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Sample records for neuromuscular control mechanisms

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

    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.

  2. NEUROMUSCULAR CONTROL IN LUMBAR DISORDERS

    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

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

    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

  4. Influence of Fatigue in Neuromuscular Control of Spinal Stability

    Granata, Kevin P.; Slota, Greg P.; Wilson, Sara E.

    2004-01-01

    Lifting-induced fatigue may influence neuromuscular control of spinal stability. Stability is primarily controlled by muscle recruitment, active muscle stiffness, and reflex response. Fatigue has been observed to affect each of these neuromuscular parameters and may therefore affect spinal stability. A biomechanical model of spinal stability was implemented to evaluate the effects of fatigue on spinal stability. The model included a 6-degree-of-freedom representation of the spine controlled b...

  5. Neuromuscular control and rehabilitation of the unstable ankle

    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...

  6. Synaptic dynamics at the neuromuscular junction: mechanisms and models.

    Van Essen, D C; Gordon, H; Soha, J M; Fraser, S E

    1990-01-01

    During development, the neuromuscular junction passes through a stage of extensive polyinnervation followed by a period of wholesale synapse elimination. In this report we discuss mechanisms and interactions that could mediate many of the key aspects of these important developmental events. Our emphasis is on (1) establishing an overall conceptual framework within which the role of many distinct cellular interactions and molecular factors can be evaluated, and (2) generating computer simulations that systematically test the adequacy of different models in accounting for a wide range of biological data. Our analysis indicates that several relatively simple mechanisms are each capable of explaining a variety of experimental observations. On the other hand, no one mechanism can account for the full spectrum of experimental results. Thus, it is important to consider models that are based on interactions among multiple mechanisms. A potentially powerful combination is one based on (1) a scaffold within the basal lamina or in the postsynaptic membrane which is induced by nerve terminals and which serves to stabilize terminals by a positive feedback mechanism; (2) a sprouting factor whose release by muscle fibers is down-regulated by activity and perhaps other factors; and (3) an intrinsic tendency of motor neurons to withdraw some connections while allowing others to grow. PMID:2181065

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

    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

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

    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

  9. Neuromuscular training and the risk of leg injuries in female floorball players: cluster randomised controlled study

    Pasanen, Kati; Parkkari, Jari; Pasanen, Matti; Hiilloskorpi, Hannele; Mäkinen, Tanja; Järvinen, Markku; Kannus, Pekka

    2008-01-01

    Objective To investigate whether a neuromuscular training programme is effective in preventing non-contact leg injuries in female floorball players. Design Cluster randomised controlled study. Setting 28 top level female floorball teams in Finland. Participants 457 players (mean age 24 years)—256 (14 teams) in the intervention group and 201 (14 teams) in the control group—followedup for one league season (six months). Intervention A neuromuscular training programme to enhance players’ motor s...

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

    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. Neuromuscular function during stair descent in meniscectomized patients and controls

    Thorlund, Jonas Bloch; Roos, Ewa M; Aagaard, Per

    2011-01-01

    The aim of this study was to identify differences in knee range of motion (ROM), movement speed, ground reaction forces (GRF) profile, neuromuscular activity, and muscle coactivation during the transition between stair descent and level walking in meniscectomized patients at high risk of knee...

  12. Propiocepción y control neuromuscular en el fútblo infantil

    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...

  13. Valoració i entrenament del control neuromuscular per a la millora del rendiment esportiu

    Fort Vanmeerhaeghe, Azahara

    2010-01-01

    El control neuromuscular ha estat descrit com un important factor per a l'èxit en el rendiment esportiu. De la mateixa manera, també s'ha identificat com a clau en la prevenció i readaptació de les lesions esportives. El principal objectiu d'aquesta tesi doctoral és avaluar l'eficàcia de diferents tipus d'entrenament neuromuscular en esportistes.S'ha utilitzat una mostra de 81 esportistes sans entre els diferents estudis que s'hi presenten. Les diferents avaluacions realitzades han registrat ...

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

    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.

  15. Neuromechanical evidence of improved neuromuscular control around knee joint in volleyball players.

    Masci, Ilaria; Vannozzi, Giuseppe; Gizzi, Leonardo; Bellotti, Pasquale; Felici, Francesco

    2010-02-01

    The aim of the present work was to verify that skilled volleyball players present specific adaptations in both neuromuscular control and movement biomechanics, showing an improved neuromuscular control around the knee joint than in non-jumper athletes. Seven male volleyball players and seven male non-jumper athletes were recruited for this study. The following tests were performed in a random order: single countermovement jump (CMJ), single squat jump. At the end of the series, subjects performed a repetitive CMJ test. Electromyographic signals were recorded from vastus lateralis and biceps femoris muscles on both sides. Ground reaction forces and moments were measured with a force plate. Volleyball athletes performed better in all tests and were more resistant to fatigue than non-jumper athletes. Furthermore, volleyball athletes showed a reduced co-activation of knee flexor/extensor muscles. The present results seem to stand for a neural adaptation of the motor control scheme to training. PMID:19826834

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

    A. Asadi

    2016-01-01

    Objective: The effects of exercise protocols on postural control changes have been supported, but the influence of a common and specific type neuromuscular exercise such as plyometric on postural control is not clear. Therefore, the aim of this study was to examine the effects of plyometric type neuromuscular exercise on balance or postural control performance of young male volleyball players. Method: Ten professional young male volleyball players participated in this study and performed p...

  17. Single leg jumping neuromuscular control is improved following whole body, long-axis rotational training.

    Nyland, John; Burden, Robert; Krupp, Ryan; Caborn, David N M

    2011-04-01

    Improved lower extremity neuromuscular control during sports may decrease injury risk. This prospective study evaluated progressive resistance, whole body, long-axis rotational training on the Ground Force 360 device. Our hypothesis was that device training would improve lower extremity neuromuscular control based on previous reports of kinematic, ground reaction force (GRF) or electromyographic (EMG) evidence of safer or more efficient dynamic knee stability during jumping. Thirty-six healthy subjects were randomly assigned to either training (Group 1) or control (Group 2) groups. Using a pre-test, post-test study design data were collected from three SLVJ trials. Unpaired t-tests with adjustments for multiple comparisons were used to evaluate group mean change differences (P≤0.05/25≤0.002). During propulsion Group 1 standardized EMG amplitude mean change differences for gluteus maximus (-21.8% vs. +17.4%), gluteus medius (-28.6% vs. +15.0%), rectus femoris (-27.1% vs. +11.2%), vastus medialis (-20.2% vs. +9.1%), and medial hamstrings (-38.3% vs. +30.3%) differed from Group 2. During landing Group 1 standardized EMG amplitude mean change differences for gluteus maximus (-32.9% vs. +11.1%) and rectus femoris (-33.3% vs. +29.0%) also differed from Group 2. Group 1 peak propulsion vertical GRF (+0.24N/kg vs. -0.46N/kg) and landing GRF stabilization timing (-0.68 vs. +0.05s) mean change differences differed from Group 2. Group 1 mean hip (-16.3 vs. +7.8°/s) and knee (-21.4 vs. +18.5°/s) flexion velocity mean change differences also differed from Group 2. Improved lower extremity neuromuscular efficiency, increased peak propulsive vertical GRF, decreased mean hip and knee flexion velocities during landing, and earlier landing stabilization timing in the training group suggests improved lower extremity neuromuscular control. PMID:21123083

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

    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...

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

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

    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 with NIV (while ventilated with a modified ventilator allowing the patient to withhold ventilation as desired). Breathing-swallowing interactions were investigated by chin electromyography, cervical piezoelectric sensor, nasal flow recording and inductive plethysmography. Two water-bolus sizes (5 and 10ml) and a textured yogurt bolus were tested in a random order. Results NIV use significantly improved swallowing fragmentation (defined as the number of respiratory interruption of the swallowing of a single bolus) (p = 0.003) and breathing-swallowing synchronization (with a significant increase of swallows followed by an expiration) (p <0.0001). Patient exhibited piecemeal swallowing which was not influenced by NIV use (p = 0.07). NIV use also significantly reduced dyspnea during swallowing (p = 0.04) while preserving swallowing comfort, regardless of bolus type. Conclusion The use of patient controlled NIV improves swallowing parameters in patients with severe neuromuscular respiratory failure requiring daytime NIV, without impairing swallowing comfort. Trial Registration ClinicalTrials.gov NCT01519388 PMID:26938617

  20. No effect on performance tests from a neuromuscular warm-up programme in youth female football: a randomised controlled trial

    Lindblom, Hanna; Waldén, Markus; Hägglund, Martin

    2012-01-01

    The objective of the present randomised controlled trial was to study the effect of a neuromuscular warm-up programme on performance tests in youth female football. less thanbrgreater than less thanbrgreater thanFour youth female football teams with players aged 12-16 years were randomised into an intervention group and control group. The intervention was a 15-min neuromuscular warm-up programme carried out twice a week during the 11-week study period. Baseline and follow-up measurements of p...

  1. Neuromuscular activation strategies of voluntary andelectrically elicited muscle fatigue: Underlying mechanisms and clinicalimplications

    Doix, Aude-Clémence

    2013-01-01

    The clinical care of muscle fatigue with exercise therapies aim at quality of life improvement and usually involve unilateral exercises or neuromuscular electrical stimulation to compensate impaired muscle function in both healthy and health-compromised people. The overall objective of this thesis was to study the effect of neuromuscular activation strategies during muscle fatigue, endurance and muscle performance after unilateral fatiguing voluntary and electrically evoked contractions (NMES...

  2. The Significance of Transcutaneous Continuous Overnight CO2 Monitoring in Determining Initial Mechanical Ventilator Application for Patients with Neuromuscular Disease

    Lee, Soon Kyu; Kim, Dong-Hyun; Choi, Won Ah; Won, Yu Hui; Kim, Sun Mi; Kang, Seong-Woong

    2012-01-01

    Objective To reveal the significance of continuous transcutaneous carbon dioxide (CO2) level monitoring through reviewing cases which showed a discrepancy in CO2 levels between arterial blood gas analysis (ABGA) and continuous transcutaneous blood gas monitoring. Method Medical record review was conducted retrospectively of patients with neuromuscular diseases who had started home mechanical ventilation between June 2008 and May 2010. The 89 patients underwent ABGA at the 1st hospital day, an...

  3. Modeling and simulating the neuromuscular mechanisms regulating ankle and knee joint stiffness during human locomotion.

    Sartori, Massimo; Maculan, Marco; Pizzolato, Claudio; Reggiani, Monica; Farina, Dario

    2015-10-01

    This work presents an electrophysiologically and dynamically consistent musculoskeletal model to predict stiffness in the human ankle and knee joints as derived from the joints constituent biological tissues (i.e., the spanning musculotendon units). The modeling method we propose uses electromyography (EMG) recordings from 13 muscle groups to drive forward dynamic simulations of the human leg in five healthy subjects during overground walking and running. The EMG-driven musculoskeletal model estimates musculotendon and resulting joint stiffness that is consistent with experimental EMG data as well as with the experimental joint moments. This provides a framework that allows for the first time observing 1) the elastic interplay between the knee and ankle joints, 2) the individual muscle contribution to joint stiffness, and 3) the underlying co-contraction strategies. It provides a theoretical description of how stiffness modulates as a function of muscle activation, fiber contraction, and interacting tendon dynamics. Furthermore, it describes how this differs from currently available stiffness definitions, including quasi-stiffness and short-range stiffness. This work offers a theoretical and computational basis for describing and investigating the neuromuscular mechanisms underlying human locomotion. PMID:26245321

  4. Delayed effect of Kinesio Taping on neuromuscular performance, balance, and lower limb function in healthy individuals: a randomized controlled trial

    Caio A. A. Lins; Daniel T. Borges; Liane B. Macedo; Karinna S. A. Costa; Jamilson S. Brasileiro

    2016-01-01

    ABSTRACT Background Kinesio Taping (KT) is an elastic bandage that aims to improve neuromuscular performance, although there is no consensus as to its benefits. Objective To analyze the immediate and delayed effects of KT on the neuromuscular performance of the femoral quadriceps, on balance, and lower limb function in healthy subjects. Method This is a randomized controlled trial. Thirty-six women with a mean age of 22.2±3.6 years and BMI of 22.5±2.3 Kg/m2 were divided into three groups: ...

  5. Neuromuscular complications in cancer.

    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

  6. The Effect of Plyometric Training on Trunk Muscle Pre-activation in Active Females with Trunk Neuromuscular Control Deficit

    M Hadadnezhad; R. Rajabi; A Ashraf Jamshidi; E Shirzad

    2014-01-01

    Introduction: Plyometric training via neuromuscular adaptations to the stretch reflex, elasticity of muscle and Golgi tendon organs has an important role in pre-activation of muscles. Due to lack of research in regard to effect of plyometric training on lumbo pelvic muscle, this study aimed to investigate the effect of plyometric training on lumbo pelvic muscle pre-activation in active females with trunk control deficit. Methods: Twenty-five active females who suffered from trunk control de...

  7. Delayed effect of Kinesio Taping on neuromuscular performance, balance, and lower limb function in healthy individuals: a randomized controlled trial

    Caio A. A. Lins

    2016-01-01

    Full Text Available ABSTRACT Background Kinesio Taping (KT is an elastic bandage that aims to improve neuromuscular performance, although there is no consensus as to its benefits. Objective To analyze the immediate and delayed effects of KT on the neuromuscular performance of the femoral quadriceps, on balance, and lower limb function in healthy subjects. Method This is a randomized controlled trial. Thirty-six women with a mean age of 22.2±3.6 years and BMI of 22.5±2.3 Kg/m2 were divided into three groups: control, with ten minutes of rest (control, n=12, application of Kinesio Taping without tension (placebo, n=12 and with tension (KT, n=12 on the quadriceps. The primary outcome was isokinetic performance, while secondary outcomes were the single-hop test, one-footed static balance, and electromyographic activity. The evaluations were carried out in five stages: 1 before application of KT, 2 immediately after the application of KT, 3 after 24h, 4 after 48h, and 5 after 72h. Mixed ANOVA was used to determine differences between groups. Results There was no change in one-footed static balance, electromyographic activity of the VL in the lower limb function, nor in isokinetic performance between groups. Conclusion KT promotes neither immediate nor delayed changes in neuromuscular performance of the femoral quadriceps in healthy women.

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

    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

  9. Neuromuscular blockade in children Bloqueadores neuromusculares em crianças

    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.

  10. Effect of 1-year regular Tai Chi on neuromuscular reaction in elderly women: a randomized controlled study.

    Sun, Wei; Zhang, Cui; Song, Qipeng; Li, Weiping; Cong, Yan; Chang, Shuwan; Mao, Dewei; Hong, Youlian

    2016-01-01

    This study assessed the effect of 1-year regular Tai Chi (TC) on neuromuscular reaction in elderly women. A total of 41 elderly women (55 years-68 years) completed the study. The TC group (n = 21) performed the 24-form TC, while the control group (C, n = 20) was instructed to read newspapers or watch television when the TC group practised. Electromyogram measurements were conducted before and after intervention. After a year-long intervention, the post-test results of between-group neuromuscular reaction time showed significant differences in the rectus femoris (t = 3.607, p = 0.001), semitendinosus (t = 2.678, p = 0.011), anterior tibialis (t = 3.455, p = 0.001), and gastrocnemius muscles (t = 4.061, p = 0.000). Within-group results showed that the TC group had significantly shorter neuromuscular reaction time compared to its baseline value in the rectus femoris (t = 3.066, p = 0.006), semitendinosus (t = 2.485, p = 0.022), anterior tibialis (t = 2.311, p = 0.032), and gastrocnemius muscles (t = 2.462, p = 0.023). Results suggested that year-long regular TC can improve neuromuscular reaction function in elderly women. PMID:27161956

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

    Larsen, C M; Søgaard, Karen; Chreiteh, S S; Holtermann, Andreas; Juul-Kristensen, B

    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...

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

    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

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

    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

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

    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

  15. [Fatigue in neuromuscular disease].

    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

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

    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

  17. HYDRAULIC SERVO CONTROL MECHANISM

    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)

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

    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

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

    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...

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

    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.

    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. Effects of neuromuscular electrical stimulation combined with effortful swallowing on post-stroke oropharyngeal dysphagia: a randomised controlled trial.

    Park, J-S; Oh, D-H; Hwang, N-K; Lee, J-H

    2016-06-01

    Neuromuscular electrical stimulation (NMES) has been used as a therapeutic intervention for dysphagia. However, the therapeutic effects of NMES lack supporting evidence. In recent years, NMES combined with traditional swallowing therapy has been used to improve functional recovery in patients with post-stroke dysphagia. This study aimed to investigate the effects of effortful swallowing combined with neuromuscular electrical stimulation on hyoid bone movement and swallowing function in stroke patients. Fifty stroke patients with mild dysphagia who were able to swallow against the resistance applied by using NMES and cooperate actively in training were included. This study was designed as a 6-week single-blind, randomised, controlled study. In the experimental group, two pairs of electrodes were placed horizontally in the infrahyoid region to depress the hyoid bone. The NMES intensity was increased gradually until the participants felt a grabbing sensation in their neck and performed an effortful swallow during the stimulation. In the placebo group, the same procedure was followed except for the intensity, which was increased gradually until the participants felt an electrical sensation. All participants underwent this intervention for 30 min per session, 5 sessions per week, for 6 weeks. Videofluoroscopic swallowing studies (VFSS) were carried out before and after the intervention and kinematics of the hyoid bone and swallowing function were analysed based on the VFSS. The experimental group revealed a significant increase in anterior and superior hyoid bone movement and the pharyngeal phase of the swallowing function. This intervention can be used as a novel remedial approach in dysphagic stroke patients. PMID:26969528

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

    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. Nonholonomic mechanics and control

    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...

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

    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

  6. Effects of home-based resistance training and neuromuscular electrical stimulation in knee osteoarthritis: a randomized controlled trial

    Bruce-Brand Robert A

    2012-07-01

    Full Text Available Abstract Background Quadriceps femoris muscle (QFM weakness is a feature of knee osteoarthritis (OA and exercise programs that strengthen this muscle group can improve function, disability and pain. Traditional supervised resistance exercise is however resource intensive and dependent on good adherence which can be challenging to achieve in patients with significant knee OA. Because of the limitations of traditional exercise programs, interest has been shown in the use of neuromuscular electrical stimulation (NMES to strengthen the QFM. We conducted a single-blind, prospective randomized controlled study to compare the effects of home-based resistance training (RT and NMES on patients with moderate to severe knee OA. Methods 41 patients aged 55 to 75 years were randomised to 6 week programs of RT, NMES or a control group receiving standard care. The primary outcome was functional capacity measured using a walk test, stair climb test and chair rise test. Additional outcomes were self-reported disability, quadriceps strength and cross-sectional area. Outcomes were assessed pre- and post-intervention and at 6 weeks post-intervention (weeks 1, 8 and 14 respectively. Results There were similar, significant improvements in functional capacity for the RT and NMES groups at week 8 compared to week 1 (p≤0.001 and compared to the control group (p  Conclusions Home-based NMES is an acceptable alternative to exercise therapy in the management of knee OA, producing similar improvements in functional capacity. Trial registration: Current Controlled Trials ISRCTN85231954

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

    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

  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

    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.

    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

    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

  11. 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

    Junge, Tina; Wedderkopp, N; Thorlund, J B;

    2015-01-01

    Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single-Leg-Hop-......Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single...... 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...

  12. 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

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

    2015-01-01

    Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single-Leg-Hop-......Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single...... 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...

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

    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

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

    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...

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

    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.

