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Sample records for motor links nr1

  1. A non-muscle myosin II motor links NR1 to retrograde trafficking and proteasomal degradation in PC12 cells.

    PubMed

    Vazhappilly, Rema; Wee, Karen Siaw-Ling; Sucher, Nikolaus J; Low, Chian-Ming

    2010-03-01

    Rat pheochromocytoma (PC12) cells have been shown to lack functional NMDA receptors; yet, these cells express NR1 subunits of the NMDA receptor. The reason for the lack of functional receptors has been attributed to the absence of significant levels of NR2 subunits to co-assemble with NR1. It is known that PC12 expresses very low levels of NR2C, with complete absence of other types of NR2 subunits. The purpose of the present study is to describe the molecular mechanism of trafficking and degradation of unassembled NR1 subunits in PC12 cells. The localization of NR1 subunits in PC12 cells were evaluated by immunofluorescence and co-immunoprecipitation, which showed that NR1 was present in the endoplasmic reticulum and cis-middle compartments of the Golgi apparatus. Upon treatment with a proteasome inhibitor, MG132, the ubiquitinylated species of NR1 subunit were detected, suggesting that NR1 is being targeted for endoplasmic reticulum-associated proteasomal degradation. Our previous studies suggest that NR1 subunits from the Golgi do not proceed to trans-Golgi, hence they will require re-routing to the endoplasmic reticulum for degradation. Further investigations on the factors involved in the trafficking of NR1 from Golgi to endoplasmic reticulum were performed using co-immunoprecipitation and matrix assisted laser desorption/ionization time-of-flight mass spectrometry. These revealed the co-association of NR1 with non-muscle myosin heavy chain II isoforms A and B. We also demonstrate the functional significance of this interaction through the use of a myosin inhibitor, blebbistatin, to disrupt brefeldin A-induced Golgi-to-endoplasmic reticulum trafficking of NR1. In conclusion, our results suggest that non-muscle myosin II is involved in the retrograde trafficking of NR1 subunits from the cis/middle-Golgi to the endoplasmic reticulum for proteasomal degradation in PC12.

  2. ALS-linked protein disulfide isomerase variants cause motor dysfunction.

    PubMed

    Woehlbier, Ute; Colombo, Alicia; Saaranen, Mirva J; Pérez, Viviana; Ojeda, Jorge; Bustos, Fernando J; Andreu, Catherine I; Torres, Mauricio; Valenzuela, Vicente; Medinas, Danilo B; Rozas, Pablo; Vidal, Rene L; Lopez-Gonzalez, Rodrigo; Salameh, Johnny; Fernandez-Collemann, Sara; Muñoz, Natalia; Matus, Soledad; Armisen, Ricardo; Sagredo, Alfredo; Palma, Karina; Irrazabal, Thergiory; Almeida, Sandra; Gonzalez-Perez, Paloma; Campero, Mario; Gao, Fen-Biao; Henny, Pablo; van Zundert, Brigitte; Ruddock, Lloyd W; Concha, Miguel L; Henriquez, Juan P; Brown, Robert H; Hetz, Claudio

    2016-04-15

    Disturbance of endoplasmic reticulum (ER) proteostasis is a common feature of amyotrophic lateral sclerosis (ALS). Protein disulfide isomerases (PDIs) areERfoldases identified as possibleALSbiomarkers, as well as neuroprotective factors. However, no functional studies have addressed their impact on the disease process. Here, we functionally characterized fourALS-linked mutations recently identified in two majorPDIgenes,PDIA1 andPDIA3/ERp57. Phenotypic screening in zebrafish revealed that the expression of thesePDIvariants induce motor defects associated with a disruption of motoneuron connectivity. Similarly, the expression of mutantPDIs impaired dendritic outgrowth in motoneuron cell culture models. Cellular and biochemical studies identified distinct molecular defects underlying the pathogenicity of thesePDImutants. Finally, targetingERp57 in the nervous system led to severe motor dysfunction in mice associated with a loss of neuromuscular synapses. This study identifiesERproteostasis imbalance as a risk factor forALS, driving initial stages of the disease.

  3. Focal dystonia in musicians: linking motor symptoms to somatosensory dysfunction.

    PubMed

    Konczak, Jürgen; Abbruzzese, Giovanni

    2013-01-01

    Musician's dystonia (MD) is a neurological motor disorder characterized by involuntary contractions of those muscles involved in the play of a musical instrument. It is task-specific and initially only impairs the voluntary control of highly practiced musical motor skills. MD can lead to a severe decrement in a musician's ability to perform. While the etiology and the neurological pathomechanism of the disease remain unknown, it is known that MD like others forms of focal dystonia is associated with somatosensory deficits, specifically a decreased precision of tactile and proprioceptive perception. The sensory component of the disease becomes also evident by the patients' use of "sensory tricks" such as touching dystonic muscles to alleviate motor symptoms. The central premise of this paper is that the motor symptoms of MD have a somatosensory origin and are not fully explained as a problem of motor execution. We outline how altered proprioceptive feedback ultimately leads to a loss of voluntary motor control and propose two scenarios that explain why sensory tricks are effective. They are effective, because the sensorimotor system either recruits neural resources normally involved in tactile-proprioceptive (sensory) integration, or utilizes a fully functioning motor efference copy mechanism to align experienced with expected sensory feedback. We argue that an enhanced understanding of how a primary sensory deficit interacts with mechanisms of sensorimotor integration in MD provides helpful insights for the design of more effective behavioral therapies.

  4. Focal dystonia in musicians: linking motor symptoms to somatosensory dysfunction

    PubMed Central

    Konczak, Jürgen; Abbruzzese, Giovanni

    2013-01-01

    Musician's dystonia (MD) is a neurological motor disorder characterized by involuntary contractions of those muscles involved in the play of a musical instrument. It is task-specific and initially only impairs the voluntary control of highly practiced musical motor skills. MD can lead to a severe decrement in a musician's ability to perform. While the etiology and the neurological pathomechanism of the disease remain unknown, it is known that MD like others forms of focal dystonia is associated with somatosensory deficits, specifically a decreased precision of tactile and proprioceptive perception. The sensory component of the disease becomes also evident by the patients' use of “sensory tricks” such as touching dystonic muscles to alleviate motor symptoms. The central premise of this paper is that the motor symptoms of MD have a somatosensory origin and are not fully explained as a problem of motor execution. We outline how altered proprioceptive feedback ultimately leads to a loss of voluntary motor control and propose two scenarios that explain why sensory tricks are effective. They are effective, because the sensorimotor system either recruits neural resources normally involved in tactile-proprioceptive (sensory) integration, or utilizes a fully functioning motor efference copy mechanism to align experienced with expected sensory feedback. We argue that an enhanced understanding of how a primary sensory deficit interacts with mechanisms of sensorimotor integration in MD provides helpful insights for the design of more effective behavioral therapies. PMID:23805090

  5. Body side and predominant motor features at the onset of Parkinson's disease are linked to motor and nonmotor progression.

    PubMed

    Baumann, Christian R; Held, Ulrike; Valko, Philipp O; Wienecke, Miriam; Waldvogel, Daniel

    2014-02-01

    Patients with Parkinson's disease most often have asymmetric motor features at onset, and specific motor signs (ie, tremor versus bradykinesia and rigidity) frequently characterize the first few years of disease evolution. Some previous clinical evidence has suggested that body side and a predominance of motor manifestations at disease onset are linked to long-term evolution and disease progression. We prospectively analyzed 206 patients with Parkinson's disease according to the most affected side and predominant motor signs at onset. Patients were divided into left-side rigid-akinetic (n = 71), right-side rigid-akinetic (n = 59), left-side tremor (n = 41), and right-side tremor (n = 35) subgroups. These subgroups were compared in terms of motor and cognitive functions, mean motor deterioration per year (calculated as the motor score divided by disease duration), total equivalent doses of dopaminergic drugs, and the presence of hallucinations and rapid eye movement sleep behavior disorder. Disease duration was similar in all groups. Motor fluctuations were more likely to occur in rigid-akinetic patients. In a multiple model analysis adjusted for potential confounders, faster disease progression was associated with right-side (P = 0.045) and rigid-akinetic onset (P = 0.001). With respect to nonmotor symptoms, the rigid-akinetic type was associated with increased risk of cognitive decline (P = 0.004) compared with the tremor type. A trend was noticed toward an increased risk of developing visual hallucinations in rigid-akinetic patients and toward an increased frequency of rapid eye movement sleep behavior disorder in those who had left-sided onset of symptoms. Our findings corroborate that body side and type of motor signs at the time of diagnosis affect the evolution of motor severity and may also have an impact on some nonmotor manifestations.

  6. Adaptive control of rigid-link electrically-driven robots actuated with brushless DC motors

    SciTech Connect

    Bridges, M.M.; Dawson, D.M.

    1994-12-31

    In this paper, we extend the work of [1] and [2] to design an adaptive controller for rigid-link electrically-driven (RLED) robot manipulators specifically actuated with Brushless Direct Current (BLDC) motors. In particular the adaptive controller presented is tailored to handle the multi-link dynamics of a rigid-link robot as opposed to a simple inertial load. Furthermore, the linear electrical dynamics of brushed DC motors used in the development of [1], are replaced with the multiple input nonlinear dynamics of BLDC motors. The result is an adaptive controller that guarantees globally asymptotic convergence of the link position tracking error in spite of parametric uncertainty throughout the entire electro-mechanical model.

  7. Spinal NMDA NR1 Subunit Expression Following Transient TNBS Colitis

    PubMed Central

    Zhou, QiQi; Price, Donald D.; Caudle, Robert M.; Verne, G. Nicholas

    2009-01-01

    Background: N-methyl-D-aspartic acid (NMDA) receptors play an important role in the development of hypersensitivity to visceral and somatic stimuli following inflammation or tissue injury. Our objective was to investigate the role of NMDA NR1 receptors in the spinal cord (T10-L1; L4-S1) of a subset of rats that remain hypersensitive following histological resolution of TNBS-induced colitis compared to saline treated rats and rats that had recovered both behaviorally and histologically. We hypothesized that NMDA NR1 subunit expression mediates hypersensitivity following transient TNBS colitis. Methods: Male Sprague-Dawley rats (150g-250g) received 20mg/rat intracolonic trinitrobenzene sulfonic acid (TNBS) in 50% ethanol or saline. Animals underwent nociceptive visceral/somatic pain testing 16 weeks after resolution of TNBS colitis. Animals were sacrificed and their spinal cord (T10-L1; L4-S1) was retrieved and 2-dimensional polyacrylamide gel electrophoresis and immunohistocytochemistry techniques were used to investigate spinal-NMDA receptor expression. Results: NR1001 was the only NMDA NR1 receptor subunit that was expressed in recovered and control rats, whereas hypersensitive animals expressed NR1011 and NR1111 as well as NR1001 subunits. Immunohistochemistry analysis demonstrated increased expression of NMDA NR1-N1, C1, and C2-plus expression in lamina I & II of the spinal cord (T10-L1; L4-S1) in hypersensitive rats but not in recovered/control rats. Conclusions: Selective increases in the expression of the NMDA NR1 splice variants occur in hypersensitive rats following resolution of TNBS colitis. This suggests that the NMDA NR1 receptor play an important role in the development of neuronal plasticity and central sensitization. The recombination of NR1 splice variants may serve as a key functional protein that maintains hypersensitivity following resolution of TNBS colitis. PMID:19406112

  8. Multilevel DC Link Inverter for Brushless Permanent Magnet Motors with Very Low Inductance

    SciTech Connect

    Su, G.J.

    2001-10-29

    Due to their long effective air gaps, permanent magnet motors tend to have low inductance. The use of ironless stator structure in present high power PM motors (several tens of kWs) reduces the inductance even further (< 100 {micro}H). This low inductance imposes stringent current regulation demands for the inverter to obtain acceptable current ripple. An analysis of the current ripple for these low inductance brushless PM motors shows that a standard inverter with the most commonly used IGBT switching devices cannot meet the current regulation demands and will produce unacceptable current ripples due to the IGBT's limited switching frequency. This paper introduces a new multilevel dc link inverter, which can dramatically reduce the current ripple for brushless PM motor drives. The operating principle and design guidelines are included.

  9. Nuclear receptor NR1H3 in familial multiple sclerosis

    PubMed Central

    Wang, Zhe; Sadovnick, A. Dessa; Traboulsee, Anthony L.; Ross, Jay P.; Bernales, Cecily Q.; Encarnacion, Mary; Yee, Irene M.; de Lemos, Madonna; Greenwood, Talitha; Lee, Joshua D.; Wright, Galen; Ross, Colin J.; Zhang, Si; Song, Weihong; Vilariño-Güell, Carles

    2016-01-01

    SUMMARY Multiple sclerosis (MS) is an inflammatory disease characterized by myelin loss and neuronal dysfunction. Despite the aggregation observed in some families, pathogenic mutations have remained elusive. In this study we describe the identification of NR1H3 p.Arg415Gln in seven MS patients from two multi-incident families presenting severe and progressive disease, with an average age at onset of 34 years. Additionally, association analysis of common variants in NR1H3 identified rs2279238 conferring a 1.35-fold increased risk of developing progressive MS. The p.Arg415Gln position is highly conserved in orthologs and paralogs, and disrupts NR1H3 heterodimerization and transcriptional activation of target genes. Protein expression analysis revealed that mutant NR1H3 (LXRA) alters gene expression profiles, suggesting a disruption in transcriptional regulation as one of the mechanisms underlying MS pathogenesis. Our study indicates that pharmacological activation of LXRA or its targets may lead to effective treatments for the highly debilitating and currently untreatable progressive phase of MS. PMID:27253448

  10. Exome Sequencing Links Corticospinal Motor Neuron Disease to Common Neurodegenerative Disorders

    PubMed Central

    Hofree, Matan; Silhavy, Jennifer L.; Heiberg, Andrew D.; Abdellateef, Mostafa; Rosti, Basak; Scott, Eric; Mansour, Lobna; Masri, Amira; Kayserili, Hulya; Al-Aama, Jumana Y.; Abdel-Salam, Ghada M. H.; Karminejad, Ariana; Kara, Majdi; Kara, Bulent; Bozorgmehri, Bita; Ben-Omran, Tawfeg; Mojahedi, Faezeh; El Din Mahmoud, Iman Gamal; Bouslam, Naima; Bouhouche, Ahmed; Benomar, Ali; Hanein, Sylvain; Raymond, Laure; Forlani, Sylvie; Mascaro, Massimo; Selim, Laila; Shehata, Nabil; Al-Allawi, Nasir; Bindu, P.S.; Azam, Matloob; Gunel, Murat; Caglayan, Ahmet; Bilguvar, Kaya; Tolun, Aslihan; Issa, Mahmoud Y.; Schroth, Jana; Spencer, Emily G.; Rosti, Rasim O.; Akizu, Naiara; Vaux, Keith K.; Johansen, Anide; Koh, Alice A.; Megahed, Hisham; Durr, Alexandra; Brice, Alexis; Stevanin, Giovanni; Gabriel, Stacy B.; Ideker, Trey; Gleeson, Joseph G.

    2014-01-01

    Hereditary spastic paraplegias (HSPs) are neurodegenerative motor neuron diseases characterized by progressive age-dependent loss of corticospinal motor tract function. Although the genetic basis is partly understood, only a fraction of cases can receive a genetic diagnosis, and a global view of HSP is lacking. By using whole-exome sequencing in combination with network analysis, we identified 18 previously unknown putative HSP genes and validated nearly all of these genes functionally or genetically. The pathways highlighted by these mutations link HSP to cellular transport, nucleotide metabolism, and synapse and axon development. Network analysis revealed a host of further candidate genes, of which three were mutated in our cohort. Our analysis links HSP to other neurodegenerative disorders and can facilitate gene discovery and mechanistic understanding of disease. PMID:24482476

  11. Active force generation in cross-linked filament bundles without motor proteins.

    PubMed

    Walcott, Sam; Sun, Sean X

    2010-11-01

    Cytoskeletal filaments often interact laterally through cross-linking proteins, contributing to passive cellular viscoelasticity and, perhaps surprisingly, active force generation. We present a theory, based on the formation and rupture of cross-linker bonds, that relates molecular properties of those interactions to the macroscale mechanics of filament bundles. Computing the force-velocity relation for such a bundle, we demonstrate significant contractile forces in the absence of molecular motors. This theory provides insight into cytokinesis, cytoskeletal mechanics, and stress-fiber contraction.

  12. Structural determinants of D-cycloserine efficacy at the NR1/NR2C NMDA receptors

    PubMed Central

    Dravid, Shashank M.; Burger, Pieter B.; Prakash, Anand; Geballe, Matthew T.; Yadav, Roopali; Le, Phuong; Vellano, Kimberly; Snyder, James P.; Traynelis, Stephen F.

    2010-01-01

    We have studied relative efficacies of NR1 agonists glycine and D-cycloserine (DCS), and found efficacy to be dependent on the NR2 subunit. DCS shows partial agonism at NR1/NR2B but has higher relative efficacy than glycine at NR1/NR2C receptor. Molecular dynamics (MD) simulations of the NR1/NR2B and NR1/NR2C agonist binding domain dimer suggest only subtle differences in the interactions of DCS with NR1 binding site residues relative to glycine. The most pronounced differences were observed in the NR1/NR2C simulation between the orientation of helix F and G of the NR1 subunit. Interestingly, Helix F was previously proposed to influence receptor gating and to adopt an orientation depending on agonist efficacy. MD simulations and site-directed mutagenesis further suggest a role for residues at the agonist binding domain dimer interface in regulating DCS efficacy. To relate the structural rearrangements to receptor gating, we recorded single-channel currents from outside-out patches containing a single active NR1/NR2C receptor. DCS increased the mean open time and open probability of NR1/NR2C receptors in comparison to glycine. Maximum likelihood fitting of a gating model for NR1/NR2C receptor activation to the single channel data suggests that DCS specifically accelerates the rate constant governing a fast gating step and reduces the closing rate. These changes appear to reflect a decreased activation energy for a pregating step and increased stability of the open states. We suggest that the higher efficacy of DCS at NR1/NR2C receptors involves structural rearrangements at the dimer interface and an effect on NR1/NR2C receptor pre-gating conformational changes. PMID:20164358

  13. Efficiency consideration of DC link soft-switching inverters for motor drive applications

    SciTech Connect

    Lai, J.S.; Young, R.W.; McKeever, J.W.

    1994-12-31

    This paper critically evaluates efficiency of soft switching inverters including an actively clamped resonant dc link inverter and a clamped-mode resonant pole inverter. An analytical approach to evaluating efficiency of the clamped-mode soft switching inverter has been developed. The evaluation results are compared with that of the standard pulse-width-modulation (PWM) inverter. A 50-kW induction motor is used as the variable load, and the inverter efficiency is evaluated under different speed and torque conditions. The clamped-mode soft-switching inverter, although eliminating the switching loss, shows poor efficiency over the entire load range. Under low load conditions, the efficiency profile is even worse. The actively clamped resonant dc link inverter shows highest efficiency over the entire speed and torque range. However, its energy saving over the standard PWM inverter is marginal under full load or high speed conditions.

  14. Single-Phase Drive Ultrasonic Linear Motor Using a Linked Twin Square Plate Vibrator

    NASA Astrophysics Data System (ADS)

    Yokoyama, Keiji; Tamura, Hideki; Masuda, Kentaro; Takano, Takehiro

    2013-07-01

    A novel linear motion ultrasonic motor, which uses a single resonance mode driven by a single phase and has the same motor characteristics for operation in reverse directions, is developed. An in-plane breathing mode in the square plate is strongly driven by the transverse effect of a piezoelectric ceramic. A stator resonator consists of twin square plates linked by V-shaped beams. Only one side of the square plate can be excited by the resonance of the breathing mode, when the other passive side plate is electrically opened so that the effective elasticities and the resonant frequencies between both plates are different; as a result, the friction edge of the resonator vibrates in a slant locus to move a load slider. The reverse operation is easily obtained by switching the driving side of the square plates. We designed the stator resonator by FEM analysis and fabricated a prototype for our experiment. The prototype motor showed good characteristics, for example, a moving slider velocity of 100 mm/s, a thrust force of 3.5 N, and an efficiency of 30% when the preload was 10 N, the input effective voltage was 5 V, and the input power was 1.2 W.

  15. Deep-brain photoreception links luminance detection to motor output in Xenopus frog tadpoles

    PubMed Central

    Currie, Stephen P.; Doherty, Gayle H.; Sillar, Keith T.

    2016-01-01

    Nonvisual photoreceptors are widely distributed in the retina and brain, but their roles in animal behavior remain poorly understood. Here we document a previously unidentified form of deep-brain photoreception in Xenopus laevis frog tadpoles. The isolated nervous system retains sensitivity to light even when devoid of input from classical eye and pineal photoreceptors. These preparations produce regular bouts of rhythmic swimming activity in ambient light but fall silent in the dark. This sensitivity is tuned to short-wavelength UV light; illumination at 400 nm initiates motor activity over a broad range of intensities, whereas longer wavelengths do not cause a response. The photosensitive tissue is located in a small region of caudal diencephalon—this region is necessary to retain responses to illumination, whereas its focal illumination is sufficient to drive them. We present evidence for photoreception via the light-sensitive proteins opsin (OPN)5 and/or cryptochrome 1, because populations of OPN5-positive and cryptochrome-positive cells reside within the caudal diencephalon. This discovery represents a hitherto undescribed vertebrate pathway that links luminance detection to motor output. The pathway provides a simple mechanism for light avoidance and/or may reinforce classical circadian systems. PMID:27166423

  16. Increased phosphorylation of the NR1 subunit of the NMDA receptor following cerebral ischemia.

    PubMed

    Cheung, H H; Teves, L; Wallace, M C; Gurd, J W

    2001-09-01

    The effects of transient cerebral ischemia on phosphorylation of the NR1 subunit of the NMDA receptor by protein kinase C (PKC) and protein kinase A (PKA) were investigated. Adult rats received 15 min of cerebral ischemia followed by various times of recovery. Phosphorylation was examined by immunoblotting hippocampal homogenates with antibodies that recognized NR1 phosphorylated on the PKC phosphorylation sites Ser890 and Ser896, the PKA phosphorylation site Ser897, or dually phosphorylated on Ser896 and Ser897. The phosphorylation of all sites examined increased following ischemia. The increase in phosphorylation by PKC was greater than by PKA. The ischemia-induced increase in phosphorylation was predominantly associated with the population of NR1 that was insoluble in 1% deoxycholate. Enhanced phosphorylation of NR1 by PKC and PKA may contribute to alterations in NMDA receptor function in the postischemic brain.

  17. X-linked spinal muscular atrophy in mice caused by autonomous loss of ATP7A in the motor neuron

    PubMed Central

    Hodgkinson, Victoria L.; Dale, Jeffery M.; Garcia, Michael L.; Weisman, Gary A.; Lee, Jaekwon; Gitlin, Jonathan D.; Petris, Michael J.

    2015-01-01

    ATP7A is a copper transporting P-type ATPase that is essential for cellular copper homeostasis. Loss-of-function mutations in the ATP7A gene result in Menkes disease, a fatal neurodegenerative disorder resulting in seizures, hypotonia, and failure to thrive due to systemic copper deficiency. Most recently, rare missense mutations in ATP7A that do not impact systemic copper homeostasis have been shown to cause X-linked Spinal Muscular Atrophy type 3 (SMAX3), a distal hereditary motor neuropathy. An understanding of the mechanistic and pathophysiological basis of SMAX3 is currently lacking, in part because the disease-causing mutations have been shown to confer both loss- and gain-of-function properties to ATP7A, and because there is currently no animal model of the disease. In this study, the Atp7a gene was specifically deleted in the motor neurons of mice resulting in a degenerative phenotype consistent with the clinical features in affected patients with SMAX3, including the progressive deterioration of gait, age-dependent muscle atrophy, denervation of neuromuscular junctions, and a loss of motor neuron cell bodies. Taken together these data reveal autonomous requirements for ATP7A that reveal essential roles for copper in the maintenance and function of the motor neuron, and suggest that SMAX3 is caused by a loss of ATP7A function that specifically impacts in the spinal motor neuron. PMID:25639447

  18. X-linked spinal muscular atrophy in mice caused by autonomous loss of ATP7A in the motor neuron.

    PubMed

    Hodgkinson, Victoria L; Dale, Jeffery M; Garcia, Michael L; Weisman, Gary A; Lee, Jaekwon; Gitlin, Jonathan D; Petris, Michael J

    2015-06-01

    ATP7A is a copper-transporting P-type ATPase that is essential for cellular copper homeostasis. Loss-of-function mutations in the ATP7A gene result in Menkes disease, a fatal neurodegenerative disorder resulting in seizures, hypotonia and failure to thrive, due to systemic copper deficiency. Most recently, rare missense mutations in ATP7A that do not impact systemic copper homeostasis have been shown to cause X-linked spinal muscular atrophy type 3 (SMAX3), a distal hereditary motor neuropathy. An understanding of the mechanistic and pathophysiological basis of SMAX3 is currently lacking, in part because the disease-causing mutations have been shown to confer both loss- and gain-of-function properties to ATP7A, and because there is currently no animal model of the disease. In this study, the Atp7a gene was specifically deleted in the motor neurons of mice, resulting in a degenerative phenotype consistent with the clinical features in affected patients with SMAX3, including the progressive deterioration of gait, age-dependent muscle atrophy, denervation of neuromuscular junctions and a loss of motor neuron cell bodies. Taken together, these data reveal autonomous requirements for ATP7A that reveal essential roles for copper in the maintenance and function of the motor neuron, and suggest that SMAX3 is caused by a loss of ATP7A function that specifically impacts the spinal motor neuron.

  19. Mental Representation and Mental Practice: Experimental Investigation on the Functional Links between Motor Memory and Motor Imagery

    PubMed Central

    Frank, Cornelia; Land, William M.; Popp, Carmen; Schack, Thomas

    2014-01-01

    Recent research on mental representation of complex action has revealed distinct differences in the structure of representational frameworks between experts and novices. More recently, research on the development of mental representation structure has elicited functional changes in novices' representations as a result of practice. However, research investigating if and how mental practice adds to this adaptation process is lacking. In the present study, we examined the influence of mental practice (i.e., motor imagery rehearsal) on both putting performance and the development of one's representation of the golf putt during early skill acquisition. Novice golfers (N = 52) practiced the task of golf putting under one of four different practice conditions: mental, physical, mental-physical combined, and no practice. Participants were tested prior to and after a practice phase, as well as after a three day retention interval. Mental representation structures of the putt were measured, using the structural dimensional analysis of mental representation. This method provides psychometric data on the distances and groupings of basic action concepts in long-term memory. Additionally, putting accuracy and putting consistency were measured using two-dimensional error scores of each putt. Findings revealed significant performance improvements over the course of practice together with functional adaptations in mental representation structure. Interestingly, after three days of practice, the mental representations of participants who incorporated mental practice into their practice regime displayed representation structures that were more similar to a functional structure than did participants who did not incorporate mental practice. The findings of the present study suggest that mental practice promotes the cognitive adaptation process during motor learning, leading to more elaborate representations than physical practice only. PMID:24743576

  20. Links between motor control and classroom behaviors: Moderation by low birth weight.

    PubMed

    Razza, Rachel A; Martin, Anne; Brooks-Gunn, Jeanne

    2016-08-01

    It is unclear from past research on effortful control whether one of its components, motor control, independently contributes to adaptive classroom behaviors. The goal of this study was to identify associations between early motor control, measured by the walk-a-line task at age 3, and teacher-reported learning-related behaviors (approaches to learning and attention problems) and behavior problems in kindergarten classrooms. Models tested whether children who were vulnerable to poorer learning behaviors and more behavior problems due to having been born low birth weight benefited more, less, or the same as other children from better motor control. Data were drawn from the national Fragile Families and Child-Wellbeing Study (n = 751). Regression models indicated that motor control was significantly associated with better approaches to learning and fewer behavior problems. Children who were low birth weight benefitted more than normal birth weight children from better motor control with respect to their approaches to learning, but equally with respect to behavior problems. Additionally, for low but not normal birth weight children, better motor control predicted fewer attention problems. These findings suggest that motor control follows a compensatory model of development for low birth weight children and classroom behaviors.

  1. Aerospace induction motor actuators driven from a 20-kHz power link

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1990-01-01

    Aerospace electromechanical actuators utilizing induction motors are under development in sizes up to 40 kW. While these actuators have immediate application to the Advanced Launch System (ALS) program, several potential applications are currently under study including the Advanced Aircraft Program. Several recent advances developed for the Space Station Freedom have allowed induction motors to be selected as a first choice for such applications. Among these technologies are bi-directional electronics and high frequency power distribution techniques. Each of these technologies are discussed with emphasis on their impact upon induction motor operation.

  2. Inferior frontal gyrus links visual and motor cortices during a visuomotor precision grip force task.

    PubMed

    Papadelis, Christos; Arfeller, Carola; Erla, Silvia; Nollo, Giandomenico; Cattaneo, Luigi; Braun, Christoph

    2016-11-01

    Coordination between vision and action relies on a fronto-parietal network that receives visual and proprioceptive sensory input in order to compute motor control signals. Here, we investigated with magnetoencephalography (MEG) which cortical areas are functionally coupled on the basis of synchronization during visuomotor integration. MEG signals were recorded from twelve healthy adults while performing a unimanual visuomotor (VM) task and control conditions. The VM task required the integration of pinch motor commands with visual sensory feedback. By using a beamformer, we localized the neural activity in the frequency range of 1-30Hz during the VM compared to rest. Virtual sensors were estimated at the active locations. A multivariate autoregressive model was used to estimate the power and coherence of estimated activity at the virtual sensors. Event-related desynchronisation (ERD) during VM was observed in early visual areas, the rostral part of the left inferior frontal gyrus (IFG), the right IFG, the superior parietal lobules, and the left hand motor cortex (M1). Functional coupling in the alpha frequency band bridged the regional activities observed in motor and visual cortices (the start and the end points in the visuomotor loop) through the left or right IFG. Coherence between the left IFG and left M1 correlated inversely with the task performance. Our results indicate that an occipital-prefrontal-motor functional network facilitates the modulation of instructed motor responses to visual cues. This network may supplement the mechanism for guiding actions that is fully incorporated into the dorsal visual stream.

  3. Comparison between NOx Evolution Mechanisms of Wild-Type and nr1 Mutant Soybean Leaves 1

    PubMed Central

    Klepper, Lowell

    1990-01-01

    The nr1 soybean (Glycine max [L.] Merr.) mutant does not contain the two constitutive nitrate reductases, one of which is responsible for enzymic conversion of nitrite to NOx (NO + NO2). It was tested for possible nonenzymic NOx formation and evolution because of known chemical reactions between NO2− and plant metabolites and the instability of nitrous acid. It did not evolve NOx during the in vivo NR assay, but intact leaves did evolve small amounts of NOx under dark, anaerobic conditions. Experiments were conducted to compare NO3− reduction, NO2− accumulation, and the NOx evolution processes of the wild type (cv Williams) and the nr1 mutant. In vivo NR assays showed that wild-type leaves had three times more NO3− reducing capacity than the nr1 mutant. NOx evolution from intact, anerobic nr1 leaves was approximately 10 to 20% that from wild-type leaves. Nitrite content of the nr1 mutant leaves was usually higher than wild type due to low NOx evolution. Lag times and threshold NO2− concentrations for NOx evolution were similar for the two genotypes. While only 1 to 2% of NOx from wild type is NO2, the nr1 mutant evolved 15 to 30% NO2. The kinetic patterns of NOx evolution with time weré completely different for the mutant and wild type. Comparisons of light and heat treatments also gave very different results. It is generally accepted that the NOx evolution by wild type is primarily an enzymic conversion of NO2− to NO. However, this report concludes that NOx evolution by the nr1 mutant was due to nonenzymic, chemical reactions between plant metabolites and accumulated NO2− and/or decomposition of nitrous acid. Nonenzymic NOx evolution probably also occurs in wild type to a degree but could be easily masked by high rates of the enzymic process. PMID:16667445

  4. Effective Connectivity Hierarchically Links Temporoparietal and Frontal Areas of the Auditory Dorsal Stream with the Motor Cortex Lip Area during Speech Perception

    ERIC Educational Resources Information Center

    Murakami, Takenobu; Restle, Julia; Ziemann, Ulf

    2012-01-01

    A left-hemispheric cortico-cortical network involving areas of the temporoparietal junction (Tpj) and the posterior inferior frontal gyrus (pIFG) is thought to support sensorimotor integration of speech perception into articulatory motor activation, but how this network links with the lip area of the primary motor cortex (M1) during speech…

  5. From action representation to action execution: exploring the links between cognitive and biomechanical levels of motor control

    PubMed Central

    Land, William M.; Volchenkov, Dima; Bläsing, Bettina E.; Schack, Thomas

    2013-01-01

    Along with superior performance, research indicates that expertise is associated with a number of mediating cognitive adaptations. To this extent, extensive practice is associated with the development of general and task-specific mental representations, which play an important role in the organization and control of action. Recently, new experimental methods have been developed, which allow for investigating the organization and structure of these representations, along with the functional structure of the movement kinematics. In the current article, we present a new approach for examining the overlap between skill representations and motor output. In doing so, we first present an architecture model, which addresses links between biomechanical and cognitive levels of motor control. Next, we review the state of the art in assessing memory structures underlying complex action. Following we present a new spatio-temporal decomposition method for illuminating the functional structure of movement kinematics, and finally, we apply these methods to investigate the overlap between the structure of motor representations in memory and their corresponding kinematic structures. Our aim is to understand the extent to which the output at a kinematic level is governed by representations at a cognitive level of motor control. PMID:24065915

  6. Tryptophan hydroxylase 2 aggregates through disulfide cross-linking upon oxidation: Possible link to serotonin deficits and non-motor symptoms in Parkinson's disease

    PubMed Central

    Kuhn, Donald M.; Sykes, Catherine E.; Geddes, Timothy J.; Jaunarajs, Karen L. Eskow; Bishop, Christopher

    2010-01-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopamine neurons of the nigrostriatal system, resulting in severe motor disturbances. Although much less appreciated, non-motor symptoms are also very common in PD and many can be traced to serotonin neuronal deficits. Tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme in the serotonin biosynthesis, is a phenotypic marker for serotonin neurons and is known to be extremely labile to oxidation. Therefore, the oxidative processes that prevail in PD could cause TPH2 misfolding and modify 5HT neuronal function much as is seen in dopamine neurons. Oxidation of TPH2 inhibits enzyme activity and leads to the formation of high molecular weight aggregates in a dithiothreitol-reversible manner. Cysteine-scanning mutagenesis shows that as long as a single cysteine residue (out of a total of 13 per monomer) remains in TPH2, it cross-links upon oxidation and only cysteine-less mutants are resistant to this effect. The effects of oxidants on TPH2 catalytic function and cross-linking are also observed in intact TPH2-expressing HEK293 cells. Oxidation shifts TPH2 from the soluble compartment into membrane fractions and large inclusion bodies. Sequential non-reducing/reducing two-dimensional SDS-PAGE and immunoblotting confirmed that TPH2 was one of a small number of cytosolic proteins that form disulfide-bonded aggregates. The propensity of TPH2 to misfold upon oxidation of its cysteine residues is responsible for its catalytic lability and may be related to loss of serotonin neuronal function in PD and the emergence of non-motor (psychiatric) symptoms. PMID:21105877

  7. Motor Difficulties in Autism Spectrum Disorder: Linking Symptom Severity and Postural Stability

    ERIC Educational Resources Information Center

    Travers, Brittany G.; Powell, Patrick S.; Klinger, Laura G.; Klinger, Mark R.

    2013-01-01

    Postural stability is a fundamental aspect of motor ability that allows individuals to sustain and maintain the desired physical position of one's body. The present study examined postural stability in average-IQ adolescents and adults with Autism Spectrum Disorder (ASD). Twenty-six individuals with ASD and 26 age-and-IQ-matched individuals…

  8. Integrative proteomic analysis of the NMDA NR1 knockdown mouse model reveals effects on central and peripheral pathways associated with schizophrenia and autism spectrum disorders

    PubMed Central

    2014-01-01

    found only in the frontal cortex and abnormalities of proteins involved in the purinergic system were found exclusively in the hippocampus. Conclusions Taken together, this multi-platform profiling study has identified peripheral changes which are potentially linked to central alterations in synaptic plasticity and neuronal function associated with NMDAR-NR1 hypofunction. Therefore, the reported proteomic changes may be useful as translational biomarkers in human and rodent model drug discovery efforts. PMID:25061506

  9. Trouble at Tsavo: The Tale of the Black Rhino. BrainLink: Motor Highways.

    ERIC Educational Resources Information Center

    Boyle, Grace

    The BrainLink project offers educational materials that focus on current neuroscience issues with the goal of promoting a deeper understanding of how the nervous system works and why the brain makes each individual special while conveying the excitement of "doing science" among upper elementary and middle school students. Project materials engage…

  10. Increased Motor Activity During REM Sleep Is Linked with Dopamine Function in Idiopathic REM Sleep Behavior Disorder and Parkinson Disease

    PubMed Central

    Zoetmulder, Marielle; Nikolic, Miki; Biernat, Heidi; Korbo, Lise; Friberg, Lars; Jennum, Poul

    2016-01-01

    Study Objectives: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by impaired motor inhibition during REM sleep, and dream-enacting behavior. RBD is especially associated with α-synucleinopathies, such as Parkinson disease (PD). Follow-up studies have shown that patients with idiopathic RBD (iRBD) have an increased risk of developing an α-synucleinopathy in later life. Although abundant studies have shown that degeneration of the nigrostriatal dopaminergic system is associated with daytime motor function in Parkinson disease, only few studies have investigated the relation between this system and electromyographic (EMG) activity during sleep. The objective of this study was to investigate the relationship between the nigrostriatal dopamine system and muscle activity during sleep in iRBD and PD. Methods: 10 iRBD patients, 10 PD patients with PD, 10 PD patients without RBD, and 10 healthy controls were included and assessed with (123)I-N-omega-fluoropropyl-2-beta-carboxymethoxy-3beta-(4-iodophenyl) nortropane ((123)I-FP-CIT) Single-photon emission computed tomography (SPECT) scanning (123I-FP-CIT SPECT), neurological examination, and polysomnography. Results: iRBD patients and PD patients with RBD had increased EMG-activity compared to healthy controls. 123I-FP-CIT uptake in the putamen-region was highest in controls, followed by iRBD patients, and lowest in PD patients. In iRBD patients, EMG-activity in the mentalis muscle was correlated to 123I-FP-CIT uptake in the putamen. In PD patients, EMG-activity was correlated to anti-Parkinson medication. Conclusions: Our results support the hypothesis that increased EMG-activity during REM sleep is at least partly linked to the nigrostriatal dopamine system in iRBD, and with dopamine function in PD. Citation: Zoetmulder M, Nikolic M, Biernat H, Korbo L, Friberg L, Jennum P. Increased motor activity during rem sleep is linked with dopamine function in idiopathic REM sleep behavior

  11. Neurochemical and motor changes in mice with combined mutations linked to Parkinson’s disease

    PubMed Central

    Bai, Xiang; Wey, Margaret Chia-Ying; Martinez, Paul Anthony; Shi, Chao; Fernandez, Elizabeth; Strong, Randy

    2017-01-01

    ABSTRACT Considerable evidence suggests that oxidative stress plays a role in the pathogenesis of Parkinson’s disease (PD), the most prevalent neurodegenerative movement disorder. Reduced expression of aldehyde dehydrogenase-1 (ALDH1) and glutathione peroxidase-1 (GPX1), enzymes that function to detoxify aldehydes and hydroxyl radicals, respectively, has been reported in the substantia nigra of patients who died with PD. To determine whether deficiency in these two genes contributes to the pathogenesis of PD, mice were generated with homozygous null mutations of both Aldh1a1 (the murine homolog of ALDH1) and Gpx1 genes [knockout (KO) mice]. At 6 and 18 months of age, KO mice showed a significantly decreased latency to fall in the automated accelerating rotarod test and increased time to complete the pole test opamine levels were not altered; however, the dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) and the DOPAC/dopamine ratio were significantly reduced at 18 months of age. Proteins adducted with 4-hydroxynonenal, the end-product of lipid peroxidation, were increased in the. midbrain and striatum of KO mice at 6 and 18 months. In conclusion, dual mutations in Gpx1 and Aldh1a1 genes are associated with motor deficits and increased lipid peroxidation in adult mice. PMID:28326165

  12. The link between texting and motor vehicle collision frequency in the orthopaedic trauma population

    PubMed Central

    Issar, Neil M.; Kadakia, Rishin J.; Tsahakis, James M.; Yoneda, Zachary T.; Sethi, Manish K.; Mir, Hassan R.; Archer, Kristin; Obremskey, William T.; Jahangir, Amir A.

    2013-01-01

    Abstract: Background: This study will evaluate whether or not texting frequency while driving and/or texting frequency in general are associated with an increased risk of incurring a motor vehicle collision (MVC) resulting in orthopaedic trauma injuries. Methods: All patients who presented to the Vanderbilt University Medical Center Orthopaedic Trauma Clinic were administered a questionnaire to determine background information, mean phone use, texting frequency, texting frequency while driving, and whether or not the injury was the result of an MVC in which the patient was driving. Results: 237 questionnaires were collected. 60 were excluded due to incomplete date, leaving 57 questionnaires in the MVC group and 120 from patients with non-MVC injuries. Patients who sent more than 30 texts per week (“heavy texters”) were 2.22 times more likely to be involved in an MVC than those who texted less frequently. 84% of respondents claimed to never text while driving. Dividing the sample into subsets on the basis of age (25 years of age or below considered “young adult,” and above 25 years of age considered “adult”),young, heavy texters were 6.76 times more likely to be involved in an MVC than adult non-heavy texters (p = 0.000). Similarly, young adult, non-heavy texters were 6.65 (p = 0.005) times more likely to be involved in an MVC, and adult, heavy texters were 1.72 (p = 0.186) times more likely to be involved in an MVC. Conclusions: Patients injured in an MVC sent more text messages per week than non-MVC patients. Additionally, controlling for age demonstrated that young age and heavy general texting frequency combined had the highest increase in MVC risk, with the former being the variable of greatest effect. PMID:23416747

  13. Link between the enzymatic kinetics and mechanical behavior in an actomyosin motor.

    PubMed Central

    Amitani, I; Sakamoto, T; Ando, T

    2001-01-01

    We have attempted to link the solution actomyosin ATPase with the mechanical properties of in vitro actin filament sliding over heavy meromyosin. To accomplish this we perturbed the system by altering the substrate with various NTPs and divalent cations, and by altering ionic strength. A wide variety of enzymatic and mechanical measurements were made under very similar solution conditions. Excellent correlations between the mechanical and enzymatic quantities were revealed. Analysis of these correlations based on a force-balance model led us to two fundamental equations, which can be described approximately as follows: the maximum sliding velocity is proportional to square root of V(max)K(m)(A), where K(m)(A) is the actin concentration at which the substrate turnover rate is half of its maximum (V(max)). The active force generated by a cross-bridge under no external load or under a small external load is proportional to square root of V(max)/K(m)(A). The equations successfully accounted for the correlations observed in the present study and observations in other laboratories. PMID:11159410

  14. MMP-7 cleaves the NR1 NMDA receptor subunit and modifies NMDA receptor function

    PubMed Central

    Szklarczyk, Arek; Ewaleifoh, Osefame; Beique, Jean-Claude; Wang, Yue; Knorr, David; Haughey, Norman; Malpica, Tanya; Mattson, Mark P.; Huganir, Richard; Conant, Katherine

    2008-01-01

    Matrix metalloproteinases (MMPs) are zinc-dependent enzymes that play a role in the inflammatory response. These enzymes have been well studied in the context of cancer biology and inflammation. Recent studies, however, suggest that these enzymes also play roles in brain development and neurodegenerative disease. Select MMPs can target proteins critical to synaptic structure and neuronal survival, including integrins and cadherins. Here, we show that one member of the MMP family, MMP-7, which may be released from cells, including microglia, can target a protein critical to synaptic function. Through analysis of extracts from murine cortical slice preparations, we show that MMP-7 cleaves the NR1 subunit of the N-methyl-d-aspartate (NMDA) receptor to generate an N-terminal fragment of ∼65 kDa. Moreover, studies with recombinant protein show that MMP-7-mediated cleavage of NR1 occurs at amino acid 517, which is extracellular and just distal to the first transmembrane domain. Data suggest that NR2A, which shares sequence homology with NR1, is also cleaved following treatment of slices with MMP-7, while select AMPA receptor subunits are not. Consistent with a potential effect of MMP-7 on ligand binding, additional experiments demonstrate that NMDA-mediated calcium flux is significantly diminished by MMP-7 pretreatment of cultures. In addition, the AMPA/NMDA ratio is increased by MMP-7 pretreatment. These data suggest that synaptic function may be altered in neurological conditions associated with increased levels of MMP-7.—Szklarczyk, A., Ewaleifoh, O., Beique, J.-C., Wang, Y., Knorr, D., Haughey, N., Malpica, T., Mattson, M. P., Huganir, R., Conant, K. MMP-7 cleaves the NR1 NMDA receptor subunit and modifies NMDA receptor function. PMID:18644839

  15. Association of NR1I2 gene polymorphisms and time of progression to AIDS

    PubMed Central

    de Medeiros, Rúbia Marília; Menti, Carolina Fialho; Benelli, Jéssica Louise; Matte, Maria Cristina Cotta; de Melo, Marineide Gonçalves; Almeida, Sabrina Esteves de Matos; Fiegenbaum, Marilu

    2017-01-01

    BACKGROUND The time of progression towards AIDS can vary greatly among seropositive patients, and may be associated with host genetic variation. The NR1I2 (PXR) gene, a ligand-activated transcription factor, regulates the transcription immune pathway genes and can therefore be targets of viral replication mechanisms influencing time of progression to AIDS. OBJECTIVE To verify the association of single nucleotide polymorphisms (SNPs) rs3814057, rs6785049, rs7643645, and rs2461817 in the NR1I2 (PXR) gene with progression to AIDS in HIV-1 infected patients. METHODS Blood samples were obtained from 96 HIV-1 positive individuals following informed consent. DNA was isolated and genotyped through real time polymerase chain reaction (PCR) for the presence of SNPs in the NR1I2. Questionnaires on socio-demographic features and behaviors were answered and time of progression to AIDS was estimated based on medical chart analysis. FINDINGS Patients with the GG genotype for rs7643645 were shown to be related with a more rapid disease progression when compared to GA and AA genotypes. This result was maintained by the Multivariate Cox Regression considering sex, ethnicity, and presence of HLA-B*57, HLA-B*27, and CCR5del32 polymorphisms. MAIN CONCLUSIONS Recent studies reported the expression of the nuclear receptors in T-Lymphocytes, suggesting their possible role in the immune response. In addition, nuclear receptors have been shown to inhibit the HIV replication, although no such mechanism has been thoroughly elucidated to date. This is the first time an association between NR1I2 polymorphism and time of progression to AIDS is reported and supports an apparent relationship between the gene in the immune response and identifies another genetic factor influencing AIDS progression. PMID:28327790

  16. Voltage-dependent gating of NR1/2B NMDA receptors

    PubMed Central

    Clarke, Richard J; Johnson, Jon W

    2008-01-01

    Ligand-gated ion channels are activated by agonist binding, but may also be modulated by membrane voltage. N-Methyl-d-aspartate receptors (NMDARs) exhibit especially strong voltage dependence due to channel block by external Mg2+ (Mgo2+). Here we demonstrate that activity of NMDARs composed of NR1 and NR2B subunits (NR1/2B receptors) is enhanced by depolarization even in 0 Mgo2+, causing slow current relaxations in response to rapid voltage changes. We present a kinetic model of receptor activation that incorporates voltage-dependent gating-associated NR2B subunit conformational changes. The model accurately reproduces current relaxations during depolarizations and subsequent repolarizations in 0 Mgo2+. Model simulations in physiological Mgo2+ concentrations show that voltage-dependent receptor gating also underlies the slow component of Mgo2+ unblock, a phenomenon that previously was shown to influence Mgo2+ unblock kinetics during dendritic spikes. We propose that voltage-dependent gating of NR1/2B receptors confers enhanced voltage and time dependence on NMDAR-mediated signalling. PMID:18936081

  17. Inhibition of N-methyl-D-aspartate-activated current by bis(7)-tacrine in HEK-293 cells expressing NR1/NR2A or NR1/NR2B receptors.

    PubMed

    Liu, Yuwei; Li, Chaoying

    2012-12-01

    In normal rat forebrain, the NR1/NR2A and NR1/NR2B dimmers are the main constitutional forms of NMDA receptors. The present study was carried out to determine the functional properties of the heteromeric NMDA receptor subunits and their inhibition by bis(7)-tacrine (B7T). Rat NR1, NR2A and NR2B cDNAs were transfected into human embryonic kidney 293 cells (HEK-293). The inhibition of NMDA-activated currents by B7T was detected in HEK-293 cell expressing NR1/NR2A or NR1/NR2B receptors by using whole-cell patch-clamp techniques. The results showed that in HEK-293 cells expressing NR1/NR2A receptor, 1 μmol/L B7T inhibited 30 μmol/L NMDA- and 1000 μmol/L NMDA-activated steady-state currents by 46% and 40%, respectively (P>0.05; n=5), suggesting that the inhibition of B7T on NR1/NR2A receptor doesn't depend on NMDA concentration, which is consistent with a non-competitive mechanism of inhibition. But for the NR1/NR2B receptor, 1 μmol/L B7T inhibited 30 μmol/L NMDA- and 1000 μmol/L NMDA-activated steady-state currents by 61% and 13%, respectively (P<0.05; n=6), showing that B7T appears to be competitive with NMDA. In addition, simultaneous application of 1 μmol/L B7T and 1000 μmol/L NMDA produced a moderate inhibition of peak NMDA-activated current, followed by a gradual decline of the current to a steady state. However, the gradual onset of inhibition produced by B7T applied simultaneously with NMDA was eliminated when B7T was given 5 s before NMDA. These results suggested that B7T inhibition of NMDA current mediated by NR1/NR2B receptor was slow onset, and it did not depend on the presence of the agonist. With holding potentials ranging from -50 to +50 mV, the B7T inhibition rate of NMDA currents didn't change significantly, and neither did the reversal potential. We are led to conclude that the NR1/NR2B recombinant receptor can serve as a very useful model for studying the molecular mechanism of NMDA receptor inhibition by B7T.

  18. Molecular dynamics simulations and cross-link analysis of the rotary molecular motor F(o) of ATP synthase

    NASA Astrophysics Data System (ADS)

    Kanchanawarin, Chalermpol

    The protein F1Fo ATP synthase is responsible for the generation of the molecule adenosine tri-phosphate (ATP). It consists of two coupled rotary motors, F1 and Fo. ATP is generated via a rotary mechanism that couples the synthesis of ATP in F1 to the proton translocation across Fo which is driven by the electrochemical proton gradient across the membrane. F1 consists of three different subunits in the stoichiometry a1b2c10. So far, only the structure of the c-subunit and a partial structure of the b-subunit have been solved at atomic level detail. However, enough biochemical and structural information is available to construct an atomic model of Fo. There are still many open questions about Fo operation ranging from the subunit arrangement to the proton pathway and proton conduction mechanism to the rotary mechanism that couples the proton conduction to the rotation of its rotor. In this thesis study, I investigated the following four aspects of Fo: the proton pathway in Fo; the motion of F o subunits during its rotation; the rotation of the C-terminal helix of the c-subunit induced by a pH change; the forced rotation of a c10 ring in a membrane. Using molecular dynamics (MD) simulations, I was able to identify a proton pathway formed as two half proton channels in F o, i.e., a proton entrance channel and a proton exit channel. This is in good agreement with experiment. Furthermore, based on the diagramatic cross-link analysis, I propose a new Fo rotary mechanism which shows the cooperative movement of helices in Fo during proton transport and can explain experimental results which could not be explained by previous models. The investigation of the C-terminal helix rotation by NM simulations showed no pH induced rotation of the helix of the c-subunit. Finally, using steered MD simulations, I found that the c10 ring is mechanically robust against forced rotation in vacuum but not in a membrane on the MD time scale. Overall, structural information combined with my

  19. AmeriFlux US-NR1 Niwot Ridge Forest (LTER NWT1)

    DOE Data Explorer

    Blanken, Peter [University of Colorado

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-NR1 Niwot Ridge Forest (LTER NWT1). Site Description - The Niwot Ridge AmeriFlux site is located in a subalpine forest ecosystem just below the Continental Divide near Nederland, CO. The site is located at 3050 m elevation, within 600m of the NOAA C1 long-term monitoring station, approximately 8 km east of the Continental Divide. The surrounding subalpine forest is ~97 years old and in a state of aggradation, having recovered from early twentieth century logging (Monson, et al. Global Change Biology (2002), 8 459-478).

  20. Role of a circadian-relevant gene NR1D1 in brain development: possible involvement in the pathophysiology of autism spectrum disorders

    PubMed Central

    Goto, Masahide; Mizuno, Makoto; Matsumoto, Ayumi; Yang, Zhiliang; Jimbo, Eriko F.; Tabata, Hidenori; Yamagata, Takanori; Nagata, Koh-ichi

    2017-01-01

    In our previous study, we screened autism spectrum disorder (ASD) patients with and without sleep disorders for mutations in the coding regions of circadian-relevant genes, and detected mutations in several clock genes including NR1D1. Here, we further screened ASD patients for NR1D1 mutations and identified three novel mutations including a de novo heterozygous one c.1499 G > A (p.R500H). We then analyzed the role of Nr1d1 in the development of the cerebral cortex in mice. Acute knockdown of mouse Nr1d1 with in utero electroporation caused abnormal positioning of cortical neurons during corticogenesis. This aberrant phenotype was rescued by wild type Nr1d1, but not by the c.1499 G > A mutant. Time-lapse imaging revealed characteristic abnormal migration phenotypes in Nr1d1-deficient cortical neurons. When Nr1d1 was knocked down, axon extension and dendritic arbor formation of cortical neurons were also suppressed while proliferation of neuronal progenitors and stem cells at the ventricular zone was not affected. Taken together, Nr1d1 was found to play a pivotal role in corticogenesis via regulation of excitatory neuron migration and synaptic network formation. These results suggest that functional defects in NR1D1 may be related to ASD etiology and pathophysiology. PMID:28262759

  1. A potential psychological mechanism linking disaster-related prenatal maternal stress with child cognitive and motor development at 16 months: The QF2011 Queensland Flood Study.

    PubMed

    Moss, Katrina M; Simcock, Gabrielle; Cobham, Vanessa; Kildea, Sue; Elgbeili, Guillaume; Laplante, David P; King, Suzanne

    2017-04-01

    Fetal exposure to prenatal maternal stress can have lifelong consequences, with different types of maternal stress associated with different areas of child development. Fewer studies have focused on motor skills, even though they are strongly predictive of later development across a range of domains. Research on mechanisms of transmission has identified biological cascades of stress reactions, yet links between psychological stress reactions are rarely studied. This study investigates the relationship between different aspects of disaster-related prenatal maternal stress and child cognitive and motor development, and proposes a cascade of stress reactions as a potential mechanism of transmission. Mothers in the Queensland Flood Study (QF2011) exposed to a major flood during pregnancy completed questionnaires assessing flood exposure, symptoms of peritraumatic distress, dissociation, and posttraumatic stress (PTSD), and cognitive appraisal of the overall flood consequences. At 16 months post-partum, children's (N = 145) cognitive and motor development was assessed using the Bayley-III. Flood exposure predicted child cognitive development and maternal PTSD symptoms and negative cognitive appraisal were significantly negatively related to child motor development, with all relationships moderated by timing of exposure. Together, a cascade of stress reactions linked maternal flood exposure to poorer fine motor development. These findings suggest that the way stress reactions operate together is as important as the way they operate in isolation, and identifies a potential psychological mechanism of transmission for the effects of prenatal stress. Results have implications for conceptualizing prenatal stress research and optimizing child development in the wake of natural disasters. (PsycINFO Database Record

  2. Two distinct interneuron circuits in human motor cortex are linked to different subsets of physiological and behavioral plasticity.

    PubMed

    Hamada, Masashi; Galea, Joseph M; Di Lazzaro, Vincenzo; Mazzone, Paolo; Ziemann, Ulf; Rothwell, John C

    2014-09-17

    How does a single brain region participate in multiple behaviors? Here we argue that two separate interneuron circuits in the primary motor cortex (M1) contribute differently to two varieties of physiological and behavioral plasticity. To test this in human brain noninvasively, we used transcranial magnetic stimulation (TMS) of M1 hand area to activate two independent sets of synaptic inputs to corticospinal neurons by changing the direction of current induced in the brain: posterior-to-anterior current (PA inputs) and anterior-to-posterior current (AP inputs). We demonstrate that excitability changes produced by repetitive activation of AP inputs depend on cerebellar activity and selectively alter model-based motor learning. In contrast, the changes observed with repetitive stimulation of PA inputs are independent of cerebellar activity and specifically modulate model-free motor learning. The findings are highly suggestive that separate circuits in M1 subserve different forms of motor learning.

