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Sample records for slow processive motor

  1. Human myosin VIIa is a very slow processive motor protein on various cellular actin structures.

    Science.gov (United States)

    Sato, Osamu; Komatsu, Satoshi; Sakai, Tsuyoshi; Tsukasaki, Yoshikazu; Tanaka, Ryosuke; Mizutani, Takeomi; Watanabe, Tomonobu M; Ikebe, Reiko; Ikebe, Mitsuo

    2017-06-30

    Human myosin VIIa (MYO7A) is an actin-linked motor protein associated with human Usher syndrome (USH) type 1B, which causes human congenital hearing and visual loss. Although it has been thought that the role of human myosin VIIa is critical for USH1 protein tethering with actin and transportation along actin bundles in inner-ear hair cells, myosin VIIa's motor function remains unclear. Here, we studied the motor function of the tail-truncated human myosin VIIa dimer (HM7AΔTail/LZ) at the single-molecule level. We found that the HM7AΔTail/LZ moves processively on single actin filaments with a step size of 35 nm. Dwell-time distribution analysis indicated an average waiting time of 3.4 s, yielding ∼0.3 s -1 for the mechanical turnover rate; hence, the velocity of HM7AΔTail/LZ was extremely slow, at 11 nm·s -1 We also examined HM7AΔTail/LZ movement on various actin structures in demembranated cells. HM7AΔTail/LZ showed unidirectional movement on actin structures at cell edges, such as lamellipodia and filopodia. However, HM7AΔTail/LZ frequently missed steps on actin tracks and exhibited bidirectional movement at stress fibers, which was not observed with tail-truncated myosin Va. These results suggest that the movement of the human myosin VIIa motor protein is more efficient on lamellipodial and filopodial actin tracks than on stress fibers, which are composed of actin filaments with different polarity, and that the actin structures influence the characteristics of cargo transportation by human myosin VIIa. In conclusion, myosin VIIa movement appears to be suitable for translocating USH1 proteins on stereocilia actin bundles in inner-ear hair cells. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR

    African Journals Online (AJOL)

    Dr Obe

    1984-09-01

    Sep 1, 1984 ... VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR by. L. A. Agu ... order as that of the screw-thread motor can be obtained. LIST OF .... The n stator have equal non- magnetic spacers .... induction motor. An.

  3. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes, and motor system excitability

    Directory of Open Access Journals (Sweden)

    Petra eStuder

    2014-07-01

    Full Text Available Neurofeedback (NF is being successfully applied, among others, in children with ADHD and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B, and slow cortical potential (SCP training, two protocols established in NF in ADHD. In the present randomized controlled investigation in adults without a clinical diagnosis (n = 59, the specificity of the effects of these two NF protocols on attentional processes, and motor system excitability were to be examined, focusing on the underlying neuronal mechanisms. NF training consisted of 10 double sessions, and self-regulation skills were analyzed. Pre- and post-training assessments encompassed performance and event-related potential measures during an attention task, and motor system excitability assessed by transcranial magnetic stimulation. Some NF protocol specific effects have been obtained. However, due to the limited sample size medium effects didn’t reach the level of significance. Self-regulation abilities during negativity trials of the SCP training were associated with increased contingent negative variation amplitudes, indicating improved resource allocation during cognitive preparation. Theta/beta training was associated with increased response speed and decreased target-P3 amplitudes after successful theta/beta regulation suggested reduced attentional resources necessary for stimulus evaluation. Motor system excitability effects after theta/beta training paralleled the effects of methylphenidate. Overall, our results are limited by the non-sufficiently acquired self-regulation skills, but some specific effects between good and poor learners could be described. Future studies with larger sample sizes and sufficient acquisition of self-regulation skills are needed to further evaluate the protocol specific effects on attention and motor system excitability

  4. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes, and motor system excitability

    OpenAIRE

    Petra eStuder; Oliver eKratz; Holger eGevensleben; Aribert eRothenberger; Gunther H Moll; Martin eHautzinger; Hartmut eHeinrich; Hartmut eHeinrich

    2014-01-01

    Neurofeedback (NF) is being successfully applied, among others, in children with ADHD and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B), and slow cortical potential (SCP) training, two protocols established in NF in ADHD. In the present randomized controlled investigation in adults without a clinical diagnosis (n = 59), the specificity of the effects of ...

  5. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes and motor system excitability

    OpenAIRE

    Studer, Petra; Kratz, Oliver; Gevensleben, Holger; Rothenberger, Aribert; Moll, Gunther H.; Hautzinger, Martin; Heinrich, Hartmut

    2014-01-01

    Neurofeedback (NF) is being successfully applied, among others, in children with attention deficit/hyperactivity disorder (ADHD) and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B), and slow cortical potential (SCP) training, two protocols established in NF in ADHD. In the present, randomized, controlled investigation in adults without a clinical diagnosis...

  6. Very Slow Speed Axial Motion Reluctance Motor | Agu | Nigerian ...

    African Journals Online (AJOL)

    Abstract. This paper presents the scheme for a very slow speed linear machine which uses conventional laminations and with which speeds of the same low order as that of the screw-thread motor can be obtained.

  7. Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery.

    Science.gov (United States)

    Keller, Martin; Taube, Wolfgang; Lauber, Benedikt

    2018-02-22

    Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions. The aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions. H-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest. In contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions. This study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Comparison of Theta/Beta, Slow Cortical Potential, and Adaptive Neurofeedback Training in Adults: Training Effects on Attentional Processes, Motor System, and Mood

    OpenAIRE

    Studer, Petra

    2011-01-01

    Neurofeedback (NF) training is being applied in an increasing number of clinical and peak performance fields. The aim oft he present investigation in adults was three-fold: 1) to shed further light on the neuronal mechanisms underlying different NF protocols with respect to attentional processes and motor system excitability, 2) to examine the effects of different neurofeedback protocols on well-being / mood, 3) to evaluate the effects of an adaptive type of NF training. Neurof...

  9. Unmasking the linear behaviour of slow motor adaptation to prolonged convergence.

    Science.gov (United States)

    Erkelens, Ian M; Thompson, Benjamin; Bobier, William R

    2016-06-01

    Adaptation to changing environmental demands is central to maintaining optimal motor system function. Current theories suggest that adaptation in both the skeletal-motor and oculomotor systems involves a combination of fast (reflexive) and slow (recalibration) mechanisms. Here we used the oculomotor vergence system as a model to investigate the mechanisms underlying slow motor adaptation. Unlike reaching with the upper limbs, vergence is less susceptible to changes in cognitive strategy that can affect the behaviour of motor adaptation. We tested the hypothesis that mechanisms of slow motor adaptation reflect early neural processing by assessing the linearity of adaptive responses over a large range of stimuli. Using varied disparity stimuli in conflict with accommodation, the slow adaptation of tonic vergence was found to exhibit a linear response whereby the rate (R(2)  = 0.85, P < 0.0001) and amplitude (R(2)  = 0.65, P < 0.0001) of the adaptive effects increased proportionally with stimulus amplitude. These results suggest that this slow adaptive mechanism is an early neural process, implying a fundamental physiological nature that is potentially dominated by subcortical and cerebellar substrates. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  10. Frequency response of slow beam extraction process

    International Nuclear Information System (INIS)

    Toyama, Takeshi; Sato, Hikaru; Marutsuka, Katsumi; Shirakata, Masashi.

    1994-01-01

    A servo control system has been incorporated into the practical slow extraction system in order to stabilize the spill structure less than a few kHz. Frequency responses of the components of the servo-spill control system and the open-loop frequency response were measured. The beam transfer function of the slow extraction process was derived from the measured data and approximated using a simple function. This is utilized to improve the performance of the servo-loop. (author)

  11. Early Boost and Slow Consolidation in Motor Skill Learning

    Science.gov (United States)

    Hotermans, Christophe; Peigneux, Philippe; de Noordhout, Alain Maertens; Moonen, Gustave; Maquet, Pierre

    2006-01-01

    Motor skill learning is a dynamic process that continues covertly after training has ended and eventually leads to delayed increments in performance. Current theories suggest that this off-line improvement takes time and appears only after several hours. Here we show an early transient and short-lived boost in performance, emerging as early as…

  12. Concurrent TMS to the primary motor cortex augments slow motor learning

    Science.gov (United States)

    Narayana, Shalini; Zhang, Wei; Rogers, William; Strickland, Casey; Franklin, Crystal; Lancaster, Jack L.; Fox, Peter T.

    2013-01-01

    Transcranial magnetic stimulation (TMS) has shown promise as a treatment tool, with one FDA approved use. While TMS alone is able to up- (or down-) regulate a targeted neural system, we argue that TMS applied as an adjuvant is more effective for repetitive physical, behavioral and cognitive therapies, that is, therapies which are designed to alter the network properties of neural systems through Hebbian learning. We tested this hypothesis in the context of a slow motor learning paradigm. Healthy right-handed individuals were assigned to receive 5 Hz TMS (TMS group) or sham TMS (sham group) to the right primary motor cortex (M1) as they performed daily motor practice of a digit sequence task with their non-dominant hand for 4 weeks. Resting cerebral blood flow (CBF) was measured by H215O PET at baseline and after 4 weeks of practice. Sequence performance was measured daily as the number of correct sequences performed, and modeled using a hyperbolic function. Sequence performance increased significantly at 4 weeks relative to baseline in both groups. The TMS group had a significant additional improvement in performance, specifically, in the rate of skill acquisition. In both groups, an improvement in sequence timing and transfer of skills to non-trained motor domains was also found. Compared to the sham group, the TMS group demonstrated increases in resting CBF specifically in regions known to mediate skill learning namely, the M1, cingulate cortex, putamen, hippocampus, and cerebellum. These results indicate that TMS applied concomitantly augments behavioral effects of motor practice, with corresponding neural plasticity in motor sequence learning network. These findings are the first demonstration of the behavioral and neural enhancing effects of TMS on slow motor practice and have direct application in neurorehabilitation where TMS could be applied in conjunction with physical therapy. PMID:23867557

  13. Markov process of muscle motors

    International Nuclear Information System (INIS)

    Kondratiev, Yu; Pechersky, E; Pirogov, S

    2008-01-01

    We study a Markov random process describing muscle molecular motor behaviour. Every motor is either bound up with a thin filament or unbound. In the bound state the motor creates a force proportional to its displacement from the neutral position. In both states the motor spends an exponential time depending on the state. The thin filament moves at a velocity proportional to the average of all displacements of all motors. We assume that the time which a motor stays in the bound state does not depend on its displacement. Then one can find an exact solution of a nonlinear equation appearing in the limit of an infinite number of motors

  14. Explicit and Implicit Processes Constitute the Fast and Slow Processes of Sensorimotor Learning.

    Science.gov (United States)

    McDougle, Samuel D; Bond, Krista M; Taylor, Jordan A

    2015-07-01

    A popular model of human sensorimotor learning suggests that a fast process and a slow process work in parallel to produce the canonical learning curve (Smith et al., 2006). Recent evidence supports the subdivision of sensorimotor learning into explicit and implicit processes that simultaneously subserve task performance (Taylor et al., 2014). We set out to test whether these two accounts of learning processes are homologous. Using a recently developed method to assay explicit and implicit learning directly in a sensorimotor task, along with a computational modeling analysis, we show that the fast process closely resembles explicit learning and the slow process approximates implicit learning. In addition, we provide evidence for a subdivision of the slow/implicit process into distinct manifestations of motor memory. We conclude that the two-state model of motor learning is a close approximation of sensorimotor learning, but it is unable to describe adequately the various implicit learning operations that forge the learning curve. Our results suggest that a wider net be cast in the search for the putative psychological mechanisms and neural substrates underlying the multiplicity of processes involved in motor learning. Copyright © 2015 the authors 0270-6474/15/359568-12$15.00/0.

  15. Age-related dedifferentiation of cognitive and motor slowing: Insight from the comparison of Hick-Hyman and Fitts’ laws

    Directory of Open Access Journals (Sweden)

    Rita eSleimen-Malkoun

    2013-10-01

    Full Text Available The present study aimed to determine whether the general slowing hypothesis could be extended to the motor domain by comparing cognitive and motor age-related slowing. To achieve this objective, we compared the slopes of Hick-Hyman’s law and Fitts’ law, in young and older adults. The general hypothesis was that, due to the dedifferentiation of cognitive and motor neural resources during aging, the slopes of Hick-Hyman's law and Fitts’ law should become closer, if not similar, in older adults. Ten young adults (mean age = 26 ± 3 years and fourteen older adults (mean age = 78 ± 7 years participated in the experiment. They had to perform a discrete rapid-aiming task and a reaction time task. In the aiming task, five ID levels were used (from 3 to 7 bits by increments of 1.0 bit. Task difficulty was scaled via the manipulation of target distance from home position. In the reaction time task, 5 IDs were selected: 0, 1, 2, 3 and 4 bits, with incompatible S-R associations. Reaction time and movement times were recorded. Efficiency and Brinley regression functions were calculated. Age-related slowing ratios were estimated. Response times increased in both tasks in older adults. The slopes of Hick-Hyman’s law and Fitts’ law were steeper in older adults than in young participants. In young participants, the slope of Hick-Hyman’s law was smaller than that of Fitts’ law. In older adults, no difference was found. Slowing ratios observed in both tasks were equivalent. The present results extended the general slowing hypothesis to the motor domain. They suggested that, due to dedifferentiation of cognitive and motor neural resources, decrease in processing speed acts as a common cause to behavioral slowing in both cognitive and motor tasks.

  16. Behaviour of motor units of human arm muscles: differences between slow isometric contraction and relaxation

    NARCIS (Netherlands)

    Denier van der Gon, J.J.; Haar Romenij, ter B.M.; Zuylen, Van E.J.

    1985-01-01

    The behaviour of motor units in the m. biceps brachii (long head), in the m. brachialis and in the m. supinator during slow isometric contraction and relaxation was studied when subjects were performing different motor tasks. These tasks were: flexion of the elbow joint, supination of the forearm

  17. Cued memory reactivation during slow-wave sleep promotes explicit knowledge of a motor sequence.

    Science.gov (United States)

    Cousins, James N; El-Deredy, Wael; Parkes, Laura M; Hennies, Nora; Lewis, Penelope A

    2014-11-26

    Memories are gradually consolidated after initial encoding, and this can sometimes lead to a transition from implicit to explicit knowledge. The exact physiological processes underlying this reorganization remain unclear. Here, we used a serial reaction time task to determine whether targeted memory reactivation (TMR) of specific memory traces during slow-wave sleep promotes the emergence of explicit knowledge. Human participants learned two 12-item sequences of button presses (A and B). These differed in both cue order and in the auditory tones associated with each of the four fingers (one sequence had four higher-pitched tones). Subsequent overnight sleep was monitored, and the tones associated with one learned sequence were replayed during slow-wave sleep. After waking, participants demonstrated greater explicit knowledge (p = 0.005) and more improved procedural skill (p = 0.04) for the cued sequence relative to the uncued sequence. Furthermore, fast spindles (13.5-15 Hz) at task-related motor regions predicted overnight enhancement in procedural skill (r = 0.71, p = 0.01). Auditory cues had no effect on post-sleep memory performance in a control group who received TMR before sleep. These findings suggest that TMR during sleep can alter memory representations and promote the emergence of explicit knowledge, supporting the notion that reactivation during sleep is a key mechanism in this process. Copyright © 2014 Cousins et al.

  18. Fast and slow spindles during the sleep slow oscillation: disparate coalescence and engagement in memory processing.

    Science.gov (United States)

    Mölle, Matthias; Bergmann, Til O; Marshall, Lisa; Born, Jan

    2011-10-01

    Thalamo-cortical spindles driven by the up-state of neocortical slow (memory consolidation during sleep. We examined interactions between SOs and spindles in human slow wave sleep, focusing on the presumed existence of 2 kinds of spindles, i.e., slow frontocortical and fast centro-parietal spindles. Two experiments were performed in healthy humans (24.5 ± 0.9 y) investigating undisturbed sleep (Experiment I) and the effects of prior learning (word paired associates) vs. non-learning (Experiment II) on multichannel EEG recordings during sleep. Only fast spindles (12-15 Hz) were synchronized to the depolarizing SO up-state. Slow spindles (9-12 Hz) occurred preferentially at the transition into the SO down-state, i.e., during waning depolarization. Slow spindles also revealed a higher probability to follow rather than precede fast spindles. For sequences of individual SOs, fast spindle activity was largest for "initial" SOs, whereas SO amplitude and slow spindle activity were largest for succeeding SOs. Prior learning enhanced this pattern. The finding that fast and slow spindles occur at different times of the SO cycle points to disparate generating mechanisms for the 2 kinds of spindles. The reported temporal relationships during SO sequences suggest that fast spindles, driven by the SO up-state feed back to enhance the likelihood of succeeding SOs together with slow spindles. By enforcing such SO-spindle cycles, particularly after prior learning, fast spindles possibly play a key role in sleep-dependent memory processing.

  19. Early boost and slow consolidation in motor skill learning.

    Science.gov (United States)

    Hotermans, Christophe; Peigneux, Philippe; Maertens de Noordhout, Alain; Moonen, Gustave; Maquet, Pierre

    2006-01-01

    Motorskill learning is a dynamic process that continues covertly after training has ended and eventually leads to delayed increments in performance. Current theories suggest that this off-line improvement takes time and appears only after several hours. Here we show an early transient and short-lived boost in performance, emerging as early as 5-30 min after training but no longer observed 4 h later. This early boost is predictive of the performance achieved 48 h later, suggesting its functional relevance for memory processes.

  20. Motor conduction velocity in the human spinal cord: slowed conduction in multiple sclerosis and radiation myelopathy

    International Nuclear Information System (INIS)

    Snooks, S.J.; Swash, M.

    1985-01-01

    Transcutaneous electrical stimulation of the central nervous system was used to measure motor conduction velocity in the human spinal cord in 21 subjects aged 22 to 75 years (mean 55 years), none of whom had neurological disease. The motor conduction velocity between the sixth cervical (C6) and first lumbar (L1) vertebral levels was 67.4+-9.1 m/s. This probably represents conduction velocity in the corticospinal tracts. In these subjects the motor conduction velocity in the cauda equina, between the first lumbar (L1) and fourth lumbar (L4) vertebral levels, was 57.9+-10.3 m/s. In four of five patients with multiple sclerosis, all with corticospinal signs in the legs, motor conduction velocity between C6 and L1 was slowed (41.8+-16.8 m/s), but cauda equina conduction was normal (55.8+-7.8 m/s). Similar slowing of spinal cord motor conduction was found in a patient with radiation myelopathy. This method should provide a relevant, simple clinical test in patients with spinal cord disease. (author)

  1. Acute changes in motor cortical excitability during slow oscillatory and constant anodal transcranial direct current stimulation

    DEFF Research Database (Denmark)

    Bergmann, Til Ole; Groppa, Sergiu; Seeger, Markus

    2009-01-01

    Transcranial oscillatory current stimulation has recently emerged as a noninvasive technique that can interact with ongoing endogenous rhythms of the human brain. Yet, there is still little knowledge on how time-varied exogenous currents acutely modulate cortical excitability. In ten healthy...... individuals we used on-line single-pulse transcranial magnetic stimulation (TMS) to search for systematic shifts in corticospinal excitability during anodal sleeplike 0.8-Hz slow oscillatory transcranial direct current stimulation (so-tDCS). In separate sessions, we repeatedly applied 30-s trials (two blocks...... at 20 min) of either anodal so-tDCS or constant tDCS (c-tDCS) to the primary motor hand area during quiet wakefulness. Simultaneously and time-locked to different phase angles of the slow oscillation, motor-evoked potentials (MEPs) as an index of corticospinal excitability were obtained...

  2. Serum metabolomics of slow vs. rapid motor progression Parkinson's disease: a pilot study.

    Directory of Open Access Journals (Sweden)

    James R Roede

    Full Text Available Progression of Parkinson's disease (PD is highly variable, indicating that differences between slow and rapid progression forms could provide valuable information for improved early detection and management. Unfortunately, this represents a complex problem due to the heterogeneous nature of humans in regards to demographic characteristics, genetics, diet, environmental exposures and health behaviors. In this pilot study, we employed high resolution mass spectrometry-based metabolic profiling to investigate the metabolic signatures of slow versus rapidly progressing PD present in human serum. Archival serum samples from PD patients obtained within 3 years of disease onset were analyzed via dual chromatography-high resolution mass spectrometry, with data extraction by xMSanalyzer and used to predict rapid or slow motor progression of these patients during follow-up. Statistical analyses, such as false discovery rate analysis and partial least squares discriminant analysis, yielded a list of statistically significant metabolic features and further investigation revealed potential biomarkers. In particular, N8-acetyl spermidine was found to be significantly elevated in the rapid progressors compared to both control subjects and slow progressors. Our exploratory data indicate that a fast motor progression disease phenotype can be distinguished early in disease using high resolution mass spectrometry-based metabolic profiling and that altered polyamine metabolism may be a predictive marker of rapidly progressing PD.

  3. Serum metabolomics of slow vs. rapid motor progression Parkinson's disease: a pilot study.

    Science.gov (United States)

    Roede, James R; Uppal, Karan; Park, Youngja; Lee, Kichun; Tran, Vilinh; Walker, Douglas; Strobel, Frederick H; Rhodes, Shannon L; Ritz, Beate; Jones, Dean P

    2013-01-01

    Progression of Parkinson's disease (PD) is highly variable, indicating that differences between slow and rapid progression forms could provide valuable information for improved early detection and management. Unfortunately, this represents a complex problem due to the heterogeneous nature of humans in regards to demographic characteristics, genetics, diet, environmental exposures and health behaviors. In this pilot study, we employed high resolution mass spectrometry-based metabolic profiling to investigate the metabolic signatures of slow versus rapidly progressing PD present in human serum. Archival serum samples from PD patients obtained within 3 years of disease onset were analyzed via dual chromatography-high resolution mass spectrometry, with data extraction by xMSanalyzer and used to predict rapid or slow motor progression of these patients during follow-up. Statistical analyses, such as false discovery rate analysis and partial least squares discriminant analysis, yielded a list of statistically significant metabolic features and further investigation revealed potential biomarkers. In particular, N8-acetyl spermidine was found to be significantly elevated in the rapid progressors compared to both control subjects and slow progressors. Our exploratory data indicate that a fast motor progression disease phenotype can be distinguished early in disease using high resolution mass spectrometry-based metabolic profiling and that altered polyamine metabolism may be a predictive marker of rapidly progressing PD.

  4. Slow Muscle Precursors Lay Down a Collagen XV Matrix Fingerprint to Guide Motor Axon Navigation.

    Science.gov (United States)

    Guillon, Emilie; Bretaud, Sandrine; Ruggiero, Florence

    2016-03-02

    The extracellular matrix (ECM) provides local positional information to guide motoneuron axons toward their muscle target. Collagen XV is a basement membrane component mainly expressed in skeletal muscle. We have identified two zebrafish paralogs of the human COL15A1 gene, col15a1a and col15a1b, which display distinct expression patterns. Here we show that col15a1b is expressed and deposited in the motor path ECM by slow muscle precursors also called adaxial cells. We further demonstrate that collagen XV-B deposition is both temporally and spatially regulated before motor axon extension from the spinal cord in such a way that it remains in this region after the adaxial cells have migrated toward the periphery of the myotome. Loss- and gain-of-function experiments in zebrafish embryos demonstrate that col15a1b expression and subsequent collagen XV-B deposition and organization in the motor path ECM depend on a previously undescribed two-step mechanism involving Hedgehog/Gli and unplugged/MuSK signaling pathways. In silico analysis predicts a putative Gli binding site in the col15a1b proximal promoter. Using col15a1b promoter-reporter constructs, we demonstrate that col15a1b participates in the slow muscle genetic program as a direct target of Hedgehog/Gli signaling. Loss and gain of col15a1b function provoke pathfinding errors in primary and secondary motoneuron axons both at and beyond the choice point where axon pathway selection takes place. These defects result in muscle atrophy and compromised swimming behavior, a phenotype partially rescued by injection of a smyhc1:col15a1b construct. These reveal an unexpected and novel role for collagen XV in motor axon pathfinding and neuromuscular development. In addition to the archetypal axon guidance cues, the extracellular matrix provides local information that guides motor axons from the spinal cord to their muscle targets. Many of the proteins involved are unknown. Using the zebrafish model, we identified an

  5. Fast But Fleeting: Adaptive Motor Learning Processes Associated with Aging and Cognitive Decline

    Science.gov (United States)

    Trewartha, Kevin M.; Garcia, Angeles; Wolpert, Daniel M.

    2014-01-01

    Motor learning has been shown to depend on multiple interacting learning processes. For example, learning to adapt when moving grasped objects with novel dynamics involves a fast process that adapts and decays quickly—and that has been linked to explicit memory—and a slower process that adapts and decays more gradually. Each process is characterized by a learning rate that controls how strongly motor memory is updated based on experienced errors and a retention factor determining the movement-to-movement decay in motor memory. Here we examined whether fast and slow motor learning processes involved in learning novel dynamics differ between younger and older adults. In addition, we investigated how age-related decline in explicit memory performance influences learning and retention parameters. Although the groups adapted equally well, they did so with markedly different underlying processes. Whereas the groups had similar fast processes, they had different slow processes. Specifically, the older adults exhibited decreased retention in their slow process compared with younger adults. Within the older group, who exhibited considerable variation in explicit memory performance, we found that poor explicit memory was associated with reduced retention in the fast process, as well as the slow process. These findings suggest that explicit memory resources are a determining factor in impairments in the both the fast and slow processes for motor learning but that aging effects on the slow process are independent of explicit memory declines. PMID:25274819

  6. Fast but fleeting: adaptive motor learning processes associated with aging and cognitive decline.

    Science.gov (United States)

    Trewartha, Kevin M; Garcia, Angeles; Wolpert, Daniel M; Flanagan, J Randall

    2014-10-01

    Motor learning has been shown to depend on multiple interacting learning processes. For example, learning to adapt when moving grasped objects with novel dynamics involves a fast process that adapts and decays quickly-and that has been linked to explicit memory-and a slower process that adapts and decays more gradually. Each process is characterized by a learning rate that controls how strongly motor memory is updated based on experienced errors and a retention factor determining the movement-to-movement decay in motor memory. Here we examined whether fast and slow motor learning processes involved in learning novel dynamics differ between younger and older adults. In addition, we investigated how age-related decline in explicit memory performance influences learning and retention parameters. Although the groups adapted equally well, they did so with markedly different underlying processes. Whereas the groups had similar fast processes, they had different slow processes. Specifically, the older adults exhibited decreased retention in their slow process compared with younger adults. Within the older group, who exhibited considerable variation in explicit memory performance, we found that poor explicit memory was associated with reduced retention in the fast process, as well as the slow process. These findings suggest that explicit memory resources are a determining factor in impairments in the both the fast and slow processes for motor learning but that aging effects on the slow process are independent of explicit memory declines. Copyright © 2014 the authors 0270-6474/14/3413411-11$15.00/0.

  7. Delineating psychomotor slowing from reduced processing speed in schizophrenia

    NARCIS (Netherlands)

    Morrens, M.; Hulstijn, W.; Matton, C.; Madani, Y.; Bouwel, L. van; Peuskens, J.; Sabbe, B.G.C.

    2008-01-01

    Introduction. Psychomotor slowing is an intrinsic feature of schizophrenia that is poorly delineated from generally reduced processing speed. Although the Symbol Digit Substitution Test (SDST) is widely used to assess psychomotor speed, the task also taps several higher-order cognitive processes.

  8. Study of Dynamic Characteristics of Slow-Changing Process

    Directory of Open Access Journals (Sweden)

    Yinong Li

    2000-01-01

    Full Text Available A vibration system with slow-changing parameters is a typical nonlinear system. Such systems often occur in the working and controlled process of some intelligent structures when vibration and deformation exist synchronously. In this paper, a system with slow-changing stiffness, damping and mass is analyzed in an intelligent structure. The relationship between the amplitude and the frequency of the system is studied, and its dynamic characteristic is also discussed. Finally, a piecewise linear method is developed on the basis of the asymptotic method. The simulation and the experiment show that a suitable slow-changing stiffness can restrain the amplitude of the system when the system passes through the resonant region.

  9. Voltage-Gated Potassium Channel Antibodies in Slow-Progression Motor Neuron Disease.

    Science.gov (United States)

    Godani, Massimiliano; Zoccarato, Marco; Beronio, Alessandro; Zuliani, Luigi; Benedetti, Luana; Giometto, Bruno; Del Sette, Massimo; Raggio, Elisa; Baldi, Roberta; Vincent, Angela

    2017-01-01

    The spectrum of autoimmune neurological diseases associated with voltage-gated potassium channel (VGKC)-complex antibodies (Abs) ranges from peripheral nerve disorders to limbic encephalitis. Recently, low titers of VGKC-complex Abs have also been reported in neurodegenerative disorders, but their clinical relevance is unknown. The aim of the study was to explore the prevalence of VGKC-complex Abs in slow-progression motor neuron disease (MND). We compared 11 patients affected by slow-progression MND with 9 patients presenting typical progression illness. Sera were tested for VGKC-complex Abs by radioimmunoassay. The distribution of VGKC-complex Abs was analyzed with the Mann-Whitney U test. The statistical analysis showed a significant difference between the mean values in the study and control groups. A case with long-survival MND harboring VGKC-complex Abs and treated with intravenous immunoglobulins is described. Although VGKC-complex Abs are not likely to be pathogenic, these results could reflect the coexistence of an immunological activation in patients with slow disease progression. © 2016 S. Karger AG, Basel.

  10. Slow-oscillatory transcranial direct current stimulation can induce bidirectional shifts in motor cortical excitability in awake humans

    DEFF Research Database (Denmark)

    Groppa, S; Bergmann, T O; Siems, C

    2010-01-01

    Constant transcranial direct stimulation (c-tDCS) of the primary motor hand area (M1(HAND)) can induce bidirectional shifts in motor cortical excitability depending on the polarity of tDCS. Recently, anodal slow oscillation stimulation at a frequency of 0.75 Hz has been shown to augment intrinsic...... slow oscillations during sleep and theta oscillations during wakefulness. To embed this new type of stimulation into the existing tDCS literature, we aimed to characterize the after effects of slowly oscillating stimulation (so-tDCS) on M1(HAND) excitability and to compare them to those of c-tDCS. Here...

  11. Reappraisal of VAChT-Cre: Preference in slow motor neurons innervating type I or IIa muscle fibers.

    Science.gov (United States)

    Misawa, Hidemi; Inomata, Daijiro; Kikuchi, Miseri; Maruyama, Sae; Moriwaki, Yasuhiro; Okuda, Takashi; Nukina, Nobuyuki; Yamanaka, Tomoyuki

    2016-11-01

    VAChT-Cre.Fast and VAChT-Cre.Slow mice selectively express Cre recombinase in approximately one half of postnatal somatic motor neurons. The mouse lines have been used in various studies with selective genetic modifications in adult motor neurons. In the present study, we crossed VAChT-Cre lines with a reporter line, CAG-Syp/tdTomato, in which synaptophysin-tdTomato fusion proteins are efficiently sorted to axon terminals, making it possible to label both cell bodies and axon terminals of motor neurons. In the mice, Syp/tdTomato fluorescence preferentially co-localized with osteopontin, a recently discovered motor neuron marker for slow-twitch fatigue-resistant (S) and fast-twitch fatigue-resistant (FR) types. The fluorescence did not preferentially co-localize with matrix metalloproteinase-9, a marker for fast-twitch fatigable (FF) motor neurons. In the neuromuscular junctions, Syp/tdTomato fluorescence was detected mainly in motor nerve terminals that innervate type I or IIa muscle fibers. These results suggest that the VAChT-Cre lines are Cre-drivers that have selectivity in S and FR motor neurons. In order to avoid confusion, we have changed the mouse line names from VAChT-Cre.Fast and VAChT-Cre.Slow to VAChT-Cre.Early and VAChT-Cre.Late, respectively. The mouse lines will be useful tools to study slow-type motor neurons, in relation to physiology and pathology. © 2016 Wiley Periodicals, Inc.

  12. Sentence processing: linking language to motor chains

    Directory of Open Access Journals (Sweden)

    Fabian Chersi

    2010-05-01

    Full Text Available A growing body of evidence in cognitive science and neuroscience is pointing towards the existence of a deep interconnection between cognition, perception and action. According to this embodied perspective language understanding is based on a mental simulation process involving a sensory-motor matching system known as the mirror neuron system. However, the precise dynamics underling the relation between language and action are not yet well understood. In fact, experimental studies are not always coherent as some report that language processing interferes with action execution while others find facilitation. In this work we present a detailed neural network model capable of reproducing experimentally observed influences of the processing of action-related sentences on the execution of motor sequences. The proposed model is based on three main points. The first is that the processing of action-related sentences causes the resonance of motor and mirror neurons encoding the corresponding actions. The second is that there exists a varying degree of crosstalk between neuronal populations depending on whether they encode the same motor act, the same effector or the same action-goal. The third is the fact that neuronal populations’ internal dynamics, which results from the combination of multiple processes taking place at different time scales, can facilitate or interfere with successive activations of the same or of partially overlapping pools.

  13. Proprioceptive deafferentation slows down the processing of visual hand feedback

    DEFF Research Database (Denmark)

    Balslev, Daniela; Miall, R Chris; Cole, Jonathan

    2007-01-01

    During visually guided movements both vision and proprioception inform the brain about the position of the hand, so interaction between these two modalities is presumed. Current theories suggest that this interaction occurs by sensory information from both sources being fused into a more reliable...... proprioception facilitates the processing of visual information during motor control. Subjects used a computer mouse to move a cursor to a screen target. In 28% of the trials, pseudorandomly, the cursor was rotated or the target jumped. Reaction time for the trajectory correction in response to this perturbation......, multimodal, percept of hand location. In the literature on perception, however, there is evidence that different sensory modalities interact in the allocation of attention, so that a stimulus in one modality facilitates the processing of a stimulus in a different modality. We investigated whether...

  14. Distinguishing Fast and Slow Processes in Accuracy - Response Time Data.

    Directory of Open Access Journals (Sweden)

    Frederik Coomans

    Full Text Available We investigate the relation between speed and accuracy within problem solving in its simplest non-trivial form. We consider tests with only two items and code the item responses in two binary variables: one indicating the response accuracy, and one indicating the response speed. Despite being a very basic setup, it enables us to study item pairs stemming from a broad range of domains such as basic arithmetic, first language learning, intelligence-related problems, and chess, with large numbers of observations for every pair of problems under consideration. We carry out a survey over a large number of such item pairs and compare three types of psychometric accuracy-response time models present in the literature: two 'one-process' models, the first of which models accuracy and response time as conditionally independent and the second of which models accuracy and response time as conditionally dependent, and a 'two-process' model which models accuracy contingent on response time. We find that the data clearly violates the restrictions imposed by both one-process models and requires additional complexity which is parsimoniously provided by the two-process model. We supplement our survey with an analysis of the erroneous responses for an example item pair and demonstrate that there are very significant differences between the types of errors in fast and slow responses.

  15. 10 CFR 431.383 - Enforcement process for electric motors.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Enforcement process for electric motors. 431.383 Section... COMMERCIAL AND INDUSTRIAL EQUIPMENT Enforcement § 431.383 Enforcement process for electric motors. (a) Test... motor sold by a particular manufacturer or private labeler, which indicates that the electric motor may...

  16. The space charge effects on the slow extraction process

    International Nuclear Information System (INIS)

    Ohmori, Chihiro.

    1992-06-01

    The calculation of the slow extraction which includes the space charge effects has been performed for the Compressor/Stretcher Ring (CSR) of the proposed Japanese Hadron Project. We have investigated the slow extraction of 1 GeV proton beam with an average current of 100μA. Calculation shows not only the emittance growth of the extracted beam but also decrease of the extraction efficiency and discontinuity of beam spill. (author)

  17. Processing of metaphors in transcortical motor aphasia

    Directory of Open Access Journals (Sweden)

    Renata Mancopes

    Full Text Available Abstract Great emphasis has been placed on the right hemisphere, due to its possible selective contribution, in the processing of metaphorical statements. Objectives: To describe the processing of metaphors in the case of a patient with transcortical motor aphasia, using specific tests for patients with encephalic injuries of the right hemisphere, and to contribute to the discussion on the inter-hemispheric relationships associated with this function. Methods: A 54 year-old man with transcortical motor aphasia was evaluated three years after a left hemisphere stroke. The tasks of comprehension of metaphors were based on the subtest Metaphor Comprehension Task of the Montreal Evaluation of Communications Scale (MEC. Two metaphor comprehension tests were applied, in 45-minute sessions with a 48 hour interval between each. Test 1 involved comprehension of the metaphors according to the options offered, and Test 2 the comprehension of metaphors measured by response time and visual field. Results: Although the right hemisphere was not affected by the stroke in this case, difficulties were observed in the processing of metaphors. Conclusions: This study suggests that the left hemisphere participates in the processing of figurative meanings. The adaptability of the brain can also re-accommodate the uninjured areas of the brain, causing the dynamic of the brain to be modified. As a result, deducing cerebral functions based on clinical data can be problematic. The value of this study is that it can contribute to clinical aspects of language rehabilitation.

  18. Optical signal processing using slow and fast light technologies

    DEFF Research Database (Denmark)

    Capmany, J.; Sales, Salvador; Xue, Weiqi

    2009-01-01

    We review the theory of slow and fat light effects due to coherent population oscillations in semiconductor waveguides, which can be potentially applied in microwave photonic systems as a RF phase shifters. In order to satisfy the application requirement of 360 degrees RF phase shift at different...

  19. Protein Synthesis Inhibition in the Peri-Infarct Cortex Slows Motor Recovery in Rats.

    OpenAIRE

    Schubring-Giese Maximilian; Leemburg Susan; Luft Andreas Rüdiger; Hosp Jonas Aurel

    2016-01-01

    Neuroplasticity and reorganization of brain motor networks are thought to enable recovery of motor function after ischemic stroke. Especially in the cortex surrounding the ischemic scar (i.e., peri-infarct cortex), evidence for lasting reorganization has been found at the level of neurons and networks. This reorganization depends on expression of specific genes and subsequent protein synthesis. To test the functional relevance of the peri-infarct cortex for recovery we assessed the effect of ...

  20. Protein Synthesis Inhibition in the Peri-Infarct Cortex Slows Motor Recovery in Rats.

    Science.gov (United States)

    Schubring-Giese, Maximilian; Leemburg, Susan; Luft, Andreas Rüdiger; Hosp, Jonas Aurel

    2016-01-01

    Neuroplasticity and reorganization of brain motor networks are thought to enable recovery of motor function after ischemic stroke. Especially in the cortex surrounding the ischemic scar (i.e., peri-infarct cortex), evidence for lasting reorganization has been found at the level of neurons and networks. This reorganization depends on expression of specific genes and subsequent protein synthesis. To test the functional relevance of the peri-infarct cortex for recovery we assessed the effect of protein synthesis inhibition within this region after experimental stroke. Long-Evans rats were trained to perform a skilled-reaching task (SRT) until they reached plateau performance. A photothrombotic stroke was induced in the forelimb representation of the primary motor cortex (M1) contralateral to the trained paw. The SRT was re-trained after stroke while the protein synthesis inhibitor anisomycin (ANI) or saline were injected into the peri-infarct cortex through implanted cannulas. ANI injections reduced protein synthesis within the peri-infarct cortex by 69% and significantly impaired recovery of reaching performance through re-training. Improvement of motor performance within a single training session remained intact, while improvement between training sessions was impaired. ANI injections did not affect infarct size. Thus, protein synthesis inhibition within the peri-infarct cortex impairs recovery of motor deficits after ischemic stroke by interfering with consolidation of motor memory between training sessions but not short-term improvements within one session.

  1. Sound asleep: Processing and retention of slow oscillation phase-targeted stimuli

    NARCIS (Netherlands)

    Cox, R.; Korjoukov, I.; de Boer, M.; Talamini, L.M.

    2014-01-01

    The sleeping brain retains some residual information processing capacity. Although direct evidence is scarce, a substantial literature suggests the phase of slow oscillations during deep sleep to be an important determinant for stimulus processing. Here, we introduce an algorithm for predicting slow

  2. The effect of fast and slow motor unit activation on whole-muscle mechanical performance: the size principle may not pose a mechanical paradox.

    Science.gov (United States)

    Holt, N C; Wakeling, J M; Biewener, A A

    2014-05-22

    The output of skeletal muscle can be varied by selectively recruiting different motor units. However, our knowledge of muscle function is largely derived from muscle in which all motor units are activated. This discrepancy may limit our understanding of in vivo muscle function. Hence, this study aimed to characterize the mechanical properties of muscle with different motor unit activation. We determined the isometric properties and isotonic force-velocity relationship of rat plantaris muscles in situ with all of the muscle active, 30% of the muscle containing predominately slower motor units active or 20% of the muscle containing predominately faster motor units active. There was a significant effect of active motor unit type on isometric force rise time (p motor units were active than when either fast or slow motor units were selectively activated. We propose this is due to the greater relative effects of factors such as series compliance and muscle resistance to shortening during sub-maximal contractions. The findings presented here suggest that recruitment according to the size principle, where slow motor units are activated first and faster ones recruited as demand increases, may not pose a mechanical paradox, as has been previously suggested.

  3. Motor fatigue measurement by distance-induced slow down of walking speed in multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Rémy Phan-Ba

    Full Text Available BACKGROUND AND RATIONALE: Motor fatigue and ambulation impairment are prominent clinical features of people with multiple sclerosis (pMS. We hypothesized that a multimodal and comparative assessment of walking speed on short and long distance would allow a better delineation and quantification of gait fatigability in pMS. Our objectives were to compare 4 walking paradigms: the timed 25-foot walk (T25FW, a corrected version of the T25FW with dynamic start (T25FW(+, the timed 100-meter walk (T100MW and the timed 500-meter walk (T500MW. METHODS: Thirty controls and 81 pMS performed the 4 walking tests in a single study visit. RESULTS: The 4 walking tests were performed with a slower WS in pMS compared to controls even in subgroups with minimal disability. The finishing speed of the last 100-meter of the T500MW was the slowest measurable WS whereas the T25FW(+ provided the fastest measurable WS. The ratio between such slowest and fastest WS (Deceleration Index, DI was significantly lower only in pMS with EDSS 4.0-6.0, a pyramidal or cerebellar functional system score reaching 3 or a maximum reported walking distance ≤ 4000 m. CONCLUSION: The motor fatigue which triggers gait deceleration over a sustained effort in pMS can be measured by the WS ratio between performances on a very short distance and the finishing pace on a longer more demanding task. The absolute walking speed is abnormal early in MS whatever the distance of effort when patients are unaware of ambulation impairment. In contrast, the DI-measured ambulation fatigability appears to take place later in the disease course.

  4. Slowed EEG rhythmicity in patients with chronic pancreatitis: evidence of abnormal cerebral pain processing?

    DEFF Research Database (Denmark)

    Olesen, Søren Schou; Hansen, Tine Maria; Gravesen, Carina

    2011-01-01

    Intractable pain usually dominates the clinical presentation of chronic pancreatitis (CP). Slowing of electroencephalogram (EEG) rhythmicity has been associated with abnormal cortical pain processing in other chronic pain disorders. The aim of this study was to investigate the spectral distribution...

  5. Driving through the Great Recession: Why does motor vehicle fatality decrease when the economy slows down?

    Science.gov (United States)

    He, Monica M

    2016-04-01

    The relationship between short-term macroeconomic growth and temporary mortality increases remains strongest for motor vehicle (MV) crashes. In this paper, I investigate the mechanisms that explain falling MV fatality rates during the recent Great Recession. Using U.S. state-level panel data from 2003 to 2013, I first estimate the relationship between unemployment and MV fatality rate and then decompose it into risk and exposure factors for different types of MV crashes. Results reveal a significant 2.9 percent decrease in MV fatality rate for each percentage point increase in unemployment rate. This relationship is almost entirely explained by changes in the risk of driving rather than exposure to the amount of driving and is particularly robust for crashes involving large commercial trucks, multiple vehicles, and speeding cars. These findings provide evidence suggesting traffic patterns directly related to economic activity lead to higher risk of MV fatality rates when the economy improves. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Dynamically slow processes in supercooled water confined between hydrophobic plates

    Energy Technology Data Exchange (ETDEWEB)

    Franzese, Giancarlo [Departamento de Fisica Fundamental, Universidad de Barcelona, Diagonal 647, Barcelona 08028 (Spain); Santos, Francisco de los, E-mail: gfranzese@ub.ed, E-mail: fdlsant@ugr.e [Departamento de Electromagnetismo y Fisica de la Materia, Universidad de Granada, Fuentenueva s/n, 18071 Granada (Spain)

    2009-12-16

    We study the dynamics of water confined between hydrophobic flat surfaces at low temperature. At different pressures, we observe different behaviors that we understand in terms of the hydrogen bond dynamics. At high pressure, the formation of the open structure of the hydrogen bond network is inhibited and the surfaces can be rapidly dried (dewetted) by formation of a large cavity with decreasing temperature. At lower pressure we observe strong non-exponential behavior of the correlation function, but with no strong increase of the correlation time. This behavior can be associated, on the one hand, to the rapid ordering of the hydrogen bonds that generates heterogeneities and, on the other hand, to the lack of a single timescale as a consequence of the cooperativity in the vicinity of the liquid-liquid critical point that characterizes the phase diagram at low temperature of the water model considered here. At very low pressures, the gradual formation of the hydrogen bond network is responsible for the large increase of the correlation time and, eventually, the dynamical arrest of the system, with a strikingly different dewetting process, characterized by the formation of many small cavities.

  7. Dynamically slow processes in supercooled water confined between hydrophobic plates

    International Nuclear Information System (INIS)

    Franzese, Giancarlo; Santos, Francisco de los

    2009-01-01

    We study the dynamics of water confined between hydrophobic flat surfaces at low temperature. At different pressures, we observe different behaviors that we understand in terms of the hydrogen bond dynamics. At high pressure, the formation of the open structure of the hydrogen bond network is inhibited and the surfaces can be rapidly dried (dewetted) by formation of a large cavity with decreasing temperature. At lower pressure we observe strong non-exponential behavior of the correlation function, but with no strong increase of the correlation time. This behavior can be associated, on the one hand, to the rapid ordering of the hydrogen bonds that generates heterogeneities and, on the other hand, to the lack of a single timescale as a consequence of the cooperativity in the vicinity of the liquid-liquid critical point that characterizes the phase diagram at low temperature of the water model considered here. At very low pressures, the gradual formation of the hydrogen bond network is responsible for the large increase of the correlation time and, eventually, the dynamical arrest of the system, with a strikingly different dewetting process, characterized by the formation of many small cavities.

  8. Phase of Spontaneous Slow Oscillations during Sleep Influences Memory-Related Processing of Auditory Cues.

    Science.gov (United States)

    Batterink, Laura J; Creery, Jessica D; Paller, Ken A

    2016-01-27

    Slow oscillations during slow-wave sleep (SWS) may facilitate memory consolidation by regulating interactions between hippocampal and cortical networks. Slow oscillations appear as high-amplitude, synchronized EEG activity, corresponding to upstates of neuronal depolarization and downstates of hyperpolarization. Memory reactivations occur spontaneously during SWS, and can also be induced by presenting learning-related cues associated with a prior learning episode during sleep. This technique, targeted memory reactivation (TMR), selectively enhances memory consolidation. Given that memory reactivation is thought to occur preferentially during the slow-oscillation upstate, we hypothesized that TMR stimulation effects would depend on the phase of the slow oscillation. Participants learned arbitrary spatial locations for objects that were each paired with a characteristic sound (eg, cat-meow). Then, during SWS periods of an afternoon nap, one-half of the sounds were presented at low intensity. When object location memory was subsequently tested, recall accuracy was significantly better for those objects cued during sleep. We report here for the first time that this memory benefit was predicted by slow-wave phase at the time of stimulation. For cued objects, location memories were categorized according to amount of forgetting from pre- to post-nap. Conditions of high versus low forgetting corresponded to stimulation timing at different slow-oscillation phases, suggesting that learning-related stimuli were more likely to be processed and trigger memory reactivation when they occurred at the optimal phase of a slow oscillation. These findings provide insight into mechanisms of memory reactivation during sleep, supporting the idea that reactivation is most likely during cortical upstates. Slow-wave sleep (SWS) is characterized by synchronized neural activity alternating between active upstates and quiet downstates. The slow-oscillation upstates are thought to provide a

  9. Motor Processes in Children's Mental Rotation

    Science.gov (United States)

    Frick, Andrea; Daum, Moritz M.; Walser, Simone; Mast, Fred W.

    2009-01-01

    Previous studies with adult human participants revealed that motor activities can influence mental rotation of body parts and abstract shapes. In this study, we investigated the influence of a rotational hand movement on mental rotation performance from a developmental perspective. Children at the age of 5, 8, and 11 years and adults performed a…

  10. Altered cortical processing of motor inhibition in schizophrenia.

    Science.gov (United States)

    Lindberg, Påvel G; Térémetz, Maxime; Charron, Sylvain; Kebir, Oussama; Saby, Agathe; Bendjemaa, Narjes; Lion, Stéphanie; Crépon, Benoît; Gaillard, Raphaël; Oppenheim, Catherine; Krebs, Marie-Odile; Amado, Isabelle

    2016-12-01

    Inhibition is considered a key mechanism in schizophrenia. Short-latency intracortical inhibition (SICI) in the motor cortex is reduced in schizophrenia and is considered to reflect locally deficient γ-aminobutyric acid (GABA)-ergic modulation. However, it remains unclear how SICI is modulated during motor inhibition and how it relates to neural processing in other cortical areas. Here we studied motor inhibition Stop signal task (SST) in stabilized patients with schizophrenia (N = 28), healthy siblings (N = 21) and healthy controls (n = 31) matched in general cognitive status and educational level. Transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) were used to investigate neural correlates of motor inhibition. SST performance was similar in patients and controls. SICI was modulated by the task as expected in healthy controls and siblings but was reduced in patients with schizophrenia during inhibition despite equivalent motor inhibition performance. fMRI showed greater prefrontal and premotor activation during motor inhibition in schizophrenia. Task-related modulation of SICI was higher in subjects who showed less inhibition-related activity in pre-supplementary motor area (SMA) and cingulate motor area. An exploratory genetic analysis of selected markers of inhibition (GABRB2, GAD1, GRM1, and GRM3) did not explain task-related differences in SICI or cortical activation. In conclusion, this multimodal study provides direct evidence of a task-related deficiency in SICI modulation in schizophrenia likely reflecting deficient GABA-A related processing in motor cortex. Compensatory activation of premotor areas may explain similar motor inhibition in patients despite local deficits in intracortical processing. Task-related modulation of SICI may serve as a useful non-invasive GABAergic marker in development of therapeutic strategies in schizophrenia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Sound asleep: processing and retention of slow oscillation phase-targeted stimuli.

    Science.gov (United States)

    Cox, Roy; Korjoukov, Ilia; de Boer, Marieke; Talamini, Lucia M

    2014-01-01

    The sleeping brain retains some residual information processing capacity. Although direct evidence is scarce, a substantial literature suggests the phase of slow oscillations during deep sleep to be an important determinant for stimulus processing. Here, we introduce an algorithm for predicting slow oscillations in real-time. Using this approach to present stimuli directed at both oscillatory up and down states, we show neural stimulus processing depends importantly on the slow oscillation phase. During ensuing wakefulness, however, we did not observe differential brain or behavioral responses to these stimulus categories, suggesting no enduring memories were formed. We speculate that while simpler forms of learning may occur during sleep, neocortically based memories are not readily established during deep sleep.

  12. Sound asleep: processing and retention of slow oscillation phase-targeted stimuli.

    Directory of Open Access Journals (Sweden)

    Roy Cox

    Full Text Available The sleeping brain retains some residual information processing capacity. Although direct evidence is scarce, a substantial literature suggests the phase of slow oscillations during deep sleep to be an important determinant for stimulus processing. Here, we introduce an algorithm for predicting slow oscillations in real-time. Using this approach to present stimuli directed at both oscillatory up and down states, we show neural stimulus processing depends importantly on the slow oscillation phase. During ensuing wakefulness, however, we did not observe differential brain or behavioral responses to these stimulus categories, suggesting no enduring memories were formed. We speculate that while simpler forms of learning may occur during sleep, neocortically based memories are not readily established during deep sleep.

  13. Motor cortical processing is causally involved in object recognition.

    Science.gov (United States)

    Decloe, Rebecca; Obhi, Sukhvinder S

    2013-12-14

    Motor activity during vicarious experience of actions is a widely reported and studied phenomenon, and motor system activity also accompanies observation of graspable objects in the absence of any actions. Such motor activity is thought to reflect simulation of the observed action, or preparation to interact with the object, respectively. Here, in an initial exploratory study, we ask whether motor activity during observation of object directed actions is involved in processes related to recognition of the object after initial exposure. Single pulse Transcranial Magnetic Stimulation (TMS) was applied over the thumb representation of the motor cortex, or over the vertex, during observation of a model thumb typing on a cell-phone, and performance on a phone recognition task at the end of the trial was assessed. Disrupting motor processing over the thumb representation 100 ms after the onset of the typing video impaired the ability to recognize the phone in the recognition test, whereas there was no such effect for TMS applied over the vertex and no TMS trials. Furthermore, this effect only manifested for videos observed from the first person perspective. In an additional control condition, there was no evidence for any effects of TMS to the thumb representation or vertex when observing and recognizing non-action related shape stimuli. Overall, these data provide evidence that motor cortical processing during observation of object-directed actions from a first person perspective is causally linked to the formation of enduring representations of objects-of-action.

  14. Motor cortical processing is causally involved in object recognition

    Science.gov (United States)

    2013-01-01

    Background Motor activity during vicarious experience of actions is a widely reported and studied phenomenon, and motor system activity also accompanies observation of graspable objects in the absence of any actions. Such motor activity is thought to reflect simulation of the observed action, or preparation to interact with the object, respectively. Results Here, in an initial exploratory study, we ask whether motor activity during observation of object directed actions is involved in processes related to recognition of the object after initial exposure. Single pulse Transcranial Magnetic Stimulation (TMS) was applied over the thumb representation of the motor cortex, or over the vertex, during observation of a model thumb typing on a cell-phone, and performance on a phone recognition task at the end of the trial was assessed. Disrupting motor processing over the thumb representation 100 ms after the onset of the typing video impaired the ability to recognize the phone in the recognition test, whereas there was no such effect for TMS applied over the vertex and no TMS trials. Furthermore, this effect only manifested for videos observed from the first person perspective. In an additional control condition, there was no evidence for any effects of TMS to the thumb representation or vertex when observing and recognizing non-action related shape stimuli. Conclusion Overall, these data provide evidence that motor cortical processing during observation of object-directed actions from a first person perspective is causally linked to the formation of enduring representations of objects-of-action. PMID:24330638

  15. Processing abstract language modulates motor system activity.

    Science.gov (United States)

    Glenberg, Arthur M; Sato, Marc; Cattaneo, Luigi; Riggio, Lucia; Palumbo, Daniele; Buccino, Giovanni

    2008-06-01

    Embodiment theory proposes that neural systems for perception and action are also engaged during language comprehension. Previous neuroimaging and neurophysiological studies have only been able to demonstrate modulation of action systems during comprehension of concrete language. We provide neurophysiological evidence for modulation of motor system activity during the comprehension of both concrete and abstract language. In Experiment 1, when the described direction of object transfer or information transfer (e.g., away from the reader to another) matched the literal direction of a hand movement used to make a response, speed of responding was faster than when the two directions mismatched (an action-sentence compatibility effect). In Experiment 2, we used single-pulse transcranial magnetic stimulation to study changes in the corticospinal motor pathways to hand muscles while reading the same sentences. Relative to sentences that do not describe transfer, there is greater modulation of activity in the hand muscles when reading sentences describing transfer of both concrete objects and abstract information. These findings are discussed in relation to the human mirror neuron system.

  16. The Mechanical Transient Process at Asynchronous Motor Oscillating Mode

    Science.gov (United States)

    Antonovičs, Uldis; Bražis, Viesturs; Greivulis, Jānis

    2009-01-01

    The research object is squirrel-cage asynchronous motor connected to single-phase sinusoidal. There are shown, that by connecting to the stator windings a certain sequence of half-period positive and negative voltage, a motor rotor is rotated, but three times slower than in the three-phase mode. Changing the connecting sequence of positive and negative half-period voltage to stator windings, motor can work in various oscillating modes. It is tested experimentally. The mechanical transient processes had been researched in rotation and oscillating modes.

  17. Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children.

    Science.gov (United States)

    Doucette, Margaret R; Kurth, Salome; Chevalier, Nicolas; Munakata, Yuko; LeBourgeois, Monique K

    2015-11-04

    Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG), little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10-13 Hz) and fast (13.25-17 Hz) sigma power from all-night high-density electroencephalography (EEG) in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years). Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV²; and fast sigma power was 0.9 ± 0.2 μV². Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities.

  18. Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children

    Directory of Open Access Journals (Sweden)

    Margaret R. Doucette

    2015-11-01

    Full Text Available Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG, little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10–13 Hz and fast (13.25–17 Hz sigma power from all-night high-density electroencephalography (EEG in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years. Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV2; and fast sigma power was 0.9 ± 0.2 μV2. Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p < 0.05, r ranging from −0.6 to −0.8, such that greater power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities.

