WorldWideScience

Sample records for neuromuscular control mechanisms

  1. Molecular control of neuromuscular junction development.

    Ferraro, Elisabetta; Molinari, Francesca; Berghella, Libera

    2012-03-01

    Skeletal muscle innervation is a multi-step process leading to the neuromuscular junction (NMJ) apparatus formation. The transmission of the signal from nerve to muscle occurs at the NMJ level. The molecular mechanism that orchestrates the organization and functioning of synapses is highly complex, and it has not been completely elucidated so far. Neuromuscular junctions are assembled on the muscle fibers at very precise locations called end plates (EP). Acetylcholine receptor (AChR) clusterization at the end plates is required for an accurate synaptic transmission. This review will focus on some mechanisms responsible for accomplishing the correct distribution of AChRs at the synapses. Recent evidences support the concept that a dual transcriptional control of AChR genes in subsynaptic and extrasynaptic nuclei is crucial for AChR clusterization. Moreover, new players have been discovered in the agrin-MuSK pathway, the master organizer of postsynaptical differentiation. Mutations in this pathway cause neuromuscular congenital disorders. Alterations of the postynaptic apparatus are also present in physiological conditions characterized by skeletal muscle wasting. Indeed, recent evidences demonstrate how NMJ misfunctioning has a crucial role at the onset of age-associated sarcopenia. PMID:22450265

  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 to sense a rotational movement in the lumbar area and thus had clearly impaired lumbar movement perception (p = 0.006. Abnormal MEPs had only inconsistent and SEPs showed no associations with impaired movement perception and postural stability in LSS. Abnormal needle EMG findings and flexion-extension activation of paraspinal muscles were frequently observed in LSS patients. Lumbar paraspinal muscle endurance was better than in previously evaluated healthy subjects and chronic LBP patients (p < 0.001. The results demonstrated clearly impaired lumbar sensory and motor function in sciatica and LSS patients. The pure reflex activation of paraspinal muscles was not affected in sciatica but a difference was found in the premotoneuronal response control. The impaired proprioceptive functions and premotoneuronal response control seem to recover at least partially but the maintenance of postural stability is a complex activity which does not seem to recover automatically in operated sciatica patients at least in three months follow-up. Paraspinal muscle denervation and dysfunction were clearly detectable in LSS but lumbar paraspinal muscle endurance was unexpectedly good.

  3. 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...

  4. Neuromuscular control and rehabilitation of the unstable ankle.

    Hung, You-Jou

    2015-06-18

    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. However, there is no consensus on whether the neuromuscular control and proprioception are compromised in unstable ankles. To reduce the prevalence of ankle sprains, the effectiveness of engaging balance training to enhance the neuromuscular control and proprioception of the ankle joint is also questionable. PMID:26085985

  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. Mobile home ventilators are available for the implementation of the ventilation. Their technical performance however, differs regrettably. Studies comparing the economic aspects of ventilation in a hospital to outpatient ventilation, describe home ventilation as a more cost-effective alternative to in-patient care in an intensive care unit, however, more expensive in comparison to a noninvasive (via mask ventilation. Higher expenses arise due to the necessary equipment and the high expenditure of time for the partial 24-hour care of the affected patients through highly qualified personnel. However, none of the studies applies to the German provisionary conditions. The calculated costs strongly depend on national medical fees and wages of caregivers, which barely allows a transmission of the results. The results of quality-of-life studies are mostly qualitative. The patient’s quality of life using mechanical ventilation is predominantly considered well. Caregivers of ventilated patients report positive as well as negative ratings. Regarding the ethical questions, it was researched which aspects of ventilation implementation will have to be considered. From a legal point of view the financing of home ventilation, especially invasive mechanical ventilation, requiring specialised technical nursing is regulated in the code of social law (Sozialgesetzbuch V. The absorption of costs is distributed to different insurance carriers, who often, due to cost pressures within the health care system, insurance carriers, who consider others and not themselves as responsible. Therefore in practice, the necessity to enforce a claim of cost absorption often arises in order to exercise the basic right of free choice of location. Conclusion: Positive effects of the invasive mechanical ventilation (overall survival and symptomatic are highly probable based on the analysed literature, although with a low level of evidence. An establishment of a home ventilation registry and health care research to ascertain valid data to improve outpatient structures is necessary. Gathering specific German data is needed to adequately depict the national concepts of provision and reimbursement. A differentiation of the cost structure according to the type of chosen outpatient care is currently not possible. There is no existing literature concerning the difference of life quality depending on the chosen outpatient care (homecare, assisted living, or in a nursing home specialised in invasive home ventilation. Further research is required. For a so called participative decision – made by the patient after intense counselling – an early and honest patient education pro respectively contra invasive mechanical ventilation is needed. Besides the long term survival, the quality of life and individual, social and religious aspects have also to be considered.

  8. Autoimmune Neuromuscular Disorders

    Kraker, Jessica; Živković, Saša A

    2011-01-01

    Autoimmune neuromuscular disorders affecting peripheral nerves, neuromuscular junction or muscle have a wide clinical spectrum with diverse pathogenetic mechanisms. Peripheral nervous system may be targeted in the context of complex immune reactions involving different cytokines, antigen-presenting cells, B cells and different types of T cells. Various immunomodulating and cytotoxic treatments block proliferation or activation of immune cells by different mechanisms attempting to control the ...

  9. Effects of hamstring-emphasized neuromuscular training on strength and sprinting mechanics in football players.

    Mendiguchia, J; Martinez-Ruiz, E; Morin, J B; Samozino, P; Edouard, P; Alcaraz, P E; Esparza-Ros, F; Mendez-Villanueva, A

    2015-12-01

    The objective of this study was to examine the effects of a neuromuscular training program combining eccentric hamstring muscle strength, plyometrics, and free/resisted sprinting exercises on knee extensor/flexor muscle strength, sprinting performance, and horizontal mechanical properties of sprint running in football (soccer) players. Sixty footballers were randomly assigned to an experimental group (EG) or a control group (CG). Twenty-seven players completed the EG and 24 players the CG. Both groups performed regular football training while the EG performed also a neuromuscular training during a 7-week period. The EG showed a small increases in concentric quadriceps strength (ES = 0.38/0.58), a moderate to large increase in concentric (ES = 0.70/0.74) and eccentric (ES = 0.66/0.87) hamstring strength, and a small improvement in 5-m sprint performance (ES = 0.32). By contrast, the CG presented lower magnitude changes in quadriceps (ES = 0.04/0.29) and hamstring (ES = 0.27/0.34) concentric muscle strength and no changes in hamstring eccentric muscle strength (ES = -0.02/0.11). Thus, in contrast to the CG (ES = -0.27/0.14), the EG showed an almost certain increase in the hamstring/quadriceps strength functional ratio (ES = 0.32/0.75). Moreover, the CG showed small magnitude impairments in sprinting performance (ES = -0.35/-0.11). Horizontal mechanical properties of sprint running remained typically unchanged in both groups. These results indicate that a neuromuscular training program can induce positive hamstring strength and maintain sprinting performance, which might help in preventing hamstring strains in football players. PMID:25556888

  10. Functional Connectivity under Optogenetic Control Allows Modeling of Human Neuromuscular Disease.

    Steinbeck, Julius A; Jaiswal, Manoj K; Calder, Elizabeth L; Kishinevsky, Sarah; Weishaupt, Andreas; Toyka, Klaus V; Goldstein, Peter A; Studer, Lorenz

    2016-01-01

    Capturing the full potential of human pluripotent stem cell (PSC)-derived neurons in disease modeling and regenerative medicine requires analysis in complex functional systems. Here we establish optogenetic control in human PSC-derived spinal motorneurons and show that co-culture of these cells with human myoblast-derived skeletal muscle builds a functional all-human neuromuscular junction that can be triggered to twitch upon light stimulation. To model neuromuscular disease we incubated these co-cultures with IgG from myasthenia gravis patients and active complement. Myasthenia gravis is an autoimmune disorder that selectively targets neuromuscular junctions. We saw a reversible reduction in the amplitude of muscle contractions, representing a surrogate marker for the characteristic loss of muscle strength seen in this disease. The ability to recapitulate key aspects of disease pathology and its symptomatic treatment suggests that this neuromuscular junction assay has significant potential for modeling of neuromuscular disease and regeneration. PMID:26549107

  11. The use of “stabilization exercises” to affect neuromuscular control in the lumbopelvic region: a narrative review

    Bruno, Paul

    2014-01-01

    It is well-established that the coordination of muscular activity in the lumbopelvic region is vital to the generation of mechanical spinal stability. Several models illustrating mechanisms by which dysfunctional neuromuscular control strategies may serve as a cause and/or effect of low back pain have been described in the literature. The term “core stability” is variously used by clinicians and researchers, and this variety has led to several rehabilitative approaches suggested to affect the...

  12. 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...

  13. Computationally efficient models of neuromuscular recruitment and mechanics

    Song, D.; Raphael, G.; Lan, N.; Loeb, G. E.

    2008-06-01

    We have improved the stability and computational efficiency of a physiologically realistic, virtual muscle (VM 3.*) model (Cheng et al 2000 J. Neurosci. Methods 101 117-30) by a simpler structure of lumped fiber types and a novel recruitment algorithm. In the new version (VM 4.0), the mathematical equations are reformulated into state-space representation and structured into a CMEX S-function in SIMULINK. A continuous recruitment scheme approximates the discrete recruitment of slow and fast motor units under physiological conditions. This makes it possible to predict force output during smooth recruitment and derecruitment without having to simulate explicitly a large number of independently recruited units. We removed the intermediate state variable, effective length (Leff), which had been introduced to model the delayed length dependency of the activation-frequency relationship, but which had little effect and could introduce instability under physiological conditions of use. Both of these changes greatly reduce the number of state variables with little loss of accuracy compared to the original VM. The performance of VM 4.0 was validated by comparison with VM 3.1.5 for both single-muscle force production and a multi-joint task. The improved VM 4.0 model is more suitable for the analysis of neural control of movements and for design of prosthetic systems to restore lost or impaired motor functions. VM 4.0 is available via the internet and includes options to use the original VM model, which remains useful for detailed simulations of single motor unit behavior.

  14. 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

  15. 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

  16. Doenas neuromusculares / Neuromuscular disorders

    Umbertina C., Reed.

    2002-08-01

    Full Text Available Objetivo: apresentar os dados essenciais para o diagnstico diferencial entre as principais doenas neuromusculares, denominao genrica sob a qual agrupam-se diferentes afeces, decorrentes do acometimento primrio da unidade motora (motoneurnio medular, raiz nervosa, nervo perifrico, juno mi [...] oneural e msculo). Fontes dos dados: os aspectos clnicos fundamentais para estabelecer o diagnstico diferencial entre as diferentes doenas neuromusculares, bem como entre estas e as causas de hipotonia muscular secundria ao comprometimento do sistema nervoso central ou a doenas sistmicas no-neurolgicas, so enfatizados, com base na experincia clnica vinda do atendimento a crianas com doenas neuromusculares durante os ltimos 12 anos, no ambulatrio de doenas neuromusculares do Hospital das Clnicas da Faculdade de Medicina, da Universidade de So Paulo. A reviso bibliogrfica foi efetuada atravs do Medline e do peridico Neuromuscular Disorders, publicao oficial da World Muscle Society. Sntese dos dados: nas crianas, a maior parte destas afeces geneticamente determinada, sendo as mais comuns a distrofia muscular progressiva ligada ao sexo, de Duchenne, a amiotrofia espinal infantil, a distrofia muscular congnita, a distrofia miotnica de Steinert, e as miopatias congnitas, estruturais e no estruturais. Polineuropatias hereditrias, sndrome miastnica congnita e miopatias metablicas so menos comuns, porm mostram correlao geno-fenotpica cada vez mais precisa. Concluses: na dcada passada, inmeros avanos da gentica molecular facilitaram imensamente o diagnstico e o aconselhamento gentico das doenas neuromusculares mais comuns das crianas, inclusive possibilitando diagnstico fetal e, adicionalmente, vieram permitir melhor caracterizao fenotpica e classificao mais objetiva. Abstract in english Objective: to discuss the most important aspects for performing a differential diagnosis among the main neuromuscular disorders in children, that include the diseases affecting the motor unity, i.e. spinal motor neurons, peripheral nerves, neuromuscular junction and muscular fibers. Sources: the rev [...] iew of the clinical aspects that should be considered for a prompt differential diagnosis among several neuromuscular disorders as well as between those and the main causes of secondary muscular hypotonia due to central nervous system or systemic disturbances is based on the clinical experience acquired along the last 12 years in following-up children with Neuromuscular Disorders attended at the outpatient Service of Neuromuscular Disorders at the Hospital das Clnicas da Faculdade de Medicina da Universidade de So Paulo. In addition, it is based on Medline and on the review of the most recent numbers of Neuromuscular Disorders, the official journal of the World Muscle Society. Summary of the findings: most of neuromuscular disorders are genetic conditions in children and the most common of them are X-linked Progressive Muscular Dystrophy of Duchenne, Spinal Muscular Atrophy, Congenital Muscular Dystrophy, Myotonic Dystrophy and Congenital Myopathies. Conclusions: due to the phenomenal development in human molecular genetics the pathogenesis of several neuromuscular disorders in children has been clarified over the last decade. Nowadays many new diagnostic methods, including techniques of fetal diagnosis, and a more objective genotype-phenotype correlation as well as classification are available.

  17. Rab3-GEF Controls Active Zone Development at the Drosophila Neuromuscular Junction123

    Bae, Haneui; Chen, Shirui; Roche, John P.; Ai, Minrong; Wu, Chunlai

    2016-01-01

    Abstract Synaptic signaling involves the release of neurotransmitter from presynaptic active zones (AZs). Proteins that regulate vesicle exocytosis cluster at AZs, composing the cytomatrix at the active zone (CAZ). At the Drosophila neuromuscular junction (NMJ), the small GTPase Rab3 controls the distribution of CAZ proteins across release sites, thereby regulating the efficacy of individual AZs. Here we identify Rab3-GEF as a second protein that acts in conjunction with Rab3 to control AZ protein composition. At rab3-GEF mutant NMJs, Bruchpilot (Brp) and Ca2+ channels are enriched at a subset of AZs, leaving the remaining sites devoid of key CAZ components in a manner that is indistinguishable from rab3 mutant NMJs. As the Drosophila homologue of mammalian DENN/MADD and Caenorhabditis elegans AEX-3, Rab3-GEF is a guanine nucleotide exchange factor (GEF) for Rab3 that stimulates GDP to GTP exchange. Mechanistic studies reveal that although Rab3 and Rab3-GEF act within the same mechanism to control AZ development, Rab3-GEF is involved in multiple roles. We show that Rab3-GEF is required for transport of Rab3. However, the synaptic phenotype in the rab3-GEF mutant cannot be fully explained by defective transport and loss of GEF activity. A transgenically expressed GTP-locked variant of Rab3 accumulates at the NMJ at wild-type levels and fully rescues the rab3 mutant but is unable to rescue the rab3-GEF mutant. Our results suggest that although Rab3-GEF acts upstream of Rab3 to control Rab3 localization and likely GTP-binding, it also acts downstream to regulate CAZ development, potentially as a Rab3 effector at the synapse.

  18. Rapid and reversible responses to IVIG in autoimmune neuromuscular diseases suggest mechanisms of action involving competition with functionally important autoantibodies

    Berger, Melvin; McCallus, Daniel E.; Lin, Cindy Shin-Yi

    2013-01-01

    Intravenous immunoglobulin (IVIG) is widely used in autoimmune neuromuscular diseases whose pathogenesis is undefined. Many different effects of IVIG have been demonstrated in vitro, but few studies actually identify the mechanism(s) most important in vivo. Doses and treatment intervals are generally chosen empirically. Recent studies in Guillain-Barr syndrome and chronic inflammatory demyelinating polyneuropathy show that some effects of IVIG are readily reversible and highly dependent on t...

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

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

    2016-01-01

    This study analyzed the effect of 4 weeks of jumping interval training (JIT), included in endurance training, on neuromuscular and physiological parameters. Eighteen recreational runners, randomized in control and experimental groups, performed 40 min of running at 70% of velocity at peak oxygen uptake, for 3 times per week. Additionally, the experimental group performed the JIT twice per week, which consisted of 4 to 6 bouts of continuous vertical jumps (30 s) with 5-min intervals. Three days before and after the training period, the countermovement (CMJ) and continuous jump (CJ30), isokinetic and isometric evaluation of knee extensors/flexors, progressive maximal exercise, and submaximal constant-load exercise were performed. The JIT provoked improvement in neuromuscular performance, indicated by (i) increased jump height (4.7%; effect size (ES) = 0.99) and power output (≈3.7%; ES ≈ 0.82) of CMJ and rate of torque development of knee extensors in isometric contraction (29.5%; ES = 1.02); (ii) anaerobic power and capacity, represented by the mean of jump height (7.4%; ES = 0.8), and peak power output (PPO) (5.6%; ES = 0.73) of the first jumps of CJ30 and the mean of jump height (10.2%, ES = 1.04) and PPO (9.5%, ES = 1.1), considering all jumps of CJ30; and (iii) aerobic power and capacity, represented by peak oxygen uptake (9.1%, ES = 1.28), velocity at peak oxygen uptake (2.7%, ES = 1.11), and velocity corresponding to the onset of blood lactate accumulation (9.7%, ES = 1.23). These results suggest that the JIT included in traditional endurance training induces moderate to large effects on neuromuscular and physiological parameters. PMID:26624965

  20. Controlled pilot study of the effects of neuromuscular therapy in patients with Parkinson's disease.

    Craig, Lauren H; Svircev, Anna; Haber, Michael; Juncos, Jorge L

    2006-12-01

    The objectives of this study is to examine the effects of neuromuscular therapy (NMT) on motor and nonmotor symptoms in Parkinson's disease (PD). Thirty-six subjects with PD were randomly assigned to NMT or music relaxation (MR, or active control). Subjects received treatment twice a week for 4 weeks. Testing was conducted at baseline, after final treatment, and 8 days after final treatment. Primary outcome measures were the Motor subscale of the United Parkinson Disease Rating Scale (UPDRS) and the Clinical Global Impression scale (CGI-Change). Secondary outcome measures included a PD-specific quality of life scale (PDQ-39), quantitative measures of motor function, and severity scales for anxiety and depression symptoms. NMT resulted in a significant and sustained improvement in the Motor subscale of the UPDRS (P < or = 0.0001), most notable in the tremor scores. Also improved 1 week after the last treatment were the CGI scores (P = 0.007) and the finger-tapping speed (P = 0.001). The MR active control group had a slight improvement in tremor but evidenced no other change in motor function. Both groups exhibited a modest improvement in quality of life immediately after the last treatment. This effect was sustained for 8 days only in the MR group. In the nonmotor domains, the MR group evidenced improvements in mood (P = 0.001) and anxiety (P = 0.002), whereas NMT had no effect on mood (P = 0.09), and its initial effect on anxiety (P = 0.0009) dissipated after 8 days (P = 0.40). Group differences for UPDRS motor score and patient CGI-Change were superior in the NMT compared to the MR group. There was no group difference in PDQ-39 scores or in nonmotor measures. The findings suggest that NMT can improve motor and selected nonmotor symptoms in PD and that this effect is more durable for the motor symptoms. The results of this pilot study warrant larger controlled studies to examine dose range, durability, and mechanisms of NMT in PD function. PMID:17044088

  1. 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...

  2. Further Results on Predictor-Based Control of Neuromuscular Electrical Stimulation.

    Alibeji, Naji; Kirsch, Nicholas; Farrokhi, Shawn; Sharma, Nitin

    2015-11-01

    Electromechanical delay (EMD) and uncertain nonlinear muscle dynamics can cause destabilizing effects and performance loss during closed-loop control of neuromuscular electrical stimulation (NMES). Linear control methods for NMES often perform poorly due to these technical challenges. A new predictor-based closed-loop controller called proportional integral derivative controller with delay compensation (PID-DC) is presented in this paper. The PID-DC controller was designed to compensate for EMDs during NMES. Further, the robust controller can be implemented despite uncertainties or in the absence of model knowledge of the nonlinear musculoskeletal dynamics. Lyapunov stability analysis was used to synthesize the new controller. The effectiveness of the new controller was validated and compared with two recently developed nonlinear NMES controllers, through a series of closed-loop control experiments on four able-bodied human subjects. Experimental results depict statistically significant improved performance with PID-DC. The new controller is shown to be robust to variations in an estimated EMD value. PMID:25850093

  3. The Effect of Neuromuscular Blockade on Oxygen Consumption and Energy Expenditure in Mechanically Ventilated Acute Respiratory Insufficiency Patients

    Esra Yksel

    2012-04-01

    Full Text Available Objective: The aim of this study is to investigate the effect of neuromuscular blockade on oxygen consumption and energy expenditure in sedated patients with acute respiratory failure who were followed under mechanical ventilation support. Material and Method: 21 acute respiratory failure patients under mechanical ventilation support were included in the study. All patients were sedated with propofol infusion to have a sedation level of 3 on the Ramsay scale. After adequate sedation and hemodynamic stability was achieved, baseline values of oxygen consumption, carbondioxide production and energy consumption of the patients were measured by indirect calorimetry device and recorded. Neuromuscular transmission was monitorized by TOF-Guard, and then 0,1 mg/kg bolus dose vecuronium was administered to the patients. When TOF 0, 25, 50, 90 values were obtained, oxygen, carbondioxide and energy consumption were measured by indirect calorimetry device and recorded. Results: No statistically significant difference were found between pre- and post-curarisation hemodynamic parameters, ventilation parameters, arterial blood gas values (p>0.05. A statistically significant decrease was observed between the oxygen consumption, carbondioxide production and energy consumption measured before curarisation and when TOF value was 0 (p0.05. Conclusion: It was concluded that the effect of neuromuscular blockage on reducing energy and oxygen consumption should be taken into consideration while calculating the daily energy need in intensive care in patients curarized at TOF 0 level. (Journal of the Turkish Society Intensive Care 2012; 10: 8-12

  4. Estimulao eltrica neuromuscular e o alongamento passivo manual na recuperao das propriedades mecnicas do msculo gastrocnmio imobilizado Neuromuscular electric stimulation and manual passive stretching when recovering mechanical properties of immobilized gastrocnemius muscles

    Leonardo Csar Carvalho

    2008-01-01

    Full Text Available Avaliamos a influncia da imobilizao, remobilizao livre, remobilizao com alongamento passivo manual, remobilizao com estimulao eltrica neuromuscular (NMES e remobilizao por NMES e alongamento passivo manual associados sobre algumas propriedades mecnicas do msculo gastrocnmio de ratas. Foram avaliadas 60 ratas divididas em seis grupos.Um destes grupos foi usado como controle. Todos os outros grupos tiveram o membro posterior direito imobilizado por 14 dias consecutivos. Destes grupos um foi imobilizado e em seguida avaliado, um foi liberado da imobilizao e permaneceu nas gaiolas plsticas por 10 dias, outro foi submetido a tcnica de alongamento passivo manual por 10 dias consecutivos, outro foi submetido a NMES por 10 dias consecutivos e o ltimo foi submetido a NMES somado ao alongamento passivo manual por 10 dias consecutivos. Observamos que a imobilizao reduziu os valores das propriedades mecnicas avaliadas no msculo. A remobilizao livre no restabeleceu nenhuma das propriedades avaliadas. A remobilizao por alongamento passivo manual devolveu ao msculo as propriedades de alongamento no limite de proporcionalidade, rigidez e resilincia. A remobilizao estimulada por NMES restabeleceu todas as propriedades estudadas. A remobilizao por NMES somada ao alongamento passivo restabeleceu as propriedades mecnicas de alongamento no limite mximo e de proporcionalidade e rigidez.We evaluated the influence of immobilization, free remobilization, remobilization with manual passive stretching, remobilization with neuromuscular electric stimulation (NMES and remobilization with electric stimulation and associated passive stretching on some mechanical properties of the gastrocnemius muscle of female rats. Sixty female rats were assessed, being distributed into 6 experimental groups. One of these groups served as control. The animals of the five remaining groups had their right posterior limb immobilized for 14 consecutive days. From the five groups, one was sacrificed right after the immobilization period, a second group was released from immobilization, a third was submitted to the manual passive stretching technique for 10 consecutive days, a fourth was submitted to NMES for 10 consecutive days and the last one was submitted to NMES and manual passive stretching for 10 consecutive days. We found that the immobilization caused a significant reduction of the mechanical properties values evaluated on the muscle. The free remobilization could not reestablish any of the properties. The remobilization by manual passive stretching restored the mechanical properties of stretching at the proportionality limit, stiffness and resilience. The remobilization stimulated by NMES reestablished all of studied properties. The remobilization by electric stimulation and passive stretching reestablished the mechanical properties of stretching at the maximum limit, proportionality limit, and stiffness.

  5. Comparison of Twitch Responses During Current- or Voltage-Controlled Transcutaneous Neuromuscular Electrical Stimulation.

    Vargas Luna, José Luis; Krenn, Matthias; Löfler, Stefan; Kern, Helmut; Cortés R, Jorge A; Mayr, Winfried

    2015-10-01

    Neuromuscular electrical stimulation (NMES) is an established method for functional restoration of muscle function, rehabilitation, and diagnostics. In this work, NMES was applied with surface electrodes placed on the anterior thigh to identify the main differences between current-controlled (CC) and voltage-controlled (VC) modes. Measurements of the evoked knee extension force and the myoelectric signal of quadriceps and hamstrings were taken during stimulation with different amplitudes, pulse widths, and stimulation techniques. The stimulation pulses were rectangular and symmetric biphasic for both stimulation modes. The electrode-tissue impedance influences the differences between CC and VC stimulation. The main difference is that for CC stimulation, variation of pulse width and amplitude influences the amount of nerve depolarization, whereas VC stimulation is only dependent on amplitude variations for pulse widths longer than 150 μs. An important remark is that these findings are strongly dependent on the characteristics of the electrode-skin interface. In our case, we used large stimulation electrodes placed on the anterior thigh, which cause higher capacitive effects. The controllability, voltage compliance, and charge characteristics of each stimulation technique should be considered during the stimulators design. For applications that require the activation of a large amount of nerve fibers, VC is a more suitable option. In contrast, if the application requires a high controllability, then CC should be chosen prior to VC. PMID:26471138

  6. Effects of a 12-hour neuromuscular electrical stimulation treatment program on the recovery of upper extremity function in sub-acute stroke patients: a randomized controlled pilot trial

    Cui, Bao-Juan; Wang, Dao-Qing; Qiu, Jian-Qing; Huang, Lai-Gang; Zeng, Fan-Shuo; Zhang, Qi; Sun, Min; Liu, Ben-Ling; Sun, Qiang-San

    2015-01-01

    [Purpose] This study investigated the effects of a 12-hour neuromuscular electrical stimulation program in the evening hours on upper extremity function in sub-acute stroke patients. [Subjects and Methods] Forty-five subjects were randomized to one of three groups: 12-hour neuromuscular electrical stimulation group (n=15), which received 12 hours of neuromuscular electrical stimulation and conventional rehabilitation for the affected upper extremity; neuromuscular electrical stimulation group (n=15), which received 30 min of neuromuscular electrical stimulation and conventional rehabilitation; and control group (n=15), which received conventional rehabilitation only. The Fugl-Meyer assessment, Action Research Arm Test, and modified Ashworth scale were used to evaluate the effects before and after intervention, and 4 weeks later. [Results] The improvement in the distal (wrist-hand) components of the Fugl-Meyer assessment and Action Research Arm Test in the 12-hour neuromuscular electrical stimulation group was more significant than that in the neuromuscular electrical stimulation group. No significant difference was found between the two groups in the proximal component (shoulder-elbow) of the Fugl-Meyer assessment. [Conclusion] The 12-hour neuromuscular electrical stimulation group achieved better improvement in upper extremity motor function, especially in the wrist-hand function. This alternative therapeutic approach is easily applicable and can be used in stroke patients during rest or sleep. PMID:26311975

  7. 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...

  8. Center of Mass Acceleration Feedback Control of Functional Neuromuscular Stimulation for Standing in the Presence of Internal Postural Perturbations

    Nataraj, Raviraj; Audu, Musa L; Triolo, Ronald J.

    2012-01-01

    This study determined the feasibility and performance of center of mass (COM) acceleration feedback control of a neuroprosthesis utilizing functional neuromuscular stimulation (FNS) to restore standing balance to a single subject paralyzed by a motor and sensory complete, thoracic-level spinal cord injury (SCI). An artificial neural network (ANN) was created to map gain-modulated changes in total body COM acceleration estimated from body-mounted sensors to optimal changes in stimulation requi...

  9. Slackline training and neuromuscular performance in seniors: A randomized controlled trial.

    Donath, L; Roth, R; Zahner, L; Faude, O

    2016-03-01

    Slackline training (balancing on nylon ribbons) has been shown to improve neuromuscular performance in children and adults. Comparable studies in seniors are lacking. Thus, 32 seniors were randomly assigned [strata: age, gender, physical activity (PA)] to an intervention [INT; n = 16, age: 65 ± 4 years, PA: 9 ± 5 h/week] or control [CON, n = 16, age: 63 ± 4 years, PA: 8 ± 4 h/week] group. Slackline training was given for 6 weeks (3 times per week, attendance 97%). Static and slackline standing balance performance, force development, and maximal strength of the ankle muscles were assessed before and after slackline training. Muscle activity (lower limb and trunk) was recorded during balance testing. Moderate to large group × time interactions (0.02 performance, ankle strength, and power were not affected. Slackline training induced large task-specific improvements of slackline standing performance accompanied with reductions of lower limb and trunk muscle activity. Transfer effects to static balance and strength measures seem limited. PMID:25756231

  10. The miRNA pathway controls rapid changes in activity-dependent synaptic structure at the Drosophila melanogaster neuromuscular junction.

    Nesler, Katherine R; Sand, Robert I; Symmes, Breanna A; Pradhan, Sarala J; Boin, Nathan G; Laun, Anna E; Barbee, Scott A

    2013-01-01

    It is widely accepted that long-term changes in synapse structure and function are mediated by rapid activity-dependent gene transcription and new protein synthesis. A growing amount of evidence suggests that the microRNA (miRNA) pathway plays an important role in coordinating these processes. Despite recent advances in this field, there remains a critical need to identify specific activity-regulated miRNAs as well as their key messenger RNA (mRNA) targets. To address these questions, we used the larval Drosophila melanogaster neuromuscular junction (NMJ) as a model synapse in which to identify novel miRNA-mediated mechanisms that control activity-dependent synaptic growth. First, we developed a screen to identify miRNAs differentially regulated in the larval CNS following spaced synaptic stimulation. Surprisingly, we identified five miRNAs (miRs-1, -8, -289, -314, and -958) that were significantly downregulated by activity. Neuronal misexpression of three miRNAs (miRs-8, -289, and -958) suppressed activity-dependent synaptic growth suggesting that these miRNAs control the translation of biologically relevant target mRNAs. Functional annotation cluster analysis revealed that putative targets of miRs-8 and -289 are significantly enriched in clusters involved in the control of neuronal processes including axon development, pathfinding, and growth. In support of this, miR-8 regulated the expression of a wingless 3'UTR (wg 3' untranslated region) reporter in vitro. Wg is an important presynaptic regulatory protein required for activity-dependent axon terminal growth at the fly NMJ. In conclusion, our results are consistent with a model where key activity-regulated miRNAs are required to coordinate the expression of genes involved in activity-dependent synaptogenesis. PMID:23844193

  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. Time scale dependence of the center of pressure entropy: What characteristics of the neuromuscular postural control system influence stabilographic entropic half-life?

    Federolf, Peter; Zandiyeh, Payam; von Tscharner, Vinzenz

    2015-12-01

    The center of pressure (COP) movement in studies of postural control reveals a highly regular structure (low entropy) over short time periods and a highly irregular structure over large time scales (high entropy). Entropic half-life (EnHL) is a novel measure that quantifies the time over which short-term temporal correlations in a time series deteriorate to an uncorrelated, random structure. The current study suggested and tested three hypotheses about how characteristics of the neuromuscular postural control system may affect stabilometric EnHL: (H1) control system activity hypothesis: EnHL decreases with increased frequency of control system interventions adjusting COP motion; (H2) abundance of states hypothesis: EnHL decreases with increased number of mechanically equivalent states available to the postural system; and (H3) neurologic process hierarchy hypothesis: EnHL increases if postural control functions shift from the spinal level to the motor cortex. Thirty healthy participants performed quiet stance tests for 90 s in 18 different conditions: stance (bipedal, one-legged, and tandem); footwear (bare foot, regular sports shoe, and rocker sole shoes); and simultaneous cognitive task (two-back working memory task, no challenge). A four-way repeated-measures ANOVA revealed significant changes in EnHL for the different stance positions and for different movement directions (medio-lateral, anterior-posterior). These changes support H1 and H2. Significant differences were also found between rocker sole shoes and normal or barefoot standing, which supports H3. This study contributes to the understanding of how and why EnHL is a useful measure to monitor neuromuscular control of balance. PMID:26303025

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

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

    2015-09-10

    Hydrogen sulfide (H2S) is a widespread gasotransmitter also known as a powerful neuroprotective agent in the central nervous system. However, the action of H2S in peripheral synapses is much less studied. In the current project we studied the modulatory effects of the H2S donor sodium hydrosulfide (NaHS) on synaptic transmission in the mouse neuromuscular junction using microelectrode technique. Using focal recordings of presynaptic response and evoked transmitter release we have shown that NaHS (300 μM) increased evoked end-plate currents (EPCs) without changes of presynaptic waveforms which indicated the absence of NaHS effects on sodium and potassium currents of motor nerve endings. Using intracellular recordings it was shown that NaHS increased the frequency of miniature end-plate potentials (MEPPs) without changing their amplitudes indicating a pure presynaptic effect. Furthermore, NaHS increased the amplitude of end-plate potentials (EPPs) without influencing the resting membrane potential of muscle fibers. L-cysteine, a substrate of H2S synthesis induced, similar to NaHS, an increase of EPC amplitudes whereas inhibitors of H2S synthesis (β-cyano-L-alanine and aminooxyacetic acid) had the opposite effect. Inhibition of adenylate cyclase using MDL 12,330A hydrochloride (MDL 12,330A) or elevation of cAMP level with 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (pCPT-cAMP) completely prevented the facilitatory action of NaHS indicating involvement of the cAMP signaling cascade. The facilitatory effect of NaHS was significantly diminished when intracellular calcium (Ca(2+)) was buffered by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis acetoxymethyl ester (BAPTA-AM) and ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid acetoxymethyl ester (EGTA-AM). Activation of ryanodine receptors by caffeine or ryanodine increased acetylcholine release and prevented further action of NaHS on transmitter release, likely due to an occlusion effect. Inhibition of ryanodine receptors by ryanodine or dantrolene also reduced the action of NaHS on EPC amplitudes. Our results indicate that in mammalian neuromuscular synapses endogenously produced H2S increases spontaneously and evoked quantal transmitter release from motor nerve endings without changing the response of nerve endings. The presynaptic effect of H2S appears mediated by intracellular Ca(2+) and cAMP signaling and involves presynaptic ryanodine receptors. PMID:26192092

  14. Efeitos da estimulao eltrica neuromuscular durante a imobilizao nas propriedades mecnicas do msculo esqueltico / Effects of neuromuscular electric stimulation during immobilization in the mechanical properties of the skeletal muscle / Efectos de la estimulacin elctrica neuromuscular durante la inmovilizacin en las propiedades mecnicas del msculo esqueltico

    Joo Paulo Chieregato, Matheus; Liana Barbaresco, Gomide; Juliana Goulart Prata de, Oliveira; Jos Batista, Volpon; Antnio Carlos, Shimano.