  3. Expression and characterization of a glycine-binding fragment of the N-methyl-D-aspartate receptor subunit NR1.

    PubMed Central

    Miyazaki, J; Nakanishi, S; Jingami, H

    1999-01-01

    N-Methyl-D-aspartate receptor channels are composed of an NR1 subunit and at least one of the NR2 subunits (NR2A-D). Activation of the N-methyl-d-aspartate receptor requires the co-agonists glycine and glutamate. It has been proposed that the NR1 subunit possesses a glycine-binding site. We have expressed a soluble form of the NR1 subunit, which was produced by connecting the N-terminal extracellular region with the extracellular loop between the third and fourth membrane segments, by a baculovirus system along with full-length and truncated membrane-bound forms. The soluble NR1 receptor was efficiently secreted into the culture medium and showed a high affinity for ligands. The Kd of a glycine-site antagonist, [3H]MDL 105,519 [(E)-3-(2-phenyl-2-carboxyethenyl)-4, 6-dichloro-1H-indole-2-carboxylic acid], for the soluble receptor was 3.89+/-0.97 nM, which was comparable to the Kd of 4.47+/-1.39 nM for the membrane-bound full-length form. These values were close to the values reported previously with the use of rat brain membranes and Chinese hamster ovary cells expressing the full-length form of the NR1 subunit. The Ki values of other glycine-site antagonists, L-689,560 (trans-2-carboxy-5,7-dichloro - 4 - phenylaminocarbonylamino - 1,2,3,4 - tetrahydroquinoline), 5, 7-dichlorokynurenate and 5,7-dinitroquinoxaline-2,3-dione, for the soluble receptor were also similar to those for the full-length form of NR1. [3H]MDL 105,519 binding was also inhibited by the agonists glycine and d-serine. Thus the affinity and selectivity of ligand-binding characteristics of the NR1 subunit is conferred on the soluble form of the NR1 subunit. This soluble receptor provides a good experimental tool for initiating a biophysical analysis of the N-methyl-d-aspartate receptor channel protein. PMID:10359652

  4. ALS-linked TDP-43 mutations produce aberrant RNA splicing and adult-onset motor neuron disease without aggregation or loss of nuclear TDP-43.

    PubMed

    Arnold, Eveline S; Ling, Shuo-Chien; Huelga, Stephanie C; Lagier-Tourenne, Clotilde; Polymenidou, Magdalini; Ditsworth, Dara; Kordasiewicz, Holly B; McAlonis-Downes, Melissa; Platoshyn, Oleksandr; Parone, Philippe A; Da Cruz, Sandrine; Clutario, Kevin M; Swing, Debbie; Tessarollo, Lino; Marsala, Martin; Shaw, Christopher E; Yeo, Gene W; Cleveland, Don W

    2013-02-19

    Transactivating response region DNA binding protein (TDP-43) is the major protein component of ubiquitinated inclusions found in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) with ubiquitinated inclusions. Two ALS-causing mutants (TDP-43(Q331K) and TDP-43(M337V)), but not wild-type human TDP-43, are shown here to provoke age-dependent, mutant-dependent, progressive motor axon degeneration and motor neuron death when expressed in mice at levels and in a cell type-selective pattern similar to endogenous TDP-43. Mutant TDP-43-dependent degeneration of lower motor neurons occurs without: (i) loss of TDP-43 from the corresponding nuclei, (ii) accumulation of TDP-43 aggregates, and (iii) accumulation of insoluble TDP-43. Computational analysis using splicing-sensitive microarrays demonstrates alterations of endogenous TDP-43-dependent alternative splicing events conferred by both human wild-type and mutant TDP-43(Q331K), but with high levels of mutant TDP-43 preferentially enhancing exon exclusion of some target pre-mRNAs affecting genes involved in neurological transmission and function. Comparison with splicing alterations following TDP-43 depletion demonstrates that TDP-43(Q331K) enhances normal TDP-43 splicing function for some RNA targets but loss-of-function for others. Thus, adult-onset motor neuron disease does not require aggregation or loss of nuclear TDP-43, with ALS-linked mutants producing loss and gain of splicing function of selected RNA targets at an early disease stage.

  5. The effects of rTMS over the primary motor cortex: the link between action and language.

    PubMed

    Repetto, Claudia; Colombo, Barbara; Cipresso, Pietro; Riva, Giuseppe

    2013-01-01

    Is the primary motor cortex (M1) necessary for language comprehension? The present study investigates the role of the primary motor cortex during verbs comprehension, within the framework of the embodied theories of language. We applied rTMS over the right and left hand portion of M1 and tested the effects of the stimulation toward the processing of hand-related action verbs versus abstract verbs. Results underlined a specific inhibition effect following left stimulation, only with hand-related action verbs. These findings seem to corroborate the hypothesis of a functional role of M1 in action verbs comprehension.

  6. Aquatic studies at the 100-HR-3 and 100-NR-1 operable units

    SciTech Connect

    Cushing, C.E.

    1993-04-01

    Pacific Northwest Laboratory initiated a program to characterize selected aquatic biological populations to determine (1) existing levels of inorganic chemical and radionuclide contamination, and (2) the populations` suitability as indicators of chemical releases during cleanup activities at the US Department of Energy`s Hanford Site. Following work plans for the ground-water operable units, lower trophic levels in the aquatic habitat (periphyton and caddisfly larvae) were evaluated for contaminants at the 100-HR-3 Operable Unit and 100-NR-1 Operable Unit. The results were evaluated to determine the need for further sampling. If the results showed no significant contamination compared to upriver levels, sampling would be discontinued. The periphyton community appears to be suitable for determining contamination levels. Baseline concentrations for stable chromium were established and will be useful for comparing samples collected when contaminant release is expected. Concentrations of {sup 60}Co, {sup 90}Sr, and {sup 137}Cs in periphyton were essentially below detectable limits, which will also make this community useful in detecting potential releases of radionuclides during cleanup activities. Levels for both stable chromium and radionuclides were essentially below detection limits for caddisfly larvae. Thus, these organisms may be used to monitor suspected contaminant releases from cleanup activities; if concentrations exceed detection limits, they may be related to these activities. Two candidate threatened and endangered species of molluscs occur in the Hanford Reach of the Columbia River. These are the shortface lanx (Fisherola nuttalli), which is a Washington State candidate species, and the Columbia pebblesnail (Fluminicola columbiana), which is both a state and federal candidate species. Specimens of the shortface lanx were observed in the vicinity of N Springs (100-NR-1 Operable Unit); they likely occur throughout this area.

  7. Aquatic studies at the 100-HR-3 and 100-NR-1 operable units

    SciTech Connect

    Cushing, C.E.

    1993-04-01

    Pacific Northwest Laboratory initiated a program to characterize selected aquatic biological populations to determine (1) existing levels of inorganic chemical and radionuclide contamination, and (2) the populations' suitability as indicators of chemical releases during cleanup activities at the US Department of Energy's Hanford Site. Following work plans for the ground-water operable units, lower trophic levels in the aquatic habitat (periphyton and caddisfly larvae) were evaluated for contaminants at the 100-HR-3 Operable Unit and 100-NR-1 Operable Unit. The results were evaluated to determine the need for further sampling. If the results showed no significant contamination compared to upriver levels, sampling would be discontinued. The periphyton community appears to be suitable for determining contamination levels. Baseline concentrations for stable chromium were established and will be useful for comparing samples collected when contaminant release is expected. Concentrations of [sup 60]Co, [sup 90]Sr, and [sup 137]Cs in periphyton were essentially below detectable limits, which will also make this community useful in detecting potential releases of radionuclides during cleanup activities. Levels for both stable chromium and radionuclides were essentially below detection limits for caddisfly larvae. Thus, these organisms may be used to monitor suspected contaminant releases from cleanup activities; if concentrations exceed detection limits, they may be related to these activities. Two candidate threatened and endangered species of molluscs occur in the Hanford Reach of the Columbia River. These are the shortface lanx (Fisherola nuttalli), which is a Washington State candidate species, and the Columbia pebblesnail (Fluminicola columbiana), which is both a state and federal candidate species. Specimens of the shortface lanx were observed in the vicinity of N Springs (100-NR-1 Operable Unit); they likely occur throughout this area.

  8. A reconsideration of the link between the energetics of water and of ATP hydrolysis energy in the power strokes of molecular motors in protein structures.

    PubMed

    Widdas, Wilfred F

    2008-09-01

    Mechanical energy from oxygen metabolism by mammalian tissues has been studied since 1837. The production of heat by mechanical work was studied by Fick in about 1860. Prior to Fick's work, energetics were revised by Joule's experiments which founded the First Law of Thermodynamics. Fenn in 1923/24 found that frog muscle contractions generated extra heat proportional to the amount of work done in shortening the muscle. This was fully consistent with the Joule, Helmholtz concept used for the First Law of Thermodynamics. The link between the energetics of water and ATP hydrolysis in molecular motors is recommended for reconsideration.

  9. A Reconsideration of the Link between the Energetics of Water and of ATP Hydrolysis Energy in the Power Strokes of Molecular Motors in Protein Structures

    PubMed Central

    Widdas, Wilfred F.

    2008-01-01

    Mechanical energy from oxygen metabolism by mammalian tissues has been studied since 1837. The production of heat by mechanical work was studied by Fick in about 1860. Prior to Fick’s work, energetics were revised by Joule’s experiments which founded the First Law of Thermodynamics. Fenn in 1923/24 found that frog muscle contractions generated extra heat proportional to the amount of work done in shortening the muscle. This was fully consistent with the Joule, Helmholtz concept used for the First Law of Thermodynamics. The link between the energetics of water and ATP hydrolysis in molecular motors is recommended for reconsideration. PMID:19325829

  10. A mollusk VDR/PXR/CAR-like (NR1J) nuclear receptor provides insight into ancient detoxification mechanisms.

    PubMed

    Cruzeiro, Catarina; Lopes-Marques, Mónica; Ruivo, Raquel; Rodrigues-Oliveira, Nádia; Santos, Miguel M; Rocha, Maria João; Rocha, Eduardo; Castro, L Filipe C

    2016-05-01

    The origin and diversification of the metazoan endocrine systems represents a fundamental research issue in biology. Nuclear receptors are critical components of these systems. A particular group named VDR/PXR/CAR (NR1I/J) is central in the mediation of detoxification responses. While orthologues have been thoroughly characterized in vertebrates, a sparse representation is currently available for invertebrates. Here, we provide the first isolation and characterization of a lophotrochozoan protostome VDR/PXR/CAR nuclear receptor (NR1J), in the estuarine bivalve the peppery furrow shell (Scrobicularia plana). Using a reporter gene assay, we evaluated the xenobiotic receptor plasticity comparing the human PXR with the S. plana NR1Jβ. Our results show that the molluscan receptor responds to a natural toxin (okadaic acid) in a similar fashion to that reported for other invertebrates. In contrast, the pesticide esfenvalerate displayed a unique response, since it down regulated transactivation at higher concentrations, while for triclosan no response was observed. Additionally, we uncovered lineage specific gene duplications and gene loss in the gene group encoding NRs in protostomes with likely impacts on the complexity of detoxification mechanisms across different phyla. Our findings pave the way for the development of multi-specific sensor tools to screen xenobiotic compounds acting via the NR1I/J group.

  11. Effective connectivity hierarchically links temporoparietal and frontal areas of the auditory dorsal stream with the motor cortex lip area during speech perception.

    PubMed

    Murakami, Takenobu; Restle, Julia; Ziemann, Ulf

    2012-09-01

    A left-hemispheric cortico-cortical network involving areas of the temporoparietal junction (Tpj) and the posterior inferior frontal gyrus (pIFG) is thought to support sensorimotor integration of speech perception into articulatory motor activation, but how this network links with the lip area of the primary motor cortex (M1) during speech perception is unclear. Using paired-coil focal transcranial magnetic stimulation (TMS) in healthy subjects, we demonstrate that Tpj→M1 and pIFG→M1 effective connectivity increased when listening to speech compared to white noise. A virtual lesion induced by continuous theta-burst TMS (cTBS) of the pIFG abolished the task-dependent increase in pIFG→M1 but not Tpj→M1 effective connectivity during speech perception, whereas cTBS of Tpj abolished the task-dependent increase of both effective connectivities. We conclude that speech perception enhances effective connectivity between areas of the auditory dorsal stream and M1. Tpj is situated at a hierarchically high level, integrating speech perception into motor activation through the pIFG.

  12. ALS-linked TDP-43 mutations produce aberrant RNA splicing and adult-onset motor neuron disease without aggregation or loss of nuclear TDP-43

    PubMed Central

    Arnold, Eveline S.; Ling, Shuo-Chien; Huelga, Stephanie C.; Lagier-Tourenne, Clotilde; Polymenidou, Magdalini; Ditsworth, Dara; Kordasiewicz, Holly B.; McAlonis-Downes, Melissa; Platoshyn, Oleksandr; Parone, Philippe A.; Da Cruz, Sandrine; Clutario, Kevin M.; Swing, Debbie; Tessarollo, Lino; Marsala, Martin; Shaw, Christopher E.; Yeo, Gene W.; Cleveland, Don W.

    2013-01-01

    Transactivating response region DNA binding protein (TDP-43) is the major protein component of ubiquitinated inclusions found in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) with ubiquitinated inclusions. Two ALS-causing mutants (TDP-43Q331K and TDP-43M337V), but not wild-type human TDP-43, are shown here to provoke age-dependent, mutant-dependent, progressive motor axon degeneration and motor neuron death when expressed in mice at levels and in a cell type-selective pattern similar to endogenous TDP-43. Mutant TDP-43-dependent degeneration of lower motor neurons occurs without: (i) loss of TDP-43 from the corresponding nuclei, (ii) accumulation of TDP-43 aggregates, and (iii) accumulation of insoluble TDP-43. Computational analysis using splicing-sensitive microarrays demonstrates alterations of endogenous TDP-43–dependent alternative splicing events conferred by both human wild-type and mutant TDP-43Q331K, but with high levels of mutant TDP-43 preferentially enhancing exon exclusion of some target pre-mRNAs affecting genes involved in neurological transmission and function. Comparison with splicing alterations following TDP-43 depletion demonstrates that TDP-43Q331K enhances normal TDP-43 splicing function for some RNA targets but loss-of-function for others. Thus, adult-onset motor neuron disease does not require aggregation or loss of nuclear TDP-43, with ALS-linked mutants producing loss and gain of splicing function of selected RNA targets at an early disease stage. PMID:23382207

  13. Activation of Steroid and Xenobiotic Receptor (SXR, NR1I2) and Its Orthologs in Laboratory, Toxicologic, and Genome Model Species

    PubMed Central

    Milnes, Matthew R.; Garcia, Adriana; Grossman, Emily; Grün, Felix; Shiotsugu, Jason; Tabb, Michelle M.; Kawashima, Yukio; Katsu, Yoshinao; Watanabe, Hajime; Iguchi, Taisen; Blumberg, Bruce

    2008-01-01

    Background Nuclear receptor subfamily 1, group I, member 2 (NR1I2), commonly known as steroid and xenobiotic receptor (SXR) in humans, is a key ligand-dependent transcription factor responsible for the regulation of xenobiotic, steroid, and bile acid metabolism. The ligand-binding domain is principally responsible for species-specific activation of NR1I2 in response to xenobiotic exposure. Objectives Our objective in this study was to create a common framework for screening NR1I2 orthologs from a variety of model species against environmentally relevant xenobiotics and to evaluate the results in light of using these species as predictors of xenobiotic disposition and for assessment of environmental health risk. Methods Sixteen chimeric fusion plasmid vectors expressing the Gal4 DNA-binding domain and species-specific NR1I2 ligand-binding domain were screened for activation against a spectrum of 27 xenobiotic compounds using a standardized cotransfection receptor activation assay. Results NR1I2 orthologs were activated by various ligands in a dose-dependent manner. Closely related species show broadly similar patterns of activation; however, considerable variation to individual compounds exists, even among species varying in only a few amino acid residues. Conclusions Interspecies variation in NR1I2 activation by various ligands can be screened through the use of in vitro NR1I2 activation assays and should be taken into account when choosing appropriate animal models for assessing environmental health risk. PMID:18629309

  14. Nuclear receptor Rev-erb alpha (Nr1d1) functions in concert with Nr2e3 to regulate transcriptional networks in the retina.

    PubMed

    Mollema, Nissa J; Yuan, Yang; Jelcick, Austin S; Sachs, Andrew J; von Alpen, Désirée; Schorderet, Daniel; Escher, Pascal; Haider, Neena B

    2011-03-08

    The majority of diseases in the retina are caused by genetic mutations affecting the development and function of photoreceptor cells. The transcriptional networks directing these processes are regulated by genes such as nuclear hormone receptors. The nuclear hormone receptor gene Rev-erb alpha/Nr1d1 has been widely studied for its role in the circadian cycle and cell metabolism, however its role in the retina is unknown. In order to understand the role of Rev-erb alpha/Nr1d1 in the retina, we evaluated the effects of loss of Nr1d1 to the developing retina and its co-regulation with the photoreceptor-specific nuclear receptor gene Nr2e3 in the developing and mature retina. Knock-down of Nr1d1 expression in the developing retina results in pan-retinal spotting and reduced retinal function by electroretinogram. Our studies show that NR1D1 protein is co-expressed with NR2E3 in the outer neuroblastic layer of the developing mouse retina. In the adult retina, NR1D1 is expressed in the ganglion cell layer and is co-expressed with NR2E3 in the outer nuclear layer, within rods and cones. Several genes co-targeted by NR2E3 and NR1D1 were identified that include: Nr2c1, Recoverin, Rgr, Rarres2, Pde8a, and Nupr1. We examined the cyclic expression of Nr1d1 and Nr2e3 over a twenty-four hour period and observed that both nuclear receptors cycle in a similar manner. Taken together, these studies reveal a novel role for Nr1d1, in conjunction with its cofactor Nr2e3, in regulating transcriptional networks critical for photoreceptor development and function.

  15. Novel dynein DYNC1H1 neck and motor domain mutations link distal SMA and abnormal cortical development

    PubMed Central

    Fiorillo, Chiara; Moro, Francesca; Yi, Julie; Weil, Sarah; Brisca, Giacomo; Astrea, Guja; Severino, Mariasavina; Romano, Alessandro; Battini, Roberta; Rossi, Andrea; Minetti, Carlo; Bruno, Claudio; Santorelli, Filippo M.; Vallee, Richard

    2014-01-01

    DYNC1H1 encodes the heavy chain of cytoplasmic dynein 1, a motor protein complex implicated in retrograde axonal transport, neuronal migration, and other intracellular motility functions. Mutations in DYNC1H1 have been described in autosomal dominant Charcot-Marie-Tooth type 2 and in families with distal spinal muscular atrophy (SMA) predominantly affecting the legs (SMA-LED). Recently, defects of cytoplasmic dynein 1 were also associated with a form of mental retardation and neuronal migration disorders. Here we describe two unrelated patients presenting a combined phenotype of congenital motor neuron disease associated with focal areas of cortical malformation. In each patient we identified a novel de novo mutation in DYNC1H1: c.3581A>G (p.Gln1194Arg) in one case and c.9142G>A (p.Glu3048Lys) in the other. The mutations lie in different domains of the dynein heavy chain, and are deleterious to protein function as indicated by assays for Golgi recovery after nocodazole washout in patient fibroblasts. Our results expand the set of pathological mutations in DYNC1H1, reinforce the role of cytoplasmic dynein in disorders of neuronal migration and provide evidence for a syndrome including spinal nerve degeneration and brain developmental problems. PMID:24307404

  16. Neuroprotective effects of the Sigma-1 receptor (S1R) agonist PRE-084, in a mouse model of motor neuron disease not linked to SOD1 mutation.

    PubMed

    Peviani, Marco; Salvaneschi, Eleonora; Bontempi, Leonardo; Petese, Alessandro; Manzo, Antonio; Rossi, Daniela; Salmona, Mario; Collina, Simona; Bigini, Paolo; Curti, Daniela

    2014-02-01

    The identification of novel molecular targets crucially involved in motor neuron degeneration/survival is a necessary step for the development of hopefully more effective therapeutic strategies for amyotrophic lateral sclerosis (ALS) patients. In this view, S1R, an endoplasmic reticulum (ER)-resident receptor with chaperone-like activity, has recently attracted great interest. S1R is involved in several processes leading to acute and chronic neurodegeneration, including ALS pathology. Treatment with the S1R agonist PRE-084 improves locomotor function and motor neuron survival in presymptomatic and early symptomatic mutant SOD1-G93A ALS mice. Here, we tested the efficacy of PRE-084 in a model of spontaneous motor neuron degeneration, the wobbler mouse (wr) as a proof of concept that S1R may be regarded as a key therapeutic target also for ALS cases not linked to SOD1 mutation. Increased staining for S1R was detectable in morphologically spared cervical spinal cord motor neurons of wr mice both at early (6th week) and late (12th week) phases of clinical progression. S1R signal was also detectable in hypertrophic astrocytes and reactive microglia of wr mice. Chronic treatment with PRE-084 (three times a week, for 8weeks), starting at symptom onset, significantly increased the levels of BDNF in the gray matter, improved motor neuron survival and ameliorated paw abnormality and grip strength performance. In addition, the treatment significantly reduced the number of reactive astrocytes whereas, that of CD11b+ microglial cells was increased. A deeper evaluation of microglial markers revealed significant increased number of cells positive for the pan-macrophage marker CD68 and of CD206+ cells, involved in tissue restoration, in the white matter of PRE-084-treated mice. The mRNA levels of TNF-α and IL-1β were not affected by PRE-084 treatment. Thus, our results support pharmacological manipulation of S1R as a promising strategy to cure ALS and point to increased

  17. Motor dysfunction in the tottering mouse is linked to cerebellar spontaneous low frequency oscillations revealed by flavoprotein autofluorescence optical imaging

    NASA Astrophysics Data System (ADS)

    Chen, Gang; Popa, Laurentiu S.; Wang, Xinming; Gao, Wangcai; Barnes, Justin; Hendrix, Claudia M.; Hess, Ellen J.; Ebner, Timothy J.

    2009-02-01

    Flavoprotein autofluorescence optical imaging is developing into a powerful research tool to study neural activity, particularly in vivo. In this study we used this imaging technique to investigate the neuronal mechanism underlying the episodic movement disorder that is characteristic of the tottering (tg) mouse, a model of episodic ataxia type 2. Both EA2 and the tg mouse are caused by mutations in the gene encoding Cav2.1 (P/Q-type) voltage-gated Ca2+ channels. These mutations result in a reduction in P/Q Ca2+ channel function. Both EA2 patients and tg mice have a characteristic phenotype consisting of transient motor attacks triggered by stress, caffeine or ethanol. The neural events underlying these episodes of dystonia are unknown. Flavoprotein autofluorescence optical imaging revealed spontaneous, transient, low frequency oscillations in the cerebellar cortex of the tg mouse. Lasting from 30 - 120 minutes, the oscillations originate in one area then spread to surrounding regions over 30 - 60 minutes. The oscillations are reduced by removing extracellular Ca2+ and blocking Cav 1.2/1.3 (L-type) Ca2+ channels. The oscillations are not affected by blocking AMPA receptors or by electrical stimulation of the parallel fiber - Purkinje cell circuit, suggesting the oscillations are generated intrinsically in the cerebellar cortex. Conversely, L-type Ca2+ agonists generate oscillations with similar properties. In the awake tg mouse, transcranial flavoprotein imaging revealed low frequency oscillations that are accentuated during caffeine induced attacks of dystonia. The oscillations increase during the attacks of dystonia and are coupled to oscillations in face and hindlimb EMG activity. These transient oscillations and the associated cerebellar dysfunction provide a novel mechanism by which an ion channel disorder results in episodic motor dysfunction.

  18. Receptor to glutamate NMDA-type: the functional diversity of the nr1 isoforms and pharmacological properties.

    PubMed

    Flores-Soto, Mario Eduardo; Chaparro-Huerta, Verónica; Escoto-Delgadillo, Martha; Ureña-Guerrero, Mónica Elisa; Camins, Antoni; Beas-Zarate, Carlos

    2013-01-01

    Glutamic acid (Glu) is the major excitatory neurotransmitter in the central nervous system, and interacts with two classes of receptor: metabotropic and ionotropic receptors. Ionotropic receptors are divided according to the affinity of their specific agonists: Nmethyl- D-aspartate (NMDA), amino acid-3-hydroxy-5-methyl-4-isoxazole acid (AMPA) and kainic acid (KA). NMDA receptors (NMDA-R) are macromolecular structures that are formed by different combinations of subunits: NMDAR1 (NR1), NMDAR2 (NR2) and NMDAR3 (NR3). The study of this receptor has aroused great interest, partly due to its role in synaptic plasticity but mainly because of its permeability to the Ca(2+) ion. This review examines the molecular composition of NMDA-R and the variants of NR1 subunit editing in association with NR2 subunit dimers, which form the main components of this receptor. Their composition, structure, function and distinct temporal and spatial expression patterns demonstrate the versatility and diversity of functionally different isoforms of NR1 subunits and the various pharmacological properties of the NR2 subunit. Finally, the involvement of NMDA-R in the excitotoxicity phenomenon, as well as, its expression changes under these conditions as neuronal response are also discussed.

  19. Cloning and characterization of the N-methyl-D-aspartate receptor subunit NR1 gene from chum salmon, Oncorhynchus keta (Walbaum, 1792).

    PubMed

    Yu, Jeong-Nam; Ham, Seung Hyub; Lee, Seung Il; Jin, Hyung-Joo; Ueda, Hiroshi; Jin, Deuk-Hee

    2014-01-01

    Here, we report the information about molecular and expression characterization of NR1 gene in chum salmon for the first time. The complete NR1 subunit showed a large open-reading frame of 2844 bp in the total length of 3193 bp, and this cDNA contained a coding region encoding 948 amino acids and a stop codon. The organization of the NR1 subunit of chum salmon were similar of most other fishes, except C' terminal. The expression of NR1 subunit was to show higher in the natal river near to the hatchery than near to the coast. We expect that the information reported herein may facilitate further investigations on the relationship between memory factors of natal rivers and homing mechanisms in Salmonidae.

  20. Study of the generator/motor operation of induction machines in a high frequency link space power system

    NASA Technical Reports Server (NTRS)

    Lipo, Thomas A.; Sood, Pradeep K.

    1987-01-01

    Static power conversion systems have traditionally utilized dc current or voltage source links for converting power from one ac or dc form to another since it readily achieves the temporary energy storage required to decouple the input from the output. Such links, however, result in bulky dc capacitors and/or inductors and lead to relatively high losses in the converters due to stresses on the semiconductor switches. The feasibility of utilizing a high frequency sinusoidal voltage link to accomplish the energy storage and decoupling function is examined. In particular, a type of resonant six pulse bridge interface converter is proposed which utilizes zero voltage switching principles to minimize switching losses and uses an easy to implement technique for pulse density modulation to control the amplitude, frequency, and the waveshape of the synthesized low frequency voltage or current. Adaptation of the proposed topology for power conversion to single-phase ac and dc voltage or current outputs is shown to be straight forward. The feasibility of the proposed power circuit and control technique for both active and passive loads are verified by means of simulation and experiment.

  1. Elasticity of a semiflexible filament with a discontinuous tension due to a cross-link or a molecular motor

    NASA Astrophysics Data System (ADS)

    Razbin, Mohammadhosein; Benetatos, Panayotis; Zippelius, Annette

    2016-05-01

    We analyze the stretching elasticity of a wormlike chain with a tension discontinuity resulting from a Hookean spring connecting its backbone to a fixed point. The elasticity of isolated semiflexible filaments has been the subject in a significant body of literature, primarily because of its relevance to the mechanics of biological matter. In real systems, however, these filaments are usually part of supramolecular structures involving cross-linkers or molecular motors, which cause tension discontinuities. Our model is intended as a minimal structural element incorporating such a discontinuity. We obtain analytical results in the weakly bending limit of the filament, concerning its force-extension relation and the response of the two parts in which the filament is divided by the spring. For a small tension discontinuity, the linear response of the filament extension to this discontinuity strongly depends on the external tension. For large external tension f , the spring force contributes a subdominant correction ˜1 /f3 /2 to the well-known ˜1 /√{f } -dependence of the end-to-end extension.

  2. Protons trap NR1/NR2B NMDA receptors in a nonconducting state.

    PubMed

    Banke, Tue G; Dravid, Shashank M; Traynelis, Stephen F

    2005-01-05

    NMDA receptors are highly expressed in the CNS and are involved in excitatory synaptic transmission, as well as synaptic plasticity. Given that overstimulation of NMDA receptors can cause cell death, it is not surprising that these channels are under tight control by a series of inhibitory extracellular ions, including zinc, magnesium, and H+. We studied the inhibition by extracellular protons of recombinant NMDA receptor NR1/NR2B single-channel and macroscopic responses in transiently transfected human embryonic kidney HEK 293 cells using patch-clamp techniques. We report that proton inhibition proceeds identically in the absence or presence of agonist, which rules out the possibility that protonation inhibits receptors by altering coagonist binding. The response of macroscopic currents in excised patches to rapid jumps in pH was used to estimate the microscopic association and dissociation rates for protons, which were 1.4 x 10(9) m(-1) sec(-1) and 110-196 sec(-1), respectively (K(d) corresponds to pH 7.2). Protons reduce the open probability without altering the time course of desensitization or deactivation. Protons appear to slow at least one time constant describing the intra-activation shut-time histogram and modestly reduce channel open time, which we interpret to reflect a reduction in the overall channel activation rate and possible proton-induced termination of openings. This is consistent with a modest proton-dependent slowing of the macroscopic response rise time. From these data, we propose a physical model of proton inhibition that can describe macroscopic and single-channel properties of NMDA receptor function over a range of pH values.

  3. The hsp90-FKBP52 Complex Links the Mineralocorticoid Receptor to Motor Proteins and Persists Bound to the Receptor in Early Nuclear Events▿

    PubMed Central

    Galigniana, Mario D.; Erlejman, Alejandra G.; Monte, Martín; Gomez-Sanchez, Celso; Piwien-Pilipuk, Graciela

    2010-01-01

    In this study, we demonstrate that the subcellular localization of the mineralocorticoid receptor (MR) is regulated by tetratricopeptide domain (TPR) proteins. The high-molecular-weight immunophilin (IMM) FKBP52 links the MR-hsp90 complex to dynein/dynactin motors favoring the cytoplasmic transport of MR to the nucleus. Replacement of this hsp90-binding IMM by FKBP51 or the TPR peptide favored the cytoplasmic localization of MR. The complete movement machinery, including dynein and tubulin, could be recovered from paclitaxel/GTP-stabilized cytosol and was fully reassembled on stripped MR immune pellets. The whole MR-hsp90-based heterocomplex was transiently recovered in the soluble fraction of the nucleus after 10 min of incubation with aldosterone. Moreover, cross-linked MR-hsp90 heterocomplexes accumulated in the nucleus in a hormone-dependent manner, demonstrating that the heterocomplex can pass undissociated through the nuclear pore. On the other hand, a peptide that comprises the DNA-binding domain of MR impaired the nuclear export of MR, suggesting the involvement of this domain in the process. This study represents the first report describing the entire molecular system that commands MR nucleocytoplasmic trafficking and proposes that the MR-hsp90-TPR protein heterocomplex is dissociated in the nucleus rather than in the cytoplasm. PMID:20038533

  4. Changes in oxygenated hemoglobin link freezing of gait to frontal activation in patients with Parkinson disease: an fNIRS study of transient motor-cognitive failures.

    PubMed

    Maidan, Inbal; Bernad-Elazari, Hagar; Gazit, Eran; Giladi, Nir; Hausdorff, Jeffery M; Mirelman, Anat

    2015-01-01

    Recent studies have suggested that deficits in executive function contribute to freezing of gait (FOG), an episodic disturbance common among patients with Parkinson's disease (PD). To date, most findings provide only indirect evidence of this relationship. Here, we evaluated a more direct link between FOG and frontal lobe dysfunction. Functional, near infrared spectroscopy measured frontal activation, i.e., oxygenated hemoglobin (HbO2) levels in Brodmann area 10 before and during FOG. Eleven patients with PD and eleven healthy older adults were studied. Changes in frontal lobe activation before and during FOG that occurred during turns were determined. Altogether, 49 FOG episodes were observed-28 occurred during turns that were anticipated (i.e., the patient knew in advance that the turn was coming), 21 during unanticipated turns that were performed "abruptly", according to the examiner's request. During anticipated turns, HbO2 increased by 0.22 ± 0.08 µM (p = 0.004) before FOG and by an additional 0.19 ± 0.13 µM (p = 0.072) during FOG. In contrast, during unanticipated turns, HbO2 did not increase before or during FOG. HbO2 decreased by 0.32 ± 0.08 µM (p = 0.004) during turns without FOG; in healthy controls HbO2 did not change during turns. These findings support the existence of an association between FOG episodes and changes in frontal lobe HbO2. Increased activation in Brodmann area 10 before FOG, specifically during anticipated turns, highlights the connections between motor planning, information processing, and FOG. These results support the idea that alterations in executive control play a role in this debilitating motor disturbance.

  5. NR1H4 analysis in patients with progressive familial intrahepatic cholestasis, drug-induced cholestasis or intrahepatic cholestasis of pregnancy unrelated to ATP8B1, ABCB11 and ABCB4 mutations.

    PubMed

    Davit-Spraul, Anne; Gonzales, Emmanuel; Jacquemin, Emmanuel

    2012-12-01

    Farnesoid X receptor (FXR, NR1H4) controls bile acid homeostasis. NR1H4 variants may predispose to intrahepatic cholestasis of pregnancy (ICP). We report on NR1H4 analysis in eight patients with progressive familial intrahepatic cholestasis (PFIC) and in eight women with either ICP and/or drug-induced cholestasis (DIC) in whom no disease causing mutation in ATP8B1, ABCB11 and/or ABCB4 were found. No NR1H4 mutation was found in PFIC patients. In one woman with ICP/DIC, a NR1H4 heterozygous variant (c.-1G>T) was found. This suggests that a NR1H4 mutation is not or rarely involved in hepatocellular cholestasis of unknown cause.

  6. Transition of deletion mutants of the composite resistance plasmid NR1 in Escherichia coli and Salmonella typhimurium.

    PubMed Central

    Huffman, G A; Rownd, R H

    1984-01-01

    Derivatives of the composite R plasmid NR1 from which a portion of the resistance determinants (r-determinants) component had been deleted were found to undergo amplification of the remaining r-determinants region in Escherichia coli and Salmonella typhimurium. The wild-type NR1 plasmid does not amplify in these genera, although all of these plasmids undergo amplification in Proteus mirabilis. The deletion mutants retained the mercuric ion resistance operon (mer) but conferred a much lower level of sulfonamide resistance than NR1. The remaining r-determinants region, which is bounded by direct repeats of the insertion element IS1, formed multiple tandem duplications in E. coli, S. typhimurium, and P. mirabilis after subculturing the host cells in medium containing high concentrations of sulfonamide. Gene amplification was characterized by restriction endonuclease analysis, analytical buoyant density centrifugation, DNA-DNA hybridization, and sedimentation in sucrose gradients. The tandem repeats remained attached to the resistance transfer factor component of the plasmid in at least part of the plasmid population; autonomous tandem repeats of r-determinants were probably also present. Amplification did not occur in host recA mutants. Amplified strains subcultured in drug-free medium lost the amplified r-determinants. By using a strain temperature sensitive for the recA gene, it was possible to obtain gene amplification at the permissive temperature. Loss of r-determinants took place at the permissive temperature, but not at the nonpermissive temperature. The termini of the deletions of several independent mutants which conferred low sulfonamide resistance were found to be located within the adjacent streptomycin-spectinomycin resistance gene. Images PMID:6086573

  7. NR1H3 Expression is a Prognostic Factor of Overall Survival for Patients with Muscle-Invasive Bladder Cancer

    PubMed Central

    Wu, Junlong; Wan, Fangning; Sheng, Haoyue; Shi, Guohai; Shen, Yijun; Lin, Guowen; Dai, Bo; Zhu, Yiping; Ye, Dingwei

    2017-01-01

    Background: Nuclear receptors (NRs) are a class of transcription factors that regulate many cellular functions through manipulation of gene expression and also play important roles in tumorigenesis, proliferation, progression and prognosis in various kinds of cancers according to recent studies. This work aimed to determine the predictive ability of NRs in muscle-invasive bladder cancer (MIBC). Patients and methods: A total of 308 MIBC patients with complete clinicopathological and RNASeq data from The Cancer Genome Atlas (TCGA) cohort were collected for filtration. Genes showed clear correlations with overall survival (OS) and recurrence free survival (RFS) were further validated in 123 MIBC patients recruited consecutively from 2008 to 2012 in Fudan University Shanghai Cancer Center (FUSCC) cohort. Cox proportional hazards regression model and Kaplan-Meier plot were used to assess the relative factors. Results: In TCGA cohort, we found that high NR1H3 (HR=0.779, 95% CI: 0.634 - 0.957), NR2C1 (HR=0.673, 95% CI: 0.458 - 0.989) and NR2F6 (HR=0.750, 95% CI: 0.574 - 0.980) expressions were independent factors of favorable OS, while only low NR1H3 (log-rank test, P=0.0076) and NR2F6 (log-rank test, P=0.0395) expressions had the ability to predict poor prognosis for RFS. Further, in FUSCC validating cohort, we confirmed that low NR1H3 expression level was independent factor of poor OS (HR=1.295, 95% CI: 1.064 - 1.576) and it had the ability to predict poor RFS (log-rank test, P=0.0059). Conclusions: Low NR1H3 expression level is an independent prognostic factor of poor OS, and can also predict worse RFS in MIBC patients. Our “TCGA filtrating and local database validating” model can help reveal more prognostic biomarkers and cast a new light in understanding certain gene function in MIBC. PMID:28382148

  8. Differential contribution of the NR1- and NR2A-subunits to the selectivity filter of recombinant NMDA receptor channels.

    PubMed Central

    Wollmuth, L P; Kuner, T; Seeburg, P H; Sakmann, B

    1996-01-01

    1. The molecular determinants for the narrow constriction of recombinant N-methyl-D-aspartate (NMDA) receptor channels composed of wild-type and mutant NR1- and NR2A-subunits were studied in Xenopus oocytes. 2. The relative permeability of differently sized organic cations was used as an indicator of the size of the narrow constriction. From measured reversal potentials under bi-ionic conditions with K+ as the reference solution, permeability ratios were calculated with the Lewis equation. 3. For wild-type NMDA receptor channels, five organic cations showed clear reversal potentials, with permeability ratios (PX/PK): ammonium, 1.28; methylammonium, 0.48; dimethylammonium (DMA), 0.20; diethylammonium, 0.07; and dimethylethanol-ammonium, 0.02. 4. Mutation of the N-site asparagine (N) to glutamine (Q) at homologous positions in either NR1 (position 598) or NR2A (position 595) increased the permeability of DMA relative to wild-type channels about equally. However, for larger sized organic cations, the NR1(N598Q) mutation had stronger effects on increasing their permeability whereas the NR2A(N595Q) mutation was without effect. These changes in organic cation permeability suggest that the NR1(N598Q) mutation increases the pore size while the NR2A(N595Q) mutation does not. 5. Channels in which the NR1 N-site asparagine was replaced by the smaller glycine (G), NR1(N598G)-NR2A, showed the largest increase in pore size of all sites examined in either subunit. In contrast, in the NR2A-subunit the same N-site substitution to glycine produced only small effects on pore size. 6. For the NR2A-subunit, an asparagine residue (position 596) on the C-terminal side of the N-site, when mutated to larger or smaller sized amino acids, produced large, volume-specific effects on pore size. The mutant channel NR1-NR2A(N596G) had the largest increase in pore size of all sites examined in the NR2A-subunit. In contrast, mutation of the homologous position in the NR1-subunit had no effect on

  9. Introduction to ultrasonic motors

    SciTech Connect

    Sashida, Toshiiku; Kenjo, Takashi.

    1993-01-01

    The ultrasonic motor, invented in 1980, utilizes the piezoelectric effect in the ultrasonic frequency range to provide the motive force. (In conventional electric motors the motive force is electromagnetic.) The result is a motor with unusually good low-speed high-torque and power-to-weight characteristics. It has already found applications in camera autofocus mechanisms, medical equipment subject to high magnetic fields, and motorized car accessories. Its applications will increase as designers become more familiar with its unique characteristics. This book is the result of a collaboration between the inventor and an expert in conventional electric motors: the result is an introduction to the general theory presented in a way that links it to conventional motor theory. It will be invaluable both to motor designers and to those who design with and use electric motors as an introduction to this important new invention.

  10. Role of a novel dual flavin reductase (NR1) and an associated histidine triad protein (DCS-1) in menadione-induced cytotoxicity

    SciTech Connect

    Kwasnicka-Crawford, Dorota A.; Vincent, Steven R. . E-mail: svincent@interchg.ubc.ca

    2005-10-21

    Microsomal cytochrome P450 reductase catalyzes the one-electron transfer from NADPH via FAD and FMN to various electron acceptors, such as cytochrome P450s or to some anti-cancer quinone drugs. This results in generation of free radicals and toxic oxygen metabolites, which can contribute to the cytotoxicity of these compounds. Recently, a cytosolic NADPH-dependent flavin reductase, NR1, has been described which is highly homologous to the microsomal cytochrome P450 reductase. In this study, we show that over-expression of NR1 in human embryonic kidney cells enhances the cytotoxic action of the model quinone, menadione. Furthermore, we show that a novel human histidine triad protein DCS-1, which is expressed together with NR1 in many tissues, can significantly reduce menadione-induced cytotoxicity in these cells. We also show that DCS-1 binds NF1 and directly modulates its activity. These results suggest that NR1 may play a role in carcinogenicity and cell death associated with one-electron reductions.

  11. Evolution and Function of the NR1I Nuclear Hormone Receptor Subfamily (VDR, PXR, and CAR) with Respect to Metabolism of Xenobiotics and Endogenous Compounds

    PubMed Central

    Reschly, E.J.; Krasowski, M.D.

    2008-01-01

    The NR1I subfamily of nuclear hormone receptors includes the 1,25-(OH)2-vitamin D3 receptor (VDR; NR1I1), pregnane X receptor (PXR; NR1I2), and constitutive androstane receptor (CAR; NR1I3). PXR and VDR are found in diverse vertebrates from fish to mammals while CAR is restricted to mammals. Current evidence suggests that the CAR gene arose from a duplication of an ancestral PXR gene, and that PXR and VDR arose from duplication of an ancestral gene, represented now by a single gene in the invertebrate Ciona intestinalis. Aside from the high-affinity effects of 1,25-(OH)2-vitamin D3 on VDRs, the NR1I subfamily members are functionally united by the ability to bind potentially toxic endogenous compounds with low affinity and initiate changes in gene expression that lead to enhanced metabolism and elimination (e.g., induction of cytochrome P450 3A4 expression in humans). The detoxification role of VDR seems limited to sensing high concentrations of certain toxic bile salts, such as lithocholic acid, whereas PXR and CAR have the ability to recognize structurally diverse compounds. PXR and CAR show the highest degree of cross-species variation in the ligand-binding domain of the entire vertebrate nuclear hormone receptor superfamily, suggesting adaptation to species-specific ligands. This review examines the insights that phylogenetic and experimental studies provide into the function of VDR, PXR, and CAR, and how the functions of these receptors have expanded to evolutionary advantage in humans and other animals. PMID:16724925

  12. Environmental contaminants activate human and polar bear (Ursus maritimus) pregnane X receptors (PXR, NR1I2) differently

    PubMed Central

    Roger, Lille-Langøy; V, Goldstone Jared; Marte, Rusten; R, Milnes Matthew; Rune, Male; J, Stegeman John; Bruce, Blumberg; Anders, Goksøyr

    2015-01-01

    BACKGROUND Many persistent organic pollutants (POPs) accumulate readily in polar bears because of their position as apex predators in Arctic food webs. The pregnane X receptor (PXR, formally NR1I2, here proposed to be named promiscuous xenobiotic receptor) is a xenobiotic sensor that is directly involved in metabolizing pathways of a wide range of environmental contaminants. OBJECTIVES In the present study, we comparably assess the ability of 51 selected pharmaceuticals, pesticides and emerging contaminants to activate PXRs from polar bears and humans using an in vitro luciferase reporter gene assay. RESULTS We found that polar bear PXR is activated by a wide range of our test compounds (68%) but has a slightly more narrow ligand specificity than human PXR that was activated by 86% of the 51 test compounds. The majority of the agonists identified (70%) produces a stronger induction of the reporter gene via human PXR than via polar bear PXR, however with some notable and environmentally relevant exceptions. CONCLUSIONS Due to the observed differences in activation of polar bear and human PXRs, exposure of each species to environmental agents is likely to induce biotransformation differently in the two species. Bioinformatics analyses and structural modelling studies suggests that amino acids that are not part of the ligand-binding domain and do not interact with the ligand can modulate receptor activation. PMID:25680588

  13. Severity of infantile nystagmus syndrome-like ocular motor phenotype is linked to the extent of the underlying optic nerve projection defect in zebrafish belladonna mutant.

    PubMed

    Huber-Reggi, Sabina P; Chen, Chien-Cheng; Grimm, Lea; Straumann, Dominik; Neuhauss, Stephan C F; Huang, Melody Ying-Yu

    2012-12-12

    Infantile nystagmus syndrome (INS), formerly known as congenital nystagmus, is an ocular motor disorder in humans characterized by spontaneous eye oscillations (SOs) and, in several cases, reversed optokinetic response (OKR). Its etiology and pathomechanism is largely unknown, but misrouting of the optic nerve has been observed in some patients. Likewise, optic nerve misrouting, a reversed OKR and SOs with INS-like waveforms are observed in zebrafish belladonna (bel) mutants. We aimed to investigate whether and how misrouting of the optic nerve correlates with the ocular motor behaviors in bel larvae. OKR and SOs were quantified and subsequently the optic nerve fibers were stained with fluorescent lipophilic dyes. Eye velocity during OKR was reduced in larvae with few misprojecting optic nerve fibers and reversed in larvae with a substantial fraction of misprojecting fibers. All larvae with reversed OKR also displayed SOs. A stronger reversed OKR correlated with more frequent SOs. Since we did not find a correlation between additional retinal defects and ocular motor behavior, we suggest that axon misrouting is in fact origin of INS in the zebrafish animal model. Depending on the ratio between misprojecting ipsilateral and correctly projecting contralateral fibers, the negative feedback loop normally regulating OKR can turn into a positive loop, resulting in an increase in retinal slip. Our data not only give new insights into the etiology of INS but may also be of interest for studies on how the brain deals with and adapts to conflicting inputs.

  14. Evolutionary selection across the nuclear hormone receptor superfamily with a focus on the NR1I subfamily (vitamin D, pregnane X, and constitutive androstane receptors)

    PubMed Central

    Krasowski, Matthew D; Yasuda, Kazuto; Hagey, Lee R; Schuetz, Erin G

    2005-01-01

    Background The nuclear hormone receptor (NR) superfamily complement in humans is composed of 48 genes with diverse roles in metabolic homeostasis, development, and detoxification. In general, NRs are strongly conserved between vertebrate species, and few examples of molecular adaptation (positive selection) within this superfamily have been demonstrated. Previous studies utilizing two-species comparisons reveal strong purifying (negative) selection of most NR genes, with two possible exceptions being the ligand-binding domains (LBDs) of the pregnane X receptor (PXR, NR1I2) and the constitutive androstane receptor (CAR, NR1I3), two proteins involved in the regulation of toxic compound metabolism and elimination. The aim of this study was to apply detailed phylogenetic analysis using maximum likelihood methods to the entire complement of genes in the vertebrate NR superfamily. Analyses were carried out both across all vertebrates and limited to mammals and also separately for the two major domains of NRs, the DNA-binding domain (DBD) and LBD, in addition to the full-length sequences. Additional functional data is also reported for activation of PXR and the vitamin D receptor (VDR; NR1I1) to gain further insight into the evolution of the NR1I subfamily. Results The NR genes appear to be subject to strong purifying selection, particularly in the DBDs. Estimates of the ratio of the non-synonymous to synonymous nucleotide substitution rates (the ω ratio) revealed that only the PXR LBD had a sub-population of codons with an estimated ω ratio greater than 1. CAR was also unusual in showing high relative ω ratios in both the DBD and LBD, a finding that may relate to the recent appearance of the CAR gene (presumably by duplication of a pre-mammalian PXR gene) just prior to the evolution of mammals. Functional analyses of the NR1I subfamily show that human and zebrafish PXRs show similar activation by steroid hormones and early bile salts, properties not shared by sea

  15. Environmental contaminants activate human and polar bear (Ursus maritimus) pregnane X receptors (PXR, NR1I2) differently

    SciTech Connect

    Lille-Langøy, Roger; Goldstone, Jared V.; Rusten, Marte; Milnes, Matthew R.; Male, Rune; Stegeman, John J.; Blumberg, Bruce; Goksøyr, Anders

    2015-04-01

    Background: Many persistent organic pollutants (POPs) accumulate readily in polar bears because of their position as apex predators in Arctic food webs. The pregnane X receptor (PXR, formally NR1I2, here proposed to be named promiscuous xenobiotic receptor) is a xenobiotic sensor that is directly involved in metabolizing pathways of a wide range of environmental contaminants. Objectives: In the present study, we comparably assess the ability of 51 selected pharmaceuticals, pesticides and emerging contaminants to activate PXRs from polar bears and humans using an in vitro luciferase reporter gene assay. Results: We found that polar bear PXR is activated by a wide range of our test compounds (68%) but has a slightly more narrow ligand specificity than human PXR that was activated by 86% of the 51 test compounds. The majority of the agonists identified (70%) produces a stronger induction of the reporter gene via human PXR than via polar bear PXR, however with some notable and environmentally relevant exceptions. Conclusions: Due to the observed differences in activation of polar bear and human PXRs, exposure of each species to environmental agents is likely to induce biotransformation differently in the two species. Bioinformatics analyses and structural modeling studies suggest that amino acids that are not part of the ligand-binding domain and do not interact with the ligand can modulate receptor activation. - Highlights: • Comparative study of ligand activation of human and polar bear PXRs. • Polar bear PXR is a promiscuous ligand-activated nuclear receptor but less so than human PXR. • Environmental contaminants activate human and polar bear PXRs differently. • Expression and ligand promiscuity indicate that PXR is a xenosensor in polar bears.

  16. The orphan nuclear receptor DAX-1 functions as a potent corepressor of the constitutive androstane receptor (NR1I3).

    PubMed

    Laurenzana, Elizabeth M; Chen, Tao; Kannuswamy, Malavika; Sell, Brian E; Strom, Stephen C; Li, Yong; Omiecinski, Curtis J

    2012-11-01

    Regulation of gene transcription is controlled in part by nuclear receptors that function coordinately with coregulator proteins. The human constitutive androstane receptor (CAR; NR1I3) is expressed primarily in liver and regulates the expression of genes involved in xenobiotic metabolism as well as hormone, energy, and lipid homeostasis. In this report, DAX-1, a nuclear receptor family member with corepressor properties, was identified as a potent CAR regulator. Results of transaction and mutational studies demonstrated that both DAX-1's downstream LXXLL and its PCFQVLP motifs were critical contributors to DAX-1's corepression activities, although two other LXXM/LL motifs located nearer the N terminus had no impact on the CAR functional interaction. Deletion of DAX-1's C-terminal transcription silencing domain restored CAR1 transactivation activity in reporter assays to approximately 90% of control, demonstrating its critical function in mediating the CAR repression activities. Furthermore, results obtained from mammalian two-hybrid experiments assessing various domain configurations of the respective receptors showed that full-length DAX-1 inhibited the CAR-SRC1 interaction by approximately 50%, whereas the same interaction was restored to 90% of control when the DAX-1 transcription silencing domain was deleted. Direct interaction between CAR and DAX-1 was demonstrated with both alpha-screen and coimmunoprecipitation experiments, and this interaction was enhanced in the presence of the CAR activator 6-(4-chlorophenyl)imidazo[2,1-b]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO). Results obtained in primary human hepatocytes further demonstrated DAX-1 inhibition of CAR-mediated CITCO induction of the CYP2B6 target gene. The results of this investigation identify DAX-1 as a novel and potent CAR corepressor and suggest that DAX-1 functions as a coordinate hepatic regulator of CAR's biological function.

  17. The Orphan Nuclear Receptor DAX-1 Functions as a Potent Corepressor of the Constitutive Androstane Receptor (NR1I3)

    PubMed Central

    Laurenzana, Elizabeth M.; Chen, Tao; Kannuswamy, Malavika; Sell, Brian E.; Strom, Stephen C.; Li, Yong

    2012-01-01

    Regulation of gene transcription is controlled in part by nuclear receptors that function coordinately with coregulator proteins. The human constitutive androstane receptor (CAR; NR1I3) is expressed primarily in liver and regulates the expression of genes involved in xenobiotic metabolism as well as hormone, energy, and lipid homeostasis. In this report, DAX-1, a nuclear receptor family member with corepressor properties, was identified as a potent CAR regulator. Results of transaction and mutational studies demonstrated that both DAX-1's downstream LXXLL and its PCFQVLP motifs were critical contributors to DAX-1's corepression activities, although two other LXXM/LL motifs located nearer the N terminus had no impact on the CAR functional interaction. Deletion of DAX-1's C-terminal transcription silencing domain restored CAR1 transactivation activity in reporter assays to approximately 90% of control, demonstrating its critical function in mediating the CAR repression activities. Furthermore, results obtained from mammalian two-hybrid experiments assessing various domain configurations of the respective receptors showed that full-length DAX-1 inhibited the CAR-SRC1 interaction by approximately 50%, whereas the same interaction was restored to 90% of control when the DAX-1 transcription silencing domain was deleted. Direct interaction between CAR and DAX-1 was demonstrated with both alpha-screen and coimmunoprecipitation experiments, and this interaction was enhanced in the presence of the CAR activator 6-(4-chlorophenyl)imidazo[2,1-b]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO). Results obtained in primary human hepatocytes further demonstrated DAX-1 inhibition of CAR-mediated CITCO induction of the CYP2B6 target gene. The results of this investigation identify DAX-1 as a novel and potent CAR corepressor and suggest that DAX-1 functions as a coordinate hepatic regulator of CAR's biological function. PMID:22896671

  18. Understanding the Goals of Everyday Instrumental Actions Is Primarily Linked to Object, Not Motor-Kinematic, Information: Evidence from fMRI

    PubMed Central

    Nicholson, Toby; Roser, Matt; Bach, Patric

    2017-01-01

    Prior research conceptualised action understanding primarily as a kinematic matching of observed actions to own motor representations but has ignored the role of object information. The current study utilized fMRI to identify (a) regions uniquely involved in encoding the goal of others’ actions, and (b) to test whether these goal understanding processes draw more strongly on regions involved in encoding object semantics or movement kinematics. Participants watched sequences of instrumental actions while attending to either the actions’ goal (goal task), the movements performed (movement task) or the objects used (object task). The results confirmed, first, a unique role of the inferior frontal gyrus, middle temporal gyrus and medial frontal gyrus in action goal understanding. Second, they show for the first time that activation in the goal task overlaps directly with object- but not movement-related activation. Moreover, subsequent parametric analyses revealed that movement-related regions become activated only when goals are unclear, or observers have little action experience. In contrast to motor theories of action understanding, these data suggest that objects—rather than movement kinematics—carry the key information about others’ actions. Kinematic information is additionally recruited when goals are ambiguous or unfamiliar. PMID:28081175

  19. Sensory plasticity in human motor learning

    PubMed Central

    Ostry, David J; Gribble, Paul L

    2015-01-01

    Summary There is accumulating evidence from behavioural, neurophysiological and neuroimaging studies that the acquisition of motor skills involves both perceptual and motor learning. Perceptual learning alters movements, motor learning and motor networks of the brain. Motor learning changes perceptual function and the brain’s sensory circuits. Here we review studies of both human limb movement and speech which indicate that plasticity in sensory and motor systems is reciprocally linked. Taken together, this points to an approach to motor learning in which perceptual learning and sensory plasticity play a fundamental role. PMID:26774345

  20. Sensory Plasticity in Human Motor Learning.

    PubMed

    Ostry, David J; Gribble, Paul L

    2016-02-01

    There is accumulating evidence from behavioral, neurophysiological, and neuroimaging studies that the acquisition of motor skills involves both perceptual and motor learning. Perceptual learning alters movements, motor learning, and motor networks of the brain. Motor learning changes perceptual function and the sensory circuits of the brain. Here, we review studies of both human limb movement and speech that indicate that plasticity in sensory and motor systems is reciprocally linked. Taken together, this points to an approach to motor learning in which perceptual learning and sensory plasticity have a fundamental role.

  1. 4-Hydroxy-1-[2-(4-hydroxyphenoxy)ethyl]-4-(4-methylbenzyl)piperidine: a novel, potent, and selective NR1/2B NMDA receptor antagonist.

    PubMed

    Zhou, Z L; Cai, S X; Whittemore, E R; Konkoy, C S; Espitia, S A; Tran, M; Rock, D M; Coughenour, L L; Hawkinson, J E; Boxer, P A; Bigge, C F; Wise, L D; Weber, E; Woodward, R M; Keana, J F

    1999-07-29

    A structure-based search and screen of our compound library identified N-(2-phenoxyethyl)-4-benzylpiperidine (8) as a novel N-methyl-D-aspartate (NMDA) receptor antagonist that has high selectivity for the NR1/2B subunit combination (IC(50) = 0.63 microM). We report on the optimization of this lead compound in terms of potency, side effect liability, and in vivo activity. Potency was assayed by electrical recordings in Xenopus oocytes expressing cloned rat NMDA receptors. Side effect liability was assessed by measuring affinity for alpha(1)-adrenergic receptors and inhibition of neuronal K(+) channels. Central bioavailability was gauged indirectly by determining anticonvulsant activity in a mouse maximal electroshock (MES) assay. Making progressive modifications to 8, a hydroxyl substituent on the phenyl ring para to the oxyethyl tether (10a) resulted in a approximately 25-fold increase in NR1A/2B potency (IC(50) = 0.025 microM). p-Methyl substitution on the benzyl ring (10b) produced a approximately 3-fold increase in MES activity (ED(50) = 0.7 mg/kg iv). Introduction of a second hydroxyl group into the C-4 position on the piperidine ring (10e) resulted in a substantial decrease in affinity for alpha(1) receptors and reduction in inhibition of K(+) channels with only a modest decrease in NR1A/2B and MES potencies. Among the compounds described, 10e (4-hydroxy-N-[2-(4-hydroxyphenoxy)ethyl]-4-(4-methylbenzyl)piperid ine, Co 101244/PD 174494) had the optimum pharmacological profile and was selected for further biological evaluation.

  2. Modifier genes as therapeutics: the nuclear hormone receptor Rev Erb alpha (Nr1d1) rescues Nr2e3 associated retinal disease.