  19. Parkinson’s disease motor disorganization and temporal processing

    OpenAIRE

    Florio, Tiziana M.

    2017-01-01

    Motor control is essential for everyday life and highly contributes to the development and organisation of higher cognitive functions. Embodied cognition endemically approaches cognitive activities, grounding on sensory-motor processes and the ability to switch from each other in response to specific context and situations. In this view, it is possible to deliberate higher functions such as “expertise” and “decision making” as the ability to reactivate, deconstruct and reconstruct different m...

  20. Myelin Breakdown Mediates Age-Related Slowing in Cognitive Processing Speed in Healthy Elderly Men

    Science.gov (United States)

    Lu, Po H.; Lee, Grace J.; Tishler, Todd A.; Meghpara, Michael; Thompson, Paul M.; Bartzokis, George

    2013-01-01

    Background: To assess the hypothesis that in a sample of very healthy elderly men selected to minimize risk for Alzheimer's disease (AD) and cerebrovascular disease, myelin breakdown in late-myelinating regions mediates age-related slowing in cognitive processing speed (CPS). Materials and methods: The prefrontal lobe white matter and the genu of…

  1. Simulations to investigate the eect of circuit imperfections on the slow extraction process

    CERN Document Server

    Van De Pontseele, Wouter

    2016-01-01

    The Super Proton Synchrotron (SPS) is a 400 GeV proton accelerator at CERN. Its main purpose is the last step in pre-acceleration of particles before injecting them into the Large Hadron Collider. Besides that, it is used for experiments directly connected to the SPS. For these xed target experiments, a steady slow extraction of the SPS beam is necessary over thousands of turns. The SPS slow extraction process makes use of the third-integer resonance in combination with an electrostatic septum. The stability of the extracted intensity and the losses at the septum are in uenced by the imperfections of the current circuit that drives the SPS quadrupoles. This report summarizes the studies that were carried out with MAD-X to simulate these imperfections.

  2. Effects of TMS on different stages of motor and non-motor verb processing in the primary motor cortex.

    Directory of Open Access Journals (Sweden)

    Liuba Papeo

    Full Text Available The embodied cognition hypothesis suggests that motor and premotor areas are automatically and necessarily involved in understanding action language, as word conceptual representations are embodied. This transcranial magnetic stimulation (TMS study explores the role of the left primary motor cortex in action-verb processing. TMS-induced motor-evoked potentials from right-hand muscles were recorded as a measure of M1 activity, while participants were asked either to judge explicitly whether a verb was action-related (semantic task or to decide on the number of syllables in a verb (syllabic task. TMS was applied in three different experiments at 170, 350 and 500 ms post-stimulus during both tasks to identify when the enhancement of M1 activity occurred during word processing. The delays between stimulus onset and magnetic stimulation were consistent with electrophysiological studies, suggesting that word recognition can be differentiated into early (within 200 ms and late (within 400 ms lexical-semantic stages, and post-conceptual stages. Reaction times and accuracy were recorded to measure the extent to which the participants' linguistic performance was affected by the interference of TMS with M1 activity. No enhancement of M1 activity specific for action verbs was found at 170 and 350 ms post-stimulus, when lexical-semantic processes are presumed to occur (Experiments 1-2. When TMS was applied at 500 ms post-stimulus (Experiment 3, processing action verbs, compared with non-action verbs, increased the M1-activity in the semantic task and decreased it in the syllabic task. This effect was specific for hand-action verbs and was not observed for action-verbs related to other body parts. Neither accuracy nor RTs were affected by TMS. These findings suggest that the lexical-semantic processing of action verbs does not automatically activate the M1. This area seems to be rather involved in post-conceptual processing that follows the retrieval of motor

  3. Lyapunov exponent for aging process in induction motor

    Science.gov (United States)

    Bayram, Duygu; Ünnü, Sezen Yıdırım; Şeker, Serhat

    2012-09-01

    Nonlinear systems like electrical circuits and systems, mechanics, optics and even incidents in nature may pass through various bifurcations and steady states like equilibrium point, periodic, quasi-periodic, chaotic states. Although chaotic phenomena are widely observed in physical systems, it can not be predicted because of the nature of the system. On the other hand, it is known that, chaos is strictly dependent on initial conditions of the system [1-3]. There are several methods in order to define the chaos. Phase portraits, Poincaré maps, Lyapunov Exponents are the most common techniques. Lyapunov Exponents are the theoretical indicator of the chaos, named after the Russian mathematician Aleksandr Lyapunov (1857-1918). Lyapunov Exponents stand for the average exponential divergence or convergence of nearby system states, meaning estimating the quantitive measure of the chaotic attractor. Negative numbers of the exponents stand for a stable system whereas zero stands for quasi-periodic systems. On the other hand, at least if one of the exponents is positive, this situation is an indicator of the chaos. For estimating the exponents, the system should be modeled by differential equation but even in that case mathematical calculation of Lyapunov Exponents are not very practical and evaluation of these values requires a long signal duration [4-7]. For experimental data sets, it is not always possible to acquire the differential equations. There are several different methods in literature for determining the Lyapunov Exponents of the system [4, 5]. Induction motors are the most important tools for many industrial processes because they are cheap, robust, efficient and reliable. In order to have healthy processes in industrial applications, the conditions of the machines should be monitored and the different working conditions should be addressed correctly. To the best of our knowledge, researches related to Lyapunov exponents and electrical motors are mostly

  4. Role of association cortices and cerebellum during motor consolidation process

    International Nuclear Information System (INIS)

    Nagata, Ken; Wright, David K.; Box, Georgia A.

    2008-01-01

    Positron emission tomography (PET) studies of cerebral circulation activated during the first (naive) and second (learned) visual-motor tasks were performed to confirm the hypothesis that activated brain regions are different before and after the motor work. Subjects were 30 normal healthy right-handed volunteers (av. age 21 y), who had the first 10 tasks of cursor tracing (regular tracing, rt), as rapidly and accurately as possible, along the given star features and then second 15 tasks of tracing with the cursor with inverse polarity (mirror tracing, mt). During the tasks, PET images were obtained at 7th and 9th rt, and 10 times (1st-15th) during mt, with the high-resolution positron camera (HEADTOME V) to measure the cerebral blood flow after intravenous 15 O-water and were processed into 3D for statistics. At the 1st mt (under the most unfamiliar condition), stimulated were the right frontal and supplementary motor areas and temporal lobe, bilateral centriciput lobe, anterior cingulated gyrus, and left cerebellum hemisphere. Under the learned condition (at 15th mt), the primary motor area, lingual gyrus, cuneus, anterior cuneus, occipital lobe involving posterior cingulated gyrus and left cerebellum hemisphere were activated. Thus the hypothesis above was confirmed: reconfirmation of the brain plasticity. (R.T.)

  5. Solid propellant processing factor in rocket motor design

    Science.gov (United States)

    1971-01-01

    The ways are described by which propellant processing is affected by choices made in designing rocket engines. Tradeoff studies, design proof or scaleup studies, and special design features are presented that are required to obtain high product quality, and optimum processing costs. Processing is considered to include the operational steps involved with the lining and preparation of the motor case for the grain; the procurement of propellant raw materials; and propellant mixing, casting or extrusion, curing, machining, and finishing. The design criteria, recommended practices, and propellant formulations are included.

  6. How Radiologists Think: Understanding Fast and Slow Thought Processing and How It Can Improve Our Teaching.

    Science.gov (United States)

    van der Gijp, Anouk; Webb, Emily M; Naeger, David M

    2017-06-01

    Scholars have identified two distinct ways of thinking. This "Dual Process Theory" distinguishes a fast, nonanalytical way of thinking, called "System 1," and a slow, analytical way of thinking, referred to as "System 2." In radiology, we use both methods when interpreting and reporting images, and both should ideally be emphasized when educating our trainees. This review provides practical tips for improving radiology education, by enhancing System 1 and System 2 thinking among our trainees. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  7. The influence of scopolamine on motor control and attentional processes

    Directory of Open Access Journals (Sweden)

    Emma Bestaven

    2016-05-01

    Full Text Available Background: Motion sickness may be caused by a sensory conflict between the visual and the vestibular systems. Scopolamine, known to be the most effective therapy to control the vegetative symptoms of motion sickness, acts on the vestibular nucleus and potentially the vestibulospinal pathway, which may affect balance and motor tasks requiring both attentional process and motor balance. The aim of this study was to explore the effect of scopolamine on motor control and attentional processes. Methods: Seven subjects were evaluated on four different tasks before and after a subcutaneous injection of scopolamine (0.2 mg: a one-minute balance test, a subjective visual vertical test, a pointing task and a galvanic vestibular stimulation with EMG recordings. Results: The results showed that the reaction time and the movement duration were not modified after the injection of scopolamine. However, there was an increase in the center of pressure displacement during the balance test, a decrease in EMG muscle response after galvanic vestibular stimulation and an alteration in the perception of verticality. Discussion: These results confirm that low doses of scopolamine such as those prescribed to avoid motion sickness have no effect on attentional processes, but that it is essential to consider the responsiveness of each subject. However, scopolamine did affect postural control and the perception of verticality. In conclusion, the use of scopolamine to prevent motion sickness must be considered carefully because it could increase imbalances in situations when individuals are already at risk of falling (e.g., sailing, parabolic flight.

  8. MMRW-BOOKS, Legacy books on slowing down, thermalization, particle transport theory, random processes in reactors

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    2007-01-01

    Description: Prof. M.M..R Williams has now released three of his legacy books for free distribution: 1 - M.M.R. Williams: The Slowing Down and Thermalization of Neutrons, North-Holland Publishing Company - Amsterdam, 582 pages, 1966. Content: Part I - The Thermal Energy Region: 1. Introduction and Historical Review, 2. The Scattering Kernel, 3. Neutron Thermalization in an Infinite Homogeneous Medium, 4. Neutron Thermalization in Finite Media, 5. The Spatial Dependence of the Energy Spectrum, 6. Reactor Cell Calculations, 7. Synthetic Scattering Kernels. Part II - The Slowing Down Region: 8. Scattering Kernels in the Slowing Down Region, 9. Neutron Slowing Down in an Infinite Homogeneous Medium, 10.Neutron Slowing Down and Diffusion. 2 - M.M.R. Williams: Mathematical Methods in Particle Transport Theory, Butterworths, London, 430 pages, 1971. Content: 1 The General Problem of Particle Transport, 2 The Boltzmann Equation for Gas Atoms and Neutrons, 3 Boundary Conditions, 4 Scattering Kernels, 5 Some Basic Problems in Neutron Transport and Rarefied Gas Dynamics, 6 The Integral Form of the Transport Equation in Plane, Spherical and Cylindrical Geometries, 7 Exact Solutions of Model Problems, 8 Eigenvalue Problems in Transport Theory, 9 Collision Probability Methods, 10 Variational Methods, 11 Polynomial Approximations. 3 - M.M.R. Williams: Random Processes in Nuclear Reactors, Pergamon Press Oxford New York Toronto Sydney, 243 pages, 1974. Content: 1. Historical Survey and General Discussion, 2. Introductory Mathematical Treatment, 3. Applications of the General Theory, 4. Practical Applications of the Probability Distribution, 5. The Langevin Technique, 6. Point Model Power Reactor Noise, 7. The Spatial Variation of Reactor Noise, 8. Random Phenomena in Heterogeneous Reactor Systems, 9. Associated Fluctuation Problems, Appendix: Noise Equivalent Sources. Note to the user: Prof. M.M.R Williams owns the copyright of these books and he authorises the OECD/NEA Data Bank

  9. Mental slowness in patients with Parkinson's disease: Associations with cognitive functions?

    Science.gov (United States)

    Vlagsma, Thialda T; Koerts, Janneke; Tucha, Oliver; Dijkstra, Hilde T; Duits, Annelien A; van Laar, Teus; Spikman, Jacoba M

    2016-10-01

    Motor slowness (bradykinesia) is a core feature of Parkinson's disease (PD). It is often assumed that patients show mental slowness (bradyphrenia) as well; however, evidence for this is debated. The aims of this study were to determine whether PD patients show mental slowness apart from motor slowness and, if this is the case, to what extent this affects their performance on neuropsychological tests of attention, memory, and executive functions (EF). Fifty-five nondemented PD patients and 65 healthy controls were assessed with a simple information-processing task in which reaction and motor times could be separated. In addition, all patients and a second control group (N = 138) were assessed with neuropsychological tests of attention, memory, and EF. While PD patients showed significantly longer reaction times than healthy controls, their motor times were not significantly longer. Reaction and motor times were only moderately correlated and were not related to clinical measures of disease severity. PD patients performed significantly worse on tests of attention and EF, and for the majority of neuropsychological tests 11-51% of the patients showed a clinically impaired performance. Reaction times did not, however, predict patients' test performance, while motor times were found to have a significant negative influence on tests of attention. PD patients show mental slowness, which can be separated from motor slowness. Neuropsychological test performance is not influenced by mental slowness; however, motor slowness can have a negative impact. When interpreting neuropsychological test performance of PD patients in clinical practice, motor slowness needs to be taken into account.

  10. Developmental Relations Among Motor and Cognitive Processes and Mathematics Skills.

    Science.gov (United States)

    Kim, Helyn; Duran, Chelsea A K; Cameron, Claire E; Grissmer, David

    2018-03-01

    This study explored transactional associations among visuomotor integration, attention, fine motor coordination, and mathematics skills in a diverse sample of one hundred thirty-five 5-year-olds (kindergarteners) and one hundred nineteen 6-year-olds (first graders) in the United States who were followed over the course of 2 school years. Associations were dynamic, with more reciprocal transactions occurring in kindergarten than in the later grades. Specifically, visuomotor integration and mathematics exhibited ongoing reciprocity in kindergarten and first grade, attention contributed to mathematics in kindergarten and first grade, mathematics contributed to attention across the kindergarten year only, and fine motor coordination contributed to mathematics indirectly, through visuomotor integration, across kindergarten and first grade. Implications of examining the hierarchical interrelations among processes underlying the development of children's mathematics skills are discussed. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

  11. Outcome and Process in Motor Performance: A Comparison of Jumping by Typically Developing Children and Those with Low Motor Proficiency

    Science.gov (United States)

    Williams, Morgan D.; Saunders, John E.; Maschette, Wayne E.; Wilson, Cameron J.

    2013-01-01

    The motivation for this study was to explore a conceptual framework to understand the outcomes and processes of motor performance in children. Vertical jumping, a fundamental movement skill, was used to compare children (ages 6-12 years) who were typically developing (TD) and those identified as having low motor proficiency (LMP). Jumps were…

  12. Low-Altitude and Slow-Speed Small Target Detection Based on Spectrum Zoom Processing

    Directory of Open Access Journals (Sweden)

    Xuwang Zhang

    2018-01-01

    Full Text Available This paper proposes a spectrum zoom processing based target detection algorithm for detecting the weak echo of low-altitude and slow-speed small (LSS targets in heavy ground clutter environments, which can be used to retrofit the existing radar systems. With the existing range-Doppler frequency images, the proposed method firstly concatenates the data from the same Doppler frequency slot of different images and then applies the spectrum zoom processing. After performing the clutter suppression, the target detection can be finally implemented. Through the theoretical analysis and real data verification, it is shown that the proposed algorithm can obtain a preferable spectrum zoom result and improve the signal-to-clutter ratio (SCR with a very low computational load.

  13. The study of transient processes in the asynchronous starting of the synchronous motor

    OpenAIRE

    Alexandru Bârlea; Olivian Chiver

    2012-01-01

    Starting synchronous motors can be achieved by several ethods: starting with an auxiliary motor launch, starting in asynchronous regim, by feeding from a variable frequency source, auto-synchronization with the network.. In our case we study the transient processes in a asynchronous regim . In this case the synchronous motor is started like a squirrel cage induction motor . To start, the synchronous motor is equipped with a starting winding cage placed in the pole pieces of polar inducers; la...

  14. World's gas processing growth slows; U.S., Canada retain greatest share

    International Nuclear Information System (INIS)

    True, W.R.

    1994-01-01

    Growth in the world's natural-gas processing industry slowed somewhat in 1993 after strong expansion a year earlier. In 1993, slower growth was more evenly distributed among the world's regions than in 1992 with the US and Canada adding capacity along with the Middle East and Asia-Pacific. The US and Canada continue to lead the world in capacity with more than 107 bcfd; in throughput with almost 76 bcfd; and in production with nearly 115 million gpd (2.7 million b/d). The two countries also continued to lead the world in petroleum-derived sulfur production with more than 54% of the world's capacity and production last year. The paper discusses industry trends; the picture in the US; activities in Texas, Louisiana, Alaska, Alabama, Colorado, Kansas, and Oklahoma; new capacity worldwide; expansion plans in North America; and sulfur recovery

  15. One- and two-electron processes in collisions between hydrogen molecules and slow highly charged ions

    International Nuclear Information System (INIS)

    Wells, E.; Carnes, K.D.; Tawara, H.; Ali, R.; Sidky, Emil Y.; Illescas, Clara; Ben-Itzhak, I.

    2005-01-01

    A coincidence time-of-flight technique coupled with projectile charge state analysis was used to study electron capture in collisions between slow highly charged ions and hydrogen molecules. We found single electron capture with no target excitation to be the dominant process for both C 6+ projectiles at a velocity of 0.8 atomic units and Ar 11+ projectiles at v 0.63 a.u. Double electron capture and transfer excitation, however, were found to be comparable and occur about 30% of the time relative to single capture. Most projectiles (96%) auto-ionize quickly following double capture into doubly excited states. The data are compared to classical and quantum mechanical model calculations

  16. Timing of the Crab pulsar III. The slowing down and the nature of the random process

    International Nuclear Information System (INIS)

    Groth, E.J.

    1975-01-01

    The Crab pulsar arrival times are analyzed. The data are found to be consistent with a smooth slowing down with a braking index of 2.515+-0.005. Superposed on the smooth slowdown is a random process which has the same second moments as a random walk in the frequency. The strength of the random process is R 2 >=0.53 (+0.24, -0.12) x10 -22 Hz 2 s -1 , where R is the mean rate of steps and 2 > is the second moment of the step amplitude distribution. Neither the braking index nor the strength of the random process shows evidence of statistically significant time variations, although small fluctuations in the braking index and rather large fluctuations in the noise strength cannot be ruled out. There is a possibility that the random process contains a small component with the same second moments as a random walk in the phase. If so, a time scale of 3.5 days is indicated

  17. Interaction of attentional and motor control processes in handwriting.

    Science.gov (United States)

    Brown, T L; Donnenwirth, E E

    1990-01-01

    The interaction between attentional capacity, motor control processes, and strategic adaptations to changing task demands was investigated in handwriting, a continuous (rather than discrete) skilled performance. Twenty-four subjects completed 12 two-minute handwriting samples under instructions stressing speeded handwriting, normal handwriting, or highly legible handwriting. For half of the writing samples, a concurrent auditory monitoring task was imposed. Subjects copied either familiar (English) or unfamiliar (Latin) passages. Writing speed, legibility ratings, errors in writing and in the secondary auditory task, and a derived measure of the average number of characters held in short-term memory during each sample ("planning unit size") were the dependent variables. The results indicated that the ability to adapt to instructions stressing speed or legibility was substantially constrained by the concurrent listening task and by text familiarity. Interactions between instructions, task concurrence, and text familiarity in the legibility ratings, combined with further analyses of planning unit size, indicated that information throughput from temporary storage mechanisms to motor processes mediated the loss of flexibility effect. Overall, the results suggest that strategic adaptations of a skilled performance to changing task circumstances are sensitive to concurrent attentional demands and that departures from "normal" or "modal" performance require attention.

  18. Enhanced IMC design of load disturbance rejection for integrating and unstable processes with slow dynamics.

    Science.gov (United States)

    Liu, Tao; Gao, Furong

    2011-04-01

    In view of the deficiencies in existing internal model control (IMC)-based methods for load disturbance rejection for integrating and unstable processes with slow dynamics, a modified IMC-based controller design is proposed to deal with step- or ramp-type load disturbance that is often encountered in engineering practices. By classifying the ways through which such load disturbance enters into the process, analytical controller formulae are correspondingly developed, based on a two-degree-of-freedom (2DOF) control structure that allows for separate optimization of load disturbance rejection from setpoint tracking. An obvious merit is that there is only a single adjustable parameter in the proposed controller, which in essence corresponds to the time constant of the closed-loop transfer function for load disturbance rejection, and can be monotonically tuned to meet a good trade-off between disturbance rejection performance and closed-loop robust stability. At the same time, robust tuning constraints are given to accommodate process uncertainties in practice. Illustrative examples from the recent literature are used to show effectiveness and merits of the proposed method for different cases of load disturbance. Copyright © 2010. Published by Elsevier Ltd.

  19. Vectorial loading of processive motor proteins: implementing a landscape picture

    International Nuclear Information System (INIS)

    Kim, Young C; Fisher, Michael E

    2005-01-01

    Individual processive molecular motors, of which conventional kinesin is the most studied quantitatively, move along polar molecular tracks and, by exerting a force F = (F x ,F y ,F z ) on a tether, drag cellular cargoes, in vivo, or spherical beads, in vitro, taking up to hundreds of nanometre-scale steps. From observations of velocities and the dispersion of displacements with time, under measured forces and controlled fuel supply (typically ATP), one may hope to obtain insight into the molecular motions undergone in the individual steps. In the simplest situation, the load force F may be regarded as a scalar resisting force, F x z >0, while more recently Block and co-workers (2002 Biophys. J. 83 491, 2003 Proc. Natl Acad. Sci. USA 100 2351) and Carter and Cross (2005 Nature 435 308) have studied assisting (or reverse) loads, F x >0, and also sideways (or transverse) loads F y ≠ 0. We extend previous mechanochemical kinetic models by explicitly implementing a free-energy landscape picture in order to allow for the full vectorial nature of the force F transmitted by the tether. The load-dependence of the various forward and reverse transition rates is embodied in load distribution vectors, θ j + and θ j - , which relate to substeps of the motor, and in next order, in compliance matrices η j + and η j - . The approach is applied specifically to discuss the experiments of Howard and co-workers (1996 Biophys.?J. 70 418) in which the buckling of partially clamped microtubules was measured under the action of bound kinesin molecules which induced determined perpendicular loads. But in the normal single-bead assay it also proves imperative to allow for F z >0: the appropriate analysis for kinesin, suggesting that the motor 'crouches' on binding ATP prior to stepping, is sketched. It yields an expression for the velocity, V (F x ,F z ;[ATP]), needed to address the buckling experiments

  20. High frequency electromagnetic processes in induction motors supplied from PWM inverters

    Directory of Open Access Journals (Sweden)

    Ioan Ţilea

    2010-12-01

    Full Text Available The paper presents the electromagnetic interference between induction motors and inverters when at high frequency electromagnetic process appears in induction motors having a parallel resonant effect because of parasitic capacitive coupling between windings and ground, using a numerical model in simulink and a high frequency induction motor equivalent circuit model this effect is shown.

  1. Probing the positron moderation process using high-intensity, highly polarized slow-positron beams

    Science.gov (United States)

    Van House, J.; Zitzewitz, P. W.

    1984-01-01

    A highly polarized (P = 0.48 + or - 0.02) intense (500,000/sec) beam of 'slow' (Delta E = about 2 eV) positrons (e+) is generated, and it is shown that it is possible to achieve polarization as high as P = 0.69 + or - 0.04 with reduced intensity. The measured polarization of the slow e+ emitted by five different positron moderators showed no dependence on the moderator atomic number (Z). It is concluded that only source positrons with final kinetic energy below 17 keV contribute to the slow-e+ beam, in disagreement with recent yield functions derived from low-energy measurements. Measurements of polarization and yield with absorbers of different Z between the source and moderator show the effects of the energy and angular distributions of the source positrons on P. The depolarization of fast e+ transmitted through high-Z absorbers has been measured. Applications of polarized slow-e+ beams are discussed.

  2. Hydrothermal processes in the Edmond deposits, slow- to intermediate-spreading Central Indian Ridge

    Science.gov (United States)

    Cao, Hong; Sun, Zhilei; Zhai, Shikui; Cao, Zhimin; Jiang, Xuejun; Huang, Wei; Wang, Libo; Zhang, Xilin; He, Yongjun

    2018-04-01

    The Edmond hydrothermal field, located on the Central Indian Ridge (CIR), has a distinct mineralization history owing to its unique magmatic, tectonic, and alteration processes. Here, we report the detailed mineralogical and geochemical characteristics of hydrothermal metal sulfides recovered from this area. Based on the mineralogical investigations, the Edmond hydrothermal deposits comprise of high-temperature Fe-rich massive sulfides, medium-temperature Zn-rich sulfide chimney and low-temperature Ca-rich sulfate mineral assemblages. According to these compositions, three distinctive mineralization stages have been identified: (1) low-temperature consisting largely of anhydrite and pyrite/marcasite; (2) medium-high temperature distinguished by the mineral assemblage of pyrite, sphalerite and chalcopyrite; and (3) low-temperature stage characterized by the mineral assemblage of colloidal pyrite/marcasite, barite, quartz, anglesite. Several lines of evidence suggest that the sulfides were influenced by pervasive low-temperature diffuse flows in this area. The hydrothermal deposits are relatively enriched in Fe (5.99-18.93 wt%), Zn (2.10-10.00 wt%) and Ca (0.02-19.15 wt%), but display low Cu (0.28-0.81 wt%). The mineralogical varieties and low metal content of sulfides in the Edmond hydrothermal field both indicate that extensive water circulation is prevalent below the Edmond hydrothermal field. With regard to trace elements, the contents of Pb, Ba, Sr, As, Au, Ag, and Cd are significantly higher than those in other sediment-starved mid-ocean ridges, which is indicative of contribution from felsic rock sources. Furthermore, the multiphase hydrothermal activity and the pervasive water circulation underneath are speculated to play important roles in element remobilization and enrichment. Our findings deepen our understanding about the complex mineralization process in slow- to intermediate-spreading ridges globally.

  3. A parameter estimation for DC servo motor by using optimization process

    International Nuclear Information System (INIS)

    Arjoni Amir

    2010-01-01

    Modeling and simulation parameters of DC servo motor using Matlab Simulink software have been done. The objective to define the DC servo motor parameter estimation is to get DC servo motor parameter values (B, La, Ra, Km, J) which are significant value that can be used for actuation process of control systems. In the analysis of control systems DC the servo motor expressed by transfer function equation to make faster to be analyzed as a component of the actuator. To obtain the data model parameters and initial conditions of the DC servo motors is then carried out the processor modeling and simulation in which the DC servo motor combined with other components. To obtain preliminary data of the DC servo motor parameters as estimated venue, it is obtained from the data factory of the DC servo motor. The initial data parameters of the DC servo motor are applied for the optimization process by using nonlinear least square algorithm and minimize the cost function value so that the DC servo motors parameter values are obtained significantly. The result of the optimization process of the DC servo motor parameter values are B = 0.039881, J= 1.2608e-007, Km = 0.069648, La = 2.3242e-006 and Ra = 1.8837. (author)

  4. Indices of slowness of information processing in head injury patients : Tests for selective attention related to ERP latencies

    NARCIS (Netherlands)

    Spikman, Jacoba M.; Naalt, van der Joukje; Weerden , van Tiemen; Zomeren , van Adriaan H.

    2004-01-01

    We explored the relation between neuropsychological (attention tests involving time constraints) and neurophysiological (N2 and P3 event-related potential (ERP) latencies) indices of slowness of information processing after closed head injury (CHI). A group of 44 CHI patients performed worse than

  5. Motor-cognitive dual-task performance: effects of a concurrent motor task on distinct components of visual processing capacity.

    Science.gov (United States)

    Künstler, E C S; Finke, K; Günther, A; Klingner, C; Witte, O; Bublak, P

    2018-01-01

    Dual tasking, or the simultaneous execution of two continuous tasks, is frequently associated with a performance decline that can be explained within a capacity sharing framework. In this study, we assessed the effects of a concurrent motor task on the efficiency of visual information uptake based on the 'theory of visual attention' (TVA). TVA provides parameter estimates reflecting distinct components of visual processing capacity: perceptual threshold, visual processing speed, and visual short-term memory (VSTM) storage capacity. Moreover, goodness-of-fit values and bootstrapping estimates were derived to test whether the TVA-model is validly applicable also under dual task conditions, and whether the robustness of parameter estimates is comparable in single- and dual-task conditions. 24 subjects of middle to higher age performed a continuous tapping task, and a visual processing task (whole report of briefly presented letter arrays) under both single- and dual-task conditions. Results suggest a decline of both visual processing capacity and VSTM storage capacity under dual-task conditions, while the perceptual threshold remained unaffected by a concurrent motor task. In addition, goodness-of-fit values and bootstrapping estimates support the notion that participants processed the visual task in a qualitatively comparable, although quantitatively less efficient way under dual-task conditions. The results support a capacity sharing account of motor-cognitive dual tasking and suggest that even performing a relatively simple motor task relies on central attentional capacity that is necessary for efficient visual information uptake.

  6. A shared resource between declarative memory and motor memory

    OpenAIRE

    Keisler, Aysha; Shadmehr, Reza

    2010-01-01

    The neural systems that support motor adaptation in humans are thought to be distinct from those that support the declarative system. Yet, during motor adaptation changes in motor commands are supported by a fast adaptive process that has important properties (rapid learning, fast decay) that are usually associated with the declarative system. The fast process can be contrasted to a slow adaptive process that also supports motor memory, but learns gradually and shows resistance to forgetting....

  7. Study of Liquid Breakup Process in Solid Rocket Motor Nozzle

    Science.gov (United States)

    2016-02-16

    Laboratory, Edwards, CA Abstract In a solid rocket motor (SRM), when the aluminum based propellant combusts, the fuel is oxidized into alumina (Al2O3...34Chemical Erosion of Refractory-Metal Nozzle Inserts in Solid - Propellant Rocket Motors," J. Propulsion and Power, Vol. 25, no.1,, 2009. [4] E. Y. Wong...34 Solid Rocket Nozzle Design Summary," in 4th AIAA Propulsion Joint Specialist Conference, Cleveland, OH, 1968. [5] Nayfeh, A. H.; Saric, W. S

  8. Compromised Motor Dexterity Confounds Processing Speed Task Outcomes in Stroke Patients

    Directory of Open Access Journals (Sweden)

    Essie Low

    2017-09-01

    Full Text Available Most conventional measures of information processing speed require motor responses to facilitate performance. However, although not often addressed clinically, motor impairment, whether due to age or acquired brain injury, would be expected to confound the outcome measure of such tasks. The current study recruited 29 patients (20 stroke and 9 transient ischemic attack with documented reduction in dexterity of the dominant hand, and 29 controls, to investigate the extent to which 3 commonly used processing speed measures with varying motor demands (a Visuo-Motor Reaction Time task, and the Wechsler Adult Intelligence Scale-IV Symbol Search and Coding subtests may be measuring motor-related speed more so than cognitive speed. Analyses include correlations between indices of cognitive and motor speed obtained from two other tasks (Inspection Time and Pegboard task, respectively with the three speed measures, followed by hierarchical regressions to determine the relative contribution of cognitive and motor speed indices toward task performance. Results revealed that speed outcomes on tasks with relatively high motor demands, such as Coding, were largely reflecting motor speed in individuals with reduced dominant hand dexterity. Thus, findings indicate the importance of employing measures with minimal motor requirements, especially when the assessment of speed is aimed at understanding cognitive rather than physical function.

  9. Motor-cognitive dual-task performance: effects of a concurrent motor task on distinct components of visual processing capacity

    OpenAIRE

    Künstler, E. C. S.; Finke, K.; Günther, A.; Klingner, C.; Witte, O.; Bublak, P.

    2017-01-01

    Dual tasking, or the simultaneous execution of two continuous tasks, is frequently associated with a performance decline that can be explained within a capacity sharing framework. In this study, we assessed the effects of a concurrent motor task on the efficiency of visual information uptake based on the ‘theory of visual attention’ (TVA). TVA provides parameter estimates reflecting distinct components of visual processing capacity: perceptual threshold, visual processing speed, and visual sh...

  10. System of business-processes management at motor-transport enterprise

    OpenAIRE

    Коgut, Y.

    2010-01-01

    The place of the system of business-processes management at motor-transport enterprise in the general system of management of the enterprise has been substantiated. The subsystems of strategic management, business-processes management of strategic orientation and current activity, processes of enterprise functioning management have been marked out. The system of motor-transport enterprise business-processes management has been formed, which, unlike the existing ones, is based on the system-cy...

  11. Imbricated slip rate processes during slow slip transients imaged by low-frequency earthquakes

    Science.gov (United States)

    Lengliné, O.; Frank, W.; Marsan, D.; Ampuero, J. P.

    2017-12-01

    Low Frequency Earthquakes (LFEs) often occur in conjunction with transient strain episodes, or Slow Slip Events (SSEs), in subduction zones. Their focal mechanism and location consistent with shear failure on the plate interface argue for a model where LFEs are discrete dynamic ruptures in an otherwise slowly slipping interface. SSEs are mostly observed by surface geodetic instruments with limited resolution and it is likely that only the largest ones are detected. The time synchronization of LFEs and SSEs suggests that we could use the recorded LFEs to constrain the evolution of SSEs, and notably of the geodetically-undetected small ones. However, inferring slow slip rate from the temporal evolution of LFE activity is complicated by the strong temporal clustering of LFEs. Here we apply dedicated statistical tools to retrieve the temporal evolution of SSE slip rates from the time history of LFE occurrences in two subduction zones, Mexico and Cascadia, and in the deep portion of the San Andreas fault at Parkfield. We find temporal characteristics of LFEs that are similar across these three different regions. The longer term episodic slip transients present in these datasets show a slip rate decay with time after the passage of the SSE front possibly as t-1/4. They are composed of multiple short term transients with steeper slip rate decay as t-α with α between 1.4 and 2. We also find that the maximum slip rate of SSEs has a continuous distribution. Our results indicate that creeping faults host intermittent deformation at various scales resulting from the imbricated occurrence of numerous slow slip events of various amplitudes.

  12. Developmental Relations among Motor and Cognitive Processes and Mathematics Skills

    Science.gov (United States)

    Kim, Helyn; Duran, Chelsea A. K.; Cameron, Claire E.; Grissmer, David

    2018-01-01

    This study explored transactional associations among visuomotor integration, attention, fine motor coordination, and mathematics skills in a diverse sample of one hundred thirty-five 5-year-olds (kindergarteners) and one hundred nineteen 6-year-olds (first graders) in the United States who were followed over the course of 2 school years.…

  13. Short-Term Limb Immobilization Affects Cognitive Motor Processes

    Science.gov (United States)

    Toussaint, Lucette; Meugnot, Aurore

    2013-01-01

    We examined the effects of a brief period of limb immobilization on the cognitive level of action control. A splint placed on the participants' left hand was used as a means of immobilization. We used a hand mental rotation task to investigate the immobilization-induced effects on motor imagery performance (Experiments 1 and 2) and a number mental…

  14. A shared resource between declarative memory and motor memory.

    Science.gov (United States)

    Keisler, Aysha; Shadmehr, Reza

    2010-11-03

    The neural systems that support motor adaptation in humans are thought to be distinct from those that support the declarative system. Yet, during motor adaptation changes in motor commands are supported by a fast adaptive process that has important properties (rapid learning, fast decay) that are usually associated with the declarative system. The fast process can be contrasted to a slow adaptive process that also supports motor memory, but learns gradually and shows resistance to forgetting. Here we show that after people stop performing a motor task, the fast motor memory can be disrupted by a task that engages declarative memory, but the slow motor memory is immune from this interference. Furthermore, we find that the fast/declarative component plays a major role in the consolidation of the slow motor memory. Because of the competitive nature of declarative and nondeclarative memory during consolidation, impairment of the fast/declarative component leads to improvements in the slow/nondeclarative component. Therefore, the fast process that supports formation of motor memory is not only neurally distinct from the slow process, but it shares critical resources with the declarative memory system.

  15. A shared resource between declarative memory and motor memory

    Science.gov (United States)

    Keisler, Aysha; Shadmehr, Reza

    2010-01-01

    The neural systems that support motor adaptation in humans are thought to be distinct from those that support the declarative system. Yet, during motor adaptation changes in motor commands are supported by a fast adaptive process that has important properties (rapid learning, fast decay) that are usually associated with the declarative system. The fast process can be contrasted to a slow adaptive process that also supports motor memory, but learns gradually and shows resistance to forgetting. Here we show that after people stop performing a motor task, the fast motor memory can be disrupted by a task that engages declarative memory, but the slow motor memory is immune from this interference. Furthermore, we find that the fast/declarative component plays a major role in the consolidation of the slow motor memory. Because of the competitive nature of declarative and non-declarative memory during consolidation, impairment of the fast/declarative component leads to improvements in the slow/non-declarative component. Therefore, the fast process that supports formation of motor memory is not only neurally distinct from the slow process, but it shares critical resources with the declarative memory system. PMID:21048140

  16. Learning-performance distinction and memory processes for motor skills: a focused review and perspective.

    Science.gov (United States)

    Kantak, Shailesh S; Winstein, Carolee J

    2012-03-01

    Behavioral research in cognitive psychology provides evidence for an important distinction between immediate performance that accompanies practice and long-term performance that reflects the relative permanence in the capability for the practiced skill (i.e. learning). This learning-performance distinction is strikingly evident when challenging practice conditions may impair practice performance, but enhance long-term retention of motor skills. A review of motor learning studies with a specific focus on comparing differences in performance between that at the end of practice and at delayed retention suggests that the delayed retention or transfer performance is a better indicator of motor learning than the performance at (or end of) practice. This provides objective evidence for the learning-performance distinction. This behavioral evidence coupled with an understanding of the motor memory processes of encoding, consolidation and retrieval may provide insight into the putative mechanism that implements the learning-performance distinction. Here, we propose a simplistic empirically-based framework--motor behavior-memory framework--that integrates the temporal evolution of motor memory processes with the time course of practice and delayed retention frequently used in behavioral motor learning paradigms. In the context of the proposed framework, recent research has used noninvasive brain stimulation to decipher the role of each motor memory process, and specific cortical brain regions engaged in motor performance and learning. Such findings provide beginning insights into the relationship between the time course of practice-induced performance changes and motor memory processes. This in turn has promising implications for future research and practical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Slow sedimentary processes on-a-chip: experiments on porous flow effects on granular bed creep

    Science.gov (United States)

    Houssais, M.; Maldarelli, C.; Shattuck, M.; Morris, J. F.

    2017-12-01

    Steep soils dynamics is hard to catch. they exhibit very slow granular creep most of the time, and sometimes, mostly under or after rain, turn into a landslide, a very fast avalanche flow.The conditions of transition from soil creep to avalanching remains a lot non-understood, and Safe Factor law (empirical criteria, function of rain intensity and duration). On another side, in marine fast deposition environments, compaction drives vertical porous flow, which makes bed shear resistance change, and form over time bed size patterns (pipes, dishes) or mechanical heterogeneities.Capturing how the slow creep dynamics depends on the porous flow would allow for much more accurate landscape evolution modeling.We present here preliminary results of an experimental investigation of one the major triggering condition for soils destabilization: rain infiltration, and more generally porous flow through a tilted granular bed. In a quasi-2D microfluidics channel, a flat sediment bed made of spherical particles is prepared, in fully submerged condition. It is thereafter tilted (at slope under critical slope of avalanching) and simultaneously put under vertical weak porous flow (well under the critical flow of liquefaction regarding positive pressure gradients). The two control parameters are varied, and local particles concentration and motion are measured. Interestingly, although staying in the sub-critical creeping regime, we observe an acceleration of the bed deformation downward, as the porous flow and the bed slope are increased, until the criteria for avalanching is reached. Those results appear to present similitudes with the case of tilted dry sediment bed under controlled vibrations. Consequently it opens the discussion about a potential universal model of landslides triggering due to frequent seismological and rainstorm events.

  18. Assessing the Impact of Electrostatic Drag on Processive Molecular Motor Transport.

    Science.gov (United States)

    Smith, J Darby; McKinley, Scott A

    2018-06-04

    The bidirectional movement of intracellular cargo is usually described as a tug-of-war among opposite-directed families of molecular motors. While tug-of-war models have enjoyed some success, recent evidence suggests underlying motor interactions are more complex than previously understood. For example, these tug-of-war models fail to predict the counterintuitive phenomenon that inhibiting one family of motors can decrease the functionality of opposite-directed transport. In this paper, we use a stochastic differential equations modeling framework to explore one proposed physical mechanism, called microtubule tethering, that could play a role in this "co-dependence" among antagonistic motors. This hypothesis includes the possibility of a trade-off: weakly bound trailing molecular motors can serve as tethers for cargoes and processing motors, thereby enhancing motor-cargo run lengths along microtubules; however, this introduces a cost of processing at a lower mean velocity. By computing the small- and large-time mean-squared displacement of our theoretical model and comparing our results to experimental observations of dynein and its "helper protein" dynactin, we find some supporting evidence for microtubule tethering interactions. We extrapolate these findings to predict how dynein-dynactin might interact with the opposite-directed kinesin motors and introduce a criterion for when the trade-off is beneficial in simple systems.

  19. Evolution amplified processing with temporally dispersed slow neuronal connectivity in primates.

    Science.gov (United States)

    Caminiti, Roberto; Ghaziri, Hassan; Galuske, Ralf; Hof, Patrick R; Innocenti, Giorgio M

    2009-11-17

    The corpus callosum (CC) provides the main route of communication between the 2 hemispheres of the brain. In monkeys, chimpanzees, and humans, callosal axons of distinct size interconnect functionally different cortical areas. Thinner axons in the genu and in the posterior body of the CC interconnect the prefrontal and parietal areas, respectively, and thicker axons in the midbody and in the splenium interconnect primary motor, somatosensory, and visual areas. At all locations, axon diameter, and hence its conduction velocity, increases slightly in the chimpanzee compared with the macaque because of an increased number of large axons but not between the chimpanzee and man. This, together with the longer connections in larger brains, doubles the expected conduction delays between the hemispheres, from macaque to man, and amplifies their range about 3-fold. These changes can have several consequences for cortical dynamics, particularly on the cycle of interhemispheric oscillators.

  20. Role of medial premotor areas in action language processing in relation to motor skills.

    Science.gov (United States)

    Courson, Melody; Macoir, Joël; Tremblay, Pascale

    2017-10-01

    The literature reports that the supplementary motor area (SMA) and pre-supplementary motor area (pre-SMA) are involved in motor planning and execution, and in motor-related cognitive functions such as motor imagery. However, their specific role in action language processing remains unclear. In the present study, we investigated the impact of repetitive transcranial magnetic stimulation (rTMS) over SMA and pre-SMA during an action semantic analogy task (SAT) in relation with fine motor skills (i.e., manual dexterity) and motor imagery abilities in healthy non-expert adults. The impact of rTMS over SMA (but not pre-SMA) on reaction times (RT) during SAT was correlated with manual dexterity. Specifically, results show that rTMS over SMA modulated RT for those with lower dexterity skills. Our results therefore demonstrate a causal involvement of SMA in action language processing, as well as the existence of inter-individual differences in this involvement. We discuss these findings in light of neurolinguistic theories of language processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Energy conversion assessment of vacuum, slow and fast pyrolysis processes for low and high ash paper waste sludge

    International Nuclear Information System (INIS)

    Ridout, Angelo J.; Carrier, Marion; Collard, François-Xavier; Görgens, Johann

    2016-01-01

    Highlights: • Vacuum, slow and fast pyrolysis of low and high ash paper waste sludge (PWS) is compared. • Reactor temperature and pellet size optimised to maximise liquid and solid product yields. • Gross energy recovery from solid and liquid was assessed. • Fast pyrolysis of low and high ash PWS offers higher energy conversions. - Abstract: The performance of vacuum, slow and fast pyrolysis processes to transfer energy from the paper waste sludge (PWS) to liquid and solid products was compared. Paper waste sludges with low and high ash content (8.5 and 46.7 wt.%) were converted under optimised conditions for temperature and pellet size to maximise both product yields and energy content. Comparison of the gross energy conversions, as a combination of the bio-oil/tarry phase and char (EC_s_u_m), revealed that the fast pyrolysis performance was between 18.5% and 20.1% higher for the low ash PWS, and 18.4% and 36.5% higher for high ash PWS, when compared to the slow and vacuum pyrolysis processes respectively. For both PWSs, this finding was mainly attributed to higher production of condensable organic compounds and lower water yields during FP. The low ash PWS chars, fast pyrolysis bio-oils and vacuum pyrolysis tarry phase products had high calorific values (∼18–23 MJ kg"−"1) making them promising for energy applications. Considering the low calorific values of the chars from alternative pyrolysis processes (∼4–7 MJ kg"−"1), the high ash PWS should rather be converted to fast pyrolysis bio-oil to maximise the recovery of usable energy products.

  2. Reconciling the influence of task-set switching and motor inhibition processes on stop signal after-effects.

    Science.gov (United States)

    Anguera, Joaquin A; Lyman, Kyle; Zanto, Theodore P; Bollinger, Jacob; Gazzaley, Adam

    2013-01-01

    Executive response functions can be affected by preceding events, even if they are no longer associated with the current task at hand. For example, studies utilizing the stop signal task have reported slower response times to "GO" stimuli when the preceding trial involved the presentation of a "STOP" signal. However, the neural mechanisms that underlie this behavioral after-effect are unclear. To address this, behavioral and electroencephalography (EEG) measures were examined in 18 young adults (18-30 years) on "GO" trials following a previously "Successful Inhibition" trial (pSI), a previously "Failed Inhibition" trial (pFI), and a previous "GO" trial (pGO). Like previous research, slower response times were observed during both pSI and pFI trials (i.e., "GO" trials that were preceded by a successful and unsuccessful inhibition trial, respectively) compared to pGO trials (i.e., "GO" trials that were preceded by another "GO" trial). Interestingly, response time slowing was greater during pSI trials compared to pFI trials, suggesting executive control is influenced by both task set switching and persisting motor inhibition processes. Follow-up behavioral analyses indicated that these effects resulted from between-trial control adjustments rather than repetition priming effects. Analyses of inter-electrode coherence (IEC) and inter-trial coherence (ITC) indicated that both pSI and pFI trials showed greater phase synchrony during the inter-trial interval compared to pGO trials. Unlike the IEC findings, differential ITC was present within the beta and alpha frequency bands in line with the observed behavior (pSI > pFI > pGO), suggestive of more consistent phase synchrony involving motor inhibition processes during the ITI at a regional level. These findings suggest that between-trial control adjustments involved with task-set switching and motor inhibition processes influence subsequent performance, providing new insights into the dynamic nature of executive control.

  3. Changes in the carotenoid metabolism of capsicum fruits during application of modelized slow drying process for paprika production.

    Science.gov (United States)

    Pérez-Gálvez, Antonio; Hornero-Méndez, Dámaso; Mínguez-Mosquera, María Isabel

    2004-02-11

    A temperature profile simulating the traditional slow drying process of red pepper fruits, which is conducted in La Vera region (Spain) for paprika production, was developed. Carotenoid and ascorbic acid content, as well as moisture of fruits, were monitored during the slow drying process designed. Data obtained suggested that the evolution of carotenoid concentration, the main quality trait for paprika, directly depend on the physical conditions imposed. During the drying process, three different stages could be observed in relation to the carotenoids. The first stage corresponds to a physiological adaptation to the new imposed conditions that implied a decrease (ca. 20%) in the carotenoid content during the first 24 h. After that short period and during 5 days, a second stage was noticed, recovering the biosynthetic (carotenogenic) capability of the fruits, which denotes an accommodation of the fruits to the new environmental conditions. During the following 48 h (third stage) a sharp increase in the carotenoid content was observed. This last phenomenon seems to be related with an oxidative-thermal stress, which took place during the first stage, inducing a carotenogenesis similar to that occurring in over-ripening fruits. Results demonstrate that a fine control of the temperature and moisture content would help to positively modulate carotenogenesis and minimize catabolism, making it possible to adjust the drying process to the ripeness stage of fruits with the aim of improving carotenoid retention and therefore quality of the resulting product. In the case of ascorbic acid, data demonstrated that this compound is very sensitive to the drying process, with a decrease of about 76% during the first 24 h and remaining only at trace levels during the rest of the process. Therefore, no antioxidant role should be expected from ascorbic acid during the whole process and in the corresponding final product (paprika), despite that red pepper fruit is well-known to be rich

  4. How Kinesthetic Motor Imagery works: A predictive-processing theory of visualization in sports and motor expertise

    NARCIS (Netherlands)

    Ridderinkhof, K.R.; Brass, M.

    2015-01-01

    Kinesthetic Motor Imagery (KMI) is an important technique to acquire and refine motor skills. KMI is widely used by professional athletes as an effective way to improve motor performance without overt motor output. Despite this obvious relevance, the functional mechanisms and neural circuits

  5. Differential Effects of Motor Efference Copies and Proprioceptive Information on Response Evaluation Processes

    Science.gov (United States)

    Stock, Ann-Kathrin; Wascher, Edmund; Beste, Christian

    2013-01-01

    It is well-kown that sensory information influences the way we execute motor responses. However, less is known about if and how sensory and motor information are integrated in the subsequent process of response evaluation. We used a modified Simon Task to investigate how these streams of information are integrated in response evaluation processes, applying an in-depth neurophysiological analysis of event-related potentials (ERPs), time-frequency decomposition and sLORETA. The results show that response evaluation processes are differentially modulated by afferent proprioceptive information and efference copies. While the influence of proprioceptive information is mediated via oscillations in different frequency bands, efference copy based information about the motor execution is specifically mediated via oscillations in the theta frequency band. Stages of visual perception and attention were not modulated by the interaction of proprioception and motor efference copies. Brain areas modulated by the interactive effects of proprioceptive and efference copy based information included the middle frontal gyrus and the supplementary motor area (SMA), suggesting that these areas integrate sensory information for the purpose of response evaluation. The results show how motor response evaluation processes are modulated by information about both the execution and the location of a response. PMID:23658624

  6. Process and catalysts for hydrocarbon conversion. [high antiknock motor fuel

    Energy Technology Data Exchange (ETDEWEB)

    1940-02-14

    High anti-knock motor fuel is produced from hydrocarbons by subjecting it at an elevated temperature to contact with a calcined mixture of hydrated silica, hydrated alumina, and hydrated zirconia, substantially free from alkali metal compounds. The catalyst may be prepared by precipitating silica gel by the acidification of an aqueous solution of an alkali metal silicate, intimately mixing hydrated alumina and hydrated zirconia therewith, drying, purifying the composite to substantially remove alkali metal compounds, again drying, forming the dried material into particles, and finally calcining. The resultant conversion products may be fractionated to produce gasoline, hydrocarbon oil above gasoling boiling point range, and a gaseous fraction of olefins which are polymerized into gasoline boiling range polymers.

  7. On the functional relationship between language and motor processing in typewriting: an EEG study

    OpenAIRE

    Scaltritti, Michele; Pinet, Svetlana; Longcamp, Marieke; Alario, F-Xavier

    2017-01-01

    International audience; The functional relationship between language and motor processing was investigated to elucidate whether it is better described in terms of a discrete or a continuous account of information flow. To this end, we recorded event-related potentials during a typewriting task that combined a semantic priming paradigm with a manipulation of response side (response initiated with right vs. left hand), and focused on the lateralised potentials indexing motor-response activation...

  8. Reversal of long-term potentiation-like plasticity processes after motor learning disrupts skill retention.

    Science.gov (United States)

    Cantarero, Gabriela; Lloyd, Ashley; Celnik, Pablo

    2013-07-31

    Plasticity of synaptic connections in the primary motor cortex (M1) is thought to play an essential role in learning and memory. Human and animal studies have shown that motor learning results in long-term potentiation (LTP)-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. Moreover, biochemical processes essential for LTP are also crucial for certain types of motor learning and memory. Thus, it has been speculated that the occlusion of LTP-like plasticity after learning, indicative of how much LTP was used to learn, is essential for retention. Here we provide supporting evidence of it in humans. Induction of LTP-like plasticity can be abolished using a depotentiation protocol (DePo) consisting of brief continuous theta burst stimulation. We used transcranial magnetic stimulation to assess whether application of DePo over M1 after motor learning affected (1) occlusion of LTP-like plasticity and (2) retention of motor skill learning. We found that the magnitude of motor memory retention is proportional to the magnitude of occlusion of LTP-like plasticity. Moreover, DePo stimulation over M1, but not over a control site, reversed the occlusion of LTP-like plasticity induced by motor learning and disrupted skill retention relative to control subjects. Altogether, these results provide evidence of a link between occlusion of LTP-like plasticity and retention and that this measure could be used as a biomarker to predict retention. Importantly, attempts to reverse the occlusion of LTP-like plasticity after motor learning comes with the cost of reducing retention of motor learning.

  9. Automated processing of data on the use of motor vehicles in the Serbian Armed Forces

    Directory of Open Access Journals (Sweden)

    Nikola S. Osmokrović

    2012-10-01

    Full Text Available The main aim of introducing information technology into the armed forces is the automation of the management process. The management in movement and transport (M&T in our armed forces has been included in the process of automation from the beginning. For that reason, today we can speak about the automated processing of data on road traffic safety and on the use of motor vehicles. With regard to the overall development of the information system of the movement and transport service, the paper presents an information system of the M&T service for the processing of data on the use of motor vehicles. The main features, components and functions of the 'Vozila' application, which was specially developed for the automated processing of data on motor vehicle use, are explained in particular.

  10. A slow atomic diffusion process in high-entropy glass-forming metallic melts

    Science.gov (United States)

    Chen, Changjiu; Wong, Kaikin; Krishnan, Rithin P.; Embs, Jan P.; Chathoth, Suresh M.

    2018-04-01

    Quasi-elastic neutron scattering has been used to study atomic relaxation processes in high-entropy glass-forming metallic melts with different glass-forming ability (GFA). The momentum transfer dependence of mean relaxation time shows a highly collective atomic transport process in the alloy melts with the highest and lowest GFA. However, a jump diffusion process is the long-range atomic transport process in the intermediate GFA alloy melt. Nevertheless, atomic mobility close to the melting temperature of these alloy melts is quite similar, and the temperature dependence of the diffusion coefficient exhibits a non-Arrhenius behavior. The atomic mobility in these high-entropy melts is much slower than that of the best glass-forming melts at their respective melting temperatures.

  11. When fast logic meets slow belief: Evidence for a parallel-processing model of belief bias

    OpenAIRE

    Trippas, Dries; Thompson, Valerie A.; Handley, Simon J.

    2016-01-01

    Two experiments pitted the default-interventionist account of belief bias against a parallel-processing model. According to the former, belief bias occurs because a fast, belief-based evaluation of the conclusion pre-empts a working-memory demanding logical analysis. In contrast, according to the latter both belief-based and logic-based responding occur in parallel. Participants were given deductive reasoning problems of variable complexity and instructed to decide whether the conclusion was ...

  12. Virtual process of product development for electric motors; Virtueller Produktentwicklungsprozess fuer Elektromotoren

    Energy Technology Data Exchange (ETDEWEB)

    Schoening, Marc Christian

    2008-07-01

    In order to consider all relevant design aspects and their mutual interdependences, current design practice uses a selection of different software packages. The design tools as a rule specialize in a single design criterion, so that tools must be combined in order to consider the mutual interaction of electromagnetic, thermal, and acoustic effects. So far, this has been done individually and manually, with a new model of the motor under investigation generated in every single program. This means that the parameters of a motor must be managed several times. The publication presents a novel simulation tool which provides a comprehensive methodology in which all design aspects of electric motors are considered by a standardised and uniform virtual development process. Further, the virtual reality method is used for representing 3D motor models in their natural dimensions, thus providing better understanding of the numeric simulation results. (orig.)

  13. Body-part specific interactions of action verb processing with motor behaviour.

    Science.gov (United States)

    Klepp, Anne; Niccolai, Valentina; Sieksmeyer, Jan; Arnzen, Stephanie; Indefrey, Peter; Schnitzler, Alfons; Biermann-Ruben, Katja

    2017-06-15

    The interaction of action-related language processing with actual movement is an indicator of the functional role of motor cortical involvement in language understanding. This paper describes two experiments using single action verb stimuli. Motor responses were performed with the hand or the foot. To test the double dissociation of language-motor facilitation effects within subjects, Experiments 1 and 2 used a priming procedure where both hand and foot reactions had to be performed in response to different geometrical shapes, which were preceded by action verbs. In Experiment 1, the semantics of the verbs could be ignored whereas Experiment 2 included semantic decisions. Only Experiment 2 revealed a clear double dissociation in reaction times: reactions were facilitated when preceded by verbs describing actions with the matching effector. In Experiment 1, by contrast, there was an interaction between verb-response congruence and a semantic variable related to motor features of the verbs. Thus, the double dissociation paradigm of semantic motor priming was effective, corroborating the role of the motor system in action-related language processing. Importantly, this effect was body part specific. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. When fast logic meets slow belief: Evidence for a parallel-processing model of belief bias.