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

    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

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

    Sennels, Søren; Biering-Sørensen, Fin; Andersen, Ole Trier; Hansen, Steffen Duus

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

    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

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

    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

  20. Mechanisms in environmental control

    The theory of implementation provides methods for decentralization of decisions in societies. By using mechanisms (game forms) it is possible (in theory) to implement attractive states in different economic environments. As an example the market mechanisms can implement Pareto-efficient and individual rational allocations in an Arrow-Debreu economic environment without market failures. And even when there exists externalities the market mechanism sometime can be used if it is possible to make a market for the goods not allocated on a market already - examples are marketable emission permits, and deposit refund systems. But environmental problems can often be explained by the existence of other market failures (e.g. asymmetric information), and then the market mechanism do not work properly. And instead of using regulation or traditional economic instruments (subsidies, charges, fees, liability insurance, marketable emission permits, or deposit refund systems) to correct the problems caused by market failures, some other methods can be used to deal with these problems. This paper contains a survey of mechanisms that can be used in environmental control when the problems are caused by the existence of public goods, externalities, asymmetric information, and indivisible goods in the economy. By examples it will be demonstrated how the Clarke-Groves mechanism, the Cournot-Lindahl mechanism, and other mechanisms can be used to solve specific environmental problems. This is only theory and examples, but a recent field study have used the Cournot-Lindahl mechanism to solve the problem of lake liming in Sweden. So this subject may be of some interests for environmental policy in the future. (au) 23 refs

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

    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.

  2. Genetics and Neuromuscular Diseases

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

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

    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

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

    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. PMID:25563677

  5. Control rod drive mechanisms

    Purpose: To accurately measure the loads generated upon scram and judge the absence or presence of deceleration in control rod drive mechanisms. Constitution: Control rod drive mechanisms for use in a BWR type reactor includes an index tube vertically movably, connected at the upper end to the control rod and having a drive piston at the lower end. A piezoelectric member for detecting the load generated upon uprise of the index tube is disposed and signals from the piezoelectric member is connected to a calculation processing device. A load exerted when the index tube uprises is measured by way of the piezoelectric member upon scram thereby judging the absence or presence of the decelerating operation. Therefore, the nuclear reactor can be shutdown only when it is required with no excess safety operation than required. As a result, the reactor availability can be improved and, in addition, it is also possible to mitigate the burden of in-service inspection and reduce the operators' exposure. (Kamimura, M.)

  6. Doenças neuromusculares Neuromuscular disorders

    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...

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

    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.

  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

    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...

  9. Doenças neuromusculares Neuromuscular disorders

    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

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

    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...

  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

    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

  12. 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

    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 ...

  13. Regulation and restoration of motoneuronal synaptic transmission during neuromuscular regeneration in the pulmonate snail Helisoma trivolvis.

    Turner, M B; Szabo-Maas, T M; Poyer, J C; Zoran, M J

    2011-08-01

    Regeneration of motor systems involves reestablishment of central control networks, reinnervation of muscle targets by motoneurons, and reconnection of neuromodulatory circuits. Still, how these processes are integrated as motor function is restored during regeneration remains ill defined. Here, we examined the mechanisms underlying motoneuronal regeneration of neuromuscular synapses related to feeding movements in the pulmonate snail Helisoma trivolvis. Neurons B19 and B110, although activated during different phases of the feeding pattern, innervate similar sets of muscles. However, the percentage of muscle fibers innervated, the efficacy of excitatory junction potentials, and the strength of muscle contractions were different for each cell's specific connections. After peripheral nerve crush, a sequence of transient electrical and chemical connections formed centrally within the buccal ganglia. Neuromuscular synapse regeneration involved a three-phase process: the emergence of spontaneous synaptic transmission (P1), the acquisition of evoked potentials of weak efficacy (P2), and the establishment of functional reinnervation (P3). Differential synaptic efficacy at muscle contacts was recapitulated in cell culture. Differences in motoneuronal presynaptic properties (i.e., quantal content) were the basis of disparate neuromuscular synapse function, suggesting a role for retrograde target influences. We propose a homeostatic model of molluscan motor system regeneration. This model has three restoration events: (1) transient central synaptogenesis during axonal outgrowth, (2) intermotoneuronal inhibitory synaptogenesis during initial neuromuscular synapse formation, and (3) target-dependent regulation of neuromuscular junction formation. PMID:21876114

  14. Hereditary neuromuscular diseases

    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.

  15. Electrodiagnosis in neuromuscular disease.

    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

  16. The Effect of Plyometric Training on Trunk Muscle Pre-activation in Active Females with Trunk Neuromuscular Control Deficit

    M Hadadnezhad

    2014-02-01

    Results: the results of independent sample T-test indicated that there are significant differences between post-test of control and experimental groups in regard to Gluteus Medius (p=0.021, Quadratus Lumborum (p=0.011, Transverse Abdominis/Internal oblique (p=0.006, External Oblique (p=0.023 muscles activations which reveals effectiveness of plyometric training on pre-activation of muscles. Conclusion: Based on the study results, plyometric training affects the activation of muscles and thus improving the pre-activation can prevent mechanisms related to anterior cruciate ligament injury. Therefore, plyometric training can reduce incidence of anterior cruciate ligament injury.

  17. Cross-disease comparison of amyotrophic lateral sclerosis and spinal muscular atrophy reveals conservation of selective vulnerability but differential neuromuscular junction pathology.

    Comley, Laura H; Nijssen, Jik; Frost-Nylen, Johanna; Hedlund, Eva

    2016-05-01

    Neuromuscular junctions are primary pathological targets in the lethal motor neuron diseases spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Synaptic pathology and denervation of target muscle fibers has been reported prior to the appearance of clinical symptoms in mouse models of both diseases, suggesting that neuromuscular junctions are highly vulnerable from the very early stages, and are a key target for therapeutic intervention. Here we examined neuromuscular pathology longitudinally in three clinically relevant muscle groups in mouse models of ALS and SMA in order to assess their relative vulnerabilities. We show for the first time that neuromuscular junctions of the extraocular muscles (responsible for the control of eye movement) were resistant to degeneration in endstage SMA mice, as well as in late symptomatic ALS mice. Tongue muscle neuromuscular junctions were also spared in both animal models. Conversely, neuromuscular junctions of the lumbrical muscles of the hind-paw were vulnerable in both SMA and ALS, with a loss of neuronal innervation and shrinkage of motor endplates in both diseases. Thus, the pattern of selective vulnerability was conserved across these two models of motor neuron disease. However, the first evidence of neuromuscular pathology occurred at different timepoints of disease progression, with much earlier evidence of presynaptic involvement in ALS, progressing to changes on the postsynaptic side. Conversely, in SMA changes appeared concomitantly at the neuromuscular junction, suggesting that mechanisms of neuromuscular disruption are distinct in these diseases. J. Comp. Neurol. 524:1424-1442, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26502195

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

    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.

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

    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.

  20. Control Processes and Defense Mechanisms

    HOROWITZ, MARDI; Cooper, Steven; FRIDHANDLER, BRAM; Perry, J. Christopher; Bond, Michael; VAILLANT, GEORGE

    1992-01-01

    Defense-mechanism theory and control-process theory are related psychodynamic approaches to explaining and classifying how people ward off emotional upsets. Although both theories explain defensive maneuvers in the same motivational terms, each defines categories different1y. Classic categories define defense mechanisms at a relatively macroscopic level, whereas control-process theory aims at relatively microgenetic analysis of how cognitive maneuvers—involving what is th...

  1. Neuromuscular Control Training Programs and Noncontact Anterior Cruciate Ligament Injury Rates in Female Athletes: A Numbers-Needed-to-Treat Analysis

    Grindstaff, Terry L.; Hammill, Robert R; Tuzson, Ann E.; Hertel, Jay

    2006-01-01

    Objective: To determine the numbers needed to treat (NNT) and relative risk reduction (RRR) associated with neuromuscular training programs aimed at preventing noncontact anterior cruciate ligament (ACL) injuries in female athletes.

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

    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...

  3. 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.

    Junge, Tina; Wedderkopp, Niels; Thorlund, Jonas Bloch; Søgaard, Karen; Juul-Kristensen, Birgit

    2015-06-01

    Generalised Joint Hypermobility (GJH) is considered an intrinsic risk factor for knee injuries. Knee neuromuscular control during landing may be altered in GJH due to reduced passive stability. The aim was to identify differences in knee neuromuscular control during landing of the Single-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 than controls, all significant findings. Although the groups performed equally in SLHD, GJH had a Gastrocnemius Medialis dominated neuromuscular strategy before landing, plausibly caused by reduced Semitendinosus activity. Reduced Semitendinosus activity was seen in GJH after landing, 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. PMID:25801907

  4. Optimal Control of Mechanical Systems

    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.

  5. Neuromuscular junctional disorders.

    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

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

    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

  7. Cellular mechanisms that control mistranslation

    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...

  8. Monitoring of neuromuscular function in the clinical setting.

    Kelly, D; Brull, S. J.

    1993-01-01

    This paper will review the basics of neurostimulation in the perioperative period. Following a brief overview of neuromuscular physiology, the mechanism of action of depolarizing and non-depolarizing relaxants will be discussed. The principles of neurostimulation will then be applied clinically when different patterns of stimulation (single twitch, train-of-four, post-tetanic twitch count, double burst) are described. Clinical assessment of neuromuscular function will then be compared with bo...

  9. MRI in neuromuscular disorders

    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.)

  10. Neuromuscular Impairment Following Backpack Load Carriage

    Blacker, Sam D.; Fallowfield, Joanne L; Bilzon, James L.J.; Willems, Mark E.T.

    2013-01-01

    Load Carriage using backpacks is an occupational task and can be a recreational pursuit. The aim of this study was to investigate the mechanisms responsible for changes in neuromuscular function of the m. quadriceps femoris following load carriage. The physiological responses of 10 male participants to voluntary and electrically stimulated isometric contractions were measured before and immediately after two hours of treadmill walking at 6.5 km•h −1 during level walking with no load [LW], and...

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

    Sennels, Søren; Fin, Biering-Sørensen; Andersen, Ole Trier; Hansen, Steffen Duus

    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 ...

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

    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.

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

    Sennels, Søren; Fin, Biering-Sørensen; Andersen, Ole Trier; Hansen, Steffen Duus

    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...... a non-stationary signal, therefore an adaptive linear prediction filter is proposed. The filter is derived and tested for three filter lengths on both simulated and real data. The performance is compared with a conventional fixed comb filter. The simulations indicate that the adaptive filter is...... comparable with the background noise. It is thus possible to extract the voluntary EMG from a partly paralysed muscle and use it for controlling the stimulation of the same muscle....

  14. Burn Control Mechanisms in Tokamaks

    Hill, Maxwell; Stacey, Weston

    2013-10-01

    Burn control and passive safety in accident scenarios will be an important design consideration in future tokamaks, especially those used as a neutron source for fusion-fission hybrid reactors, such as the Subcritical Advanced Burner Reactor (SABR) concept. At Georgia Tech, we are developing a new burning plasma dynamics code to investigate passive safety mechanisms that could prevent power excursions in tokamak reactors. This code solves the coupled set of balance equations governing burning plasmas in conjunction with a two-point SOL-divertor model. Predictions have been benchmarked against data from DIII-D. We are examining several potential negative feedback mechanisms to limit power excursions: i) ion-orbit loss, ii) thermal instabilities, iii) the degradation of alpha-particle confinement resulting from ripples in the toroidal field, iv) modifications to the radial current profile, v) ``divertor choking'' and vi) Type 1 ELMs.

  15. The effect of shoe design and lateral wedges on knee load and neuromuscular control in healthy subjects during walking

    Mølgaard, Carsten Møller; Kersting, Uwe G.

    2013-01-01

    The increasing number of patients with developing osteoarthritis is accompanied by a growing scientific interest in non-operative early treatment strategies. It is generally believed that laterally wedged insoles can change the distribution of knee loading. However, the importance of footwear...... three-dimensional gait analysis. Barefoot walking, walking in a running shoe, an Oxford-type leather shoe, and a rocker shoe were analysed. The shoes were tested both with and without a 10-degree full-length laterally wedged insole. Results: There were significant shoe wedge interactions on the first......: Lateral wedging is effective regardless of shoe design. Differences between the three neutral walking conditions underline the importance of footwear choice in individuals. It is safe to apply lateral wedges without jeopardising muscular control during walking regardless of shoe type. Possible effects of...

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

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

    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 c...

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

    de Araújo Carlos José Soares; Gonçalves Fernanda Souza; Bittencourt Hugo Souza; dos Santos Noélia Gonçalves; Junior Sérgio Vitor Mecca; Neves Júlio Leal Bandeira; Fernandes André Maurício Souza; Junior Roque Aras; dos Reis FranciscoJoséFariasBorges; Guimarães Armênio Costa; Junior ErenaldodeSouzaRodrigues; Carvalho Vitor Oliveira

    2012-01-01

    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 failu...

  18. Control mechanisms for ecological-economic systems

    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.

  19. Neuromuscular Ultrasound of Cranial Nerves

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

    2015-01-01

    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 re...

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

    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

  1. 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

    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

  2. Neuromuscular disease classification system

    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.

  3. Active zone stability:insights from fly neuromuscular junction

    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.

  4. Control of a mechanical gripper with a fuzzy controller

    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)

  5. Neuromuscular disorders in acute leukemia and lymphoma treatment

    E. A. Politova

    2014-07-01

    Full Text Available Different mechanisms of neuromuscular complications, their clinical presentation, methods of diagnosis, prognosis and treatment options arepresented. The material is presented according to the level of nervous system damage, with inclusion of different clinical entities. Authors revieweda wide range of disease – disease of the spinal cord, peripheral nerves and plexus, neuromuscular junction and muscle – as a result of chemotherapy and radiation therapy. Systemic effects of drugs on peripheral nervous system, various departments of which can be simultaneously involved in the pathological process, were also highlighted.

  6. Neuromuscular Exercise Post Partial Medial Meniscectomy

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

    2015-01-01

    PURPOSE: To evaluate the effects of a 12-week, home-based, physiotherapist-guided neuromuscular exercise program on the knee adduction moment (an indicator of mediolateral knee load distribution) in people with a medial arthroscopic partial meniscectomy within the past 3-12 months. METHODS...... or a control group with no exercise. The exercise program included eight individual sessions with one of seven physiotherapists in private clinics, together with home exercises. Primary outcomes were the peak external knee adduction moment during normal pace walking and during a one-leg sit-to-stand. Secondary...

  7. Protein defects in neuromuscular diseases

    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.

  8. Dengue-associated neuromuscular complications

    Ravindra Kumar Garg

    2015-01-01

    Full Text Available 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 evolving course; benign nature; excellent response to potassium; and, often leads to diagnostic confusion with other dengue-associated neuromuscular disorders. Rhabdomyolysis is the most severe form of muscle involvement and may be life-threatening. Guillain-Barrι syndrome is another frequent neuromuscular dengue-associated complication. Dengue-associated Guillain-Barrι syndrome responds very well to intravenous immunoglobulins. Predominant spinal gray matter involvement has been reported in a patient presenting with areflexic paraparesis. Mononeuropathies often manifest with paralysis of the diaphragm due to phrenic nerve dysfunction. Brachial plexopathy, in the form of neuralgic amyotrophy, has been described much more frequently than lumbo-sacral plexopathy. Early recognition of these neuromuscular complications is needed for successful treatment and to prevent further disabilities.

  9. Dengue-associated neuromuscular complications.

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

    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 evolving course; benign nature; excellent response to potassium; and, often leads to diagnostic confusion with other dengue-associated neuromuscular disorders. Rhabdomyolysis is the most severe form of muscle involvement and may be life-threatening. Guillain-Barrι syndrome is another frequent neuromuscular dengue-associated complication. Dengue-associated Guillain-Barrι syndrome responds very well to intravenous immunoglobulins. Predominant spinal gray matter involvement has been reported in a patient presenting with areflexic paraparesis. Mononeuropathies often manifest with paralysis of the diaphragm due to phrenic nerve dysfunction. Brachial plexopathy, in the form of neuralgic amyotrophy, has been described much more frequently than lumbo-sacral plexopathy. Early recognition of these neuromuscular complications is needed for successful treatment and to prevent further disabilities. PMID:26238884

  10. Measurement and control for mechanical compressive stress

    Li, Qing; Ye, Guang; Pan, Lan; Wu, Xiushan

    2001-12-01

    At present, the indirect method is applied to measuring and controlling mechanical compressive stress, which is the measurement and control of rotating torque of screw with torque transducer during screw revolving. Because the friction coefficient between every screw-cap and washer, of screw-thread is different, the compressive stress of every screw may is different when the machinery is equipped. Therefore, the accurate measurement and control of mechanical compressive stress is realized by the direct measurement of mechanical compressive stress. The author introduces the research of contrast between compressive stress and rotating torque in the paper. The structure and work principle of a special washer type transducer is discussed emphatically. The special instrument cooperates with the washer type transducer for measuring and controlling mechanical compressive stress. The control tactics based on the rate of compressive stress is put to realize accurate control of mechanical compressive stress.

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

    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)....

  12. Dual acting slit control mechanism

    Struthoff, G. L. (Inventor)

    1980-01-01

    A dual acting control system for mass spectrometers is described, which permits adjustment of the collimating slit width and centering of the collimating slit while using only one vacuum penetration. Coaxial shafts, each with independent vacuum bellows are used to independently move the entire collimating assembly or to adjust the slit dimension through a parallelogram linkage.

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

    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

  14. LRP4 is critical for neuromuscular junction maintenance.

    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

  15. Neuromuscular disruption with ultrashort electrical pulses

    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.

  16. Neuromuscular dressing effects: a literature review

    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.

  17. Tests of gastric neuromuscular function.

    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

  18. Dengue-associated neuromuscular complications

    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...

  19. The undesirable effects of neuromuscular blocking drugs

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

    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 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...... 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...

  20. Degeneration of Neuromuscular Junction in Age and Dystrophy

    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.

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

    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

  3. 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.

    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

  4. Musculoskeletal complications of neuromuscular disease in children.

    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

  5. 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

    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

  6. Noise control mechanisms of inside aircraft

    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.

  7. Neuronal mechanisms of feedback postural control

    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...

  8. Robot Control in Terms of Hamiltonian Mechanics

    Záda, V.; Belda, Květoslav

    Praha: Ústav termomechaniky AV ČR, v. v. i, 2016 - (Zolotarev, I.; Radolf, V.) ISBN 978-80-87012-59-8. ISSN 1805-8248. [Engineering Mechanics 2016. Svratka (CZ), 09.05.2016-12.05.2016] Institutional support: RVO:67985556 Keywords : Robot -manipulator * Hamiltonian formalism * Modeling * Robot control * PD control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2016/AS/belda-0459349.pdf

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

    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. 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

    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...

  11. Computed tomography of muscles in neuromuscular disease

    137 patients with neuromuscular diseases were studied by CT scan. Four levels were chosen: mid-calf, mid-thigh, pelvic girdle, and spinal muscles. The scans were compared with normal control scans taken from the same sites. The patients were divided into those with myogenic diseases and those with neurogenic diseases. Of the 102 patients with myogenic changes, 17 had X-linked dystrophy, 13 had facio-scapulo-humeral dystrophy, 22 had limb girdle dystrophy, 19 had myotonic dystrophy, 14 had inflammatory muscle diseases, and 17 had miscellaneous muscular diseases. Of the 35 patients with neurogenic changes, 8 had amyotrophic lateral sclerosis (ALS), 16 had chronic spinal amyotrophies, 9 had peripheral neuropathies, and 2 had Friedreich's disease. The analysis of muscles changes (volume, outline, density) was established on the following muscles: tibialis anterior, peroneus, soleus, gastrocnemius mediale, gastrocnemius laterale, quadriceps, semitendinosus, semimembranosus, sartorius, adductor, gracilis, gluteus, spine extensors, and psoas

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

    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

  13. Electrophysiological study in neuromuscular junction disorders

    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...