    PubMed

    Cruz, Nelly M; Yuan, Yang; Leehy, Barrett D; Baid, Rinku; Kompella, Uday; DeAngelis, Margaret M; Escher, Pascal; Haider, Neena B

    2014-01-01

    Nuclear hormone receptors play a major role in many important biological processes. Most nuclear hormone receptors are ubiquitously expressed and regulate processes such as metabolism, circadian function, and development. They function in these processes to maintain homeostasis through modulation of transcriptional gene networks. In this study we evaluate the effectiveness of a nuclear hormone receptor gene to modulate retinal degeneration and restore the integrity of the retina. Currently, there are no effective treatment options for retinal degenerative diseases leading to progressive and irreversible blindness. In this study we demonstrate that the nuclear hormone receptor gene Nr1d1 (Rev-Erbα) rescues Nr2e3-associated retinal degeneration in the rd7 mouse, which lacks a functional Nr2e3 gene. Mutations in human NR2E3 are associated with several retinal degenerations including enhanced S cone syndrome and retinitis pigmentosa. The rd7 mouse, lacking Nr2e3, exhibits an increase in S cones and slow, progressive retinal degeneration. A traditional genetic mapping approach previously identified candidate modifier loci. Here, we demonstrate that in vivo delivery of the candidate modifier gene, Nr1d1 rescues Nr2e3 associated retinal degeneration. We observed clinical, histological, functional, and molecular restoration of the rd7 retina. Furthermore, we demonstrate that the mechanism of rescue at the molecular and functional level is through the re-regulation of key genes within the Nr2e3-directed transcriptional network. Together, these findings reveal the potency of nuclear receptors as modulators of disease and specifically of NR1D1 as a novel therapeutic for retinal degenerations.

  3. Loss of ULK1 increases RPS6KB1-NCOR1 repression of NR1H/LXR-mediated Scd1 transcription and augments lipotoxicity in hepatic cells

    PubMed Central

    Sinha, Rohit Anthony; Singh, Brijesh K.; Zhou, Jin; Xie, Sherwin; Farah, Benjamin L.; Lesmana, Ronny; Ohba, Kenji; Tripathi, Madhulika; Ghosh, Sujoy; Hollenberg, Anthony N.; Yen, Paul M.

    2017-01-01

    ABSTRACT Lipotoxicity caused by saturated fatty acids (SFAs) induces tissue damage and inflammation in metabolic disorders. SCD1 (stearoyl-coenzyme A desaturase 1) converts SFAs to mono-unsaturated fatty acids (MUFAs) that are incorporated into triglycerides and stored in lipid droplets. SCD1 thus helps protect hepatocytes from lipotoxicity and its reduced expression is associated with increased lipotoxic injury in cultured hepatic cells and mouse models. To further understand the role of SCD1 in lipotoxicity, we examined the regulation of Scd1 in hepatic cells treated with palmitate, and found that NR1H/LXR (nuclear receptor subfamily 1 group H) ligand, GW3965, induced Scd1 expression and lipid droplet formation to improve cell survival. Surprisingly, ULK1/ATG1 (unc-51 like kinase) played a critical role in protecting hepatic cells from SFA-induced lipotoxicity via a novel mechanism that did not involve macroautophagy/autophagy. Specific loss of Ulk1 blocked the induction of Scd1 gene transcription by GW3965, decreased lipid droplet formation, and increased apoptosis in hepatic cells exposed to palmitate. Knockdown of ULK1 increased RPS6KB1 (ribosomal protein S6 kinase, polypeptide 1) signaling that, in turn, induced NCOR1 (nuclear receptor co-repressor 1) nuclear uptake, interaction with NR1H/LXR, and recruitment to the Scd1 promoter. These events abrogated the stimulation of Scd1 gene expression by GW3965, and increased lipotoxicity in hepatic cells. In summary, we have identified a novel autophagy-independent role of ULK1 that regulates NR1H/LXR signaling, Scd1 expression, and intracellular lipid homeostasis in hepatic cells exposed to a lipotoxic environment. PMID:27846372

  4. Influence of a threonine residue in the S2 ligand binding domain in determining agonist potency and deactivation rate of recombinant NR1a/NR2D NMDA receptors.

    PubMed

    Chen, Philip E; Johnston, Alexander R; Mok, M H Selina; Schoepfer, Ralf; Wyllie, David J A

    2004-07-01

    NR1/NR2D NMDA receptors display unusually slow deactivation kinetics which may be critical for their role as extrasynaptic receptors. A threonine to alanine point mutation has been inserted at amino acid position 692 of the NR2D subunit (T692A). Recombinant NR1a/NR2D(T692A) NMDA receptors have been expressed in Xenopus laevis oocytes and their pharmacological and single-channel properties examined using two-electrode voltage-clamp and patch-clamp recording techniques. Glutamate dose-response curves from NR1a/NR2D(T692A) receptor channels produced an approximately 1600-fold reduction in glutamate potency compared to wild-type NR1a/NR2D receptors. There was no change in Hill slopes or gross reduction in mean maximal currents recorded in oocytes expressing either wild-type or mutant receptors. The mutation did not affect the potency of the co-agonist glycine. The shifts in potency produced by NR2D(T692A) containing receptors when activated by other glutamate-site agonists such as aspartate or NMDA were 30- to 60-fold compared to wild-type. Single-channel conductance levels of NR1a/NR2D(T692A) mutant receptors were indistinguishable from wild-type NR2D-containing channels. Additionally NR1a/NR2D(T692A) receptors showed the transitional asymmetry that is characteristic of NR2D-containing NMDA receptors. Rapid applications of glutamate on outside-out patches containing NR1a/NR2D(T692A) receptors produced macroscopic current deactivations that were about 60-fold faster than wild-type NR1a/NR2D receptors. Our results suggest that this conserved threonine residue plays a crucial role in ligand binding to NMDA NR2 receptor subunits and supports the idea that the slow decay kinetics associated with NR1a/NR2D NMDA receptors can be explained by the slow dissociation of glutamate from this NMDA receptor subtype.

  5. Association between Community Ambulation Walking Patterns and Cognitive Function in Patients with Parkinson's Disease: Further Insights into Motor-Cognitive Links

    PubMed Central

    Weiss, Aner; Herman, Talia; Giladi, Nir; Hausdorff, Jeffrey M.

    2015-01-01

    Background. Cognitive function is generally evaluated based on testing in the clinic, but this may not always reflect real-life function. We tested whether parameters derived from long-term, continuous monitoring of gait are associated with cognitive function in patients with Parkinson's disease (PD). Methods. 107 patients with PD (age: 64.9 ± 9.3 yrs; UPDRS motor sum “off”: 40.4 ± 13.2; 25.23% women) wore a 3D accelerometer on their lower back for 3 days. Computerized measures of global cognitive function, executive function, attention, and nonverbal memory were assessed. Three-day acceleration derived measures included cadence, variability, bilateral coordination, and dynamic postural control. Associations between the acceleration derived measures and cognitive function were determined. Results. Linear regression showed associations between vertical gait variability and cadence and between global cognitive score, attention, and executive function (p ≤ 0.048). Dynamic postural control was associated with global cognitive score and attention (p ≤ 0.027). Nonverbal memory was not associated with the acceleration-derived measures. Conclusions. These findings suggest that metrics derived from a 3-day worn body-fixed sensor reflect cognitive function, further supporting the idea that the gait pattern may be altered as cognition declines and that gait provides a window into cognitive function in patients with PD. PMID:26605103

  6. Association between Community Ambulation Walking Patterns and Cognitive Function in Patients with Parkinson's Disease: Further Insights into Motor-Cognitive Links.

    PubMed

    Weiss, Aner; Herman, Talia; Giladi, Nir; Hausdorff, Jeffrey M

    2015-01-01

    Background. Cognitive function is generally evaluated based on testing in the clinic, but this may not always reflect real-life function. We tested whether parameters derived from long-term, continuous monitoring of gait are associated with cognitive function in patients with Parkinson's disease (PD). Methods. 107 patients with PD (age: 64.9 ± 9.3 yrs; UPDRS motor sum "off": 40.4 ± 13.2; 25.23% women) wore a 3D accelerometer on their lower back for 3 days. Computerized measures of global cognitive function, executive function, attention, and nonverbal memory were assessed. Three-day acceleration derived measures included cadence, variability, bilateral coordination, and dynamic postural control. Associations between the acceleration derived measures and cognitive function were determined. Results. Linear regression showed associations between vertical gait variability and cadence and between global cognitive score, attention, and executive function (p ≤ 0.048). Dynamic postural control was associated with global cognitive score and attention (p ≤ 0.027). Nonverbal memory was not associated with the acceleration-derived measures. Conclusions. These findings suggest that metrics derived from a 3-day worn body-fixed sensor reflect cognitive function, further supporting the idea that the gait pattern may be altered as cognition declines and that gait provides a window into cognitive function in patients with PD.

  7. Sensory change following motor learning.

    PubMed

    Mattar, Andrew A G; Nasir, Sazzad M; Darainy, Mohammad; Ostry, David J

    2011-01-01

    Here we describe two studies linking perceptual change with motor learning. In the first, we document persistent changes in somatosensory perception that occur following force field learning. Subjects learned to control a robotic device that applied forces to the hand during arm movements. This led to a change in the sensed position of the limb that lasted at least 24 h. Control experiments revealed that the sensory change depended on motor learning. In the second study, we describe changes in the perception of speech sounds that occur following speech motor learning. Subjects adapted control of speech movements to compensate for loads applied to the jaw by a robot. Perception of speech sounds was measured before and after motor learning. Adapted subjects showed a consistent shift in perception. In contrast, no consistent shift was seen in control subjects and subjects that did not adapt to the load. These studies suggest that motor learning changes both sensory and motor function.

  8. Motor syndromes.

    PubMed

    Corea, Francesco; Micheli, Sara

    2012-01-01

    Motor disturbances alone or associated with other focal deficits are the most common symptoms suggesting a neurovascular event. An appropriate clinical assessment of these signs and symptoms may help physicians to better diagnose and to both better treat and predict outcome. In this paper the main clinical features of motor deficit are described together with other motor-related events such as ataxia and movement disturbances.

  9. Molecular motors

    NASA Astrophysics Data System (ADS)

    Allemand, Jean François Desbiolles, Pierre

    2015-10-01

    How do we move? More precisely, what are the molecular mechanisms that can explain that our muscles, made of very small components can move at a osopic scale? To answer these questions we must introduce molecular motors. Those motors are proteins, or small protein assemblies that, in our cells, transform chemical energy into mechanical work. Then, like we could do for a oscopic motor, used in a car or in a fan, we are going to study the basic behavior of these molecular machines, present what are their energy sources, calculate their power, their yield. If molecular motors are crucial for our oscopic movements, we are going to see that they are also essential to cellular transport and that considering the activity of some enzymes as molecular motors bring some interesting new insights on their activity.

  10. The circadian clock regulates autophagy directly through the nuclear hormone receptor Nr1d1/Rev-erbα and indirectly via Cebpb/(C/ebpβ) in zebrafish

    PubMed Central

    Huang, Guodong; Zhang, Fanmiao; Ye, Qiang; Wang, Han

    2016-01-01

    ABSTRACT Autophagy is a highly conserved intracellular degradation system, and recently was shown to display circadian rhythms in mice. The mechanisms underlying circadian regulation of autophagy, however, are still unclear. Here, we observed that numbers of autophagosomes and autolysosomes exhibit daily rhythms in the zebrafish liver, and cebpb/(c/ebpβ) and various autophagy genes are rhythmically expressed in zebrafish larvae but significantly upregulated in per1b and TALEN-generated nr1d1/rev-erbα mutant fish, indicating that both Per1b and Nr1d1 play critical roles in autophagy rhythms. Luciferase reporter and ChIP assays show that the circadian clock directly regulates autophagy genes through Nr1d1, and also regulates transcription of cebpb through Per1b. We also found that fasting leads to altered expression of both circadian clock genes and autophagy genes in zebrafish adult peripheral organs. Further, transcriptome analysis reveals multiple functions of Nr1d1 in zebrafish. Taken together, these findings provide evidence for how the circadian clock regulates autophagy, imply that nutritional signaling affects both circadian regulation and autophagy activities in peripheral organs, and shed light on how circadian gene mutations act through autophagy to contribute to common metabolic diseases such as obesity. PMID:27171500

  11. Characterisation of N-methyl-D-aspartate receptor-specific [(3)H]Ifenprodil binding to recombinant human NR1a/NR2B receptors compared with native receptors in rodent brain membranes.

    PubMed

    Grimwood, S; Richards, P; Murray, F; Harrison, N; Wingrove, P B; Hutson, P H

    2000-12-01

    We have performed [(3)H]ifenprodil binding experiments under NMDA receptor-specific assay conditions to provide the first detailed characterisation of the pharmacology of the ifenprodil site on NMDA NR1/NR2B receptors, using recombinant human NR1a/NR2B receptors stably expressed in L(tk-) cells, in comparison with rat cortex/hippocampus membranes. [(3)H]Ifenprodil bound to a single, saturable site on both human recombinant NR1a/NR2B receptors and native rat receptors with B:(max) values of 1.83 and 2.45 pmol/mg of protein, respectively, and K:(D) values of 33.5 and 24.8 nM:, respectively. The affinity of various ifenprodil site ligands-eliprodil, (R:(*), R:(*))-4-hydroxy-alpha-(4-hydroxyphenyl)-beta-methyl-4-pehnyl-1-pi per idineethanol [(+/-)-CP-101,606], cis-3-[4-(4-fluorophenyl)-4-hydroxy-1-piperidinyl]-3, 4-dihydro-2H:-1-benzopyran-4,7-diol [(+/-)-CP-283,097], and (R:(*), S:(*))-alpha-(4-hydroxyphenyl)-beta-methyl-4-(phenylmethyl)-1-piperid inepropanol [(+/-)-Ro 25-6981] was very similar for inhibition of [(3)H]ifenprodil binding to recombinant human NR1a/NR2B and native rat receptors, whereas allosteric inhibition of [(3)H]ifenprodil binding by polyamine site ligands (spermine, spermidine, and arcaine) showed approximately twofold lower affinity for recombinant receptors compared with native receptors. Glutamate site ligands were less effective at modulating [(3)H]ifenprodil binding to recombinant NR1a/NR2B receptors compared with native rat receptors. The NMDA receptor-specific [(3)H]ifenprodil binding conditions described were also applied to ex vivo experiments to determine the receptor occupancy of ifenprodil site ligands [ifenprodil, (+/-)-CP-101,606, (+/-)-CP-283,097, and (+/-)-Ro 25-6981] given systemically.

  12. Stepper motor

    NASA Technical Reports Server (NTRS)

    Dekramer, Cornelis

    1994-01-01

    The purpose of this document is to describe the more commonly used permanent magnet stepper motors for spaceflight. It will discuss the mechanical and electrical aspects of the devices, their torque behavior, those parameters which need to be controlled and measured, and test methods to be employed. It will also discuss torque margins, compare these to the existing margin requirements, and determine the applicability of these requirements. Finally it will attempt to generate a set of requirements which will be used in any stepper motor procurement and will fully characterize the stepper motor behavior in a consistent and repeatable fashion.

  13. Game Changer: Linked Learning Detroit

    ERIC Educational Resources Information Center

    ConnectEd: The California Center for College and Career, 2016

    2016-01-01

    JP Morgan Chase joins the Skillman Foundation, the Ford Foundation, and the Ford Motor Company Fund, whose grants total $7 million and will connect 10,000 Detroit high school students to career education and work experiences over the next three years through Linked Learning Detroit. Learn about Linked Learning Detroit through interviews with…

  14. Advanced Motors

    SciTech Connect

    Knoth, Edward A; Chelluri, Bhanumathi; Schumaker, Edward J

    2012-12-14

    vProject Summary Transportation energy usage is predicted to increase substantially by 2020. Hybrid vehicles and fuel cell powered vehicles are destined to become more prominent as fuel prices rise with the demand. Hybrid and fuel cell vehicle platforms are both dependent on high performance electric motors. Electric motors for transportation duty will require sizeable low-speed torque to accelerate the vehicle. As motor speed increases, the torque requirement decreases which results in a nearly constant power motor output. Interior permanent magnet synchronous motors (IPMSM) are well suited for this duty. , , These rotor geometries are configured in straight lines and semi circular arc shapes. These designs are of limited configurations because of the lack of availability of permanent magnets of any other shapes at present. We propose to fabricate rotors via a novel processing approach where we start with magnet powders and compact them into a net shape rotor in a single step. Using this approach, widely different rotor designs can be implemented for efficiency. The current limitation on magnet shape and thickness will be eliminated. This is accomplished by co-filling magnet and soft iron powders at specified locations in intricate shapes using specially designed dies and automatic powder filling station. The process fundamentals for accomplishing occurred under a previous Applied Technology Program titled, Motors and Generators for the 21st Century. New efficient motor designs that are not currently possible (or cost prohibitive) can be accomplished by this approach. Such an approach to motor fabrication opens up a new dimension in motor design. Feasibility Results We were able to optimize a IPMSM rotor to take advantage of the powder co-filling and DMC compaction processing methods. The minimum low speed torque requirement of 5 N-m can be met through an optimized design with magnet material having a Br capability of 0.2 T. This level of magnetic performance can

  15. Multilevel DC link inverter

    DOEpatents

    Su, Gui-Jia

    2003-06-10

    A multilevel DC link inverter and method for improving torque response and current regulation in permanent magnet motors and switched reluctance motors having a low inductance includes a plurality of voltage controlled cells connected in series for applying a resulting dc voltage comprised of one or more incremental dc voltages. The cells are provided with switches for increasing the resulting applied dc voltage as speed and back EMF increase, while limiting the voltage that is applied to the commutation switches to perform PWM or dc voltage stepping functions, so as to limit current ripple in the stator windings below an acceptable level, typically 5%. Several embodiments are disclosed including inverters using IGBT's, inverters using thyristors. All of the inverters are operable in both motoring and regenerating modes.

  16. [Motor rehabilitation].

    PubMed

    Doménech, J; García-Aymerich, V; Juste, J; Ortiz, A

    2002-02-01

    The child's rehabilitation objectives are the same of the early intervention. The early intervention include motor approaches to facilitate the unique way of the newborn's expression: the movement and with it his holistic development. The motor approach is a classic aspect of early intervention but it is not itself early intervention. When the treatment objective is a term or preterm newborn or neonate the motor approach may be the principal method to facilitate perceptions experiences and basic habits. This intervention is not made with a specific physiotherapeutic technique. It is a sequential stimulation or development, without forget that the child must be taken as a whole. This point of view has special importance the first days of life and must be included in perinatal approach routines. In this paper we expose the work method of a Child Rehabilitation Team liked to a Newborn Unit.

  17. Motor Dynamics of Embodied Cognition

    ERIC Educational Resources Information Center

    Anderson, Sarah Elizabeth

    2011-01-01

    Predominant theories of cognition have previously emphasized the modularity of processing, in which individual isolated modules process information free from the influence of other types of information. However, more recent theories suggest that cognition is much more linked to motor and sensory processes than modular theories suggest. In this…

  18. The Niwot Ridge Subalpine Forest US-NR1 AmeriFlux site - Part 1: Data acquisition and site record-keeping

    NASA Astrophysics Data System (ADS)

    Burns, Sean P.; Maclean, Gordon D.; Blanken, Peter D.; Oncley, Steven P.; Semmer, Steven R.; Monson, Russell K.

    2016-09-01

    The Niwot Ridge Subalpine Forest AmeriFlux site (US-NR1) has been measuring eddy-covariance ecosystem fluxes of carbon dioxide, heat, and water vapor since 1 November 1998. Throughout this 17-year period there have been changes to the instrumentation and improvements to the data acquisition system. Here, in Part 1 of this three-part series of papers, we describe the hardware and software used for data-collection and metadata documentation. We made changes to the data acquisition system that aimed to reduce the system complexity, increase redundancy, and be as independent as possible from any network outages. Changes to facilitate these improvements were (1) switching to a PC/104-based computer running the National Center for Atmospheric Research (NCAR) In-Situ Data Acquisition Software (NIDAS) that saves the high-frequency data locally and over the network, and (2) time-tagging individual 10 Hz serial data samples using network time protocol (NTP) coupled to a GPS-based clock, providing a network-independent, accurate time base. Since making these improvements almost 2 years ago, the successful capture of high-rate data has been better than 99.98 %. We also provide philosophical concepts that shaped our design of the data system and are applicable to many different types of environmental data collection.

  19. Sigma-1 Receptor Antagonist BD1047 Reduces Mechanical Allodynia in a Rat Model of Bone Cancer Pain through the Inhibition of Spinal NR1 Phosphorylation and Microglia Activation

    PubMed Central

    Zhu, Shanshan; Wang, Chenchen; Han, Yuan; Song, Chao; Hu, Xueming; Liu, Yannan

    2015-01-01

    Previous studies have demonstrated that sigma-1 receptor plays important roles in the induction phase of rodent neuropathic pain; however, whether it is involved in bone cancer pain (BCP) and the underlying mechanisms remain elusive. The aim of this study was to examine the potential role of the spinal sigma-1 receptor in the development of bone cancer pain. Walker 256 mammary gland carcinoma cells were implanted into the intramedullary space of the right tibia of Sprague-Dawley rats to induce ongoing bone cancer-related pain behaviors; our findings indicated that, on days 7, 10, 14, and 21 after operation, the expression of sigma-1 receptor in the spinal cord was higher in BCP rats compared to the sham rats. Furthermore, intrathecal injection of 120 nmol of sigma-1 receptor antagonist BD1047 on days 5, 6, and 7 after operation attenuated mechanical allodynia as well as the associated induction of c-Fos and activation of microglial cells, NR1, and the subsequent Ca2+-dependent signals of BCP rats. These results suggest that sigma-1 receptor is involved in the development of bone cancer pain and that targeting sigma-1 receptor may be a new strategy for the treatment of bone cancer pain. PMID:26696751

  20. The Niwot Ridge Subalpine Forest US-NR1 AmeriFlux site – Part 1: Data acquisition and site record-keeping

    DOE PAGES

    Burns, Sean P.; Maclean, Gordon D.; Blanken, Peter D.; ...

    2016-09-29

    The Niwot Ridge Subalpine Forest AmeriFlux site (US-NR1) has been measuring eddy-covariance ecosystem fluxes of carbon dioxide, heat, and water vapor since 1 November 1998. Throughout this 17-year period there have been changes to the instrumentation and improvements to the data acquisition system. Here, in Part 1 of this three-part series of papers, we describe the hardware and software used for data-collection and metadata documentation. We made changes to the data acquisition system that aimed to reduce the system complexity, increase redundancy, and be as independent as possible from any network outages. Changes to facilitate these improvements were (1) switching to a PC/104-based computer runningmore » the National Center for Atmospheric Research (NCAR) In-Situ Data Acquisition Software (NIDAS) that saves the high-frequency data locally and over the network, and (2) time-tagging individual 10 Hz serial data samples using network time protocol (NTP) coupled to a GPS-based clock, providing a network-independent, accurate time base. Since making these improvements almost 2 years ago, the successful capture of high-rate data has been better than 99.98 %. We also provide philosophical concepts that shaped our design of the data system and are applicable to many different types of environmental data collection.« less

  1. Sigma-1 Receptor Antagonist BD1047 Reduces Mechanical Allodynia in a Rat Model of Bone Cancer Pain through the Inhibition of Spinal NR1 Phosphorylation and Microglia Activation.

    PubMed

    Zhu, Shanshan; Wang, Chenchen; Han, Yuan; Song, Chao; Hu, Xueming; Liu, Yannan

    2015-01-01

    Previous studies have demonstrated that sigma-1 receptor plays important roles in the induction phase of rodent neuropathic pain; however, whether it is involved in bone cancer pain (BCP) and the underlying mechanisms remain elusive. The aim of this study was to examine the potential role of the spinal sigma-1 receptor in the development of bone cancer pain. Walker 256 mammary gland carcinoma cells were implanted into the intramedullary space of the right tibia of Sprague-Dawley rats to induce ongoing bone cancer-related pain behaviors; our findings indicated that, on days 7, 10, 14, and 21 after operation, the expression of sigma-1 receptor in the spinal cord was higher in BCP rats compared to the sham rats. Furthermore, intrathecal injection of 120 nmol of sigma-1 receptor antagonist BD1047 on days 5, 6, and 7 after operation attenuated mechanical allodynia as well as the associated induction of c-Fos and activation of microglial cells, NR1, and the subsequent Ca(2+)-dependent signals of BCP rats. These results suggest that sigma-1 receptor is involved in the development of bone cancer pain and that targeting sigma-1 receptor may be a new strategy for the treatment of bone cancer pain.

  2. Therma motor

    DOEpatents

    Kandarian, R.

    The disclosure is directed to a thermal motor utilizing two tapered prestressed parallel adjacent cylinders lengthwise disposed about one third in a coolant. Heat is applied to contacting portions of the cylinders outside the coolant to cause them to deform and turn. Heat sources such as industrial waste heat, geothermal hot water, solar radiation, etc. can be used.

  3. Motor Controllers

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Kollmorgen Corporation's Mermaid II two person submersible is propeller-driven by a system of five DC brushless motors with new electronic controllers that originated in work performed in a NASA/DOE project managed by Lewis Research Center. A key feature of the system is electric commutation rather than mechanical commutation for converting AC current to DC.

  4. The link in Linking

    PubMed Central

    Caldwell, Jane C; Chiale, Pablo A; Gonzalez, Mario D; Baranchuk, Adrian

    2013-01-01

    We present 2 cases of the slow-fast form of AVNRT with initially narrow QRS complexes followed by sudden unexpected transition to persistently wide QRS complexes due to aberrant intraventricular conduction. Introduction of a properly timed extrastimulus in one case and critical oscillations in cycle length due to short-long coupling in the second case set the stage for the initial bundle branch block. However, persistence of the aberrancy pattern once the initial event abated was maintained by the "linking" phenomenon. Delayed, retrograde concealed activation from the contralateral bundle branch perpetuated the initial bundle branch block. PMID:23840106

  5. The link in Linking.

    PubMed

    Caldwell, Jane C; Chiale, Pablo A; Gonzalez, Mario D; Baranchuk, Adrian

    2013-05-01

    We present 2 cases of the slow-fast form of AVNRT with initially narrow QRS complexes followed by sudden unexpected transition to persistently wide QRS complexes due to aberrant intraventricular conduction. Introduction of a properly timed extrastimulus in one case and critical oscillations in cycle length due to short-long coupling in the second case set the stage for the initial bundle branch block. However, persistence of the aberrancy pattern once the initial event abated was maintained by the "linking" phenomenon. Delayed, retrograde concealed activation from the contralateral bundle branch perpetuated the initial bundle branch block.

  6. Interaction of ApoA-IV with NR4A1 and NR1D1 Represses G6Pase and PEPCK Transcription: Nuclear Receptor-Mediated Downregulation of Hepatic Gluconeogenesis in Mice and a Human Hepatocyte Cell Line

    PubMed Central

    Li, Xiaoming; Xu, Min; Wang, Fei; Ji, Yong; DavidsoN, W. Sean; Li, Zongfang; Tso, Patrick

    2015-01-01

    We have previously shown that the nuclear receptor, NR1D1, is a cofactor in ApoA-IV-mediated downregulation of gluconeogenesis. Nuclear receptor, NR4A1, is involved in the transcriptional regulation of various genes involved in inflammation, apoptosis, and glucose metabolism. We investigated whether NR4A1 influences the effect of ApoA-IV on hepatic glucose metabolism. Our in situ proximity ligation assays and coimmunoprecipitation experiments indicated that ApoA-IV colocalized with NR4A1 in human liver (HepG2) and kidney (HEK-293) cell lines. The chromatin immunoprecipitation experiments and luciferase reporter assays indicated that the ApoA-IV and NR4A1 colocalized at the RORα response element of the human G6Pase promoter, reducing its transcriptional activity. Our RNA interference experiments showed that knocking down the expression of NR4A1 in primary mouse hepatocytes treated with ApoA-IV increased the expression of NR1D1, G6Pase, and PEPCK, and that knocking down NR1D1 expression increased the level of NR4A1. We also found that ApoA-IV induced the expression of endogenous NR4A1 in both cultured primary mouse hepatocytes and in the mouse liver, and decreased glucose production in primary mouse hepatocytes. Our findings showed that ApoA-IV colocalizes with NR4A1, which suppresses G6Pase and PEPCK gene expression at the transcriptional level, reducing hepatic glucose output and lowering blood glucose. The ApoA-IV-induced increase in NR4A1 expression in hepatocytes mediates further repression of gluconeogenesis. Our findings suggest that NR1D1 and NR4A1 serve similar or complementary functions in the ApoA-IV-mediated regulation of gluconeogenesis. PMID:26556724

  7. The Development of Oral Motor Control and Language

    ERIC Educational Resources Information Center

    Alcock, Katie

    2006-01-01

    Motor control has long been associated with language skill, in deficits, both acquired and developmental, and in typical development. Most evidence comes from limb praxis however; the link between oral motor control and speech and language has been neglected, despite the fact that most language users talk with their mouths. Oral motor control is…

  8. Motor Proficiency Predicts Cognitive Ability in Four-Year-Olds

    ERIC Educational Resources Information Center

    Hernandez, Amanda Martinez; Caçola, Priscila

    2015-01-01

    Research has shown links between motor proficiency and cognition in school-age children, however, few have explored earlier ages. We aimed to determine the association between motor proficiency and cognitive ability in four-year-olds. Motor and cognitive skills were examined in 32 (15 males, 17 females) four-year-olds (±5.59 months) using the…

  9. Modeling an electric motor in 1-D

    NASA Technical Reports Server (NTRS)

    Butler, Thomas G.

    1991-01-01

    Quite often the dynamicist will be faced with having an electric drive motor as a link in the elastic path of a structure such that the motor's characteristics must be taken into account to properly represent the dynamics of the primary structure. He does not want to model it so accurately that he could get detailed stress and displacements in the motor proper, but just sufficiently to represent its inertia loading and elastic behavior from its mounting bolts to its drive coupling. Described here is how the rotor and stator of such a motor can be adequately modeled as a colinear pair of beams.

  10. Chemistry in motion: tiny synthetic motors.

    PubMed

    Colberg, Peter H; Reigh, Shang Yik; Robertson, Bryan; Kapral, Raymond

    2014-12-16

    of the dynamics of chemically powered motors are illustrated by presenting the results of particle-based simulations of sphere-dimer motors constructed from linked catalytic and noncatalytic spheres. The geometries of both Janus and sphere-dimer motors with asymmetric catalytic activity support the formation of concentration gradients around the motors. Because directed motion can occur only when the system is not in equilibrium, the nature of the environment and the role it plays in motor dynamics are described. Rotational Brownian motion also acts to limit directed motion, and it has especially strong effects for very small motors. We address the following question: how small can motors be and still exhibit effects due to propulsion, even if only to enhance diffusion? Synthetic motors have the potential to transform the manner in which chemical dynamical processes are carried out for a wide range of applications.

  11. Motor actuated vacuum door

    NASA Astrophysics Data System (ADS)

    Hanagud, A. V.

    1986-10-01

    Doors that allow scientific instruments to record and retrieve the observed data are often required to be designed and installed as a part of sounding rocket hardware. The motor-actuated vacuum door was designed to maintain a medium vacuum of the order of 0.0001 torr or better while closed, and to provide an opening 15 inches long x 8.5 inches wide while open for cameras to image Halley's comet. When the electric motor receives the instruction to open the door through the payload battery, timer, and relay circuit, the first operation is to unlock the door. After unlatching, the torque transmitted by the motor to the main shaft through the links opens the door. A microswitch actuator, which rides on the linear motion conversion mechanism, is adjusted to trip the limit switch at the end of the travel. The process is repeated in the reverse order to close the door. 'O' rings are designed to maintain the seal. Door mechanisms similar to the one described have flown on Aerobee 17.018 and Black Brant 27.047 payloads.

  12. Link direction for link prediction

    NASA Astrophysics Data System (ADS)

    Shang, Ke-ke; Small, Michael; Yan, Wei-sheng

    2017-03-01

    Almost all previous studies on link prediction have focused on using the properties of the network to predict the existence of links between pairs of nodes. Unfortunately, previous methods rarely consider the role of link direction for link prediction. In fact, many real-world complex networks are directed and ignoring the link direction will mean overlooking important information. In this study, we propose a phase-dynamic algorithm of the directed network nodes to analyse the role of link directions and demonstrate that the bi-directional links and the one-directional links have different roles in link prediction and network structure formation. From this, we propose new directional prediction methods and use six real networks to test our algorithms. In real networks, we find that compared to a pair of nodes which are connected by a one-directional link, a pair of nodes which are connected by a bi-directional link always have higher probabilities to connect to the common neighbours with only bi-directional links (or conversely by one-directional links). We suggest that, in the real networks, the bi-directional links will generally be more informative for link prediction and network structure formation. In addition, we propose a new directional randomized algorithm to demonstrate that the direction of the links plays a significant role in link prediction and network structure formation.

  13. Attention Deficit Hyperactivity Disorder and Motor Impairment.

    PubMed

    Goulardins, Juliana B; Marques, Juliana C B; De Oliveira, Jorge A

    2017-04-01

    Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorder during childhood, affecting approximately 3-6% of school-aged children; its cardinal symptoms of high activity, impulsivity, and behavioral distractibility might be assumed to have close relationships to interferences with motor skills. A separate body of literature attests to ways that motor problems can severely impact children's daily lives, as motor problems may occur in 30-50% of children with ADHD. This article critically reviews research on motor impairment in children with ADHD, notable differences in motor performance of individuals with ADHD compared with age-matched controls, and possible neural underpinnings of this impairment. We discuss the highly prevalent link between ADHD and developmental coordination disorder (DCD) and the lack of a clear research consensus about motor difficulties in ADHD. Despite increasing evidence and diagnostic classifications that define DCD by motor impairment, the role of ADHD symptoms in DCD has not been delineated. Similarly, while ADHD may predispose children to motor problems, it is unclear whether any such motor difficulties observed in this population are inherent to ADHD or are mediated by comorbid DCD. Future research should address the exact nature and long-term consequences of motor impairment in children with ADHD and elucidate effective treatment strategies for these disorders together and apart.

  14. 49 CFR 385.303 - How does a motor carrier register with the FMCSA?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 5 2013-10-01 2013-10-01 false How does a motor carrier register with the FMCSA... register with the FMCSA? Link to an amendment published at 78 FR 52649, Aug. 23, 2013. A motor carrier may... motor carrier register with the FMCSA? A motor carrier registers with FMCSA by completing Form...

  15. Forging Links.

    ERIC Educational Resources Information Center

    Stewig, John Warren

    Blacksmiths and their craft have changed with the times, and as times change for teachers, they too should be forgers of links. Teacher-to-teacher links should extend beyond the faculty lounge to support systems and active groups of individuals concerned about each other. Another personal link can be made by developing a grade level, system-wide…

  16. Gross motor control

    MedlinePlus

    Gross motor control is the ability to make large, general movements (such as waving an arm or lifting a ... Gross motor control is a milestone in the development of an infant. Infants develop gross motor control before they ...

  17. Starting motor

    SciTech Connect

    Tanaka, T.; Hamano, I

    1989-05-23

    This patent describes a starting motor having a housing, planetary reduction gears including an internal gear in the housing. The improvement consists of an elastic member having a first annular portion mounted in engagement with a fixed annular member of the housing and a plurality of protruding axially extending elastic portions providing a corrugated surface pressed into engagement with an end portion of the internal gear, the elastic member being sandwiched between the internal gear and the housing member, the protruding axially extending elastic portions providing resilient means which flex and incline circumferentially under turning force from the internal gear and exert reactive thrust on the internal gear elastically so that the frictional force at the abutting surfaces of the protruding portions holds the internal gear in resilient engagement with the elastic member and the resilient means acts as a buffer to absorb rotary impact force developing in the planetary reduction gears.

  18. Motor control for a brushless DC motor

    NASA Technical Reports Server (NTRS)

    Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)

    1985-01-01

    This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

  19. Na+-driven bacterial flagellar motors.

    PubMed

    Imae, Y; Atsumi, T

    1989-12-01

    Bacterial flagellar motors are the reversible rotary engine which propels the cell by rotating a helical flagellar filament as a screw propeller. The motors are embedded in the cytoplasmic membrane, and the energy for rotation is supplied by the electrochemical potential of specific ions across the membrane. Thus, the analysis of motor rotation at the molecular level is linked to an understanding of how the living system converts chemical energy into mechanical work. Based on the coupling ions, the motors are divided into two types; one is the H+-driven type found in neutrophiles such as Bacillus subtilis and Escherichia coli and the other is the Na+-driven type found in alkalophilic Bacillus and marine Vibrio. In this review, we summarize the current status of research on the rotation mechanism of the Na+-driven flagellar motors, which introduces several new aspects in the analysis.

  20. Corticospinal circuit plasticity in motor rehabilitation from spinal cord injury.

    PubMed

    Serradj, Najet; Agger, Sydney F; Hollis, Edmund R

    2016-12-06

    Restoring corticospinal function after spinal cord injury is a significant challenge as the corticospinal tract elicits no substantive, spontaneous regeneration, and its interruption leaves a permanent deficit. The corticospinal circuit serves multiple motor and sensory functions within the mammalian nervous system as the direct link between isocortex and spinal cord. Maturation of the corticospinal circuit involves the refinement of projections within the spinal cord and a subsequent refinement of motor maps within the cortex. The plasticity of these cortical motor maps mirrors the acquisition of skilled motor learning, and both the maps and motor skills are disrupted following injury to the corticospinal tract. The motor cortex exhibits the capacity to incorporate changes in corticospinal projections induced by both spontaneous and therapeutic-mediated plasticity of corticospinal axons through appropriate rehabilitation. An understanding of the mechanisms of corticospinal plasticity in motor learning will undoubtedly help inform strategies to improve motor rehabilitation after spinal cord injury.

  1. Motor unit recruitment by size does not provide functional advantages for motor performance

    PubMed Central

    Dideriksen, Jakob L; Farina, Dario

    2013-01-01

    It is commonly assumed that the orderly recruitment of motor units by size provides a functional advantage for the performance of movements compared with a random recruitment order. On the other hand, the excitability of a motor neuron depends on its size and this is intrinsically linked to its innervation number. A range of innervation numbers among motor neurons corresponds to a range of sizes and thus to a range of excitabilities ordered by size. Therefore, if the excitation drive is similar among motor neurons, the recruitment by size is inevitably due to the intrinsic properties of motor neurons and may not have arisen to meet functional demands. In this view, we tested the assumption that orderly recruitment is necessarily beneficial by determining if this type of recruitment produces optimal motor output. Using evolutionary algorithms and without any a priori assumptions, the parameters of neuromuscular models were optimized with respect to several criteria for motor performance. Interestingly, the optimized model parameters matched well known neuromuscular properties, but none of the optimization criteria determined a consistent recruitment order by size unless this was imposed by an association between motor neuron size and excitability. Further, when the association between size and excitability was imposed, the resultant model of recruitment did not improve the motor performance with respect to the absence of orderly recruitment. A consistent observation was that optimal solutions for a variety of criteria of motor performance always required a broad range of innervation numbers in the population of motor neurons, skewed towards the small values. These results indicate that orderly recruitment of motor units in itself does not provide substantial functional advantages for motor control. Rather, the reason for its near-universal presence in human movements is that motor functions are optimized by a broad range of innervation numbers. PMID:24144879

  2. Wind motor

    SciTech Connect

    Biscomb, L. I.

    1985-07-09

    A spider-like carrier having at least three generally horizontal arms has a hub mounted to the vertical, rotary-axis input shaft of a load. Each arm has at least one horizontal cross-arm secured to it near its radially outer end, which is supported from the ground by a low-friction support device such as a wheel or set of wheels. Mounted on each arm at the cross-arm or cross-arms is at least one sail, vane, airfoil or similar working member which is erected or spread generally normally to the wind when the respective arm is located for the working member to be blown downwind and is feathered or headed to the wind when the respective arm is located for the working member to be driven upwind. Horizontal axis and vertical axis journalling options for the working members and various sail shapes are shown, including a concave/convex sail and motor-oriented airfoil shape which provides lift when being driven upwind are shown.

  3. Eye movements may cause motor contagion effects.

    PubMed

    Constable, Merryn D; de Grosbois, John; Lung, Tiffany; Tremblay, Luc; Pratt, Jay; Welsh, Timothy N

    2016-10-26

    When a person executes a movement, the movement is more errorful while observing another person's actions that are incongruent rather than congruent with the executed action. This effect is known as "motor contagion". Accounts of this effect are often grounded in simulation mechanisms: increased movement error emerges because the motor codes associated with observed actions compete with motor codes of the goal action. It is also possible, however, that the increased movement error is linked to eye movements that are executed simultaneously with the hand movement because oculomotor and manual-motor systems are highly interconnected. In the present study, participants performed a motor contagion task in which they executed horizontal arm movements while observing a model making either vertical (incongruent) or horizontal (congruent) movements under three conditions: no instruction, maintain central fixation, or track the model's hand with the eyes. A significant motor contagion-like effect was only found in the 'track' condition. Thus, 'motor contagion' in the present task may be an artifact of simultaneously executed incongruent eye movements. These data are discussed in the context of stimulation and associative learning theories, and raise eye movements as a critical methodological consideration for future work on motor contagion.

  4. Resources and Fact Sheets on Servicing Motor Vehicle Air Conditioners (Summary Page)

    EPA Pesticide Factsheets

    Page provides links to resources that can assist motor vehicle air-conditioning system technicians in understanding system servicing requirements and best practices, and learn about alternative refrigerants.

  5. Community Links

    ERIC Educational Resources Information Center

    Nelson, Mary

    1975-01-01

    At Moraine Valley Community College (Illinois), a chain of events, programs, activities, and services has linked the college and community in such areas as fine arts, ethnic groups, public services, community action, community service, and community education. (Author/NHM)

  6. Link Analysis

    NASA Astrophysics Data System (ADS)

    Donoho, Steve

    Link analysis is a collection of techniques that operate on data that can be represented as nodes and links. This chapter surveys a variety of techniques including subgraph matching, finding cliques and K-plexes, maximizing spread of influence, visualization, finding hubs and authorities, and combining with traditional techniques (classification, clustering, etc). It also surveys applications including social network analysis, viral marketing, Internet search, fraud detection, and crime prevention.

  7. Simple motor drive system operates heavy hinged door

    NASA Technical Reports Server (NTRS)

    Pitkin, R. G.

    1966-01-01

    Motor drive system remotely operates heavy steel radiation shielding doors. The drive consists of a standard motor reducer unit which is mounted on the door. This reducer drives a sprocket which is linked by chain to a fixed sprocket of the same size on the door jamb.

  8. Directed flux motor

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A directed flux motor described utilizes the directed magnetic flux of at least one magnet through ferrous material to drive different planetary gear sets to achieve capabilities in six actuated shafts that are grouped three to a side of the motor. The flux motor also utilizes an interwoven magnet configuration which reduces the overall size of the motor. The motor allows for simple changes to modify the torque to speed ratio of the gearing contained within the motor as well as simple configurations for any number of output shafts up to six. The changes allow for improved manufacturability and reliability within the design.

  9. Molecular motors: thermodynamics and the random walk.

    PubMed Central

    Thomas, N.; Imafuku, Y.; Tawada, K.

    2001-01-01

    The biochemical cycle of a molecular motor provides the essential link between its thermodynamics and kinetics. The thermodynamics of the cycle determine the motor's ability to perform mechanical work, whilst the kinetics of the cycle govern its stochastic behaviour. We concentrate here on tightly coupled, processive molecular motors, such as kinesin and myosin V, which hydrolyse one molecule of ATP per forward step. Thermodynamics require that, when such a motor pulls against a constant load f, the ratio of the forward and backward products of the rate constants for its cycle is exp [-(DeltaG + u(0)f)/kT], where -DeltaG is the free energy available from ATP hydrolysis and u(0) is the motor's step size. A hypothetical one-state motor can therefore act as a chemically driven ratchet executing a biased random walk. Treating this random walk as a diffusion problem, we calculate the forward velocity v and the diffusion coefficient D and we find that its randomness parameter r is determined solely by thermodynamics. However, real molecular motors pass through several states at each attachment site. They satisfy a modified diffusion equation that follows directly from the rate equations for the biochemical cycle and their effective diffusion coefficient is reduced to D-v(2)tau, where tau is the time-constant for the motor to reach the steady state. Hence, the randomness of multistate motors is reduced compared with the one-state case and can be used for determining tau. Our analysis therefore demonstrates the intimate relationship between the biochemical cycle, the force-velocity relation and the random motion of molecular motors. PMID:11600075

  10. Energy efficient motors

    NASA Astrophysics Data System (ADS)

    1995-01-01

    This TechData Sheet is intended to help activity personnel identify cost effective energy projects for energy efficient motors. With this guide an energy manager can identify when an energy efficient induction motor should be used.

  11. Chronic motor tic disorder

    MedlinePlus

    Chronic vocal tic disorder; Tic - chronic motor tic disorder ... Chronic motor tic disorder is more common than Tourette syndrome . Chronic tics may be forms of Tourette syndrome. Tics usually start ...

  12. Motor patterns during active electrosensory acquisition

    PubMed Central

    Hofmann, Volker; Geurten, Bart R. H.; Sanguinetti-Scheck, Juan I.; Gómez-Sena, Leonel; Engelmann, Jacob

    2014-01-01

    Motor patterns displayed during active electrosensory acquisition of information seem to be an essential part of a sensory strategy by which weakly electric fish actively generate and shape sensory flow. These active sensing strategies are expected to adaptively optimize ongoing behavior with respect to either motor efficiency or sensory information gained. The tight link between the motor domain and sensory perception in active electrolocation make weakly electric fish like Gnathonemus petersii an ideal system for studying sensory-motor interactions in the form of active sensing strategies. Analyzing the movements and electric signals of solitary fish during unrestrained exploration of objects in the dark, we here present the first formal quantification of motor patterns used by fish during electrolocation. Based on a cluster analysis of the kinematic values we categorized the basic units of motion. These were then analyzed for their associative grouping to identify and extract short coherent chains of behavior. This enabled the description of sensory behavior on different levels of complexity: from single movements, over short behaviors to more complex behavioral sequences during which the kinematics alter between different behaviors. We present detailed data for three classified patterns and provide evidence that these can be considered as motor components of active sensing strategies. In accordance with the idea of active sensing strategies, we found categorical motor patterns to be modified by the sensory context. In addition these motor patterns were linked with changes in the temporal sampling in form of differing electric organ discharge frequencies and differing spatial distributions. The ability to detect such strategies quantitatively will allow future research to investigate the impact of such behaviors on sensing. PMID:24904337

  13. Synthesis and characterization of tritium labeled N-((R)-1-((S)-4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidin-1-yl)-3-methyl-1-oxobutan-2-yl)-3-sulfamoylbenzamide.

    PubMed

    Hong, Yang; Hynes, John; Tian, Yuan; Balasubramanian, Balu; Bonacorsi, Samuel

    2015-08-01

    N-((R)-1-((S)-4-(4-chlorophenyl)-4-hydroxy-3,3-dimethylpiperidin-1-yl)-3-methyl-1-oxobutan-2-yl)-3-sulfamoylbenzamide is a potent C-C chemokine receptor 1 (CCR1) antagonist. The compound, possessing benzamide functionality, successfully underwent tritium/hydrogen (T/H) exchange with an organoiridium catalyst (Crabtree's catalyst). The labeling pattern in the product was studied with liquid chromatography-mass spectrometry, time-of-flight mass spectrometry, and (3) H-NMR. Overall, multiple labeled species were identified. In addition to the anticipated incorporation of tritium in the benzamide moiety, tritium labeling was observed in the valine portion of the molecule including substitution at its chiral carbon. Using authentic standards, liquid chromatography analysis of the labeled compound showed complete retention of stereochemical configuration.

  14. Smart motor technology

    NASA Technical Reports Server (NTRS)

    Packard, D.; Schmitt, D.

    1984-01-01

    Current spacecraft design relies upon microprocessor control; however, motors usually require extensive additional electronic circuitry to interface with these microprocessor controls. An improved control technique that allows a smart brushless motor to connect directly to a microprocessor control system is described. An actuator with smart motors receives a spacecraft command directly and responds in a closed loop control mode. In fact, two or more smart motors can be controlled for synchronous operation.

  15. Piezoelectric ultrasonic motors

    SciTech Connect

    Wallaschek, J.

    1994-12-31

    Piezoelectric ultrasonic motors are a new type of actuator. They are characterized by high torque at low rotational speed, simple mechanical design and good controllability. They also provide a high holding torque even if no power is applied. Compared to electromagnetic actuators the torque per volume ratio of piezoelectric ultrasonic motors can be higher by an order of magnitude. Recently various types of piezoelectric ultrasonic motors have been developed for industrial applications. This paper describes several types of piezoelectric ultrasonic motors.

  16. Antibody-mediated targeted gene transfer to NMDA NR1-containing neurons in rat neocortex by helper virus-free HSV-1 vector particles containing a chimeric HSV-1 glycoprotein C-staphylococcus A protein.

    PubMed

    Cao, Haiyan; Zhang, Guo-Rong; Geller, Alfred I

    2010-09-10

    Because of the heterogeneous cellular composition of the brain, and especially the forebrain, cell type-specific expression will benefit many potential applications of direct gene transfer. The two prevalent approaches for achieving cell type-specific expression are using a cell type-specific promoter or targeting gene transfer to a specific cell type. Targeted gene transfer with Herpes Simplex Virus (HSV-1) vectors modifies glycoprotein C (gC) to replace the heparin binding domain, which binds to many cell types, with a binding activity for a specific cell surface protein. We previously reported targeted gene transfer to nigrostriatal neurons using chimeric gC-glial cell line-derived neurotrophic factor or gC-brain-derived neurotrophic factor protein. Unfortunately, this approach is limited to cells that express the cognate receptor for either neurotrophic factor. Thus, a general strategy for targeting gene transfer to many different types of neurons is desirable. Antibody-mediated targeted gene transfer has been developed for targeting specific virus vectors to specific peripheral cell types; a specific vector particle protein is modified to contain the Staphylococcus A protein ZZ domain, which binds immunoglobulin (Ig) G. Here, we report antibody-mediated targeted gene transfer of HSV-1 vectors to a specific type of forebrain neuron. We constructed a chimeric gC-ZZ protein, and showed this protein is incorporated into vector particles and binds Ig G. Complexes of these vector particles and an antibody to the NMDA receptor NR1 subunit supported targeted gene transfer to NR1-containing neocortical neurons in the rat brain, with long-term (2 months) expression.

  17. Motor learning in animal models of Parkinson's disease: Aberrant synaptic plasticity in the motor cortex.

    PubMed

    Xu, Tonghui; Wang, Shaofang; Lalchandani, Rupa R; Ding, Jun B

    2017-03-25

    In Parkinson's disease (PD), dopamine depletion causes major changes in the brain, resulting in the typical cardinal motor features of the disease. PD neuropathology has been restricted to postmortem examinations, which are limited to only a single time of PD progression. Models of PD in which dopamine tone in the brain is chemically or physically disrupted are valuable tools in understanding the mechanisms of the disease. The basal ganglia have been well studied in the context of PD, and circuit changes in response to dopamine loss have been linked to the motor dysfunctions in PD. However, the etiology of the cognitive dysfunctions that are comorbid in PD patients has remained unclear until now. In this article, we review recent studies exploring how dopamine depletion affects the motor cortex at the synaptic level. In particular, we highlight our recent findings on abnormal spine dynamics in the motor cortex of PD mouse models through in vivo time-lapse imaging and motor skill behavior assays. In combination with previous studies, a role of the motor cortex in skill learning and the impairment of this ability with the loss of dopamine are becoming more apparent. Taken together, we conclude with a discussion on the potential role for the motor cortex in PD, with the possibility of targeting the motor cortex for future PD therapeutics. © 2017 International Parkinson and Movement Disorder Society.

  18. Cloning of SmNCoA-62, a novel nuclear receptor co-activator from Schistosoma mansoni: assembly of a complex with a SmRXR1/SmNR1 heterodimer, SmGCN5 and SmCBP1.

    PubMed

    Fantappié, Marcelo Rosado; Bastos de Oliveira, Francisco Meirelles; de Moraes Maciel, Renata; Rumjanek, Franklin David; Wu, Wenjie; Loverde, Philip T

    2008-08-01

    The Schistosoma mansoni nuclear receptors (NR) SmRXR1 and SmNR1 have recently been shown to form a heterodimer and to bind to canonic hormone response DNA elements. Recruitment of co-regulatory proteins to NRs is required for their transcriptional and biological activities. Here, we cloned a novel S. mansoni NR co-activator, SmNCoA-62. SmNCoA-62 is highly homologous to the human Vitamin D receptor co-activator NCoA62/SKIP. SmNCoA-62 contains the SNW nuclear receptor interaction domain and a putative C-terminus transactivation domain. By using in vitro pull-down assays, we fully mapped the interaction domains of S. mansoni NR co-activators, SmNCoA-62, SmGCN5 and SmCBP1 with SmRXR1 and SmNR1, as well as the domains that mediate interactions amongst the co-activators themselves. By mutagenesis analysis, we showed that SmCBP1 LxxLL motif 2 and LxxLL motif 3, but not LxxLL motif 1, were essential to mediate the interactions of SmCBP1 with the EF domains of SmRXR1 and SmNR1. Histone acetyltransferases SmGCN5 and SmCBP1 specifically acetylated the C/D domains of SmRXR1 and SmNR1. In addition, two acetylation sites of SmNR1 were identified. SmGCN5 and SmCBP1 also acetylated SmNCoA-62 but with significant differences in their acetylation activities. Using gel shift analysis, we were able to demonstrate, in vitro, the assembly of the co-activators on the SmRXR1/SmNR1 heterodimer bound to DNA. LxxLL motifs 2 and 3 of SmCBP1 seemed to play a crucial role for the assembly of the co-activators to the DNA-bound SmRXR1/SmNR1 heterodimer.

  19. A quantitative review of the postmortem evidence for decreased cortical N-methyl-D-aspartate receptor expression levels in schizophrenia: How can we link molecular abnormalities to mismatch negativity deficits?

    PubMed

    Catts, Vibeke S; Lai, Yan Ling; Weickert, Cyndi Shannon; Weickert, Thomas W; Catts, Stanley V

    2016-04-01

    Evidence suggests that anomalous mismatch negativity (MMN) in schizophrenia is related to glutamatergic abnormalities, possibly involving N-methyl-D-aspartate (NMDA) receptors. Decreased cortical expressions of NMDA receptor subunits have been observed in schizophrenia, though not consistently. To aid with integration and interpretation of previous work, we performed a meta-analysis of effect sizes of mRNA or protein levels of the obligatory NR1 subunit in prefrontal cortex from people with schizophrenia. In schizophrenia compared to unaffected controls the pooled effect size was -0.64 (95% confidence interval: -1.08 to -0.20) for NR1 mRNA reduction and -0.44 (95% confidence interval: -0.80 to -0.07) for NR1 protein reduction. These results represent the first step to a deeper understanding of the region-specific, cell-specific, and stage-specific NMDA receptor hypofunction in schizophrenia, which could be linked to mismatch negativity deficits via transgenic and pharmacological animal models.

  20. A Reconfigurable Stepping Motor

    NASA Astrophysics Data System (ADS)

    Rogers, Charles; Selvaggi, Richard

    2009-04-01

    Multiphase brushless actuators, commonly known as the stepper motors, are ubiquitous for many precision control applications. Developments in the microelectronics have lead to their use as efficient drive motors for modern electric vehicles. Understanding the physics and the control logic for interfacing these transducers continues to be important for scientists and engineers. An overview of the stepping motor principles and interfacing requirements is presented and a simple working model used to teach the concepts of stepper motors is described and demonstrated. This model was used to design a much larger stepper motor required to precisely rotate a massive optical system in the undergraduate advanced physics laboratory.

  1. Motor/generator

    DOEpatents

    Hickam, Christopher Dale

    2008-05-13

    A motor/generator is provided for connecting between a transmission input shaft and an output shaft of a prime mover. The motor/generator may include a motor/generator housing, a stator mounted to the motor/generator housing, a rotor mounted at least partially within the motor/generator housing and rotatable about a rotor rotation axis, and a transmission-shaft coupler drivingly coupled to the rotor. The transmission-shaft coupler may include a clamp, which may include a base attached to the rotor and a plurality of adjustable jaws.

  2. Solid propellant motor

    NASA Technical Reports Server (NTRS)

    Shafer, J. I.; Marsh, H. E., Jr. (Inventor)

    1978-01-01

    A case bonded end burning solid propellant rocket motor is described. A propellant with sufficiently low modulus to avoid chamber buckling on cooling from cure and sufficiently high elongation to sustain the stresses induced without cracking is used. The propellant is zone cured within the motor case at high pressures equal to or approaching the pressure at which the motor will operate during combustion. A solid propellant motor with a burning time long enough that its spacecraft would be limited to a maximum acceleration of less than 1 g is provided by one version of the case bonded end burning solid propellant motor of the invention.

  3. Piezoceramic Ultrasonic Motor Technology

    SciTech Connect

    Burden, J.S.

    1999-02-24

    The objective of this project was to team Aerotech and AlliedSignal FM and T (AS) to develop a cost-efficient process for small-batch, high performance PZT motor production. Aerotech would acquire the basic process expertise in motor fabrication, assembly, and testing from AS. Together, Aerotech and AS were to identify appropriate process improvements, focusing on raw material quality, manufacturing processes, and durability assessment. Aerotech would then design and build a motor in consultation with AS. Aerotech engineering observed motor manufacturing in the AS piezo lab and worked side by side with AS personnel to build and test a prototype motor to facilitate learning the technology. Using information from AS and hands-on experience with the AS motor drive system enabled Aerotech to design and build its own laboratory drive system to operate motors. The team compiled information to establish a potential piezo motor users' list, and an intellectual property search was conducted to understand current patent and IP (intellectual property) status of motor design. Work was initiated to identify and develop an American source for piezo motor elements; however, due to manpower restraints created by the resignation of the AS Ph.D. ceramist responsible for these tasks, the project schedule slipped. The project was subsequently terminated before significant activities were accomplished. AS did, however, provide Aerotech with contacts in Japanese industry that are willing and capable of supplying them with special design motor elements.