    Science.gov (United States)

    Trippas, Dries; Thompson, Valerie A; Handley, Simon J

    2017-05-01

    Two experiments pitted the default-interventionist account of belief bias against a parallel-processing model. According to the former, belief bias occurs because a fast, belief-based evaluation of the conclusion pre-empts a working-memory demanding logical analysis. In contrast, according to the latter both belief-based and logic-based responding occur in parallel. Participants were given deductive reasoning problems of variable complexity and instructed to decide whether the conclusion was valid on half the trials or to decide whether the conclusion was believable on the other half. When belief and logic conflict, the default-interventionist view predicts that it should take less time to respond on the basis of belief than logic, and that the believability of a conclusion should interfere with judgments of validity, but not the reverse. The parallel-processing view predicts that beliefs should interfere with logic judgments only if the processing required to evaluate the logical structure exceeds that required to evaluate the knowledge necessary to make a belief-based judgment, and vice versa otherwise. Consistent with this latter view, for the simplest reasoning problems (modus ponens), judgments of belief resulted in lower accuracy than judgments of validity, and believability interfered more with judgments of validity than the converse. For problems of moderate complexity (modus tollens and single-model syllogisms), the interference was symmetrical, in that validity interfered with belief judgments to the same degree that believability interfered with validity judgments. For the most complex (three-term multiple-model syllogisms), conclusion believability interfered more with judgments of validity than vice versa, in spite of the significant interference from conclusion validity on judgments of belief.

  15. Fairness, fast and slow: A review of dual process models of fairness

    DEFF Research Database (Denmark)

    Hallsson, Bjørn Gunnar; Hulme, Oliver; Siebner, Hartwig Roman

    2018-01-01

    -control to override with reasoning-based fairness concerns, or whether fairness itself can be intuitive. While we find strong support for rejecting the notion that self-interest is always intuitive, the literature has reached conflicting conclusions about the neurocognitive systems underpinning fairness. We propose...... that this disagreement can largely be resolved in light of an extended Social Heuristics Hypothesis. Divergent findings may be attributed to the interpretation of behavioral effects of ego depletion or neurostimulation, reverse inference from brain activity to the underlying psychological process, and insensitivity...

  16. Localized atrophy of the thalamus and slowed cognitive processing speed in MS patients.

    Science.gov (United States)

    Bergsland, Niels; Zivadinov, Robert; Dwyer, Michael G; Weinstock-Guttman, Bianca; Benedict, Ralph Hb

    2016-09-01

    Deep gray matter (DGM) atrophy is common in multiple sclerosis (MS), but no studies have investigated surface-based structure changes over time with respect to healthy controls (HCs). Moreover, the relationship between cognition and the spatio-temporal evolution of DGM atrophy is poorly understood. To explore DGM structural differences between MS and HCs over time in relation to neuropsychological (NP) outcomes. The participants were 44 relapsing-remitting and 20 secondary progressive MS patients and 22 HCs. All were scanned using 3T magnetic resonance imaging (MRI) at baseline and 3-year follow-up. NP examination emphasized consensus standard tests of processing speed and memory. We performed both volumetric and shape analysis of DGM structures and assessed their relationships with cognition. Compared to HCs, MS patients presented with significantly smaller DGM volumes. For the thalamus and caudate, differences in shape were mostly localized along the lateral ventricles. NP outcomes were related to both volume and shape of the DGM structures. Over 3 years, decreased cognitive processing speed was related to localized atrophy on the anterior and superior surface of the left thalamus. These findings highlight the role of atrophy in the anterior nucleus of the thalamus and its relation to cognitive decline in MS. © The Author(s), 2015.

  17. Question of automation of periodical slow process in nuclear power stations

    International Nuclear Information System (INIS)

    Berta, S.

    1985-01-01

    In Hungary one 440 MW PRW unit is in service and the second one is under commission. Two units have one background complex. Further two PWR units are being made and of course another background complex. In the PWR technology these background technological processes ensure safe and contamination free operation. Their task is to prevent the escape of noxious, chemical or radioactive by-products. The main technological parts of the background complex are: Fuel cell resting; Four different water filtering systems; Hydrogen contact burners; Two gas filtering systems; Fluid wastage and contaminated resin handling; Preparation of chemical solutions. The aim of this article is to study the possibilities of automation of the background complex

  18. Possibility of a crossed-beam experiment involving slow-neutron capture by unstable nuclei - ``rapid-process tron''

    Science.gov (United States)

    Yamazaki, T.; Katayama, I.; Uwamino, Y.

    1993-02-01

    The possibility of a crossed beam facility of slow neutrons capturing unstable nuclei is examined in connection with the Japanese Hadron Project. With a pulsed proton beam of 50 Hz repetition and with a 100 μA average beam current, one obtains a spallation neutron source of 2.4 × 10 8 thermal neutrons/cm 3/spill over a 60 cm length with a 3 ms average duration time by using a D 2O moderator. By confining radioactive nuclei of 10 9 ions in a beam circulation ring of 0.3 MHz revolution frequency, so that nuclei pass through the neutron source, one obtains a collision luminosity of 3.9 × 10 24/cm 2/s. A new research domain aimed at studying rapid processes in nuclear genetics in a laboratory will be created.

  19. Ions and electrons thermal effects on the fast-slow mode conversion process in a three components plasma

    International Nuclear Information System (INIS)

    Fidone, I.; Gomberoff, L.

    1977-07-01

    Fast-slow mode conversion in a deuterium plasma with a small amount of hydrogen impurity, for frequencies close to the two-ion hybrid frequency, is investigated. It is shown that while electron thermal effects tend to inhibit the wave conversion process, ion thermal effects tend to restore, qualitatively, the cold plasma properties, favouring therefore, the energy exchange between the two modes. The aforementioned effects are competitive for zetasub(o)sup(e)=1/nsub(parall).vsub(e)>=1. For zetasub(o)sup(e)<=1, electron thermal effects, in particular Landau damping, dominate over ion Larmor radius effects, drastically diminishing the wave conversion efficacy. For zetasub(o)sup(e)<<1, the coupling between the modes disappears altogether

  20. Broadband true time delay for microwave signal processing, using slow light based on stimulated Brillouin scattering in optical fibers.

    Science.gov (United States)

    Chin, Sanghoon; Thévenaz, Luc; Sancho, Juan; Sales, Salvador; Capmany, José; Berger, Perrine; Bourderionnet, Jérôme; Dolfi, Daniel

    2010-10-11

    We experimentally demonstrate a novel technique to process broadband microwave signals, using all-optically tunable true time delay in optical fibers. The configuration to achieve true time delay basically consists of two main stages: photonic RF phase shifter and slow light, based on stimulated Brillouin scattering in fibers. Dispersion properties of fibers are controlled, separately at optical carrier frequency and in the vicinity of microwave signal bandwidth. This way time delay induced within the signal bandwidth can be manipulated to correctly act as true time delay with a proper phase compensation introduced to the optical carrier. We completely analyzed the generated true time delay as a promising solution to feed phased array antenna for radar systems and to develop dynamically reconfigurable microwave photonic filters.

  1. Slow briefs: slow food....slow architecture

    OpenAIRE

    Crotch, Joanna

    2012-01-01

    We are moving too fast…fast lives, fast cars, fast food…..and fast architecture. We are caught up in a world that allows no time to stop and think; to appreciate and enjoy all the really important things in our lives. Recent responses to this seemingly unstoppable trend are the growing movements of Slow Food and Cittaslow. Both initiatives are, within their own realms, attempting to reverse speed, homogeny, expediency and globalisation, considering the values of regionality, patience, craft, ...

  2. MOTORIZATION PROCESS AND MANAGEMENT IN BIG CITIES IN CHINA

    Directory of Open Access Journals (Sweden)

    Hong MA

    2007-01-01

    This paper expresses and analyzes the mobility development process in big cities in China, taking Beijing as an example. The evolution of transportation policy is described. Both transportation demand management and infrastructure contraction should be considered simultaneously in the policy.

  3. Fairness, fast and slow: A review of dual process models of fairness.

    Science.gov (United States)

    Hallsson, Bjørn G; Siebner, Hartwig R; Hulme, Oliver J

    2018-06-01

    Fairness, the notion that people deserve or have rights to certain resources or kinds of treatment, is a fundamental dimension of moral cognition. Drawing on recent evidence from economics, psychology, and neuroscience, we ask whether self-interest is always intuitive, requiring self-control to override with reasoning-based fairness concerns, or whether fairness itself can be intuitive. While we find strong support for rejecting the notion that self-interest is always intuitive, the literature has reached conflicting conclusions about the neurocognitive systems underpinning fairness. We propose that this disagreement can largely be resolved in light of an extended Social Heuristics Hypothesis. Divergent findings may be attributed to the interpretation of behavioral effects of ego depletion or neurostimulation, reverse inference from brain activity to the underlying psychological process, and insensitivity to social context and inter-individual differences. To better dissect the neurobiological basis of fairness, we outline how future research should embrace cross-disciplinary methods that combine psychological manipulations with neuroimaging, and that can probe inter-individual, and cultural heterogeneities. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Implementing the National Council of Teachers of Mathematics Standards: A slow process

    Directory of Open Access Journals (Sweden)

    Joseph M. Furner

    2004-10-01

    Full Text Available The purpose of this study was to look at inservice teachers’ pedagogical beliefs about the National Council of Teachers of Mathematics Standards (1989 & 2000.  The Standards’ Belief Instrument (Zollman and Mason, 1992 was administered on teachers.  An ANOVA was used to look for a significant difference between teachers with five years or less experience of teaching mathematics, and those with more than five years teaching experience. One expectation was  that teachers who are recent graduates of teacher education programmes may have more training  on the NCTM Standards. Although there were no statistically significant differences between the two groups, this study did support the expectation. Current training with in-service teachers shows that many of the teachers are familiar with neither the National Council of Teachers of Mathematics nor their Standards.  It seems then from this study that the implementation process of the NCTM Standards, and  perhaps any standards or best practices and new curriculum implementation, is very sluggish.

  5. The advantage of being slow: The quasi-neutral contact process.

    Directory of Open Access Journals (Sweden)

    Marcelo Martins de Oliveira

    Full Text Available According to the competitive exclusion principle, in a finite ecosystem, extinction occurs naturally when two or more species compete for the same resources. An important question that arises is: when coexistence is not possible, which mechanisms confer an advantage to a given species against the other(s? In general, it is expected that the species with the higher reproductive/death ratio will win the competition, but other mechanisms, such as asymmetry in interspecific competition or unequal diffusion rates, have been found to change this scenario dramatically. In this work, we examine competitive advantage in the context of quasi-neutral population models, including stochastic models with spatial structure as well as macroscopic (mean-field descriptions. We employ a two-species contact process in which the "biological clock" of one species is a factor of α slower than that of the other species. Our results provide new insights into how stochasticity and competition interact to determine extinction in finite spatial systems. We find that a species with a slower biological clock has an advantage if resources are limited, winning the competition against a species with a faster clock, in relatively small systems. Periodic or stochastic environmental variations also favor the slower species, even in much larger systems.

  6. The advantage of being slow: The quasi-neutral contact process.

    Science.gov (United States)

    de Oliveira, Marcelo Martins; Dickman, Ronald

    2017-01-01

    According to the competitive exclusion principle, in a finite ecosystem, extinction occurs naturally when two or more species compete for the same resources. An important question that arises is: when coexistence is not possible, which mechanisms confer an advantage to a given species against the other(s)? In general, it is expected that the species with the higher reproductive/death ratio will win the competition, but other mechanisms, such as asymmetry in interspecific competition or unequal diffusion rates, have been found to change this scenario dramatically. In this work, we examine competitive advantage in the context of quasi-neutral population models, including stochastic models with spatial structure as well as macroscopic (mean-field) descriptions. We employ a two-species contact process in which the "biological clock" of one species is a factor of α slower than that of the other species. Our results provide new insights into how stochasticity and competition interact to determine extinction in finite spatial systems. We find that a species with a slower biological clock has an advantage if resources are limited, winning the competition against a species with a faster clock, in relatively small systems. Periodic or stochastic environmental variations also favor the slower species, even in much larger systems.

  7. Frictional processes in smectite-rich gouges sheared at slow to high slip rates

    Science.gov (United States)

    Aretusini, Stefano; Mittempergher, Silvia; Gualtieri, Alessandro; Di Toro, Giulio

    2015-04-01

    The slipping zones of shallow sections of megathrusts and of large landslides are often smectite-rich (e.g., montmorillonite type). Consequently, similar "frictional" processes operating at high slip rates (> 1 m/s) might be responsible of the large slips estimated in megathrust (50 m for the 2011 Tohoku Mw 9.1 earthquake) and measured in large landslides (500 m for the 1963 Vajont slide, Italy). At present, only rotary shear apparatuses can reproduce simultaneously the large slips and slip rates of these events. Noteworthy, the frictional processes proposed so far (thermal and thermochemical pressurization, etc.) remain rather obscure. Here we present preliminary results obtained with the ROtary Shear Apparatus (ROSA) installed at Padua University. Thirty-one experiments were performed at ambient conditions on pure end-members of (1) smectite-rich standard powders (STx-1b: ~68 wt% Ca-montmorillonite, ~30 wt% opal-CT and ~2 wt% quartz), (2) quartz powders (qtz) and (3) on 80:20 = Stx-1b:qtz mixtures. The gouges were sandwiched between two (1) hollow (25/15 mm external/internal diameter) or (2) solid (25 mm in diameter) stainless-steel made cylinders and confined by inner and outer Teflon rings (only outer for solid cylinders). Gouges were sheared at a normal stress of 5 MPa, slip rates V from 300 μm/s to 1.5 m/s and total slip of 3 m. The deformed gouges were investigated with quantitative (Rietveld method with internal standard) X-ray powder diffraction (XRPD) and Scanning Electron Microscopy (SEM). In the smectite-rich standard endmember, (1) for 300 μm/s ≤ V ≤ 0.1 m/s, initial friction coefficient (μi) was 0.6±0.05 whereas the steady-state friction coefficient (μss) was velocity and slip strengthening (μss 0.85±0.05), (2) for 0.1 m/s 0.8 m/s, velocity and slip weakening (μi = 0.7±0.1 and μss = 0.25±0.05). In the 80:20 Stx-1b:qtz mixtures, (1) for 300 μm/s ≤ V ≤ 0.1 m/s, μi ranged was 0.7±0.05 and increased with slip to μss = 0.77±0

  8. Taking account of sample finite dimensions in processing measurements of double differential cross sections of slow neutron scattering

    International Nuclear Information System (INIS)

    Lisichkin, Yu.V.; Dovbenko, A.G.; Efimenko, B.A.; Novikov, A.G.; Smirenkina, L.D.; Tikhonova, S.I.

    1979-01-01

    Described is a method of taking account of finite sample dimensions in processing measurement results of double differential cross sections (DDCS) of slow neutron scattering. A necessity of corrective approach to the account taken of the effect of sample finite dimensions is shown, and, in particular, the necessity to conduct preliminary processing of DDCS, the account being taken of attenuation coefficients of single scattered neutrons (SSN) for measurements on the sample with a container, and on the container. Correction for multiple scattering (MS) calculated on the base of the dynamic model should be obtained, the account being taken of resolution effects. To minimize the effect of the dynamic model used in calculations it is preferred to make absolute measurements of DDCS and to use the subraction method. The above method was realized in the set of programs for the BESM-5 computer. The FISC program computes the coefficients of SSN attenuation and correction for MS. The DDS program serves to compute a model DDCS averaged as per the resolution function of an instrument. The SCATL program is intended to prepare initial information necessary for the FISC program, and permits to compute the scattering law for all materials. Presented are the results of using the above method while processing experimental data on measuring DDCS of water by the DIN-1M spectrometer

  9. Processing biogas to obtain motor fuel - Operational experience

    International Nuclear Information System (INIS)

    Seifert, M.

    2008-01-01

    This article takes a look at how raw biogas can be processed in order to remove carbon dioxide and corrosive substances and thus bring it up to natural gas quality. The ecological advantages of using biogas as a fuel are discussed and the situation in Europe and Switzerland is examined. Also, feeding biogas into the normal natural gas mains is discussed and the technologies necessary for the cleaning and preparation of the biogas are described. These include absorption and adsorption processes as well as membrane systems that are used to remove excessive carbon dioxide. The costs involved are discussed on the basis of experience gained in Sweden and Switzerland. Finally, the environmental aspects of methane losses are discussed.

  10. The Role of Motor Processes in Three-Dimensional Mental Rotation: Shaping Cognitive Processing via Sensorimotor Experience

    Science.gov (United States)

    Moreau, David

    2012-01-01

    An extensive body of literature has explored the involvement of motor processes in mental rotation, yet underlying individual differences are less documented and remain to be fully understood. We propose that sensorimotor experience shapes spatial abilities such as assessed in mental rotation tasks. Elite wrestlers' and non-athletes' mental…

  11. Motor cognitive processing speed estimation among the primary schoolchildren by deriving prediction formula: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Vencita Priyanka Aranha

    2017-01-01

    Full Text Available Objectives: Motor cognitive processing speed (MCPS is often reported in terms of reaction time. In spite of being a significant indicator of function, behavior, and performance, MCPS is rarely used in clinics and schools to identify kids with slowed motor cognitive processing. The reason behind this is the lack of availability of convenient formula to estimate MCPS. Thereby, the aim of this study is to estimate the MCPS in the primary schoolchildren. Materials and Methods: Two hundred and four primary schoolchildren, aged 6–12 years, were recruited by the cluster sampling method for this cross-sectional study. MCPS was estimated by the ruler drop method (RDM. By this method, a metallic stainless steel ruler was suspended vertically such that 5 cm graduation of the lower was aligned between the web space of the child's hand, and the child was asked to catch the moving ruler as quickly as possible, once released from the examiner's hand. Distance the ruler traveled was recorded and converted into time, which is the MCPS. Multiple regression analysis of variables was performed to determine the influence of independent variables on MCPS. Results: Mean MCPS of the entire sample of 204 primary schoolchildren is 230.01 ms ± 26.5 standard deviation (95% confidence interval; 226.4–233.7 ms that ranged from 162.9 to 321.6 ms. By stepwise regression analysis, we derived the regression equation, MCPS (ms = 279.625–5.495 × age, with 41.3% (R = 0.413 predictability and 17.1% (R2 = 0.171 and adjusted R2 = 0.166 variability. Conclusion: MCPS prediction formula through RDM in the primary schoolchildren has been established.

  12. Effect Of Variable Practice On The Motor Learning Process In Manual Wheelchair Propulsion

    NARCIS (Netherlands)

    Leving, Marika T; Vegter, Riemer J K; de Groot, Sonja; van der Woude, Lucas H V

    Handrim wheelchair propulsion is a cyclic skill that needs to be learned during rehabilitation. It has been suggested that a higher intra-individual variability benefits the motor learning process of wheelchair propulsion. PURPOSE: The goal of the current study was to determine the effect of

  13. Epigenomic maintenance through dietary intervention can facilitate DNA repair process to slow down the progress of premature aging.

    Science.gov (United States)

    Ghosh, Shampa; Sinha, Jitendra Kumar; Raghunath, Manchala

    2016-09-01

    DNA damage caused by various sources remains one of the most researched topics in the area of aging and neurodegeneration. Increased DNA damage causes premature aging. Aging is plastic and is characterised by the decline in the ability of a cell/organism to maintain genomic stability. Lifespan can be modulated by various interventions like calorie restriction, a balanced diet of macro and micronutrients or supplementation with nutrients/nutrient formulations such as Amalaki rasayana, docosahexaenoic acid, resveratrol, curcumin, etc. Increased levels of DNA damage in the form of double stranded and single stranded breaks are associated with decreased longevity in animal models like WNIN/Ob obese rats. Erroneous DNA repair can result in accumulation of DNA damage products, which in turn result in premature aging disorders such as Hutchinson-Gilford progeria syndrome. Epigenomic studies of the aging process have opened a completely new arena for research and development of drugs and therapeutic agents. We propose here that agents or interventions that can maintain epigenomic stability and facilitate the DNA repair process can slow down the progress of premature aging, if not completely prevent it. © 2016 IUBMB Life, 68(9):717-721, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

  14. Comparison of performance on process- and product-oriented assessments of fundamental motor skills across childhood.

    Science.gov (United States)

    Logan, Samuel W; Barnett, Lisa M; Goodway, Jacqueline D; Stodden, David F

    2017-04-01

    Process-oriented motor competence (MC) assessments evaluate how a movement is performed. Product-oriented assessments evaluate the outcome of a movement. Determining the concurrent validity of process and product assessments is important to address the predictive utility of motor competence for health. The current study aimed to: (1) compare process and product assessments of the standing long jump, hop and throw across age groups and (2) determine the capacity of process assessments to classify levels of MC. Participants included 170 children classified into three age groups: 4-5, 7-8 and 10-11 years old. Participants' skills were examined concurrently using three process assessments ((Test of Gross Motor Development-2nd edition [TGMD-2]), Get Skilled; Get Active, and developmental sequences) and one product measure (throw speed, jump and hop distance). Results indicate moderate to strong correlations between (1) process assessments across skills and age groups (r range = .37-70) and (2) process and product assessments across skills and age groups (r range = .26-.88). In general, sensitivity to detect advanced skill level is lowest for TGMD-2 and highest for developmental sequences for all three skills. The use of process and product assessments is suggested to comprehensively capture levels of MC in human movement.

  15. Molecular motors that digest their track to rectify Brownian motion: processive movement of exonuclease enzymes.

    Science.gov (United States)

    Xie, Ping

    2009-09-16

    A general model is presented for the processive movement of molecular motors such as λ-exonuclease, RecJ and exonuclease I that use digestion of a DNA track to rectify Brownian motion along this track. Using this model, the translocation dynamics of these molecular motors is studied. The sequence-dependent pausing of λ-exonuclease, which results from a site-specific high affinity DNA interaction, is also studied. The theoretical results are consistent with available experimental data. Moreover, the model is used to predict the lifetime distribution and force dependence of these paused states.

  16. Molecular motors that digest their track to rectify Brownian motion: processive movement of exonuclease enzymes

    International Nuclear Information System (INIS)

    Xie Ping

    2009-01-01

    A general model is presented for the processive movement of molecular motors such as λ-exonuclease, RecJ and exonuclease I that use digestion of a DNA track to rectify Brownian motion along this track. Using this model, the translocation dynamics of these molecular motors is studied. The sequence-dependent pausing of λ-exonuclease, which results from a site-specific high affinity DNA interaction, is also studied. The theoretical results are consistent with available experimental data. Moreover, the model is used to predict the lifetime distribution and force dependence of these paused states.

  17. POSITION CONTROL OF BRUSHLESS DC MOTOR BASED ON DIGITAL SIGNAL PROCESSING

    Directory of Open Access Journals (Sweden)

    Çetin GENÇER

    2006-01-01

    Full Text Available Brushless DC Motors (BLDC have been used widely high performance control systems which are depended on to development of power electronic and control technology. In these motors to fed commutated supply, the control of position without oscilation has been required. In this study, position control of BLDC with digital signal processing has been implemented by a proportional-derivative (PD controller because of its simple structure. It has been seen that the controller which is proposed from simulation and experimental studies, has a quick dynamic responce with nonoscillation.

  18. Brief Overview of Motor Learning and It's Application to Rehabilitation: Part Ⅰ: Motor Learning Theory

    Institute of Scientific and Technical Information of China (English)

    Christopher A Zaino

    2003-01-01

    @@ 1 DEFINITION OF MOTOR LEARNING Motor learning is the study of how we acquire and modify movements.1 The acquisition of motor skills is the process of learning how to do a particular movement (performance), but the real key to therapeutic intervention is being able to affect permanent changes in motor skills via the process of motor learning. Therefore, motor learning is defined as the ability to retain the ability to perform a motor task at a later time. In rehabilitation, it is important to be cognizant of the concepts of acquisition and retention. We can facilitate acquisition,but do little to assist in the retention of the task (learning). Conversely, we can arrange practice such that acquisition is slowed, but we can actually be assisting learning the task. It is important to have a clear goal in mind and work towards the eventual learning of the task to allow full functional use of that skill.

  19. Physiological basis and image processing in functional magnetic resonance imaging: Neuronal and motor activity in brain

    Directory of Open Access Journals (Sweden)

    Sharma Rakesh

    2004-05-01

    Full Text Available Abstract Functional magnetic resonance imaging (fMRI is recently developing as imaging modality used for mapping hemodynamics of neuronal and motor event related tissue blood oxygen level dependence (BOLD in terms of brain activation. Image processing is performed by segmentation and registration methods. Segmentation algorithms provide brain surface-based analysis, automated anatomical labeling of cortical fields in magnetic resonance data sets based on oxygen metabolic state. Registration algorithms provide geometric features using two or more imaging modalities to assure clinically useful neuronal and motor information of brain activation. This review article summarizes the physiological basis of fMRI signal, its origin, contrast enhancement, physical factors, anatomical labeling by segmentation, registration approaches with examples of visual and motor activity in brain. Latest developments are reviewed for clinical applications of fMRI along with other different neurophysiological and imaging modalities.

  20. Conscious motor processing and movement self-consciousness: two dimensions of personality that influence laparoscopic training.

    Science.gov (United States)

    Malhotra, Neha; Poolton, Jamie M; Wilson, Mark R; Fan, Joe K M; Masters, Rich S W

    2014-01-01

    Identifying personality factors that account for individual differences in surgical training and performance has practical implications for surgical education. Movement-specific reinvestment is a potentially relevant personality factor that has a moderating effect on laparoscopic performance under time pressure. Movement-specific reinvestment has 2 dimensions, which represent an individual's propensity to consciously control movements (conscious motor processing) or to consciously monitor their 'style' of movement (movement self-consciousness). This study aimed at investigating the moderating effects of the 2 dimensions of movement-specific reinvestment in the learning and updating (cross-handed technique) of laparoscopic skills. Medical students completed the Movement-Specific Reinvestment Scale, a psychometric assessment tool that evaluates the conscious motor processing and movement self-consciousness dimensions of movement-specific reinvestment. They were then trained to a criterion level of proficiency on a fundamental laparoscopic skills task and were tested on a novel cross-handed technique. Completion times were recorded for early-learning, late-learning, and cross-handed trials. Propensity for movement self-consciousness but not conscious motor processing was a significant predictor of task completion times both early (p = 0.036) and late (p = 0.002) in learning, but completion times during the cross-handed trials were predicted by the propensity for conscious motor processing (p = 0.04) rather than movement self-consciousness (p = 0.21). Higher propensity for movement self-consciousness is associated with slower performance times on novel and well-practiced laparoscopic tasks. For complex surgical techniques, however, conscious motor processing plays a more influential role in performance than movement self-consciousness. The findings imply that these 2 dimensions of movement-specific reinvestment have a differential influence in the learning and updating

  1. Sub-processes of motor learning revealed by a robotic manipulandum for rodents.

    Science.gov (United States)

    Lambercy, O; Schubring-Giese, M; Vigaru, B; Gassert, R; Luft, A R; Hosp, J A

    2015-02-01

    Rodent models are widely used to investigate neural changes in response to motor learning. Usually, the behavioral readout of motor learning tasks used for this purpose is restricted to a binary measure of performance (i.e. "successful" movement vs. "failure"). Thus, the assignability of research in rodents to concepts gained in human research - implying diverse internal models that constitute motor learning - is still limited. To solve this problem, we recently introduced a three-degree-of-freedom robotic platform designed for rats (the ETH-Pattus) that combines an accurate behavioral readout (in the form of kinematics) with the possibility to invasively assess learning related changes within the brain (e.g. by performing immunohistochemistry or electrophysiology in acute slice preparations). Here, we validate this platform as a tool to study motor learning by establishing two forelimb-reaching paradigms that differ in degree of skill. Both conditions can be precisely differentiated in terms of their temporal pattern and performance levels. Based on behavioral data, we hypothesize the presence of several sub-processes contributing to motor learning. These share close similarities with concepts gained in humans or primates. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Reconciling the influence of task-set switching and motor inhibition processes on stop signal after-effects

    Directory of Open Access Journals (Sweden)

    Joaquin A. Anguera

    2013-09-01

    Full Text Available Executive response functions can be affected by preceding events, even if they are no longer associated with the current task at hand. For example, studies utilizing the stop signal task have reported slower response times to ‘GO’ stimuli when the preceding trial involved the presentation of a ‘STOP’ signal. However, the neural mechanisms that underlie this behavioral after-effect are unclear. To address this, behavioral and electroencephalography (EEG measures were examined in 18 young adults (18-30yrs on 'GO' trials following a previously ‘Successful Inhibition’ trial (pSI, a previously ‘Failed Inhibition’ trial (pFI, and a previous ‘GO’ trial (pGO. Like previous research, slower response times were observed during both pSI and pFI trials (i.e., ‘GO’ trials that were preceded by a successful and unsuccessful inhibition trial, respectively compared to pGO trials (i.e., ‘GO’ trials that were preceded by another ‘GO’ trial. Interestingly, response time slowing was greater during pSI trials compared to pFI trials, suggesting executive control is influenced by both task set switching and persisting motor inhibition processes. Follow-up behavioral analyses indicated that these effects resulted from between-trial control adjustments rather than repetition priming effects. Analyses of inter-electrode coherence (IEC and inter-trial coherence (ITC indicated that both pSI and pFI trials showed greater phase synchrony during the inter-trial interval compared to pGO trials. Unlike the IEC findings, differential ITC was present within the beta and alpha frequency bands in line with the observed behavior (pSI > pFI > pGO, suggestive of more consistent phase synchrony involving motor inhibition processes during the ITI at a regional level. These findings suggest that between-trial control adjustments involved with task-set switching and motor inhibition processes influence subsequent performance, providing new insights into the

  3. Slow perceptual processing at the core of developmental dyslexia: a parameter-based assessment of visual attention.

    Science.gov (United States)

    Stenneken, Prisca; Egetemeir, Johanna; Schulte-Körne, Gerd; Müller, Hermann J; Schneider, Werner X; Finke, Kathrin

    2011-10-01

    The cognitive causes as well as the neurological and genetic basis of developmental dyslexia, a complex disorder of written language acquisition, are intensely discussed with regard to multiple-deficit models. Accumulating evidence has revealed dyslexics' impairments in a variety of tasks requiring visual attention. The heterogeneity of these experimental results, however, points to the need for measures that are sufficiently sensitive to differentiate between impaired and preserved attentional components within a unified framework. This first parameter-based group study of attentional components in developmental dyslexia addresses potentially altered attentional components that have recently been associated with parietal dysfunctions in dyslexia. We aimed to isolate the general attentional resources that might underlie reduced span performance, i.e., either a deficient working memory storage capacity, or a slowing in visual perceptual processing speed, or both. Furthermore, by analysing attentional selectivity in dyslexia, we addressed a potential lateralized abnormality of visual attention, i.e., a previously suggested rightward spatial deviation compared to normal readers. We investigated a group of high-achieving young adults with persisting dyslexia and matched normal readers in an experimental whole report and a partial report of briefly presented letter arrays. Possible deviations in the parametric values of the dyslexic compared to the control group were taken as markers for the underlying deficit. The dyslexic group showed a striking reduction in perceptual processing speed (by 26% compared to controls) while their working memory storage capacity was in the normal range. In addition, a spatial deviation of attentional weighting compared to the control group was confirmed in dyslexic readers, which was larger in participants with a more severe dyslexic disorder. In general, the present study supports the relevance of perceptual processing speed in disorders

  4. Motor dysfunction in complex regional pain syndrome : the role of sensory processing and sensory-motor integration

    NARCIS (Netherlands)

    Bank, Paulina Johanna Maria

    2014-01-01

    In the chronic stage of Complex Regional Pain Syndrome (CRPS), motor disturbances are common and cause significant disability. The motor dysfunction of CRPS is a poorly understood phenomenon that is characterized predominantly by a decrease or loss of voluntary muscle control. This thesis aims to

  5. How Kinesthetic Motor Imagery works: a predictive-processing theory of visualization in sports and motor expertise.

    Science.gov (United States)

    Ridderinkhof, K Richard; Brass, Marcel

    2015-01-01

    Kinesthetic Motor Imagery (KMI) is an important technique to acquire and refine motor skills. KMI is widely used by professional athletes as an effective way to improve motor performance without overt motor output. Despite this obvious relevance, the functional mechanisms and neural circuits involved in KMI in sports are still poorly understood. In the present article, which aims at bridging the sport sciences and cognitive neurophysiology literatures, we give a brief overview of relevant research in the field of KMI. Furthermore, we develop a theoretical account that relates KMI to predictive motor control theories assuming that it is based on internal activation of anticipatory images of action effects. This mechanism allows improving motor performance solely based on internal emulation of action. In accordance with previous literature, we propose that this emulation mechanism is implemented in brain regions that partially overlap with brain areas involved in overt motor performance including the posterior parietal cortex, the cerebellum, the basal ganglia and the premotor cortex. Finally, we outline one way to test the heuristic value of our theoretical framework for KMI; we suggest that experience with motor performance improves the ability to correctly infer the goals of others, in particular in penalty blocking in soccer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The effect of deep and slow breathing on pain perception, autonomic activity, and mood processing--an experimental study.

    Science.gov (United States)

    Busch, Volker; Magerl, Walter; Kern, Uwe; Haas, Joachim; Hajak, Göran; Eichhammer, Peter

    2012-02-01

    Deep and slow breathing (DSB) techniques, as a component of various relaxation techniques, have been reported as complementary approaches in the treatment of chronic pain syndromes, but the relevance of relaxation for alleviating pain during a breathing intervention was not evaluated so far. In order to disentangle the effects of relaxation and respiration, we investigated two different DSB techniques at the same respiration rates and depths on pain perception, autonomic activity, and mood in 16 healthy subjects. In the attentive DSB intervention, subjects were asked to breathe guided by a respiratory feedback task requiring a high degree of concentration and constant attention. In the relaxing DSB intervention, the subjects relaxed during the breathing training. The skin conductance levels, indicating sympathetic tone, were measured during the breathing maneuvers. Thermal detection and pain thresholds for cold and hot stimuli and profile of mood states were examined before and after the breathing sessions. The mean detection and pain thresholds showed a significant increase resulting from the relaxing DSB, whereas no significant changes of these thresholds were found associated with the attentive DSB. The mean skin conductance levels indicating sympathetic activity decreased significantly during the relaxing DSB intervention but not during the attentive DSB. Both breathing interventions showed similar reductions in negative feelings (tension, anger, and depression). Our results suggest that the way of breathing decisively influences autonomic and pain processing, thereby identifying DSB in concert with relaxation as the essential feature in the modulation of sympathetic arousal and pain perception. Wiley Periodicals, Inc.

  7. How does the interaction between spelling and motor processes build up during writing acquisition?

    Science.gov (United States)

    Kandel, Sonia; Perret, Cyril

    2015-03-01

    How do we recall a word's spelling? How do we produce the movements to form the letters of a word? Writing involves several processing levels. Surprisingly, researchers have focused either on spelling or motor production. However, these processes interact and cannot be studied separately. Spelling processes cascade into movement production. For example, in French, producing letters PAR in the orthographically irregular word PARFUM (perfume) delays motor production with respect to the same letters in the regular word PARDON (pardon). Orthographic regularity refers to the possibility of spelling a word correctly by applying the most frequent sound-letter conversion rules. The present study examined how the interaction between spelling and motor processing builds up during writing acquisition. French 8-10 year old children participated in the experiment. This is the age handwriting skills start to become automatic. The children wrote regular and irregular words that could be frequent or infrequent. They wrote on a digitizer so we could collect data on latency, movement duration and fluency. The results revealed that the interaction between spelling and motor processing was present already at age 8. It became more adult-like at ages 9 and 10. Before starting to write, processing irregular words took longer than regular words. This processing load spread into movement production. It increased writing duration and rendered the movements more dysfluent. Word frequency affected latencies and cascaded into production. It modulated writing duration but not movement fluency. Writing infrequent words took longer than frequent words. The data suggests that orthographic regularity has a stronger impact on writing than word frequency. They do not cascade in the same extent. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. [Motor capacities involved in the psychomotor skills of the cardiopulmonary resuscitation technique: recommendations for the teaching-learning process].

    Science.gov (United States)

    Miyadahira, A M

    2001-12-01

    It is a bibliographic study about the identification of the motor capacities involved in the psychomotor skills of the cardiopulmonary resuscitation (CPR) which aims to obtain subsidies to the planning of the teaching-learning process of this skill. It was found that: the motor capacities involved in the psychomotor skill of the CPR technique are predominantly cognitive and motor, involving 9 perceptive-motor capacities and 8 physical proficiency capacities. The CPR technique is a psychomotor skill classified as open, done in series and categorized as a thin and global skill and the teaching-learning process of the CPR technique has an elevated degree of complexity.

  9. Kinesin-73 is a processive motor that localizes to Rab5-containing organelles.

    Science.gov (United States)

    Huckaba, Thomas M; Gennerich, Arne; Wilhelm, James E; Chishti, Athar H; Vale, Ronald D

    2011-03-04

    Drosophila Kinesin-73 (Khc-73), which plays a role in mitotic spindle polarity in neuroblasts, is a metazoan-specific member of the Kinesin-3 family of motors, which includes mammalian KIF1A and Caenorhabditis elegans Unc-104. The mechanism of Kinesin-3 motors has been controversial because some studies have reported that they transport cargo as monomers whereas other studies have suggested a dimer mechanism. Here, we have performed single-molecule motility and cell biological studies of Khc-73. We find that constructs containing the motor and the conserved short stretches of putative coiled-coil-forming regions are predominantly monomeric in vitro, but that dimerization allows for fast, processive movement and high force production (7 piconewtons). In Drosophila cell lines, we present evidence that Khc-73 can dimerize in vivo. We also show that Khc-73 is recruited specifically to Rab5-containing endosomes through its "tail" domain. Our results suggest that the N-terminal half of Khc-73 can undergo a monomer-dimer transition to produce a fast processive motor and that its C-terminal half possesses a specific Rab5-vesicle binding domain.

  10. Increased Reliance on Value-based Decision Processes Following Motor Cortex Disruption.

    Science.gov (United States)

    Zénon, Alexandre; Klein, Pierre-Alexandre; Alamia, Andrea; Boursoit, François; Wilhelm, Emmanuelle; Duque, Julie

    2015-01-01

    During motor decision making, the neural activity in primary motor cortex (M1) encodes dynamically the competition occurring between potential action plans. A common view is that M1 represents the unfolding of the outcome of a decision process taking place upstream. Yet, M1 could also be directly involved in the decision process. Here we tested this hypothesis by assessing the effect of M1 disruption on a motor decision-making task. We applied continuous theta burst stimulation (cTBS) to inhibit either left or right M1 in different groups of subjects and included a third control group with no stimulation. Following cTBS, participants performed a task that required them to choose between two finger key-presses with the right hand according to both perceptual and value-based information. Effects were assessed by means of generalized linear mixed models and computational simulations. In all three groups, subjects relied both on perceptual (P < 0.0001) and value-based information (P = 0.003) to reach a decision. Yet, left M1 disruption led to an increased reliance on value-based information (P = 0.03). This result was confirmed by a computational model showing an increased weight of the valued-based process on the right hand finger choices following left M1 cTBS (P < 0.01). These results indicate that M1 is involved in motor decision making, possibly by weighting the final integration of multiple sources of evidence driving motor behaviors. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. The "handwriting brain": a meta-analysis of neuroimaging studies of motor versus orthographic processes.

    Science.gov (United States)

    Planton, Samuel; Jucla, Mélanie; Roux, Franck-Emmanuel; Démonet, Jean-François

    2013-01-01

    Handwriting is a modality of language production whose cerebral substrates remain poorly known although the existence of specific regions is postulated. The description of brain damaged patients with agraphia and, more recently, several neuroimaging studies suggest the involvement of different brain regions. However, results vary with the methodological choices made and may not always discriminate between "writing-specific" and motor or linguistic processes shared with other abilities. We used the "Activation Likelihood Estimate" (ALE) meta-analytical method to identify the cerebral network of areas commonly activated during handwriting in 18 neuroimaging studies published in the literature. Included contrasts were also classified according to the control tasks used, whether non-specific motor/output-control or linguistic/input-control. These data were included in two secondary meta-analyses in order to reveal the functional role of the different areas of this network. An extensive, mainly left-hemisphere network of 12 cortical and sub-cortical areas was obtained; three of which were considered as primarily writing-specific (left superior frontal sulcus/middle frontal gyrus area, left intraparietal sulcus/superior parietal area, right cerebellum) while others related rather to non-specific motor (primary motor and sensorimotor cortex, supplementary motor area, thalamus and putamen) or linguistic processes (ventral premotor cortex, posterior/inferior temporal cortex). This meta-analysis provides a description of the cerebral network of handwriting as revealed by various types of neuroimaging experiments and confirms the crucial involvement of the left frontal and superior parietal regions. These findings provide new insights into cognitive processes involved in handwriting and their cerebral substrates. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Planning-related motor processes underlie mental practice and imitation learning.

    Science.gov (United States)

    Bach, Patric; Allami, Bassem Khalaf; Tucker, Mike; Ellis, Rob

    2014-06-01

    It is still controversial whether mental practice-the internal rehearsal of movements to improve later performance-relies on processes engaged during physical motor performance and, if so, which processes these are. We report data from 5 experiments, in which participants mentally practiced complex rhythms with either feet or hands while using the same or different body parts to respond to unrelated sounds. We found that responses were impaired for those body parts that were concurrently used in mental practice, suggesting a binding of body-part-specific motor processes to action plans. This result was found when participants mentally trained to memorize the rhythms, to merely improve their performance, when mental practice and execution directly followed one another and when separated by a different task. Finally, it was found irrespective of whether participants practiced on the basis of a symbolic rhythm description and when they practiced by watching somebody perform the rhythms (imitation learning). The effect was eliminated only when the requirement for mental practice was eliminated from the task while keeping visual stimulation identical. These data link mental practice not to execution but planning related motor processes and reveal that these planning processes underlie both mental practice and imitation learning. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  13. Fast or slow-foods? Describing natural variations in oral processing characteristics across a wide range of Asian foods.

    Science.gov (United States)

    Forde, C G; Leong, C; Chia-Ming, E; McCrickerd, K

    2017-02-22

    The structural properties of foods have a functional role to play in oral processing behaviours and sensory perception, and also impact on meal size and the experience of fullness. This study adopted a new approach by using behavioural coding analysis of eating behaviours to explore how a range of food textures manifest as the microstructural properties of eating and expectations of fullness. A selection of 47 Asian foods were served in fixed quantities to a panel of participants (N = 12) and their eating behaviours were captured via web-camera recordings. Behavioural coding analysis was completed on the recordings to extract total bites, chews and swallows and cumulative time of the food spent in the mouth. From these measurements a series of microstructural properties including average bite size (g), chews per bite, oro-sensory exposure time (seconds) and average eating rate (g min -1 ) were derived per food. The sensory and macronutrient properties of each food were correlated with the microstructure of eating to compare the differences in eating behaviour on a gram for gram basis. There were strong relationships between the perceived food textural properties and its eating behaviours and a food's total water content was the best predictor of its eating rate. Foods that were eaten at a slower eating rate, with smaller bites and more chews per bite were rated as higher in the expected fullness. These relationships are important as oral processing behaviours and beliefs about the potential satiating value of food influence portion decisions and moderate meal size. These data support the idea that naturally occurring differences in the food structure and texture could be used to design meals that slow the rate of eating and maximise fullness.

  14. Using Low-Frequency Earthquakes to Investigate Slow Slip Processes and Plate Interface Structure Beneath the Olympic Peninsula, WA

    Science.gov (United States)

    Chestler, Shelley

    This dissertation seeks to further understand the LFE source process, the role LFEs play in generating slow slip, and the utility of using LFEs to examine plate interface structure. The work involves the creation and investigation of a 2-year-long catalog of low-frequency earthquakes beneath the Olympic Peninsula, Washington. In the first chapter, we calculate the seismic moments for 34,264 low-frequency earthquakes (LFEs) beneath the Olympic Peninsula, WA. LFE moments range from 1.4x1010- 1.9x1012 N-m (M W=0.7-2.1). While regular earthquakes follow a power-law moment-frequency distribution with a b-value near 1 (the number of events increases by a factor of 10 for each unit increase in MW), we find that while for large LFEs the b-value is ˜6, for small LFEs it is families, or spots on the plate interface where LFEs repeat, can also be fit by exponential distributions. An exponential moment-frequency distribution implies a scale-limited source process. We consider two end-member models where LFE moment is limited by (1) the amount of slip or (2) slip area. We favor the area-limited model. Based on the observed exponential distribution of LFE moment and geodetically observed total slip we estimate that the total area that slips within an LFE family has a diameter of 300 m. Assuming an area-limited model, we estimate the slips, sub-patch diameters, stress drops, and slip rates for LFEs during ETS events. We allow for LFEs to rupture smaller sub-patches within the LFE family patch. Models with 1-10 sub-patches produce slips of 0.1-1 mm, sub-patch diameters of 80-275 m, and stress drops of 30-1000 kPa. While one sub-patch is often assumed, we believe 3-10 sub-patches are more likely. In the second chapter, using high-resolution relative low-frequency earthquake (LFE) locations, we calculate the patch areas (Ap) of LFE families. During Episodic Tremor and Slip (ETS) events, we define AT as the area that slips during LFEs and ST as the total amount of summed LFE slip

  15. Slow-transit Constipation.

    Science.gov (United States)

    Bharucha, Adil E.; Philips, Sidney F.

    2001-08-01

    Idiopathic slow-transit constipation is a clinical syndrome predominantly affecting women, characterized by intractable constipation and delayed colonic transit. This syndrome is attributed to disordered colonic motor function. The disorder spans a spectrum of variable severity, ranging from patients who have relatively mild delays in transit but are otherwise indistinguishable from irritable bowel syndrome to patients with colonic inertia or chronic megacolon. The diagnosis is made after excluding colonic obstruction, metabolic disorders (hypothyroidism, hypercalcemia), drug-induced constipation, and pelvic floor dysfunction (as discussed by Wald ). Most patients are treated with one or more pharmacologic agents, including dietary fiber supplementation, saline laxatives (milk of magnesia), osmotic agents (lactulose, sorbitol, and polyethylene glycol 3350), and stimulant laxatives (bisacodyl and glycerol). A subtotal colectomy is effective and occasionally is indicated for patients with medically refractory, severe slow-transit constipation, provided pelvic floor dysfunction has been excluded or treated.

  16. Slow information processing after very severe closed head injury : impaired access to declarative knowledge and intact application and acquisition of procedural knowledge

    NARCIS (Netherlands)

    Timmerman, ME; Brouwer, WH

    As an explanation of the pattern of slow information processing after closed head injury (CHI), hypotheses of impaired access to declarative memory and intact application and acquisition of procedural memory after CHI are presented. These two hypotheses were tested by means of four cognitive

  17. Cohesive zone model for intergranular slow crack growth in ceramics: influence of the process and the microstructure

    International Nuclear Information System (INIS)

    Romero de la Osa, M; Olagnon, C; Chevalier, J; Estevez, R; Tallaron, C

    2011-01-01

    Ceramic polycrystals are prone to slow crack growth (SCG) which is stress and environmentally assisted, similarly to observations reported for silica glasses. The kinetics of fracture are known to be dependent on the load level, the temperature and the relative humidity. In addition, evidence is available on the influence of the microstructure on the SCG rate with an increase in the crack velocity with decreasing the grain size. Crack propagation takes place beyond a load threshold, which is grain size dependent. We present a cohesive zone model for the intergranular failure process. The methodology accounts for an intrinsic opening that governs the length of the cohesive zone and allows the investigation of grain size effects. A rate and temperature-dependent cohesive model is proposed (Romero de la Osa M, Estevez R et al 2009 J. Mech. Adv. Mater. Struct. 16 623–31) to mimic the reaction–rupture mechanism. The formulation is inspired by Michalske and Freiman's picture (Michalske and Freiman 1983 J. Am. Ceram. Soc. 66 284–8) together with a recent study by Zhu et al (2005 J. Mech. Phys. Solids 53 1597–623) of the reaction–rupture mechanism. The present investigation extends a previous work (Romero de la Osa et al 2009 Int. J. Fracture 158 157–67) in which the problem is formulated. Here, we explore the influence of the microstructure in terms of grain size, their elastic properties and residual thermal stresses originating from the cooling from the sintering temperature down to ambient conditions. Their influence on SCG for static loadings is reported and the predictions compared with experimental trends. We show that the initial stress state is responsible for the grain size dependence reported experimentally for SCG. Furthermore, the account for the initial stresses enables the prediction of a load threshold below which no crack growth is observed: a crack arrest takes place when the crack path meets a region in compression

  18. Language for action: Motor resonance during the processing of human and robotic voices.

    Science.gov (United States)

    Di Cesare, G; Errante, A; Marchi, M; Cuccio, V

    2017-11-01

    In this fMRI study we evaluated whether the auditory processing of action verbs pronounced by a human or a robotic voice in the imperative mood differently modulates the activation of the mirror neuron system (MNs). The study produced three results. First, the activation pattern found during listening to action verbs was very similar in both the robot and human conditions. Second, the processing of action verbs compared to abstract verbs determined the activation of the fronto-parietal circuit classically involved during the action goal understanding. Third, and most importantly, listening to action verbs compared to abstract verbs produced activation of the anterior part of the supramarginal gyrus (aSMG) regardless of the condition (human and robot) and in the absence of any object name. The supramarginal gyrus is a region considered to underpin hand-object interaction and associated to the processing of affordances. These results suggest that listening to action verbs may trigger the recruitment of motor representations characterizing affordances and action execution, coherently with the predictive nature of motor simulation that not only allows us to re-enact motor knowledge to understand others' actions but also prepares us for the actions we might need to carry out. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Slow Antihydrogen

    International Nuclear Information System (INIS)

    Gabrielse, G.; Speck, A.; Storry, C.H.; Le Sage, D.; Guise, N.; Larochelle, P.C.; Grzonka, D.; Oelert, W.; Schepers, G.; Sefzick, T.; Pittner, H.; Herrmann, M.; Walz, J.; Haensch, T.W.; Comeau, D.; Hessels, E.A.

    2004-01-01

    Slow antihydrogen is now produced by two different production methods. In Method I, large numbers of H atoms are produced during positron-cooling of antiprotons within a nested Penning trap. In a just-demonstrated Method II, lasers control the production of antihydrogen atoms via charge exchange collisions. Field ionization detection makes it possible to probe the internal structure of the antihydrogen atoms being produced - most recently revealing atoms that are too tightly bound to be well described by the guiding center atom approximation. The speed of antihydrogen atoms has recently been measured for the first time. After the requested overview, the recent developments are surveyed

  20. Deficits in motor control processes involved in the production of graphomotor movements in children with Attention-Deficit Hyperactivity Disorder

    NARCIS (Netherlands)

    Schoemaker, MM; Ketelaars, Cornelis; van Zonneveld, M; Minderaa, RB; Mulder, T

    This study aimed to investigate whether two distinct motor control processes, i.e. motor planning and parameter setting, were impaired in children with attention-deficit-hyperactivity disorder (ADHD). An experiment was designed in which children copied figures of increasing complexity under

  1. The influence of slow cooling on Y211 size and content in single-grain YBCO bulk superconductor through the infiltration-growth process

    Energy Technology Data Exchange (ETDEWEB)

    Ouerghi, A [Systems and Applied Mechanics Laboratory LASMAP, Polytechnic School of Tunisia, Rue El Kawarezmi La Marsa 743, Université de Carthage Tunis (Tunisia); Moutalbi, N., E-mail: nahed.moutalbi@yahoo.fr [Systems and Applied Mechanics Laboratory LASMAP, Polytechnic School of Tunisia, Rue El Kawarezmi La Marsa 743, Université de Carthage Tunis (Tunisia); Noudem, J.G. [CRISMAT-ENSICAEN (UMR-CNRS 6508), Université de Caen-Basse-Normandie, F-14050 Caen (France); LUSAC, Université de Caen-Basse-Normandie F-50130 Cherbourg-Octeville (France); M' chirgui, A. [Systems and Applied Mechanics Laboratory LASMAP, Polytechnic School of Tunisia, Rue El Kawarezmi La Marsa 743, Université de Carthage Tunis (Tunisia)

    2017-03-15

    Highlights: • YBCO bulk superconductors are produced by optimized Seeded Infiltration and Growth process. • The slow cooling time, in a fixed slow cooling temperature window, affects considerably the surface morphology and the bulk’s microstructure. • The Y211 particle’s size and content depend on the slow cooling time and its distribution behavior changes from one position to another. • There is an optimum slow cooling time, estimated to 88h, over which the shrinkage for both the liquid phase and the Y211 pellet is maximal, without any improvement of the crystal grain growth. • The magnetic trapped flux distribution for a given sample brings out the single grain characteristic. - Abstract: Highly textured YBa{sub 2}Cu{sub 3}O{sub 7-δ} (Y123) superconductors were produced using modified Textured Top Seeded Infiltration Growth (TSIG) process. The liquid source is made of only Y123 powder whereas the solid source is composed of Y{sub 2}BaCuO{sub 5} (Y211) powder. We aim to control the amount of liquid that infiltrates the solid pellet, which in turn controls the final amount of Y{sub 2}BaCuO{sub 5} particles in Y123 matrix. The effect of the slow cooling kinetics on sample morphology, on grain growth and on final microstructure was too investigated. It is shown that appropriate slow cooling time may also contribute to the control of the amount of Y211 inclusions in the final structure of Y123 bulk. We report herein the Y211 particle size and density distribution in the whole Y123 matrix. The present work proves that finest Y211 particles locate under the seed and that their size and density increase with distance from the seed.

  2. RESONANT PROCESSES IN STARTING MODES OF SYNCHRONOUS MOTORS WITH CAPACITORS IN THE EXCITATION WINDINGS CIRCUIT

    Directory of Open Access Journals (Sweden)

    V. S. Malyar

    2017-08-01

    Full Text Available Purpose. Development of a mathematical model that enables to detect resonance modes during asynchronous startup of salient-pole synchronous motors, in which capacitors are switched on to increase the electromagnetic moment in the circuit of the excitation winding. Methodology. The asynchronous mode is described by a system of differential equations of the electric equilibrium of motor circuits written in orthogonal coordinate axes. The basis of the developed algorithm is the mathematical model of the high-level adequacy motor and the projection method for solving the boundary value problem for the equations of the electric equilibrium of the circuits written in orthogonal coordinate axes, taking into account the presence of capacitors in the excitation winding. The coefficients of differential equations are the differential inductances of the motor circuits, which are determined on the basis of the calculation of its magnetic circuit. As a result of the asymmetry of the rotor windings in the asynchronous mode, the current coupling and currents change according to the periodic law. The problem of its definition is solved as a boundary one. Results. A mathematical model for studying the asynchronous characteristics of synchronous motors with capacitors in an excitation winding is developed, by means of which it is possible to investigate the influence of the size of the capacity on the motor's starting properties and the resonance processes which may arise in this case. Scientific novelty. The developed method of mathematical modeling is based on a fundamentally new mathematical basis for the calculation of stationary dynamic modes of nonlinear electromagnetic circuits, which enables to obtain periodic coordinate dependencies, without resorting to the calculation of the transients. The basis of the developed algorithm is based on the approximation of state variables by cubic splines, the projection method of decomposition for the boundary value

  3. Cognitive alterations in motor imagery process after left hemispheric ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Jing Yan

    Full Text Available BACKGROUND: Motor imagery training is a promising rehabilitation strategy for stroke patients. However, few studies had focused on the neural mechanisms in time course of its cognitive process. This study investigated the cognitive alterations after left hemispheric ischemic stroke during motor imagery task. METHODOLOGY/PRINCIPAL FINDINGS: Eleven patients with ischemic stroke in left hemisphere and eleven age-matched control subjects participated in mental rotation task (MRT of hand pictures. Behavior performance, event-related potential (ERP and event-related (desynchronization (ERD/ERS in beta band were analyzed to investigate the cortical activation. We found that: (1 The response time increased with orientation angles in both groups, called "angle effect", however, stoke patients' responses were impaired with significantly longer response time and lower accuracy rate; (2 In early visual perceptual cognitive process, stroke patients showed hypo-activations in frontal and central brain areas in aspects of both P200 and ERD; (3 During mental rotation process, P300 amplitude in control subjects decreased while angle increased, called "amplitude modulation effect", which was not observed in stroke patients. Spatially, patients showed significant lateralization of P300 with activation only in contralesional (right parietal cortex while control subjects showed P300 in both parietal lobes. Stroke patients also showed an overall cortical hypo-activation of ERD during this sub-stage; (4 In the response sub-stage, control subjects showed higher ERD values with more activated cortical areas particularly in the right hemisphere while angle increased, named "angle effect", which was not observed in stroke patients. In addition, stroke patients showed significant lower ERD for affected hand (right response than that for unaffected hand. CONCLUSIONS/SIGNIFICANCE: Cortical activation was altered differently in each cognitive sub-stage of motor imagery after

  4. Constraining movement alters the recruitment of motor processes in mental rotation.

    Science.gov (United States)

    Moreau, David

    2013-02-01

    Does mental rotation depend on the readiness to act? Recent evidence indicates that the involvement of motor processes in mental rotation is experience-dependent, suggesting that different levels of expertise in sensorimotor interactions lead to different strategies to solve mental rotation problems. Specifically, experts in motor activities perceive spatial material as objects that can be acted upon, triggering covert simulation of rotations. Because action simulation depends on the readiness to act, movement restriction should therefore disrupt mental rotation performance in individuals favoring motor processes. In this experiment, wrestlers and non-athletes judged whether pairs of three-dimensional stimuli were identical or different, with their hands either constrained or unconstrained. Wrestlers showed higher performance than controls in the rotation of geometric stimuli, but this difference disappeared when their hands were constrained. However, movement restriction had similar consequences for both groups in the rotation of hands. These findings suggest that expert's advantage in mental rotation of abstract objects is based on the readiness to act, even when physical manipulation is impossible.