    2007-02-01

    Full Text Available A estimulao eltrica neuromuscular (EENM) um importante recurso utilizado em medicina esportiva para acelerar processos de recuperao. O objetivo deste estudo foi analisar os efeitos da EENM durante a imobilizao do msculo gastrocnmio, em posies de alongamento (LP) e encurtamento (SP). Par [...] a tanto, 60 ratas fmeas jovens Wistar foram distribudas em seis grupos e acompanhadas durante sete dias: controle (C), eletroestimuladas (EE), imobilizadas em encurtamento (ISP), imobilizadas em alongamento (ILP), imobilizadas em encurtamento e eletroestimuladas (ISP + EE) e imobilizadas em alongamento e eletroestimuladas (ILP + EE). Para a imobilizao, o membro posterior direito foi envolvido por uma malha tubular e ataduras de algodo juntamente atadura gessada. A EENM foi utilizada com freqncia de 50Hz, 10 minutos por dia, totalizando 20 contraes em cada sesso. Aps sete dias os animais foram submetidos a eutansia e os msculos gastrocnmios retirados para a realizao do ensaio mecnico de trao em uma mquina universal de ensaios (EMIC). A partir dos grficos carga versus alongamento, foram calculadas as seguintes propriedades mecnicas: alongamento no limite de proporcionalidade (ALP), carga no limite de proporcionalidade (CLP) e rigidez. As imobilizaes SP e LP promoveram redues significativas (p Abstract in spanish La estimulacin elctrica neuromuscular (EENM) es un importante recurso utilizado en medicina deportiva para acelerar procesos de recuperacin. El objetivo de este estudio ha sido analizar los efectos de la EENM durante la inmovilizacin del msculo gastrocnemio, en posiciones de alongamiento (LP) y [...] contraccin (SP). Para tal fin, 60 ratones hembras jvenes Wistar fueron distribuidas en seis grupos y monitoreadas durante 7 das: control (C), electro estimuladas (EE), inmovilizadas en contraccin (ISP), inmovilizadas en alongamiento (ILP), inmovilizadas en contraccin y electro estimuladas (ISP + EE) e inmovilizadas en alongamiento y electro estimuladas (ILP + EE). Para la inmovilizacin, el miembro posterior derecho fue envuelto por una malla tubular y vendas de algodn en conjunto con vendas de escayola. La EENM fue utilizada con una frecuencia de 50 Hz, 10 minutos por da, totalizando 20 contracciones en cada sesin. Despus de 7 das los animales fueron sometidos a eutanasia y los msculos gastrocnemios fueron retirados para la realizacin del ensayo mecnico de traccin en una mquina universal de ensayos (EMIC). A partir de los grficos carga versus alongamiento se calcul las siguientes propiedades mecnicas: alongamiento en el lmite de proporcionalidad (ALP), carga en el lmite de proporcionalidad (CLP) y rigidez. Las inmovilizaciones SP y LP dieron reducciones significativas (p Abstract in english 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 youn [...] g 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 a

  15. Adaptive Control of Movement for Neuromuscular Stimulation-Assisted Therapy in a Rodent Model

    Kim, Seung-jae; Fairchild, Mallika D.; Iarkov, Alexandre; Abbas, James J.; Jung, Ranu

    2008-01-01

    Neuromotor therapy after spinal cord or brain injury often attempts to utilize activity-dependent plasticity to promote functional recovery. Neuromuscular electrical stimulation that activates paralyzed or paretic muscles may enhance passive assistance therapy by activating more muscle mass and enriching the sensory pattern with appropriately timed muscle spindle activation. To enable studies of activity-dependent plasticity, a rodent model for stimulation-assisted locomotor therapy was devel...

  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 effect of the combined use of braces and neuromuscular training, against the use of either braces or neuromuscular training as separate secondary preventive measures. This study expects to identify the most effective and cost-efficient secondary preventive measure for ankle sprains. The study results could lead to changes in the clinical guidelines on the prevention of ankle sprains, and they will become available in 2012. Trial registration Netherlands Trial Register (NTR: NTR2157

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

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

    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-...

  18. Differences in neuromuscular control between impact and no impact roundhouse kick in athletes of different skill levels.

    Quinzi, Federico; Camomilla, Valentina; Felici, Francesco; Di Mario, Alberto; Sbriccoli, Paola

    2013-02-01

    This study aimed at investigating two aspects of neuromuscular control around the hip and knee joint while executing the roundhouse kick (RK) using two techniques: Impact RK (IRK) at trunk level and No-Impact RK at face level (NIRK). The influence of technical skill level was also investigated by comparing two groups: elite Karateka and Amateurs. Surface electromyographic (sEMG) signals have been recorded from the Vastus Lateralis (VL), Biceps Femoris (BF), Rectus Femoris (RF), Gluteus Maximum (GM) and Gastrocnemious (GA) muscles of the kicking leg in six Karateka and six Amateurs performing the RKs. Hip and knee kinematics were also assessed. EMG data were rectified, filtered and normalized to the maximal value obtained for each muscle over all trials; co-activation (CI) indexes of antagonist vs. overall (agonist and antagonist) activity were computed for hip and knee flexion and extension. Muscle Fiber Conduction Velocity (CV) obtained from VL and BF muscles was assessed as well. The effect of group and kick on angular velocity, CIs, and CVs was tested through a two-way ANOVA (p strategy in the execution of the two kicks. CV results are suggestive of an improved ability of elite Karateka to recruit fast MUs as a part of training induced neuromuscular adaptation. PMID:23089236

  19. Control rod drive mechanism

    Object: To provide a control rod drive mechanism used for a BWR reactor, with which mechanism the speed of withdrawal of the control rod can be readily controlled according to the reactor power. Structure: In a control rod drive mechanism in which a first cylinder chamber for urging the control rod in the direction of insertion is formed on one side of a piston and a second cylinder chamber for urging the control rod in the direction of withdrawal is formed on the other side, a control valve for controlling the quantity of fluid flowing out of the first cylinder chamber is provided in a fluid passage communicating with the first cylinder chamber. This control valve is operated to control the in-flow and out-flow of drive water to thereby control the control rod withdrawal speed. (Ikeda, J.)

  20. Brain-controlled neuromuscular stimulation to drive neural plasticity and functional recovery.

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

    2015-08-01

    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 match 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

  1. 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; Døssing, Simon; Alkjaer, T; Magnusson, S Peter; Kjaer, Michael; Aagaard, Per

    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...

  2. 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...

  3. 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

  4. The drop-jump video screening test: retention of improvement in neuromuscular control in female volleyball players.

    Barber-Westin, Sue D; Smith, Stephanie T; Campbell, Thomas; Noyes, Frank R

    2010-11-01

    A valgus lower limb alignment is commonly documented during noncontact anterior cruciate ligament injuries. We previously developed a videographic drop-jump test to measure overall lower limb alignment in the coronal plane as a screening tool to detect such an abnormal (valgus) position on landing. A neuromuscular retraining program developed for female athletes was shown to be effective in improving lower limb alignment on this test immediately after completion of training. What remained unknown was whether these improvements would be retained for longer periods of time. Therefore, this study was undertaken to determine if these improvements in overall lower limb alignment would be retained up to 1 year after the training. Sixteen competitive, experienced female high-school volleyball players underwent the video drop-jump test and then completed the neuromuscular retraining program. The program consisted of a dynamic warm-up, jump training, speed and agility drills, strength training, and static stretching and was performed 3 times a week for 6 weeks. The athletes repeated the drop-jump test immediately upon completion of training and then 3- and 12-months later. Significant improvements were found in the mean normalized knee separation distance between the pre and posttrained values for all test sessions (p improvements in the mean normalized knee separation distance that were retained 12 months later. Five athletes failed to improve. The video drop-jump test, although not a risk indicator for a knee ligament injury, provides a cost-effective general assessment of lower limb position and depicts athletes who have poor control on landing and acceleration into a vertical jump. PMID:20940643

  5. 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

  6. Control rod drive mechanism

    Object: To facilitate mounting and removal of a control rod drive mechanism for facilitating inspection and maintenance and also improving the availability of the reactor by providing a housing of a control rod drive mechanism penetrating the pressure vessel of the reactor with a device for mounting and removing the control rod drive mechanism. Structure: A reactor pressure vessel containing a reactor core is provided at its bottom with a control rod drive mechanism housing penetrating the pressure vessel. The housing is provided with a connecting mechanism, which comprises a connecting section having an anti-rotation engagement section, and engagement section meshing with the anti-rotation engagement section, and springs mounted in the connecting section and engagement section. Thus, the control rod drive mechanism can be easily mounted in or removed from the housing by engagement or separation of the connecting section and engagement section in the connecting mechanism. In addition, since the mounting or removal operation can be carried out in a short period of time, it is possible to reduce the possibility of the exposure of operators to radiation and also improve the availability of the reactor. (Moriyama, K.)

  7. Center of mass acceleration feedback control of functional neuromuscular stimulation for standing in presence of internal postural perturbations

    Raviraj Nataraj

    2012-08-01

    Full Text Available This study determined the feasibility and performance of center of mass (COM acceleration feedback control of a neuroprosthesis utilizing functional neuromuscular stimulation (FNS to restore standing balance to a single subject paralyzed by a motor and sensory complete, thoracic-level spinal cord injury. An artificial neural network (ANN was created to map gain-modulated changes in total body COM acceleration estimated from body-mounted sensors to optimal changes in stimulation required to maintain standing. Feedback gains were systematically tuned to minimize the upper-limb (UL loads applied by the subject to an instrumented support device during internally generated postural perturbations produced by volitional reaching and object manipulation. Total body COM acceleration was accurately estimated (>90% variance explained from 2 three-dimensional (3-D accelerometers mounted on the pelvis and torso. Compared with constant muscle stimulation employed clinically, COM acceleration feedback control of stimulation improved standing performance by reducing the UL loading required to resist internal postural disturbances by 27%. This case study suggests that COM acceleration feedback could potentially be advantageous in a standing neuroprosthesis since it can be implemented with only a few feedback parameters and requires minimal instrumentation for comprehensive 3-D control of dynamic standing function.

  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

    Full Text Available 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 (Grupo I; rocurônio - 4 µg.mL-1 (Grupo II e rocurônio - 4 µg.mL-1 e procainamida - 20 µg.mL-1 (Grupo III. Avaliaram-se: 1 a amplitude das contrações musculares sob estimulação indireta em cada grupo, antes e após a adição dos fármacos; 2 os potenciais de placa terminal em miniatura (PPTM; 3 a eficácia da 4-aminopiridina na reversão do bloqueio neuromuscular. O mecanismo da interação foi estudado em Biventer cervicis (n = 5 e diafragma de rato desnervado (n = 5, observando-se a influência da procainamida na resposta à acetilcolina antes e após a adição da procainamida. RESULTADOS: A procainamida isoladamente não alterou as respostas neuromusculares. O bloqueio produzido com o Grupo III foi de 68,6% ± 7,1%, com diferença significativa (p = 0,0067 em relação ao Grupo II (10,4% ± 4,5%, revertido pela 4-aminopiridina. A procainamida ocasionou aumento na freqüência dos PPTM, seguido de bloqueio revertido pela 4-aminopiridina. Em Biventer cervicis a procainamida aumentou a resposta à ação de contração da acetilcolina, resultado não observado com o diafragma desnervado. CONCLUSÕES: A procainamida potencializou o bloqueio produzido pelo rocurônio. As alterações observadas com PPTM e Biventer cervicis identificaram ação pré-sináptica. O antagonismo da 4-aminopiridina sobre o bloqueio dos PPTM sugeriu dessensibilização dos receptores pela procainamida.JUSTIFICATIVA Y OBJETIVOS: La potenciación de la procainamida sobre el bloqueo neuromuscular producido por la d-tubocurarina ya está comprobada, pero sin embargo el mecanismo es controvertido. El objetivo del estudio fue el de evaluar la influencia de la procainamida en el bloqueo neuromuscular producido por el rocuronio e investigar los mecanismos de esa interacción. MÉTODO: Se utilizaron 15 ratones (250 a 300 g en preparación descrita por Bülbring. Se formaron los siguientes grupos (n = 5 cada: procainamida - 20 µg.mL-1 (Grupo I; rocuronio - 4 µg.mL-1 (Grupo II y rocuronio - 4µg.mL-1 y procainamida - 20µg.mL-1 (Grupo III. Se evaluó: 1 la amplitud de las contracciones musculares bajo la estimulación indirecta en cada grupo, antes y después de la adición de los fármacos; 2 los potenciales de placa terminal en miniatura (PPTM; 3 la eficacia de la 4-aminopiridina en la reversión del bloqueo neuromuscular. El mecanismo de la interacción se estudió en Biventer cervicis (n = 5 y diafragma de ratón desnervado (n = 5, observándose la influencia de la procainamida en la respuesta a la acetilcolina antes y después de la adición de la procainamida. RESULTADOS: De forma aislada, la procainamida no alteró las respuestas neuromusculares. El bloqueo producido con el Grupo III fue de 68,6% ± 7,1%, con una diferencia significativa (p = 0,0067 con relación al Grupo II (10,4% ± 4,5%, revertido por la 4-aminopiridina. La procainamida ocasionó un aumento en la frecuencia de los PPTM, seguido de bloqueo revertido por la 4-aminopiridina. En Biventer cervicis, la procainamida aumentó la respuesta a la acción de contracción de la acetilcolina, resultado no observado con el diafragma desnervado. CONCLUSIONES: La procainamida potenció el bloqueo producido por el rocuronio. Las alteraciones observadas con PPTM y Biventer cervicis identificaron una acción presináptica. El antagonismo de la 4-aminopiridina sobre el bloqueo de los PPTMs sugirió la desensibilización de los receptores por la procainamida.BACKGROUND AND OBJECTIVES: 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. Effects of repetitive work on proprioception and of stretching on sensory mechanisms : implications for work-related neuromuscular disorders

    Bjrklund, 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...

  10. 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-based, physiotherapist-supervised neuromuscular exercise program on medial knee joint load during various tasks in people with a partial medial meniscectomy. If shown to reduce the knee adduction moment, neuromuscular exercise has the potential to prevent the onset of osteoarthritis or slow its progression in those with early disease. Trial Registration Australian New Zealand Clinical Trials Registry reference: ACTRN12612000542897

  11. Efeitos dos exercícios funcionais e neuromusculares no tempo de internação e controle pressórico de pacientes hospitalizados

    Murillo Frazão de Lima e Costa; Jefferson Petto; Vinícius Afonso Gomes; Lorena Silles dos Prazeres; Alan Carlos Nery dos Santos; Maria da Conceição Gomes Almeida; Fabiano Leichsenring Silva; Mateus Souza Esquivel; Francisco Tiago Oliveira de Oliveira

    2015-01-01

    Introdução: Exercícios funcionais e neuromusculares são importantes ferramentas em centros de reabilitação, porém são pouco explorados em protocolos hospitalares. Objetivo: Verificar se exercícios funcionais e neuromusculares são mais eficazes na redução do tempo de internamento e controle da pressão arterial (PA) dos indivíduos hospitalizados do que a fisioterapia hospitalar de rotina. Métodos: Foram incluídos pacientes hospitalizados por enfermidades não cardiológicas e sem hipertensão arte...

  12. Comparison of the effectiveness of active and passive neuromuscular electrical stimulation of hemiplegic upper extremities: a randomized, controlled trial.

    Boyaci, Ahmet; Topuz, Oya; Alkan, Hakan; Ozgen, Merih; Sarsan, Ayse; Yildiz, Necmettin; Ardic, Fusun

    2013-12-01

    To compare the efficacy of electromyography (EMG)-triggered (active) neuromuscular electrical stimulation (NMES) and passive NMES in enhancing the upper extremity (UE) motor and functional recovery of subacute and chronic stage stroke patients. Thirty-one hemiplegic patients were randomly assigned to active NMES (n=11), passive NMES (n=10), and control (sham stimulation) (n=10) groups. Each treatment regimen was applied five times per week for 45 min for 3 weeks. All of the patients performed the same neurophysiologic exercise program for 45 min five times per week for 3 weeks. Patients were assessed by the UE component of the Fugl-Meyer Motor Assessment (UE-FMA), the self-care component of the Functional Independence Measure (self-care FIM), the Motor Activity Log (MAL), goniometric measurements of active wrist and metacarpophalangeal joint extension, surface EMG potentials, grip strength, and the modified Ashworth scale in a blinded manner. Data were obtained before and at the end of the treatment. Participants were similar in all clinical and demographic features (P>0.05). All groups were comparable with respect to UE-FMA, MAL, self-care FIM, wrist and finger flexor spasticity, active range of motion (ROM), grip strength, and surface EMG potentials before treatment (P>0.05). The active ROM, grip strength, FMA, FIM, surface EMG potentials, and MAL: amount of use were significantly improved in the EMG-triggered NMES group compared with the controls (Pevaluated at the end of the treatment (P>0.05). Both active and passive NMES as adjuvant therapy in the neurophysiologic exercise program effectively enhanced the UE motor and functional recovery of stroke survivors. PMID:23579106

  13. 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

  14. Control rod drive mechanism

    Purpose: To provide a control rod drive mechanism using water as an operating source, which prevents a phenomenon for forming two-layers of water in the neighbourhood of a return nozzle in a reactor to limit formation of excessive thermal stress to improve a safety. Constitution: In the control rod drive mechanism of the present invention, a heating device is installed in the neighbourhood of a pressure container for a reactor. This heating device is provided to heat return water in the reactor to a level equal to the temperature of reactor water thereby preventing a phenomenon for forming two-layers of water in the reactor. This limits formation of thermal stress in the return nozzle in the reactor. Accordingly, it is possible to minimize damages in the return nozzle portion and yet a possibility of failure in reactor water. (Kawakami, Y.)

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

    van der Wilt Gert-Jan

    2011-08-01

    Full Text Available Abstract Background Shared medical appointments are a series of one-to-one doctor-patient contacts, in presence of a group of 6-10 fellow patients. This group visits substitute the annual control visits of patients with the neurologist. The same items attended to in a one-to- one appointment are addressed. The possible advantages of a shared medical appointment could be an added value to the present management of neuromuscular patients. The currently problem-focused one-to-one out-patient visits often leave little time for the patient's psychosocial needs, patient education, and patient empowerment. Methods/design A randomized, prospective controlled study (RCT with a follow up of 6 months will be conducted to evaluate the clinical and cost-effectiveness of shared medical appointments compared to usual care for 300 neuromuscular patients and their partners at the Radboud University Nijmegen Medical Center. Every included patient will be randomly allocated to one of the two study arms. This study has been reviewed and approved by the medical ethics committee of the region Arnhem-Nijmegen, the Netherlands. The primary outcome measure is quality of life as measured by the EQ-5D, SF-36 and the Individualized neuromuscular Quality of Life Questionnaire. The primary analysis will be an intention-to-treat analysis on the area under the curve of the quality of life scores. A linear mixed model will be used with random factor group and fixed factors treatment, baseline score and type of neuromuscular disease. For the economic evaluation an incremental cost-effectiveness analysis will be conducted from a societal perspective, relating differences in costs to difference in health outcome. Results are expected in 2012. Discussion This study will be the first randomized controlled trial which evaluates the effect of shared medical appointments versus usual care for neuromuscular patients. This will enable to determine if there is additional value of shared medical appointments to the current therapeutical spectrum. When this study shows that group visits produce the alleged benefits, this may help to increase the acceptance of this innovative and creative way of using one of the most precious resources in health care more efficiently: time. Trial registration DutchTrial Register http://www.trialregister.nlNTR1412

  16. Speed adaptation in a powered transtibial prosthesis controlled with a neuromuscular model

    Markowitz, Jared; Krishnaswamy, Pavitra; Eilenberg, Michael F.; Endo, Ken; Barnhart, Chris; Herr, Hugh

    2011-01-01

    Control schemes for powered ankle–foot prostheses would benefit greatly from a means to make them inherently adaptive to different walking speeds. Towards this goal, one may attempt to emulate the intact human ankle, as it is capable of seamless adaptation. Human locomotion is governed by the interplay among legged dynamics, morphology and neural control including spinal reflexes. It has been suggested that reflexes contribute to the changes in ankle joint dynamics that correspond to walking ...

  17. 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 58.816.3 and 62.022.4nmol/L, respectively) than PNP patients (mean 42.111.5nmol/L, p=0.01) and healthy controls (mean 45.713.8nmol/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

  18. 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...... generated by the stimulation current, are relatively easy to eliminate by shutting down the EMG-amplifier at the onset of the stimulation pulses. The muscle response is a nonstationary signal, therefore, an adaptive linear prediction filter is proposed. The filter is implemented and for three filter lengths...... shut-down circuit and the adaptive filter both the stimulation artifacts and the muscle responses can be effectively eliminated from the EMG signal from a stimulated muscle. It is therefore possible to extract the volitional EMG from a partly paralyzed muscle and use it for controlling the stimulation...

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

  20. 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.)

  1. 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-reported physical function measured at baseline and immediately following the program. Secondary outcomes include the external knee adduction moment angular impulse, electromyographic muscle activation patterns, knee and hip muscle strength, balance, functional ability, and quality-of-life. Discussion The findings will help determine whether neuromuscular exercise is superior to traditional quadriceps strengthening regarding effects on knee load, pain and physical function in people with medial knee osteoarthritis and varus malalignment. Trial Registration Australian New Zealand Clinical Trials Registry reference: ACTRN12610000660088

  2. Age-related neuromuscular function and dynamic balance control during slow and fast balance perturbations.

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

    2013-12-01

    This study investigated age-related differences in dynamic balance control and its connection to reflexes and explosive isometric plantar flexor torque in 19 males (9 Young aged 20-33 yr, 10 Elderly aged 61-72 yr). Dynamic balance was measured during Slow (15 cm/s) and Fast (25 cm/s) anterior and posterior perturbations. H/M-ratio was measured at 20% of maximal M-wave (H/M20%) 10, 30, and 90 ms after perturbations. Stretch reflexes were measured from tibialis anterior and soleus during anterior and posterior perturbations, respectively. In Slow, Elderly exhibited larger peak center-of-pressure (COP) displacement (15%; P wave latency was similar between groups (6.2 ± 0.7 vs. 6.9 ± 1.2 ms), whereas Elderly showed a longer H-reflex latency (33.7 ± 2.3 vs. 36.4 ± 1.7 ms; P < 0.01). H/M20% was higher in Young 30 ms after Fast anterior (50%; P < 0.05) and posterior (51%; P < 0.05) perturbations. Plantar flexor rapid torque was also higher in Young (26%; P < 0.05). After combining both groups' data, H/M20% correlated negatively with Slow peak COP displacement (r = -0.510, P < 0.05) and positively with Fast recovery time (r = 0.580, P < 0.05) for anterior perturbations. Age-related differences in balance control seem to be more evident in anterior than posterior perturbations, and rapid sensory feedback is generally important for balance perturbation recovery. PMID:24047908

  3. Unmammed Gun Control Mechanism

    LAXMI NIDHI, PRATYUSHA ROY, SRISHTY NAYAK, RAJINE SWETHA R

    2013-05-01

    Full Text Available From ages it has been a desire of humans to achieve the ultimate in security and make his loved ones and loved things secure. It is this desire that prompted him to make the boundaries and secure them too from all unseen and unknown sources. For this it has been always necessary to maintain a huge sum of people to guard and raise alarms in cases of emergencies. To accomplish this we propose a mechanism which will employ image processing in which a camera (webcam will be continuously observing the ‘area under surveillance’. This data will be then processed by a MatLab code which will be running on a PC and will be able to detect a particular colour (Say Red in front of a white back ground (depicting snow. Depending on this processed data the information about the intruder location will be sent to a micro-controller (89c51 via the Serial/Parallel port of the PC and then a motor controlled gun will be used to point in the direction of the intruder. This mechanism will be online i.e. the gun will continuously be pointing in the direction of the intruder. Further depending on range (distance from the gun (fixed range in this project the gun can be activated and a Laser pointer will be switched ON depict “shooting the target”.

  4. Training for improved neuro-muscular control of balance in middle aged females.

    Anderson, Gregory S; Deluigi, Fabio; Belli, Guido; Tentoni, Claudio; Gaetz, Michael B

    2016-01-01

    This study examined improvements in static balance and muscle electromyographic (EMG) activity following a four week progressive training program in 16 middle aged females (mean age = 46.9 ± 8.7 yrs; height 161.1 ± 6.0 cm; weight 65.4 ± 11.2 kg). Participants trained 3 times per week for 4 weeks, for 50 min per session, progressing base of support, stability, vision, resistance and torque in each of six basic exercises. Pre and post training measures of balance included feet together standing, a tandem stance and a one-leg stand (unsupported leg in the saggital plane) performed with the eyes closed, and a Stork Stand (unsupported leg in the frontal plane) with both eyes open and closed. In each position postural deviations were tallied for each individual while muscle recruitment was determined using root mean squared (RMS) EMG activity for the soleus, biceps femoris, erector spinae, rectus abdominis and internal oblique muscles of the dominant foot side. Balance scores were significantly improved post training in both the Balance Error Score System (p balance and reduced body sway. The core muscles were able to control body position with less activity post training suggesting improved muscle coordination and efficiency. These results suggest that short term progressive floor to BOSU™ balance training can improve standing balance in middle aged women. PMID:26891632

  5. 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

  6. 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; Roos, Ewa M.; Hodges, Paul W; Staples, Margaret; Bennell, Kim L

    2012-01-01

    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...

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

    Bruce-Brand Robert A; Walls Raymond J; Ong Joshua C; Emerson Barry S; OByrne John M; Moyna Niall M

    2012-01-01

    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 elec...

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

    AlessandraPedrocchi

    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.

  9. 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...

  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. Effects of neuromuscular training (NEMEX-TJR) on patient-reported outcomes and physical function in severe primary hip or knee osteoarthritis: a controlled before-and-after study

    Ageberg, Eva; Nilsdotter, Anna; Kosek, Eva; Roos, Ewa M.

    2013-01-01

    Background: 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 before-and-after study were to compare baseline status to an age-matched population-based reference group and to examine the effects of neuromuscular training on patient-reported outcomes and...

  12. 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

  13. 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

    Full Text Available 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 alongamento (ILP, imobilizadas em encurtamento e eletroestimuladas (ISP + EE e imobilizadas em alongamento e eletroestimuladas (ILP + EE. Para a imobilização, o membro posterior direito foi envolvido por uma malha tubular e ataduras de algodão juntamente à atadura gessada. A EENM foi utilizada com freqüência de 50Hz, 10 minutos por dia, totalizando 20 contrações em cada sessão. Após sete dias os animais foram submetidos a eutanásia e os músculos gastrocnêmios retirados para a realização do ensaio mecânico de tração em uma máquina universal de ensaios (EMIC®. A partir dos gráficos carga versus alongamento, foram calculadas as seguintes propriedades mecânicas: alongamento no limite de proporcionalidade (ALP, carga no limite de proporcionalidade (CLP e rigidez. As imobilizações SP e LP promoveram reduções significativas (p La estimulación eléctrica neuromuscular (EENM es un importante recurso utilizado en medicina deportiva para acelerar procesos de recuperación. El objetivo de este estudio ha sido analizar los efectos de la EENM durante la inmovilización del músculo gastrocnemio, en posiciones de alongamiento (LP y contracción (SP. Para tal fin, 60 ratones hembras jóvenes Wistar fueron distribuidas en seis grupos y monitoreadas durante 7 días: control (C, electro estimuladas (EE, inmovilizadas en contracción (ISP, inmovilizadas en alongamiento (ILP, inmovilizadas en contracción y electro estimuladas (ISP + EE e 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 immobilizations promoted significant reductions (p < 0.05 in the EPL and LPL properties, b

  14. Efeitos dos exercícios funcionais e neuromusculares no tempo de internação e controle pressórico de pacientes hospitalizados

    Murillo Frazão de Lima e Costa

    2015-05-01

    Full Text Available Introdução: Exercícios funcionais e neuromusculares são importantes ferramentas em centros de reabilitação, porém são pouco explorados em protocolos hospitalares. Objetivo: Verificar se exercícios funcionais e neuromusculares são mais eficazes na redução do tempo de internamento e controle da pressão arterial (PA dos indivíduos hospitalizados do que a fisioterapia hospitalar de rotina. Métodos: Foram incluídos pacientes hospitalizados por enfermidades não cardiológicas e sem hipertensão arterial sistêmica, sendo estes randomizados para grupo controle (GC, que realizou exercícios respiratórios, exercícios ativo-livres para membros superiores/inferiores e caminhada no corredor, ou grupo de reabilitação funcional (GRF, submetido a exercícios neuromusculares para membros superiores/inferiores, cicloergômetro e treino de subir/descer degraus. Ambos os grupos receberam intervenção 2x/dia. A PA foi aferida na admissão, durante o internamento e na alta hospitalar. O tratamento estatístico foi realizado adotando-se intervalo de confiança de 95% e nível de significância de 5%. Resultados: Avaliados 42 voluntários, dos quais 26 atenderam aos critérios de elegibilidade. Porém, seis foram excluídos, quatro por permanência hospitalar inferior a três dias e dois por não completarem o protocolo de tratamento. A média de idade no GC foi de 72±11 versus 73±8 no GRF. Não houve diferenças estatísticas da PA na admissão. Evidenciou-se redução da PA apenas no GRF durante o internamento (p<0,01, assim como na alta hospitalar (p<0,01. O GC apresentou maior tempo (dias de internação 7,2±1,8 versus 5,5±1,3 do GRF (p<0,05. Conclusão: Exercícios funcionais e neuromusculares parecem mais eficazes na redução do tempo de internamento e controle da PA dos indivíduos hospitalizados do que a fisioterapia hospitalar de rotina.

  15. 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.

  16. Automatic control rod drive mechanism

    Object: To permit control rods for controlling reactor power to be automatically driven from start to shut-down and permit self-diagnosis of each operation for preventing erroneous operation. Structure: A prescribed control rod is selected from a control rod co-ordinate specification means. As signal from the control rod co-ordinate specification means is coupled to an input means of an electronic computer and compared with the content of a memorizing/operation means. If the compared signals coincide with each other, a control rod position specification means is placed into a ready state by a signal from an output means. When a control rod withdrawal insertion means is placed in a ready state, a signal is transmitted to a control rod drive mechanism for driving the control rod. A lead switch detects the tip of the control rod, whereby the control rod is positioned in a specified position. (Nakamura, S.)

  17. 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.

  18. 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

  19. 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...

  20. Aprotinin in pediatric neuromuscular scoliosis surgery.

    Kasimian, Stepan; Skaggs, David L; Sankar, Wudbhav N; Farlo, Joseph; Goodarzi, Mashallah; Tolo, Vernon T

    2008-12-01

    Reduction of blood transfusions in patients with neuromuscular scoliosis can decrease potential complications such as immune suppression, infection, hemolytic reaction and viral transmission. Aprotinin (Trasylol), Bayer), an antifibrinolytic, has proven to be effective in reducing blood loss in cardiac and liver surgery, but little data exists in patients undergoing spinal fusion for neuromuscular scoliosis. The purpose of this study was to evaluate the safety and efficacy of aprotinin in pediatric neuromuscular scoliosis patients undergoing spinal fusion. The medical records of all patients undergoing initial spinal fusions for neuromuscular scoliosis between January 1999 and March 2003 were reviewed to determine demographic data, perioperative data, wound drainage and number of transfusion required. Cases were compared to a matched group of historical controls. We had 14 patients in the aprotinin group and 17 in the control group. Total blood loss in the aprotinin group was significantly lower compared to the control group (715 vs. 2,110 ml; P = 0.007). Significantly less blood loss occurred in the aprotinin group when blood loss per kilogram was evaluated as well (23 vs. 60 ml/kg, respectively; P = 0.002). Intra-operative packed red blood cell (PRBC) transfusions were also significantly lower in the aprotinin group (1.25 vs. 3.16 units; P = 0.001). No clinical evidence of anaphylaxis, deep vein thrombosis (DVT) or renal failure was observed in the aprotinin group. After considering the price of drug therapy, operating room time, and the cost of blood products, the use of aprotinin saved an average of $8,577 per patient. In our series, the use of aprotinin resulted in decreased blood loss and a decreased rate of transfusions in children with neuromuscular scoliosis undergoing extensive spinal fusion. At out institution, the use of aprotinin is safe and cost effective for patients with neuromuscular scoliosis. PMID:18820953

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

    Madsen, Matias Vested; Donatsky, Anders Meller; Jensen, Bente Rona; Rosenberg, Jacob; Hammelev, Karsten Pharao; Gätke, Mona Ring

    2015-01-01

    endotracheally intubated, mechanically ventilated, anesthetized with propofol and fentanyl, and randomized into two groups in a cross-over assessor-blinded design. Neuromuscular block was established with rocuronium. Artificial laparotomy for ileus was performed. We investigated the influence of intense...... 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...... suctioning the lungs at intense neuromuscular block. Without neuromuscular block we detected abdominal contractions seen as hiccups and bucking. In all six pigs during intense neuromuscular block we found no visible electromyographic (EMG) activity in the abdominal muscles while suctioning the lungs. Without...

  2. Neuromuscular Exercise Post Partial Medial Meniscectomy

    Hall, Michelle; Hinman, Rana S; Wrigley, Tim V; Roos, Ewa M.; Hodges, Paul W; Staples, Margaret P; Bennell, Kim L

    2015-01-01

    assessor-blinded, randomised controlled trial including people aged 30-50 years with no to mild pain following medial arthroscopic partial meniscectomy was conducted. Participants were randomly allocated to either a 12-week neuromuscular exercise program that targeted neutral lower limb alignment or a....... CONCLUSIONS: In patients 3-12 months following a medial arthroscopic partial meniscectomy, a neuromuscular exercise program did not alter the peak knee adduction moment, a key predictor of osteoarthritis structural disease progression. Australia and New Zealand Clinical Trials Registry (#ACTRN12612000542897).......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: An...

  3. Neuromuscular control of trout swimming in a vortex street: implications for energy economy during the Karman gait.

    Liao, James C

    2004-09-01

    Approximating the complexity of natural locomotor conditions provides insight into the diversity of mechanisms that enable animals to successfully navigate through their environment. When exposed to vortices shed from a cylinder, fishes hold station by adopting a mode of locomotion called the Kármán gait, whereby the body of the fish displays large, lateral oscillations and the tail-beat frequency matches the vortex shedding frequency of the cylinder. Although field studies indicate that fishes often prefer turbulent flows over uniform currents, the effect of hydrodynamic perturbations on the mechanics, control and energetics of locomotion is still poorly understood. In this study, electromyography is used to measure red and white axial muscle activity for rainbow trout (Oncorhynchus mykiss) holding station in a vortex street. When trout Kármán gait, they show a significantly reduced but still rhythmic pattern of muscle activity compared with that seen when they swim steadily in uniform flow. Specifically, trout selectively activated only their anterior red axial muscles and abandoned the antero-posterior wave of red muscle activity that drives undulatory locomotion in uniform flow. This supports a previously proposed hypothesis that trout are not just swimming in the reduced flow behind a cylinder (drafting). Anterior axial muscle activity was correlated to head amplitude during steady swimming but not during the Kármán gait, indicating that while activation of muscles during the Kármán gait may aid in stability and control, vortices determined overall head motion. Furthermore, anterior red axial muscle activity, the only region of muscle activity shared between both the Kármán gait and steady swimming, had a lower intensity and longer duration during the Kármán gait. At times when paired fins were active during the Kármán gait, there was no axial muscle activity measured, lending support to a passive mechanism of thrust generation in oscillating flows. Comparisons with dead trout towed behind a cylinder confirm this intriguing observation that live trout may temporarily adopt the Kármán gait with no axial muscle activity, revealing paradoxically that at times fish can passively move against turbulent flow. To Kármán gait for prolonged periods, however, trout must adapt to the demands of turbulence by eliciting a shift in neural control strategy. By decoupling motor output both down and across the body, the pattern of rhythmic Kármán gait muscle activity may reflect the entrainment of a central pattern generator to environmental vortices. PMID:15339945

  4. 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.

  5. 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.

  6. 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.

  7. Dynamic Flexibility and Proprioceptive Neuromuscular Facilitation.

    Hardy, Lew; Jones, David

    1986-01-01

    Two experiments are described which investigated whether results obtained in studies of static flexibility tranfer to dynamic flexibility. In both experiments, subjects were assigned to a group receiving proprioceptive neuromuscular facilitation training, ballistic stretching technique training or a control group. Results are presented and…

  8. Dynamic Flexibility and Proprioceptive Neuromuscular Facilitation.

    Hardy, Lew; Jones, David

    1986-01-01

    Two experiments are described which investigated whether results obtained in studies of static flexibility tranfer to dynamic flexibility. In both experiments, subjects were assigned to a group receiving proprioceptive neuromuscular facilitation training, ballistic stretching technique training or a control group. Results are presented and

  9. 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...

  10. Kinesio Taping(®) does not alter neuromuscular performance of femoral quadriceps or lower limb function in healthy subjects: randomized, blind, controlled, clinical trial.