  4. Motor degradation prediction methods

    SciTech Connect

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-12-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

  5. Motorized support jack

    DOEpatents

    Haney, Steven J.; Herron, Donald Joe

    2001-01-01

    A compact, vacuum compatible motorized jack for supporting heavy loads and adjusting their positions is provided. The motorized jack includes: (a) a housing having a base; (b) a first roller device that provides a first slidable surface and that is secured to the base; (c) a second roller device that provides a second slidable surface and that has an upper surface; (d) a wedge that is slidably positioned between the first roller device and the second roller device so that the wedge is in contact with the first slidable surface and the second slidable surface; (e) a motor; and (d) a drive mechanism that connects the motor and the wedge to cause the motor to controllably move the wedge forwards or backwards. Individual motorized jacks can support and lift of an object at an angle. Two or more motorized jacks can provide tip, tilt and vertical position adjustment capabilities.

  6. Motorized support jack

    DOEpatents

    Haney, Steven J.; Herron, Donald Joe

    2003-05-13

    A compact, vacuum compatible motorized jack for supporting heavy loads and adjusting their positions is provided. The motorized jack includes: (a) a housing having a base; (b) a first roller device that provides a first slidable surface and that is secured to the base; (c) a second roller device that provides a second slidable surface and that has an upper surface; (d) a wedge that is slidably positioned between the first roller device and the second roller device so that the wedge is in contact with the first slidable surface and the second slidable surface; (e) a motor; and (d) a drive mechanism that connects the motor and the wedge to cause the motor to controllably move the wedge forwards or backwards. Individual motorized jacks can support and lift of an object at an angle. Two or more motorized jacks can provide tip, tilt and vertical position adjustment capabilities.

  7. Brain-Computer Link Restores Some Movement to Quadraplegic Man

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_164322.html Brain-Computer Link Restores Some Movement to Quadraplegic Man ... aspirin -- in the motor cortex area of his brain. That's the brain region responsible for hand movement. ...

  8. Measuring collective transport by defined numbers of processive and nonprocessive kinesin motors.

    PubMed

    Furuta, Ken'ya; Furuta, Akane; Toyoshima, Yoko Y; Amino, Misako; Oiwa, Kazuhiro; Kojima, Hiroaki

    2013-01-08

    Intracellular transport is thought to be achieved by teams of motor proteins bound to a cargo. However, the coordination within a team remains poorly understood as a result of the experimental difficulty in controlling the number and composition of motors. Here, we developed an experimental system that links together defined numbers of motors with defined spacing on a DNA scaffold. By using this system, we linked multiple molecules of two different types of kinesin motors, processive kinesin-1 or nonprocessive Ncd (kinesin-14), in vitro. Both types of kinesins markedly increased their processivities with motor number. Remarkably, despite the poor processivity of individual Ncd motors, the coupling of two Ncd motors enables processive movement for more than 1 μm along microtubules (MTs). This improvement was further enhanced with decreasing spacing between motors. Force measurements revealed that the force generated by groups of Ncd is additive when two to four Ncd motors work together, which is much larger than that generated by single motors. By contrast, the force of multiple kinesin-1s depends only weakly on motor number. Numerical simulations and single-molecule unbinding measurements suggest that this additive nature of the force exerted by Ncd relies on fast MT binding kinetics and the large drag force of individual Ncd motors. These features would enable small groups of Ncd motors to crosslink MTs while rapidly modulating their force by forming clusters. Thus, our experimental system may provide a platform to study the collective behavior of motor proteins from the bottom up.

  9. Dissociating motor cortex from the motor

    PubMed Central

    Schieber, Marc H

    2011-01-01

    Abstract During closed-loop control of a brain–computer interface, neurons in the primary motor cortex can be intensely active even though the subject may be making no detectable movement or muscle contraction. How can neural activity in the primary motor cortex become dissociated from the movements and muscles of the native limb that it normally controls? Here we examine circumstances in which motor cortex activity is known to dissociate from movement – including mental imagery, visuo-motor dissociation and instructed delay. Many such motor cortex neurons may be related to muscle activity only indirectly. Furthermore, the integration of thousands of synaptic inputs by individual α-motoneurons means that under certain circumstances even cortico-motoneuronal cells, which make monosynaptic connections to α-motoneurons, can become dissociated from muscle activity. The natural ability of motor cortex neurons under voluntarily control to become dissociated from bodily movement may underlie the utility of this cortical area for controlling brain–computer interfaces. PMID:22005673

  10. Sensory-motor transformations for speech occur bilaterally.

    PubMed

    Cogan, Gregory B; Thesen, Thomas; Carlson, Chad; Doyle, Werner; Devinsky, Orrin; Pesaran, Bijan

    2014-03-06

    Historically, the study of speech processing has emphasized a strong link between auditory perceptual input and motor production output. A kind of 'parity' is essential, as both perception- and production-based representations must form a unified interface to facilitate access to higher-order language processes such as syntax and semantics, believed to be computed in the dominant, typically left hemisphere. Although various theories have been proposed to unite perception and production, the underlying neural mechanisms are unclear. Early models of speech and language processing proposed that perceptual processing occurred in the left posterior superior temporal gyrus (Wernicke's area) and motor production processes occurred in the left inferior frontal gyrus (Broca's area). Sensory activity was proposed to link to production activity through connecting fibre tracts, forming the left lateralized speech sensory-motor system. Although recent evidence indicates that speech perception occurs bilaterally, prevailing models maintain that the speech sensory-motor system is left lateralized and facilitates the transformation from sensory-based auditory representations to motor-based production representations. However, evidence for the lateralized computation of sensory-motor speech transformations is indirect and primarily comes from stroke patients that have speech repetition deficits (conduction aphasia) and studies using covert speech and haemodynamic functional imaging. Whether the speech sensory-motor system is lateralized, like higher-order language processes, or bilateral, like speech perception, is controversial. Here we use direct neural recordings in subjects performing sensory-motor tasks involving overt speech production to show that sensory-motor transformations occur bilaterally. We demonstrate that electrodes over bilateral inferior frontal, inferior parietal, superior temporal, premotor and somatosensory cortices exhibit robust sensory-motor neural

  11. Auditory-perceptual learning improves speech motor adaptation in children.

    PubMed

    Shiller, Douglas M; Rochon, Marie-Lyne

    2014-08-01

    Auditory feedback plays an important role in children's speech development by providing the child with information about speech outcomes that is used to learn and fine-tune speech motor plans. The use of auditory feedback in speech motor learning has been extensively studied in adults by examining oral motor responses to manipulations of auditory feedback during speech production. Children are also capable of adapting speech motor patterns to perceived changes in auditory feedback; however, it is not known whether their capacity for motor learning is limited by immature auditory-perceptual abilities. Here, the link between speech perceptual ability and the capacity for motor learning was explored in two groups of 5- to 7-year-old children who underwent a period of auditory perceptual training followed by tests of speech motor adaptation to altered auditory feedback. One group received perceptual training on a speech acoustic property relevant to the motor task while a control group received perceptual training on an irrelevant speech contrast. Learned perceptual improvements led to an enhancement in speech motor adaptation (proportional to the perceptual change) only for the experimental group. The results indicate that children's ability to perceive relevant speech acoustic properties has a direct influence on their capacity for sensory-based speech motor adaptation.

  12. Piezoelectric Motors and Transformers

    NASA Astrophysics Data System (ADS)

    Uchino, K.

    Piezoelectric ceramics forms a new field between electronic and structural ceramics [1-4]. Application fields are classified into three categories: positioners, motors, and vibration suppressors. From the market research result for 80 Japanese component industries in 1992, tiny motors in the range of 5-8 mm are required in large numbers for office and portable equipment; the conventional electromagnetic (EM) motors are rather difficult to produce in this size with sufficient energy efficiency, while Silicon MEMS actuators are too small to be used in practice. Piezoelectric ultrasonic motors whose efficiency is insensitive to size are superior in the millimeter motor area. The manufacturing precision of optical instruments such as lasers and cameras, and the positioning accuracy for fabricating semiconductor chips are of the order of 0.1μm which is much smaller than the backlash of the EM motors. Vibration suppression in space structures and military vehicles also require compact but mighty piezoelectric actuators.

  13. High-intensity Interval Exercise Promotes Motor Cortex Disinhibition and Early Motor Skill Consolidation.

    PubMed

    Stavrinos, Ellen L; Coxon, James P

    2017-04-01

    Gamma-aminobutyric acid (GABA) inhibition shapes motor cortex output, gates synaptic plasticity in the form of long-term potentiation, and plays an important role in motor learning. Remarkably, recent studies have shown that acute cardiovascular exercise can improve motor memory, but the cortical mechanisms are not completely understood. We investigated whether an acute bout of lower-limb high-intensity interval (HIT) exercise could promote motor memory formation in humans through changes in cortical inhibition within the hand region of the primary motor cortex. We used TMS to assess the input-output relationship, along with inhibition involving GABAA and GABAB receptors. Measures were obtained before and after a 20-min session of HIT cycling (exercise group) or rest (control group). We then had the same participants learn a new visuomotor skill and perform a retention test 5 hr later in the absence of sleep. No differences were found in corticomotor excitability or GABAB inhibition; however, synaptic GABAA inhibition was significantly reduced for the exercise group but not the control group. HIT exercise was found to enhance motor skill consolidation. These findings link modification of GABA to improved motor memory consolidation after HIT exercise and suggest that the beneficial effects of exercise on consolidation might not be dependent on sleep.

  14. Cryogenic Electric Motor Tested

    NASA Technical Reports Server (NTRS)

    Brown, Gerald V.

    2004-01-01

    Technology for pollution-free "electric flight" is being evaluated in a number of NASA Glenn Research Center programs. One approach is to drive propulsive fans or propellers with electric motors powered by fuel cells running on hydrogen. For large transport aircraft, conventional electric motors are far too heavy to be feasible. However, since hydrogen fuel would almost surely be carried as liquid, a propulsive electric motor could be cooled to near liquid hydrogen temperature (-423 F) by using the fuel for cooling before it goes to the fuel cells. Motor windings could be either superconducting or high purity normal copper or aluminum. The electrical resistance of pure metals can drop to 1/100th or less of their room-temperature resistance at liquid hydrogen temperature. In either case, super or normal, much higher current density is possible in motor windings. This leads to more compact motors that are projected to produce 20 hp/lb or more in large sizes, in comparison to on the order of 2 hp/lb for large conventional motors. High power density is the major goal. To support cryogenic motor development, we have designed and built in-house a small motor (7-in. outside diameter) for operation in liquid nitrogen.

  15. Sensorless, online motor diagnostics

    SciTech Connect

    Kliman, G.B.; Premerlani, W.J.; Yazici, B.; Koegl, R.A.; Mazereeuw, J.

    1997-04-01

    Electric motors play a very important role in the safe and efficient running of any industrial plant. Early detection of abnormalities in the motors will help avoid expensive failures. Motor current signature analysis (MCSA) implemented in a computer-based motor monitor can contribute to such condition-based maintenance functions. Such a system may also detect an abnormality in the process as well as the motor. Extensive online monitoring of the motors can lead to greater plant availability, extended plant life, higher quality product, and smoother plant operation. With advances in digital technology over the last several years, adequate data processing capability is now available on cost-effective, microprocessor-based, protective-relay platforms to monitor motors for a variety of abnormalities in addition to the normal protection functions. Such multifunction monitors, first introduced by Multilin, are displacing the multiplicity of electromechanical devices commonly applied for many years. Following some background information on motor monitoring, this article features recent developments in providing tools for the diagnosis of faults or incipient faults in electric motor drives: Sensorless torque measurement, direct detection of turn-to-turn short circuits, detection of cracked or broken rotor bars, and detection of bearing deterioration.

  16. Hybrid vehicle motor alignment

    DOEpatents

    Levin, Michael Benjamin

    2001-07-03

    A rotor of an electric motor for a motor vehicle is aligned to an axis of rotation for a crankshaft of an internal combustion engine having an internal combustion engine and an electric motor. A locator is provided on the crankshaft, a piloting tool is located radially by the first locator to the crankshaft. A stator of the electric motor is aligned to a second locator provided on the piloting tool. The stator is secured to the engine block. The rotor is aligned to the crankshaft and secured thereto.

  17. Transatlantic link

    NASA Astrophysics Data System (ADS)

    (left) European Geophysical Society (EGS) President Rolf Meissner at AGU Headquarters with (center) Executive Director Fred Spilhaus and (right) Foreign Secretary Juan Roederer. Meissner attended the meeting of AGU's Committee on International Participation (CIP) on February 26, 1988. At that meeting, specific ways of fostering close links between AGU and EGS were discussed.A few weeks later, Roederer and AGU staff, working with EGS Secretary-General Arne Richter at the EGS meeting in Bologna, Italy, March 21-25, planned details of the establishment of an AGU office in Europe. The Copernicus Gesellschaft, a new entity located on the premises of the Max Planck Institute for Aeronomy in Lindau, Federal Republic of Germany, will provide the administrative staff and handle logistics.

  18. A catalytic oligomeric motor that walks along a filament track

    SciTech Connect

    Huang, Mu-Jie Kapral, Raymond

    2015-06-28

    Most biological motors in the cell execute chemically powered conformational changes as they walk on biopolymer filaments in order to carry out directed transport functions. Synthetic motors that operate in a similar manner are being studied since they have the potential to perform similar tasks in a variety of applications. In this paper, a synthetic nanomotor that moves along a filament track, without invoking motor conformational changes, is constructed and its properties are studied in detail. The motor is an oligomer comprising three linked beads with specific binding properties. The filament track is a stiff polymer chain, also described by a linear chain of linked coarse-grained molecular groups modeled as beads. Reactions on the filament that are catalyzed by a motor bead and use fuel in the environment, in conjunction within the binding affinities of the motor beads to the filament beads, lead to directed motion. The system operates out of equilibrium due to the state of the filament and supply of fuel. The motor, filament, and surrounding medium are all described at microscopic level that permits a full analysis of the motor motion. A stochastic model that captures the main trends seen in the simulations is also presented. The results of this study point to some of the key features that could be used to construct nanomotors that undergo biased walks powered by chemical reactions on filaments.

  19. Discrete Motor Coordinates for Vowel Production

    PubMed Central

    Assaneo, María Florencia; Trevisan, Marcos A.; Mindlin, Gabriel B.

    2013-01-01

    Current models of human vocal production that capture peripheral dynamics in speech require large dimensional measurements of the neural activity, which are mapped into equally complex motor gestures. In this work we present a motor description for vowels as points in a discrete low-dimensional space. We monitor the dynamics of 3 points at the oral cavity using Hall-effect transducers and magnets, describing the resulting signals during normal utterances in terms of active/inactive patterns that allow a robust vowel classification in an abstract binary space. We use simple matrix algebra to link this representation to the anatomy of the vocal tract and to recent reports of highly tuned neuronal activations for vowel production, suggesting a plausible global strategy for vowel codification and motor production. PMID:24244681

  20. Discrete motor coordinates for vowel production.

    PubMed

    Assaneo, María Florencia; Trevisan, Marcos A; Mindlin, Gabriel B

    2013-01-01

    Current models of human vocal production that capture peripheral dynamics in speech require large dimensional measurements of the neural activity, which are mapped into equally complex motor gestures. In this work we present a motor description for vowels as points in a discrete low-dimensional space. We monitor the dynamics of 3 points at the oral cavity using Hall-effect transducers and magnets, describing the resulting signals during normal utterances in terms of active/inactive patterns that allow a robust vowel classification in an abstract binary space. We use simple matrix algebra to link this representation to the anatomy of the vocal tract and to recent reports of highly tuned neuronal activations for vowel production, suggesting a plausible global strategy for vowel codification and motor production.

  1. Transcriptome profile analysis of young floral buds of fertile and sterile plants from the self-pollinated offspring of the hybrid between novel restorer line NR1 and Nsa CMS line in Brassica napus

    PubMed Central

    2013-01-01

    Background The fertile and sterile plants were derived from the self-pollinated offspring of the F1 hybrid between the novel restorer line NR1 and the Nsa CMS line in Brassica napus. To elucidate gene expression and regulation caused by the A and C subgenomes of B. napus, as well as the alien chromosome and cytoplasm from Sinapis arvensis during the development of young floral buds, we performed a genome-wide high-throughput transcriptomic sequencing for young floral buds of sterile and fertile plants. Results In this study, equal amounts of total RNAs taken from young floral buds of sterile and fertile plants were sequenced using the Illumina/Solexa platform. After filtered out low quality data, a total of 2,760,574 and 2,714,441 clean tags were remained in the two libraries, from which 242,163 (Ste) and 253,507 (Fer) distinct tags were obtained. All distinct sequencing tags were annotated using all possible CATG+17-nt sequences of the genome and transcriptome of Brassica rapa and those of Brassica oleracea as the reference sequences, respectively. In total, 3231 genes of B. rapa and 3371 genes of B. oleracea were detected with significant differential expression levels. GO and pathway-based analyses were performed to determine and further to understand the biological functions of those differentially expressed genes (DEGs). In addition, there were 1089 specially expressed unknown tags in Fer, which were neither mapped to B. oleracea nor to B. rapa, and these unique tags were presumed to arise basically from the added alien chromosome of S. arvensis. Fifteen genes were randomly selected and their expression levels were confirmed by quantitative RT-PCR, and fourteen of them showed consistent expression patterns with the digital gene expression (DGE) data. Conclusions A number of genes were differentially expressed between the young floral buds of sterile and fertile plants. Some of these genes may be candidates for future research on CMS in Nsa line, fertility

  2. Advanced Motor and Motor Control Development

    DTIC Science & Technology

    1988-08-01

    dc motor with electronic controller over a wide load and speed range was demonstrated. A centrifugal pump was used as the loading mechanism and hydraulic fluid was pumped in simulation of an aircraft engine fuel pump requirement. A motor speed of 45,000 rpm was reached and a maximum output of 68.5 hp was demonstrated. The response of the system to step commands for speed change was established. Reduction of size and weight of electronic control was established as a primary future goal. The program system concept with minor rotating machine improvements is viable for

  3. Information on stepping motors

    NASA Astrophysics Data System (ADS)

    Fongarland, G.

    1982-04-01

    The principles of the stepping motors which are often used in servomechanisms are reviewed. Variable reluctance as well as permanent magnet stepping motors are considered. Their operation is explained which includes permanent rotation, starting, stopping, and resonance effects. Several application examples, drawn from problems in automation, are outlined.

  4. Stepping motor controller

    DOEpatents

    Bourret, Steven C.; Swansen, James E.

    1984-01-01

    A stepping motor is microprocessingly controlled by digital circuitry which monitors the output of a shaft encoder adjustably secured to the stepping motor and generates a subsequent stepping pulse only after the preceding step has occurred and a fixed delay has expired. The fixed delay is variable on a real-time basis to provide for smooth and controlled deceleration.

  5. Stepping motor controller

    DOEpatents

    Bourret, S.C.; Swansen, J.E.

    1982-07-02

    A stepping motor is microprocessor controlled by digital circuitry which monitors the output of a shaft encoder adjustably secured to the stepping motor and generates a subsequent stepping pulse only after the preceding step has occurred and a fixed delay has expired. The fixed delay is variable on a real-time basis to provide for smooth and controlled deceleration.

  6. Induction motor control

    NASA Astrophysics Data System (ADS)

    Hansen, Irving G.

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  7. Induction motor control

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly utilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilizes induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  8. Induction motor control

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  9. Does intrinsic motivation enhance motor cortex excitability?

    PubMed

    Radel, Rémi; Pjevac, Dusan; Davranche, Karen; d'Arripe-Longueville, Fabienne; Colson, Serge S; Lapole, Thomas; Gruet, Mathieu

    2016-11-01

    Intrinsic motivation (IM) is often viewed as a spontaneous tendency for action. Recent behavioral and neuroimaging evidence indicate that IM, in comparison to extrinsic motivation (EM), solicits the motor system. Accordingly, we tested whether IM leads to greater excitability of the motor cortex than EM. To test this hypothesis, we used two different tasks to induce the motivational orientation using either words representing each motivational orientation or pictures previously linked to each motivational orientation through associative learning. Single-pulse transcranial magnetic stimulation over the motor cortex was applied when viewing the stimuli. Electromyographic activity was recorded on the contracted first dorsal interosseous muscle. Two indexes of corticospinal excitability (the amplitude of motor-evoked potential and the length of cortical silent period) were obtained through unbiased automatic detection and analyzed using a mixed model that provided both statistical power and a high level of control over all important individual, task, and stimuli characteristics. Across the two tasks and the two indices of corticospinal excitability, the exposure to IM-related stimuli did not lead to a greater corticospinal excitability than EM-related stimuli or than stimuli with no motivational valence (ps > .20). While these results tend to dismiss the advantage of IM at activating the motor cortex, we suggest alternative hypotheses to explain this lack of effect, which deserves further research.

  10. Linear summation of cat motor cortex outputs.

    PubMed

    Ethier, Christian; Brizzi, Laurent; Darling, Warren G; Capaday, Charles

    2006-05-17

    Recruitment of movement-related muscle synergies involves the functional linking of motor cortical points. We asked how the outputs of two simultaneously stimulated motor cortical points would interact. To this end, experiments were done in ketamine-anesthetized cats. When prolonged (e.g., 500 ms) trains of intracortical microstimulation were applied in the primary motor cortex, stimulus currents as low as 10-20 microA evoked coordinated movements of the contralateral forelimb. Paw kinematics in three dimensions and the electromyographic (EMG) activity of eight muscles were simultaneously recorded. We show that the EMG outputs of two cortical points simultaneously stimulated are additive. The movements were represented as displacement vectors pointing from initial to final paw position. The displacement vectors resulting from simultaneous stimulation of two cortical points pointed in nearly the same direction as the algebraic resultant vector. Linear summation of outputs was also found when inhibition at one of the cortical points was reduced by GABAA receptor antagonists. A simple principle emerges from these results. Notwithstanding the underlying complex neuronal circuitry, motor cortex outputs combine nearly linearly in terms of movement direction and muscle activation patterns. Importantly, simultaneous activation does not change the nature of the output at each point. An additional implication is that not all possible movements need be explicitly represented in the motor cortex; a large number of different movements may be synthesized from a smaller repertoire.

  11. Multiple dynamic representations in the motor cortex during sensorimotor learning.

    PubMed

    Huber, D; Gutnisky, D A; Peron, S; O'Connor, D H; Wiegert, J S; Tian, L; Oertner, T G; Looger, L L; Svoboda, K

    2012-04-25

    The mechanisms linking sensation and action during learning are poorly understood. Layer 2/3 neurons in the motor cortex might participate in sensorimotor integration and learning; they receive input from sensory cortex and excite deep layer neurons, which control movement. Here we imaged activity in the same set of layer 2/3 neurons in the motor cortex over weeks, while mice learned to detect objects with their whiskers and report detection with licking. Spatially intermingled neurons represented sensory (touch) and motor behaviours (whisker movements and licking). With learning, the population-level representation of task-related licking strengthened. In trained mice, population-level representations were redundant and stable, despite dynamism of single-neuron representations. The activity of a subpopulation of neurons was consistent with touch driving licking behaviour. Our results suggest that ensembles of motor cortex neurons couple sensory input to multiple, related motor programs during learning.

  12. ISRO's solid rocket motors

    NASA Astrophysics Data System (ADS)

    Nagappa, R.; Kurup, M. R.; Muthunayagam, A. E.

    1989-08-01

    Solid rocket motors have been the mainstay of ISRO's sounding rockets and the first generation satellite launch vehicles. For the new launch vehicle under development also, the solid rocket motors contribute significantly to the vehicle's total propulsive power. The rocket motors in use and under development have been developed for a variety of applications and range in size from 30 mm dia employing 450 g of solid propellant—employed for providing a spin to the apogee motors—to the giant 2.8 m dia motor employing nearly 130 tonnes of solid propellant. The initial development, undertaken in 1967 was of small calibre motor of 75 mm dia using a double base charge. The development was essentially to understand the technological elements. Extruded aluminium tubes were used as a rocket motor casing. The fore and aft closures were machined from aluminium rods. The grain was a seven-pointed star with an enlargement of the port at the aft end and was charged into the chamber using a polyester resin system. The nozzle was a metallic heat sink type with graphite throat insert. The motor was ignited with a black powder charge and fired for 2.0 s. Subsequent to this, further developmental activities were undertaken using PVC plastisol based propellants. A class of sounding rockets ranging from 125 to 560 mm calibre were realized. These rocket motors employed improved designs and had delivered lsp ranging from 2060 to 2256 Ns/kg. Case bonding could not be adopted due to the higher cure temperatures of the plastisol propellants but improvements were made in the grain charging techniques and in the design of the igniters and the nozzle. Ablative nozzles based on asbestos phenolic and silica phenolic with graphite inserts were used. For the larger calibre rocket motors, the lsp could be improved by metallic additives. In the early 1970s designs were evolved for larger and more efficient motors. A series of 4 motors for the country's first satellite launch vehicle SLV-3 were

  13. Motor Priming in Neurorehabilitation

    PubMed Central

    Stoykov, Mary Ellen; Madhavan, Sangeetha

    2014-01-01

    Priming is a type of implicit learning wherein a stimulus prompts a change in behavior. Priming has been long studied in the field of psychology. More recently, rehabilitation researchers have studied motor priming as a possible way to facilitate motor learning. For example, priming of the motor cortex is associated with changes in neuroplasticity that are associated with improvements in motor performance. Of the numerous motor priming paradigms under investigation, only a few are practical for the current clinical environment, and the optimal priming modalities for specific clinical presentations are not known. Accordingly, developing an understanding of the various types of motor priming paradigms and their underlying neural mechanisms is an important step for therapists in neurorehabilitation. Most importantly, an understanding of the methods and their underlying mechanisms is essential for optimizing rehabilitation outcomes. The future of neurorehabilitation is likely to include these priming methods, which are delivered prior to or in conjunction with primary neurorehabilitation therapies. In this Special Interest article we discuss those priming paradigms that are supported by the greatest amount of evidence including: (i) stimulation-based priming, (ii) motor imagery and action observation, (iii) sensory priming, (iv) movement-based priming, and (v) pharmacological priming. PMID:25415551

  14. Disrupting the ipsilateral motor cortex interferes with training of a complex motor task in older adults.

    PubMed

    Zimerman, Máximo; Heise, Kirstin-F; Gerloff, Christian; Cohen, Leonardo G; Hummel, Friedhelm C

    2014-04-01

    Performance of unimanual movements is associated with bihemispheric activity in the motor cortex in old adults. However, the causal functional role of the ipsilateral MC (iMC) for motor control is still not completely known. Here, the behavioral consequences of interference of the iMC during training of a complex motor skill were tested. Healthy old (58-85 years) and young volunteers (22-35 years) were tested in a double-blind, cross-over, sham-controlled design. Participants attended 2 different study arms with either cathodal transcranial direct current stimulation (ctDCS) or sham concurrent with training. Motor performance was evaluated before, during, 90 min, and 24 h after training. During training, a reduced slope of performance with ctDCS relative to sham was observed in old compared with young (F = 5.8, P = 0.02), with a decrease of correctly rehearsed sequences, an effect that was evident even after 2 consecutive retraining periods without intervention. Furthermore, the older the subject, the more prominent was the disruptive effect of ctDCS (R(2) = 0.50, P = 0.01). These data provide direct evidence for a causal functional link between the iMC and motor skill acquisition in old subjects pointing toward the concept that the recruitment of iMC in old is an adaptive process in response to age-related declines in motor functions.

  15. Miniature laser ignited bellows motor

    NASA Technical Reports Server (NTRS)

    Renfro, Steven L.; Beckman, Tom M.

    1994-01-01

    A miniature optically ignited actuation device has been demonstrated using a laser diode as an ignition source. This pyrotechnic driven motor provides between 4 and 6 lbs of linear force across a 0.090 inch diameter surface. The physical envelope of the device is 1/2 inch long and 1/8 inch diameter. This unique application of optical energy can be used as a mechanical link in optical arming systems or other applications where low shock actuation is desired and space is limited. An analysis was performed to determine pyrotechnic materials suitable to actuate a bellows device constructed of aluminum or stainless steel. The aluminum bellows was chosen for further development and several candidate pyrotechnics were evaluated. The velocity profile and delivered force were quantified using an non-intrusive optical motion sensor.

  16. Tug of War in Motor Protein Ensembles Revealed with a Programmable DNA Origami Scaffold

    PubMed Central

    Derr, N. D.; Goodman, B. S.; Jungmann, R.; Leschziner, A. E.; Shih, W. M.; Reck-Peterson, S. L.

    2013-01-01

    Cytoplasmic dynein and kinesin-1 are opposite-polarity, microtubule-based motors that transport a wide variety of cargo in eukaryotic cells. Many cellular cargos demonstrate bi-directional movement due to the presence of ensembles of dynein and kinesin, but are ultimately sorted with spatial and temporal precision. To investigate the mechanisms that coordinate motor ensemble behavior, we built a programmable synthetic cargo using three-dimensional DNA origami to which varying numbers of DNA oligonucleotide-linked motors could be attached, allowing control of motor type, number, spacing, and orientation in vitro. In ensembles of 1–7 identical-polarity motors, motor number had minimal affect on directional velocity, while ensembles of opposite-polarity motors engaged in a tug of war resolvable by disengaging one motor species. PMID:23065903

  17. Relations among motor, social, and cognitive skills in pre-kindergarten children with developmental disabilities.

    PubMed

    Kim, Helyn; Carlson, Abby G; Curby, Timothy W; Winsler, Adam

    2016-01-01

    Despite the comorbidity between motor difficulties and certain disabilities, limited research has examined links between early motor, cognitive, and social skills in preschool-aged children with developmental disabilities. The present study examined the relative contributions of gross motor and fine motor skills to the prediction of improvements in children's cognitive and social skills among 2,027 pre-kindergarten children with developmental disabilities, including specific learning disorder, speech/language impairment, intellectual disability, and autism spectrum disorder. Results indicated that for pre-kindergarten children with developmental disabilities, fine motor skills, but not gross motor skills, were predictive of improvements in cognitive and social skills, even after controlling for demographic information and initial skill levels. Moreover, depending on the type of developmental disability, the pattern of prediction of gross motor and fine motor skills to improvements in children's cognitive and social skills differed. Implications are discussed.

  18. Optimizing Word Learning via Links to Perceptual and Motoric Experience

    ERIC Educational Resources Information Center

    Hald, Lea A.; de Nooijer, Jacqueline; van Gog, Tamara; Bekkering, Harold

    2016-01-01

    The aim of this review is to consider how current vocabulary training methods could be optimized by considering recent scientific insights in how the brain represents conceptual knowledge. We outline the findings from several methods of vocabulary training. In each case, we consider how taking an embodied cognition perspective could impact word…

  19. Time Processing and Motor Control in Movement Disorders.

    PubMed

    Avanzino, Laura; Pelosin, Elisa; Vicario, Carmelo M; Lagravinese, Giovanna; Abbruzzese, Giovanni; Martino, Davide

    2016-01-01

    cerebral networks including cortical areas, cerebellum, and other subcortical structures (Ivry and Spencer, 2004; Coull and Nobre, 2008). Timing is an essential component of motor control primarily within two types of motor tasks: (i) when producing sequential rhythmic movements or sustained movements of a definite duration (explicit timing); (ii) when the temporal information is used implicitly, such as when coordinating our movements to those of moving objects or individuals within the external environment (implicit timing). In this review, we will provide a brief description of the neural network supporting motor timing focusing only on instrumental information to explain the link between timing and motor control in movement disorders. Then we will review available data on motor timing in Parkinson's disease, dystonia, Huntington's disease, and Tourette syndrome, and discuss how this body of evidence integrates with the available information on the pathophysiology of these movement disorders. Finally, we will discuss the translational aspects of the explored neural mechanisms with respect to future rehabilitation strategies.

  20. Time Processing and Motor Control in Movement Disorders

    PubMed Central

    Avanzino, Laura; Pelosin, Elisa; Vicario, Carmelo M.; Lagravinese, Giovanna; Abbruzzese, Giovanni; Martino, Davide

    2016-01-01

    diffuse cerebral networks including cortical areas, cerebellum, and other subcortical structures (Ivry and Spencer, 2004; Coull and Nobre, 2008). Timing is an essential component of motor control primarily within two types of motor tasks: (i) when producing sequential rhythmic movements or sustained movements of a definite duration (explicit timing); (ii) when the temporal information is used implicitly, such as when coordinating our movements to those of moving objects or individuals within the external environment (implicit timing). In this review, we will provide a brief description of the neural network supporting motor timing focusing only on instrumental information to explain the link between timing and motor control in movement disorders. Then we will review available data on motor timing in Parkinson's disease, dystonia, Huntington's disease, and Tourette syndrome, and discuss how this body of evidence integrates with the available information on the pathophysiology of these movement disorders. Finally, we will discuss the translational aspects of the explored neural mechanisms with respect to future rehabilitation strategies. PMID:28018198

  1. Role of the motor system in language knowledge.

    PubMed

    Berent, Iris; Brem, Anna-Katharine; Zhao, Xu; Seligson, Erica; Pan, Hong; Epstein, Jane; Stern, Emily; Galaburda, Albert M; Pascual-Leone, Alvaro

    2015-02-17

    All spoken languages express words by sound patterns, and certain patterns (e.g., blog) are systematically preferred to others (e.g., lbog). What principles account for such preferences: does the language system encode abstract rules banning syllables like lbog, or does their dislike reflect the increased motor demands associated with speech production? More generally, we ask whether linguistic knowledge is fully embodied or whether some linguistic principles could potentially be abstract. To address this question, here we gauge the sensitivity of English speakers to the putative universal syllable hierarchy (e.g., blif ≻ bnif ≻ bdif ≻ lbif) while undergoing transcranial magnetic stimulation (TMS) over the cortical motor representation of the left orbicularis oris muscle. If syllable preferences reflect motor simulation, then worse-formed syllables (e.g., lbif) should (i) elicit more errors; (ii) engage more strongly motor brain areas; and (iii) elicit stronger effects of TMS on these motor regions. In line with the motor account, we found that repetitive TMS pulses impaired participants' global sensitivity to the number of syllables, and functional MRI confirmed that the cortical stimulation site was sensitive to the syllable hierarchy. Contrary to the motor account, however, ill-formed syllables were least likely to engage the lip sensorimotor area and they were least impaired by TMS. Results suggest that speech perception automatically triggers motor action, but this effect is not causally linked to the computation of linguistic structure. We conclude that the language and motor systems are intimately linked, yet distinct. Language is designed to optimize motor action, but its knowledge includes principles that are disembodied and potentially abstract.

  2. Disentangling Fine Motor Skills' Relations to Academic Achievement: The Relative Contributions of Visual-Spatial Integration and Visual-Motor Coordination

    ERIC Educational Resources Information Center

    Carlson, Abby G.; Rowe, Ellen; Curby, Timothy W.

    2013-01-01

    Recent research has established a connection between children's fine motor skills and their academic performance. Previous research has focused on fine motor skills measured prior to elementary school, while the present sample included children ages 5-18 years old, making it possible to examine whether this link remains relevant throughout…

  3. System and method for motor parameter estimation

    DOEpatents

    Luhrs, Bin; Yan, Ting

    2014-03-18

    A system and method for determining unknown values of certain motor parameters includes a motor input device connectable to an electric motor having associated therewith values for known motor parameters and an unknown value of at least one motor parameter. The motor input device includes a processing unit that receives a first input from the electric motor comprising values for the known motor parameters for the electric motor and receive a second input comprising motor data on a plurality of reference motors, including values for motor parameters corresponding to the known motor parameters of the electric motor and values for motor parameters corresponding to the at least one unknown motor parameter value of the electric motor. The processor determines the unknown value of the at least one motor parameter from the first input and the second input and determines a motor management strategy for the electric motor based thereon.

  4. Advanced motor and motor control development

    NASA Astrophysics Data System (ADS)

    Wuertz, Kenneth L.; Beauchamp, Edward D.

    1988-08-01

    The capability of operating a high speed permanent magnet brushless dc motor with electronic controller over a wide load and speed range was demonstrated. A centrifugal pump was used as the loading mechanism and hydraulic fluid was pumped in simulation of an aircraft engine fuel pump requirement. A motor speed of 45,000 rpm was reached and a maximum output of 68.5 hp was demonstrated. The response of the system to step commands for speed change was established. Reduction of size and weight of electronic control was established as a primary future goal. The program system concept with minor rotating machine improvements is viable for high speed drive applications up to 100-hp level.

  5. Motor Vehicle Safety

    MedlinePlus

    ... these crashes is one part of motor vehicle safety. Here are some things you can do to ... speed or drive aggressively Don't drive impaired Safety also involves being aware of others. Share the ...

  6. Booster separation motor

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The design, development, fabrication, testing, evaluation and flight qualification of the space shuttle booster separation motor is discussed. Delivery of flight hardware to support the research and development flights of the space shuttle is discussed.

  7. MotorWeek

    ScienceCinema

    None

    2016-07-12

    In 2008, PBS's MotorWeek, television's original automotive magazine, visited Argonne's Transportation Technology R&D Center "to learn what it really takes to make clean power sources a viable reality."

  8. Molecular Motors from DNA

    NASA Astrophysics Data System (ADS)

    Turberfield, Andrew

    2013-03-01

    DNA is a wonderful material for nanoscale construction: its self-assembly can be programmed by making use of its information-carrying capability and its hybridization or hydrolysis can be used as to provide energy for synthetic molecular machinery. With DNA it is possible to design and build three-dimensional scaffolds, to attach molecular components to them with sub-nanometre precision-and then to make them move. I shall describe our work on autonomous, biomimetic molecular motors powered by chemical fuels and the use of synthetic molecular machinery to control covalent chemical synthesis. I shall demonstrate bipedal motors whose operation depends on the coordination of the chemomechanical cycles of two separate catalytic centres and burnt bridges motors that can be programmed to navigate networks of tracks. I shall also discuss the use of kinesin motor proteins to power synthetic devices.

  9. MotorWeek

    SciTech Connect

    2009-01-01

    In 2008, PBS's MotorWeek, television's original automotive magazine, visited Argonne's Transportation Technology R&D Center "to learn what it really takes to make clean power sources a viable reality."

  10. Piezoelectric Rotary Tube Motor

    NASA Technical Reports Server (NTRS)

    Fisher, Charles D.; Badescu, Mircea; Braun, David F.; Culhane, Robert

    2011-01-01

    A custom rotary SQUIGGLE(Registered TradeMark) motor has been developed that sets new benchmarks for small motor size, high position resolution, and high torque without gear reduction. Its capabilities cannot be achieved with conventional electromagnetic motors. It consists of piezoelectric plates mounted on a square flexible tube. The plates are actuated via voltage waveforms 90 out of phase at the resonant frequency of the device to create rotary motion. The motors were incorporated into a two-axis postioner that was designed for fiber-fed spectroscopy for ground-based and space-based projects. The positioner enables large-scale celestial object surveys to take place in a practical amount of time.

  11. High Power Density Motors

    NASA Technical Reports Server (NTRS)

    Kascak, Daniel J.

    2004-01-01

    With the growing concerns of global warming, the need for pollution-free vehicles is ever increasing. Pollution-free flight is one of NASA's goals for the 21" Century. , One method of approaching that goal is hydrogen-fueled aircraft that use fuel cells or turbo- generators to develop electric power that can drive electric motors that turn the aircraft's propulsive fans or propellers. Hydrogen fuel would likely be carried as a liquid, stored in tanks at its boiling point of 20.5 K (-422.5 F). Conventional electric motors, however, are far too heavy (for a given horsepower) to use on aircraft. Fortunately the liquid hydrogen fuel can provide essentially free refrigeration that can be used to cool the windings of motors before the hydrogen is used for fuel. Either High Temperature Superconductors (HTS) or high purity metals such as copper or aluminum may be used in the motor windings. Superconductors have essentially zero electrical resistance to steady current. The electrical resistance of high purity aluminum or copper near liquid hydrogen temperature can be l/lOO* or less of the room temperature resistance. These conductors could provide higher motor efficiency than normal room-temperature motors achieve. But much more importantly, these conductors can carry ten to a hundred times more current than copper conductors do in normal motors operating at room temperature. This is a consequence of the low electrical resistance and of good heat transfer coefficients in boiling LH2. Thus the conductors can produce higher magnetic field strengths and consequently higher motor torque and power. Designs, analysis and actual cryogenic motor tests show that such cryogenic motors could produce three or more times as much power per unit weight as turbine engines can, whereas conventional motors produce only 1/5 as much power per weight as turbine engines. This summer work has been done with Litz wire to maximize the current density. The current is limited by the amount of heat it

  12. Rocket Motor Microphone Investigation

    NASA Technical Reports Server (NTRS)

    Pilkey, Debbie; Herrera, Eric; Gee, Kent L.; Giraud, Jerom H.; Young, Devin J.

    2010-01-01

    At ATK's facility in Utah, large full-scale solid rocket motors are tested. The largest is a five-segment version of the reusable solid rocket motor, which is for use on the Ares I launch vehicle. As a continuous improvement project, ATK and BYU investigated the use of microphones on these static tests, the vibration and temperature to which the instruments are subjected, and in particular the use of vent tubes and the effects these vents have at low frequencies.

  13. Motor Energy Conservation Measures

    SciTech Connect

    Ian Metzger, Jesse Dean

    2010-12-31

    This software requires inputs of simple motor inventory information and calculates the energy and cost benefits of various retrofit opportunities. This tool includes energy conservation measures for: High Efficiency Motor retrofit and Cogged V-belts retrofit. This tool calculates energy savings, demand reduction, cost savings, and building life cycle costs including: simple payback, discounted payback, net-present value, and savings to investment ratio. In addition this tool also displays the environmental benefits of a project.

  14. Maintaining Motor Skill Performance

    DTIC Science & Technology

    1982-06-18

    trials eacb--ac--yIecon- ,, :;. - taed p- --d-t-trias,--P-t- rilk --r. expermenter-difie-d- ovementu con- strained by the stop. The distance between...processing in motor control-i ... and -laIg- e-rr--’- cae -clrsj--98 I Y. ag.L., K. A., & D5oWe-l, M. R. Serial-position effects in motor short-! term

  15. Development Motor-8

    NASA Technical Reports Server (NTRS)

    1980-01-01

    One of the key tests in the effort to return the Space Shuttle to flight following the Challenger accident was testing the development Motor-8 (DM-8). The 126-foot long, 1.2-million-pound motor, designated DM-8, underwent a full-duration horizontal test firing for two minutes at the Thiokol test facility in Utah. It was fitted with more than 500 instruments to measure such things as acceleration, pressure, deflection thrust, strain, temperature, and electrical properties.

  16. Cargo Transport by Two Coupled Myosin Va Motors on Actin Filaments and Bundles.

    PubMed

    Ali, M Yusuf; Vilfan, Andrej; Trybus, Kathleen M; Warshaw, David M

    2016-11-15

    Myosin Va (myoVa) is a processive, actin-based molecular motor essential for intracellular cargo transport. When a cargo is transported by an ensemble of myoVa motors, each motor faces significant physical barriers and directional challenges created by the complex actin cytoskeleton, a network of actin filaments and actin bundles. The principles that govern the interaction of multiple motors attached to the same cargo are still poorly understood. To understand the mechanical interactions between multiple motors, we developed a simple in vitro model in which two individual myoVa motors labeled with different-colored Qdots are linked via a third Qdot that acts as a cargo. The velocity of this two-motor complex was reduced by 27% as compared to a single motor, whereas run length was increased by only 37%, much less than expected from multimotor transport models. Therefore, at low ATP, which allowed us to identify individual motor steps, we investigated the intermotor dynamics within the two-motor complex. The randomness of stepping leads to a buildup of tension in the linkage between motors-which in turn slows down the leading motor-and increases the frequency of backward steps and the detachment rate. We establish a direct relationship between the velocity reduction and the distribution of intermotor distances. The analysis of run lengths and dwell times for the two-motor complex, which has only one motor engaged with the actin track, reveals that half of the runs are terminated by almost simultaneous detachment of both motors. This finding challenges the assumptions of conventional multimotor models based on consecutive motor detachment. Similar, but even more drastic, results were observed with two-motor complexes on actin bundles, which showed a run length that was even shorter than that of a single motor.

  17. Electric vehicle motors and controllers

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.

    1981-01-01

    Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

  18. Applying torque to the Escherichia coli flagellar motor using magnetic tweezers

    PubMed Central

    van Oene, Maarten M.; Dickinson, Laura E.; Cross, Bronwen; Pedaci, Francesco; Lipfert, Jan; Dekker, Nynke H.

    2017-01-01

    The bacterial flagellar motor of Escherichia coli is a nanoscale rotary engine essential for bacterial propulsion. Studies on the power output of single motors rely on the measurement of motor torque and rotation under external load. Here, we investigate the use of magnetic tweezers, which in principle allow the application and active control of a calibrated load torque, to study single flagellar motors in Escherichia coli. We manipulate the external load on the motor by adjusting the magnetic field experienced by a magnetic bead linked to the motor, and we probe the motor’s response. A simple model describes the average motor speed over the entire range of applied fields. We extract the motor torque at stall and find it to be similar to the motor torque at drag-limited speed. In addition, use of the magnetic tweezers allows us to force motor rotation in both forward and backward directions. We monitor the motor’s performance before and after periods of forced rotation and observe no destructive effects on the motor. Our experiments show how magnetic tweezers can provide active and fast control of the external load while also exposing remaining challenges in calibration. Through their non-invasive character and straightforward parallelization, magnetic tweezers provide an attractive platform to study nanoscale rotary motors at the single-motor level. PMID:28266562

  19. Robust transport by multiple motors with nonlinear force-velocity relations and stochastic load sharing

    NASA Astrophysics Data System (ADS)

    Kunwar, Ambarish; Mogilner, Alexander

    2010-03-01

    Transport by processive molecular motors plays an important role in many cell biological phenomena. In many cases, motors work together to transport cargos in the cell, so it is important to understand the mechanics of the multiple motors. Based on earlier modeling efforts, here we study effects of nonlinear force-velocity relations and stochastic load sharing on multiple motor transport. We find that when two or three motors transport the cargo, then the nonlinear and stochastic effects compensate so that the mechanical properties of the transport are robust. Similarly, the transport is insensitive to compliance of the cargo-motor links. Furthermore, the rate of movement against moderate loads is not improved by increasing the small number of motors. When the motor number is greater than 4, correlations between the motors become negligible, and the earlier analytical mean-field theory of the multiple motor transport holds. We predict that the effective diffusion of the cargo driven by the multiple motors under load increases by an order of magnitude compared to that for the single motor. Finally, our simulations predict that the stochastic effects are responsible for a significant dispersion of velocities generated by the 'tug-of-war' of the multiple opposing motors.

  20. External forces influence the elastic coupling effects during cargo transport by molecular motors.

    PubMed

    Berger, Florian; Keller, Corina; Klumpp, Stefan; Lipowsky, Reinhard

    2015-02-01

    Cellular transport is achieved by the cooperative action of molecular motors which are elastically linked to a common cargo. When the motors pull on the cargo at the same time, they experience fluctuating elastic strain forces induced by the stepping of the other motors. These elastic coupling forces can influence the motors' stepping and unbinding behavior and thereby the ability to transport cargos. Based on a generic single motor description, we introduce a framework that explains the response of two identical molecular motors to a constant external force. In particular, we relate the single motor parameters, the coupling strength and the external load force to the dynamics of the motor pair. We derive four distinct transport regimes and determine how the crossover lines between the regimes depend on the load force. Our description of the overall cargo dynamics takes into account relaxational displacements of the cargo caused by the unbinding of one motor. For large forces and weak elastic coupling these back-shifts dominate the displacements. To develop an intuitive understanding about motor cooperativity during cargo transport, we introduce a time scale for load sharing. This time scale allows us to predict how the regulation of single motor parameters influences the cooperativity. As an example, we show that up-regulating the single motor processivity enhances load sharing of the motor pair.

  1. Robust transport by multiple motors with nonlinear force-velocity relations and stochastic load sharing.

    PubMed

    Kunwar, Ambarish; Mogilner, Alexander

    2010-02-10

    Transport by processive molecular motors plays an important role in many cell biological phenomena. In many cases, motors work together to transport cargos in the cell, so it is important to understand the mechanics of the multiple motors. Based on earlier modeling efforts, here we study effects of nonlinear force-velocity relations and stochastic load sharing on multiple motor transport. We find that when two or three motors transport the cargo, then the nonlinear and stochastic effects compensate so that the mechanical properties of the transport are robust. Similarly, the transport is insensitive to compliance of the cargo-motor links. Furthermore, the rate of movement against moderate loads is not improved by increasing the small number of motors. When the motor number is greater than 4, correlations between the motors become negligible, and the earlier analytical mean-field theory of the multiple motor transport holds. We predict that the effective diffusion of the cargo driven by the multiple motors under load increases by an order of magnitude compared to that for the single motor. Finally, our simulations predict that the stochastic effects are responsible for a significant dispersion of velocities generated by the 'tug-of-war' of the multiple opposing motors.

  2. Robust transport by multiple motors with nonlinear force–velocity relations and stochastic load sharing

    PubMed Central

    Kunwar, Ambarish; Mogilner, Alexander

    2010-01-01

    Transport by processive molecular motors plays an important role in many cell biological phenomena. In many cases, motors work together to transport cargos in the cell, so it is important to understand the mechanics of the multiple motors. Based on earlier modeling efforts, here we study effects of nonlinear force–velocity relations and stochastic load sharing on multiple motor transport. We find that when two or three motors transport the cargo, then the nonlinear and stochastic effects compensate so that the mechanical properties of the transport are robust. Similarly, the transport is insensitive to compliance of the cargo-motor links. Furthermore, the rate of movement against moderate loads is not improved by increasing the small number of motors. When the motor number is greater than 4, correlations between the motors become negligible, and the earlier analytical mean-field theory of the multiple motor transport holds. We predict that the effective diffusion of the cargo driven by the multiple motors under load increases by an order of magnitude compared to that for the single motor. Finally, our simulations predict that the stochastic effects are responsible for a significant dispersion of velocities generated by the ‘tug-of-war’ of the multiple opposing motors. PMID:20147778

  3. Competing neural ensembles in motor cortex gate goal-directed motor output

    PubMed Central

    Zagha, Edward; Ge, Xinxin; McCormick, David A.

    2015-01-01

    Summary Unit recordings in behaving animals have revealed the transformation of sensory to motor representations in cortical neurons. However, we still lack basic insights into the mechanisms by which neurons interact to generate such transformations. Here, we study cortical circuits related to behavioral control in mice engaged in a sensory detection task. We recorded neural activity using extracellular and intracellular techniques and analyzed the task-related neural dynamics to reveal underlying circuit processes. Within motor cortex, we find two populations of neurons that have opposing spiking patterns in anticipation of movement. From correlation analyses and circuit modeling, we suggest that these dynamics reflect neural ensembles engaged in a competition. Furthermore, we demonstrate how this competitive circuit may convert a transient, sensory stimulus into a motor command. Together, these data reveal cellular and circuit processes underlying behavioral control, and establish an essential framework for future studies linking cellular activity to behavior. PMID:26593093

  4. Seeing fearful body language rapidly freezes the observer's motor cortex.

    PubMed

    Borgomaneri, Sara; Vitale, Francesca; Gazzola, Valeria; Avenanti, Alessio

    2015-04-01

    Fearful body language is a salient signal alerting the observer to the presence of a potential threat in the surrounding environment. Although detecting potential threats may trigger an immediate reduction of motor output in animals (i.e., freezing behavior), it is unclear at what point in time similar reductions occur in the human motor cortex and whether they originate from excitatory or inhibitory processes. Using single-pulse and paired-pulse transcranial magnetic stimulation (TMS), here we tested the hypothesis that the observer's motor cortex implements extremely fast suppression of motor readiness when seeing emotional bodies - and fearful body expressions in particular. Participants observed pictures of body postures and categorized them as happy, fearful or neutral while receiving TMS over the right or left motor cortex at 100-125 msec after picture onset. In three different sessions, we assessed corticospinal excitability, short intracortical inhibition (SICI) and intracortical facilitation (ICF). Independently of the stimulated hemisphere and the time of the stimulation, watching fearful bodies suppressed ICF relative to happy and neutral body expressions. Moreover, happy expressions reduced ICF relative to neutral actions. No changes in corticospinal excitability or SICI were found during the task. These findings show extremely rapid bilateral modulation of the motor cortices when seeing emotional bodies, with stronger suppression of motor readiness when seeing fearful bodies. Our results provide neurophysiological support for the evolutionary notions that emotion perception is inherently linked to action systems and that fear-related cues induce an urgent mobilization of motor reactions.

  5. Obsessive-compulsive disorder: a "sensory-motor" problem?

    PubMed

    Russo, M; Naro, A; Mastroeni, C; Morgante, F; Terranova, C; Muscatello, M R; Zoccali, R; Calabrò, R S; Quartarone, A

    2014-05-01

    Obsessive-compulsive disorder (OCD) is a clinically heterogeneous condition. Although its pathophysiology is not completely understood, neurophysiologic and neuroimaging data have disclosed functional abnormalities in the networks linking frontal cortex, supplementary motor and premotor areas, striatum, globus pallidus, and thalamus (CSPT circuits). By means of transcranial magnetic stimulation (TMS) it is possible to test inhibitory and excitatory circuits within motor cortex. Previous studies on OCD patients under medication have demonstrated altered cortical inhibitory circuits as tested by TMS. On the other hand there is growing evidence suggesting an alteration of sensory-motor integration. Therefore, the aim of the present study was to evaluate sensory-motor integration (SAI and LAI), intracortical inhibition, and facilitation in drug-naïve OCD patients, using TMS. In our sample, we have demonstrated a significant SAI reduction in OCD patients when compared to a cohort of healthy individuals. SAI abnormalities may be related to a dysfunction of CSPT circuits which are involved in sensory-motor integration processes. Thus, it can be speculated that hypofunctioning of such system might impair the ability of OCD patients to suppress internally triggered intrusive and repetitive movements and thoughts. In conclusion, our data suggest that OCD may be considered as a sensory motor disorder where a dysfunction of sensory-motor integration may play an important role in the release of motor compulsions.

  6. Sensory-motor problems in Autism.

    PubMed

    Whyatt, Caroline; Craig, Cathy

    2013-01-01

    Despite being largely characterized as a social and cognitive disorder, strong evidence indicates the presence of significant sensory-motor problems in Autism Spectrum Disorder (ASD). This paper outlines our progression from initial, broad assessment using the Movement Assessment Battery for Children (M-ABC2) to subsequent targeted kinematic assessment. In particular, pronounced ASD impairment seen in the broad categories of manual dexterity and ball skills was found to be routed in specific difficulties on isolated tasks, which were translated into focused experimental assessment. Kinematic results from both subsequent studies highlight impaired use of perception-action coupling to guide, adapt and tailor movement to task demands, resulting in inflexible and rigid motor profiles. In particular difficulties with the use of temporal adaption are shown, with "hyperdexterity" witnessed in ballistic movement profiles, often at the cost of spatial accuracy and task performance. By linearly progressing from the use of a standardized assessment tool to targeted kinematic assessment, clear and defined links are drawn between measureable difficulties and underlying sensory-motor assessment. Results are specifically viewed in-light of perception-action coupling and its role in early infant development suggesting that rather than being "secondary" level impairment, sensory-motor problems may be fundamental in the progression of ASD. This logical and systematic process thus allows a further understanding into the potential root of observable motor problems in ASD; a vital step if underlying motor problems are to be considered a fundamental aspect of autism and allow a route of non-invasive preliminary diagnosis.

  7. A New Type of Motor: Pneumatic Step Motor

    PubMed Central

    Stoianovici, Dan; Patriciu, Alexandru; Petrisor, Doru; Mazilu, Dumitru; Kavoussi, Louis

    2011-01-01

    This paper presents a new type of pneumatic motor, a pneumatic step motor (PneuStep). Directional rotary motion of discrete displacement is achieved by sequentially pressurizing the three ports of the motor. Pulsed pressure waves are generated by a remote pneumatic distributor. The motor assembly includes a motor, gearhead, and incremental position encoder in a compact, central bore construction. A special electronic driver is used to control the new motor with electric stepper indexers and standard motion control cards. The motor accepts open-loop step operation as well as closed-loop control with position feedback from the enclosed sensor. A special control feature is implemented to adapt classic control algorithms to the new motor, and is experimentally validated. The speed performance of the motor degrades with the length of the pneumatic hoses between the distributor and motor. Experimental results are presented to reveal this behavior and set the expectation level. Nevertheless, the stepper achieves easily controllable precise motion unlike other pneumatic motors. The motor was designed to be compatible with magnetic resonance medical imaging equipment, for actuating an image-guided intervention robot, for medical applications. For this reason, the motors were entirely made of nonmagnetic and dielectric materials such as plastics, ceramics, and rubbers. Encoding was performed with fiber optics, so that the motors are electricity free, exclusively using pressure and light. PneuStep is readily applicable to other pneumatic or hydraulic precision-motion applications. PMID:21528106

  8. Sensory-motor integration in focal dystonia.

    PubMed

    Avanzino, Laura; Tinazzi, Michele; Ionta, Silvio; Fiorio, Mirta

    2015-12-01

    Traditional definitions of focal dystonia point to its motor component, mainly affecting planning and execution of voluntary movements. However, focal dystonia is tightly linked also to sensory dysfunction. Accurate motor control requires an optimal processing of afferent inputs from different sensory systems, in particular visual and somatosensory (e.g., touch and proprioception). Several experimental studies indicate that sensory-motor integration - the process through which sensory information is used to plan, execute, and monitor movements - is impaired in focal dystonia. The neural degenerations associated with these alterations affect not only the basal ganglia-thalamic-frontal cortex loop, but also the parietal cortex and cerebellum. The present review outlines the experimental studies describing impaired sensory-motor integration in focal dystonia, establishes their relationship with changes in specific neural mechanisms, and provides new insight towards the implementation of novel intervention protocols. Based on the reviewed state-of-the-art evidence, the theoretical framework summarized in the present article will not only result in a better understanding of the pathophysiology of dystonia, but it will also lead to the development of new rehabilitation strategies.

