, p<0.001 compared to wild type. Noting the similarity of these symptoms to those of Amyotrophic Lateral Sclerosis (ALS model mice and fish, we asked if mutations in gdf6a would enhance the phenotypes observed in the latter, i.e. in zebrafish over-expressing mutant Superoxide Dismutase 1 (SOD1. Amongst younger adult fish only bigenic fish harboring both the SOD1 transgene and gdf6a mutations, but not siblings with other combinations of these gene modifications, displayed significantly reduced endurance (75%, p<0.05 and strength/power (75%, p<0.05, as well as disrupted NMJ morphology (p<0.001 compared to wild type siblings. Bigenic fish also had lower survival rates compared to other genotypes. Thus conclusions regarding a role for BMP ligands in effecting NMJ can be extended to vertebrates, supporting conservation of mechanisms relevant to neuromuscular degenerative diseases. These conclusions synergize with past findings to argue for further analysis of GDF6 and other BMP genes as

  4. Therapeutic effect and mechanism of neuromuscular facilitation techniques in treatment of hemiplegic stroke patients'osteoporosis%神经肌肉促进技术对脑卒中后偏瘫患者肢体骨质疏松的疗效及作用机制

    Institute of Scientific and Technical Information of China (English)

    贾立坤; 王聪聪; 李秀华; 张秀清

    2014-01-01

    目的:通过检测脑卒中后偏瘫患者的骨密度( BMD )及血清瘦素( LP )、碱性磷酸酶( ALP )、骨钙素(BGP)、白介素-6(IL-6)水平,观察神经肌肉促进技术(NFT)对其肢体骨质疏松的影响。方法将52例脑卒中偏瘫患者随机分为治疗组和对照组,对照组行常规治疗,治疗组在常规治疗基础上早期给予NFT治疗。采用双能X线吸收法检测两组入院第2天及治疗6个月后的BMD,采用ELISA法检测两组血清LP、ALP、BGP、IL-6水平,并进行比较。结果6个月后两组患肢BMD、对照组健肢与患肢BMD比较差异均有统计学意义(P均<0.05);两组血清LP、ALP、BGP、IL-6水平比较差异均有统计学意义(P<0.05或<0.01)。结论 NFT能影响脑卒中后偏瘫患者骨代谢指标,增加偏瘫肢体BMD;NFT对防治脑卒中后偏瘫患者的骨质疏松有效。%Objective To observe the therapeutic effect of neuromuscular facilitation techniques (NFT) on hemiplegic stroke patients'osteoporosis through the detections of serum leptin (LP), alkaline phosphatase (ALP), bone gla-protein (BGP), interleukin-6 (IL-6) and bone mineral density (BMD).Methods Fifty-two hemiplegic stroke patients were randomly divided into 2 groups:the control group which received conventional treatment, and the treatment group which received NFT early be-sides conventional treatment.The serum LP, ALP, BGP, IL-6 and BMD of all cases in the second day of admission and 6 months after the treatment were detected by using ELISA method and double X-ray absorption method, and then contrastive analysis was conducted.Results The BMD of hemiplegic limbs between the two groups 6 months later, and the BMD between the hemiplegic limbs and the healthy limbs in the control group 6 months later all had statistically significant differences (all P<0.05).The se-rum ALP, BGP, IL-6 and LP levels 6 months later all had statistically significant differences

  5. Controlling mechanisms of moisture diffusion in convective drying of leather

    Science.gov (United States)

    Benmakhlouf, Naima; Azzouz, Soufien; Monzó-Cabrera, Juan; Khdhira, Hechmi; ELCafsi, Afif

    2016-08-01

    Leather manufacturing involves a crucial energy-intensive drying stage in the finishing process to remove its residual moisture. It occurs several times in the tanning course. As it is the target of this paper to depict an experimental way to determine moisture diffusion in the convective drying of leather. The effective diffusion coefficient is estimated by a method derived from Fick's law and by analytic method. The effective diffusion coefficients are obtained from drying tests and the diffusivity behaviour is studied versus the controlling parameter such as the convective airflow temperature. The experiments were conducted at hot air temperatures of 40, 45, 50, 55 and 60 °C and hot air speed of 1 m/s. The hot air temperature had significant effect on the effective moisture diffusivity of the leather sample. The average effective moisture diffusivity in rosehip ranged between 5.87 × 10-11 and 14.48 × 10-11 m2/s for leather at the temperatures studied. Activation energy for convective drying was found to be 38.46 kJ/mol for leather. The obtained results fully confirm the theoretical study in which an exponentially increasing relationship between effective diffusivity and temperature is predicted. The results of this study provide a better understanding of the drying mechanisms and may lead to a series of recommendations for leather drying optimization. It opens the possibility for further investigations on the description of drying conditions.

  6. Weathering controls on mechanisms of carbon storage in grassland soils

    Energy Technology Data Exchange (ETDEWEB)

    Masiello, C.A.; Chadwick, O.A.; Southon, J.; Torn, M.S.; Harden, J.W.

    2004-09-01

    On a sequence of soils developed under similar vegetation, temperature, and precipitation conditions, but with variations in mineralogical properties, we use organic carbon and 14C inventories to examine mineral protection of soil organic carbon. In these soils, 14C data indicate that the creation of slow-cycling carbon can be modeled as occurring through reaction of organic ligands with Al3+ and Fe3+ cations in the upper horizons, followed by sorption to amorphous inorganic Al compounds at depth. Only one of these processes, the chelation of Al3+ and Fe3+ by organic ligands, is linked to large carbon stocks. Organic ligands stabilized by this process traverse the soil column as dissolved organic carbon (both from surface horizons and root exudates). At our moist grassland site, this chelation and transport process is very strongly correlated with the storage and long-term stabilization of soil organic carbon. Our 14C results show that the mechanisms of organic carbon transport and storage at this site follow a classic model previously believed to only be significant in a single soil order (Spodosols), and closely related to the presence of forests. The presence of this process in the grassland Alfisol, Inceptisol, and Mollisol soils of this chronosequence suggests that this process is a more significant control on organic carbon storage than previously thought.

  7. Weathering controls on mechanisms of carbon storage in grassland soils

    Science.gov (United States)

    Masiello, C.A.; Chadwick, O.A.; Southon, J.; Torn, M.S.; Harden, J.W.

    2004-01-01

    On a sequence of soils developed under similar vegetation, temperature, and precipitation conditions, but with variations in mineralogical properties, we use organic carbon and 14C inventories to examine mineral protection of soil organic carbon. In these soils, 14C data indicate that the creation of slow-cycling carbon can be modeled as occurring through reaction of organic ligands with Al3+ and Fe3+ cations in the upper horizons, followed by sorption to amorphous inorganic Al compounds at depth. Only one of these processes, the chelation Al3+ and Fe3+ by organic ligands, is linked to large carbon stocks. Organic ligands stabilized by this process traverse the soil column as dissolved organic carbon (both from surface horizons and root exudates). At our moist grassland site, this chelation and transport process is very strongly correlated with the storage and long-term stabilization of soil organic carbon. Our 14C results show that the mechanisms of organic carbon transport and storage at this site follow a classic model previously believed to only be significant in a single soil order (Spodosols), and closely related to the presence of forests. The presence of this process in the grassland Alfisol, Inceptisol, and Mollisol soils of this chronosequence suggests that this process is a more significant control on organic carbon storage than previously thought. Copyright 2004 by the American Geophysical Union.

  8. Controlled growth mechanism of poly (3-hexylthiophene) nanowires

    Science.gov (United States)

    Kiymaz, D.; Yagmurcukardes, M.; Tomak, A.; Sahin, H.; Senger, R. T.; Peeters, F. M.; Zareie, H. M.; Zafer, C.

    2016-11-01

    Synthesis of 1D-polymer nanowires by a self-assembly method using marginal solvents is an attractive technique. While the formation mechanism is poorly understood, this method is essential in order to control the growth of nanowires. Here we visualized the time-dependent assembly of poly (3-hexyl-thiophene-2,5-diyl) (P3HT) nanowires by atomic force microscopy and scanning tunneling microscopy. The assembly of P3HT nanowires was carried out at room temperature by mixing cyclohexanone (CHN), as a poor solvent, with polymer solution in 1,2-dichlorobenzene (DCB). Both π–π stacking and planarization, obtained at the mix volume ratio of P3HT (in DCB):CHN (10:7), were considered during the investigation. We find that the length of nanowires was determined by the ordering of polymers in the polymer repetition direction. Additionally, our density functional theory calculations revealed that the presence of DCB and CHN molecules that stabilize the structural distortions due to tail group of polymers was essential for the core-wire formation.

  9. Effects of neuromuscular training (NEMEX-TJR) on patient-reported outcomes and physical function in severe primary hip or knee osteoarthritis

    DEFF Research Database (Denmark)

    Ageberg, Eva; Nilsdotter, Anna; Kosek, Eva;

    2013-01-01

    The benefits of exercise in mild and moderate knee or hip osteoarthritis (OA) are apparent, but the evidence in severe OA is less clear. We recently reported that neuromuscular training was well tolerated and feasible in patients with severe primary hip or knee OA. The aims of this controlled...

  10. Mechanical Engineering Design Project report: Enabler control systems

    Science.gov (United States)

    Cullen, Christian; Delvecchio, Dave; Scarborough, Alan; Havics, Andrew A.

    1992-01-01

    The Controls Group was assigned the responsibility for designing the Enabler's control system. The requirement for the design was that the control system must provide a simple user interface to control the boom articulation joints, chassis articulation joints, and the wheel drive. The system required controlling hydraulic motors on the Enabler by implementing 8-bit microprocessor boards. In addition, feedback to evaluate positions and velocities must be interfaced to provide the operator with confirmation as well as control.

  11. EFEITO DO TREINO NEUROMUSCULAR NA ROTAÇÃO DO JOELHO DURANTE A ATERRISSAGEM EM MULHERES

    Directory of Open Access Journals (Sweden)

    Narayana Vianna Spanó

    2016-04-01

    Full Text Available Introdução: O grande índice de lesões do ligamento cruzado anterior sem envolver contato em mulheres é motivo de curiosidade entre os cientistas, pois avaliações de aterrissagem podem sugerir a predisposição ao risco dessa lesão. Neste sentido, vários protocolos de treinamento foram utilizados como intervenção e obtiveram resultados diversificados na alteração desse fator de risco. Objetivo: O objetivo deste projeto foi avaliar as possíveis alterações de rotação do joelho na aterrissagem unipodal após a intervenção de um programa de treinamento neuromuscular. Métodos: Participaram do estudo 18 mulheres com idade entre 18 e 51 anos, que foram distribuídas em dois grupos: grupo de treinamento neuromuscular de oito semanas (GTN (n = 11 e grupo controle (GC (n = 7. Além disso, não apresentavam lesão musculoesquelética ou dores nos membros inferiores. Cada participante realizou cinco aterrissagens unipodais válidas de uma plataforma de 40 cm de altura. O processo de captura de movimento foi realizado com 12 câmeras infravermelho do sistema OptiTrack(tm para obter as coordenadas tridimensionais de marcadores fixados nos pontos anatômicos de interesse. Os sistemas de coordenadas locais da coxa e da perna foram definidos por meio dos respectivos marcadores fixados nos pontos anatômicos. Dessa forma, foram calculados os ângulos de rotação do joelho nos planos sagital, frontal e transverso através das sequências dos ângulos de Euler e as velocidades angulares através das formulações dos quatérnions. Resultados: Os resultados mostraram que houve um aumento na velocidade de rotação do joelho após o treinamento neuromuscular. Conclusão: Conclui-se que o treinamento neuromuscular resultou em maior velocidade de rotação no joelho nos 40 milissegundos que sucedem a aterrissagem unipodal.

  12. Neuromuscular Electrical Stimulation for Mobility Support of Elderly.

    Science.gov (United States)

    Mayr, Winfried

    2015-08-24

    The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within "MOBIL" we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in "compliance data storage" as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC) and maximum stimulation induced contraction (MSC) were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period. Therefore the

  13. Neuromuscular electrical stimulation for mobility support of elderly

    Directory of Open Access Journals (Sweden)

    Winfried Mayr

    2015-10-01

    Full Text Available The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within "MOBIL" we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in “compliance data storage” as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC and maximum stimulation induced contraction (MSC were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period

  14. Neuromuscular Retraining in Female Adolescent Athletes: Effect on Athletic Performance Indices and Noncontact Anterior Cruciate Ligament Injury Rates

    Directory of Open Access Journals (Sweden)

    Frank R. Noyes

    2015-05-01

    Full Text Available While many anterior cruciate ligament (ACL prevention programs have been published, few have achieved significant reductions in injury rates and improvements in athletic performance indices; both of which may increase compliance and motivation of athletes to participate. A supervised neuromuscular retraining program (18 sessions was developed, aimed at achieving both of these objectives. The changes in neuromuscular indices were measured after training in 1000 female athletes aged 13–18 years, and the noncontact ACL injury rate in 700 of these trained athletes was compared with that of 1120 control athletes. There were significant improvements in the drop-jump test, (p < 0.0001, effect size [ES] 0.97, the single-leg triple crossover hop (p < 0.0001, ES 0.47, the t-test (p < 0.0001, ES 0.64, the multi-stage fitness test (p < 0.0001, ES 0.57, hamstring strength (p < 0.0001, and quadriceps strength (p < 0.01. The trained athletes had a significant reduction in the noncontact ACL injury incidence rate compared with the controls (1 ACL injury in 36,724 athlete-exposures [0.03] and 13 ACL injuries in 61,244 exposures [0.21], respectively, p = 0.03. The neuromuscular retraining program was effective in reducing noncontact ACL injury rate and improving athletic performance indicators.

  15. Chronic respiratory failure in patients with neuromuscular diseases: diagnosis and treatment.

    Science.gov (United States)

    Paschoal, Ilma Aparecida; Villalba, Wander de Oliveira; Pereira, Mônica Corso

    2007-01-01

    Neuromuscular diseases affect alveolar air exchange and therefore cause chronic respiratory failure. The onset of respiratory failure can be acute, as in traumas, or progressive (slow or rapid), as in amyotrophic lateral sclerosis, muscular dystrophies, diseases of the myoneural junction, etc. Respiratory muscle impairment also affects cough efficiency and, according to the current knowledge regarding the type of treatment available in Brazil to these patients, it can be said that the high rates of morbidity and mortality in these individuals are more often related to the fact that they cough inefficiently rather than to the fact that they ventilate poorly. In this review, with the objective of presenting the options of devices available to support and substitute for natural ventilation in patients with neuromuscular diseases, we have compiled a brief history of the evolution of orthopedic braces and prostheses used to aid respiration since the end of the 19th century. In addition, we highlight the elements that are fundamental to the diagnosis of alveolar hypoventilation and of failure of the protective cough mechanism: taking of a clinical history; determination of peak cough flow; measurement of maximal inspiratory and expiratory pressures; spirometry in two positions (sitting and supine); pulse oximetry; capnography; and polysomnography. Furthermore, the threshold values available in the literature for the use of nocturnal ventilatory support and for the extension of this support through the daytime period are presented. Moreover, the maneuvers used to increase cough efficiency, as well as the proper timing of their introduction, are discussed.