    Lins, Caio Alano de Almeida; Neto, Francisco Locks; Amorim, Anita Barros Carlos de; Macedo, Liane de Brito; Brasileiro, Jamilson Simões

    2013-02-01

    The aim of this study was to analyze the immediate effects of applying Kinesio Taping(®) (KT) on the neuromuscular performance of femoral quadriceps, postural balance and lower limb function in healthy subjects. This is a randomized, blind, controlled, clinical trial, where sixty female volunteers (age: 23.3 ± 2.5 years; BMI: 22.2 ± 2.1 kg/m(2)) were randomly assigned to three groups of 20 subjects each: control (10 min at rest); nonelastic adhesive tape (application over the rectus femoris, vastus lateralis and vastus medialis muscles); and KT (KT application over the same muscles). All individuals were assessed for single and triple hops, postural balance (by baropodometry), peak concentric and eccentric torque and electromyographic activity of vastus lateralis, before and after interventions. No significant differences in electromyographic activity of the VL or concentric and eccentric knee peak torque were recorded, between groups and initial and final assessment in any of the three groups. We also observed no significant alteration in single and triple-hop distance and one-footed static balance between the three groups. Application of KT to RF, VL and VM muscles did not significantly change lower limb function, postural balance, knee extensor peak torque or electromyographic activity of VL muscle in healthy women. PMID:22796389

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

    Holtermann, A; Roeleveld, K; Mork, P J; Grönlund, C; Karlsson, J S; Andersen, L L; Olsen, H B; Zebis, M K; Sjøgaard, G; Søgaard, K

    2009-01-01

    Task-dependent differences in relative activity between "functional" subdivisions within human muscles are well documented. Contrary, independent voluntary control of anatomical subdivisions, termed neuromuscular compartments is not observed in human muscles. Therefore, the main aim of this study...

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

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

    2014-04-01

    The present study compared neuromuscular adaptations to 12weeks of plyometric (PLY) or pneumatic (PNE) power training and their effects on dynamic balance control. Twenty-two older adults aged 60-70 (PLY n=9, PNE n=11) participated in the study. Measurements were conducted at Pre, 4, 8 and 12weeks. Dynamic balance was assessed as anterior-posterior center of pressure (COP) displacement in response to sudden perturbations. Explosive isometric knee extension and plantar flexion maximal voluntary contractions (MVCs) were performed. Maximal drop jump performance from optimal dropping height was measured in a sledge ergometer. Increases in knee extensor and ankle plantar flexor torque and muscle activity were higher and occurred sooner in PNE, whereas in drop jumping, PLY showed a clearer increase in optimal drop height (24%, pcontrol after 4weeks of training (PLY 38%, pcontrol in older individuals. As COP displacement was negatively correlated with rapid knee extension torque in both groups (PLY r=-0.775, p<0.05; PNE r=-0.734, p<0.05) after training, the results also highlight the importance of targeting rapid force production when training older adults to improve dynamic balance. PMID:24581701

  13. Universal Controller for Spacecraft Mechanisms

    Levanas, Greg; McCarthy, Thomas; Hunter, Don; Buchanan, Christine; Johnson, Michael; Cozy, Raymond; Morgan, Albert; Tran, Hung

    2006-01-01

    An electronic control unit has been fabricated and tested that can be replicated as a universal interface between the electronic infrastructure of a spacecraft and a brushless-motor (or other electromechanical actuator) driven mechanism that performs a specific mechanical function within the overall spacecraft system. The unit includes interfaces to a variety of spacecraft sensors, power outputs, and has selectable actuator control parameters making the assembly a mechanism controller. Several control topologies are selectable and reconfigurable at any time. This allows the same actuator to perform different functions during the mission life of the spacecraft. The unit includes complementary metal oxide/semiconductor electronic components on a circuit board of a type called rigid flex (signifying flexible printed wiring along with a rigid substrate). The rigid flex board is folded to make the unit fit into a housing on the back of a motor. The assembly has redundant critical interfaces, allowing the controller to perform time-critical operations when no human interface with the hardware is possible. The controller is designed to function over a wide temperature range without the need for thermal control, including withstanding significant thermal cycling, making it usable in nearly all environments that spacecraft or landers will endure. A prototype has withstood 1,500 thermal cycles between 120 and +85 C without significant deterioration of its packaging or electronic function. Because there is no need for thermal control and the unit is addressed through a serial bus interface, the cabling and other system hardware are substantially reduced in quantity and complexity, with corresponding reductions in overall spacecraft mass and cost.

  14. Optimal Control of Mechanical Systems

    Vadim Azhmyakov

    2007-08-01

    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.

  15. 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.)

  16. Age-related neuromuscular function during drop jumps.

    Hoffrén, M; Ishikawa, M; Komi, P V

    2007-10-01

    Muscle- and movement-specific fascicle-tendon interaction affects the performance of the neuromuscular system. This interaction is unknown among elderly and consequently contributes to the lack of understanding the age-related problems on neuromuscular control. The present experiment studied the age specificity of fascicle-tendon interaction of the gastrocnemius medialis (GM) muscle in drop jump (DJ) exercises. Twelve young and thirteen elderly subjects performed maximal squat jumps and DJs with maximal rebound effort on a sledge apparatus. Ankle and knee joint angles, reaction force, and electromyography (EMG) from the soleus (Sol), GM, and tibialis anterior (TA) muscles were measured together with the GM fascicle length by ultrasonography. The results showed that the measured ankle joint stiffness (AJS) during the braking phase correlated positively with the rebound speed in both age groups and that both parameters were significantly lower in the elderly than in young subjects. In both groups, the AJS correlated positively with averaged EMG (aEMG) in Sol during the braking phase and was further associated with GM activation (r = 0.55, P braking phase and higher aEMG in the push-off phase, indicating less utilization of tendinous tissue (TT) elasticity. These different activation patterns are in line with the mechanical behavior of GM showing significantly less fascicle shortening and relative TT stretching in the braking phase in the elderly than in the young subjects. These results suggest that age-specific muscle activation patterns as well as mechanical behaviors exist during DJs. PMID:17690197

  17. 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.

  18. 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.

  19. 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....

  20. Gene and splicing therapies for neuromuscular diseases.

    Benchaouir, Rachid; Robin, Valerie; Goyenvalle, Aurelie

    2015-01-01

    Neuromuscular disorders (NMD) are heterogeneous group of genetic diseases characterized by muscle weakness and wasting. Duchenne Muscular dystrophy (DMD) and Spinal muscular atrophy (SMA) are two of the most common and severe forms in humans and although the molecular mechanisms of these diseases have been extensively investigated, there is currently no effective treatment. However, new gene-based therapies have recently emerged with particular noted advances in using conventional gene replacement strategies and RNA-based technology. Whilst proof of principle have been demonstrated in animal models, several clinical trials have recently been undertaken to investigate the feasibility of these strategies in patients. In particular, antisense mediated exon skipping has shown encouraging results and hold promise for the treatment of dystrophic muscle. In this review, we summarize the recent progress of therapeutic approaches to neuromuscular diseases, with an emphasis on gene therapy and splicing modulation for DMD and SMA, focusing on the advantages offered by these technologies but also their challenges. PMID:25961553

  1. 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.

  2. Flight style of the black-billed magpie: variation in wing kinematics, neuromuscular control, and muscle composition.

    Tobalske, B W; Olson, N E; Dial, K P

    1997-11-01

    Black-billed magpies (Pica pica; Corvidae) exhibit an unusual flight style with pronounced, cyclic variation in wingbeat frequency and amplitude during level, cruising flight. In an effort to better understand the underlying internal mechanisms associated with this flight style, we studied muscle activity patterns, fiber composition of the pectoralis muscle, and wingbeat kinematics using both laboratory and field techniques. Over a wide range of speeds in a windtunnel (0-13.4 m s-1), wingbeat frequency, wingtip elevation, and relative intensity of electromyographic (EMG) signals s-1 from the flight muscles were least at intermediate speeds, and increased at both slower and faster speeds, in approximate agreement with theoretical models that predict a U-shaped curve of power output with flight speed. Considerable variation was evident in kinematic and electromyographic variables, but variation was continuous, and, thus, was not adequately described by the simple two-gait system which is currently accepted as describing gait selection during vertebrate flight. Indirect evidence suggests that magpies vary their flight style consistent with reducing average power costs in comparison to costs associated with continuous flapping at a fixed level of power per wingbeat. The range of variation for the kinematic variables was similar in the field and lab; however, in the field, proportionally fewer flights showed significant correlations between wingbeat frequency and the other variables. Average flight speed in the field was 8.0 m s-1. Average wingbeat frequency was less in the field than in the windtunnel, but mean values for wingtip elevation and wingspan at midupstroke were not significantly different. Histological study revealed that the pectoralis muscle of magpies contained only fast-twitch (acid-stable) muscle fibers, which were classified as red (R) and intermediate (I) based on oxidative and glycolytic capacities along with fiber diameter. This fiber composition may be related to variation in wingbeat kinematics, but such composition is found in the pectoralis of other bird species. This suggests that the muscle fibers commonly found in the pectoralis of small to medium sized birds are capable of a wider range of efficient contractile velocities than predicted by existing theory. Future studies should explore alternative explanations for variation in wingbeat kinematics, including the potential role of nonverbal communication among cospecifics. PMID:9360313

  3. Neuromuscular adaptation to actual and simulated weightlessness

    Edgerton, V. R.; Roy, R. R.

    1994-01-01

    The chronic "unloading" of the neuromuscular system during spaceflight has detrimental functional and morphological effects. Changes in the metabolic and mechanical properties of the musculature can be attributed largely to the loss of muscle protein and the alteration in the relative proportion of the proteins in skeletal muscle, particularly in the muscles that have an antigravity function under normal loading conditions. These adaptations could result in decrements in the performance of routine or specialized motor tasks, both of which may be critical for survival in an altered gravitational field, i.e., during spaceflight and during return to 1 G. For example, the loss in extensor muscle mass requires a higher percentage of recruitment of the motor pools for any specific motor task. Thus, a faster rate of fatigue will occur in the activated muscles. These consequences emphasize the importance of developing techniques for minimizing muscle loss during spaceflight, at least in preparation for the return to 1 G after spaceflight. New insights into the complexity and the interactive elements that contribute to the neuromuscular adaptations to space have been gained from studies of the role of exercise and/or growth factors as countermeasures of atrophy. The present chapter illustrates the inevitable interactive effects of neural and muscular systems in adapting to space. It also describes the considerable progress that has been made toward the goal of minimizing the functional impact of the stimuli that induce the neuromuscular adaptations to space.

  4. 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

  5. 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...

  6. 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)

  7. 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

  8. 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.

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

    Rathleff, Michael Skovdal; Samani, Afshin; Olesen, Jens L.; Roos, Ewa M.; Rasmussen, Sten; Christensen, Birgitte Hede; Madeleine, Pascal

    2013-01-01

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

  10. Paradoxical antagonism of neuromuscular block by vecuronium metabolites.

    Ohta,Yoshio

    1985-12-01

    Full Text Available Vecuronium is hydrolyzed in the body to 3-deacetyl (ORG 7268, 17-deacetyl (ORG NC58, and 3, 17-bis-deacetyl (ORG 7402 derivatives. Interactions of vecuronium and these metabolites were studied in phrenic nerve-hemidiaphragm preparations of rats. As already reported, ORG 7268 had a potent neuromuscular blocking action, and ORG NC58 and ORG 7402 had a weak neuromuscular blocking action. As expected, ORG 7268 increased the degree of neuromuscular block by vecuronium. However, a low concentration (10 microM of ORG NC58 and ORG 7402 reversed the block by vecuronium. At a high concentration (50 microM, ORG NC58 and ORG 7402 increased the degree of block by vecuronium. Although we do not have enough data to explain these paradoxical reversal of neuromuscular block at this moment, we postulate that these results reflect the interaction between "slow" and "fast" competitive antagonists. Regardless of the mechanism, it should be emphasized that the concentrations of ORG NC58 and ORG 7402 which are necessary to reverse the block are much lower than those which facilitate the block. It is conceivable that this paradoxical reversal of the block occurs in experimental and clinical situations. Therefore, in determining the neuromuscular blocking action of a compound, the "antagonistic" effect of its metabolites should also be considered.

  11. Automatic exchanger for control rod drive mechanisms

    Purpose: To surely stop a control rod drive mechanism at an aimed position within an allowable range of error. Constitution: The automatic exchanger has a function of determining a parameter representing a relationship of a moving distance of a control rod drive mechanism relative to the time period for a moving instruction output by applying pulse-like moving instructions of different time periods for several times to the drive mechanism and a forecasting calculation control function of outputting a required moving instruction by the use of a parameter determined based on a difference between the aimed position and the present position in the case of moving the drive mechanism to its aimed position. As the result of the forecasting calculation control, if the drive mechanism is deviated from the aimed position exceeding a predetermined allowable range, the forecasting calculation controls are repeated so that the drive mechanism can reach within the allowable range for the aimed position. (Horiuchi, T.)

  12. Immune mechanisms of HIV control

    Chakrabarti, Lisa A.; Simon, Viviana

    2010-01-01

    HIV-1 can be contained by the immune system, as demonstrated by the existence of rare individuals who spontaneously control HIV-1 replication in the absence of antiretroviral therapy. Emerging evidence points to the importance of a very active cellular immune response in mediating HIV-1 control. The rapid induction of interferon-dependent HIV restriction factors, the presence of protective MHC class I alleles, and the development of a high avidity T-cell response may all cooperate in limiting...

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

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

    2015-05-01

    [Purpose] Stretching using proprioceptive neuromuscular facilitation involve physiological reflex mechanisms through submaximal contraction of agonists which activate Golgi organ, promoting the relaxation reflex. The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation alone and with prior application of cryotherapy and thermotherapy on hamstring stretching. [Subjects and Methods] The sample comprised of 32 young subjects with hamstring retraction of the right limb. The subjects were randomly allocated to four groups: the control, flexibility PNF, flexibility PNF associated with cryotherapy, flexibility PNF in association with ultrasound therapy. [Results] After 12 stretching sessions, experimental groups showed significant improvements compared to the control group. Moreover, we did not find any significant differences among the experimental groups indicating PNF stretching alone elicits similar results to PNF stretching with prior administration of cryotherapy or thermotherapy. [Conclusion] PNF without other therapy may be a more practical and less expensive choice for clinical care. PMID:26157261

  14. 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.

  15. In vitro contracture tests in patients with various neuromuscular diseases.

    Heytens, L; Martin, J J; Van de Kelft, E; Bossaert, L L

    1992-01-01

    In order to investigate the relationship between neuromuscular disease and malignant hyperthermia (MH) susceptibility, the caffeine and halothane in vitro contracture test (European Malignant Hyperthermia Group Protocol) were performed in 60 patients who underwent muscle biopsy for investigation of a clinically suspected neuromuscular disorder. Two test results were classified as MH susceptible, 10 as MH equivocal and 48 MH negative. The large number of equivocal results is thought to indicate the lack of specificity of the individual components of this test in patients with clinical or histological evidence of neuromuscular disease. The increased in vitro sensitivity to the drugs tested may nevertheless provide some explanation for several in vivo "MH-like reactions" reported frequently in these patients. These reactions, however, are likely to be based on pathophysiological mechanisms different from those responsible for a true MH crisis. PMID:1739572

  16. Mechanical control of cardiac myofibroblasts.

    van Putten, Sander; Shafieyan, Yousef; Hinz, Boris

    2016-04-01

    Fibroblasts produce and turn over collagenous extracellular matrix as part of the normal adaptive response to increased mechanical load in the heart, e.g. during prolonged exercise. However, chronic overload as a consequence of hypertension or myocardial injury trigger a repair program that culminates in the formation of myofibroblasts. Myofibroblasts are opportunistically activated from various precursor cells that all acquire a phenotype promoting excessive collagen secretion and contraction of the neo-matrix into stiff scar tissue. Stiff fibrotic tissue reduces heart distensibility, impedes pumping and valve function, contributes to diastolic and systolic dysfunction, and affects myocardial electrical transmission, potentially leading to arrhythmia and heart failure. Here, we discuss how mechanical factors, such as matrix stiffness and strain, are feeding back and cooperate with cytokine signals to drive myofibroblast activation. We elaborate on the importance of considering the mechanical boundary conditions in the heart to generate better cell culture models for mechanistic studies of cardiac fibroblast function. Elements of the force transmission and mechanoperception apparatus acting in myofibroblasts are presented as potential therapeutic targets to treat fibrosis. PMID:26620422

  17. 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.

  18. Neuromuscular Electrical Stimulation for Motor Restoration in Hemiplegia.

    Knutson, Jayme S; Fu, Michael J; Sheffler, Lynne R; Chae, John

    2015-11-01

    This article reviews the most common therapeutic and neuroprosthetic applications of neuromuscular electrical stimulation (NMES) for upper and lower extremity stroke rehabilitation. Fundamental NMES principles and purposes in stroke rehabilitation are explained. NMES modalities used for upper and lower limb rehabilitation are described, and efficacy studies are summarized. The evidence for peripheral and central mechanisms of action is also summarized. PMID:26522909

  19. Neuromuscular Manifestations of West Nile Virus Infection

    A. ArturoLeis

    2012-03-01

    Full Text Available The most common neuromuscular manifestation of West Nile virus (WNV infection is a poliomyelitis syndrome with asymmetric paralysis variably involving one (monoparesis to four limbs (quadriparesis, with or without brainstem involvement and respiratory failure. This syndrome of acute flaccid paralysis may occur without overt fever or meningoencephalitis. Although involvement of anterior horn cells in the spinal cord and motor neurons in the brainstem are the major sites of pathology responsible for neuromuscular signs, inflammation also may involve skeletal or cardiac muscle (myositis, myocarditis, motor axons (polyradiculitis, peripheral nerve (Guillain-Barr syndrome, brachial plexopathy. In addition, involvement of spinal sympathetic neurons and ganglia provides a plausible explanation for autonomic instability seen in some patients. Many patients also experience prolonged subjective generalized weakness and disabling fatigue. Despite recent evidence that WNV may persist long term in the central nervous system or periphery in animals, the evidence in humans is controversial. WNV persistence would be of great concern in immunosuppressed patients or in those with prolonged or recurrent symptoms. Support for the contention that WNV can lead to autoimmune disease arises from reports of patients presenting with various neuromuscular diseases that presumably involve autoimmune mechanisms (GBS, other demyelinating neuropathies, myasthenia gravis, brachial plexopathies, stiff-person syndrome, and delayed or recurrent symptoms. Although there is no specific treatment or vaccine currently approved in humans, and the standard remains supportive care, drugs that can alter the cascade of immunobiochemical events leading to neuronal death may be potentially useful (high-dose corticosteroids, interferon preparations, and intravenous immune globulin containing WNV-specific antibodies. Human experience with these agents seems promising based on anecdotal reports.

  20. 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

  1. 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.

  2. Wireless Control Mechanism for a Trolling Motor

    Basnet, Rupesh

    2013-01-01

    The goal of the project was to develop a wireless control mechanism for a trolling motor. Widely used trolling motors are expensive ranging from 100 to over 1000 Euros. Manual control trolling motors are relatively less expensive than wireless trolling motor. The project was carried out to minimize the cost involved in wireless trolling motors. A goal was that having this mechanism developed, one could enjoy unconfined mobility within a boat while fishing at a lower cost. A manual control ...

  3. Exercise of mechanisms for dynamic stability control increases stability performance in the elderly.

    Arampatzis, Adamantios; Peper, Andreas; Bierbaum, Stefanie

    2011-01-01

    Old adults show a decreased recovery performance compared to young ones after unexpected perturbations increasing the risk of falls. Therefore, the purpose of the present study was to examine the effect of a specific training of mechanisms responsible for dynamic stability on the recovery performance of old adults after simulated forward falls and the contribution of muscle strength exercise. 38 old adults (two experimental groups each n=13 and a control group, n=12) participated in the study. Group 1 exercised the mechanisms responsible for dynamic stability like increase in base of support and counter-rotating segments around the centre of mass by practicing specific tasks including these mechanisms. Group 2 exercised these mechanisms of dynamic stability and muscle strength. The exercise volume was equal in both interventions (14 weeks, two times per week and ∼ 1.5h per session). Stability performance has been examined by simulated forward falls before and after the intervention. The two experimental groups improved in a similar extent (∼ 35%) their ability to regain balance during forward falls after the intervention. The reason was a faster increase in base of support. Further, the performance enhancement was related to an increase in the rate of hip moment generation. Exercising the mechanisms responsible for dynamic stability control in old adults affects their ability to regain balance after forward falls. A faster utilization of these mechanisms due to improved neuromuscular coordination resulted in the significant performance enhancement. PMID:20832803

  4. Drive mechanism nuclear reactor control rod

    An improved method and apparatus for operating magnetic stepping-type mechanisms. The current flowing in the coils of magnetic stepping-type mechanisms of the kind, for instance, that are used in control-element drive mechanisms is sensed and used to monitor operation of the mechanism. Current waveforms that characterize the motion of the mechanism are used to trigger changes in drive voltage and to verify that the drive mechanism is operating properly. In addition, incipient failures are detected through the observation of differences between the observed waveform and waveforms that characterize proper operation

  5. Explosive neuromuscular performance of males versus females.

    Hannah, Ricci; Minshull, Claire; Buckthorpe, Matthew W; Folland, Jonathan P

    2012-05-01

    The purpose of the study was to investigate sex-related differences in explosive muscular force production, as measured by electromechanical delay (EMD) and rate of force development (RFD), and to examine the physiological mechanisms responsible for any differences. The neuromuscular performance of untrained males (n = 20) and females (n = 20) was assessed during a series of isometric knee extension contractions; explosive and maximal voluntary efforts, as well as supramaximal evoked twitches and octets (eight pulses at 300 Hz). Evoked and voluntary EMD were determined from twitch and explosive contractions. The RFD was recorded over consecutive 50 ms time windows from force onset during evoked and explosive contractions, and normalized to maximal strength. Neuromuscular activity during explosive voluntary contractions was measured with EMG of the superficial knee extensors normalized to maximal M-wave. Muscle size (thickness) and muscle-tendon unit (MTU) stiffness were assessed using ultrasonic images of the vastus lateralis at rest and during ramped contractions. Males and females had similar evoked and voluntary EMD. Males were 33% stronger (P explosive voluntary contractions (P > 0.05). This was consistent with the similar normalized twitch and octet RFD, MTU stiffness and agonist EMG (all P > 0.05). When differences in maximal strength were accounted for, the evoked capacity of the knee extensors for explosive force production and the ability to utilize that capacity during explosive voluntary contractions was similar for males and females. PMID:22308163

  6. 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

  7. Hydrauric control device for control rod drive mechanism

    Purpose: To eliminate occurrence of rust at piping material by setting the temperature of scram water supplied to a control rod drive mechanism so as not to become lower than that of coolant flowing through an inserted pipe normally. Constitution: a hydraulic control device for a control rod drive mechanism consists of a scram piston mechanism provided at the joining point between the rear flow side of a check valve of a coolant feed pipe and the rear flow side of an inserted side scram valve, and a pressure equalizing pipe and a pressure equalizing solenoid valve interposed with the inserted side scram valve side and a scram piston mechanism. On the other hand, the scram piston mechanism consists of an outer cylinder, a scram piston, a spring for fixing the piston, and a coolant feed pipe, a scram pipe connected from the inserted side scram valve and an inserted pipe connected to the outer cylinder. Therefore, control rod coolant always flowing can be fed through the inserted pipe as scram water to the control rod drive mechanism. When the temperature of the control rod coolant is controlled, the temperature of the inserted pipe can be controlled to eliminate the condensation of dew. (Yoshino, Y.)

  8. 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...

  9. DYNAMIC NEUROMUSCULAR STABILIZATION & SPORTS REHABILITATION

    Frank, Clare; Kobesova, Alena; KOLAR, Pavel

    2013-01-01

    Dynamic neuromuscular (core) stability is necessary for optimal athletic performance and is not achieved purely by adequate strength of abdominals, spinal extensors, gluteals or any other musculature; rather, core stabilization is accomplished through precise coordination of these muscles and intra‐abdominal pressure regulation by the central nervous system. Understanding developmental kinesiology provides a framework to appreciate the regional interdependence and the inter‐linking of the ske...

  10. 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

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

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

    2015-01-01

    [Purpose] Stretching using proprioceptive neuromuscular facilitation involve physiological reflex mechanisms through submaximal contraction of agonists which activate Golgi organ, promoting the relaxation reflex. The aim of this study was to evaluate the effects of proprioceptive neuromuscular facilitation alone and with prior application of cryotherapy and thermotherapy on hamstring stretching. [Subjects and Methods] The sample comprised of 32 young subjects with hamstring ret...

  12. 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

  13. Use of neuromuscular blockers in Brazil

    Giovani de Figueiredo Locks

    2015-10-01

    Full Text Available ABSTRACTThe objective of this study was to evaluate how Brazilian anesthesiologists are using neuromuscular blockers, focusing on how they establish the diagnosis of postoperative residual curarization and the incidence of complications associated with the use of neuromuscular blockers. A questionnaire was sent to anesthesiologists inviting them to participate in the study. The online data collection remained open from March 2012 to June 2013. During the study period, 1296 responses were collected. Rocuronium, atracurium, and cisatracurium were the main neuromuscular blockers used in cases of elective surgery. Succinylcholine and rocuronium were the main neuromuscular blockers used in cases of emergency surgery. Less than 15% of anesthesiologists reported the frequent use of neuromuscular function monitors. Only 18% of those involved in the study reported that all workplaces have such a monitor. Most respondents reported using only the clinical criteria to assess whether the patient is recovered from the muscle relaxant. Most respondents also reported always using some form of neuromuscular blockade reversal. The major complications attributed to neuromuscular blockers were residual curarization and prolonged blockade. Eighteen anesthesiologists reported death attributed to neuromuscular blockers. Residual or prolonged blockade is possibly recorded as a result of the high rate of using clinical criteria to diagnose whether the patient has recovered or not from motor block and, as a corollary, the poor use of neuromuscular transmission monitors in daily practice.

  14. Use of neuromuscular blockers in Brazil.

    Locks, Giovani de Figueiredo; Cavalcanti, Ismar Lima; Duarte, Nadia Maria Conceio; da Cunha, Rafael Martins; de Almeida, Maria Cristina Simes

    2015-01-01

    The objective of this study was to evaluate how Brazilian anesthesiologists are using neuromuscular blockers, focusing on how they establish the diagnosis of postoperative residual curarization and the incidence of complications associated with the use of neuromuscular blockers. A questionnaire was sent to anesthesiologists inviting them to participate in the study. The online data collection remained open from March 2012 to June 2013. During the study period, 1296 responses were collected. Rocuronium, atracurium, and cisatracurium were the main neuromuscular blockers used in cases of elective surgery. Succinylcholine and rocuronium were the main neuromuscular blockers used in cases of emergency surgery. Less than 15% of anesthesiologists reported the frequent use of neuromuscular function monitors. Only 18% of those involved in the study reported that all workplaces have such a monitor. Most respondents reported using only the clinical criteria to assess whether the patient is recovered from the muscle relaxant. Most respondents also reported always using some form of neuromuscular blockade reversal. The major complications attributed to neuromuscular blockers were residual curarization and prolonged blockade. Eighteen anesthesiologists reported death attributed to neuromuscular blockers. Residual or prolonged blockade is possibly recorded as a result of the high rate of using clinical criteria to diagnose whether the patient has recovered or not from motor block and, as a corollary, the poor use of neuromuscular transmission monitors in daily practice. PMID:26323727

  15. 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...

  16. Nuclear envelope proteins and neuromuscular diseases.

    Ostlund, Cecilia; Worman, Howard J

    2003-04-01

    Several neuromuscular diseases are caused by mutations in emerin and A-type lamins, proteins of the nuclear envelope. Emery-Dreifuss muscular dystrophy is caused by mutations in emerin (X-linked) or A-type lamins (autosomal dominant). Mutations in A-type lamins also cause limb-girdle muscular dystrophy type 1B, dilated cardiomyopathy with conduction defect, and Charcot-Marie-Tooth disorder type 2B1. They also cause partial lipodystrophy syndromes. The functions of emerin and A-type lamins and the mechanisms of how mutations in these proteins cause tissue-specific diseases are not well understood. The mutated proteins may cause structural damage to cells but may also affect processes such as gene regulation. This review gives an overview of this topic and describes recent advances in identification of disease-causing mutations, studies of cells and tissues from subjects with these diseases, and animal and cell culture models. PMID:12661041

  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

    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. 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.

  20. Mechanical components design for PWR - control rod drive mechanism

    The Control Rod Drive Mechanism (CRDM) is usually - a high precision - equipment incorporating mechanical and electrical components designed to move the control rods. The 'control rods' refer to all rods or assemblies that are moved to assess the performance of the reactor. The CRDM here presented is the Nut and Lead Screw type. This type is basically a power screw type magnetically coupled to a slow speed reluctance electric motor that provides a means of axially positioning the movable fuel assemblies in the reactor core for purpose of controlling core reactivity. A helically threaded lead screw assembly, comprising one element of power screw, is attached to a movable fuel assemblies. The CRDM usually has closer and more consistent contact with environment peculiar to the reactor than has only other machinery component. This environment includes not only the radiation field of the reactor, but also the temperature, pressure and chemical properties associated with the material used as the coolant for reactor fuel. Specific and special materials are needed because of the above mentioned application. Due to the importance of the above described CRDM functions, this paper will also consider the nuclear functions and their safety classes as well as the CRDM nuclear design criteria. (author)

  1. 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

  2. Control rod drive mechanism vent valve assembly

    The invention relates generally to a device for closing a tubular object and more particularly to a device having venting means incorporated therein and used for closing a control rod drive mechanism which is installed on a nuclear reactor. A ball valve that is capable of performing the necessary function is described

  3. 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.

  4. 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.

  5. Reactive Neuromuscular Training: A Multi-level Approach to Rehabilitation of the Unstable Shoulder

    Guido, John A.; Stemm, John

    2007-01-01

    In this clinical commentary, the use of reactive neuromuscular training (RNT) will be discussed as part of an overall functional rehabilitation program in the treatment of the unstable glenohumeral joint. The RNT program is designed to restore the synchrony and synergy of muscle firing patterns about the shoulder, which are required for dynamic joint stability and fine motor control. Reactive neuromuscular training allows the clinician to bridge the gap between the achievement of clinical bas...

  6. Computed tomography of skeletal muscles in neuromuscular disease

    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. (orig.)

  7. Whole body vibration: stimulus characteristics and acute neuromuscular responses

    Sanderson, Mark Findlay

    2014-01-01

    Whole body vibration (WBV) delivers a stimulus to the body via an oscillating platform and remains a relatively new area of research. Several applications of WBV stimuli have been developed as strength training and rehabilitation modalities, but inconsistent results have been published. There is little knowledge underpinning the mechanisms to explain the elicited neuromuscular responses to WBV and a wide range of WBV parameters across the literature. As a result, safe and effec...

  8. Controlling Mechanical Dissipation through Phononic Bandgap Substrates

    Chang, Laura; Chakram, Srivatsan; Patil, Yogesh Sharad; Vengalattore, Mukund

    2015-05-01

    One of the fundamental challenges for the quantum control of mechanical systems is the realization of resonators with exceptionally low dissipation, through appropriate material choice and resonator and substrate design. Stoichiometric silicon nitride membrane resonators have in recent years emerged as an ultralow loss mechanical platform. In such resonators, we have demonstrated mechanical quality factors as high as 50 106 and f Q products of 1 1014 Hz, with radiation loss to the the supporting substrate being the dominant loss process. We demonstrate the suppression of radiation loss by creating resonators on substrates with a phononic bandgap. We characterize the mechanical properties of these resonators for various substrate parameters and discuss prospects for the observation of quantum optomechanical effects at room temperature. This work was supported by the DARPA QuASAR program through a grant from the ARO and an NSF INSPIRE award.

  9. 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

  10. 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

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

    Carla Falugi

    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.

  12. [Feedback control mechanisms of plant cell expansion

    Cosgrove, D.J.

    1992-01-01

    We have generated considerable evidence for the significance of wall stress relaxation in the control of plant growth and found that several agents (gibberellin, light, genetic loci for dwarf stature) influence growth rate via alteration of wall relaxation. We have refined our methods for measuring wall relaxation and, moreover, have found that wall relaxation properties bear only a distance relationship to wall mechanical properties. We have garnered novel insights into the nature of cell expansion mechanisms by analyzing spontaneous fluctuations of plant growth rate in seedlings. These experiments involved the application of mathematical techniques for analyzing growth rate fluctuations and the development of new instrumentation for measuring and forcing plant growth in a controlled fashion. These studies conclude that growth rate fluctuations generated by the plant as consequence of a feedback control system. This conclusion has important implications for the nature of wall loosening processes and demands a different framework for thinking about growth control. It also implies the existence of a growth rate sensor.

  13. 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 disease and spinal deformity treated between 1984 and 2008 consecutively by the senior author (G.D.G.) with Cotrel-Dubousset instrumentation and minimum 36 months follow-up were reviewed, evaluating correction of coronal deformity, sagittal balance and pelvic obliquity, and rate of complications. 24 patients (Friedreich's ataxia, 1; cerebral palsy, 14; muscular dystrophy, 2; polio, 2; syringomyelia, 3; spinal atrophy, 2) were included. According the evidence that the study period is too long (1984-2008) and that in more than 20 years many things changed in surgical strategy and techniques, all patients were divided in two groups: only hooks (8 patients) or hybrid construct (16 patients). Mean age was 18.1 years at surgery (range 11 years 7 months-max 31 years; in 17 cases the age at surgery time was between 10 and 20 years old; in 6 cases it was between 20 and 30 and only in 1 case was over 30 years old). Mean follow-up was 142 months (range 36-279). The most frequent patterns of scoliosis were thoracic (10 cases) and thoracolumbar (9 cases). In 8 cases we had hypokyphosis, in 6 normal kyphosis and in 9 hyperkyphosis. In 8 cases we had a normal lordosis, in 11 a hypolordosis and in 4 a hyperlordosis. In 1 case we had global T4-L4 kyphosis. In 8 cases there were also a thoracolumbar kyphosis (mean value 24°, min 20°-max 35°). The mean fusion area included 13 vertebrae (range 6-19); in 17 cases the upper end vertebra was over T4 and in 11 cases the lower end vertebra was over L4 or L5. In 7 cases the lower end vertebra was S1 to correct the pelvic obliquity. In 5 cases the severity of the deformity (mean Cobb's angle 84.2°) imposed a preoperative halo traction treatment. There were 5 anteroposterior and 19 posterior-only procedures. In 10 cases, with low bone quality, the arthrodesis was performed using iliac grafting technique while in the other (14 cases) using autologous bone graft obtained in situ from vertebral arches and spinous processes (in all 7 cases with fusion extended until S1, it was augmented with calcium phosphate). The mean correction of coronal deformity and pelvic obliquity averaged, respectively, 57.2% (min 31.8%; max 84.8%) and 58.9% (mean value preoperative, 18.43°; mean value postoperative, 7.57°; mean value at last follow-up, 7.57°). The sagittal balance was always restored, reducing hypo or hyperkyphosis and hypo or hyperlordosis. Also in presence of a global kyphosis, we observed a very good restoration (preoperatory, 65°; postoperatory, 18° kyphosis and 30° lordosis, unmodified at last f.u.). The thoracolumbar kyphosis, when present (33.3% of our group) was always corrected to physiological values (mean 2°, min 0°-max 5°). The mean intraoperative blood lost were 2,100 cc (min 1,400, max 5,350). Major complications affected 8.3% of patients, and included 1 postoperative death and 1 deep infection. Minor complications affected none of patients. CD technique provides lasting correction of spinal deformity in patients with neuromuscular scoliosis, with a lower complications rate compared to reports on second-generation instrumented spinal fusion. PMID:21404030

  14. 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

  15. 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

  16. Fluorescence control through multiple interference mechanisms

    Paspalakis, E; Knight, P L

    1998-01-01

    We discuss the spontaneous emission from a coherently prepared and microwave driven doublet of potentially closely spaced excited states to a common ground level. Multiple interference mechanisms are identified which may lead to fluorescence inhibition in well-separated regions of the spectrum or act jointly in cancelling the spontaneous emission. In addition to phase independent quantum interferences due to combined absorptions and emissions of driving field photons, we distinguish two competing phase dependent interference mechanisms as means of controlling the fluorescence. The indistinguishable quantum paths may involve the spontaneous emission from the same state of the doublet, originating from the two different components of the initial coherent superposition. Alternatively the paths involve a different spontaneous photon from each of two decaying states, necessarily with the same polarization. This makes these photons indistinguishable in principle within the uncertainty of the two decay rates. The ph...