  14. Diagnostic NGS for Severe Neuromuscular Disorders

    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.

  15. Common complications of pediatric neuromuscular disorders.

    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

  16. Diagnostic NGS for Severe Neuromuscular Disorders

    Radhika Dhamija

    2015-12-01

    Full Text Available 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.

  17. Nonsmooth mechanics models, dynamics and control

    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...

  18. Operation of Control Rod Driving Mechanism controller at HANARO

    Gyu, Doo Seung; Woo, Lee Min; San, Choe Yeong; Kyoo, Kim Hyung [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    HANARO (High flux Advanced Neutron Application Reactor) achieved its first critical operation in 1995. Recently, there has been fast developments in the field of electronics. Many manufacturers of I and C components have disappeared or merged with the other companies. The suppliers of the control systems of the CRDM (Control Rod Driving Mechanism) at HANARO have disappeared. Therefore, we needed to change the control system of the CRDM since we cannot be provided with maintenance any longer. In this paper, we investigated the operation of the control system of the CRDM when the controller and motor driver are changed.

  19. Upper airway neuromuscular compensation during sleep is defective in obstructive sleep apnea

    McGinley, Brian M.; Schwartz, Alan R.; Schneider, Hartmut; Kirkness, Jason P.; Smith, Philip L; Patil, Susheel P.

    2008-01-01

    Obstructive sleep apnea is the result of repeated episodes of upper airway obstruction during sleep. Recent evidence indicates that alterations in upper airway anatomy and disturbances in neuromuscular control both play a role in the pathogenesis of obstructive sleep apnea. We hypothesized that subjects without sleep apnea are more capable of mounting vigorous neuromuscular responses to upper airway obstruction than subjects with sleep apnea. To address this hypothesis we lowered nasal pressu...

  20. Acetylcholinesterase Clustering at the Neuromuscular Junction Involves Perlecan and Dystroglycan

    Peng, H. Benjamin; Xie, Hongbo; Rossi, Susanna G.; Rotundo, Richard L.

    1999-01-01

    Formation of the synaptic basal lamina at vertebrate neuromuscular junction involves the accumulation of numerous specialized extracellular matrix molecules including a specific form of acetylcholinesterase (AChE), the collagenic-tailed form. The mechanisms responsible for its localization at sites of nerve– muscle contact are not well understood. To understand synaptic AChE localization, we synthesized a fluorescent conjugate of fasciculin 2, a snake α-neurotoxin that tightly binds to the ca...

  1. Computed tomography of skeletal muscles in neuromuscular disease

    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.

  2. Neuromuscular impairment following backpack load carriage.

    Blacker, Sam D; Fallowfield, Joanne L; Bilzon, James L J; Willems, Mark E T

    2013-01-01

    Load Carriage using backpacks is an occupational task and can be a recreational pursuit. The aim of this study was to investigate the mechanisms responsible for changes in neuromuscular function of the m. quadriceps femoris following load carriage. The physiological responses of 10 male participants to voluntary and electrically stimulated isometric contractions were measured before and immediately after two hours of treadmill walking at 6.5 km•h(-1) during level walking with no load [LW], and level walking with load carriage (25 kg backpack) [LC]. Maximal voluntary contraction force decreased by 15 ± 11 % following LC (p=0.006), with no change following LW (p=0.292). Voluntary activation decreased after LW and LC (p=0.033) with no difference between conditions (p=0.405). Doublet contraction time decreased after both LW and LC (p=0.002), with no difference between conditions (p=0.232). There were no other changes in electrically invoked doublet parameters in either condition. The 20:50 Hz ratio did not change following LW (p=0.864) but decreased from 0.88 ± 0.04 to 0.84 ± 0.04 after LC (p=0.011) indicating reduced Ca2+ release from the sarcoplasmic reticulum during excitation contraction coupling. In conclusion, two hours of load carriage carrying a 25 kg back pack caused neuromuscular impairment through a decrease in voluntary activation (i.e. central drive) and fatigue or damage to the peripheral muscle, including impairment of the excitation contraction coupling process. This may reduce physical performance and increase the risk of musculoskeletal injury. PMID:24146709

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

    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

  4. LRP4 Is Critical for Neuromuscular Junction Maintenance

    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...

  5. Neuromuscular physiology of Hymenolepis diminuta and H. microstoma (Cestoda).

    Thompson, C S; Mettrick, D F

    1984-12-01

    The physiology of the neuromuscular systems in Hymenolepis diminuta and H. microstoma was studied in vitro using intact, adult worm and strips of worm body wall. Intact worms were insensitive to ionic changes in the in vitro buffering system. However, strips of body wall containing longitudinal muscles were extremely sensitive to ionic manipulation. In intact worms tension generated in the strobila had two components; small brief tension peaks up to 500 mg amplitude are superimposed on larger, longer peaks of up to 1200 mg amplitude. Removal of the scolex and neck region either failed to show significant changes in tension, or showed a reduction in amplitude but not of frequency. Muscle contraction of both H. diminuta and H. microstoma were qualitatively similar. In split-worm preparations the concentration of Ca2+ in the bathing solution significantly affected both spontaneous and evoked contractions in H. diminuta and H. microstoma; the addition of CaCl2 greatly reduced the amplitude and frequency of the contractions. The chloride salts of cobalt, barium, cadmium and manganese elicited prolonged contractions of the longitudinal musculature of both H. diminuta and H. microstoma. While CoCl2 was the most effective in stimulating muscle contraction, the magnitude of the response varied with the concentration of Ca2+ in the bath. The results indicate that peripheral inhibition is extremely important in cestode motor control and that extracellular calcium ions may regulate the peripheral inhibitory mechanisms. PMID:6440096

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

    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.

  7. Electrochemical biofilm control: mechanism of action

    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 ...

  8. Cotrel-Dubousset instrumentation in neuromuscular scoliosis.

    Piazzolla, Andrea; Solarino, G; De Giorgi, S; Mori, C M; Moretti, L; De Giorgi, G

    2011-05-01

    The study design is retrospective. The aim is to describe our experience about the treatment of patients with neuromuscular scoliosis (NMS) using Cotrel-Dubousset instrumentation. Neuromuscular scoliosis are difficult deformities to treat. A careful assessment and an understanding of the primary disease and its prognosis are essential for planning treatment which is aimed at maximizing function. These patients may have pelvic obliquity, dislocation of the hip, limited balance or ability to sit, back pain, and, in some cases, a serious decrease in pulmonary function. Spinal deformity is difficult to control with a brace, and it may progress even after skeletal maturity has been reached. Surgery is the main stay of treatment for selected patients. The goals of surgery are to correct the deformity producing a balanced spine with a level pelvis and a solid spinal fusion to prevent or delay secondary respiratory complications. The instrumented spinal fusion (ISF) with second-generation instrumentation (e.g., Luque-Galveston and unit rod constructs), are until 1990s considered the gold standard surgical technique for neuromuscular scoliosis (NMS). Still in 2008 Tsirikos et al. said that "the Unit rod instrumentation is a common standard technique and the primary instrumentation system for the treatment of pediatric patients with cerebral palsy and neuromuscular scoliosis because it is simple to use, it is considerably less expensive than most other systems, and can achieve good deformity correction with a low loss of correction, as well as a low prevalence of associated complications and a low reoperation rate." In spite of the Cotrel-Dubousset (CD) surgical technique, used since the beginning of the mid 1980s, being already considered the highest level achieved in correction of scoliosis by a posterior approach, Teli et al., in 2006, said that reports are lacking on the results of third-generation instrumentation for the treatment of NMS. Patients with neuromuscular

  9. Neuromuscular Highlights-AAN 2005.

    Cheema, Zahid; Saperstein, David; Jackson, Carolyn; Newman, Daniel

    2006-06-01

    Summary of Neuromuscular Presentations at the 57 Annual AAN 2005 meeting in Miami Florida on topics of Facioscapulohumeral muscular dystrophy (FSHD), Duchenne muscular dystrophy (DMD), Diabetic Neuropathy, Charco Marie Tooth disease (CMT), Comparison of injected steroids versus Surgery for carpal tunnel syndrome, Rituximab in Anti-MAG associated polyneuropathy, Cannabis based medicine (CBM) in the treatment of neuropathic pain, utility of skin biopsy with intraepidermal nerve fiber density (IENFD) in sensory complaints, comparing sympathetic skin responses (SSRs) and skin biopsy in diagnosing small fiber sensory neuropathy, Chronic inflammatory demyelinating polyneuropathy (CIDP) clinical and electrophysiologic predictors, affect of limb warming in mild ulnar nerve conduction study (NCS) abnormalities, Tamoxifen affect in ALS, open label study of 3,4 DAP, Pyridostigmine and Ephedrine in fast channel syndrome, Mexilitine as an antimyotonia treatment in myotonic dystrophy (DM1), frontal lobe impairment evaluation in DM1 and DM2 patients and phenotype-genotype correlation in patients with dysferlinopathy. PMID:19078809

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

    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

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

    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

  12. Replacement means for control rod drive mechanism

    Object: To permit assembling and removal operation of a control rod drive mechanism to be carried out speedily and properly irrespective of the degree of skill of the operating personnel. Structure: When removing a control rod drive mechanism (CRD) a service platform and a frame body are operated for bringing a CRD lift guide frame to a position below the CRD to be removed. Then, a CRD receptacle is placed at the lower end of the CRD, and water is drained from the CRD. Subsequently, a chain is driven by a drive means in a direction which lowers the receptacle, and only the CRD is lowered along the CRD lift guide frame. Thereafter, the CRD is secured at its upper portion by a support means, and the CRD lift guide frame is lowered by a lift jack to thereby permit revolution of the CRD, The CRD lift frame after revolution is lifted and then removed to the outside. (Kamimura, M.)

  13. Mechanical Control of Individual Superconducting Vortices.

    Kremen, Anna; Wissberg, Shai; Haham, Noam; Persky, Eylon; Frenkel, Yiftach; Kalisky, Beena

    2016-03-01

    Manipulating individual vortices in a deterministic way is challenging; ideally, manipulation should be effective, local, and tunable in strength and location. Here, we show that vortices respond to local mechanical stress applied in the vicinity of the vortex. We utilized this interaction to move individual vortices in thin superconducting films via local mechanical contact without magnetic field or current. We used a scanning superconducting quantum interference device to image vortices and to apply local vertical stress with the tip of our sensor. Vortices were attracted to the contact point, relocated, and were stable at their new location. We show that vortices move only after contact and that more effective manipulation is achieved with stronger force and longer contact time. Mechanical manipulation of vortices provides a local view of the interaction between strain and nanomagnetic objects as well as controllable, effective, and reproducible manipulation technique. PMID:26836018

  14. Control rod drive mechanisms seismic analysis

    In the Taishan joint-design, in order to finish Control Rod Drive Mechanism (CRDM) seismic analysis, a response spectrum analysis in combination with quasi-static analysis and a time history analysis are performed according to the different design stages and inputs. The simulated and simplified model of nonlinear structure is studied in the basic design stage; the translation of seismic input data and the use of nonlinear elements are studied in the detailed design stage. (authors)

  15. Concurrency Control Mechanism of Complex Objects

    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.

  16. Control mechanisms for assuring better IS quality:

    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 ...

  17. Development of Mechanical Water Level Controller

    Akonyi Nasiru Sule; Chinedu Cletus Obinwa; Christian Ebele Okekeze; Eyo Ifreke

    2012-01-01

    The automatic water level controller is a device designed to regulate automatically the pumping of water to an overhead tank without allowing the water in the tank to be exhausted. The design of this mechanical device was achieved using the Archimedes principle of floatation; having a float which determines the water level in the tank depending on the choice of the minimum (lower) and maximum (upper) level inscribed in the tank. The fundamental attribute of this device is the ease in design, ...

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

    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.

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

    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.

  20. Tracheal intubation without neuromuscular block in children

    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...

  1. Pelvic fixation for neuromuscular scoliosis deformity correction

    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...

  2. Neuromuscular Electrical Stimulation for Skeletal Muscle Function

    Doucet, Barbara M.; Lam, Amy; Griffin, Lisa

    2012-01-01

    Lack of neural innervation due to neurological damage renders muscle unable to produce force. Use of electrical stimulation is a medium in which investigators have tried to find a way to restore movement and the ability to perform activities of daily living. Different methods of applying electrical current to modify neuromuscular activity are electrical stimulation (ES), neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and functional electrical ...

  3. New Interference Mechanism Controls Ultracold Chemistry

    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.).

  4. Gain control mechanisms in the nociceptive system.

    Treede, Rolf-Detlef

    2016-06-01

    The "gate control theory of pain" of 1965 became famous for integrating clinical observations and the understanding of spinal dorsal horn circuitry at that time into a testable model. Although it became rapidly clear that spinal circuitry is much more complex than that proposed by Melzack and Wall, their prediction of the clinical efficacy of transcutaneous electrical nerve stimulation and spinal cord stimulation has left an important clinical legacy also 50 years later. In the meantime, it has been recognized that the sensitivity of the nociceptive system can be decreased or increased and that this "gain control" can occur at peripheral, spinal, and supraspinal levels. The resulting changes in pain sensitivity can be rapidly reversible or persistent, highly localized or widespread. Profiling of spatio-temporal characteristics of altered pain sensitivity (evoked pain to mechanical and/or heat stimuli) allows implications on the mechanisms likely active in a given patient, including peripheral or central sensitization, intraspinal or descending inhibition. This hypothesis generation in the diagnostic process is an essential step towards a mechanism-based treatment of pain. The challenge now is to generate the rational basis of multimodal pain therapy algorithms by including profile-based stratification of patients into studies on efficacy of pharmacological and nonpharmacological treatment modalities. This review outlines the current evidence base for this approach. PMID:26817644

  5. Control mechanisms in mitochondrial oxidative phosphorylation

    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.

  6. PICU EXTUBATION FAILURE: THE ROLE OF NEUROMUSCULAR DISORDERS

    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

  7. Urgencias en patología neuromuscular Emergencies in neuromuscular pathology

    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. Gain control mechanisms in spinal motoneurons

    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.

  9. Neuromuscular Adaptations to Reduced Use

    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.

  10. Splicing therapy for neuromuscular disease.

    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

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

    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

  12. Dynamic congestion control mechanisms for MPLS networks

    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.

  13. Electrochemical biofilm control: mechanism of action.

    Istanbullu, Ozlem; Babauta, Jerome; Duc Nguyen, Hung; 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 (H(2)O(2)) on metal surfaces. However, there are literature studies in which H(2)O(2) could not be detected in the bulk solution. This is most likely because H(2)O(2) was produced at a low concentration near the surface and could not be detected in the bulk solution. The goals of this research were (1) to develop a well-controlled system to explain the mechanism of action of the bioelectrochemical effect on 316L stainless steel (SS) surfaces and (2) to test whether the produced H(2)O(2) can reduce cell growth on metal surfaces. It was found that H(2)O(2) was produced near 316L SS surfaces when a negative potential was applied. The H(2)O(2) concentration increased towards the surface, while the dissolved oxygen decreased when the SS surface was polarized to -600 mV(Ag/AgCl). When polarized and non-polarized surfaces with identical Pseudomonas aeruginosa PAO1 biofilms were continuously fed with air-saturated growth medium, the polarized surfaces showed minimal biofilm growth while there was significant biofilm growth on the non-polarized surfaces. Although there was no detectable H(2)O(2) in the bulk solution, it was found that the surface concentration of H(2)O(2) was able to prevent biofilm growth. PMID:22827804

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

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

    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.

  16. Discrete Mechanics and Optimal Control: an Analysis

    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...

  17. Employment profiles in neuromuscular diseases.

    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

  18. Tracheal intubation without neuromuscular block in children

    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.

  19. Mechanism and control of lake eutrophication

    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

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

    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. Research highlights of partial neuromuscular disorders

    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

  2. Cellular Mechanisms of Ciliary Length Control

    Jacob Keeling

    2016-01-01

    Full Text Available Cilia and flagella are evolutionarily conserved, membrane-bound, microtubule-based organelles on the surface of most eukaryotic cells. They play important roles in coordinating a variety of signaling pathways during growth, development, cell mobility, and tissue homeostasis. Defects in ciliary structure or function are associated with multiple human disorders called ciliopathies. These diseases affect diverse tissues, including, but not limited to the eyes, kidneys, brain, and lungs. Many processes must be coordinated simultaneously in order to initiate ciliogenesis. These include cell cycle, vesicular trafficking, and axonemal extension. Centrioles play a central role in both cell cycle progression and ciliogenesis, making the transition between basal bodies and mitotic spindle organizers integral to both processes. The maturation of centrioles involves a functional shift from cell division toward cilium nucleation which takes place concurrently with its migration and fusion to the plasma membrane. Several proteinaceous structures of the distal appendages in mother centrioles are required for this docking process. Ciliary assembly and maintenance requires a precise balance between two indispensable processes; so called assembly and disassembly. The interplay between them determines the length of the resulting cilia. These processes require a highly conserved transport system to provide the necessary substances at the tips of the cilia and to recycle ciliary turnover products to the base using a based microtubule intraflagellar transport (IFT system. In this review; we discuss the stages of ciliogenesis as well as mechanisms controlling the lengths of assembled cilia.

  3. EXERCISE ENHANCING CALCIUM ABSORPTION MECHANISM

    Muliani

    2013-01-01

    Calcium has important role in many biological processes therefore calcium homeostasis should be maintained. Imbalance in calcium homeostasis would affects the bone metabolism, neuromuscular function, blood coagulation, cell proliferation and signal transduction. Homeostasis of calcium is maintained by three major organs: gastrointestinal tract, bone and kidney. Intestinal calcium absorption is the sole mechanism to supply calcium to the body. Calcium absorption controlled by calcitropic hormo...

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

    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

  5. Neuromuscular hamartoma arising in the brachial plexus

    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.)

  6. Neuromuscular hamartoma arising in the brachial plexus

    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.)

  7. Pregnancy and Childbirth with Neuromuscular Disease

    ... 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. ( ...

  8. Spin-controlled mechanics in nanoelectromechanical systems

    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

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

    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

  10. Neuromuscular function in different stages of sarcopenia.

    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

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

    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

  12. Controlled Unusual Stiffness of Mechanical Metamaterials

    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.

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

    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.

  14. Robust Position Control of Electro-mechanical Systems

    Rong Mei; Mou Chen

    2013-01-01

    In this work, the robust position control scheme is proposed for the electro-mechanical system using the disturbance observer and backstepping control method. To the external unknown load of the electro-mechanical system, the nonlinear disturbance observer is given to estimate the external unknown load. Combining the output of the developed nonlinear disturbance observer with backstepping technology, the robust position control scheme is proposed for the electro-mechanical system. The stabili...

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

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

    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.

  17. Critical length scale controls adhesive wear mechanisms

    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.

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

    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.

  19. Control Engineering Analysis of Mechanical Pitch Systems

    With the help of a local stability analysis the coefficient range of a discrete damper, used for centrifugal forced, mechanical pitch system of small wind turbines (SWT), is gained for equilibrium points. – By a global stability analysis the gained coefficient range can be validated. An appropriate approach by Takagi-Sugeno is presented in the paper

  20. Desarrollo neuromuscular en la atrofia muscular espinal

    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...

  1. Splicing therapy for neuromuscular disease ☆

    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...

  2. The emerging diversity of neuromuscular junction disorders

    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...

  3. Acute neuromuscular responses to car racing

    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...

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

    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 ...

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

    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.

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

    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. Influence of intense neuromuscular blockade on surgical conditions during laparotomy

    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...... influence the force needed to close the fascia....