  16. Histochemical and immunohistological approach to comparative neuromuscular diseases.

    Directory of Open Access Journals (Sweden)

    Serenella Papparella

    2009-12-01

    Full Text Available The broad category of neuromuscular diseases covers conditions that involve the weakness or wasting of the body muscles. These problems may occur in the spinal cord, the peripheral nerves or the muscle fibers. Some may be hereditary, while others are acquired. Commonly recognized conditions fall into the categories of myopathies, which are diseases of the muscle like muscular dystrophy, disorders of the junction where the nerve impulses are transmitted to the muscle like myasthenia gravis, and neuropathies, which are diseases of the peripheral nervous system. The diagnosis of most neuromuscular diseases rest on careful clinical evaluation of the patient, electromyography, the muscle biopsy, and in some instances, molecular genetic studies. Muscle biopsy, associated to histochemical and immunohistological techniques, plays a key role in diagnosis of many neuromuscular disorders. A number of morphological abnormalities of muscle can be recognized on histological stains such as haematoxylin and eosin and Engel trichrome. Histochemical techniques are essential for the study of muscle biopsies for four main reasons. First, they demonstrate the non-uniform nature of the muscle highlighting the different biochemical properties of specific fibre type and their selective involvement in certain disease processes. Second, they may show an absences of a particular enzyme. Third, an excess of a particular substrate can be demonstrated. Fourth, they may show structural changes in the muscle which would not be apparent with routine histological stains, such as the enzyme-deficient cores in central core disease "mouth-eaten" fibers, and abnormalities in the distribution of mitochondria. In some neuromuscular disorders there could be only non-specific myopathological features. However, a number of proteins, including sarcolemmal, sarcomeric, and nuclear proteins as well as enzymes with defects responsible for neuromuscular disorders, have been identified during

  17. Efectos del vendaje neuromuscular sobre la flexibilidad del raquis lumbar

    Directory of Open Access Journals (Sweden)

    A.M. Labrador-Cerrato

    2015-03-01

    Full Text Available Introducción: El vendaje neuromuscular es una técnica que produce una estimulación muy selectiva sobre la piel a través de la aplicación de unas vendas elásticas especiales con el fin de lograr cambios propioceptivos, aumento o inhibición del tono muscular y mitigación de algias, entre otros. Objetivos: Comprobar si la aplicación del vendaje neuromuscular permite aumentar la flexión del raquis lumbar comparándola con otras técnicas de vendaje placebo (esparadrapo rígido convencional; Omniplaste®-E; observar la concordancia entre la prueba sit-and-reach y el test de Schober en la valoración de la ganancia de flexión lumbar. Material y métodos: Estudio piloto experimental a triple ciego. Se distribuyeron aleatoriamente 45 sujetos sanos de 20-55 años en tres grupos: 1 esparadrapo convencional; 2 Omniplaste®-E; 3 vendaje neuromuscular. En todos los participantes se evaluó la flexión del raquis lumbar mediante la prueba sit-and-reach y el test de Schober antes y después de la intervención siguiendo el mismo protocolo. Resultados: Considerado un intervalo de confianza del 95% y grado de significación estadística p<0,05 en todos los casos, se obtuvo un incremento estadísticamente significativo de la flexión lumbar en todos los grupos según la prueba sit-and-reach, que fue mayor en el grupo del vendaje neuromuscular (1,5 cm de mediana; p=0,011. Según el test de Schober, solamente el vendaje neuromuscular se mostró eficiente (p<0,001, incrementándose el valor basal en un 6,25% (1 cm de mediana. Conclusiones: La aplicación del vendaje neuromuscular sobre la columna lumbar mejora la flexión lumbar respecto a técnicas placebo a partir de los resultados obtenidos mediante el test de Schober, así como una mayor flexión global del tronco que estas técnicas según la prueba sit-and-reach. El test de Schober parece ser más fiable y preciso que la prueba sit-and-reach para estudios de este tipo.

  18. Genomic and proteomic profiling reveals reduced mitochondrial function and disruption of the neuromuscular junction driving rat sarcopenia.

    Science.gov (United States)

    Ibebunjo, Chikwendu; Chick, Joel M; Kendall, Tracee; Eash, John K; Li, Christine; Zhang, Yunyu; Vickers, Chad; Wu, Zhidan; Clarke, Brian A; Shi, Jun; Cruz, Joseph; Fournier, Brigitte; Brachat, Sophie; Gutzwiller, Sabine; Ma, QiCheng; Markovits, Judit; Broome, Michelle; Steinkrauss, Michelle; Skuba, Elizabeth; Galarneau, Jean-Rene; Gygi, Steven P; Glass, David J

    2013-01-01

    Molecular mechanisms underlying sarcopenia, the age-related loss of skeletal muscle mass and function, remain unclear. To identify molecular changes that correlated best with sarcopenia and might contribute to its pathogenesis, we determined global gene expression profiles in muscles of rats aged 6, 12, 18, 21, 24, and 27 months. These rats exhibit sarcopenia beginning at 21 months. Correlation of the gene expression versus muscle mass or age changes, and functional annotation analysis identified gene signatures of sarcopenia distinct from gene signatures of aging. Specifically, mitochondrial energy metabolism (e.g., tricarboxylic acid cycle and oxidative phosphorylation) pathway genes were the most downregulated and most significantly correlated with sarcopenia. Also, perturbed were genes/pathways associated with neuromuscular junction patency (providing molecular evidence of sarcopenia-related functional denervation and neuromuscular junction remodeling), protein degradation, and inflammation. Proteomic analysis of samples at 6, 18, and 27 months confirmed the depletion of mitochondrial energy metabolism proteins and neuromuscular junction proteins. Together, these findings suggest that therapeutic approaches that simultaneously stimulate mitochondrogenesis and reduce muscle proteolysis and inflammation have potential for treating sarcopenia.

  19. Influência do lítio no bloqueio neuromuscular produzido pelo atracúrio e pelo cisatracúrio: estudo em preparações nervo frênico-diafragma de rato Influencia del litio en el bloqueo neuromuscular producido por el atracurio y por el cisatracurio: estudio en preparo nervio frénico-diafragma del ratón Influence of lithium on the neuromuscular blockade produced by atracurium and cisatracurium: study on rat phrenic nerve-diaphragm preparations

    Directory of Open Access Journals (Sweden)

    Samanta Cristina Antoniassi Fernandes

    2007-06-01

    alteraciones en los potenciales de placa terminal en miniatura mostraron una acción presináptica.BACKGROUND AND OBJECTIVES: Lithium is widely used for the treatment of bipolar disorders and can interact with neuromuscular blockers. There is a controversy about the mechanisms by which it affects neuromuscular transmission and its interaction with neuromuscular blockers. The objective of this study was to evaluate, on the rat diaphragm, the effects of lithium on the muscular response and indirect stimulation, and the possible interaction with neuromuscular blockers. METHODS: Rats weighing between 250 and 300 g were sacrificed under urethane anesthesia. The phrenic nerve-diaphragm preparation was assembled according to the Bulbring technique. The diaphragm was kept under tension, connected to an isometric transducer, and submitted to indirect stimulation with a frequency of 0.1 Hz. The contractions of the diaphragm were registered on a physiograph. The analysis of the amplitude of the muscular responses evaluated: the effects of the isolated drugs: lithium (1.5 mg.mL-1; atracurium (20 µg.mL-1, and cisatracurium (3 µg.mL-1; the lithium-neuromuscular blockers association; and the effects of lithium on the neuromuscular blockade produced by atracurium (35 µg.mL-1 and cisatracurium (5 µg.mL-1. The effects were evaluated before and 45 minutes after the addition of the drugs. The effects of lithium on membrane potentials (MP and miniature end-plate potentials (MEPP were also evaluated. RESULTS: Lithium by itself did not change the amplitude of the muscular responses, but it decreased significantly the neuromuscular blockade produced by atracurium and cisatracurium. It did not change MP and caused an initial increase in MEPP. CONCLUSIONS: Lithium by itself did not compromise neuromuscular transmission and increased the resistance to the effects of atracurium and cisatracurium. It did not show any action on the muscle fiber, and the changes in miniature end-plate potentials

  20. The Neuromuscular Junction (NMJ: aging at the crossroad between nerves and muscle

    Directory of Open Access Journals (Sweden)

    Marta eGonzalez-Freire

    2014-08-01

    Full Text Available Aging is associated with a progressive loss of muscle mass and strength and a decline in neurophysiological functions. Age-related neuromuscular junction (NMJ plays a key role in musculoskeletal impairment that occurs with aging. However, whether changes in the NMJ precede or follow the decline of muscle mass and strength remains unresolved. Many factors such as mitochondrial dysfunction, oxidative stress, inflammation, changes in the innervation of muscle fibers and mechanical properties of the motor units probably perform an important role in NMJ degeneration and muscle mass and strength decline in late life. This review addresses the primary events that might lead to NMJ dysfunction with aging, including studies on biomarkers, signaling pathways and animal models. Interventions such as caloric restriction (CR and exercise may positively affect the NMJ through this mechanism and attenuate the age-related progressive impairment in motor function.

  1. Differential neuromuscular training effects onACL injury risk factors in"high-risk" versus "low-risk" athletes

    Directory of Open Access Journals (Sweden)

    Ford Kevin R

    2007-05-01

    Full Text Available Abstract Background Neuromuscular training may reduce risk factors that contribute to ACL injury incidence in female athletes. Multi-component, ACL injury prevention training programs can be time and labor intensive, which may ultimately limit training program utilization or compliance. The purpose of this study was to determine the effect of neuromuscular training on those classified as "high-risk" compared to those classified as "low-risk." The hypothesis was that high-risk athletes would decrease knee abduction moments while low-risk and control athletes would not show measurable changes. Methods Eighteen high school female athletes participated in neuromuscular training 3×/week over a 7-week period. Knee kinematics and kinetics were measured during a drop vertical jump (DVJ test at pre/post training. External knee abduction moments were calculated using inverse dynamics. Logistic regression indicated maximal sensitivity and specificity for prediction of ACL injury risk using external knee abduction (25.25 Nm cutoff during a DVJ. Based on these data, 12 study subjects (and 4 controls were grouped into the high-risk (knee abduction moment >25.25 Nm and 6 subjects (and 7 controls were grouped into the low-risk (knee abduction Results Athletes classified as high-risk decreased their knee abduction moments by 13% following training (Dominant pre: 39.9 ± 15.8 Nm to 34.6 ± 9.6 Nm; Non-dominant pre: 37.1 ± 9.2 to 32.4 ± 10.7 Nm; p = 0.033 training X risk factor interaction. Athletes grouped into the low-risk category did not change their abduction moments following training (p > 0.05. Control subjects classified as either high or low-risk also did not significantly change from pre to post-testing. Conclusion These results indicate that "high-risk" female athletes decreased the magnitude of the previously identified risk factor to ACL injury following neuromuscular training. However, the mean values for the high-risk subjects were not reduced to

  2. Enteric neuromuscular junctions: comparison of ultrastructural features in different phylogenetic groups.

    Science.gov (United States)

    Halasy, K; Benedeczky, I; Fekete, E; Tóth, L; Gábriel, R

    1988-04-01

    The enteric neuromuscular junctions of snail (Helix pomatia), locust (Locusta migratoria migratorioides), cockroach (Periplaneta americana), carp (Cyprinus carpio) and tench (Tinca tinca) were studied by means of different light and electron microscopic methods. The nitroblue tetrazolium staining revealed that the myenteric plexuses of the above species are composed of nerve cells, a network of varicose nerves and nerve bundles. Instead of highly organized ganglia, single neurons or small groups of 2-4 cells are characteristic of the invertebrates and fish studied. Catecholaminergic fluorescence induced by glyoxylic acid was detected in the muscular layer of the entire alimentary tract in snail and the hindgut of tench. Fluorescent nerves and perikarya were frequent in the snail gut, while only nerves and no perikarya were found in tench. A close contact between enteric muscles and nerves is the most common form of enteric neuromuscular junction in both the smooth (i.e. the molluscan and fish gut) and the striated (i.e. the insect gut) musculature. The striated musculature (i.e. the insect gut, the oesophagus of carp, and the oesophagus, stomach and the midgut of tench) also receives a synaptic input. Cytochemical evidence is provided of the cholinergic character of fish motor endplates. The ultrastructural appearance and vesicle population of certain nerve terminals suggest a universal role of aminergic and peptidergic control in gut motility. PMID:3393275

  3. Passive dynamic controllers for non-linear mechanical systems

    Science.gov (United States)

    Juang, Jer-Nan; Wu, Shih-Chin; Phan, Minh; Longman, Richard W.

    1992-01-01

    The objective is to develop active model-independent controllers for slewing and vibration control of nonlinear multibody flexible systems, including flexible robots. The topics are presented in viewgraph form and include: passive stabilization; work-energy rate principle; Liapunov theory; displacement feedback; dynamic controller; displacement and acceleration feedback; velocity feedback; displacement feedback; physical interaction; a 6-DOF robot; and simulation results.

  4. Modular overconstrained weak-link mechanism for ultraprecision motion control

    International Nuclear Information System (INIS)

    We have designed and constructed a novel miniature overconstrained weak-link mechanism that will allow positioning of two crystals with better than 50 nrad angular resolution and nanometer linear driving sensitivity. The precision and stability of this structure allow the user to align or adjust an assembly of crystals to achieve the same performance as does a single channel-cut crystal, so we call it an ''artificial channel-cut crystal.'' Unlike the traditional kinematic linear spring mechanisms, the overconstrained weak-link mechanism provides much higher structure stiffness and stability. Using a laminar structure configured and manufactured by chemical etching and lithography techniques, we are able to design and build a planar-shape, high stiffness, high precision weak-link mechanism. In this paper, we present recent developments for the overconstrained weak-link mechanism. Applications of this new technique to synchrotron radiation instrumentation are also discussed

  5. Impaired Axonal Na(+) Current by Hindlimb Unloading: Implication for Disuse Neuromuscular Atrophy.

    Science.gov (United States)

    Banzrai, Chimeglkham; Nodera, Hiroyuki; Kawarai, Toshitaka; Higashi, Saki; Okada, Ryo; Mori, Atsuko; Shimatani, Yoshimitsu; Osaki, Yusuke; Kaji, Ryuji

    2016-01-01

    This study aimed to characterize the excitability changes in peripheral motor axons caused by hindlimb unloading (HLU), which is a model of disuse neuromuscular atrophy. HLU was performed in normal 8-week-old male mice by fixing the proximal tail by a clip connected to the top of the animal's cage for 3 weeks. Axonal excitability studies were performed by stimulating the sciatic nerve at the ankle and recording the compound muscle action potential (CMAP) from the foot. The amplitudes of the motor responses of the unloading group were 51% of the control amplitudes [2.2 ± 1.3 mV (HLU) vs. 4.3 ± 1.2 mV (Control), P = 0.03]. Multiple axonal excitability analysis showed that the unloading group had a smaller strength-duration time constant (SDTC) and late subexcitability (recovery cycle) than the controls [0.075 ± 0.01 (HLU) vs. 0.12 ± 0.01 (Control), P < 0.01; 5.4 ± 1.0 (HLU) vs. 10.0 ± 1.3 % (Control), P = 0.01, respectively]. Three weeks after releasing from HLU, the SDTC became comparable to the control range. Using a modeling study, the observed differences in the waveforms could be explained by reduced persistent Na(+) currents along with parameters related to current leakage. Quantification of RNA of a SCA1A gene coding a voltage-gated Na(+) channel tended to be decreased in the sciatic nerve in HLU. The present study suggested that axonal ion currents are altered in vivo by HLU. It is still undetermined whether the dysfunctional axonal ion currents have any pathogenicity on neuromuscular atrophy or are the results of neural plasticity by atrophy. PMID:26909041