  9. Genetic deficiency of GABA differentially regulates respiratory and non-respiratory motor neuron development.

    PubMed

    Fogarty, Matthew J; Smallcombe, Karen L; Yanagawa, Yuchio; Obata, Kunihiko; Bellingham, Mark C; Noakes, Peter G

    2013-01-01

    Central nervous system GABAergic and glycinergic synaptic activity switches from postsynaptic excitation to inhibition during the stage when motor neuron numbers are being reduced, and when synaptic connections are being established onto and by motor neurons. In mice this occurs between embryonic (E) day 13 and birth (postnatal day 0). Our previous work on mice lacking glycinergic transmission suggested that altered motor neuron activity levels correspondingly regulated motor neuron survival and muscle innervation for all respiratory and non respiratory motor neuron pools, during this period of development [1]. To determine if GABAergic transmission plays a similar role, we quantified motor neuron number and the extent of muscle innervation in four distinct regions of the brain stem and spinal cord; hypoglossal, phrenic, brachial and lumbar motor pools, in mice lacking the enzyme GAD67. These mice display a 90% drop in CNS GABA levels ( [2]; this study). For respiratory-based motor neurons (hypoglossal and phrenic motor pools), we have observed significant drops in motor neuron number (17% decline for hypoglossal and 23% decline for phrenic) and muscle innervations (55% decrease). By contrast for non-respiratory motor neurons of the brachial lateral motor column, we have observed an increase in motor neuron number (43% increase) and muscle innervations (99% increase); however for more caudally located motor neurons within the lumbar lateral motor column, we observed no change in either neuron number or muscle innervation. These results show in mice lacking physiological levels of GABA, there are distinct regional changes in motor neuron number and muscle innervation, which appear to be linked to their physiological function and to their rostral-caudal position within the developing spinal cord. Our results also suggest that for more caudal (lumbar) regions of the spinal cord, the effect of GABA is less influential on motor neuron development compared to that of

  10. Magnetostrictive direct drive motor

    NASA Technical Reports Server (NTRS)

    Naik, Dipak; Dehoff, P. H.

    1991-01-01

    Highly magnetostrictive materials such as Tb.3Dy.7Fe2, commercially known as TERFENOL-D, have been used to date in a variety of devices such as high power actuators and linear motors. The larger magnetostriction available in twinned single crystal TERFENOL-D, approx. 2000 ppm at moderate magnetic field strengths, makes possible a new generation of magnetomechanical devices. NASA researchers are studying the potential of this material as the basis for a direct microstepping rotary motor with torque densities on the order of industrial hydraulics and five times greater than that of the most efficient, high power electric motors. Such a motor would be a micro-radian stepper, capable of precision movements and self-braking in the power-off state. Innovative mechanical engineering techniques are juxtaposed on proper magnetic circuit design to reduce losses in structural flexures, inertias, thermal expansions, eddy currents, and magneto-mechanical coupling, thus optimizing motor performance and efficiency. Mathematical models are presented, including magnetic, structural, and both linear and nonlinear dynamic calculations and simulations. In addition, test results on prototypes are presented.

  11. Damage to Fronto-Parietal Networks Impairs Motor Imagery Ability after Stroke: A Voxel-Based Lesion Symptom Mapping Study

    PubMed Central

    Oostra, Kristine M.; Van Bladel, Anke; Vanhoonacker, Ann C. L.; Vingerhoets, Guy

    2016-01-01

    Background: Mental practice with motor imagery has been shown to promote motor skill acquisition in healthy subjects and patients. Although lesions of the common motor imagery and motor execution neural network are expected to impair motor imagery ability, functional equivalence appears to be at least partially preserved in stroke patients. Aim: To identify brain regions that are mandatory for preserved motor imagery ability after stroke. Method: Thirty-seven patients with hemiplegia after a first time stroke participated. Motor imagery ability was measured using a Motor Imagery questionnaire and temporal congruence test. A voxelwise lesion symptom mapping approach was used to identify neural correlates of motor imagery in this cohort within the first year post-stroke. Results: Poor motor imagery vividness was associated with lesions in the left putamen, left ventral premotor cortex and long association fibers linking parieto-occipital regions with the dorsolateral premotor and prefrontal areas. Poor temporal congruence was otherwise linked to lesions in the more rostrally located white matter of the superior corona radiata. Conclusion: This voxel-based lesion symptom mapping study confirms the association between white matter tract lesions and impaired motor imagery ability, thus emphasizing the importance of an intact fronto-parietal network for motor imagery. Our results further highlight the crucial role of the basal ganglia and premotor cortex when performing motor imagery tasks. PMID:26869894

  12. An Examination of the Relationship between Motor Coordination and Executive Functions in Adolescents

    ERIC Educational Resources Information Center

    Rigoli, Daniela; Piek, Jan P.; Kane, Robert; Oosterlaan, Jaap

    2012-01-01

    Aim: Research suggests important links between motor coordination and executive functions. The current study examined whether motor coordination predicts working memory, inhibition, and switching performance, extending previous research by accounting for attention-deficit-hyperactivity disorder (ADHD) symptomatology and other confounding factors,…

  13. Effects of Dispositional Mindfulness on the Self-Controlled Learning of a Novel Motor Task

    ERIC Educational Resources Information Center

    Kee, Ying Hwa; Liu, Yeou-Teh

    2011-01-01

    Current literature suggests that mindful learning is beneficial to learning but its links with motor learning is seldom examined. In the present study, we examine the effects of learners' mindfulness disposition on the self-controlled learning of a novel motor task. Thirty-two participants undertook five practice sessions, in addition to a pre-,…

  14. Magnetostrictive direct drive motors

    NASA Technical Reports Server (NTRS)

    Naik, Dipak; Dehoff, P. H.

    1990-01-01

    Developing magnetostrictive direct drive research motors to power robot joints is discussed. These type motors are expected to produce extraordinary torque density, to be able to perform microradian incremental steps and to be self-braking and safe with the power off. Several types of motor designs have been attempted using magnetostrictive materials. One of the candidate approaches (the magnetostrictive roller drive) is described. The method in which the design will function is described as is the reason why this approach is inherently superior to the other approaches. Following this, the design will be modelled and its expected performance predicted. This particular candidate design is currently undergoing detailed engineering with prototype construction and testing scheduled for mid 1991.

  15. Micromachine Wedge Stepping Motor

    SciTech Connect

    Allen, J.J.; Schriner, H.K.

    1998-11-04

    A wedge stepping motor, which will index a mechanism, has been designed and fabricated in the surface rnicromachine SUMMiT process. This device has demonstrated the ability to index one gear tooth at a time with speeds up to 205 teeth/see. The wedge stepper motor has the following features, whi:h will be useful in a number of applications. o The ability to precisely position mechanical components. . Simple pulse signals can be used for operation. o Only 2 drive signals are requixed for operation. o Torque and precision capabilities increase with device size . The device to be indexed is restrained at all times by the wedge shaped tooth that is used for actuation. This paper will discuss the theory of operation and desi=m of the wedge stepping motor. The fabrication and testing of I he device will also be presented.

  16. Bent shaft motor

    DOEpatents

    Benavides, Gilbert L.

    1998-01-01

    A nonelectromagnetic motor comprising a base, a bent shaft which is rotable relative to the base wherein the bent shaft comprises a straight portion aligned with a main axis and an offset portion that is offset with respect to the main axis; and a drive means for driving the offset portion of the bent shaft along a generally circular path in a plane perpendicular to the main axis to rotate the bent shaft. The bent shaft and drive means for driving the bent shaft can be selected from piezoelectric, magnetostrictive, rheological and shape memory alloys. The drive means of the nonelectromagnetic motor can additionally comprise a shell which shell surrounds and houses the bent shaft and precesses or gyrates which in turn causes the bent drive shaft to rotate. The nonelectromagnetic motor does not rely on friction for the application of torque upon a rotor.

  17. Bent shaft motor

    DOEpatents

    Benavides, G.L.

    1998-05-05

    A nonelectromagnetic motor comprising a base, a bent shaft which is rotatable relative to the base wherein the bent shaft comprises a straight portion aligned with a main axis and an offset portion that is offset with respect to the main axis; and a drive means for driving the offset portion of the bent shaft along a generally circular path in a plane perpendicular to the main axis to rotate the bent shaft. The bent shaft and drive means for driving the bent shaft can be selected from piezoelectric, magnetostrictive, rheological and shape memory alloys. The drive means of the nonelectromagnetic motor can additionally comprise a shell which shell surrounds and houses the bent shaft and precesses or gyrates which in turn causes the bent drive shaft to rotate. The nonelectromagnetic motor does not rely on friction for the application of torque upon a rotor. 11 figs.

  18. The functional alterations associated with motor imagery training: a comparison between motor execution and motor imagery of sequential finger tapping

    NASA Astrophysics Data System (ADS)

    Zhang, Hang; Yao, Li; Long, Zhiying

    2011-03-01

    Motor imagery training, as an effective strategy, has been more and more applied to mental disorders rehabilitation and motor skill learning. Studies on the neural mechanism underlying motor imagery have suggested that such effectiveness may be related to the functional congruence between motor execution and motor imagery. However, as compared to the studies on motor imagery, the studies on motor imagery training are much fewer. The functional alterations associated with motor imagery training and the effectiveness of motor imagery training on motor performance improvement still needs further investigation. Using fMRI, we employed a sequential finger tapping paradigm to explore the functional alterations associated with motor imagery training in both motor execution and motor imagery task. We hypothesized through 14 consecutive days motor imagery training, the motor performance could be improved and the functional congruence between motor execution and motor imagery would be sustained form pre-training phase to post-training phase. Our results confirmed the effectiveness of motor imagery training in improving motor performance and demonstrated in both pre and post-training phases, motor imagery and motor execution consistently sustained the congruence in functional neuroanatomy, including SMA (supplementary motor cortex), PMA (premotor area); M1( primary motor cortex) and cerebellum. Moreover, for both execution and imagery tasks, a similar functional alteration was observed in fusiform through motor imagery training. These findings provided an insight into the effectiveness of motor imagery training and suggested its potential therapeutic value in motor rehabilitation.

  19. Disentangling fine motor skills' relations to academic achievement: the relative contributions of visual-spatial integration and visual-motor coordination.

    PubMed

    Carlson, Abby G; Rowe, Ellen; Curby, Timothy W

    2013-01-01

    Recent research has established a connection between children's fine motor skills and their academic performance. Previous research has focused on fine motor skills measured prior to elementary school, while the present sample included children ages 5-18 years old, making it possible to examine whether this link remains relevant throughout childhood and adolescence. Furthermore, the majority of research linking fine motor skills and academic achievement has not determined which specific components of fine motor skill are driving this relation. The few studies that have looked at associations of separate fine motor tasks with achievement suggest that copying tasks that tap visual-spatial integration skills are most closely related to achievement. The present study examined two separate elements of fine motor skills--visual-motor coordination and visual-spatial integration--and their associations with various measures of academic achievement. Visual-motor coordination was measured using tracing tasks, while visual-spatial integration was measured using copy-a-figure tasks. After controlling for gender, socioeconomic status, IQ, and visual-motor coordination, and visual-spatial integration explained significant variance in children's math and written expression achievement. Knowing that visual-spatial integration skills are associated with these two achievement domains suggests potential avenues for targeted math and writing interventions for children of all ages.

  20. ac bidirectional motor controller

    NASA Technical Reports Server (NTRS)

    Schreiner, K.

    1988-01-01

    Test data are presented and the design of a high-efficiency motor/generator controller at NASA-Lewis for use with the Space Station power system testbed is described. The bidirectional motor driver is a 20 kHz to variable frequency three-phase ac converter that operates from the high-frequency ac bus being designed for the Space Station. A zero-voltage-switching pulse-density-modulation technique is used in the converter to shape the low-frequency output waveform.

  1. Tuning Multiple Motor Travel Via Single Motor Velocity

    PubMed Central

    Xu, Jing; Shu, Zhanyong; King, Stephen J.; Gross, Steven P.

    2012-01-01

    Microtubule-based molecular motors often work in small groups to transport cargos in cells. A key question in understanding transport (and its regulation in vivo) is to identify the sensitivity of multiple-motor-based motion to various single molecule properties. Whereas both single-motor travel distance and microtubule binding rate have been demonstrated to contribute to cargo travel, the role of single-motor velocity is yet to be explored. Here, we recast a previous theoretical study, and make explicit a potential contribution of velocity to cargo travel. We test this possibility experimentally, and demonstrate a strong negative correlation between single-motor velocity and cargo travel for transport driven by two motors. Our study thus discovers a previously unappreciated role of single-motor velocity in regulating multiple-motor transport. PMID:22672518

  2. Motor current signature analysis method for diagnosing motor operated devices

    DOEpatents

    Haynes, Howard D.; Eissenberg, David M.

    1990-01-01

    A motor current noise signature analysis method and apparatus for remotely monitoring the operating characteristics of an electric motor-operated device such as a motor-operated valve. Frequency domain signal analysis techniques are applied to a conditioned motor current signal to distinctly identify various operating parameters of the motor driven device from the motor current signature. The signature may be recorded and compared with subsequent signatures to detect operating abnormalities and degradation of the device. This diagnostic method does not require special equipment to be installed on the motor-operated device, and the current sensing may be performed at remote control locations, e.g., where the motor-operated devices are used in accessible or hostile environments.

  3. Multiscale polar theory of microtubule and motor-protein assemblies.

    PubMed

    Gao, Tong; Blackwell, Robert; Glaser, Matthew A; Betterton, M D; Shelley, Michael J

    2015-01-30

    Microtubules and motor proteins are building blocks of self-organized subcellular biological structures such as the mitotic spindle and the centrosomal microtubule array. These same ingredients can form new "bioactive" liquid-crystalline fluids that are intrinsically out of equilibrium and which display complex flows and defect dynamics. It is not yet well understood how microscopic activity, which involves polarity-dependent interactions between motor proteins and microtubules, yields such larger-scale dynamical structures. In our multiscale theory, Brownian dynamics simulations of polar microtubule ensembles driven by cross-linking motors allow us to study microscopic organization and stresses. Polarity sorting and cross-link relaxation emerge as two polar-specific sources of active destabilizing stress. On larger length scales, our continuum Doi-Onsager theory captures the hydrodynamic flows generated by polarity-dependent active stresses. The results connect local polar structure to flow structures and defect dynamics.

  4. Multiscale Polar Theory of Microtubule and Motor-Protein Assemblies

    NASA Astrophysics Data System (ADS)

    Gao, Tong; Blackwell, Robert; Glaser, Matthew A.; Betterton, M. D.; Shelley, Michael J.

    2015-01-01

    Microtubules and motor proteins are building blocks of self-organized subcellular biological structures such as the mitotic spindle and the centrosomal microtubule array. These same ingredients can form new "bioactive" liquid-crystalline fluids that are intrinsically out of equilibrium and which display complex flows and defect dynamics. It is not yet well understood how microscopic activity, which involves polarity-dependent interactions between motor proteins and microtubules, yields such larger-scale dynamical structures. In our multiscale theory, Brownian dynamics simulations of polar microtubule ensembles driven by cross-linking motors allow us to study microscopic organization and stresses. Polarity sorting and cross-link relaxation emerge as two polar-specific sources of active destabilizing stress. On larger length scales, our continuum Doi-Onsager theory captures the hydrodynamic flows generated by polarity-dependent active stresses. The results connect local polar structure to flow structures and defect dynamics.

  5. Multiscale Polar Theory of Microtubule and Motor-Protein Assemblies

    PubMed Central

    Gao, Tong; Blackwell, Robert; Glaser, Matthew A.; Betterton, M. D.; Shelley, Michael J.

    2015-01-01

    Microtubules and motor proteins are building blocks of self-organized subcellular biological structures such as the mitotic spindle and the centrosomal microtubule array. These same ingredients can form new “bioactive” liquid-crystalline fluids that are intrinsically out of equilibrium and which display complex flows and defect dynamics. It is not yet well understood how microscopic activity, which involves polarity-dependent interactions between motor proteins and microtubules, yields such larger-scale dynamical structures. In our multiscale theory, Brownian dynamics simulations of polar microtubule ensembles driven by cross-linking motors allow us to study microscopic organization and stresses. Polarity sorting and cross-link relaxation emerge as two polar-specific sources of active destabilizing stress. On larger length scales, our continuum Doi-Onsager theory captures the hydrodynamic flows generated by polarity-dependent active stresses. The results connect local polar structure to flow structures and defect dynamics. PMID:25679909

  6. Multiscale polar theory of microtubule and motor-protein assemblies

    DOE PAGES

    Gao, Tong; Blackwell, Robert; Glaser, Matthew A.; ...

    2015-01-27

    Microtubules and motor proteins are building blocks of self-organized subcellular biological structures such as the mitotic spindle and the centrosomal microtubule array. These same ingredients can form new “bioactive” liquid-crystalline fluids that are intrinsically out of equilibrium and which display complex flows and defect dynamics. It is not yet well understood how microscopic activity, which involves polarity-dependent interactions between motor proteins and microtubules, yields such larger-scale dynamical structures. In our multiscale theory, Brownian dynamics simulations of polar microtubule ensembles driven by cross-linking motors allow us to study microscopic organization and stresses. Polarity sorting and cross-link relaxation emerge as two polar-specificmore » sources of active destabilizing stress. On larger length scales, our continuum Doi-Onsager theory captures the hydrodynamic flows generated by polarity-dependent active stresses. Finally, the results connect local polar structure to flow structures and defect dynamics.« less

  7. Multiscale polar theory of microtubule and motor-protein assemblies

    SciTech Connect

    Gao, Tong; Blackwell, Robert; Glaser, Matthew A.; Betterton, Meredith D.; Shelley, Michael J.

    2015-01-27

    Microtubules and motor proteins are building blocks of self-organized subcellular biological structures such as the mitotic spindle and the centrosomal microtubule array. These same ingredients can form new “bioactive” liquid-crystalline fluids that are intrinsically out of equilibrium and which display complex flows and defect dynamics. It is not yet well understood how microscopic activity, which involves polarity-dependent interactions between motor proteins and microtubules, yields such larger-scale dynamical structures. In our multiscale theory, Brownian dynamics simulations of polar microtubule ensembles driven by cross-linking motors allow us to study microscopic organization and stresses. Polarity sorting and cross-link relaxation emerge as two polar-specific sources of active destabilizing stress. On larger length scales, our continuum Doi-Onsager theory captures the hydrodynamic flows generated by polarity-dependent active stresses. Finally, the results connect local polar structure to flow structures and defect dynamics.

  8. 46 CFR 169.684 - Overcurrent protection for motors and motor branch circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Overcurrent protection for motors and motor branch... motors and motor branch circuits. (a) Except as provided in paragraph (d) of this section, each motor... motor that is responsive to motor current or to both motor current and temperature may be used. (b)...

  9. 46 CFR 169.684 - Overcurrent protection for motors and motor branch circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Overcurrent protection for motors and motor branch... motors and motor branch circuits. (a) Except as provided in paragraph (d) of this section, each motor... motor that is responsive to motor current or to both motor current and temperature may be used. (b)...

  10. Magnetically Coupled Adjustable Speed Motor Drives - Motor Tip Sheet #13

    SciTech Connect

    2008-07-01

    Alternating current electric motors rotate at a nearly constant speed that is determined by motor design and line frequency. Energy savings of 50% or more may be available when fixed speed systems are modified to allow the motor speed to match variable load requirements of a centrifugal fan or pump.

  11. Method for assessing motor insulation on operating motors

    DOEpatents

    Kueck, J.D.; Otaduy, P.J.

    1997-03-18

    A method for monitoring the condition of electrical-motor-driven devices is disclosed. The method is achieved by monitoring electrical variables associated with the functioning of an operating motor, applying these electrical variables to a three phase equivalent circuit and determining non-symmetrical faults in the operating motor based upon symmetrical components analysis techniques. 15 figs.

  12. Method for assessing motor insulation on operating motors

    DOEpatents

    Kueck, John D.; Otaduy, Pedro J.

    1997-01-01

    A method for monitoring the condition of electrical-motor-driven devices. The method is achieved by monitoring electrical variables associated with the functioning of an operating motor, applying these electrical variables to a three phase equivalent circuit and determining non-symmetrical faults in the operating motor based upon symmetrical components analysis techniques.

  13. Electric motor model repair specifications

    SciTech Connect

    1995-08-01

    These model repair specifications list the minimum requirements for repair and overhaul of polyphase AC squireel cage induction motors. All power ranges, voltages, and speeds of squirrel cage motors are covered.

  14. Reciprocating Linear Electric Motor

    NASA Technical Reports Server (NTRS)

    Goldowsky, M. P.

    1984-01-01

    Features include structural simplicity and good force/displacement characteristics. Reciprocating motor has simple, rugged construction, relatively low reciprocating weight, improved power delivery, and improved force control. Wear reduced by use of magnetic bearings. Intended to provide drivers for long-lived Stirling-cycle cryogenic refrigerators, concept has less exotic applications, such as fuel pumps.

  15. Perceptual-Motor Dysfunction.

    ERIC Educational Resources Information Center

    Pyfer, Jean L.

    Discussed are theoretical and treatment aspects of perceptual motor dysfunction and rehabilitation in 4- to 12-year-old academically failing children involved in a 3-year investigation at the University of Kansas. The program is said to stress increasing the amount of stimulation received by sensory receptors of the vestibular, reflex, and haptic…

  16. Thiokol Solid Rocket Motors

    NASA Technical Reports Server (NTRS)

    Graves, S. R.

    2000-01-01

    This paper presents viewgraphs on thiokol solid rocket motors. The topics include: 1) Communications; 2) Military and government intelligence; 3) Positioning satellites; 4) Remote sensing; 5) Space burial; 6) Science; 7) Space manufacturing; 8) Advertising; 9) Space rescue space debris management; 10) Space tourism; 11) Space settlements; 12) Hazardous waste disposal; 13) Extraterrestrial resources; 14) Fast package delivery; and 15) Space utilities.

  17. The St. Louis Motor

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2011-01-01

    The St. Louis Motor, invented in 1909, is unique among physics apparatus for being named for a geographical place rather than a physicist. The sturdy little device (Fig. 1) has never been out of production. Any older school or physics department that has not done a catastrophic housecleaning in the last 20 years will certainly have a small flock…

  18. Changes in visual and sensory-motor resting-state functional connectivity support motor learning by observing

    PubMed Central

    McGregor, Heather R.

    2015-01-01

    Motor learning occurs not only through direct first-hand experience but also through observation (Mattar AA, Gribble PL. Neuron 46: 153–160, 2005). When observing the actions of others, we activate many of the same brain regions involved in performing those actions ourselves (Malfait N, Valyear KF, Culham JC, Anton JL, Brown LE, Gribble PL. J Cogn Neurosci 22: 1493–1503, 2010). Links between neural systems for vision and action have been reported in neurophysiological (Strafella AP, Paus T. Neuroreport 11: 2289–2292, 2000; Watkins KE, Strafella AP, Paus T. Neuropsychologia 41: 989–994, 2003), brain imaging (Buccino G, Binkofski F, Fink GR, Fadiga L, Fogassi L, Gallese V, Seitz RJ, Zilles K, Rizzolatti G, Freund HJ. Eur J Neurosci 13: 400–404, 2001; Iacoboni M, Woods RP, Brass M, Bekkering H, Mazziotta JC, Rizzolatti G. Science 286: 2526–2528, 1999), and eye tracking (Flanagan JR, Johansson RS. Nature 424: 769–771, 2003) studies. Here we used a force field learning paradigm coupled with resting-state fMRI to investigate the brain areas involved in motor learning by observing. We examined changes in resting-state functional connectivity (FC) after an observational learning task and found a network consisting of V5/MT, cerebellum, and primary motor and somatosensory cortices in which changes in FC were correlated with the amount of motor learning achieved through observation, as assessed behaviorally after resting-state fMRI scans. The observed FC changes in this network are not due to visual attention to motion or observation of movement errors but rather are specifically linked to motor learning. These results support the idea that brain networks linking action observation and motor control also facilitate motor learning. PMID:25995349

  19. Tandem motors reduce well costs

    SciTech Connect

    Hooper, M.; Daigle, C.; Crowe, R.

    1995-10-01

    The new generation of tandem mud motors that recently appeared on the drilling scene is significantly affecting drilling efficiency worldwide. These motors provide drillers with increased horsepower at the bit, higher torque, and faster rates of penetration (ROP). With advanced engineering and more durable materials, motor life is being extended, thereby increasing the time between bit trips and reducing drilling costs. This article reviews the performance, design, and operation of these motors.

  20. Motor Vehicle Theft. Special Report.

    ERIC Educational Resources Information Center

    Harlow, Caroline Wolf

    Thirteen years of data from the National Crime Survey were analyzed to examine the characteristics of motor vehicle theft, to identify trends during the past 13 years, and to determine who are most likely to be victims of motor vehicle theft. All motor vehicle thefts reported to the National Crime Survey from 1973 through 1985 were examined.…

  1. Speed control for synchronous motors

    NASA Technical Reports Server (NTRS)

    Packard, H.; Schott, J.

    1981-01-01

    Feedback circuit controls fluctuations in speed of synchronous ac motor. Voltage proportional to phase angle is developed by phase detector, rectified, amplified, compared to threshold, and reapplied positively or negatively to motor excitation circuit. Speed control reduces wow and flutter of audio turntables and tape recorders, and enhances hunting in gyroscope motors.

  2. Experiments with a DC Motor

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2010-01-01

    Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the…

  3. Brushless direct-current motors

    NASA Technical Reports Server (NTRS)

    Bahm, E. J.

    1970-01-01

    Survey results are presented on the use of unconventional motor windings and switching sequences to optimize performance of brushless dc motors. A motor was built, each coil terminal having a separate, accessible lead. With the shaft and all electronics excluded, length and outside diameter measured 1.25 and 0.75 in., respectively.

  4. Motor Education: Educational Development Programs.

    ERIC Educational Resources Information Center

    Tansley, A. E.

    This booklet presents educational programs and activities focusing on motor skills for 5- to 9-year-old children and older children with learning problems. The premise of the activities is that the acquisition of motor skills is essential to basic learning. The role of language as a mediator and controller of motor development is emphasized. The…

  5. Multiple stage miniature stepping motor

    DOEpatents

    Niven, William A.; Shikany, S. David; Shira, Michael L.

    1981-01-01

    A stepping motor comprising a plurality of stages which may be selectively activated to effect stepping movement of the motor, and which are mounted along a common rotor shaft to achieve considerable reduction in motor size and minimum diameter, whereby sequential activation of the stages results in successive rotor steps with direction being determined by the particular activating sequence followed.

  6. Brief Report: Children with ADHD without Co-Morbid Autism Do Not Have Impaired Motor Proficiency on the Movement Assessment Battery for Children

    ERIC Educational Resources Information Center

    Papadopoulos, Nicole; Rinehart, Nicole; Bradshaw, John L.; McGinley, Jennifer L.

    2013-01-01

    Motor proficiency was investigated in a sample of children with Attention Deficit Hyperactivity Disorder-Combined type (ADHD-CT) without autism. Accounting for the influence of co-morbid autistic symptoms in ADHD motor studies is vital given that motor impairment has been linked to social-communication symptoms in children who have co-morbid ADHD…

  7. Toward a new theory of motor synergies.

    PubMed

    Latash, Mark L; Scholz, John P; Schöner, Gregor

    2007-07-01

    Driven by recent empirical studies, we offer a new understanding of the degrees of freedom problem, and propose a refined concept of synergy as a neural organization that ensures a one-to-many mapping of variables providing for both stability of important performance variables and flexibility of motor patterns to deal with possible perturbations and/or secondary tasks. Empirical evidence is reviewed, including a discussion of the operationalization of stability/flexibility through the method of the uncontrolled manifold. We show how this concept establishes links between the various accounts for how movement is organized in redundant effector systems.

  8. Motor sequence learning and motor adaptation in primary cervical dystonia.

    PubMed

    Katschnig-Winter, Petra; Schwingenschuh, Petra; Davare, Marco; Sadnicka, Anna; Schmidt, Reinhold; Rothwell, John C; Bhatia, Kailash P; Edwards, Mark J

    2014-06-01

    Motor sequence learning and motor adaptation rely on overlapping circuits predominantly involving the basal ganglia and cerebellum. Given the importance of these brain regions to the pathophysiology of primary dystonia, and the previous finding of abnormal motor sequence learning in DYT1 gene carriers, we explored motor sequence learning and motor adaptation in patients with primary cervical dystonia. We recruited 12 patients with cervical dystonia and 11 healthy controls matched for age. Subjects used a joystick to move a cursor from a central starting point to radial targets as fast and accurately as possible. Using this device, we recorded baseline motor performance, motor sequence learning and a visuomotor adaptation task. Patients with cervical dystonia had a significantly higher peak velocity than controls. Baseline performance with random target presentation was otherwise normal. Patients and controls had similar levels of motor sequence learning and motor adaptation. Our patients had significantly higher peak velocity compared to controls, with similar movement times, implying a different performance strategy. The preservation of motor sequence learning in cervical dystonia patients contrasts with the previously observed deficit seen in patients with DYT1 gene mutations, supporting the hypothesis of differing pathophysiology in different forms of primary dystonia. Normal motor adaptation is an interesting finding. With our paradigm we did not find evidence that the previously documented cerebellar abnormalities in cervical dystonia have a behavioral correlate, and thus could be compensatory or reflect "contamination" rather than being directly pathological.

  9. Variation in motor output and motor performance in a centrally generated motor pattern.

    PubMed

    Wenning, Angela; Norris, Brian J; Doloc-Mihu, Anca; Calabrese, Ronald L

    2014-07-01

    Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved.

  10. Dynamic Re-wiring of Neural Circuits in the Motor Cortex in Mouse Models of Parkinson's Disease

    PubMed Central

    Lalchandani, Rupa R.; Cui, Yuting; Shu, Yu; Xu, Tonghui; Ding, Jun B.

    2015-01-01

    SUMMARY Dynamic adaptations in synaptic plasticity are critical for learning new motor skills and maintaining memory throughout life, which rapidly decline with Parkinson's disease (PD). Plasticity in the motor cortex is important for acquisition and maintenance of novel motor skills, but how the loss of dopamine in PD leads to disrupted structural and functional plasticity in the motor cortex is not well understood. Here, we utilized mouse models of PD and 2-photon imaging to show that dopamine depletion resulted in structural changes in the motor cortex. We further discovered that dopamine D1 and D2 receptor signaling were linked to selectively and distinctly regulating these aberrant changes in structural and functional plasticity. Our findings suggest that both D1 and D2 receptor signaling regulate motor cortex plasticity, and loss of dopamine results in atypical synaptic adaptations that may contribute to the impairment of motor performance and motor memory observed in PD. PMID:26237365

  11. Five-site model for a motor protein walking on a bead-spring substrate

    NASA Astrophysics Data System (ADS)

    Paudyal, Nabina; Adeli Koudehi, Maral; Luettmer-Strathmann, Jutta

    2014-03-01

    Motor proteins play an important role in many biological processes. For example, kinesin molecules are responsible for the transport of vesicles in nerve cells and their malfunction has been linked to neurodegenerative diseases. Motor proteins are also responsible for the unique mechanical properties of active matter. To study non-equilibrium aspects of motor-substrate systems, biological chain molecules interacting with motor proteins have been investigated in single-chain pulling experiments. Unfortunately, the complexity of motor proteins and their environment makes it difficult to model the detailed dynamics of molecular motors over long time scales. In this work, we develop a simple coarse-grained model for a motor protein on a bead-spring substrate under tension. In our model, different pair potentials describe interactions between substrate and motor, motor components and substrate components. The movement of motor proteins entails ATP hydrolysis, which is modeled in terms of mechano-chemical states that couple positional and chemical degrees of freedom. The goal of this work is to simulate cargo transport in confined geometries and to investigate the mechanical response of a single chain interacting with motor proteins.

  12. Dissociated functional connectivity profiles for motor and attention deficits in acute right-hemisphere stroke.

    PubMed

    Baldassarre, Antonello; Ramsey, Lenny; Rengachary, Jennifer; Zinn, Kristi; Siegel, Joshua S; Metcalf, Nicholas V; Strube, Michael J; Snyder, Abraham Z; Corbetta, Maurizio; Shulman, Gordon L

    2016-07-01

    Strokes often cause multiple behavioural deficits that are correlated at the population level. Here, we show that motor and attention deficits are selectively associated with abnormal patterns of resting state functional connectivity in the dorsal attention and motor networks. We measured attention and motor deficits in 44 right hemisphere-damaged patients with a first-time stroke at 1-2 weeks post-onset. The motor battery included tests that evaluated deficits in both upper and lower extremities. The attention battery assessed both spatial and non-spatial attention deficits. Summary measures for motor and attention deficits were identified through principal component analyses on the raw behavioural scores. Functional connectivity in structurally normal cortex was estimated based on the temporal correlation of blood oxygenation level-dependent signals measured at rest with functional magnetic resonance imaging. Any correlation between motor and attention deficits and between functional connectivity in the dorsal attention network and motor networks that might spuriously affect the relationship between each deficit and functional connectivity was statistically removed. We report a double dissociation between abnormal functional connectivity patterns and attention and motor deficits, respectively. Attention deficits were significantly more correlated with abnormal interhemispheric functional connectivity within the dorsal attention network than motor networks, while motor deficits were significantly more correlated with abnormal interhemispheric functional connectivity patterns within the motor networks than dorsal attention network. These findings indicate that functional connectivity patterns in structurally normal cortex following a stroke link abnormal physiology in brain networks to the corresponding behavioural deficits.

  13. Motor technology for mining applications advances

    SciTech Connect

    Fiscor, S.

    2009-08-15

    AC motors are steadily replacing DC motors in mining and mineral processing equipment, requiring less maintenance. The permanent magnet rotor, or the synchronous motor, has enabled Blador to introduce a line of cooling tower motors. Synchronous motors are soon likely to take over from the induction motor. 1 photo.

  14. Big Savings from Smart Motors

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Chesebrough-Pond's operates 32 plants across the nation and in those plants are more than 10,000 electric motors. In an effort to cut down on waste of electrical power used by these motors, Chesebrough organized a Corporate Advanced Technology Group to devise ways of improving productivity and cut manufacturing costs. Chesebrough used NASA's Marshall Space Flight Center's Power Factor Controller technology as a departure point for development of their own computerized motor controller that enables motors to operate at maximum efficiency regardless of the motor's applications or operating condition.

  15. Molecular Motors and Stochastic Models

    NASA Astrophysics Data System (ADS)

    Lipowsky, Reinhard

    The behavior of single molecular motors such as kinesin or myosin V, which move on linear filaments, involves a nontrivial coupling between the biochemical motor cycle and the stochastic movement. This coupling can be studied in the framework of nonuniform ratchet models which are characterized by spatially localized transition rates between the different internal states of the motor. These models can be classified according to their functional relationships between the motor velocity and the concentration of the fuel molecules. The simplest such relationship applies to two subclasses of models for dimeric kinesin and agrees with experimental observations on this molecular motor.

  16. The Relationship between Social and Motor Cognition in Primary School Age-Children

    PubMed Central

    Kenny, Lorcan; Hill, Elisabeth; Hamilton, Antonia F. de C.

    2016-01-01

    There is increased interest in the relationship between motor skills and social skills in child development, with evidence that the mechanisms underlying these behaviors may be linked. We took a cognitive approach to this problem, and examined the relationship between four specific cognitive domains: theory of mind, motor skill, action understanding, and imitation. Neuroimaging and adult research suggest that action understanding and imitation are closely linked, but are somewhat independent of theory of mind and low-level motor control. Here, we test if a similar pattern is shown in child development. A sample of 101 primary school aged children with a wide ability range completed tests of IQ (Raven’s matrices), theory of mind, motor skill, action understanding, and imitation. Parents reported on their children’s social, motor and attention performance as well as developmental concerns. The results showed that action understanding and imitation correlate, with the latter having a weak link to motor control. Theory of mind was independent of the other tasks. These results imply that independent cognitive processes for social interaction (theory of mind) and for motor control can be identified in primary school age children, and challenge approaches that link all these domains together. PMID:26941685

  17. The neural correlates of speech motor sequence learning.

    PubMed

    Segawa, Jennifer A; Tourville, Jason A; Beal, Deryk S; Guenther, Frank H

    2015-04-01

    Speech is perhaps the most sophisticated example of a species-wide movement capability in the animal kingdom, requiring split-second sequencing of approximately 100 muscles in the respiratory, laryngeal, and oral movement systems. Despite the unique role speech plays in human interaction and the debilitating impact of its disruption, little is known about the neural mechanisms underlying speech motor learning. Here, we studied the behavioral and neural correlates of learning new speech motor sequences. Participants repeatedly produced novel, meaningless syllables comprising illegal consonant clusters (e.g., GVAZF) over 2 days of practice. Following practice, participants produced the sequences with fewer errors and shorter durations, indicative of motor learning. Using fMRI, we compared brain activity during production of the learned illegal sequences and novel illegal sequences. Greater activity was noted during production of novel sequences in brain regions linked to non-speech motor sequence learning, including the BG and pre-SMA. Activity during novel sequence production was also greater in brain regions associated with learning and maintaining speech motor programs, including lateral premotor cortex, frontal operculum, and posterior superior temporal cortex. Measures of learning success correlated positively with activity in left frontal operculum and white matter integrity under left posterior superior temporal sulcus. These findings indicate speech motor sequence learning relies not only on brain areas involved generally in motor sequencing learning but also those associated with feedback-based speech motor learning. Furthermore, learning success is modulated by the integrity of structural connectivity between these motor and sensory brain regions.

  18. Sexual motivation is reflected by stimulus-dependent motor cortex excitability.

    PubMed

    Schecklmann, Martin; Engelhardt, Kristina; Konzok, Julian; Rupprecht, Rainer; Greenlee, Mark W; Mokros, Andreas; Langguth, Berthold; Poeppl, Timm B

    2015-08-01

    Sexual behavior involves motivational processes. Findings from both animal models and neuroimaging in humans suggest that the recruitment of neural motor networks is an integral part of the sexual response. However, no study so far has directly linked sexual motivation to physiologically measurable changes in cerebral motor systems in humans. Using transcranial magnetic stimulation in hetero- and homosexual men, we here show that sexual motivation modulates cortical excitability. More specifically, our results demonstrate that visual sexual stimuli corresponding with one's sexual orientation, compared with non-corresponding visual sexual stimuli, increase the excitability of the motor cortex. The reflection of sexual motivation in motor cortex excitability provides evidence for motor preparation processes in sexual behavior in humans. Moreover, such interrelationship links theoretical models and previous neuroimaging findings of sexual behavior.

  19. Quantifying Motor Experience in the Infant Brain: EEG Power, Coherence, and Mu Desynchronization

    PubMed Central

    Gonzalez, Sandy L.; Reeb-Sutherland, Bethany C.; Nelson, Eliza L.

    2016-01-01

    The emergence of new motor skills, such as reaching and walking, dramatically changes how infants engage with the world socially and cognitively. Several examples of how motor experience can cascade into cognitive and social development have been documented, yet a significant knowledge gap remains in our understanding of whether these observed behavioral changes are accompanied by underlying neural changes. We propose that electroencephalography (EEG) measures such as power, coherence, and mu desynchronization are optimal tools to quantify motor experience in the infant brain. In this mini-review, we will summarize existing infant research that has separately assessed the relation between motor, cognitive, or social development with coherence, power, or mu desynchronization. We will discuss how the reviewed neural changes seen in seemingly separate developmental domains may be linked based on existing behavioral evidence. We will further propose that power, coherence, and mu desynchronization be used in research exploring the links between motor experience and cognitive and social development. PMID:26925022

  20. Prospective errors determine motor learning

    PubMed Central

    Takiyama, Ken; Hirashima, Masaya; Nozaki, Daichi

    2015-01-01

    Diverse features of motor learning have been reported by numerous studies, but no single theoretical framework concurrently accounts for these features. Here, we propose a model for motor learning to explain these features in a unified way by extending a motor primitive framework. The model assumes that the recruitment pattern of motor primitives is determined by the predicted movement error of an upcoming movement (prospective error). To validate this idea, we perform a behavioural experiment to examine the model’s novel prediction: after experiencing an environment in which the movement error is more easily predictable, subsequent motor learning should become faster. The experimental results support our prediction, suggesting that the prospective error might be encoded in the motor primitives. Furthermore, we demonstrate that this model has a strong explanatory power to reproduce a wide variety of motor-learning-related phenomena that have been separately explained by different computational models. PMID:25635628

  1. Magnetostrictive direct drive motors

    NASA Technical Reports Server (NTRS)

    Naik, Dipak; Dehoff, P. H.

    1992-01-01

    A new rare earth alloy, Terfenol-D, combines low frequency operation and extremely high energy density with high magnetostriction. Its material properties make it suitable as a drive element for actuators requiring high output torque. The high strains, the high forces and the high controllability of Terfenol alloys provide a powerful and challenging basis for new ways to generate motion in actuators. Two prototypes of motors using Terfenol-D rods were developed at NASA Goddard. The basic principles of operation are provided of the motor along with other relevant details. A conceptual design of a torque limiting safety clutch/brake under development is illustrated. Also, preliminary design drawings of a linear actuator using Terfenol-D is shown.

  2. Ironless armature torque motor

    NASA Technical Reports Server (NTRS)

    Fisher, R. L.

    1972-01-01

    Four iron-less armature torque motors, four Hall device position sensor assemblies, and two test fixtures were fabricated. The design approach utilized samarium cobalt permanent magnets, a large airgap, and a three-phase winding in a stationary ironless armature. Hall devices were employed to sense rotor position. An ironless armature torque motor having an outer diameter of 4.25 inches was developed to produce a torque constant of 65 ounce-inches per ampere with a resistance of 20.5 ohms. The total weight, including structural elements, was 1.58 pounds. Test results indicated that all specifications were met except for generated voltage waveform. It is recommended that investigations be made concerning the generated voltage waveform to determine if it may be improved.

  3. Advanced Motor Drives Studies

    NASA Technical Reports Server (NTRS)

    Ehsani, M.; Tchamdjou, A.

    1997-01-01

    This report presents an evaluation of advanced motor drive systems as a replacement for the hydrazine fueled APU units. The replacement technology must meet several requirements which are particular to the space applications and the Orbiter in general. Some of these requirements are high efficiency, small size, high power density. In the first part of the study several motors are compared, based on their characteristics and in light of the Orbiter requirements. The best candidate, the brushless DC is chosen because of its particularly good performance with regards to efficiency. Several power electronics drive technologies including the conventional three-phase hard switched and several soft-switched inverters are then presented. In the last part of the study, a soft-switched inverter is analyzed and compared to its conventional hard-switched counterpart. Optimal efficiency is a basic requirement for space applications and the soft-switched technology represents an unavoidable trend for the future.

  4. The St. Louis Motor

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2011-10-01

    The St. Louis Motor, invented in 1909, is unique among physics apparatus for being named for a geographical place rather than a physicist. The sturdy little device (Fig. 1) has never been out of production. Any older school or physics department that has not done a catastrophic housecleaning in the last 20 years will certainly have a small flock of them in the back room.

  5. Motor neurone disease.

    PubMed

    2016-03-23

    Essential facts Motor neurone disease describes a group of related diseases, affecting the neurones in the brain and spinal cord. Progressive, incurable and life-limiting, MND is rare, with about 1,100 people developing it each year in the UK and up to 5,000 people affected at any one time. One third of people will die within a year of diagnosis and more than half within two years. About 5% to 10% are alive at ten years.

  6. EPDM rocket motor insulation

    NASA Technical Reports Server (NTRS)

    Guillot, David G. (Inventor); Harvey, Albert R. (Inventor)

    2004-01-01

    A novel and improved EPDM formulation for a solid propellant rocket motor is described wherein hexadiene EPDM monomer components are replaced by alkylidene norbornene components, and, with appropriate adjustment of curing and other additives, functionally required rheological and physical characteristics are achieved with the desired compatibility with any one of a plurality of solid filler materials, e.g., powder silica, carbon fibers or aramid fibers, and with appropriate adhesion and extended storage or shelf-life characteristics.

  7. Libert-E Motor

    ERIC Educational Resources Information Center

    Sieloff, Susan F.; Kinnunen, Raymond; Chevarley, Joseph

    2011-01-01

    Kei Yun Wong has big dreams. She has been entrusted with the United States launch of Libert-E Motor, a new line of Chinese-manufactured electric scooters. With only $750,000 of her original budget of $3 million left, she needs to make sure that the launch succeeds, as it represents the initial step in her desire to create the first Chinese global…

  8. EPDM rocket motor insulation

    NASA Technical Reports Server (NTRS)

    Guillot, David G. (Inventor); Harvey, Albert R. (Inventor)

    2008-01-01

    A novel and improved EPDM formulation for a solid propellant rocket motor is described wherein hexadiene EPDM monomer components are replaced by alkylidene norbornene components, and, with appropriate adjustment of curing and other additives, functionally required rheological and physical characteristics are achieved with the desired compatibility with any one of a plurality of solid filler materials, e.g., powder silica, carbon fibers or aramid fibers, and with appropriate adhesion and extended storage or shelf-life characteristics.

  9. EPDM rocket motor insulation

    NASA Technical Reports Server (NTRS)

    Guillot, David G. (Inventor); Harvey, Albert R. (Inventor)

    2003-01-01

    A novel and improved EPDM formulation for a solid propellant rocket motor is described wherein hexadiene EPDM monomer components are replaced by alkylidene norbornene components and with appropriate adjustment of curing and other additives functionally-required rheological and physical characteristics are achieved with the desired compatibility with any one of a plurality of solid filler materials, e.g. powder silica, carbon fibers or aramid fibers, and with appropriate adhesion and extended storage or shelf life characteristics.

  10. Dyspraxia, motor function and visual-motor integration in autism.

    PubMed

    Miller, M; Chukoskie, L; Zinni, M; Townsend, J; Trauner, D

    2014-08-01

    This project assessed dyspraxia in high-functioning school aged children with autism with a focus on Ideational Praxis. We examined the association of specific underlying motor function including eye movement with ideational dyspraxia (sequences of skilled movements) as well as the possible role of visual-motor integration in dyspraxia. We found that compared to IQ-, sex- and age-matched typically developing children, the children with autism performed significantly worse on: Ideational and Buccofacial praxis; a broad range of motor tests, including measures of simple motor skill, timing and accuracy of saccadic eye movements and motor coordination; and tests of visual-motor integration. Impairments in individual children with autism were heterogeneous in nature, although when we examined the praxis data as a function of a qualitative measure representing motor timing, we found that children with poor motor timing performed worse on all praxis categories and had slower and less accurate eye movements while those with regular timing performed as well as typical children on those same tasks. Our data provide evidence that both motor function and visual-motor integration contribute to dyspraxia. We suggest that dyspraxia in autism involves cerebellar mechanisms of movement control and the integration of these mechanisms with cortical networks implicated in praxis.

  11. Motor Fuel Excise Taxes

    SciTech Connect

    2015-09-01

    A new report from the National Renewable Energy Laboratory (NREL) explores the role of alternative fuels and energy efficient vehicles in motor fuel taxes. Throughout the United States, it is common practice for federal, state, and local governments to tax motor fuels on a per gallon basis to fund construction and maintenance of our transportation infrastructure. In recent years, however, expenses have outpaced revenues creating substantial funding shortfalls that have required supplemental funding sources. While rising infrastructure costs and the decreasing purchasing power of the gas tax are significant factors contributing to the shortfall, the increased use of alternative fuels and more stringent fuel economy standards are also exacerbating revenue shortfalls. The current dynamic places vehicle efficiency and petroleum use reduction polices at direct odds with policies promoting robust transportation infrastructure. Understanding the energy, transportation, and environmental tradeoffs of motor fuel tax policies can be complicated, but recent experiences at the state level are helping policymakers align their energy and environmental priorities with highway funding requirements.

  12. A universal computer control system for motors

    NASA Astrophysics Data System (ADS)

    Szakaly, Zoltan F.

    1991-09-01

    A control system for a multi-motor system such as a space telerobot, having a remote computational node and a local computational node interconnected with one another by a high speed data link is described. A Universal Computer Control System (UCCS) for the telerobot is located at each node. Each node is provided with a multibus computer system which is characterized by a plurality of processors with all processors being connected to a common bus, and including at least one command processor. The command processor communicates over the bus with a plurality of joint controller cards. A plurality of direct current torque motors, of the type used in telerobot joints and telerobot hand-held controllers, are connected to the controller cards and responds to digital control signals from the command processor. Essential motor operating parameters are sensed by analog sensing circuits and the sensed analog signals are converted to digital signals for storage at the controller cards where such signals can be read during an address read/write cycle of the command processing processor.

  13. A universal computer control system for motors

    NASA Technical Reports Server (NTRS)

    Szakaly, Zoltan F. (Inventor)

    1991-01-01

    A control system for a multi-motor system such as a space telerobot, having a remote computational node and a local computational node interconnected with one another by a high speed data link is described. A Universal Computer Control System (UCCS) for the telerobot is located at each node. Each node is provided with a multibus computer system which is characterized by a plurality of processors with all processors being connected to a common bus, and including at least one command processor. The command processor communicates over the bus with a plurality of joint controller cards. A plurality of direct current torque motors, of the type used in telerobot joints and telerobot hand-held controllers, are connected to the controller cards and responds to digital control signals from the command processor. Essential motor operating parameters are sensed by analog sensing circuits and the sensed analog signals are converted to digital signals for storage at the controller cards where such signals can be read during an address read/write cycle of the command processing processor.

  14. Analog Optical Links

    NASA Astrophysics Data System (ADS)

    Cox, Charles H., III

    2004-05-01

    Unlike books that focus on the devices used in links, such as lasers and photodiodes, among others, this text focuses on the next level. It covers the collection of devices that form a link, how the individual device performance affects the link performance, or the reverse. Analog links are used for the distribution of cable TV signals, and in conveying the signals to and from antennas (so called antenna remoting). The design of analog links differs significantly from digital links which are primarily used in telecommunications.

  15. Link performance of mobile optical links

    NASA Astrophysics Data System (ADS)

    Henniger, H.

    2007-09-01

    High data-rate atmospheric free-space optical (FSO) lasercom systems typically suffer from relatively long time duration link degradations. These are caused by pointing- and tracking-errors or deep signal-fades produced by the index of refraction fluctuations caused by atmospheric turbulence. Based on measurement results we will present in this paper a channel characterization model for free-space optical links. Further a forward-error-correction (FEC) coding scheme is introduced that is able to overcome link outages. The performance of these codes has been proven by measurements. Code design recommendations and validation test results are discussed in this paper.

  16. Coordinated Switching of Bacterial Flagellar Motors: Evidence for Direct Motor-Motor Coupling?

    NASA Astrophysics Data System (ADS)

    Hu, Bo; Tu, Yuhai

    2013-04-01

    The swimming of Escherichia coli is powered by its multiple flagellar motors. Each motor spins either clockwise or counterclockwise, under the control of an intracellular regulator, CheY-P. There can be two mechanisms (extrinsic and intrinsic) to coordinate the switching of bacterial motors. The extrinsic one arises from the fact that different motors in the same cell sense a common input (CheY-P) which fluctuates near the motors’ response threshold. An alternative, intrinsic mechanism is direct motor-motor coupling which makes synchronized switching energetically favorable. Here, we develop simple models for both mechanisms and uncover their different hallmarks. A quantitative comparison to the recent experiments suggests that the direct coupling mechanism may be accountable for the observed sharp correlation between motors in a single Escherichia coli. Possible origins of this coupling (e.g., hydrodynamic interaction) are discussed.

  17. An Inverter-Driven Induction Motor System with a Deadlock Breaking Capability

    NASA Astrophysics Data System (ADS)

    Ichikawa, Takuto; Yoshida, Toshiya; Miyashita, Osamu

    Induction motors are very widely used in various industrial applications. In semiconductor manufacturing processes, deadlock failure of pumps may occur by the adhering of glass material contained in the gas to the rotor. This can lead to the shutdown of the manufacturing plant. Therefore, a countermeasure to prevent deadlocking of a motor is required. This paper proposes a method for generating an impulse torque in an induction motor fed by an inverter. The proposed inverter circuit is composed of a conventional inverter and a few additional relays. The on-and-off control of the relays supplies an appropriate magnetizing current and a large torque current from the dc-link capacitor. In experiment, a 1.5-kW cage-type induction motor generated a torque that was approximately seven times larger than the rated torque of the motor. This large impulse torque is useful for breaking the motor deadlock.

  18. Imparting Motion to a Test Object Such as a Motor Vehicle in a Controlled Fashion

    NASA Technical Reports Server (NTRS)

    Southward, Stephen C. (Inventor); Reubush, Chandler (Inventor); Pittman, Bryan (Inventor); Roehrig, Kurt (Inventor); Gerard, Doug (Inventor)

    2014-01-01

    An apparatus imparts motion to a test object such as a motor vehicle in a controlled fashion. A base has mounted on it a linear electromagnetic motor having a first end and a second end, the first end being connected to the base. A pneumatic cylinder and piston combination have a first end and a second end, the first end connected to the base so that the pneumatic cylinder and piston combination is generally parallel with the linear electromagnetic motor. The second ends of the linear electromagnetic motor and pneumatic cylinder and piston combination being commonly linked to a mount for the test object. A control system for the linear electromagnetic motor and pneumatic cylinder and piston combination drives the pneumatic cylinder and piston combination to support a substantial static load of the test object and the linear electromagnetic motor to impart controlled motion to the test object.

  19. Sleep and Motor Learning: Implications for Physical Rehabilitation After Stroke

    PubMed Central

    Gudberg, Christel; Johansen-Berg, Heidi

    2015-01-01

    Sleep is essential for healthy brain function and plasticity underlying learning and memory. In the context of physical impairment such as following a stroke, sleep may be particularly important for supporting critical recovery of motor function through similar processes of reorganization in the brain. Despite a link between stroke and poor sleep, current approaches to rehabilitative care often neglect the importance of sleep in clinical assessment and treatment. This review assimilates current evidence on the role of sleep in motor learning, with a focus on the implications for physical rehabilitation after stroke. We further outline practical considerations for integrating sleep assessment as a vital part of clinical care. PMID:26635718

  20. Multiple-motor based transport and its regulation by Tau

    PubMed Central

    Vershinin, Michael; Carter, Brian C.; Razafsky, David S.; King, Stephen J.; Gross, Steven P.

    2007-01-01

    Motor-based intracellular transport and its regulation are crucial to the functioning of a cell. Disruption of transport is linked to Alzheimer's and other neurodegenerative diseases. However, many fundamental aspects of transport are poorly understood. An important issue is how cells achieve and regulate efficient long-distance transport. Mounting evidence suggests that many in vivo cargoes are transported along microtubules by more than one motor, but we do not know how multiple motors work together or can be regulated. Here we first show that multiple kinesin motors, working in conjunction, can achieve very long distance transport and apply significantly larger forces without the need of additional factors. We then demonstrate in vitro that the important microtubule-associated protein, tau, regulates the number of engaged kinesin motors per cargo via its local concentration on microtubules. This function of tau provides a previously unappreciated mechanism to regulate transport. By reducing motor reattachment rates, tau affects cargo travel distance, motive force, and cargo dispersal. We also show that different isoforms of tau, at concentrations similar to those in cells, have dramatically different potency. These results provide a well defined mechanism for how altered tau isoform levels could impair transport and thereby lead to neurodegeneration without the need of any other pathway. PMID:17190808

  1. Implicit chord processing and motor representation in pianists.

    PubMed

    Trimarchi, Pietro Davide; Luzzatti, Claudio

    2011-03-01

    The aim of this paper is to assess the relevance of pitch dimension in auditory-motor interaction. Several behavioural and brain imaging studies have shown that auditory processing of sounds can activate motor representations, an effect which is however elicited only by action-related sounds, i.e., sounds linked to a specific motor repertoire. Music provides an appropriate framework for further exploration of this issue. Three groups of participants (pianists, non-pianist musicians and non-musicians) were tested with a shape decision task where left-hand and right-hand responses were required; each visual stimulus was paired with an auditory task-irrelevant stimulus (high-pitched or low-pitched piano-timbre chords). Of the three groups, only pianists had longer reaction times for left-hand/high-pitched chords and right-hand/low-pitched chords associations. These findings are consistent with an auditory-motor effect elicited by pitch dimension, as only pianists show an interaction between motor responses and implicit pitch processing. This interaction is consistent with the canonical mapping of hand gestures and pitch dimension on the piano keyboard. The results are discussed within the ideo-motor theoretical framework offered by the Theory of Event Coding (Hommel et al. in Behav Brain Sci 24:849-937, 2001).

  2. Wind motor applications for transportation

    SciTech Connect

    Lysenko, G.P.; Grigoriev, B.V.; Karpin, K.B.

    1996-12-31

    Motion equation for a vehicle equipped with a wind motor allows, taking into account the drag coefficients, to determine the optimal wind drag velocity in the wind motor`s plane, and hence, obtain all the necessary data for the wind wheel blades geometrical parameters definition. This optimal drag velocity significantly differs from the flow drag velocity which determines the maximum wind motor power. Solution of the motion equation with low drag coefficients indicates that the vehicle speed against the wind may be twice as the wind speed. One of possible transportation wind motor applications is its use on various ships. A ship with such a wind motor may be substantially easier to steer, and if certain devices are available, may proceed in autonomous control mode. Besides, it is capable of moving within narrow fairways. The cruise speed of a sailing boat and wind-motored ship were compared provided that the wind velocity direction changes along a harmonic law with regard to the motion direction. Mean dimensionless speed of the wind-motored ship appears to be by 20--25% higher than that of a sailing boat. There was analyzed a possibility of using the wind motors on planet rovers in Mars or Venus atmospheric conditions. A Mars rover power and motor system has been assessed for the power level of 3 kW.