  17. Humor regulates cognitive control: a neural mechanism

    Guido P H Band

    2011-11-01

    Full Text Available Positive emotional states are known to reduce the impact of cognitive demands and information-processing conflict on human behavior, but the underlying neural mechanism of this modulation is unknown. We used functional magnetic resonance imaging (fMRI to examine how pleasure induced by funny cartoons regulates behavioral control and neural adaptations to cognitive conflict. Humor activated hedonic hotspots in the basal ganglia, which attenuated the rostral anterior cingulate cortex (ACC response to conflict. This reduced subsequent conflict adaptation as observed in behavior and monitoring-related dorsal ACC activation. Our observations reveal the neural mechanism by which positive emotions regulate adaptive goal-directed behavior. Funding: Supported by a NWO grant to G. Band.

  18. Stirling engine control mechanism and method

    Dineen, John J. (Durham, NH)

    1983-01-01

    A reciprocating-to-rotating motion conversion and power control device for a Stirling engine includes a hub mounted on an offset portion of the output shaft for rotation relative to the shaft and for sliding motion therealong which causes the hub to tilt relative to the axis of rotation of the shaft. This changes the angle of inclination of the hub relative to the shaft axis and changes the axial stroke of a set of arms connected to the hub and nutating therewith. A hydraulic actuating mechanism is connected to the hub for moving its axial position along the shaft. A balancing wheel is linked to the hub and changes its angle of inclination as the angle of inclination of the hub changes to maintain the mechanism in perfect balance throughout its range of motion.

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

    Curtis S. To, PhD

    2011-08-01

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

  20. Maintenance of BWR control rod drive mechanisms

    Control rod drive mechanism (CRDM) replacement and rebuilding is one of the highest dose, most physically demanding, and complicated maintenance activities routinely accomplished by BWR utilities. A recent industry workshop sponsored by the Oak Ridge National Laboratory, which dealt with the effects of CRDM aging, revealed enhancements in maintenance techniques and tooling which have reduced ALARA, improved worker comfort and productivity, and have provided revised guidelines for CRDM changeout selection. Highlights of this workshop and ongoing research on CRDM aging are presented in this paper

  1. Maintenance of BWR control rod drive mechanisms

    Greene, R.H.

    1991-01-01

    Control rod drive mechanism (CRDM) replacement and rebuilding is one of the highest dose, most physically demanding, and complicated maintenance activities routinely accomplished by BWR utilities. A recent industry workshop sponsored by the Oak Ridge National Laboratory, which dealt with the effects of CRDM aging, revealed enhancements in maintenance techniques and tooling which have reduced ALARA, improved worker comfort and productivity, and have provided revised guidelines for CRDM changeout selection. Highlights of this workshop and ongoing research on CRDM aging are presented in this paper.

  2. Pneumatic, PLC Controlled, Automotive Gear Shifting Mechanism

    Muntaser Momani

    2010-05-01

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

  3. Exercise modulates synaptic acetylcholinesterase at neuromuscular junctions.

    Blotnick, E; Anglister, L

    2016-04-01

    Acetylcholinesterase plays a major role in neuromuscular transmission and is regulated by neuromuscular activity. Since fast-twitch motor units are recruited with increased motor demand, we examined acetylcholinesterase regulation in rat leg muscles following treadmill training. Total acetylcholinesterase and specifically the membrane-bound tetramer increased in exercised fast-, but not slow-twitch muscles, while other isoforms remained unchanged. Synaptic acetylcholinesterase increased markedly in neuromuscular junctions of trained fibers, without concomitant changes in synaptic acetylcholine receptor, thus elevating synaptic acetylcholinesterase/receptor ratios. Electron microscopy showed that acetylcholinesterase increased in postjunctional folds and primary cleft, where it was added adjacent to the postsynaptic muscle membrane. Thus, although the primary acetylcholinesterase at the neuromuscular junction is the collagen-tailed asymmetric isoform associated with synaptic basal lamina, physiological demands such as strenuous exercise, or potentially pathological conditions, can selectively recruit the membrane-bound acetylcholinesterase tetramer to the synapse for optimal synaptic transmission. PMID:26820598

  4. 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.

  5. 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 ...

  6. Assessment of vibratory stimulation on neuromuscular system

    Di Iorio, Felice

    2013-01-01

    The thesis analyze a subject of renewed interest in bioengineering, the research and analysis of exercise parameters that maximize the neuromuscular and cardiovascular involvement in vibration treatment. The research activity was inspired by the increasing use of device able to provide localized or whole body vibration (WBV). In particular, the focus was placed on the vibrating platform and the effect that the vibrations have on the neuromuscular system and cardiovascular system. T...

  7. Neuromuscular blockade during laparoscopic ventral herniotomy

    Medici, Roar; Madsen, Matias V; Asadzadeh, Sami; Flsgaard, Sren; Rosenberg, Jacob; Gtke, Mona R

    2015-01-01

    INTRODUCTION: Laparoscopic herniotomy is the preferred technique for some ventral hernias. Several factors may influence the surgical conditions, one being the depth of neuromuscular blockade (NMB) applied. We hypothesised that deep neuromuscular blockade defined as a post-tetanic count below eig...... provide knowledge relevant to other laparoscopic techniques. FUNDING: The study is funded by a research grant from the Investigator Initiated Studies Program of Merck Sharp & Dohme Corp. TRIAL REGISTRATION: NCT02247466....

  8. Cotrel–Dubousset instrumentation in neuromuscular scoliosis

    PIAZZOLLA, ANDREA; Solarino, G.; S. GIORGI; Mori, C. M.; L. Moretti; Giorgi, G

    2011-01-01

    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 si...

  9. 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

  10. Adenosine receptors and muscarinic receptors cooperate in acetylcholine release modulation in the neuromuscular synapse.

    Santafe, M M; Priego, M; Obis, T; Garcia, N; Tomàs, M; Lanuza, M A; Tomàs, J

    2015-07-01

    Adenosine receptors (ARs) are present in the motor terminals at the mouse neuromuscular junction. ARs and the presynaptic muscarinic acetylcholine receptors (mAChRs) share the functional control of the neuromuscular junction. We analysed their mutual interaction in transmitter release modulation. In electrophysiological experiments with unaltered synaptic transmission (muscles paralysed by blocking the voltage-dependent sodium channel of the muscle cells with μ-conotoxin GIIIB), we found that: (i) a collaborative action between different AR subtypes reduced synaptic depression at a moderate activity level (40 Hz); (ii) at high activity levels (100 Hz), endogenous adenosine production in the synaptic cleft was sufficient to reduce depression through A1 -type receptors (A1 Rs) and A2 A-type receptors (A2 A Rs); (iii) when the non-metabolizable 2-chloroadenosine (CADO) agonist was used, both the quantal content and depression were reduced; (iv) the protective effect of CADO on depression was mediated by A1 Rs, whereas A2 A Rs seemed to modulate A1 Rs; (v) ARs and mAChRs absolutely depended upon each other for the modulation of evoked and spontaneous acetylcholine release in basal conditions and in experimental conditions with CADO stimulation; (vi) the purinergic and muscarinic mechanisms cooperated in the control of depression by sharing a common pathway although the purinergic control was more powerful than the muscarinic control; and (vii) the imbalance of the ARs created by using subtype-selective and non-selective inhibitory and stimulatory agents uncoupled protein kinase C from evoked transmitter release. In summary, ARs (A1 Rs, A2 A Rs) and mAChRs (M1 , M2 ) cooperated in the control of activity-dependent synaptic depression and may share a common protein kinase C pathway. PMID:25892551

  11. 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 process needs to be done gradually in these patients, and in conjunction with supportive measures, such as close observation for at least for 72 hours following extubation to monitor any possibility of recurrence of hypercapnic respiratory failure.

  12. Urgencias en patología neuromuscular Emergencies in neuromuscular pathology

    T. Ayuso

    2008-01-01

    Full Text Available 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 parálisis flácida aguda; puede ocasionar fallo respiratorio en un tercio de los casos precisando ventilación mecánica. El diagnóstico preciso de este síndrome permitirá iniciar tratamiento inmunomodulador, que ha demostrado que modifica el curso de la enfermedad. Además, la valoración clínica de los pacientes y el conocimiento de sencillos tests neurofisiológicos y de función respiratoria guiarán la decisión de ventilación mecánica evitando la intubación de urgencia. La urgencia más frecuente que ocasiona la MG es la crisis miasténica, definida por el deterioro en la función bulbar con insuficiencia respiratoria aguda y riesgo de parada respiratoria. Ocurre en un 15-20% de pacientes miasténicos y puede desencadenarse por múltiples factores. Además del diagnóstico preciso de la crisis es importante la supresión de los factores desencadenantes y medidas de soporte ventilatorio. Entre las medidas farmacológicas son la plasmaféresis y las inmunoglobulinas intravenosas los instrumentos más útiles en la actualidad; estos tratamientos no sustituyen la vigilancia intensiva y el reconocimiento de los signos inminentes de fallo respiratorio que implican soporte ventilatorio invasivo o no invasivo.Acute muscle weakness (AMW is the predominant symptom of neuromuscular emergencies, especially if it affects the respiratory or oropharyngeal musculature . AMW is a multi-etiological syndrome, with different lesion levels in the motor unit. 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.

  13. Control rod drive mechanism vent valve assembly

    A closure insert assembly for a control rod drive mechanism that has incorporated therein a vent valve arrangement which permits the release of air trapped in the nuclear reactor during the filling of the primary coolant system therein and allows the entrance of air into the reactor for the draining of same. To accomplish this, the vent valve is of the ball type which engages two oppositely disposed conical ball seats, one of which is allowed to move laterally with respect to the other, causing the ball and ball seats to be ''self-centering'' and resulting in a uniform compressive force being applied over minor circumferences on the ball. The use of conical ball seats, one of which is laterally movable, also permits the axes of the conical ball seats to be non-parallel and/or non-concentric without hindering the operation and effectiveness of the vent valve

  14. 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.

  15. [Pretreatment with lidocaine accelerates onset of vecuronium-induced neuromuscular blockade].

    Nonaka, Akihiko; Sugawara, Takeshi; Suzuki, Satomi; Masamune, Taishi; Kumazawa, Teruo

    2002-08-01

    The purpose of this study was to investigate the effect of pre-treatment with lidocaine on the onset of vecuronium-induced neuromuscular block in a randomized, double-blinded trial. Thirty-one patients were randomly allocated to one of two groups according to the agents administrated 3 min prior to vecuronium injection; Group C, normal saline 0.75 ml.kg-1 and Group L, 2% lidocaine 1.5 mg.kg-1. Anesthesia was induced with propofol 1.5 mg.kg-1 followed by continuous infusion at 8 mg.kg-1.hr-1. Neuromuscular blockade was evaluated with accelerometry, which measured a train-of-four (TOF) pattern of abductor policies muscle. The disappearance of the first response in TOF was regarded as onset of neuromuscular block. Changes in systolic and diastolic arterial pressure (SBP, DBP) and heart rate (HR) were measured before and after tracheal intubation. Times to onset of neuromuscular blockade induced by vecuronium in Group L and Group C were 115 +/- 20 sec and 174 +/- 45 sec, respectively. After tracheal intubation, SBP, DBP and HR in both groups increased compared with those before tracheal intubation, but the changes were not significant. Changes in SBP, DBP and HR did not differ between Group L and Group C. The mechanisms by which lidocaine reduced the time to onset of neuromuscular block caused by vecuronium could not be clarified from our study, but this may be related to pre- and post-junctional effects of lidocaine at neuromuscular junction. In conclusion, administration of lidocaine prior to tracheal intubation reduces the time to onset of neuromuscular block caused by vecuronium, but does not attenuate changes in blood pressure and heart rate caused by tracheal intubation. PMID:12229137

  16. Motor axonal sprouting and neuromuscular junction loss in an animal model of Charcot-Marie-Tooth disease

    Ang, Eng-Tat; Schafer, Ralf; Baltensperger, Richard; Wernig, Anton; Celio, Marco; Sancho Oliver, Sara

    2010-01-01

    Muscle weakness in Charcot-Marie-Tooth Type 1A disease (CMT1A) caused by mutations in peripheral myelin protein 22 (PMP22) has been attributed to an axonopathy that results in denervation and muscle atrophy. The underlying pathophysiological mechanisms involved are not understood. We investigated motor performance, neuromuscular junctions (NMJs), physiological parameters, and muscle morphometry of PMP22 transgenic mice. Neuromuscular junctions were progressively lost in hindlimb muscles of PM...

  17. Control mechanisms for a nonlinear model of international relations

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

    1997-07-15

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

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

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

  19. [Use of neuromuscular blockers in Brazil].

    Locks, Giovani de Figueiredo; Cavalcanti, Ismar Lima; Duarte, Nadia Maria Conceio; Cunha, Rafael Martins da; Almeida, Maria Cristina Simes de

    2015-01-01

    The objective of this study was to evaluate how Brazilian anesthesiologists are using neuromuscular blockers (NMB), focusing on how they establish the diagnosis of postoperative residual curarization and the incidence of complications associated with the use of NMB. A questionnaire was sent to anesthesiologists inviting them to participate in the study. The online data collection remained open from March 2012 to June 2013. During the study period, 1296 responses were collected. Rocuronium, atracurium, and cisatracurium were the main neuromuscular blockers used in cases of elective surgery. Succinylcholine and rocuronium were the main NMB used in cases of emergency surgery. Less than 15% of anesthesiologists reported the frequent use of neuromuscular function monitors. Only 18% of those involved in the study reported that all workplaces have such a monitor. Most respondents reported using only the clinical criteria to assess whether the patient is recovered from the muscle relaxant. Most respondents also reported always using some form of neuromuscular blockade reversal. The major complications attributed to NMB were residual curarization and prolonged blockade. Eighteen anesthesiologists reported death attributed to NMB. Residual or prolonged blockade is possibly recorded as a result of the high rate of using clinical criteria to diagnose whether the patient has recovered or not from motor block and, as a corollary, the poor use of neuromuscular transmission monitors in daily practice. PMID:26160168

  20. Spectrum of Cyber threats & Available Control Mechanisms

    Vikram Mangla, Dr.S.N.Panda

    2013-04-01

    Full Text Available The Internet is undoubtedly the largest public data network enabling and facilitating both personal & business communications worldwide. Wireless networking has experienced a tremendous growth becoming an integral part of homes, offices & all type of businesses. It provides many advantages, but it is also coupled with many security threats and alters the organizations overall information security risk profile. Although implementation of technological solution is the usual respond to the wireless security threats and vulnerabilities, wireless security is primarily a management issue. Cyber crime is constantly evolving and the growing increase in the number of threats that use social engineering techniques is causing concern for several businesses. All it takes is for one user to click on a malicious link and a firm’s network can be brought to a grinding halt. But the early days of cyber threats have gone now. Cyber threats have increased in large number. The volume of effect of these attacks has increased tremendously whereas the transaction time has decreased. The sources of attacks and exploitations are difficult to determine within time frames that enable victims to avoid damage, and any defensive measure is likely eventually to fail given the vulnerabilities of most cyber systems and the incapacities of users. In this paper we review different cyber threats and control mechanisms available and how these are affecting the network world.

  1. Brain mechanisms that control sleep and waking

    Siegel, Jerome

    This review paper presents a brief historical survey of the technological and early research that laid the groundwork for recent advances in sleep-waking research. A major advance in this field occurred shortly after the end of World War II with the discovery of the ascending reticular activating system (ARAS) as the neural source in the brain stem of the waking state. Subsequent research showed that the brain stem activating system produced cortical arousal via two pathways: a dorsal route through the thalamus and a ventral route through the hypothalamus and basal forebrain. The nuclei, pathways, and neurotransmitters that comprise the multiple components of these arousal systems are described. Sleep is now recognized as being composed of two very different states: rapid eye movements (REMs) sleep and non-REM sleep. The major findings on the neural mechanisms that control these two sleep states are presented. This review ends with a discussion of two current views on the function of sleep: to maintain the integrity of the immune system and to enhance memory consolidation.

  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. 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.

  4. 21 CFR 882.5860 - Implanted neuromuscular stimulator.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted neuromuscular stimulator. 882.5860... (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices 882.5860 Implanted neuromuscular stimulator. (a) Identification. An implanted neuromuscular stimulator is a device that...

  5. 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

  6. 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

  7. Bloqueio neuromuscular residual aps o uso de rocurnio ou cisatracrio Bloqueo neuromuscular residual despus del uso de rocuronio o cisatracrio Residual neuromuscular block after rocuronium or cisatracurium

    Bruno Salom de Morais

    2005-12-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O bloqueio neuromuscular residual na sala de recuperao ps-anestsica (SRPA um fenmeno que pode aumentar a morbidade ps-operatria, com incidncia variando entre 0% e 93%. O objetivo deste estudo foi avaliar a incidncia do bloqueio neuromuscular residual na SRPA. MTODO: Foram estudados 93 pacientes submetidos cirurgia geral com o uso de cisatracrio ou rocurnio. Aps a admisso na SRPA foi realizada a monitorizao objetiva da funo neuromuscular (aceleromiografia - TOF GUARD. O bloqueio neuromuscular residual foi definido como SQE JUSTIFICATIVA Y OBJETIVOS: El bloqueo neuromuscular residual en la sala de recuperacin posanestsica (SRPA es un fenmeno que puede aumentar la morbidez posoperatoria, con incidencia variando entre 0% y 93%. La finalidad de este estudio fue evaluar la incidencia del bloqueo neuromuscular residual en la SRPA. MTODO: Fueron estudiados 93 pacientes sometidos a ciruga general con el uso de cisatracrio o rocuronio. Despus de la admisin en la SRPA fue realizada la monitorizacin objetiva de la funcin neuromuscular (aceleromiografia - TOF-GUARD. El bloqueo neuromuscular residual fue definido como TOF BACKGROUND AND OBJECTIVES: Residual neuromuscular block in the post-anesthetic recovery unit (PACU may increase postoperative morbidity from 0% to 93%. This study aimed at evaluating the incidence of residual neuromuscular block in the PACU. METHODS: Participated in this study 93 patients submitted to general anesthesia with cisatracurium or rocuronium. After PACU admission, neuromuscular function was objectively monitored (acceleromyography - TOF GUARD. Residual neuromuscular block was defined as TOF < 0.9. RESULTS: From 93 patients, 53 received cisatracurium and 40 rocuronium. Demographics, procedure length and the use of antagonists were comparable between groups. Residual neuromuscular block was 32% in subgroup C (cisatracurium and 30% in subgroup R (rocuronium. Residual neuromuscular block was unrelated to dose, age and use of antagonists, but was related to procedure length. In subgroup C, mean procedure length was 135 minutes for patients with neuromuscular block and 161 minutes for patients without (p < 0.029. In subgroup R, mean surgery length was 122 and 150 minutes, respectively (p < 0.039. CONCLUSIONS: Both groups had high incidence of residual neuromuscular block in the PACU. Residual postoperative curarization is still a problem even with new intermediary action neuromuscular blockers. It is highly important to objectively monitor all patients submitted to general anesthesia with neuromuscular blockers.

  8. 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...

  9. Comparison of mechanomyography and acceleromyography for the assessment of rocuronium induced neuromuscular block in myotonic dystrophy type 1.

    Vanlinthout, L E H; Booij, L H D J; van Egmond, J; Robertson, E N

    2010-06-01

    We measured acceleromyography and mechanomyography simultaneously with monitoring of rocuronium-induced neuromuscular block in four patients with myotonic dystrophy type 1. Furthermore, we compared neuromuscular block measures from these patients with those from normal controls from previous studies. In myotonic dystrophy type 1 patients, the dose-response curve obtained with acceleromyography was steeper and right-shifted compared with that obtained using mechanomyography. However, the effective doses to produce 95% neuromuscular block determined with both acceleromyography and mechanomyography were similar to each other and to values found in normal patients. In the three myotonic dystrophy type 1 patients with mild to moderate disease, times to recovery from block were similar to those observed in normal controls. In both patients and normal controls, neuromuscular block recovered faster with acceleromyography. However, in one patient with severe muscle wasting, recovery of neuromuscular block was prolonged. We conclude that mechanomyography and acceleromyography cannot be used interchangeably to monitor neuromuscular block in myotonic dystrophy type 1 patients. PMID:20565393

  10. The influence of gender on neuromuscular pre-activity during side-cutting

    Bencke, Jesper; Zebis, Mette K

    2011-01-01

    It is well established that female athletes are at increased risk for sustaining ACL injuries in sports, where sudden changes of direction are a frequent movement pattern. The underlying neuromuscular mechanisms related to the elevated ACL injury rate in female athletes has yet to be fully invest...

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

    Maria Cristina Simes de Almeida

    2004-12-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Dados estatsticos referentes ao uso de bloqueadores neuromusculares no Brasil so desconhecidos. Este trabalho se prope a anlise estatstica desse tpico. MTODO: Foram compiladas 831 respostas de um questionrio preenchido em parte por anestesiologistas presentes ao 48 Congresso Brasileiro de Anestesiologia em Recife, 2001 e em parte via Internet, por anestesiologistas cujos endereos eletrnicos constam na pgina da Sociedade Brasileira de Anestesiologia (www.sba.com.br. Foram analisados os seguintes dados: tempo de contato com a especialidade, regio onde atuam os anestesiologistas, uso de bloqueadores neuromusculares (BNM em ordem de preferncia, indicaes do uso de succinilcolina, uso do monitor da transmisso neuromuscular, critrios para se considerar o paciente descurarizado, uso de neostigmina, forma de administrao dos BNM e descrio de complicaes observadas. RESULTADOS: A maioria dos anestesiologistas em questo exerce a profisso h mais de 11 anos e o maior nmero de respostas foi proveniente da regio sudeste do Brasil. O BNM mais empregado o atracrio, seguido de pancurnio e succinilcolina. A succinilcolina mais empregada na induo rpida e em crianas (80% e 25% respectivamente. Monitores da transmisso neuromuscular, 53% dos anestesiologistas nunca usam, e como critrio de recuperao, 92% consideram o paciente descurarizado mediante sinais clnicos. 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 complicao decorrente do uso de BNM. As complicaes mais apontadas foram o bloqueio prolongado, o broncoespasmo grave e a curarizao residual. CONCLUSES: O atracrio o bloqueador neuromuscular mais empregado no Brasil, h percentual alto de uso da succinilcolina em situaes no emergenciais, o uso de monitores da transmisso neuromuscular raro, e, como um corolrio, um percentual significativo de uso de critrios eminentemente clnicos para considerar o paciente descurarizado. Registrou-se que, cerca de 30% dos anestesiologistas teve algum tipo de complicao decorrente do uso desses frmacos.JUSTIFICATIVA Y OBJETIVOS: Dados estadsticos referentes al uso de bloqueadores neuromusculares en Brasil son desconocidos. Este trabajo se propone el anlisis estadstico de ese tpico. MTODO: Fueron compiladas 831 respuestas de un cuestionario llenado en parte por anestesiologistas presentes al 48 Congreso Brasileo de Anestesiologia en la ciudad de Recife, 2001 y en parte va Internet, por anestesiologistas cuyas direcciones electrnicas constan en la pgina de la Sociedad Brasilea de Anestesiologia (www.sba.com.br. Fueron analizados los siguientes datos: tiempo de contacto con la especialidad, regin donde actan los anestesiologistas, uso de bloqueadores neuromusculares (BNM en orden de preferencia, indicaciones del uso de succinilcolina, uso del monitor de transmisin neuromuscular, criterios para considerar el paciente descurarizado, uso de neostigmina, forma de administracin de los BNM y descripcin de complicaciones observadas. RESULTADOS: La mayora de los anestesiologistas en cuestin ejerce la profesin hace ms de 11 aos y el mayor nmero de respuestas fue proveniente de la regin sudeste de Brasil. El BNM ms empleado es el atracrio, seguido de pancurnio y succinilcolina. La succinilcolina es ms empleada en la induccin rpida y en nios (80% y 25% respectivamente. Monitores de la transmisin neuromuscular, 53% de los anestesiologistas nunca usan, y como criterio de recuperacin, 92% consideran el paciente descurarizado mediante seales clnicas. En un 45% de las veces los profesionales emplean la neostigmina de forma rutinaria, y 94% administra los BNM bajo forma de bolus. Cerca del 30% registra que tuvieron complicacin consecuente del uso de BNM. Las complicaciones ms apuntadas fueron el bloqueo prolongado, el broncoespasmo gr

  12. Effects of a short proprioceptive neuromuscular facilitation stretching bout on quadriceps neuromuscular function, flexibility, and vertical jump performance.

    Place, Nicolas; Blum, Yannick; Armand, Stéphane; Maffiuletti, Nicola A; Behm, David G

    2013-02-01

    The inclusion of relatively long bouts of stretching (repeated static stretches of ∼30 seconds) in the warm-up is usually associated with a drop in muscle performance. The purpose of this study was to assess the effect of a novel self-administered proprioceptive neuromuscular facilitation (PNF) paradigm with short periods of stretching and contraction on quadriceps neuromuscular function, vertical jump performance, and articular range of motion (ROM). Twelve healthy men (age: 27.7 ± 7.3 years, height: 178.4 ± 10.4 cm, weight: 73.8 ± 16.9 kg) volunteered to participate in a PNF session and a control session separated by 2-7 days. The PNF stretching lasted 2 minutes and consisted of 4 sets of 5-second isometric hamstring contraction immediately followed by 5 seconds of passive static stretch of the quadriceps immediately followed by 5 seconds isometric quadriceps contraction for each leg. For the control session, the participants were asked to walk at a comfortable speed for 2 minutes. Active ROM of knee flexion, vertical jump performance, and quadriceps neuromuscular function were tested before, immediately after, and 15 minutes after the intervention. The PNF stretching procedure did not affect ROM, squat jump, and countermovement jump performances. Accordingly, we did not observe any change in maximal voluntary contraction force, voluntary activation level, M-wave and twitch contractile properties that could be attributed to PNF stretching. The present self-administered PNF stretching of the quadriceps with short (5-second) stretches is not recommended before sports where flexibility is mandatory for performance. PMID:22505131

  13. 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.

  14. Analysis and control of underactuated mechanical systems

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

    2014-01-01

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

  15. 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

  16. Method of inspecting control rod drive mechanism

    Purpose: To conduct inspection for control rod drives and fuel handling operations in parallel without taking out the entire fuel, while maintaining the reactor in a subcritical state. Method: Control rod drives are inspected through the release of connection between control rods and control rod drives, detachment and dismantling of control rod drives, etc. In this case, structural materials having neutron absorbing power equal to or greater than the control rods are inserted into the gap after taking out fuels. Since the structural materials have neutron absorbing portion, subcriticality is maintained by the neutron absorbing effect. Accordingly, there is no requirement for taking out all of the fuels, thereby enabling to check the control rod drives and conduct handling for the fuels in parallel. As a result, the number of days required for the inspection can be shortened and it is possible to improve the working efficiency for the decomposition, inspection, etc. of the control rod drives and, thus, improve the operation efficiency of the nuclear power plant thereby attaining the predetermined purpose. (Kawakami, Y.)

  17. Neuromuscular Adaptations to Eccentric Strength Training in Children and Adolescents with Cerebral Palsy

    Reid, Siobhan; Hamer, Peter; Alderson, Jacqueline; Lloyd, David

    2010-01-01

    Aim: To determine the neuromuscular outcomes of an eccentric strength-training programme for children and adolescents with cerebral palsy (CP). Method: In this randomised, parallel-group trial with waiting control, 14 participants with CP (six males, eight females; mean age 11y, SD 2y range 9-15y), diagnosed with upper-limb spasticity were…

  18. Mirror Visual Feedback Induces Lower Neuromuscular Activity in Children with Spastic Hemiparetic Cerebral Palsy

    Feltham, Max G.; Ledebt, Annick; Deconinck, Frederik J. A.; Savelsbergh, Geert J. P.

    2010-01-01

    The study examined the effects of mirror feedback information on neuromuscular activation during bimanual coordination in eight children with spastic hemiparetic cerebral palsy (SHCP) and a matched control group. The "mirror box" creates a visual illusion, which gives rise to a visual perception of a zero lag, symmetric movement between the two…

  19. Family Stress with Chronic Childhood Illness: Cystic Fibrosis, Neuromuscular Disease, and Renal Disease.

    Holroyd, Jean; Guthrie, Donald

    1986-01-01

    Parents of children with neuromuscular disease, cystic fibrosis, and renal disease were compared with parents of control subjects matched by age to the clinical cases. The three clinical groups exhibited different patterns of stressful response, consistent with the nature of their illnesses and the requirements for care imposed on the families.

  20. Cutaneous mechanisms of isometric ankle force control

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

    2013-01-01

    The sense of force is critical in the control of movement and posture. Multiple factors influence our perception of exerted force, including inputs from cutaneous afferents, muscle afferents and central commands. Here, we studied the influence of cutaneous feedback on the control of ankle force output. We used repetitive electrical stimulation of the superficial peroneal (foot dorsum) and medial plantar nerves (foot sole) to disrupt cutaneous afferent input in 8 healthy subjects. We measured ...

  1. 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

  2. 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.

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

    de la Rosa, Ramon; Alonso, Alonso; Carrera, Albano; Durn, Ramon; Fernndez, Patricia

    2010-01-01

    This paper presents the UVa-NTS (University of Valladolid Neuromuscular Training System), a multifunction and portable Neuromuscular Training System. The UVa-NTS is designed to analyze the voluntary control of severe neuromotor handicapped patients, their interactive response, and their adaptation to neuromuscular interface systems, such as neural prostheses or domotic applications. Thus, it is an excellent tool to evaluate the residual muscle capabilities in the handicapped. The UVa-NTS is composed of a custom signal conditioning front-end and a computer. The front-end electronics is described thoroughly as well as the overall features of the custom software implementation. The software system is composed of a set of graphical training tools and a processing core. The UVa-NTS works with two classes of neuromuscular signals: the classic myoelectric signals (MES) and, as a novelty, the myomechanic signals (MMS). In order to evaluate the performance of the processing core, a complete analysis has been done to classify its efficiency and to check that it fulfils with the real-time constraints. Tests were performed both with healthy and selected impaired subjects. The adaptation was achieved rapidly, applying a predefined protocol for the UVa-NTS set of training tools. Fine voluntary control was demonstrated to be reached with the myoelectric signals. And the UVa-NTS demonstrated to provide a satisfactory voluntary control when applying the myomechanic signals. PMID:22163515

  4. Molecular motors: design, mechanism and control

    Chowdhury, Debashish

    2007-01-01

    Biological functions in each animal cell depend on coordinated operations of a wide variety of molecular motors. Some of the these motors transport cargo to their respective destinations whereas some others are mobile workshops which synthesize macromolecules while moving on their tracks. Some other motors are designed to function as packers and movers. All these motors require input energy for performing their mechanical works and operate under conditions far from thermodynamic equilibrium. ...

  5. Control Mechanism and Security Region for Intentional Islanding Transition

    Chen, Yu; Xu, Zhao; Østergaard, Jacob

    2009-01-01

    grid. The concept of Islanding Security Region (ISR) has been proposed as an organic composition of the developed control mechanism. The purpose of this control mechanism is to maintain the frequency stability and eventually the security of power supply to the customers, by utilizing resources from...

  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. The tested control rod drive mechanism system based on PLC

    In order to test control rod drive mechanism would be match the functions and performance of the requirements of the design specifications, and complete the factory test, design this test device for test drive mechanism. The device based on programmable logic controller realized rod lifting, rod keeping, rod inserting and integrated alarm etc. Function. It introduces the working principle and realization method of the test device of control rod drive mechanism. Through connecting debugging with driving mechanism. The result proved that the test device would be match requirements of the technical agreement, the function and performance of CRDM meet the requirements of the design specifications of the production. (authors)

  8. Sarcocystis fayeri in skeletal muscle of horses with neuromuscular disease.

    Aleman, Monica; Shapiro, Karen; Sisó, Silvia; Williams, Diane C; Rejmanek, Daniel; Aguilar, Beatriz; Conrad, Patricia A

    2016-01-01

    Recent reports of Sarcocystis fayeri-induced toxicity in people consuming horse meat warrant investigation on the prevalence and molecular characterization of Sarcocystis spp. infection in horses. Sarcocysts in skeletal muscle of horses have been commonly regarded as an incidental finding. In this study, we investigated the prevalence of sarcocysts in skeletal muscle of horses with neuromuscular disease. Our findings indicated that S. fayeri infection was common in young mature horses with neuromuscular disease and could be associated with myopathic and neurogenic processes. The number of infected muscles and number of sarcocysts per muscle were significantly higher in diseased than in control horses. S. fayeri was predominantly found in low oxidative highly glycolytic myofibers. This pathogen had a high glycolytic metabolism. Common clinical signs of disease included muscle atrophy, weakness with or without apparent muscle pain, gait deficits, and dysphagia in horses with involvement of the tongue and esophagus. Horses with myositis were lethargic, apparently painful, stiff, and reluctant to move. Similar to humans, sarcocystosis and cardiomyopathy can occur in horses. This study did not establish causality but supported a possible association (8.9% of cases) with disease. The assumption of Sarcocysts spp. being an incidental finding in every case might be inaccurate. PMID:26522989

  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. Control mechanisms in mitochondrial oxidative phosphorylation☆

    Hroudová, Jana; Fišar, Zdeněk

    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. Recen...

  11. Network-Based Mechanism of Prefrontal Control

    Katsuyuki Sakai

    2010-06-01

    Full Text Available Our voluntary behaviors are thought to be controlled by top-down signals from the prefrontal cortex (PFC, which modulate the connectivity weighting of the brain network in favor of the processing of task-relevant information. Neuroimaging and single unit recording studies have shown that the PFC is active when subjects need to control behavior according to the behavioral goal. It remains open, however, how the prefrontal activation modulates the functional connectivity of the neural network downstream to the PFC. Here I will present the findings of our recent studies in which we applied a single-pulse transcranial magnetic stimulation (TMS over the PFC while normal human subjects performed tasks that require cognitive control. Here the TMS was used to probe the connectivity weighting of the neural network connected with the PFC rather than disturb the neural processing and behavior. To this end, we examined the short-latency TMS-induced activation in distant cortical regions using EEG. TMS-induced activation was observed in different cortical regions depending on what task the subjects were about to perform and also depending on what task the subjects had performed on the previous trial. The task-dependent changes in the pattern of neural impulse transmission are considered to reflect use-dependent modulation of efficacy of signal transmission from the prefrontal to posterior regions.

  12. 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.

  13. 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...

  14. Neuromuscular Diseases Associated with HIV-1 Infection

    Robinson-Papp, Jessica; David M. Simpson

    2009-01-01

    Neuromuscular disorders are common in HIV, occurring at all stages of disease and affecting all parts of the peripheral nervous system. These disorders have diverse etiologies including HIV itself, immune suppression and dysregulation, co-morbid illnesses and infections, and side effects of medications. In this article, we review the following HIV-associated conditions: distal symmetric polyneuropathy, inflammatory demyelinating polyneuropathy, mononeuropathy, mononeuropathy multiplex, autono...

  15. Flightless Flies: Drosophila models of neuromuscular disease

    Lloyd, Thomas E.; Taylor, J. Paul

    2010-01-01

    The fruit fly, Drosophila melanogaster, has a long and rich history as an important model organism for biologists. In particular, study of the fruit fly has been essential to much of our fundamental understanding of the development and function of the nervous system. In recent years, studies using fruit flies have provided important insights into the pathogenesis of neurodegenerative and neuromuscular diseases. Fly models of spinal muscular atrophy, spinobulbar muscular atrophy, myotonic dyst...

  16. Metabolic changes following neuromuscular electrical stimulation

    Sillen, M.J.H.

    2009-01-01

    SUMMARY Purpose The thesis exists of two parts. In the first part the results of trials focused on enzyme activity, motor unit recruitment and changes in fiber type distribution in human lower limb muscle following neuromuscular electrical stimulation (NMES). Secondly, the metabolic response and symptom perception are compared of low-frequency NMES and high-frequency NMES of the quadriceps femoris muscles in patients with COPD. Methods A systematic review was performed to identi...

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

    Nguyen Kim Quoc; Vo Thanh Tu; Nguyen Thuc Hai

    2014-01-01

    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 rea...