  6. Anormalidades neuromuscular no desuso, senilidade e caquexia Neuromuscular abnormalities in disuse, cachexia and ageing

    Directory of Open Access Journals (Sweden)

    João Aris Kouyoumdjian

    1993-09-01

    Full Text Available É feita revisão de literatura sobre as principais alterações do sistema neuromuscular no desuso, senilidade e caquexia no ser humano e em modelos animais. A diminuição do diâmetro das fibras musculares após período de inatividade/imobilidade (desuso deve-se à perda de miofibrilas periféricas não ocorrendo formação de core-targetóides ou diminuição da atividade da miofosforilase, próprias da desnervação; mantêm-se a liberação espontânea de acetilcolina e fatores tróficos na junção mio-neural; em geral são afetadas preferencialmente fibras II, que podem assumir forma angular. Existe um processo contínuo intrínseco de envelhecimento de nervos e músculos, com desnervação e reinervação lenta e progressiva; o número de unidades motoras se reduz após 60 anos, sem ocorrência de atividade elétrica desnervatória; a quantidade de acetilcolina liberada nos neurônios terminais e a capacidade máxima de utilização de oxigênio estão diminuídas; a redução da capacidade oxidativa mitocondrial pode explicar o aumento de fibras I, mantendo-se o equilíbrio energético. Após poucas semanas de caquexia as fibras musculares podem ter o diâmetro reduzido em 30%, essa redução ocorre em ordem decrescente nos músculos dos membros inferiores, superiores e tronco; existe atrofia II preferencial com fibras angulares ocasionais, redução de RNA/síntese proteica, mantendo-se DNA normal.Cachexia, ageing and disuse and their effects on the human and animals neuromuscular system are reviewed. Disuse induces reduction of muscle fibers (mainly II diameter with peripheral myofibrils lost; there is no core-targetoid or even reduction on myophosphorilase activity, both typical of denervation; the acetylcholine spontaneous release and trophic factors on myoneural junction are maintained; muscle fibers could change to angular shape. Ageing affects nerve and muscle by a continuous and progressive process of denervation and reinner

  7. The effect of a Lucia jig for 30 minutes on neuromuscular re-programming, in normal subjects

    Directory of Open Access Journals (Sweden)

    Mariangela Salles Pereira Nassar

    2012-12-01

    Full Text Available The Lucia jig is a technique that promotes neuromuscular reprogramming of the masticatory system and allows the stabilization of the mandible without the interference of dental contacts, maintaining the mandible position in harmonic condition with the musculature in normal subjects or in patients with temporomandibular dysfunction (TMD. This study aimed to electromyographically analyze the activity (RMS of the masseter and temporal muscles in normal subjects (control group during the use of an anterior programming device, the Lucia jig, in place for 0, 5, 10, 20 and 30 minutes to demonstrate its effect on the stomatognathic system. Forty-two healthy dentate individuals (aged 21 to 40 years with normal occlusion and without parafunctional habits or temporomandibular dysfunction (RDC/TMD were evaluated on the basis of the electromyographic activity of the masseter and temporal muscles before placement of a neuromuscular re-programming device, the Lucia jig, on the upper central incisors. There were no statistically significant differences (p < 0.05 in the electromyographic activity of the masticatory muscles in the different time periods. The Lucia jig changed the electromyographic activity by promoting a neuromuscular reprogramming. In most of the time periods, it decreased the activation of the masticatory muscles, showing that this device has wide applicability in dentistry. The use of a Lucia jig over 0, 5, 10, 15, 20 and 30 minutes did not promote any statistically significant increase in muscle activity despite differences in the data, thus showing that this intra-oral device can be used in dentistry.

  8. Neuromuscular exercise prior to joint arthroplasty in patients with osteoarthritis of the hip or knee.

    Science.gov (United States)

    Villadsen, Allan

    2016-04-01

    neuromuscular exercise prior to TJA result in further improvement in self-reported outcomes during the first three months? To answer this, a randomised controlled trial (RCT) enrolling patients with severe symptomatic OA scheduled for TJA was conducted. Self-reported ADL was the primary outcome of the trial and self-reported pain and quality of life were the main secondary outcomes. A test battery of three functional performance measures and four lower extremity muscle power tests was chosen to complement the questionnaires and to explore the physical function in these patients. In the first study, the test battery was evaluated with regard to agreement and reliability. Identification of the smallest detectable differences in the tests was needed to assist in the interpretation of the RCT results and aid clinicians in future evaluation of patients in their daily clinical practice. A cohort of 20 patients with severe symptomatic OA of the hip or knee (56-79 years, 50% women) was evaluated in the test battery on two occasions separated by one week. We found that muscle power can safely be evaluated with poor to good agreement and good to excellent reliability. Hence, some measures (20 m walk, chair stands) are more reliable to detect change over time, e.g. longitudinal research, whereas others may be useful in a daily clinical setting to evaluate to what extent the patient's muscle function is affected  (single- and multi-joint muscle power). Seen as a whole, the entire test battery is time-consuming (1½-2 hours) and not suited for evaluation of larger cohorts. The enrollment of patients in the RCT began in January 2010. A cohort of 165 hip and knee OA patients (43-89 years, 56% women, 84 hip OA) was enrolled after approximately one year. This sample size would also allow stratified analysis, e.g. evaluation of possible differences in the treatment effect between hip or knee OA patients. The intervention group participated in an eight week neuromuscular exercise programme prior

  9. The Control System Modeling and The Mechanical Structure Analysis For EMCVT

    Directory of Open Access Journals (Sweden)

    Lei ZHANG

    2013-07-01

    Full Text Available The current automotive metallic belt continuously variable transmission (CVT mostly use hydraulic system to push the cone disc and achieve the speed ratio control. A new Electrical Mechanical Continuously Variable Transmission without hydraulic control (Electrical Mechanical CVT, EMCVT studied in this paper, uses the rolling screw mechanism to press cone disc, achieves speed regulation through the electronic control mechanism, and abandons the energy-intensive hydraulic system. In this paper, based on the analysis of mechanical configuration, the EMCVT's transmission system and its speed regulation process, speed ratio control characteristic and the clamping force control feature are studied and modeled. Besides, the Control strategy of the transmission system driven by motor is built, so as to provide an important theoretical basis for the further building of EMVCT's control system and the selection and implementation of Control strategy.

  10. Degeneration of Neuromuscular Junction in Age and Dystrophy

    OpenAIRE

    Rudolf, Rüdiger; Khan, Muzamil Majid; Labeit, Siegfried; Deschenes, Michael R.

    2014-01-01

    Functional denervation is a hallmark of aging sarcopenia as well as of muscular dystrophy. It is thought to be a major factor reducing skeletal muscle mass, particularly in the case of sarcopenia. Neuromuscular junctions (NMJs) serve as the interface between the nervous and skeletal muscular systems, and thus they may receive pathophysiological input of both pre- and post-synaptic origin. Consequently, NMJs are good indicators of motor health on a systemic level. Indeed, upon sarcopenia and d...

  11. Ultrastructural muscle and neuro-muscular junction alterations in polymyositis

    Directory of Open Access Journals (Sweden)

    L. L. Babakova

    2015-02-01

    Full Text Available Ultrastructural analysis of 7 biopsies from m.palmaris longus and m.deltoideus in patients with confirmed polymyositis revealed alterationand degeneration of muscle fibers and anomalies of neuro-muscular junction (NMJ. The NMJ abnormalities and following denervation ofmuscle fibers in polymyositis start with subsynaptic damages. The occurance of regeneration features in muscle fibers at any stage is characteristic for PM.

  12. Progress in therapeutic antisense applications for neuromuscular disorders

    OpenAIRE

    Aartsma-Rus, Annemieke; van Ommen, Gert-Jan B.

    2009-01-01

    Neuromuscular disorders are a frequent cause of chronic disability in man. They often result from mutations in single genes and are thus, in principle, well suited for gene therapy. However, the tissues involved (muscle and the central nervous system) are post-mitotic, which poses a challenge for most viral vectors. In some cases, alternative approaches may use small molecules, for example, antisense oligonucleotides (AONs). These do not deliver a new gene, but rather modulate existing gene p...

  13. Myasthenia and related disorders of the neuromuscular junction

    OpenAIRE

    Spillane, Jennifer; Beeson, David J; Kullmann, Dimitri M.

    2010-01-01

    Abstract Our understanding of transmission at the neuromuscular junction has increased greatly in recent years. We now recognise a wide variety of autoimmune and genetic diseases that affect this specialised synapse, causing muscle weakness and fatigue. These disorders greatly affect quality of life and rarely can be fatal. Myasthenia Gravis is the most common disorder and is most commonly caused by auto-antibodies targeting postsynaptic acetylcholine receptors (AChRs). Antibodie...

  14. Report on Adaptive Force, a specific neuromuscular function

    Directory of Open Access Journals (Sweden)

    Marko Hoff

    2015-08-01

    Full Text Available In real life motions, as well as in sports, the adaptation of the neuromuscular systems to externally applied forces plays an important role. The term Adaptive Force (AF shall characterize the ability of the nerve-muscle-system to adapt to impacting external forces during isometric and eccentric muscle action. The focus in this paper is on the concept of this neuromuscular action, which is not yet described in this way. A measuring system was constructed and evaluated for this specific neuromuscular function, but only the main information of the evaluation of the measuring system and the preliminary reference values are mentioned here, while an article with detailed description will be published separately. This paper concentrates on the three following points: 1 What is the peculiarity of this neuromuscular function, introduced as AF? 2 Is the measuring system able to capture its specific characteristics and which phases of measurement occur? 3 It seems reasonable to discuss if AF can be distinguished and classified among the known force concepts. The article describes the measuring system and how it is able to capture special features of real life motions like submaximal intensities and the subjects’ option to react adequately on external varying forces. Furthermore, within one measurement the system records three different force qualities: the isometric submaximal Adaptive Force (AFiso, the maximal isometric Adaptive Force (AFisomax and the maximal eccentric Adaptive Force (AFeccmax. Each of these phases provide different and unique information on the nerve-muscle-system that are discussed in detail. Important, in terms of the Adaptive Force, seems to be the combination of conditional and coordinative abilities.

  15. Cardiac involvement in children with neuro-muscular disorders

    OpenAIRE

    E. N. Arkhipova

    2015-01-01

    Many inherited neuromuscular disorders include cardiac involvement as a typical clinical feature. Among the most common of them is the group of muscular dystrophies. Dilated cardiomyopathy, ventricular arrhythmias, atrial fibrillations, atrioventricular and intraventricular conduction abnormalities, and sudden cardiac death are well known pathological findings in Duchenne muscular dystrophies, myotonic dystrophy type I and 2, Emery-Dreifuss muscular dystrophies and different types of limb-gir...

  16. Aggravated neuromuscular symptoms of mercury exposure from dental amalgam fillings.

    Science.gov (United States)

    Akbal, Ayla; Yılmaz, Hınç; Tutkun, Engin; Köş, Durdu Mehmet

    2014-01-01

    Dental amalgam fillings are widely used all over the world. However, their mercury content can lead to various side effects and clinical problems. Acute or chronic mercury exposure can cause several side effects on the central nerve system, renal and hepatic functions, immune system, fetal development and it can play a role on exacerbation of neuromuscular diseases. In this case, we will present a patient with vacuolar myopathy whose symptoms were started and aggravated with her dental amalgam fillings.

  17. Neuromuscular responses to simulated brazilian jiu-jitsu fights.

    Science.gov (United States)

    da Silva, Bruno Victor Corrêa; Ide, Bernardo Neme; de Moura Simim, Mário Antônio; Marocolo, Moacir; da Mota, Gustavo Ribeiro

    2014-12-01

    The aim of this study was to investigate the neuromuscular performance responses following successive Brazilian Jiu-Jitsu (BJJ) fights. Twenty-three BJJ athletes (age: 26.3 ± 6.3 years; body mass: 79.4 ± 9.7 kg; body height: 1.80 ± 0.1 m) undertook 3 simulated BJJ fights (10 min duration each separated by 15 min of rest). Neuromuscular performance was measured by the bench press throw (BPT) and vertical counter movement jump (VCMJ) tests, assessed before the 1st fight (Pre) and after the last one (Post). Blood lactate (LA) was measured at Pre, 1 min Post, and 15 min Post fights. Paired t-tests were employed in order to compare the BPT and VCMJ results. One-way ANOVA with Bonferroni post hoc tests were utilized to compare LA responses. The results revealed a significant (p BJJ fights demanded considerable anaerobic contribution of ATP supply, reinforcing the high-intensity intermittent nature of the sport. Nevertheless, no negative impact on acute neuromuscular performance (power) was observed.

  18. Fatty replacement of lower paraspinal muscles: normal and neuromuscular disorders

    Energy Technology Data Exchange (ETDEWEB)

    Hader, H.; Gadoth, N.; Heifetz, H.

    1983-11-01

    The physiologic replacement of the lower paraspinal muscles by fat was evaluated in 157 patients undergoing computed tomography for reasons unrelated to abnormalities of the locomotor system. Five patients with neuromuscular disorders were similarly evaluated. The changes were graded according to severity at three spinal levels: lower thoracic-upper lumbar, midlumbar, and lumbosacral. The results were analyzed in relation to age and gender. It was found that fatty replacement of paraspinal muscles is a normal age-progressive phenomenon most prominent in females. It progresses down the spine, being most advanced in the lumbosacral region. The severest changes in the five patients with neuromuscular disorders (three with poliomyelitis and two with progressive muscular dystrophy) consisted of complete muscle group replacement by fat. In postpoliomyelitis atrophy, the distribution was typically asymmetric and sometimes lacked clinical correlation. In muscular dystrophy, fatty replacement was symmetric, showing relative sparing of the psoas and multifidus muscles. In patients with neuromuscular diseases, computed tomography of muscles may be helpful in planning a better rehabilitation regimen.