  8. Urgencias en patología neuromuscular Emergencies in neuromuscular pathology

    T. Ayuso; I. Jericó

    2008-01-01

    La debilidad muscular aguda (DMA) es el síntoma predominante de las urgencias neuromusculares, especialmente si afecta a la musculatura respiratoria u orofaríngea. La DMA es un síndrome plurietiológico y con distintos niveles lesionales en la unidad motora. Dentro del amplio grupo de enfermedades neuromusculares, las que con mayor frecuencia provocan DMA e insuficiencia respiratoria son el síndrome de Guillain-Barré (SGB) y la miastenia gravis (MG). El SGB constituye la causa más frecuente de...

  9. Quality control of cadweld (mechanical) splices

    Test data for cadweld splicing of reinforcing steel collected during a study of quality assurance practices on nine nuclear power plant construction projects are presented and evaluated. These data lead to an important hypothesis that the visual inspection identifies procedural deficiencies, and the tensile test identifies material defects. It is also suggested that a material testing program and the visual inspection will detect essentially all substandard cadwell splices. This would permit the deletion of the expensive tensile testing program. Accordingly, most quality control programs require overtesting and overdocumentation of cadweld splices; and furthermore, these programs fail to recognize material defects. The project specifications and quality control requirements for the nine projects are compared. Where possible, these are evaluated against the industry standards and Federal regulations. It is shown that there are a number of deficiencies in these standards, and that in most cases, the testing requirements are not commensurate with the quality that is being achieved in the field

  10. Cutaneous mechanisms of isometric ankle force control

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

    2013-01-01

    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...... 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....

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

    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.

  12. Modeling and control of vibration in mechanical structures

    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...

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

    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)

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

    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.

  15. Control of Drop Motion by Mechanical Vibrations

    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.

  16. Novel Mechanism Control Algorithm for Wired Network

    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.

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

    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....

  18. Urgent epidemic control mechanism for aviation networks

    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.

  19. EFFECTIVENESS OF NEUROMUSCULAR TRAINING FOR BASKET BALL PLAYERS ON PERFORMANCE OF STAR EXCURSION BALANCE TEST

    Bhargava Kumar Bhaskar; Vinod Babu. K *; Sai Kumar. N; Vikas Kadam V

    2013-01-01

    Background and introduction:To determine the effect of neuromuscular training program (NMTP) focused oncore stability and lower extremity strength on performance of star excursion balance test (SEBT) inbasketballplayers.Method:: Pre to post test experimental study design randomisedthirty Basketball players each 15 into NMTPand control group. Players trained together as a team in which NMTP group participated 4 weeks of NMTPtwice a week and Control group followed their regular protocol as guid...

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

    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...

  1. Mechanisms controlling radionuclide mobility in forest soils

    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)

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

    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.

  3. Mechanisms of using mutations in pest control

    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)

  4. A feedback inclusive neuromuscular training program alters frontal plane kinematics.

    Greska, Eric K; Cortes, Nelson; Van Lunen, Bonnie L; Oñate, James A

    2012-06-01

    Anterior cruciate ligament (ACL) neuromuscular training programs have demonstrated beneficial effects in reducing ACL injuries, yet further evaluation of their effects on biomechanical measures across a sports team season is required to elucidate the specific factors that are modifiable. The purpose of this study was to evaluate the effects of a 10-week off-season neuromuscular training program on lower extremity kinematics. Twelve Division I female soccer players (age: 19.2 ± 0.8 years, height: 1.67 ± 0.1 m, weight: 60.2 ± 6.5 kg) performed unanticipated dynamic trials of a running stop-jump task pretraining and posttraining. Data collection was performed using an 8-camera Vicon system (Los Angeles, CA, USA) and 2 Bertec (Columbus, OH, USA) force plates. The 10-week training program consisted of resistance training 2 times per week and field training, consisting of plyometric, agility, and speed drills, 2 times per week. Repeated measures analyses of variance (ANOVAs) were used to assess the differences between pretraining and posttraining kinetics and kinematics of the hip, knee, and ankle at initial contact (IC), peak knee flexion (PKF), and peak stance. Repeated measures ANOVAs were also used to assess isometric strength differences pretraining and posttraining. The alpha level was set at 0.05 a priori. The training program demonstrated significant increases in left hip extension, left and right hip flexion, and right hip adduction isometric strength. At IC, knee abduction angle moved from an abducted to an adducted position (-1.48 ± 3.65° to 1.46 ± 3.86°, p = 0.007), and hip abduction angle increased (-6.05 ± 4.63° to -10.34 ± 6.83°, p = 0.007). Hip abduction angle at PKF increased (-2.23 ± 3.40° to 6.01 ± 3.82°, p = 0.002). The maximum knee extension moment achieved at peak stance increased from pretraining to posttraining (2.02 ± 0.32 to 2.38 ± 0.75 N·m·kg⁻¹, p = 0.027). The neuromuscular training program demonstrated a potential

  5. Mechanical systems a unified approach to vibrations and controls

    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 ...

  6. Acute neuromuscular weakness associated with dengue infection

    Harmanjit Singh Hira

    2012-01-01

    Full Text Available Background: Dengue infections may present with neurological complications. Whether these are due to neuromuscular disease or electrolyte imbalance is unclear. Materials and Methods: Eighty-eight patients of dengue fever required hospitalization during epidemic in year 2010. Twelve of them presented with acute neuromuscular weakness. We enrolled them for study. Diagnosis of dengue infection based on clinical profile of patients, positive serum IgM ELISA, NS1 antigen, and sero-typing. Complete hemogram, kidney and liver functions, serum electrolytes, and creatine phosphokinase (CPK were tested. In addition, two patients underwent nerve conduction velocity (NCV test and electromyography. Results: Twelve patients were included in the present study. Their age was between 18 and 34 years. Fever, myalgia, and motor weakness of limbs were most common presenting symptoms. Motor weakness developed on 2 nd to 4 th day of illness in 11 of 12 patients. In one patient, it developed on 10 th day of illness. Ten of 12 showed hypokalemia. One was of Guillain-Barré syndrome and other suffered from myositis; they underwent NCV and electromyography. Serum CPK and SGOT raised in 8 out of 12 patients. CPK of patient of myositis was 5098 IU. All of 12 patients had thrombocytopenia. WBC was in normal range. Dengue virus was isolated in three patients, and it was of serotype 1. CSF was normal in all. Within 24 hours, those with hypokalemia recovered by potassium correction. Conclusions: It was concluded that the dengue virus infection led to acute neuromuscular weakness because of hypokalemia, myositis, and Guillain-Barré syndrome. It was suggested to look for presence of hypokalemia in such patients.

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

    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. PMID:25663251

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

    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

  9. Analysis and Comparison of Access Control Policies Validation Mechanisms

    Muhammad Aqib; Riaz Ahmed Shaikh

    2014-01-01

    Validation and verification of security policies is a critical and important task to ensure that access control policies are error free. The two most common problems present in access control policies are: inconsistencies and incompleteness. In order to detect such problems, various access control policy validation mechanisms are proposed by the researchers. However, comprehensive analysis and evaluation of the existing access control policy validation techniques is missing in the literature....

  10. Recent achievements in restorative neurology: Progressive neuromuscular diseases

    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

  11. Stress in Families of Children With Neuromuscular Disease.

    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.…

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

    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.

  13. Repetitive Daily Point of Choice Prompts and Occupational Sit-Stand Transfers, Concentration and Neuromuscular Performance in Office Workers: An RCT

    Lars Donath; Oliver Faude; Yannick Schefer; Ralf Roth; Lukas Zahner

    2015-01-01

    Objective: Prolonged office sitting time adversely affects neuromuscular and cardiovascular health parameters. As a consequence, the present study investigated the effects of prompting the use of height-adjustable working desk (HAWD) on occupational sitting and standing time, neuromuscular outcomes and concentration in office workers. Methods: A single-blinded randomized controlled trial (RCT) with parallel group design was conducted. Thirty-eight office workers were supplied with HAWDs and r...

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

    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, ...

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

    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.

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

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

    Occupational Therapy, Bergen University College, Bergen, Norway 3National Research Centre for the Working Environment, Copenhagen, DK E-mail: cmlarsen@health.sdu.dk AIMS: The aims were to understand potential mechanisms for impairment in the neuromuscular function of the scapular stabilisers in a general...... with SIS, however, SIS patients may benefit from biofeedback training. Lastly, these results indicate that very few clinical assessment methods have sufficient clinimetric properties that can be recommended for clinical use....

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

    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...

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

    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...

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

    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.

  20. Analysis and Comparison of Access Control Policies Validation Mechanisms

    Muhammad Aqib

    2014-12-01

    Full Text Available Validation and verification of security policies is a critical and important task to ensure that access control policies are error free. The two most common problems present in access control policies are: inconsistencies and incompleteness. In order to detect such problems, various access control policy validation mechanisms are proposed by the researchers. However, comprehensive analysis and evaluation of the existing access control policy validation techniques is missing in the literature. In this paper, we have provided a first detailed survey of this domain and presented the taxonomy of the access control policy validation mechanisms. Furthermore, we have provided a qualitative comparison and trend analysis of the existing schemes. From this survey, we found that only few validation mechanisms exist that can handle both inconsistency and incompleteness problem. Also, most of the policy validation techniques are inefficient in handling continuous values and Boolean expressions.

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

    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.

  2. Electrophysiological study in neuromuscular junction disorders.

    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

  3. Electrophysiological study in neuromuscular junction disorders

    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.

  4. Neuromuscular imaging in inherited muscle diseases

    Wattjes, Mike P. [VU University Medical Center, Department of Radiology, De Boelelaan 1117, HV, Amsterdam (Netherlands); Kley, Rudolf A. [Klinken Bergmannsheil, Ruhr-University, Department of Neurology, Neuromuscular Centre Ruhrgebiet, Bochum (Germany); Fischer, Dirk [University Hospital of Basel, Department of Neurology, Basel (Switzerland); University Children' s Hospital Basel, Department of Neuropaediatrics, Basel (Switzerland)

    2010-10-15

    Driven by increasing numbers of newly identified genetic defects and new insights into the field of inherited muscle diseases, neuromuscular imaging in general and magnetic resonance imaging (MRI) in particular are increasingly being used to characterise the severity and pattern of muscle involvement. Although muscle biopsy is still the gold standard for the establishment of the definitive diagnosis, muscular imaging is an important diagnostic tool for the detection and quantification of dystrophic changes during the clinical workup of patients with hereditary muscle diseases. MRI is frequently used to describe muscle involvement patterns, which aids in narrowing of the differential diagnosis and distinguishing between dystrophic and non-dystrophic diseases. Recent work has demonstrated the usefulness of muscle imaging for the detection of specific congenital myopathies, mainly for the identification of the underlying genetic defect in core and centronuclear myopathies. Muscle imaging demonstrates characteristic patterns, which can be helpful for the differentiation of individual limb girdle muscular dystrophies. The aim of this review is to give a comprehensive overview of current methods and applications as well as future perspectives in the field of neuromuscular imaging in inherited muscle diseases. We also provide diagnostic algorithms that might guide us through the differential diagnosis in hereditary myopathies. (orig.)

  5. 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

    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...

  6. System defense mechanisms in nuclear power generation control computers

    Dual-redundant computers are used to control and monitor the production of power from Ontario Hydro's nuclear power reactors. Each computer must have the capability of monitoring its own performance and detecting faults. Upon fault detection, each computer must initiate corrective responses to ensure the integrity of critical control functions. This paper reviews those features the authors have termed system defense mechanisms

  7. Soft Time-Suboptimal Controlling Structure for Mechanical Systems

    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....

  8. Improving Network Performance by Ameliorating TCP Congestion Control Mechanism

    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.

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

    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 ...

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

    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 ...

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

    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...

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

    Pageaux, Benjamin; Marcora, Samuele; Lepers, Romuald

    2013-01-01

    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 cognitive tasks lasted 90...

  13. The effects of band exercise using proprioceptive neuromuscular facilitation on muscular strength in lower extremity

    Rhyu, Hyun-seung; Kim, Su-Hyun; Park, Hye-Sang

    2015-01-01

    The purpose of this study was to examine whether a six-week elastic band exercise program using proprioceptive neuromuscular facilitation (PNF) can increase isotonic strength of abductor muscles in the lower extremity. Twenty-eight healthy students from S university were divided into an experimental group and control group. Each group was participated in pre and post-measurement in isotonic strength using an isotonic analyzer, En-treeM. Experimental group performed elastic band exercise using...

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

    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.

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

    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.

  16. Evaluation of skeletal muscular involvement in neuromuscular disorders with thallium-201 whole body scintigraphy

    The extent as well as severity of pathologic changes of skeletal muscles were analyzed with thallium-201 whole body scintigraphy (WBS) in 29 cases of various types of neuromuscular diseases (18 cases of myogenic and 11 cases of neurogenic muscular diseases) and 14 cases of normal controls. After intravenous injection of 2 mCi of thallium-201 chloride, WBS was performed for 15 minutes using a gamma camera with twin-opposed large rectangular detectors. Counts at brachia, forearms, thighs, and calves were assessed after reconstruction of the scintigram of the whole body by taking the geometric mean of the anterior and posterior data. WBS showed uniform tracer activities in the 4 extremities in 12 cases among 14 controls. Laterality in distribution of counts of both legs and arms was noted in the remaining 2 controls. WBS revealed decrease of perfusion in the extremities with muscular atrophy and/or weakness in neuromuscular diseases. The overall diagnostic accuracy of WBS for evaluation of skeletal muscle involvement was 75 to 80 % except for the bilateral brachia for which it decreased to 65 %. All of the three cases of muscular dystrophy with pseudohypertrophy of the calves or thighs showed unequivocal decrease of perfusion of those regions in WBS. In conclusion, thallium-201 WBS was considered to be a useful clinical means in evaluating the extent and severity of muscular involvement of various types of neuromuscular disorders. (author)

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

    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.

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

    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.

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

    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.

  20. Molecular Mechanisms Controlling the Early Mouse Embryo Development

    Alexandra Ivan

    2010-05-01

    Full Text Available Few are known about the molecular mechanism controlling the early embryo development. The reduce dimension of the embryos, only a few μm, the small quantities of proteins synthesized and the artificial environment influence makes difficult to decode the mechanisms controlling early embryonic stages of development. Although, in the last few years many genes have been showed to be active in the early embryonic stages of development, only a few have been characterized and found to be implicated in the molecular mechanism responsible of preimplantational embryos development. Ped gene (Preimplantational embryo development is considered to be involved in regulation of embryonic cleavage division and subsequent embryo survival. This review presents, based on a rich documentation, the main mechanisms involved in early embryo development.

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

    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

  2. Controlling disease spread on networks with feedback mechanism

    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.

  3. Activation of fast skeletal muscle troponin as a potential therapeutic approach for treating neuromuscular diseases

    Russell, Alan J.; Hartman, James J.; Hinken, Aaron C; Muci, Alexander R; Kawas, Raja; Driscoll, Lena; Godinez, Guillermo; Lee, Kenneth H; Marquez, David; Browne, William F; Chen, Michael M.; Clarke, David; Collibee, Scott E; Garard, Marc; Hansen, Richard

    2012-01-01

    Limited neuromuscular input results in muscle weakness in neuromuscular disease either because of a reduction in the density of muscle innervation, the rate of neuromuscular junction activation or the efficiency of synaptic transmission 1 . We developed a small molecule fast skeletal troponin activator, CK-2017357, as a means to increase muscle strength by amplifying the response of muscle when neuromuscular input is diminished secondary to a neuromuscular disease. Binding selectively to the ...

  4. Neuromuscular synaptogenesis: coordinating partners with multiple functions.

    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

  5. Anormalidades neuromuscular no desuso, senilidade e caquexia

    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;...

  6. Prevalence of complications in neuromuscular scoliosis surgery

    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...... 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...... have moderate to high variability. The studies were heterogeneous in methodology and outcome types, which are plausible explanations for the variability; sensitivity analysis with respect to age at surgery, sample size, publication year and diagnosis could also partly explain this variability. In...

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

    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.

  8. [What are the effects of the aging of the neuromuscular system on postural stability?].

    Cattagni, Thomas; Scaglioni, Gil; Cornu, Christophe; Berrut, Gilles; Martin, Alain

    2015-12-01

    Aging is frequently associated with a decreased postural stability, essentially after 60 years, leading to an increased risk of falling. In this article we propose to highlight the influence of the aging of the neuromuscular system on postural stability when standing upright. To maintain balance while standing upright, human needs to control the activity of ankle muscles and particularly the plantar flexors. During the aging process, the performance of these muscles are strongly altered. It is commonly observed large deficits in elderly people with history of falls. Some authors reported an inverse correlation between the amplitude of postural sway and the capacity of force production of ankle muscles suggesting that the assessment of neuromuscular function could be an index of postural stability or even of the falling risk. Finally, enhance the strength of ankle muscles in elderly through physical exercise could be an adequate intervention to improve postural stability and reduce the incidence of falls. PMID:26707554

  9. Combination of the Sorting Line Priority Polling Control Mechanism

    Wenxue Ran

    2013-10-01

    Full Text Available The paper proposed the priority polling control mechanism of the unit material combinations sorting lines, and sorters operating process is understood to be the arrival process of orders, service process of each sorter sorts orders and the conversion process between sorting machines. Control process, sorters of the combined sorting lines are divided into the priority sorters and ordinary sorters, priority sorters use full service control, ordinary sorters use limited service (k = 1, applies the polling service system theory, through the embedded Markov chain and probability generating function to establish the mathematical model of the system, the exact solution of the control mechanism of the polling system model and the first and second characteristic parameters, combined with the actual production priority parameters of orders picking for simulation analysis

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

    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.

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

    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

  12. Quality control of injection moulded micro mechanical parts

    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. Designing Crane Controls with applied Mechanical and Electrical Safety Features

    Lytle, Bradford P.; Walczak, Thomas A.; Delgado, H. (Technical Monitor)

    2002-01-01

    The use of overhead traveling bridge cranes in many varied applications is common practice. In particular, the use of cranes in the nuclear, military, commercial, aerospace, and other industries can involve safety critical situations. Considerations for Human Injury or Casualty, Loss of Assets, Endangering the Environment, or Economic Reduction must be addressed. Traditionally, in order to achieve additional safety in these applications, mechanical systems have been augmented with a variety of devices. These devices assure that a mechanical component failure shall reduce the risk of a catastrophic loss of the correct and/or safe load carrying capability. ASME NOG-1-1998, (Rules for Construction of Overhead and Gantry Cranes, Top Running Bridge, and Multiple Girder), provides design standards for cranes in safety critical areas. Over and above the minimum safety requirements of todays design standards, users struggle with obtaining a higher degree of reliability through more precise functional specifications while attempting to provide "smart" safety systems. Electrical control systems also may be equipped with protective devices similar to the mechanical design features. Demands for improvement of the cranes "control system" is often recognized, but difficult to quantify for this traditionally "mechanically" oriented market. Finite details for each operation must be examined and understood. As an example, load drift (or small motions) at close tolerances can be unacceptable (and considered critical). To meet these high functional demands encoders and other devices are independently added to control systems to provide motion and velocity feedback to the control drive. This paper will examine the implementation of Programmable Electronic Systems (PES). PES is a term this paper will use to describe any control system utilizing any programmable electronic device such as Programmable Logic Controllers (PLC), or an Adjustable Frequency Drive (AID) 'smart' programmable

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

    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. Mechanical Control of Graphene on Engineered Pyramidal Strain Arrays

    Gill, Stephen T.; Hinnefeld, John H.; Zhu, Shuze; Swanson, William T.; Li, Teng; Mason, Nadya

    2015-01-01

    Strain can tune desirable electronic behavior in graphene, but there has been limited progress in controlling strain in graphene devices. In this paper, we study the mechanical response of graphene on substrates patterned with arrays of mesoscale pyramids. Using atomic force microscopy, we demonstrate that the morphology of graphene can be controlled from conformal to suspended depending on the arrangement of pyramids and the aspect ratio of the array. Non-uniform strains in graphene suspende...