  5. DIAGNOSTICS OF MOTOR ABILITY AS A BASE OF CORRECTION PLANNING OF TRANSFORMATION PROCESSES IN SPECIAL POPULATIONS

    Directory of Open Access Journals (Sweden)

    Kosta Goranović

    2011-08-01

    Full Text Available In the research, at sample of 80 tested, employees in the special police force, as representatives of police population age from 20 to 25, diagnostics of motor potential in transitive period of annual macrostructure was done. The aim of the research was doing potential correction in planning and programming of transformation process in the next cycles of sports preparation on the base of diagnosed quantitative value of motor abilities. Besides analyses of achieved values, the difference was established between two leading teams in the space of measuring potential. The research results indicated to statistically important differences between two groups of tested people, as well as to unacceptable level of development in some abilities. The achieved results are, from aspect of training process’ control, the indicator to instructors’ team on the need of correction of transformation process’ content, with aim of improving bad segments. Diagnostics of motor abilities with measuring instruments in terrain conditions is one of methods, which can be in function of valorising transformation process of the special police force, taking into account specifics of their professional manifestation.

  6. iPSC-Based Models to Unravel Key Pathogenetic Processes Underlying Motor Neuron Disease Development

    Directory of Open Access Journals (Sweden)

    Irene Faravelli

    2014-10-01

    Full Text Available Motor neuron diseases (MNDs are neuromuscular disorders affecting rather exclusively upper motor neurons (UMNs and/or lower motor neurons (LMNs. The clinical phenotype is characterized by muscular weakness and atrophy leading to paralysis and almost invariably death due to respiratory failure. Adult MNDs include sporadic and familial amyotrophic lateral sclerosis (sALS-fALS, while the most common infantile MND is represented by spinal muscular atrophy (SMA. No effective treatment is ccurrently available for MNDs, as for the vast majority of neurodegenerative disorders, and cures are limited to supportive care and symptom relief. The lack of a deep understanding of MND pathogenesis accounts for the difficulties in finding a cure, together with the scarcity of reliable in vitro models. Recent progresses in stem cell field, in particular in the generation of induced Pluripotent Stem Cells (iPSCs has made possible for the first time obtaining substantial amounts of human cells to recapitulate in vitro some of the key pathogenetic processes underlying MNDs. In the present review, recently published studies involving the use of iPSCs to unravel aspects of ALS and SMA pathogenesis are discussed with an overview of their implications in the process of finding a cure for these still orphan disorders.

  7. Discerning measures of conscious brain processes associated with superior early motor performance: Capacity, coactivation, and character.

    Science.gov (United States)

    van Duijn, Tina; Buszard, Tim; Hoskens, Merel C J; Masters, Rich S W

    2017-01-01

    This study explored the relationship between working memory (WM) capacity, corticocortical communication (EEG coherence), and propensity for conscious control of movement during the performance of a complex far-aiming task. We were specifically interested in the role of these variables in predicting motor performance by novices. Forty-eight participants completed (a) an assessment of WM capacity (an adapted Rotation Span task), (b) a questionnaire that assessed the propensity to consciously control movement (the Movement Specific Reinvestment Scale), and (c) a hockey push-pass task. The hockey push-pass task was performed in a single task (movement only) condition and a combined task (movement plus decision) condition. Electroencephalography (EEG) was used to examine brain activity during the single task. WM capacity best predicted single task performance. WM capacity in combination with T8-Fz coherence (between the visuospatial and motor regions of the brain) best predicted combined task performance. We discuss the implied roles of visuospatial information processing capacity, neural coactivation, and propensity for conscious processing during performance of complex motor tasks. © 2017 Elsevier B.V. All rights reserved.

  8. Crossfit training in the process of preparation of the motorized athletes

    Directory of Open Access Journals (Sweden)

    Krzysztof Byzdra

    2017-08-01

    Full Text Available The work describes the impact of crossfit training on the level of motor skills of athletes, practicing individual and team disciplines. In the first chapter, I analyzed the progress of each component of human efficiency. I presented how you can use them in your sport. The next chapter contains a description of the use of specific crossfit training exercises in the process of motor preparation of athletes and their impact on the achieved sports results. Also i have included  a chapter on the possibilities of self-accelerating regeneration after training and optimization of the biomechanical conditions of the athlete's body, which gives mobility training. The third chapter contains information about programming and periodisation of trainings, taking into account the individual needs of the athlete and the part of the season in which I am currently. The applications are full of concise information about the benefits of this training, but also about the possible dangers of its practice.

  9. Carbon monoxide exposure and information processing during perceptual-motor performance

    Energy Technology Data Exchange (ETDEWEB)

    Mihevic, P.M.; Gliner, J.A.; Horvath, S.M.

    1983-01-01

    This study examined the influence of exposure to ambient carbon monoxide resulting in final carboxyhemoglobin (COHb) levels of approximately 5.0% on the ability to process information during motor performance. Subjects (n . 16) performed a primary reciprocal tapping task and a secondary digit manipulation task singly and/or concurrently during 2.5 h exposure to room air (0 ppm CO) or 100 ppm CO. Five levels of tapping difficulty and two levels of digit manipulation were employed. Tapping performance was unaffected when COHb levels were as high as 5%. However, at this level of COHb it was noted that CO exposure interacted with task difficulty of both tasks to influence reaction time on the digit manipulation task. It was concluded that motor performance was not influenced by exposure to CO leading to COHb concentrations of 5%. Task difficulty was a significant factor mediating behavioral effects of CO exposure.

  10. Carbon monoxide exposure and information processing during perceptual-motor performance

    Energy Technology Data Exchange (ETDEWEB)

    Mihevic, P.M.; Gliner, J.A.; Horvath, S.M.

    1983-04-01

    This study examined the influence of exposure to ambient carbon monoxide resulting in final carboxyhemoglobin (COHb) levels of approximately 5.0% on the ability to process information during motor performance. Subjects (n = 16) performed a primary reciprocal tapping task and a secondary digit manipulation task singly and/or concurrently during 2.5 h exposure to room air (0 ppm CO) or 100 ppm CO. Five levels of tapping difficulty and two levels of digit manipulation were employed. Tapping performance was unaffected when COHb levels were as high as 5%. However, at this level of COHb it was noted that CO exposure interacted with task difficulty of both tasks to influence reaction time on the digit manipulation task. It was concluded that motor performance was not influenced by exposure to CO leading to COHb concentrations of 5%. Task difficulty was a significant factor mediating behavioral effects of CO exposure.

  11. [Use of nondeclarative and automatic memory processes in motor learning: how to mitigate the effects of aging].

    Science.gov (United States)

    Chauvel, Guillaume; Maquestiaux, François; Didierjean, André; Joubert, Sven; Dieudonné, Bénédicte; Verny, Marc

    2011-12-01

    Does normal aging inexorably lead to diminished motor learning abilities? This article provides an overview of the literature on the question, with particular emphasis on the functional dissociation between two sets of memory processes: declarative, effortful processes, and non-declarative, automatic processes. There is abundant evidence suggesting that aging does impair learning when past memories of former actions are required (episodic memory) and recollected through controlled processing (working memory). However, other studies have shown that aging does not impair learning when motor actions are performed non verbally and automatically (tapping procedural memory). These findings led us to hypothesize that one can minimize the impact of aging on the ability to learn new motor actions by favouring procedural learning. Recent data validating this hypothesis are presented. Our findings underline the importance of developing new motor learning strategies, which "bypass" declarative, effortful memory processes.

  12. Motor dysfunction of complex regional pain syndrome is related to impaired central processing of proprioceptive information.

    Science.gov (United States)

    Bank, Paulina J M; Peper, C Lieke E; Marinus, Johan; Beek, Peter J; van Hilten, Jacobus J

    2013-11-01

    Our understanding of proprioceptive deficits in complex regional pain syndrome (CRPS) and its potential contribution to impaired motor function is still limited. To gain more insight into these issues, we evaluated accuracy and precision of joint position sense over a range of flexion-extension angles of the wrist of the affected and unaffected sides in 25 chronic CRPS patients and in 50 healthy controls. The results revealed proprioceptive impairment at both the patients' affected and unaffected sides, characterized predominantly by overestimation of wrist extension angles. Precision of the position estimates was more prominently reduced at the affected side. Importantly, group differences in proprioceptive performance were observed not only for tests at identical percentages of each individual's range of wrist motion but also when controls were tested at wrist angles that corresponded to those of the patient's affected side. More severe motor impairment of the affected side was associated with poorer proprioceptive performance. Based on additional sensory tests, variations in proprioceptive performance over the range of wrist angles, and comparisons between active and passive displacements, the disturbances of proprioceptive performance most likely resulted from altered processing of afferent (and not efferent) information and its subsequent interpretation in the context of a distorted "body schema." The present results point at a significant role for impaired central processing of proprioceptive information in the motor dysfunction of CRPS and suggest that therapeutic strategies aimed at identification of proprioceptive impairments and their restoration may promote the recovery of motor function in CRPS patients. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  13. The influence of vascularization of transplanted processed allograft nerve on return of motor function in rats.

    Science.gov (United States)

    Giusti, Guilherme; Lee, Joo-Yup; Kremer, Thomas; Friedrich, Patricia; Bishop, Allen T; Shin, Alexander Y

    2016-02-01

    Processed nerve allografts have become an alternative to repair segmental nerve defects, with results comparable with autografts regarding sensory recovery; however, they have failed to reproduce comparable motor recovery. The purpose of this study was to determine how revascularizaton of processed nerve allograft would affect motor recovery. Eighty-eight rats were divided in four groups of 22 animals each. A unilateral 10-mm sciatic nerve defect was repaired with allograft (group I), allograft wrapped with silicone conduit (group II), allograft augmented with vascular endothelial growth factor (group III), or autograft (group IV). Eight animals from each group were sacrificed at 3 days, and the remaining animals at 16 weeks. Revascularization was evaluated by measuring the graft capillary density at 3 days and 16 weeks. Measurements of ankle contracture, compound muscle action potential, tibialis anterior muscle weight and force, and nerve histomorphometry were performed at 16 weeks. All results were normalized to the contralateral side. The results of capillary density at 3 days were 0.99% ± 1.3% for group I, 0.33% ± 0.6% for group II, 0.05% ± 0.1% for group III, and 75.6% ± 45.7% for group IV. At 16 weeks, the results were 69.9% ± 22.4% for group I, 37.0% ± 16.6% for group II, 84.6% ± 46.6% for group III, and 108.3% ± 46.8% for group IV. The results of muscle force were 47.5% ± 14.4% for group I, 21.7% ± 13.5% for group II, 47.1% ± 7.9% for group III, and 54.4% ± 10.6% for group IV. The use of vascular endothelial growth factor in the fashion used in this study improved neither the nerve allograft short-term revascularization nor the functional motor recovery after 16 weeks. Blocking allograft vascularization from surrounding tissues was detrimental for motor recovery. The processed nerve allografts used in this study showed similar functional motor recovery compared with that of the autograft. © 2014

  14. A flight sensory-motor to olfactory processing circuit in the moth Manduca sexta

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    Samual P Bradley

    2016-02-01

    Full Text Available Neural circuits projecting information from motor pathways to sensory pathways are common across sensory domains. These circuits typically modify sensory function as a result of motor pattern activation; this is particularly so in cases where the resultant behavior affects the sensory experience or its processing. However, such circuits have not been observed projecting to an olfactory pathway in any species despite well characterized active sampling behaviors that produce reafferent mechanical stimuli, such as sniffing in mammals and wing beating in the moth Manduca sexta. In this study we characterize a circuit that connects a flight sensory-motor center to an olfactory center in Manduca. This circuit consists of a single pair of histamine immunoreactive (HA-ir neurons that project from the mesothoracic ganglion to innervate a subset of ventral antennal lobe (AL glomeruli. Furthermore, within the AL we show that the Manduca sexta histamine B receptor (MsHisClB is exclusively expressed by a subset of GABAergic and peptidergic LNs, which broadly project to all olfactory glomeruli. Finally, the HA-ir cell pair is present in fifth stage instar larvae; however, the absence of MsHisClB-ir in the larval antennal center (LAC indicates that the circuit is incomplete prior to metamorphosis and importantly prior to the expression of flight behavior. Although the functional consequences of this circuit remain unknown, these results provide the first detailed description of a circuit that interconnects an olfactory system with motor centers driving flight behaviors including odor-guided flight.

  15. Parallel processing streams for motor output and sensory prediction during action preparation.

    Science.gov (United States)

    Stenner, Max-Philipp; Bauer, Markus; Heinze, Hans-Jochen; Haggard, Patrick; Dolan, Raymond J

    2015-03-15

    Sensory consequences of one's own actions are perceived as less intense than identical, externally generated stimuli. This is generally taken as evidence for sensory prediction of action consequences. Accordingly, recent theoretical models explain this attenuation by an anticipatory modulation of sensory processing prior to stimulus onset (Roussel et al. 2013) or even action execution (Brown et al. 2013). Experimentally, prestimulus changes that occur in anticipation of self-generated sensations are difficult to disentangle from more general effects of stimulus expectation, attention and task load (performing an action). Here, we show that an established manipulation of subjective agency over a stimulus leads to a predictive modulation in sensory cortex that is independent of these factors. We recorded magnetoencephalography while subjects performed a simple action with either hand and judged the loudness of a tone caused by the action. Effector selection was manipulated by subliminal motor priming. Compatible priming is known to enhance a subjective experience of agency over a consequent stimulus (Chambon and Haggard 2012). In line with this effect on subjective agency, we found stronger sensory attenuation when the action that caused the tone was compatibly primed. This perceptual effect was reflected in a transient phase-locked signal in auditory cortex before stimulus onset and motor execution. Interestingly, this sensory signal emerged at a time when the hemispheric lateralization of motor signals in M1 indicated ongoing effector selection. Our findings confirm theoretical predictions of a sensory modulation prior to self-generated sensations and support the idea that a sensory prediction is generated in parallel to motor output (Walsh and Haggard 2010), before an efference copy becomes available. Copyright © 2015 the American Physiological Society.

  16. Basal ganglia-dependent processes in recalling learned visual-motor adaptations.

    Science.gov (United States)

    Bédard, Patrick; Sanes, Jerome N

    2011-03-01

    Humans learn and remember motor skills to permit adaptation to a changing environment. During adaptation, the brain develops new sensory-motor relationships that become stored in an internal model (IM) that may be retained for extended periods. How the brain learns new IMs and transforms them into long-term memory remains incompletely understood since prior work has mostly focused on the learning process. A current model suggests that basal ganglia, cerebellum, and their neocortical targets actively participate in forming new IMs but that a cerebellar cortical network would mediate automatization. However, a recent study (Marinelli et al. 2009) reported that patients with Parkinson's disease (PD), who have basal ganglia dysfunction, had similar adaptation rates as controls but demonstrated no savings at recall tests (24 and 48 h). Here, we assessed whether a longer training session, a feature known to increase long-term retention of IM in healthy individuals, could allow PD patients to demonstrate savings. We recruited PD patients and age-matched healthy adults and used a visual-motor adaptation paradigm similar to the study by Marinelli et al. (2009), doubling the number of training trials and assessed recall after a short and a 24-h delay. We hypothesized that a longer training session would allow PD patients to develop an enhanced representation of the IM as demonstrated by savings at the recall tests. Our results showed that PD patients had similar adaptation rates as controls but did not demonstrate savings at both recall tests. We interpret these results as evidence that fronto-striatal networks have involvement in the early to late phase of motor memory formation, but not during initial learning.

  17. Study on Power Switching Process of a Hybrid Electric Vehicle with In-Wheel Motors

    Directory of Open Access Journals (Sweden)

    Shaohua Wang

    2016-01-01

    Full Text Available Hybrid electric vehicles with in-wheel motors (IWM achieve a variety of driving modes by two power sources—the engine and the IWM. One of the critical problems that exists in such vehicle is the different transient characteristics between the engine and the IWM. Therefore, switching processes between the power sources have noteworthy impacts on vehicle dynamics and driving performance. For the particular switching process of the pure electric mode to the engine driving mode, a specific control strategy coordinating clutch torque, motor torque, and engine torque was proposed to solve drivability issues caused by inconsistent responses of different power sources during the mode transition. The specific switching process could be described as follows: the engine was started by IWM with the clutch serving as a key enabling actuator, dynamic torque compensation through IWM was implemented after engine started, and, meanwhile, engine speed was controlled to track the target speed through the closed loop PID control strategy. The bench tests results showed that the vehicle jerk caused during mode switching was reduced and fast and smooth mode switching was realized, which leads to the improvement of vehicle’s riding comfort.

  18. The effect of mastication on human motor preparation processing: a study with CNV and MRCP.

    Science.gov (United States)

    Sakamoto, Kiwako; Nakata, Hiroki; Honda, Yukiko; Kakigi, Ryusuke

    2009-07-01

    To clarify the effect of mastication on motor preparation processing using electroencephalography (EEG), we investigated the effect of mastication on contingent negative variation (CNV) and reaction time (RT) in Experiment 1, and movement-related cortical potentials (MRCPs) in Experiment 2. The twelve subjects performed four CNV or MRCP sessions, and in the Mastication condition chewed a gum base during the resting period between sessions, Pre (before chewing) and Post 1, 2, and 3 (after chewing). In the Control condition, the subjects performed the same sessions without chewing gum during the intervals between sessions on another day. In Experiment 1, the mean amplitudes of the early- and late-CNV were significantly larger in Mastication than Control at Post 2 and Post 3. RT also differed significantly between Mastication and Control at Post 3. By contrast, in Experiment 2, there were no significant differences between Mastication and Control for the mean amplitudes of MRCPs including Bereitschaftspotential (BP) and negative slope (NS') in any session. These results suggest that mastication influences cognitive processing reflected by CNV with stimulus-triggered movement, rather than motor-related processing reflected by MRCPs relating to self-initiated movement, and provide evidence concerning the mechanisms for the effect of mastication on the human brain.

  19. Motor Control Abnormalities in Parkinson’s Disease

    Science.gov (United States)

    Mazzoni, Pietro; Shabbott, Britne; Cortés, Juan Camilo

    2012-01-01

    The primary manifestations of Parkinson’s disease are abnormalities of movement, including movement slowness, difficulties with gait and balance, and tremor. We know a considerable amount about the abnormalities of neuronal and muscle activity that correlate with these symptoms. Motor symptoms can also be described in terms of motor control, a level of description that explains how movement variables, such as a limb’s position and speed, are controlled and coordinated. Understanding motor symptoms as motor control abnormalities means to identify how the disease disrupts normal control processes. In the case of Parkinson’s disease, movement slowness, for example, would be explained by a disruption of the control processes that determine normal movement speed. Two long-term benefits of understanding the motor control basis of motor symptoms include the future design of neural prostheses to replace the function of damaged basal ganglia circuits, and the rational design of rehabilitation strategies. This type of understanding, however, remains limited, partly because of limitations in our knowledge of normal motor control. In this article, we review the concept of motor control and describe a few motor symptoms that illustrate the challenges in understanding such symptoms as motor control abnormalities. PMID:22675667

  20. PROGame: A process framework for serious game development for motor rehabilitation therapy.

    Science.gov (United States)

    Amengual Alcover, Esperança; Jaume-I-Capó, Antoni; Moyà-Alcover, Biel

    2018-01-01

    Serious game development for rehabilitation therapy is becoming increasingly popular because of the motivational advantages that these types of applications provide. Consequently, the need for a common process framework for this category of software development has become increasingly evident. The goal is to guarantee that products are developed and validated by following a coherent and systematic method that leads to high-quality serious games. This paper introduces a new process framework for the development of serious games for motor rehabilitation therapy. We introduce the new model and demonstrate its application for the development of a serious game for the improvement of the balance and postural control of adults with cerebral palsy. The development of this application has been facilitated by two technological transfer contracts and is being exploited by two different organizations. According to clinical measurements, patients using the application improved from high fall risk to moderate fall risk. We believe that our development strategy can be useful not only for motor rehabilitation therapy, but also for the development of serious games in many other rehabilitation areas.

  1. Effects of practice schedule and task specificity on the adaptive process of motor learning.

    Science.gov (United States)

    Barros, João Augusto de Camargo; Tani, Go; Corrêa, Umberto Cesar

    2017-10-01

    This study investigated the effects of practice schedule and task specificity based on the perspective of adaptive process of motor learning. For this purpose, tasks with temporal and force control learning requirements were manipulated in experiments 1 and 2, respectively. Specifically, the task consisted of touching with the dominant hand the three sequential targets with specific movement time or force for each touch. Participants were children (N=120), both boys and girls, with an average age of 11.2years (SD=1.0). The design in both experiments involved four practice groups (constant, random, constant-random, and random-constant) and two phases (stabilisation and adaptation). The dependent variables included measures related to the task goal (accuracy and variability of error of the overall movement and force patterns) and movement pattern (macro- and microstructures). Results revealed a similar error of the overall patterns for all groups in both experiments and that they adapted themselves differently in terms of the macro- and microstructures of movement patterns. The study concludes that the effects of practice schedules on the adaptive process of motor learning were both general and specific to the task. That is, they were general to the task goal performance and specific regarding the movement pattern. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Visual but not motor processes predict simple visuomotor reaction time of badminton players.

    Science.gov (United States)

    Hülsdünker, Thorben; Strüder, Heiko K; Mierau, Andreas

    2018-03-01

    The athlete's brain exhibits significant functional adaptations that facilitate visuomotor reaction performance. However, it is currently unclear if the same neurophysiological processes that differentiate athletes from non-athletes also determine performance within a homogeneous group of athletes. This information can provide valuable help for athletes and coaches aiming to optimize existing training regimes. Therefore, this study aimed to identify the neurophysiological correlates of visuomotor reaction performance in a group of skilled athletes. In 36 skilled badminton athletes, electroencephalography (EEG) was used to investigate pattern reversal and motion onset visual-evoked potentials (VEPs) as well as visuomotor reaction time (VMRT) during a simple reaction task. Stimulus-locked and response-locked event-related potentials (ERPs) in visual and motor regions as well as the onset of muscle activation (EMG onset) were determined. Correlation and multiple regression analyses identified the neurophysiological parameters predicting EMG onset and VMRT. For pattern reversal stimuli, the P100 latency and age best predicted EMG onset (r = 0.43; p = .003) and VMRT (r = 0.62; p = .001). In the motion onset experiment, EMG onset (r = 0.80; p badminton players while motor-related processes, although differentiating athletes from non-athletes, are not associated simple with visuomotor reaction performance.

  3. Neurogenetics of slow axonal transport: from cells to animals.

    Science.gov (United States)

    Sadananda, Aparna; Ray, Krishanu

    2012-09-01

    Slow axonal transport is a multivariate phenomenon implicated in several neurodegenerative disorders. Recent reports have unraveled the molecular basis of the transport of certain slow component proteins, such as the neurofilament subunits, tubulin, and certain soluble enzymes such as Ca(2+)/calmodulin-dependent protein kinase IIa (CaM kinase IIa), etc., in tissue cultured neurons. In addition, genetic analyses also implicate microtubule-dependent motors and other housekeeping proteins in this process. However, the biological relevance of this phenomenon is not so well understood. Here, the authors have discussed the possibility of adopting neurogenetic analyses in multiple model organisms to correlate molecular level measurements of the slow transport phenomenon to animal behavior, thus facilitating the investigation of its biological efficacy.

  4. Motor system contributions to verbal and non-verbal working memory

    Directory of Open Access Journals (Sweden)

    Diana A Liao

    2014-09-01

    Full Text Available Working memory (WM involves the ability to maintain and manipulate information held in mind. Neuroimaging studies have shown that secondary motor areas activate during WM for verbal content (e.g., words or letters, in the absence of primary motor area activation. This activation pattern may reflect an inner speech mechanism supporting online phonological rehearsal. Here, we examined the causal relationship between motor system activity and WM processing by using transcranial magnetic stimulation (TMS to manipulate motor system activity during WM rehearsal. We tested WM performance for verbalizable (words and pseudowords and non-verbalizable (Chinese characters visual information. We predicted that disruption of motor circuits would specifically affect WM processing of verbalizable information. We found that TMS targeting motor cortex slowed response times on verbal WM trials with high (pseudoword vs. low (real word phonological load. However, non-verbal WM trials were also significantly slowed with motor TMS. WM performance was unaffected by sham stimulation or TMS over visual cortex. Self-reported use of motor strategy predicted the degree of motor stimulation disruption on WM performance. These results provide evidence of the motor system’s contributions to verbal and non-verbal WM processing. We speculate that the motor system supports WM by creating motor traces consistent with the type of information being rehearsed during maintenance.

  5. Manipulability impairs association-memory: revisiting effects of incidental motor processing on verbal paired-associates.

    Science.gov (United States)

    Madan, Christopher R

    2014-06-01

    Imageability is known to enhance association-memory for verbal paired-associates. High-imageability words can be further subdivided by manipulability, the ease by which the named object can be functionally interacted with. Prior studies suggest that motor processing enhances item-memory, but impairs association-memory. However, these studies used action verbs and concrete nouns as the high- and low-manipulability words, respectively, confounding manipulability with word class. Recent findings demonstrated that nouns can serve as both high- and low-manipulability words (e.g., CAMERA and TABLE, respectively), allowing us to avoid this confound. Here participants studied pairs of words that consisted of all possible pairings of high- and low-manipulability words and were tested with immediate cued recall. Recall was worse for pairs that contained high-manipulability words. In free recall, participants recalled more high- than low-manipulability words. Our results provide further evidence that manipulability influences memory, likely occurring through automatic motor imagery. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Transient simulation of regression rate on thrust regulation process in hybrid rocket motor

    Directory of Open Access Journals (Sweden)

    Tian Hui

    2014-12-01

    Full Text Available The main goal of this paper is to study the characteristics of regression rate of solid grain during thrust regulation process. For this purpose, an unsteady numerical model of regression rate is established. Gas–solid coupling is considered between the solid grain surface and combustion gas. Dynamic mesh is used to simulate the regression process of the solid fuel surface. Based on this model, numerical simulations on a H2O2/HTPB (hydroxyl-terminated polybutadiene hybrid motor have been performed in the flow control process. The simulation results show that under the step change of the oxidizer mass flow rate condition, the regression rate cannot reach a stable value instantly because the flow field requires a short time period to adjust. The regression rate increases with the linear gain of oxidizer mass flow rate, and has a higher slope than the relative inlet function of oxidizer flow rate. A shorter regulation time can cause a higher regression rate during regulation process. The results also show that transient calculation can better simulate the instantaneous regression rate in the operation process.

  7. The use of quasi-isothermal modulated temperature differential scanning calorimetry for the characterization of slow crystallization processes in lipid-based solid self-emulsifying systems.

    Science.gov (United States)

    Otun, Sarah O; Meehan, Elizabeth; Qi, Sheng; Craig, Duncan Q M

    2015-04-01

    Slow or incomplete crystallization may be a significant manufacturing issue for solid lipid-based dosage forms, yet little information is available on this phenomenon. In this investigation we suggest a novel means by which slow solidification may be monitored in Gelucire 44/14 using quasi-isothermal modulated temperature DSC (QiMTDSC). Conventional linear heating and cooling DSC methods were employed, along with hot stage microscopy (HSM), for basic thermal profiling of Gelucire 44/14. QiMTDSC experiments were performed on cooling from the melt, using a range of incremental decreases in temperature and isothermal measurement periods. DSC and HSM highlighted the main (primary) crystallization transition; solid fat content analysis and kinetic analysis were used to profile the solidification process. The heat capacity profile from QiMTDSC indicated that after an initial energetic primary crystallisation, the lipid underwent a slower period of crystallization which continued to manifest at much lower temperatures than indicated by standard DSC. We present evidence that Gelucire 44/14 undergoes an initial crystallization followed by a secondary, slower process. QIMTDSC appears to be a promising tool in the investigation of this secondary crystallization process.

  8. Transcranial magnetic stimulation probes the excitability of the primary motor cortex: A framework to account for the facilitating effects of acute whole-body exercise on motor processes

    Directory of Open Access Journals (Sweden)

    Karen Davranche

    2015-03-01

    Full Text Available The effects of exercise on decision-making performance have been studied using a wide variety of cognitive tasks and exercise interventions. Although the current literature supports a beneficial influence of acute exercise on cognitive performance, the mechanisms underlying this phenomenon have not yet been elucidated. We review studies that used single-pulse transcranial magnetic stimulation (TMS to probe the excitability of motor structures during whole-body exercise and present a framework to account for the facilitating effects of acute exercise on motor processes. Recent results suggest that, even in the absence of fatigue, the increase in corticospinal excitability classically reported during submaximal and exhausting exercises may be accompanied by a reduction in intracortical inhibition. We propose that reduced intracortical inhibition elicits an adaptive central mechanism that counteracts the progressive reduction in muscle responsiveness caused by peripheral fatigue. Such a reduction would render the motor cortex more sensitive to upstream influences, thus causing increased corticospinal excitability. Furthermore, reduction of intracortical inhibition may account for the more efficient descending drive and for the improvement of reaction time performance during exercise. The adaptive modulation in intracortical inhibition could be implemented through a general increase in reticular activation that would further account for enhanced sensory sensitivity.

  9. Graded motor imagery and the impact on pain processing in a case of CRPS.

    Science.gov (United States)

    Walz, Andrea D; Usichenko, Taras; Moseley, G Lorimer; Lotze, Martin

    2013-03-01

    Graded motor imagery (GMI) shows promising results for patients with complex regional pain syndrome (CRPS). In a case with chronic unilateral CRPS type I, we applied GMI for 6 weeks and recorded clinical parameters and cerebral activation using functional magnetic resonance imaging (fMRI; pre-GMI, after each GMI block, and after 6 mo). Changes in fMRI activity were mapped during movement execution in areas associated with pain processing. A healthy participant served as a control for habituation effects. Pain intensity decreased over the course of GMI, and relief was maintained at follow-up. fMRI during movement execution revealed marked changes in S1 and S2 (areas of discriminative pain processing), which seemed to be associated with pain reduction, but none in the anterior insula and the anterior cingulate cortex (areas of affective pain processing). After mental rotation training, the activation intensity of the posterior parietal cortex was reduced to one third. Our case report develops a design capable of differentiating cerebral changes associated with behavioral therapy of CRPS type I study.

  10. Levels of processing and the coding of position cues in motor short-term memory.

    Science.gov (United States)

    Ho, L; Shea, J B

    1978-06-01

    The present study investigated the appropriateness of the levels-of-processing framework of memory for explaining retention of information in motor short-term memory. Subjects were given labels descriptive of the positions to be remembered by the experimenter (EL), were given no labels (NL), or provided their own labels (SL). A control group (CONT) was required to count backwards during the presentation of the criterion positions. The inclusion of a 30-sec filled retention interval as well as 0-sec and 30-sec unfilled retention intervals tested a prediction by Craik and Lockhart (1972), when attention is diverted from an item, information will be lost at a rate appropriate to its level of processing - that is, slower rates for deeper levels. Groups EL and SL had greater accuracy at recall for all three retention intervals than groups CONT and NL. In addition, there was no significant increase in error between 30-sec unfilled and 30-sec filled intervals for groups EL and SL, while there was a significant increase in error for groups CONT and NL. The data were interpreted in terms of Craik and Lockhart's (1972) levels-of-processing approach to memory.

  11. FROM SLOW FOOD TO SLOW TOURISM

    Directory of Open Access Journals (Sweden)

    Bac Dorin Paul

    2014-12-01

    Full Text Available One of the effects of globalization is the faster pace of our lives. This rhythm can be noticed in all aspects of life: travel, work, shopping, etc. and it has serious negative effects. It has become common knowledge that stress and speed generate serious medical issues. Food and eating habits in the modern world have taken their toll on our health. However, some people took a stand and argued for a new kind of lifestyle. It all started in the field of gastronomy, where a new movement emerged – Slow Food, based on the ideas and philosophy of Carlo Petrini. Slow Food represents an important adversary to the concept of fast food, and is promoting local products, enjoyable meals and healthy food. The philosophy of the Slow Food movement developed in several directions: Cittaslow, slow travel and tourism, slow religion and slow money etc. The present paper will account the evolution of the concept and its development during the most recent years. We will present how the philosophy of slow food was applied in all the other fields it reached and some critical points of view. Also we will focus on the presence of the slow movement in Romania, although it is in a very early stage of development. The main objectives of the present paper are: to present the chronological and ideological evolution of the slow movement; to establish a clear separation of slow travel and slow tourism, as many mistake on for the other; to review the presence of the slow movement in Romania. Regarding the research methodology, information was gathered from relevant academic papers and books and also from interviews and discussions with local entrepreneurs. The research is mostly theoretical and empirical, as slow food and slow tourism are emerging research themes in academic circles.

  12. Can stereotype threat affect motor performance in the absence of explicit monitoring processes? Evidence using a strength task.

    Science.gov (United States)

    Chalabaev, Aïna; Brisswalter, Jeanick; Radel, Rémi; Coombes, Stephen A; Easthope, Christopher; Clément-Guillotin, Corentin

    2013-04-01

    Previous evidence shows that stereotype threat impairs complex motor skills through increased conscious monitoring of task performance. Given that one-step motor skills may not be susceptible to these processes, we examined whether performance on a simple strength task may be reduced under stereotype threat. Forty females and males performed maximum voluntary contractions under stereotypical or nullified-stereotype conditions. Results showed that the velocity of force production within the first milliseconds of the contraction decreased in females when the negative stereotype was induced, whereas maximal force did not change. In males, the stereotype induction only increased maximal force. These findings suggest that stereotype threat may impair motor skills in the absence of explicit monitoring processes, by influencing the planning stage of force production.

  13. Sensorimotor nucleus NIf is necessary for auditory processing but not vocal motor output in the avian song system.

    Science.gov (United States)

    Cardin, Jessica A; Raksin, Jonathan N; Schmidt, Marc F

    2005-04-01

    Sensorimotor integration in the avian song system is crucial for both learning and maintenance of song, a vocal motor behavior. Although a number of song system areas demonstrate both sensory and motor characteristics, their exact roles in auditory and premotor processing are unclear. In particular, it is unknown whether input from the forebrain nucleus interface of the nidopallium (NIf), which exhibits both sensory and premotor activity, is necessary for both auditory and premotor processing in its target, HVC. Here we show that bilateral NIf lesions result in long-term loss of HVC auditory activity but do not impair song production. NIf is thus a major source of auditory input to HVC, but an intact NIf is not necessary for motor output in adult zebra finches.

  14. Somato-motor haptic processing in posterior inner perisylvian region (SII/pIC of the macaque monkey.

    Directory of Open Access Journals (Sweden)

    Hiroaki Ishida

    Full Text Available The posterior inner perisylvian region including the secondary somatosensory cortex (area SII and the adjacent region of posterior insular cortex (pIC has been implicated in haptic processing by integrating somato-motor information during hand-manipulation, both in humans and in non-human primates. However, motor-related properties during hand-manipulation are still largely unknown. To investigate a motor-related activity in the hand region of SII/pIC, two macaque monkeys were trained to perform a hand-manipulation task, requiring 3 different grip types (precision grip, finger exploration, side grip both in light and in dark conditions. Our results showed that 70% (n = 33/48 of task related neurons within SII/pIC were only activated during monkeys' active hand-manipulation. Of those 33 neurons, 15 (45% began to discharge before hand-target contact, while the remaining neurons were tonically active after contact. Thirty-percent (n = 15/48 of studied neurons responded to both passive somatosensory stimulation and to the motor task. A consistent percentage of task-related neurons in SII/pIC was selectively activated during finger exploration (FE and precision grasping (PG execution, suggesting they play a pivotal role in control skilled finger movements. Furthermore, hand-manipulation-related neurons also responded when visual feedback was absent in the dark. Altogether, our results suggest that somato-motor neurons in SII/pIC likely contribute to haptic processing from the initial to the final phase of grasping and object manipulation. Such motor-related activity could also provide the somato-motor binding principle enabling the translation of diachronic somatosensory inputs into a coherent image of the explored object.

  15. Movement - uncontrolled or slow

    Science.gov (United States)

    Dystonia; Involuntary slow and twisting movements; Choreoathetosis; Leg and arm movements - uncontrollable; Arm and leg movements - uncontrollable; Slow involuntary movements of large muscle groups; Athetoid movements

  16. Living Slow and Being Moral : Life History Predicts the Dual Process of Other-Centered Reasoning and Judgments.

    Science.gov (United States)

    Zhu, Nan; Hawk, Skyler T; Chang, Lei

    2018-06-01

    Drawing from the dual process model of morality and life history theory, the present research examined the role of cognitive and emotional processes as bridges between basic environmental challenges (i.e., unpredictability and competition) and other-centered moral orientation (i.e., prioritizing the welfare of others). In two survey studies, cognitive and emotional processes represented by future-oriented planning and emotional attachment, respectively (Study 1, N = 405), or by perspective taking and empathic concern, respectively (Study 2, N = 424), positively predicted other-centeredness in prosocial moral reasoning (Study 1) and moral judgment dilemmas based on rationality or intuition (Study 2). Cognitive processes were more closely related to rational aspects of other-centeredness, whereas the emotional processes were more closely related to the intuitive aspects of other-centeredness (Study 2). Finally, the cognitive and emotional processes also mediated negative effects of unpredictability (i.e., negative life events and childhood financial insecurity), as well as positive effects of individual-level, contest competition (i.e., educational and occupational competition) on other-centeredness. Overall, these findings support the view that cognitive and emotional processes do not necessarily contradict each other. Rather, they might work in concert to promote other-centeredness in various circumstances and might be attributed to humans' developmental flexibility in the face of environmental challenges.

  17. Slow wave cyclotron maser

    International Nuclear Information System (INIS)

    Kho, T.H.; Lin, A.T.

    1988-01-01

    Cyclotron masers such as Gyrotrons and the Autoresonance Masers, are fast wave devices: the electromagnetic wave's phase velocity v rho , is greater than the electron beam velocity, v b . To be able to convert the beam kinetic energy into radiation in these devices the beam must have an initial transverse momentum, usually obtained by propagating the beam through a transverse wiggler magnet, or along a nonuniform guide magnetic field before entry into the interaction region. Either process introduces a significant amount of thermal spread in the beam which degrades the performance of the maser. However, if the wave phase velocity v rho v b , the beam kinetic energy can be converted directly into radiation without the requirement of an initial transverse beam momentum, making a slow wave cyclotron maser a potentially simpler and more compact device. The authors present the linear and nonlinear physics of the slow wave cyclotron maser and examine its potential for practical application

  18. No specific role for the manual motor system in processing the meanings of words related to the hand

    Directory of Open Access Journals (Sweden)

    Natasha ePostle

    2013-02-01

    Full Text Available The present study explored whether semantic and motor systems are functionally interwoven via the use of a dual-task paradigm. According to embodied language accounts that propose an automatic and necessary involvement of the motor system in conceptual processing, concurrent processing of hand-related information should interfere more with hand movements than processing of unrelated body-part (i.e., foot, mouth information. Across three experiments, 100 right-handed participants performed left- or right-hand tapping movements while repeatedly reading action words related to different body-parts, or different body-part names, in both aloud and silent conditions. Concurrent reading of single words related to specific body-parts, or the same words embedded in sentences differing in syntactic and phonological complexity (to manipulate context-relevant processing, and reading while viewing videos of the actions and body-parts described by the target words (to elicit visuomotor associations all interfered with right-hand but not left-hand tapping rate. However, this motor interference was not affected differentially by hand-related stimuli. Thus, the results provide no support for proposals that body-part specific resources in cortical motor systems are shared between overt manual movements and meaning-related processing of words related to the hand.

  19. Transmodal comparison of auditory, motor, and visual post-processing with and without intentional short-term memory maintenance.

    Science.gov (United States)

    Bender, Stephan; Behringer, Stephanie; Freitag, Christine M; Resch, Franz; Weisbrod, Matthias

    2010-12-01

    To elucidate the contributions of modality-dependent post-processing in auditory, motor and visual cortical areas to short-term memory. We compared late negative waves (N700) during the post-processing of single lateralized stimuli which were separated by long intertrial intervals across the auditory, motor and visual modalities. Tasks either required or competed with attention to post-processing of preceding events, i.e. active short-term memory maintenance. N700 indicated that cortical post-processing exceeded short movements as well as short auditory or visual stimuli for over half a second without intentional short-term memory maintenance. Modality-specific topographies pointed towards sensory (respectively motor) generators with comparable time-courses across the different modalities. Lateralization and amplitude of auditory/motor/visual N700 were enhanced by active short-term memory maintenance compared to attention to current perceptions or passive stimulation. The memory-related N700 increase followed the characteristic time-course and modality-specific topography of the N700 without intentional memory-maintenance. Memory-maintenance-related lateralized negative potentials may be related to a less lateralised modality-dependent post-processing N700 component which occurs also without intentional memory maintenance (automatic memory trace or effortless attraction of attention). Encoding to short-term memory may involve controlled attention to modality-dependent post-processing. Similar short-term memory processes may exist in the auditory, motor and visual systems. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  20. Context-dependent motor skill: perceptual processing in memory-based sequence production.

    Science.gov (United States)

    Ruitenberg, Marit F L; Abrahamse, Elger L; De Kleine, Elian; Verwey, Willem B

    2012-10-01

    Previous studies have shown that motor sequencing skill can benefit from the reinstatement of the learning context-even with respect to features that are formally not required for appropriate task performance. The present study explored whether such context-dependence develops when sequence execution is fully memory-based-and thus no longer assisted by stimulus-response translations. Specifically, we aimed to distinguish between preparation and execution processes. Participants performed two keying sequences in a go/no-go version of the discrete sequence production task in which the context consisted of the color in which the target keys of a particular sequence were displayed. In a subsequent test phase, these colors either were the same as during practice, were reversed for the two sequences or were novel. Results showed that, irrespective of the amount of practice, performance across all key presses in the reversed context condition was impaired relative to performance in the same and novel contexts. This suggests that the online preparation and/or execution of single key presses of the sequence is context-dependent. We propose that a cognitive processor is responsible both for these online processes and for advance sequence preparation and that combined findings from the current and previous studies build toward the notion that the cognitive processor is highly sensitive to changes in context across the various roles that it performs.

  1. Encoding the world around us: motor-related processing influences verbal memory.

    Science.gov (United States)

    Madan, Christopher R; Singhal, Anthony

    2012-09-01

    It is known that properties of words such as their imageability can influence our ability to remember those words. However, it is not known if other object-related properties can also influence our memory. In this study we asked whether a word representing a concrete object that can be functionally interacted with (i.e., high-manipulability word) would enhance the memory representations for that item compared to a word representing a less manipulable object (i.e., low-manipulability word). Here participants incidentally encoded high-manipulability (e.g., CAMERA) and low-manipulability words (e.g., TABLE) while making word judgments. Using a between-subjects design, we varied the depth-of-processing involved in the word judgment task: participants judged the words based on personal experience (deep/elaborative processing), word length (shallow), or functionality (intermediate). Participants were able to remember high-manipulability words better than low-manipulability words in both the personal experience and word length groups; thus presenting the first evidence that manipulability can influence memory. However, we observed better memory for low- than high-manipulability words in the functionality group. We explain this surprising interaction between manipulability and memory as being mediated by automatic vs. controlled motor-related cognition. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Deliberate Laterality Practice Facilitates Sensory-Motor Processing in Developing Children

    Science.gov (United States)

    Pedersen, Scott J.

    2014-01-01

    Background: The innate ability for typically developing children to attain developmental motor milestones early in life has been a thoroughly researched area of inquiry. Nonetheless, as children grow and are required to perform more complex motor skills in order to experience success in physical activity and sport pursuits, the range of…

  3. Interaction of Language Processing and Motor Skill in Children with Specific Language Impairment

    Science.gov (United States)

    DiDonato Brumbach, Andrea C.; Goffman, Lisa

    2014-01-01

    Purpose: To examine how language production interacts with speech motor and gross and fine motor skill in children with specific language impairment (SLI). Method: Eleven children with SLI and 12 age-matched peers (4-6 years) produced structurally primed sentences containing particles and prepositions. Utterances were analyzed for errors and for…

  4. Interaction of language processing and motor skill in children with specific language impairment.

    Science.gov (United States)

    DiDonato Brumbach, Andrea C; Goffman, Lisa

    2014-02-01

    To examine how language production interacts with speech motor and gross and fine motor skill in children with specific language impairment (SLI). Eleven children with SLI and 12 age-matched peers (4-6 years) produced structurally primed sentences containing particles and prepositions. Utterances were analyzed for errors and for articulatory duration and variability. Standard measures of motor, language, and articulation skill were also obtained. Sentences containing particles, as compared with prepositions, were less likely to be produced in a priming task and were longer in duration, suggesting increased difficulty with this syntactic structure. Children with SLI demonstrated higher articulatory variability and poorer gross and fine motor skills compared with aged-matched controls. Articulatory variability was correlated with generalized gross and fine motor performance. Children with SLI show co-occurring speech motor and generalized motor deficits. Current theories do not fully account for the present findings, though the procedural deficit hypothesis provides a framework for interpreting overlap among language and motor domains.

  5. Factors that challenge health for people involved in the compensation process following a motor vehicle crash: A longitudinal study

    NARCIS (Netherlands)

    Elbers, N.A.; Akkermans, A.J.; Lockwood, K.; Craig, A.; Cameron, I.D.

    2014-01-01

    Background People who claim compensation after a motor vehicle accident do not recover as well as people with similar injuries who do not claim compensation. It has been suggested that this impeded recovery is caused by the stressful compensation process and the adversarial attitude of

  6. Anthropogenic control on geomorphic process rates: can we slow down the erosion rates? (Geomorphology Outstanding Young Scientist Award & Penck Lecture)

    Science.gov (United States)

    Vanacker, V.

    2012-04-01

    The surface of the Earth is changing rapidly, largely in response to anthropogenic perturbation. Direct anthropogenic disturbance of natural environments may be much larger in many places than the (projected) indirect effects of climate change. There is now large evidence that humans have significantly altered geomorphic process rates, mainly through changes in vegetation composition, density and cover. While much attention has been given to the impact of vegetation degradation on geomorphic process rates, I suggest that the pathway of restoration is equally important to investigate. First, vegetation recovery after crop abandonment has a rapid and drastic impact on geomorphic process rates. Our data from degraded catchments in the tropical Andes show that erosion rates can be reduced by up to 100 times when increasing the protective vegetation cover. During vegetation restoration, the combined effects of the reduction in surface runoff, sediment production and hydrological connectivity are stronger than the individual effects together. Therefore, changes in erosion and sedimentation during restoration are not simply the reverse of those observed during degradation. Second, anthropogenic perturbation causes a profound but often temporary change in geomorphic process rates. Reconstruction of soil erosion rates in Spain shows us that modern erosion rates in well-vegetated areas are similar to long-term rates, despite evidence of strong pulses in historical erosion rates after vegetation clearance and agriculture. The soil vegetation system might be resilient to short pulses of accelerated erosion (and deposition), as there might exist a dynamic coupling between soil erosion and production also in degraded environments.

  7. MODELING OF DYNAMIC PROCESSES IN PLANETARY IN-WHEEL MOTOR GEARBOXES OF MINE TRUCKS DURING ITS STARTING AND ACCELERATION

    Directory of Open Access Journals (Sweden)

    V. V. Mikhailov

    2012-01-01

    Full Text Available The paper describes a mathematical model for planetary double-row in-wheel motor gear box. Main parameters of its dynamic system have been determined in the paper. The paper reveals simulation of transition processes during starting and acceleration of a mine truck with electric motor wheels. Its own gear box frequency has been established theoretically and experimentally in the paper. The paper proposes an algorithm and program for calculations as an alternative to high-cost tests while investigating gear mechanism dynamics of large-size planetary gearboxes.

  8. A comparative study of using spindle motor power and eddy current for the detection of tool conditions in milling processes

    OpenAIRE

    Abbass, JK; Al-Habaibeh, A

    2015-01-01

    This paper investigates the use of the power of the driving motor of a CNC spindle in comparison to two perpendicular eddy current sensors for the detection of tool wear in milling processes. Monitoring the power through the current profile is a low cost system which has been utilised in this study as an attempt to detect the fluctuation in the motor load as a result of the conditions of the cutting tool. Eddy current sensors are dedicated sensors that are installed on the spindle to measure ...

  9. Cloning, overexpression, crystallization and preliminary X-ray crystallographic analysis of a slow-processing mutant of penicillin G acylase from Kluyvera citrophila

    International Nuclear Information System (INIS)

    Varshney, Nishant Kumar; Ramasamy, Sureshkumar; Brannigan, James A.; Wilkinson, Anthony J.; Suresh, C. G.

    2013-01-01

    The pac gene encoding penicillin G acylase from K. citrophila was cloned and a slow-processing site-directed mutant was prepared, expressed, purified and crystallized. Triclinic and monoclinic crystal forms were obtained which diffracted to 2.5 and 3.5 Å resolution, respectively. Kluyvera citrophila penicillin G acylase (KcPGA) has recently attracted increased attention relative to the well studied and commonly used Escherichia coli PGA (EcPGA) because KcPGA is more resilient to harsh conditions and is easier to immobilize for the industrial hydrolysis of natural penicillins to generate the 6-aminopenicillin (6-APA) nucleus, which is the starting material for semi-synthetic antibiotic production. Like other penicillin acylases, KcPGA is synthesized as a single-chain inactive pro-PGA, which upon autocatalytic processing becomes an active heterodimer of α and β chains. Here, the cloning of the pac gene encoding KcPGA and the preparation of a slow-processing mutant precursor are reported. The purification, crystallization and preliminary X-ray analysis of crystals of this precursor protein are described. The protein crystallized in two different space groups, P1, with unit-cell parameters a = 54.0, b = 124.6, c = 135.1 Å, α = 104.1, β = 101.4, γ = 96.5°, and C2, with unit-cell parameters a = 265.1, b = 54.0, c = 249.2 Å, β = 104.4°, using the sitting-drop vapour-diffusion method. Diffraction data were collected at 100 K and the phases were determined using the molecular-replacement method. The initial maps revealed electron density for the spacer peptide

  10. Is the motor system necessary for processing action and abstract emotion words? Evidence from focal brain lesions

    Directory of Open Access Journals (Sweden)

    Felix R. Dreyer

    2015-11-01

    Full Text Available Neuroimaging and neuropsychological experiments suggest that modality-preferential cortices, including motor- and somatosensory areas contribute to the semantic processing of action related concrete words. In contrast, a possible role of modality-preferential – including sensorimotor – areas in processing abstract meaning remains under debate. However, recent fMRI studies indicate an involvement of the left sensorimotor cortex in the processing of abstract-emotional words (e.g. love. But are these areas indeed necessary for processing action-related and abstract words? The current study now investigates word processing in two patients suffering from focal brain lesion in the left frontocentral motor system. A speeded lexical decision task (LDT on meticulously matched word groups showed that the recognition of nouns from different semantic categories – related to food, animals, tools and abstract-emotional concepts – was differentially affected. Whereas patient HS with a lesion in dorsolateral central sensorimotor cortex next to the hand area showed a category-specific deficit in recognizing tool words, patient CA suffering from lesion centered in the left SMA was primarily impaired in abstract-emotional word processing. These results point to a causal role of the motor cortex in the semantic processing of both action-related object concepts and abstract-emotional concepts and therefore suggest that the motor areas previously found active in action-related and abstract word processing can serve a meaning-specific necessary role in word recognition. The category-specific nature of the observed dissociations is difficult to reconcile with the idea that sensorimotor systems are somehow peripheral or ‘epiphenomenal’ to meaning and concept processing. Rather, our results are consistent with the claim that cognition is grounded in action and perception and based on distributed action perception circuits reaching into sensorimotor areas.

  11. Materials processing, pulsed field magnetization and field-pole application to propulsion motors on Gd123 bulk superconductors

    International Nuclear Information System (INIS)

    Izumi, M; Xu, C; Xu, Y; Morita, E; Kimura, Y; Hu, A; Ichihara, M; Murakami, M; Sakai, N; Hirabayashi, I; Sugimoto, H; Miki, M

    2008-01-01

    Gd123 bulk superconductor is one of the promising magnet materials. We studied the materials processing to grow high performance magnet with a doping of nano-sized metal oxides such as ZrO 2 as a candidature of pinning centre. The enhancement of the critical current density was obtained. Growth of nano-sized particles of Gd211 in addition to BaZrO 3 were observed by TEM. The formation of nano-sized particles appears a key to improve the integrated flux trapped inside the bulks and the TEM reveals an intriguing effect of the addition to the microstructure of bulk materials. Magnetization process is crucial especially for an extended machinery. Pulsed field magnetization was applied to the field-pole bulk on the rotor disk of the tested synchronous motor. The trapped flux density of 1.3 T for Gd123 bulk sample and of 60 mm diameter was reached in the limited dimension of the tested motor by a step cooling method down to 38 K with a closed-cycle condensed neon. The pulsed magnetic field was applied with a new type of split-armature coil. A large bulk of 140 mm diameter has also shown a potential flux trapping superior to other smaller specimens. The bulk magnet provides a strong magnetic field around the bulk body itself with high current density relative to a coil winding. A comparative drawing of a 'torque density' of a variety of motors which is defined as the torque divided by the volume of the motor indicates a potential advantage of bulk motor as a super permanent magnet motor

  12. Dynamics of soil CO2 efflux under varying atmospheric CO2 concentrations reveal dominance of slow processes.

    Science.gov (United States)

    Kim, Dohyoung; Oren, Ram; Clark, James S; Palmroth, Sari; Oishi, A Christopher; McCarthy, Heather R; Maier, Chris A; Johnsen, Kurt

    2017-09-01

    We evaluated the effect on soil CO 2 efflux (F CO 2 ) of sudden changes in photosynthetic rates by altering CO 2 concentration in plots subjected to +200 ppmv for 15 years. Five-day intervals of exposure to elevated CO 2 (eCO 2 ) ranging 1.0-1.8 times ambient did not affect F CO 2 . F CO 2 did not decrease until 4 months after termination of the long-term eCO 2 treatment, longer than the 10 days observed for decrease of F CO 2 after experimental blocking of C flow to belowground, but shorter than the ~13 months it took for increase of F CO 2 following the initiation of eCO 2 . The reduction of F CO 2 upon termination of enrichment (~35%) cannot be explained by the reduction of leaf area (~15%) and associated carbohydrate production and allocation, suggesting a disproportionate contraction of the belowground ecosystem components; this was consistent with the reductions in base respiration and F CO 2 -temperature sensitivity. These asymmetric responses pose a tractable challenge to process-based models attempting to isolate the effect of individual processes on F CO2 . © 2017 John Wiley & Sons Ltd.

  13. Change in cognitive process during dance video game play with different appendages for motor output

    Science.gov (United States)

    Suzuki, Kota; Ono, Yumie; Shimada, Sotaro; Tachibana, Atsumichi; Noah, Jack Adam

    2018-02-01

    Playing a dance video game (DVG) requires fine temporal control of foot positions based on simultaneous visuoauditory integration. Despite the highly-demanding nature of its cognitive processes, DVG could offer promising exercise opportunities for elderly people to maintain their cognitive abilities due to its strong adherence. Using functional near-infrared spectroscopy, we have previously shown that DVG play with the foot activates prefrontal and temporoparietal cortices. However, it is still in debate whether this brain-stimulatory effect of DVG could also be maintained in case that DVG is played with the hand by people who have difficulty to play DVG in a standing position. We therefore investigated the regional brain activity of 12 healthy, right-handed young-adults when they played DVG with their dominant hand and foot. We found that the DVG-related hemodynamic activity was comparable in the prefrontal area regardless of the appendages while that was significantly smaller in case of playing with the hand related to the foot in the left superior/middle temporal gyrus (S/MTG). A similar trend was also observed in the right S/MTG. These results suggest that the motor preparatory function mediated by the prefrontal cortices is equally employed regardless of appendages while more cognitive load is required in the temporal cortices with foot-played DVG, possibly to integrate visual, auditory, and proprioceptive information. Hand-played DVG may partially substitute foot-played DVG in the sense of cognitive training in the elderly.

  14. Can a single pulse transcranial magnetic stimulation targeted to the motor cortex interrupt pain processing?

    Science.gov (United States)

    Kisler, Lee-Bareket; Gurion, Ilan; Granovsky, Yelena; Sinai, Alon; Sprecher, Elliot; Shamay-Tsoory, Simone; Weissman-Fogel, Irit

    2018-01-01

    The modulatory role of the primary motor cortex (M1), reflected by an inhibitory effect of M1-stimulation on clinical pain, motivated us to deepen our understanding of M1's role in pain modulation. We used Transcranial Magnetic Stimulation (TMS)-induced virtual lesion (VL) to interrupt with M1 activity during noxious heat pain. We hypothesized that TMS-VL will effect experimental pain ratings. Three VL protocols were applied consisting of single-pulse TMS to transiently interfere with right M1 activity: (1) VLM1- TMS applied to 11 subjects, 20 msec before the individual's first pain-related M1 peak activation, as determined by source analysis (sLORETA), (2) VL-50 (N = 16; TMS applied 50 ms prior to noxious stimulus onset), and (3) VL+150 (N = 16; TMS applied 150 ms after noxious stimulus onset). Each protocol included 3 conditions ('pain-alone', ' TMS-VL', and 'SHAM-VL'), each consisted of 30 noxious heat stimuli. Pain ratings were compared, in each protocol, for TMS-VL vs. SHAM-VL and vs. pain-alone conditions. Repeated measures analysis of variance, corrected for multiple comparisons revealed no significant differences in the pain ratings between the different conditions within each protocol. Therefore, our results from this exploratory study suggest that a single pulse TMS-induced VL that is targeted to M1 failed to interrupt experimental pain processing in the specific three stimulation timing examined here.