  19. Neuromuscular conditions for physicians - what you need to know.

    Science.gov (United States)

    Edwards, Laura; Phillips, Margaret

    2016-06-01

    The Royal College of Physicians (RCP) and the British Society of Rehabilitation Medicine co-hosted a meeting entitled 'Neuromuscular conditions for physicians - what you need to know' at the RCP on 30 November 2015. There was a series of talks, ranging from in-depth genetic and molecular descriptions of pathology to multidisciplinary management of chronic neuromuscular conditions, which stimulated lively debate and discussion. Some overarching themes emerged from the day, most notably: i) the changing expectations and survival rates in Duchenne muscular dystrophy (DMD), which are transforming this disorder into an adult as much as a paediatric condition; ii) the need for integrated management and good communication -between services - whether primary, secondary and tertiary care, medical teams and intensivists, or the multiple teams involved in providing treatment to neuromuscular patients; and iii) in line with the above, the essential need for streamlining care such that patients can avoid spending most of their time attending outpatient appointments, and instead concentrate on living full lives and exploring educational, occupational, leisure and social opportunities. PMID:27251916

  20. Adiposity, physical activity and neuromuscular performance in children.

    Science.gov (United States)

    Haapala, Eero A; Väistö, Juuso; Lintu, Niina; Tompuri, Tuomo; Brage, Soren; Westgate, Kate; Ekelund, Ulf; Lampinen, Eeva-Kaarina; Sääkslahti, Arja; Lindi, Virpi; Lakka, Timo A

    2016-09-01

    We investigated the associations of body fat percentage (BF%), objectively assessed moderate-to-vigorous physical activity (MVPA) and different types of physical activity assessed by a questionnaire with neuromuscular performance. The participants were 404 children aged 6-8 years. BF% was assessed using dual-energy x-ray absorptiometry and physical activity by combined heart rate and movement sensing and a questionnaire. The results of 50-m shuttle run, 15-m sprint run, hand grip strength, standing long jump, sit-up, modified flamingo balance, box-and-block and sit-and-reach tests were used as measures of neuromuscular performance. Children who had a combination of higher BF% and lower levels of physical activity had the poorest performance in 50-m shuttle run, 15-m sprint run and standing long jump tests. Higher BF% was associated with slower 50-m shuttle run and 15-m sprint times, shorter distance jumped in standing long jump test, fewer sit-ups, more errors in balance test and less cubes moved in box-and-block test. Higher levels of physical activity and particularly MVPA assessed objectively by combined accelerometer and heart rate monitor were related to shorter 50-m shuttle run and 15-m sprint times. In conclusion, higher BF% and lower levels of physical activity and particularly the combination of these two factors were associated with worse neuromuscular performance. PMID:26734777

  1. Ketogenic Diet in Neuromuscular and Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Antonio Paoli

    2014-01-01

    Full Text Available An increasing number of data demonstrate the utility of ketogenic diets in a variety of metabolic diseases as obesity, metabolic syndrome, and diabetes. In regard to neurological disorders, ketogenic diet is recognized as an effective treatment for pharmacoresistant epilepsy but emerging data suggests that ketogenic diet could be also useful in amyotrophic lateral sclerosis, Alzheimer, Parkinson’s disease, and some mitochondriopathies. Although these diseases have different pathogenesis and features, there are some common mechanisms that could explain the effects of ketogenic diets. These mechanisms are to provide an efficient source of energy for the treatment of certain types of neurodegenerative diseases characterized by focal brain hypometabolism; to decrease the oxidative damage associated with various kinds of metabolic stress; to increase the mitochondrial biogenesis pathways; and to take advantage of the capacity of ketones to bypass the defect in complex I activity implicated in some neurological diseases. These mechanisms will be discussed in this review.

  2. Mechanisms of surgical control of type 2 diabetes

    DEFF Research Database (Denmark)

    Holst, Jens Juul; Madsbad, Sten

    2016-01-01

    responsible for postprandial hypoglycemia sometimes observed after bypass. Other operations (biliopancreatic-diversion and or sleeve gastrectomy) appear to involve different and/or additional mechanisms, and so does experimental bariatric surgery in rodents. However, unlike bypass surgery in humans...

  3. The effects of Duvernoy's gland secretion from the xenodontine colubrid Philodryas olfersii on striated muscle and the neuromuscular junction: partial characterization of a neuromuscular fraction.

    Science.gov (United States)

    Prado-Franceschi, J; Hyslop, S; Cogo, J C; Andrade, A L; Assakura, M; Cruz-Höfling, M A; Rodrigues-Simioni, L

    1996-04-01

    The effect of Philodryas olfersii Duvernoy's secretion was studied in vivo in mice and chicks as well as in the mouse phrenic nerve-diaphragm and the chick biventer cervicis preparations. The whole secretion (20-40 micrograms/ml) increased the creatine kinase (CK) levels in mice but had no effect on the mouse phrenic nerve-diaphragm preparation. In the chick, the secretion caused head drop and paresia as well as irreversible blockade of the twitch-tension evoked by indirect stimulation in the chick biventer cervicis preparation (50% paralysis in 34.5 +/- 2.7 min, n = 4). The secretion also caused muscle contracture (30% of the maximal twitch-tension generated) after a latency of nearly 9 min. Following fractionation on a Superose 12 FPLC column, the neuromuscular activity was recovered in the high mol. wt fraction (Peak I). At a concentration of 10 micrograms/ml in the chick biventer cervicis preparation, Peak I caused 50% paralysis within 18.5 +/- 3.0 min (n = 4), and evoked a strong contracture (70% of the maximal twitch-tension generated). The contractile responses of the chick preparation to ACh and KCL were partially blocked (90%) by the whole secretion and totally blocked by Peak I. CK release was increased by the whole secretion but not by Peak I. The whole secretion also produced various degrees of muscle cell lysis and extensive widening of the intercellular spaces. The latter showed a loosely arranged membranous network. In general, Peak I caused only minor morphological alterations compared with the whole secretion, although these were still significantly different from those observed in the control preparations. The changes principally involved hypercontraction of the muscle fibers. Based on the above results, we conclude that Peak I contains the factor(s) responsible for the in vitro effects on neuromuscular transmission, whereas the direct myotoxic effect is apparently caused by at least one other component of the Duvernoy's secretion. PMID:8735245

  4. The Parent Control in the Mechanical Engineering Management-Holding

    Science.gov (United States)

    Šnircová, Jana; Hodulíková, Petra; Joehnk, Peter

    2012-12-01

    The group of entities under the control of parent, so called holding, is arisen as the result and the most often used form of the business concentration nowadays. The paper is focused to find special tasks of parent company for to preserve effective unified economic control in the management-holding. The unified economic control the holding exists in the conditions of the main conflict of interest - holding is not a legal but economic unit and the connected companies into it have a legal autonomy with the economic dependence. The unified economic control limits the financial independence of every individual company of the holding. The attention in the paper is concentrated to the management concept of the parent control, i.e. the parent company supervises the control of intragroup flows and all of subsidiaries production activities.

  5. Pheromonal control: reconciling physiological mechanism with signalling theory.

    Science.gov (United States)

    Peso, Marianne; Elgar, Mark A; Barron, Andrew B

    2015-05-01

    Pheromones are intraspecific chemical signals. They can have profound effects on the behaviour and/or physiology of the receiver, and it is still common to hear pheromones described as controlling of the behaviour of the receiver. The discussion of pheromonal control arose initially from a close association between hormones and pheromones in the comparative physiological literature, but the concept of a controlling pheromone is at odds with contemporary signal evolution theory, which predicts that a manipulative pheromonal signal negatively affecting the receiver's fitness should not be stable over evolutionary time. Here we discuss the meaning of pheromonal control, and the ecological circumstances by which it might be supported. We argue that in discussing pheromonal control it is important to differentiate between control applied to the effects of a pheromone on a receiver's physiology (proximate control), and control applied to the effects of a pheromone on a receiver's fitness (ultimate control). Critically, a pheromone signal affecting change in the receiver's behaviour or physiology need not necessarily manipulate the fitness of a receiver. In cases where pheromonal signalling does lead to a reduction in the fitness of the receiver, the signalling system would be stable if the pheromone were an honest signal of a social environment that disadvantages the receiver, and the physiological and behavioural changes observed in the receiver were an adaptive response to the new social circumstances communicated by the pheromone. PMID:24925630

  6. Adaptive Clutch Engaging Process Control for Automatic Mechanical Transmission

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-ou; CHEN Hui-yan; DING Hua-rong; HE Zhong-bo

    2005-01-01

    Based on detail analysis of clutch engaging process control targets and adaptive demands, a control strategy which is based on speed signal, different from that of based on main clutch displacement signal, is put forward. It considers both jerk and slipping work which are the most commonly used quality evaluating indexes of vehicle starting phase. The adaptive control system and its reference model are discussed profoundly.Taking the adaptability to different starting gears and different road conditions as examples, some proving field test records are shown to illustrate the main clutch adaptive control strategy at starting phase. Proving field test gives acceptable results.

  7. Prognostics Enhanced Reconfigurable Control of Electro-Mechanical Actuators

    Data.gov (United States)

    National Aeronautics and Space Administration — Actuator systems are employed widely in aerospace, transportation and industrial processes to provide power to critical loads, such as aircraft control surfaces....

  8. The effect of cognitive fatigue on prefrontal cortex correlates of neuromuscular fatigue in older women

    OpenAIRE

    Shortz, Ashley E.; Pickens, Adam; Zheng, Qi; Mehta, Ranjana K.

    2015-01-01

    Background As the population of adults aged 65 and above is rapidly growing, it is crucial to identify physical and cognitive limitations pertaining to daily living. Cognitive fatigue has shown to adversely impact neuromuscular function in younger adults, however its impact on neuromuscular fatigue, and associated brain function changes, in older adults is not well understood. The aim of the study was to examine the impact of cognitive fatigue on neuromuscular fatigue and associated prefronta...

  9. Balancing the balance: Self-control mechanisms and compulsive buying

    NARCIS (Netherlands)

    Horváth, C.; Büttner, O.B.; Belei, N.V.T.; Adigüzel, F.

    2015-01-01

    Previous research has mainly focused on identifying why compulsive buyers engage in excessive buying, while their attempts to control problematic buying behavior have largely been ignored. The present research examines the self-control attempts of compulsive buyers. Study 1 uses qualitative in-depth

  10. An Intelligent Call Admission Control Decision Mechanism for Wireless Networks

    CERN Document Server

    S., Ramesh Babu H; S, Satyanarayana P

    2010-01-01

    The Call admission control (CAC) is one of the Radio Resource Management (RRM) techniques plays instrumental role in ensuring the desired Quality of Service (QoS) to the users working on different applications which have diversified nature of QoS requirements. This paper proposes a fuzzy neural approach for call admission control in a multi class traffic based Next Generation Wireless Networks (NGWN). The proposed Fuzzy Neural Call Admission Control (FNCAC) scheme is an integrated CAC module that combines the linguistic control capabilities of the fuzzy logic controller and the learning capabilities of the neural networks .The model is based on Recurrent Radial Basis Function Networks (RRBFN) which have better learning and adaptability that can be used to develop the intelligent system to handle the incoming traffic in the heterogeneous network environment. The proposed FNCAC can achieve reduced call blocking probability keeping the resource utilisation at an optimal level. In the proposed algorithm we have c...

  11. Physical damping in IDA-PBC controlled underactuated mechanical systems : Special issue on Hamiltonian and Lagrangian Methods for Nonlinear Control

    NARCIS (Netherlands)

    Gómez-Estern, F.; Schaft, A.J. van der

    2004-01-01

    Energy shaping and passivity-based control designs have proven to be effective in solving control problems for underactuated mechanical systems. In recent works, Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC) has been successfully applied to open loop conservative models, i

  12. Correction: β-Sialon nanowires, nanobelts and hierarchical nanostructures: morphology control, growth mechanism and cathodoluminescence properties

    Science.gov (United States)

    Huang, Juntong; Huang, Zhaohui; Liu, Yangai; Fang, Minghao; Chen, Kai; Huang, Yaoting; Huang, Saifang; Ji, Haipeng; Yang, Jingzhou; Wu, Xiaowen; Zhang, Shaowei

    2016-07-01

    Correction for `β-Sialon nanowires, nanobelts and hierarchical nanostructures: morphology control, growth mechanism and cathodoluminescence properties' by Juntong Huang, et al., Nanoscale, 2014, 6, 424-432.

  13. Metabolic and structural changes in lower-limb skeletal muscle following neuromuscular electrical stimulation: a systematic review.

    Directory of Open Access Journals (Sweden)

    Maurice J H Sillen

    Full Text Available BACKGROUND: Transcutaneous neuromuscular electrical stimulation (NMES can be applied as a complementary intervention to regular exercise training programs. A distinction can be made between high-frequency (HF NMES and low-frequency (LF NMES. In order to increase understanding of the mechanisms of functional improvements following NMES, the purpose of this study was to systematically review changes in enzyme activity, muscle fiber type composition and muscle fiber size in human lower-limb skeletal muscles following only NMES. METHODS: Trials were collected up to march 2012 and were identified by searching the Medline/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL and The Physical Therapy Evidence Database (PEDro databases and reference lists. 18 trials were reviewed in detail: 8 trials studied changes in enzyme activities, 7 trials studied changes in muscle fiber type composition and 14 trials studied changes in muscle fiber size following NMES. RESULTS: The methodological quality generally was poor, and the heterogeneity in study design, study population, NMES features and outcome parameters prohibited the use of meta-analysis. Most of the LF-NMES studies reported significant increases in oxidative enzyme activity, while the results concerning changes in muscle fiber composition and muscle size were conflicting. HF-NMES significantly increased muscle size in 50% of the studies. CONCLUSION: NMES seems to be a training modality resulting in changes in oxidative enzyme activity, skeletal muscle fiber type and skeletal muscle fiber size. However, considering the small sample sizes, the variance in study populations, the non-randomized controlled study designs, the variance in primary outcomes, and the large heterogeneity in NMES protocols, it is difficult to draw definitive conclusions about the effects of stimulation frequencies on muscular changes.

  14. RESEARCH ON MECHANICAL MEASUREMENT-ORIENTED INTELLIGENT VIRTUAL CONTROLS

    Institute of Scientific and Technical Information of China (English)

    Tang Baoping; Qin Shuren

    2004-01-01

    Intelligent virtual control (IVC) is an intelligent measurement instrument unit with the function of actual measurement instruments, and the unit can be used as basic building block for a variety of more complex virtual measurement instruments on a PC. IVC is a further advancement from virtual instrument (VI), and it fuses the function modules and the controls modules so that the relationship between the functions and controls of an instrument is imbedded in one or more units. The design, implementation and optimization methods of IVCs are introduced. The computer software representation of IVCs is discussed. An example of an actual VI constructed with the building blocks of IVCs is given.

  15. CONCEPTUAL APPROACHES TO CREATE CONTROL MECHANISM BY PASSENGER COMMUTATION SERVICES

    Directory of Open Access Journals (Sweden)

    V. O. Zadoya

    2010-11-01

    Full Text Available In the article the basic approaches of improving a management mechanism for passenger suburban railway transportations are considered, and the classification of reformation models for passenger suburban railway transportations depending on scales, degree of independence, department subordination and amount of proprietors of future company is offered.

  16. Quantum and classical control of single photon states via a mechanical resonator

    Science.gov (United States)

    Basiri-Esfahani, Sahar; Myers, Casey R.; Combes, Joshua; Milburn, G. J.

    2016-06-01

    Optomechanical systems typically use light to control the quantum state of a mechanical resonator. In this paper, we propose a scheme for controlling the quantum state of light using the mechanical degree of freedom as a controlled beam splitter. Preparing the mechanical resonator in non-classical states enables an optomechanical Stern-Gerlach interferometer. When the mechanical resonator has a small coherent amplitude it acts as a quantum control, entangling the optical and mechanical degrees of freedom. As the coherent amplitude of the resonator increases, we recover single photon and two-photon interference via a classically controlled beam splitter. The visibility of the two-photon interference is particularly sensitive to coherent excitations in the mechanical resonator and this could form the basis of an optically transduced weak-force sensor.