  16. Pole assignment for control of flexible link mechanisms

    Ouyang, H.; Richiedei, D.; Trevisani, A.

    2013-06-01

    Although the dynamics of flexible link mechanisms and manipulators is nonlinear, motion and vibration control often relies on linear or piecewise-linear controllers based on linearized models in order to ensure real-time implementability. Keeping such an objective in mind, this paper proposes a general receptance-based method for pole assignment in flexible link mechanisms with a single rigid-body degree of freedom (dof) using a single control force (i.e. rank-one control). A chief advantage of the approach proposed is that it makes use of the second-order system model representation through the receptance matrix of the symmetric part of the asymmetric model. The asymmetric terms in the stiffness and damping matrices arise from the coupling between rigid-body motion and elastic motion. The proposed receptance-based formulation ensures numerical reliability and efficiency also for large dimensional and ill-conditioned system models originating from the simultaneous presence of high-frequency and weakly controllable oscillating modes, and of rigid-body motion low-frequency dynamics, which may also be unstable. The validation of the proposed technique is carried out by performing pole assignment through position and velocity feedback or acceleration and velocity feedback on a mechanism. Integral control is also introduced to improve the steady state system response. Numerical results indicate that the proposed method is more accurate and robust than two popular established methods.

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

    Elias, Leonardo Abdala; Watanabe, Renato Naville; Kohn, André Fabio

    2014-11-01

    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 on the

  18. Spinal Mechanisms May Provide a Combination of Intermittent and Continuous Control of Human Posture: Predictions from a Biologically Based Neuromusculoskeletal Model

    Elias, Leonardo Abdala; Watanabe, Renato Naville; Kohn, André Fabio

    2014-01-01

    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 on the

  19. An examination of neuromuscular and metabolic fatigue thresholds

    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)

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

    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

  1. [Neuromuscular relaxation and CCMDP. The Zilgrei and Feldenkrais methods 2].

    Santoro, F; Maiorana, C; Faccin, C

    1989-10-31

    The Authors show two neuromuscular release methods employed in the treatment of cranio-cervico-mandibular syndrome; these methods work at the place of origin of the pathology resolving the symptoms in different districts of the body. PMID:2701432

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

    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.

  3. Improvement Research of Control Rod Drive Mechanism in CARR

    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

  4. Fluid Mechanics of Wing Adaptation for Separation Control

    Chandrasekhara, M. S.; Wilder, M. C.; Carr, L. W.; Davis, Sanford S. (Technical Monitor)

    1997-01-01

    The unsteady fluid mechanics associated with use of a dynamically deforming leading edge airfoil for achieving compressible flow separation control has been experimentally studied. Changing the leading edge curvature at rapid rates dramatically alters the flow vorticity dynamics which is responsible for the many effects observed in the flow.

  5. Control rod drive mechanism test program. Revision 3

    A description is given of the testing and development of three control rod drive mechanisms for use on commercial PWR plants designed by B and W. The test results indicate that all three drives are reliable and ensure safe, dependable reactor operation

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

    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.

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

    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...

  8. Hexosamine Biosynthetic Pathway Mutations Cause Neuromuscular Transmission Defect

    Senderek, Jan; Müller, Juliane S.; Dusl, Marina; Strom, Tim M.; Guergueltcheva, Velina; Diepolder, Irmgard; Laval, Steven H.; Maxwell, Susan; Cossins, Judy; Krause, Sabine; Muelas, Nuria; Vilchez, Juan J.; Colomer, Jaume; Mallebrera, Cecilia Jimenez; Nascimento, Andres

    2011-01-01

    Neuromuscular junctions (NMJs) are synapses that transmit impulses from motor neurons to skeletal muscle fibers leading to muscle contraction. Study of hereditary disorders of neuromuscular transmission, termed congenital myasthenic syndromes (CMS), has helped elucidate fundamental processes influencing development and function of the nerve-muscle synapse. Using genetic linkage, we find 18 different biallelic mutations in the gene encoding glutamine-fructose-6-phosphate transaminase 1 (GFPT1)...

  9. Degeneration of Neuromuscular Junction in Age and Dystrophy

    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...

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

    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

  11. The Effect of Headquarter Integration Mechanisms on Subsidiaries’ New Product Success: From Control to Coordination Mechanism

    Firmanzah

    2007-10-01

    Full Text Available New product launching (NPL to the local market by subsidiary managers is a strategic activity, which requires organizational supports from MNC global network. The NPL activity is marked by high level of uncertainty, risk, and market failure. Thus, a headquarter needs to integrate the subsidiary NPL into global strategy. There are two mechanisms to integrate subsidiaries’ activities during NPL process; coordination and control process. By testing the effect of each mechanism on role clarity and functional conflict, I found that coordination mechanism increase role clarity between headquarter and subsidiaries’ managers. In contrast, exercising control mechanism reduces role clarity and functional conflict between headquarter and subsidiaries’ managers during NPL. This research shows that both role clarity and functional conflict increase new product commercial performance introduced by subsidiary in the local market.

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

    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.

  13. Sliding mode control on electro-mechanical systems

    Utkin Vadim I.

    2002-01-01

    Full Text Available The first sliding mode control application may be found in the papers back in the 1930s in Russia. With its versatile yet simple design procedure the methodology is proven to be one of the most powerful solutions for many practical control designs. For the sake of demonstration this paper is oriented towards application aspects of sliding mode control methodology. First the design approach based on the regularization is generalized for mechanical systems. It is shown that stability of zero dynamics should be taken into account when the regular form consists of blocks of second-order equations. Majority of applications in the paper are related to control and estimation methods of automotive industry. New theoretical methods are developed in the context of these studies: sliding made nonlinear observers, observers with binary measurements, parameter estimation in systems with sliding mode control.

  14. Recovery from mivacurium-induced neuromuscular blockade is not affected by anticonvulsant therapy.

    Jellish, W S; Thalji, Z; Brundidge, P K; Tempelhoff, R

    1996-01-01

    Long-term chronic anticonvulsant therapy produces a resistance to the effects of all nondepolarizing neuromuscular blocking agents studied to date. Since the metabolism of mivacurium is unique among the nondepolarizing neuromuscular blocking agents, the effect of anticonvulsants on its recovery parameters was examined. Forty-five patients were separated into three groups based on the number of chronic anticonvulsant medications the subjects were taking: subjects in group 1, the control group, took no anticonvulsant medication; group 2 subjects took one medication; and group 3 subjects took two medications. Mivacurium, 0.15 mg/kg i.v., was administered after induction of general anesthesia with thiopental sodium, 4-6 mg/kg, and fentanyl 2-4 micrograms/kg i.v. Maintenance anesthesia consisted of N2O in O2. 0.2-0.3% end-tidal isoflurane, and a fentanyl infusion. The evoked compound electromyograph (ECEMG) of the adductor pollicis-brevis muscle was measured for time of onset, T-1 (time at which ECEMG signal reaches 5, 25, 50, and 75% of baseline), TR (TOF ratio), and recovery index. T-1 at 25% was 18.2 +/- 1.8, 20.7 +/- 1.9, and 21.5 +/- 1.4 min for groups 1, 2, and 3, respectively, with TR at 25% being 23.7 +/- 2.3, 26.9 +/- 2.4, and 27.3 +/- 2.3 min. No significant differences were noted in neuromuscular recovery between groups at any time point. These results fail to demonstrate the resistance to the nondepolarizing neuromuscular blockade of mivacurium that has been observed with other nondepolarizing agents. PMID:8719185

  15. Obesity and upper airway control during sleep

    Schwartz, Alan R.; Patil, Susheel P.; Squier, Samuel; Schneider, Hartmut; Kirkness, Jason P.; Smith, Philip L

    2009-01-01

    Mechanisms linking obesity with upper airway dysfunction in obstructive sleep apnea are reviewed. Obstructive sleep apnea is due to alterations in upper airway anatomy and neuromuscular control. Upper airway structural alterations in obesity are related to adipose deposition around the pharynx, which can increase its collapsibility or critical pressure (Pcrit). In addition, obesity and, particularly, central adiposity lead to reductions in resting lung volume, resulting in loss of caudal trac...

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

    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

  17. Animal models for genetic neuromuscular diseases.

    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

  18. Ecological production of dryland hairy vetch by mechanical control

    AVCI, Muzaffer; Akar, Taner

    2006-01-01

    Winter hairy vetch, Vicia villosa Roth, gives high grain and hay yields. Mechanical control of weeds is an ecological alternative to the use of herbicides. Among the various mechanical methods, interrow weeding is cheap and practical. Nonetheless, wider row spacing than common practice is needed to ease the operation. We optimized row spacing and seed rates for high grain yield and to ease interrow cultivation. We used two row spacings of 45 and 60 cm as main plots and five seeding rates of 1...

  19. Mechanical control of floating aquatic weed: Kainji Lake experience

    Daddy, F.; Ladu, B.M.B.; Salzwedel, H.; Isa, A.U.

    2003-01-01

    The paper describes the uniqueness and invasiveness of water hyacinth (Eichhornia crassipes) on Lake Kainji (Nigeria). The mechanical blocking device design concept based on the Kainji Lake flooding regime is also highlighted. Water hyacinth coverage, that was over 23% at high water in level in 1994, was reduced to 0.75% in the same period in 2000. Although this feat cannot be wholly ascribed to mechanical control effort alone, the first year of the device's full operation more than 1.04 mill...

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

    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

  1. Applications of shape memory alloys for neurology and neuromuscular rehabilitation.

    Pittaccio, Simone; Garavaglia, Lorenzo; Ceriotti, Carlo; Passaretti, Francesca

    2015-01-01

    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. PMID:26023790

  2. Degeneration of neuromuscular junction in age and dystrophy.

    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

  3. Mechanical Impedance Control in the Human Arm While Manually Transporting an Open-Top Fluid Filled Dish

    Navit Roth; Rami Seliktar; Joseph Mizrahi

    2011-01-01

    The present study deals with stabilizing aspects of a hand-held dish filled with liquid while walking steadily. This is an attempt to decipher the neuro-muscular strategies employed and the mechanical responses of the arm during certain tasks of manual materials handling. The experimental configuration included a cup and the test-subject’s hand as an ‘end-effector’ of a serial three-link system representing the upper limb. These links are connected together by the wrist, elbow and shoulder jo...

  4. Comparative Study on New AQM Mechanisms for Congestion Control

    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.

  5. Biomimetic Control of Mechanical Systems Equipped with Musculotendon Actuators

    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.

  6. Mechanisms in Adaptive Feedback Control: Photoisomerization in a Liquid

    Hoki, K; Hoki, Kunihito; Brumer, Paul

    2005-01-01

    The underlying mechanism for Adaptive Feedback Control in the experimental photoisomerization of NK88 in methanol is exposed theoretically. With given laboratory limitations on laser output, the complicated electric fields are shown to achieve their targets in qualitatively simple ways. Further, control over the cis population without laser limitations reveals an incoherent pump-dump scenario as the optimal isomerization strategy. In neither case are there substantial contributions from quantum multiple-path interference or from nuclear wavepacket coherence. Environmentally induced decoherence is shown to justify the use of a simplified theoretical model.

  7. Research on control rod drive mechanism seismic test acceptance criteria

    Background: There is no clear requirement on the rod drop performance of Control Rod Drive Mechanism (CRDM) in seismic condition. Purpose: Acceptance criteria of AP1OOO CRDM seismic test need to be determined. Methods: Related regulations and the safety function of AP1000 CRDM are investigated, as well as the conclusions drawn from the CRDM seismic tests worldwide. Results: Acceptance criteria of this test should be in accordance with the limit is in AP1OOO Nuclear Plant Safety Analysis Report. Conclusions: Drop time of control rods in AP1000 CRDM seismic test at the room temperature without flow is 2.7 s before and after Safe Shutdown Earthquake (SSE). (authors)

  8. Neuromuscular Fatigue During 200 M Breaststroke

    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.

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

    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.

  10. Antenna mechanism of length control of actin cables

    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...

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

    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.

  12. A Unified Approach to Robust Control of Flexible Mechanical Systems Using H-Infinity Control Powered by PD Control

    Toda, Masayoshi

    2010-01-01

    In this article, we have presented the control design method based on H∞ control and PD control aiming at a uniform approach to motion control of various flexible mechanical systems. In particular, with a special emphasis on MIMO systems and the optimal PD gains, we have introduced and demonstrated the concept of the generic problem setting in the modeling phase, the physics behind our control method, that is, how the PD control scheme elaborately powers the H∞ control system, the promisi...

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

    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.)

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

    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 ...

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

    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

  16. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    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...

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

    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.

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

    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...

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

    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.

  20. Antenna Mechanism of Length Control of Actin Cables.

    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.

  1. Conceptual Design of Bottom-mounted Control Rod Drive Mechanism

    Lee, Jin Haeng; Kim, Sanghaun; Yoo, Yeonsik; Cho, Yeonggarp; Kim, Dongmin; Kim, Jong In [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The arrangement of the BMCRDMs and irradiation holes in the core is therefore easier than that of the top-mounted CRDM. Hence, many foreign research reactors, such as JRR-3M, JMTR, OPAL, and CARR, have adopted the BMCRDM concept. The purpose of this paper is to introduce the basic design concept on the BMCRDM. The major differences of the CRDMs between HANARO and KJRR are compared, and the design features and individual system of the BMCRDM for the KJRR are described. The Control Rod Drive Mechanism (CRDM) is a device to regulate the reactor power by changing the position of a Control Absorber Rod (CAR) and to shut down the reactor by fully inserting the CAR into the core within a specified time. The Bottom-Mounted CRDM (BMCRDM) for the KiJang Research Reactor (KJRR) is a quite different design concept compared to the top-mounted CRDM such as HANARO and JRTR. The main drive mechanism of the BMCRDM is located in a Reactivity Control Mechanism (RCM) room under the reactor pool bottom, which makes the interference with equipment in the reactor pool reduced.

  2. Conceptual Design of Bottom-mounted Control Rod Drive Mechanism

    The arrangement of the BMCRDMs and irradiation holes in the core is therefore easier than that of the top-mounted CRDM. Hence, many foreign research reactors, such as JRR-3M, JMTR, OPAL, and CARR, have adopted the BMCRDM concept. The purpose of this paper is to introduce the basic design concept on the BMCRDM. The major differences of the CRDMs between HANARO and KJRR are compared, and the design features and individual system of the BMCRDM for the KJRR are described. The Control Rod Drive Mechanism (CRDM) is a device to regulate the reactor power by changing the position of a Control Absorber Rod (CAR) and to shut down the reactor by fully inserting the CAR into the core within a specified time. The Bottom-Mounted CRDM (BMCRDM) for the KiJang Research Reactor (KJRR) is a quite different design concept compared to the top-mounted CRDM such as HANARO and JRTR. The main drive mechanism of the BMCRDM is located in a Reactivity Control Mechanism (RCM) room under the reactor pool bottom, which makes the interference with equipment in the reactor pool reduced

  3. Using factor analysis to identify neuromuscular synergies during treadmill walking

    Merkle, L. A.; Layne, C. S.; Bloomberg, J. J.; Zhang, J. J.

    1998-01-01

    Neuroscientists are often interested in grouping variables to facilitate understanding of a particular phenomenon. Factor analysis is a powerful statistical technique that groups variables into conceptually meaningful clusters, but remains underutilized by neuroscience researchers presumably due to its complicated concepts and procedures. This paper illustrates an application of factor analysis to identify coordinated patterns of whole-body muscle activation during treadmill walking. Ten male subjects walked on a treadmill (6.4 km/h) for 20 s during which surface electromyographic (EMG) activity was obtained from the left side sternocleidomastoid, neck extensors, erector spinae, and right side biceps femoris, rectus femoris, tibialis anterior, and medial gastrocnemius. Factor analysis revealed 65% of the variance of seven muscles sampled aligned with two orthogonal factors, labeled 'transition control' and 'loading'. These two factors describe coordinated patterns of muscular activity across body segments that would not be evident by evaluating individual muscle patterns. The results show that factor analysis can be effectively used to explore relationships among muscle patterns across all body segments to increase understanding of the complex coordination necessary for smooth and efficient locomotion. We encourage neuroscientists to consider using factor analysis to identify coordinated patterns of neuromuscular activation that would be obscured using more traditional EMG analyses.

  4. Dynamics and control of mechanical systems in offshore engineering

    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:                                                                                                                                 ...

  5. Comparison of different mechanical weed control strategies in sugar beets

    Kunz, Christoph

    2016-02-01

    Full Text Available In sugar beet (Beta vulgaris weed control is commonly performed by herbicide application applied broadcast at splitting during the cultivation period. Mechanical weeding can be an alternative to chemical weed control. The aim of this experiment was the estimation of weed control efficacy with the use of automatic steering technologies by camera guidance, the use of different intra row weed control implements in conservation tillage systems and the influence of these techniques to the number of uprooted sugar beets. A field experiment with a randomized complete plot design was conducted in 2015 at Ihinger Hof, Germany. Weed density ranged from 0 to 12 plants m-2 with Chenopodium album, Polygonum convolvulus, Polygonum aviculare as the most abundant weed species. Hoeing with the use of automatic steering technologies reduced the weed density by 82%. The use of finger weeders, rotary-harrow and torsion finger weeder reduced the weed density by 29% compared to common hoeing strategies. Differences in the number of uprooted sugar beets were not found across all treatments. We revealed the possibility of a more intense use of mechanical weeding technologies in combination with precision farming technologies in sugar beet.

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

    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

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

    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

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

    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

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

    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

  10. Steroidal Ammonium Compounds as New Neuromuscular Blocking Agents.

    Rao, Zhigang; Hu, Hao; Tang, Jiazhi; Liu, Zhiying; Yang, Yue; Qiu, Guofu; Xiao, Yuling; Liu, Peng; Hu, Xianming; Zhou, Xiaoju; Hong, Xuechuan

    2016-05-01

    Neuromuscular blocking agents are widely used as an anesthesia auxiliary in surgery, which induce relaxation of skeletal muscles by blocking signal transmission at the neuromuscular junction. Many neuromuscular blocking agents s were developed over the past decades, but none of them fully meets the needs of the clinic by various reasons. In this study, a series of quaternary ammonium steroidal neuromuscular blocking agents were synthesized and evaluated on isolated mouse phrenic nerve-hemidiaphragms for their bioactivities. The initial separation of mono- and bis-quaternary ammonium compounds turned out to be very challenging on regular silica gel chromatography. Therefore, a facile purification method, in which the silica gel was pretreated with methanolic sodium bromide solution, was finally achieved. Compounds 3g (0.36 μm) and 4g (0.37 μm) exhibited excellent neuromuscular blocking activities, which were about sixfold to sevenfold higher in potency than that of rocuronium (2.50 μm). In addition, other bis-quaternized compounds also showed good potencies close to that of rocuronium. Furthermore, the preliminary structure-activity relationship of this series was also elucidated. Benzyl group was found to be a promising quaternary group in this series. PMID:26684806

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

    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

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

    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.

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

    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.

  14. Study on dynamic lifting characteristics of control rod drive mechanism

    Based on the equations of the electric circuit and the magnetic circuit and analysis of the dynamic lifting process for the control rod drive mechanism (CRDM), coupled magnetic-electric-mechanical equations both for the static status and the dynamic status are derived. The analytical method is utilized to obtain the current and the time when the lift starts. The numerical simulation method of dynamic analysis recommended by ASME Code is utilized to simulate the dynamic lifting process of CRDM, and the dynamic features of the system with different design gaps are studied. Conclusions are drawn as: (1) the lifting-start time increases with the design gap, and the time for the lifting process is longer with larger gaps; (2) the lifting velocity increases with time; (3) the lifting acceleration increases with time, and with smaller gaps, the impact acceleration is larger. (author)

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

    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...