  3. Linking Policy | Smokefree 60+

    Cancer.gov

    Links to individual pages within the Smokefree 60+ website are permissible, provided attribution is made to 60plus.smokefree.gov and any descriptive notes accurately reflect the content of the linked page(s).

  4. Comparison of capabilities of reluctance synchronous motor and induction motor

    NASA Astrophysics Data System (ADS)

    Štumberger, Gorazd; Hadžiselimović, Miralem; Štumberger, Bojan; Miljavec, Damijan; Dolinar, Drago; Zagradišnik, Ivan

    2006-09-01

    This paper compares the capabilities of a reluctance synchronous motor (RSM) with those of an induction motor (IM). An RSM and IM were designed and made, with the same rated power and speed. They differ only in the rotor portion while their stators, housings and cooling systems are identical. The capabilities of both motors in a variable speed drive are evaluated by comparison of the results obtained by magnetically nonlinear models and by measurements.

  5. Developmental contributions to motor sequence learning.

    PubMed

    Savion-Lemieux, Tal; Bailey, Jennifer A; Penhune, Virginia B

    2009-05-01

    of sequence learning is consistent with the hypothesis that accuracy or finger-stimulus association may rely on cortical pathways that show the greatest maturation between ages 6 and 10; whereas motor timing and sensorimotor integration may rely on subcortical pathways that continue to develop into young adulthood. Despite developmental differences across blocks of practice on both behavioral measures, there were no significant group differences for either the Recognition or Recall tests. We suggest that explicit knowledge of the MFST is not directly linked to task performance, thus challenging the implicit-explicit distinction in pediatric SRT studies assessing the developmental invariance model.

  6. Commercial Web Site Links.

    ERIC Educational Resources Information Center

    Thelwall, Mike

    2001-01-01

    Discusses business use of the Web and related search engine design issues as well as research on general and academic links before reporting on a survey of the links published by a collection of business Web sites. Results indicate around 66% of Web sites do carry external links, most of which are targeted at a specific purpose, but about 17%…

  7. Motor unit activity after eccentric exercise and muscle damage in humans.

    PubMed

    Semmler, J G

    2014-04-01

    It is well known that unaccustomed eccentric exercise leads to muscle damage and soreness, which can produce long-lasting effects on muscle function. How this muscle damage influences muscle activation is poorly understood. The purpose of this brief review is to highlight the effect of eccentric exercise on the activation of muscle by the nervous system, by examining the change in motor unit activity obtained from surface electromyography (EMG) and intramuscular recordings. Previous research shows that eccentric exercise produces unusual changes in the EMG–force relation that influences motor performance during isometric, shortening and lengthening muscle contractions and during fatiguing tasks. When examining the effect of eccentric exercise at the single motor unit level, there are substantial changes in recruitment thresholds, discharge rates, motor unit conduction velocities and synchronization, which can last for up to 1 week after eccentric exercise. Examining the time course of these changes suggests that the increased submaximal EMG after eccentric exercise most likely occurs through a decrease in motor unit conduction velocity and an increase in motor unit activity related to antagonist muscle coactivation and low-frequency fatigue. Furthermore, there is a commonly held view that eccentric exercise produces preferential damage to high-threshold motor units, but the evidence for this in humans is limited. Further research is needed to establish whether there is preferential damage to high-threshold motor units after eccentric exercise in humans, preferably by linking changes in motor unit activity with estimates of motor unit size using selective intramuscular recording techniques.

  8. Sport expert's motor imagery: functional imaging of professional motor skills and simple motor skills.

    PubMed

    Wei, Gaoxia; Luo, Jing

    2010-06-23

    Numerous studies provide evidence that motor skill acquisition is associated with dynamic changes in cortical and subcortical regions. Athletes are a professional population who are engaged in extensive motor training for long periods. However, the neural substrates of extreme level motor performance have not been clarified. We used kinesthetic imagery task to induce the mental representation of sport expert's extraordinary performance in view of the shared substrates of executing movement and motor imagery. For the first time, we compared, through functional magnetic resonance imaging (fMRI), the pattern of cerebral activations in 12 professional divers and 12 normal people without extensive training, during imagery of professional skills and imagery of simple motor skills. The sport experts showed significant activation in the parahippocampus during imagery of professional skills relative to the novices, which might reflect the representation adapted to experience-related motor tasks. No significant difference was found between experts and novices when they imagined simple motor skills. These results indicated the experts might utilize their kinesthetic imagery more efficiently than novices, but only for the activity in which they had expertise. The sport experts also demonstrated more focused activation patterns in prefrontal areas in both of imagery tasks, which may be relevant to higher order of motor control during motor imagery. Moreover, this study suggested that the brains of sport experts could be regarded as the ideal subjects to explore the relationship between cerebral plasticity and learning of complex motor skills.

  9. Motor Skill Competence and Physical Activity in Preschoolers: A Review.

    PubMed

    Figueroa, Roger; An, Ruopeng

    2017-01-01

    Objectives Preschoolers 3-5 years of age are in a crucial stage of motor skill competence. While preschoolers develop their motor skill competence through engagement in physical activity, a majority of them fail to meet guideline-recommended physical activity level. This study reviews scientific evidence on the relationship between motor skill competence and physical activity among preschoolers. Methods This systematic review followed the PRISMA framework. Keyword and reference search were conducted in PubMed, Cochrane Library, PsycINFO, Web of Science, and Google Scholar. Inclusion criteria included-age: 3-5 years of age; setting: preschool environment (e.g., preschool, childcare, head start); main outcomes: motor skill competence and physical activity; study design: cross-sectional study, case-control study, retrospective cohort study, prospective cohort study, or randomized controlled trial; language: English; and article type: peer-reviewed publication. Results Eleven studies met the inclusion criteria, including 6 randomized controlled trials and 5 cross-sectional studies. Studies were conducted in 5 countries: United States (5), United Kingdom (2), Australia (2), Switzerland (1), and Finland (1). Eight out of the 11 studies included in the review reported a significant relationship between motor skill competence and physical activity. The specific pattern and strength of the relationship tend to differ by gender, physical activity intensity, motor skill type, and day of the week (weekdays versus weekends). Conclusions An association has been consistently documented between motor skill competence and physical activity. Future research is warranted to elucidate the underlining causal link, examine potential heterogeneity, and determine the role of environment in the relationship between motor skill competence and physical activity among preschoolers.

  10. Dissociation of motor maturation.

    PubMed

    DiMario, Francis J

    2003-06-01

    We prospectively acquired clinical data regarding the presentation, evaluation, and developmental progress of all patients identified with dissociated motor maturation to define their clinical outcomes. Children (N = 8) referred for evaluation of suspected cerebral palsy because of delayed sitting or walking and identified to have dissociated motor maturation were followed with serial clinical examination. All displayed the characteristic "sitting on air" posture while held in vertical suspension and had otherwise normal developmental assessments. This posture is composed of the hips held in flexion and abduction with the knees extended and feet plantar or dorsiflexed. Three children were initially evaluated at 10 months of age owing to absence of sitting and five other children were evaluated at a mean of 14 months (range 12-19 months) owing to inability to stand. Follow-up evaluations were conducted over a mean of 10.5 months (range 5-34 months). Five children were born prematurely at 34 to 36 weeks gestation. Denver Developmental Screening Test and general and neurologic examinations were normal except to note hypotonia in six children and the "sitting on air" posture in all of the children. Four children have older siblings or parents who "walked late" (after 15 months). On average, the children attained sitting by 8 months (range 7-10 months). One child did not crawl prior to independent walking, two children scooted rather than crawled, and five children crawled at an average of 13.5 months (range 10-16 months). All children cruised by a mean of 18 months (range 16-21.5 months) and attained independent walking by 20.1 months (range 18-25 months). Neuroimaging and serum creatine kinase enzyme testing were normal in two children who were tested. These eight children conform to the syndrome of dissociated motor maturation. The "sitting on air" posture serves as a diagnostic sign and anticipated excellent prognosis, but follow-up is required to ensure a normal

  11. Electric motor analysis at Dofasco

    SciTech Connect

    Brooks, D.; Morgan, V.A.; Nicholas, J.R. Jr.

    1997-03-01

    Initiatives adopted by Dofasco to enhance electric motor reliability and availability include: Enhancement of the electrical repair shop testing and repair capabilities; More stringent standards for motor repair service vendors; Application of predictive technologies to motors in service within manufacturing units; Training of personnel in electrical predictive condition monitoring and analysis methods; and Periodic audit and comparison of central support and operating unit predictive technology application and integration. The basis for the initiative is discussed together with illustrative case histories.

  12. Torque-Summing Brushless Motor

    NASA Technical Reports Server (NTRS)

    Vaidya, J. G.

    1986-01-01

    Torque channels function cooperatively but electrically independent for reliability. Brushless, electronically-commutated dc motor sums electromagnetic torques on four channels and applies them to single shaft. Motor operates with any combination of channels and continues if one or more of channels fail electrically. Motor employs single stator and rotor and mechanically simple; however, each of channels electrically isolated from other so that failure of one does not adversely affect others.

  13. Motor timing under microgravity.

    PubMed

    Semjen, A; Leone, G; Lipshits, M

    1998-01-01

    Five participants were tested on their ability to produce accurate and regular inter-response intervals in the 350 to 530 ms time range. Three of them were members of the French-Russian CASSIOPEE 96 spaceflight mission, and the other two were control subjects tested on the ground. During spaceflight, the target inter-response intervals were increasingly undershot and the timing became more variable (less regular). The increase in the timing variability was mostly attributable to the internal timekeeping processes rather than those involved in motor execution. The results are discussed with reference to the physiological mechanisms possibly underlying the timing of fast serial movements.

  14. Imagery and Motor Processes--When Are They Connected? The Mental Rotation of Body Parts in Development

    ERIC Educational Resources Information Center

    Kruger, Markus; Krist, Horst

    2009-01-01

    Motor influences on the mental transformation of body parts have been observed in both children and adults. Previous findings indicated that these influences were more pronounced in children than in adults, suggesting a stronger link between motor processes and imagery in children. The present series of two experiments casts doubt on the general…

  15. 76 FR 12792 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; General...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... TRANSPORTATION National Highway Traffic Safety Administration Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; General Motors Corporation AGENCY: National Highway Traffic.... SUMMARY: This document grants in full the petition of General Motors Corporation's (GM) petition for...

  16. Motor power control circuit for ac induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1983-01-01

    A motor power control of the type which functions by controlling the power factor wherein one of the parameters of power factor current on time is determined by the on time of a triac through which current is supplied to the motor. By means of a positive feedback circuit, a wider range of control is effected.

  17. 27. View, looking north, of motor house; the electric motor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. View, looking north, of motor house; the electric motor and electric-powered winch are housed in section of building to the left. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  18. Motor vehicle drivers' injuries in train-motor vehicle crashes.

    PubMed

    Zhao, Shanshan; Khattak, Aemal

    2015-01-01

    The objectives of this research were to: (1) identify a more suitable model for modeling injury severity of motor vehicle drivers involved in train-motor vehicle crashes at highway-rail grade crossings from among three commonly used injury severity models and (2) to investigate factors associated with injury severity levels of motor vehicle drivers involved in train-motor vehicle crashes at such crossings. The 2009-2013 highway-rail grade crossing crash data and the national highway-rail crossing inventory data were combined to produce the analysis dataset. Four-year (2009-2012) data were used for model estimation while 2013 data were used for model validation. The three injury severity levels-fatal, injury and no injury-were based on the reported intensity of motor-vehicle drivers' injuries at highway-rail grade crossings. The three injury severity models evaluated were: ordered probit, multinomial logit and random parameter logit. A comparison of the three models based on different criteria showed that the random parameter logit model and multinomial logit model were more suitable for injury severity analysis of motor vehicle drivers involved in crashes at highway-rail grade crossings. Some of the factors that increased the likelihood of more severe crashes included higher train and vehicle speeds, freight trains, older drivers, and female drivers. Where feasible, reducing train and motor vehicle speeds and nighttime lighting may help reduce injury severities of motor vehicle drivers.

  19. Spinal muscular atrophy: Factors that modulate motor neurone vulnerability.

    PubMed

    Tu, Wen-Yo; Simpson, Julie E; Highley, J Robin; Heath, Paul R

    2017-02-02

    Spinal muscular atrophy (SMA), a leading genetic cause of infant death, is a neurodegenerative disease characterised by the selective loss of particular groups of motor neurones in the anterior horn of the spinal cord with concomitant muscle weakness. To date, no effective treatment is available, however, there are ongoing clinical trials are in place which promise much for the future. However, there remains an ongoing problem in trying to link a single gene loss to motor neurone degeneration. Fortunately, given successful disease models that have been established and intensive studies on SMN functions in the past ten years, we are fast approaching the stage of identifying the underlying mechanisms of SMA pathogenesis Here we discuss potential disease modifying factors on motor neurone vulnerability, in the belief that these factors give insight into the pathological mechanisms of SMA and therefore possible therapeutic targets.

  20. To What Extent Can Motor Imagery Replace Motor Execution While Learning a Fine Motor Skill?

    PubMed Central

    Sobierajewicz, Jagna; Szarkiewicz, Sylwia; Przekoracka-Krawczyk, Anna; Jaśkowski, Wojciech; van der Lubbe, Rob

    2016-01-01

    Motor imagery is generally thought to share common mechanisms with motor execution. In the present study, we examined to what extent learning a fine motor skill by motor imagery may substitute physical practice. Learning effects were assessed by manipulating the proportion of motor execution and motor imagery trials. Additionally, learning effects were compared between participants with an explicit motor imagery instruction and a control group. A Go/NoGo discrete sequence production (DSP) task was employed, wherein a five-stimulus sequence presented on each trial indicated the required sequence of finger movements after a Go signal. In the case of a NoGo signal, participants either had to imagine carrying out the response sequence (the motor imagery group), or the response sequence had to be withheld (the control group). Two practice days were followed by a final test day on which all sequences had to be executed. Learning effects were assessed by computing response times (RTs) and the percentages of correct responses (PCs). The electroencephalogram (EEG ) was additionally measured on this test day to examine whether motor preparation and the involvement of visual short term memory (VST M) depended on the amount of physical/mental practice. Accuracy data indicated strong learning effects. However, a substantial amount of physical practice was required to reach an optimal speed. EEG results suggest the involvement of VST M for sequences that had less or no physical practice in both groups. The absence of differences between the motor imagery and the control group underlines the possibility that motor preparation may actually resemble motor imagery. PMID:28154614

  1. To What Extent Can Motor Imagery Replace Motor Execution While Learning a Fine Motor Skill?

    PubMed

    Sobierajewicz, Jagna; Szarkiewicz, Sylwia; Przekoracka-Krawczyk, Anna; Jaśkowski, Wojciech; van der Lubbe, Rob

    2016-01-01

    Motor imagery is generally thought to share common mechanisms with motor execution. In the present study, we examined to what extent learning a fine motor skill by motor imagery may substitute physical practice. Learning effects were assessed by manipulating the proportion of motor execution and motor imagery trials. Additionally, learning effects were compared between participants with an explicit motor imagery instruction and a control group. A Go/NoGo discrete sequence production (DSP) task was employed, wherein a five-stimulus sequence presented on each trial indicated the required sequence of finger movements after a Go signal. In the case of a NoGo signal, participants either had to imagine carrying out the response sequence (the motor imagery group), or the response sequence had to be withheld (the control group). Two practice days were followed by a final test day on which all sequences had to be executed. Learning effects were assessed by computing response times (RTs) and the percentages of correct responses (PCs). The electroencephalogram (EEG ) was additionally measured on this test day to examine whether motor preparation and the involvement of visual short term memory (VST M) depended on the amount of physical/mental practice. Accuracy data indicated strong learning effects. However, a substantial amount of physical practice was required to reach an optimal speed. EEG results suggest the involvement of VST M for sequences that had less or no physical practice in both groups. The absence of differences between the motor imagery and the control group underlines the possibility that motor preparation may actually resemble motor imagery.

  2. Aberrant supplementary motor complex and limbic activity during motor preparation in motor conversion disorder.

    PubMed

    Voon, Valerie; Brezing, Christina; Gallea, Cecile; Hallett, Mark

    2011-11-01

    Conversion disorder (CD) is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that CD with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amygdala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Subjects performed either an internally or externally generated 2-button action selection task in a functional MRI study. Eleven CD patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula, and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system, which is both hypoactive and functionally disconnected from prefrontal top-down regulation.

  3. Motor learning and its sensory effects: time course of perceptual change and its presence with gradual introduction of load.

    PubMed

    Mattar, Andrew A G; Darainy, Mohammad; Ostry, David J

    2013-02-01

    A complex interplay has been demonstrated between motor and sensory systems. We showed recently that motor learning leads to changes in the sensed position of the limb (Ostry DJ, Darainy M, Mattar AA, Wong J, Gribble PL. J Neurosci 30: 5384-5393, 2010). Here, we document further the links between motor learning and changes in somatosensory perception. To study motor learning, we used a force field paradigm in which subjects learn to compensate for forces applied to the hand by a robotic device. We used a task in which subjects judge lateral displacements of the hand to study somatosensory perception. In a first experiment, we divided the motor learning task into incremental phases and tracked sensory perception throughout. We found that changes in perception occurred at a slower rate than changes in motor performance. A second experiment tested whether awareness of the motor learning process is necessary for perceptual change. In this experiment, subjects were exposed to a force field that grew gradually in strength. We found that the shift in sensory perception occurred even when awareness of motor learning was reduced. These experiments argue for a link between motor learning and changes in somatosensory perception, and they are consistent with the idea that motor learning drives sensory change.

  4. 46 CFR 111.70-3 - Motor controllers and motor-control centers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Motor controllers and motor-control centers. 111.70-3... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-3 Motor controllers and motor-control centers. (a) General. The enclosure for each motor controller or...

  5. 46 CFR 111.70-3 - Motor controllers and motor-control centers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Motor controllers and motor-control centers. 111.70-3... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-3 Motor controllers and motor-control centers. (a) General. The enclosure for each motor controller or...

  6. 46 CFR 111.70-3 - Motor controllers and motor-control centers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Motor controllers and motor-control centers. 111.70-3... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-3 Motor controllers and motor-control centers. (a) General. The enclosure for each motor controller or...

  7. 46 CFR 111.70-3 - Motor controllers and motor-control centers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Motor controllers and motor-control centers. 111.70-3... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-3 Motor controllers and motor-control centers. (a) General. The enclosure for each motor controller or...

  8. 46 CFR 111.70-3 - Motor controllers and motor-control centers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Motor controllers and motor-control centers. 111.70-3... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-3 Motor controllers and motor-control centers. (a) General. The enclosure for each motor controller or...

  9. Genetic heterogeneity of motor neuropathies

    PubMed Central

    Bansagi, Boglarka; Griffin, Helen; Whittaker, Roger G.; Antoniadi, Thalia; Evangelista, Teresinha; Miller, James; Greenslade, Mark; Forester, Natalie; Duff, Jennifer; Bradshaw, Anna; Kleinle, Stephanie; Boczonadi, Veronika; Steele, Hannah; Ramesh, Venkateswaran; Franko, Edit; Pyle, Angela; Lochmüller, Hanns; Chinnery, Patrick F.

    2017-01-01

    Objective: To study the prevalence, molecular cause, and clinical presentation of hereditary motor neuropathies in a large cohort of patients from the North of England. Methods: Detailed neurologic and electrophysiologic assessments and next-generation panel testing or whole exome sequencing were performed in 105 patients with clinical symptoms of distal hereditary motor neuropathy (dHMN, 64 patients), axonal motor neuropathy (motor Charcot-Marie-Tooth disease [CMT2], 16 patients), or complex neurologic disease predominantly affecting the motor nerves (hereditary motor neuropathy plus, 25 patients). Results: The prevalence of dHMN is 2.14 affected individuals per 100,000 inhabitants (95% confidence interval 1.62–2.66) in the North of England. Causative mutations were identified in 26 out of 73 index patients (35.6%). The diagnostic rate in the dHMN subgroup was 32.5%, which is higher than previously reported (20%). We detected a significant defect of neuromuscular transmission in 7 cases and identified potentially causative mutations in 4 patients with multifocal demyelinating motor neuropathy. Conclusions: Many of the genes were shared between dHMN and motor CMT2, indicating identical disease mechanisms; therefore, we suggest changing the classification and including dHMN also as a subcategory of Charcot-Marie-Tooth disease. Abnormal neuromuscular transmission in some genetic forms provides a treatable target to develop therapies. PMID:28251916

  10. Advanced solid propellant motor insulation

    NASA Technical Reports Server (NTRS)

    Smith, P. L.; Russ, R. F.

    1972-01-01

    An advanced lightweight insulation system suitable for use in long duration, low pressure planetary orbiter-type motor applications was developed. Experiments included the screening of various filler and binder materials with optimization studies combining the best of each. Small scale test motor data were used to judge the degree of success.

  11. Computational approaches to motor control.

    PubMed

    Flash, T; Sejnowski, T J

    2001-12-01

    New concepts and computational models that integrate behavioral and neurophysiological observations have addressed several of the most fundamental long-standing problems in motor control. These problems include the selection of particular trajectories among the large number of possibilities, the solution of inverse kinematics and dynamics problems, motor adaptation and the learning of sequential behaviors.

  12. Motors and Bulbs in Series

    ERIC Educational Resources Information Center

    Whitaker, Robert J.

    2009-01-01

    One of Paul Hewitt's "Figuring Physics" that appeared in this journal dealt with the heating of a motor. This phenomenon can be demonstrated with a miniature motor and a bulb as part of a series of activities with "batteries and bulbs." Students examine the effect on the brightness of a single bulb when a second, identical bulb is placed in series…

  13. Motor Coordination and Executive Functions

    ERIC Educational Resources Information Center

    Michel, Eva

    2012-01-01

    Since Piaget, the view that motor and cognitive development are interrelated has gained wide acceptance. However, empirical research on this issue is still rare. Few studies show a correlation of performance in cognitive and motor tasks in typically developing children. More specifically, Diamond A. (2000) hypothesizes an involvement of executive…

  14. Conical Bearingless Motor/Generators

    NASA Technical Reports Server (NTRS)

    Kascak, P.; Jansen, R.; Dever, T.

    2008-01-01

    Motor/generators based on conical magnetic bearings have been invented as an improved alternative to prior such machines based, variously, on radial and/or axial magnetic bearings. Both the present and prior machines are members of the class of so-called bearingless or self bearing (in the sense of not containing mechanical bearings) rotary machines. Each motor/generator provides both a torque and force allowing it to either function as a motor and magnetic bearing or a generator and magnetic bearing concurrently. Because they are not subject to mechanical bearing wear, these machines have potentially long operational lives and can function without lubrication and over wide ranges of speed and temperature that include conditions under which lubricants would become depleted, degraded, or ineffective and mechanical bearings would fail. The figure shows three typical configurations of conical bearingless motor/generators. The main elements of each motor/generator are concentric rotor and stator portions having conically tapered surfaces facing each other across a gap. Because a conical motor/generator imposes both radial and axial magnetic forces, it acts, in effect, as a combination of an axial and a radial magnetic bearing. Therefore, only two conical motor/generators - one at each end of a rotor - are needed to effect complete magnetic leviation of the rotor, whereas previously, it was necessary to use a combination of an axial and a radial magnetic bearing at each end of the rotor to achieve complete magnetic levitation and a separate motor to provide torque.

  15. Power control for ac motor

    NASA Technical Reports Server (NTRS)

    Dabney, R. W. (Inventor)

    1984-01-01

    A motor controller employing a triac through which power is supplied to a motor is described. The open circuit voltage appearing across the triac controls the operation of a timing circuit. This timing circuit triggers on the triac at a time following turn off which varies inversely as a function of the amplitude of the open circuit voltage of the triac.

  16. Individualized Motor-Perceptual Study.

    ERIC Educational Resources Information Center

    Portland Public Schools, OR.

    This guide is being used in the Individualized Motor-Perceptual Study to determine whether working directly with kindergarten children to improve performance on motor-perceptual tasks will affect reading ability at the end of grades one, two, and three. The 5-year project involves six schools. In this guide, there are tips for teaching, suggested…

  17. Torque control for electric motors

    NASA Technical Reports Server (NTRS)

    Bernard, C. A.

    1980-01-01

    Method for adjusting electric-motor torque output to accomodate various loads utilizes phase-lock loop to control relay connected to starting circuit. As load is imposed, motor slows down, and phase lock is lost. Phase-lock signal triggers relay to power starting coil and generate additional torque. Once phase lock is recoverd, relay restores starting circuit to its normal operating mode.

  18. High efficiency motor rewind study

    NASA Astrophysics Data System (ADS)

    Wallace, A. K.; Spee, R.

    1991-02-01

    The objective of performing this work was to evaluate a new technology used for rewinding electric motors. Motor performance evaluation was conducted at the motor test facility at Oregon State University. The test program consisted of comparing new high efficiency motor technology and standard rewind technology with the Unity-Plus system. The Unity-Plus configuration exhibited reduced efficiency over the complete load range compared to the other motors. Appropriately sized capacitors connected to the terminals of the conventional induction motor produced the same power factor improvement as the Unity-Plus system. Torque production and torque pulsation were very similar for all systems. The Unity-Plus configuration drew lower starting currents but the duration of the starting transient was increased. Motor temperature rise was about the same for all systems. Noise levels were about the same in all systems. Although determination of time to failure was not undertaken, the expected lifetime of the Unit-Plus system is probably less due to higher capacitor stress and higher insulation stress. The investigation concludes that a conventional induction motor with terminal capacitors is the most acceptable way of obtaining good efficiency and power factor and the Unity-Plus system cannot be recommended on the basis of any of the evaluation criteria used in this study.

  19. Activities for a Perceptual Motor Program.

    ERIC Educational Resources Information Center

    Brinning, Dorothy; And Others

    Perceptual motor activities for physically handicapped children are presented in the areas of fine and gross motor skills. Also detailed are activities to develop body image, visual motor skills, and tactile and auditory perception. (JD)

  20. Industrial motor repair in the United States

    SciTech Connect

    Schueler, V.; Leistner, P.; Douglass, J.

    1994-09-01

    This report characterizes the motor repair industry in the United States; summarizes current motor repair and testing practice; and identifies barriers to energy motor repair practice and recommends strategies for overcoming those barriers.

  1. An interacting adiabatic quantum motor

    NASA Astrophysics Data System (ADS)

    Viola Kusminskiy, Silvia; Bruch, Anton; von Oppen, Felix

    We consider the effect of electron-electron interactions on the performance of an adiabatic quantum motor based on a Thouless pump operating in reverse. We model such a device by electrons in a 1d wire coupled to a slowly moving periodic potential associated with the classical mechanical degree of freedom of the motor. This periodic degree of freedom is set into motion by a bias voltage applied to the 1d electron channel. We investigate the Thouless motor with interacting leads modeled as Luttinger liquids. We show that interactions enhance the energy gap opened by the periodic potential and thus the robustness of the Thouless motor against variations in the chemical potential. We show that the motor degree of freedom can be described as a mobile impurity in a Luttinger liquid obeying Langevin dynamics with renormalized coefficients due to interactions, for which we give explicit expressions.

  2. Motor-operated gearbox efficiency

    SciTech Connect

    DeWall, K.G.; Watkins, J.C.; Bramwell, D.; Weidenhamer, G.H.

    1996-12-01

    Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, the authors compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators they tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer.

  3. Magnetic bearing and motor

    NASA Technical Reports Server (NTRS)

    Studer, Philip A. (Inventor)

    1983-01-01

    A magnetic bearing assembly (10) has an intermediate rotatable section (33) having an outer cylindrical member (30) coaxially suspended by a torsion wire (72) around an axially polarized cylindrical magnet (32). Axial alignment between the pole faces (40-43) of the intermediate section (33) and end surfaces (50-53) of opposed end bells (20, 22) provides a path of least reluctance across intervening air gaps (60-63) for the magnetic flux emanating from magnet (32). Radial dislocation increases the reluctance and creates a radial restoring force. Substitution of radially polarized magnets 107 fixed to a magnetically permeable cylinder (32') and insertion of pairs of armature coil windings (109-112) between the cylinder pair (33') provides an integral magnetic bearing and torsion motor (100) able to provide arcuately limited rotational drive.

  4. DNA based molecular motors

    NASA Astrophysics Data System (ADS)

    Michaelis, Jens; Muschielok, Adam; Andrecka, Joanna; Kügel, Wolfgang; Moffitt, Jeffrey R.

    2009-12-01

    Most of the essential cellular processes such as polymerisation reactions, gene expression and regulation are governed by mechanical processes. Controlled mechanical investigations of these processes are therefore required in order to take our understanding of molecular biology to the next level. Single-molecule manipulation and force spectroscopy have over the last 15 years been developed into extremely powerful techniques. Applying these techniques to the investigation of proteins and DNA molecules has led to a mechanistic understanding of protein function on the level of single molecules. As examples for DNA based molecular machines we will describe single-molecule experiments on RNA polymerases as well as on the packaging of DNA into a viral capsid-a process that is driven by one of the most powerful molecular motors.

  5. Piezoelectric wave motor

    DOEpatents

    Yerganian, Simon Scott

    2003-02-11

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase-shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in the direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  6. Piezoelectric wave motor

    DOEpatents

    Yerganian, Simon Scott

    2001-07-17

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  7. Reciprocating linear motor

    NASA Technical Reports Server (NTRS)

    Goldowsky, Michael P. (Inventor)

    1987-01-01

    A reciprocating linear motor is formed with a pair of ring-shaped permanent magnets having opposite radial polarizations, held axially apart by a nonmagnetic yoke, which serves as an axially displaceable armature assembly. A pair of annularly wound coils having axial lengths which differ from the axial lengths of the permanent magnets are serially coupled together in mutual opposition and positioned with an outer cylindrical core in axial symmetry about the armature assembly. One embodiment includes a second pair of annularly wound coils serially coupled together in mutual opposition and an inner cylindrical core positioned in axial symmetry inside the armature radially opposite to the first pair of coils. Application of a potential difference across a serial connection of the two pairs of coils creates a current flow perpendicular to the magnetic field created by the armature magnets, thereby causing limited linear displacement of the magnets relative to the coils.

  8. Perception of the color red enhances the force and velocity of motor output.

    PubMed

    Elliot, Andrew J; Aarts, Henk

    2011-04-01

    The present research examined whether perception of the color red influences basic motor functioning. Prior research on color and motor functioning has been guided by ill-defined theoretical statements, and has been plagued by methodological problems. Drawing on theoretical and empirical work on the threat-behavior link in human and nonhuman animals, we proposed and tested the prediction that perceiving red enhances the force and velocity of motor output. Experiment 1 demonstrated that red, relative to gray (matched to red on lightness), facilitates pinchgrip force. Experiment 2 demonstrated that red, relative to gray (matched to red on lightness) and blue (matched to red on lightness and chroma) facilitates handgrip force and the velocity of that force. These findings clearly establish a link between red and basic motor action, illustrate the importance of rigorous experimental methods when testing color effects, and highlight the need to attend to the functional, as well as aesthetic, value of color.

  9. Multimotor transport in a system of active and inactive kinesin-1 motors.

    PubMed

    Scharrel, Lara; Ma, Rui; Schneider, René; Jülicher, Frank; Diez, Stefan

    2014-07-15

    Long-range directional transport in cells is facilitated by microtubule-based motor proteins. One example is transport in a nerve cell, where small groups of motor proteins, such as kinesins and cytoplasmic dynein, work together to ensure the supply and clearance of cellular material along the axon. Defects in axonal transport have been linked to Alzheimer's and other neurodegenerative diseases. However, it is not known in detail how multimotor-based cargo transport is impaired if a fraction of the motors are defective. To mimic impaired multimotor transport in vitro, we performed gliding motility assays with varying fractions of active kinesin-1 motors and inactive kinesin-1 motor mutants. We found that impaired transport manifests in multiple motility regimes: 1), a fast-motility regime characterized by gliding at velocities close to the single-molecule velocity of the active motors; 2), a slow-motility regime characterized by gliding at close-to zero velocity or full stopping; and 3), a regime in which fast and slow motilities coexist. Notably, the transition from the fast to the slow regime occurred sharply at a threshold fraction of active motors. Based on single-motor parameters, we developed a stochastic model and a mean-field theoretical description that explain our experimental findings. Our results demonstrate that impaired multimotor transport mostly occurs in an either/or fashion: depending on the ratio of active to inactive motors, transport is either performed at close to full speed or is out of action.

  10. Pattern Formations in Polymer-Molecular Motor Networks

    NASA Astrophysics Data System (ADS)

    Smith, David; Humphrey, David; Duggan, Cynthia; Käs, Josef

    2001-03-01

    In previous studies with the microtubule-kinesin system, organized patterns such as asters and rotating vortices have been seen (Nedelec et al, Nature 1997), which were of a dynamic nature and dependent on active motors. A similar system was constructed using actin and myosin, which displays similar patterns, however, with drastically different dynamics. These patterns arise independent of the initial amount of immediate use energy (in the form of ATP), assembling only upon the near exhaustion of available ATP. Further studies have clearly shown that in fact these patterns are not dependent upon the motor activity of the myosin but its propensity to serve as a cross-linking element in an actin network, with the motor activity serving to prevent the arising of order in the system. We believe the dynamic differences inherent between the two polymer-motor systems studied lies primarily in the structural nature of the motor complexes, with the kinesin complex ordering the system by pushing multiple filaments in a parallel direction, and the myosin complexes disordering the system by pushing filaments in an antiparallel manner.

  11. Molecular motors and the 2nd law of thermodynamics

    NASA Astrophysics Data System (ADS)

    Wang, Zhisong

    2014-03-01

    Molecular motors from biology and nanotechnology often operate on chemical energy of fuel molecules in an isothermal environment, unlike macroscopic heat engines that draw energy from a heat flow between two temperatures. Nevertheless, isothermal molecular motors are still subject to the 2nd law of thermodynamics in a fundamental way: their directional motion must cost a finite amount of energy other than the environmental heat even though no work is done; otherwise the 2nd law would be violated. Hence the 2nd law requires a finite energy price for pure direction of molecular motors. But what is the lowest price of direction allowed by the 2nd law? And how does the 2nd law-decreed price of direction limit performance of molecular motors? In the talk, I shall present our theoretical study of the 2nd law-molecular motor link on basis of the accumulated biomotor phenomenology, and also introduce our experimental effort to develop biomimetic DNA bipedal nanomotors following the mechanistic guidelines out of the theoretical study. [Main contents of this talk are from references:] This work is partially supported by FRC grants R-144-000-259-112, R-144-000-290-112 and R-144-000-320-112.

  12. Constructive role of Brownian motion: Brownian motors and Stochastic Resonance

    NASA Astrophysics Data System (ADS)

    Hänggi, Peter

    2005-03-01

    Noise is usually thought of as the enemy of order rather as a constructive influence. For the phenomena of Stochastic Resonance [1] and Brownian motors [2], however, stochastic noise can play a beneficial role in enhancing detection and/or facilitating directed transmission of information in absence of biasing forces. Brownian motion assisted Stochastic Resonance finds useful applications in physical, technological, biological and biomedical contexts [1,3]. The basic principles that underpin Stochastic Resonance are elucidated and novel applications for nonlinear classical and quantum systems will be addressed. The presence of non-equilibrium disturbances enables to rectify Brownian motion so that quantum and classical objects can be directed around on a priori designed routes in biological and physical systems (Brownian motors). In doing so, the energy from the haphazard motion of (quantum) Brownian particles is extracted to perform useful work against an external load. This very concept together with first experimental realizations are discussed [2,4,5]. [1] L. Gammaitoni, P. Hä'nggi, P. Jung and F. Marchesoni, Stochastic Resonance, Rev. Mod. Phys. 70, 223 (1998).[2] R. D. Astumian and P. Hä'nggi, Brownian motors, Physics Today 55 (11), 33 (2002).[3] P. Hä'nggi, Stochastic Resonace in Physics and Biology, ChemPhysChem 3, 285 (2002).[4] H. Linke, editor, Special Issue on Brownian Motors, Applied Physics A 75, No. 2 (2002).[5] P. Hä'nggi, F. Marchesoni, F. Nori, Brownian motors, Ann. Physik (Leipzig) 14, xxx (2004); cond-mat/0410033.

  13. Atypical motor neuron disease and related motor syndromes.

    PubMed

    Verma, A; Bradley, W G

    2001-06-01

    There is an imperative need for the early diagnosis of amyotrophic lateral sclerosis/motor neuron disease (ALS/MND) in the current era of emerging treatments. When evaluating the patient with ALS/MND, the neurologist must consider a number of other motor neuron disorders and related motor syndromes that may have clinical features resembling ALS/MND. The revised Airlie House-El Escorial diagnostic criteria have been established through the consensus of experts meeting at workshops. However, by definition, using these criteria a patient is likely to have fairly advanced disease at the time of a definitive ALS/MND diagnosis. The reasons for the difficulty in making an early ALS/MND diagnosis are several. No surrogate diagnostic marker currently exists for ALS/MND. ALS/MND at its onset is heterogeneous in clinical presentation, its clinical course is variable, and several clinical variants are recognized. In addition, certain motor syndromes, such as monomelic amyotrophy, postpolio muscular atrophy, and multifocal motor neuropathy, can clinically mimic ALS/MND. Therefore, not only may the diagnosis of ALS/MND be clinically missed in the early stages, but worse, the patient may be wrongly labeled as having ALS/MND. The diagnosis of ALS/MND requires a combination of upper motor neuron (UMN) and lower motor neuron (LMN) involvement. Motor syndromes in which the deficit is restricted to the UMN or LMN through the entire course of the disease are described as atypical MND in this review. Approximately 5% of patients with ALS/MND have overt dementia with a characteristic frontal affect. ALS/MND with parkinsonism and dementia is rare outside the western Pacific region. The clinical course of motor disorder in these overlap syndromes does not differ from that in typical ALS/MND.

  14. Cognitive-motor interactions of the basal ganglia in development.

    PubMed

    Leisman, Gerry; Braun-Benjamin, Orit; Melillo, Robert

    2014-01-01

    Neural circuits linking activity in anatomically segregated populations of neurons in subcortical structures and the neocortex throughout the human brain regulate complex behaviors such as walking, talking, language comprehension, and other cognitive functions associated with frontal lobes. The basal ganglia, which regulate motor control, are also crucial elements in the circuits that confer human reasoning and adaptive function. The basal ganglia are key elements in the control of reward-based learning, sequencing, discrete elements that constitute a complete motor act, and cognitive function. Imaging studies of intact human subjects and electrophysiologic and tracer studies of the brains and behavior of other species confirm these findings. We know that the relation between the basal ganglia and the cerebral cortical region allows for connections organized into discrete circuits. Rather than serving as a means for widespread cortical areas to gain access to the motor system, these loops reciprocally interconnect a large and diverse set of cerebral cortical areas with the basal ganglia. Neuronal activity within the basal ganglia associated with motor areas of the cerebral cortex is highly correlated with parameters of movement. Neuronal activity within the basal ganglia and cerebellar loops associated with the prefrontal cortex is related to the aspects of cognitive function. Thus, individual loops appear to be involved in distinct behavioral functions. Damage to the basal ganglia of circuits with motor areas of the cortex leads to motor symptoms, whereas damage to the subcortical components of circuits with non-motor areas of the cortex causes higher-order deficits. In this report, we review some of the anatomic, physiologic, and behavioral findings that have contributed to a reappraisal of function concerning the basal ganglia and cerebellar loops with the cerebral cortex and apply it in clinical applications to attention deficit/hyperactivity disorder (ADHD

  15. Can the structure of motor variability predict learning rate?

    PubMed

    Barbado Murillo, David; Caballero Sánchez, Carla; Moreside, Janice; Vera-García, Francisco J; Moreno, Francisco J

    2017-03-01

    Recent studies show that motor variability is actively regulated as an exploration tool to promote learning in reward-based tasks. However, its role in learning processes during error-based tasks, when a reduction of the motor variability is required to achieve good performance, is still unclear. In this study, we hypothesized that error-based learning not only depends on exploration but also on the individuals' ability to measure and predict the motor error. Previous studies identified a less auto-correlated motor variability as a higher ability to perform motion adjustments. Two experiments investigated the relationship between motor learning and variability, analyzing the long-range autocorrelation of the center of pressure fluctuations through the α score of a Detrended Fluctuation Analysis in balance tasks. In Experiment 1, we assessed the relationship between variability and learning rate using a standing balance task. Based on the results of this experiment, and to maximize learning, we performed a second experiment with a more difficult sitting balance task and increased practice. The learning rate of the 2 groups with similar balance performances but different α scores was compared. Individuals with a lower α score showed a higher learning rate. Because the α scores reveal how the motor output changes over time, instead of the magnitude of those changes, the higher learning rate is mainly linked to the higher error sensitivity rather than the exploration strategies. The results of this study highlight the relevance of the structure of output motor variability as a predictor of learning rate in error-based tasks. (PsycINFO Database Record

  16. Cognitive-motor interactions of the basal ganglia in development

    PubMed Central

    Leisman, Gerry; Braun-Benjamin, Orit; Melillo, Robert

    2014-01-01

    Neural circuits linking activity in anatomically segregated populations of neurons in subcortical structures and the neocortex throughout the human brain regulate complex behaviors such as walking, talking, language comprehension, and other cognitive functions associated with frontal lobes. The basal ganglia, which regulate motor control, are also crucial elements in the circuits that confer human reasoning and adaptive function. The basal ganglia are key elements in the control of reward-based learning, sequencing, discrete elements that constitute a complete motor act, and cognitive function. Imaging studies of intact human subjects and electrophysiologic and tracer studies of the brains and behavior of other species confirm these findings. We know that the relation between the basal ganglia and the cerebral cortical region allows for connections organized into discrete circuits. Rather than serving as a means for widespread cortical areas to gain access to the motor system, these loops reciprocally interconnect a large and diverse set of cerebral cortical areas with the basal ganglia. Neuronal activity within the basal ganglia associated with motor areas of the cerebral cortex is highly correlated with parameters of movement. Neuronal activity within the basal ganglia and cerebellar loops associated with the prefrontal cortex is related to the aspects of cognitive function. Thus, individual loops appear to be involved in distinct behavioral functions. Damage to the basal ganglia of circuits with motor areas of the cortex leads to motor symptoms, whereas damage to the subcortical components of circuits with non-motor areas of the cortex causes higher-order deficits. In this report, we review some of the anatomic, physiologic, and behavioral findings that have contributed to a reappraisal of function concerning the basal ganglia and cerebellar loops with the cerebral cortex and apply it in clinical applications to attention deficit/hyperactivity disorder (ADHD

  17. A West African Link

    ERIC Educational Resources Information Center

    Cook, Angela; Davies, Penny

    2003-01-01

    The authors visited Ghana in West Africa to strengthen a link established the previous year as part of Channel 4's "On the Line" project. The initial link established in 1999/2000 was between an all-age special school in Enfield and a similar school in Accra. Over the course of that year further partnerships were created between five UK…

  18. School-Linked Services.

    ERIC Educational Resources Information Center

    Family Resource Coalition, Chicago, IL.

    Noting that educating children requires commitment and resources from the whole community as well as the schools, this document explores school-based collaborations with social services and family programs to improve students' performance. The document first provides a rationale for school-linked programs, then describes the School-Linked Services…

  19. Synthesising topological links

    DOE PAGES

    Baas, Nils A.; Seeman, Nadrian C.; Stacey, Andrew

    2014-10-14

    In this paper, we discuss the chemical synthesis of topological links, in particular higher order links which have the Brunnian property (namely that removal of any one component unlinks the entire system). Finally, we suggest how to obtain both two dimensional and three dimensional objects (surfaces and solids, respectively) which also have this Brunnian property.

  20. Changes in neural circuitry associated with depression at pre-clinical, pre-motor and early motor phases of Parkinson's disease.

    PubMed

    Borgonovo, Janina; Allende-Castro, Camilo; Laliena, Almudena; Guerrero, Néstor; Silva, Hernán; Concha, Miguel L

    2017-02-01

    Although Parkinson's Disease (PD) is mostly considered a motor disorder, it can present at early stages as a non-motor pathology. Among the non-motor clinical manifestations, depression shows a high prevalence and can be one of the first clinical signs to appear, even a decade before the onset of motor symptoms. Here, we review the evidence of early dysfunction in neural circuitry associated with depression in the context of PD, focusing on pre-clinical, pre-motor and early motor phases of the disease. In the pre-clinical phase, structural and functional changes in the substantia nigra, basal ganglia and limbic structures are already observed. Some of these changes are linked to motor compensation mechanisms while others correspond to pathological processes common to PD and depression and thus could underlie the appearance of depressive symptoms during the pre-motor phase. Studies of the early motor phase (less than five years post diagnosis) reveal an association between the extent of damage in different monoaminergic systems and the appearance of emotional disorders. We propose that the limbic loop of the basal ganglia and the lateral habenula play key roles in the early genesis of depression in PD. Alterations in the neural circuitry linked with emotional control might be sensitive markers of the ongoing neurodegenerative process and thus may serve to facilitate an early diagnosis of this disease. To take advantage of this, we need to improve the clinical criteria and develop biomarkers to identify depression, which could be used to determine individuals at risk to develop PD.

  1. Androgen receptor YAC transgenic mice recapitulate SBMA motor neuronopathy and implicate VEGF164 in the motor neuron degeneration.

    PubMed

    Sopher, Bryce L; Thomas, Patrick S; LaFevre-Bernt, Michelle A; Holm, Ida E; Wilke, Scott A; Ware, Carol B; Jin, Lee-Way; Libby, Randell T; Ellerby, Lisa M; La Spada, Albert R

    2004-03-04

    X-linked spinal and bulbar muscular atrophy (SBMA) is an inherited neuromuscular disorder characterized by lower motor neuron degeneration. SBMA is caused by polyglutamine repeat expansions in the androgen receptor (AR). To determine the basis of AR polyglutamine neurotoxicity, we introduced human AR yeast artificial chromosomes carrying either 20 or 100 CAGs into mouse embryonic stem cells. The AR100 transgenic mice developed a late-onset, gradually progressive neuromuscular phenotype accompanied by motor neuron degeneration, indicating striking recapitulation of the human disease. We then tested the hypothesis that polyglutamine-expanded AR interferes with CREB binding protein (CBP)-mediated transcription of vascular endothelial growth factor (VEGF) and observed altered CBP-AR binding and VEGF reduction in AR100 mice. We found that mutant AR-induced death of motor neuron-like cells could be rescued by VEGF. Our results suggest that SBMA motor neuronopathy involves altered expression of VEGF, consistent with a role for VEGF as a neurotrophic/survival factor in motor neuron disease.

  2. Construction of a Chassis for a Tripartite Protein-Based Molecular Motor.

    PubMed

    Small, Lara S R; Bruning, Marc; Thomson, Andrew R; Boyle, Aimee L; Davies, Roberta B; Curmi, Paul M G; Forde, Nancy R; Linke, Heiner; Woolfson, Derek N; Bromley, Elizabeth H C

    2017-03-14

    Improving our understanding of biological motors, both to fully comprehend their activities in vital processes, and to exploit their impressive abilities for use in bionanotechnology, is highly desirable. One means of understanding these systems is through the production of synthetic molecular motors. We demonstrate the use of orthogonal coiled-coil dimers (including both parallel and antiparallel coiled coils) as a hub for linking other components of a previously described synthetic molecular motor, the Tumbleweed. We use circular dichroism, analytical ultracentrifugation, dynamic light scattering, and disulfide rearrangement studies to demonstrate the ability of this six-peptide set to form the structure designed for the Tumbleweed motor. The successful formation of a suitable hub structure is both a test of the transferability of design rules for protein folding as well as an important step in the production of a synthetic protein-based molecular motor.

  3. Solid rocket motor witness test

    NASA Technical Reports Server (NTRS)

    Welch, Christopher S.

    1991-01-01

    The Solid Rocket Motor Witness Test was undertaken to examine the potential for using thermal infrared imagery as a tool for monitoring static tests of solid rocket motors. The project consisted of several parts: data acquisition, data analysis, and interpretation. For data acquisition, thermal infrared data were obtained of the DM-9 test of the Space Shuttle Solid Rocket Motor on December 23, 1987, at Thiokol, Inc. test facility near Brigham City, Utah. The data analysis portion consisted of processing the video tapes of the test to produce values of temperature at representative test points on the rocket motor surface as the motor cooled down following the test. Interpretation included formulation of a numerical model and evaluation of some of the conditions of the motor which could be extracted from the data. These parameters included estimates of the insulation remaining following the tests and the thickness of the charred layer of insulation at the end of the test. Also visible was a temperature signature of the star grain pattern in the forward motor segment.

  4. Submersible canned motor transfer pump

    DOEpatents

    Guardiani, Richard F.; Pollick, Richard D.; Nyilas, Charles P.; Denmeade, Timothy J.

    1997-01-01

    A transfer pump used in a waste tank for transferring high-level radioactive liquid waste from a waste tank and having a column assembly, a canned electric motor means, and an impeller assembly with an upper impeller and a lower impeller connected to a shaft of a rotor assembly. The column assembly locates a motor housing with the electric motor means adjacent to the impeller assembly which creates an hydraulic head, and which forces the liquid waste, into the motor housing to cool the electric motor means and to cool and/or lubricate the radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the upper impeller and electric motor means grind large particles in the liquid waste flow. Slots in the static bearing member of the radial bearing assemblies further grind down the solid waste particles so that only particles smaller than the clearances in the system can pass therethrough, thereby resisting damage to and the interruption of the operation of the transfer pump. The column assembly is modular so that sections can be easily assembled, disassembled and/or removed. A second embodiment employs a stator jacket which provides an alternate means for cooling the electric motor means and lubricating and/or cooling the bearing assemblies, and a third embodiment employs a variable level suction device which allows liquid waste to be drawn into the transfer pump from varying and discrete levels in the waste tank.

  5. Submersible canned motor mixer pump

    DOEpatents

    Guardiani, R.F.; Pollick, R.D.

    1997-10-07

    A mixer pump is described used in a waste tank for mobilizing high-level radioactive liquid waste having a column assembly containing power cables, a motor housing with electric motor means which includes a stator can of a stator assembly and a rotor can of a rotor assembly, and an impeller assembly with an impeller connected to a shaft of the rotor assembly. The column assembly locates the motor housing with the electric motor means adjacent to the impeller which creates an hydraulic head, and which forces the liquid waste into the motor housing to cool the electric motor means and to lubricate radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the impeller and electric motor means act to grind down large particles in the liquid waste flow. These larger particles are received in slots in the static bearing members of the radial bearing assemblies. Only solid waste particles smaller than the clearances in the system can pass there through, thereby resisting damage to and the interruption of the operation of the mixer pump. 10 figs.

  6. Submersible canned motor mixer pump

    DOEpatents

    Guardiani, Richard F.; Pollick, Richard D.

    1997-01-01

    A mixer pump used in a waste tank for mobilizing high-level radioactive liquid waste having a column assembly containing power cables, a motor housing with electric motor means which includes a stator can of a stator assembly and a rotor can of a rotor assembly, and an impeller assembly with an impeller connected to a shaft of the rotor assembly. The column assembly locates the motor housing with the electric motor means adjacent to the impeller which creates an hydraulic head, and which forces the liquid waste into the motor housing to cool the electric motor means and to lubricate radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the impeller and electric motor means act to grind down large particles in the liquid waste flow. These larger particles are received in slots in the static bearing members of the radial bearing assemblies. Only solid waste particles smaller than the clearances in the system can pass therethrough, thereby resisting damage to and the interruption of the operation of the mixer pump.

  7. The mechanochemistry of molecular motors.

    PubMed Central

    Keller, D; Bustamante, C

    2000-01-01

    A theory of molecular motors is presented that explains how the energy released in single chemical reactions can generate mechanical motion and force. In the simplest case the fluctuating movements of a motor enzyme are well described by a diffusion process on a two-dimensional potential energy surface, where one dimension is a chemical reaction coordinate and the other is the spatial displacement of the motor. The coupling between chemistry and motion results from the shape of the surface, and motor velocities and forces result from diffusion currents on this surface. This microscopic description is shown to possess an equivalent kinetic mechanism in which the rate constants depend on externally applied forces. By using this equivalence we explore the characteristic properties of several broad classes of motor mechanisms and give general expressions for motor velocity versus load force for any member of each class. We show that in some cases simple plots of 1/velocity vs. 1/concentration can distinguish between classes of motor mechanisms and may be used to determine the step at which movement occurs. PMID:10653770

  8. Motor learning in individuals with autism spectrum disorder: activation in superior parietal lobule related to learning and repetitive behaviors.

    PubMed

    Travers, Brittany G; Kana, Rajesh K; Klinger, Laura G; Klein, Christopher L; Klinger, Mark R

    2015-02-01

    Motor-linked implicit learning is the learning of a sequence of movements without conscious awareness. Although motor symptoms are frequently reported in individuals with autism spectrum disorder (ASD), recent behavioral studies have suggested that motor-linked implicit learning may be intact in ASD. The serial reaction time (SRT) task is one of the most common measures of motor-linked implicit learning. The present study used a 3T functional magnetic resonance imaging scanner to examine the behavioral and neural correlates of real-time motor sequence learning in adolescents and adults with ASD (n = 15) compared with age- and intelligence quotient-matched individuals with typical development (n = 15) during an SRT task. Behavioral results suggested less robust motor sequence learning in individuals with ASD. Group differences in brain activation suggested that individuals with ASD, relative to individuals with typical development, showed decreased activation in the right superior parietal lobule (SPL) and right precuneus (Brodmann areas 5 and 7, and extending into the intraparietal sulcus) during learning. Activation in these areas (and in areas such as the right putamen and right supramarginal gyrus) was found to be significantly related to behavioral learning in this task. Additionally, individuals with ASD who had more severe repetitive behavior/restricted interest symptoms demonstrated greater decreased activation in these regions during motor learning. In conjunction, these results suggest that the SPL may play an important role in motor learning and repetitive behavior in individuals with ASD.

  9. State observer for synchronous motors

    DOEpatents

    Lang, Jeffrey H.

    1994-03-22

    A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.

  10. The Advanced Solid Rocket Motor

    NASA Technical Reports Server (NTRS)

    Mitchell, Royce E.

    1992-01-01

    The paper describes the Advanced Solid Rocket Motor (ASRM) that is being developed to replace, in 1997, the Redesigned Solid Rocket Motor which currently boosts the Space Shuttle. The ASRM will contain features to improve motor safety (fewer potential leak paths, improved seal materials, stronger case material, and fewer nozzle and case joints), an improved ignition system using through-bulkhead initiators, and highly reproducible manufacturing and inspection techniques with a large number of automated procedures. The ASRM will be able to deliver 12,000 lbs greater payloads to any given orbit of the Shuttle. There are also environmental improvements, realized by waste propellant recovery.

  11. Ultra-Compact Motor Controller

    NASA Technical Reports Server (NTRS)

    Townsend, William T.; Cromwell, Adam; Hauptman, Traveler; Pratt, Gill Andrews

    2012-01-01

    This invention is an electronically commutated brushless motor contro ller that incorporates Hall-array sensing in a small, 42-gram packag e that provides 4096 absolute counts per motor revolution position s ensing. The unit is the size of a miniature hockey puck, and is a 44 -pin male connector that provides many I/O channels, including CANbus , RS-232 communications, general-purpose analog and digital I/O (GPI O), analog and digital Hall inputs, DC power input (18-90 VDC, 0-l0 A), three-phase motor outputs, and a strain gauge amplifier.

  12. Messengers, motors and mysteries: sorting of eukaryotic mRNAs by cytoskeletal transport.

    PubMed

    Bullock, Simon L

    2011-10-01

    It has become increasingly apparent in recent years that the subcellular localization of specific mRNAs is a prevalent method for spatially controlling gene expression. In most cases, targeting of mRNAs is mediated by transport along cytoskeletal filaments by molecular motors. However, the means by which specific messages are recognized and linked to the motors are poorly understood. Here, I will provide an overview of recent progress in elucidating the molecular mechanisms and principles of mRNA transport, including several studies highlighting the co-operation of different motors during the localization process. Important outstanding questions will also be highlighted.

  13. Edited GluR2, a gatekeeper for motor neurone survival?

    PubMed

    Buckingham, S D; Kwak, S; Jones, A K; Blackshaw, S E; Sattelle, D B

    2008-11-01

    Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disorder of motor neurones. Although the genetic basis of familial forms of ALS has been well explored, the molecular basis of sporadic ALS is less well understood. Recent evidence has linked sporadic ALS with the failure to edit key residues in ionotropic glutamate receptors, resulting in excessive influx of calcium ions into motor neurones which in turn triggers cell death. Here we suggest that edited AMPA glutamate (GluR2) receptor subunits serve as gatekeepers for motor neurone survival.