  17. Mechanisms controlling pork quality development: The biochemistry controlling postmortem energy metabolism.

    Science.gov (United States)

    Scheffler, T L; Gerrard, D E

    2007-09-01

    Pale, soft and exudative (PSE) pork represents considerable economic losses for the industry due to its limited functionality and undesirable appearance. During the past several decades, exhaustive research covering various aspects of the food chain has established genotyping procedures, recommended handling practices, and quality indicators in order to reduce the incidence of inferior pork quality. Despite these efforts, there is still a relatively high occurrence of PSE pork. Development of pork quality attributes is largely governed by the rate and extent of postmortem pH decline. The combination of high temperature at low pH or abnormally low ultimate pH causes denaturation of sarcoplasmic and myofibrillar proteins, resulting in paler color and reduced water holding capacity. The pH decline is closely related to muscle energy availability and demand at or around slaughter. The postmortem degradation of glycogen through glycogenolysis and glycolysis provides ATP to help meet energy demand and decreases pH by generating lactate and H+. Therefore, the flux of metabolites through glycolysis, the involvement of energy signaling pathways that modulate glycolytic activity, and the inherent metabolism of different fiber types are critical factors influencing pH decline and pork quality. Further, recent work implicates adenosine monophosphate-activated protein kinase (AMPK) as a major energy sensor for the cell, and thus may be involved in the control of postmortem metabolism. The intent of this paper is to review the biochemistry controlling postmortem energy metabolism in pig muscle and explore new information generated using genetic mutations in order to define the fundamental mechanisms controlling the transformation of muscle to meat. PMID:22061391

  18. The impact of a firm's internal control mechanisms on the choice of innovation mode

    Institute of Scientific and Technical Information of China (English)

    LIU Xinmin; LI Yuan; SU Zhongfeng; FENG Jinlu

    2007-01-01

    A finn's internal control mechanisms may have a significant influence on the choice of innovation mode. Therefore, based on the research on the internal control mechanisms of companies, we developed a model to explore the relationship between a finn's internal control mechanisms and the choice of innovation mode. Using a sample of 585 Chinese finns, this study tests the proposed model. Results show that strategic control has a positive relationship with radical innovation, but a negative relationship with incremental innovation, while financial control has a negative relationship with radical innovation, but a positive relationship with incremental innovation.

  19. Pharmacotherapy to protect the neuromuscular junction after acute organophosphorus pesticide poisoning.

    Science.gov (United States)

    Bird, Steven B; Krajacic, Predrag; Sawamoto, Keigo; Bunya, Naofumi; Loro, Emanuele; Khurana, Tejvir S

    2016-06-01

    Organophosphorus (OP) pesticide poisoning is a leading cause of morbidity and mortality in the developing world, affecting an estimated three million people annually. Much of the morbidity is directly related to muscle weakness, which develops 1-4 days after poisoning. This muscle weakness, termed the intermediate syndrome (IMS), leads to respiratory, bulbar, and proximal limb weakness and frequently necessitates the use of mechanical ventilation. While not entirely understood, the IMS is most likely due to persistently elevated acetylcholine (ACh), which activates nicotinic ACh receptors at the neuromuscular junction (NMJ). Thus, the NMJ is potentially a target-rich area for the development of new therapies for acute OP poisoning. In this manuscript, we discuss what is known about the IMS and studies investigating the use of nicotinic ACh receptor antagonists to prevent or mitigate NMJ dysfunction after acute OP poisoning. PMID:27258847

  20. Mechanical AGN Feedback: Controlling the Thermodynamical Evolution of Elliptical Galaxies

    CERN Document Server

    Gaspari, M; Temi, P

    2012-01-01

    A fundamental gap in the current understanding of galaxies concerns the thermodynamical evolution of the ordinary, baryonic matter. On one side, radiative emission drastically decreases the thermal energy content of the interstellar plasma (ISM), inducing a slow cooling flow toward the centre. On the other side, the active galactic nucleus (AGN) struggles to prevent the runaway cooling catastrophe, injecting huge amount of energy in the ISM. The present study intends to deeply investigate the role of mechanical AGN feedback in (isolated or massive) elliptical galaxies, extending and completing the mass range of tested cosmic environments. Our previously successful feedback models, in galaxy clusters and groups, demonstrated that AGN outflows, self-regulated by cold gas accretion, are able to properly quench the cooling flow, without destroying the cool core. Via 3D hydrodynamic simulations (FLASH 3.3), including also stellar evolution, we show that massive mechanical AGN outflows can indeed solve the cooling ...

  1. Failure of latch mechanism for motion control of safety rods

    International Nuclear Information System (INIS)

    During safety rod tests in K-reactor prior to startup, one safety rod could not be lifted because the ''button'' broke off and became lodged in the mechanism. Examination of the failed latch assembly along with other assemblies from both K-Area and L-Area revealed several missing buttons as well as severely deformed ''jaw hanger extensions.'' We participated in the investigation of the damage by request of the Reactor Restart Section. Based on our study of the latch mechanism, the modifications to the ''safety rod extension,'' and the operating history of the machine, this memorandum describes the causes of the observed damage with experimental evidence and calculations to support the findings. 3 refs

  2. Mechanisms controlling renal hemodynamics and electrolyte excretion during amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Woods, L.L.; Mizelle, H.L.; Montani, J.P.; Hall, J.E.

    1986-08-01

    Our purpose was to investigate the mechanisms by which increased plasma amino acids elevate renal blood flow (RBF) and glomerular filtration rate (GFR). Since transport of amino acids and Na is linked in the proximal tubule, the authors hypothesized that increased amino acids might stimulate proximal tubular Na reabsorption (PR/sub Na/) and thus increase RBF and GFR by a macula densa feedback mechanism. A solution of four amino acids (Ala, Ser, Gly, Pro) was infused intravenously into anesthetized dogs with normal kidneys (NK) and with kidneys in which the tubuloglomerular feedback mechanism was blunted by lowering renal artery pressure (LPK) or blocked by making the kidneys nonfiltering (NFK). In NK, RBF and GFR increased by 35 +/- 4% and 30 +/- 7% after 90 min of amino acid infusion, while PR/sub Na/ (estimated from lithium clearance) and O2 consumption increased by 31 +/- 5% and 29 +/- 5% and distal Na delivery remained relatively constant. Autoregulation of RBF and GFR in response to step deceases in renal artery pressure was impaired during amino acids in NK. The hemodynamic responses to amino acids were abolished in LPK and NFK. Infusion of the nonmetabolized -aminoisobutyric acid into NK produced changes in renal hemodynamics that were similar to the responses observed with the four metabolizable amino acids. These data are consistent with the hypothesis that elevation of plasma amino acids increases RBF and GFR by a mechanism that requires an intact macula densa feedback. Metabolism of the amino acids does not appear to be necessary for these changes to occur.

  3. Neural mechanisms of attentional control in mindfulness meditation

    OpenAIRE

    Malinowski, Peter

    2013-01-01

    The scientific interest in meditation and mindfulness practice has recently seen an unprecedented surge. After an initial phase of presenting beneficial effects of mindfulness practice in various domains, research is now seeking to unravel the underlying psychological and neurophysiological mechanisms. Advances in understanding these processes are required for improving and fine-tuning mindfulness-based interventions that target specific conditions such as eating disorders or attention defici...

  4. Q-AIMD: A Congestion Aware Video Quality Control Mechanism

    OpenAIRE

    Tran-Thai, Tuan; Changuel, Nesrine; Kerboeuf, Sylvaine; Faucheux, Frederic; Lochin, Emmanuel; Lacan, Jérôme

    2013-01-01

    Following the constant increase of the multimedia traffic, it seems necessary to allow transport protocols to be aware of the video quality of the transmitted flows rather than the throughput. This paper proposes a novel transport mechanism adapted to video flows. Our proposal, called Q-AIMD for video quality AIMD (Additive Increase Multiplicative Decrease), enables fairness in video quality while transmitting multiple video flows. Targeting video quality fairness allows improving the overall...

  5. Cell cycle control, checkpoint mechanisms, and genotoxic stress.

    OpenAIRE

    R.E. Shackelford; Kaufmann, W K; Paules, R S

    1999-01-01

    The ability of cells to maintain genomic integrity is vital for cell survival and proliferation. Lack of fidelity in DNA replication and maintenance can result in deleterious mutations leading to cell death or, in multicellular organisms, cancer. The purpose of this review is to discuss the known signal transduction pathways that regulate cell cycle progression and the mechanisms cells employ to insure DNA stability in the face of genotoxic stress. In particular, we focus on mammalian cell cy...

  6. SGLT-2 Inhibitors: A New Mechanism for Glycemic Control

    OpenAIRE

    Chao, Edward C.

    2014-01-01

    Glucosuria, the presence of glucose in the urine, has long been regarded as a consequence of uncontrolled diabetes. However, glucose excretion can be induced by blocking the activity of the renal sodium-glucose cotransporter 2 (SGLT-2). This mechanism corrects hyperglycemia independently of insulin. This article provides an overview of the paradigm shift that triggered the development of the SGLT-2 inhibitor class of agents and summarizes the available evidence from clinical studies to date.

  7. Neuromuscular strain as a contributor to cognitive and other symptoms in Chronic Fatigue Syndrome: Hypothesis and conceptual model.

    Directory of Open Access Journals (Sweden)

    Peter C. Rowe

    2013-05-01

    Full Text Available Individuals with chronic fatigue syndrome (CFS have heightened sensitivity and increased symptoms following various physiologic challenges, such as orthostatic stress, physical exercise, and cognitive challenges. Similar heightened sensitivity to the same stressors in fibromyalgia (FM has led investigators to propose that these findings reflect a state of central sensitivity. A large body of evidence supports the concept of central sensitivity in FM. A more modest literature provides partial support for this model in CFS, particularly with regard to pain. Nonetheless, fatigue and cognitive dysfunction have not been explained by the central sensitivity data thus far. Peripheral factors have attracted attention recently as contributors to central sensitivity. Work by Brieg, Sunderland, and others has emphasized the ability of the nervous system to undergo accommodative changes in length in response to the range of limb and trunk movements carried out during daily activity. If that ability to elongate is impaired—due to movement restrictions in tissues adjacent to nerves, or due to swelling or adhesions within the nerve itself—the result is an increase in mechanical tension within the nerve. This adverse neural tension, also termed neurodynamic dysfunction, is thought to contribute to pain and other symptoms through a variety of mechanisms. These include mechanical sensitization and altered nociceptive signaling, altered proprioception, adverse patterns of muscle recruitment and force of muscle contraction, reduced intra-neural blood flow, and release of inflammatory neuropeptides. Because it is not possible to differentiate completely between adverse neural tension and strain in muscles, fascia, and other soft tissues, we use the more general term neuromuscular strain. In our clinical work, we have found that neuromuscular restrictions are common in CFS, and that many symptoms of CFS can be reproduced by selectively adding neuromuscular strain

  8. Mechanical characterization of calcium pectinate hydrogel for controlled drug delivery

    Directory of Open Access Journals (Sweden)

    Chung Jin Thau

    2003-01-01

    Full Text Available Calcium pectinate beads, a paniculate hydrogel system, is an attractive drug carrier for oral delivery. In this study, a poorly water-soluble model drug indomethacin was incorporated into calcium pectinate beads made of different pectin concentrations, which were produced by an extrusion method. The effect of pectin concentration on bead size, circularity, swelling behavior, and mechanical properties, as well as in vitro drug release profile was investigated. The mechanical properties of calcium pectinate beads were determined by a micromanipulation technique. The drug release profile was measured using a standard British Pharmacopoeia method. It was found that the beads made of higher pectin concentration in general had a less permeable matrix structure and greater mechanical rigidity, although they swelled more after hydration. However, such an effect was not significant when the pectin concentration was increased to above 8%. Micromanipulation measurements showed that there was significant relaxation of the force being imposed on single hydrated beads when they were held, but this phenomenon did not occur on dry beads, which means that the force relaxation was dominated by liquid loss from the beads. The rate of the force relaxation was determined, and has been related to the release rate of the model drug entrapped in the calcium pectinate beads.

  9. Probable Mechanisms of Needling Therapies for Myofascial Pain Control

    Directory of Open Access Journals (Sweden)

    Li-Wei Chou

    2012-01-01

    Full Text Available Myofascial pain syndrome (MPS has been defined as a regional pain syndrome characterized by muscle pain caused by myofascial trigger points (MTrPs clinically. MTrP is defined as the hyperirritable spot in a palpable taut band of skeletal muscle fibers. Appropriate treatment to MTrPs can effectively relieve the clinical pain of MPS. Needling therapies, such as MTrP injection, dry needling, or acupuncture (AcP can effectively eliminate pain immediately. AcP is probably the first reported technique in treating MPS patients with dry needling based on the Traditional Chinese Medicine (TCM theory. The possible mechanism of AcP analgesia were studied and published in recent decades. The analgesic effect of AcP is hypothesized to be related to immune, hormonal, and nervous systems. Compared to slow-acting hormonal system, nervous system acts in a faster manner. Given these complexities, AcP analgesia cannot be explained by any single mechanism. There are several principles for selection of acupoints based on the TCM principles: “Ah-Shi” point, proximal or remote acupoints on the meridian, and extra-meridian acupoints. Correlations between acupoints and MTrPs are discussed. Some clinical and animal studies of remote AcP for MTrPs and the possible mechanisms of remote effectiveness are reviewed and discussed.

  10. Effects of Neuromuscular Joint Facilitation on Baseball Pitching Velocity and Electromechanical Reaction Times of the Teres Major of Young Amateur Baseball Players

    OpenAIRE

    Wu, Peng; Huo, Ming; Maruyama, Hitoshi

    2013-01-01

    [Purpose] The aim of this study was to investigate the changes of baseball pitching velocity and electromechanical reaction times (EMG-RT) of the teres major of young amateur baseball players after neuromuscular joint facilitation (NJF) treatment. [Subjects] The subjects were 18 healthy males who were divided into two groups: a NJF group and a control group. The NJF group consisted of 10 subjects, and the control group consisted of 8 subjects. [Methods] Participants in the NJF group received ...

  11. Innovation in mechanical weed control in crop rows

    NARCIS (Netherlands)

    Weide, van der R.Y.; Bleeker, P.O.; Achten, V.T.J.M.; Lotz, L.A.P.; Melander, B.; Fogelberg, F.

    2008-01-01

    Weed control within crop rows is one of the main problems in organic farming. For centuries, different weed removal tools have been used to reduce weeds in the crop rows. Stimulated by the demand from organic farmers, research in several European countries over the last decade has focused on mechani

  12. Lie Algebroids in Classical Mechanics and Optimal Control

    Directory of Open Access Journals (Sweden)

    Eduardo Martínez

    2007-03-01

    Full Text Available We review some recent results on the theory of Lagrangian systems on Lie algebroids. In particular we consider the symplectic and variational formalism and we study reduction. Finally we also consider optimal control systems on Lie algebroids and we show how to reduce Pontryagin maximum principle.

  13. Preserving organelle vitality : peroxisomal quality control mechanisms in yeast

    NARCIS (Netherlands)

    Aksam, Eda Bener; de Vries, Bart; van der Klei, Ida J.; Kiel, Jan A. K. W.