  15. Excitation processes in slow K+--He, Ne, Ar, H2, N2 and Na+--He collisions

    International Nuclear Information System (INIS)

    Kikiani, B.I.; Gochitashvili, M.R.; Kvizhinadze, R.V.; Ankudinov, V.A.

    1984-01-01

    Quasimolecular features of excitation processes in K + --He, Ne, Ar, H 2 , N 2 and Na + --He collisions were investigated by measuring the cross sections for the emission of the resonance lines of potassium (lambda = 766.5 and 769.9 nm), sodium (lambda = 589 and 589.6 nm), and helium (lambda = 584 nm) atoms at ion energies in the range 0.5--10 keV. In Na + --He collisions, the resonance-line excitation functions obtained for sodium and helium atoms exhibit oscillations that are in antiphase and are due to phase interference between the quasimolecular states of the system of colliding particles. Experimental data on K + --Ar collisions are interpreted in terms of schematic correlation diagrams for molecular orbitals. The excitation mechanisms for K + --N 2 and K + --Ar have beenfound to be similar, and this leads to the conclusion that the quasimolecular model used for the ion-atom case is also valid for the ion-molecule case. It is shown that the excitation of the 4p-state of the potassium atom in the K + --Ar case is due to a Landau-Zener type of interaction in the region of the quasicrossing of (KAr) + terms. Analysis of the excitation of this state in K + --N 2 collisions also shows that the capture of an electron into the excited 4p-state of the potassium atom is due to a nonadiabatic transition in the region of quasicrossing of energy terms of the same symmetry

  16. Die casting copper motor rotors: mold materials and processing for cost-effective manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Peters, D.T.; Cowie, J.G.; Brush, E.F. Jr.

    2000-07-01

    This project seeks to demonstrate mold materials for copper pressure die-casting that are cost-effective and practical for production use in die-casting copper motor rotors. The incorporation of die-cast copper for conductor bars and end rings of the induction motor in place of aluminum would result in attractive improvements in motor energy efficiency through reductions in motor losses ranging from 15% to 20%. Die-cast motor rotors are produced in aluminum today because rotor fabrication by pressure die-casting is an established practice. Lack of a durable and cost-effective mold material has been the technical barrier preventing manufacture of the die-cast copper rotor. This project tested H-13 steel die inserts that establish the baseline. Nickel-, tungsten-, and molybdenum-based high temperature alloys were extensively tested. Results indicate that substantially extended die life is possible using high temperature die materials, pre-heated and operated at elevated temperatures. Pre-heating and high operating temperatures were shown to be critical in extending the die life by decreasing the cyclic stresses associated with thermal expansion. Extended die life provides the opportunity for economically viable copper motor rotor die-casting. (orig.)

  17. THE TRANSFORMATIONAL PROCESSES INVOLVING MOTOR SKILLS THAT OCCUR UNDER THE INFLUENCE OF BASIC PRELIMINARY TRAINING IN YOUNG HANDBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Markovic Sasa

    2011-06-01

    Full Text Available The population from which we extracted a sample of 76 subjects consisted of elementary school students in Kursumlija, all male, aged 12-13, who were divided into a sub-sample consisting of 38 young handball players who took part in the training sessions of a school of handball and another sub-sample consisting of 38 non-athletes, who only took part in their regular physical education classes. The aim of the research was to determine the transformation processes involving motor skills, which occur under the influence of basic preliminary training in young handball players. The subject matter of the study was to examine whether a statistically significant increase in the level of motor skills would occur under the influence of physical exercise as part of basic preliminary training in the final as compared to the initial state. Six motor tests which define the dimensions of explosive and repetitive strength were used. The results of the research indicate that significant transformational processes involving the motor skills of young handball players occurred in the final as compared to the initial measuring, under the influence of basic preliminary training.

  18. Participation of primary motor cortex area 4a in complex sensory processing: 3.0-T fMRI study.

    Science.gov (United States)

    Terumitsu, Makoto; Ikeda, Kotaro; Kwee, Ingrid L; Nakada, Tsutomu

    2009-05-06

    The precise movement of human fingers requires continuous and reciprocal interaction between motor and sensory systems. Similar to other primates, there is double representation of the digits and wrists within the human primary motor cortex (M1), which are generally referred to as area 4 anterior (M1-4a) and area 4 posterior (M1-4p). In this high-field (3.0 T) functional magnetic resonance imaging (fMRI) study, we hypothesized that M1-4p is more important for initiation of motion, whereas M1-4a is important for execution of a given motion involving more complex sensoriomotor interaction. We investigated M1-4a and M1-4p activation associated with two representative motor tasks, namely, finger tapping (voluntary motion, VM) and passive finger movement accomplished by continuous pressure (passive motor, PM), and two representative sensory stimulations, namely, simple stimulation of flutter vibration (simple sensory, SS), and complex stimulation by a row of pins moving either vertically or horizontally (complex sensory, CS). Both M1-4a and M1-4p were activated in both motor tasks, VM and PM. M1-4p was not activated by either of the two sensory tasks, whereas M1-4a was activated by CS but not by SS. Analysis of the center of gravities (COG) of the activated areas showed that VM and PM moved COG towards M1-4p and 3a. SS moved COG towards somatosensory cortex Brodmann areas 1, 2, and 3b, whereas CS towards M1-4a. The result clearly showed that M1-4a represents the area of secondary motor execution, which actively participates in CS processing.

  19. LoCuSS: THE SLOW QUENCHING OF STAR FORMATION IN CLUSTER GALAXIES AND THE NEED FOR PRE-PROCESSING

    Energy Technology Data Exchange (ETDEWEB)

    Haines, C. P. [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Correo Central, Santiago (Chile); Pereira, M. J.; Egami, E.; Rawle, T. D. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Smith, G. P.; Ziparo, F.; McGee, S. L. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Babul, A. [Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 1A1 (Canada); Finoguenov, A. [Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-0014 Helsinki (Finland); Okabe, N. [Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), P.O. Box 23-141, Taipei 10617, Taiwan (China); Moran, S. M., E-mail: cphaines@das.uchile.cl [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

    2015-06-10

    We present a study of the spatial distribution and kinematics of star-forming galaxies in 30 massive clusters at 0.15 < z < 0.30, combining wide-field Spitzer 24 μm and GALEX near-ultraviolet imaging with highly complete spectroscopy of cluster members. The fraction (f{sub SF}) of star-forming cluster galaxies rises steadily with cluster-centric radius, increasing fivefold by 2r{sub 200}, but remains well below field values even at 3r{sub 200}. This suppression of star formation at large radii cannot be reproduced by models in which star formation is quenched in infalling field galaxies only once they pass within r{sub 200} of the cluster, but is consistent with some of them being first pre-processed within galaxy groups. Despite the increasing f{sub SF}-radius trend, the surface density of star-forming galaxies actually declines steadily with radius, falling ∼15× from the core to 2r{sub 200}. This requires star formation to survive within recently accreted spirals for 2–3 Gyr to build up the apparent over-density of star-forming galaxies within clusters. The velocity dispersion profile of the star-forming galaxy population shows a sharp peak of 1.44 σ{sub ν} at 0.3r{sub 500}, and is 10%–35% higher than that of the inactive cluster members at all cluster-centric radii, while their velocity distribution shows a flat, top-hat profile within r{sub 500}. All of these results are consistent with star-forming cluster galaxies being an infalling population, but one that must also survive ∼0.5–2 Gyr beyond passing within r{sub 200}. By comparing the observed distribution of star-forming galaxies in the stacked caustic diagram with predictions from the Millennium simulation, we obtain a best-fit model in which star formation rates decline exponentially on quenching timescales of 1.73 ± 0.25 Gyr upon accretion into the cluster.

  20. From cognitive motor preparation to visual processing: The benefits of childhood fitness to brain health.

    Science.gov (United States)

    Berchicci, M; Pontifex, M B; Drollette, E S; Pesce, C; Hillman, C H; Di Russo, F

    2015-07-09

    The association between a fit body and a fit brain in children has led to a rise of behavioral and neuroscientific research. Yet, the relation of cardiorespiratory fitness on premotor neurocognitive preparation with early visual processing has received little attention. Here, 41 healthy, lower and higher fit preadolescent children were administered a modified version of the Eriksen flanker task while electroencephalography (EEG) and behavioral measures were recorded. Event-related potentials (ERPs) locked to the stimulus onset with an earlier than usual baseline (-900/-800 ms) allowed investigation of both the usual post-stimulus (i.e., the P1, N1 and P2) as well as the pre-stimulus ERP components, such as the Bereitschaftspotential (BP) and the prefrontal negativity (pN component). At the behavioral level, aerobic fitness was associated response accuracy, with higher fit children being more accurate than lower fit children. Fitness-related differences selectively emerged at prefrontal brain regions during response preparation, with larger pN amplitude for higher than lower fit children, and at early perceptual stages after stimulus onset, with larger P1 and N1 amplitudes in higher relative to lower fit children. Collectively, the results suggest that the benefits of being aerobically fit appear at the stage of cognitive preparation prior to stimulus presentation and the behavioral response during the performance of a task that challenges cognitive control. Further, it is likely that enhanced activity in prefrontal brain areas may improve cognitive control of visuo-motor tasks, allowing for stronger proactive inhibition and larger early allocation of selective attention resources on relevant external stimuli. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Stimulus-dependent deliberation process leading to a specific motor action demonstrated via a multi-channel EEG analysis

    Directory of Open Access Journals (Sweden)

    Sonja eHenz

    2015-07-01

    Full Text Available The aim of the study was to determine whether a deliberative process, leading to a motor action, is detectable in high density EEG recordings. Subjects were required to press one of two buttons. In a simple motor task the subject knew which button to press, whilst in a color-word Stroop task subjects had to press the right button with the right index finger when meaning and color coincided, or the left button with the left index finger when meaning and color were disparate.EEG recordings obtained during the simple motor task showed a sequence of positive (P and negative (N cortical potentials (P1-N1-P2 which are assumed to be related to the processing of the movement.The sequence of cortical potentials was similar in EEG recordings of subjects having to deliberate over how to respond, but the above sequence (P1-N1-P2 was preceded by slowly increasing negativity (N0, with N0 being assumed to represent the end of the deliberation process.Our data suggest the existence of neurophysiological correlates of deliberative processes.

  2. White Matter Fractional Anisotropy Correlates With Speed of Processing and Motor Speed in Young Childhood Cancer Survivors

    International Nuclear Information System (INIS)

    Aukema, Eline J.; Caan, Matthan W.A.; Oudhuis, Nienke; Majoie, Charles; Vos, Frans M.; Reneman, Liesbeth; Last, Bob F.; Grootenhuis, Martha A.; Schouten-van Meeteren, Antoinette Y.N.

    2009-01-01

    Purpose: To determine whether childhood medulloblastoma and acute lymphoblastic leukemia (ALL) survivors have decreased white matter fractional anisotropy (WMFA) and whether WMFA is related to the speed of processing and motor speed. Methods and Materials: For this study, 17 patients (6 medulloblastoma, 5 ALL treated with high-dose methotrexate (MTX) (4 x 5 g/m 2 ) and 6 with low-dose MTX (3 x 2 g/m 2 )) and 17 age-matched controls participated. On a 3.0-T magnetic resonance imaging (MRI) scanner, diffusion tensor imaging (DTI) was performed, and WMFA values were calculated, including specific regions of interest (ROIs), and correlated with the speed of processing and motor speed. Results: Mean WMFA in the patient group, mean age 14 years (range 8.9 - 16.9), was decreased compared with the control group (p = 0.01), as well as WMFA in the right inferior fronto-occipital fasciliculus (IFO) (p = 0.03) and in the genu of the corpus callosum (gCC) (p = 0.01). Based on neurocognitive results, significant positive correlations were present between processing speed and WMFA in the splenium (sCC) (r = 0.53, p = 0.03) and the body of the corpus callosum (bCC) (r = 0.52, p = 0.03), whereas the right IFO WMFA was related to motor speed (r = 0.49, p < 0.05). Conclusions: White matter tracts, using a 3.0-T MRI scanner, show impairment in childhood cancer survivors, medulloblastoma survivors, and also those treated with high doses of MTX. In particular, white matter tracts in the sCC, bCC and right IFO are positively correlated with speed of processing and motor speed.

  3. Motor coordination and visual information processing in high school students at risk of developmental coordination disorder: Two year follow-up study

    Directory of Open Access Journals (Sweden)

    Rudolf Psotta

    2014-03-01

    Full Text Available BACKGROUND: Developmental coordination disorder (DCD in children is characterised by the execution being substantially below that expected given the individual's chronological age. This deficit can negatively affect the psychological and social development of the children and their academic achievements. A few studies provided the evidences on the persistence of impaired motor coordination up to the middle and older adolescence. Although DCD is the heterogeneous syndrome, it seems to be associated with problems in visual information processing. AIMS: The first aim of the study was to examine how a below-average motor coordination in the adolescents can be associated with visual information processing ability. Second aim was to reveal the short-term pathway of impaired motor coordination during adolescence and whether their persistence and reduction, respectively, could be associated with a level of visual information processing. METHODS: In the first phase of the study the below average motor coordination identified by the MABC-2 test (Henderson, Sugden, & Barnett, 2007 in the students of the high and vocational schools (n = 52 was analysed on its relation to the ability of visual information processing. This ability was assessed by the simple and choice reaction tests (FiTRO Reaction Check device. In the 2nd phase of the study the students with moderate and significant motor difficulties (n = 34 were reassessed two years after the initial testing to examine the changes in motor coordination and its potential association with a level of visual information processing. RESULTS: The below-average motor coordination correlated with the several measures of choice reaction with a determination of R2 9-15%, while a level of selective attention and physical growth of the adolescents were not the significant factors of motor skills. Of 34 adolescents 18 students demonstrated the reduction of motor difficulties in two years, and the persistence of the

  4. Regarding the perturbed operating process of DB propellant rocket motor at extreme initial grain temperatures

    Directory of Open Access Journals (Sweden)

    Ioan ION

    2012-03-01

    Full Text Available Despite many decades of study, the combustion instability of several DB propellants is still of particular concern, especially at extreme grain temperature conditions of rocket motor operating. The purpose of the first part of the paper is to give an overview of our main experimental results on combustion instabilities and pressure oscillations in DB propellant segmented grain rocket motors (SPRM-01, large L/D ratio, working at extreme initial grain temperatures. Thus, we recorded some particular pressure-time traces with significant perturbed pressure signal that was FFT analysed. An updated mathematical model incorporating transient frequency-dependent combustion response, in conjunction with pressure-dependent burning, is applied to investigate and predict the DB propellant combustion instability phenomenon. The susceptibility of the tested motor SPRM-01 with DB propellant to get a perturbed working and to go unstable with pressure was evidenced and this risk has to be evaluated. In the last part of our paper we evaluated the influence of recorded perturbed thrust on the rocket behaviour on the trajectory. The study revealed that at firing-table initial conditions, this kind of perturbed motor operating may not lead to an unstable rocket flight, but the ballistic parameters would be influenced in an unacceptable manner.

  5. Enantiopure Functional Molecular Motors Obtained by a Switchable Chiral-Resolution Process

    NARCIS (Netherlands)

    van Leeuwen, Thomas; Gan, Jefri; Kistemaker, Jos C. M.; Pizzolato, Stefano F.; Chang, Mu-Chieh; Feringa, Ben L.

    2016-01-01

    Molecular switches, rotors, and motors play an important role in the development of nano-machines and devices, as well as responsive and adaptive functional materials. For unidirectional rotors based on chiral overcrowded alkenes, their stereochemical homogeneity is of crucial importance. Herein, a

  6. Random practice - one of the factors of the motor learning process

    Directory of Open Access Journals (Sweden)

    Petr Valach

    2012-01-01

    Full Text Available BACKGROUND: An important concept of acquiring motor skills is the random practice (contextual interference - CI. The explanation of the effect of contextual interference is that the memory has to work more intensively, and therefore it provides higher effect of motor skills retention than the block practice. Only active remembering of a motor skill assigns the practical value for appropriate using in the future. OBJECTIVE: The aim of this research was to determine the difference in how the motor skills in sport gymnastics are acquired and retained using the two different teaching methods - blocked and random practice. METHODS: The blocked and random practice on the three selected gymnastics tasks were applied in the two groups students of physical education (blocked practice - the group BP, random practice - the group RP during two months, in one session a week (totally 80 trials. At the end of the experiment and 6 months after (retention tests the groups were tested on the selected gymnastics skills. RESULTS: No significant differences in a level of the gymnastics skills were found between BP group and RP group at the end of the experiment. However, the retention tests showed significantly higher level of the gymnastics skills in the RP group in comparison with the BP group. CONCLUSION: The results confirmed that a retention of the gymnastics skills using the teaching method of the random practice was significantly higher than with use of the blocked practice.

  7. Motor ability and inhibitory processes in children with ADHD: a neuroelectric study.

    Science.gov (United States)

    Hung, Chiao-Ling; Chang, Yu-Kai; Chan, Yuan-Shuo; Shih, Chia-Hao; Huang, Chung-Ju; Hung, Tsung-Min

    2013-06-01

    The purpose of the current study was to examine the relationship between motor ability and response inhibition using behavioral and electrophysiological indices in children with ADHD. A total of 32 participants were recruited and underwent a motor ability assessment by administering the Basic Motor Ability Test-Revised (BMAT) as well as the Go/No-Go task and event-related potential (ERP) measurements at the same time. The results indicated that the BMAT scores were positively associated with the behavioral and ERP measures. Specifically, the BMAT average score was associated with a faster reaction time and higher accuracy, whereas higher BMAT subset scores predicted a shorter P3 latency in the Go condition. Although the association between the BMAT average score and the No-Go accuracy was limited, higher BMAT average and subset scores predicted a shorter N2 and P3 latency and a larger P3 amplitude in the No-Go condition. These findings suggest that motor abilities may play roles that benefit the cognitive performance of ADHD children.

  8. Context-dependent motor skill: perceptual processing in memory-based sequence production

    NARCIS (Netherlands)

    Ruitenberg, M.F.L.; Abrahamse, E.L.; de Kleine, Elian; Verwey, Willem B.

    2012-01-01

    Previous studies have shown that motor sequencing skill can benefit from the reinstatement of the learning context—even with respect to features that are formally not required for appropriate task performance. The present study explored whether such context-dependence develops when sequence

  9. Model of Transient Process Where Three-Phase Transducer Feeds Induction Motor Equivalent as a Variable Active-Inductive Load

    Directory of Open Access Journals (Sweden)

    Nenad Marković

    2016-01-01

    Full Text Available The paper presents a new approach in the analysis of a transient state in a system where the feeding source is a transducer-IGBT inverter and load is introduced through the induction motor with its R-L parameters. Induction motors with different parameters of powers and power factors are tested. MATLAB simulation of the three-phase inverter that feeds the induction machine has replaced the missing lab equipment with which mathematical model of this system was verified. According to the selected parameters of the inverter and induction machine and through the simulation in the MATLAB program, the results are obtained in the form of diagrams that verify the model of a transient state of the induction machine operation when it operates as a motor which is presented as a variable R-L load. The transient process of the system three-phase bridge inverter whose active-inductive load is the induction machine in the conditions of the change of the load parameters is analyzed. The model of the transient process in the system formed by the inverter in PWM (Pulse Width Modulation converter and induction machine is developed in the time domain and phase coordinates.

  10. Decoding the non-stationary neuron spike trains by dual Monte Carlo point process estimation in motor Brain Machine Interfaces.

    Science.gov (United States)

    Liao, Yuxi; Li, Hongbao; Zhang, Qiaosheng; Fan, Gong; Wang, Yiwen; Zheng, Xiaoxiang

    2014-01-01

    Decoding algorithm in motor Brain Machine Interfaces translates the neural signals to movement parameters. They usually assume the connection between the neural firings and movements to be stationary, which is not true according to the recent studies that observe the time-varying neuron tuning property. This property results from the neural plasticity and motor learning etc., which leads to the degeneration of the decoding performance when the model is fixed. To track the non-stationary neuron tuning during decoding, we propose a dual model approach based on Monte Carlo point process filtering method that enables the estimation also on the dynamic tuning parameters. When applied on both simulated neural signal and in vivo BMI data, the proposed adaptive method performs better than the one with static tuning parameters, which raises a promising way to design a long-term-performing model for Brain Machine Interfaces decoder.

  11. Influence of age, circadian and homeostatic processes on inhibitory motor control: a Go/Nogo task study.

    Directory of Open Access Journals (Sweden)

    Patricia Sagaspe

    Full Text Available INTRODUCTION: The contribution of circadian system and sleep pressure influences on executive performance as a function of age has never been studied. The aim of our study was to determine the age-related evolution of inhibitory motor control (i.e., ability to suppress a prepotent motor response and sustained attention under controlled high or low sleep pressure conditions. METHODS: 14 healthy young males (mean age = 23 ± 2.7; 20-29 years and 11 healthy older males (mean age = 68 ± 1.4; 66-70 years were recruited. The volunteers were placed for 40 hours in "constant routine". In the "Sleep Deprivation SD" condition, the volunteer was kept awake for 40 hours to obtain a high sleep pressure condition interacting with the circadian process. In the "NAP" condition, the volunteer adopted a short wake/sleep cycle (150/75 min resulting in a low sleep pressure condition to counteract the homeostatic pressure and investigate the circadian process. Performances were evaluated by a simple reaction time task and a Go/Nogo task repeated every 3H45. RESULTS: In the SD condition, inhibitory motor control (i.e., ability to inhibit an inappropriate response was impaired by extended wakefulness equally in both age groups (P<.01. Sustained attention (i.e. ability to respond accurately to appropriate stimuli on the executive task decreased under sleep deprivation in both groups, and even more in young participants (P<.05. In the NAP condition, age did not influence the time course of inhibitory motor control or sustained attention. In the SD and NAP conditions, older participants had a less fluctuating reaction time performance across time of day than young participants (P<.001. CONCLUSION: Aging could be a protective factor against the effects of extended wakefulness especially on sustained attention failures due to an attenuation of sleep pressure with duration of time awake.

  12. Numerical and experimental study of liquid breakup process in solid rocket motor nozzle

    Science.gov (United States)

    Yen, Yi-Hsin

    Rocket propulsion is an important travel method for space exploration and national defense, rockets needs to be able to withstand wide range of operation environment and also stable and precise enough to carry sophisticated payload into orbit, those engineering requirement makes rocket becomes one of the state of the art industry. The rocket family have been classified into two major group of liquid and solid rocket based on the fuel phase of liquid or solid state. The solid rocket has the advantages of simple working mechanism, less maintenance and preparing procedure and higher storage safety, those characters of solid rocket make it becomes popular in aerospace industry. Aluminum based propellant is widely used in solid rocket motor (SRM) industry due to its avalibility, combusion performance and economical fuel option, however after aluminum react with oxidant of amonimum perchrate (AP), it will generate liquid phase alumina (Al2O3) as product in high temperature (2,700˜3,000 K) combustion chamber enviornment. The liquid phase alumina particles aggromorate inside combustion chamber into larger particle which becomes major erosion calprit on inner nozzle wall while alumina aggromorates impinge on the nozzle wall surface. The erosion mechanism result nozzle throat material removal, increase the performance optimized throat diameter and reduce nozzle exit to throat area ratio which leads to the reduction of exhaust gas velocity, Mach number and lower the propulsion thrust force. The approach to avoid particle erosion phenomenon taking place in SRM's nozzle is to reduce the alumina particle size inside combustion chamber which could be done by further breakup of the alumina droplet size in SRM's combustion chamber. The study of liquid breakup mechanism is an important means to smaller combustion chamber alumina droplet size and mitigate the erosion tack place on rocket nozzle region. In this study, a straight two phase air-water flow channel experiment is set up

  13. TRANSFORMED MOTORIC CHARACTERISTICS AFTER RECEIVED PROGRAMMED TRAINING PROCESS ON SUPERIOR KARATE ATHLETES

    Directory of Open Access Journals (Sweden)

    Žarko Kostovski

    2010-03-01

    Full Text Available The research is made on intentional sample of participants, members of Macedonian Karate Representation, in the period of preparing to qualify for the world championship in Tokyo 2008. Within the research, were used 19 (nineteen variables for evaluation the following motorics areas: tests for evaluate muscles strength, explosive strength, movement frequency of lower extremity, rhythmic and coordination. Basic purpose of the research was to establish difference within the variables to evaluate motorics abilities between male karate athletes on the age of 18 to 28 (seniors, after a nine-day programmed training in the period of preparing. Using comparative method the results from the both measures, whereby there were evident numerical improvement in the whole motorist abilities, but no difference in the levels of statistic significances.

  14. The Use of Quasi-Isothermal Modulated Temperature Differential Scanning Calorimetry for the Characterization of Slow Crystallization Processes in Lipid-Based Solid Self-Emulsifying Systems

    OpenAIRE

    Otun, Sarah O.; Meehan, Elizabeth; Qi, Sheng; Craig, Duncan Q. M.

    2014-01-01

    Purpose Slow or incomplete crystallization may be a significant manufacturing issue for solid lipid-based dosage forms, yet little information is available on this phenomenon. In this investigation we suggest a novel means by which slow solidification may be monitored in Gelucire 44/14 using quasi-isothermal modulated temperature DSC (QiMTDSC). Methods Conventional linear heating and cooling DSC methods were employed, along with hot stage microscopy (HSM), for basic thermal profiling of Geluc...

  15. Tapping to a slow tempo in the presence of simple and complex meters reveals experience-specific biases for processing music.

    Directory of Open Access Journals (Sweden)

    Sangeeta Ullal-Gupta

    Full Text Available Musical meters vary considerably across cultures, yet relatively little is known about how culture-specific experience influences metrical processing. In Experiment 1, we compared American and Indian listeners' synchronous tapping to slow sequences. Inter-tone intervals contained silence or to-be-ignored rhythms that were designed to induce a simple meter (familiar to Americans and Indians or a complex meter (familiar only to Indians. A subset of trials contained an abrupt switch from one rhythm to another to assess the disruptive effects of contradicting the initially implied meter. In the unfilled condition, both groups tapped earlier than the target and showed large tap-tone asynchronies (measured in relative phase. When inter-tone intervals were filled with simple-meter rhythms, American listeners tapped later than targets, but their asynchronies were smaller and declined more rapidly. Likewise, asynchronies rose sharply following a switch away from simple-meter but not from complex-meter rhythm. By contrast, Indian listeners performed similarly across all rhythm types, with asynchronies rapidly declining over the course of complex- and simple-meter trials. For these listeners, a switch from either simple or complex meter increased asynchronies. Experiment 2 tested American listeners but doubled the duration of the synchronization phase prior to (and after the switch. Here, compared with simple meters, complex-meter rhythms elicited larger asynchronies that declined at a slower rate, however, asynchronies increased after the switch for all conditions. Our results provide evidence that ease of meter processing depends to a great extent on the amount of experience with specific meters.

  16. Tapping to a slow tempo in the presence of simple and complex meters reveals experience-specific biases for processing music.

    Science.gov (United States)

    Ullal-Gupta, Sangeeta; Hannon, Erin E; Snyder, Joel S

    2014-01-01

    Musical meters vary considerably across cultures, yet relatively little is known about how culture-specific experience influences metrical processing. In Experiment 1, we compared American and Indian listeners' synchronous tapping to slow sequences. Inter-tone intervals contained silence or to-be-ignored rhythms that were designed to induce a simple meter (familiar to Americans and Indians) or a complex meter (familiar only to Indians). A subset of trials contained an abrupt switch from one rhythm to another to assess the disruptive effects of contradicting the initially implied meter. In the unfilled condition, both groups tapped earlier than the target and showed large tap-tone asynchronies (measured in relative phase). When inter-tone intervals were filled with simple-meter rhythms, American listeners tapped later than targets, but their asynchronies were smaller and declined more rapidly. Likewise, asynchronies rose sharply following a switch away from simple-meter but not from complex-meter rhythm. By contrast, Indian listeners performed similarly across all rhythm types, with asynchronies rapidly declining over the course of complex- and simple-meter trials. For these listeners, a switch from either simple or complex meter increased asynchronies. Experiment 2 tested American listeners but doubled the duration of the synchronization phase prior to (and after) the switch. Here, compared with simple meters, complex-meter rhythms elicited larger asynchronies that declined at a slower rate, however, asynchronies increased after the switch for all conditions. Our results provide evidence that ease of meter processing depends to a great extent on the amount of experience with specific meters.

  17. A low-fat, whole-food vegan diet, as well as other strategies that down-regulate IGF-I activity, may slow the human aging process.

    Science.gov (United States)

    McCarty, Mark F

    2003-06-01

    A considerable amount of evidence is consistent with the proposition that systemic IGF-I activity acts as pacesetter in the aging process. A reduction in IGF-I activity is the common characteristic of rodents whose maximal lifespan has been increased by a wide range of genetic or dietary measures, including caloric restriction. The lifespans of breeds of dogs and strains of rats tend to be inversely proportional to their mature weight and IGF-I levels. The link between IGF-I and aging appears to be evolutionarily conserved; in worms and flies, lifespan is increased by reduction-of-function mutations in signaling intermediates homologous to those which mediate insulin/IGF-I activity in mammals. The fact that an increase in IGF-I activity plays a key role in the induction of sexual maturity, is consistent with a broader role for-IGF-I in aging regulation. If down-regulation of IGF-I activity could indeed slow aging in humans, a range of practical measures for achieving this may be at hand. These include a low-fat, whole-food, vegan diet, exercise training, soluble fiber, insulin sensitizers, appetite suppressants, and agents such as flax lignans, oral estrogen, or tamoxifen that decrease hepatic synthesis of IGF-I. Many of these measures would also be expected to decrease risk for common age-related diseases. Regimens combining several of these approaches might have a sufficient impact on IGF-I activity to achieve a useful retardation of the aging process. However, in light of the fact that IGF-I promotes endothelial production of nitric oxide and may be of especial importance to cerebrovascular health, additional measures for stroke prevention-most notably salt restriction-may be advisable when attempting to down-regulate IGF-I activity as a pro-longevity strategy.

  18. Too slow, for Milton

    OpenAIRE

    Armstrong, N.

    2011-01-01

    Too slow, for Milton was written in 2011, as part of a memorial project for Milton Babbitt. The piece borrows harmonies from Babbitt's Composition for 12 Instruments (harmonies which Babbitt had in turn borrowed from Schoenberg's Ode to Napoleon), but unfolds them as part of a musical texture characterised by repetition, resonance, and a slow rate of change. As Babbitt once told me that my music was 'too slow', this seemed an appropriately obstinate form of homage.

  19. Monte Carlo point process estimation of electromyographic envelopes from motor cortical spikes for brain-machine interfaces

    Science.gov (United States)

    Liao, Yuxi; She, Xiwei; Wang, Yiwen; Zhang, Shaomin; Zhang, Qiaosheng; Zheng, Xiaoxiang; Principe, Jose C.

    2015-12-01

    Objective. Representation of movement in the motor cortex (M1) has been widely studied in brain-machine interfaces (BMIs). The electromyogram (EMG) has greater bandwidth than the conventional kinematic variables (such as position, velocity), and is functionally related to the discharge of cortical neurons. As the stochastic information of EMG is derived from the explicit spike time structure, point process (PP) methods will be a good solution for decoding EMG directly from neural spike trains. Previous studies usually assume linear or exponential tuning curves between neural firing and EMG, which may not be true. Approach. In our analysis, we estimate the tuning curves in a data-driven way and find both the traditional functional-excitatory and functional-inhibitory neurons, which are widely found across a rat’s motor cortex. To accurately decode EMG envelopes from M1 neural spike trains, the Monte Carlo point process (MCPP) method is implemented based on such nonlinear tuning properties. Main results. Better reconstruction of EMG signals is shown on baseline and extreme high peaks, as our method can better preserve the nonlinearity of the neural tuning during decoding. The MCPP improves the prediction accuracy (the normalized mean squared error) 57% and 66% on average compared with the adaptive point process filter using linear and exponential tuning curves respectively, for all 112 data segments across six rats. Compared to a Wiener filter using spike rates with an optimal window size of 50 ms, MCPP decoding EMG from a point process improves the normalized mean square error (NMSE) by 59% on average. Significance. These results suggest that neural tuning is constantly changing during task execution and therefore, the use of spike timing methodologies and estimation of appropriate tuning curves needs to be undertaken for better EMG decoding in motor BMIs.

  20. Physiotherapists use a great variety of motor learning options in neurological rehabilitation, from which they choose through an iterative process: a retrospective think-aloud study.

    Science.gov (United States)

    Kleynen, Melanie; Moser, Albine; Haarsma, Frederike A; Beurskens, Anna J; Braun, Susy M

    2017-08-01

    The goal of this study was to examine which motor learning options are applied by experienced physiotherapists in neurological rehabilitation, and how they choose between the different options. A descriptive qualitative approach was used. A purposive sample of five expert physiotherapists from the neurological ward of a rehabilitation center participated. Data were collected using nine videotaped therapy situations. During retrospective think-aloud interviews, the physiotherapists were instructed to constantly "think aloud" while they were watching their own videos. Five "operators" were identified: "act", "know", "observe", "assess" and "argue". The "act" operator consisted of 34 motor learning options, which were clustered into "instruction", "feedback" and "organization". The "know", "observe", "assess" and "argue" operators explained how therapists chose one of these options. The four operators seem to be interrelated and together lead to a decision to apply a particular motor learning option. Results show that the participating physiotherapists used a great variety of motor learning options in their treatment sessions. Further, the decision-making process with regard to these motor learning options was identified. Results may support future intervention studies that match the content and process of therapy in daily practice. The study should be repeated with other physiotherapists. Implications for Rehabilitation The study provided insight into the way experienced therapist handle the great variety of possible motor learning options, including concrete ideas on how to operationalize these options in specific situations. Despite differences in patients' abilities, it seems that therapists use the same underlying clinical reasoning process when choosing a particular motor learning option. Participating physiotherapists used more than the in guidelines suggested motor learning options and considered more than the suggested factors, hence adding practice based

  1. Electric Motors Everywhere: Most Forms of Energy Go through Some Conversion Process to Do Useful Work for Us

    Science.gov (United States)

    Deal, Walter F., III

    2004-01-01

    This article discusses electric motors and the many ways in which they are used. Selecting the most appropriate miniature DC electric motor wisely will contribute toward success and satisfaction in designing and building motorized projects and activities. Typical parts suppliers stock a variety of miniature DC motors and provide sufficient…

  2. Torque control for electric motors

    Science.gov (United States)

    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.

  3. The dream-lag effect: Selective processing of personally significant events during Rapid Eye Movement sleep, but not during Slow Wave Sleep.

    Science.gov (United States)

    van Rijn, E; Eichenlaub, J-B; Lewis, P A; Walker, M P; Gaskell, M G; Malinowski, J E; Blagrove, M

    2015-07-01

    Incorporation of details from waking life events into Rapid Eye Movement (REM) sleep dreams has been found to be highest on the night after, and then 5-7 nights after events (termed, respectively, the day-residue and dream-lag effects). In experiment 1, 44 participants kept a daily log for 10 days, reporting major daily activities (MDAs), personally significant events (PSEs), and major concerns (MCs). Dream reports were collected from REM and Slow Wave Sleep (SWS) in the laboratory, or from REM sleep at home. The dream-lag effect was found for the incorporation of PSEs into REM dreams collected at home, but not for MDAs or MCs. No dream-lag effect was found for SWS dreams, or for REM dreams collected in the lab after SWS awakenings earlier in the night. In experiment 2, the 44 participants recorded reports of their spontaneously recalled home dreams over the 10 nights following the instrumental awakenings night, which thus acted as a controlled stimulus with two salience levels, high (sleep lab) and low (home awakenings). The dream-lag effect was found for the incorporation into home dreams of references to the experience of being in the sleep laboratory, but only for participants who had reported concerns beforehand about being in the sleep laboratory. The delayed incorporation of events from daily life into dreams has been proposed to reflect REM sleep-dependent memory consolidation. However, an alternative emotion processing or emotional impact of events account, distinct from memory consolidation, is supported by the finding that SWS dreams do not evidence the dream-lag effect. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Analysis and control of the compaction force in the composite prepreg tape winding process for rocket motor nozzles

    Directory of Open Access Journals (Sweden)

    Xiaodong He

    2017-04-01

    Full Text Available In the process of composite prepreg tape winding, the compaction force could influence the quality of winding products. According to the analysis and experiments, during the winding process of a rocket motor nozzle aft exit cone with a winding angle, there would be an error between the deposition speed of tape layers and the feeding speed of the compaction roller, which could influence the compaction force. Both a lack of compaction and overcompaction related to the feeding of the compaction roller could result in defects of winding nozzles. Thus, a flexible winding system has been developed for rocket motor nozzle winding. In the system, feeding of the compaction roller could be adjusted in real time to achieve an invariable compaction force. According to experiments, the force deformation model of the winding tape is a time-varying system. Thus, a forgetting factor recursive least square based parameter estimation proportional-integral-differential (PID controller has been developed, which could estimate the time-varying parameter and control the compaction force by adjusting the feeding of the compaction roller during the winding process. According to the experimental results, a winding nozzle with fewer voids and a smooth surface could be wounded by the invariable compaction force in the flexible winding system.

  5. Transfer Effect of Speech-sound Learning on Auditory-motor Processing of Perceived Vocal Pitch Errors.

    Science.gov (United States)

    Chen, Zhaocong; Wong, Francis C K; Jones, Jeffery A; Li, Weifeng; Liu, Peng; Chen, Xi; Liu, Hanjun

    2015-08-17

    Speech perception and production are intimately linked. There is evidence that speech motor learning results in changes to auditory processing of speech. Whether speech motor control benefits from perceptual learning in speech, however, remains unclear. This event-related potential study investigated whether speech-sound learning can modulate the processing of feedback errors during vocal pitch regulation. Mandarin speakers were trained to perceive five Thai lexical tones while learning to associate pictures with spoken words over 5 days. Before and after training, participants produced sustained vowel sounds while they heard their vocal pitch feedback unexpectedly perturbed. As compared to the pre-training session, the magnitude of vocal compensation significantly decreased for the control group, but remained consistent for the trained group at the post-training session. However, the trained group had smaller and faster N1 responses to pitch perturbations and exhibited enhanced P2 responses that correlated significantly with their learning performance. These findings indicate that the cortical processing of vocal pitch regulation can be shaped by learning new speech-sound associations, suggesting that perceptual learning in speech can produce transfer effects to facilitating the neural mechanisms underlying the online monitoring of auditory feedback regarding vocal production.

  6. Cristalização de melão pelo processo lento de açucaramento Crystallization of melon fruit through slow sugary process

    Directory of Open Access Journals (Sweden)

    Ângelo Shigueyuki Morita

    2005-06-01

    Full Text Available Este trabalho foi conduzido no laboratório de Tecnologia de Alimentos da Escola Superior de Agricultura de Mossoró (ESAM. Avaliou-se a possibilidade de processar o melão como fruta cristalizada. Foram testadas as variedades Gália, Pele de Sapo e Orange Fresh, utilizando-se o processo lento de açucaramento, retirando-se as polpas em formas de bolas e colocando-as sucessivamente em soluções de sacarose a 20, 30, 40, 50, 60 e 70º Brix até abrir a fervura, mantendo-se a polpa em repouso por 24 horas a cada solução de sacarose. Em seguida, os frutos foram colocados em uma estufa a 50ºC durante 6 horas, atingindo-se assim, a umidade final entre 26,16 a 27,53%. Foram determinados teor de umidade, pH, sólidos solúveis totais, e os produtos submetidos a uma análise sensorial. Constatou-se que a cristalização em melão foi tecnicamente viável, que a variedade Pele de Sapo foi a melhor aceita, e que não houve mudança na coloração da polpa das variedades.The experiment was carried out in the Food Technology Laboratory of the Escola Superior de Agricultura de Mossoró (ESAM, Mossoró-RN, Brazil to evaluate the possibility of processing the melon pulp as a crystallized fruit by using the us following melon varieties: Gália, Pele de Sapo, and Orange Flesh, utilizing the slow sugary process. The pulps were withdrawn in little ball form and put successively into sucrose solutions at 20, 30, 40, 50, 60 and 70°Brix, until boiling, keeping them in inactivity for 24 hours in each solution. After that, the fruits were placed in a stove at 50°C during 6 hours, reaching final humidity between 26.16 and 27.53%. Evaluations for humidity content, pH and total soluble solids were made. In addition a sensorial analysis was made. It was observed that the melon crystallization was technically feasible. Pele de Sapo melon was the best in comparison to the other types. Changing in the melon pulp colouring was not observed.

  7. Programmable dc motor controller

    Science.gov (United States)

    Hopwood, J. E.

    1982-11-01

    A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.

  8. Posterior Thalamic Nucleus Modulation of Tactile Stimuli Processing in Rat Motor and Primary Somatosensory Cortices

    Directory of Open Access Journals (Sweden)

    Diana Casas-Torremocha

    2017-09-01

    Full Text Available Rodents move rhythmically their facial whiskers and compute differences between signals predicted and those resulting from the movement to infer information about objects near their head. These computations are carried out by a large network of forebrain structures that includes the thalamus and the primary somatosensory (S1BF and motor (M1wk cortices. Spatially and temporally precise mechanorreceptive whisker information reaches the S1BF cortex via the ventroposterior medial thalamic nucleus (VPM. Other whisker-related information may reach both M1wk and S1BF via the axons from the posterior thalamic nucleus (Po. However, Po axons may convey, in addition to direct sensory signals, the dynamic output of computations between whisker signals and descending motor commands. It has been proposed that this input may be relevant for adjusting cortical responses to predicted vs. unpredicted whisker signals, but the effects of Po input on M1wk and S1BF function have not been directly tested or compared in vivo. Here, using electrophysiology, optogenetics and pharmacological tools, we compared in adult rats M1wk and S1BF in vivo responses in the whisker areas of the motor and primary somatosensory cortices to passive multi-whisker deflection, their dependence on Po activity, and their changes after a brief intense activation of Po axons. We report that the latencies of the first component of tactile-evoked local field potentials in M1wk and S1BF are similar. The evoked potentials decrease markedly in M1wk, but not in S1BF, by injection in Po of the GABAA agonist muscimol. A brief high-frequency electrical stimulation of Po decreases the responsivity of M1wk and S1BF cells to subsequent whisker stimulation. This effect is prevented by the local application of omega-agatoxin, suggesting that it may in part depend on GABA release by fast-spiking parvalbumin (PV-expressing cortical interneurons. Local optogenetic activation of Po synapses in different

  9. Motor learning processes: an electrophysiologic perspective Processos de aprendizagem motora: uma perspectiva eletrofisiológica

    Directory of Open Access Journals (Sweden)

    Bruna Velasques

    2007-12-01

    Full Text Available The goal of the present study was to investigate electrophysiologic, qEEG, changes when individuals were exposed to a motor task. Subjects’ brain electrical activity was analyzed before and after the typewriting training task. For the neurophysiological variable asymmetry, a paired t-test was performed to compare each moment, pre and post-task, in the beta bands. The findings showed a change for the qEEG variable in each scalp site, F3/F4; C3/C4 and P3/P4. These results suggest an adaptation of pre-frontal, sensory-motor and parietal cortex, as a consequence of the typewriting training.O objetivo do presente estudo foi investigar mudanças eletrofisiológicas através do EEGq quando indivíduos são expostos a uma tarefa motora. A atividade elétrica no córtex dos sujeitos foi analisada antes e após o treinamento da tarefa motora. Para a variável neurofisiológica assimetria, um teste t foi implementado para comparar cada momento, pré e pós-tarefa, na banda beta. Os achados demonstraram mudança em assimetria para as seguintes regiões no escalpo: F3/F4, C3/C4 e P3/P4. Estes resultados sugerem uma adaptação das regiões pré-frontal, somatosensorial e parietal como conseqüência do treinamento de datilografia.

  10. Very slow neutrons

    International Nuclear Information System (INIS)

    Frank, A.

    1983-01-01

    The history is briefly presented of the research so far of very slow neutrons and their basic properties are explained. The methods are described of obtaining very slow neutrons and the problems of their preservation are discussed. The existence of very slow neutrons makes it possible to perform experiments which may deepen the knowledge of the fundamental properties of neutrons. Their wavelength approximates that of visible radiation. The possibilities and use are discussed of neutron optical systems (neutron microscope) which could be an effective instrument for the study of the detailed arrangement, especially of organic substances. (B.S.)

  11. Age-related changes in oscillatory power affect motor action.

    Directory of Open Access Journals (Sweden)

    Liqing Liu

    Full Text Available With increasing age cognitive performance slows down. This includes cognitive processes essential for motor performance. Additionally, performance of motor tasks becomes less accurate. The objective of the present study was to identify general neural correlates underlying age-related behavioral slowing and the reduction in motor task accuracy. To this end, we continuously recorded EEG activity from 18 younger and 24 older right-handed healthy participants while they were performing a simple finger tapping task. We analyzed the EEG records with respect to local changes in amplitude (power spectrum as well as phase locking between the two age groups. We found differences between younger and older subjects in the amplitude of post-movement synchronization in the β band of the sensory-motor and medial prefrontal cortex (mPFC. This post-movement β amplitude was significantly reduced in older subjects. Moreover, it positively correlated with the accuracy with which subjects performed the motor task at the electrode FCz, which detects activity of the mPFC and the supplementary motor area. In contrast, we found no correlation between the accurate timing of local neural activity, i.e. phase locking in the δ-θ frequency band, with the reaction and movement time or the accuracy with which the motor task was performed. Our results show that only post-movement β amplitude and not δ-θ phase locking is involved in the control of movement accuracy. The decreased post-movement β amplitude in the mPFC of older subjects hints at an impaired deactivation of this area, which may affect the cognitive control of stimulus-induced motor tasks and thereby motor output.

  12. Transformer Industry Productivity Slows.

    Science.gov (United States)

    Otto, Phyllis Flohr

    1981-01-01

    Annual productivity increases averaged 2.4 percent during 1963-79, slowing since 1972 to 1.5 percent; computer-assisted design and product standardization aided growth in output per employee-hour. (Author)

  13. The connection of hemispheric activity in the field of audioverbal perception and the progressive lateralization of speech and motor processes.

    Directory of Open Access Journals (Sweden)

    Kovyazina, M.S.

    2015-07-01

    Full Text Available This article discusses the connection of hemispheric control over audioverbal perception processes and such individual features as “leading hand” (right-handedness and lefthandedness. We present a literature review and description of our research to provide evidence of the complexity and ambiguity of this connection. The method of dichotic listening was used for diagnosing audioverbal perception lateralization. This method allows estimation of the right-ear coefficient (REC, the efficiency coefficient (EC, and the effectiveness ratio (ER of different aspects of audioverbal perception. Our research involved 47 persons with a leading right hand (mean age, 29.04±9.97 years and 32 persons with a leading left hand (mean age, 29.41±10.34 years. Different hypotheses about the mechanisms of hemispheric control over audioverbal and motor processes were assessed. The research showed that both the leftand right-handers’ audioverbal perception characteristics depended mainly on right-hemisphere activity. The most dynamic and sensitive index of the functioning of the two hemispheres during dichotic listening was the efficiency coefficient of stimuli reproduction through the left ear (EC of the left ear. It turns out that this index depends on the coincidence/noncoincidence of the leading hemispheres in speech and motor processes. The highest efficiency of audioverbal perception revealed itself in the left-handers with a leading left ear (the hemispheric-control coincidence, and the lowest efficiency was in the left-handers with a leading right ear (the hemispheric-control divergence. The right-handers were characterized by less variation in values, although the influence of the coincidence/noncoincidence of the leading hemispheres in speech and motor processes also revealed itself as a tendency. This consistent pattern points out the necessity for further research on asymmetries of the different modalities that takes into account their probable

  14. Fine motor skills enhance lexical processing of embodied vocabulary: A test of the nimble-hands, nimble-minds hypothesis.

    Science.gov (United States)

    Suggate, Sebastian; Stoeger, Heidrun

    2017-10-01

    Research suggests that fine motor skills (FMS) are linked to aspects of cognitive development in children. Additionally, lexical processing advantages exist for words implying a high body-object interaction (BOI), with initial findings indicating that such words in turn link to children's FMS-for which we propose and evaluate four competing hypotheses. First, a maturational account argues that any links between FMS and lexical processing should not exist once developmental variables are controlled for. Second, functionalism posits that any link between FMS and lexical processing arises due to environmental interactions. Third, the semantic richness hypothesis argues that sensorimotor input improves lexical processing, but predicts no links between FMS and lexical processing. A fourth account, the nimble-hands, nimble minds (NHNM) hypothesis, proposes that having greater FMS improves lexical processing for high-BOI words. In two experiments, the response latencies of preschool children (n = 90, n = 76, ages = 5;1) to 45 lexical items encompassing high-BOI, low-BOI, and less imageable words were measured, alongside measures of FMS, reasoning, and general receptive/expressive vocabulary. High-BOI words appeared to show unique links to FMS, which remained after accounting for low-BOI and less imageable words, general vocabulary, reasoning, and chronological age. Although further work is needed, the findings provide initial support for the NHNM hypothesis.

  15. Cognitive Processes and Learner Strategies in the Acquisition of Motor Skills

    Science.gov (United States)

    1978-12-01

    children: Capacity or processing deficits? Memory and Cognition, 1976, 4, 559-S72. Craik , F. I. M., & Lockhart , R. S. Levels of processing : A framework...learning and memory research. In F. I. M. Craik & L. S. Cermak (Eds.), Levels of processing and theories of memory. Hillsdale, N. J.: Erlbaum, 1978...functions. Cognitive activities are described at a highly theoretical (technical) level as well as in a pragmatic manner. Differences in processing

  16. Mental slowness in patients with Parkinson's disease : Associations with cognitive functions?

    NARCIS (Netherlands)

    Vlagsma, Thialda T.; Koerts, Janneke; Tucha, Oliver; Dijkstra, Hilde T.; Duits, Annelien A.; Laar, van Teus; Spikman, Jacoba M.

    2016-01-01

    Introduction: Motor slowness (bradykinesia) is a core feature of Parkinson's disease (PD). It is often assumed that patients show mental slowness (bradyphrenia) as well; however, evidence for this is debated. The aims of this study were to determine whether PD patients show mental slowness apart

  17. Investigation of the Physical and Molecular Properties of Asphalt Binders Processed with Used Motor Oils

    Directory of Open Access Journals (Sweden)

    Mohyeldin Ragab

    2015-01-01

    Full Text Available In this work we investigated the performance aspects of addition of used motor oils (UMO to neat and crumb rubber modified asphalts (CRMA and related that to the change of molecular size distribution of modified asphalt’s fractions; asphaltenes, saturates, naphthene aromatics, and polar aromatics. Based on the results of temperature sweep viscoelastic tests, addition of crumb rubber modifier (CRM alone or with UMO results in the formation of internal network within the modified asphalt. Based on the results of short and long term aged asphalts, the utilization of combination of UMO and CRM enhanced the aging behavior of asphalt. Bending beam rheometer was utilized to investigate the low temperature behavior of UMO modified asphalts. Based on those tests, the utilization of the UMO and CRM enhanced the low temperature properties of asphalts. Based on the results of the asphalt separation tests and the Gel Permeation Chromatography (GPC analysis, it was found that saturates and naphthene aromatics are the two asphalt fractions that have similar molecular size fractions as those of UMO. However, UMO only shifts the molecular sizes of saturates after interaction with asphalt. Results also show that polar aromatics pose higher molecular size structures than UMO.

  18. Bio-mechanical aspects of elite cyclists’ motor system adaptation in process of competition activity

    Directory of Open Access Journals (Sweden)

    A.N. Kolumbet

    2017-10-01

    Full Text Available Purpose; to study the laws of motor structure adaptation of elite cyclists, specializing in 4 km individual pursuit racing on track. Material: in the research 18 elite athletes participated. We studied special aspects of athletes’ coordination structure in experiment, which simulated competition activity. Results: at start segment of distance high speed depends on effectiveness of right leg’s pulling; on pressing and pushing of left leg. At initial stage of distance high efficiency of pedaling is ensured by pressing and pulling of right and left legs. At middle segment high workability depends on movement of right leg; pressing, pulling and pushing of left leg. On finish speed depends by effectiveness of pressing, pulling and moving of right leg; pressing and pulling of left leg. Conclusions: the presented material creates real pre-conditions for development of bio-mechanical models of cyclists’ pedaling technique. The received data can be used for special searching of optimal movement, considering competition tactic. The received results can be used for choosing of means and methods of athletes’ movements’ pedagogic re-constructions.

  19. HISTAMINE H3 RECEPTOR INVERSE AGONISTS ON COGNITIVE AND MOTOR PROCESSES: RELEVANCE TO ALZHEIMER’S DISEASE, ADHD, SCHIZOPHRENIA AND DRUG ABUSE

    Directory of Open Access Journals (Sweden)

    Divya eVohora

    2012-10-01

    Full Text Available Histamine H3 receptor antagonists/ inverse agonists possess potential to treat diverse disease states of the central nervous system (CNS. Cognitive dysfunction and motor impairments are the hallmark of multifarious neurodegenerative and/or psychiatric disorders. This review presents the various neurobiological/ neurochemical evidences available so far following H3 receptor inverse agonists/ antagonists in the pathophysiology of Alzheimer’s disease (AD, attention-deficit hyperactivity disorder (ADHD, schizophrenia and drug abuse each of which is accompanied by deficits of some aspects of cognitive and/or motor functions. Whether the H3 receptor inverse agonism modulates the neurochemical basis underlying the disease condition or affects only the cognitive/motor component of the disease process is discussed with the aim to provide a rationale for their use in diverse disease states that are interlinked and are accompanied by some common motor, cognitive and attentional deficits.

  20. Use it or lose it: tonic activity of slow motoneurons promotes their survival and preferentially increases slow fiber-type groupings in muscles of old lifelong recreational sportsmen

    Directory of Open Access Journals (Sweden)

    Simone Mosole

    2016-11-01

    Full Text Available Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i denervation contributes to muscle atrophy, ii impaired mobility accelerates the process, and iii lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers; 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers; 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always

  1. Use it or Lose It: Tonic Activity of Slow Motoneurons Promotes Their Survival and Preferentially Increases Slow Fiber-Type Groupings in Muscles of Old Lifelong Recreational Sportsmen

    Science.gov (United States)

    Mosole, Simone; Carraro, Ugo; Kern, Helmut; Loefler, Stefan; Zampieri, Sandra

    2016-01-01

    Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i) denervation contributes to muscle atrophy, ii) impaired mobility accelerates the process, and iii) lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES) of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC) we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers); 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers); 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always more active

  2. Use it or Lose It: Tonic Activity of Slow Motoneurons Promotes Their Survival and Preferentially Increases Slow Fiber-Type Groupings in Muscles of Old Lifelong Recreational Sportsmen.

    Science.gov (United States)

    Mosole, Simone; Carraro, Ugo; Kern, Helmut; Loefler, Stefan; Zampieri, Sandra

    2016-09-15

    Histochemistry, immuno-histochemistry, gel electrophoresis of single muscle fibers and electromyography of aging muscles and nerves suggest that: i) denervation contributes to muscle atrophy, ii) impaired mobility accelerates the process, and iii) lifelong running protects against loss of motor units. Recent corroborating results on the muscle effects of Functional Electrical Stimulation (FES) of aged muscles will be also mentioned, but we will in particular discuss how and why a lifelong increased physical activity sustains reinnervation of muscle fibers. By analyzing distribution and density of muscle fibers co-expressing fast and slow Myosin Heavy Chains (MHC) we are able to distinguish the transforming muscle fibers due to activity related plasticity, to those that adapt muscle fiber properties to denervation and reinnervation. In muscle biopsies from septuagenarians with a history of lifelong high-level recreational activity we recently observed in comparison to sedentary seniors: 1. decreased proportion of small-size angular myofibers (denervated muscle fibers); 2. considerable increase of fiber-type groupings of the slow type (reinnervated muscle fibers); 3. sparse presence of muscle fibers co-expressing fast and slow MHC. Immuno-histochemical characteristics fluctuate from those with scarce fiber-type modulation and groupings to almost complete transformed muscles, going through a process in which isolated fibers co-expressing fast and slow MHC fill the gaps among fiber groupings. Data suggest that lifelong high-level exercise allows the body to adapt to the consequences of the age-related denervation and that it preserves muscle structure and function by saving otherwise lost muscle fibers through recruitment to different slow motor units. This is an opposite behavior of that described in long term denervated or resting muscles. These effects of lifelong high level activity seems to act primarily on motor neurons, in particular on those always more active

  3. Models of expert assessments and their study in problems of choice and decision-making in management of motor transport processes

    Science.gov (United States)

    Belokurov, V. P.; Belokurov, S. V.; Korablev, R. A.; Shtepa, A. A.