  14. Neural Representation and Causal Models in Motor Cortex.

    PubMed

    Chaisanguanthum, Kris S; Shen, Helen H; Sabes, Philip N

    2017-03-22

    Dorsal premotor (PMd) and primary motor (M1) cortices play a central role in mapping sensation to movement. Many studies of these areas have focused on correlation-based tuning curves relating neural activity to task or movement parameters, but the link between tuning and movement generation is unclear. We recorded motor preparatory activity from populations of neurons in PMd/M1 as macaque monkeys performed a visually guided reaching task and show that tuning curves for sensory inputs (reach target direction) and motor outputs (initial movement direction) are not typically aligned. We then used a simple, causal model to determine the expected relationship between sensory and motor tuning. The model shows that movement variability is minimized when output neurons (those that directly drive movement) have target and movement tuning that are linearly related across targets and cells. In contrast, for neurons that only affect movement via projections to output neurons, the relationship between target and movement tuning is determined by the pattern of projections to output neurons and may even be uncorrelated, as was observed for the PMd/M1 population as a whole. We therefore determined the relationship between target and movement tuning for subpopulations of cells defined by the temporal duration of their spike waveforms, which may distinguish cell types. We found a strong correlation between target and movement tuning for only a subpopulation of neurons with intermediate spike durations (trough-to-peak ∼350 μs after high-pass filtering), suggesting that these cells have the most direct role in driving motor output.SIGNIFICANCE STATEMENT This study focuses on how macaque premotor and primary motor cortices transform sensory inputs into motor outputs. We develop empirical and theoretical links between causal models of this transformation and more traditional, correlation-based "tuning curve" analyses. Contrary to common assumptions, we show that sensory and motor

  15. Optical Communications Link to Airborne Transceiver

    NASA Technical Reports Server (NTRS)

    Regehr, Martin W.; Kovalik, Joseph M.; Biswas, Abhijit

    2011-01-01

    An optical link from Earth to an aircraft demonstrates the ability to establish a link from a ground platform to a transceiver moving overhead. An airplane has a challenging disturbance environment including airframe vibrations and occasional abrupt changes in attitude during flight. These disturbances make it difficult to maintain pointing lock in an optical transceiver in an airplane. Acquisition can also be challenging. In the case of the aircraft link, the ground station initially has no precise knowledge of the aircraft s location. An airborne pointing system has been designed, built, and demonstrated using direct-drive brushless DC motors for passive isolation of pointing disturbances and for high-bandwidth control feedback. The airborne transceiver uses a GPS-INS system to determine the aircraft s position and attitude, and to then illuminate the ground station initially for acquisition. The ground transceiver participates in link-pointing acquisition by first using a wide-field camera to detect initial illumination from the airborne beacon, and to perform coarse pointing. It then transfers control to a high-precision pointing detector. Using this scheme, live video was successfully streamed from the ground to the aircraft at 270 Mb/s while simultaneously downlinking a 50 kb/s data stream from the aircraft to the ground.

  16. 26. View, looking east, of motor house; the electric motor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. View, looking east, of motor house; the electric motor and electric-powered winch are housed in section of building to the left. The U-bolt and concrete deadman which anchors the cable of the tramway is to the right. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  17. Single molecule measurements and biological motors.

    PubMed

    Knight, Alex E; Mashanov, Gregory; Molloy, Justin E

    2005-12-01

    Recent technological advances in lasers and optical detectors have enabled a variety of new, single molecule technologies to be developed. Using intense and highly collimated laser light sources in addition to super-sensitive cameras, the fluorescence of single fluorophores can now be imaged in aqueous solution. Also, laser optical tweezers have enabled the piconewton forces produced by pair of interacting biomolecules to be measured directly. However, for a researcher new to the field to begin to use such techniques in their own research might seem a daunting prospect. Most of the equipment that is in use is custom-built. However, most of the equipment is essence fairly simple and the aim of this article is to provide an entry point to the field for a newcomer. It focuses mainly on those practical aspects which are not particularly well covered in the literature, and aims to provide an overview of the field as a whole with references and web links to more detailed sources elsewhere. Indeed, the opportunity to publish an article such as this on the Internet affords many new opportunities (and more space!) for presenting scientific ideas and information. For example, we have illustrated the nature of optical trap data with an interactive Java simulation; provided links to relevant web sites and technical documents, and included a large number of colour figures and plots. Our group's research focuses on molecular motors, and the bias of this article reflects this. It turns out that molecular motors have been a paradigm (or prototype) for single molecule research and the field has seen a rapid development in the techniques. It is hoped that the methods described here will be broadly applicable to other biological systems.

  18. Turn Motors Off When Not in Use - Motor Tip Sheet #10

    SciTech Connect

    2008-07-01

    Motors use no energy when turned off. Reducing motor operating time by just 10% usually saves more energy than replacing a standard efficiency motor with a NEMA Premium® efficiency motor. In fact, given that 97% of the life cycle cost of purchasing and operating a motor is energy-related, turning a motor off 10% of the time could reduce energy costs enough to purchase three new motors.

  19. 75 FR 72863 - Motor Carrier Safety Advisory Committee Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-26

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration, DOT. ACTION: Notice of Motor Carrier Safety Advisory Committee Meeting. SUMMARY: FMCSA announces that the Agency's Motor Carrier Safety Advisory Committee...

  20. 76 FR 12214 - Motor Carrier Safety Advisory Committee Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-04

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration, DOT. ACTION: Notice: Announcement of Motor Carrier Safety Advisory Committee meeting; request for comment. SUMMARY: The Federal Motor Carrier Safety...

  1. 75 FR 50797 - Motor Carrier Safety Advisory Committee Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice of Motor Carrier Safety Advisory Committee Meeting. SUMMARY: FMCSA announces that its Motor Carrier Safety Advisory Committee (MCSAC)...

  2. 75 FR 29384 - Motor Carrier Safety Advisory Committee Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-25

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee Public Meeting AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice of Motor Carrier Safety Advisory Committee meeting. SUMMARY: FMCSA announces that its Motor Carrier Safety Advisory Committee (MCSAC)...

  3. Mechanical thermal motor

    NASA Technical Reports Server (NTRS)

    Hein, L. A.; Myers, W. N. (Inventor)

    1976-01-01

    An apparatus is described for converting thermal energy such as solar energy into mechanical motion for driving fluid pumps and similar equipment. The thermal motor comprises an inner concentric cylinder carried by a stationary core member. The core member has a cylindrical disc plate fixed adjacent to a lower portion and extending radially from it. An outer concentric cylinder rotatably carried on the disc plate defining a space between the inner and outer concentric cylinders. A spiral tubular member encircles the inner concentric cylinder and is contained within the space between the inner and outer cylinders. One portion is connected to the inner concentric cylinder and a second portion connected to the outer concentric cylinder. A heated fluid is conveyed through the tubular member and is periodically cooled causing the tubular member to expand and contract. This causes the outer concentric cylinder to reciprocally rotate on the base plate accordingly. The reciprocating motion of the outer concentric cylinder is then utilized to drive a pump member in a pump chamber.

  4. Motor proteins 1: kinesins.

    PubMed

    Bloom, G S; Endow, S A

    1995-01-01

    Progress regarding the kinesins is now being made at a rapid and accelerating rate. The in vivo-functions, and biophysical and enzymatic properties of kinesin itself are being explored at ever increasing levels of detail. The kinesin-related proteins now number several dozen, and although more is known about primary structure than function for most of the proteins, this trend is already reversing. For example, knowledge about the kinesin-related protein, ncd, is expanding rapidly, and more is already known about its three-dimensional structure than is known for kinesin heavy chain. This volume presents a comprehensive review of the major published works on kinesin and kinesin-related proteins. Hopefully, this manuscript will complement other recent review articles [17, 20, 25, 37, 60-62, 67, 69, 75, 85-88, 231, 233, 238, 244, 269-271, 281, 282, 292] or books [49, 227, 293] that have focused on more selective aspects of the kinesin family, or have been aimed more generally at MT motor proteins. In line with the stated purpose of the Protein Profile series, annual updates of the review on the kinesins are planned for at least the next few years.

  5. Magnetic bearing and motor

    NASA Technical Reports Server (NTRS)

    Studer, P. A. (Inventor)

    1983-01-01

    A magnetic bearing for passively suspending a rotatable element subjected to axial and radial thrust forces is disclosed. The magnetic bearing employs a taut wire stretched along the longitudinal axis of the bearing between opposed end pieces and an intermediate magnetic section. The intermediate section is segmented to provide oppositely directed magnetic flux paths between the end pieces and may include either an axially polarized magnets interposed between the segments. The end pieces, separated from the intermediate section by air gaps, control distribution of magnetic flux between the intermediate section segments. Coaxial alignment of the end pieces with the intermediate section minimizes magnetic reluctance in the flux paths endowing the bearing with self-centering characteristics when subjected to radial loads. In an alternative embodiment, pairs of oppositely wound armature coils are concentrically interposed between segments of the intermediate section in concentric arcs adjacent to radially polarized magnets to equip a magnetic bearing as a torsion drive motor. The magnetic suspension bearing disclosed provides long term reliability without maintenance with application to long term space missions such as the VISSR/VAS scanning mirror instrument in the GOES program.

  6. Controlled wind motor

    SciTech Connect

    Boswell, F.A.

    1983-12-27

    A mechanical sail including a rotatable mast, the mast including a top vane mount and a bottom vane mount, the mounts being spaced from each other on the mast and rotatable therewith, a series of rotatable vanes spaced from and surrounding the mast and supported by and between the mounts, cam operaters extending between the mounts and connected to the vanes for controlling the rotation of the vanes, a first controller associated with the mast below the bottom vane mount for controlling the cam operators, the first controller being movable vertically with respect to the mast, a second controller for moving the first controller vertically with respect to the mast, the vanes being flexible and bowed outwardly, the bottom vane mount being movable with respect to the mast and connected to the second controller whereby when the second controller is operated, the bottom vane mount will move toward the top vane mount causing the vanes to bow outwardly at a desired arc and whereby when the first controller is moved, the vanes are caused to rotate to the desired angle of attack with respect to wind velocity and direction. When the sail is connected to a motor drive, the vessel may be driven forward or rearward depending on the angle of attack of the vanes through 180/sup 0/.

  7. Plasma motor generator system

    NASA Technical Reports Server (NTRS)

    Hite, Gerald E.

    1987-01-01

    The significant potential advantages of a plasma motor generator system over conventional systems for the generation of electrical power and propulsion for spacecraft in low Earth orbits warrants its further investigation. The two main components of such a system are a long insulated wire and the plasma generating hollow cathodes needed to maintain electrical contact with the ionosphere. Results of preliminary theoretical and experimental investigations of this system are presented. The theoretical work involved the equilibrium configurations of the wire and the nature of small oscillation about these equilibrium positions. A particularly interesting result was that two different configurations are allowed when the current is above a critical value. Experimental investigations were made of the optimal starting and running conditions for the proposed, low current hollow cathodes. Although optimal ranges of temperature, argon pressure and discharge voltage were identified, start up became progressively more difficult. This supposed depletion or contamination of the emissive surface could be countered by the addition of new emissive material.

  8. Small Solid Rocket Motor Test

    NASA Video Gallery

    It was three-two-one to brilliant fire as NASA's Marshall Space Flight Center tested a small solid rocket motor designed to mimic NASA's Space Launch System booster. The Mar. 14 test provides a qui...

  9. Battery powererd electric motor vehicle

    SciTech Connect

    Muhlbacker, K.

    1984-02-28

    A battery powered vehicle is provided with a vehicle frame and an electric motor whose main shaft is connected to a differential gear by means of a gear train with a variable transmission ratio, the motor shaft and all gear shafts being parallel to the axle of the driving wheels. In order to achieve a compact design and to avoid power-consuming drive elements the electric motor and the variable transmission gear as well as a potential reducing gear mounted between the latter and the differential gear, are positioned on a subframe which is connected to the housing of the driving wheel axle on the one side whereas the other side carrying the electric motor is attached to the vehicle frame by means of a cardanic suspension.

  10. The influence of Oxytocin on automatic motor simulation.

    PubMed

    De Coster, Lize; Mueller, Sven C; T'Sjoen, Guy; De Saedeleer, Lien; Brass, Marcel

    2014-12-01

    Motor simulation is important for imitation, action understanding, and a wide range of social cognitive skills. Furthermore, the neuropeptide hormone Oxytocin (OT) has also been related to social information processing in humans, improving perception of social stimuli and increasing altruism and trust. Surprisingly, however, a direct link between OT and motor simulation has never been systematically investigated. The current study examined this question using the imitation-inhibition task, a paradigm used to investigate automatic imitation behaviour and motor simulation. In this task, participants carry out simple finger movements while observing irrelevant movements that either match (congruent condition) or do not match (incongruent condition) the instructed movements. In a double-blind, placebo-controlled design, male participants were administered either OT (N=24) or placebo (N=24), and subsequently performed the imitation-inhibition task. To ensure specificity of OT effects to imitative behaviour, participants additionally performed a Stroop colour-word interference task (adapted to optimize similarities with the imitation inhibition task) to rule out general effects on cognitive control. As predicted, OT selectively influenced the congruency effect in the imitation-inhibition task but not the congruency effect in the Stroop task. This effect showed that OT led to a larger congruency effect by slowing down reaction times on incongruent trials when observed and own actions did not match. The findings suggest that OT leads to a decrease of control over automatic imitative behaviour mediated by increased self-other merging. Thus, for the first time, a link between OT and motor simulation is demonstrated, providing a window into the role of OT in motoric aspects of social cognition.

  11. Direct drive field actuator motors

    DOEpatents

    Grahn, A.R.

    1998-03-10

    A positive-drive field actuator motor is described which includes a stator carrying at least one field actuator which changes in dimension responsive to application of an energy field, and at least one drive shoe movable by the dimensional changes of the field actuator to contact and move a rotor element with respect to the stator. Various embodiments of the motor are disclosed, and the rotor element may be moved linearly or arcuately. 62 figs.

  12. Motor Activity Improves Temporal Expectancy

    PubMed Central

    Fautrelle, Lilian; Mareschal, Denis; French, Robert; Addyman, Caspar; Thomas, Elizabeth

    2015-01-01

    Certain brain areas involved in interval timing are also important in motor activity. This raises the possibility that motor activity might influence interval timing. To test this hypothesis, we assessed interval timing in healthy adults following different types of training. The pre- and post-training tasks consisted of a button press in response to the presentation of a rhythmic visual stimulus. Alterations in temporal expectancy were evaluated by measuring response times. Training consisted of responding to the visual presentation of regularly appearing stimuli by either: (1) pointing with a whole-body movement, (2) pointing only with the arm, (3) imagining pointing with a whole-body movement, (4) simply watching the stimulus presentation, (5) pointing with a whole-body movement in response to a target that appeared at irregular intervals (6) reading a newspaper. Participants performing a motor activity in response to the regular target showed significant improvements in judgment times compared to individuals with no associated motor activity. Individuals who only imagined pointing with a whole-body movement also showed significant improvements. No improvements were observed in the group that trained with a motor response to an irregular stimulus, hence eliminating the explanation that the improved temporal expectations of the other motor training groups was purely due to an improved motor capacity to press the response button. All groups performed a secondary task equally well, hence indicating that our results could not simply be attributed to differences in attention between the groups. Our results show that motor activity, even when it does not play a causal or corrective role, can lead to improved interval timing judgments. PMID:25806813

  13. Solid rocket motor internal insulation

    NASA Technical Reports Server (NTRS)

    Twichell, S. E. (Editor); Keller, R. B., Jr.

    1976-01-01

    Internal insulation in a solid rocket motor is defined as a layer of heat barrier material placed between the internal surface of the case propellant. The primary purpose is to prevent the case from reaching temperatures that endanger its structural integrity. Secondary functions of the insulation are listed and guidelines for avoiding critical problems in the development of internal insulation for rocket motors are presented.

  14. Meissner-Effect Stepping Motor

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    1991-01-01

    Proposed stepping motor derives torque from diamagnetic repulsion produced by Meissner effect - exclusion of magnetic field from interior of superconductor. Design of motor takes advantage of silver-doped YB2Cu3O and other compounds superconductive at temperatures as high as that of liquid nitrogen. Skin of rotor cooled below its superconducting-transition temperature by liquid nitrogen. O-rings prevent leaks of liquid nitrogen from rotor. Weight, cost, and maintenance reduced.

  15. Electrical stimulation and motor recovery.

    PubMed

    Young, Wise

    2015-01-01

    In recent years, several investigators have successfully regenerated axons in animal spinal cords without locomotor recovery. One explanation is that the animals were not trained to use the regenerated connections. Intensive locomotor training improves walking recovery after spinal cord injury (SCI) in people, and >90% of people with incomplete SCI recover walking with training. Although the optimal timing, duration, intensity, and type of locomotor training are still controversial, many investigators have reported beneficial effects of training on locomotor function. The mechanisms by which training improves recovery are not clear, but an attractive theory is available. In 1949, Donald Hebb proposed a famous rule that has been paraphrased as "neurons that fire together, wire together." This rule provided a theoretical basis for a widely accepted theory that homosynaptic and heterosynaptic activity facilitate synaptic formation and consolidation. In addition, the lumbar spinal cord has a locomotor center, called the central pattern generator (CPG), which can be activated nonspecifically with electrical stimulation or neurotransmitters to produce walking. The CPG is an obvious target to reconnect after SCI. Stimulating motor cortex, spinal cord, or peripheral nerves can modulate lumbar spinal cord excitability. Motor cortex stimulation causes long-term changes in spinal reflexes and synapses, increases sprouting of the corticospinal tract, and restores skilled forelimb function in rats. Long used to treat chronic pain, motor cortex stimuli modify lumbar spinal network excitability and improve lower extremity motor scores in humans. Similarly, epidural spinal cord stimulation has long been used to treat pain and spasticity. Subthreshold epidural stimulation reduces the threshold for locomotor activity. In 2011, Harkema et al. reported lumbosacral epidural stimulation restores motor control in chronic motor complete patients. Peripheral nerve or functional electrical

  16. A soft and dexterous motor

    NASA Astrophysics Data System (ADS)

    Anderson, Iain A.; Tse, Tony Chun Hin; Inamura, Tokushu; O'Brien, Benjamin M.; McKay, Thomas; Gisby, Todd

    2011-03-01

    We present a soft, bearing-free artificial muscle motor that cannot only turn a shaft but also grip and reposition it through a flexible gear. The bearing-free operation provides a foundation for low complexity soft machines, with multiple degree-of-freedom actuation, that can act simultaneously as motors and manipulators. The mechanism also enables an artificial muscle controlled gear change. Future work will include self-sensing feedback for precision, multidegree-of-freedom operation.

  17. Advanced Motor-Controller Development.

    DTIC Science & Technology

    1983-06-22

    which document the three stages of develop- _ - fment. "U Volume Summary A. Phase I Report Flux Synthesis and PWM Synthesis Techniques Theory and...Three Phase Power Bridge and Evaluation of Motor Controller Volume Summary The three reports assembled in this votume represent work performed...1963-A * I ADVANCED MOTOR-CONTROLLER * DEVELOPMENT Final Report for Period October 1979 - June 1983 June 22, 1983 Report DTNSRDC-PASD-CR-1-83

  18. Segmented rail linear induction motor

    DOEpatents

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  19. Segmented rail linear induction motor

    DOEpatents

    Cowan, M. Jr.; Marder, B.M.

    1996-09-03

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces. 6 figs.

  20. Direct drive field actuator motors

    SciTech Connect

    Grahn, Allen R.

    1998-01-01

    A positive-drive field actuator motor including a stator carrying at least one field actuator which changes in dimension responsive to application of an energy field, and at least one drive shoe movable by the dimensional changes of the field actuator to contact and move a rotor element with respect to the stator. Various embodiments of the motor are disclosed, and the rotor element may be moved linearly or arcuately.

  1. Latest Research: Genetic Links

    MedlinePlus

    ... Current Issue Past Issues Feature: Vision Latest Research: Genetic Links Past Issues / Summer 2008 Table of Contents ... laboratories is one way the NEI is expanding genetic testing of eye diseases. Photo courtesy of National ...

  2. 29 CFR 1926.601 - Motor vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Motor vehicles. 1926.601 Section 1926.601 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Motor Vehicles, Mechanized Equipment, and Marine Operations § 1926.601 Motor vehicles. (a) Coverage. Motor vehicles as covered by this part are those...

  3. 30 CFR 18.34 - Motors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Motors. 18.34 Section 18.34 Mineral Resources... PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.34 Motors. Explosion-proof electric motor assemblies intended for use in approved equipment in...

  4. 30 CFR 18.34 - Motors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Motors. 18.34 Section 18.34 Mineral Resources... PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.34 Motors. Explosion-proof electric motor assemblies intended for use in approved equipment in...

  5. 29 CFR 1926.601 - Motor vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Motor vehicles. 1926.601 Section 1926.601 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Motor Vehicles, Mechanized Equipment, and Marine Operations § 1926.601 Motor vehicles. (a) Coverage. Motor vehicles as covered by this part are those...

  6. Electric motor for laser-mechanical drilling

    DOEpatents

    Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.

    2015-07-07

    A high power laser drilling system utilizing an electric motor laser bottom hole assembly. A high power laser beam travels within the electric motor for advancing a borehole. High power laser drilling system includes a down hole electrical motor having a hollow rotor for conveying a high power laser beam through the electrical motor.

  7. LTD, RP, and Motor Learning.

    PubMed

    Hirano, Tomoo; Yamazaki, Yoshito; Nakamura, Yoji

    2016-02-01

    Long-term depression (LTD) at excitatory synapses between parallel fibers and a Purkinje cell has been regarded as a critical cellular mechanism for motor learning. However, it was demonstrated that normal motor learning occurs under LTD suppression, suggesting that cerebellar plasticity mechanisms other than LTD also contribute to motor learning. One candidate for such plasticity is rebound potentiation (RP), which is long-term potentiation at inhibitory synapses between a stellate cell and a Purkinje cell. Both LTD and RP are induced by the increase in postsynaptic Ca(2+) concentration, and work to suppress the activity of a Purkinje cell. Thus, LTD and RP might work synergistically, and one might compensate defects of the other. RP induction is dependent on the interaction between GABAA receptor and GABAA receptor binding protein (GABARAP). Transgenic mice expressing a peptide which inhibits binding of GABARAP and GABAA receptor only in Purkinje cells show defects in both RP and adaptation of vestibulo-ocular reflex (VOR), a motor learning paradigm. However, another example of motor learning, adaptation of optokinetic response (OKR), is normal in the transgenic mice. Both VOR and OKR are reflex eye movements suppressing the slip of visual image on the retina during head movement. Previously, we reported that delphilin knockout mice show facilitated LTD induction and enhanced OKR adaptation, but we recently found that VOR adaptation was not enhanced in the knockout mice. These results together suggest that animals might use LTD and RP differently depending on motor learning tasks.

  8. Supplementary motor area (SMA) volume is associated with psychotic aberrant motor behaviour of patients with schizophrenia.

    PubMed

    Stegmayer, Katharina; Horn, Helge; Federspiel, Andrea; Razavi, Nadja; Bracht, Tobias; Laimböck, Karin; Strik, Werner; Dierks, Thomas; Wiest, Roland; Müller, Thomas J; Walther, Sebastian

    2014-07-30

    We aimed to investigate whether aberrant motor behavior in schizophrenia was associated with structural alterations in the motor system. Whole brain voxel based morphometry of patients with different severity of motor symptoms identified altered gray matter volume in the supplementary motor area (SMA), a key region of the motor system.

  9. The Infant Motor Profile: A Standardized and Qualitative Method to Assess Motor Behaviour in Infancy

    ERIC Educational Resources Information Center

    Heineman, Kirsten R.; Bos, Arend F.; Hadders-Algra, Mijna

    2008-01-01

    A reliable and valid instrument to assess neuromotor condition in infancy is a prerequisite for early detection of developmental motor disorders. We developed a video-based assessment of motor behaviour, the Infant Motor Profile (IMP), to evaluate motor abilities, movement variability, ability to select motor strategies, movement symmetry, and…

  10. 41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle...

  11. 41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle...

  12. 41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle...

  13. 41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle...

  14. 41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle...

  15. At the interface of sensory and motor dysfunctions and Alzheimer’s Disease

    PubMed Central

    Albers, Mark W.; Gilmore, Grover C.; Kaye, Jeffrey; Murphy, Claire; Wingfield, Arthur; Bennett, David A.; Boxer, Adam L.; Buchman, Aron S.; Cruickshanks, Karen J.; Devanand, Davangere P.; Duffy, Charles J.; Gall, Christine M.; Gates, George A.; Granholm, Ann-Charlotte; Hensch, Takao; Holtzer, Roee; Hyman, Bradley T.; Lin, Frank R.; McKee, Ann C.; Morris, John C.; Petersen, Ronald C.; Silbert, Lisa C.; Struble, Robert G.; Trojanowski, John Q.; Verghese, Joe; Wilson, Donald A.; Xu, Shunbin; Zhang, Li I.

    2014-01-01

    Recent evidence indicates that sensory and motor changes may precede the cognitive symptoms of Alzheimer’s disease (AD) by several years and may signify increased risk of developing AD. Traditionally, sensory and motor dysfunctions in aging and AD have been studied separately. To ascertain the evidence supporting the relationship between age-related changes in sensory and motor systems and the development of AD and to facilitate communication between several disciplines, the National Institute on Aging held an exploratory workshop titled “Sensory and Motor Dysfunctions in Aging and Alzheimer’s Disease”. The scientific sessions of the workshop focused on age-related and neuropathological changes in the olfactory, visual, auditory, and motor systems, followed by extensive discussion and hypothesis generation related to the possible links among sensory, cognitive, and motor domains in aging and AD. Based on the data presented and discussed at this workshop, it is clear that sensory and motor regions of the CNS are affected by Alzheimer pathology and that interventions targeting amelioration of sensory-motor deficits in AD may enhance patient function as AD progresses. PMID:25022540

  16. At the interface of sensory and motor dysfunctions and Alzheimer's disease.

    PubMed

    Albers, Mark W; Gilmore, Grover C; Kaye, Jeffrey; Murphy, Claire; Wingfield, Arthur; Bennett, David A; Boxer, Adam L; Buchman, Aron S; Cruickshanks, Karen J; Devanand, Davangere P; Duffy, Charles J; Gall, Christine M; Gates, George A; Granholm, Ann-Charlotte; Hensch, Takao; Holtzer, Roee; Hyman, Bradley T; Lin, Frank R; McKee, Ann C; Morris, John C; Petersen, Ronald C; Silbert, Lisa C; Struble, Robert G; Trojanowski, John Q; Verghese, Joe; Wilson, Donald A; Xu, Shunbin; Zhang, Li I

    2015-01-01

    Recent evidence indicates that sensory and motor changes may precede the cognitive symptoms of Alzheimer's disease (AD) by several years and may signify increased risk of developing AD. Traditionally, sensory and motor dysfunctions in aging and AD have been studied separately. To ascertain the evidence supporting the relationship between age-related changes in sensory and motor systems and the development of AD and to facilitate communication between several disciplines, the National Institute on Aging held an exploratory workshop titled "Sensory and Motor Dysfunctions in Aging and AD." The scientific sessions of the workshop focused on age-related and neuropathologic changes in the olfactory, visual, auditory, and motor systems, followed by extensive discussion and hypothesis generation related to the possible links among sensory, cognitive, and motor domains in aging and AD. Based on the data presented and discussed at this workshop, it is clear that sensory and motor regions of the central nervous system are affected by AD pathology and that interventions targeting amelioration of sensory-motor deficits in AD may enhance patient function as AD progresses.

  17. The Effect of Teachers Trained in a Fundamental Movement Skills Programme on Children's Self-Perceptions and Motor Competence

    ERIC Educational Resources Information Center

    Breslin, Gavin; Murphy, Marie; McKee, David; Delaney, Brian; Dempster, Martin

    2012-01-01

    Perceived and actual motor competence are hypothesized to have potential links to children and young people's physical activity (PA) levels with a potential consequential link to long-term health. In this cross-sectional study, Harter's (1985, "Manual for the Self-perception Profile for Children." Denver, CO: University of Denver)…

  18. A Circuit for Motor Cortical Modulation of Auditory Cortical Activity

    PubMed Central

    Nelson, Anders; Schneider, David M.; Takatoh, Jun; Sakurai, Katsuyasu; Wang, Fan

    2013-01-01

    Normal hearing depends on the ability to distinguish self-generated sounds from other sounds, and this ability is thought to involve neural circuits that convey copies of motor command signals to various levels of the auditory system. Although such interactions at the cortical level are believed to facilitate auditory comprehension during movements and drive auditory hallucinations in pathological states, the synaptic organization and function of circuitry linking the motor and auditory cortices remain unclear. Here we describe experiments in the mouse that characterize circuitry well suited to transmit motor-related signals to the auditory cortex. Using retrograde viral tracing, we established that neurons in superficial and deep layers of the medial agranular motor cortex (M2) project directly to the auditory cortex and that the axons of some of these deep-layer cells also target brainstem motor regions. Using in vitro whole-cell physiology, optogenetics, and pharmacology, we determined that M2 axons make excitatory synapses in the auditory cortex but exert a primarily suppressive effect on auditory cortical neuron activity mediated in part by feedforward inhibition involving parvalbumin-positive interneurons. Using in vivo intracellular physiology, optogenetics, and sound playback, we also found that directly activating M2 axon terminals in the auditory cortex suppresses spontaneous and stimulus-evoked synaptic activity in auditory cortical neurons and that this effect depends on the relative timing of motor cortical activity and auditory stimulation. These experiments delineate the structural and functional properties of a corticocortical circuit that could enable movement-related suppression of auditory cortical activity. PMID:24005287

  19. A circuit for motor cortical modulation of auditory cortical activity.

    PubMed

    Nelson, Anders; Schneider, David M; Takatoh, Jun; Sakurai, Katsuyasu; Wang, Fan; Mooney, Richard

    2013-09-04

    Normal hearing depends on the ability to distinguish self-generated sounds from other sounds, and this ability is thought to involve neural circuits that convey copies of motor command signals to various levels of the auditory system. Although such interactions at the cortical level are believed to facilitate auditory comprehension during movements and drive auditory hallucinations in pathological states, the synaptic organization and function of circuitry linking the motor and auditory cortices remain unclear. Here we describe experiments in the mouse that characterize circuitry well suited to transmit motor-related signals to the auditory cortex. Using retrograde viral tracing, we established that neurons in superficial and deep layers of the medial agranular motor cortex (M2) project directly to the auditory cortex and that the axons of some of these deep-layer cells also target brainstem motor regions. Using in vitro whole-cell physiology, optogenetics, and pharmacology, we determined that M2 axons make excitatory synapses in the auditory cortex but exert a primarily suppressive effect on auditory cortical neuron activity mediated in part by feedforward inhibition involving parvalbumin-positive interneurons. Using in vivo intracellular physiology, optogenetics, and sound playback, we also found that directly activating M2 axon terminals in the auditory cortex suppresses spontaneous and stimulus-evoked synaptic activity in auditory cortical neurons and that this effect depends on the relative timing of motor cortical activity and auditory stimulation. These experiments delineate the structural and functional properties of a corticocortical circuit that could enable movement-related suppression of auditory cortical activity.

  20. Fine and gross motor skills differ between healthy-weight and obese children.

    PubMed

    Gentier, Ilse; D'Hondt, Eva; Shultz, Sarah; Deforche, Benedicte; Augustijn, Mireille; Hoorne, Sofie; Verlaecke, Katja; De Bourdeaudhuij, Ilse; Lenoir, Matthieu

    2013-11-01

    Within the obesity literature, focus is put on the link between weight status and gross motor skills. However, research on fine motor skills in the obese (OB) childhood population is limited. Therefore, the present study focused on possible weight related differences in gross as well as fine motor skill tasks. Thirty-four OB children (12 ♀ and 22 ♂, aged 7-13 years) were recruited prior to participating in a multidisciplinary treatment program at the Zeepreventorium (De Haan, Belgium). Additionally, a control group of 34 age and gender-matched healthy-weight (HW) children was included in the study. Anthropometric measures were recorded and gross and fine motor skills were assessed using the Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2). Results were analyzed by independent samples t-tests, multivariate analysis of variance, and a chi-squared test. Being OB was detrimental for all subtests evaluating gross motor skill performance (i.e., upper-limb coordination, bilateral coordination, balance, running speed and agility, and strength). Furthermore, OB children performed worse in fine motor precision and a manual dexterity task, when compared to their HW peers. No group differences existed for the fine motor integration task. Our study provides evidence that lower motor competence in OB children is not limited to gross motor skills alone; OB children are also affected by fine motor skill problems. Further investigation is warranted to provide possible explanations for these differences. It is tentatively suggested that OB children experience difficulties with the integration and processing of sensory information. Future research is needed to explore whether this assumption is correct and what the underlying mechanism(s) could be.

  1. Linked Ocean Data

    NASA Astrophysics Data System (ADS)

    Leadbetter, Adam; Arko, Robert; Chandler, Cynthia; Shepherd, Adam

    2014-05-01

    "Linked Data" is a term used in Computer Science to encapsulate a methodology for publishing data and metadata in a structured format so that links may be created and exploited between objects. Berners-Lee (2006) outlines the following four design principles of a Linked Data system: Use Uniform Resource Identifiers (URIs) as names for things. Use HyperText Transfer Protocol (HTTP) URIs so that people can look up those names. When someone looks up a URI, provide useful information, using the standards (Resource Description Framework [RDF] and the RDF query language [SPARQL]). Include links to other URIs so that they can discover more things. In 2010, Berners-Lee revisited his original design plan for Linked Data to encourage data owners along a path to "good Linked Data". This revision involved the creation of a five star rating system for Linked Data outlined below. One star: Available on the web (in any format). Two stars: Available as machine-readable structured data (e.g. An Excel spreadsheet instead of an image scan of a table). Three stars: As two stars plus the use of a non-proprietary format (e.g. Comma Separated Values instead of Excel). Four stars: As three stars plus the use of open standards from the World Wide Web Commission (W3C) (i.e. RDF and SPARQL) to identify things, so that people can point to your data and metadata. Five stars: All the above plus link your data to other people's data to provide context Here we present work building on the SeaDataNet common vocabularies served by the NERC Vocabulary Server, connecting projects such as the Rolling Deck to Repository (R2R) and the Biological and Chemical Oceanography Data Management Office (BCO-DMO) and other vocabularies such as the Marine Metadata Interoperability Ontology Register and Repository and the NASA Global Change Master Directory to create a Linked Ocean Data cloud. Publishing the vocabularies and metadata in standard RDF XML and exposing SPARQL endpoints renders them five-star Linked

  2. Lower Motor Neuron Findings after Upper Motor Neuron Injury: Insights from Postoperative Supplementary Motor Area Syndrome

    PubMed Central

    Florman, Jeffrey E.; Duffau, Hugues; Rughani, Anand I.

    2013-01-01

    Hypertonia and hyperreflexia are classically described responses to upper motor neuron injury. However, acute hypotonia and areflexia with motor deficit are hallmark findings after many central nervous system insults such as acute stroke and spinal shock. Historic theories to explain these contradictory findings have implicated a number of potential mechanisms mostly relying on the loss of descending corticospinal input as the underlying etiology. Unfortunately, these simple descriptions consistently fail to adequately explain the pathophysiology and connectivity leading to acute hyporeflexia and delayed hyperreflexia that result from such insult. This article highlights the common observation of acute hyporeflexia after central nervous system insults and explores the underlying anatomy and physiology. Further, evidence for the underlying connectivity is presented and implicates the dominant role of supraspinal inhibitory influence originating in the supplementary motor area descending through the corticospinal tracts. Unlike traditional explanations, this theory more adequately explains the findings of postoperative supplementary motor area syndrome in which hyporeflexia motor deficit is observed acutely in the face of intact primary motor cortex connections to the spinal cord. Further, the proposed connectivity can be generalized to help explain other insults including stroke, atonic seizures, and spinal shock. PMID:23508473

  3. Submersible canned motor transfer pump

    DOEpatents

    Guardiani, R.F.; Pollick, R.D.; Nyilas, C.P.; Denmeade, T.J.

    1997-08-19

    A transfer pump is described which is used in a waste tank for transferring high-level radioactive liquid waste from a waste tank and having a column assembly, a canned electric motor means, and an impeller assembly with an upper impeller and a lower impeller connected to a shaft of a rotor assembly. The column assembly locates a motor housing with the electric motor means adjacent to the impeller assembly which creates an hydraulic head, and which forces the liquid waste, into the motor housing to cool the electric motor means and to cool and/or lubricate the radial and thrust bearing assemblies. Hard-on-hard bearing surfaces of the bearing assemblies and a ring assembly between the upper impeller and electric motor means grind large particles in the liquid waste flow. Slots in the static bearing member of the radial bearing assemblies further grind down the solid waste particles so that only particles smaller than the clearances in the system can pass there through, thereby resisting damage to and the interruption of the operation of the transfer pump. The column assembly is modular so that sections can be easily assembled, disassembled and/or removed. A second embodiment employs a stator jacket which provides an alternate means for cooling the electric motor means and lubricating and/or cooling the bearing assemblies, and a third embodiment employs a variable level suction device which allows liquid waste to be drawn into the transfer pump from varying and discrete levels in the waste tank. 17 figs.

  4. 78 FR 76265 - Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ... Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety AGENCY: National... is rules that specifically relate to passenger cars, multipurpose passenger vehicles, trucks, buses, trailers, motorcycles, and motor vehicle equipment. DATES: You should submit comments early enough...

  5. 75 FR 76692 - Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-09

    ..., and 571 Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety AGENCY... passenger vehicles, trucks, buses, trailers, incomplete vehicles, motorcycles, and motor vehicle equipment... impacts. 523 Vehicle classification. 525 Exemptions from average fuel economy standards. 526 Petitions...

  6. Improve Motor Operation at Off-Design Voltages - Motor Tip Sheet #9

    SciTech Connect

    2008-07-01

    Motors are designed to operate within +/- 10% of their nameplate rated voltages. When motors operate at conditions of over- or under-voltage, motor efficiency and other performance parameters are degraded.

  7. 75 FR 62879 - Individual Exemption Involving General Motors Company, General Motors Holdings LLC, and General...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-13

    ... Benefits Security Administration Individual Exemption Involving General Motors Company, General Motors Holdings LLC, and General Motors LLC, Located in Detroit, MI AGENCY: Employee Benefits Security... ERISA (the Notice).\\2\\ The proposed exemption was requested in an application filed by General...

  8. Subcortical evoked activity and motor enhancement in Parkinson's disease.

    PubMed

    Anzak, Anam; Tan, Huiling; Pogosyan, Alek; Khan, Sadaquate; Javed, Shazia; Gill, Steven S; Ashkan, Keyoumars; Akram, Harith; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Green, Alexander L; Aziz, Tipu; Brown, Peter

    2016-03-01

    Enhancements in motor performance have been demonstrated in response to intense stimuli both in healthy subjects and in the form of 'paradoxical kinesis' in patients with Parkinson's disease. Here we identify a mid-latency evoked potential in local field potential recordings from the region of the subthalamic nucleus, which scales in amplitude with both the intensity of the stimulus delivered and corresponding enhancements in biomechanical measures of maximal handgrips, independent of the dopaminergic state of our subjects with Parkinson's disease. Recordings of a similar evoked potential in the related pedunculopontine nucleus - a key component of the reticular activating system - provide support for this neural signature in the subthalmic nucleus being a novel correlate of ascending arousal, propagated from the reticular activating system to exert an 'energizing' influence on motor circuitry. Future manipulation of this system linking arousal and motor performance may provide a novel approach for the non-dopaminergic enhancement of motor performance in patients with hypokinetic disorders such as Parkinson's disease.

  9. Subcortical evoked activity and motor enhancement in Parkinson's disease

    PubMed Central

    Anzak, Anam; Tan, Huiling; Pogosyan, Alek; Khan, Sadaquate; Javed, Shazia; Gill, Steven S.; Ashkan, Keyoumars; Akram, Harith; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Green, Alexander L.; Aziz, Tipu; Brown, Peter

    2016-01-01

    Enhancements in motor performance have been demonstrated in response to intense stimuli both in healthy subjects and in the form of ‘paradoxical kinesis’ in patients with Parkinson's disease. Here we identify a mid-latency evoked potential in local field potential recordings from the region of the subthalamic nucleus, which scales in amplitude with both the intensity of the stimulus delivered and corresponding enhancements in biomechanical measures of maximal handgrips, independent of the dopaminergic state of our subjects with Parkinson's disease. Recordings of a similar evoked potential in the related pedunculopontine nucleus – a key component of the reticular activating system – provide support for this neural signature in the subthalmic nucleus being a novel correlate of ascending arousal, propagated from the reticular activating system to exert an ‘energizing’ influence on motor circuitry. Future manipulation of this system linking arousal and motor performance may provide a novel approach for the non-dopaminergic enhancement of motor performance in patients with hypokinetic disorders such as Parkinson's disease. PMID:26687971

  10. Non-Motor Aspects of Tic Disorders—New Developments

    PubMed Central

    Ruhrman, Daphna; Gev, Ella; Benaroya-Milshtein, Noa; Fennig, Silvana; Krispin, Orit; Apter, Alan; Steinberg, Tamar

    2017-01-01

    The cardinal characteristics of tic-related disorders are stereotyped motor movements and vocalizations. However, they may be accompanied by non-motor features that appear sequentially during the course of the disorder and can sometimes be more disabling than the tics themselves. This review presents our perspectives on several non-motor aspects of Tourette syndrome based on the long experience of the Neuropsychiatric Tourette Clinic of a tertiary pediatric medical center. The effect of premonitory urges, sensory modulation disorder, tic-related cognitions, and environmental conditions on the expression and intensity of tics is elaborated, with suggestions for treatment approaches to each. We also describe the mediatory effect of parental attachment style on the link between maternal stress and ticcing intensity and the need to adjust psychotherapy interventions to account for the importance of this factor in emotion regulation. This review is intended to direct attention to the non-motor aspects of Tourette syndrome. An in-depth understanding of this complex and debilitating disorder will facilitate the formulation of innovative therapeutic protocols. PMID:28119635

  11. Modulation of motor cortex inhibition during motor imagery.

    PubMed

    Chong, Benjamin W X; Stinear, Cathy M

    2017-04-01

    Motor imagery (MI) is similar to overt movement, engaging common neural substrates and facilitating the corticomotor pathway; however, it does not result in excitatory descending motor output. Transcranial magnetic stimulation (TMS) can be used to assess inhibitory networks in the primary motor cortex via measures of 1-ms short-interval intracortical inhibition (SICI), long-interval intracortical inhibition (LICI), and late cortical disinhibition (LCD). These measures are thought to reflect extrasynaptic GABAA tonic inhibition, postsynaptic GABAB inhibition, and presynaptic GABAB disinhibition, respectively. The behavior of 1-ms SICI, LICI, and LCD during MI has not yet been explored. This study aimed to investigate how 1-ms SICI, LICI, and LCD are modulated during MI and voluntary relaxation (VR) of a target muscle. Twenty-five healthy young adults participated. TMS was used to assess nonconditioned motor evoked potential (MEP) amplitude, 1-ms SICI, 100- (LICI100) and 150-ms LICI, and LCD in the right abductor pollicis brevis (APB) and right abductor digiti minimi during rest, MI, and VR of the hand. Compared with rest, MEP amplitudes were facilitated in APB during MI. SICI was not affected by task or muscle. LICI100 decreased in both muscles during VR but not MI, whereas LCD was recruited in both muscles during both tasks. This indicates that VR modulates postsynaptic GABAB inhibition, whereas both tasks modulate presynaptic GABAB inhibition in a non-muscle-specific way. This study highlights further neurophysiological parallels between actual and imagined movement, which may extend to voluntary relaxation.NEW & NOTEWORTHY This is the first study to investigate how 1-ms short-interval intracortical inhibition, long-interval intracortical inhibition, and late cortical disinhibition are modulated during motor imagery and voluntary muscle relaxation. We present novel findings of decreased 100-ms long-interval intracortical inhibition during voluntary muscle

  12. Early identification of motor delay

    PubMed Central

    Harris, Susan R.

    2016-01-01

    Objective To describe the Harris Infant Neuromotor Test (HINT), an infant neuromotor test using Canadian norms published in 2010 that could be used to screen for motor delay during the first year of life. Quality of evidence Extensive research has been published on the intrarater, interrater, and test-retest reliability and the content, concurrent, predictive, and known-groups validity of the HINT, as well as on the sensitivity, specificity, and positive and negative predictive values of parental concerns, as assessed by the HINT. Most evidence is level II. Main message Diagnosing motor delays during the first year of life is important because these often indicate more generalized developmental delays or specific disabilities, such as cerebral palsy. Parental concerns about their children’s motor development are strongly predictive of subsequent diagnoses involving motor delay. Conclusion Only through early identification of developmental motor delays, initially with screening tools such as the HINT, is it possible to provide referrals for early intervention that could benefit both the infant and the family. PMID:27521388

  13. Filament overwrapped motor case technology

    NASA Astrophysics Data System (ADS)

    Compton, Joel P.

    1993-11-01

    Atlantic Research Corporation (ARC) joined with the French Societe Europeenne de Propulsion (SEP) to develop and deliver to the U.S. Navy a small quantity of composite filament wound rocket motors to demonstrate a manufacturing technique that was being applied at the two companies. It was perceived that the manufacturing technique could produce motors that would be light in weight, inexpensive to produce, and that had a good chance of meeting insensitive munitions (IM) requirements that were being formulated by the Navy in the early 1980s. Under subcontract to ARC, SEP designed, tested, and delivered 2.75-inch rocket motors to the U.S. Navy for IM tests that were conducted in 1989 at China Lake, California. The program was one of the first to be founded by Nunn Amendment money. The Government-to-Government program was sponsored by the Naval Air Systems Command and was monitored by the Naval Surface Warfare Center, Indian Head (NSWC-IH), Maryland. The motor propellant that was employed was a new, extruded composite formulation that was under development at the Naval Surface Warfare Center. The following paper describes the highlights of the program and gives the results of structural and ballistic static tests and insensitive munitions tests that were conducted on demonstration motors.

  14. Three phase AC motor controller

    DOEpatents

    Vuckovich, Michael; Wright, Maynard K.; Burkett, John P.

    1984-03-20

    A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

  15. A miniscale ballistic test motor for propellant burning rate characterization from one motor firing

    NASA Astrophysics Data System (ADS)

    Rast, Robert H.; Boyles, Sharon M.; Obney, Phyllis

    1992-07-01

    A mini ballistic test motor for burn rate characterization from one motor firing has been developed. The small charge weight required for this motor allows ballistic characterization of small scale lot set evaluation and R&D propellant mixes in a rocket motor environment. This paper presents results comparing the mini-motor to the standard Naval Surface Warfare Center, Indian Head (IHDIVNAVSURFWARCEN) ballistic test motor, (BTM). Burn rate data from the standard BTM and mini BTM show excellent agreement.

  16. Coordination of individual and ensemble cytoskeletal motors studied using tools from DNA nanotechnology

    NASA Astrophysics Data System (ADS)

    Derr, Nathan Dickson

    The cytoskeletal molecular motors kinesin-1 and cytoplasmic dynein drive many diverse functions within eukaryotic cells. They are responsible for numerous spatially and temporally dependent intracellular processes crucial for cellular activity, including cytokinesis, maintenance of sub-cellular organization and the transport of myriad cargos along microtubule tracks. Cytoplasmic dynein and kinesin-1 are processive, but opposite polarity, homodimeric motors; they each can take hundreds of thousands of consecutive steps, but do so in opposite directions along their microtubule tracks. These steps are fueled by the binding and hydrolysis of ATP within the homodimer's two identical protomers. Individual motors achieve their processivity by maintaining asynchrony between the stepping cycles of each protomer, insuring that at least one protomer always maintains contact with the track. How dynein coordinates the asynchronous stepping activity of its protomers is unknown. We developed a versatile method for assembling Saccharomyces cerevisiae dynein heterodimers, using complementary DNA oligonucleotides covalently linked to dynein monomers labeled with different organic fluorophores. Using two-color, single-molecule microscopy and high-precision, two-dimensional tracking, we found that dynein has a highly variable stepping pattern that is distinct from all other processive cytoskeletal motors, which use "hand-over-hand" mechanisms. Uniquely, dynein stepping is stochastic when its two motor domains are close together. However, coordination emerges as the distance between motor domains increases, implying that a tension-based mechanism governs these steps. Many cellular cargos demonstrate bidirectional movement due to the presence of ensembles of both cytoplasmic dynein and kinesin-1. To investigate the mechanisms that coordinate the interactions between motors within an ensemble, we constructed programmable synthetic cargos using three-dimensional DNA origami. This system

  17. Learning in the Rodent Motor Cortex.

    PubMed

    Peters, Andrew J; Liu, Haixin; Komiyama, Takaki

    2017-03-31

    The motor cortex is far from a stable conduit for motor commands and instead undergoes significant changes during learning. An understanding of motor cortex plasticity has been advanced greatly using rodents as experimental animals. Two major focuses of this research have been on the connectivity and activity of the motor cortex. The motor cortex exhibits structural changes in response to learning, and substantial evidence has implicated the local formation and maintenance of new synapses as crucial substrates of motor learning. This synaptic reorganization translates into changes in spiking activity, which appear to result in a modification and refinement of the relationship between motor cortical activity and movement. This review presents the progress that has been made using rodents to establish the motor cortex as an adaptive structure that supports motor learning. Expected final online publication date for the Annual Review of Neuroscience Volume 40 is July 8, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  18. Sleep-Dependent Reactivation of Ensembles in Motor Cortex Promotes Skill Consolidation

    PubMed Central

    Ramanathan, Dhakshin S.; Gulati, Tanuj; Ganguly, Karunesh

    2015-01-01

    Despite many prior studies demonstrating offline behavioral gains in motor skills after sleep, the underlying neural mechanisms remain poorly understood. To investigate the neurophysiological basis for offline gains, we performed single-unit recordings in motor cortex as rats learned a skilled upper-limb task. We found that sleep improved movement speed with preservation of accuracy. These offline improvements were linked to both replay of task-related ensembles during non-rapid eye movement (NREM) sleep and temporal shifts that more tightly bound motor cortical ensembles to movements; such offline gains and temporal shifts were not evident with sleep restriction. Interestingly, replay was linked to the coincidence of slow-wave events and bursts of spindle activity. Neurons that experienced the most consistent replay also underwent the most significant temporal shift and binding to the motor task. Significantly, replay and the associated performance gains after sleep only occurred when animals first learned the skill; continued practice during later stages of learning (i.e., after motor kinematics had stabilized) did not show evidence of replay. Our results highlight how replay of synchronous neural activity during sleep mediates large-scale neural plasticity and stabilizes kinematics during early motor learning. PMID:26382320

  19. Sleep-Dependent Reactivation of Ensembles in Motor Cortex Promotes Skill Consolidation.

    PubMed

    Ramanathan, Dhakshin S; Gulati, Tanuj; Ganguly, Karunesh

    2015-01-01

    Despite many prior studies demonstrating offline behavioral gains in motor skills after sleep, the underlying neural mechanisms remain poorly understood. To investigate the neurophysiological basis for offline gains, we performed single-unit recordings in motor cortex as rats learned a skilled upper-limb task. We found that sleep improved movement speed with preservation of accuracy. These offline improvements were linked to both replay of task-related ensembles during non-rapid eye movement (NREM) sleep and temporal shifts that more tightly bound motor cortical ensembles to movements; such offline gains and temporal shifts were not evident with sleep restriction. Interestingly, replay was linked to the coincidence of slow-wave events and bursts of spindle activity. Neurons that experienced the most consistent replay also underwent the most significant temporal shift and binding to the motor task. Significantly, replay and the associated performance gains after sleep only occurred when animals first learned the skill; continued practice during later stages of learning (i.e., after motor kinematics had stabilized) did not show evidence of replay. Our results highlight how replay of synchronous neural activity during sleep mediates large-scale neural plasticity and stabilizes kinematics during early motor learning.

  20. Remote control for motor vehicle

    NASA Technical Reports Server (NTRS)

    Johnson, Dale R. (Inventor); Ciciora, John A. (Inventor)

    1984-01-01

    A remote controller is disclosed for controlling the throttle, brake and steering mechanism of a conventional motor vehicle, with the remote controller being particularly advantageous for use by severely handicapped individuals. The controller includes a remote manipulator which controls a plurality of actuators through interfacing electronics. The remote manipulator is a two-axis joystick which controls a pair of linear actuators and a rotary actuator, with the actuators being powered by electric motors to effect throttle, brake and steering control of a motor vehicle adapted to include the controller. The controller enables the driver to control the adapted vehicle from anywhere in the vehicle with one hand with minimal control force and range of motion. In addition, even though a conventional vehicle is adapted for use with the remote controller, the vehicle may still be operated in the normal manner.

  1. Linear Synchronous Motor Repeatability Tests

    SciTech Connect

    Ward, C.R.

    2002-10-18

    A cart system using linear synchronous motors was being considered for the Plutonium Immobilization Plant (PIP). One of the applications in the PIP was the movement of a stack of furnace trays, filled with the waste form (pucks) from a stacking/unstacking station to several bottom loaded furnaces. A system was ordered to perform this function in the PIP Ceramic Prototype Test Facility (CPTF). This system was installed and started up in SRTC prior to being installed in the CPTF. The PIP was suspended and then canceled after the linear synchronous motor system was started up. This system was used to determine repeatability of a linear synchronous motor cart system for the Modern Pit Facility.

  2. Miniaturization of planar horn motors

    NASA Astrophysics Data System (ADS)

    Sherrit, Stewart; Ostlund, Patrick N.; Chang, Zensheu; Bao, Xiaoqi; Bar-Cohen, Yoseph; Widholm, Scott E.; Badescu, Mircea

    2012-04-01

    There is a great need for compact, efficient motors for driving various mechanisms including robots or mobility platforms. A study is currently underway to develop a new type of piezoelectric actuators with significantly more strength, low mass, small footprint, and efficiency. The actuators/motors utilize piezoelectric actuated horns which have a very high power density and high electromechanical conversion efficiency. The horns are fabricated using our recently developed novel pre-stress flexures that make them thermally stable and increases their coupling efficiency. The monolithic design and integrated flexures that pre-stresses the piezoelectric stack eliminates the use of a stress bolt. This design allows embedding solid-state motors and actuators in any structure so that the only macroscopically moving parts are the rotor or the linear translator. The developed actuator uses a stack/horn actuation and has a Barth motor configuration, which potentially generates very large torque and speeds that do not require gearing. Finite element modeling and design tools were investigated to determine the requirements and operation parameters and the results were used to design and fabricate a motor. This new design offers a highly promising actuation mechanism that can potentially be miniaturized and integrated into systems and structures. It can be configured in many shapes to operate as multi-degrees of freedom and multi-dimensional motors/actuators including unidirectional, bidirectional, 2D and 3D. In this manuscript, we are reporting the experimental measurements from a bench top design and the results from the efforts to miniaturize the design using 2×2×2 mm piezoelectric stacks integrated into thin plates that are of the order of 3 × 3 × 0.2 cm.

  3. Miniaturization of Planar Horn Motors

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Ostlund, Patrick N.; Chang, Zensheu; Bao, Xiaoqi; Bar-Cohen, Yoseph; Widholm, Scott E.; Badescu, Mircea

    2012-01-01

    There is a great need for compact, efficient motors for driving various mechanisms including robots or mobility platforms. A study is currently underway to develop a new type of piezoelectric actuators with significantly more strength, low mass, small footprint, and efficiency. The actuators/motors utilize piezoelectric actuated horns which have a very high power density and high electromechanical conversion efficiency. The horns are fabricated using our recently developed novel pre-stress flexures that make them thermally stable and increases their coupling efficiency. The monolithic design and integrated flexures that pre-stresses the piezoelectric stack eliminates the use of stress bolt. This design allows embedding solid-state motors and actuators in any structure so that the only macroscopically moving parts are the rotor or the linear translator. The developed actuator uses a stack/horn actuation and has a Barth motor configuration, which potentially generates very large torque and speeds that do not require gearing. Finite element modeling and design tools were investigated to determine the requirements and operation parameters and the results were used to design and fabricate a motor. This new design offers a highly promising actuation mechanism that can potentially be miniaturized and integrated into systems and structures. It can be configured in many shapes to operate as multi-degrees of freedom and multi-dimensional motors/actuators including unidirectional, bidirectional, 2D and 3D. In this manuscript, we are reporting the experimental measurements from a bench top design and the results from the efforts to miniaturize the design using 2x2x2 mm piezoelectric stacks integrated into thin plates that are of the order of3 x 3x 0.2 cm.

  4. Helically linked mirror arrangement

    SciTech Connect

    Ranjan, P.

    1986-08-01

    A scheme is described for helical linking of mirror sections, which endeavors to combine the better features of toroidal and mirror devices by eliminating the longitudinal loss of mirror machines, having moderately high average ..beta.. and steady state operation. This scheme is aimed at a device, with closed magnetic surfaces having rotational transform for equilibrium, one or more axisymmetric straight sections for reduced radial loss, a simple geometrical axis for the links and an overall positive magnetic well depth for stability. We start by describing several other attempts at linking of mirror sections, made both in the past and the present. Then a description of our helically linked mirror scheme is given. This example has three identical straight sections connected by three sections having helical geometric axes. A theoretical analysis of the magnetic field and single-particle orbits in them leads to the conclusion that most of the passing particles would be confined in the device and they would have orbits independent of pitch angle under certain conditions. Numerical results are presented, which agree well with the theoretical results as far as passing particle orbits are concerned.

  5. Link Influence Entropy

    NASA Astrophysics Data System (ADS)

    Singh, Priti; Chakraborty, Abhishek; Manoj, B. S.

    2017-01-01

    In this paper we propose a new metric, Link Influence Entropy (LInE), which describes importance of each node based on the influence of each link present in a network. Influence of a link can neither be effectively estimated using betweenness centrality nor using degree based probability measures. The proposed LInE metric which provides an effective way to estimate the influence of a link in the network and incorporates this influence to identify nodal characteristics, performs better compared to degree based entropy. We found that LInE can differentiate various network types which degree-based or betweenness centrality based node influence metrics cannot. Our findings show that spatial wireless networks and regular grid networks, respectively, have lowest and highest LInE values. Finally, performance analysis of LInE is carried out on a real-world network as well as on a wireless mesh network testbed to study the influence of our metric as well as influence stability of nodes in dynamic networks.