    2009-01-01

    Cellular proteins and organelles such as peroxisomes are under continuous quality control. Upon synthesis in the cytosol, peroxisomal proteins are kept in an import-competent state by chaperones or specific proteins with an analogous function to prevent degradation by the ubiquitin-proteasome system

  14. Efeito do priming na redução da latência do pipecurônio, novo bloqueador neuromuscular não-despolarizante Efecto del priming en la reducción de la latencia del pipecuronio, nuevo bloqueador neuromuscular no despolarizante Effect of priming in shortening onset of pipecuronium, a new nondepolarizing neuromuscular blocker

    Directory of Open Access Journals (Sweden)

    José Carlos Canga

    2005-08-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Uma das mais importantes propriedades dos bloqueadores neuromusculares é o rápido início de ação, possibilitando intubação traqueal precoce. A administração de pequena dose de bloqueador não-despolarizante antes da dose plena é sabidamente redutora da latência da maioria dos bloqueadores neuromusculares utilizados. O brometo de pipecurônio é um agente aminoesteróide de longa duração com grande estabilidade cardiovascular, porém, com início de ação tardio. O objetivo desse estudo foi avaliar o efeito do priming do pipecurônio em pacientes adultos submetidos a cirurgias eletivas sob anestesia geral. MÉTODO: Foram estudados 33 pacientes adultos de ambos os sexos, com idade entre 20 e 65 anos, estado físico ASA I ou II, submetidos a cirurgias eletivas sob anestesia geral. Foram excluídos do estudo pacientes com insuficiência renal ou hepática, neuromiopatia, uso concomitante de drogas que influenciem a sua farmacocinética ou pacientes com histórico familiar de hipertermia maligna. Foram divididos em dois grupos: Grupo 1 onde foi utilizado o priming com 0,01 mg.kg-1 e três minutos depois completada a dose de 0,08 mg.kg-1 e o Grupo 2, sem dose priming (Grupo Controle. O relaxamento neuromuscular foi controlado pela aceleromiografia (Aparelho TOF-Guard e no momento em que T1 JUSTIFICATIVA Y OBJETIVOS: Una de las más importantes propiedades de los bloqueadores neuromusculares es el rápido inicio de acción, posibilitando intubación orotraqueal precoz. La administración de pequeña dosis del bloqueador no despolarizante antes de la dosis completa es consabidamente reductora de la latencia de la mayoría de los bloqueadores neuromusculares utilizados. El bromuro de pipecuronio es un agente aminoesteroide de larga duración con grande estabilidad cardiovascular, sin embargo, con inicio de acción tardía. El objetivo de ese estudio es evaluar el efecto del priming del pipecuronio en pacientes

  15. 14 CFR 27.923 - Rotor drive system and control mechanism tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor drive system and control mechanism... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.923 Rotor drive system and control mechanism tests. (a) Each part tested as prescribed in this...

  16. 14 CFR 29.923 - Rotor drive system and control mechanism tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor drive system and control mechanism... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.923 Rotor drive system and control mechanism tests. (a) Endurance tests, general. Each rotor...

  17. Chemical and mechanical control of corrosion product transport

    Energy Technology Data Exchange (ETDEWEB)

    Hede Larsen, O.; Blum, R. [I/S Fynsvaerket, Faelleskemikerne, Odense (Denmark); Daucik, K. [I/S Skaerbaekvaerket, Faelleskemikerne, Fredericia (Denmark)

    1996-12-01

    The corrosion products formed in the condensate and feedwater system of once-through boilers are precipitated and deposited inside the evaporator tubes mainly in the burner zone at the highest heat flux. Depositions lead to increased oxidation rate and increased metal temperature of the evaporator tubes, hereby decreasing tube lifetime. This effect is more important in the new high efficiency USC boilers due to increased feedwater temperature and hence higher thermal load on the evaporator tubes. The only way to reduce the load on the evaporator tubes is to minimise corrosion product transport to the boiler. Two general methods for minimising corrosion product transport to the boiler have been evaluated through measurement campaigns for Fe in the water/steam cycle in supercritical boilers within the ELSAM area. One method is to reduce corrosion in the low temperature condensate system by changing conditioning mode from alkaline volatile treatment (AVT) to oxygenated treatment (OT). The other method is to filtrate part of the condensate with a mechanical filter at the deaerator. The results show, that both methods are effective at minimising Fe-transport to the boiler, but changing to OT has the highest effect and should always be used, whenever high purity condensate is maintained. Whether mechanical filtration also is required, depends on the boiler, specifically the load on the evaporator. A simplified calculation model for lifetime evaluation of evaporator tubes has been developed. This model has been used for evaluating the effect of corrosion product transport to the boiler on evaporator tube lifetime. Conventional supercritical boilers generally can achieve sufficient lifetime by AVT and even better by OT, whereas all measures to reduce Fe-content of feedwater, including OT and mechanical filtration, should be taken, to ensure sufficient lifetime for the new boilers with advanced steam data - 290 bar/580 deg. C and above. (au)

  18. Automatic detection of AutoPEEP during controlled mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Nguyen Quang-Thang

    2012-06-01

    Full Text Available Abstract Background Dynamic hyperinflation, hereafter called AutoPEEP (auto-positive end expiratory pressure with some slight language abuse, is a frequent deleterious phenomenon in patients undergoing mechanical ventilation. Although not readily quantifiable, AutoPEEP can be recognized on the expiratory portion of the flow waveform. If expiratory flow does not return to zero before the next inspiration, AutoPEEP is present. This simple detection however requires the eye of an expert clinician at the patient’s bedside. An automatic detection of AutoPEEP should be helpful to optimize care. Methods In this paper, a platform for automatic detection of AutoPEEP based on the flow signal available on most of recent mechanical ventilators is introduced. The detection algorithms are developed on the basis of robust non-parametric hypothesis testings that require no prior information on the signal distribution. In particular, two detectors are proposed: one is based on SNT (Signal Norm Testing and the other is an extension of SNT in the sequential framework. The performance assessment was carried out on a respiratory system analog and ex-vivo on various retrospectively acquired patient curves. Results The experiment results have shown that the proposed algorithm provides relevant AutoPEEP detection on both simulated and real data. The analysis of clinical data has shown that the proposed detectors can be used to automatically detect AutoPEEP with an accuracy of 93% and a recall (sensitivity of 90%. Conclusions The proposed platform provides an automatic early detection of AutoPEEP. Such functionality can be integrated in the currently used mechanical ventilator for continuous monitoring of the patient-ventilator interface and, therefore, alleviate the clinician task.

  19. [Control of fertilization by self-incompatibility mechanisms].

    Science.gov (United States)

    Fobis-Loisy, Isabelle; Gaude, Thierry

    2010-01-01

    Flowering plants (angiosperms) are the most prevalent and evolutionarily advanced group of plants. Reproductive strategies that promote cross-fertilization have played an essential role in the success of angiosperms as they contribute to genetic variability among plant species. A major genetic barrier to self-fertilization is self-incompatibility (SI), which allows female reproductive cells to discriminate between self- and non-self pollen and specifically reject self-pollen. In this review, we describe three SI mechanisms showing that different flowering plant families use distinct molecules for recognition of self as well as diverse biochemical pathways to arrest pollen tube growth.

  20. Biochemical Mechanisms Controlling Terminal Electron Transfer in Geobacter sulfurreducens

    Science.gov (United States)

    Helmus, R.; Liermann, L. J.; Brantley, S. L.; Tien, M.

    2009-04-01

    The ability of Geobacter sulfurreducens to use a variety of metals as terminal electron acceptors (TEAs) for cellular respiration makes it attractive for use in bioremediation and implies its importance to mineral cycling in the environment. This study is aimed at understanding the biochemical mechanisms that allow Geobacter sulfurreducens to use soluble and insoluble iron and manganese forms as TEAs for cellular respiration and is the first of its kind to address the kinetics of manganese use as a TEA by G. sulfurreducens. First, G. sulfurreducens was conditioned to grow on various soluble and insoluble iron and manganese forms. G. sulfurreducens demonstrated enhanced growth rates when cultured using soluble TEAs compared with insoluble TEAs. However, the lower growth rate on insoluble iron compared with soluble iron was observed concomitantly with a 1-2 log lower cell density in stationary phase in insoluble iron cultures and a lower growth yield per electron donor used in log growth phase. Furthermore, the growth yield per electron was similar with both soluble and insoluble iron. These results suggest that the net amount of energy available for biomass production achieved from reducing insoluble iron is lower than with soluble iron, which may be due to a different biochemical mechanism catalyzing the electron transfer to TEA dependent upon the solubility of the TEA. One scenario consistent with this notion is that protein(s) in the outer membrane of G. sulfurreducens that transfers electrons to insoluble TEAs does so in a manner that uncouples electron flow from the proton pump in the cellular membrane, similar to what we have observed with Shewanella oneidensis MR-1. Both the growth rate and growth yield of G. sulfurreducens on insoluble manganese were higher than on insoluble iron, indicating that there is a difference in the flow of electrons to the TEA in these two situations. While the different redox potentials of these elements may affect these values

  1. Mechanical control over valley magnetotransport in strained graphene

    Science.gov (United States)

    Ma, Ning; Zhang, Shengli; Liu, Daqing

    2016-05-01

    Recent experiments report that the graphene exhibits Landau levels (LLs) that form in the presence of a uniform strain pseudomagnetic field with magnitudes up to hundreds of tesla. We further reveal that the strain removes the valley degeneracy in LLs, and leads to a significant valley polarization with inversion symmetry broken. This accordingly gives rise to the well separated valley Hall plateaus and Shubnikov-de Haas oscillations. These effects are absent in strainless graphene, and can be used to generate and detect valley polarization by mechanical means, forming the basis for the new paradigm "valleytronics" applications.

  2. Mechanical design and driving mechanism of an isokinetic functional electrical stimulation-based leg stepping trainer.

    Science.gov (United States)

    Hamzaid, N A; Fornusek, C; Ruys, A; Davis, G M

    2007-12-01

    The mechanical design of a constant velocity (isokinetic) leg stepping trainer driven by functional electrical stimulation-evoked muscle contractions was the focus of this paper. The system was conceived for training the leg muscles of neurologically-impaired patients. A commercially available slider crank mechanism for elliptical stepping exercise was adapted to a motorized isokinetic driving mechanism. The exercise system permits constant-velocity pedalling at cadences of 1-60 rev x min(-1). The variable-velocity feature allows low pedalling forces for individuals with very weak leg muscles, yet provides resistance to higher pedalling effort in stronger patients. In the future, the system will be integrated with a computer-controlled neuromuscular stimulator and a feedback control unit to monitor training responses of spinal cord-injured, stroke and head injury patients. PMID:18274073

  3. Neuromuscular function in patients with Subacromial Impingement Syndrome and clinical assessment of scapular kinematics

    DEFF Research Database (Denmark)

    Larsen, Camilla Marie

    2014-01-01

    Neuromuscular function in patients with Subacromial Impingement Syndrome and clinical assessment of scapular kinematics Larsen CM1, Juul-Kristensen B1,2 Holtermann A3, Lund H1,2, Søgaard K1 1University of Southern Denmark, Institute of Sports Science and Clinical Biomechanics, DK 2Institute...... patient sample with SIS, and to assess the clinimetric properties of clinical assessment methods of scapular kinematics as important aspects for optimising effect measures of treatment in order to improve clinical guidelines in this area. METHODS: Scapular muscle activity was examined, 1) during......, the SIS group had a lower scapular muscle control, 3) When addressing the possibility for measuring scapular kinematics clinically, the findings show a substantially larger number of clinical assessment methods for scapular position and function than previously reported. None of the included clinical...

  4. Effects of intensive physical rehabilitation on neuromuscular adaptations in adults with poststroke hemiparesis

    DEFF Research Database (Denmark)

    Andersen, Lars L; Zeeman, Peter; Jørgensen, Jørgen R;

    2011-01-01

    Hemiparesis-disability and muscle weakness of 1 side of the body-is a common consequence of stroke. High-intensity strength training may be beneficial to regain function, but strength coaches in the field of rehabilitation need evidence-based guidelines. The purpose of this study was to evaluate...... the effect of intensive physical rehabilitation on neuromuscular and functional adaptations in outpatients suffering from hemiparesis after stroke. A within-subject repeated-measures design with the paretic leg as the experimental leg and the nonparetic leg as the control leg was used. Eleven outpatients...... with hemiparesis after stroke participated in 12 weeks of intensive physical rehabilitation comprising unilateral high-intensity strength training with near-maximal loads (4-12 repetition maximum) and body weight supported treadmill training. At baseline and 12-week follow-up, the patients went through testing...

  5. Coordinated motor neuron axon growth and neuromuscular synaptogenesis are promoted by CPG15 in vivo.

    Science.gov (United States)

    Javaherian, Ashkan; Cline, Hollis T

    2005-02-17

    We have used in vivo time-lapse two-photon imaging of single motor neuron axons labeled with GFP combined with labeling of presynaptic vesicle clusters and postsynaptic acetylcholine receptors in Xenopus laevis tadpoles to determine the dynamic rearrangement of individual axon branches and synaptogenesis during motor axon arbor development. Control GFP-labeled axons are highly dynamic during the period when axon arbors are elaborating. Axon branches emerge from sites of synaptic vesicle clusters. These data indicate that motor neuron axon elaboration and synaptogenesis are concurrent and iterative. We tested the role of Candidate Plasticity Gene 15 (CPG15, also known as Neuritin), an activity-regulated gene that is expressed in the developing motor neurons in this process. CPG15 expression enhances the development of motor neuron axon arbors by promoting neuromuscular synaptogenesis and by increasing the addition of new axon branches. PMID:15721237

  6. Immediate Efficacy of Neuromuscular Exercise in Patients with Severe Osteoarthritis of the Hip or Knee

    DEFF Research Database (Denmark)

    Villadsen, Allan; Overgaard, Søren; Holsgaard-Larsen, Anders;

    2014-01-01

    muscle power. RESULTS: Included were 165 patients, 56% female, average age 67 years (SD ± 8), and a body mass index of 30 (SD ± 5), who were scheduled for primary hip or knee replacement. The postintervention difference between mean changes in ADL was 7.2 points (95% CI 3.5 to 10.9, p = 0.0002) in favor......OBJECTIVE: Knowledge about the effects of exercise in severe and endstage osteoarthritis (OA) is limited. The aim was to evaluate the efficacy of a neuromuscular exercise program in patients with clinically severe hip or knee OA. METHODS: This was a randomized controlled assessor-blinded trial...... and Osteoarthritis Outcome Score (HOOS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. The secondary outcomes were the HOOS/KOOS subscales Pain, Symptoms, Sport and Recreation, and Joint-related Quality of Life. Exploratory outcomes were functional performance measures and lower limb...