  18. 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 ...

  19. An immunosurveillance mechanism controls cancer cell ploidy.

    Senovilla, Laura; Vitale, Ilio; Martins, Isabelle; Tailler, Maximilien; Pailleret, Claire; Michaud, Mickal; Galluzzi, Lorenzo; Adjemian, Sandy; Kepp, Oliver; Niso-Santano, Mireia; Shen, Shensi; Mario, Guillermo; Criollo, Alfredo; Boilve, Alice; Job, Bastien; Ladoire, Sylvain; Ghiringhelli, Franois; Sistigu, Antonella; Yamazaki, Takahiro; Rello-Varona, Santiago; Locher, Clara; Poirier-Colame, Vichnou; Talbot, Monique; Valent, Alexander; Berardinelli, Francesco; Antoccia, Antonio; Ciccosanti, Fabiola; Fimia, Gian Maria; Piacentini, Mauro; Fueyo, Antonio; Messina, Nicole L; Li, Ming; Chan, Christopher J; Sigl, Verena; Pourcher, Guillaume; Ruckenstuhl, Christoph; Carmona-Gutierrez, Didac; Lazar, Vladimir; Penninger, Josef M; Madeo, Frank; Lpez-Otn, Carlos; Smyth, Mark J; Zitvogel, Laurence; Castedo, Maria; Kroemer, Guido

    2012-09-28

    Cancer cells accommodate multiple genetic and epigenetic alterations that initially activate intrinsic (cell-autonomous) and extrinsic (immune-mediated) oncosuppressive mechanisms. Only once these barriers to oncogenesis have been overcome can malignant growth proceed unrestrained. Tetraploidization can contribute to oncogenesis because hyperploid cells are genomically unstable. We report that hyperploid cancer cells become immunogenic because of a constitutive endoplasmic reticulum stress response resulting in the aberrant cell surface exposure of calreticulin. Hyperploid, calreticulin-exposing cancer cells readily proliferated in immunodeficient mice and conserved their increased DNA content. In contrast, hyperploid cells injected into immunocompetent mice generated tumors only after a delay, and such tumors exhibited reduced DNA content, endoplasmic reticulum stress, and calreticulin exposure. Our results unveil an immunosurveillance system that imposes immunoselection against hyperploidy in carcinogen- and oncogene-induced cancers. PMID:23019653

  20. Molecular motors: design, mechanism and control

    Chowdhury, Debashish

    2007-01-01

    Biological functions in each animal cell depend on coordinated operations of a wide variety of molecular motors. Some of the these motors transport cargo to their respective destinations whereas some others are mobile workshops which synthesize macromolecules while moving on their tracks. Some other motors are designed to function as packers and movers. All these motors require input energy for performing their mechanical works and operate under conditions far from thermodynamic equilibrium. The typical size of these motors and the forces they generate are of the order of nano-meters and pico-Newtons, respectively. They are subjected to random bombardments by the molecules of the surrounding aqueous medium and, therefore, follow noisy trajectories. Because of their small inertia, their movements in the viscous intracellular space exhibits features that are characteristics of hydrodynamics at low Reynold's number. In this article we discuss how theoretical modeling and computer simulations of these machines by...

  1. 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.

  2. 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.

  3. 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)

  4. 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.

  5. Installing and detaching apparatus for a control rod drive mechanism

    Object: To facilitate maintenance and repair of a control rod drive mechanism. Structure: The apparatus comprises a means moving in a moving direction of a control rod within a reactor vessel, said moving means having a housing mounted thereon, a means mounted on the reactor vessel to release a connection between a control rod drive mechanism connected to the control rod and the control rod, and a means for mounting and removing a fixing means which connects the reactor vessel to the control rod drive means. With this arrangement, cooling water of high radioactivity level may not be leaked outside to thereby notably reduce dangerousness of exposure and materially cut time required for mounting and removing the control rod drive mechanism. (Ohara, T.)

  6. The controller design for kicker magnet adjustment mechanism in SSRF

    The kicker magnet adjustment mechanism controller in SSRF is to improve the efficiency of injection by changing the magnet real-time, especially in the top-up mode. The controller mainly consists of Programmable logic controller (PLC), stepper motor, reducer, worm and mechanism. PLC controls the stepper motors for adjusting the azimuth of the magnet, monitors and regulates the magnet with tilt sensor. It also monitors the interlock. In addition, the controller is provided with local and remote working mode. This paper mainly introduces related hardware and software designs for this device. (authors)

  7. Cutaneous mechanisms of isometric ankle force control

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

    2013-01-01

    output. We used repetitive electrical stimulation of the superficial peroneal (foot dorsum) and medial plantar nerves (foot sole) to disrupt cutaneous afferent input in 8 healthy subjects. We measured the effects of repetitive nerve stimulation on (1) tactile thresholds, (2) performance in an ankle force...... cutaneous sensory function as evidenced by increased touch threshold. Absolute dorsiflexion force error increased without visual feedback during peroneal nerve stimulation. This was not a general effect of stimulation because force error did not increase during plantar nerve stimulation. The effects of...... transient stimulation on force error were greater when compared to continuous stimulation and lidocaine injection. Position-matching performance was unaffected by peroneal nerve or plantar nerve stimulation. Our results show that cutaneous feedback plays a role in the control of force output at the ankle...

  8. 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.

  9. Robust Position Control of Electro-mechanical Systems

    Rong Mei

    2013-01-01

    Full Text Available 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 stability of the closed-loop control system has been proved via the Lyapunov analysis technique. Simulation results are presented to demonstrate the feasibility of the proposed disturbance-observer-based position control scheme of the electro-mechanical system.

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

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

    2009-10-01

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

  11. 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)

  12. 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 ...

  13. 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....

  14. Patología neuromuscular en cuidados intensivos Neuromuscular abnormalities in critical illness

    R. Amaya Villar

    2009-04-01

    Full Text Available La patología neuromuscular en los pacientes críticos ha comenzado a ser objeto de un importante número de estudios en los últimos años, si bien aún quedan muchas lagunas en el conocimiento de su etiología, patogenia, tratamiento y pronóstico. Dentro de esta patología debemos distinguir dos grandes grupos. En el primero, la debilidad muscular aparece antes del ingreso en UCI y es posible identificar una causa conocida. El síndrome de Guillain-Barré y la miastenia grave son las dos entidades que con mayor frecuencia requieren ser atendidas en nuestras unidades. En el segundo grupo, la debilidad muscular se adquiere en la UCI, en pacientes sin enfermedad neuromuscular previa, y es secundaria a la gravedad de la enfermedad que originó su ingreso en esta unidad y/o al tratamiento empleado. La polineuropatía del paciente crítico (PPC es, de todas ellas, la entidad más precisamente definida y de la que conocemos mejor sus características clínicas, diagnóstico y pronóstico; no obstante, aún quedan muchas sombras en cuanto a su etiopatogenia. Las alteraciones de la placa neuromuscular y sobre todo la miopatía, que frecuentemente coexiste con la PPC, son las otras complicaciones del sistema nervioso periférico que se desarrollan en pacientes críticos. Los avances en el conocimiento de estas afecciones podrían tener un importante impacto, sobre todo para el desarrollo de intervenciones terapéuticas y preventivas efectivas que mejoren el pronóstico de estos pacientes.The spectrum of neuromuscular disease encountered in today's intensive care units (ICU has evolved over the last few decades. However, in spite of many studies on neuromuscular disorders complicating critical illness as well as its epidemiology, etiology, treatment and prognosis, several key areas remain unclear. Two main groups are found among these neuromuscular abnormalities. The first group includes primary neuromuscular disorders present on admission to the ICU in which a possible etiology can be identified. Guillain-Barré syndrome and myasthenia gravis are two of the most common diseases admitted to ours units. In the second group, weakness is acquired in the ICU in the absence of preexisting neuromuscular disease. It is believed to reflect illnesses or treatments occurring in the ICU. Critical illness polyneuropathy (CIP is the most clearly defined neuromuscular complication in this group. However, although we have better knowledge of its clinical, diagnosis, and prognosis features, its pathophysiological substrate has not been fully elucidated. Neuromuscular junction defects and specially myopathies, that frequently coexist with CIP, are the others main causes of acquired weakness in critically ill patients. Advances in understanding of these neuromuscular disorders could have an important impact in terms of developing effective preventive and therapeutic interventions that could help to improve the poor prognosis of these patients.

  15. 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....

  16. 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...

  17. Effects of mechanical ventilation on control of breathing.

    Georgopoulos, D B; Anastasaki, M; Katsanoulas, K

    1997-06-01

    During spontaneous breathing, respiratory muscle pressure (Pmus) waveform is determined by a complex system consisting of a motor arm, a control centre and various feedback mechanisms that convey information to the control centre. In mechanically ventilated patients, the pressure delivered by the ventilator (Paw) is incorporated into the system that controls breathing and may alter Pmus, which in turn modifies the Paw waveform. Thus, the response of the patient's respiratory effort to Paw and the response of Paw to patient effort constitute the two components of the control of breathing during mechanical ventilation. The response of Paw to patient effort depends on: 1) the mode of ventilatory support; 2) the mechanics of the respiratory system; and 3) the characteristics of the patient's respiratory effort. On the other hand, the response of patient effort to Paw is mediated through four feedback systems: 1) mechanical; 2) chemical; 3) reflex; and 4) behavioural. It follows that in mechanically ventilated patients the ventilatory output is determined by the interaction between the function of the ventilator and the patient's breathing control system. This interaction should be taken into account in the management of mechanically ventilated patients. PMID:9270253

  18. 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.

  19. 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.

  20. A novel synaptic plasticity rule explains homeostasis of neuromuscular transmission.

    Ouanounou, Gilles; Baux, Gérard; Bal, Thierry

    2016-01-01

    Excitability differs among muscle fibers and undergoes continuous changes during development and growth, yet the neuromuscular synapse maintains a remarkable fidelity of execution. Here we show in two evolutionarily distant vertebrates (Xenopus laevis cell culture and mouse nerve-muscle ex-vivo) that the skeletal muscle cell constantly senses, through two identified calcium signals, synaptic events and their efficacy in eliciting spikes. These sensors trigger retrograde signal(s) that control presynaptic neurotransmitter release, resulting in synaptic potentiation or depression. In the absence of spikes, synaptic events trigger potentiation. Once the synapse is sufficiently strong to initiate spiking, the occurrence of these spikes activates a negative retrograde feedback. These opposing signals dynamically balance the synapse in order to continuously adjust neurotransmitter release to a level matching current muscle cell excitability. PMID:27138195

  1. 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 positive effect in altering mechanics that influence the risk of incurring an ACL injury. PMID:21921815

  2. Modelling and Design of Admission Control Mechanisms for Web Servers using Non-linear Control Theory

    Andersson, Mikael; Kihl, Maria; Robertsson, Anders

    2003-01-01

    Web sites are exposed to high rates of incoming requests. Since web sites are sensitive to overload, admission control mechanisms are often implemented. The purpose of such a mechanism is to prevent requests from entering the web server during high loads. This paper presents how admission control mechanisms can be designed and implemented with a combination of queueing theory and control theory. Since web servers behave non-linear and stochastic, queueing theory can be used for web server mod...

  3. 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.

  4. 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

  5. Soft Time-Suboptimal Controlling Structure for Mechanical Systems

    Kulczycki, Piotr; Wisniewski, Rafal; Kowalski, Piotr; Krawiec, Karol

    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...

  6. MECHANISMS OF BIOLOGICAL CONTROL OF PLANT DISEASES WITH TRICHODERMA

    Research on biological control with Trichoderma species has demonstrated that different mechanisms are important for different host/disease/biocontrol agent interactions. While antibiosis is important in the control of seedling disease caused by Pythium species, antibiosis and mycoparasitism have l...

  7. 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

  8. 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

  9. Monolithic Controlled Delivery Systems: Part I. Basic Characteristics and Mechanisms

    Rumiana Blagoeva

    2006-04-01

    Full Text Available The article considers contemporary systems for controlled delivery of active agents, such as drugs, agricultural chemicals, pollutants and additives in the environment. A useful classification of the available controlled release systems (CRS is proposed according to the type of control (passive, active or self-preprogrammed and according to the main controlling mechanism (diffusion, swelling, dissolution or erosion. Special attention is given to some of the most used CRS - polymer monoliths. The structural and physical-chemical characteristics of CRS as well as the basic approaches to their production are examined. The basic mechanisms of controlled agent release are reviewed in detail and factors influencing the release kinetics are classified according to their importance. The present study can be helpful for understanding and applying the available mathematical models and for developing more comprehensive ones intended for design of new controlled delivery systems.

  10. Research on Internal Flow Control Mechanism of For CES Routers

    Bin Zhuge

    2011-01-01

    Full Text Available To improve the communication efficiency and security between Control Elements (CEs and Forwarding Elements (FEs of For CES routers, this study researches on internal flow control mechanism. Firstly, an evaluation model based on communication of Transport Mapping Layer (TML is proposed, which is used to improve service performance of TML. Secondly, in order to prevent redirect channel interference with control channel, this study proposes a bandwidth allocation algorithm called Dynamic Probabilistic Priority Based on Rate and Buffer (DPPBRB. Lastly, to avoid the potential congestion on control channel between one CE and multiple FEs, this study puts forward an internal flow control mechanism. These internal flow control methods that this study proposed effectively prevents the DoS attack from redirect messages and improves reliability of For CES routers. Simulation and experiment results show the feasibility and effectiveness of these methods.

  11. Sliding mode control on electro-mechanical systems

    Utkin, Vadim I.; Hao-Chi Chang

    2002-01-01

    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 dy...

  12. 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...

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

    Leininger, Elizabeth C.; Darcy B. Kelley

    2013-01-01

    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 fro...

  14. Shared Resistance to Aging and ALS in Neuromuscular Junctions of Specific Muscles

    Valdez, Gregorio; Tapia, Juan C.; Lichtman, Jeff; Sanes, Joshua R.

    2012-01-01

    Normal aging and neurodegenerative diseases both lead to structural and functional alterations in synapses. Comparison of synapses that are generally similar but respond differently to insults could provide the basis for discovering mechanisms that underlie susceptibility or resistance to damage. Here, we analyzed skeletal neuromuscular junctions (NMJs) in 16 mouse muscles to seek such differences. We find that muscles respond in one of three ways to aging. In some, including most limb and tr...

  15. Applying Workspace Limitations in a Velocity-Controlled Robotic Mechanism

    Abdallah, Muhammad E. (Inventor); Hargrave, Brian (Inventor); Platt, Robert J., Jr. (Inventor)

    2014-01-01

    A robotic system includes a robotic mechanism responsive to velocity control signals, and a permissible workspace defined by a convex-polygon boundary. A host machine determines a position of a reference point on the mechanism with respect to the boundary, and includes an algorithm for enforcing the boundary by automatically shaping the velocity control signals as a function of the position, thereby providing smooth and unperturbed operation of the mechanism along the edges and corners of the boundary. The algorithm is suited for application with higher speeds and/or external forces. A host machine includes an algorithm for enforcing the boundary by shaping the velocity control signals as a function of the reference point position, and a hardware module for executing the algorithm. A method for enforcing the convex-polygon boundary is also provided that shapes a velocity control signal via a host machine as a function of the reference point position.

  16. 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.

  17. Implementacin de la electromiografa cuantitativa para el estudio de las enfermedades neuromusculares / Implementation of quantitative electromyography for studying neuromuscular diseases

    Roger, lvarez Fiallo; Carlos, Santos Anzoranda; Esther, Medina Herrera.

    2005-03-01

    Full Text Available Se implementaron mtodos de anlisis de la electromiografa cuantitativa, en particular los mtodos de procesamiento manual de Buchthal, de descomposicin de la seal electromiogrfica, turns-amplitudes y el anlisis espectral para obtener los valores normativos de 2 msculos de referencia, el bcep [...] s braquial y el tibial anterior, con el objetivo de utilizarlos posteriormente en la prctica asistencial en el estudio de las enfermedades neuromusculares. Se realiz un estudio transversal de 50 sujetos controles, 20 del sexo femenino, 30 del sexo masculino, con una edad promedio de 38,52 aos entre 25 y 55 aos. Se tomaron un total de 12 000 muestras. Se concluy que el mtodo de anlisis de descomposicin de la seal electromiogrfica empleado es ms factible de aplicar en la prctica asistencial que el manual de Buchthal por su eficacia y rapidez, y se obtuvieron los valores normativos de los msculos bceps braquial y tibial anterior para los estudios de electromiografa cuantitativa Abstract in english In this research, the methods of analysis of quantitative electromyography, in particular the methods of Buchthal's manual processing, the decomposition of the electromyographic signal, the turns-amplitude analysis and the spectral analysis to obtain the normative values of two reference muscles, th [...] e brachial biceps and the anterior tibial, were implemented in order to use them later in medical practice to study neuromuscular diseases. A cross-sectional study of 50 controls aged 25-55, 20 females and 30 males, with an average age of 38.52 years old, was conducted. 12 000 samples were taken in all. It was concluded that the method analysis of decomposition of the electromyographic signal used is more feasible to be used in medical practice than Buchthal's manual method due to its efficiency and celerity. The normative values of the brachial biceps and anterior tibial muscles were obtained for the studies of quantitative electromyography

  18. Implementacin de la electromiografa cuantitativa para el estudio de las enfermedades neuromusculares Implementation of quantitative electromyography for studying neuromuscular diseases

    Roger lvarez Fiallo

    2005-03-01

    Full Text Available Se implementaron mtodos de anlisis de la electromiografa cuantitativa, en particular los mtodos de procesamiento manual de Buchthal, de descomposicin de la seal electromiogrfica, turns-amplitudes y el anlisis espectral para obtener los valores normativos de 2 msculos de referencia, el bceps braquial y el tibial anterior, con el objetivo de utilizarlos posteriormente en la prctica asistencial en el estudio de las enfermedades neuromusculares. Se realiz un estudio transversal de 50 sujetos controles, 20 del sexo femenino, 30 del sexo masculino, con una edad promedio de 38,52 aos entre 25 y 55 aos. Se tomaron un total de 12 000 muestras. Se concluy que el mtodo de anlisis de descomposicin de la seal electromiogrfica empleado es ms factible de aplicar en la prctica asistencial que el manual de Buchthal por su eficacia y rapidez, y se obtuvieron los valores normativos de los msculos bceps braquial y tibial anterior para los estudios de electromiografa cuantitativaIn this research, the methods of analysis of quantitative electromyography, in particular the methods of Buchthal's manual processing, the decomposition of the electromyographic signal, the turns-amplitude analysis and the spectral analysis to obtain the normative values of two reference muscles, the brachial biceps and the anterior tibial, were implemented in order to use them later in medical practice to study neuromuscular diseases. A cross-sectional study of 50 controls aged 25-55, 20 females and 30 males, with an average age of 38.52 years old, was conducted. 12 000 samples were taken in all. It was concluded that the method analysis of decomposition of the electromyographic signal used is more feasible to be used in medical practice than Buchthal's manual method due to its efficiency and celerity. The normative values of the brachial biceps and anterior tibial muscles were obtained for the studies of quantitative electromyography

  19. Deficits in Endogenous Adenosine Formation by Ecto-5′-Nucleotidase/CD73 Impair Neuromuscular Transmission and Immune Competence in Experimental Autoimmune Myasthenia Gravis

    Cristina Costa, Ana; Guerra-Gomes, Sónia; Ferreirinha, Fátima; Magalhães-Cardoso, Maria Teresa; Correia-de-Sá, Paulo

    2015-01-01

    AMP dephosphorylation via ecto-5′-nucleotidase/CD73 is the rate limiting step to generate extracellular adenosine (ADO) from released adenine nucleotides. ADO, via A2A receptors (A2ARs), is a potent modulator of neuromuscular and immunological responses. The pivotal role of ecto-5′-nucleotidase/CD73, in controlling extracellular ADO formation, prompted us to investigate its role in a rat model of experimental autoimmune myasthenia gravis (EAMG). Results show that CD4+CD25+FoxP3+ regulatory T cells express lower amounts of ecto-5′-nucleotidase/CD73 as compared to controls. Reduction of endogenous ADO formation might explain why proliferation of CD4+ T cells failed upon blocking A2A receptors activation with ZM241385 or adenosine deaminase in EAMG animals. Deficits in ADO also contribute to neuromuscular transmission failure in EAMG rats. Rehabilitation of A2AR-mediated immune suppression and facilitation of transmitter release were observed by incubating the cells with the nucleoside precursor, AMP. These findings, together with the characteristic increase in serum adenosine deaminase activity of MG patients, strengthen our hypothesis that the adenosinergic pathway may be dysfunctional in EAMG. Given that endogenous ADO formation is balanced by ecto-5′-nucleotidase/CD73 activity and that A2ARs exert a dual role to restore use-dependent neurocompetence and immune suppression in myasthenics, we hypothesize that stimulation of the two mechanisms may have therapeutic potential in MG. PMID:25691808

  20. Effects of oxamniquine on neuromuscular transmission.

    Adewunmi, C O; Ojewole, J A

    1985-06-01

    The effects of oxamniquine on neuromuscular transmission have been investigated in some experimental animals in an effort to unveil some of the unwanted effects of this commonly prescribed schistosomicide. Results obtained show that relatively low concentrations of the drug (oxamniquine, 10-100 micrograms/ml) potentiated acetylcholine-, carbachol- and nicotine-evoked contractions of the toad (Bufo regularis) isolated rectus abdominis muscle. Moderate to high concentrations of the compound (oxamniquine, 500 micrograms/ml and above) contracted rectus abdominis muscle preparations, and depressed indirect electrically-induced twitches of the rat isolated hemidiaphragm and chick isolated biventer muscle preparations. The depression of electrically-evoked twitches of the chick biventer and rat phrenic nerve-hemidiaphragm muscle preparations in vitro induced by moderate to high concentrations of oxamniquine (500 micrograms/ml and above) were resistant to bath-applied physostigmine (1-15 micrograms/ml), but deepened by d-tubocurarine (3-10 micrograms/ml). These findings suggest that the neuromuscular blocking action of oxamniquine is probably post-junctional in origin. PMID:2992404

  1. 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.

  2. 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.)

  3. Characteristics of Mechanical Pumps and Energy Saving Automatic Control System

    Ueda, Tadashi; Uchida, Yoshiyuki; Shingu, Hiroyasu

    In the 21st century, global warming has become a very serious ecological problem. It is necessary to prevent global warming from increasing the greenhouse effect gas such as carbon dioxide. A new energy saving technique using mechanical pump system is proposed as a solution to this problem. The pump carrying the water, which is the heat source, for the air conditioner has an effect on energy saving by using effective automatic control. Since there is a lack of knowledge related to mechanical pump, effective automatic control systems combined with some pumps are implemented only in a few buildings. In this paper, the machine characteristics of a mechanical pump and a system design combined with some pumps are applied to a decrease in energy consumption. Based on the characteristics of the pump, the automatic control techniques are constant discharged pressure control technique, estimated end pressure control technique and real end pressure control technique. In this paper, the estimated end pressure control technique is recommended as a result of testing the automatic control system combined with the pumps. Also, improvement in conditions of the pump is proposed as a new energy saving technique.

  4. 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...

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

    Andersen, Lars L; Zeeman, Peter; Jørgensen, Jørgen R; Bech-Pedersen, Daniel T; Sørensen, Janne Gress; Kjær, Michael; Andersen, Jesper L

    2011-01-01

    the effect of intensive physical rehabilitation on neuromuscular and functional adaptations in outpatients suffering from hemiparesis after stroke. A within-subject repeated-measures design with the paretic leg as the experimental leg and the nonparetic leg as the control leg was used. Eleven...... outpatients with hemiparesis after stroke participated in 12 weeks of intensive physical rehabilitation comprising unilateral high-intensity strength training with near-maximal loads (4-12 repetition maximum) and body weight supported treadmill training. At baseline and 12-week follow-up, the patients went...... 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...

  6. 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.

  7. The Effects of Neuromuscular Electrical Stimulation Training on Abdominal Strength, Endurance, and Selected Anthropometric Measures

    Tom Kernozek; Karen McLean; Mark Gibson; Carl Foster; Kelly Cornwell; Jennifer Miller; John P. Porcari

    2005-01-01

    We studied the effects of self-administered neuromuscular electrical stimulation (NMES) on changes in strength, endurance, selected anthropometric measures, and subject's perceived shape and satisfaction of the abdominal wall. Twenty-four adults (experimental group) stimulated their abdominals 5 days per week (20-40 minutes per session) for 8 weeks and refrained from engaging in any additional exercise during the study. A control group (N=16) refrained from exercising the abdominals or engagi...

  8. PGC-1? regulates the neuromuscular junction program and ameliorates Duchenne muscular dystrophy

    Handschin, Christoph; Kobayashi, Yvonne M.; Chin, Sherry; Seale, Patrick; Campbell, Kevin P.; Spiegelman, Bruce M

    2007-01-01

    The coactivator PGC-1? mediates key responses of skeletal muscle to motor nerve activity. We show here that neuregulin-stimulated phosphorylation of PGC-1? and GA-binding protein (GABP) allows recruitment of PGC-1? to the GABP complex and enhances transcription of a broad neuromuscular junction gene program. Since a subset of genes controlled by PGC-1? and GABP is dysregulated in Duchenne muscular dystrophy (DMD), we examined the effects of transgenic PGC-1? in muscle of mdx mice. These anima...

  9. 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...

  10. A Mechanism Design Approach for Coordination of Thermostatically Controlled Loads

    Li, Sen; Zhang, Wei; Lian, Jianming; Kalsi, Karanjit

    2015-01-01

    This paper focuses on the coordination of a population of thermostatically controlled loads (TCLs) with unknown parameters to achieve group objectives. The problem involves designing the device bidding and market clearing strategies to motivate self-interested users to realize efficient energy allocation subject to a peak energy constraint. This coordination problem is formulated as a mechanism design problem, and we propose a mechanism to implement the social choice function in dominant stra...

  11. Governance control mechanisms in Portuguese agricultural credit cooperatives

    Paula CABO; Rebelo, João

    2005-01-01

    Over the last decade Portuguese Agricultural Credit Cooperatives (ACCs) have increasingly face survival challenges related to their difficulty in gathering equity. The main source of ACCs equity is the net benefit; thus, understanding how ACCs governance can work on correcting bad economic performance is of crucial importance to overcome this constraint. The main objective of this paper is to describe the governance control mechanisms in the ACCs. Five governance mechanisms are identified: bo...

  12. Consecuencias clnicas de las alteraciones neuromusculares en el paciente crtico / Clinical consequences of neuromuscular impairments in critically ill patients

    A., Mesejo; E., Prez-Sancho; E., Moreno.

    2006-05-01

    Full Text Available La patologa neuromuscular en el paciente crtico se desarrolla en dos contextos: enfermedades neurolgicas primarias que requieren su ingreso en Medicina Intensiva por necesitar vigilancia estricta o ventilacin mecnica y manifestaciones del sistema nervioso perifrico secundarias a enfermedades s [...] istmicas crticas. En el primer grupo son las ms frecuentes el Sndrome de Guillain-Barr y la Miastenia Gravis y en el segundo la Polineuropata y la Miopata del paciente crtico. El patrn clnico comn ms frecuente consiste en el desarrollo de un cuadro de acusada debilidad y cuadriparesia cuya manifestacin ms tpica es la necesidad de respiracin asistida o la dificultad/imposibilidad para su retirada. Se consideran factores desencadenantes el fracaso multiorgnico y la sepsis en la polineuropata y los esteroides y bloqueantes neuromusculares en la miopata, actuando como coadyuvantes en ambos casos la malnutricin, particularmente la hipoalbimunemia, y la hiperglucemia. Considerando que la afectacin neuroptica y mioptica coexisten con frecuencia, se ha acuado el trmino polineuromiopata del paciente crtico. Tanto el Sndrome de Guillain-Barr como la polineuropata del paciente crtico se localizan a nivel del nervio perifrico, por lo que debe efectuarse un diagnstico diferencial entre ambos. La forma de presentacin es diferente ya que el primero es una patologa aguda que motiva su ingreso en UCI, mientras que la polineuropata se adquiere durante la hospitalizacin. En el primero es frecuente la afectacin del sistema nervioso autnomo y la disociacin albmino-citolgica en el LCR, lo que no se da en la polineuropata. Los estudios electrofisiolgicos muestran signos de desmelinizacin con disminucin de la velocidad de conduccin y normalidad en la amplitud de potenciales motores en el Sndrome de Guillain- Barr frente a velocidad de conduccin normal y amplitud reducida de potenciales motores en la polineuropata axonal. La crisis miastnica afecta a la unin neuromuscular y su diagnstico suele ser ms fcil al tener en la mayora de los casos un diagnstico previo de miastenia gravis.La debilidad muscular aumenta durante la actividad repetida (fatiga muscular) y mejora con el reposo. Su confirmacin diagnstica se realiza con el test del edofronio y con la estimulacin nerviosa repetitiva, que provoca una rpida disminucin del 10-15% en la amplitud de las respuestas provocadas. La miopata del paciente crtico se localiza en el msculo y provoca una debilidad generalizada con cuadriparesia, muy similar a la de la polineuropata, que impide o retrasa la desconexin de la ventilacin mecnica y que en sus grados avanzados puede provocar un aumento de CPK y mioglobina, junto con alteraciones en la exploracin neurofisiolgica. Esta ltima es difcil de discernir de la encontrada en la polineuropata, aunque la normalidad en los potenciales de accin sensitiva y la reducin en el potencial de acin motora con estimulacin muscular directa, puede ayudar a diferenciarlos. El pronstico funcional de las alteraciones musculares primarias suele ser bastante bueno, pero tanto la polineuropata como la miopata evolucionan lentamente a lo largo de semanas o meses, pudiendo quedar un importante dficit residual a los dos aos en los casos ms graves. Abstract in english Neuromuscular pathology in the critically ill patient develops within two settings: primary neurological diseases that require admission in the Intensive Care Medicine Unit for close monitoring or mechanical ventilation, and peripheral nervous system manifestations secondary to critical systemic dis [...] eases. The most frequent conditions in the first group are Guillain-Barr syndrome and Myasthenia Gravis, and in the second group, polyneuropathy and myopathy of the critically ill patient. The most commonly shared clinical pattern is the development of severe weakness and quadriplegia which most typical manifestation is the

  13. 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

  14. 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

  15. A control system for the drive mechanism of full-length control rods

    This article describes the control system manufactured by Mitsubishi Electric in 1973 for the drive mechanism that inserts and withdraws the control rods of the pressurized-water reactor of the No.2 unit of Kansai Electric Power's Takahama Power Plant. The drive mechanism is the magnetic jacking type equipped with three coils, which are energized according to an appropriate timing pattern to move the control-rod drive shaft in or out as required. (auth.)

  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. Quality control of injection moulded micro mechanical parts

    Gasparin, Stefania; Tosello, Guido; Hansen, Hans Nørgaard; Jørgensen, Martin Bondo

    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...

  19. Electrical characterization of DNA in mechanically controlled break-junctions

    Kang, Ning; Erbe, Artur; Scheer, Elke

    2008-01-01

    Electrical characterization of DNA molecules using the mechanically controlled break-junction technique is presented. The mainadvantage of the technique is the control over the electrode distance during the measurement. This can be used to stretch the DNA and search for the in?uence of the conformation on the conduction process. The DNA is characterized in liquid and dry environments. From our data, we conclude that only a small number of molecules are contacted in each measurement.

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

    Rolando Grave de Peralta; Sara Gonzalez Andino; Stephen Perrig

    2013-01-01

    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, a...

  1. 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...

  2. 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.

  3. Development of control rod and control-rod drive mechanism for fast breeder reactor

    The development of control rods and control-rod driving mechanisms for liquid-sodium-cooled fast breeder reactors is making steady headway by activities centering around Power Reactor and Nuclear Fuel Development Corporation. Toshiba, actively taking part in this plan, carried out various developmental examinations, and constructed a practical unit of experimental reactor ''JOYO'', and took charge of designing and testing the prototype reactor ''MONJU''. The control rod and the control-rod driving mechanism, working in high-temperature sodium, involve various problems, such as abrasion of sliding portions, change of characteristics of materials in high-temperature sodium, seal of reactor cover gas, removal of heat on control rods, and prevention of vibration. The control rod and control-rod driving mechanisms for ''JOYO'' and ''MONJU'' have been developed by the application of the solutions of these problems. (author)

  4. A systematic literature review on the use of proprioceptive neuromuscular facilitation in neuromuscular rehabilitation

    Shrestha, Yugal

    2013-01-01

    The purpose of this thesis was to review and critically analyze the literatures from 1990 to 2013 in order to investigate the methodological quality of the studies, indications and goals of PNF treatment, and to explore the components of PNF that are being used in treatment of neurological disorders. And to overview on the effectiveness and use of PNF approach in neuromuscular rehabilitation through the findings of this study. The research method used for this thesis was systematic litera...

  5. 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.

  6. An accurate error control mechanism for simplification before generation algorithms

    Guerra, Oscar; Rodriguez-Garcia, J. D.; Roca, E. (Esther); Fernndez, Francisco V.; Rodrguez Vzquez, Angel

    1999-01-01

    The use of simplification before generation techniques to enable the approximate symbolic analysis of large analog circuits is discussed. This paper introduces an error control mechanism to drive the circuit reduction, which overcomes the accuracy problems of previous approaches. The features and efficiency of the new methodology are demonstrated through several practical examples.

  7. Drive mechanism for the control device of a nuclear reactor

    The drive mechanism is based on the couple screw-roller nut and is suited for control devices in BWR reactors. It consists of an electromotor with stator and a rotor with two-armed rocking levers and rolls forming a multipart roller nut. It interacts with a lead screw under the influence of the electromagnetic field of the stator. (RW)

  8. Quasivelocities and Optimal Control for underactuated Mechanical Systems

    This paper is concerned with the application of the theory of quasivelocities for optimal control for underactuated mechanical systems. Using this theory, we convert the original problem in a variational second-order lagrangian system subjected to constraints. The equations of motion are geometrically derived using an adaptation of the classical Skinner and Rusk formalism.

  9. 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 other hand showed that this effect may arise without any anticipatory neural control mechanism. PMID:25393548

  10. A versatile feedback controller for electro-mechanical stimulation devices.

    Bohnenberger, J; Seyfarth, E A; Barth, F G

    1983-12-01

    Neurophysiological and behavioral work often requires that various laboratory stimulators be feedback-stabilized. We describe the design and performance of a versatile electronic controller that can be used to extend and flatten the frequency response of commercially available stimulating devices. The design includes flexible proportional-integral-derivative control action and active second-order, high-pass compensation. As an example application of this controller to 3 different electro-mechanical vibrator/transducer combinations demonstrates that the useful frequency response can be extended by more than a decade as compared with the uncontrolled device. PMID:6668958

  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. 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;...

  13. 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 ...

  14. 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.

  15. Postoperative effects of neuromuscular exercise prior to hip or knee arthroplasty

    Villadsen, Allan; Overgaard, Søren; Holsgaard-Larsen, Anders; Christensen, Robin; Roos, Ewa M

    2014-01-01

    OBJECTIVE: To investigate the postoperative efficacy of a supervised programme of neuromuscular exercise prior to hip or knee arthroplasty. METHODS: In this assessor-blinded randomised controlled trial, we included 165 patients scheduled for hip or knee arthroplasty due to severe osteoarthritis (OA......). An 8-week preoperative neuromuscular supervised exercise programme was delivered twice a week for 1 h as adjunct treatment to the standard arthroplasty procedure and compared with the standard arthroplasty procedure alone. The primary outcome was self-reported physical function measured on the......, no difference was found between groups for ADL (4.4, 95% CI -0.8 to 9.5) or pain (4.5, 95% CI -0.8 to 9.9). However, there was a statistically significant difference indicating an effect of exercise over the entire period (baseline to 3-months postoperatively) (p=0.0029). CONCLUSIONS: Eight weeks of...

  16. Feasibility of neuromuscular training in patients with severe hip or knee OA

    Ageberg, Eva; Link, Anne; Roos, Ewa M

    2010-01-01

    BACKGROUND: Although improvements are achieved by general exercise, training to improve sensorimotor control may be needed for people with osteoarthritis (OA). The aim was to apply the principles of neuromuscular training, which have been successfully used in younger and middle-aged patients with...... knee injuries, to older patients with severe hip or knee OA. We hypothesized that the training program was feasible, determined as: 1) at most acceptable self-reported pain following training; 2) decreased or unchanged pain during the training period; 3) few joint specific adverse events related to...... training, and 4) achieved progression of training level during the training period. METHODS: Seventy-six patients, between 60 and 77 years, with severe hip (n = 38, 55% women) or knee OA (n = 38, 61% women) underwent an individualized, goal-based neuromuscular training program (NEMEX-TJR) in groups for a...