    2018-05-01

    The article deals with decision making concerning transport tasks on search iterations in the management of motor transport processes. An optimal selection of the best option for specific situations is suggested in the management of complex multi-criteria transport processes.

  4. How do German bilingual schoolchildren process German prepositions? – A study on language-motor interactions

    Science.gov (United States)

    Bischoff, Heike; Strozyk, Jessica Vanessa; Bryant, Doreen; Kaup, Barbara

    2018-01-01

    While much support is found for embodied language processing in a first language (L1), evidence for embodiment in second language (L2) processing is rather sparse. In a recent study, we found support for L2 embodiment, but also an influence of L1 on L2 processing in adult learners. In the present study, we compared bilingual schoolchildren who speak German as one of their languages with monolingual German schoolchildren. We presented the German prepositions auf (on), über (above), and unter (under) in a Stroop-like task. Upward or downward responses were made depending on the font colour, resulting in compatible and incompatible trials. We found compatibility effects for all children, but in contrast to the adult sample, there were no processing differences between the children depending on the nature of their other language, suggesting that the processing of German prepositions of bilingual children is embodied in a similar way as in monolingual German children. PMID:29538404

  5. How do German bilingual schoolchildren process German prepositions? - A study on language-motor interactions.

    Science.gov (United States)

    Ahlberg, Daniela Katharina; Bischoff, Heike; Strozyk, Jessica Vanessa; Bryant, Doreen; Kaup, Barbara

    2018-01-01

    While much support is found for embodied language processing in a first language (L1), evidence for embodiment in second language (L2) processing is rather sparse. In a recent study, we found support for L2 embodiment, but also an influence of L1 on L2 processing in adult learners. In the present study, we compared bilingual schoolchildren who speak German as one of their languages with monolingual German schoolchildren. We presented the German prepositions auf (on), über (above), and unter (under) in a Stroop-like task. Upward or downward responses were made depending on the font colour, resulting in compatible and incompatible trials. We found compatibility effects for all children, but in contrast to the adult sample, there were no processing differences between the children depending on the nature of their other language, suggesting that the processing of German prepositions of bilingual children is embodied in a similar way as in monolingual German children.

  6. Coaxial slow source

    International Nuclear Information System (INIS)

    Brooks, R.D.; Jarboe, T.R.

    1990-01-01

    Field reversed configurations (FRCs) are a class of compact toroid with not toroidal field. The field reversed theta pinch technique has been successfully used for formation of FRCs since their inception in 1958. In this method an initial bias field is produced. After ionization of the fill gas, the current in the coil is rapidly reversed producing the radial implosion of a current sheath. At the ends of the coil the reversed field lines rapidly tear and reconnect with the bias field lines until no more bias flux remains. At this point, vacuum reversed field accumulates around the configuration which contracts axially until an equilibrium is reached. When extrapolating the use of such a technique to reactor size plasmas two main shortcomings are found. First, the initial bias field, and hence flux in a given device, which can be reconnected to form the configuration is limited from above by destructive axial dynamics. Second, the voltages required to produce rapid current reversal in the coil are very large. Clearly, a low voltage formation technique without limitations on flux addition is desirable. The Coaxial Slow Source (CSS) device was designed to meet this need. It has two coaxial theta pinch coils. Coaxial coil geometry allows for the addition of as much magnetic flux to the annular plasma between them as can be generated inside the inner coil. Furthermore the device can be operated at charging voltages less than 10 kV and on resistive diffusion, rather than implosive time scales. The inner coil is a novel, concentric, helical design so as to allow it to be cantilevered on one end to permit translation of the plasma. Following translation off the inner coil the Annular Field Reversed Configuration would be re-formed as a true FRC. In this paper we investigate the formation process in the new parallel configuration., CSSP, in which the inner and outer coils are connected in parallel to the main capacitor bank

  7. Associations among measures of sequential processing in motor and linguistics tasks in adults with and without a family history of childhood apraxia of speech: a replication study.

    Science.gov (United States)

    Button, Le; Peter, Beate; Stoel-Gammon, Carol; Raskind, Wendy H

    2013-03-01

    The purpose of this study was to address the hypothesis that childhood apraxia of speech (CAS) is influenced by an underlying deficit in sequential processing that is also expressed in other modalities. In a sample of 21 adults from five multigenerational families, 11 with histories of various familial speech sound disorders, 3 biologically related adults from a family with familial CAS showed motor sequencing deficits in an alternating motor speech task. Compared with the other adults, these three participants showed deficits in tasks requiring high loads of sequential processing, including nonword imitation, nonword reading and spelling. Qualitative error analyses in real word and nonword imitations revealed group differences in phoneme sequencing errors. Motor sequencing ability was correlated with phoneme sequencing errors during real word and nonword imitation, reading and spelling. Correlations were characterized by extremely high scores in one family and extremely low scores in another. Results are consistent with a central deficit in sequential processing in CAS of familial origin.

  8. The dream-lag effect: selective processing of personally significant events during Rapid Eye Movement sleep, but not during Slow Wave Sleep

    OpenAIRE

    van Rijn, E.; Eichenlaub, J.-B.; Lewis, Penelope A.; Walker, M.P.; Gaskell, M.G.; Malinowski, J.E.; Blagrove, M.

    2015-01-01

    Incorporation of details from waking life events into Rapid Eye Movement (REM) sleep dreams has been found to be highest on the night after, and then 5-7 nights after events (termed, respectively, the day-residue and dream-lag effects). In experiment 1, 44 participants kept a daily log for 10. days, reporting major daily activities (MDAs), personally significant events (PSEs), and major concerns (MCs). Dream reports were collected from REM and Slow Wave Sleep (SWS) in the laboratory, or from ...

  9. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  10. At the interface of the auditory and vocal motor systems: NIf and its role in vocal processing, production and learning.

    Science.gov (United States)

    Lewandowski, Brian; Vyssotski, Alexei; Hahnloser, Richard H R; Schmidt, Marc

    2013-06-01

    Communication between auditory and vocal motor nuclei is essential for vocal learning. In songbirds, the nucleus interfacialis of the nidopallium (NIf) is part of a sensorimotor loop, along with auditory nucleus avalanche (Av) and song system nucleus HVC, that links the auditory and song systems. Most of the auditory information comes through this sensorimotor loop, with the projection from NIf to HVC representing the largest single source of auditory information to the song system. In addition to providing the majority of HVC's auditory input, NIf is also the primary driver of spontaneous activity and premotor-like bursting during sleep in HVC. Like HVC and RA, two nuclei critical for song learning and production, NIf exhibits behavioral-state dependent auditory responses and strong motor bursts that precede song output. NIf also exhibits extended periods of fast gamma oscillations following vocal production. Based on the converging evidence from studies of physiology and functional connectivity it would be reasonable to expect NIf to play an important role in the learning, maintenance, and production of song. Surprisingly, however, lesions of NIf in adult zebra finches have no effect on song production or maintenance. Only the plastic song produced by juvenile zebra finches during the sensorimotor phase of song learning is affected by NIf lesions. In this review, we carefully examine what is known about NIf at the anatomical, physiological, and behavioral levels. We reexamine conclusions drawn from previous studies in the light of our current understanding of the song system, and establish what can be said with certainty about NIf's involvement in song learning, maintenance, and production. Finally, we review recent theories of song learning integrating possible roles for NIf within these frameworks and suggest possible parallels between NIf and sensorimotor areas that form part of the neural circuitry for speech processing in humans. Copyright © 2013 Elsevier

  11. Dynamic disconnection of the supplementary motor area after processing of dismissive biographic narratives

    NARCIS (Netherlands)

    Borchardt, Viola; Krause, Anna L.; Li, Meng; van Tol, Marie-Jose; Demenescu, Liliana Ramona; Buchheim, Anna; Metzger, Coraline D.; Sweeney-Reed, Catherine M.; Nolte, Tobias; Lord, Anton R.; Walter, Martin

    2015-01-01

    Introduction: To understand the interplay between affective social information processing and its influence on mental states we investigated changes in functional connectivity (FC) patterns after audio exposure to emotional biographic narratives. Methods: While lying in the 7T MR scanner, 23 male

  12. Intrathecal infusion of a Ca(2+)-permeable AMPA channel blocker slows loss of both motor neurons and of the astrocyte glutamate transporter, GLT-1 in a mutant SOD1 rat model of ALS.

    Science.gov (United States)

    Yin, Hong Z; Tang, Darryl T; Weiss, John H

    2007-10-01

    Elevated extracellular glutamate, resulting from a loss of astrocytic glutamate transport capacity, may contribute to excitotoxic motor neuron (MN) damage in ALS. Accounting for their high excitotoxic vulnerability, MNs possess large numbers of unusual Ca(2+)-permeable AMPA channels (Ca-AMPA channels), the activation of which triggers mitochondrial Ca(2+) overload and strong reactive oxygen species (ROS) generation. However, the causes of the astrocytic glutamate transport loss remain unexplained. To assess the role of Ca-AMPA channels on the evolution of pathology in vivo, we have examined effects of prolonged intrathecal infusion of the Ca-AMPA channel blocker, 1-naphthyl acetylspermine (NAS), in G93A transgenic rat models of ALS. In wild-type animals, immunoreactivity for the astrocytic glutamate transporter, GLT-1, was particularly strong around ventral horn MNs. However, a marked loss of ventral horn GLT-1 was observed, along with substantial MN damage, prior to onset of symptoms (90-100 days) in the G93A rats. Conversely, labeling with the oxidative marker, nitrotyrosine, was increased in the neuropil surrounding MNs in the transgenic animals. Compared to sham-treated G93A animals, 30-day NAS infusions (starting at 67+/-2 days of age) markedly diminished the loss of both MNs and of astrocytic GLT-1 labeling. These observations are compatible with the hypothesis that activation of Ca-AMPA channels on MNs contributes, likely in part through oxidative mechanisms, to loss of glutamate transporter in surrounding astrocytes.

  13. SPS slow extraction septa

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    SPS long straight section (LSS) with a series of 5 septum tanks for slow extraction (view in the direction of the proton beam). There are 2 of these: in LSS2, towards the N-Area; in LSS6 towards the W-Area. See also Annual Report 1975, p.175.

  14. AGS slow extraction improvements

    International Nuclear Information System (INIS)

    Glenn, J.W.; Smith, G.A.; Sandberg, J.N.; Repeta, L.; Weisberg, H.

    1979-01-01

    Improvement of the straightness of the F5 copper septum increased the AGS slow extraction efficiency from approx. 80% to approx. 90%. Installation of an electrostatic septum at H2O, 24 betatron wavelengths upstream of F5, further improved the extraction efficiency to approx. 97%

  15. PF slow positron source

    International Nuclear Information System (INIS)

    Shirakawa, A.; Enomoto, A.; Kurihara, T.

    1993-01-01

    A new slow-positron source is under construction at the Photon Factory. Positrons are produced by bombarding a tantalum rod with high-energy electrons; they are moderated in multiple tungsten vanes. We report here the present status of this project. (author)

  16. Selection of electric motors for industrial processes with the rational energy use criteria; Seleccion de motores electricos para procesos industriales con criterios de uso racional de la energia

    Energy Technology Data Exchange (ETDEWEB)

    Morales Collantes, Arturo [Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico)

    1993-12-31

    Under the energy and ecological crisis we are now going through, but fundamentally because as human beings we can not keep on acting in such a thoughtless way, I write these notes, with the intention that we take more into consideration that whatever we do to improve the ways of energy consumption, will ease the human life preservation. The electric motors selection, plays an important roll in this respect, since it represents the highest percentage of electric energy consumption at national level. Therefore I will point out some basic criteria for an adequate selection. [Espanol] Ante la crisis energetica y ecologica por la que actualmente pasamos, pero fundamentalmente porque como seres humanos no podemos seguir actuando en forma tan irreflexiva, escribo estas notas, con la intencion de que tomemos mas en cuenta, que lo que hagamos para mejorar las formas de consumo de energia, facilitara la preservacion de la vida humana. La seleccion de motores electricos, juega un importante papel al respecto, ya que representa el mayor porcentaje del consumo de energia electrica a nivel nacional, por lo tanto senalare algunos criterios basicos para una adecuada seleccion.

  17. Selection of electric motors for industrial processes with the rational energy use criteria; Seleccion de motores electricos para procesos industriales con criterios de uso racional de la energia

    Energy Technology Data Exchange (ETDEWEB)

    Morales Collantes, Arturo [Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico)

    1992-12-31

    Under the energy and ecological crisis we are now going through, but fundamentally because as human beings we can not keep on acting in such a thoughtless way, I write these notes, with the intention that we take more into consideration that whatever we do to improve the ways of energy consumption, will ease the human life preservation. The electric motors selection, plays an important roll in this respect, since it represents the highest percentage of electric energy consumption at national level. Therefore I will point out some basic criteria for an adequate selection. [Espanol] Ante la crisis energetica y ecologica por la que actualmente pasamos, pero fundamentalmente porque como seres humanos no podemos seguir actuando en forma tan irreflexiva, escribo estas notas, con la intencion de que tomemos mas en cuenta, que lo que hagamos para mejorar las formas de consumo de energia, facilitara la preservacion de la vida humana. La seleccion de motores electricos, juega un importante papel al respecto, ya que representa el mayor porcentaje del consumo de energia electrica a nivel nacional, por lo tanto senalare algunos criterios basicos para una adecuada seleccion.

  18. Comparison of the sensitivity to change of the Functional Independence Measure with the Assessment of Motor and Process Skills within different rehabilitation populations.

    Science.gov (United States)

    Choo, Silvana X; Stratford, Paul; Richardson, Julie; Bosch, Jackie; Pettit, Susan M; Ansley, Barbara J; Harris, Jocelyn E

    2017-09-10

    To determine whether there was a difference in the sensitivity to change of the subscales of the Functional Independence Measure and the Assessment of Motor and Process Skills within three different post-acute inpatient rehabilitation populations. We conducted retrospective chart review of patients consecutively admitted to inpatient rehabilitation units, with both admission and discharge Functional Independence Measure and Assessment of Motor and Process Skills scores. A total of 276 participants were included and categorized into diagnostic groups (orthopedic, oncology, and geriatric). Within group, sensitivity to change was evaluated for the subscales of each measure by calculating the difference in standardized response means (SRM) and 95% confidence intervals (CI). The Functional Independence Measure motor subscale was more sensitive to change than the Assessment of Motor and Process Skills in the orthopedic and geriatric groups (SRM difference  = 1.53 [95% CI 0.93, 2.3] and 0.65 [95% CI 0.3, 1.02], respectively) but not in the oncology group (SRM difference  = 0.42 [95% CI -0.2, 1.04]). For the cognitive subscales, the Assessment of Motor and Process Skills was more sensitive to change than the Functional Independence Measure in all three groups (SRM difference  = 0.38 [95% CI 004, 0.74], 0.65 [95% CI 0.45, 0.90], and 1.15 [95% CI 0.77, 1.69] for orthopedic, geriatric, and oncology, respectively). The Functional Independence Measure is a mandated measure for all rehabilitation units in Canada. As the cognitive subscale of the Assessment of Motor and Process Skills is more sensitive to change than the Functional Independence Measure, we recommend also administering the Assessment of Motor and Process Skills to better detect changes in the cognitive aspect of function. Implications for rehabilitation When deciding between the Functional Independence Measure or the Assessment of Motor and Process Skills, it is important to consider whether patients

  19. Slow sleep spindle and procedural memory consolidation in patients with major depressive disorder

    Directory of Open Access Journals (Sweden)

    Nishida M

    2016-01-01

    Full Text Available Masaki Nishida,1 Yusaku Nakashima,2 Toru Nishikawa11Department of Psychiatry and Behavioral Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Yushima, Bunkyo, 2Medical Technology Research Laboratory, Research and Development Division, Medical Business Unit, Sony Corporation, Tokyo, JapanIntroduction: Evidence has accumulated, which indicates that, in healthy individuals, sleep enhances procedural memory consolidation, and that sleep spindle activity modulates this process. However, whether sleep-dependent procedural memory consolidation occurs in patients medicated for major depressive disorder remains unclear, as are the pharmacological and physiological mechanisms that underlie this process.Methods: Healthy control participants (n=17 and patients medicated for major depressive disorder (n=11 were recruited and subjected to a finger-tapping motor sequence test (MST; nondominant hand paradigm to compare the averaged scores of different learning phases (presleep, postsleep, and overnight improvement. Participants' brain activity was recorded during sleep with 16 electroencephalography channels (between MSTs. Sleep scoring and frequency analyses were performed on the electroencephalography data. Additionally, we evaluated sleep spindle activity, which divided the spindles into fast-frequency spindle activity (12.5–16 Hz and slow-frequency spindle activity (10.5–12.5 Hz.Result: Sleep-dependent motor memory consolidation in patients with depression was impaired in comparison with that in control participants. In patients with depression, age correlated negatively with overnight improvement. The duration of slow-wave sleep correlated with the magnitude of motor memory consolidation in patients with depression, but not in healthy controls. Slow-frequency spindle activity was associated with reduction in the magnitude of motor memory consolidation in both groups.Conclusion: Because the changes in slow

  20. Slow movement execution in event-related potentials (P300).

    Science.gov (United States)

    Naruse, Kumi; Sakuma, Haruo; Hirai, Takane

    2002-02-01

    We examined whether slow movement execution has an effect on cognitive and information processing by measuring the P300 component. 8 subjects performed a continuous slow forearm rotational movement using 2 task speeds. Slow (a 30-50% decrease from the subject's Preferred speed) and Very Slow (a 60-80% decrease). The mean coefficient of variation for rotation speed under Very Slow was higher than that under Slow, showing that the subjects found it difficult to perform the Very Slow task smoothly. The EEG score of alpha-1 (8-10 Hz) under Slow Condition was increased significantly more than under the Preferred Condition; however, the increase under Very Slow was small when compared with Preferred. After performing the task. P300 latency under Very Slow increased significantly as compared to that at pretask. Further, P300 amplitude decreased tinder both speed conditions when compared to that at pretask, and a significant decrease was seen under the Slow Condition at Fz, whereas the decrease under the Very Slow Condition was small. These differences indicated that a more complicated neural composition and an increase in subjects' attention might have been involved when the task was performed under the Very Slow Condition. We concluded that slow movement execution may have an influence on cognitive function and may depend on the percentage of decrease from the Preferred speed of the individual.

  1. Structural Model of the Relationships among Cognitive Processes, Visual Motor Integration, and Academic Achievement in Students with Mild Intellectual Disability (MID)

    Science.gov (United States)

    Taha, Mohamed Mostafa

    2016-01-01

    This study aimed to test a proposed structural model of the relationships and existing paths among cognitive processes (attention and planning), visual motor integration, and academic achievement in reading, writing, and mathematics. The study sample consisted of 50 students with mild intellectual disability or MID. The average age of these…

  2. Neural and Computational Mechanisms of Action Processing: Interaction between Visual and Motor Representations.

    Science.gov (United States)

    Giese, Martin A; Rizzolatti, Giacomo

    2015-10-07

    Action recognition has received enormous interest in the field of neuroscience over the last two decades. In spite of this interest, the knowledge in terms of fundamental neural mechanisms that provide constraints for underlying computations remains rather limited. This fact stands in contrast with a wide variety of speculative theories about how action recognition might work. This review focuses on new fundamental electrophysiological results in monkeys, which provide constraints for the detailed underlying computations. In addition, we review models for action recognition and processing that have concrete mathematical implementations, as opposed to conceptual models. We think that only such implemented models can be meaningfully linked quantitatively to physiological data and have a potential to narrow down the many possible computational explanations for action recognition. In addition, only concrete implementations allow judging whether postulated computational concepts have a feasible implementation in terms of realistic neural circuits. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Neural processes mediating the preparation and release of focal motor output are suppressed or absent during imagined movement

    Science.gov (United States)

    Eagles, Jeremy S.; Carlsen, Anthony N.

    2016-01-01

    Movements that are executed or imagined activate a similar subset of cortical regions, but the extent to which this activity represents functionally equivalent neural processes is unclear. During preparation for an executed movement, presentation of a startling acoustic stimulus (SAS) evokes a premature release of the planned movement with the spatial and temporal features of the tasks essentially intact. If imagined movement incorporates the same preparatory processes as executed movement, then a SAS should release the planned movement during preparation. This hypothesis was tested using an instructed-delay cueing paradigm during which subjects were required to rapidly release a handheld weight while maintaining the posture of the arm or to perform first-person imagery of the same task while holding the weight. In a subset of trials, a SAS was presented at 1500, 500, or 200 ms prior to the release cue. Task-appropriate preparation during executed and imagined movements was confirmed by electroencephalographic recording of a contingent negative variation waveform. During preparation for executed movement, a SAS often resulted in premature release of the weight with the probability of release progressively increasing from 24 % at −1500 ms to 80 % at −200 ms. In contrast, the SAS rarely (movement. However, the SAS frequently evoked the planned postural response (suppression of bicep brachii muscle activity) irrespective of the task or timing of stimulation (even during periods of postural hold without preparation). These findings provide evidence that neural processes mediating the preparation and release of the focal motor task (release of the weight) are markedly attenuated or absent during imagined movement and that postural and focal components of the task are prepared independently. PMID:25744055

  4. Effects of the amount and schedule of varied practice after constant practice on the adaptive process of motor learning

    Directory of Open Access Journals (Sweden)

    Umberto Cesar Corrêa

    2014-12-01

    Full Text Available This study investigated the effects of different amounts and schedules of varied practice, after constant practice, on the adaptive process of motor learning. Participants were one hundred and seven children with a mean age of 11.1 ± 0.9 years. Three experiments were carried out using a complex anticipatory timing task manipulating the following components in the varied practice: visual stimulus speed (experiment 1; sequential response pattern (experiment 2; and visual stimulus speed plus sequential response pattern (experiment 3. In all experiments the design involved three amounts (18, 36, and 63 trials, and two schedules (random and blocked of varied practice. The experiments also involved two learning phases: stabilization and adaptation. The dependent variables were the absolute, variable, and constant errors related to the task goal, and the relative timing of the sequential response. Results showed that all groups worsened the performances in the adaptation phase, and no difference was observed between them. Altogether, the results of the three experiments allow the conclusion that the amounts of trials manipulated in the random and blocked practices did not promote the diversification of the skill since no adaptation was observed.

  5. Slow, slow, quick, quick, slow: Saudi Arabia's 'Gas Initiative'

    International Nuclear Information System (INIS)

    Robins, Philip

    2004-01-01

    This article sets out to analyse the Saudi gas initiative in the context of the decision-making process in Saudi Arabia between 1998 and 2002. It describes the overall context in which the initiative was made. It focuses on the personalities and institutions that were important in its birth and its evolution. The article argues that a mixture of personalities (especially that of Crown Prince Abdullah and foreign minister Saud al-Faisal) and institutions (especially a clutch of new bodies formed in 1999 and 2000) were pivotal in the emergence of the initiative. It also looks at the obstacles that were placed in the way of the initiative, arguing that Saudi Aramco and the minister of oil, Ali Naimi, were key blocking players. Over time, the Saudi gas initiative has come to be seen as a benchmark of the wider cause of economic liberalization in the Kingdom. The lack of progress in the initiative since the initial indicative contract awards in June 2001 has reflected the lack of movement in the general reformist strategy

  6. Motor network plasticity and low-frequency oscillations abnormalities in patients with brain gliomas: a functional MRI study.

    Directory of Open Access Journals (Sweden)

    Chen Niu

    Full Text Available Brain plasticity is often associated with the process of slow-growing tumor formation, which remodels neural organization and optimizes brain network function. In this study, we aimed to investigate whether motor function plasticity would display deficits in patients with slow-growing brain tumors located in or near motor areas, but who were without motor neurological deficits. We used resting-state functional magnetic resonance imaging to probe motor networks in 15 patients with histopathologically confirmed brain gliomas and 15 age-matched healthy controls. All subjects performed a motor task to help identify individual motor activity in the bilateral primary motor cortex (PMC and supplementary motor area (SMA. Frequency-based analysis at three different frequencies was then used to investigate possible alterations in the power spectral density (PSD of low-frequency oscillations. For each group, the average PSD was determined for each brain region and a nonparametric test was performed to determine the difference in power between the two groups. Significantly reduced inter-hemispheric functional connectivity between the left and right PMC was observed in patients compared with controls (P<0.05. We also found significantly decreased PSD in patients compared to that in controls, in all three frequency bands (low: 0.01-0.02 Hz; middle: 0.02-0.06 Hz; and high: 0.06-0.1 Hz, at three key motor regions. These findings suggest that in asymptomatic patients with brain tumors located in eloquent regions, inter-hemispheric connection may be more vulnerable. A comparison of the two approaches indicated that power spectral analysis is more sensitive than functional connectivity analysis for identifying the neurological abnormalities underlying motor function plasticity induced by slow-growing tumors.

  7. Absolute quantitative profiling of the key metabolic pathways in slow and fast skeletal muscle

    DEFF Research Database (Denmark)

    Rakus, Dariusz; Gizak, Agnieszka; Deshmukh, Atul

    2015-01-01

    . Proteomic analysis of mouse slow and fast muscles allowed estimation of the titers of enzymes involved in the carbohydrate, lipid, and energy metabolism. Notably, we observed that differences observed between the two muscle types occur simultaneously for all proteins involved in a specific process......Slow and fast skeletal muscles are composed of, respectively, mainly oxidative and glycolytic muscle fibers, which are the basic cellular motor units of the motility apparatus. They largely differ in excitability, contraction mechanism, and metabolism. Because of their pivotal role in body motion...... and homeostasis, the skeletal muscles have been extensively studied using biochemical and molecular biology approaches. Here we describe a simple analytical and computational approach to estimate titers of enzymes of basic metabolic pathways and proteins of the contractile machinery in the skeletal muscles...

  8. On the Nature of Extraversion: Variation in Conditioned Contextual Activation of Dopamine-Facilitated Affective, Cognitive, and Motor Processes

    Directory of Open Access Journals (Sweden)

    Richard allen Depue

    2013-06-01

    Full Text Available Research supports an association between extraversion and dopamine (DA functioning. DA facilitates incentive motivation and the conditioning and incentive encoding of contexts that predict reward. Therefore, we assessed whether extraversion is related to the efficacy of acquiring conditioned contextual facilitation of three processes that are dependent on DA: motor velocity, positive affect, and visuospatial working memory. We exposed high and low extraverts to three days of association of drug reward (methylphenidate, MP with a particular laboratory context (Paired group, a test day of conditioning, and three days of extinction in the same laboratory. A Placebo group and an Unpaired group (that had MP in a different laboratory context served as controls. Conditioned contextual facilitation was assessed by (i presenting video clips that varied in their pairing with drug and laboratory context and in inherent incentive value, and (ii measuring increases from day 1 to Test day on the three processes above. Results showed acquisition of conditioned contextual facilitation across all measures to video clips that had been paired with drug and laboratory context in the Paired high extraverts, but no conditioning in the Paired low extraverts (nor in either of the control groups. Increases in the Paired high extraverts were correlated across the three measures. Also, conditioned facilitation was evident on the first day of extinction in Paired high extraverts, despite the absence of the unconditioned effects of MP. By the last day of extinction, responding returned to day 1 levels. The findings suggest that extraversion is associated with variation in the acquisition of contexts that predict reward. Over time, this variation may lead to differences in the breadth of networks of conditioned contexts. Thus, individual differences in extraversion may be maintained by activation of differentially encoded central representations of incentive contexts that

  9. Motor Preparation Disrupts Proactive Control in the Stop Signal Task

    Directory of Open Access Journals (Sweden)

    Wuyi Wang

    2018-05-01

    Full Text Available In a study of the stop signal task (SST we employed Bayesian modeling to compute the estimated likelihood of stop signal or P(Stop trial by trial and identified regional processes of conflict anticipation and response slowing. A higher P(Stop is associated with prolonged go trial reaction time (goRT—a form of sequential effect—and reflects proactive control of motor response. However, some individuals do not demonstrate a sequential effect despite similar go and stop success (SS rates. We posited that motor preparation may disrupt proactive control more in certain individuals than others. Specifically, the time interval between trial and go signal onset—the fore-period (FP—varies across trials and a longer FP is associated with a higher level of motor preparation and shorter goRT. Greater motor preparatory activities may disrupt proactive control. To test this hypothesis, we compared brain activations and Granger causal connectivities of 81 adults who demonstrated a sequential effect (SEQ and 35 who did not (nSEQ. SEQ and nSEQ did not differ in regional activations to conflict anticipation, motor preparation, goRT slowing or goRT speeding. In contrast, SEQ and nSEQ demonstrated different patterns of Granger causal connectivities. P(Stop and FP activations shared reciprocal influence in SEQ but FP activities Granger caused P(Stop activities unidirectionally in nSEQ, and FP activities Granger caused goRT speeding activities in nSEQ but not SEQ. These findings support the hypothesis that motor preparation disrupts proactive control in nSEQ and provide direct neural evidence for interactive go and stop processes.

  10. Vegetative deviation in patients with slow-repair processes in the post-operative wound and effect of the combined use of low-intensity laser therapy and pantovegin electrophoresis

    Directory of Open Access Journals (Sweden)

    Dugieva M.Z.

    2013-12-01

    Full Text Available Aim of this study was to evaluate the influence of combined use of low-intensity infrared laser therapy when exposed area of the thymus and electrophoresis of pantovegin on vegetative status of patients with the slowdown in the wound recovery reparative processes. Material study were 190 patients after gynecological laparotomy. Result. The article presents data on changes in vegetative status in postoperative gynecological patients with a slowdown in the wound recovery reparative processes. In this group of patients in the postoperative period parasimpatikotony prevails. By combination of low-intensity infrared laser therapy when exposed area of the thymus and pantovegin electrophoresis achieved more rapid normalization of available changes with the transition to the use of combination eitony. It is recommended to use physiotherapy method for slowing reparative processes in the wound.

  11. Cognitive-motor interference during fine and gross motor tasks in children with Developmental Coordination Disorder (DCD).

    Science.gov (United States)

    Schott, Nadja; El-Rajab, Inaam; Klotzbier, Thomas

    2016-10-01

    While typically developing children produce relatively automatized postural control processes, children with DCD seem to exhibit an automatization deficit. Dual tasks with various cognitive loads seem to be an effective way to assess the automatic deficit hypothesis. The aims of the study were: (1) to examine the effect of a concurrent cognitive task on fine and gross motor tasks in children with DCD, and (2) to determine whether the effect varied with different difficulty levels of the concurrent task. We examined dual-task performance (Trail-Making-Test, Trail-Walking-Test) in 20 children with DCD and 39 typically developing children. Based on the idea of the Trail-Making-Test, participants walked along a fixed pathway, following a prescribed path, delineated by target markers of (1) increasing sequential numbers, and (2) increasing sequential numbers and letters. The motor and cognitive dual-task effects (DTE) were calculated for each task. Regardless of the cognitive task, children with DCD performed equally well in fine and gross motor tasks, and were slower in the dual task conditions than under single task-conditions, compared with children without DCD. Increased cognitive task complexity resulted in slow trail walking as well as slower trail tracing. The motor interference for the gross motor tasks was least for the simplest conditions and greatest for the complex conditions and was more pronounced in children with DCD. Cognitive interference was low irrespective of the motor task. Children with DCD show a different approach to allocation of cognitive resources, and have difficulties making motor skills automatic. The latter notion is consistent with impaired cerebellar function and the "automatization deficit hypothesis", suggesting that any deficit in the automatization process will appear if conscious monitoring of the motor skill is made more difficult by integrating another task requiring attentional resources. Copyright © 2016 Elsevier Ltd. All

  12. Slow Off-rates and Strong Product Binding Are Required for Processivity and Efficient Degradation of Recalcitrant Chitin by Family 18 Chitinases.

    Science.gov (United States)

    Kurašin, Mihhail; Kuusk, Silja; Kuusk, Piret; Sørlie, Morten; Väljamäe, Priit

    2015-11-27

    Processive glycoside hydrolases are the key components of enzymatic machineries that decompose recalcitrant polysaccharides, such as chitin and cellulose. The intrinsic processivity (P(Intr)) of cellulases has been shown to be governed by the rate constant of dissociation from polymer chain (koff). However, the reported koff values of cellulases are strongly dependent on the method used for their measurement. Here, we developed a new method for determining koff, based on measuring the exchange rate of the enzyme between a non-labeled and a (14)C-labeled polymeric substrate. The method was applied to the study of the processive chitinase ChiA from Serratia marcescens. In parallel, ChiA variants with weaker binding of the N-acetylglucosamine unit either in substrate-binding site -3 (ChiA-W167A) or the product-binding site +1 (ChiA-W275A) were studied. Both ChiA variants showed increased off-rates and lower apparent processivity on α-chitin. The rate of the production of insoluble reducing groups on the reduced α-chitin was an order of magnitude higher than koff, suggesting that the enzyme can initiate several processive runs without leaving the substrate. On crystalline chitin, the general activity of the wild type enzyme was higher, and the difference was magnifying with hydrolysis time. On amorphous chitin, the variants clearly outperformed the wild type. A model is proposed whereby strong interactions with polymer in the substrate-binding sites (low off-rates) and strong binding of the product in the product-binding sites (high pushing potential) are required for the removal of obstacles, like disintegration of chitin microfibrils. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Traditional Procurement is too Slow

    Directory of Open Access Journals (Sweden)

    Ann Kong

    2012-11-01

    Full Text Available This paper reports on an exploratory interview survey of construction project participants aimed at identifying the reasons for the decrease in use of the traditional, lump-sum, procurement system in Malaysia. The results show that most people believe it is too slow. This appears to be in part due to the contiguous nature of the various phase and stages of the process and especially the separation of the design and construction phases. The delays caused by disputes between the various parties are also seen as a contributory factor - the most prominent cause being the frequency of variations, with design and scope changes being a particular source of discontent. It is concluded that an up scaling of the whole of the time related reward/penalty system may be the most appropriate measure for the practice in future.

  14. Carotenoid content of the varieties Jaranda and Jariza (Capsicumannuum L.) and response during the industrial slow drying and grinding steps in paprika processing.

    Science.gov (United States)

    Mínguez-Mosquera, M I; Pérez-Gálvez, A; Garrido-Fernández, J

    2000-07-01

    Fruits of the pepper varieties Jaranda and Jariza (Capsicum annuum L. ) ripen as a group, enabling a single harvesting, showed a uniform carotenoid content that is high enough (7.9 g/kg) for the production of paprika. The drying system at mild temperature showed that fruits with moisture content of 85-88% generated a dry product with carotenoid content equal to or higher than the initial one. Those high moisture levels allowed the fruits to have a longer period of metabolic activity, increasing the yellow fraction, the red fraction, or both as a function of what biosynthetic process was predominant. This fact indicates under-ripeness of the fruits in the drying step. The results obtained allow us to establish that both varieties, Jaranda and Jariza, fit the dehydration process employed, yielding a dry fruit with carotenoid concentration similar to that the initial one. During the grinding step of the dry fruit, the heat generated by the hammers of the mill caused degradation of the yellow fraction, while the red fraction is maintained. The ripeness state of the harvested fruits and the appropriateness or severity of the processing steps are indicated by the ratio of red to yellow (R/Y) and/or red to total (R/T) pigments, since fluctuations in both fractions and in total pigments are reflected in and monitored by these parameters.

  15. The Roles of Cortical Slow Waves in Synaptic Plasticity and Memory Consolidation

    OpenAIRE

    Miyamoto, Daisuke; Hirai, Daichi; Murayama, Masanori

    2017-01-01

    Sleep plays important roles in sensory and motor memory consolidation. Sleep oscillations, reflecting neural population activity, involve the reactivation of learning-related neurons and regulate synaptic strength and, thereby affect memory consolidation. Among sleep oscillations, slow waves (0.5–4 Hz) are closely associated with memory consolidation. For example, slow-wave power is regulated in an experience-dependent manner and correlates with acquired memory. Furthermore, manipulating slow...

  16. No psychomotor slowing in fine motor tasks in dysthymia

    NARCIS (Netherlands)

    Pier, M.P.B.I.; Hulstijn, W.; Sabbe, B.G.C.

    2004-01-01

    Introduction Few studies using objective and sensitive measuring techniques have investigated whether psychomotor retardation (PR), an important symptom of a major depressive disorder (MDD), is also present in dysthymic patients. In this study, the following questions were addressed: (1) is PR also

  17. Using LabVIEW for the design and control of digital signal processing systems. Simulation of the ultra slow extraction at COSY

    International Nuclear Information System (INIS)

    Heinrichs, G.; Rongen, H.; Jamal, R.

    1994-01-01

    For the ultraslow extraction system of the COler SYnchrotron COSY a direct digital synthesis system is being developed. LabVIEW from National Instruments has been chosen as a tool for the simulation of the digital signal processing algorithms as well as the generation of test sequences. In order to generate adjustable band-limited noise centered at a carrier frequency, alternative algorithms have been studied. LabVIEW permits the interactive variation of relevant system parameters by means of a graphical language in order to study the quality of the frequency band limitation as a function of noise parameters, digital accuracy and frequency range and to generate test sequences by means of a real-time function generator. Advantages and limitations of LabVIEW for such applications are discussed. ((orig.))

  18. The kinematic portrait of a patient as an objective indicator of motor function in the process of neurorehabilitation with hand exoskeleton controlled by the brain – computer interface

    Directory of Open Access Journals (Sweden)

    А. А. Kondur

    2016-01-01

    Full Text Available The results of biomechanical analysis of the motor function of the arm of poststroke patient in the process of neuroreha bilitation with exoskeleton of the hand controlled by brain – computer interface are presented in this paper. At the beginning and end of the course it was registered the kinematic portrait of the patient– isolated random movements for each of the seven degrees of freedom as the paretic and intact arms.Angular accelerations were taken as an assessment of muscle forces, the number of reverse movements was taken as an assessment of joint spasticity, and the kinematic content of the movement as a description of pathological synergy arising after stroke. These parameters give an objective numerical asses sment of motor function as well as of rehabilitation technology effectiveness.

  19. Higher Efficiency HVAC Motors

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Charles Joseph [QM Power, Inc., Kansas City, MO (United States)

    2018-02-13

    The objective of this project was to design and build a cost competitive, more efficient heating, ventilation, and air conditioning (HVAC) motor than what is currently available on the market. Though different potential motor architectures among QMP’s primary technology platforms were investigated and evaluated, including through the building of numerous prototypes, the project ultimately focused on scaling up QM Power, Inc.’s (QMP) Q-Sync permanent magnet synchronous motors from available sub-fractional horsepower (HP) sizes for commercial refrigeration fan applications to larger fractional horsepower sizes appropriate for HVAC applications, and to add multi-speed functionality. The more specific goal became the research, design, development, and testing of a prototype 1/2 HP Q-Sync motor that has at least two operating speeds and 87% peak efficiency compared to incumbent electronically commutated motors (EC or ECM, also known as brushless direct current (DC) motors), the heretofore highest efficiency HVACR fan motor solution, at approximately 82% peak efficiency. The resulting motor prototype built achieved these goals, hitting 90% efficiency and .95 power factor at full load and speed, and 80% efficiency and .7 power factor at half speed. Q-Sync, developed in part through a DOE SBIR grant (Award # DE-SC0006311), is a novel, patented motor technology that improves on electronically commutated permanent magnet motors through an advanced electronic circuit technology. It allows a motor to “sync” with the alternating current (AC) power flow. It does so by eliminating the constant, wasteful power conversions from AC to DC and back to AC through the synthetic creation of a new AC wave on the primary circuit board (PCB) by a process called pulse width modulation (PWM; aka electronic commutation) that is incessantly required to sustain motor operation in an EC permanent magnet motor. The Q-Sync circuit improves the power factor of the motor by removing all

  20. Study on the VFD (Variable Frequency Drive) for RCP (Reactor Coolant Pump) Motors of APR1400

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jung Ha; Robert, M. Field; Kim, Tae Ryong [Department of NPP Engineering, KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2014-10-15

    Most industrial facilities are continually searching for ways to reduce energy costs while increasing or maintaining current production. In terms of electric motors, Variable Frequency Drive (VFD) units represent a critical opportunity for energy savings. Currently, VFDs are used on about ten (10) percent of industrial process motors, and this percentage is increasing every year. Properly applied VFDs have been documented to save as much as fifty percent of the energy consumed by certain industrial processes. Nuclear Power - Power plants in general and Nuclear Power Plants (NPPs) in particular are slow to adopt new technology. The nuclear power industry requires a nearly absolute demonstration through operating experience in other industries in which the new approach will result in a net improvement in plant reliability without any surprises. Only recently has the nuclear industry begun to adapt VFD units for large motors. Specifically, there are several examples in the Boiling Water Reactor (BWR) fleet of replacing Motor-Generator (M-G) sets with VFD units for Reactor Recirculation (RR) pump motor service. At one station, VFD units were introduced upstream of the Circulating Water (CWP) pump motors to address environmental issues. They units are taking advantage of VFD technology whose benefits include increased reliability, reduction in electrical house load, improved flow control, and reduced maintenance. RCP Application - In the case of new generation, it has been reported that the Westinghouse AP1000 will make use of VFD units for the Reactor Coolant Pump (RCP) motors.

  1. Human gamma oscillations during slow wave sleep.

    Directory of Open Access Journals (Sweden)

    Mario Valderrama

    Full Text Available Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS. At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz and high (60-120 Hz frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves ("IN-phase" pattern, confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave ("ANTI-phase" pattern. This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks.

  2. Speed of mental processing in the middle of the night

    Science.gov (United States)

    Monk, T. H.; Carrier, J.

    1997-01-01

    This study aimed to determine whether human mental processing actually slows down during the night hours, separately from the previously documented microsleeps, lapses in attention, and general slowing of motor responses. Eighteen healthy young adults were studied during 36 hours of constant wakeful bedrest. Every 2 hours, they performed a logical reasoning task. Items phrased in the negative voice took reliably longer to respond to than items phrased in the positive voice, indicating the need for more mental processing in those items. By subtracting "negative" from "positive" reaction times at each time of day, we were able to plot a circadian rhythm in the time taken for this extra mental processing to be done separately from microsleeps, psychomotor slowing, and inattention. The extra mental processing took longer at night and on the day following sleep loss than it did during the day before the sleep loss, suggesting that human mental processing slows down during the night under sleep deprivation.

  3. Acute exercise improves motor memory

    DEFF Research Database (Denmark)

    Skriver, Kasper Christen; Roig, Marc; Lundbye-Jensen, Jesper

    2014-01-01

    We have recently shown that a single bout of acute cardiovascular exercise improves motor skill learning through an optimization of long-term motor memory. Here we expand this previous finding, to explore potential exercise-related biomarkers and their association with measures of motor memory...... practice whereas lactate correlated with better retention 1 hour as well as 24 hours and 7 days after practice. Thus, improvements in motor skill acquisition and retention induced by acute cardiovascular exercise are associated with increased concentrations of biomarkers involved in memory and learning...... processes. More mechanistic studies are required to elucidate the specific role of each biomarker in the formation of motor memory....

  4. Selective impairment of verb processing associated with pathological changes in Brodmann areas 44 and 45 in the motor neurone disease-dementia-aphasia syndrome.

    Science.gov (United States)

    Bak, T H; O'Donovan, D G; Xuereb, J H; Boniface, S; Hodges, J R

    2001-01-01

    We report six patients with clinically diagnosed and electrophysiologically confirmed motor neurone disease (MND), in whom communication problems were an early and dominant feature. All patients developed a progressive non-fluent aphasia culminating in some cases in complete mutism. In five cases, formal testing revealed deficits in syntactic comprehension. Comprehension and production of verbs were consistently more affected those that of nouns and this effect remained stable upon subsequent testing, despite overall deterioration. The classical signs of MND, including wasting, fasciculations and severe bulbar symptoms, occurred over the following 6-12 months. The behavioural symptoms ranged from mild anosognosia to personality change implicating frontal-lobe dementia. In three cases, post-mortem examination has confirmed the clinical diagnosis of MND-dementia. In addition to the typical involvement of motor and premotor cortex, particularly pronounced pathological changes were observed in the Brodmann areas 44 (Broca's area) and 45. The finding of a selective impairment of verb/action processing in association with the dementia/aphasia syndrome of MND suggests that the neural substrate underlying verb representation is strongly connected to anterior cortical motor systems.

  5. Evaluating the integration of the sensory-motor abilities to facilitate teachinglearning processes: a comparison between Italian and Indian models of teaching through the use of VMI test

    Directory of Open Access Journals (Sweden)

    CLAUDIO MACCHI

    2011-06-01

    Full Text Available Nowadays a great number of evidences seems to prove that the movement plays a central role in the integrationof different mental processes. The visual-motor feedback may be considered the first sensorial integration of thedevelopment. The importance of an effective support to the pre-adolescent development of the sensory-motorintegration ability seems one of most important aim that every school system should follow. The aim of thisresearch is to investigate and monitor on international scale if the current Italian and Indian schools systems canadequately support the development of the student’s sensory-motor integration ability. According to the datashowed in this paper, it is clear that the scores obtained by the Italian and Indian students are lower than theinternational mean. However if a wider analysis based on a larger and more representative sample of the twoCountries should confirm the output of this research, it will be clear that the two school systems cannoteffectively support the development of the visual-motor integration abilities of the students. If the trend showedin this work should be confirmed by future and more precise researches, it will be necessary an accurate analysisaimed to identify the possible reasons of this phenomenon and the possible school support, since without them, awhole generation of students will risk to reduce the cultural level of the two nations and to be not competitive onan international level.

  6. EEG Theta Dynamics within Frontal and Parietal Cortices for Error Processing during Reaching Movements in a Prism Adaptation Study Altering Visuo-Motor Predictive Planning.

    Science.gov (United States)

    Arrighi, Pieranna; Bonfiglio, Luca; Minichilli, Fabrizio; Cantore, Nicoletta; Carboncini, Maria Chiara; Piccotti, Emily; Rossi, Bruno; Andre, Paolo

    2016-01-01

    Modulation of frontal midline theta (fmθ) is observed during error commission, but little is known about the role of theta oscillations in correcting motor behaviours. We investigate EEG activity of healthy partipants executing a reaching task under variable degrees of prism-induced visuo-motor distortion and visual occlusion of the initial arm trajectory. This task introduces directional errors of different magnitudes. The discrepancy between predicted and actual movement directions (i.e. the error), at the time when visual feedback (hand appearance) became available, elicits a signal that triggers on-line movement correction. Analysis were performed on 25 EEG channels. For each participant, the median value of the angular error of all reaching trials was used to partition the EEG epochs into high- and low-error conditions. We computed event-related spectral perturbations (ERSP) time-locked either to visual feedback or to the onset of movement correction. ERSP time-locked to the onset of visual feedback showed that fmθ increased in the high- but not in the low-error condition with an approximate time lag of 200 ms. Moreover, when single epochs were sorted by the degree of motor error, fmθ started to increase when a certain level of error was exceeded and, then, scaled with error magnitude. When ERSP were time-locked to the onset of movement correction, the fmθ increase anticipated this event with an approximate time lead of 50 ms. During successive trials, an error reduction was observed which was associated with indices of adaptations (i.e., aftereffects) suggesting the need to explore if theta oscillations may facilitate learning. To our knowledge this is the first study where the EEG signal recorded during reaching movements was time-locked to the onset of the error visual feedback. This allowed us to conclude that theta oscillations putatively generated by anterior cingulate cortex activation are implicated in error processing in semi-naturalistic motor

  7. The electric motor handbook

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, R.W.; Feltham, P. (eds.)

    2004-05-01

    This handbook outlines the important role that electric motors play in modern society. It covers the field of motor applications from various motor types to their use and repair. It also presents practical applications of electric motors and methods on motor efficiency. More than half of all electricity generated, and 75 per cent of all industrial electricity consumption is consumed by electric motors. Electrical personnel must be aware of all factors involved in electric motors in order to choose and apply the appropriate size of electric motor. These factors include efficiency, sizing and proper application. The efficient use and maximum life expectancy of electric motors depends on proper motor protection, control and maintenance. This handbook includes articles from leading experts on electric motors in modern electrical systems. The content includes: design considerations; proper electric motor sizing techniques; optimal electric motor application; electric motor protection technology; electric motor control principles; electric motor maintenance and troubleshooting; induction electric motors; electric motor bearing currents; electric motor bearing lubrication; electromagnetism; electric motor enclosures; electric motor testing; electric motor repair; DC electric motor; electric motor starters; electric motor brushes; industrial electric motors; electric motor diagrams; AC electric motors; electric motor wiring; electric motor service; electric motor rewinding; electric motor winding; diagram of electric motor wiring; electric motor kit; and, troubleshooting electric motors. A directory of motor manufacturers and suppliers was also included. refs., tabs., figs.

  8. Slow Tourism: Exploring the discourses

    Directory of Open Access Journals (Sweden)

    J. Guiver

    2016-05-01

    Full Text Available ‘Slow travel’ and ‘slow tourism’ are relatively new, but contested, concepts. This paper examines the meanings ascribed to them in the academic literature and websites targeted at potential tourists. It finds concurrence on aspects of savouring time at the destination and investing time to appreciate the locality, its people, history, culture and products, but detects different emphases. The academic literature stresses the benefits to the destination and global sustainability, while the websites focus on the personal benefits and ways of becoming a ‘slow tourist’. Food and drink epitomise the immersion in and absorption of the destination and the multi-dimensional tourism experience, contrasted with the superficiality of mainstream tourism. The paper discusses whether tourists practising slow tourism without using the label are slow tourists or not.

  9. Slow Earthquake Hunters: A New Citizen Science Project to Identify and Catalog Slow Slip Events in Geodetic Data

    Science.gov (United States)

    Bartlow, N. M.

    2017-12-01

    Slow Earthquake Hunters is a new citizen science project to detect, catalog, and monitor slow slip events. Slow slip events, also called "slow earthquakes", occur when faults slip too slowly to generate significant seismic radiation. They typically take between a few days and over a year to occur, and are most often found on subduction zone plate interfaces. While not dangerous in and of themselves, recent evidence suggests that monitoring slow slip events is important for earthquake hazards, as slow slip events have been known to trigger damaging "regular" earthquakes. Slow slip events, because they do not radiate seismically, are detected with a variety of methods, most commonly continuous geodetic Global Positioning System (GPS) stations. There is now a wealth of GPS data in some regions that experience slow slip events, but a reliable automated method to detect them in GPS data remains elusive. This project aims to recruit human users to view GPS time series data, with some post-processing to highlight slow slip signals, and flag slow slip events for further analysis by the scientific team. Slow Earthquake Hunters will begin with data from the Cascadia subduction zone, where geodetically detectable slow slip events with a duration of at least a few days recur at regular intervals. The project will then expand to other areas with slow slip events or other transient geodetic signals, including other subduction zones, and areas with strike-slip faults. This project has not yet rolled out to the public, and is in a beta testing phase. This presentation will show results from an initial pilot group of student participants at the University of Missouri, and solicit feedback for the future of Slow Earthquake Hunters.

  10. The Speed of Visual Attention and Motor-Response Decisions in Adult Attention-Deficit/Hyperactivity Disorder

    DEFF Research Database (Denmark)

    Cross-Villasana, Fernando; Finke, Kathrin; Hennig-Fast, Kristina

    2015-01-01

    Abstract Background: Adults with Attention Deficit/Hyperactivity Disorder (ADHD) exhibit slowed reaction times (RTs) in various attention tasks. The exact origins of this slowing, however, have not been yet established. Potential candidates are early sensory processes mediating the deployment...... of focal-attention, stimulus-response translation processes deciding upon the appropriate motor-response, and motor processes generating the response. Methods: We combined mental chronometry (RT) measures of adult ADHD (n = 15) and healthy control (n = 15) participants with their lateralized event...... (sLRP) and response events (rLRP) were used to index the times taken for response selection and production, respectively. To assess the clinical relevance of ERPs, a correlation analysis between neural measures and subjective current and retrospective ADHD symptom ratings was performed. Results: ADHD...

  11. Longitudinal evaluation of fine motor skills in children with leukemia.

    Science.gov (United States)

    Hockenberry, Marilyn; Krull, Kevin; Moore, Ki; Gregurich, Mary Ann; Casey, Marissa E; Kaemingk, Kris

    2007-08-01

    Improved survival for children with acute lymphocytic leukemia (ALL) has allowed investigators to focus on the adverse or side effects of treatment and to develop interventions that promote cure while decreasing the long-term effects of therapy. Although much attention has been given to the significant neurocognitive sequelae that can occur after ALL therapy, limited investigation is found addressing fine motor function in these children and motor function that may contribute to neurocognitive deficits in ALL survivors. Fine motor and sensory-perceptual performances were examined in 82 children with ALL within 6-months of diagnosis and annually for 2 years (year 1 and year 2, respectively) during therapy. Purdue Pegboard assessments indicated significant slowing of fine motor speed and dexterity for the dominant hand, nondominant hand, and both hands simultaneously for children in this study. Mean Visual-Motor Integration (VMI) scores for children with low-risk and high-risk ALL decreased from the first evaluation to year 1 and again at year 2. Mean VMI scores for children with standard risk ALL increased from the first evaluation to year 1 and then decreased at year 2. Significant positive correlations were found between the Purdue and the VMI at both year 1 and year 2, suggesting that the Pegboard performance consistently predicts the later decline in visual-motor integration. Significant correlations were found between the Purdue Pegboard at baseline and the Performance IQ during year 1, though less consistently during year 2. A similar pattern was also observed between the baseline Pegboard performance and performance on the Coding and Symbol Search subtests during year 1 and year 2. In this study, children with ALL experienced significant and persistent visual-motor problems throughout therapy. These problems continued during the first and second years of treatment. These basic processing skills are necessary to the development of higher-level cognitive

  12. Improvement of Dance Composition Skills During the Study Process in the Perspective of the Newest Motor Learning Models

    Directory of Open Access Journals (Sweden)

    Spalva Rita

    2016-12-01

    Full Text Available In today’s dynamic world, where technologies have changed the understanding of time and space, the discussion about the body as a communicative performer in the new information field becomes a topic of interest. Different body techniques have become prevalent (sports, fitness, dance, which contribute to the scientific interest in the movement determination, inheritance, ergonomics and other aspects of movement quality. This article analyses recent motor learning models (Fitts, Posner, Gentile, etc and substantiates the usefulness to introduce the three-stage learning model in any field related to motor skills. The article analyses the effectiveness of the proposed model in practice as part of the study course Dance Composition at the Riga Teacher Training and Educational Management Academy. The research results show that the ability to transfer acquired movement skills into new situations and to use them for performing independent creative tasks is a testimony to a high level of application, what is the goal of the introduction of the proposed model.

  13. Motor performance of tongue with a computer-integrated system under different levels of background physical exertion

    Science.gov (United States)

    Huo, Xueliang; Johnson-Long, Ashley N.; Ghovanloo, Maysam; Shinohara, Minoru

    2015-01-01

    The purpose of this study was to compare the motor performance of tongue, using Tongue Drive System, to hand operation for relatively complex tasks under different levels of background physical exertion. Thirteen young able-bodied adults performed tasks that tested the accuracy and variability in tracking a sinusoidal waveform, and the performance in playing two video games that require accurate and rapid movements with cognitive processing using tongue and hand under two levels of background physical exertion. Results show additional background physical activity did not influence rapid and accurate displacement motor performance, but compromised the slow waveform tracking and shooting performances in both hand and tongue. Slow waveform tracking performance by the tongue was compromised with an additional motor or cognitive task, but with an additional motor task only for the hand. Practitioner Summary We investigated the influence of task complexity and background physical exertion on the motor performance of tongue and hand. Results indicate the task performance degrades with an additional concurrent task or physical exertion due to the limited attentional resources available for handling both the motor task and background exertion. PMID:24003900

  14. Space shuttle booster separation motor design

    Science.gov (United States)

    Smith, G. W.; Chase, C. A.

    1976-01-01

    The separation characteristics of the space shuttle solid rocket boosters (SRBs) are introduced along with the system level requirements for the booster separation motors (BSMs). These system requirements are then translated into specific motor requirements that control the design of the BSM. Each motor component is discussed including its geometry, material selection, and fabrication process. Also discussed is the propellant selection, grain design, and performance capabilities of the motor. The upcoming test program to develop and qualify the motor is outlined.

  15. Being Yourself and Thinking About the Future in People With Motor Neuron Disease: A Grounded Theory of Self-care Processes.

    Science.gov (United States)

    Bassola, Barbara; Sansone, Valeria Ada; Lusignani, Maura

    2018-06-01

    Self-care is a crucial aspect in the management of people with motor neuron disease (MND). Nurses and healthcare professionals must know the processes used by patients in performing self-care to identify problems and help them. Decision-making processes, self-understanding, and political and social support influence the self-care process in chronic diseases. Little is known about the self-care process in MND. The aim of this study was to gain insight on the self-care processes in people with MND. A grounded theory method was chosen for this study. Data from interviews were gathered, and a simultaneous comparative analysis was conducted to identify categories and codes. Twenty-one people with spinal muscular atrophy and amyotrophic lateral sclerosis participated in the study. Five categories were identified as grounded in the data. The process starts from "being yourself in the care," and it develops thanks to "growing and changing" and with a "thinking about the future" approach. "Family role" and "you and who helps you" categories affect the process itself. The self-care process in people with MND is not seen in a daily perspective but changes with the evolution of the disease. For the growing patients with MND, changing, accepting and controlling the disease while deciding autonomously are the foundations of the process.