  7. Molecular Alignment and Orientation From Laser-Induced Mechanisms to Optimal Control

    CERN Document Server

    Atabek, O

    2002-01-01

    Genetic algorithms, as implemented in optimal control strategies, are currently successfully exploited in a wide range of problems in molecular physics. In this context, laser control of molecular alignment and orientation remains a very promising issue with challenging applications extending from chemical reactivity to nanoscale design. We emphasize the complementarity between basic quantum mechanisms monitoring alignment/orientation processes and optimal control scenarios. More explicitly, if on one hand we can help the optimal control scheme to take advantage of such mechanisms by appropriately building the targets and delineating the parameter sampling space, on the other hand we expect to learn, from optimal control results, some robust and physically sound dynamical mechanisms. We present basic mechanisms for alignment and orientation, such as pendular states accommodated by the molecule-plus-field effective potential and the "kick" mechanism obtained by a sudden excitation. Very interestingly, an optim...

  8. Mechanisms of daughter cell-size control during cell division.

    Science.gov (United States)

    Kiyomitsu, Tomomi

    2015-05-01

    Daughter cell size is tightly regulated during cell division. In animal cells, the position of the anaphase spindle specifies the cell cleavage site to dictate the relative size of the daughter cells. Although spindle orientation is regulated by dynein-dependent cortical pulling forces exerted on astral microtubules in many cell types, it was unclear how these forces are precisely regulated to center or displace the spindle. Recently, intrinsic signals derived from chromosomes or spindle poles have been demonstrated to regulate dynein-dependent pulling forces in symmetrically dividing cells. Unexpectedly, myosin-dependent contractile forces have also been shown to control spindle position by altering the cellular boundaries during anaphase. In this review, I discuss how dynein- and myosin-dependent forces are coordinately regulated to control daughter cell size. PMID:25548067

  9. Sexual orientation biases attentional control: a possible gaydar mechanism

    Directory of Open Access Journals (Sweden)

    Lorenza S Colzato

    2010-05-01

    Full Text Available Homosexuals are believed to have a “sixth sense” for recognizing each other, an ability referred to as gaydar. We considered that being a homosexual might rely on systematic practice of processing relatively specific, local perceptual features, which might lead to a corresponding chronic bias of attentional control. This was tested by comparing male and female homosexuals and heterosexuals--brought up in the same country and culture and matched in terms of race, intelligence, sex, mood, age, personality, religious background, educational style, and socio-economic situation--in their efficiency to process global and local features of hierarchically-constructed visual stimuli. Both homosexuals and heterosexuals showed better performance on global features—the standard global precedence effect. However, this effect was significantly reduced in homosexuals, suggesting a relative preference for detail. Findings are taken to demonstrate chronic, generalized biases in attentional control parameters that reflect the selective reward provided by the respective sexual orientation.

  10. Sexual orientation biases attentional control: a possible gaydar mechanism

    OpenAIRE

    Colzato, Lorenza S; Linda Van Hooidonk; Wery Van Den Wildenberg; Fieke Harinck; Bernhard Hommel

    2010-01-01

    Homosexuals are believed to have a “sixth sense” for recognizing each other, an ability referred to as gaydar. We considered that being a homosexual might rely on systematic practice of processing relatively specific, local perceptual features, which might lead to a corresponding chronic bias of attentional control. This was tested by comparing male and female homosexuals and heterosexuals--brought up in the same country and culture and matched in terms of race, intelligence, sex,...

  11. Cognitive Control Deficits in Schizophrenia: Mechanisms and Meaning

    OpenAIRE

    Lesh, Tyler A.; Niendam, Tara A; Minzenberg, Michael J.; Carter, Cameron S.

    2010-01-01

    Although schizophrenia is an illness that has been historically characterized by the presence of positive symptomatology, decades of research highlight the importance of cognitive deficits in this disorder. This review proposes that the theoretical model of cognitive control, which is based on contemporary cognitive neuroscience, provides a unifying theory for the cognitive and neural abnormalities underlying higher cognitive dysfunction in schizophrenia. To support this model, we outline con...

  12. Mechanisms of motor adaptation in reactive balance control.

    Directory of Open Access Journals (Sweden)

    Torrence D J Welch

    Full Text Available Balance control must be rapidly modified to provide stability in the face of environmental challenges. Although changes in reactive balance over repeated perturbations have been observed previously, only anticipatory postural adjustments preceding voluntary movements have been studied in the framework of motor adaptation and learning theory. Here, we hypothesized that adaptation occurs in task-level balance control during responses to perturbations due to central changes in the control of both anticipatory and reactive components of balance. Our adaptation paradigm consisted of a Training set of forward support-surface perturbations, a Reversal set of novel countermanding perturbations that reversed direction, and a Washout set identical to the Training set. Adaptation was characterized by a change in a motor variable from the beginning to the end of each set, the presence of aftereffects at the beginning of the Washout set when the novel perturbations were removed, and a return of the variable at the end of the Washout to a level comparable to the end of the Training set. Task-level balance performance was characterized by peak center of mass (CoM excursion and velocity, which showed adaptive changes with repetitive trials. Only small changes in anticipatory postural control, characterized by body lean and background muscle activity were observed. Adaptation was found in the evoked long-latency muscular response, and also in the sensorimotor transformation mediating that response. Finally, in each set, temporal patterns of muscle activity converged towards an optimum predicted by a trade-off between maximizing motor performance and minimizing muscle activity. Our results suggest that adaptation in balance, as well as other motor tasks, is mediated by altering central sensitivity to perturbations and may be driven by energetic considerations.

  13. Corticolimbic Mechanisms in the Control of Trial and Error Learning

    OpenAIRE

    Luu, Phan; Shane, Matthew; Pratt, Nikki; Tucker, Don M.

    2008-01-01

    As learning progresses, human and animal studies suggest that a frontal executive system is strongly involved early in learning, whereas a posterior monitoring and control system comes online as learning progress. In a previous study, we employed dense array EEG methodology to delineate the involvement of these two systems as human participants learn, through trial and error, to associate manual responses with arbitrary digit codes. The results were generally consistent with the dual-system l...

  14. Sensory mechanisms of balance control in cerebellar disease

    OpenAIRE

    Bunn, L. M.

    2011-01-01

    A wealth of evidence exists to suggest that the cerebellum has an important role in the integration of vestibular, proprioceptive and visual sensory signals. Human bipedal balance depends on sensory integration and balance impairment is a common feature of cerebellar disease. I test the hypothesis that disrupted sensori-motor processing is responsible for balance impairment in cerebellar disease. Balance control in subjects with pure cerebellar disease (SCA6) was compared with matched healthy...

  15. Molecular Mechanisms to Control Post-Transplantation Hepatitis B Recurrence

    Directory of Open Access Journals (Sweden)

    Akinobu Takaki

    2015-07-01

    Full Text Available Hepatitis B often progresses to decompensated liver cirrhosis requiring orthotopic liver transplantation (OLT. Although newer nucleos(tide analogues result in >90% viral and hepatitis activity control, severely decompensated patients still need OLT because of drug-resistant virus, acute exacerbation, or hepatocellular carcinoma. Acute hepatitis B is also an indication for OLT, because it can progress to fatal acute liver failure. After OLT, the hepatitis B recurrence rate is >80% without prevention, while >90% of transplant recipients are clinically controlled with combined hepatitis B immunoglobulin (HBIG and nucleos(tide analogue treatment. However, long-term HBIG administration is associated with several unresolved issues, including limited availability and extremely high cost; therefore, several treatment protocols with low-dose HBIG, combined with nucleos(tide analogues, have been investigated. Another approach is to induce self-producing anti-hepatitis B virus (HBV antibodies using an HBV envelope (HBs antigen vaccine. Patients who are not HBV carriers, such as those with acutely infected liver failure, are good candidates for vaccination. For chronic HBV carrier liver cirrhosis patients, a successful vaccine response can only be achieved in selected patients, such as those treated with experimentally reduced immunosuppression protocols. The present protocol for post-OLT HBV control and the future prospects of newer treatment strategies are reviewed.

  16. High-Order Stochastic Adaptive Controller Design with Application to Mechanical System

    OpenAIRE

    Jie Tian; Wei Feng; Yuzhen Wang

    2012-01-01

    The main purpose of this paper is to apply stochastic adaptive controller design to mechanical system. Firstly, by a series of coordinate transformations, the mechanical system can be transformed to a class of special high-order stochastic nonlinear system, based on which, a more general mathematical model is considered, and the smooth state-feedback controller is designed. At last, the simulation for the mechanical system is given to show the effectiveness of the design scheme.

  17. Neuromuscular adaptations to electrostimulation resistance training.

    Science.gov (United States)

    Maffiuletti, Nicola A; Zory, Raphael; Miotti, Danilo; Pellegrino, Maria A; Jubeau, Marc; Bottinelli, Roberto

    2006-02-01

    A combination of in vivo and in vitro analyses was performed to investigate muscular and neural adaptations of the weaker (nondominant) quadriceps femoris muscle of one healthy individual to short-term electrostimulation resistance training. The increase in maximal voluntary strength (+12%) was accompanied by neural (cross-education effect and increased muscle activation) and muscle adaptations (impairment of whole-muscle contractile properties). Significant changes in myosin heavy chain (MHC) isoforms relative content (+22% for MHC-2A and -28% for MHC-2X), single-fiber cross-sectional area (+27% for type 1 and +6% for type 2A muscle fibers), and specific tension of type 1 (+67%) but not type 2A fibers were also observed after training. Plastic changes in neural control confirm the possible involvement of both spinal and supraspinal structures to electrically evoked contractions. Changes at the single muscle fiber level induced by electrostimulation resistance training were significant and preferentially affected slow, type 1 fibers.

  18. Neuromuscular Responses to Simulated Brazilian Jiu-Jitsu Fights

    Directory of Open Access Journals (Sweden)

    Corrêa da Silva Bruno Victor

    2014-12-01

    Full Text Available The aim of this study was to investigate the neuromuscular performance responses following successive Brazilian Jiu-Jitsu (BJJ fights. Twenty-three BJJ athletes (age: 26.3 ± 6.3 years; body mass: 79.4 ± 9.7 kg; body height: 1.80 ± 0.1 m undertook 3 simulated BJJ fights (10 min duration each separated by 15 min of rest. Neuromuscular performance was measured by the bench press throw (BPT and vertical counter movement jump (VCMJ tests, assessed before the 1st fight (Pre and after the last one (Post. Blood lactate (LA was measured at Pre, 1 min Post, and 15 min Post fights. Paired t-tests were employed in order to compare the BPT and VCMJ results. One-way ANOVA with Bonferroni post hoc tests were utilized to compare LA responses. The results revealed a significant (p < 0.05 increase in VCMJ performance (40.8 ± 5.5 cm Pre vs. 42.0 ± 5.8 cm Post, but no significant changes in the BPT (814 ± 167 W Pre vs. 835 ± 213 W Post were observed. LA concentration increased significantly (p < 0.05 at Post, both in the 1st min and the 15th min of recovery. We concluded that successive simulated BJJ fights demanded considerable anaerobic contribution of ATP supply, reinforcing the high-intensity intermittent nature of the sport. Nevertheless, no negative impact on acute neuromuscular performance (power was observed.

  19. Quality of life after surgery for neuromuscular scoliosis

    Directory of Open Access Journals (Sweden)

    Peter Obid

    2013-02-01

    Full Text Available Surgery in patients with neuromuscular scoliosis is associated with a higher rate of complications. It is still controversially discussed whether the patients truly benefit from deformity correction. The purpose of this study is to investigate if the quality of life has been improved and if the patients and their caregivers are satisfied with the results of surgery. This is a retrospective clinical outcome study of 46 patients with neuromuscular scoliosis which were treated with primary stable posterior pedicle screw instrumentation and correction. To achieve fusion only autologous bone was used. Follow up was minimum 2 years and maximum 5 years with an average of 36 months. The patients and/or their caregivers received a questionnaire based on the PEDI (pediatric disability inventory and the GMFS (gross motor function score. The patients (and their caregivers were also asked if the quality of life has improved after surgery. Only 32 of 46 patients answered the questionnaire. The answers showed a high approval-rate regarding the patients satisfaction with the surgery and the improvement of quality of life. The questionnaire could be answered from 1 (I do not agree to 4 (I completely agree. The average agreement to the following statements was: i the quality of life has improved: 3.35; ii I am satisfied with surgery: 3.95; iii the operation has fulfilled my expectations: 3.76. The average age at surgery was 12.7 years. The mean pre-operative cobb-angle of the main curve was 83.1° with a correction post-operatively to a mean of 36.9° and 42.6° at final follow-up. That is an average correction of 56.9%. Although spinal fusion in neuromuscular scoliosis is associated with a higher rate of complications our results show that the patients and their caregivers are satisfied with the operation and the quality of life has improved after surgery.

  20. Development of passive-controlled HUB (teetered brake & damper mechanism) of horizontal axis wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yukimaru; Kamada, Yasunari; Maeda, Takao [Mie Univ. (Japan)

    1997-12-31

    For the purpose of the improvement of reliability of the Mega-Watt wind turbine, this paper indicates the development of an original mechanism for the passive-controlled hub, which has the effects of braking and damping on aerodynamic forces. This mechanism is useful for variable speed control of the large wind turbine. The passive-controlled hub is the combination of two mechanisms. One is the passive-teetered and damping mechanism, and the other is the passive-variable-pitch mechanism. These mechanism are carried out by the combination of the teetering and feathering motions. When the wind speed exceeds the rated wind speed, the blade is passively teetered in a downwind direction and, simultaneously, a feathering mechanism, which is linked to the teetering mechanism through a connecting rods, is activated. Testing of the model horizontal axis wind turbine in a wind tunnel showed that the passive-controlled hub mechanism can suppress the over-rotational speed of the rotor. By the application of the passive-controlled hub mechanism, the maximum rotor speed is reduced to about 60%.

  1. MRI in neuromuscular disorders; MRT bei neuromuskulaeren Erkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Fischmann, Arne [Klinik St. Anna, Luzern (Switzerland). Inst. fuer Radiologie und Nuklearmedizin; Fischer, Dirk [Kantonsspital Bruderholz (Switzerland)

    2014-03-15

    Neuromuscular disorders are caused by damage of the skeletal muscles or supplying nerves, in many cases due to a genetic defect, resulting in progressive disability, loss of ambulation and often a reduced life expectancy. Previously only supportive care and steroids were available as treatments, but several novel therapies are under development or in clinical trial phase. Muscle imaging can detect specific patterns of involvement and facilitate diagnosis and guide genetic testing. Quantitative MRT can be used to monitor disease progression either to monitor treatment or as a surrogate parameter for clinical trails. Novel imaging sequences can provide insights into disease pathology and muscle metabolism. (orig.)

  2. Cardiac involvement in children with neuro-muscular disorders

    Directory of Open Access Journals (Sweden)

    E. N. Arkhipova

    2015-01-01

    Full Text Available Many inherited neuromuscular disorders include cardiac involvement as a typical clinical feature. Among the most common of them is the group of muscular dystrophies. Dilated cardiomyopathy, ventricular arrhythmias, atrial fibrillations, atrioventricular and intraventricular conduction abnormalities, and sudden cardiac death are well known pathological findings in Duchenne muscular dystrophies, myotonic dystrophy type I and 2, Emery-Dreifuss muscular dystrophies and different types of limb-girdle muscular dystrophies and other disorders. Detection of cardiac pathology in patients with different muscular dystrophies is possible with ECG, echocardiography and cardiovascular magnetic resonance imaging, which are recommended for screening and early cardioprotective treatment.