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

    Brueckmann, B; Sasaki, N; Grobara, P; Li, M K; Woo, T; de Bie, J; Maktabi, M; Lee, J; Kwo, J; Pino, R; Sabouri, A S; McGovern, F; Stæhr Rye, Anne Kathrine; Eikermann, M

    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, followed...... residual neuromuscular blockade at PACU admission, defined as a train-of-four (TOF) ratio <0.9, using TOF-Watch® SX. Key secondary endpoint was time between reversal agent administration and operating room discharge-readiness; analysed with analysis of covariance. RESULTS: Of 154 patients randomized, 150...... evidence of partial paralysis. Time between reversal agent administration and operating room discharge-readiness was shorter for sugammadex vs usual care (14.7 vs 18.6 min respectively; P=0.02). CONCLUSIONS: After abdominal surgery, sugammadex reversal eliminated residual neuromuscular blockade in the PACU...

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

    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

  18. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    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.

  19. Control and Virtual Reality Simulation of Tendon Driven Mechanisms

    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

  20. Tracking control mechanisms for positioning automatic CRD exchanger

    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.)

  1. Heralded Control of Mechanical Motion by Single Spins

    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.

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

    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.

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

    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)

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

    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

  5. Neuromuscular block after intra-arterially injected acetylcholine. 2. Effects of ACTH treatments as possible detectors of desensitization level in the receptor site.

    Pinelli, P; Tonali, P; Gambi, D

    1973-04-01

    It has been suggested that the effect of ACTH in myasthenia gravis may be ascribed to an action involving neuromuscular transmission which favours repolarization processes, with a tendency towards hyperpolarization of the membranes of muscle fibres and motor nerve endings. A similar mechanism has been postulated for the action of ACTH in epilepsy (Klein, 1970). A direct or indirect action on nerve membrane would interfere with depolarization. There is evidence of raised concentration of intracellular potassium and increased outflow of sodium ions which would cause hyperpolarization of the membrane. This paper studies the effect of ACTH on the late block of neuromuscular transmission caused by acetylcholine (ACTH). PMID:4350704

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

    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;...

  7. Neuromuscular exercise as treatment of degenerative knee disease

    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...... 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....

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

    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...... lumped-parameter approach and the actuating principle for control of forced vibration is investigated....

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

    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

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

    Rathleff, Michael S.; Samani, Afshin; Olesen, Jens L.; Roos, Ewa M.; Rasmussen, Sten; Madeleine, Pascal

    2016-01-01

    random subsample of 57 female adolescents was included and tested at baseline and after 3months. Neuromuscular control of the knee was quantified as the complexity of surface electromyography of the vastus lateralis and vastus medialis during stair descent. Secondary outcomes were complexity of knee...... during stair descent than those receiving patient education alone. This suggest that exercise therapy has an effect not only on self-reported outcome measures but also on objective measures of thigh muscle function in female adolescents with patellofemoral pain....

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

    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...

  12. Mechanism of controlled release kinetics from medical devices

    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.

  13. Neural mechanisms of attentional control in mindfulness meditation

    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.

  14. Anormalidades neuromuscular no desuso, senilidade e caquexia

    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.

  15. Development of embedded Control System for Control and Safety Rod Drive Mechanisms (CSRDMs) of PFBR

    Prototype Fast Breeder Reactor (PFBR), a 500 MWe, Sodium cooled, fast breeder reactor is nearing completion at Kalpakkam, Tamil Nadu. PFBR has two independent, fast acting and diverse shutdown systems, one with nine Control and Safety Rods (CSRs) and another with three Diverse Safety Rods (DSRs), with independent driving mechanisms called CSRDMs and DSRDMs respectively. This paper deals with the development of Real Time Computer based Control system for controlling nine CSRDMs with model based software development environment - SCADE (Safety Critical Application Development Environment). (author)

  16. Phloem transport: a review of mechanisms and controls.

    De Schepper, Veerle; De Swaef, Tom; Bauweraerts, Ingvar; Steppe, Kathy

    2013-11-01

    It is generally believed that an osmotically generated pressure gradient drives the phloem mass flow. So far, this widely accepted Münch theory has required remarkably few adaptations, but the debate on alternative and additional hypotheses is still ongoing. Recently, a possible shortcoming of the Münch theory has been pointed out, suggesting that the Münch pressure flow is more suitable for herbs than for trees. Estimation of the phloem resistance indicates that a point might be reached in long sieve tubes where the pressure required to drive the Münch flow cannot be generated. Therefore, the relay hypothesis regained belief as it implies that the sieve tubes are shorter then the plant's axial axis. In the source phloem, three different loading strategies exist which probably result from evolutionary advantages. Passive diffusion seems to be the most primitive one, whereas active loading strategies substantially increase the growth potential. Along the transport phloem, a leakage-retrieval mechanism is observed. Appreciable amounts of carbohydrates are lost from the sieve tubes to feed the lateral sinks, while a part of these lost carbohydrates is subsequently reloaded into the sieve tubes. This mechanism is probably involved to buffer short-term irregularities in phloem turgor and gradient. In the long term, the mechanism controls the replenishment and remobilization of lateral stem storage tissues. As phloem of higher plants has multiple functions in plant development, reproduction, signalling, and growth, the fundamental understanding of the mechanisms behind phloem transport should be elucidated to increase our ability to influence plant growth and development. PMID:24106290

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

    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

  18. 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

    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...

  19. Effectiveness of teleassistance on the improvement of health related quality of life in people with neuromuscular diseases

    Oscar Martínez; Amaia Jometón; Esther Lázaro; Imanol Amayra; Juan Francisco López-Paz; Manuel Pérez; Patricia Caballero; Luís De Nicolás; Alberto Lasa; Jorge Roldán; Natalia Martín; Joseba Bárcena; Luís Varona

    2012-01-01

    Background Neuromuscular diseases are a group of pathologies characterized by the progressive loss of muscular strength, atrophy or hypertrophy, fatigue, muscle pain and degeneration of the muscles and the nerves controlling them (The French Muscular Dystrophy Association, 2004). Perceived isolation and health related quality of life are affected in the majority of cases due to the illness chronicity. Internet, and in this way, the use of chat and videoconferencing programs, is an alternative...

  20. Chemo-mechanical control of neural stem cell differentiation

    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

  1. EFFECTIVENESS OF NEUROMUSCULAR TRAINING FOR BASKET BALL PLAYERS ON PERFORMANCE OF STAR EXCURSION BALANCE TEST

    Bhargava Kumar Bhaskar

    2013-12-01

    Full Text Available Background and introduction:To determine the effect of neuromuscular training program (NMTP focused oncore stability and lower extremity strength on performance of star excursion balance test (SEBT inbasketballplayers.Method:: Pre to post test experimental study design randomisedthirty Basketball players each 15 into NMTPand control group. Players trained together as a team in which NMTP group participated 4 weeks of NMTPtwice a week and Control group followed their regular protocol as guided by their coach.Results:When means of post intervention compared using Independent‘t’between NMTP and Control groupthere is no statistically significant difference (p<0.05 in anterior, posterior-medial and posterior-Lateral directionreach distance of star Excursion test but there is a statistically significant difference in means of anterior, posterior-medial and posterior-Lateral direction reach distance when analyzed within in groups using Paired‘t’test andWilcoxon signed rank test.Conclusion:Neuromuscular Training program found to be effective for Basketball Players on Performance ofStar Excursion Balance Test and this improvement can significantly predict the prevention of injury.

  2. Translational regulation of acetylcholinesterase by the RNA-binding protein Pumilio-2 at the neuromuscular synapse.

    Marrero, Emilio; Rossi, Susana G; Darr, Andrew; Tsoulfas, Pantelis; Rotundo, Richard L

    2011-10-21

    Acetylcholinesterase (AChE) is highly expressed at sites of nerve-muscle contact where it is regulated at both the transcriptional and post-transcriptional levels. Our understanding of the molecular mechanisms underlying its regulation is incomplete, but they appear to involve both translational and post-translational events as well. Here, we show that Pumilio-2 (PUM2), an RNA binding translational repressor, is highly localized at the neuromuscular junction where AChE mRNA concentrates. Immunoprecipitation of muscle cell extracts with a PUM2 specific antibody precipitated AChE mRNA, suggesting that PUM2 binds to the AChE transcripts in a complex. Gel shift assays using a bacterially expressed PUM2 RNA binding domain showed specific binding using wild type AChE 3'-UTR RNA segment that was abrogated by mutation of the consensus recognition site. Transfecting skeletal muscle cells with shRNAs specific for PUM2 up-regulated AChE expression, whereas overexpression of PUM2 decreased AChE activity. We conclude that PUM2 binds to AChE mRNA and regulates AChE expression translationally at the neuromuscular synapse. Finally, we found that PUM2 is regulated by the motor nerve suggesting a trans-synaptic mechanism for locally regulating translation of specific proteins involved in modulating synaptic transmission, analogous to CNS synapses. PMID:21865157

  3. Translational Regulation of Acetylcholinesterase by the RNA-binding Protein Pumilio-2 at the Neuromuscular Synapse*

    Marrero, Emilio; Rossi, Susana G.; Darr, Andrew; Tsoulfas, Pantelis; Rotundo, Richard L.

    2011-01-01

    Acetylcholinesterase (AChE) is highly expressed at sites of nerve-muscle contact where it is regulated at both the transcriptional and post-transcriptional levels. Our understanding of the molecular mechanisms underlying its regulation is incomplete, but they appear to involve both translational and post-translational events as well. Here, we show that Pumilio-2 (PUM2), an RNA binding translational repressor, is highly localized at the neuromuscular junction where AChE mRNA concentrates. Immunoprecipitation of muscle cell extracts with a PUM2 specific antibody precipitated AChE mRNA, suggesting that PUM2 binds to the AChE transcripts in a complex. Gel shift assays using a bacterially expressed PUM2 RNA binding domain showed specific binding using wild type AChE 3′-UTR RNA segment that was abrogated by mutation of the consensus recognition site. Transfecting skeletal muscle cells with shRNAs specific for PUM2 up-regulated AChE expression, whereas overexpression of PUM2 decreased AChE activity. We conclude that PUM2 binds to AChE mRNA and regulates AChE expression translationally at the neuromuscular synapse. Finally, we found that PUM2 is regulated by the motor nerve suggesting a trans-synaptic mechanism for locally regulating translation of specific proteins involved in modulating synaptic transmission, analogous to CNS synapses. PMID:21865157

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

    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

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

    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.

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

    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...

  7. Drug Development and Challenges for Neuromuscular Clinical Trials.

    El Mouelhi, Mohamed

    2016-03-01

    Drug development process faces many challenges, including those encountered in clinical trials for neuromuscular diseases. Drug development is a lengthy and highly costly process. Out of 10 compounds entering first study in man (phase 1), only one compound reaches the market after an average of 14 years with a cost of $2.7 billion. Nevertheless, according to the Centers for Medicare and Medicaid services, prescription drugs constituted only 9 % of each health care dollar spent in USA in 2013. Examples of challenges encountered in neuromuscular clinical trials include lack of validated patient-reported outcome tools, blinding issues, and the use of placebo in addition to lack of health authority guidance for orphan diseases. Patient enrollment challenge is the leading cause of missed clinical trial deadlines observed in about 80 % of clinical trials, resulting in delayed availability of potentially life-saving therapies. Another specific challenge introduced by recent technology is the use of social media and risk of bias. Sharing personal experiences while in the study could easily introduce bias among patients that would interfere with accurate interpretation of collected data. To minimize this risk, recent neuromuscular studies incorporate as an inclusion criterion the patient's agreement not to share any of study experiences through social media with other patients during the study conduct. Consideration of these challenges will allow timely response to the high unmet medical needs for many neuromuscular diseases. PMID:26691331

  8. Ultrastructural muscle and neuro-muscular junction alterations in polymyositis

    L. L. Babakova; O. M. Pozdnyakov

    2015-01-01

    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.

  9. Diagnostic value of CT scanning in neuromuscular diseases

    The diagnosis of myopathies has become easier since the CT technique is available. In this article the possibilities of CT for diagnostic procedures of neuromuscular diseases are pointed out. Density measurements increase differentiation of atrophy or hypertrophy of muscles as well as other pathological changes. (orig.)

  10. Bacterial cell curvature through mechanical control of cell growth

    Cabeen, M.; Charbon, Godefroid; Vollmer, W.;

    2009-01-01

    The cytoskeleton is a key regulator of cell morphogenesis. Crescentin, a bacterial intermediate filament-like protein, is required for the curved shape of Caulobacter crescentus and localizes to the inner cell curvature. Here, we show that crescentin forms a single filamentous structure that coll...... cell wall insertion to produce curved growth. Our study suggests that bacteria may use the cytoskeleton for mechanical control of growth to alter morphology......The cytoskeleton is a key regulator of cell morphogenesis. Crescentin, a bacterial intermediate filament-like protein, is required for the curved shape of Caulobacter crescentus and localizes to the inner cell curvature. Here, we show that crescentin forms a single filamentous structure that...

  11. An evidence-based review of hip-focused neuromuscular exercise interventions to address dynamic lower extremity valgus

    Ford KR

    2015-08-01

    Full Text Available 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 several knee pathologies, specifically anterior cruciate ligament ruptures and patellofemoral pain. Therefore, hip-focused interventions have gained considerable attention and been successful in addressing these knee pathologies. The purpose of the review was to identify and discuss hip-focused exercise interventions that aim to address dynamic lower extremity valgus. Previous electromyography, kinematics, and kinetics research support the use of targeted hip exercises with non-weight-bearing, controlled weight-bearing, functional exercise, and, to a lesser extent, dynamic exercises in reducing dynamic lower extremity valgus. Further studies should be developed to identify and understand the mechanistic relationship between optimized biomechanics during sports and hip-focused neuromuscular exercise interventions.Keywords: dynamic lower extremity valgus, hip neuromuscular control, ACL injury rehabilitation, patellofemoral pain, hip muscular activation

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

    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

  13. Line-tension controlled mechanism for influenza fusion.

    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.

  14. Passive Flow Separation Control Mechanism Inspired by Shark Skin

    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.

  15. Mechanisms controlling the distribution of two invasive Bromus species

    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.

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

    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.

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

    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.

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

    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

  19. Professional Soccer Player Neuromuscular Responses and Perceptions to Acute Whole Body Vibration Differ from Amateur Counterparts

    Ross Cloak, Andrew Lane, Matthew Wyon

    2016-03-01

    Full Text Available Acute whole body vibration (WBV is an increasingly popular training technique amongst athletes immediately prior to performance and during scheduled breaks in play. Despite its growing popularity, evidence to demonstrate its effectiveness on acute neuromuscular responses is unclear, and suggestions that athlete ability impacts effectiveness warrant further investigation. The purpose of this study was to compare the neuromuscular effects of acute WBV and perceptions of whether WBV is an effective intervention between amateur and professional soccer players. Participants were 44 male soccer players (22 professional and 22 amateur; age: 23.1 ± 3.7 years, body mass: 75.6 ± 8.8 kg and height: 1.77 ± 0.05 m. Participants in each group were randomly assigned to either an intervention of 3 x 60 s of WBV at 40 Hz (8mm peak-to-peak displacement or control group. Peak knee isometric force, muscle activation and post activation potentiation (PAP of the knee extensors along with self-report questionnaire of the perceived benefits of using the intervention were collected. A three-way ANOVA with repeated measures revealed professional players demonstrated a significant 10.6% increase (p < 0.01, Partial Eta2 = 0.22 in peak knee isometric force following acute WBV with no significant differences among amateur players. A significant difference (p < 0.01, Partial Eta2 = 0.16 in PAP amongst professional players following acute WBVT was also reported. No significant differences amongst amateur players were reported across measurements. Results also indicated professional players reported significantly stronger positive beliefs in the effectiveness of the WBV intervention (p < 0.01, Partial Eta2 = 0.27 compared to amateur players. Acute WBV elicited a positive neuromuscular response amongst professional players identified by PAP and improvements in knee isometric peak force as well as perceived benefits of the intervention, benefits not found among amateur players.

  20. Method of controlling moving-coil type control rod driving mechanisms

    Purpose: To enable solenoid plungers to sufficiently follow after abrupt changes of moving speed of moving-coils in nuclear reactors. Method: In a control circuit for moving-coil type control rod driving mechanisms of nuclear reactors, the velocity of a driving device for the moving-coils is detected by a velocity detector to control the velocity change of exciting currents in the coils depending on a velocity instruction signal. Since the velocity change of the coil exciting current varies depending on the change in the velocity instruction signal, the solenoid plunger can smoothly follow after the moving coils electromagnetically coupled therewith, and the deviation between the moving-coils and the solenoid plunger, that is, the driving axis can be minimized. Accordingly, smooth reactor control can be attained. (Takahashi, M.)

  1. Monitoring device for operation of reactor control rod driving mechanism

    The device of the present invention detects occurrence of abnormality of control rod driving mechanisms in an early stage by extracting changes of a controlling current for the CRDM of a PWR type reactor. Namely, the device of the present invention comprises an abnormality detection and processing device which performs wavelet conversion of signals of the current flowing in a lift coil, signals of the current flowing in a movable griper coil and signals of the current flowing in a stationary griper coil in the CRDM. The device compares the effective value of the wavelet conversion with a previously set reference value. The abnormality of CRDM is analyzed based on the comparative results showing that the effective value of the WAVELET conversion exceeds a predetermined relationship with the reference value. With such procedures, slight change of waveforms can be recognized accurately based on the information represented by three axes, namely, a time axis, the extent of extension/contraction of a base function and a corelationship of the base functions, without using an expensive accelerometer. (I.S.)

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

    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).

  3. Electro-Mechanical Actuator. DC Resonant Link Controller

    Schreiner, Kenneth E.

    1996-01-01

    This report summarizes the work performed on the 68 HP electro-mechanical actuator (EMA) system developed on NASA contract for the Electrical Actuation (ELA) Technology Bridging Program. The system was designed to demonstrate the capability of large, high power linear ELAs for applications such as Thrust Vector Control (TVC) on rocket engines. It consists of a motor controller, drive electronics and a linear actuator capable of up to 32,00 lbs loading at 7.4 inches/second. The drive electronics are based on the Resonant DC link concept and operate at a nominal frequency of 55 kHz. The induction motor is a specially designed high speed, low inertia motor capable of a 68 peak HP. The actuator was originally designed by MOOG Aerospace under an internal R & D program to meet Space Shuttle Main Engine (SSME) TVC requirements. The design was modified to meet this programs linear rate specification of 7.4 inches/second. The motor and driver were tested on a dynamometer at the Martin Marietta Space Systems facility. System frequency response, step response and force-velocity tests were conducted at the MOOG Aerospace facility. A complete description of the system and all test results can be found in the body of the report.