  6. TWSTFT Link Calibration Report

    DTIC Science & Technology

    2015-09-01

    Serrano, G. Brunetti (2013) Relative Calibration of the Time Transfer Link between CERN and LNGS for Precise Neutrino Time of Flight Measurements. Proc...Esteban, M. Pallavicini, Va. Pettiti, C. Plantard, A. Razeto (2012) Measurement of CNGS Muon Neutrinos Speed with Borexino: INRIM and ROA Contribution

  7. Linking Literacy and Movement

    ERIC Educational Resources Information Center

    Pica, Rae

    2010-01-01

    There are many links between literacy and movement. Movement and language are both forms of communication and self-expression. Rhythm is an essential component of both language and movement. While people may think of rhythm primarily in musical terms, there is a rhythm to words and sentences as well. Individuals develop an internal rhythm when…

  8. CERES Web Links

    Atmospheric Science Data Center

    2013-03-21

        Web Links to Relevant CERES Information Relevant information about ... questions about the CERES data can be found at the following web sites: CERES Home Page CERES TRMM Home Page ... Information page  on the Atmospheric Science Data Center site CERES "ARM" Validation Experiment (CAVE) Home Page  has ...

  9. Predictive motor control of sensory dynamics in auditory active sensing.

    PubMed

    Morillon, Benjamin; Hackett, Troy A; Kajikawa, Yoshinao; Schroeder, Charles E

    2015-04-01

    Neuronal oscillations present potential physiological substrates for brain operations that require temporal prediction. We review this idea in the context of auditory perception. Using speech as an exemplar, we illustrate how hierarchically organized oscillations can be used to parse and encode complex input streams. We then consider the motor system as a major source of rhythms (temporal priors) in auditory processing, that act in concert with attention to sharpen sensory representations and link them across areas. We discuss the circuits that could mediate this audio-motor interaction, notably the potential role of the somatosensory system. Finally, we reposition temporal predictions in the context of internal models, discussing how they interact with feature-based or spatial predictions. We argue that complementary predictions interact synergistically according to the organizational principles of each sensory system, forming multidimensional filters crucial to perception.

  10. Reorganization between preparatory and movement population responses in motor cortex

    PubMed Central

    Elsayed, Gamaleldin F.; Lara, Antonio H.; Kaufman, Matthew T.; Churchland, Mark M.; Cunningham, John P.

    2016-01-01

    Neural populations can change the computation they perform on very short timescales. Although such flexibility is common, the underlying computational strategies at the population level remain unknown. To address this gap, we examined population responses in motor cortex during reach preparation and movement. We found that there exist exclusive and orthogonal population-level subspaces dedicated to preparatory and movement computations. This orthogonality yielded a reorganization in response correlations: the set of neurons with shared response properties changed completely between preparation and movement. Thus, the same neural population acts, at different times, as two separate circuits with very different properties. This finding is not predicted by existing motor cortical models, which predict overlapping preparation-related and movement-related subspaces. Despite orthogonality, responses in the preparatory subspace were lawfully related to subsequent responses in the movement subspace. These results reveal a population-level strategy for performing separate but linked computations. PMID:27807345

  11. The Advanced Solid Rocket Motor

    NASA Technical Reports Server (NTRS)

    Mitchell, Royce E.

    1992-01-01

    The Advanced Solid Rocket Motor will utilize improved design features and automated manufacturing methods to produce an inherently safer propulsive system for the Space Shuttle and future launch systems. This second-generation motor will also provide an additional 12,000 pounds of payload to orbit, enhancing the utility and efficiency of the Shuttle system. The new plant will feature strip-wound, asbestos-free insulation; propellant continuous mixing and casting; and extensive robotic systems. Following a series of static tests at the Stennis Space Center, MS flights are targeted to begin in early 1997.

  12. The Advanced Solid Rocket Motor

    NASA Astrophysics Data System (ADS)

    Mitchell, Royce E.

    1992-08-01

    The Advanced Solid Rocket Motor will utilize improved design features and automated manufacturing methods to produce an inherently safer propulsive system for the Space Shuttle and future launch systems. This second-generation motor will also provide an additional 12,000 pounds of payload to orbit, enhancing the utility and efficiency of the Shuttle system. The new plant will feature strip-wound, asbestos-free insulation; propellant continuous mixing and casting; and extensive robotic systems. Following a series of static tests at the Stennis Space Center, MS flights are targeted to begin in early 1997.

  13. Thermoelectric generator for motor vehicle

    DOEpatents

    Bass, John C.

    1997-04-29

    A thermoelectric generator for producing electric power for a motor vehicle from the heat of the exhaust gasses produced by the engine of the motor vehicle. The exhaust gasses pass through a finned heat transfer support structure which has seat positions on its outside surface for the positioning of thermoelectric modules. A good contact cylinder provides a framework from which a spring force can be applied to the thermoelectric modules to hold them in good contact on their seats on the surface of the heat transfer support structure.

  14. Homopolar motor with dual rotors

    DOEpatents

    Hsu, J.S.

    1998-12-01

    A homopolar motor has a field rotor mounted on a frame for rotation in a first rotational direction and for producing an electromagnetic field, and an armature rotor mounted for rotation on said frame within said electromagnetic field and in a second rotational direction counter to said first rotational direction of said field rotor. The two rotors are coupled through a 1:1 gearing mechanism, so as to travel at the same speed but in opposite directions. This doubles the output voltage and output power, as compared to a motor in which only the armature is rotated. Several embodiments are disclosed. 7 figs.

  15. Homopolar motor with dual rotors

    DOEpatents

    Hsu, John S.

    1998-01-01

    A homopolar motor (10) has a field rotor (15) mounted on a frame (11) for rotation in a first rotational direction and for producing an electromagnetic field, and an armature rotor (17) mounted for rotation on said frame (11) within said electromagnetic field and in a second rotational direction counter to said first rotational direction of said field rotor (15). The two rotors (15, 17) are coupled through a 1:1 gearing mechanism (19), so as to travel at the same speed but in opposite directions. This doubles the output voltage and output power, as compared to a motor in which only the armature is rotated. Several embodiments are disclosed.

  16. Odd sensation induced by moving-phantom which triggers subconscious motor program.

    PubMed

    Fukui, Takao; Kimura, Toshitaka; Kadota, Koji; Shimojo, Shinsuke; Gomi, Hiroaki

    2009-06-03

    Our motor actions are sometimes not properly performed despite our having complete understanding of the environmental situation with a suitable action intention. In most cases, insufficient skill for motor control can explain the improper performance. A notable exception is the action of stepping onto a stopped escalator, which causes clumsy movements accompanied by an odd sensation. Previous studies have examined short-term sensorimotor adaptations to treadmills and moving sleds, but the relationship between the odd sensation and behavioral properties in a real stopped-escalator situation has never been examined. Understanding this unique action-perception linkage would help us to assess the brain function connecting automatic motor controls and the conscious awareness of action. Here we directly pose a question: Does the odd sensation emerge because of the unfamiliar motor behavior itself toward the irregular step-height of a stopped escalator or as a consequence of an automatic habitual motor program cued by the escalator itself. We compared the properties of motor behavior toward a stopped escalator (SE) with those toward moving escalator and toward a wooden stairs (WS) that mimicked the stopped escalator, and analyzed the subjective feeling of the odd sensation in the SE and WS conditions. The results show that moving escalator-specific motor actions emerged after participants had stepped onto the stopped escalator despite their full awareness that it was stopped, as if the motor behavior was guided by a "phantom" of a moving escalator. Additionally, statistical analysis reveals that postural forward sway that occurred after the stepping action is directly linked with the odd sensation. The results suggest a dissociation between conscious awareness and subconscious motor control: the former makes us perfectly aware of the current environmental situation, but the latter automatically emerges as a result of highly habituated visual input no matter how unsuitable

  17. SDRE control strategy applied to a nonlinear robotic including drive motor

    SciTech Connect

    Lima, Jeferson J. de E-mail: tusset@utfpr.edu.br E-mail: piccirillo@utfpr.edu.br Tusset, Angelo M. E-mail: tusset@utfpr.edu.br E-mail: piccirillo@utfpr.edu.br Janzen, Frederic C. E-mail: tusset@utfpr.edu.br E-mail: piccirillo@utfpr.edu.br Piccirillo, Vinicius E-mail: tusset@utfpr.edu.br E-mail: piccirillo@utfpr.edu.br Nascimento, Claudinor B. E-mail: tusset@utfpr.edu.br E-mail: piccirillo@utfpr.edu.br; Balthazar, José M.; Brasil, Reyolando M. L. R. da Fonseca

    2014-12-10

    A robotic control design considering all the inherent nonlinearities of the robot-engine configuration is developed. The interactions between the robot and joint motor drive mechanism are considered. The proposed control combines two strategies, one feedforward control in order to maintain the system in the desired coordinate, and feedback control system to take the system into a desired coordinate. The feedback control is obtained using State-Dependent Riccati Equation (SDRE). For link positioning two cases are considered. Case I: For control positioning, it is only used motor voltage; Case II: For control positioning, it is used both motor voltage and torque between the links. Simulation results, including parametric uncertainties in control shows the feasibility of the proposed control for the considered system.

  18. Motor imagery facilitates force field learning.

    PubMed

    Anwar, Muhammad Nabeel; Tomi, Naoki; Ito, Koji

    2011-06-13

    Humans have the ability to produce an internal reproduction of a specific motor action without any overt motor output. Recent findings show that the processes underlying motor imagery are similar to those active during motor execution and both share common neural substrates. This suggests that the imagery of motor movements might play an important role in acquiring new motor skills. In this study we used haptic robot in conjunction with motor imagery technique to improve learning in a robot-based adaptation task. Two groups of subjects performed reaching movements with or without motor imagery in a velocity-dependent and position-dependent mixed force field. The groups performed movements with motor imagery produced higher after effects and decreased muscle co-contraction with respect to no-motor imagery group. These results showed a positive influence of motor imagery on acquiring new motor skill and suggest that motor learning can be facilitated by mental practice and could be used to increase the rate of adaptation.

  19. Resolving Interference between Body Movements: Retrieval-Induced Forgetting of Motor Sequences

    ERIC Educational Resources Information Center

    Tempel, Tobias; Frings, Christian

    2013-01-01

    When body movements are stored in memory in an organized manner, linked to a common retrieval cue like the effector with which to execute the movement, interference may arise as soon as one initiates the execution of a specific body movement in the presence of the retrieval cue because related motor programs also are activated. We investigated the…

  20. Closed-loop motor control using high-speed fiber optics

    NASA Technical Reports Server (NTRS)

    Dawson, Reginald (Inventor); Rodriquiz, Dagobert (Inventor)

    1991-01-01

    A closed-loop control system for controlling the operation of one or more servo motors or other controllable devices is described. The system employs a fiber optics link immune to electromagnetic interference, for transmission of control signals from a controller or controllers at a remote station to the power electronics located in proximity to the motors or other devices at the local station. At the remote station the electrical control signals are time-multiplexed, converted to a formatted serial bit stream, and converted to light signals for transmission over a single fiber of the fiber optics link. At the local station, the received optical signals are reconstructed as electrical control signals for the controlled motors or other devices. At the local station, an encoder sensor linked to the driven device generates encoded feedback signals which provide information as to a condition of the controlled device. The encoded signals are placed in a formatted serial bit stream, multiplexed, and transmitted as optical signals over a second fiber of the fiber optic link which closes the control loop of the closed-loop motor controller. The encoded optical signals received at the remote station are demultiplexed, reconstructed and coupled to the controller(s) as electrical feedback signals.

  1. Do Nimble Hands Make for Nimble Lexicons? Fine Motor Skills Predict Knowledge of Embodied Vocabulary Items

    ERIC Educational Resources Information Center

    Suggate, Sebastian P.; Stoeger, Heidrun

    2014-01-01

    Theories and research in embodied cognition postulate that cognition grounded in action enjoys a processing advantage. Extending this theory to the study of how fine motor skills (FMS) link to vocabulary development in preschool children, the authors investigated FMS and vocabulary in 76 preschoolers. Building on previous research, they…

  2. 48 CFR 970.5223-5 - DOE motor vehicle fleet fuel efficiency.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... fuel efficiency. 970.5223-5 Section 970.5223-5 Federal Acquisition Regulations System DEPARTMENT OF... efficiency. Link to an amendment published at 75 FR 57695, Sept. 22, 2010. As prescribed in 48 CFR 970.2307-2.... DOE motor vehicle fleet fuel efficiency (OCT 2003) When managing Government-owned vehicles for...

  3. Self-organization of waves and pulse trains by molecular motors in cellular protrusions.

    PubMed

    Yochelis, A; Ebrahim, S; Millis, B; Cui, R; Kachar, B; Naoz, M; Gov, N S

    2015-09-03

    Actin-based cellular protrusions are an ubiquitous feature of cells, performing a variety of critical functions ranging from cell-cell communication to cell motility. The formation and maintenance of these protrusions relies on the transport of proteins via myosin motors, to the protrusion tip. While tip-directed motion leads to accumulation of motors (and their molecular cargo) at the protrusion tip, it is observed that motors also form rearward moving, periodic and isolated aggregates. The origins and mechanisms of these aggregates, and whether they are important for the recycling of motors, remain open puzzles. Motivated by novel myosin-XV experiments, a mass conserving reaction-diffusion-advection model is proposed. The model incorporates a non-linear cooperative interaction between motors, which converts them between an active and an inactive state. Specifically, the type of aggregate formed (traveling waves or pulse-trains) is linked to the kinetics of motors at the protrusion tip which is introduced by a boundary condition. These pattern selection mechanisms are found not only to qualitatively agree with empirical observations but open new vistas to the transport phenomena by molecular motors in general.

  4. Self-organization of waves and pulse trains by molecular motors in cellular protrusions

    PubMed Central

    Yochelis, A.; Ebrahim, S.; Millis, B.; Cui, R.; Kachar, B.; Naoz, M.; Gov, N. S.

    2015-01-01

    Actin-based cellular protrusions are an ubiquitous feature of cells, performing a variety of critical functions ranging from cell-cell communication to cell motility. The formation and maintenance of these protrusions relies on the transport of proteins via myosin motors, to the protrusion tip. While tip-directed motion leads to accumulation of motors (and their molecular cargo) at the protrusion tip, it is observed that motors also form rearward moving, periodic and isolated aggregates. The origins and mechanisms of these aggregates, and whether they are important for the recycling of motors, remain open puzzles. Motivated by novel myosin-XV experiments, a mass conserving reaction-diffusion-advection model is proposed. The model incorporates a non-linear cooperative interaction between motors, which converts them between an active and an inactive state. Specifically, the type of aggregate formed (traveling waves or pulse-trains) is linked to the kinetics of motors at the protrusion tip which is introduced by a boundary condition. These pattern selection mechanisms are found not only to qualitatively agree with empirical observations but open new vistas to the transport phenomena by molecular motors in general. PMID:26335545

  5. Evolution of EEG Motor Rhythms after Spinal Cord Injury: A Longitudinal Study

    PubMed Central

    López-Larraz, Eduardo; Montesano, Luis; Gil-Agudo, Ángel; Minguez, Javier; Oliviero, Antonio

    2015-01-01

    Spinal cord injury (SCI) does not only produce a lack of sensory and motor function caudal to the level of injury, but it also leads to a progressive brain reorganization. Chronic SCI patients attempting to move their affected limbs present a significant reduction of brain activation in the motor cortex, which has been linked to the deafferentation. The aim of this work is to study the evolution of the motor-related brain activity during the first months after SCI. Eighteen subacute SCI patients were recruited to participate in bi-weekly experimental sessions during at least two months. Their EEG was recorded to analyze the temporal evolution of the event-related desynchronization (ERD) over the motor cortex, both during motor attempt and motor imagery of their paralyzed hands. The results show that the α and β ERD evolution after SCI is negatively correlated with the clinical progression of the patients during the first months after the injury. This work provides the first longitudinal study of the event-related desynchronization during the subacute phase of spinal cord injury. Furthermore, our findings reveal a strong association between the ERD changes and the clinical evolution of the patients. These results help to better understand the brain transformation after SCI, which is important to characterize the neuroplasticity mechanisms involved after this lesion and may lead to new strategies for rehabilitation and motor restoration of these patients. PMID:26177457

  6. What factors influence motor complications in Parkinson disease?: a 10-year prospective study.

    PubMed

    García-Ruiz, Pedro J; Del Val, Javier; Fernández, Ignacio Mahillo; Herranz, Antonio

    2012-01-01

    The causes and mechanism behind motor complications in Parkinson disease (PD) are still a subject of debate. Several factors including age at onset, evolution in years, and initial medication can influence the onset and severity of motor complications in PD.We studied patients with recent diagnosis of PD who were followed up prospectively for 10 years. Analysis included the progression of these patients, as measured by the Unified Parkinson Disease Rating Scale scores and the presence of motor complications (motors fluctuations, dyskinesias, and gait freezing) over time. The patient group was studied as a whole and by subgroups classified according to age at onset, initial treatment, and sex.By the end of the first decade, most patients exhibited dyskinesias (91%), motor fluctuations (62%), and freezing of gait (68%). An association was found between several patients' characteristics and presence of motor complications by 5 years, though not after 10 years of follow up. The apparition of motor fluctuations was mainly related to initial treatment (odds ratio [OR], 3.87). The development of dyskinesias was linked to initial treatment (OR, 8.31), age at onset (OR, 0.90), and sex (OR, 12.87).

  7. Modeling and control of a hydraulically actuated flexible-prismatic link robot

    SciTech Connect

    Love, L.; Kress, R.; Jansen, J.

    1996-12-01

    Most of the research related to flexible link manipulators to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long reach systems. This manuscript describes a new hydraulically actuated, long reach manipulator with a flexible prismatic link at Oak Ridge National Laboratory (ORNL). Focus is directed towards both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.

  8. Chemistry: No turning back for motorized molecules

    NASA Astrophysics Data System (ADS)

    Clayden, Jonathan

    2016-06-01

    Two molecular motors have been developed that use chemical energy to drive rotational motion in a single direction. The findings bring the prospect of devices powered by such motors a tantalizing step closer. See Letter p.235

  9. Duty ratio of cooperative molecular motors.

    PubMed

    Dharan, Nadiv; Farago, Oded

    2012-02-01

    Molecular motors are found throughout the cells of the human body and have many different and important roles. These micromachines move along filament tracks and have the ability to convert chemical energy into mechanical work that powers cellular motility. Different types of motors are characterized by different duty ratios, which is the fraction of time that a motor is attached to its filament. In the case of myosin II (a nonprocessive molecular machine with a low duty ratio), cooperativity between several motors is essential to induce motion along its actin filament track. In this work we use statistical mechanical tools to calculate the duty ratio of cooperative molecular motors. The model suggests that the effective duty ratio of nonprocessive motors that work in cooperation is lower than the duty ratio of the individual motors. The origin of this effect is the elastic tension that develops in the filament which is relieved when motors detach from the track.

  10. Failure analysis of solid rocket apogee motors

    NASA Technical Reports Server (NTRS)

    Martin, P. J.

    1972-01-01

    The analysis followed five selected motors through initial design, development, test, qualification, manufacture, and final flight reports. An audit was conducted at the manufacturing plants to complement the literature search with firsthand observations of the current philosophies and practices that affect reliability of the motors. A second literature search emphasized acquisition of spacecraft and satellite data bearing on solid motor reliability. It was concluded that present practices at the plants yield highly reliable flight hardware. Reliability can be further improved by new developments of aft-end bonding and initiator/igniter nondestructive test methods, a safe/arm device, and an insulation formulation. Minimum diagnostic instrumentation is recommended for all motor flights. Surplus motors should be used in margin testing. Criteria should be established for pressure and zone curing. The motor contractor should be represented at launch. New design analyses should be made of stretched motors and spacecraft/motor pairs.

  11. CDC Vital Signs: Motor Vehicle Crash Deaths

    MedlinePlus

    ... Press Kit Read the MMWR Science Clips Motor Vehicle Crash Deaths How is the US doing? Language: ... Sweden, Switzerland, and the United Kingdom. Problem Motor vehicle crash deaths in the US are still too ...

  12. Duty ratio of cooperative molecular motors

    NASA Astrophysics Data System (ADS)

    Dharan, Nadiv; Farago, Oded

    2012-02-01

    Molecular motors are found throughout the cells of the human body and have many different and important roles. These micromachines move along filament tracks and have the ability to convert chemical energy into mechanical work that powers cellular motility. Different types of motors are characterized by different duty ratios, which is the fraction of time that a motor is attached to its filament. In the case of myosin II (a nonprocessive molecular machine with a low duty ratio), cooperativity between several motors is essential to induce motion along its actin filament track. In this work we use statistical mechanical tools to calculate the duty ratio of cooperative molecular motors. The model suggests that the effective duty ratio of nonprocessive motors that work in cooperation is lower than the duty ratio of the individual motors. The origin of this effect is the elastic tension that develops in the filament which is relieved when motors detach from the track.

  13. Trophic Factor Expression in Phrenic Motor Neurons

    PubMed Central

    Mantilla, Carlos B.; Sieck, Gary C.

    2008-01-01

    The function of a motor neuron and the muscle fibers it innervates (i.e., a motor unit) determines neuromotor output. Unlike other skeletal muscles, respiratory muscles (e.g., the diaphragm, DIAm) must function from birth onwards in sustaining ventilation. DIAm motor units are capable of both ventilatory and non-ventilatory behaviors, including expulsive behaviors important for airway clearance. There is significant diversity in motor unit properties across different types of motor units in the DIAm. The mechanisms underlying the development and maintenance of motor unit diversity in respiratory muscles (including the DIAm) are not well understood. Recent studies suggest that trophic factor influences contribute to this diversity. Remarkably little is known about the expression of trophic factors and their receptors in phrenic motor neurons. This review will focus on the contribution of trophic factors to the establishment and maintenance of motor unit diversity in the DIAm, during development and in response to injury or disease. PMID:18708170

  14. Small-Scale Rocket Motor Test

    NASA Video Gallery

    Engineers at NASA's Marshall Space Flight Center in Huntsville, Ala. successfully tested a sub-scale solid rocket motor on May 27. Testing a sub-scale version of a rocket motor is a cost-effective ...

  15. Force Generation by Molecular-Motor-Powered Microtubule Bundles; Implications for Neuronal Polarization and Growth

    PubMed Central

    Jakobs, Maximilian; Franze, Kristian; Zemel, Assaf

    2015-01-01

    The heavily cross-linked microtubule (MT) bundles found in neuronal processes play a central role in the initiation, growth and maturation of axons and dendrites; however, a quantitative understanding of their mechanical function is still lacking. We here developed computer simulations to investigate the dynamics of force generation in 1D bundles of MTs that are cross-linked and powered by molecular motors. The motion of filaments and the forces they exert are investigated as a function of the motor type (unipolar or bipolar), MT density and length, applied load, and motor connectivity. We demonstrate that only unipolar motors (e.g., kinesin-1) can provide the driving force for bundle expansion, while bipolar motors (e.g., kinesin-5) oppose it. The force generation capacity of the bundles is shown to depend sharply on the fraction of unipolar motors due to a percolation transition that must occur in the bundle. Scaling laws between bundle length, force, MT length and motor fraction are presented. In addition, we investigate the dynamics of growth in the presence of a constant influx of MTs. Beyond a short equilibration period, the bundles grow linearly in time. In this growth regime, the bundle extends as one mass forward with most filaments sliding with the growth velocity. The growth velocity is shown to be dictated by the inward flux of MTs, to inversely scale with the load and to be independent of the free velocity of the motors. These findings provide important molecular-level insights into the mechanical function of the MT cytoskeleton in normal axon growth and regeneration after injury. PMID:26617489

  16. Force Generation by Molecular-Motor-Powered Microtubule Bundles; Implications for Neuronal Polarization and Growth.

    PubMed

    Jakobs, Maximilian; Franze, Kristian; Zemel, Assaf

    2015-01-01

    The heavily cross-linked microtubule (MT) bundles found in neuronal processes play a central role in the initiation, growth and maturation of axons and dendrites; however, a quantitative understanding of their mechanical function is still lacking. We here developed computer simulations to investigate the dynamics of force generation in 1D bundles of MTs that are cross-linked and powered by molecular motors. The motion of filaments and the forces they exert are investigated as a function of the motor type (unipolar or bipolar), MT density and length, applied load, and motor connectivity. We demonstrate that only unipolar motors (e.g., kinesin-1) can provide the driving force for bundle expansion, while bipolar motors (e.g., kinesin-5) oppose it. The force generation capacity of the bundles is shown to depend sharply on the fraction of unipolar motors due to a percolation transition that must occur in the bundle. Scaling laws between bundle length, force, MT length and motor fraction are presented. In addition, we investigate the dynamics of growth in the presence of a constant influx of MTs. Beyond a short equilibration period, the bundles grow linearly in time. In this growth regime, the bundle extends as one mass forward with most filaments sliding with the growth velocity. The growth velocity is shown to be dictated by the inward flux of MTs, to inversely scale with the load and to be independent of the free velocity of the motors. These findings provide important molecular-level insights into the mechanical function of the MT cytoskeleton in normal axon growth and regeneration after injury.

  17. Thermodynamic Interrogation of the Assembly of a Viral Genome Packaging Motor Complex

    PubMed Central

    Yang, Teng-Chieh; Ortiz, David; Nosaka, Lyn’Al; Lander, Gabriel C.; Catalano, Carlos Enrique

    2015-01-01

    Viral terminase enzymes serve as genome packaging motors in many complex double-stranded DNA viruses. The functional motors are multiprotein complexes that translocate viral DNA into a capsid shell, powered by a packaging ATPase, and are among the most powerful molecular motors in nature. Given their essential role in virus development, the structure and function of these biological motors is of considerable interest. Bacteriophage λ-terminase, which serves as a prototypical genome packaging motor, is composed of one large catalytic subunit tightly associated with two DNA recognition subunits. This protomer assembles into a functional higher-order complex that excises a unit length genome from a concatemeric DNA precursor (genome maturation) and concomitantly translocates the duplex into a preformed procapsid shell (genome packaging). While the enzymology of λ-terminase has been well described, the nature of the catalytically competent nucleoprotein intermediates, and the mechanism describing their assembly and activation, is less clear. Here we utilize analytical ultracentrifugation to determine the thermodynamic parameters describing motor assembly and define a minimal thermodynamic linkage model that describes the effects of salt on protomer assembly into a tetrameric complex. Negative stain electron microscopy images reveal a symmetric ring-like complex with a compact stem and four extended arms that exhibit a range of conformational states. Finally, kinetic studies demonstrate that assembly of the ring tetramer is directly linked to activation of the packaging ATPase activity of the motor, thus providing a direct link between structure and function. The implications of these results with respect to the assembly and activation of the functional packaging motor during a productive viral infection are discussed. PMID:26488657

  18. NASA's Advanced solid rocket motor

    NASA Technical Reports Server (NTRS)

    Mitchell, Royce E.

    1993-01-01

    The Advanced Solid Rocket Motor (ASRM) will not only bring increased safety, reliability and performance for the Space Shuttle Booster, it will enhance overall Shuttle safety by effectively eliminating 174 failure points in the Space Shuttle Main Engine throttling system and by reducing the exposure time to aborts due to main engine loss or shutdown. In some missions, the vulnerability time to Return-to-Launch Site aborts is halved. The ASRM uses case joints which will close or remain static under the effects of motor ignition and pressurization. The case itself is constructed of the weldable steel alloy HP 9-4-0.30, having very high strength and with superior fracture toughness and stress corrosion resistance. The internal insulation is strip-wound and is free of asbestos. The nozzle employs light weight ablative parts and is some 5,000 pounds lighter than the Shuttle motor used to date. The payload performance of the ASRM-powered Shuttle is 12,000 pounds higher than that provided by the present motor. This is of particular benefit for payloads delivered to higher inclinations and/or altitudes. The ASRM facility uses state-of-the-art manufacturing techniques, including continuous propellant mixing and direct casting.

  19. Improving Motor Skills through Listening

    ERIC Educational Resources Information Center

    Wang, Lin

    2004-01-01

    In this article, the author discusses how to improve a child's motor skills through listening by using three simple steps--recording the auditory model, determining when to use the auditory model, and considering where to use the auditory model. She points out the importance of using a demonstration technique that helps learners understand the…

  20. Putting Motor Resonance in Perspective

    ERIC Educational Resources Information Center

    Lozano, Sandra C.; Hard, Bridgette Martin; Tversky, Barbara

    2008-01-01

    Perceiving another person's actions changes the spatial perspective people use to describe objects in a scene, possibly because seeing human action induces people to map the actions, including their spatial context, to their own body and motor representations [Lozano, S. C., Hard, B. M., & Tversky, B. (2007). Putting action in perspective.…

  1. Motor neurone disease: an overview.

    PubMed

    Kent, Anna

    Motor neurone disease (MND) is a relatively rare, progressive and incurable neurological condition affecting patients' speech, mobility and respiratory function. Care of patients with MND is complex and involves various healthcare professionals and services. There is a need to discuss symptom management and promote palliative and end of life care from the point of diagnosis to ensure appropriate holistic care is provided.

  2. Fluctuation Relations for Molecular Motors

    NASA Astrophysics Data System (ADS)

    Lacoste, David; Mallick, Kirone

    This review is focused on the application of specific fluctuation relations, such as the Gallavotti-Cohen relation, to ratchet models of a molecular motor. A special emphasis is placed on two-state models such as the flashing ratchet model. We derive the Gallavotti-Cohen fluctuation relation for these models and we discuss some of its implications.

  3. Motor interference in interactive contexts

    PubMed Central

    Chinellato, Eris; Castiello, Umberto; Sartori, Luisa

    2015-01-01

    Action observation and execution share overlapping neural substrates, so that simultaneous activation by observation and execution modulates motor performance. Previous literature on simple prehension tasks has revealed that motor influence can be two-sided: facilitation for observed and performed congruent actions and interference for incongruent actions. But little is known of the specific modulations of motor performance in complex forms of interaction. Is it possible that the very same observed movement can lead either to interference or facilitation effects on a temporally overlapping congruent executed action, depending on the context? To answer this question participants were asked to perform a reach-to-grasp movement adopting a precision grip (PG) while: (i) observing a fixation cross, (ii) observing an actor performing a PG with interactive purposes, (iii) observing an actor performing a PG without interactive purposes. In particular, in the interactive condition the actor was shown trying to pour some sugar on a large cup located out of her reach but close to the participant watching the video, thus eliciting in reaction a complementary whole-hand grasp. Notably, fine-grained kinematic analysis for this condition revealed a specific delay in the grasping and reaching components and an increased trajectory deviation despite the observed and executed movement’s congruency. Moreover, early peaks of trajectory deviation seem to indicate that socially relevant stimuli are acknowledged by the motor system very early. These data suggest that interactive contexts can determine a prompt modulation of stimulus–response compatibility effects. PMID:26113835

  4. Stages of motor skill learning.

    PubMed

    Luft, Andreas R; Buitrago, Manuel M

    2005-12-01

    Successful learning of a motor skill requires repetitive training. Once the skill is mastered, it can be remembered for a long period of time. The durable memory makes motor skill learning an interesting paradigm for the study of learning and memory mechanisms. To gain better understanding, one scientific approach is to dissect the process into stages and to study these as well as their interactions. This article covers the growing evidence that motor skill learning advances through stages, in which different storage mechanisms predominate. The acquisition phase is characterized by fast (within session) and slow learning (between sessions). For a short period following the initial training sessions, the skill is labile to interference by other skills and by protein synthesis inhibition, indicating that consolidation processes occur during rest periods between training sessions. During training as well as rest periods, activation in different brain regions changes dynamically. Evidence for stages in motor skill learning is provided by experiments using behavioral, electrophysiological, functional imaging, and cellular/molecular methods.

  5. NASA's Advanced solid rocket motor

    NASA Astrophysics Data System (ADS)

    Mitchell, Royce E.

    The Advanced Solid Rocket Motor (ASRM) will not only bring increased safety, reliability and performance for the Space Shuttle Booster, it will enhance overall Shuttle safety by effectively eliminating 174 failure points in the Space Shuttle Main Engine throttling system and by reducing the exposure time to aborts due to main engine loss or shutdown. In some missions, the vulnerability time to Return-to-Launch Site aborts is halved. The ASRM uses case joints which will close or remain static under the effects of motor ignition and pressurization. The case itself is constructed of the weldable steel alloy HP 9-4-0.30, having very high strength and with superior fracture toughness and stress corrosion resistance. The internal insulation is strip-wound and is free of asbestos. The nozzle employs light weight ablative parts and is some 5,000 pounds lighter than the Shuttle motor used to date. The payload performance of the ASRM-powered Shuttle is 12,000 pounds higher than that provided by the present motor. This is of particular benefit for payloads delivered to higher inclinations and/or altitudes. The ASRM facility uses state-of-the-art manufacturing techniques, including continuous propellant mixing and direct casting.

  6. Ironless-armature brushless motor

    NASA Technical Reports Server (NTRS)

    Fisher, R. L.

    1977-01-01

    Device uses 12-pole samarium cobalt permanent-magnet rotor and three Hall-effect sensors for commutation. In prototype motor, torque constant (3-phase delta) is 65 oz-in/amp; electrical time constant (L/R) is 0.2 x 0.001 sec, and armature resistance is 20 ohms.

  7. Motor systems and postural instability.

    PubMed

    Vassar, Rachel L; Rose, Jessica

    2014-01-01

    Acute alcohol intoxication and chronic alcohol dependence alter the neurologic control of posture and motor function. Ethanol delays the conduction of electric signals from the central nervous system to the muscles controlling posture and impairs the integration of sensory inputs required for maintaining vertical stance. Consequently, alcohol intoxication delays the ability to detect postural changes and enact the appropriate response. Common signs of acute alcohol intoxication include spinocerebellar and vestibulocerebellar ataxia, oculomotor changes, and increased reliance on visuospatial clues. Chronic alcoholism results in postural tremors and excessive sway during quiet stance that can persist even after sobriety is achieved. Underlying neurologic changes due to chronic alcoholism have been found to be associated with these characteristic postural changes and include decreased volume of the anterior superior vermis of the cerebellum, decreased connectivity within the corpus callosum, and overall cortical atrophy. Severity of motor impairments and other symptoms from alcoholism relate to a variety of factors, including duration of alcoholism, age, sex, and other health determinants and comorbidities. Imaging studies highlight the potential for partial recovery from neurologic and motor deficits caused by alcoholism. Emerging evidence on the motor and neurologic changes caused by alcohol dependence may allow for improved treatment and prevention of the morbidities associated with alcoholism.

  8. Motor Action and Emotional Memory

    ERIC Educational Resources Information Center

    Casasanto, Daniel; Dijkstra, Katinka

    2010-01-01

    Can simple motor actions affect how efficiently people retrieve emotional memories, and influence what they choose to remember? In Experiment 1, participants were prompted to retell autobiographical memories with either positive or negative valence, while moving marbles either upward or downward. They retrieved memories faster when the direction…

  9. Technology and Motor Ability Development

    ERIC Educational Resources Information Center

    Wang, Lin; Lang, Yong; Luo, Zhongmin

    2014-01-01

    As a new member joining the technology family, active video games have been developed to promote physical exercise. This working-in-progress paper shares an ongoing project on examining the basic motor abilities that are enhanced through participating in commercially available active video games. [For the full proceedings see ED557181.

  10. Linear Motor With Air Slide

    NASA Technical Reports Server (NTRS)

    Johnson, Bruce G.; Gerver, Michael J.; Hawkey, Timothy J.; Fenn, Ralph C.

    1993-01-01

    Improved linear actuator comprises air slide and linear electric motor. Unit exhibits low friction, low backlash, and more nearly even acceleration. Used in machinery in which positions, velocities, and accelerations must be carefully controlled and/or vibrations must be suppressed.

  11. A sensory-motor control model of animal flight explains why bats fly differently in light versus dark.

    PubMed

    Bar, Nadav S; Skogestad, Sigurd; Marçal, Jose M; Ulanovsky, Nachum; Yovel, Yossi

    2015-01-01

    Animal flight requires fine motor control. However, it is unknown how flying animals rapidly transform noisy sensory information into adequate motor commands. Here we developed a sensorimotor control model that explains vertebrate flight guidance with high fidelity. This simple model accurately reconstructed complex trajectories of bats flying in the dark. The model implies that in order to apply appropriate motor commands, bats have to estimate not only the angle-to-target, as was previously assumed, but also the angular velocity ("proportional-derivative" controller). Next, we conducted experiments in which bats flew in light conditions. When using vision, bats altered their movements, reducing the flight curvature. This change was explained by the model via reduction in sensory noise under vision versus pure echolocation. These results imply a surprising link between sensory noise and movement dynamics. We propose that this sensory-motor link is fundamental to motion control in rapidly moving animals under different sensory conditions, on land, sea, or air.

  12. Molecular motors and their functions in plants

    NASA Technical Reports Server (NTRS)

    Reddy, A. S.

    2001-01-01

    Molecular motors that hydrolyze ATP and use the derived energy to generate force are involved in a variety of diverse cellular functions. Genetic, biochemical, and cellular localization data have implicated motors in a variety of functions such as vesicle and organelle transport, cytoskeleton dynamics, morphogenesis, polarized growth, cell movements, spindle formation, chromosome movement, nuclear fusion, and signal transduction. In non-plant systems three families of molecular motors (kinesins, dyneins, and myosins) have been well characterized. These motors use microtubules (in the case of kinesines and dyneins) or actin filaments (in the case of myosins) as tracks to transport cargo materials intracellularly. During the last decade tremendous progress has been made in understanding the structure and function of various motors in animals. These studies are yielding interesting insights into the functions of molecular motors and the origin of different families of motors. Furthermore, the paradigm that motors bind cargo and move along cytoskeletal tracks does not explain the functions of some of the motors. Relatively little is known about the molecular motors and their roles in plants. In recent years, by using biochemical, cell biological, molecular, and genetic approaches a few molecular motors have been isolated and characterized from plants. These studies indicate that some of the motors in plants have novel features and regulatory mechanisms. The role of molecular motors in plant cell division, cell expansion, cytoplasmic streaming, cell-to-cell communication, membrane trafficking, and morphogenesis is beginning to be understood. Analyses of the Arabidopsis genome sequence database (51% of genome) with conserved motor domains of kinesin and myosin families indicates the presence of a large number (about 40) of molecular motors and the functions of many of these motors remain to be discovered. It is likely that many more motors with novel regulatory

  13. Flexible Data Link

    DTIC Science & Technology

    2015-04-01

    continuously-interleaved Reed- Solomon scheme with 8% overhead has the best trade-off of performance (net coding gain) and overhead. Therefore, this is...disparity between attenuation at sea level versus at a 9150 meter altitude. As the Flexible Data Link system is an airborne asset which may operate...Quadrature Amplitude Modulation QPSK Quadrature Phase Shift Key RF Radio Frequency RS Reed- Solomon S&E Scientist & Engineers SFP Small Form-factor

  14. Masticatory motor pattern in the koala (Phascolarctos cinereus): a comparison of jaw movements in marsupial and placental herbivores.

    PubMed

    Crompton, Alfred Walter; Owerkowicz, Tomasz; Skinner, Jayne

    2010-11-01

    Do closely related marsupial herbivores (Diprotodontia) conserve a common masticatory motor pattern or are motor patterns linked to the structure and function of the masticatory apparatus? We recorded the sequence and duration of activity of the individual jaw closing muscles during rhythmic chewing in koalas and then compared their motor pattern with that of their closest extant relatives, wombats, and their more distant marsupial relatives, macropodoids. These three lineages prove to have fundamentally different motor patterns and jaw movements during mastication. Each motor pattern represents independent modifications of an earlier motor pattern that was probably present in an ancestral diprotodontian. We show that koalas evolved a motor program that is in many aspects similar to that of placental herbivores with a fused mandibular symphysis (artiodactyls, perissodactyls, and higher primates) and almost identical to one artiodactyl, viz. alpacas. Anatomically, koalas are convergent on placental herbivores because they lost the inflected mandibular angle and large external part of the medial pterygoid muscle characteristic of other marsupials. We support the view that many different motor programs evolved for the control of transverse jaw movements, but identical motor programs for the control of transverse jaw movements can evolve independently in distantly related taxa.

  15. Relationship between brain structure on magnetic resonance imaging and motor outcomes in children with cerebral palsy: a systematic review.

    PubMed

    Arnfield, Evyn; Guzzetta, Andrea; Boyd, Roslyn

    2013-07-01

    Magnetic resonance imaging (MRI) is recommended in all children with cerebral palsy (CP) where the aetiology has not been established, and the major presenting problem in CP is reduced motor capacity. A systematic review of the literature was performed to investigate the relationship between brain structure on MRI and motor outcomes in children with CP. A total of 37 studies met inclusion criteria, and were analysed in terms of (a) population characteristics, (b) MRI data, (c) motor outcome data, and (d) the relationship between MRI data and motor outcomes. All studies used a qualitative system to classify brain lesions; however, few reported information about the location and extent of lesions. Valid and reliable classifications of motor abilities were not always used, and three studies did not link motor findings to MRI features. There was, however, a relationship between the type of brain lesion on MRI and two specific motor outcomes, namely gross motor functional classification (using GMFCS) and motor type. This relationship could aid in the prediction and optimisation of early interventions for children with CP. There is also need for a quantitative MRI classification measure which includes detailed information about the location and severity of lesions.

  16. Interaction of motor proteins of various types at melanosome redistribution in melanocytes under action of UV radiation

    NASA Astrophysics Data System (ADS)

    Stolnitz, Mikhail M.; Kudryashov, Alexey A.

    2004-05-01

    In the report the mathematical model of melanosome transport along filaments in intact and UV-irradiated melanocytes is submitted. Processes at three levels are considered: dynamics of the single motor, transport of melanosome by ensemble of motors, and melanosomes distribution along microtubules. A single motor is considered as <> modeling of transitions between internal states described by chemical kinetics equations allows to determine "force-velocity" dependence for motor. The ensemble of motors is described by system of equations for average motor velocities, and transported melanosome moves with average velocity, which in turn is determined by sum of force generated by each elastic-coupled motor (self-consistence problem). Distribution of melanosomes along a microtubule is described by system of equations for bidirectional motion of attached melanosome under coordinated action of "plus-end" and "minus-end" motors and free diffusion of unattached melanosomes. Influence of UV-radiation is resulted in change of number of each type motors simultaneously linked to one melanosome. It induces redistribution of melanosomes between centre and periphery of melanocyte.

  17. Effect of the Children’s Health Activity Motor Program on Motor Skills and Self-Regulation in Head Start Preschoolers: An Efficacy Trial

    PubMed Central

    Robinson, Leah E.; Palmer, Kara K.; Bub, Kristen L.

    2016-01-01

    Self-regulatory skills are broadly defined as the ability to manage emotions, focus attention, and inhibit some behaviors while activating others in accordance with social expectations and are an established indicator of academic success. Growing evidence links motor skills and physical activity to self-regulation. This study examined the efficacy of a motor skills intervention (i.e., the Children’s Health Activity Motor Program, CHAMP) that is theoretically grounded in Achievement Goal Theory on motor skill performance and self-regulation in Head Start preschoolers. A sample of 113 Head Start preschoolers (Mage = 51.91 ± 6.5 months; 49.5% males) were randomly assigned to a treatment (n = 68) or control (n = 45) program. CHAMP participants engaged in 15, 40-min sessions of a mastery climate intervention that focused on the development of motor skills over 5 weeks while control participants engaged in their normal outdoor recess period. The Delay of Gratification Snack Task was used to measure self-regulation and the Test of Gross Motor Development-2nd Edition was used to assess motor skills. All measures were assessed prior to and following the intervention. Linear mixed models were fit for both self-regulation and motor skills. Results revealed a significant time × treatment interaction (p < 0.001). In regard to motor skills, post hoc comparisons found that all children improved their motor skills (p < 0.05), but the CHAMP group improved significantly more than the control group (p < 0.001). Children in CHAMP maintained their self-regulation scores across time, while children in the control group scored significantly lower than the CHAMP group at the posttest (p < 0.05). CHAMP is a mastery climate movement program that enhance skills associated with healthy development in children (i.e., motor skills and self-regulation). This efficacy trial provided evidence that CHAMP helped maintain delay of gratification in preschool

  18. Effect of the Children's Health Activity Motor Program on Motor Skills and Self-Regulation in Head Start Preschoolers: An Efficacy Trial.

    PubMed

    Robinson, Leah E; Palmer, Kara K; Bub, Kristen L

    2016-01-01

    Self-regulatory skills are broadly defined as the ability to manage emotions, focus attention, and inhibit some behaviors while activating others in accordance with social expectations and are an established indicator of academic success. Growing evidence links motor skills and physical activity to self-regulation. This study examined the efficacy of a motor skills intervention (i.e., the Children's Health Activity Motor Program, CHAMP) that is theoretically grounded in Achievement Goal Theory on motor skill performance and self-regulation in Head Start preschoolers. A sample of 113 Head Start preschoolers (Mage = 51.91 ± 6.5 months; 49.5% males) were randomly assigned to a treatment (n = 68) or control (n = 45) program. CHAMP participants engaged in 15, 40-min sessions of a mastery climate intervention that focused on the development of motor skills over 5 weeks while control participants engaged in their normal outdoor recess period. The Delay of Gratification Snack Task was used to measure self-regulation and the Test of Gross Motor Development-2nd Edition was used to assess motor skills. All measures were assessed prior to and following the intervention. Linear mixed models were fit for both self-regulation and motor skills. Results revealed a significant time × treatment interaction (p < 0.001). In regard to motor skills, post hoc comparisons found that all children improved their motor skills (p < 0.05), but the CHAMP group improved significantly more than the control group (p < 0.001). Children in CHAMP maintained their self-regulation scores across time, while children in the control group scored significantly lower than the CHAMP group at the posttest (p < 0.05). CHAMP is a mastery climate movement program that enhance skills associated with healthy development in children (i.e., motor skills and self-regulation). This efficacy trial provided evidence that CHAMP helped maintain delay of gratification in preschool

  19. Motorized control for mirror mount apparatus

    SciTech Connect

    Cutburth, Ronald W.

    1989-01-01

    A motorized control and automatic braking system for adjusting mirror mount apparatus is disclosed. The motor control includes a planetary gear arrangement to provide improved pitch adjustment capability while permitting a small packaged design. The motor control for mirror mount adjustment is suitable for laser beam propagation applications. The brake is a system of constant contact, floating detents which engage the planetary gear at selected between-teeth increments to stop rotation instantaneously when the drive motor stops.

  20. Motorized control for mirror mount apparatus

    SciTech Connect

    Cutburth, R.W.

    1989-03-14

    This patent describes a motorized control and automatic braking system for adjusting mirror mount apparatus. The motor control includes a planetary gear arrangement to provide improved pitch adjustment capability while permitting a small packaged design. The motor control for mirror mount adjustment is suitable for laser beam propagation applications. The brake is a system of constant contact, floating detents which engage the planetary gear at selected between-teeth increments to stop rotation instantaneously when the drive motor stops.

  1. Lipid - Motor Interactions: Soap Opera or Symphony?

    PubMed

    Pathak, Divya; Mallik, Roop

    2016-09-30

    Intracellular transport of organelles can be driven by multiple motor proteins that bind to the lipid membrane of the organelle and work as a team. We review present knowledge on how lipids orchestrate the recruitment of motors to a membrane. Looking beyond recruitment, we also discuss how heterogeneity and local mechanical properties of the membrane may influence function of motor-teams. These issues gain importance because phagocytosed pathogens use lipid-centric strategies to manipulate motors and survive in host cells.

  2. Frequency modulation drive for a piezoelectric motor

    DOEpatents

    Mittas, Anthony

    2001-01-01

    A piezoelectric motor has peak performance at a specific frequency f.sub.1 that may vary over a range of frequencies. A drive system is disclosed for operating such a motor at peak performance without feedback. The drive system consists of the motor and an ac source connected to power the motor, the ac source repeatedly generating a frequency over a range from f.sub.1 -.DELTA.x to f.sub.1 +.DELTA.y.

  3. Motor function in the elderly

    PubMed Central

    Vicente-Vytopilova, Pavla; Tavernier, Béatrice; Sabia, Séverine; Dumurgier, Julien; Mazoyer, Bernard; Singh-Manoux, Archana; Tzourio, Christophe

    2013-01-01

    Objective: The reserve hypothesis accounts for the lack of direct relationship between brain pathology and its clinical manifestations. Research has mostly focused on cognition; our objective is to examine whether the reserve hypothesis applies to motor function. We investigated whether education, a marker of reserve, modifies the association between white matter lesions (WMLs), a marker of vascular brain damage, and maximum walking speed (WS), an objective measure of motor function. We also examined the cross-sectional and longitudinal association between education and WS. Methods: Data are from 4,010 participants aged 65–85 years in the longitudinal Three-City–Dijon Study with up to 4 WS measures over 10 years. We examined the interaction between education and WMLs for baseline WS. We studied the association between education and repeated WS measures using linear mixed models, and the role of covariates in explaining the education-WS association. Results: Education was strongly associated with baseline WS; the difference in mean WS between the high and low education groups (0.145 m/s, 95% confidence interval = 0.125–0.165) was equivalent to 7.4 years of age. WMLs were associated with slow WS only in the low education group (p interaction = 0.026). WS declined significantly over time (−0.194 m/s/10 years, 95% confidence interval = −0.206, −0.182), but education did not influence rate of decline. Anthropometric characteristics, parental education, general health, and cognition had the strongest role in explaining the baseline education-WS association. Conclusions: Participants with more education were less susceptible to WMLs' effect on motor function. Higher education was associated with better motor performances but not with motor decline. These results are consistent with the passive reserve hypothesis. PMID:23803317

  4. FUZZY LOGIC CONTROL OF ELECTRIC MOTORS AND MOTOR DRIVES: FEASIBILITY STUDY

    EPA Science Inventory

    The report gives results of a study (part 1) of fuzzy logic motor control (FLMC). The study included: 1) reviews of existing applications of fuzzy logic, of motor operation, and of motor control; 2) a description of motor control schemes that can utilize FLMC; 3) selection of a m...

  5. 75 FR 49527 - General Motors Company Formerly Known as General Motors Corporation, Willow Run Transmission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ..., Willow Run Transmission Plant Including On-Site Leased Workers From Aerotek; Ypsilanti, MI; Amended... General Motors Company, formerly known as General Motors Corporation, Willow Run Transmission Plant... location of General Motors Company, formerly known as General Motors Corporation, Willow Run...

  6. Descending motor pathways and the spinal motor system - Limbic and non-limbic components

    NASA Technical Reports Server (NTRS)

    Holstege, Gert

    1991-01-01

    Research on descending motor pathways to caudal brainstem and spinal cord in the spinal motor system is reviewed. Particular attention is given to somatic and autonomic motoneurons in the spinal cord and brainstem, local projections to motoneurons, bulbospinal interneurons projecting to motoneurons, descending pathways of somatic motor control systems, and descending pathways involved in limbic motor control systems.

  7. 78 FR 4193 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; Volvo

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-18

    ... National Highway Traffic Safety Administration Petition for Exemption From the Federal Motor Vehicle Motor... is likely to be as effective in reducing and deterring motor vehicle theft as compliance with the... the MY 2014 S60 vehicle line is effective in reducing and deterring motor vehicle theft. Volvo...

  8. 76 FR 12220 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; Jaguar...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-04

    ... National Highway Traffic Safety Administration Petition for Exemption From the Federal Motor Vehicle Motor... on the line as standard equipment is likely to be as effective in reducing and deterring motor... deterring motor vehicle theft as compliance with ] the parts-marking requirements of the Theft...

  9. 77 FR 22383 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; TESLA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-13

    ... National Highway Traffic Safety Administration Petition for Exemption From the Federal Motor Vehicle Motor... full the petition of Tesla Motors Inc's. (Tesla) for an exemption of the Model S vehicle line in... is likely to be as effective in reducing and deterring motor vehicle theft as compliance with...

  10. 77 FR 4396 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; Toyota

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

    ... National Highway Traffic Safety Administration Petition for Exemption From the Federal Motor Vehicle Motor... full the petition of Toyota Motor North America, Inc's., (Toyota) petition for an exemption of the... the line as standard equipment is likely to be as effective in reducing and deterring motor...

  11. Assessment of Preschoolers' Gross Motor Proficiency: Revisiting Bruininks-Oseretsky Test of Motor Proficiency

    ERIC Educational Resources Information Center

    Lam, Hazel Mei Yung

    2011-01-01

    Literature reveals that there are very few validated motor proficiency tests for young children. According to Gallahue and Ozmun, the Bruininks-Oseretsky Test of Motor Proficiency is a valid test. However, manipulative skills, which are classified as gross motor skills by most motor development specialists, are only tested in the Upper Limb…

  12. 78 FR 66801 - Motor Carrier Safety Advisory Committee; Charter Renewal

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

    ... Federal Motor Carrier Safety Administration Motor Carrier Safety Advisory Committee; Charter Renewal AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Announcement of advisory... Committee that provides the Agency with advice and recommendations on motor carrier safety programs...

  13. Agricultural Electricity. Electric Motors. Student Manual.

    ERIC Educational Resources Information Center

    Benson, Robert T.

    Addressed to the student, this manual, which includes supplementary diagrams, discusses the following topics and principles: Electromagnetic fields, electromagnets, parts of an electric motor, determining speed of an electric motor, types of electric motors in common use (split-phase, capacitor, repulsion-induction, three-phase), the electric…

  14. Motor Programming in Apraxia of Speech

    ERIC Educational Resources Information Center

    Maas, Edwin; Robin, Donald A.; Wright, David L.; Ballard, Kirrie J.

    2008-01-01

    Apraxia of Speech (AOS) is an impairment of motor programming. However, the exact nature of this deficit remains unclear. The present study examined motor programming in AOS in the context of a recent two-stage model [Klapp, S. T. (1995). Motor response programming during simple and choice reaction time: The role of practice. "Journal of…

  15. Motor Development: Manual of Alternative Procedures.

    ERIC Educational Resources Information Center

    McCormack, James E.

    The manual of alternative procedures for teaching handicapped children focuses on programming, planning, and implementing training in the gross motor (posture, limb control, locomotion) and fine motor (facial, digital) skills. The manual consists of the following sections: specific teaching tactics commonly used in motor training stiuations…

  16. The Diagnosis of Sensory-Motor Disabilities.

    ERIC Educational Resources Information Center

    Zaeske, Arnold

    The importance of motor and perceptual learning in the educational process is discussed. It is hypothesized that an internalization of sensory-motor learnings is important to the perceptual and cognitive development of a child. Developmental and corrective motor training by physical educationalists is suggested. It is concluded that although the…

  17. Dynamic instability of collective myosin II motors

    NASA Astrophysics Data System (ADS)

    Li, Jin-Fang; Wang, Zi-Qing; Li, Qi-Kun; Xing, Jian-Jun; Wang, Guo-Dong

    2016-11-01

    Some kinds of muscles can oscillate spontaneously, which is related to the dynamic instability of the collective motors. Based on the two-state ratchet model and with consideration of the motor stiffness, the dynamics of collective myosin II motors are studied. It is shown that when the motor stiffness is small, the velocity of the collective motors decreases monotonically with load increasing. When the motor stiffness becomes large, dynamic instability appears in the force-velocity relationship of the collective-motor transport. For a large enough motor stiffness, the zero-velocity point lies in the unstable range of the force-velocity curve, and the motor system becomes unstable before the motion is stopped, so spontaneous oscillations can be generated if the system is elastically coupled to its environment via a spring. The oscillation frequency is related to the motor stiffness, motor binding rate, spring stiffness, and the width of the ATP excitation interval. For a medium motor stiffness, the zero-velocity point lies outside the unstable range of the force-velocity curve, and the motion will be stopped before the instability occurs. Project supported by the National Natural Science Foundation of China (Grant No. 11205123).

  18. Neuropsychological Investigation of Motor Impairments in Autism

    PubMed Central

    Duffield, Tyler; Trontel, Haley; Bigler, Erin D.; Froehlich, Alyson; Prigge, Molly B.; Travers, Brittany; Green, Ryan R.; Cariello, Annahir N.; Cooperrider, Jason; Nielsen, Jared; Alexander, Andrew; Anderson, Jeffrey; Fletcher, P. Thomas; Lange, Nicholas; Zielinski, Brandon; Lainhart, Janet

    2013-01-01

    It is unclear how standardized neuropsychological measures of motor function relate to brain volumes of motor regions in autism spectrum disorder (ASD). An all male sample composed of 59 ASD and 30 controls (ages 5–33 years) completed three measures of motor function: strength of grip (SOG), finger tapping test (FTT), and grooved peg-board test (GPT). Likewise, all participants underwent magnetic resonance imaging with region of interest (ROI) volumes obtained to include the following regions: motor cortex (pre-central gyrus), somatosensory cortex (post-central gyrus), thalamus, basal ganglia, cerebellum and caudal middle frontal gyrus. These traditional neuropsychological measures of motor function are assumed to differ in motor complexity with GPT requiring the most followed by FTT and SOG. Performance by ASD participants on the GPT and FTT differed significantly from controls, with the largest effect size differences observed on the more complex GPT task. Differences on the SOG task between the two groups were non-significant. Since more complex motor tasks tap more complex networks, poorer GPT performance by those with ASD may reflect less efficient motor networks. There was no gross pathology observed in classic motor areas of the brain in ASD, as region of interest (ROI) volumes did not differ, but FTT was negatively related to motor cortex volume in ASD. The results suggest a hierarchical motor disruption in ASD, with difficulties evident only in more complex tasks as well as a potential anomalous size-function relation in motor cortex in ASD. PMID:23985036

  19. Proceedings Region East Perceptual Motor Conference.

    ERIC Educational Resources Information Center

    American Alliance for Health, Physical Education, and Recreation, Washington, DC.

    This book of conference proceeding presents speeches and panel discussions from the Region East Perceptual-Motor Conference. The purpose of the conference was to seek an understanding of children and their perceptual-motor development through (a) exchange of knowledge and practices in perceptual-motor development, (b) examination of program…

  20. Motor Acquisition Rate in Brazilian Infants

    ERIC Educational Resources Information Center

    Lopes, Virlaine Bardella; de Lima, Carolina Daniel; Tudella, Eloisa

    2009-01-01

    This study used the Alberta Infant Motor Scale (AIMS) with the aim of characterizing motor acquisition rate in 70 healthy 0-6-month-old Brazilian infants, as well as comparing both emergence (initial age) and establishment (final age) of each skill between the study sample and the AIMS normative data. New motor skills were continuously acquired…