  3. Tissue engineering for neuromuscular disorders of the gastrointestinal tract

    Institute of Scientific and Technical Information of China (English)

    Kenneth L Koch; Khalil N Bitar; John E Fortunato

    2012-01-01

    The digestive tract is designed for the optimal processing of food that nourishes all organ systems.The esophagus,stomach,small bowel,and colon are sophisticated neuromuscular tubes with specialized sphincters that transport ingested food-stuffs from one region to another.Peristaltic contractions move ingested solids and liquids from the esophagus into the stomach; the stomach mixes the ingested nutrients into chyme and empties chyme from the stomach into the duodenum.The to-and-fro movement of the small bowel maximizes absorption of fat,protein,and carbohydrates.Peristaltic contractions are necessary for colon function and defecation.

  4. Factors controlling alkalisalt deposition in recovery boiler- release mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    McKeough, P.; Kylloenen, H.; Kurkela, M. [VTT Energy, Espoo (Finland). Process Technology Group

    1996-12-01

    As part of a cooperative effort to develop a model to describe the behaviour of inorganic compounds in kraft recovery boilers, an experimental investigation of the release of sulphur during black liquor pyrolysis has been undertaken. Previous to these studies, the mechanisms of sulphur release and the reasons for the observed effects of process conditions on sulphur release were very poorly understood. On the basis of the experimental results, the main reactions leading to sulphur release have been elucidated with a fair degree of certainty. Logical explanations for the variations of sulphur release with temperature and with liquor solids content have been proposed. The influence of pressure has been investigated in order to gain insights into the effects of mass transfer on the sulphur-release rate. In the near future, the research will be aimed at generating the kinetic data necessary for modelling the release of sulphur in the recovery furnace. (author)

  5. The prejunctional inhibitory effect of suramin on neuromuscular transmission in vitro

    NARCIS (Netherlands)

    Henning, RH; Rowan, EG; Braga, MFM; Nelemans, A; Harvey, AL

    1996-01-01

    The P-2 purinoceptor antagonist suramin reverses skeletal muscle paralysis evoked by non-depolarizing neuromuscular blocking agents in vitro and in vivo. To further study the action of suramin on neuromuscular transmission, (miniature) endplate potentials ((m.)e.p.ps), motor nerve terminal currents

  6. Pharmacokinetic studies of neuromuscular blocking agents : Good Clinical Research Practice (GCRP)

    NARCIS (Netherlands)

    Viby-Mogensen, J; Ostergaard, D; Donati, F; Fisher, D; Hunter, J; Kampmann, JP; Kopman, A; Proost, JH; Rasmussen, SN; Skovgaard, LT; Varin, F; Wright, PMC

    2000-01-01

    In September 1997, an international consensus conference on standardization of studies of neuromuscular blocking agents was held in Copenhagen, Denmark. Based on the conference, a set of guidelines fur good clinical research practice (GCRT) in pharmacokinetic studies of neuromuscular blocking agents

  7. Sugammadex, a new reversal agent for neuromuscular block induced by rocuronium in the anaesthetized Rhesus monkey.

    NARCIS (Netherlands)

    Boer, H.D. de; Egmond, J. van; Pol, F. van de; Bom, A.; Booij, L.H.D.J.

    2006-01-01

    BACKGROUND: Binding of the steroidal molecule of rocuronium by a cyclodextrin is a new concept for reversal of neuromuscular block. The present study evaluated the ability of Sugammadex Org 25969, a synthetic gamma-cyclodextrin derivative, to reverse constant neuromuscular block of about 90% induced

  8. Plantar flexor neuromuscular adjustments following match-play football in hot and cool conditions

    DEFF Research Database (Denmark)

    Girard, O; Nybo, Lars; Mohr, Magni;

    2015-01-01

    We assessed neuromuscular fatigue and recovery of the plantar flexors after playing football with or without severe heat stress. Neuromuscular characteristics of the plantar flexors were assessed in 17 male players at baseline and ∼30 min, 24, and 48 h after two 90-min football matches in tempera...

  9. Impeller leakage flow modeling for mechanical vibration control

    Science.gov (United States)

    Palazzolo, Alan B.

    1996-01-01

    HPOTP and HPFTP vibration test results have exhibited transient and steady characteristics which may be due to impeller leakage path (ILP) related forces. For example, an axial shift in the rotor could suddenly change the ILP clearances and lengths yielding dynamic coefficient and subsequent vibration changes. ILP models are more complicated than conventional-single component-annular seal models due to their radial flow component (coriolis and centrifugal acceleration), complex geometry (axial/radial clearance coupling), internal boundary (transition) flow conditions between mechanical components along the ILP and longer length, requiring moment as well as force coefficients. Flow coupling between mechanical components results from mass and energy conservation applied at their interfaces. Typical components along the ILP include an inlet seal, curved shroud, and an exit seal, which may be a stepped labyrinth type. Von Pragenau (MSFC) has modeled labyrinth seals as a series of plain annular seals for leakage and dynamic coefficient prediction. These multi-tooth components increase the total number of 'flow coupled' components in the ILP. Childs developed an analysis for an ILP consisting of a single, constant clearance shroud with an exit seal represented by a lumped flow-loss coefficient. This same geometry was later extended to include compressible flow. The objective of the current work is to: supply ILP leakage-force impedance-dynamic coefficient modeling software to MSFC engineers, base on incompressible/compressible bulk flow theory; design the software to model a generic geometry ILP described by a series of components lying along an arbitrarily directed path; validate the software by comparison to available test data, CFD and bulk models; and develop a hybrid CFD-bulk flow model of an ILP to improve modeling accuracy within practical run time constraints.

  10. Line-Tension Controlled Mechanism for Influenza Fusion

    OpenAIRE

    Herre Jelger Risselada; Giovanni Marelli; Marc Fuhrmans; Smirnova, Yuliya G.; Helmut Grubmüller; Siewert Jan Marrink; Marcus Müller

    2012-01-01

    Our molecular simulations reveal that wild-type influenza fusion peptides are able to stabilize a highly fusogenic pre-fusion structure, i.e. a peptide bundle formed by four or more trans-membrane arranged fusion peptides. We rationalize that the lipid rim around such bundle has a non-vanishing rim energy (line-tension), which is essential to (i) stabilize the initial contact point between the fusing bilayers, i.e. the stalk, and (ii) drive its subsequent evolution. Such line-tension controll...

  11. Innovation in Bio-disaster Prevention and Control Mechanism after Forest Tenure Reform at County Level

    OpenAIRE

    Zhan, Zu-ren

    2012-01-01

    Taking Youxi County of Fujian Province as an example, I introduced basic situations of new bio-disaster prevention and control mechanism for forest resource protection and social service works after the forest tenure reform. Then, I analyzed new problems faced by bio-disaster prevention and control in forestry. Finally, I present the existing problems of bio-disaster prevention and control at the county level from five aspects: innovating upon plant quarantine management mechanism; innovation...

  12. The Wnt and BMP Families of Signaling Morphogens at the Vertebrate Neuromuscular Junction

    Directory of Open Access Journals (Sweden)

    Juan P. Henríquez

    2011-12-01

    Full Text Available The neuromuscular junction has been extensively employed in order to identify crucial determinants of synaptogenesis. At the vertebrate neuromuscular synapse, extracellular matrix and signaling proteins play stimulatory and inhibitory roles on the assembly of functional synapses. Studies in invertebrate species have revealed crucial functions of early morphogens during the assembly and maturation of the neuromuscular junction. Here, we discuss growing evidence addressing the function of Wnt and Bone morphogenetic protein (BMP signaling pathways at the vertebrate neuromuscular synapse. We focus on the emerging role of Wnt proteins as positive and negative regulators of postsynaptic differentiation. We also address the possible involvement of BMP pathways on motor neuron behavior for the assembly and/or regeneration of the neuromuscular junction.

  13. Radial basis function (RBF) neural network control for mechanical systems design, analysis and Matlab simulation

    CERN Document Server

    Liu, Jinkun

    2013-01-01

    Radial Basis Function (RBF) Neural Network Control for Mechanical Systems is motivated by the need for systematic design approaches to stable adaptive control system design using neural network approximation-based techniques. The main objectives of the book are to introduce the concrete design methods and MATLAB simulation of stable adaptive RBF neural control strategies. In this book, a broad range of implementable neural network control design methods for mechanical systems are presented, such as robot manipulators, inverted pendulums, single link flexible joint robots, motors, etc. Advanced neural network controller design methods and their stability analysis are explored. The book provides readers with the fundamentals of neural network control system design.   This book is intended for the researchers in the fields of neural adaptive control, mechanical systems, Matlab simulation, engineering design, robotics and automation. Jinkun Liu is a professor at Beijing University of Aeronautics and Astronauti...

  14. Model analysis of mechanisms controlling pneumatic soil vapor extraction.

    Science.gov (United States)

    Høier, C K; Sonnenborg, T O; Jensen, K H; Gudbjerg, J

    2009-01-26

    The efficiency of traditional soil venting or soil vapor extraction (SVE) highly depends on the architecture of the subsurface because imposed advective air flow tends to bypass low-permeable contaminated areas. Pneumatic SVE is a technique developed to enhance remediation efficiency of heterogeneous soils by enforcing large fluctuating pressure fronts through the contaminated area. Laboratory experiments have suggested that pneumatic SVE considerably improves the recovery rate from low-permeable units. We have analyzed the experimental results using a numerical code and quantified the physical processes controlling the functioning of the method. A sensitivity analysis for selected boundary conditions, initial conditions and parameters was carried out to examine how the method behaves under conditions different from the experimental set-up. The simulations show that at the laboratory level the pneumatic venting technology is superior to the traditional technique, and that the method is particularly efficient in cases where large permeability contrasts exist between soil units in the subsurface. PMID:19004522

  15. Laser induced mechanisms controlling the size distribution of metallic nanoparticles.

    Science.gov (United States)

    Liu, Zeming; Vitrant, Guy; Lefkir, Yaya; Bakhti, Said; Destouches, Nathalie

    2016-09-21

    This paper describes a model to simulate changes in the size distribution of metallic nanoparticles (NPs) in TiO2 films upon continuous wave light excitation. Interrelated laser induced physical and chemical processes initiated directly by photon absorption or by plasmon induced thermal heating are considered. Namely the model takes into account the NP coalescence, Ostwald ripening, the reduction of silver ions and the oxidation of metallic NPs, competitive mechanisms that can lead to counter-intuitive behaviors depending on the exposure conditions. Theoretical predictions are compared successfully to the experimental results deduced from a thorough analysis of scanning transmission electron microscopy (STEM) pictures of Ag:TiO2 films processed with a scanning visible laser beam at different speeds. Ag:TiO2 systems are considered for many applications in solar energy conversion, photocatalysis or secured data printing. Numerical investigations of such a system provide a better understanding of light induced growth and shrinking processes and open up prospects for designing more efficient photocatalytic devices based on metal NP doped TiO2 or for improving the size homogeneity in self-organized metallic NP patterns, for instance. PMID:27539293

  16. Enhanced Role Based Access Control Mechanism for Electronic Examination System

    Directory of Open Access Journals (Sweden)

    Adebukola Onashoga

    2014-02-01

    Full Text Available Over the years, e-learning and e-examination has become standard in many institutions of higher learning. It has been observed that examination questions and results can be easily intercepted by invalid users, thus the security of resources shared among valid users is not guaranteed. In order to solve these problems as it relates to access control, a Role based Examination System (RBES was designed, developed and evaluated. RBES attempted to solve the security issue by the combination of two authentication techniques: text-based authentication and graphical password authentication. The Text-based authentication utilizes two text-based parameters namely the username and password. The graphical password authentication makes use of a finite set of controls (RBES chooses radio buttons which are identified by numbers. These numbers constitute the password used for graphical authentication. To improve on resource sharing among users in the examination system, RBES proposes role management (role creation, role update, role removal and user management (user creation, user update and user removal. The developed system made use of asp.net, C#, IIS server, WAMP server, Mysql and other tools for its development. RBES was tested by some legitimate and illegitimate users and the performance of the system was found to be satisfactory, hence RBES shows an efficient and reliable scheme that can be deployed in any examination or e-learning system. Finally the potential threats to the system were modeled and the use of weak passwords was found to be the most likely threat the system could be vulnerable to.

  17. Position Fuzzy Control for a Two-Axis Shaking Table based on Slider-Crank Mechanism

    Directory of Open Access Journals (Sweden)

    Carlos H. Esparza-Franco

    2013-11-01

    Full Text Available Different mechanisms have been designed to generate vibratory motion to test the evaluation of seismic control systems to be used in structural buildings. These systems are called "shaking-tables" and they are usually designed with linear actuators which facilitate the implementation of classical control systems for its proper operation. This paper presents a position fuzzy control system designed to control the displacement behavior of earthquakes on the shaking-table based on a slider-crank mechanism. The results show repeatability greater than 97%, adequate to the validation of anti-seismic controllers on small-scale models.

  18. Disentangling the Impact of Control-Enhancing Mechanisms on Firm Performance

    DEFF Research Database (Denmark)

    Zattoni, Alessandro; Pedersen, Torben

    2011-01-01

    Governance scholars and investors traditionally advocate against the use of control enhancing mechanisms, i.e. mechanisms aimed at separating voting and cash flow rights. These mechanisms may, in fact, determine a deviation from the proportionality principle and may encourage large and controlling...... shareholders to expropriate minority shareholders. The aim of this article is to contribute to the current debate investigating the implications of these control-enhancing mechanisms on firm performance. To reach this purpose, we collected ownership data on the (100) largest listed companies per capitalization......, and (ii) the negative impact on firm performance of mechanisms aimed at enhancing control by leveraging voting power is mediated by the divergence in voting and cash flow rights....

  19. An evidence-based review of hip-focused neuromuscular exercise interventions to address dynamic lower extremity valgus

    OpenAIRE

    Ford KR; Nguyen AD; Dischiavi SL; Hegedus EJ; Zuk EF; Taylor JB

    2015-01-01

    Kevin R Ford,1 Anh-Dung Nguyen,2 Steven L Dischiavi,1 Eric J Hegedus,1 Emma F Zuk,2 Jeffrey B Taylor11Department of Physical Therapy, High Point University, High Point, NC, USA; 2Department of Athletic Training, School of Health Sciences, High Point University, High Point, NC, USAAbstract: Deficits in proximal hip strength or neuromuscular control may lead to dynamic lower extremity valgus. Measures of dynamic lower extremity valgus have been previously shown to relate to increased risk of se...

  20. Effect of Low Frequency Neuromuscular Electrical Stimulation on Glucose Profile of Persons with Type 2 Diabetes: A Pilot Study

    OpenAIRE

    Georges Jabbour; Lise Belliveau; David Probizanski; Ian Newhouse; Jim McAuliffe; Jennifer Jakobi; Michel Johnson

    2015-01-01

    The purpose of this study was to examine the effect of low-frequency neuromuscular electrical stimulation (NMES) on glucose profile in persons with type 2 diabetes mellitus (T2DM). Eight persons with T2DM (41 to 65 years) completed a glucose tolerance test with and without NMES delivered to the knee extensors for a 1-hour period at 8 Hz. Three blood samples were collected: at rest, and then 60 and 120 minutes after consumption of a glucose load on the NMES and control days. In NMES groups glu...