  16. Motor homopolar

    OpenAIRE

    Martín Muñoz, Agustín

    2007-01-01

    Mostramos la construcción de un modelo de motor homopolar, uno de los más antiguos tipos de motores eléctricos. Se caracterizan porque el campo magnético del imán mantiene siempre la misma polaridad (de ahí su nombre, del griego homos, igual), de modo que, cuando una corriente eléctrica atraviesa el campo magnético, aparece una fuerza que hace girar los elementos no fijados mecánicamente. En el sencillísimo motor homopolar colgado (Schlichting y Ucke 2004), el imán puede girar ...

  17. Error Sonification of a Complex Motor Task

    Directory of Open Access Journals (Sweden)

    Riener Robert

    2011-12-01

    Full Text Available Visual information is mainly used to master complex motor tasks. Thus, additional information providing augmented feedback should be displayed in other modalities than vision, e.g. hearing. The present work evaluated the potential of error sonification to enhance learning of a rowing-type motor task. In contrast to a control group receiving self-controlled terminal feedback, the experimental group could not significantly reduce spatial errors. Thus, motor learning was not enhanced by error sonification, although during the training the participant could benefit from it. It seems that the motor task was too slow, resulting in immediate corrections of the movement rather than in an internal representation of the general characteristics of the motor task. Therefore, further studies should elaborate the impact of error sonification when general characteristics of the motor tasks are already known.

  18. Slow light in moving media

    Science.gov (United States)

    Leonhardt, U.; Piwnicki, P.

    2001-06-01

    We review the theory of light propagation in moving media with extremely low group velocity. We intend to clarify the most elementary features of monochromatic slow light in a moving medium and, whenever possible, to give an instructive simplified picture.

  19. Birth control - slow release methods

    Science.gov (United States)

    Contraception - slow-release hormonal methods; Progestin implants; Progestin injections; Skin patch; Vaginal ring ... might want to consider a different birth control method. SKIN PATCH The skin patch is placed on ...

  20. Slowed ageing, welfare, and population problems.

    Science.gov (United States)

    Wareham, Christopher

    2015-10-01

    Biological studies have demonstrated that it is possible to slow the ageing process and extend lifespan in a wide variety of organisms, perhaps including humans. Making use of the findings of these studies, this article examines two problems concerning the effect of life extension on population size and welfare. The first--the problem of overpopulation--is that as a result of life extension too many people will co-exist at the same time, resulting in decreases in average welfare. The second--the problem of underpopulation--is that life extension will result in too few people existing across time, resulting in decreases in total welfare. I argue that overpopulation is highly unlikely to result from technologies that slow ageing. Moreover, I claim that the problem of underpopulation relies on claims about life extension that are false in the case of life extension by slowed ageing. The upshot of these arguments is that the population problems discussed provide scant reason to oppose life extension by slowed ageing.

  1. Slow rupture of frictional interfaces

    OpenAIRE

    Sinai, Yohai Bar; Brener, Efim A.; Bouchbinder, Eran

    2011-01-01

    The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not comple...

  2. Are there cross-cultural differences of ADL ability in children measured with the Assessment of Motor and Process Skills (AMPS)?

    Science.gov (United States)

    Peny-Dahlstrand, Marie; Gosman-Hedström, Gunilla; Krumlinde-Sundholm, Lena

    2012-01-01

    In many studies of self-care assessments for children, cultural differences in age-norm values have been shown. No study has evaluated whether there are cross-cultural differences in ADL motor and/or process skills in children when measured with the Assessment of Motor and Process Skills (AMPS). To investigate if there were systematic differences in ADL ability measured with the AMPS between children from the Nordic countries and North America and to evaluate the applicability of the existing international age-normative values for children from these two regions. Values from a total of 4 613 children, 3-15 years old, without known disabilities, from these geographical regions were compared with ANOVA. The difference in logits between each region and the mean values for each age group were calculated. No differences of relevance in age-related ADL ability measures between children from the two geographical regions were found, and the age-norm values are applicable to both regions. The AMPS may be considered free from cultural bias and useful in both clinical practice and research concerned with children in both the Nordic countries and North America.

  3. Interplanetary space flight compared with fetal/neonatal motor strategy: Theoretical and practical implications.

    Science.gov (United States)

    Meigal, Alexander

    2012-09-01

    The condition of simulated or real manned spaceflight, i.e. thermally comfortable microgravitation (G∼0), is very similar to the intrauterine immersion to the amniotic fluid. Domination of fast muscle fibers and phasic movements forms the fetal strategy to survive in heating, strongly hypoxic, albeit normal for fetus, immersion. In adults, the adaptive response separately to microgravitation, heat stress and hypoxia also shifts muscle fiber properties to faster values. That allows to speculate about specific motor strategy induced by micro-or hypogravitation (fetal/microgravitation, or FM-strategy). After birth the newborn is subjected to a combined 'sensory attack' of Earth gravitation, cooler ambient temperature and normoxia which is actually hyperoxic for fetus. The process of parturition can be considered as equivalent to cosmonaut's/astronaut's transition from microgravitation back to Earth gravitation (G=1) during landing. These factors also act simultaneously and constitute another set of sensory inputs with the effect that is opposite to the intrauterine condition. In normal gravitation, comfortable temperature and normoxia decreases the motor unit activity (MU) firing rate to a level, characteristic for the regular Earth condition. In contrast to 'faster' fetal adaptive motor response (microgravitation, heat, hypoxia), the post-natal adult set of conditions (lower, but still normal temperature, normoxia, 1G gravitation, healthy maturation) may represent the 'Earth' adaptive motor response, or the (gravitation/Earth, or GE-strategy). The motor system undergoes a second profound remodeling in older people during healthy ageing that results in further domination of slow muscle fibers and slowing down motor unit activity, simulating the condition of hypergravitation (G>1). Similar slowing adaptive responses are represented by cold and hyperoxia thus forming further motor strategy that could be named as SJ-strategy (after 'slow' and Jupiter - the most massive

  4. Application of stepping motor

    International Nuclear Information System (INIS)

    1980-10-01

    This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

  5. Dynamics of relaxation to a stationary state for interacting molecular motors

    Science.gov (United States)

    Gomes, Luiza V. F.; Kolomeisky, Anatoly B.

    2018-01-01

    Motor proteins are active enzymatic molecules that drive a variety of biological processes, including transfer of genetic information, cellular transport, cell motility and muscle contraction. It is known that these biological molecular motors usually perform their cellular tasks by acting collectively, and there are interactions between individual motors that specify the overall collective behavior. One of the fundamental issues related to the collective dynamics of motor proteins is the question if they function at stationary-state conditions. To investigate this problem, we analyze a relaxation to the stationary state for the system of interacting molecular motors. Our approach utilizes a recently developed theoretical framework, which views the collective dynamics of motor proteins as a totally asymmetric simple exclusion process of interacting particles, where interactions are taken into account via a thermodynamically consistent approach. The dynamics of relaxation to the stationary state is analyzed using a domain-wall method that relies on a mean-field description, which takes into account some correlations. It is found that the system quickly relaxes for repulsive interactions, while attractive interactions always slow down reaching the stationary state. It is also predicted that for some range of parameters the fastest relaxation might be achieved for a weak repulsive interaction. Our theoretical predictions are tested with Monte Carlo computer simulations. The implications of our findings for biological systems are briefly discussed.

  6. Slowing down modernity: A critique : A critique

    OpenAIRE

    Vostal , Filip

    2017-01-01

    International audience; The connection between modernization and social acceleration is now a prominent theme in critical social analysis. Taking a cue from these debates, I explore attempts that aim to 'slow down modernity' by resisting the dynamic tempo of various social processes and experiences. The issue of slowdown now accounts for a largely unquestioned measure, expected to deliver unhasty tempo conditioning good and ethical life, mental well-being and accountable democracy. In princip...

  7. Socio-technical transition as a co-evolutionary process: Innovation and the role of niche markets in the transition to motor vehicles

    Science.gov (United States)

    Birky, Alicia K.

    2008-10-01

    Significant reductions in greenhouse emissions from personal transportation will require a transition to an alternative technology regime based on renewable energy sources. Two bodies of research, the quasi-evolutionary (QE) model and the multi-level perspective (MLP) assert that processes within niches play a fundamental role in such transitions. This research asks whether the description of transitions based on this niche hypothesis and its underlying assumptions is consistent with the historical U.S. transition to motor vehicles at the beginning of the 20th century. Unique to this dissertation is the combination of the perspective of the entrepreneur with co-evolutionary approaches to socio-technical transitions. This approach is augmented with concepts from the industry life-cycle model and with a taxonomy of mechanisms of learning. Using this analytic framework, I examine specifically the role of entrepreneurial behavior and processes within and among firms in the co-evolution of technologies and institutions during the transition to motor vehicles. I find that niche markets played an important role in the development of the technology, institutions, and the industry. However, I also find that the diffusion of the automobile is not consistent with the niche hypothesis in the following ways: (1) product improvements and cost reductions were not realized in niche markets, but were achieved simultaneously with diffusion into mass markets; (2) in addition to learning-by-doing and learning-by-interacting with users, knowledge spillovers and interacting with suppliers were critical in this process; (3) cost reductions were not automatic results of expanding markets, but rather arose from the strategies of entrepreneurs based on personal perspectives and values. This finding supports the use of a behavioral approach with a micro-focus in the analysis of socio-technical change. I also find that the emergence and diffusion of the motor vehicle can only be understood by

  8. Movement Sonification: Audiovisual benefits on motor learning

    Directory of Open Access Journals (Sweden)

    Weber Andreas

    2011-12-01

    Full Text Available Processes of motor control and learning in sports as well as in motor rehabilitation are based on perceptual functions and emergent motor representations. Here a new method of movement sonification is described which is designed to tune in more comprehensively the auditory system into motor perception to enhance motor learning. Usually silent features of the cyclic movement pattern "indoor rowing" are sonified in real time to make them additionally available to the auditory system when executing the movement. Via real time sonification movement perception can be enhanced in terms of temporal precision and multi-channel integration. But beside the contribution of a single perceptual channel to motor perception and motor representation also mechanisms of multisensory integration can be addressed, if movement sonification is configured adequately: Multimodal motor representations consisting of at least visual, auditory and proprioceptive components - can be shaped subtly resulting in more precise motor control and enhanced motor learning.

  9. The Potential of/for 'Slow': Slow Tourists and Slow Destinations

    Directory of Open Access Journals (Sweden)

    J. Guiver

    2016-05-01

    Full Text Available Slow tourism practices are nothing new; in fact, they were once the norm and still are for millions of people whose annual holiday is spent camping, staying in caravans, rented accommodation, with friends and relations or perhaps in a second home, who immerse themselves in their holiday environment, eat local food, drink local wine and walk or cycle around the area. So why a special edition about slow tourism? Like many aspects of life once considered normal (such as organic farming or free-range eggs, the emergence of new practices has highlighted differences and prompted a re-evaluation of once accepted practices and values. In this way, the concept of ‘slow tourism’ has recently appeared as a type of tourism that contrasts with many contemporary mainstream tourism practices. It has also been associated with similar trends already ‘branded’ slow: slow food and cittaslow (slow towns and concepts such as mindfulness, savouring and well-being.

  10. EEG Theta Dynamics within Frontal and Parietal Cortices for Error Processing during Reaching Movements in a Prism Adaptation Study Altering Visuo-Motor Predictive Planning.

    Directory of Open Access Journals (Sweden)

    Pieranna Arrighi

    Full Text Available Modulation of frontal midline theta (fmθ is observed during error commission, but little is known about the role of theta oscillations in correcting motor behaviours. We investigate EEG activity of healthy partipants executing a reaching task under variable degrees of prism-induced visuo-motor distortion and visual occlusion of the initial arm trajectory. This task introduces directional errors of different magnitudes. The discrepancy between predicted and actual movement directions (i.e. the error, at the time when visual feedback (hand appearance became available, elicits a signal that triggers on-line movement correction. Analysis were performed on 25 EEG channels. For each participant, the median value of the angular error of all reaching trials was used to partition the EEG epochs into high- and low-error conditions. We computed event-related spectral perturbations (ERSP time-locked either to visual feedback or to the onset of movement correction. ERSP time-locked to the onset of visual feedback showed that fmθ increased in the high- but not in the low-error condition with an approximate time lag of 200 ms. Moreover, when single epochs were sorted by the degree of motor error, fmθ started to increase when a certain level of error was exceeded and, then, scaled with error magnitude. When ERSP were time-locked to the onset of movement correction, the fmθ increase anticipated this event with an approximate time lead of 50 ms. During successive trials, an error reduction was observed which was associated with indices of adaptations (i.e., aftereffects suggesting the need to explore if theta oscillations may facilitate learning. To our knowledge this is the first study where the EEG signal recorded during reaching movements was time-locked to the onset of the error visual feedback. This allowed us to conclude that theta oscillations putatively generated by anterior cingulate cortex activation are implicated in error processing in semi

  11. Sensorimotor and cognitive slowing in schizophrenia as measured by the Symbol Digit Substitution Test

    NARCIS (Netherlands)

    Morrens, M.; Hulstijn, W.; Hecke, J. van; Peuskens, J.; Sabbe, B.G.C.

    2006-01-01

    Objectives A vast amount of studies demonstrates the presence of psychomotor slowing in schizophrenia. The objective of the present study was to investigate whether this overall psychomotor slowing can be divided into distinct processes that differentially affect cognitive functioning in

  12. Relationship of 5-HTTLPR Polymorphism with Various Factors of Pain Processing : Subjective Experience, Motor Responsiveness and Catastrophizing

    NARCIS (Netherlands)

    Kunz, Miriam; Hennig, Juergen; Karmann, Anna J.; Lautenbacher, Stefan

    2016-01-01

    Although serotonin is known to play an important role in pain processing, the relationship between the polymorphism in 5-HTTLPR and pain processing is not well understood. To examine the relationship more comprehensively, various factors of pain processing having putative associations with 5-HT

  13. Motor cortex is required for learning but not for executing a motor skill.

    Science.gov (United States)

    Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu L; Dhawale, Ashesh K; Kampff, Adam R; Ölveczky, Bence P

    2015-05-06

    Motor cortex is widely believed to underlie the acquisition and execution of motor skills, but its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex's established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in "tutoring" these circuits during learning. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Motor cortex is required for learning but not executing a motor skill

    Science.gov (United States)

    Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu; Dhawale, Ashesh; Kampff, Adam R.; Ölveczky, Bence P.

    2018-01-01

    Motor cortex is widely believed to underlie the acquisition and execution of motor skills, yet its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex’s established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in ‘tutoring’ these circuits during learning. PMID:25892304

  15. Slow, stopped and stored light

    International Nuclear Information System (INIS)

    Welch, G.; Scully, M.

    2005-01-01

    Light that can been slowed to walking pace could have applications in telecommunications, optical storage and quantum computing. Whether we use it to estimate how far away a thunderstorm is, or simply take it for granted that we can have a conversation with someone on the other side of the world, we all know that light travels extremely fast. Indeed, special relativity teaches us that nothing in the universe can ever move faster than the speed of light in a vacuum: 299 792 458 ms sup - sup 1. However, there is no such limitation on how slowly light can travel. For the last few years, researchers have been routinely slowing light to just a few metres per second, and have recently even stopped it dead in its tracks so that it can be stored for future use. Slow-light has considerable popular appeal, deriving perhaps from the importance of the speed of light in relativity and cosmology. If everyday objects such as cars or people can travel faster than 'slow' light, for example, then it might appear that relativistic effects could be observed at very low speeds. Although this is not the case, slow light nonetheless promises to play an important role in optical technology because it allows light to be delayed for any period of time desired. This could lead to all-optical routers that would increase the bandwidth of the Internet, and applications in optical data storage, quantum information and even radar. (U.K.)

  16. Slow rupture of frictional interfaces

    Science.gov (United States)

    Bar Sinai, Yohai; Brener, Efim A.; Bouchbinder, Eran

    2012-02-01

    The failure of frictional interfaces and the spatiotemporal structures that accompany it are central to a wide range of geophysical, physical and engineering systems. Recent geophysical and laboratory observations indicated that interfacial failure can be mediated by slow slip rupture phenomena which are distinct from ordinary, earthquake-like, fast rupture. These discoveries have influenced the way we think about frictional motion, yet the nature and properties of slow rupture are not completely understood. We show that slow rupture is an intrinsic and robust property of simple non-monotonic rate-and-state friction laws. It is associated with a new velocity scale cmin, determined by the friction law, below which steady state rupture cannot propagate. We further show that rupture can occur in a continuum of states, spanning a wide range of velocities from cmin to elastic wave-speeds, and predict different properties for slow rupture and ordinary fast rupture. Our results are qualitatively consistent with recent high-resolution laboratory experiments and may provide a theoretical framework for understanding slow rupture phenomena along frictional interfaces.

  17. MURPHYS-HSFS-2014: 7th International Workshop on MUlti-Rate Processes and HYSteresis (MURPHYS) and the 2nd International Workshop on Hysteresis and Slow-Fast Systems (HSFS)

    International Nuclear Information System (INIS)

    2016-01-01

    Foreword MURPHYS-HSFS-2014 was the 7th International Workshop on MUlti-Rate Processes and HYSteresis (MURPHYS) in conjunction with the 2nd International Workshop on Hysteresis and Slow-Fast Systems (HSFS) . It took place at the Weierstrass Institute for Applied Analysis and Stochastics (WIAS), Berlin, Germany, from April 7 to April 11 in 2014. The international workshop on “Multi-Rate Processes and Hysteresis” continued a series of biennial conferences (Cork, Ireland, 2002-2008; Pecs, Hungary, 2010; Suceava, Romania, 2012) and the international workshop on “Hysteresis and Slow-Fast Systems” was the follow-up of the HSFS-workshop that had taken place in Lutherstadt Wittenberg, Germany, in 2011. More then 60 scientists from nine European countries and from the USA participated in MURPHYS-HSFS-2014. The program of the workshop featured 49 talks, including 15 main lectures and 15 invited talks. Recent mathematical results for systems with hysteresis operators, multiple scale systems, rate-independent systems, systems with energetic solutions, singularly perturbed systems, and systems with stochastic effects were presented. The considered applications included magnetization dynamics, biological systems, smart materials, networks, ferroelectric and ferroelastic hysteresis, fatigue in materials, market models with hysteresis, biomedical applications, chemical reactions, noise-induced phenomena, partially saturated soils, colloidal films and evaporation of automotive fuel droplets. Statement of Peer Review: All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing. International steering committee: E. Benoit (France), M. Brokate (Germany), R. Cross (UK), K. Dahmen (USA), M. Dimian (Romania), M. Eleuteri (Italy), G. Friedman (USA

  18. Development of slow pyrolysis business operations in Finland - Hidaspyro

    Energy Technology Data Exchange (ETDEWEB)

    Fagernas, L. [VTT Technical Research Centre of Finland, Espoo (Finland)], email: leena.fagernas@vtt.fi

    2012-07-01

    Birch distillate, a by-product in slow pyrolysis process of charcoal production, was found to be a promising source for biological pesticides. However, product commercialization was problematic, for EU registration is costly, and composition, active ingredients and ecotoxicological properties were not known. In addition, constant quality and process optimisation were needed. More collaboration between SMEs and research institutes was required. The primary aim was to support and develop slow pyrolysis business operations of SMEs in Finland by generating knowledge that was needed.

  19. Slow Images and Entangled Photons

    International Nuclear Information System (INIS)

    Swordy, Simon

    2007-01-01

    I will discuss some recent experiments using slow light and entangled photons. We recently showed that it was possible to map a two dimensional image onto very low light level signals, slow them down in a hot atomic vapor while preserving the amplitude and phase of the images. If time remains, I will discuss some of our recent work with time-energy entangled photons for quantum cryptography. We were able to show that we could have a measurable state space of over 1000 states for a single pair of entangled photons in fiber.

  20. Pulsar slow-down epochs

    International Nuclear Information System (INIS)

    Heintzmann, H.; Novello, M.

    1981-01-01

    The relative importance of magnetospheric currents and low frequency waves for pulsar braking is assessed and a model is developed which tries to account for the available pulsar timing data under the unifying aspect that all pulsars have equal masses and magnetic moments and are born as rapid rotators. Four epochs of slow-down are distinguished which are dominated by different braking mechanisms. According to the model no direct relationship exists between 'slow-down age' and true age of a pulsar and leads to a pulsar birth-rate of one event per hundred years. (Author) [pt

  1. Prediction of Tungsten CMP Pad Life Using Blanket Removal Rate Data and Endpoint Data Obtained from Process Temperature and Carrier Motor Current Measurments

    International Nuclear Information System (INIS)

    Hetherington, Dale L.; Stein, David J.

    1999-01-01

    Several techniques to predict pad failure during tungsten CMP were investigated for a specific consumable set. These techniques include blanket polish rate measurements and metrics derived from two endpoint detection schemes. Blanket polish rate decreased significantly near pad failure. Metrics from the thermal endpoint technique included change in peak temperature, change in the time to reach peak temperature, and the change in the slope of the temperature trace just prior to peak temperature all as a function of pad life. Average carrier motor current before endpoint was also investigated. Changes in these metrics were observed however these changes, excluding time to peak process temperature, were either not consistent between pads or too noisy to be reliable predictors of pad failure

  2. Age-related slowing of response selection and production in a visual choice reaction time task

    Directory of Open Access Journals (Sweden)

    David L Woods

    2015-04-01

    Full Text Available Aging is associated with delayed processing in choice reaction time (CRT tasks, but the processing stages most impacted by aging have not been clearly identified. Here, we analyzed CRT latencies in a computerized serial visual feature-conjunction task. Participants responded to a target letter (probability 40% by pressing one mouse button, and responded to distractor letters differing either in color, shape, or both features from the target (probabilities 20% each, by pressing the other mouse button. Stimuli were presented randomly to the left and right visual fields and stimulus onset asynchronies (SOAs were adaptively reduced following correct responses using a staircase procedure. In Experiment 1, we tested 1466 participants who ranged in age from 18 to 65 years. CRT latencies increased significantly with age (r = 0.47, 2.80 ms/year. Central processing time (CPT, isolated by subtracting simple reaction times (obtained in a companion experiment performed on the same day from CRT latencies, accounted for more than 80% of age-related CRT slowing, with most of the remaining increase in latency due to slowed motor responses. Participants were faster and more accurate when the stimulus location was spatially compatible with the mouse button used for responding, and this effect increased slightly with age. Participants took longer to respond to distractors with target color or shape than to distractors with no target features. However, the additional time needed to discriminate the more target-like distractors did not increase with age. In Experiment 2, we replicated the findings of Experiment 1 in a second population of 178 participants (ages 18-82 years. CRT latencies did not differ significantly in the two experiments, and similar effects of age, distractor similarity, and stimulus-response spatial compatibility were found. The results suggest that the age-related slowing in visual CRT latencies is largely due to delays in response selection and

  3. A slowing-down problem

    Energy Technology Data Exchange (ETDEWEB)

    Carlvik, I; Pershagen, B

    1958-06-15

    An infinitely long circular cylinder of radius a is surrounded by an infinite moderator. Both media are non-capturing. The cylinder emits neutrons of age zero with a constant source density of S. We assume that the ratios of the slowing-down powers and of the diffusion constants are independent of the neutron energy. The slowing-down density is calculated for two cases, a) when the slowing-down power of the cylinder medium is very small, and b) when the cylinder medium is identical with the moderator. The ratios of the slowing-down density at the age {tau} and the source density in the two cases are called {psi}{sub V}, and {psi}{sub M} respectively. {psi}{sub V} and {psi}{sub M} are functions of y=a{sup 2}/4{tau}. These two functions ({psi}{sub V} and {psi}{sub M}) are calculated and tabulated for y = 0-0.25.

  4. Numerical modeling of slow shocks

    International Nuclear Information System (INIS)

    Winske, D.

    1987-01-01

    This paper reviews previous attempt and the present status of efforts to understand the structure of slow shocks by means of time dependent numerical calculations. Studies carried out using MHD or hybrid-kinetic codes have demonstrated qualitative agreement with theory. A number of unresolved issues related to hybrid simulations of the internal shock structure are discussed in some detail. 43 refs., 8 figs

  5. On line protection systems for induction motors

    International Nuclear Information System (INIS)

    Colak, I.; Celik, H.; Sefa, I.; Demirbas, S.

    2005-01-01

    Protection of induction motors is very important since they are widely used in industry for many applications due to their high robustness, reliability, low cost and maintenance, high efficiency and long service life. So, protecting these motors is crucial for operations. This paper presents a combined protection approach for induction motors. To achieve this, the electrical values of the induction motor were measured with sensitivity ±1% through a data acquisition card and processed with software developed in Visual C++. An on line protection system for induction motors was achieved easily and effectively. The experimental results have shown that the induction motor was protected against the possible problems faced during the operation. The software developed for this protection provides flexible and reliable media for operators and their motors. It is expected that the motor protection achieved in this study might be faster than the classical techniques and also may be applied to larger motors easily after small modifications of the software

  6. Electrodynamic ratchet motor.

    Science.gov (United States)

    Lim, Jiufu; Sader, John E; Mulvaney, Paul

    2009-03-01

    Brownian ratchets produce directed motion through rectification of thermal fluctuations and have been used for separation processes and colloidal transport. We propose a flashing ratchet motor that enables the transduction of electrical energy into rotary micromechanical work. This is achieved through torque generation provided by boundary shaping of equipotential surfaces. The present device contrasts to previous implementations that focus on translational motion. Stochastic simulations elucidate the performance characteristics of this device as a function of its geometry. Miniaturization to nanoscale dimensions yields rotational speeds in excess of 1 kHz, which is comparable to biomolecular motors of similar size.

  7. Flood-proof motors

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Marcus [AREVA NP GmbH, Erlangen (Germany)

    2013-07-01

    Even before the Fukushima event occurred some German nuclear power plants (NPP) have considered flooding scenarios. As a result of one of these studies, AREVA performed an upgrade project in NPP Isar 1 with flood-proof motors as a replacement of existing air-cooled low-voltage and high-voltage motors of the emergency cooling chain. After the Fukushima event, in which the cooling chains failed, the topic flood-proof equipment gets more and more into focus. This compact will introduce different kinds of flood-proof electrical motors which are currently installed or planned for installation into NPPs over the world. Moreover the process of qualification, as it was performed during the project in NPP Isar 1, will be shown. (orig.)

  8. Flood-proof motors

    International Nuclear Information System (INIS)

    Schmitt, Marcus

    2013-01-01

    Even before the Fukushima event occurred some German nuclear power plants (NPP) have considered flooding scenarios. As a result of one of these studies, AREVA performed an upgrade project in NPP Isar 1 with flood-proof motors as a replacement of existing air-cooled low-voltage and high-voltage motors of the emergency cooling chain. After the Fukushima event, in which the cooling chains failed, the topic flood-proof equipment gets more and more into focus. This compact will introduce different kinds of flood-proof electrical motors which are currently installed or planned for installation into NPPs over the world. Moreover the process of qualification, as it was performed during the project in NPP Isar 1, will be shown. (orig.)

  9. Adult rat motor neurons do not re-establish electrical coupling during axonal regeneration and muscle reinnervation.

    Directory of Open Access Journals (Sweden)

    Morgana Favero

    Full Text Available Gap junctions (GJs between neurons are present in both the newborn and the adult nervous system, and although important roles have been suggested or demonstrated in a number of instances, in many other cases a full understanding of their physiological role is still missing. GJs are expressed in the rodent lumbar cord at birth and mediate both dye and electrical coupling between motor neurons. This expression has been proposed to mediate: (i fast synchronization of motoneuronal spike activity, in turn linked to the process of refinement of neuromuscular connections, and (ii slow synchronization of locomotor-like oscillatory activity. Soon after birth this coupling disappears. Since in the adult rat regeneration of motor fibers after peripheral nerve injury leads to a recapitulation of synaptic refinement at the target muscles, we tested whether GJs between motor neurons are transiently re-expressed. We found that in conditions of maximal responsiveness of lumbar motor neurons (such as no depression by anesthetics, decerebrate release of activity of subsets of motor neurons, use of temporal and spatial summation by antidromic and orthodromic stimulations, testing of large ensembles of motor neurons no firing is observed in ventral root axons in response to antidromic spike invasion of nearby counterparts. We conclude that junctional coupling between motor neurons is not required for the refinement of neuromuscular innervation in the adult.

  10. Theory of neutron slowing down in nuclear reactors

    CERN Document Server

    Ferziger, Joel H; Dunworth, J V

    2013-01-01

    The Theory of Neutron Slowing Down in Nuclear Reactors focuses on one facet of nuclear reactor design: the slowing down (or moderation) of neutrons from the high energies with which they are born in fission to the energies at which they are ultimately absorbed. In conjunction with the study of neutron moderation, calculations of reactor criticality are presented. A mathematical description of the slowing-down process is given, with particular emphasis on the problems encountered in the design of thermal reactors. This volume is comprised of four chapters and begins by considering the problems

  11. The unappreciated slowness of conventional tourism

    Directory of Open Access Journals (Sweden)

    G.R. Larsen

    2016-05-01

    Full Text Available Most tourists are not consciously engaging in ‘slow travel’, but a number of travel behaviours displayed by conventional tourists can be interpreted as slow travel behaviour. Based on Danish tourists’ engagement with the distances they travel across to reach their holiday destination, this paper explores unintended slow travel behaviours displayed by these tourists. None of the tourists participating in this research were consciously doing ‘slow travel’, and yet some of their most valued holiday memories are linked to slow travel behaviours. Based on the analysis of these unintended slow travel behaviours, this paper will discuss the potential this insight might hold for promotion of slow travel. If unappreciated and unintentional slow travel behaviours could be utilised in the deliberate effort of encouraging more people to travel slow, ‘slow travel’ will be in a better position to become integrated into conventional travel behaviour.

  12. Embodiment and second-language: automatic activation of motor responses during processing spatially associated L2 words and emotion L2 words in a vertical Stroop paradigm.

    Science.gov (United States)

    Dudschig, Carolin; de la Vega, Irmgard; Kaup, Barbara

    2014-05-01

    Converging evidence suggests that understanding our first-language (L1) results in reactivation of experiential sensorimotor traces in the brain. Surprisingly, little is known regarding the involvement of these processes during second-language (L2) processing. Participants saw L1 or L2 words referring to entities with a typical location (e.g., star, mole) (Experiment 1 & 2) or to an emotion (e.g., happy, sad) (Experiment 3). Participants responded to the words' ink color with an upward or downward arm movement. Despite word meaning being fully task-irrelevant, L2 automatically activated motor responses similar to L1 even when L2 was acquired rather late in life (age >11). Specifically, words such as star facilitated upward, and words such as root facilitated downward responses. Additionally, words referring to positive emotions facilitated upward, and words referring to negative emotions facilitated downward responses. In summary our study suggests that reactivation of experiential traces is not limited to L1 processing. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Impact of operational factors on fossil energy inputs in motor-manual tree felling and processing: results of two case studies

    Directory of Open Access Journals (Sweden)

    Gheorghe Ignea

    2017-07-01

    Full Text Available In many cases tree felling and processing operations are carried out motor-manually and knowledge about fossil fuel consumption and direct energy inputs when using such equipment is required for different purposes starting with operational costing and ending with environmental assessment of forest operations. In this study, fuel mixture, chain oil and direct fossil energy inputs were evaluated for two chainsaws which were used to fell and process trees in two silvicultural systems. The results of this study suggest that there is a strong dependence relation between selected tree size variables such as the diameter at breast height and tree volume on one hand and the fuel mixture, chain oil and direct fossil energy inputs when felling and processing broadleaved hardwood and resinous softwood trees on the other hand. For the broadleaved trees (mean tree volume of 1.50 m3 × tree-1, DBH of 45.5 cm and tree height of 21.84 m the mean direct fossil energy input was of 3.86 MJ m-3 while for resinous trees (mean tree volume of 1.77 m3 tree-1, DBH of 39.28 cm and tree height of 32.49 m it was of 3.93 MJ m-3. Other variables, including but not limited to the technology used, work experience and procedural pattern, may influence the mentioned figures and extensive studies are required to clarify their effects.

  14. Deficits in Sequential Processing Manifest in Motor and Linguistic Tasks in a Multigenerational Family with Childhood Apraxia of Speech

    Science.gov (United States)

    Peter, Beate; Button, Le; Stoel-Gammon, Carol; Chapman, Kathy; Raskind, Wendy H.

    2013-01-01

    The purpose of this study was to evaluate a global deficit in sequential processing as candidate endophenotypein a family with familial childhood apraxia of speech (CAS). Of 10 adults and 13 children in a three-generational family with speech sound disorder (SSD) consistent with CAS, 3 adults and 6 children had past or present SSD diagnoses. Two…

  15. Primary motor cortex functionally contributes to language comprehension: An online rTMS study.

    Science.gov (United States)

    Vukovic, Nikola; Feurra, Matteo; Shpektor, Anna; Myachykov, Andriy; Shtyrov, Yury

    2017-02-01

    Among various questions pertinent to grounding human cognitive functions in a neurobiological substrate, the association between language and motor brain structures is a particularly debated one in neuroscience and psychology. While many studies support a broadly distributed model of language and semantics grounded, among other things, in the general modality-specific systems, theories disagree as to whether motor and sensory cortex activity observed during language processing is functional or epiphenomenal. Here, we assessed the role of motor areas in linguistic processing by investigating the responses of 28 healthy volunteers to different word types in semantic and lexical decision tasks, following repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex. We found that early rTMS (delivered within 200ms of word onset) produces a left-lateralised and meaning-specific change in reaction speed, slowing down behavioural responses to action-related words, and facilitating abstract words - an effect present only during semantic, but not lexical, decision. We interpret these data in light of action-perception theory of language, bolstering the claim that motor cortical areas play a functional role in language comprehension. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Fault diagnosis of induction motors

    CERN Document Server

    Faiz, Jawad; Joksimović, Gojko

    2017-01-01

    This book is a comprehensive, structural approach to fault diagnosis strategy. The different fault types, signal processing techniques, and loss characterisation are addressed in the book. This is essential reading for work with induction motors for transportation and energy.

  17. Perceptions of the Slow Food Cultural Trend among the Youth

    OpenAIRE

    Lelia Voinea; Anca Atanase; Ion Schileru

    2016-01-01

    As they become increasingly aware of the importance of healthy eating and of the serious food imbalance caused by the overconsumption of industrial, ultra-processed and superorganoleptic food, consumers are now beginning to turn their attention to food choices guaranteeing both individual health and also of the environment . Thus, in recent years we are witnessing the rise of a cultural trend ‒ Slow Food. Slow Food has become an international movement that advocates for satisfying culinary pl...

  18. The Speed of Visual Attention and Motor-Response Decisions in Adult Attention-Deficit/Hyperactivity Disorder.

    Science.gov (United States)

    Cross-Villasana, Fernando; Finke, Kathrin; Hennig-Fast, Kristina; Kilian, Beate; Wiegand, Iris; Müller, Hermann Joseph; Möller, Hans-Jürgen; Töllner, Thomas

    2015-07-15

    Adults with attention-deficit/hyperactivity disorder (ADHD) exhibit slowed reaction times (RTs) in various attention tasks. The exact origins of this slowing, however, have not been established. Potential candidates are early sensory processes mediating the deployment of focal attention, stimulus response translation processes deciding upon the appropriate motor response, and motor processes generating the response. We combined mental chronometry (RT) measures of adult ADHD (n = 15) and healthy control (n = 15) participants with their lateralized event-related potentials during the performance of a visual search task to differentiate potential sources of slowing at separable levels of processing: the posterior contralateral negativity (PCN) was used to index focal-attentional selection times, while the lateralized readiness potentials synchronized to stimulus and response events were used to index the times taken for response selection and production, respectively. To assess the clinical relevance of event-related potentials, a correlation analysis between neural measures and subjective current and retrospective ADHD symptom ratings was performed. ADHD patients exhibited slower RTs than control participants, which were accompanied by prolonged PCN and lateralized readiness potentials synchronized to stimulus, but not lateralized readiness potentials synchronized to response events, latencies. Moreover, the PCN timing was positively correlated with ADHD symptom ratings. The behavioral RT slowing of adult ADHD patients was based on a summation of internal processing delays arising at perceptual and response selection stages; motor response production, by contrast, was not impaired. The correlation between PCN times and ADHD symptom ratings suggests that this brain signal may serve as a potential candidate for a neurocognitive endophenotype of ADHD. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  19. A Primer to Slow Light

    OpenAIRE

    Leonhardt, U.

    2001-01-01

    Laboratory-based optical analogs of astronomical objects such as black holes rely on the creation of light with an extremely low or even vanishing group velocity (slow light). These brief notes represent a pedagogical attempt towards elucidating this extraordinary form of light. This paper is a contribution to the book Artificial Black Holes edited by Mario Novello, Matt Visser and Grigori Volovik. The paper is intended as a primer, an introduction to the subject for non-experts, not as a det...

  20. Capillary waves in slow motion

    International Nuclear Information System (INIS)

    Seydel, Tilo; Tolan, Metin; Press, Werner; Madsen, Anders; Gruebel, Gerhard

    2001-01-01

    Capillary wave dynamics on glycerol surfaces has been investigated by means of x-ray photon correlation spectroscopy performed at grazing angles. The measurements show that thermally activated capillary wave motion is slowed down exponentially when the sample is cooled below 273 K. This finding directly reflects the freezing of the surface waves. The wave-number dependence of the measured time constants is in quantitative agreement with theoretical predictions for overdamped capillary waves

  1. The fast slow TDPAC spectrometer

    International Nuclear Information System (INIS)

    Cekic, B.; Koicki, S.; Manasijevic, M.; Ivanovic, N.; Koteski, V.; Milosevic, Z.; Radisavljevic, I.; Cavor, J.; Novakovic, N.; Marjanovic, D.

    2001-01-01

    A 2-BaF 2 detector - fast slow time spectrometer for time differential perturbed angular correlations (TDPAC) experiments is described. This apparatus has been developed in the Group for Hyperfine Interactions in the Institute for Nuclear Sciences in VINCA. The excellent time resolution combined with high efficiency offered by these detectors enables one high counting rate performance and is operating in the wide temperature range 78-1200 K. (author)

  2. ANALYSIS OF PROCESSES IN AN INDEPENDENT GENERATOR WITH A NONCONTACT CASCADE THREE-PHASE MODULATED EXCITER VIA A STAR-CONNECTED CIRCUIT WITH A COMMON MODULATOR PHASE CONNECTION UNDER OPERATION TO AN INDUCTION MOTORS SITE

    Directory of Open Access Journals (Sweden)

    K.M. Vasyliv

    2013-04-01

    Full Text Available By means of a mathematical experiment, electromagnetic and electromechanical processes in an independent electric power supply system based on an asynchronized generator with a three-phase modulated exciter are investigated. The processes are analyzed to specify the working capacity of the power supply system during its operation to an induction motors site. Regularities of the electromagnetic and electromechanical processes behavior versus load intensity and the switch control system parameters are identified.

  3. Hidden slow pulsars in binaries

    Science.gov (United States)

    Tavani, Marco; Brookshaw, Leigh

    1993-01-01

    The recent discovery of the binary containing the slow pulsar PSR 1718-19 orbiting around a low-mass companion star adds new light on the characteristics of binary pulsars. The properties of the radio eclipses of PSR 1718-19 are the most striking observational characteristics of this system. The surface of the companion star produces a mass outflow which leaves only a small 'window' in orbital phase for the detection of PSR 1718-19 around 400 MHz. At this observing frequency, PSR 1718-19 is clearly observable only for about 1 hr out of the total 6.2 hr orbital period. The aim of this Letter is twofold: (1) to model the hydrodynamical behavior of the eclipsing material from the companion star of PSR 1718-19 and (2) to argue that a population of binary slow pulsars might have escaped detection in pulsar surveys carried out at 400 MHz. The possible existence of a population of partially or totally hidden slow pulsars in binaries will have a strong impact on current theories of binary evolution of neutron stars.

  4. Jidosha's Motors

    OpenAIRE

    Shirakawa Okuma, Rosely; Calderón Orejuela, Javier

    2016-01-01

    La tesis narra la situación de una empresa concesionaria de vehículos nuevos, Jidosha's Motors, perteneciente a una corporación japonesa que cuenta con una cultura muy arraigada de ética y de cumplimiento. Se plantean respuestas, se identifican problemas y sus alternativas de solución para una toma adecuada de decisiones por parte de los directivos, siguiendo una estructura de análisis de situaciones de negocios (ASN). Tesis

  5. Responsive demand to mitigate slow recovery voltage sags

    DEFF Research Database (Denmark)

    Garcia-Valle, Rodrigo; da Silva, Luiz Carlos Pereira; Xu, Zhao

    2012-01-01

    , and reactive power reserve for peak load management through price responsive methods and also as energy providers through embedded generation technologies. This article introduces a new technology, called demand as voltagecontrolled reserve, which can help mitigation of momentary voltage sags. The technology...... faults. This article presents detailed models, discussion, and simulation tests to demonstrate the technical viability and effectiveness of the demand as voltage-controlled reserve technology for mitigating voltage sags....... can be provided by thermostatically controlled loads as well as other types of load. This technology has proven to be effective in distribution systems with a large composition of induction motors, when voltage sags present slow recovery characteristics because of the deceleration of the motors during...

  6. Motorist comprehension of the slow-moving vehicle (SMV) emblem.

    Science.gov (United States)

    Garvey, P M

    2003-05-01

    While attaining widespread use and institutional acceptance in its 40 years on the road, crash data indicate that the slow-moving vehicle (SMV) emblem may not be meeting the safety needs of either the motoring public or SMV operators. This article addresses the possibility that the reasons for this include its inconsistent day/night appearance, potential confusion with other roadway symbols, its uncontrolled misuse, and poor driver education. This study is also the first to systematically evaluate the SMV emblem's comprehensibility by the general motoring public. Over 100 male and female drivers from 18 to 84 years of age gave open-ended responses to the presentation of a scale model SMV emblem displayed in its daytime and nighttime appearance. While the older drivers understood the meaning of the emblem better than their younger counterparts, overall emblem comprehension was still under 30%.

  7. En sammenligning af selvstændighedsbegrebet for Assessment of Motor and Process Skills (AMPS) og Barthel Index (BI-100) – for patienter indlagt på apopleksi afsnit

    DEFF Research Database (Denmark)

    Lauridsen, Sussi

    2008-01-01

    selvstændighed og/eller behov for assistance. Blandt disse instrumenter findes Barthel Index 100 (BI-100) og Assessment of Motor and Process Skills (AMPS). Formålet med studiet var, at vurdere på hvilken måde BI-100 og AMPS korrelere i graden af selvstændighed ved bedømmelse af apopleksipatienter. Baggrunden...

  8. Processing of sub- and supra-second intervals in the primate brain results from the calibration of neuronal oscillators via sensory, motor, and feedback processes

    Science.gov (United States)

    Gupta, Daya S.

    2014-01-01

    The processing of time intervals in the sub- to supra-second range by the brain is critical for the interaction of primates with their surroundings in activities, such as foraging and hunting. For an accurate processing of time intervals by the brain, representation of physical time within neuronal circuits is necessary. I propose that time dimension of the physical surrounding is represented in the brain by different types of neuronal oscillators, generating spikes or spike bursts at regular intervals. The proposed oscillators include the pacemaker neurons, tonic inputs, and synchronized excitation and inhibition of inter-connected neurons. Oscillators, which are built inside various circuits of brain, help to form modular clocks, processing time intervals or other temporal characteristics specific to functions of a circuit. Relative or absolute duration is represented within neuronal oscillators by “neural temporal unit,” defined as the interval between regularly occurring spikes or spike bursts. Oscillator output is processed to produce changes in activities of neurons, named frequency modulator neuron, wired within a separate module, represented by the rate of change in frequency, and frequency of activities, proposed to encode time intervals. Inbuilt oscillators are calibrated by (a) feedback processes, (b) input of time intervals resulting from rhythmic external sensory stimulation, and (c) synchronous effects of feedback processes and evoked sensory activity. A single active clock is proposed per circuit, which is calibrated by one or more mechanisms. Multiple calibration mechanisms, inbuilt oscillators, and the presence of modular connections prevent a complete loss of interval timing functions of the brain. PMID:25136321

  9. Experimental thermodynamics of single molecular motor.

    Science.gov (United States)

    Toyabe, Shoichi; Muneyuki, Eiro

    2013-01-01

    Molecular motor is a nano-sized chemical engine that converts chemical free energy to mechanical motions. Hence, the energetics is as important as kinetics in order to understand its operation principle. We review experiments to evaluate the thermodynamic properties of a rotational F1-ATPase motor (F1-motor) at a single-molecule level. We show that the F1-motor achieves 100% thermo dynamic efficiency at the stalled state. Furthermore, the motor reduces the internal irreversible heat inside the motor to almost zero and achieves a highly-efficient free energy transduction close to 100% during rotations far from quasistatic process. We discuss the mechanism of how the F1-motor achieves such a high efficiency, which highlights the remarkable property of the nano-sized engine F1-motor.

  10. Slow electrons kill the ozone

    International Nuclear Information System (INIS)

    Maerk, T.

    2001-01-01

    A new method and apparatus (Trochoidal electron monochromator) to study the interactions of electrons with atoms, molecules and clusters was developed. Two applications are briefly reported: a) the ozone destruction in the atmosphere is caused by different reasons, a new mechanism is proposed, that slow thermal electrons are self added to the ozone molecule (O 3 ) with a high frequency, then O 3 is destroyed ( O 3 + e - → O - + O 2 ); b) another application is the study of the binding energy of the football molecule C60. (nevyjel)

  11. The CUORE slow monitoring systems

    Science.gov (United States)

    Gladstone, L.; Biare, D.; Cappelli, L.; Cushman, J. S.; Del Corso, F.; Fujikawa, B. K.; Hickerson, K. P.; Moggi, N.; Pagliarone, C. E.; Schmidt, B.; Wagaarachchi, S. L.; Welliver, B.; Winslow, L. A.

    2017-09-01

    CUORE is a cryogenic experiment searching primarily for neutrinoless double decay in 130Te. It will begin data-taking operations in 2016. To monitor the cryostat and detector during commissioning and data taking, we have designed and developed Slow Monitoring systems. In addition to real-time systems using LabVIEW, we have an alarm, analysis, and archiving website that uses MongoDB, AngularJS, and Bootstrap software. These modern, state of the art software packages make the monitoring system transparent, easily maintainable, and accessible on many platforms including mobile devices.

  12. Blowup for flat slow manifolds

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall

    2017-01-01

    In this paper, we present a way of extending the blowup method, in the formulation of Krupa and Szmolyan, to flat slow manifolds that lose hyperbolicity beyond any algebraic order. Although these manifolds have infinite co-dimensions, they do appear naturally in certain settings; for example, in (a......) the regularization of piecewise smooth systems by tanh, (b) a particular aircraft landing dynamics model, and finally (c) in a model of earthquake faulting. We demonstrate the approach using a simple model system and the examples (a) and (b)....

  13. Blowup for flat slow manifolds

    Science.gov (United States)

    Kristiansen, K. U.

    2017-05-01

    In this paper, we present a way of extending the blowup method, in the formulation of Krupa and Szmolyan, to flat slow manifolds that lose hyperbolicity beyond any algebraic order. Although these manifolds have infinite co-dimensions, they do appear naturally in certain settings; for example, in (a) the regularization of piecewise smooth systems by \\tanh , (b) a particular aircraft landing dynamics model, and finally (c) in a model of earthquake faulting. We demonstrate the approach using a simple model system and the examples (a) and (b).

  14. What happens to the motor theory of perception when the motor system is damaged?

    Science.gov (United States)

    Stasenko, Alena; Garcea, Frank E; Mahon, Bradford Z

    2013-09-01

    Motor theories of perception posit that motor information is necessary for successful recognition of actions. Perhaps the most well known of this class of proposals is the motor theory of speech perception, which argues that speech recognition is fundamentally a process of identifying the articulatory gestures (i.e. motor representations) that were used to produce the speech signal. Here we review neuropsychological evidence from patients with damage to the motor system, in the context of motor theories of perception applied to both manual actions and speech. Motor theories of perception predict that patients with motor impairments will have impairments for action recognition. Contrary to that prediction, the available neuropsychological evidence indicates that recognition can be spared despite profound impairments to production. These data falsify strong forms of the motor theory of perception, and frame new questions about the dynamical interactions that govern how information is exchanged between input and output systems.

  15. Motor performance is not enhanced by daytime naps in older adults

    Directory of Open Access Journals (Sweden)

    Winifried eBackhaus

    2016-05-01

    Full Text Available The impact of sleep on motor learning in the aging brain was investigated using an experimental diurnal nap setup. As the brain ages several components of learning as well as motor performance change. In addition, aging is also related to sleep architectural changes. This combination of slowed learning processes and impaired sleep behavior raises the question of whether sleep can enhance learning and specifically performance of procedural tasks in healthy, older adults. Previous research was able to show sleep-dependent consolidation overnight for numerous tasks in young adults. Some of these study findings can also be replicated for older adults. This study aims to clarify whether sleep-dependent consolidation can also be found during shorter periods of diurnal sleep. The impact of midday naps on motor consolidation was analyzed by comparing procedural learning using a sequence and a motor adaptation task, in a crossover fashion in healthy, non-sleep deprived, older adults randomly subjected to wake (45 min, short nap (10-20 min sleep or long nap (50-70 min sleep conditions. Older adults exhibited learning gains, these were not found to be sleep-dependent in either task. The results suggest that daytime naps do not have an impact on performance and motor learning in an aging population.

  16. Workload, Exposure to Noise, and Risk of Musculoskeletal Disorders: A Case Study of Motor-Manual Tree Feeling and Processing in Poplar Clear Cuts

    Directory of Open Access Journals (Sweden)

    Marius Cheţa

    2018-05-01

    Full Text Available Motor-manual tree felling and processing (MMTFP is among the most used options in timber harvesting operations and it is formally known to be a heavy job exposing the workers to safety hazards and harmful factors. Nevertheless, both workload and exposure depend on many operational, organizational, and worker-related parameters. Few studies have evaluated the ergonomics of such operations and fewer have been carried out using an integrated approach able to collect and interpret data for more than one ergonomic parameter. This study evaluated the ergonomic conditions of task-based MMTFP operations in flatland poplar forests by the means of workload, exposure to noise, and risk of musculoskeletal disorders. A fully-automatic approach was used to collect and pair the heart rate and noise exposure data that was complemented by video recording to collect postural data. Workload experienced by the worker was evaluated in terms of heart rate reserve (%HRR, indicating a heavy load during the productive time (%HRR = 46%; exposure to noise was calculated at the task and study level, exceeding (LAeq = 97.15 dB(A; LEX,8h = 96.18 dB(A the acceptable limits; and the risk of musculoskeletal disorders was evaluated using the concepts and procedures of the Ovako Working Posture Analysis System, indicating a high postural risk index (PRI = 275, which can cause musculoskeletal disorders (MSD. For more conclusive results, the research should be extended to cover the relevant variability factors.

  17. What is the evidence of impaired motor skills and motor control among children with attention deficit hyperactivity disorder (ADHD)? Systematic review of the literature.

    Science.gov (United States)

    Kaiser, M-L; Schoemaker, M M; Albaret, J-M; Geuze, R H

    2014-11-06

    This article presents a review of the studies that have analysed the motor skills of ADHD children without medication and the influence of medication on their motor skills. The following two questions guided the study: What is the evidence of impairment of motor skills and aspects of motor control among children with ADHD aged between 6 and 16 years? What are the effects of ADHD medication on motor skills and motor control? The following keywords were introduced in the main databases: attention disorder and/or ADHD, motor skills and/or handwriting, children, medication. Of the 45 articles retrieved, 30 described motor skills of children with ADHD and 15 articles analysed the influence of ADHD medication on motor skills and motor control. More than half of the children with ADHD have difficulties with gross and fine motor skills. The children with ADHD inattentive subtype seem to present more impairment of fine motor skills, slow reaction time, and online motor control during complex tasks. The proportion of children with ADHD who improved their motor skills to the normal range by using medication varied from 28% to 67% between studies. The children who still show motor deficit while on medication might meet the diagnostic criteria of developmental coordination disorder (DCD). It is important to assess motor skills among children with ADHD because of the risk of reduced participation in activities of daily living that require motor coordination and attention. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Connecting slow earthquakes to huge earthquakes

    OpenAIRE

    Obara, Kazushige; Kato, Aitaro

    2016-01-01

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of th...

  19. Integrated Photonics Enabled by Slow Light

    DEFF Research Database (Denmark)

    Mørk, Jesper; Chen, Yuntian; Ek, Sara

    2012-01-01

    In this talk we will discuss the physics of slow light in semiconductor materials and in particular the possibilities offered for integrated photonics. This includes ultra-compact slow light enabled optical amplifiers, lasers and pulse sources.......In this talk we will discuss the physics of slow light in semiconductor materials and in particular the possibilities offered for integrated photonics. This includes ultra-compact slow light enabled optical amplifiers, lasers and pulse sources....

  20. Reduction in Cortical Gamma Synchrony during Depolarized State of Slow Wave Activity in Mice

    Directory of Open Access Journals (Sweden)

    EUNJIN eHWANG

    2013-12-01

    Full Text Available EEG gamma band oscillations have been proposed to account for the neural synchronization crucial for perceptual integration. While increased gamma power and synchronization is generally observed during cognitive tasks performed during wake, several studies have additionally reported increased gamma power during sleep or anesthesia, raising questions about the characteristics of gamma oscillation during impaired consciousness and its role in conscious processing. Phase-amplitude modulation has been observed between slow wave activity (SWA, 0.5–4 Hz and gamma oscillations during ketamine/xylazine anesthesia or sleep, showing increased gamma activity corresponding to the depolarized (ON state of SWA. Here we divided gamma activity into its ON and OFF (hyperpolarized state components based on the phase of SWA induced by ketamine/xylazine anesthesia and compared their power and synchrony with wake state levels in mice. We further investigated the state-dependent changes in both gamma power and synchrony across primary motor and primary somatosensory cortical regions and their interconnected thalamic regions throughout anesthesia and recovery. As observed previously, gamma power was as high as during wake specifically during the ON state of SWA. However, the synchrony of this gamma activity between somatosensory-motor cortical regions was significantly reduced compared to the baseline wake state. In addition, the somatosensory-motor cortical synchrony of gamma oscillations was reduced and restored in an anesthetic state-dependent manner, reflecting the changing depth of anesthesia. Our results provide evidence that during anesthesia changes in long-range information integration between cortical regions might be more critical for changes in consciousness than changes in local gamma oscillatory power.

  1. Slowing down bubbles with sound

    Science.gov (United States)

    Poulain, Cedric; Dangla, Remie; Guinard, Marion

    2009-11-01

    We present experimental evidence that a bubble moving in a fluid in which a well-chosen acoustic noise is superimposed can be significantly slowed down even for moderate acoustic pressure. Through mean velocity measurements, we show that a condition for this effect to occur is for the acoustic noise spectrum to match or overlap the bubble's fundamental resonant mode. We render the bubble's oscillations and translational movements using high speed video. We show that radial oscillations (Rayleigh-Plesset type) have no effect on the mean velocity, while above a critical pressure, a parametric type instability (Faraday waves) is triggered and gives rise to nonlinear surface oscillations. We evidence that these surface waves are subharmonic and responsible for the bubble's drag increase. When the acoustic intensity is increased, Faraday modes interact and the strongly nonlinear oscillations behave randomly, leading to a random behavior of the bubble's trajectory and consequently to a higher slow down. Our observations may suggest new strategies for bubbly flow control, or two-phase microfluidic devices. It might also be applicable to other elastic objects, such as globules, cells or vesicles, for medical applications such as elasticity-based sorting.

  2. Repetitive Transcranial Magnetic Stimulation to the Primary Motor Cortex Interferes with Motor Learning by Observing

    Science.gov (United States)

    Brown, Liana E.; Wilson, Elizabeth T.; Gribble, Paul L.

    2009-01-01

    Neural representations of novel motor skills can be acquired through visual observation. We used repetitive transcranial magnetic stimulation (rTMS) to test the idea that this "motor learning by observing" is based on engagement of neural processes for learning in the primary motor cortex (M1). Human subjects who observed another person learning…

  3. Mathematical modeling of molecular motors

    OpenAIRE

    Keller, Peter

    2013-01-01

    Amongst the many complex processes taking place in living cells, transport of cargoes across the cytosceleton is fundamental to cell viability and activity. To move cargoes between the different cell parts, cells employ Molecular Motors. The motors operate by transporting cargoes along the so-called cellular micro-tubules, namely rope-like structures that connect, for instance, the cell-nucleus and outer membrane. We introduce a new Markov Chain, the killed Quasi-Random-Walk, for such transpo...