  4. Radon mitigation with pressure-controlled mechanical ventilation

    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)

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

    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

  6. Mechanical and dosimetric quality control for computer controlled radiotherapy treatment equipment.

    Thompson, A V; Lam, K L; Balter, J M; McShan, D L; Martel, M K; Weaver, T A; Fraass, B A; Ten Haken, R K

    1995-05-01

    Modern computer controlled radiotherapy treatment equipment offers the possibility of delivering complex, multiple field treatments with minimal operator intervention, thus making multiple field conformal therapy practical. Conventional quality control programs are inadequate for this new technology, so new quality control procedures are needed. A reasonably fast, sensitive, and complete daily quality control program has been developed in our clinic that includes nearly automated mechanical as well as dosimetric tests. Automated delivery of these quality control fields is performed by the control system of the MM50 racetrack microtron, directed by the CCRS sequence processor [D. L. McShan and B. A. Fraass, Proceedings of the XIth International Conference on the use of computers in Radiation Therapy, 20-24 March 1994, Manchester, U.K. (North Western Medical Physics Department, Manchester, U.K., 1994), pp. 210-211], which controls the treatment process. The mechanical tests involve multiple irradiations of a single film to check the accuracy and reproducibility of the computer controlled setup of gantry and collimator angles, table orientation, collimator jaws, and multileaf collimator shape. The dosimetric tests, which involve multiple irradiations of an array of ionization chambers in a commercial dose detector (Keithly model 90100 Tracker System) rigidly attached to the head of the treatment gantry, check the output and symmetry of the treatment unit as a function of gantry and collimator angle and other parameters. For each of the dosimetric tests, readings from the five ionization chambers are automatically read out, stored, and analyzed by the computer, along with the geometric parameters of the treatment unit for that beam.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7643792

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

    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...

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

    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.

  9. Mechanics and control of the cytoskeleton in Amoeba proteus.

    Dembo, M

    1989-06-01

    Many models of the cytoskeletal motility of Amoeba proteus can be formulated in terms of the theory of reactive interpenetrating flow (Dembo and Harlow, 1986). We have devised numerical methodology for testing such models against the phenomenon of steady axisymmetric fountain flow. The simplest workable scheme revealed by such tests (the minimal model) is the main preoccupation of this study. All parameters of the minimal model are determined from available data. Using these parameters the model quantitatively accounts for the self assembly of the cytoskeleton of A. proteus: for the formation and detailed morphology of the endoplasmic channel, the ectoplasmic tube, the uropod, the plasma gel sheet, and the hyaline cap. The model accounts for the kinematics of the cytoskeleton: the detailed velocity field of the forward flow of the endoplasm, the contraction of the ectoplasmic tube, and the inversion of the flow in the fountain zone. The model also gives a satisfactory account of measurements of pressure gradients, measurements of heat dissipation, and measurements of the output of useful work by amoeba. Finally, the model suggests a very promising (but still hypothetical) continuum formulation of the free boundary problem of amoeboid motion. by balancing normal forces on the plasma membrane as closely as possible, the minimal model is able to predict the turgor pressure and surface tension of A. proteus. Several dynamical factors are crucial to the success of the minimal model and are likely to be general features of cytoskeletal mechanics and control in amoeboid cells. These are: a constitutive law for the viscosity of the contractile network that includes an automatic process of gelation as the network density gets large; a very vigorous cycle of network polymerization and depolymerization (in the case of A. proteus, the time constant for this reaction is approximately 12 s); control of network contractility by a diffusible factor (probably calcium ion); and

  10. Effects of Dynamic Neuromuscular Analysis Training on Static and Dynamic Balance in Indian Female Basketball Players

    Archna Sharma

    2013-04-01

    Full Text Available The aim of this paper was to investigate the effects of dynamic neuromuscular analysis on static and dynamic balance of Indian state level female athletes. It was hypothesized that the training protocol would improve both static and dynamic components of the balance, improving dynamic balance more than static. A total of 43 randomly selected state level female basketball players aged 16 -18 years participated in the study. The subjects were further divided into two groups, viz. Dynamic Neuromuscular Analysis (DNA group (n=23 and control group (n = 20. Pre and post static balance was tested to all the subjects by Stork Balance Test (SBT and Balance Error Scoring System (BESS, and dynamic balance was measured by Star Excursion Balance Test (SEBT. DNA intervention of 90 minutes was given for 6 weeks while the control group followed traditional training. Results showed a significant improvement both in static and dynamic balance (p<0.001. It might be concluded that 6 week DNA training designed for the prevention of ACL injuries could also improve both static and dynamic balance in Indian female basketball players.

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

    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...... evaluated the degree of neuromuscular blockade solely by clinical criteria. The use of a nerve stimulator was found to have no effect on the dose of relaxant given during anesthesia, on the need for supplementary doses of anticholinesterase in the recovery room, on the time from end of surgery to end of...... ratios were significantly higher than those found in the pancuronium groups, which wre 0.66 (0.06-0.90) and 0.63 (0.29-0.95), respectively. However, no difference was found between the vecuronium and pancuronium groups in the number of patients showing clinical signs of residual neuromuscular blockade...

  12. Effects of evidence-based prevention training on neuromuscular and biomechanical risk factors for ACL injury in adolescent female athletes

    Zebis, Mette K.; Andersen, Lars L.; Brandt, Mikkel;

    2016-01-01

    BACKGROUND: Adolescent female football and handball players are among the athletes with the highest risk of sustaining anterior cruciate ligament (ACL) injuries. AIM: This study evaluated the effects of evidence-based lower extremity injury prevention training on neuromuscular and biomechanical...... risk factors for non-contact ACL injury. METHODS: 40 adolescent female football and handball players (15-16 years) were randomly allocated to a control group (CON, n=20) or neuromuscular training group (NMT, n=20). The NMT group performed an injury prevention programme as a warm-up before their usual....... CONCLUSIONS: A 12-week injury prevention programme in addition to training and match play in adolescent females altered the pattern of agonist-antagonist muscle preactivity during side cutting. This may represent a more ACL-protective motor strategy....

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

    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.

  14. Neuromuscular Electrical Stimulation for Mobility Support of Elderly.

    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

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

    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.

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

    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

  17. Neuromuscular Fatigue Is Not Different between Constant and Variable Frequency Stimulation

    Papaiordanidou, Maria; Billot, Maxime; Varray, Alain; Martin, Alain

    2014-01-01

    This study compared fatigue development of the triceps surae induced by two electrical stimulation protocols composed of constant and variable frequency trains (CFTs, VFTs, 450 trains, 30 Hz, 167 ms ON, 500 ms OFF and 146 ms ON, 500 ms OFF respectively). For the VFTs protocol a doublet (100 Hz) was used at the beginning of each train. The intensity used evoked 30% of a maximal voluntary contraction (MVC) and was defined using CFTs. Neuromuscular tests were performed before and after each protocol. Changes in excitation-contraction coupling were assessed by analysing the M-wave [at rest (Mmax) and during MVC (Msup)] and associated peak twitch (Pt). H-reflex [at rest (Hmax) and during MVC (Hsup)] and the motor evoked potential (MEP) during MVC were studied to assess spinal and corticospinal excitability of the soleus muscle. MVC decrease was similar between the protocols (−8%, P<0.05). Mmax, Msup and Pt decreased after both protocols (P<0.01). Hmax/Mmax was decreased (P<0.05), whereas Hsup/Msup and MEP/Msup remained unchanged after both protocols. The results indicate that CFTs and VFTs gave rise to equivalent neuromuscular fatigue. This fatigue resulted from alterations taking place at the muscular level. The finding that cortical and spinal excitability remained unchanged during MVC indicates that spinal and/or supraspinal mechanisms were activated to compensate for the loss of spinal excitability at rest. PMID:24392155

  18. Control rod driving mechanism, and control device and operation method therefor

    The upper portion of a housing of control rod driving mechanisms is secured to a reactor pressure vessel, and the lower portion thereof is sealed by a closing plug. Gears are formed on the outer circumference of a driving shaft vertically moving with the linkage of a control rod in a pressure vessel, and a linear reluctance motor comprising a stator iron core having gears on the inner circumference of a stator and a stator coil for driving the driving shaft. There are disposed a latch mechanism for holding the control rod by engaging with the gears of the driving shaft and a position detector for detecting the position of the inserted control rod by the gears of the driving shaft or magnets mounted to the gears. Since the inner structure can be simplified with no shaft-sealing portion, the frequency for the maintenance and inspection can be reduced to improve the reliability of sealing portions of the pressure vessel. The space for maintenance and inspection of the lower portion of the pressure vessel can be reduced thereby making the height of a reactor building low and strengthen the earthquake proof structure. (N.H.)

  19. Efectos del vendaje neuromuscular sobre la flexibilidad del raquis lumbar

    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.

  20. 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

    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

  1. Predictive mechanisms in the control of contour following

    Tramper, Julian J.; Flanders, Martha

    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 somatosensory system. Thus the present experiment was designed to reveal human capabilities for different types of haptic prediction. A robot arm with a large 3D workspace was attached to the index fingertip and was programmed to produce virtual surfaces with curvatures that varied within and across trials. With eyes closed, subjects moved the fingertip around elliptical hoops with flattened regions or Limaçon shapes, where the curvature varied continuously. Subjects anticipated the corner of the flattened region rather poorly, but for the Limaçon shapes they varied finger speed with upcoming curvature according to the two-thirds power law. Furthermore, although the Limaçon shapes were randomly presented in various 3D orientations, modulation of contact force also indicated good anticipation of upcoming changes in curvature. The results demonstrate that it is difficult to haptically anticipate the spatial location of an abrupt change in curvature, but smooth changes in curvature may be facilitated by anticipatory predictions. PMID:23649968

  2. The current-phase relation of a mechanically controllable breakjunction

    In order to determine the current-phase relation (CPR) of a mechanically controllable break (MCB) junction an adjustable SQUID has been developed. A ring, interrupted by a MCB junction, is cut out of a thin niobium foil using laser cutting techniques. In this SQUID the critical current can be varied continuously by adjusting the contact size of the junction. A new technique has been developed which enables us to measure directly the CPR. Superconducting current leads are attached on either side of the contact in order to determine the selfinductance of the ring. The CPR has been investigated at 4.2 K and at 1.3 K in a range of normal resistances which is estimated to be between 0.5 and 8 kΩ. A deviation from the pure sinusoidal CPR is found at 4.2 K while the CPR at 1.3 K seems to be nearly sinusoidal. It is striking that the CPRs at 4.2 K have a maximum in the current at values slightly smaller than π/2, while theories predict it to be between π/2 and π for superconducting pointcontacts with three-dimensional banks in this temperature range. (orig.)

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

    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.

  4. The Neuromuscular Junction (NMJ: aging at the crossroad between nerves and muscle

    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.

  5. Mechanical Engineering Design Project report: Enabler control systems

    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.

  6. Enteric neuromuscular junctions: comparison of ultrastructural features in different phylogenetic groups.

    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

  7. Impaired Axonal Na(+) Current by Hindlimb Unloading: Implication for Disuse Neuromuscular Atrophy.

    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

  8. The effect of a Lucia jig for 30 minutes on neuromuscular re-programming, in normal subjects

    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.

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

    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

  10. Neuromuscular exercise prior to joint arthroplasty in patients with osteoarthritis of the hip or knee.

    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

  11. Cardiac involvement in children with neuro-muscular disorders

    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...

  12. Ultrastructural muscle and neuro-muscular junction alterations in polymyositis

    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.

  13. Progress in therapeutic antisense applications for neuromuscular disorders

    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...

  14. Myasthenia and related disorders of the neuromuscular junction

    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...

  15. Degeneration of Neuromuscular Junction in Age and Dystrophy

    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...

  16. An acoustic startle alters knee joint stiffness and neuromuscular control.

    DeAngelis, A I; Needle, A R; Kaminski, T W; Royer, T R; Knight, C A; Swanik, C B

    2015-08-01

    Growing evidence suggests that the nervous system contributes to non-contact knee ligament injury, but limited evidence has measured the effect of extrinsic events on joint stability. Following unanticipated events, the startle reflex leads to universal stiffening of the limbs, but no studies have investigated how an acoustic startle influences knee stiffness and muscle activation during a dynamic knee perturbation. Thirty-six individuals were tested for knee stiffness and muscle activation of the quadriceps and hamstrings. Subjects were seated and instructed to resist a 40-degree knee flexion perturbation from a relaxed state. During some trials, an acoustic startle (50 ms, 1000 Hz, 100 dB) was applied 100 ms prior to the perturbation. Knee stiffness, muscle amplitude, and timing were quantified across time, muscle, and startle conditions. The acoustic startle increased short-range (no startle: 0.044 ± 0.011 N·m/deg/kg; average startle: 0.047 ± 0.01 N·m/deg/kg) and total knee stiffness (no startle: 0.036 ± 0.01 N·m/deg/kg; first startle 0.027 ± 0.02 N·m/deg/kg). Additionally, the startle contributed to decreased [vastus medialis (VM): 13.76 ± 33.6%; vastus lateralis (VL): 6.72 ± 37.4%] but earlier (VM: 0.133 ± 0.17 s; VL: 0.124 ± 0.17 s) activation of the quadriceps muscles. The results of this study indicate that the startle response can significantly disrupt knee stiffness regulation required to maintain joint stability. Further studies should explore the role of unanticipated events on unintentional injury. PMID:25212407

  17. Cytokinetic Control Mechanisms in Ehrlich Ascites Tumour Growth

    Ehrlich ascites tumour in mice was studied as a model system to elucidate the cytokinetic mechanisms controlling growth of cell populations. The basis for a retardation in growth rate during tumour development was determined with the aid of 3H-thymidine labelling and autoradiography. Three possible cytokinetic variables in growth regulation, namely, duration of the mitotic cell cycle, fraction of the cycling cells in the population (growth fraction) and rate of cell loss, were measured at different stages of growth. It was concluded that a deceleration in growth was a result of (1) a gradual prolongation of the cell cycle and its components and (2) a progressive decline in the growth fraction. Rate of cell loss did not appreciably change during most of the growth. It was also found that the total cell mass rather than the tumour age dictated the growth rate at any instant over a considerable range of growth. Non-cycling cells were found to resume cycle when a fraction of an old tumour was transplanted in new hosts, 3H-thymidine labelling combined with microspectrophotometric estimates of cellular DNA was utilized to locate the stages at which a cell cycle could be suspended or resumed. It was found that decycling or recycling could occur only after mitosis and before DNA synthesis; non-cycling (G0) state resembled G1, which was absent in the proliferating tumour cells. These findings are relevant to a further understanding of the molecular events leading to the initiation or suspension of a cell cycle. They are also pertinent to formulating a rationale for tumour therapy — for example with radiation — when coupled with the existing knowledge of the relative sensitivity of cells at different stages of cycle. (author)

  18. Fatty replacement of lower paraspinal muscles: normal and neuromuscular disorders

    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.

    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. Magnetic resonance imaging (MRI) in the diagnosis of neuromuscular diseases

    In the last few years imaging procedures became also important in the diagnosis of neuromuscular diseases. We examined more than 150 patients with different neuromuscular diseases with MRI. Conventional diagnostic procedures like EMG, muscle biopsy can not be replaced by imaging procedures. MRI gives the chance to get additional diagnostic informations. It is possible to determine exact distribution and intensity of pathological changes in the muscle. Inflammatory muscle diseases can be differrentiated by T1/T2 values from atrophic/dystrophic diseases. The resolving power is very high and allows the exact detection of affected areas even in a single muscle. This can help to reduce false negative muscle biopsies. This is very useful in children and young adults. MRI can be used for the early detection of genetic myopathies and neuropathies. MRI allows to examine all muscles, including the heart, bone artefacts are absent. Heart muscle involvement in neuromuscular diseases can directly be shown by this method without any risk for the patient. In addition P-spectroscopy can be done for better understanding of pathogenesis, especially if the exact distribution of pathological changes is known. (author)

  1. Adiposity, physical activity and neuromuscular performance in children.

    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

  2. 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.

    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

  3. Fatigue life estimation of ball screw in control element drive mechanism of SMART

    Various kinds of mechanisms are applied or studied for the driving control elements in reactors. One of these mechanisms is a ball screw type drive mechanism, which has advantages in precise operation and high stiffness. So this system is one of the candidate control element drive mechanism of SMART. The fatigue lifes of ball bearing and ball screws are generally limited by flaking at normal operation and are estimated by statistical method. A method to estimate the fatigue life of the ball screw on a control element drive mechanism is presented, and the suitability of ball screw type mechanism is discussed in this paper

  4. The effect of cognitive fatigue on prefrontal cortex correlates of neuromuscular fatigue in older women

    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...

  5. Passive dynamic controllers for non-linear mechanical systems

    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.

  6. On the Mechanism of Time-Delayed Feedback Control

    Just, W; Ostheimer, M; Reibold, E; Benner, H; Just, Wolfram; Bernard, Thomas; Ostheimer, Matthias; Reibold, Ekkehard; Benner, Hartmut

    1996-01-01

    The Pyragas method for controlling chaos is investigated in detail from the experimental as well as theoretical point of view. We show by an analytical stability analysis that the revolution around an unstable periodic orbit governs the success of the control scheme. Our predictions concerning the transient behaviour of the control signal are confirmed by numerical simulations and an electronic circuit experiment.

  7. Modular overconstrained weak-link mechanism for ultraprecision motion control

    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

  8. The Control System Modeling and The Mechanical Structure Analysis For EMCVT

    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.

  9. Effects of a single whole body cryotherapy (-110°C) bout on neuromuscular performance of the elbow flexors during isokinetic exercise.

    Ferreira-Junior, J B; Vieira, C A; Soares, S R S; Guedes, R; Rocha Junior, V A; Simoes, H G; Brown, L E; Bottaro, M

    2014-12-01

    It has been demonstrated that body cooling may decrease neuromuscular performance. However, the effect of a single session of whole body cryotherapy (-110°C) on neuromuscular performance has not been well documented. Thus, the aim of this study was to evaluate the effects of a single exposure of WBC on elbow flexor neuromuscular performance. Thirteen physically active, healthy young men (age=27.9±4.2 years, mass=79.4±9.7 kg, height=176.7±5.2 cm) were randomly exposed to 2 different experimental conditions separated by a minimum of 72 h: 1) whole body cryotherapy- 3 min at -110°C; 2) control- 3 min at 21°C. All subjects were tested for maximal isokinetic elbow flexion at 60°.s(-1) 30 min before and 10 min after each condition. There were no significant differences in peak torque, average power, total work or muscle activity between conditions. Peak torque was lower at post-test compared to pre-test in both conditions (F=6.58, p=0.025). However, there were no differences between pre-test and post-test for any other variables. These results indicate that strength specialists, athletic trainers and physical therapists might utilize whole body cryotherapy before training or rehabilitation without compromising neuromuscular performance of the elbow flexors. PMID:25254899

  10. Zero-cross detecting technology in control element drive mechanism control system of PWR

    Control Element Drive Mechanism Control System (CEDMCS) plays a decisive role in regulating the reactor power and shutting down the reactor in the trip condition. But, due to the failure of CEDMCS, the operating plants have had many experiences such as unexpected reactor trip or interruption during normal plant operation. To prevent those kinds of problems, it is required to improve control logic. Zero cross detection cards in CEDMCS could be made trouble which cause unexpected reactor trip resulted from fluctuating frequency of input signal coming from from M/G set. Some of the problems have been solved by modifying zero cross detection card circuit, but the other problems, such as output voltage variation resulted from input frequency change. Because current zero-cross detector was designed by analog technology, it was difficult to resolve output voltage variation problem. In this report the zero cross detector was improved to resolve voltage fluctuating problem by using new devices such as digital noise filtering circuit is better than old one. If suggested detector is applied to plant, it is possible to use it under House Load Operation because stable output voltage can be generated by new zero-cross detector. (author). 3 tabs., 21 figs., 10 refs

  11. Pharmacotherapy to protect the neuromuscular junction after acute organophosphorus pesticide poisoning.

    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

  12. The Parent Control in the Mechanical Engineering Management-Holding

    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.

  13. Mechanisms of surgical control of type 2 diabetes

    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...

  14. Model-following control applications to nonlinear mechanical systems

    Barlas, Mustafa Remzi

    1992-01-01

    Model-following control design methodology is introduced for nonlinear plants and models. The plant equations are considered to be linear in the control input. Dynamic matching conditions are presented and the resulting error dynamics are given. The stability of error dynamics is ensured, using Liapunov's second theorem; by modifying the model state rates, which effectively introduces error feedback. The methodology is applied to two problems. Motion control of an n-link manipulator wi...