  17. Neuromuscular exercise improves functional performance in patients with severe hip osteoarthritis

    Villadsen, Allan; Overgaard, Søren; Larsen, Anders Holsgaard; Roos, Ewa M.

    . Randomized controlled trial (Clinicaltrials.gov identifier: NCT01003756). 84 patients, 51% female, mean age 68.6±7.8 years, BMI 28.7±4.7 scheduled for total hip replacement at Svendborg Community Hospital, Odense University Hospital, Denmark were included. Intervention. Participants were randomized to an...... eight-week neuromuscular exercise (NEMEX-TJR) intervention or care-as-usual (verbal and written preoperative information). Intervention was supervised and offered twice a week with each session lasting one hour. The program is considered feasible and safe in this patient group and previously described...... attended 13±4 sessions (Table 1). In favor of the intervention group, the between-group difference was significant for 20-m walk (2.2 seconds, p=.009), chair stands (1.7 seconds, p=.022) and leg extension for the non operated leg (.17 W/kg, p=.049) (Table 2). Conclusion. Eight weeks neuromuscular exercise...

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

    Larsen, Camilla Marie; Lund, Hans; Juul-Kristensen, Birgit; Holtermann, Andreas; Søgaard, Karen

    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...... other muscle parts were below 1.5% activity or (ii) an activation ratio above 95% of the total activity of all muscles, significantly fewer SIS subjects than No-SIS subjects achieved selective activation of individual scapular muscle compartments without on-line biofeedback of muscle activity from each...... No-SIS subjects in neuromuscular activity of scapular stabilising muscles were observed, 2) and when provided with visual EMG feedback, the SIS group performed equally well as the No-SIS group, However, when assessing the neuromuscular function with and without the use of biofeedback, the findings...

  19. Control rod drive mechanisms in BWR type reactors

    Purpose: To reduce the intrusion of chloride ions and water of highly dissolved oxygen content to control rod drive mechanisms and the reactor core as low as possible. Constitution: Driving water for control rod drive mechanisms is usually supplied from a condensate desalter. However, if the electroconductivity at the exit of the condensate desalter is increased due to sea water leakage in the condensor, the control rod driving water is automatically switched from that of condensate storage tank water and dissolved oxygen density in the condensate storage tank water is supplied as control rod driving water in which the dissolved oxygen density is reduced to about several tens ppb by the deareation. In this way, intrusion of chloride ions by way of the control rod driving mechanisms into the reactor core upon sea water leakage in the condensor can be decreased, as well as the stress corrosion crackings in the core components can be reduced since deareated water is used as the driving water. (Kamimura, M.)

  20. Seismic analysis of control and safety rod drive mechanism

    Control rod and its driving mechanism for a Fast Breeder Reactor is to facilitate safe shutdown of the reactor in case of emergency. A theoretical study on the seismic qualification of control and safety rod driving mechanism is carried out. Earthquake excitations under Operational Basis (ORE) and Safe Shutdown condition (SSE) are considered. The time required for the control rod to reach the bottom position in order to shut down the reaction under excited condition is traced out. The maximum displaced positions and extreme stresses in various parts of the system under excitations are evaluated. The system modeled using beam elements. The connections between different parts are modeled through rigid elements. The interaction between various parts are modeled using GAP elements. (author)

  1. 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.

  2. Training the Antifragile Athlete: A Preliminary Analysis of Neuromuscular Training Effects on Muscle Activation Dynamics.

    Kiefer, Adam W; Myer, Gregory D

    2015-10-01

    Athletic injuries typically occur when the stable, emergent coordination between behavioral processes breaks down due to external noise, or variability. A physiological system that operates at an optimal point on a spectrum of rigidity and flexibility may be better prepared to handle extreme external variability, and the purpose of the current experiment was to examine whether targeted neuromuscular training resulted in changes to the rigidity and flexibility of the gluteal muscle tonus signal as measured with electromyography prior to the landing phase of a drop vertical jump task. 10 adolescent female athletes who participated in a targeted 10-week neuromuscular training program and 6 controls participated, and their tonus dynamics were examined with recurrence quantification analysis prior to training and after the 10-week program. The dependent measures, percent laminarity (%LAM) and percent determinism (%DET) were hypothesized to decrease following training, and were submitted to a one tailed mixed-model ANOVA. The training group exhibited a decrease in %LAM and %DET after training compared to pre-training and controls. The present findings indicate increased metaflexibility (i.e., greater intermittency and an increase in internal randomness) in tonus dynamics following neuromuscular training, and have important implications for the prevention of musculoskeletal injury in sport, specifically within the context of external noise and antifragility. PMID:26375937

  3. Optimal piezo-electro-mechanical coupling to control plate vibrations

    Alessandroni, S; Frezza, F

    2010-01-01

    A new way of coupling electrical and mechanical waves, using piezoelectric effect, is presented here. Since the energy exchange between two systems supporting wave propagation is maximum when their evolution is governed by similar equations, hence, an optimal electromechanical coupling is obtained by designing an electric network which is "analog" to the mechanical structure to be controlled. In this paper, we exploit this idea to enhance the coupling, between a Kirchhoff-Love plate and one possible synthesis of its circuital analog, as obtained by means of a set of piezoelectric actuators uniformly distributed upon the plate. It is shown how this approach allows for an optimal energy exchange between the mechanic and the electric forms independent of the modal evolution of the structure. Moreover, we show how an efficient electric dissipation of the mechanical energy can be obtained adding dissipative elements in the electric network.

  4. 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

  5. Non-uniform muscle oxygenation despite uniform neuromuscular activity within the vastus lateralis during fatiguing heavy resistance exercise.

    Miyamoto, Naokazu; Wakahara, Taku; Ema, Ryoichi; Kawakami, Yasuo

    2013-11-01

    Previous studies have reported for the vastus lateralis (VL) that the extent of muscle hypertrophy in response to resistance training is greater in the distal than in the middle region, despite uniform muscle fibre composition within VL along its length. In the present study, to investigate mechanism(s) for such non-uniform muscle hypertrophy, we simultaneously measured neuromuscular activity and muscle oxygenation state at the middle and distal regions of VL during fatiguing heavy resistance exercise. Twelve males performed unilateral knee extension exercise which consisted of 4 sets of 8 repetitions at intensity of 80% of the individual one repetition maximum. During the resistance exercise, neuromuscular activities and muscle oxygenation status at the middle and distal regions (50% and 70% of the thigh length, respectively) of VL were measured by using electromyography and near-infrared spectroscopy, respectively. Neuromuscular activities were similar between the distal and middle regions of VL, whereas muscle tissue oxygenation saturation was significantly lower at the distal than at the middle region of VL. These results suggest a possibility that the regional difference in muscle oxygenation but not in neuromuscular activity during fatiguing heavy resistance exercise is responsible for the regional difference in hypertrophy within a muscle. PMID:23834101

  6. Development of moving coil type control rod drive mechanism

    Kyoto University High Flux Reactor; 30 megawatt light water moderated reserarch reactor, has coupled cores in two separate core vessels surrounded by a heavy water reflector tank. Various investigations and tests were performed and a new type of control rod drive mechanism wa s developed. A plunger train connected to a control rod by a connecting rod in a guide tube is magnetically suspended with a coil train located out side of a guide tube. The drive mechanism developed has following merits. There is no leakage of core cooling water in principle because it has no sliding seal, rotary seal or reentrant thimble which are needed when the mechanisms pass through the core vessel. Maintenance is very easy because it has no complex mechanism in the core cooling water region. Scram for emergency shut down is performed on a loss of electric power. The control rod can be positioned continuously. This method will be applicable not only in nuclear reactors, but also in other plants in need of isolation. (author)

  7. [Investigation of neuromuscular blocking agents at Richter Ltd].

    Krpti, Egon; Br, Katalin; Kukorelli, Tibor

    2002-01-01

    Investigation of new neuromuscular blocking agents was started 30 years ago in Richter Ltd. This paper presents the results obtained by Richter's scientists. 2 compounds out of 100 bisquaternary ammonio steroid having androstane skeleton were selected for further pharmacological study. One of these agents, pipecuronium bromide (Arduan) elicited long-lasting block of neuromuscular transmission without cardiovascular side effects in both animal experiments and clinical studies. Arduan is a powerful competitive antagonist of acetylcholine, since it can bind pre- and postsynaptic (N1) receptors of the transmitters. It has no remarkable cumulative effect. Neostigmine rapidly and completely antagonized the neuromuscular blockade caused by pipecuronium. Arduan was introduced into clinical practice. The second compound, RGH-4201 (Duador) evoked a neuromuscular block of short duration. It showed slight atropin-like cardio-vagolytic effect in animal experiments. In the clinical studies, however, the cardiovascular side effects were found to be too strong. Therefore, it was not introduced in clinical practice. PMID:12426786

  8. Learning to Live with Neuromuscular Disease: A Message for Parents

    ... and felt quite helpless Since then weve learned a great deal, most of it very hopeful. ... This booklet is for parents whove recently learned their child has a progressive neuromuscular disease. Although ...

  9. 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

  10. [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

  11. 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.

  12. Potential Mechanisms of Cancer Prevention by Weight Control

    Jiang, Yu; Wang, Weiqun

    Weight control via dietary caloric restriction and/or physical activity has been demonstrated in animal models for cancer prevention. However, the underlying mechanisms are not fully understood. Body weight loss due to negative energy balance significantly reduces some metabolic growth factors and endocrinal hormones such as IGF-1, leptin, and adiponectin, but enhances glucocorticoids, that may be associated with anti-cancer mechanisms. In this review, we summarized the recent studies related to weight control and growth factors. The potential molecular targets focused on those growth factors- and hormones-dependent cellular signaling pathways are further discussed. It appears that multiple factors and multiple signaling cascades, especially for Ras-MAPK-proliferation and PI3K-Akt-anti-apoptosis, could be involved in response to weight change by dietary calorie restriction and/or exercise training. Considering prevalence of obesity or overweight that becomes apparent over the world, understanding the underlying mechanisms among weight control, endocrine change and cancer risk is critically important. Future studies using "-omics" technologies will be warrant for a broader and deeper mechanistic information regarding cancer prevention by weight control.

  13. 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...

  14. The sagital balance in idiopatic and neuromuscular scoliosis

    Borges, Paulo Alvim; Ocampos, Guilherme Pereira; Mancuso, José Antonio; Letaif, Olavo Biraghi; Marcon, Raphael Martus; Cristante, Alexandre Fogaça

    2014-01-01

    OBJECTIVES: To describe and compare the distribution of spinopelvic parameters (SPP) in a Brazilian population with idiopathic scoliosis (IS) and neuromuscular scoliosis (NMS), and evaluate the association between pelvic incidence (PI) and lumbar lordosis (LL). METHOD: Medical records investigation was performed. Sagital balance angles were measured in patients with neuromuscular and idiopathic scoliosis. RESULTS: IS sample means (in degrees): PI 55.55; Sacral Slope (SS) 45.35; Pelvic Tilt (P...

  15. 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)...

  16. Report on Adaptive Force, A Specific Neuromuscular Function

    Marko Hoff; Laura Schaefer; Nancy Heinke; Frank Bittmann

    2015-01-01

    In real life motions, as well as in sports, the adaptation of the neuromuscular systems to externally applied forces plays an important role. The term Adaptive Force (AF) shall characterize the ability of the nerve-muscle-system to adapt to impacting external forces during isometric and eccentric muscle action. The focus in this paper is on the concept of this neuromuscular action, which is not yet described in this way. A measuring system was constructed and evaluated for this specific neuro...

  17. Quality of life after surgery for neuromuscular scoliosis

    Peter Obid; Andrea Bevot; Almut Goll; Corinna Leichtle; Nikolaus Wlker; Thomas Niemeyer

    2013-01-01

    Surgery in patients with neuromuscular scoliosis is associated with a higher rate of complications. It is still controversially discussed whether the patients truly benefit from deformity correction. The purpose of this study is to investigate if the quality of life has been improved and if the patients and their caregivers are satisfied with the results of surgery. This is a retrospective clinical outcome study of 46 patients with neuromuscular scoliosis which were treated with primary stabl...

  18. Controlling chaos based on an adaptive nonlinear compensator mechanism

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

  19. 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.

  20. New mechanism for the control of sodium transport in wheat

    Full text: Durum and other tetraploid wheats are typically very salt-sensitive compared to hexaploid bread wheats. This is primarily due to high rates of Na+ accumulation in the leaves in tetraploid wheat. Recently, we have discovered a durum landrace with low Na+ accumulation and enhanced K+/Na+ discrimination, much lower than current durum cultivars and similar to bread wheat. We have identified 3 different mechanisms for the control of Na+ transport to the leaves in this landrace, 1) control of Na+ uptake at the epidermis of the root, 2) control of Na+ loading into the xylem and 3) partitioning of Na+ into the leaf sheath. The low Na+ durum landrace had 3-4 fold lower Na+ uptake rates than durum cultivars. Using X ray microanalysis on snap-frozen root sections, we found Na+ to be high in the epidermis, a decreasing gradient through the cortex, low in the endodermis and again high in the stele (pencycle and xylem parenchyma), indicative of control points at the epidermis and in the stele. Partitioning of Na+ between shoot and root was at least 5 times lower in the durum landrace, suggestive of greater control of Na+ transport at the site of xylem loading. A third and novel control mechanism was found in the leaf sheath. Short and long term salinity treatments showed that Na+ was partitioned preferentially into the sheaths of the low Na+ durum landrace, keeping leaf blade Na+ levels very low and similar to that of bread wheat Na+ partitioned in the leaf sheath was stored primarily in the parenchyma cells and Cl- in the epidermal cells. Collectively, these data show that we have identified germplasm that has the potential to increase the salt tolerance of durum wheat. Additionally, as bread wheat does not contain the mechanism for partitioning Na+ into the sheath, this trait may be useful for further increasing the salt tolerance of this species

  1. Analysis of femtosecond quantum control mechanisms with colored double pulses

    Vogt, Gerhard; Nuernberger, Patrick; Selle, Reimer; Dimler, Frank; Brixner, Tobias; Gerber, Gustav

    2006-09-01

    Fitness landscapes based on a limited number of laser pulse shape parameters can elucidate reaction pathways and can help to find the underlying control mechanism of optimal pulses determined by adaptive femtosecond quantum control. In a first experiment, we employ colored double pulses and systematically scan both the temporal subpulse separation and the relative amplitude of the two subpulses to acquire fitness landscapes. Comparison with results obtained from a closed-loop experiment demonstrates the capability of fitness landscapes for the revelation of possible control mechanisms. In a second experiment, using transient absorption spectroscopy, we investigate and compare the dependence of the excitation efficiency of the solvated dye molecule 5,5' -dichloro-11-diphenylamino- 3,3' -diethyl-10,12-ethylene thiatricarbocyanine perchlorate (IR140) on selected pulse shapes in two parametrizations. The results show that very different pulse profiles can be equivalently adequate to maximize a given control objective. Fitness landscapes thus provide valuable information about different pathways along which a molecular system can be controlled with shaped laser pulses.

  2. 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)

  3. 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...

  4. 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.)

  5. EXERCISE ENHANCING CALCIUM ABSORPTION MECHANISM

    Muliani **

    2013-04-01

    Full Text Available 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 hormones (1,25-dihydroxycholecalciferolvitamin D3 (1,25-(OH2D3 and parathyroid hormone (PTH. Exercise enhancing calcium absorption through transcellular and paracellular calcium transport by increasing the calcium transporter genes.

  6. 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 movements. PMID:19227523

  7. Cartesian Control of a Cable-Driven Haptic Mechanism

    Otis, Martin J.D.; Duchaine, Vincent; Billette, Greg; Perreault, Simon; Gosselin, Clement; Laurendeau, Denis

    2010-01-01

    The haptic mechanism exploits software and hardware architectures that were specifically designed for managing a Cable-Driven Locomotion Interface driven by a haptic rendering engine for real-time applications. The architecture includes hybrid impedance, admittance and inertial-wrench control classes and two physics engines that permits the best haptic display for soft and rigid virtual objects. These components are implemented and generalized following an open-architecture paradigm in order ...

  8. Safe neuromuscular electrical stimulator designed for the elderly.

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

    2011-03-01

    A stimulator for neuromuscular electrical stimulation (NMES) was designed, especially suiting the requirements of elderly people with reduced cognitive abilities and diminished fine motor skills. The aging of skeletal muscle is characterized by a progressive decline in muscle mass, force, and condition. Muscle training with NMES reduces the degradation process. The discussed system is intended for evoked muscle training of the anterior and posterior thigh. The core of the stimulator is based on a microcontroller with two modular output stages. The system has two charge-balanced biphasic voltage-controlled stimulation channels. Additionally, the evoked myoelectric signal (M-wave) and the myokinematic signal (surface acceleration) are measured. A central controller unit allows using the stimulator as a stand-alone device. To set up the training sequences and to evaluate the compliance data, a personal computer is connected to the stimulator via a universal serial bus. To help elderly people handle the stimulator by themselves, the user interface is kept very simple. For safety reasons, the electrode impedance is monitored during stimulation. A comprehensive compliance management with included measurements of muscle activity and stimulation intensity enables a scientific use of the stimulator in clinical trials. PMID:21401669

  9. 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 ...

  10. 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.

  11. Antenna Mechanism of Length Control of Actin Cables.

    Mohapatra, Lishibanya; Goode, Bruce L; Kondev, Jane

    2015-06-01

    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 concentration of myosin motors delivering Smy1. These results provide testable predictions of the antenna mechanism of actin-cable length control. PMID:26107518

  12. 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.

  13. 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

  14. From Neuromuscular Activation to End-point Locomotion: An Artificial Neural Network-based Technique for Neural Prostheses

    Chia-Lin CHANG; Jin, Zhanpeng; Chang, Hou-Cheng; Cheng, Allen C

    2009-01-01

    Neuroprostheses, implantable or non-invasive ones, are promising techniques to enable paralyzed individuals with conditions, such as spinal cord injury or spina bifida (SB), to control their limbs voluntarily. Direct cortical control of invasive neuroprosthetic devices and robotic arms have recently become feasible for primates. However, little is known about designing non-invasive, closed-loop neuromuscular control strategies for neural prostheses. Our goal was to investigate if an Artificia...

  15. 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 newborn infants. Pediatr Radiol 1993;23(3:183-5.Balachandran A, Shivbalan S, Thangavelu S. Chest physiotherapy in pediatric practice. Indian Pediatr 2005;42(6:559-68.Finer NN, Moriartey RR, Boyd J, Phillips HJ, Stewart AR, Ulan O. Postextubation atelectasis: a retrospective review and a prospective controlled study. J Pediatr 1979;94(1:110-3.Al-Alaiyan S, Dyer D, Khan B. Chest physiotherapy and post-extubation atelectasis in infants. Pediatr Pulmonol. 1996;21(4:227-30.Bloomfield FH, Teele RL, Voss M, Knight DB, Harding JE. The role of neonatal chest physiotherapy in preventing postentubation atelectasis. J pediatr 1998;133(2:269-71.Bagley CE, Gray PH, Tudehope DI, Flenady V, Shearman AD, Lamont A. Routine neonatal postextubation chest physiotherapy: a randomized controlled trial. J Paediatr Child Health 2005;41(11:592-7.Vivian-Beresford A, King C, Macauley H. Neonatal post-extubation complications: the preventive role of physiotherapy. Physiother Can 1987;39:184-90.Bagley C, Flenady V, Tudehope D, Gray P. The role of postextubation chest physiotherapy: A randomised controlled trial. Proceedings of the Perinatal Society of Australia and New Zealand 4th Annual Congress. Brisbane: 1999.Reines HD, Sade RM, Bradford BF, Marshall J. Chest physiotherapy fails to prevent postoperative atelectasis in children after cardiac surgery. Ann Surg 1982;195(4:451-5. Cavenaghi S, Moura SC, Silva TH, Venturinelli TD, Marino LH, Lamari NM. Importance of pre- and postoperative physiotherapy in pediatric cardiac surgery. Rev Bras Cir Cardiovasc 2009;24(3:397-400.Deakins K, Chatburn RL. A comparison of intrapulmonary percussive ventilation and conventional chest physiotherapy for the treatment of atelectasis in the pediatric patient. Respir Care 2002;47(10:1162-7.

  16. Analysis of admission control mechanisms using non-linear control theory

    Kihl, Maria; Robertsson, Anders; Wittenmark, Björn

    2003-01-01

    All service control nodes can be modelled as a server system with one or more servers processing incoming requests. In this paper we show how non-linear control theory may be used when analyzing admission control mechanisms for server systems. Two models are developed, one linear and one non-linear. We show that, due to the non-linearities appearing in a real server system, linear control theory is sufficient when designing controllers for these systems. With non-linear analysis, however, the...

  17. 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.

  18. Multiple replication origins with diverse control mechanisms in Haloarcula hispanica.

    Wu, Zhenfang; Liu, Jingfang; Yang, Haibo; Liu, Hailong; Xiang, Hua

    2014-02-01

    The use of multiple replication origins in archaea is not well understood. In particular, little is known about their specific control mechanisms. Here, we investigated the active replication origins in the three replicons of a halophilic archaeon, Haloarcula hispanica, by extensive gene deletion, DNA mutation and genome-wide marker frequency analyses. We revealed that individual origins are specifically dependent on their co-located cdc6 genes, and a single active origin/cdc6 pairing is essential and sufficient for each replicon. Notably, we demonstrated that the activities of oriC1 and oriC2, the two origins on the main chromosome, are differently controlled. A G-rich inverted repeat located in the internal region between the two inverted origin recognition boxes (ORBs) plays as an enhancer for oriC1, whereas the replication initiation at oriC2 is negatively regulated by an ORB-rich region located downstream of oriC2-cdc6E, likely via Cdc6E-titrating. The oriC2 placed on a plasmid is incompatible with the wild-type (but not the ?oriC2) host strain, further indicating that strict control of the oriC2 activity is important for the cell. This is the first report revealing diverse control mechanisms of origins in haloarchaea, which has provided novel insights into the use and coordination of multiple replication origins in the domain of Archaea. PMID:24271389

  19. 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:                                                                                                                                 ...

  20. 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

  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. Neuromuscular Fatigue after Submaximal Intermittent Contractions in Motorcycle Riders.

    Torrado, P; Cabib, C; Morales, M; Valls-Sole, J; Marina, M

    2015-11-01

    Highly repetitive submaximal intermittent contractions of the forearm muscles during periods of 30-50 min partially explain why motorcycle races are so demanding for the neuromuscular system. This study investigated the contribution of central and peripheral mechanisms of fatigue on the exerted and contralateral extensor digitorum communis following an intermittent fatigue protocol (IFP) designed for motorcycle riders. 12 riders performed an IFP, which simulates the braking and throttle handle gesture. We examined the time course of recovery of maximal voluntary contraction (MVC), M-wave, motor evoked potential (MEP) to transcranial magnetic stimuli in relaxed and facilitated condition, and the cortical silent period (CSP) at time windows of 1, 3, 5, 10 and 20 min after the IFP. Whereas MVC, M-wave and MEP decreased, CSP lengthened significantly in the fatigued limb after completion of the IFP. Nevertheless, no differences were observed in the contralateral limb. All neurophysiological parameters reverted to baseline values in less than 20 min, while MVC remained lower in the exercised limb. No cross-over effects were observed in the contralateral non-exercised limb. Our results suggest that local factors are those mainly responsible for the incomplete MVC recovery after an intermittent muscle contraction protocol. PMID:26140690

  3. Stem cell route to neuromuscular therapies.

    Partridge, Terence A

    2003-02-01

    As applied to skeletal muscle, stem cell therapy is a reincarnation of myoblast transfer therapy that has resulted from recent advances in the cell biology of skeletal muscle. Both strategies envisage the reconstruction of damaged muscle from its precursors, but stem cell therapy employs precursors that are earlier in the developmental hierarchy. It is founded on demonstrations of apparently multipotential cells in a wide variety of tissues that can assume, among others, a myogenic phenotype. The main demonstrated advantage of such cells is that they are capable of colonizing many tissues, including skeletal and cardiac muscle via the blood vascular system, thereby providing the potential for a body-wide distribution of myogenic progenitors. From a practical viewpoint, the chief disadvantage is that such colonization has been many orders of magnitude too inefficient to be useful. Proposals for overcoming this drawback are the subject of much speculation but, so far, relatively little experimentation. This review attempts to give some perspective to the status of the stem cell as a therapeutic instrument for neuromuscular disease and to identify issues that need to be addressed for application of this technology. PMID:12548520

  4. 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.

  5. Serotonin and synaptic transmission at invertebrate neuromuscular junctions.

    Wu, Wen-Hui; Cooper, Robin L

    2012-09-01

    The serotonergic system in vertebrates and invertebrates has been a focus for over 50 years and will likely continue in the future. Recently, genomic analysis and discovery of alternative splicing and differential expression in tissues have increased the knowledge of serotonin (5-HT) receptor types. Comparative studies can provide useful insights to the wide variety of mechanistic actions of 5-HT responsible for behaviors regulated or modified by 5-HT. To determine cellular responses and influences on neural systems as well as the efferent control of behaviors by the motor units, preparations amenable to detailed studies of synapses are beneficial as working models. The invertebrate neuromuscular junctions (NMJs) offer some unique advantages for such investigations; action of 5-HT at crustacean NMJs has been widely studied, and leech and Aplysia continue to be key organisms. However, there are few studies in insects likely due to the focus in modulation within the CNS and lack of evidence of substantial action of 5-HT at the Drosophila NMJs. There are only a few reports in gastropods and annelids as well as other invertebrates. In this review we highlight some of the key findings of 5-HT actions and receptor types associated at NMJs in a variety of invertebrate preparations in hopes that future studies will build on this knowledge base. PMID:23055788

  6. 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.

  7. 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.

  8. Controlling Mechanical Properties of Bis-leucine Oxalyl Amide Gels

    Chang, William; Carvajal, Daniel; Shull, Kenneth

    2011-03-01

    is-leucine oxalyl amide is a low molecular weight gelator capable of gelling polar and organic solvents. A fundamental understanding of self-assembled systems can lead to new methods in drug delivery and the design of new soft material systems. An important feature of self-assembled systems are the intermolecular forces between solvent and gelator molecule; by changing the environment the gel is in, the mechanical properties also change. In this project two variables were considered: the degree of neutralization present for the gelator molecule from neutral to completely ionized, and the concentration of the gelator molecule, from 1 weight percent to 8 weight percent in 1-butanol. Mechanical properties were studied using displacement controlled indentation techniques and temperature sweep rheometry. It has been found that properties such as the storage modulus, gelation temperature and maximum stress allowed increase with bis-leucine oxalyl amide concentration. The results from this study establish a 3-d contour map between the gelator concentration, the gelator degree of ionization and mechanical properties such as storage modulus and maximum stress allowed. The intermolecular forces between the bis-leucine low molecular weight gelator and 1-butanol govern the mechanical properties of the gel system, and understanding these interactions will be key to rationally designed self-assembled systems.

  9. 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)

  10. Controlling the controllers: the institutional design of Europe’s new Single Supervisory Mechanism

    Gren, Jakub

    2014-01-01

    This paper examines the institutional design of the Single Supervisory Mechanism and views the relation between the European Central Bank (ECB) and the National Competent Authorities (NCAs) as a principal-agent relation in which the NCAs are carrying out supervision of the less significant banks on behalf of the ECB. From a principal-agent perspective, the institutional design is understood as the art of choosing proper ex ante and ex post mechanisms of control by the ECB over the activities ...

  11. Auxiliary remote controlled release for positive action mechanism

    The positive action mechanism has a ram with a shaft connected at one extremity to an action part and at the other to a push piece having a spring. A spindle, parallel to the shaft of the ram is mounted inside a case joined to the body of the ram. A screw nut is engaged with the threaded part of the spindle and is connected to a prolongator that engages on the shaft of the ram to displace the shaft as the spindle is rotated. The end part of the spindle has a connector to allow remote controlled equipment to rotate the spindle

  12. Fabrication and utilization of mechanically controllable break junction for bioelectronics

    D. Xiang

    2012-01-01

    In scope of this work, a mechanically controllable break junction (MCBJ) setup was established and used for the investigation of electron transport properties of molecules in four related aspects. The main feature of MCBJs, fabricated here, is their impressive stability. Spring steel substrates with a length of 44 mm and a width of 12 mm were used for the fabrication of the MCBJ chips. Electrode structures containing a thin suspended bridge with a constriction of 30-50 nm were defined by e-be...

  13. Bellows for control rod drive mechanisms of 'MONJU'

    The full mock-up operation test of Control Rod Drive Mechanism (CRDM) for 'MONJU' has been carried out since 1972 in OEC of PNC. Welded type bellows were adopted for CRDM as the boundary between sodium and atmosphere. In design, two different locations were considered for bellows, one in sodium and the other in argon gas with sodium vapor and some experiences on the bellows have been obtained. Besides the prototype tests of CRDM, several R and D on CRDM bellows, such as environment effect test and endurance test are conducted. (author)

  14. Development of a control box for a mechanical pressure scanner

    Pérez López, Andrea

    2014-01-01

    In broad terms, the objective of this thesis is to be able to measure and analyse pressure signals coming from different points of a turbine. For this purpose it is needed to read and control a signal, that travels from the turbine to a mechanical multiplexer, which can receive a maximum of 48 pressure inputs and even though it has only one output, it is able to rotate and vary the output pressure which enables the analysis of different pressures in 48 alternate locations of our analysed turb...

  15. Tuning the Kondo effect with a mechanically controllable break junction

    Parks, J J; Hutchison, G R; Flores-Torres, S; Abruna, H D; Ralph, D C

    2006-01-01

    We study electron transport through C_60 molecules in the Kondo regime using a mechanically controllable break junction. By varying the electrode spacing, we are able to change both the width and height of the Kondo resonance, indicating modification of the Kondo temperature and the relative strength of coupling to the two electrodes. The linear conductance as a function of T/T_K agrees with the scaling function expected for the spin-1/2 Kondo problem. We are also able to tune finite-bias Kondo features which appear at the energy of the first C_60 intracage vibrational mode.

  16. Rod drive mechanism with screw and nut for reactor control

    Screw and nut mechanism for controlling a nuclear reactor by vertical travel of an assembly absorbing the neutrons in the reactor core and drop of this absorbing assembly in maximum insertion position under its own weight, for reactor scram. It comprises a mobile screw in translation, the lower end of which can be connected to the absorbing assembly through a linking rod and a fixed nut in translation, mobile in rotation, secured to the lower end of a screw holding tube, the upper end of which comprises gear for hooking the claws of the grab for holding the screw-nut assembly in vertical position

  17. Electromagnetic control rod drive mechanism, with reduced heat losses

    The electromagnetic device can be used for the control rod drive mechanism of a pressurized coater reactor. It has a sealed casing extending from the reactor cover containing two mobile poles and a mobile plunger, a coil moving the first pole to grip or release the rod, a second coil moving the plunger against the second pole to grip the rod, a third coil moving the second pole, and a cut-out for a thermal coolant siphon associated with the first pole and coil

  18. The mircrine mechanism controlling cardiac stem cell fate

    Hosoda, Toru

    2013-01-01

    The recent identification of c-kit-positive cardiac stem cells revealed the great growth reserve of the heart, in which connection among cells might be essential in regulating their fate. Especially, the mircrine mechanism, translocation of microRNAs (miRs) from a cell to another via gap junctions, appeared to be important in controlling the differentiation of cardiac stem cells. The modification on miR expression and/or translocation may be able to enhance further the clinical efficacy of ce...

  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. Computational geometric mechanics and control of rigid bodies

    Lee, Taeyoung

    This dissertation studies the dynamics and optimal control of rigid bodies from two complementary perspectives, by providing theoretical analyses that respect the fundamental geometric characteristics of rigid body dynamics and by developing computational algorithms that preserve those geometric features. This dissertation is focused on developing analytical theory and computational algorithms that are intrinsic and applicable to a wide class of multibody systems. A geometric numerical integrator, referred to as a Lie group variational integrator, is developed for rigid body dynamics. Discrete-time Lagrangian and Hamiltonian mechanics and Lie group methods are unified to obtain a systematic method for constructing numerical integrators that preserve the geometric properties of the dynamics as well as the structure of a Lie group. It is shown that Lie group variational integrators have substantial computational advantages over integrators that preserve either one of none of these properties. This approach is also extended to mechanical systems evolving on the product of two-spheres. A computational geometric approach is developed for optimal control of rigid bodies on a Lie group. An optimal control problem is discretized at the problem formulation stage by using a Lie group variational integrator, and discrete-time necessary conditions for optimality are derived using the calculus of variations. The discrete-time necessary conditions inherit the desirable computational properties of the Lie group variational integrator, as they are derived from a symplectic discrete flow. They do not exhibit the numerical dissipation introduced by conventional numerical integration schemes, and consequently, we can efficiently obtain optimal controls that respect the geometric features of the optimality conditions. The approach that combines computational geometric mechanics and optimal control is illustrated by various examples of rigid body dynamics, which include a rigid body pendulum on a cart, pure bending of an elastic rod, and two rigid bodies connected by a ball joint. Since all of the analytical and computational results developed in this dissertation are coordinate-free, they are independent of a specific choice of local coordinates, and they completely avoid any singularity, ambiguity, and complexity associated with local coordinates. This provides insight into the global dynamics of rigid bodies.

  2. 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)

  3. 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

  4. Adaptive control of vibrissae-like mechanical sensors

    Behn, Carsten

    2011-05-01

    This paper is a contribution to the modeling and the adaptive control of bio-inspired sensors which have the animal vibrissae as a paradigm. Mice and rats employ a sophisticated tactile sensory system to explore their environment in addition to their visual and auditory sense. Vibrissae in the mystical pad (region around the mouth) are used both passively to sense environmental influences (wind, objects) and actively to detect surface and object structures. Inspired by this particular version of tactile sense we consider the following three stages of a sensory system: perception, transduction and processing of information. We model this system in combining two existing mechanical models and obtain an uncertain nonlinear control system. An applied adaptive controller implements the ability of the animals to employ their vibrissae actively as well as passively. Numerical simulations show that the developed nonlinear model compensates noise signals and reacts strongly to sudden perturbations while guaranteeing a pre-specified control objective (working in active or passive mode).

  5. A Cell-Level Mechanism of Contrast Gain Control

    Schumacher, Linus J

    2013-01-01

    The gain of neurons' responses in the auditory cortex is sensitive to contrast changes in the stimulus within a spectrotemporal range similar to their receptive fields, which can be interpreted to represent the tuning of the input to a neuron. This indicates a local mechanism of contrast gain control, which we explore with a minimal mechanistic model here. Gain control through noisy input has been observed in vitro and in a range of computational models. We investigate the behaviour of the simplest of such models to showcase gain control, a stochastic leaky integrate-and-fire (sLIF) neuron, which exhibits gain control through divisive normalisation of the input both with and without accompanying subtractive shift of the input-response curve, depending on whether input noise is proportional to or independent of its mean. To get a more direct understanding of how the input statistics change the response, we construct an analytic approximation to the firing rate of a sLIF neuron constituted of the expression for...

  6. Effects of hindlimb unloading on neuromuscular development of neonatal rats

    Huckstorf, B. L.; Slocum, G. R.; Bain, J. L.; Reiser, P. M.; Sedlak, F. R.; Wong-Riley, M. T.; Riley, D. A.