  15. Mechanical characterization of calcium pectinate hydrogel for controlled drug delivery

    Chung Jin Thau; Zhibing Zhang

    2003-01-01

    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 calc...

  16. Pheromonal control: reconciling physiological mechanism with signalling theory.

    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

  17. Adaptive Clutch Engaging Process Control for Automatic Mechanical Transmission

    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.

  18. Prognostics Enhanced Reconfigurable Control of Electro-Mechanical Actuators

    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....

  19. Neuromuscular dressing effects: a literature review

    Calero PA; Cañón GA

    2012-01-01

    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...

  20. Neuromuscular strain as a contributor to cognitive and other symptoms in Chronic Fatigue Syndrome: Hypothesis and conceptual model.

    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

  1. Balancing the balance: Self-control mechanisms and compulsive buying

    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

  2. An Intelligent Call Admission Control Decision Mechanism for Wireless Networks

    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...

  3. Effects of Neuromuscular Joint Facilitation on Baseball Pitching Velocity and Electromechanical Reaction Times of the Teres Major of Young Amateur Baseball Players

    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 ...

  4. Unifying parameters in mechanical weed control research - report of the roundtable

    Rasmussen, Jesper

    2009-01-01

    This report summarises (i) the introduction given at the initiation of the roundtable discussion about unifying parameters in mechanical weed control and (ii) the following discussion at the EWRS Physical and Cultural Weed Control Group meeting in Zaragoza 2009

  5. The Application of LOGO! in Control System of a Transmission and Sorting Mechanism

    Liu, Jian; Lv, Yuan-Jun

    Logic programming of general logic control module LOGO! has been recommended the application in transmission and sorting mechanism. First, the structure and operating principle of the mechanism had been introduced. Then the pneumatic loop of the mechanism had been plotted in the software of FluidSIM-P. At last, pneumatic loop and motors had been control by LOGO!, which makes the control process simple and clear instead of the complicated control of ordinary relay. LOGO! can achieve the complicated interlock control composed of inter relays and time relays. In the control process, the logic control function of LOGO! is fully used to logic programming so that the system realizes the control of air cylinder and motor. It is reliable and adjustable mechanism after application.

  6. RESEARCH ON MECHANICAL MEASUREMENT-ORIENTED INTELLIGENT VIRTUAL CONTROLS

    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.

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

    Larsen, Camilla Marie

    2014-01-01

    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 and......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 of...... 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 a...

  8. Immediate Efficacy of Neuromuscular Exercise in Patients with Severe Osteoarthritis of the Hip or Knee

    Villadsen, Allan; Overgaard, Søren; Holsgaard-Larsen, Anders;

    2014-01-01

    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......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...... 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...

  9. Effects of intensive physical rehabilitation on neuromuscular adaptations in adults with poststroke hemiparesis

    Andersen, Lars L; Zeeman, Peter; Jørgensen, Jørgen R;

    2011-01-01

    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...... changes were observed in the nonparetic control leg. Gait performance increased 52-68%. In conclusion, intensive physical rehabilitation after stroke leads to clinically relevant neuromuscular improvements, leading to increased voluntary strength during a wide range of contraction modes and velocities......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...

  10. Disentangling the Impact of Control-Enhancing Mechanisms on Firm Performance

    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...... in five European countries (i.e. France, Germany, Italy, Spain, and the UK). Then we tested the consequences of control-enhancing mechanisms for firm performance using 2SLS regression models. Our results show that (i) mechanisms that lock-in control do have a direct and negative impact on firm...

  11. The impact of a firm's internal control mechanisms on the choice of innovation mode

    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.

  12. Composite control of the n-link chained mechanical systems

    Čelikovský, Sergej; Zikmund, Jiří

    Bratislava: Slovak University of Technology in Bratislava, 2007, 130-1-130-6. ISBN 978-80-227-2677-1. [Process Control 2007. Štrbské Pleso (SK), 11.06.2007-14.06.2007] R&D Projects: GA ČR(CZ) GA102/05/0011 Institutional research plan: CEZ:AV0Z10750506 Keywords : Nonlinear systems * Underactuated systems * Exact linearization Subject RIV: BC - Control Systems Theory

  13. Preserving organelle vitality: peroxisomal quality control mechanisms in yeast

    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. During protein translocation into the organelle, the peroxisomal targeting signal receptors (Pex5, Pex20) are also continuously undergoing quality control to enable efficient functioning of the t...

  14. CONCEPTUAL APPROACHES TO CREATE CONTROL MECHANISM BY PASSENGER COMMUTATION SERVICES

    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.

  15. Neuromuscular Responses to Simulated Brazilian Jiu-Jitsu Fights

    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.

  16. Mechanical design and driving mechanism of an isokinetic functional electrical stimulation-based leg stepping trainer.

    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

  17. Benefits of Precision Farming Technologies for Mechanical Weed Control in Soybean and Sugar Beet—Comparison of Precision Hoeing with Conventional Mechanical Weed Control

    Christoph Kunz; Jonas Felix Weber; Roland Gerhards

    2015-01-01

    Weed infestations and associated yield losses require effective weed control measures in soybean and sugar beet. Besides chemical weed control, mechanical weeding plays an important role in integrated weed management systems. Field experiments were conducted at three locations for soybean in 2013 and 2014 and at four locations for sugar beet in 2014 to investigate if automatic steering technologies for inter-row weed hoeing using a camera or RTK-GNSS increase weed control efficacy, efficiency...

  18. Nerve excitability testing and its clinical application to neuromuscular diseases.

    Nodera, Hiroyuki; Kaji, Ryuji

    2006-09-01

    Non-invasive nerve excitability testing measures the membrane polarization, ion channel function and paranodal/internodal condition of peripheral nerves. This technique has been recently used for various neuromuscular disorders, such as pure motor conduction block in multifocal motor neuropathy, conduction block in carpal tunnel syndrome and Na(+) channel function disorders in diabetic neuropathy, to shed light on their pathophysiology. Here, we review the basics of ion channel functions and membrane properties that influence nerve excitability, the basic principles of nerve excitability testing and the reported findings in various disorders. PMID:16631406

  19. Cardiac involvement in children with neuro-muscular disorders

    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.

  20. Assembly and regulation of acetylcholinesterase at the vertebrate neuromuscular junction

    Rotundo, R. L.; Ruiz, C.A.; Marrero, E.; Kimbell, L. M.; Rossi, S.G.; Rosenberry, T.; Darr, A; Tsoulfas, P.

    2008-01-01

    The collagen-tailed form of acetylcholinesterase (ColQ-AChE) is the major if not unique form of the enzyme associated with the neuromuscular junction (NMJ). This enzyme form consists of catalytic and non-catalytic subunits encoded by separate genes, assembled as three enzymatic tetramers attached to the three-stranded collagen-like tail (ColQ). This synaptic form of the enzyme is tightly attached to the basal lamina associated with the glycosaminoglycan perlecan. Fasciculin-2 is a snake toxin...

  1. Resúmenes de los trabajos sobre las Enfermedades Neuromusculares

    Congreso Nacional de Neurología

    2010-01-01

    Las enfermedades neuromusculares constituyen un conjunto de afectaciones que afectan las neuronas motoras periférica, las vías motoras eferentes o los efectores (músculos esqueléticos). Sus manifestaciones clínicas son muy variadas y dependen de la causa y de los niveles de afectación. En este acápite se pueden encontrar los resúmenes de trabajos relacionados con el síndrome de Guillain Barre, polineuropatía diabética, Atrofia Muscular Espinal, Distrofia miotónica y otros todos presentados en...

  2. Optimising abdominal space with deep neuromuscular blockade in gynaecologic laparoscopy

    Madsen, Matias Vested; Gätke, M R; Springborg, H H;

    2015-01-01

    neuromuscular blockade (NMB) would enlarge surgical space, measured as the distance from the sacral promontory to the trocar in patients undergoing gynaecologic laparoscopy. METHODS: Fourteen patients were randomised in an assessor-blinded crossover design. The distance from the sacral promontory to the trocar...... resulted in significantly better ratings of surgical conditions during suturing of the fascia (P=0.03, Mann-Whitney U-test). CONCLUSION: Deep NMB enlarged surgical space measured as the distance from the sacral promontory to the trocar. The enlargement, however, was minor and the clinical significance is...

  3. MRI in neuromuscular disorders; MRT bei neuromuskulaeren Erkrankungen

    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.)

  4. Diagnostics of neuromuscular diseases with the aid of computerized tomography

    In this article the diagnosis of neuromuscular diseases with the aid of computerized tomography is treated. Computerized tomography of skeletal muscles give no information which is pathognomonic for particular diseases. But the technique can be used in the following aspects: to choose a muscle for a biopsy; when it is not possible to examine the function of a muscle, a CT scan can visualize morphological deviations; in the differentiation of muscle hypertrophy and pseudo-hypertrophy. For some cases as Becker-type muscular dystrophy, facioscapulohumeral dystrophy and Kugelberg-Welander type spinal muscular atrophy computerized tomography gives characteristic images. 10 refs.; 6 figs

  5. Plantar flexor neuromuscular adjustments following match-play football in hot and cool conditions

    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 temperate...

  6. Pharmacokinetic studies of neuromuscular blocking agents : Good Clinical Research Practice (GCRP)

    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. Rotenone causing dysfunctional mitochondria and lysosomes in cerebral ganglions of Lumbricus terrestris degenerate giant fibers and neuromuscular junctions.

    Subaraja, Mamangam; Vanisree, Arambakkam Janardhanam

    2016-06-01

    Rotenone is well-documented to cause neurodegenerative condition such as Parkinson's, in the exposed systems. However, its detrimental effect on particular sites of neuronal pathway is still under investigation. We aimed at elucidating the impact of rotenone on cerebral ganglions (CG) of Lumbricus terrestris which control movement and behaviour of the worms. Worms were exposed to 0-0.4 ppm/mL of rotenone. Mitochondrial and lysosomal integrities were found to be affected beyond 0.2 ppm/mL of rotenone. Activities of cholinergic enzymes and the expression of tyrosine hydroxylase showed an impaired neuronal transmission in CGs at the dose of 0.2 ppm/mL of rotenone. Histopathological and immunoflourescent analyses showed neuronal apoptosis, reduced nucleic acid content and inhibited of neurosecretion at 0.3 ppm/mL. Electron microscopy showed that the neurons and neuromuscular junctions were affected at 0.2 ppm/mL. Dose-dependent changes were also observed in the motor function such as burrowing behaviours and locomotion. Conduction velocity (CV) and locomotion assessment showed that the CV of lateral giant fiber (LGF) was reduced while that of MGF remains unaffected at 0.2 ppm, the dose at which the burrowing behaviour was also not affected. LGF, cholinergic enzymes and tyrosine hydroxylase are primarily targeted by rotenone affecting locomotion at 0.2 ppm/mL while MGF, neuropile and the burrowing behaviour were affected at 0.3 ppm/mL. We demonstrate, in addition to dose-dependent effects, that the bioaccumulation factors range 0.28-0.32 ppm/μg of rotenone cause degenerative impact on giant fibers affecting neuronal behaviors/locomotion of worms. We also propose worms for studying mechanisms of neuronal pathology caused by chemicals prevailing in earth's atmosphere. PMID:27003369

  8. Estudio electrofisiológico de la funcion neuromuscular en una poblacion intoxicada con plomo

    O. M. Genovese

    1988-03-01

    Full Text Available Un grupo de 12 pacientes con cifras elevadas de plombemia y disminuidas de ALA D fueron estudiados electrofisiológicamente. Se efectuaron las siguientes determinaciones: amplitud de potencial evocado muscular; latencia distal motora; velocidad de conducción motora en los nervios mediano, ciático poplíteo externo y radial; velocidad de conducción sensitiva y amplitud del potencial evocado sensitivo de nervio en el mediano; exploración electromiográfica convencional; estudio de la transmisión neuromuscular, mediante estimulación repetitiva del nervio ciático popliteo externo a diversas frecuencias, con registro de la amplitud del potencial en músculo tibial anterior. Los datos obtenidos fueron comparados con controles. Se buscaron correlaciones entre las determinaciones bioquímicas y los diferentes hallazgos electrofisiológicos que a su vez se correlacionaron entre si y también con el tiempo de evolución de la intoxicación. Los hallazgos pusieron de manifiesto la presencia de neuropatía axonal junto a moderada desmielinización. La exploración de la transmisión neuromuscular mostró ocasional decremento o incremento de la amplitud del potencial muscular evocado, hechos que suponen cierta participación de la unión neuromuscular. Se halló correlación solamente entre disminución de ALA D y la disminución de las amplitudes del potencial sensitivo del mediano y el evocado muscular del mismo nervio y con la disminución de la VCM del nervio radial. Una débil relación se observó entre el tiempo de exposición y la disminución de la VCS del nervio mediano y VCM del radial. Las determinaciones bioquímicas y el tiempo de exposición transcurridos no probaron ser parámetros sensibles para determinar el grado de afectación del sistema nervioso periférico. El conjunto do hallazgos sugiere que el desarrollo de la neuropatía puede estar ligado a factores individuales de predisposición al daño nervioso.

  9. Mechanical AGN Feedback: Controlling the Thermodynamical Evolution of Elliptical Galaxies

    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 ...

  10. Failure of latch mechanism for motion control of safety rods

    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

  11. Mechanisms controlling renal hemodynamics and electrolyte excretion during amino acids

    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.

  12. Workflow management systems, their security and access control mechanisms

    Chehrazi, Golriz

    2007-01-01

    This paper gives an overview of workflow management systems (WfMSs) and their security requirements with focus on access mechanisms. It is a descriptive paper in which we examine the state of the art of workflow systems, describe what security risks affect WfMSs in particular, and how these can be diminiuished. WfMSs manage, illustrate and support business processes. They contribute to the performance, automation and optimization of processes, which is important in the global economy today. ...

  13. SGLT-2 Inhibitors: A New Mechanism for Glycemic Control

    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.

  14. Q-AIMD: A Congestion Aware Video Quality Control Mechanism

    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...

  15. Neural mechanisms of attentional control in mindfulness meditation

    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...

  16. Mechanical characterization of calcium pectinate hydrogel for controlled drug delivery

    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.

  17. Probable Mechanisms of Needling Therapies for Myofascial Pain Control

    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.

  18. Enhancement by calcitonin gene-related peptide of nicotinic receptor-operated noncontractile Ca2+ mobilization at the mouse neuromuscular junction.

    Kimura, I.; Tsuneki, H.; Dezaki, K.; Kimura, M

    1993-01-01

    1. The involvement of calcitonin gene-related peptide (CGRP) in the mechanism of nicotinic acetylcholine receptor-operated noncontractile Ca2+ mobilization (not accompanied by twitch tension) was investigated by measuring Ca(2+)-aequorin luminescence at the neuromuscular junction of mouse diaphragm muscle treated with neostigmine. 2. Noncontractile Ca2+ transients were enhanced by 4-aminopyridine (100 microM), a K+ channel blocker, and inhibited by botulinum toxin (1-100 micrograms, i.p.) and...

  19. The Wnt and BMP Families of Signaling Morphogens at the Vertebrate Neuromuscular Junction

    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.

  20. 14 CFR 27.923 - Rotor drive system and control mechanism tests.

    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...

  1. 14 CFR 29.923 - Rotor drive system and control mechanism tests.

    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...

  2. Effect of Dex medetomidine on Neuromuscular Blockade in Patients Undergoing Complex Major Abdominal or Pelvic Surgery

    Dex medetomidine is a highly selective α2 agonist with anesthetic, analgesic and sympatholytic properties. Its neuromuscular effects in humans are unknown. This study evaluates the effect of dex medetomidine on neuromuscular block and hemodynamics during thiopental/ isoflurane anesthesia for patients with complex abdominal or pelvic surgery. Patients and methods: During thiopental/isoflurane anesthesia, the rocuronium infusion rate was adjusted in 20 complex surgery patients to maintain a stable first response (T1) in the train of four sequence of 50% ± 3 of the pre-rocuronium value. Dex medetomidine was then administered by infusion pump, targeting a plasma dex medetomidine concentration of 0.6 ng/dL for 45 min. The evoked mechanical responses of the adductor pollicis responses (T1 response and T4/T1 ratio), systolic blood pressure, diastolic blood pressure and heart rate (HR) were measured during the dex medetomidine infusion using repeated measures analysis of variance. Plasma levels ranged from 0.73 to 1.38 ng/mL. Results: T1 values decreased during the infusion from 55(ρ2 to 38±9 ((ρ< 0.05). T4/Tl values did not change during the infusion. Dex medetomidine increased SBP (ρ< 0.001) and decreased HR ((ρ< 0.05) (10 min median values) during the infusion compared with values before the infusion. This study demonstrated that dex medetomidine decreased T1, increased SBP and decreased HR during thiopental/isoflurane anesthesia. Conclusion: We conclude that dex medetomidine induced direct vasoconstriction may alter pharmacokinetics of rocuronium, therefore increasing plasma rocuronium concentration. Although these effects were statistically significant, further studies should be held for understanding and characterizing the peripheral vasoconstrictive effects of a2 agonists that allow better management and determination of drug dosing regimens

  3. Lie Algebroids in Classical Mechanics and Optimal Control

    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.

  4. An evidence-based review of hip-focused neuromuscular exercise interventions to address dynamic lower extremity valgus

    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...

  5. Effect of Low Frequency Neuromuscular Electrical Stimulation on Glucose Profile of Persons with Type 2 Diabetes: A Pilot Study

    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...

  6. Molecular Alignment and Orientation From Laser-Induced Mechanisms to Optimal Control

    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...

  7. Automatic detection of AutoPEEP during controlled mechanical ventilation

    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.

  8. Chemical and mechanical control of corrosion product transport

    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)

  9. Mechanical control over valley magnetotransport in strained graphene

    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.

  10. Computer Studies on the Mechanisms Controlling Cellular Proliferation

    A model of the autoregulation of mitotic and functional activity of the cells is used (R. Tsanev and B. Sendov, J. theoret. Biol. 12 (1966) 327) to study by means of a digital computer the reaction of different cellular systems (a synchronous cellular population, liver and epidermis) to injuring agents disturbing the steady state of the system. The reaction of the cellular models to different kinds of injury was found to imitate adequately some particular features of the real regenerative processes. The model may also be useful to check different hypotheses concerning the mechanisms by which irradiation affects cellular proliferation. (author)

  11. High-Order Stochastic Adaptive Controller Design with Application to Mechanical System

    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.

  12. Sexual orientation biases attentional control: a possible gaydar mechanism

    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.

  13. Mechanisms of daughter cell-size control during cell division.

    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

  14. Sensory mechanisms of balance control in cerebellar disease

    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. Corticolimbic Mechanisms in the Control of Trial and Error Learning

    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...

  16. Sexual orientation biases attentional control: a possible gaydar mechanism

    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,...

  17. Cognitive Control Deficits in Schizophrenia: Mechanisms and Meaning

    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...

  18. Mechanisms of motor adaptation in reactive balance control.

    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.

  19. Efficiently making (almost) any concurrency control mechanism serializable

    Wang, Tianzheng; Johnson, Ryan; Fekete, Alan; Pandis, Ippokratis

    2016-01-01

    Concurrency control (CC) algorithms must trade off strictness for performance. In particular, serializable CC schemes generally pay higher cost to prevent anomalies, both in runtime overhead such as the maintenance of lock tables, and in efforts wasted by aborting transactions. We propose the serial safety net (SSN), a serializability-enforcing certifier which can be applied with minimal overhead on top of various CC schemes that offer higher performance but admit anomalies, such as snapshot ...

  20. Molecular Mechanisms to Control Post-Transplantation Hepatitis B Recurrence

    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.