    2000-01-01

    We hypothesized that hindlimb suspension unloading of 8-day-old neonatal rats would disrupt the normal development of muscle fiber types and the motor innervation of the antigravity (weightbearing) soleus muscles but not extensor digitorum longus (EDL) muscles. Five rats were suspended 4.5 h and returned 1.5 h to the dam for nursing on a 24 h cycle for 9 days. To control for isolation from the dam, the remaining five littermates were removed on the same schedule but not suspended. Another litter of 10 rats housed in the same room provided a vivarium control. Fibers were typed by myofibrillar ATPase histochemistry and immunostaining for embryonic, slow, fast IIA and fast IIB isomyosins. The percentage of multiple innervation and the complexity of singly-innervated motor terminal endings were assessed in silver/cholinesterase stained sections. Unique to the soleus, unloading accelerated production of fast IIA myosin, delayed expression of slow myosin and retarded increases in standardized muscle weight and fiber size. Loss of multiple innervation was not delayed. However, fewer than normal motor nerve endings achieved complexity. Suspended rats continued unloaded hindlimb movements. These findings suggest that motor neurons resolve multiple innervation through nerve impulse activity, whereas the postsynaptic element (muscle fiber) controls endplate size, which regulates motor terminal arborization. Unexpectedly, in the EDL of unloaded rats, transition from embryonic to fast myosin expression was retarded. Suspension-related foot drop, which stretches and chronically loads EDL, may have prevented fast fiber differentiation. These results demonstrate that neuromuscular development of both weightbearing and non-weightbearing muscles in rats is dependent upon and modulated by hindlimb loading.

  7. Central chemoreceptors and neural mechanisms of cardiorespiratory control

    T.S. Moreira

    2011-09-01

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

  8. 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.

  9. Multi-function magnetic jack control drive mechanism

    Bollinger, Lawrence R. (Schenectady, NY); Crawford, Donald C. (Scotia, NY)

    1986-01-01

    A multi-function magnetic jack control drive mechanism for controlling a nuclear reactor is provided. The mechanism includes an elongate pressure housing in which a plurality of closely spaced drive rods are located. Each drive rod is connected to a rod which is insertable in the reactor core. An electromechanical stationary latch device is provided which is actuatable to hold each drive rod stationary with respect to the pressure housing. An electromechanical movable latch device is also provided for each one of the drive rods. Each movable latch device is provided with a base and is actuatable to hold a respective drive rod stationary with respect to the base. An electromechanical lift device is further provided for each base which is actuatable for moving a respective base longitudinally along the pressure housing. In this manner, one or more drive rods can be moved in the pressure housing by sequentially and repetitively operating the electromechanical devices. Preferably, each latch device includes a pair of opposed latches which grip teeth located on the respective drive rod. Two, three, or four drive rods can be located symmetrically about the longitudinal axis of the pressure housing.

  10. Neural mechanisms of attentional control in mindfulness meditation

    Peter Malinowski

    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.

  11. Microscopic observation and laser-controlled microoptothermal drive mechanism.

    Zhang, Dongxian; Zhang, Haijun; Liu, Chao; Jiang, Jianzhong

    2008-02-01

    The mechanism of novel optothermal microactuators (OTA) was analyzed with a microscope system, a charge-coupled device-combined light microscope, and a computer system. One OTA, two optothermal microswitches (OTS) with different length and shape were machined by an excimer laser micromatching system using single layer material. They all had two thin expansion arms with different widths. The mechanism of the OTA/OTS is that the different optothermal expansion controlled by asymmetric topology and shape of the arms causes a magnified lateral deflection or vibration. A red laser diode (650 nm) with maximum power output of 30 mW was employed as the external power source to drive the OTA/OTS. Experiments were carried out with the microscope system, and serial images and videos were acquired. The results indicate that the structure of the OTA/OTS is simple and easy to be manufactured. They can practically generate an obvious lateral deflection or vibration. When the location of the laser spot on the OTA changed, the direction of its deflection is also changed. When the value of laser power that irradiated on the OTS increased, the lateral deflection of the OTS enlarged, the maximum could be larger than 30 microm. This kind of novel microactuator has the advantages of remote wireless controlling, large displacement, simple structure, easy to be machined, and therefore will be quite useful for the practical applications in the fields of micro/nanotechnology. PMID:17960601

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

    Viby-Mogensen, J.; Østergaard, D.; Donati, F.; Fisher, D.; Hunter, J.; Kampmann, J.P.; Kopman, A.; Proost, J.H.; Rasmussen, S.N.; Skovgaard, Lene Theil; Varin, F.; Wright, P.M.C.

    Good Clinical Research Practice (GCRP), neuromuscular blocking agents, pharmacokinetics, pharmacokinetic/pharmacodynamic modeling, population pharmacokinetics, statistics, study design......Good Clinical Research Practice (GCRP), neuromuscular blocking agents, pharmacokinetics, pharmacokinetic/pharmacodynamic modeling, population pharmacokinetics, statistics, study design...

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

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

    2005-08-16

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

  14. Dynamic Simulation of Hybrid-driven Planar Five-bar Parallel Mechanism Based on SimMechanics and Tracking Control

    Bin Zi; Jianbin Cao; Zhencai Zhu

    2011-01-01

    This paper investigates dynamic simulation and trajectory tracking control of hybrid‐driven planar five‐bar parallel mechanism (HPPM). To begin with, a simulation model of dynamics based on MATLAB/SimMechanics is established. Then, traditional PD control and closed loop PD‐type iterative learning control of the HPPM are designed. At the end, the simulation based on SimMechanics is carried out, which acquires angular, angular velocity, angular acceleration of two driving link...

  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. 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

    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...... had a TOF value measured at PACU entry. Zero out of 74 sugammadex patients and 33 out of 76 (43.4%) usual care patients had TOF-Watch® SX-assessed residual neuromuscular blockade at PACU admission (odds ratio 0.0, 95% CI [0-0.06], P<0.0001). Of these 33 usual care patients, 2 also had clinical...... 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. Activity-Dependent Regulation of the Binomial Parameters p and n at the Mouse Neuromuscular Junction In Vivo

    Wang, Xueyong; Wang, Qingbo; Engisch, Kathrin L.; RICH, MARK M.

    2010-01-01

    Block of neurotransmission at the mammalian neuromuscular junction triggers an increase in the number of vesicles released (quantal content). The increase occurs whether nerve and muscle activity are both blocked by placement of a tetrodotoxin (TTX) containing cuff on the nerve or whether muscle activity is selectively blocked by injection of ?-bungarotoxin (BTX). We used ANOVA to examine whether the mechanism underlying the increase in quantal content differed between the two types of activi...

  18. Comparative recovery from three nondepolarizing neuromuscular blockers in a patient before and after chronic anticonvulsant therapy: a case report.

    Haas, R E; Masters, J E

    1997-10-01

    We describe a 51-year-old patient undergoing a second neurosurgical procedure after being prescribed anticonvulsant therapy. The patient had significant changes in the duration of action of identical doses of nondepolarizing muscle relaxants and we were able to compare the duration of action of neuromuscular blockers before and after the chronic administration of anticonvulsant therapy. A brief review of the possible mechanisms of action of the acceleration of the patient's recovery profile is also presented. PMID:9386378

  19. 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...

  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, immunocytochemistry (ICC), and neurite measurements. Data indicates that chemo-mechanical signaling is highly combinatorial in directing differentiation of C17.2s along a neuronal lineage in vitro. Chapter 4 discusses the design, synthesis, and characterization of a novel nanomaterial platform to investigate ligand-receptor binding. PEGylated nanoparticles were successfully synthesized and found to be relatively homogenous in size and morphology, as observed by transmission electron microscopy. However, successful binding of RGD peptide to the nanoparticle was not confirmed. Finally, a method for proteomic analysis of the C17.2 secretome is discussed in Chapter 5. Secreted proteins are of great importance as they can both influence cell behaviors as well as act as biomarkers of differentiation. Methods have been selected and optimized for protein extraction and two dimensional gel electrophoresis to be followed by mass spectrometry and protein identification. A temporal analysis of unique proteins expressed by C17.2s will result in a differentiation timeline. Deducing the dynamics of neuronal cell secretions will greatly contribute to the characterization of the C17.2 cell line and improve its relevance as a neural stem cell model. Overall, results illustrate the importance of chemical and mechanical cues in manipulating neural stem cell fate. These material platforms in combination with the further characterization of the C17.2 neural stem cells could have a great impact in the fields of neuronal biology, translational therapeutics, and pharmaceutical research.

  1. 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;...

  2. 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 knee pain (RR 0.27, CI 0.14 to 0.54 in military recruits. Conclusions Effective implementation of practical neuromuscular warm-up strategies can reduce lower extremity injury incidence in young, amateur, female athletes and male and female military recruits. This is typically a warm-up strategy that includes stretching, strengthening, balance exercises, sports-specific agility drills and landing techniques applied consistently for longer than three consecutive months. In order to optimize these strategies, the mechanisms for their effectiveness require further evaluation.

  3. 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....

  4. PGC-1alpha regulates the neuromuscular junction program and ameliorates Duchenne muscular dystrophy

    Handschin, C; Kobayashi, Y M; Chin, S.; Seale, P; Campbell, K P; Spiegelman, B M

    2007-01-01

    The coactivator PGC-1alpha mediates key responses of skeletal muscle to motor nerve activity. We show here that neuregulin-stimulated phosphorylation of PGC-1alpha and GA-binding protein (GABP) allows recruitment of PGC-1alpha to the GABP complex and enhances transcription of a broad neuromuscular junction gene program. Since a subset of genes controlled by PGC-1alpha and GABP is dysregulated in Duchenne muscular dystrophy (DMD), we examined the effects of transgenic PGC-1alpha in muscle of m...

  5. 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....

  6. Papel da vitamina D na função neuro-muscular Role of vitamin D in the neuro-muscular function

    Márcia A. Carneiro Pedrosa

    2005-08-01

    Full Text Available A vitamina D, através de suas ações no intestino, rim, osso e glândulas paratiróides, é um hormônio fundamental para a homeostase do cálcio e para o desenvolvimento de um esqueleto saudável. Além disso, receptores deste hormônio podem ser encontrados em quase todos os tecidos do organismo e outras ações não relacionadas ao metabolismo mineral têm sido imputadas a ele. Na célula muscular esquelética, a vitamina D atua através do mecanismo clássico de ligação a um receptor nuclear e também através da ligação a um receptor de membrana, realizando ações que envolvem o transporte de cálcio, a síntese protéica e a velocidade de contração muscular. Clinicamente, a deficiência de vitamina D, que é bastante comum em idosos, inclusive em nosso país, tem sido relacionada a um aumento da incidência de quedas, a uma diminuição da força muscular e a uma deterioração do equilíbrio, avaliada pela oscilação do corpo na postura ereta. Por outro lado, tem sido demonstrado que a suplementação associada de cálcio e vitamina D em idosos deficientes contribui para melhoria destes aspectos da função neuro-muscular. Nesta revisão, serão discutidos os mecanismos conhecidos envolvidos na associação entre vitamina D e função neuro-muscular, e também a suplementação de vitamina D e cálcio na prevenção de fraturas osteoporóticas não-vertebrais sob a perspectiva dos efeitos neuro-musculares.Through its action in the kidney, intestines, bone and parathyroid glands vitamin D is a major regulator of calcium homeostasis and for the development of a healthy skeleton. Moreover, receptors for this hormone are present in almost all body tissues and other actions which are not related to the mineral metabolism have been imputed to it. In the skeletal muscle cell, vitamin D acts through the classic mechanism of binding to a nuclear receptor and also by binding to a membrane receptor, carrying out actions that involve calcium transport, protein synthesis and kinetics of muscle contraction. Clinically, vitamin D deficiency, which is very common among the elderly, including the ones in our country, has been related to an increase in the incidence of falls, as well as the reduction of muscle strength and deterioration of body sway, evaluated by the oscillation of the body in the erect position. On the other hand, it has been demonstrated that supplementation of calcium associated to vitamin D in deficient elderly contributes to the improvement of these aspects of the neuro-muscular function. In this review, the mechanisms involved in the association between vitamin D and neuro-muscular function will be discussed, as well as the supplementation of vitamin D and calcium to prevent non-vertebral osteoporotic fractures under the perspective of the neuro-muscular effects.

  7. Market-based control mechanisms for patient safety.

    Coiera, E; Braithwaite, J

    2009-04-01

    A new model is proposed for enhancing patient safety using market-based control (MBC), inspired by successful approaches to environmental governance. Emissions trading, enshrined in the Kyoto protocol, set a carbon price and created a carbon market--is it possible to set a patient safety price and let the marketplace find ways of reducing clinically adverse events? To "cap and trade," a regulator would need to establish system-wide and organisation-specific targets, based on the cost of adverse events, create a safety market for trading safety credits and then police the market. Organisations are given a clear policy signal to reduce adverse event rates, are told by how much, but are free to find mechanisms best suited to their local needs. The market would inevitably generate novel ways of creating safety credits, and accountability becomes hard to evade when adverse events are explicitly measured and accounted for in an organisation's bottom line. PMID:19342522

  8. Delta3: design and control of a flexure hinge mechanism

    Bacher, Jean-Philippe; Bottinelli, Stefano; Breguet, Jean-Marc; Clavel, Reymond

    2001-10-01

    In the fields of micro positioning, micromanipulation and micro machining, the required motion precision is continuously increasing. The demand also increases for high dynamic performances (large bandwidth, high closed loop stiffness.). In many cases an inappropriate mechanical structure prevents to achieve these objectives. For example backlash or friction have to be reduced as much as possible. In this paper, we propose backlash-free and friction-free manipulators using flexure hinges and direct drive actuators. A three degrees of freedom (dof) parallel robot (X, Y, Z) that is a transposition in a flexible structure of the Delta robot kinematics is presented. We focus on the design and control of the robot. A simple dynamic model is proposed and compared with measurements. The system is characterized and we propose solutions to improve performances. These solutions are tested on a linear stage.

  9. Shape-Controlled Growth of Carbon Nanostructures: Yield and Mechanism.

    Ma, Yao; Sun, Xiao; Yang, Nianjun; Xia, Junhai; Zhang, Lei; Jiang, Xin

    2015-08-24

    Carbon nanostructures with precisely controlled shapes are difficult materials to synthesize. A facet-selective-catalytic process was thus proposed to synthesize polymer-linked carbon nanostructures with different shapes, covering straight carbon nanofiber, carbon nano Y-junction, carbon nano-hexapus, and carbon nano-octopus. A thermal chemical vapor deposition process was applied to grow these multi-branched carbon nanostructures at temperatures lower than 350 °C. Cu nanoparticles were utilized as the catalyst and acetylene as the reaction gas. The growth of those multi-branched nanostructures was realized through the selective growth of polymer-like sheets on certain indexed facets of Cu catalyst. The vapor-facet-solid (VFS) mechanism, a new growth mode, has been proposed to interpret such a growth in the steps of formation, diffusion, and coupling of carbon-containing oligomers, as well as their final precipitation to form nanostructures on the selective Cu facets. PMID:26140507

  10. 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.

  11. 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.

  12. Mitochondria-controlled signaling mechanisms of brain protection in hypoxia

    Lukyanova, Ludmila D.; Kirova, Yulia I.

    2015-01-01

    The article is focused on the role of the cell bioenergetic apparatus, mitochondria, involved in development of immediate and delayed molecular mechanisms for adaptation to hypoxic stress in brain cortex. Hypoxia induces reprogramming of respiratory chain function and switching from oxidation of NAD-related substrates (complex I) to succinate oxidation (complex II). Transient, reversible, compensatory activation of respiratory chain complex II is a major mechanism of immediate adaptation to hypoxia necessary for (1) succinate-related energy synthesis in the conditions of oxygen deficiency and formation of urgent resistance in the body; (2) succinate-related stabilization of HIF-1? and initiation of its transcriptional activity related with formation of long-term adaptation; (3) succinate-related activation of the succinate-specific receptor, GPR91. This mechanism participates in at least four critical regulatory functions: (1) sensor function related with changes in kinetic properties of complex I and complex II in response to a gradual decrease in ambient oxygen concentration; this function is designed for selection of the most efficient pathway for energy substrate oxidation in hypoxia; (2) compensatory function focused on formation of immediate adaptive responses to hypoxia and hypoxic resistance of the body; (3) transcriptional function focused on activated synthesis of HIF-1 and the genes providing long-term adaptation to low pO2; (4) receptor function, which reflects participation of mitochondria in the intercellular signaling system via the succinate-dependent receptor, GPR91. In all cases, the desired result is achieved by activation of the succinate-dependent oxidation pathway, which allows considering succinate as a signaling molecule. Patterns of mitochondria-controlled activation of GPR-91- and HIF-1-dependent reaction were considered, and a possibility of their participation in cellular-intercellular-systemic interactions in hypoxia and adaptation was proved. PMID:26483619

  13. 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.

  14. Web-based neuromuscular simulator applied to the teaching of principles of neuroscience

    Leonardo Abdala, Elias; Andr Fabio, Kohn.

    2013-09-01

    Full Text Available INTRODUCTION: The learning of core concepts in neuroscience can be reinforced by a hands-on approach, either experimental or computer-based. In this work, we present a web-based multi-scale neuromuscular simulator that is being used as a teaching aid in a campus-wide course on the Principles of Neur [...] oscience. METHODS: The simulator has several built-in individual models based on cat and human biophysics, which are interconnected to represent part of the neuromuscular system that controls leg muscles. Examples of such elements are i) single neurons, representing either motor neurons or interneurons mediating reciprocal, recurrent and Ib inhibition; ii) afferent fibers that can be stimulated to generate spinal reflexes; iii) muscle unit models, generating force and electromyogram; and iv) stochastic inputs, representing the descending volitional motor drive. RESULTS: Several application examples are provided in the present report, ranging from studies of individual neuron responses to the collective action of many motor units controlling muscle force generation. A subset of them was included in an optional homework assignment for Neuroscience and Biomedical Engineering graduate students enrolled in the course cited above at our University. Almost all students rated the simulator as a good or an excellent learning tool, and approximately 90% declared that they would use the simulator in future projects. CONCLUSION: The results allow us to conclude that multi-scale neuromuscular simulator is an effective teaching tool. Special features of this free teaching resource are its direct usability from any browser (http://remoto.leb.usp.br/), its user-friendly graphical user interface (GUI) and the preset demonstrations.

  15. An Artificial Neural Network Estimation of Gait Balance Control in the Elderly Using Clinical Evaluations

    Lugade, Vipul; Lin, Victor; Farley, Arthur; Chou, Li-Shan

    2014-01-01

    The use of motion analysis to assess balance is essential for determining the underlying mechanisms of falls during dynamic activities. Clinicians evaluate patients using clinical examinations of static balance control, gait performance, cognition, and neuromuscular ability. Mapping these data to measures of dynamic balance control, and the subsequent categorization and identification of community dwelling elderly fallers at risk of falls in a quick and inexpensive manner is needed. The purpo...

  16. Advanced sliding mode control for mechanical systems design, analysis and Matlab simulation

    Liu, Jinkun

    2012-01-01

    ""Advanced Sliding Mode Control for Mechanical Systems: Design, Analysis and MATLAB Simulation"" takes readers through the basic concepts, covering the most recent research in sliding mode control. The book is written from the perspective of practical engineering and examines numerous classical sliding mode controllers, including continuous time sliding mode control, discrete time sliding mode control, fuzzy sliding mode control, neural sliding mode control, backstepping sliding mode control, dynamic sliding mode control, sliding mode control based on observer, terminal sliding mode control,

  17. Closed-loop timing controller design for control rod drive mechanism (CRDM) control system in pressurized water reactor

    The method that the operating condition of Control Rod Drive Mechanism (CRDM) can be monitored without mounting sensors within CRDM housing was developed, and by using this developed method the closed-loop controller for the CRDM was designed which can optimize the performance and maximize the reliability of CRDM operation. Neural network is utilized as pattern recognition engine in detecting CRDM actuation. In this paper, most problems in previous open loop system are resolved. The control algorithms for closed-loop system were developed and implemented within the hardware of timing controller based on microprocessor. All functions in the timing controller were verified by means of real time CRDM simulator. The results show that the timing controller performs its intended functions properly. (author)

  18. 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).

  19. 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.)

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

    Campbell, Megan

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

  1. 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.)

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

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

    1995-01-01

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

  3. 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

  4. 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; Roos, Ewa M.

    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...... before-and-after study were to compare baseline status to an age-matched population-based reference group and to examine the effects of neuromuscular training on patient-reported outcomes and physical function in patients with severe primary OA of the hip or knee....

  5. 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...

  6. The drop height determines neuromuscular adaptations and changes in jump performance in stretch-shortening cycle training

    Taube, Wolfgang; Leukel, Christian; Lauber, B.; Gollhofer, Albert

    2012-01-01

    There is an ongoing discussion about how to improve jump performance most efficiently with plyometric training. It has been proposed that drop height influences the outcome, although longitudinal studies are missing. Based on cross-sectional drop jump studies showing height-dependent Hoffmann (H)-reflex activities, we hypothesized that the drop height should influence the neuromuscular activity and thus, the training result. Thirty-three subjects participated as a control or in one of two str...

  7. Neuromuscular electrical stimulation for preventing skeletal-muscle weakness and wasting in critically ill patients: a systematic review

    Maffiuletti, Nicola A.; Roig, Marc; Karatzanos, Eleftherios; Nanas, Serafim

    2013-01-01

    Background: Neuromuscular electrical stimulation (NMES) therapy may be useful in early musculoskeletal rehabilitation during acute critical illness. The objective of this systematic review was to evaluate the effectiveness of NMES for preventing skeletal-muscle weakness and wasting in critically ill patients, in comparison with usual care. Methods: We searched PubMed, CENTRAL, CINAHL, Web of Science, and PEDro to identify randomized controlled trials exploring the effect of NMES in critically...

  8. 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.

  9. Functional Neuromuscular Stimulation Controlled by Surface Electromyographic Signals Produced by Volitional Activation of the Same Muscle:Adaptive Removal of the Muscle Response from the Recorded EMG-Signal

    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 generated by the stimulation current, are relatively easy to eliminate by shutting down the EMG-amplifier at the onset of the stimulation pulses. The muscle response is a nonstationary signal, therefor...

  10. 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

  11. 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

  12. 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

  13. Fak56 functions downstream of integrin alphaPS3betanu and suppresses MAPK activation in neuromuscular junction growth

    Van Vactor David

    2008-10-01

    Full Text Available Abstract Background Focal adhesion kinase (FAK functions in cell migration and signaling through activation of the mitogen-activated protein kinase (MAPK signaling cascade. Neuronal function of FAK has been suggested to control axonal branching; however, the underlying mechanism in this process is not clear. Results We have generated mutants for the Drosophila FAK gene, Fak56. Null Fak56 mutants display overgrowth of larval neuromuscular junctions (NMJs. Localization of phospho-FAK and rescue experiments suggest that Fak56 is required in presynapses to restrict NMJ growth. Genetic analyses imply that FAK mediates the signaling pathway of the integrin ?PS3?? heterodimer and functions redundantly with Src. At NMJs, Fak56 downregulates ERK activity, as shown by diphospho-ERK accumulation in Fak56 mutants, and suppression of Fak56 mutant NMJ phenotypes by reducing ERK activity. Conclusion We conclude that Fak56 is required to restrict NMJ growth during NMJ development. Fak56 mediates an extracellular signal through the integrin receptor. Unlike its conventional role in activating MAPK/ERK, Fak56 suppresses ERK activation in this process. These results suggest that Fak56 mediates a specific neuronal signaling pathway distinct from that in other cellular processes.

  14. 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.)

  15. 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

  16. 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...

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

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

    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.......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...... system. Due to the hysteretic effects in the magnetic material the internal losses influence the overall system’s performance. A mathematical model of the force balance in the oscillatory system is derived in a simplified, linearised form. The electric as well as mechanical system is modelled using...

  18. 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

  19. 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.

  20. 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 blending octane No. of 105, and can replace aromatics in liquid fuels.

  1. 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.

  2. 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

  3. 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.)

  4. Control rod driving mechanism of reactor, control device and operation method therefor

    The present invention provides a device for and a method of directly driving control rods of an FBR type reactor linearly by a cylinder type linear motor while having a driving shaft as an electric conductor. Namely, a linear induction motor drives a driving shaft connected with a control rod and vertically moving the control rod by electromagnetic force as an electric conductor. The position of the control rod is detected by a position detector. The driving shaft is hung by a wire by way of an electromagnet which is attachably/detachably held. With such a constitution, the driving shaft connected with the control rod can be vertically moved linearly, stopped or kept. Since they can be driven smoothly at a wide range speed, the responsibility and reliability of the reactor operation can be improved. In addition, since responsibility of the control rod operation is high, scram can be conducted by the linear motor. Since the driving mechanism can be simplified, maintenance and inspection operation can be mitigated. (I.S.)

  5. Prolactin controls mammary gland development via direct and indirect mechanisms.

    Brisken, C; Kaur, S; Chavarria, T E; Binart, N; Sutherland, R L; Weinberg, R A; Kelly, P A; Ormandy, C J

    1999-06-01

    The inactivation of the prolactin receptor gene by homologous recombination has made it possible to investigate the role of prolactin signaling in mammary gland development without resort to ablative surgery of the endocrine glands. In knockout mice lacking the prolactin receptor, mammary development is normal up to puberty. Subsequently, the ducts branch less frequently than those of wild-type animals. While terminal end buds differentiate to alveolar buds in wild-type females by the end of puberty, in knockout females terminal end bud-like structures persist at the ductal ends. To distinguish between the developmental defects that are intrinsic to the epithelium and those that result from systemic endocrine alterations in prolactin receptor knockout mice, mammary epithelium from prolactin receptor knockouts was transplanted into mammary fat pads of wild-type mice. In virgin mice, the knockout epithelial transplants developed normally at puberty, indicating an indirect effect of prolactin on ductal development. Prolactin receptor knockout females are infertile due to multiple reproductive defects, but epithelial transplants allowed us to assess the extent to which the absence of prolactin receptor is limiting, under systemic conditions that allow full mammary gland development. During pregnancy, the prolactin receptor knockout transplants showed normal side branching and the formation of alveolar buds, but no lobuloalveolar development. Thus, prolactin affects mammary morphogenesis in two different ways: it controls ductal side branching and terminal end bud regression in virgin animals via indirect mechanisms, but acts directly on the mammary epithelium to produce lobuloalveolar development during pregnancy. PMID:10364430

  6. Mechanism of remote controlled after-loading radiotherapy unit

    Employing a small amount of Radium-226 or Cesium-137 source was to be used hitherto for the treatment of carcinoma of the uterine cervix in used After-loading techniques. It involved, however, radiation risk to the staff and patient. The long treatment time are also a pain (strain) on the patient. In recent years, we have developed a remote control after-loading unit, which was named as RALSTRON, which was complete eliminated the disadvantage of conventional radium therapy. This unit also has disadvantage, however, that the design for the remote after-loader for intracavitary applicators present considerable difficulties, because many sources of different active lengths and loading patterns are required. A solution to this problem was carried out by using small point source, placed in Tandem applicator, of high activity and moving them back slowly during the treatment. Recently, this unit was installed many hospitals about 80 units in Japan, and are used. In this paper are given about a mechanism and safety deviced of this unit. (author)

  7. 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.)

  8. 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; Myklebust, Grethe; Bencke, Jesper; Lauridsen, Hanne Bloch; Bandholm, Thomas; Thorborg, Kristian; Hölmich, Per; Aagaard, Per

    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....

  9. 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.

  10. 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.

  11. Neuromuscular electrical stimulation for mobility support of elderly

    Winfried Mayr

    2015-10-01

    Full Text Available The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within "MOBIL" we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in compliance data storage as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC and maximum stimulation induced contraction (MSC were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period. Therefore the correlation between normalized MVC and normalized MSC was calculated. It is obvious that MVC can increase to strongly variable extent (3 to 65 %, but in few cases also decrease (-4 to 15 % over the study period. The correlation suggests that an increase of roughly 1 % of normalized MSC can lead to an increase of about 10 % in MVC in the given training conditions. Overall, we can say that we have a stimulator that has turned out to work sufficiently. The most important feature is the integrated compliance recording because this is very useful for interpretation of the study outcome. The electrical stimulation training has shown that even with relatively small induced contraction intensity we still get some increase in the achievable voluntary extension torque.

  12. Dynamic Simulation of Hybrid-driven Planar Five-bar Parallel Mechanism Based on SimMechanics and Tracking Control

    Bin Zi

    2011-09-01

    Full Text Available This paper investigates dynamic simulation and trajectory tracking control of hybrid‐driven planar five‐bar parallel mechanism (HPPM. To begin with, a simulation model of dynamics based on MATLAB/SimMechanics is established. Then, traditional PD control and closed loop PD‐type iterative learning control of the HPPM are designed. At the end, the simulation based on SimMechanics is carried out, which acquires angular, angular velocity, angular acceleration of two driving links and constraint reaction of kinematic pairs at any time. In addition, the performance of the closed loop PD‐type iterative learning control is compared with that of the traditional PD controller through simulations of the HPPM in the presence of the model external disturbances. The simulation results indicate that a perfect trajectory tracking of end‐effector of the HPPM is achieved by the closed loop PD‐type iterative learning controller.

  13. Estimulação elétrica neuromuscular em cães com atrofia muscular induzida Neuromuscular electric stimulation in dogs with induced muscle atrophy

    C. Pelizzari; Mazzanti, A.; A.G. Raiser; LOPES, S T A; D. L. Graça; Ramos, A.T.; F.Z. Salbego; R. Festugatto; D.V. Beckmann; L.B. Souza; M.G.M.C.M. Cunha; R. P. Santos; B. Garmatz; Silva, A. P.; D.A.F. Sturza

    2008-01-01

    Empregou-se a estimulação elétrica neuromuscular (EENM) de baixa freqüência no músculo quadríceps femoral de cães com atrofia induzida e avaliou-se a ocorrência de ganho de massa nessa musculatura. Foram utilizados oito cães com pesos entre 15 e 30kg, distribuídos aleatoriamente em dois grupos denominados de I ou controle e II ou tratado. A articulação femorotibiopatelar esquerda foi imobilizada por 30 dias pelo método de transfixação percutânea tipo II, com retirada de aparelho de imobilizaç...

  14. Snake and Spider Toxins Induce a Rapid Recovery of Function of Botulinum Neurotoxin Paralysed Neuromuscular Junction

    Elisa Duregotti

    2015-12-01

    Full Text Available Botulinum neurotoxins (BoNTs and some animal neurotoxins (?-Bungarotoxin, ?-Btx, from elapid snakes and ?-Latrotoxin, ?-Ltx, from black widow spiders are pre-synaptic neurotoxins that paralyse motor axon terminals with similar clinical outcomes in patients. However, their mechanism of action is different, leading to a largely-different duration of neuromuscular junction (NMJ blockade. BoNTs induce a long-lasting paralysis without nerve terminal degeneration acting via proteolytic cleavage of SNARE proteins, whereas animal neurotoxins cause an acute and complete degeneration of motor axon terminals, followed by a rapid recovery. In this study, the injection of animal neurotoxins in mice muscles previously paralyzed by BoNT/A or /B accelerates the recovery of neurotransmission, as assessed by electrophysiology and morphological analysis. This result provides a proof of principle that, by causing the complete degeneration, reabsorption, and regeneration of a paralysed nerve terminal, one could favour the recovery of function of a biochemically- or genetically-altered motor axon terminal. These observations might be relevant to dying-back neuropathies, where pathological changes first occur at the neuromuscular junction and then progress proximally toward the cell body.

  15. Snake and Spider Toxins Induce a Rapid Recovery of Function of Botulinum Neurotoxin Paralysed Neuromuscular Junction.

    Duregotti, Elisa; Zanetti, Giulia; Scorzeto, Michele; Megighian, Aram; Montecucco, Cesare; Pirazzini, Marco; Rigoni, Michela

    2015-01-01

    Botulinum neurotoxins (BoNTs) and some animal neurotoxins (?-Bungarotoxin, ?-Btx, from elapid snakes and ?-Latrotoxin, ?-Ltx, from black widow spiders) are pre-synaptic neurotoxins that paralyse motor axon terminals with similar clinical outcomes in patients. However, their mechanism of action is different, leading to a largely-different duration of neuromuscular junction (NMJ) blockade. BoNTs induce a long-lasting paralysis without nerve terminal degeneration acting via proteolytic cleavage of SNARE proteins, whereas animal neurotoxins cause an acute and complete degeneration of motor axon terminals, followed by a rapid recovery. In this study, the injection of animal neurotoxins in mice muscles previously paralyzed by BoNT/A or /B accelerates the recovery of neurotransmission, as assessed by electrophysiology and morphological analysis. This result provides a proof of principle that, by causing the complete degeneration, reabsorption, and regeneration of a paralysed nerve terminal, one could favour the recovery of function of a biochemically- or genetically-altered motor axon terminal. These observations might be relevant to dying-back neuropathies, where pathological changes first occur at the neuromuscular junction and then progress proximally toward the cell body. PMID:26670253

  16. 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

  17. Sugammadex, a neuromuscular blockade reversal agent, causes neuronal apoptosis in primary cultures.

    Palanca, Jos M; Aguirre-Rueda, Diana; Granell, Manuel V; Aldasoro, Martin; Garcia, Alma; Iradi, Antonio; Obrador, Elena; Mauricio, Maria Dolores; Vila, Jose; Gil-Bisquert, Anna; Valles, Soraya L

    2013-01-01

    Sugammadex, a ?-cyclodextrin that encapsulates selectively steroidal neuromuscular blocking agents, such as rocuronium or vecuronium, has changed the face of clinical neuromuscular pharmacology. Sugammadex allows a rapid reversal of muscle paralysis. Sugammadex appears to be safe and well tolerated. Its blood-brain barrier penetration is poor (brain barrier permeability can be altered under different conditions (i.e. neurodegenerative diseases, trauma, ischemia, infections, or immature nervous system). Using MTT, confocal microscopy, caspase-3 activity, cholesterol quantification and Western-blot we determine toxicity of Sugammadex in neurons in primary culture. Here we show that clinically relevant sugammadex concentrations cause apoptotic/necrosis neuron death in primary cultures. Studies on the underlying mechanism revealed that sugammadex-induced activation of mitochondria-dependent apoptosis associates with depletion of neuronal cholesterol levels. Furthermore SUG increase CytC, AIF, Smac/Diablo and CASP-3 protein expression in cells in culture. Potential association of SUG-induced alteration in cholesterol homeostasis with oxidative stress and apoptosis activation occurs. Furthermore, resistance/sensitivity to oxidative stress differs between neuronal cell types. PMID:23983586

  18. The imperative for controlled mechanical stresses in unraveling cellular mechanisms of mechanotransduction

    Sorkin Adam M

    2006-05-01

    Full Text Available Abstract Background In vitro mechanotransduction studies are designed to elucidate cell behavior in response to a well-defined mechanical signal that is imparted to cultured cells, e.g. through fluid flow. Typically, flow rates are calculated based on a parallel plate flow assumption, to achieve a targeted cellular shear stress. This study evaluates the performance of specific flow/perfusion chambers in imparting the targeted stress at the cellular level. Methods To evaluate how well actual flow chambers meet their target stresses (set for 1 and 10 dyn/cm2 for this study at a cellular level, computational models were developed to calculate flow velocity components and imparted shear stresses for a given pressure gradient. Computational predictions were validated with micro-particle image velocimetry (?PIV experiments. Results Based on these computational and experimental studies, as few as 66% of cells seeded along the midplane of commonly implemented flow/perfusion chambers are subjected to stresses within 10% of the target stress. In addition, flow velocities and shear stresses imparted through fluid drag vary as a function of location within each chamber. Hence, not only a limited number of cells are exposed to target stress levels within each chamber, but also neighboring cells may experience different flow regimes. Finally, flow regimes are highly dependent on flow chamber geometry, resulting in significant variation in magnitudes and spatial distributions of stress between chambers. Conclusion The results of this study challenge the basic premise of in vitro mechanotransduction studies, i.e. that a controlled flow regime is applied to impart a defined mechanical stimulus to cells. These results also underscore the fact that data from studies in which different chambers are utilized can not be compared, even if the target stress regimes are comparable.

  19. Working principle and structure characteristics analysis of the reactivity control drive mechanism

    The startup, power regulation and safety shutdown of the nuclear reactor are operated by the reactivity control devices. Reactivity control drive mechanism is a key mechanical transmission component, which directly control the location of the neutron absorber in the core. Its working condition is complex, and its service life should be long., which requires high reliability. PWR as well as newly developed different type of reactors have different control devices drive mechanism. This paper mainly do analysis and comparison about the working environment, mechanical transmission principle, structure, performance, service life and other aspects of PWR, HTR control devices drive mechanism. In addition, this paper is also based on the working principles of reactive control devices drive mechanism, also consider the trends of its design and test verification by the international countries, and discussed the method and feasibility of improving and perfecting the structure and function of drive mechanism. (authors)

  20. 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

  1. MECHANISMS EMPLOYED BY TRICHODERMA SPECIES IN THE BIOLOGICAL CONTROL OF PLANT DISEASES

    This paper is a review article that describes the mechanisms employed by biological control agents to suppress or prevent plant disease pathogens, and how theories regarding the importance of thse mechanisms in biological control have changed with time and further research. Mechanisms such as mycop...

  2. Smooth controllability of infinite-dimensional quantum-mechanical systems

    Manipulation of infinite-dimensional quantum systems is important to controlling complex quantum dynamics with many practical physical and chemical backgrounds. In this paper, a general investigation is casted to the controllability problem of quantum systems evolving on infinite-dimensional manifolds. Recognizing that such problems are related with infinite-dimensional controllability algebras, we introduce an algebraic mathematical framework to describe quantum control systems possessing such controllability algebras. Then we present the concept of smooth controllability on infinite-dimensional manifolds, and draw the main result on approximate strong smooth controllability. This is a nontrivial extension of the existing controllability results based on the analysis over finite-dimensional vector spaces to analysis over infinite-dimensional manifolds. It also opens up many interesting problems for future studies

  3. 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.

  4. 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.

  5. Sustained Neuromuscular Blockade after Vecuronium Use in a Premature Infant

    Mitali Sahni

    2015-10-01

    Full Text Available Background - Prolonged use of neuromuscular blocking agents (NMBAs is very common in critically ill children both in pediatric and neonatal intensive care units. There are no guidelines available for use of NMBAs in children or neonates in the US, and the data for their safety in this age group is limited. Case Description - Our case describes prolonged neuromuscular blockade following concurrent use of a NMBA along with aminoglycosides and steroids in the setting of renal failure in a premature infant. Conclusion - Prolonged use of NMBAs in preterm infants should be avoided if possible or should be restricted to the shortest possible duration and the smallest possible physiologically effective dose. Concurrent use of NMBAs with aminoglycoside and steroids should be avoided, especially in the setting of renal failure.

  6. High gender -specific susceptibility to curare- a neuromuscular blocking agent

    Santosh K Maurya

    2013-01-01

    Full Text Available Curare, a selective skeletal muscle relaxant, has been used clinically to reduce shivering and as an anesthetic auxiliary in abdominal surgery. It is also widely used in animal experiments to block neuromuscular junction activity. Effective doses of curare diminish muscle contraction without affecting brain function, but at higher doses it is known to be lethal. However, the exact dose of curare initiating muscle relaxation vs. lethal effect has not been fully characterized in mice. In this study we carefully examined the dose-response for achieving muscle inactivity over lethality in both male and female mice (C57BL6/J. The most striking finding of this study is that female mice were highly susceptible to curare; both the EDm and LDm were at least 3-fold lower than male littermates. This study shows that gender-specific differences can be an important factor when administering skeletal muscle relaxants, particularly curare or other analogous agents targeted to the neuromuscular junction.

  7. 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-vation; the number of motor units diminishes in sixties without any denervation electric activity; there is also reduction on the amount of ACh release on terminal neurons and mitochondrial oxidative capacity leading to compensatory type I muscle fiber number increase. Cachexia also induces reduction on muscle fibers diameter first on legs and then on arms and trunk; there is type II atrophy with occasional angular fibers, RNA/proteic synthesis reduction and normal DNA.

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

    Villadsen, Allan

    2016-04-01

    Osteoarthritis (OA) is a degenerative joint disease affecting the whole joint and peri-articular structures like the muscles. The hallmark of OA is cartilage loss. The main symptoms are pain and decreased physical function leading to a reduced quality of life. OA ranks eight in leading causes of disability worldwide and it generates a heavy economic burden for society. The prevalence of OA increases with age and 10-18% aged above 60 years are affected. Currently there is no cure for OA and the various treatment modalities aim at addressing symptoms, i.e. reducing pain, improving physical function and preventing further progression of the disease. Exercise has proven to be a viable treatment option with regard to reducing pain and improving physical function in patients with mild to moderate knee OA and is today regarded a cornerstone in the treatment. The documentation is less clear for hip OA. Patients with severe OA of the hip or knee are treated with total joint arthroplasty (TJA). Although, in general, it is a very successful procedure, there are still challenges to overcome in this patient group, as approximately 10% of those having hip arthroplasty and 20% of those having knee arthroplasty have persistent symptoms. The evidence on the efficacy of exercise prior to TJA is sparse. It is based on insufficiently powered trials and with interventions of questionable validity. Two recent systematic reviews and meta-analyses reach conflicting conclusions and highlight the need for high quality trials with sufficient sample sizes. In this dissertation, I wanted to evaluate the effects of an individualised neuromuscular exercise programme (NEMEX-TJR) when administered prior to joint arthroplasty in patients with severe OA of the hip or knee joint. This intervention was previously found to be feasible with regard to pain level during exercise and it was possible to progress the training level in this patient group. The main question asked was: Does the addition of 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 to TJA in addition to the usual care (information leaflets and a three-hour information session by health professionals) provided in Svendborg Hospital, Odense University Hospital, Denmark. Patients were assessed at baseline, one week prior to surgery, six weeks and three months after surgery (primary end-point). Two essential questions of interest were identified prior the development of the statistical analysis plan. Firstly: Does the addition of neuromuscular exercise prior to TJA improve the post-operative outcome? The initiation of rehabilitation prior to surgery was thought to be of general interest to the health community. Secondly: What are the effects of neuromuscular exercise when evaluated as a treatment option for patients with severe osteoarthritis? This question is most likely to be of interest to health professionals with a specific interest in exercise rehabilitation and OA research. In the second study, the cohort served as a model for patients with severe OA (regardless of the following operation). Patients were evaluated immediately after the intervention (one week). We found that participation in neuromuscular exercise for eight weeks according to the NEMEX-TJR programme improves activities of daily living, objective functional performance, and quality of life and reduces pain in patients with severe OA. The effect is greater in patients with hip OA than in patients with knee OA. The study confirms previous findings from non-randomised studies that neuromuscular exercise is feasible and safe for patients with severe OA. In the third study, the efficacy of NEMEX-TJR as an adjunct treatment to TJA was evaluated. At the primary end-point three months after surgery, there was no additional effect of an eight-week preoperative neuromuscular exercise programme in combination with total joint arthroplasty compared with total joint arthroplasty alone. However, from baseline to < three months after surgery the overall longitudinal improvements seen in physical function and pain were statistically significantly greater and occurred earlier after surgery in the intervention group receiving preoperative neuromuscular exercise compared with the control group receiving care-as-usual only. From this dissertation, I conclude that neuromuscular exercise according to NEMEX-TJR can serve as adjunct therapy to hip or knee arthroplasty of interest to individual OA patients willing to engage in preoperative exercise to achieve an earlier onset of post-operative recovery. At three months however, the effects of preoperative exercise are no longer evident.  Furthermore, for patients with severe OA of the hip joint, neuromuscular exercise may serve as a safe and viable treatment option with improvement in ADL, functional performance and a reduction in pain. Whether implementation of this adjunct therapy in clinical practice is feasible and cost-effective remains to be evaluated. PMID:27034190

  9. 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

  10. Neuromuscular Junction Integrity after Chronic Nerve Compression Injury

    Mozaffar, Tahseen; Strandberg, Erika; Abe, Kazuko; Hilgenberg, Lutz G.; Smith, Martin A.; Gupta, Ranjan

    2009-01-01

    Chronic nerve compression injuries (CNC) are progressive demyelinating disorders characterized by a gradual decline of the nerve conduction velocity (NCV) in the affected nerve region. CNC injury induces a robust Schwann cell response with axonal sprouting, but without morphologic evidence of axonal injury. We hypothesize that early CNC injury occurs without damage to neuromuscular junction of motor axons. A well-established animal model was used to assess for damage to motor axons. As sprout...

  11. Report on Adaptive Force, A Specific Neuromuscular Function.

    Hoff, Marko; Schaefer, Laura; Heinke, Nancy; Bittmann, Frank

    2015-09-11

    In real life motions, as well as in sports, the adaptation of the neuromuscular systems to externally applied forces plays an important role. The term Adaptive Force (AF) shall characterize the ability of the nerve-muscle-system to adapt to impacting external forces during isometric and eccentric muscle action. The focus in this paper is on the concept of this neuromuscular action, which is not yet described in this way. A measuring system was constructed and evaluated for this specific neuromuscular function, but only the main information of the evaluation of the measuring system and the preliminary reference values are mentioned here, while an article with detailed description will be published separately. This paper concentrates on the three following points: 1) What is the peculiarity of this neuromuscular function, introduced as AF? 2) Is the measuring system able to capture its specific characteristics and which phases of measurement occur? 3) It seems reasonable to discuss if AF can be distinguished and classified among the known force concepts. The article describes the measuring system and how it is able to capture special features of real life motions like submaximal intensities and the subjects' option to react adequately on external varying forces. Furthermore, within one measurement the system records three different force qualities: the isometric submaximal Adaptive Force (AFiso), the maximal isometric Adaptive Force (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax). Each of these phases provide different and unique information on the nerve-muscle-system that are discussed in detail. Important, in terms of the Adaptive Force, seems to be the combination of conditional and coordinative abilities. This project was funded by the Federal Ministry of Economy and Technology (Project ZIM KF2262301FO9). PMID:26913155

  12. GLUTAMATE RECEPTORS LOCALIZE POSTSYNAPTICALLY AT NEUROMUSCULAR JUNCTIONS IN MICE

    Mays, Tessily A.; SANFORD, JAMIE L.; Hanada, Toshihiko; Chishti, Athar H.; RAFAEL-FORTNEY, JILL A.

    2009-01-01

    Dlg (Discs Large) is a multidomain protein that interacts with glutamate receptors and potassium channels at Drosophila neuromuscular junctions (NMJs) and at mammalian central nervous system synapses. Dlg also localizes postsynaptically at cholinergic mammalian NMJs. We show here that α-amino-3-hydroxy-5-methylisoxazole-4-proprionate (AMPA) receptor subunits, together with glutamate, are present at the mammalian NMJ. Both AMPA and NMDA (N-methyl-D-aspartate) glutamate receptor subunits displa...

  13. Fibromatosis Arising in Association with Neuromuscular Hamartoma of the Mandible

    Taher, Leena Yaseen; Saleem, Muhammad; Velagapudi, Suresh; Dababo, Anas

    2013-01-01

    Aggressive fibromatosis is a benign but locally-aggressive tumor, which most often affects the muscles of the shoulder, the pelvic girdle, and the thigh. It usually affects adolescents and young adults. Desmoplastic fibroma, considered the bone counterpart of soft tissue fibromatosis, is a rare tumor that usually affects the metaphyseal or diaphyseal portions of long bones or, less commonly, the jaw. Neuromuscular hamartoma, a rare developmental lesion composed of mature elements of both stri...

  14. 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.

  15. Autonomic neuromuscular junctions: current developments and future directions.

    Burnstock, G

    1986-01-01

    (1) The autonomic neuromuscular junction has been defined, with emphasis on the role of muscle effector bundles and en passage release of transmitter from extensive terminal nerve varicosities to diffuse to muscle across variable and often wide junctional clefts. (2) A multiplicity of neurotransmitters is described in the autonomic nervous system, including purines, peptides, amino acids and monoamines. The ultrastructural identification, projections, roles and interactions of the different n...

  16. Neuromuscular abnormality and autonomic dysfunction in patients with cerebrotendinous xanthomatosis

    Huang Chi-Ren; Lu Cheng-Hsien; Chang Chung-Chih; Tsai Nai-Wen; Chen Shu-Fang; Chuang Yao-Chung; Chang Wen-Neng

    2011-01-01

    Abstract Background Cerebrotendinous xanthomatosis (CTX) is a rare lipid-storage disease. Neuromuscular abnormality and autonomic system (ANS) dysfuction in CTX are rarely examined in large-scale studies in the literature. We studied the peripheral nervous system, myopathology, and autonomic system of four CTX patients and performed a literature review of the reported CTX patients with peripheral neuropathy. Methods Four biochemically and genetically confirmed CTX patients, belonging to two f...

  17. Bone Health and Associated Metabolic Complications in Neuromuscular Diseases

    Joyce, Nanette C.; Hache, Lauren P; CLEMENS, PAULA R.

    2012-01-01

    This article reviews the recent literature regarding bone health as it relates to the patient living with neuromuscular disease (NMD). Poor bone health with related morbidity is a significant problem for patients with NMD. Although the evidence addressing issues of bone health and osteoporosis have increased as a result of the Bone and Joint Decade, studies defining the scope of bone-related disease in NMD are scant. The available evidence is discussed focusing on abnormal calcium metabolism,...

  18. Sarcomere Control Mechanisms and the Dynamics of the Cardiac Cycle

    R. John Solaro

    2010-01-01

    Full Text Available This review focuses on recent developments in the molecular mechanisms by which Ca activates cardiac sarcomeres and how these mechanisms play out in the cardiac cycle. I emphasize the role of mechanisms intrinsic to the sarcomeres as significant determinants of systolic elastance and ventricular stiffening during ejection. Data are presented supporting the idea that processes intrinsic to the thin filaments may promote cooperative activation of the sarcomeres and be an important factor in maintaining and modifying systolic elastance. Application of these ideas to translational medicine and rationale drug design forms an important rationale for detailed understanding of these processes.

  19. CT in neuromuscular disorders: A comparison of CT and histology

    Vliet, A.M. van der; Thijssen, H.O.M.; Merx, J.L.; Joosten, E.

    1988-11-01

    The value of CT-examination of the muscles compared to histology was studied in a retrospective analysis of 30 patients with clinical suspicion of neuromuscular disorder. In the evaluation of the CT-results descriptive criteria were used. The histologic diagnosis came from needle-biopsies taken from the quadriceps muscle. Considering the whole group of neuromuscular disorders, CT has an overall accuracy of 84.8%, a positive predictive value of 95.5% and a negative predictive value of 63.6%. This makes the use of CT as a diagnostic tool in neuromuscular disorders a reliable examination technique. In patients with a polymyositis there is even a 100% correlation between CT findings and biopsy results. Discrepancy between the biopsy results is remarkable of the quadriceps muscle and the CT findings: The number of abnormal histological findings is twice the number of abnormal CT findings. Using the more proximal gluteal region as a biopsy site would have decreased this discrepancy and would therefore have given a better correlation between CT and histology. The choice of protocol in determining the levels to be scanned is of great importance in achieving good reproducability in follow-up CT examinations.

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

    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

  1. 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

  2. Mechanisms of Motor Adaptation in Reactive Balance Control

    Welch, Torrence D. J.; Ting, Lena H.

    2014-01-01

    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 bot...

  3. Mechanisms and control of macrosegregation in DC casting

    Eskin, DG

    2014-01-01

    Macrosegregation is a severe, unrecoverable defect often occurring in large-scale castings. This paper offers a critical review of mechanisms involved in the formation of macrosegregation during DC casting of aluminum alloys. These mechanisms include thermo-solutal and forced convection, shrinkage-driven flow and transport of solid crystals. It is demonstrated that the impact of melt flow on macrosegregation depends on the flow direction and pattern, and on the extent of the slurry zone in th...

  4. Is cell polarity under mechanical control in plants?

    Hamant, Olivier; Meyerowitz, Elliot M; Traas, Jan

    2011-01-01

    Plant cells experience a tremendous amount of mechanical stress caused by turgor pressure. Because cells are glued to their neighbors by the middle lamella, supracellular patterns of physical forces are emerging during growth, usually leading to tension in the epidermis. Cortical microtubules have been shown to reorient in response to these mechanical stresses, and to resist them, indirectly via their impact on the anisotropic structure of the cell wall. In a recent study, we show that the po...

  5. 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

  6. Deafferented controllers: a fundamental failure mechanism in cortical neuroprosthetic systems.

    Galán, Ferran; Baker, Stuart N

    2015-01-01

    Brain-machine interface (BMI) research assumes that patients with disconnected neural pathways could naturally control a prosthetic device by volitionally modulating sensorimotor cortical activity usually responsible for movement coordination. However, computational approaches to motor control challenge this view. This article examines the predictions of optimal feedback control (OFC) theory on the effects that loss of motor output and sensory feedback have on the normal generation of motor commands. Example simulations of unimpaired, totally disconnected, and deafferented controllers illustrate that by neglecting the dynamic interplay between motor commands, state estimation, feedback and behavior, current BMI systems face translational challenges rooted in a debatable assumption and experimental models of limited validity. PMID:26236210

  7. Deafferented controllers: a fundamental failure mechanism in cortical neuroprosthetic systems

    Ferran Galán

    2015-07-01

    Full Text Available Brain-machine interface (BMI research assumes that patients with disconnected neural pathways could naturally control a prosthetic device by volitionally modulating sensorimotor cortical activity usually responsible for movement coordination. However, computational approaches to motor control challenge this view. This article examines the predictions of optimal feedback control (OFC theory on the effects that loss of motor output and sensory feedback have on the normal generation of motor commands. Example simulations of unimpaired, totally disconnected and deafferented controllers illustrate that by neglecting the dynamic interplay between motor commands, state estimation, feedback and behavior, current BMI systems face translational challenges rooted in a debatable assumption and experimental models of limited validity.

  8. 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....

  9. A Strategy-Proof and Non-monetary Admission Control Mechanism for Wireless Access Networks

    Kang, Xiaohan; Jaramillo, Juan José; Ying, Lei

    2010-01-01

    We study admission control mechanisms for wireless access networks where (i) each user has a minimum service requirement, (ii) the capacity of the access network is limited, and (iii) the access point is not allowed to use monetary mechanisms to guarantee that users do not lie when disclosing their minimum service requirements. To guarantee truthfulness, we use auction theory to design a mechanism where users compete to be admitted into the network. We propose admission control mechanisms und...

  10. Timing of fetal exposure to stress hormones: effects on newborn physical and neuromuscular maturation.

    Ellman, Lauren M; Schetter, Christine Dunkel; Hobel, Calvin J; Chicz-Demet, Aleksandra; Glynn, Laura M; Sandman, Curt A

    2008-04-01

    The purpose of the study was to determine the specific periods during pregnancy in which human fetal exposure to stress hormones affects newborn physical and neuromuscular maturation. Blood was collected from 158 women at 15, 19, 25, and 31 weeks' gestation. Levels of placental corticotropin-releasing hormone (CRH) and maternal cortisol were determined from plasma. Newborns were evaluated with the New Ballard Maturation Score. Results indicated that increases in maternal cortisol at 15, 19, and 25 weeks and increases in placental CRH at 31 weeks were significantly associated with decreases in infant maturation among males (even after controlling for length of gestation). Results also suggested that increases in maternal cortisol at 31 weeks were associated with increases in infant maturation among females, although these results were not significant after controlling for length of gestation. Findings suggest that stress hormones have effects on human fetal neurodevelopment that are independent of birth outcome. PMID:18335490

  11. Role of amino acid infusion in delayed recovery from neuromuscular blockers

    Seema Kalra

    2010-01-01

    Full Text Available This case report highlights the anaesthetic management of a patient who had residual muscle paralysis following neuromuscular blockade, which was attributed to hypothermia and corrected by administration of amino acid solution. The various causes of residual neuromuscular blockade should be considered when treating such a patient. Amino acid infusion has been found to hasten the recovery from neuromuscular block due to vecuronium bromide aggravated by hypothermia.

  12. Passive dynamic controllers for non-linear mechanical systems

    Juang, Jer-Nan; Wu, Shih-Chin; Phan, Minh; Longman, Richard W.

    1991-01-01

    A methodology for model-independent controller design for controlling large angular motion of multi-body dynamic systems is outlined.The controlled system may consist of rigid and flexible components that undergo large rigid body motion and small elastic deformations. Control forces/torques are applied to drive the system, and at the same time suppress the vibrations due to flexibility of the components. The proposed controller consists of passive second-order systems which may be designed with little knowledge of the system parameters, even if the controlled system is non-linear. Under rather general assumptions, the passive design assures that the closed loop system has guaranteed stability properties. Unlike positive real controller design, stabilization can be accomplished without direct velocity feedback. In addition, the second-order passive design allows dynamic feedback controllers with considerable freedom to tune for desired system response, and to avoid actuator saturation. After developing the basic mathematical formulation of the design methodology, simulation results are presented to illustrate the proposed approach applied to a flexible six-degree-of-freedom manipulator.

  13. Drive mechanism for a cruciform nuclear reactor control rod

    The improvement of the design of a cruciform control rod drive for a nuclear reactor is to decrease the linear dimensions without essentially reducing the free flow cross-section outside the reactor core. This is achieved by using the control rod guide tube simultaneously as lifting cylinder and providing the four wings with slots. (UWI)

  14. The logic control system of the control rods by hydraulic drive mechanism in the 5 MW nuclear heating reactor

    The authors describes the function and features of the logic control system to be applied to the control rods by hydraulic drive mechanism in the 5 MW nuclear heating reactor and the technical measures to enhance the availability and reliability of the system. The system coupling with hydraulic control rod drive mechanism consists of a whole control system in order to complete reactivity control of the nuclear reactor, the features of the system are stability, reliability and the high ability of anti-interference. It is successfully used in 5 MW nuclear heating reactor and meets the operational requirements of the reactor

  15. 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...

  16. Use of neuromuscular monitoring to detect prolonged effect of succinylcholine or mivacurium: three case reports.

    Cassel, J; Staehr-Rye, A K; Nielsen, C V; Gtke, M R

    2014-09-01

    Mutations in the butyrylcholinesterase gene can lead to a prolonged effect of the neuromuscular blocking agents, succinylcholine and mivacurium. If the anaesthesiologist is not aware of this condition, it may result in insufficient respiration after tracheal extubation. However, this can be avoided with the use of objective neuromuscular monitoring if used adequately. Three case reports of prolonged effect of succinylcholine or mivacurium were presented to illustrate the importance of neuromuscular monitoring during anaesthesia. In the first case, continuous intraoperative neuromuscular monitoring allowed a prolonged neuromuscular blockade to be discovered prior to tracheal extubation of the patient. The patient was extubated after successful reversal of the neuromuscular blockade. On the contrary, neuromuscular monitoring was not used during anaesthesia in the second patient; hence, the prolonged effect of the neuromuscular blocking agent was not discovered until after extubation. In the third patient, the lack of response to nerve stimulation was interpreted as a technical failure and the prolonged effect of succinylcholine was discovered when general anaesthesia was terminated. Both patients had insufficient respiration. They were therefore re-sedated, transferred to the intensive care unit and the tracheas were extubated after full recovery from neuromuscular blockade. We recommend the use of monitoring every time these agents are used, even with short-acting drugs like succinylcholine and mivacurium. PMID:24947746

  17. 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.

  18. 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...

  19. A temporary decrease in twitch response following reversal of rocuronium-induced neuromuscular block with a small dose of sugammadex in a pediatric patient.

    Iwasaki, Hajime; Takahoko, Kenichi; Otomo, Shigeaki; Sasakawa, Tomoki; Kunisawa, Takayuki; Iwasaki, Hiroshi

    2014-04-01

    We report a temporary decrease in twitch response following reversal of rocuronium-induced neuromuscular block with a small dose of sugammadex in our dose-finding study in pediatric patients. A 19-month-old female infant (9.6 kg, 80 cm) was scheduled for elective cheiloplasty surgery. Anesthesia was induced with nitrous oxide 50% and sevoflurane 5% and maintained with air, oxygen, sevoflurane 3%, and fentanyl (total, 3 ?g/kg). Neuromuscular monitoring was performed at the adductor pollicis muscle after induction of anesthesia but before the administration of rocuronium. Total dose of rocuronium during the surgery was 0.9 mg/kg. Neuromuscular block was reversed with 0.5 mg/kg sugammadex when one response was observed with post-tetanic count stimulation. Twitch responses after sugammadex administration showed a temporary decrease after its initial recovery. Maximum decreases in twitch responses were observed 17 min after initial dose of sugammadex. Twitch responses recovered to their control values after additional doses of 3.5 mg/kg sugammadex (4 mg/kg in total). Time from sugammadex administration to maximum decreases in twitch responses is earlier than has been reported in adults (20-70 min). It is demonstrated that following neuromuscular block reversal with insufficient dose of sugammadex, there is a possibility of the recurrence of residual paralysis within less than 20 min in pediatric patients. PMID:23963464

  20. 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

  1. Neutralization of the neuromuscular activity of bothropstoxin-i, a myotoxin from Bothrops jararacussu snake venom, by a hydroalcoholic extract of Casearia sylvestris Sw. (guaatonga

    Y. Oshima-Franco

    2005-12-01

    Full Text Available Numerous plants are used as snakebite antidotes in Brazilian folk medicine, including Casearia sylvestris Swartz, popularly known as guaatonga. In this study, we examined the action of a hydroalcoholic extract from C. sylvestris on the neuromuscular blockade caused by bothropstoxin-I (BthTX-I, a myotoxin from Bothrops jararacussu venom, in mouse isolated phrenic nerve-diaphragm (PND preparations. Aqueous (8 and 12 mg/ml, n=4 and 5, respectively and hydroalcoholic (12 mg/ml, n=12 extracts of the leaves of C. sylvestris caused facilitation in PND preparations followed by partial neuromuscular blockade. BthTX-I (20 g/ml, n=4 caused 50% paralysis after 6515 min (mean S.E.M. Preincubation (30 min at 37 C of BthTX-I (20 g/ml, n=4 with a concentration of the hydroalcoholic extract (4 mg/ml that had no neuromuscular activity, such as the control (n=5, prevented the neuromuscular blockade caused by the toxin. This protection may be mediated by compounds such as flavonoids and phenols identified by thin-layer chromatography and colorimetric assays.

  2. Feasibility study of a microprocessor controlled actuator test mechanism/

    Goode, Gregory Lawrence.

    1988-01-01

    This thesis describes the investigation of the feasibility of using a commercially available microcomputer to control and test a missile fin actuator. Topics discussed include system modelling, automated data acquisition, system identification, simulation and controller design. Modularity, both functional and conceptual, is stresses in the design process as well as integration of modules during the modelling and simulation process. Verification of the computer simulation is used extensively a...

  3. Neural mechanisms of impulse control in sexually risky adolescents

    Goldenberg, Diane; Eva H Telzer; Lieberman, Matthew D.; Fuligni, Andrew; Galván, Adriana

    2013-01-01

    The consequences of risky sexual behavior are of public concern. Adolescents contribute disproportionately to negative consequences of risky sexual behavior. However, no research has examined the neural correlates of impulse control and real-world engagement in risky sexual behavior in this population. The aim of the present study was to examine this question. Twenty sexually active adolescents performed an impulse control task during a functional magnetic resonance imaging (fMRI) scan and ri...

  4. Mechanisms controlling pork quality development: The biochemistry controlling postmortem energy metabolism.

    Scheffler, T L; Gerrard, D E

    2007-09-01

    Pale, soft and exudative (PSE) pork represents considerable economic losses for the industry due to its limited functionality and undesirable appearance. During the past several decades, exhaustive research covering various aspects of the food chain has established genotyping procedures, recommended handling practices, and quality indicators in order to reduce the incidence of inferior pork quality. Despite these efforts, there is still a relatively high occurrence of PSE pork. Development of pork quality attributes is largely governed by the rate and extent of postmortem pH decline. The combination of high temperature at low pH or abnormally low ultimate pH causes denaturation of sarcoplasmic and myofibrillar proteins, resulting in paler color and reduced water holding capacity. The pH decline is closely related to muscle energy availability and demand at or around slaughter. The postmortem degradation of glycogen through glycogenolysis and glycolysis provides ATP to help meet energy demand and decreases pH by generating lactate and H+. Therefore, the flux of metabolites through glycolysis, the involvement of energy signaling pathways that modulate glycolytic activity, and the inherent metabolism of different fiber types are critical factors influencing pH decline and pork quality. Further, recent work implicates adenosine monophosphate-activated protein kinase (AMPK) as a major energy sensor for the cell, and thus may be involved in the control of postmortem metabolism. The intent of this paper is to review the biochemistry controlling postmortem energy metabolism in pig muscle and explore new information generated using genetic mutations in order to define the fundamental mechanisms controlling the transformation of muscle to meat. PMID:22061391

  5. 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...

  6. Immortalized pathological human myoblasts: towards a universal tool for the study of neuromuscular disorders

    Mamchaoui Kamel

    2011-11-01

    Full Text Available Abstract Background Investigations into both the pathophysiology and therapeutic targets in muscle dystrophies have been hampered by the limited proliferative capacity of human myoblasts. Isolation of reliable and stable immortalized cell lines from patient biopsies is a powerful tool for investigating pathological mechanisms, including those associated with muscle aging, and for developing innovative gene-based, cell-based or pharmacological biotherapies. Methods Using transduction with both telomerase-expressing and cyclin-dependent kinase 4-expressing vectors, we were able to generate a battery of immortalized human muscle stem-cell lines from patients with various neuromuscular disorders. Results The immortalized human cell lines from patients with Duchenne muscular dystrophy, facioscapulohumeral muscular dystrophy, oculopharyngeal muscular dystrophy, congenital muscular dystrophy, and limb-girdle muscular dystrophy type 2B had greatly increased proliferative capacity, and maintained their potential to differentiate both in vitro and in vivo after transplantation into regenerating muscle of immunodeficient mice. Conclusions Dystrophic cellular models are required as a supplement to animal models to assess cellular mechanisms, such as signaling defects, or to perform high-throughput screening for therapeutic molecules. These investigations have been conducted for many years on cells derived from animals, and would greatly benefit from having human cell models with prolonged proliferative capacity. Furthermore, the possibility to assess in vivo the regenerative capacity of these cells extends their potential use. The innovative cellular tools derived from several different neuromuscular diseases as described in this report will allow investigation of the pathophysiology of these disorders and assessment of new therapeutic strategies.

  7. Age-related changes in neuromuscular function of the quadriceps muscle in physically active adults.

    Mau-Moeller, Anett; Behrens, Martin; Lindner, Tobias; Bader, Rainer; Bruhn, Sven

    2013-06-01

    Substantial evidence exists for the age-related decline in maximal strength and strength development. Despite the importance of knee extensor strength for physical function and mobility in the elderly, studies focusing on the underlying neuromuscular mechanisms of the quadriceps muscle weakness are limited. The aim of this study was to investigate the contributions of age-related neural and muscular changes in the quadriceps muscle to decreases in isometric maximal voluntary torque (iMVT) and explosive voluntary strength. The interpolated twitch technique and normalized surface electromyography (EMG) signal during iMVT were analyzed to assess changes in neural drive to the muscles of 15 young and 15 elderly volunteers. The maximal rate of torque development as well as rate of torque development, impulse and neuromuscular activation in the early phase of contraction were determined. Spinal excitability was estimated using the H reflex technique. Changes at the muscle level were evaluated by analyzing the contractile properties and lean mass. The age-related decrease in iMVT was accompanied by a decline in voluntary activation and normalized surface EMG amplitude. Mechanical parameters of explosive voluntary strength were reduced while the corresponding muscle activation remained primarily unchanged. The spinal excitability of the vastus medialis was not different while M wave latency was longer. Contractile properties and lean mass were reduced. In conclusion, the age-related decline in iMVT of the quadriceps muscle might be due to a reduced neural drive and changes in skeletal muscle properties. The decrease in explosive voluntary strength seemed to be more affected by muscular than by neural changes. PMID:23453325

  8. Management Control Systems and Job Stressors : Identifying the mechanisms by which budget and KPI controls influence job stressors

    Vilhelmsson, Lars-Erik; Fridlund, Eric

    2012-01-01

    This exploratory study explores how management control systems influence job stressors. More specifically, this study seeks to unravel the mechanisms by which budget and KPI controls influence job stressors. In our study we use the well-established Job Demand - Job Control - Job Support Model to compare previous research on job stressors with our case study. We interview Controllers and Managers at a manufacturing company within the industrial industry. Data was collected through semi-structu...

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

    PeterC.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 impaireddue to movement restrictions in tissues adjacent to nerves, or due to swelling or adhesions within the nerve itselfthe 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 examin

  10. Neural mechanisms of impulse control in sexually risky adolescents.

    Goldenberg, Diane; Telzer, Eva H; Lieberman, Matthew D; Fuligni, Andrew; Galván, Adriana

    2013-10-01

    The consequences of risky sexual behavior are of public concern. Adolescents contribute disproportionately to negative consequences of risky sexual behavior. However, no research has examined the neural correlates of impulse control and real-world engagement in risky sexual behavior in this population. The aim of the present study was to examine this question. Twenty sexually active adolescents performed an impulse control task during a functional magnetic resonance imaging (fMRI) scan and risky sexual behaviors were assessed through self-report. Sexual riskiness ratings were negatively associated with activation in the prefrontal cortex during response inhibition. These results suggest that diminished engagement of impulse control circuitry may contribute to sexual riskiness in adolescents. PMID:23835204

  11. Congestion control mechanisms and the best effort service model

    Gevros, P.; Crowcroft, J; Kirstein, P.; Bhatti, S

    2001-01-01

    In the last few years there has been considerable research toward extending the Internet architecture to provide quality of service guarantees for the emerging real-time multimedia applications. QoS provision is a rather controversial endeavour. At one end of the spectrum there were proposals for reservations and per-flow state in the routers. These models did not flourish due to the network's heterogeneity the complexity of the mechanisms involved, and scalability problems. At the other end,...

  12. Medicago marina (L.) seed: unravelling mechanisms controlling germination and dormancy

    Petrollini, Elisa

    2012-01-01

    The general aim of this thesis is to understand the complex and unknown mechanisms underlying dormancy and germination of Medicago marina (L.), a Mediterranean species distributed along the whole coasts of Italian peninsula and adapted to living in a specialized life habitats, like the dunes. Seeds of this species show strong dormancy that prevents germination. Results obtained during the first period of PhD program are published in a paper by Scippa et al., (2011). An integrated approach ...

  13. Neural mechanisms of attentional control in mindfulness meditation

    Peter Malinowski

    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...

  14. 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. ...

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

    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 α-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

  16. Superior compliance with a neuromuscular training programme is associated with fewer ACL injuries and fewer acute knee injuries in female adolescent football players: secondary analysis of an RCT

    Hgglund, Martin; Atroshi, Isam; Wagner, Philippe; Walden, Markus

    2013-01-01

    Background Little is known about the influence of compliance with neuromuscular training (NMT) on the knee injury rate in football. Aim To evaluate team and player compliance with an NMT programme in adolescent female football and to study the association between compliance and acute knee injury rates. Methods Prospective cohort study based on a cluster randomised controlled trial on players aged 1217?years with 184 intervention teams (2471 players) and 157 control teams (2085 players). Expo...

  17. Hydration control of the mechanical and dynamical properties of cellulose.

    Petridis, Loukas; O'Neill, Hugh M; Johnsen, Mariah; Fan, Bingxin; Schulz, Roland; Mamontov, Eugene; Maranas, Janna; Langan, Paul; Smith, Jeremy C

    2014-11-10

    The mechanical and dynamical properties of cellulose, the most abundant biomolecule on earth, are essential for its function in plant cell walls and advanced biomaterials. Cellulose is almost always found in a hydrated state, and it is therefore important to understand how hydration influences its dynamics and mechanics. Here, the nanosecond-time scale dynamics of cellulose is characterized using dynamic neutron scattering experiments and molecular dynamics (MD) simulation. The experiments reveal that hydrated samples exhibit a higher average mean-square displacement above ?240 K. The MD simulation reveals that the fluctuations of the surface hydroxymethyl atoms determine the experimental temperature and hydration dependence. The increase in the conformational disorder of the surface hydroxymethyl groups with temperature follows the cellulose persistence length, suggesting a coupling between structural and mechanical properties of the biopolymer. In the MD simulation, 20% hydrated cellulose is more rigid than the dry form, due to more closely packed cellulose chains and water molecules bridging cellulose monomers with hydrogen bonds. This finding may have implications for understanding the origin of strength and rigidity of secondary plant cell walls. The detailed characterization obtained here describes how hydration-dependent increased fluctuations and hydroxymethyl disorder at the cellulose surface lead to enhancement of the rigidity of this important biomolecule. PMID:25325376

  18. AUTOMATION OF CURRENT AND MODULE CONTROL OF KNOWLEDGES OF DISCIPLINE STRUCTURAL MECHANICS

    Bazhenov V.?.; Shishov O.V

    2014-01-01

    Original program complex CONTROL is exploited at the department of structural mechanics of Kiev national university of construction and architecture for the purpose of current and module controls of knowledge in the field of Structural mechanics. The structure of program complex and specific of its use in an educational process are examined.

  19. 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...

  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...