  4. Local synaptic signaling enhances the stochastic transport of motor-driven cargo in neurons

    KAUST Repository

    Newby, Jay

    2010-08-23

    The tug-of-war model of motor-driven cargo transport is formulated as an intermittent trapping process. An immobile trap, representing the cellular machinery that sequesters a motor-driven cargo for eventual use, is located somewhere within a microtubule track. A particle representing a motor-driven cargo that moves randomly with a forward bias is introduced at the beginning of the track. The particle switches randomly between a fast moving phase and a slow moving phase. When in the slow moving phase, the particle can be captured by the trap. To account for the possibility that the particle avoids the trap, an absorbing boundary is placed at the end of the track. Two local signaling mechanisms-intended to improve the chances of capturing the target-are considered by allowing the trap to affect the tug-of-war parameters within a small region around itself. The first is based on a localized adenosine triphosphate (ATP) concentration gradient surrounding a synapse, and the second is based on a concentration of tau-a microtubule-associated protein involved in Alzheimer\\'s disease-coating the microtubule near the synapse. It is shown that both mechanisms can lead to dramatic improvements in the capture probability, with a minimal increase in the mean capture time. The analysis also shows that tau can cause a cargo to undergo random oscillations, which could explain some experimental observations. © 2010 IOP Publishing Ltd.

  5. System xC- is a mediator of microglial function and its deletion slows symptoms in amyotrophic lateral sclerosis mice.

    Science.gov (United States)

    Mesci, Pinar; Zaïdi, Sakina; Lobsiger, Christian S; Millecamps, Stéphanie; Escartin, Carole; Seilhean, Danielle; Sato, Hideyo; Mallat, Michel; Boillée, Séverine

    2015-01-01

    Amyotrophic lateral sclerosis is the most common adult-onset motor neuron disease and evidence from mice expressing amyotrophic lateral sclerosis-causing SOD1 mutations suggest that neurodegeneration is a non-cell autonomous process where microglial cells influence disease progression. However, microglial-derived neurotoxic factors still remain largely unidentified in amyotrophic lateral sclerosis. With excitotoxicity being a major mechanism proposed to cause motor neuron death in amyotrophic lateral sclerosis, our hypothesis was that excessive glutamate release by activated microglia through their system [Formula: see text] (a cystine/glutamate antiporter with the specific subunit xCT/Slc7a11) could contribute to neurodegeneration. Here we show that xCT expression is enriched in microglia compared to total mouse spinal cord and absent from motor neurons. Activated microglia induced xCT expression and during disease, xCT levels were increased in both spinal cord and isolated microglia from mutant SOD1 amyotrophic lateral sclerosis mice. Expression of xCT was also detectable in spinal cord post-mortem tissues of patients with amyotrophic lateral sclerosis and correlated with increased inflammation. Genetic deletion of xCT in mice demonstrated that activated microglia released glutamate mainly through system [Formula: see text]. Interestingly, xCT deletion also led to decreased production of specific microglial pro-inflammatory/neurotoxic factors including nitric oxide, TNFa and IL6, whereas expression of anti-inflammatory/neuroprotective markers such as Ym1/Chil3 were increased, indicating that xCT regulates microglial functions. In amyotrophic lateral sclerosis mice, xCT deletion surprisingly led to earlier symptom onset but, importantly, this was followed by a significantly slowed progressive disease phase, which resulted in more surviving motor neurons. These results are consistent with a deleterious contribution of microglial-derived glutamate during symptomatic

  6. Deciding about fast and slow decisions.

    Science.gov (United States)

    Croskerry, Pat; Petrie, David A; Reilly, James B; Tait, Gordon

    2014-02-01

    Two reports in this issue address the important topic of clinical decision making. Dual process theory has emerged as the dominant model for understanding the complex processes that underlie human decision making. This theory distinguishes between the reflexive, autonomous processes that characterize intuitive decision making and the deliberate reasoning of an analytical approach. In this commentary, the authors address the polarization of viewpoints that has developed around the relative merits of the two systems. Although intuitive processes are typically fast and analytical processes slow, speed alone does not distinguish them. In any event, the majority of decisions in clinical medicine are not dependent on very short response times. What does appear relevant to diagnostic ease and accuracy is the degree to which the symptoms of the disease being diagnosed are characteristic ones. There are also concerns around some methodological issues related to research design in this area of enquiry. Reductionist approaches that attempt to isolate dependent variables may create such artificial experimental conditions that both external and ecological validity are sacrificed. Clinical decision making is a complex process with many independent (and interdependent) variables that need to be separated out in a discrete fashion and then reflected on in real time to preserve the fidelity of clinical practice. With these caveats in mind, the authors believe that research in this area should promote a better understanding of clinical practice and teaching by focusing less on the deficiencies of intuitive and analytical systems and more on their adaptive strengths.

  7. Early motor development and later language and reading skills in children at risk of familial dyslexia.

    Science.gov (United States)

    Viholainen, Helena; Ahonen, Timo; Lyytinen, Paula; Cantell, Marja; Tolvanen, Asko; Lyytinen, Heikki

    2006-05-01

    Relationships between early motor development and language and reading skills were studied in 154 children, of whom 75 had familial risk of dyslexia (37 females, 38 males; at-risk group) and 79 constituted a control group (32 females, 47 males). Motor development was assessed by a structured parental questionnaire during the child's first year of life. Vocabulary and inflectional morphology skills were used as early indicators of language skills at 3 years 6 months and 5 years or 5 years 6 months of age, and reading speed was used as a later indicator of reading skills at 7 years of age. The same subgroups as in our earlier study (in which the cluster analysis was described) were used in this study. The three subgroups of the control group were 'fast motor development', 'slow fine motor development', and 'slow gross motor development', and the two subgroups of the at-risk group were 'slow motor development' and 'fast motor development'. A significant difference was found between the development of expressive language skills. Children with familial risk of dyslexia and slow motor development had a smaller vocabulary with poorer inflectional skills than the other children. They were also slower in their reading speed at the end of the first grade at the age of 7 years. Two different associations are discussed, namely the connection between early motor development and language development, and the connection between early motor development and reading speed.

  8. A fast-slow logic system

    International Nuclear Information System (INIS)

    Kawashima, Hideo.

    1977-01-01

    A fast-slow logic system has been made for use in multi-detector experiments in nuclear physics such as particle-gamma and particle-particle coincidence experiments. The system consists of a fast logic system and a slow logic system. The fast logic system has a function of fast coincidences and provides timing signals for the slow logic system. The slow logic system has a function of slow coincidences and a routing control of input analog signals to the ADCs. (auth.)

  9. Progression of motor symptoms in Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    Ruiping Xia; Zhi-Hong Mao

    2012-01-01

    Parkinson's disease (PD) is a chronic progressive neurodegenerative disease that is clinically manifested by a triad of cardinal motor symptoms - rigidity,bradykinesia and tremor - due to loss of dopaminergic neurons.The motor symptoms of PD become progressively worse as the disease advances.PD is also a heterogeneous disease since rigidity and bradykinesia are the major complaints in some patients whereas tremor is predominant in others.In recent years,many studies have investigated the progression of the hallmark symptoms over time,and the cardinal motor symptoms have different rates of progression,with the disease usually progressing faster in patients with rigidity and bradykinesia than in those with predominant tremor.The current treatment regime of dopamine-replacement therapy improves motor symptoms and alleviates disability.Increasing the dosage of dopaminergic medication is commonly used to combat the worsenirtg symptoms.However,the drug-induced involuntary body movements and motor comphcations can significantly contribute to overall disability.Further,none of the currently-available therapies can slow or halt the disease progression.Significant research efforts have been directed towards developing neuroprotective or disease-modifying agents that are intended to slow the progression.In this article,the most recent clinical studies investigating disease progression and current progress on the development of disease-modifying drug trials are reviewed.

  10. Slow pyrolysis of pistachio shell

    Energy Technology Data Exchange (ETDEWEB)

    Apaydin-Varol, Esin; Putun, Ersan; Putun, Ayse E [Anadolu University, Eskisehir (Turkey). Department of Chemical Engineering

    2007-08-15

    In this study, pistachio shell is taken as the biomass sample to investigate the effects of pyrolysis temperature on the product yields and composition when slow pyrolysis is applied in a fixed-bed reactor at atmospheric pressure to the temperatures of 300, 400, 500, 550, 700{sup o}C. The maximum liquid yield was attained at about 500-550{sup o}C with a yield of 20.5%. The liquid product obtained under this optimum temperature and solid products obtained at all temperatures were characterized. As well as proximate and elemental analysis for the products were the basic steps for characterization, column chromatography, FT-IR, GC/MS and SEM were used for further characterization. The results showed that liquid and solid products from pistachio shells show similarities with high value conventional fuels. 31 refs., 9 figs., 1 tab.

  11. The TTI slowness surface approximation

    KAUST Repository

    Stovas, A.

    2011-01-01

    The relation between the vertical and horizontal slownesses, better known as the dispersion relation, for a transversely isotropic media with titled symmetry axis {left parenthesis, less than bracket}TTI{right parenthesis, greater than bracket} requires solving a quartic polynomial, which does not admit a practical explicit solution to be used, for example, in downward continuation. Using a combination of perturbation theory with respect to the anelliptic parameter and Shanks transform to improve the accuracy of the expansion, we develop an explicit formula for the dispersion relation that is highly accurate for all practical purposes. It also reveals some insights into the anisotropy parameter dependency of the dispersion relation including the low impact that the anelliptic parameter has on the vertical placement of reflectors for small tilt in the symmetry angle. © 2011 Society of Exploration Geophysicists.

  12. Fine motor control

    Science.gov (United States)

    ... gross (large, general) motor control. An example of gross motor control is waving an arm in greeting. Problems ... out the child's developmental age. Children develop fine motor skills over time, by practicing and being taught. To ...

  13. Motor skill learning and offline-changes in TGA patients with acute hippocampal CA1 lesions.

    Science.gov (United States)

    Döhring, Juliane; Stoldt, Anne; Witt, Karsten; Schönfeld, Robby; Deuschl, Günther; Born, Jan; Bartsch, Thorsten

    2017-04-01

    Learning and the formation of memory are reflected in various memory systems in the human brain such as the hippocampus based declarative memory system and the striatum-cortex based system involved in motor sequence learning. It is a matter of debate how both memory systems interact in humans during learning and consolidation and how this interaction is influenced by sleep. We studied the effect of an acute dysfunction of hippocampal CA1 neurons on the acquisition (on-line condition) and off-line changes of a motor skill in patients with a transient global amnesia (TGA). Sixteen patients (68 ± 4.4 yrs) were studied in the acute phase and during follow-up using a declarative and procedural test, and were compared to controls. Acute TGA patients displayed profound deficits in all declarative memory functions. During the acute amnestic phase, patients were able to acquire the motor skill task reflected by increasing finger tapping speed across the on-line condition, albeit to a lesser degree than during follow-up or compared to controls. Retrieval two days later indicated a greater off-line gain in motor speed in patients than controls. Moreover, this gain in motor skill performance was negatively correlated to the declarative learning deficit. Our results suggest a differential interaction between procedural and declarative memory systems during acquisition and consolidation of motor sequences in older humans. During acquisition, hippocampal dysfunction attenuates fast learning and thus unmasks the slow and rigid learning curve of striatum-based procedural learning. The stronger gains in the post-consolidation condition in motor skill in CA1 lesioned patients indicate a facilitated consolidation process probably occurring during sleep, and suggest a competitive interaction between the memory systems. These findings might be a reflection of network reorganization and plasticity in older humans and in the presence of CA1 hippocampal pathology. Copyright © 2016

  14. Decision-making and referral processes for patients with motor neurone disease: a qualitative study of GP experiences and evaluation of a new decision-support tool.

    Science.gov (United States)

    Baxter, Susan; McDermott, Christopher J

    2017-05-08

    The diagnosis of motor neurone disease (MND) is known to be challenging and there may be delay in patients receiving a correct diagnosis. This study investigated the referral process for patients who had been diagnosed with MND, and whether a newly-developed tool (The Red Flags checklist) might help General Practitioners (GPs) in making referral decisions. We carried out interviews with GPs who had recently referred a patient diagnosed with MND, and interviews/surveys with GPs who had not recently referred a patient with suspected MND. We collected data before the Red Flags checklist was introduced; and again one year later. We analysed the data to identify key recurring themes. Forty two GPs took part in the study. The presence of fasciculation was the clinical feature that most commonly led to consideration of a potential MND diagnosis. GPs perceived that their role was to make onward referrals rather than attempting to make a diagnosis, and delays in correct diagnosis tended to occur at the specialist level. A quarter of participants had some awareness of the newly-developed tool; most considered it useful, if incorporated into existing systems. While fasciculation is the most common symptom associated with MND, other bulbar, limb or respiratory features, together with progression should be considered. There is a need for further research into how decision-support tools should be designed and provided, in order to best assist GPs with referral decisions. There is also a need for further work at the level of secondary care, in order that referrals made are re-directed appropriately.

  15. Effects of slow repetitive transcranial magnetic stimulation in patients with corticobasal syndrome.

    Science.gov (United States)

    Civardi, Carlo; Pisano, Fabrizio; Delconte, Carmen; Collini, Alessandra; Monaco, Francesco

    2015-06-01

    Corticobasal syndrome is characterized by asymmetric cortical sensorimotor dysfunction and parkinsonism; an altered cortical excitability has been reported. We explored with transcranial magnetic stimulation the motor cortical excitability in corticobasal syndrome, and the effects of slow repetitive transcranial magnetic stimulation. With transcranial magnetic stimulation, we studied two corticobasal syndrome patients. We determined bilaterally from the first dorsal interosseous muscle: relaxed threshold, and contralateral and ipsilateral silent period. We also evaluated the contralateral silent period after active/sham slow repetitive transcranial magnetic stimulation on the most affected side. At T0 the silent period was bilaterally short. On the most affected side, active slow repetitive transcranial magnetic stimulation induced a short lasting prolongation of the contralateral silent period. In corticobasal syndrome, transcranial magnetic stimulation showed a reduction cortical inhibitory phenomenon potentially reversed transiently by slow repetitive transcranial magnetic stimulation.

  16. Motor control for a brushless DC motor

    Science.gov (United States)

    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.

  17. The contribution of nocturnal sleep to the consolidation of motor skill learning in healthy ageing and Parkinson's disease.

    Science.gov (United States)

    Terpening, Zoe; Naismith, Sharon; Melehan, Kerri; Gittins, Catherine; Bolitho, Sam; Lewis, Simon J G

    2013-08-01

    The benefits of sleep for the consolidation of procedural motor skills are less robust in older adults, although the precise reasons for this remain unclear. To date, even less is known about these processes in older adults with neurodegenerative diseases, particularly those which impact on motor functioning. While sleep disturbance and motor symptoms are frequent disabling features of Parkinson's disease, no known studies have directly probed sleep-dependent memory consolidation for motor skill learning in Parkinson's disease. Forty patients with idiopathic Parkinson's disease (age = 63.7 years ± 7.7; disease duration 4.1 years ± 4.4) completed a motor skill learning task pre- and post-sleep and were compared to 20 age- and sex-matched controls recruited from the community. Polysomnography was undertaken during the post-training night and measures of sleep architecture were derived. Parkinson's disease patients did not demonstrate any apparent deficits in within-session learning and overnight stabilization compared to controls, with both groups failing to demonstrate offline improvements in performance (i.e. memory consolidation). In controls, longer duration in slow wave sleep was associated with improved next-day session learning (P = 0.007). However, in Parkinson's disease, no relationships between sleep parameters and learning measures were found. Slow wave sleep microarchitecture and the use of dopaminergic medications may contribute to impaired sleep-dependent multi-session acquisition of motor skill learning in Parkinson's disease. © 2013 European Sleep Research Society.

  18. The correlation between motor impairments and event-related desynchronization during motor imagery in ALS patients

    Directory of Open Access Journals (Sweden)

    Kasahara Takashi

    2012-06-01

    Full Text Available Abstract Background The event-related desynchronization (ERD in EEG is known to appear during motor imagery, and is thought to reflect cortical processing for motor preparation. The aim of this study is to examine the modulation of ERD with motor impairment in ALS patients. ERD during hand motor imagery was obtained from 8 ALS patients with a variety of motor impairments. ERD was also obtained from age-matched 11 healthy control subjects with the same motor task. The magnitude and frequency of ERD were compared between groups for characterization of ALS specific changes. Results The ERD of ALS patients were significantly smaller than those of control subjects. Bulbar function and ERD were negatively correlated in ALS patients. Motor function of the upper extremities did was uncorrelated with ERD. Conclusions ALS patients with worsened bulbar scales may show smaller ERD. Motor function of the upper extremities did was uncorrelated with ERD.

  19. Neuronal mechanisms of motor learning and motor memory consolidation in healthy old adults.

    Science.gov (United States)

    Berghuis, K M M; Veldman, M P; Solnik, S; Koch, G; Zijdewind, I; Hortobágyi, T

    2015-06-01

    It is controversial whether or not old adults are capable of learning new motor skills and consolidate the performance gains into motor memory in the offline period. The underlying neuronal mechanisms are equally unclear. We determined the magnitude of motor learning and motor memory consolidation in healthy old adults and examined if specific metrics of neuronal excitability measured by magnetic brain stimulation mediate the practice and retention effects. Eleven healthy old adults practiced a wrist extension-flexion visuomotor skill for 20 min (MP, 71.3 years), while a second group only watched the templates without movements (attentional control, AC, n = 11, 70.5 years). There was 40 % motor learning in MP but none in AC (interaction, p learn a new motor skill and consolidate the learned skill into motor memory, processes that are most likely mediated by disinhibitory mechanisms. These results are relevant for the increasing number of old adults who need to learn and relearn movements during motor rehabilitation.

  20. Concurrent word generation and motor performance: further evidence for language-motor interaction.

    Directory of Open Access Journals (Sweden)

    Amy D Rodriguez

    Full Text Available Embodied/modality-specific theories of semantic memory propose that sensorimotor representations play an important role in perception and action. A large body of evidence supports the notion that concepts involving human motor action (i.e., semantic-motor representations are processed in both language and motor regions of the brain. However, most studies have focused on perceptual tasks, leaving unanswered questions about language-motor interaction during production tasks. Thus, we investigated the effects of shared semantic-motor representations on concurrent language and motor production tasks in healthy young adults, manipulating the semantic task (motor-related vs. nonmotor-related words and the motor task (i.e., standing still and finger-tapping. In Experiment 1 (n = 20, we demonstrated that motor-related word generation was sufficient to affect postural control. In Experiment 2 (n = 40, we demonstrated that motor-related word generation was sufficient to facilitate word generation and finger tapping. We conclude that engaging semantic-motor representations can have a reciprocal influence on motor and language production. Our study provides additional support for functional language-motor interaction, as well as embodied/modality-specific theories.

  1. A Novel Single Phase Hybrid Switched Reluctance Motor Drive System

    DEFF Research Database (Denmark)

    Liang, Jianing; Xu, Guoqing; Jian, Linni

    2011-01-01

    In this paper, a novel single phase hybrid switched reluctance motor(SRM) drive system is proposed. It integrated a single phase hybrid SRM and a novel single phase boost converter. This motor can reduce the number of phase switch. And the permanent magnet which is used in the motor can improve...... the performance and efficiency of SR motor. However, the inherent characteristic of this motor is that the negative torque is very sensitive with the excitation current near the turn-on angle. The slow excitation current limits the torque generation region and reduces the average torque. Therefore, a novel single...... phase boost converter is applied to improve the performance of this motor. It is easy to generate a double dclink voltage and dc-link voltage and switch both of them. The voltage of boost capacitor is self balance, so the protective circuit is not need to consider. The fast excitation mode helps hybrid...

  2. The Adaptive Organization and Fast-slow Systems

    DEFF Research Database (Denmark)

    Andersen, Torben Juul; Hallin, Carina Antonia

    2016-01-01

    Contemporary organizations operate under turbulent business conditions and must adapt their strategies to ongoing changes. This article argues that sustainable organizational performance is achieved when top management directs and coordinates interactive processes anchored in emerging...... organizational opportunities and forward-looking analytics. The fast and emergent processes performed by local managers at the frontline observe and respond to environmental stimuli and the slow processes initiated by decision makers interpret events and reasons about updated strategic actions. Current...

  3. Motor-sensory confluence in tactile perception.

    Science.gov (United States)

    Saig, Avraham; Gordon, Goren; Assa, Eldad; Arieli, Amos; Ahissar, Ehud

    2012-10-03

    Perception involves motor control of sensory organs. However, the dynamics underlying emergence of perception from motor-sensory interactions are not yet known. Two extreme possibilities are as follows: (1) motor and sensory signals interact within an open-loop scheme in which motor signals determine sensory sampling but are not affected by sensory processing and (2) motor and sensory signals are affected by each other within a closed-loop scheme. We studied the scheme of motor-sensory interactions in humans using a novel object localization task that enabled monitoring the relevant overt motor and sensory variables. We found that motor variables were dynamically controlled within each perceptual trial, such that they gradually converged to steady values. Training on this task resulted in improvement in perceptual acuity, which was achieved solely by changes in motor variables, without any change in the acuity of sensory readout. The within-trial dynamics is captured by a hierarchical closed-loop model in which lower loops actively maintain constant sensory coding, and higher loops maintain constant sensory update flow. These findings demonstrate interchangeability of motor and sensory variables in perception, motor convergence during perception, and a consistent hierarchical closed-loop perceptual model.

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

    Science.gov (United States)

    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. Copyright © 2011 Movement Disorder Society.

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

    Science.gov (United States)

    Voon, V; Brezing, C; Gallea, C; Hallett, M

    2014-01-01

    Background Conversion disorder 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 conversion disorder with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amgydala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Methods Subjects performed either an internally or externally generated two-button action selection task in a functional MRI study. Results Eleven conversion disorder 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. Conclusion 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. PMID:21935985

  6. Plant domestication slows pest evolution.

    Science.gov (United States)

    Turcotte, Martin M; Lochab, Amaneet K; Turley, Nash E; Johnson, Marc T J

    2015-09-01

    Agricultural practices such as breeding resistant varieties and pesticide use can cause rapid evolution of pest species, but it remains unknown how plant domestication itself impacts pest contemporary evolution. Using experimental evolution on a comparative phylogenetic scale, we compared the evolutionary dynamics of a globally important economic pest - the green peach aphid (Myzus persicae) - growing on 34 plant taxa, represented by 17 crop species and their wild relatives. Domestication slowed aphid evolution by 13.5%, maintained 10.4% greater aphid genotypic diversity and 5.6% higher genotypic richness. The direction of evolution (i.e. which genotypes increased in frequency) differed among independent domestication events but was correlated with specific plant traits. Individual-based simulation models suggested that domestication affects aphid evolution directly by reducing the strength of selection and indirectly by increasing aphid density and thus weakening genetic drift. Our results suggest that phenotypic changes during domestication can alter pest evolutionary dynamics. © 2015 John Wiley & Sons Ltd/CNRS.

  7. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1993-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  8. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1992-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  9. Schrodinger cat state generation using a slow light

    International Nuclear Information System (INIS)

    Ham, B. S.; Kim, M. S.

    2003-01-01

    We show a practical application of giant Kerr nonlinearity to quantum information processing based on superposition of two distinct macroscopic states- Schrodinger cat state. The giant Kerr nonlinearity can be achieved by using electromagnetically induced transparency, in which light propagation should be slowed down so that a pi-phase shift can be easily obtained owing to increased interaction time.

  10. Human Growth Hormone (HGH): Does It Slow Aging?

    Science.gov (United States)

    Healthy Lifestyle Healthy aging Human growth hormone is described by some as the key to slowing the aging process. Before you sign up, get the ... slowdown has triggered an interest in using synthetic human growth hormone (HGH) as a way to stave ...

  11. Biochar production from freshwater algae by slow pyrolysis

    Directory of Open Access Journals (Sweden)

    Tanongkiat Kiatsiriroat

    2012-05-01

    Full Text Available A study on the feasibility of biochar production from 3 kinds of freshwateralgae, viz. Spirulina, Spirogyra and Cladophora, was undertaken. Using a slow pyrolysis process in a specially designed reactor, biochar could be generated at 550oC under nitrogen atmosphere. The yields of biochar were between 28-31% of the dry algae.

  12. Overview of superplastic forming research at ford motor company

    Science.gov (United States)

    Friedman, P. A.; Luckey, S. G.; Copple, W. B.; Allor, R.; Miller, C. E.; Young, C.

    2004-12-01

    In an effort to reduce vehicle weight, the automotive industry has switched to aluminum sheet for many closure panels. Although the application of aluminum is compatible with existing manufacturing processes and has attractive qualities such as low density, good mechanical properties, and high corrosion resistance, it has less room-temperature formability than steel. The expanded forming limits that are possible with superplastic forming can significantly improve the ability to manufacture complex shapes from materials with limited formability. Aluminum closure panels produced by superplastic forming have been used by Ford Motor Company for over a decade. However, applications have been limited to low-volume, specialty vehicles due to the relatively slow cycle time and the cost penalty associated with the specially processed sheet alloys. While there has been substantial research on the superplastic characteristics of aluminum alloys, the bulk of this work has focused on the development of aerospace alloys, which are often too costly and perhaps inappropriate for automotive applications. Additionally, there has been a limited amount of work done to develop the technologies required to support the higher production volumes of the automotive industry. This work presents an automotive perspective on superplastic forming and an overview of the research being performed at Ford Motor Company to increase the production volume so superplastic forming can be cost competitive with more traditional forming technologies.

  13. The neural exploitation hypothesis and its implications for an embodied approach to language and cognition: Insights from the study of action verbs processing and motor disorders in Parkinson's disease.

    Science.gov (United States)

    Gallese, Vittorio; Cuccio, Valentina

    2018-03-01

    As it is widely known, Parkinson's disease is clinically characterized by motor disorders such as the loss of voluntary movement control, including resting tremor, postural instability, and bradykinesia (Bocanegra et al., 2015; Helmich, Hallett, Deuschl, Toni, & Bloem, 2012; Liu et al., 2006; Rosin, Topka, & Dichgans, 1997). In the last years, many empirical studies (e.g., Bocanegra et al., 2015; Spadacenta et al., 2012) have also shown that the processing of action verbs is selectively impaired in patients affected by this neurodegenerative disorder. In the light of these findings, it has been suggested that Parkinson disorder can be interpreted within an embodied cognition framework (e.g., Bocanegra et al., 2015). The central tenet of any embodied approach to language and cognition is that high order cognitive functions are grounded in the sensory-motor system. With regard to this point, Gallese (2008) proposed the neural exploitation hypothesis to account for, at the phylogenetic level, how key aspects of human language are underpinned by brain mechanisms originally evolved for sensory-motor integration. Glenberg and Gallese (2012) also applied the neural exploitation hypothesis to the ontogenetic level. On the basis of these premises, they developed a theory of language acquisition according to which, sensory-motor mechanisms provide a neurofunctional architecture for the acquisition of language, while retaining their original functions as well. The neural exploitation hypothesis is here applied to interpret the profile of patients affected by Parkinson's disease. It is suggested that action semantic impairments directly tap onto motor disorders. Finally, a discussion of what theory of language is needed to account for the interactions between language and movement disorders is presented. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Applications of Slow Light in Telecommunications

    National Research Council Canada - National Science Library

    Boyd, Robert W; Gauthier, Daniel J; Gaeta, Alexander L

    2006-01-01

    .... Now, optical scientists are turning their attention toward developing useful applications of slow light, including controllable optical delay lines, optical buffers and true time delay methods...

  15. Slow extraction control system of HIRFL-CSR

    International Nuclear Information System (INIS)

    Liu Wufeng; Qiao Weimin; Yuan Youjin; Mao Ruishi; Zhao Tiecheng

    2013-01-01

    For heavy-ion radiotherapy, HIRFL-CSR (Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring) needs a long term uniform ion beam extraction from HIRFL-CSR main ring to high energy beam transport line to meet the requirement of heavy-ion radiotherapy's ion beam. Slow extraction control system uses the synchronous signal of HIRFL-CSR control system's timing system to realize process control. When the synchronous event data of HIRFL-CSR control system's timing system trigger controlling and changing data (frequency value, tune value, voltage value), the waveform generator will generate waveform by frequency value, tune value and voltage value, and will amplify the generated waveform by power amplifier to electrostatic deflector to achieve RF-KO slow extraction. The synchronous event receiver of slow extraction system is designed by using FPGA and optical fiber interface to keep high transmission speed and anti-jamming. HIRFL-CSR's running for heavy-ion radiotherapy and ten thousand seconds long period slow extraction experiments show that slow extraction control system is workable and can meet the requirement of heavy-ion radiotherapy's ion beam. (authors)

  16. Slow dynamics in translation-invariant quantum lattice models

    Science.gov (United States)

    Michailidis, Alexios A.; Žnidarič, Marko; Medvedyeva, Mariya; Abanin, Dmitry A.; Prosen, Tomaž; Papić, Z.

    2018-03-01

    Many-body quantum systems typically display fast dynamics and ballistic spreading of information. Here we address the open problem of how slow the dynamics can be after a generic breaking of integrability by local interactions. We develop a method based on degenerate perturbation theory that reveals slow dynamical regimes and delocalization processes in general translation invariant models, along with accurate estimates of their delocalization time scales. Our results shed light on the fundamental questions of the robustness of quantum integrable systems and the possibility of many-body localization without disorder. As an example, we construct a large class of one-dimensional lattice models where, despite the absence of asymptotic localization, the transient dynamics is exceptionally slow, i.e., the dynamics is indistinguishable from that of many-body localized systems for the system sizes and time scales accessible in experiments and numerical simulations.

  17. Investigating the Slow Axonal Transport of Neurofilaments: A Precursor for Optimal Neuronal Signaling

    Science.gov (United States)

    Johnson, Christopher M.

    systematically vary the number of motors in the model and attempt to identify those combinations of motors that show an agreement with the motility characteristic found from the above mentioned kymographs. By pruning the modeled data in accordance with the experimental results, our model can render an estimate of how many motors are attached to the cargo during transport. The model predicts that, on average, the total number of active motors on each neurofilament is relatively small and relatively independent of polymer length, which suggests that the motors may not be distributed uniformly along the filaments. Finally, we develop a model to explore the physiological function of axon morphology sculpted by neurofilament kinetics. Specifically, nodal constrictions are generated by slowing of neurofilaments in the internodal domain (Monsma et al., 2014), but the physiological function of these constrictions is unknown. To address this, we develop a computational model to investigate the effect of nodal constrictions on the axonal conduction velocity. For a fixed number of ion channels, we find that there is an optimal extent of nodal constriction which minimizes the internodal axon caliber that is required to achieve a given target conduction velocity, and we show that this is sensitive to the precise geometry of the axon and myelin sheath in the flanking paranodal regions. Thus axonal constrictions appear to be a biological adaptation that serves to minimize axonal volume, thereby maximizing the spatial and metabolic efficiency of these processes.

  18. Educational and technical assistance to CMV drivers and motor carriers

    Science.gov (United States)

    1999-07-01

    The Peer Exchange is a process adopted by the Office of Motor Carrier and Highway Safety in which teams of professionals, representing state and federal government and private industry, identify effective commercial motor vehicle safety findings for ...

  19. [CHANGE OF CHARACTER OF INTERSYSTEMIC INTERACTIONS IN NEWBORN RAT PUPS UNDER CONDITIONS OF A DECREASE OF MOTOR ACTIVITY].

    Science.gov (United States)

    Sizonov, V A; Dmitrieva, L E; Kuznetsov, S V

    2015-01-01

    Interaction of slow-wave.rhythmic components of cardiac, respiratory.and motor activity was investigated in newborn rat pups on the first day after birth under normal conditions and after pharmacological depression of spontaneous periodic motor activity (SPMA) produced by injecting myocuran (myanesin) at low (100 mg/pg, i/p) and maximal (235 mg/pg, i/p) dosages. The data obtained allow to infer that in rat pups after birth the intersystemic interactions are realized mainly via slow-wave oscillations of about-one- and many-minute ranges whereas the rhythms of decasecond range do not play a significant role in integrative processes. Injection of miocuran at a dose causing no muscle relaxation and no inhibition of motor activity produces changes of the cardiac and respiratory rhythms as well as a transitory decrease of the magnitude of coordinate relations mediated by the rhythms of about-one- and many-minute ranges. The consequences of muscle relaxant injection were found to be more significant for intersystemic interactions with participation of the respiratory system. An increase of the dosage and, correspondingly, the total inhibition of SPMA is accompanied by reduction of the slow-wave components from the pattern of cardiac and respiratory rhythms. The cardiorespiratory interactions, more expressed in intact rat pups, are reduced in the about-one- and many-minute ranges of modulation whereas in the decasecond range of modulation they are slightly increased. Key words: early ontogenesis, intersystemic interactions, cardiac rhythm, respiration, motor activity, myocuran (myanesin).

  20. Perceptions of the Slow Food Cultural Trend among the Youth

    Directory of Open Access Journals (Sweden)

    Lelia Voinea

    2016-11-01

    Full Text Available As they become increasingly aware of the importance of healthy eating and of the serious food imbalance caused by the overconsumption of industrial, ultra-processed and superorganoleptic food, consumers are now beginning to turn their attention to food choices guaranteeing both individual health and also of the environment . Thus, in recent years we are witnessing the rise of a cultural trend ‒ Slow Food. Slow Food has become an international movement that advocates for satisfying culinary pleasure, protects biological and cultural diversity, spread taste education, links "green" producers to consumers and believes that gastronomy intersects with politics, agriculture and ecology. Slow Food proposes a holistic approach to food problem, where the economic, sociocultural and environmental aspects are interlinked, being pursued as part of an overall strategy. In order to highlight the manner in which the principles of this cultural trend are perceived by the representatives of the new generation of consumers in Romania, exploratory research marketing was conducted among the students in the second year of the master’s program Quality Management, Expertise and Consumer Protection, from the Faculty of Business and Tourism from the Buchares t University of Economic Studies . The results of this research have shown an insufficient knowledge of Slow Food phenomenon and, especially, the Slow Food network activity in Romania. To show that the Slow Food type of food is a healthier option towards which the future consumer demand should be guided, especially those belonging to the younger generation, an antithetical comparative analysis of the nutritional value of two menus was performed: a suggestive one for the Slow Food feeding style and other one, specific to the fast food style. Slow Food style was considered antithetical to the fast food because many previous studies have shown a preference of the young for the fast-food type products, despite the

  1. Response of electret dosemeter to slow neutrons

    International Nuclear Information System (INIS)

    Ghilardi, A.J.P.; Pela, C.A.; Zimmerman, R.L.

    1987-01-01

    The response of electret dosemeter to slow neutrons exposure is cited, mentioning the preparation and the irradiation of dosemeter with Am-Be source. Some theory considerations about the response of electret dosemeter to slow and fast neutrons are also presented. (C.G.C.) [pt

  2. Tandem queue with server slow-down

    NARCIS (Netherlands)

    Miretskiy, D.I.; Scheinhardt, W.R.W.; Mandjes, M.R.H.

    2007-01-01

    We study how rare events happen in the standard two-node tandem Jackson queue and in a generalization, the socalled slow-down network, see [2]. In the latter model the service rate of the first server depends on the number of jobs in the second queue: the first server slows down if the amount of

  3. Slow-light pulses in moving media

    International Nuclear Information System (INIS)

    Fiurasek, J.; Leonhardt, U.; Parentani, R.

    2002-01-01

    Slow light in moving media reaches a counterintuitive regime when the flow speed of the medium approaches the group velocity of light. Pulses can penetrate a region where a counterpropagating flow exceeds the group velocity. When the counterflow slows down, pulses are reflected

  4. Can fast and slow intelligence be differentiated?

    NARCIS (Netherlands)

    Partchev, I.; de Boeck, P.

    2012-01-01

    Responses to items from an intelligence test may be fast or slow. The research issue dealt with in this paper is whether the intelligence involved in fast correct responses differs in nature from the intelligence involved in slow correct responses. There are two questions related to this issue: 1.

  5. Slow Movement/Slow University: Critical Engagements. Introduction to the Thematic Section

    Directory of Open Access Journals (Sweden)

    Maggie O'Neill

    2014-09-01

    Full Text Available This thematic section emerged from two seminars that took place at Durham University in England in November 2013 and March 2014 on the possibilities for thinking through what a change movement towards slow might mean for the University. Slow movements have emerged in relation to a number of topics: Slow food, Citta slow and more recently, slow science. What motivated us in the seminars was to explore how far these movements could help us address the acceleration and intensification of work within our own and other universities, and indeed, what new learning, research, philosophies, practices, structures and governance might emerge. This editorial introduction presents the concept of the "slow university" and introduces our critical engagements with slow. The articles presented here interrogate the potentialities, challenges, problems and pitfalls of the slow university in an era of corporate culture and management rationality. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1403166

  6. Using the motor to monitor pump conditions

    Energy Technology Data Exchange (ETDEWEB)

    Casada, D. [Oak Ridge National Lab., TN (United States)

    1996-12-01

    When the load of a mechanical device being driven by a motor changes, whether in response to changes in the overall process or changes in the performance of the driven device, the motor inherently responds. For induction motors, the current amplitude and phase angle change as the shaft load changes. By examining the details of these changes in amplitude and phase, load fluctuations of the driven device can be observed. The usefulness of the motor as a transducer to improve the understanding of devices with high torque fluctuations, such as positive displacement compressors and motor-operated valves, has been recognized and demonstrated for a number of years. On such devices as these, the spectrum of the motor current amplitude, phase, or power normally has certain characteristic peaks associated with various load components, such as the piston stroke or gear tooth meshing frequencies. Comparison and trending of the amplitudes of these peaks has been shown to provide some indication of their mechanical condition. For most centrifugal pumps, the load fluctuations are normally low in torque amplitude, and as a result, the motor experiences a correspondingly lower level of load fluctuation. However, both laboratory and field test data have demonstrated that the motor does provide insight into some important pump performance conditions, such as hydraulic stability and pump-to-motor alignment. Comparisons of other dynamic signals, such as vibration and pressure pulsation, to motor data for centrifugal pumps are provided. The effects of inadequate suction head, misalignment, mechanical and hydraulic unbalance on these signals are presented.

  7. Using the motor to monitor pump conditions

    International Nuclear Information System (INIS)

    Casada, D.

    1996-01-01

    When the load of a mechanical device being driven by a motor changes, whether in response to changes in the overall process or changes in the performance of the driven device, the motor inherently responds. For induction motors, the current amplitude and phase angle change as the shaft load changes. By examining the details of these changes in amplitude and phase, load fluctuations of the driven device can be observed. The usefulness of the motor as a transducer to improve the understanding of devices with high torque fluctuations, such as positive displacement compressors and motor-operated valves, has been recognized and demonstrated for a number of years. On such devices as these, the spectrum of the motor current amplitude, phase, or power normally has certain characteristic peaks associated with various load components, such as the piston stroke or gear tooth meshing frequencies. Comparison and trending of the amplitudes of these peaks has been shown to provide some indication of their mechanical condition. For most centrifugal pumps, the load fluctuations are normally low in torque amplitude, and as a result, the motor experiences a correspondingly lower level of load fluctuation. However, both laboratory and field test data have demonstrated that the motor does provide insight into some important pump performance conditions, such as hydraulic stability and pump-to-motor alignment. Comparisons of other dynamic signals, such as vibration and pressure pulsation, to motor data for centrifugal pumps are provided. The effects of inadequate suction head, misalignment, mechanical and hydraulic unbalance on these signals are presented

  8. Slow, Wet and Catalytic Pyrolysis of Fowl Manure

    OpenAIRE

    Renzo Carta; Mario Cruccu; Francesco Desogus

    2012-01-01

    This work presents the experimental results obtained at a pilot plant which works with a slow, wet and catalytic pyrolysis process of dry fowl manure. This kind of process mainly consists in the cracking of the organic matrix and in the following reaction of carbon with water, which is either already contained in the organic feed or added, to produce carbon monoxide and hydrogen. Reactions are conducted in a rotating reactor maintained at a temperature of 500°C; the requi...

  9. Connecting slow earthquakes to huge earthquakes.

    Science.gov (United States)

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes. Copyright © 2016, American Association for the Advancement of Science.

  10. Effects of gross motor function and manual function levels on performance-based ADL motor skills of children with spastic cerebral palsy

    OpenAIRE

    Park, Myoung-Ok

    2017-01-01

    [Purpose] The purpose of this study was to determine effects of Gross Motor Function Classification System and Manual Ability Classification System levels on performance-based motor skills of children with spastic cerebral palsy. [Subjects and Methods] Twenty-three children with cerebral palsy were included. The Assessment of Motor and Process Skills was used to evaluate performance-based motor skills in daily life. Gross motor function was assessed using Gross Motor Function Classification S...

  11. Interference in ballistic motor learning - is motor interference really sensory?

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C

    Skill gained after a short period of practice in one motor task can be abolished if a second task is learned shortly afterwards. We hypothesised that interference requires the same circuits to be engaged in the two tasks and provoke competing processes of synaptic plasticity. To test this, subjects...

  12. Working memory contributes to elevated motor activity in adults with ADHD: an examination of the role of central executive and storage/rehearsal processes.

    Science.gov (United States)

    Hudec, Kristen L; Alderson, R Matt; Kasper, Lisa J; Patros, Connor H G

    2014-05-01

    The relationship between working memory (WM) and objectively measured motor activity was examined in adults with ADHD and healthy controls (HCs). Thirty-five adults (ADHD = 20, HC = 15) were grouped using self-report and collateral-report measures in addition to a semistructured clinical interview. All participants completed control conditions with minimal WM demands, and separate phonological (PH) and visuospatial (VS) WM tasks with recall demands ranging from four to seven stimuli. The ADHD group exhibited significantly more motor activity relative to the HC group, and both groups exhibited greater activity during PH and VS WM tasks, relative to control conditions. Finally, the central executive (CE) and PH storage/rehearsal subsystems were associated with large-magnitude between-group differences in activity. Findings suggest that increased demands on WM, particularly the CE and PH storage/rehearsal, contribute to ADHD-related hyperactivity, though a portion of excessive motor activity in adults with ADHD may occur independently of WM demands.

  13. Auditory-Motor Interactions in Pediatric Motor Speech Disorders: Neurocomputational Modeling of Disordered Development

    Science.gov (United States)

    Terband, H.; Maassen, B.; Guenther, F.H.; Brumberg, J.

    2014-01-01

    Background/Purpose Differentiating the symptom complex due to phonological-level disorders, speech delay and pediatric motor speech disorders is a controversial issue in the field of pediatric speech and language pathology. The present study investigated the developmental interaction between neurological deficits in auditory and motor processes using computational modeling with the DIVA model. Method In a series of computer simulations, we investigated the effect of a motor processing deficit alone (MPD), and the effect of a motor processing deficit in combination with an auditory processing deficit (MPD+APD) on the trajectory and endpoint of speech motor development in the DIVA model. Results Simulation results showed that a motor programming deficit predominantly leads to deterioration on the phonological level (phonemic mappings) when auditory self-monitoring is intact, and on the systemic level (systemic mapping) if auditory self-monitoring is impaired. Conclusions These findings suggest a close relation between quality of auditory self-monitoring and the involvement of phonological vs. motor processes in children with pediatric motor speech disorders. It is suggested that MPD+APD might be involved in typically apraxic speech output disorders and MPD in pediatric motor speech disorders that also have a phonological component. Possibilities to verify these hypotheses using empirical data collected from human subjects are discussed. PMID:24491630

  14. Etching of semiconductor cubic crystals: Determination of the dissolution slowness surfaces

    Science.gov (United States)

    Tellier, C. R.

    1990-03-01

    Equations of the representative surface of dissolution slowness for cubic crystals are determined in the framework of a tensorial approach of the orientation-dependent etching process. The independent dissolution constants are deduced from symmetry considerations. Using previous data on the chemical etching of germanium and gallium arsenide crystals, some possible polar diagrams of the dissolution slowness are proposed. A numerical and graphical simulation method is used to obtain the derived dissolution shapes. The influence of extrema in the dissolution slowness on the successive dissolution shapes is also examined. A graphical construction of limiting shapes of etched crystals appears possible using the tensorial representation of the dissolution slowness.

  15. Measuring the eyes of trilobites: a motorized goniometer for macropaleontology

    Energy Technology Data Exchange (ETDEWEB)

    Cowen, R.; Cooper, J.H.

    1985-01-01

    The geometry of the trilobite visual surface is important in studies of trilobite taxonomy, paleoecology, and evolution. Unfortunately, methods for measuring visual surface features have been slow and laborious. The authors have built an apparatus which allows rapid, reliable measurement of angular relationships on the trilobite cephalon. A specimen is mounted on a set of turntables rotated by steeper motors driven by impulses from a computer terminal. As the turntables are rotated, their angular displacements from zero are automatically recorded to a repeatable accuracy of less than half a degree. Thus the angular positions of lens axes, spines, glabella, and other important features can be recorded directly into the computer for further processing and graphics display. The authors apparatus was designed to study the eyes of phacopid-trilobites, for two reasons. First, the Phacops rana group of trilobites is one of the type examples of punctuated speciation. Second, it has been suggested that phacopids had stereoscopic vision in each eye. The new apparatus will allow rapid and accurate study of suites of specimens, in order to test these hypotheses. Their new apparatus, essentially a motorized goniometer, could be used or modified to work with any specimens in which rapid goniometric measurements are useful. Such applications could include routine morphometric studies of molluscan or brachiopod shells or echinoderm tests, as well as specific projects dealing with spines, pores, plates, or septa in a wide variety of fossil invertebrates.

  16. Electric motor handbook

    CERN Document Server

    Chalmers, B J

    2013-01-01

    Electric Motor Handbook aims to give practical knowledge in a wide range of capacities such as plant design, equipment specification, commissioning, operation and maintenance. The book covers topics such as the modeling of steady-state motor performance; polyphase induction, synchronous, and a.c. commutator motors; ambient conditions, enclosures, cooling and loss dissipation; and electrical supply systems and motor drives. Also covered are topics such as variable-speed drives and motor control; materials and motor components; insulation types, systems, and techniques; and the installation, sit

  17. KEK-IMSS Slow Positron Facility

    Energy Technology Data Exchange (ETDEWEB)

    Hyodo, T; Wada, K; Yagishita, A; Kosuge, T; Saito, Y; Kurihara, T; Kikuchi, T; Shirakawa, A; Sanami, T; Ikeda, M; Ohsawa, S; Kakihara, K; Shidara, T, E-mail: toshio.hyodo@kek.jp [High Energy Accelerator Research Organization (KEK) 1-1 Oho, Tsukuba, Ibaraki, 305-0801 (Japan)

    2011-12-01

    The Slow Positron Facility at the Institute of Material Structure Science (IMSS) of High Energy Accelerator Research Organization (KEK) is a user dedicated facility with an energy tunable (0.1 - 35 keV) slow positron beam produced by a dedicated 55MeV linac. The present beam line branches have been used for the positronium time-of-flight (Ps-TOF) measurements, the transmission positron microscope (TPM) and the photo-detachment of Ps negative ions (Ps{sup -}). During the year 2010, a reflection high-energy positron diffraction (RHEPD) measurement station is going to be installed. The slow positron generator (converter/ moderator) system will be modified to get a higher slow positron intensity, and a new user-friendly beam line power-supply control and vacuum monitoring system is being developed. Another plan for this year is the transfer of a {sup 22}Na-based slow positron beam from RIKEN. This machine will be used for the continuous slow positron beam applications and for the orientation training of those who are interested in beginning researches with a slow positron beam.

  18. Mathematical modeling of alignment dynamics in active motor-filament systems

    Science.gov (United States)

    Swaminathan, Sumanth

    The formation of the cytoskeleton, via motor-mediated microtubule self-organization, is an important subject of study in the biological sciences as well as in nonequilibrium, soft matter physics. Accurate modeling of the dynamics is a formidable task as it involves intrinsic nonlinearities, structural anisotropies, nonequilibrium processes, and a broad window of time scales, length scales, and densities. In this thesis, we study the ordering dynamics and pattern formations arising from motor-mediated microtubule self-organization in dilute and semi-dilute filament solutions. In the dilute case, we use a probabilistic model in which microtubules interact through motor induced, inelastic binary collisions. This model shows that initially disordered filament solutions exhibit an ordering transition resulting in the emergence of well aligned rod bundles. We study the existence and dynamic interaction of microtubule bundles analytically and numerically. Our results show a long term attraction and coalescing of bundles indicating a clear coarsening in the system; microtubule bundles concentrate into fewer orientations on a slow logarithmic time scale. In the semi-dilute case, multiple motors can bind a filament to several others and, for a critical motor density, induce a transition to an ordered state with a nonzero mean orientation. We develop a spatially homogeneous, mean-field theory that explicitly accounts for motor forcing and thermal fluctuations which enter into the model as multiplicative and additive noises respectively. Our model further incorporates a force-dependent detachment rate of motors, which in turn affects the mean and the fluctuations of the net force acting on a filament. We demonstrate that the transition to the oriented state changes from second order to first order when the force-dependent detachment becomes important. In our final analysis, we add complex spatial inhomogeneities to our mean field theory. The revised model consists of a system

  19. Motor fuels

    Energy Technology Data Exchange (ETDEWEB)

    1937-09-14

    The abstract describes a process for obtaining a maximum quantity of commercial gasoline from a composite hydrocarbon stream containing hydrocarbons within and below the gasoline boiling range including gaseous olefins. The hydrocarbon stream is separated into low vapor pressure gasoline and a gas fraction consisting of the 4 carbon atom group and possibly some of the 3 carbon atom group. The fraction is subjected to a polymerization process utilizing the products of the operation, both liquid polymers and unconverted gases to increase the yield of the gasoline and to adjust the low vapor pressure of the gasoline to the equivalent of that of commercial gasoline. A small fraction of the gaseous products are used for this purpose. The remainder are recycled through the polymerization operation.

  20. Crystal plastic earthquakes in dolostones: from slow to fast ruptures.

    Science.gov (United States)

    Passelegue, F. X.; Aubry, J.; Nicolas, A.; Fondriest, M.; Schubnel, A.; Di Toro, G.

    2017-12-01

    Dolostone is the most dominant lithology of the seismogenic upper crust around the Mediterranean Sea. Understanding the internal mechanisms controlling fault friction is crucial for understanding seismicity along active faults. Displacement in such fault zones is frequently highlighted by highly reflective (mirror-like) slip surfaces, created by thin films of nanogranular fault rock. Using saw-cut dolostone samples coming from natural fault zones, we conducted stick-slip experiments under triaxial loading conditions at 30, 60 and 90 MPa confining pressure and temperature ranging from 30 to 100 degrees C. At 30 and 65 degrees C, only slow rupture was observed and the experimental fault exhibits frictional behaviour, i.e. a dependence of normal stress on peak shear stress. At 65 degrees C, a strengthening behaviour is observed after the main rupture, leading to a succession of slow rupture. At 100 degrees C, the macroscopic behaviour of the fault becomes ductile, and no dependence of pressure on the peak shear stress is observed. In addition, the increase of the confining pressure up to 60 and 90 MPa allow the transition from slow to fast rupture, highlighted by the records of acoustic activity and by dynamic stress drop occurring in a few tens of microseconds. Using strain gages located along the fault surface and acoustic transducers, we were able to measure the rupture velocities during slow and fast rupture. Slow ruptures propagated around 0.1 m/s, in agreement with natural observations. Fast ruptures propagated up to supershear velocities, i.e. faster than the shear wave speed (>3500 m/s). A complete study of the microstructures was realized before and after ruptures. Slow ruptures lead to the production of mirror-like surface driven by the production of nanograins due to dislocation processes. Fast ruptures induce the production of amorphous material along the fault surface, which may come from decarbonation and melting processes. We demonstrate that the

  1. Handbook on linear motor application

    International Nuclear Information System (INIS)

    1988-10-01

    This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.

  2. Modeling and simulation for micro DC motor based on simulink

    Science.gov (United States)

    Shen, Hanxin; Lei, Qiao; Chen, Wenxiang

    2017-09-01

    The micro DC motor has a large market demand but there is a lack of theoretical research for it. Through detailed analysis of the commutation process of micro DC motor commutator, based on micro DC motor electromagnetic torque equation and mechanical torque equation, with the help of Simulink toolkit, a triangle connection micro DC motor simulation model is established. By using the model, a sample micro DC motor are simulated, and an experimental measurements has been carried on the sample micro DC motor. It is found that the simulation results are consistent with theoretical analysis and experimental results.

  3. Auditory-motor interactions in pediatric motor speech disorders: neurocomputational modeling of disordered development.

    Science.gov (United States)

    Terband, H; Maassen, B; Guenther, F H; Brumberg, J

    2014-01-01

    Differentiating the symptom complex due to phonological-level disorders, speech delay and pediatric motor speech disorders is a controversial issue in the field of pediatric speech and language pathology. The present study investigated the developmental interaction between neurological deficits in auditory and motor processes using computational modeling with the DIVA model. In a series of computer simulations, we investigated the effect of a motor processing deficit alone (MPD), and the effect of a motor processing deficit in combination with an auditory processing deficit (MPD+APD) on the trajectory and endpoint of speech motor development in the DIVA model. Simulation results showed that a motor programming deficit predominantly leads to deterioration on the phonological level (phonemic mappings) when auditory self-monitoring is intact, and on the systemic level (systemic mapping) if auditory self-monitoring is impaired. These findings suggest a close relation between quality of auditory self-monitoring and the involvement of phonological vs. motor processes in children with pediatric motor speech disorders. It is suggested that MPD+APD might be involved in typically apraxic speech output disorders and MPD in pediatric motor speech disorders that also have a phonological component. Possibilities to verify these hypotheses using empirical data collected from human subjects are discussed. The reader will be able to: (1) identify the difficulties in studying disordered speech motor development; (2) describe the differences in speech motor characteristics between SSD and subtype CAS; (3) describe the different types of learning that occur in the sensory-motor system during babbling and early speech acquisition; (4) identify the neural control subsystems involved in speech production; (5) describe the potential role of auditory self-monitoring in developmental speech disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. The cryogenic source of slow monochromatic positrons

    International Nuclear Information System (INIS)

    Meshkov, I.N.; Pavlov, V.N.; Sidorin, A.O.; Yakovenko, S.L.

    2008-01-01

    The cryogenic source of slow monochromatic positrons based on the 22 Na isotope has been designed and constructed at JINR. Positrons emitted from radioactive source 22 Na have a very broad energy spectrum up to 0.5 MeV. To generate monochromatic beam of slow positrons the solid neon is used as a moderator. The solid neon allows forming slow positron beam of the energy of 1.2 eV at the spectrum width of 1 eV. The efficiency of moderation is 1 % of total positron flux

  5. Dystonia Associated with Idiopathic Slow Orthostatic Tremor

    Directory of Open Access Journals (Sweden)

    Christopher Kobylecki

    2016-02-01

    Full Text Available Background: We aimed to characterize the clinical and electrophysiological features of patients with slow orthostatic tremor.Case Report: The clinical and neurophysiological data of patients referred for lower limb tremor on standing were reviewed. Patients with symptomatic or primary orthostatic tremor were excluded. Eight patients were identified with idiopathic slow 4–8 Hz orthostatic tremor, which was associated with tremor and dystonia in cervical and upper limb musculature. Coherence analysis in two patients showed findings different to those seen in primary orthostatic tremor.Discussion: Slow orthostatic tremor may be associated with dystonia and dystonic tremor.

  6. Revealing the cluster of slow transients behind a large slow slip event.

    Science.gov (United States)

    Frank, William B; Rousset, Baptiste; Lasserre, Cécile; Campillo, Michel

    2018-05-01

    Capable of reaching similar magnitudes to large megathrust earthquakes [ M w (moment magnitude) > 7], slow slip events play a major role in accommodating tectonic motion on plate boundaries through predominantly aseismic rupture. We demonstrate here that large slow slip events are a cluster of short-duration slow transients. Using a dense catalog of low-frequency earthquakes as a guide, we investigate the M w 7.5 slow slip event that occurred in 2006 along the subduction interface 40 km beneath Guerrero, Mexico. We show that while the long-period surface displacement, as recorded by Global Positioning System, suggests a 6-month duration, the motion in the direction of tectonic release only sporadically occurs over 55 days, and its surface signature is attenuated by rapid relocking of the plate interface. Our proposed description of slow slip as a cluster of slow transients forces us to re-evaluate our understanding of the physics and scaling of slow earthquakes.

  7. Motor learning as a criterion for evaluating coordination motor abilities

    Directory of Open Access Journals (Sweden)

    Boraczynski Tomasz

    2011-10-01

    Full Text Available The aim of the study was to evaluate the ability of motor learning based on objective, metric criteria, in terms of pedagogical process aimed at improving the accuracy of hits a golf ball to the target. A group of 77 students of physical education participated in the study. Within 8 months there were performed 11 measurement sessions. In each session, subjects performed 10 hits a golf ball to the target from a distance of 9 m. Accuracy of hits was recorded. Effect of motor learning has been demonstrated in the progress of 10 consecutive hits a golf ball to the target in each session (operational control; in the dynamics of performance improvement between sessions (current control; as well as in the total result of eight-month experiment (stage control. There were developed norms for quantitative and qualitative assessment of accuracy of hits a golf ball to the target. Developed quantitative and qualitative criteria for assessing the speed of motor learning in various conditions of the educational process creates the possibility of organization the operational, current and stage control of the level of human coordination motor abilities, as required by leading process.

  8. Slow feature analysis: unsupervised learning of invariances.

    Science.gov (United States)

    Wiskott, Laurenz; Sejnowski, Terrence J

    2002-04-01

    Invariant features of temporally varying signals are useful for analysis and classification. Slow feature analysis (SFA) is a new method for learning invariant or slowly varying features from a vectorial input signal. It is based on a nonlinear expansion of the input signal and application of principal component analysis to this expanded signal and its time derivative. It is guaranteed to find the optimal solution within a family of functions directly and can learn to extract a large number of decorrelated features, which are ordered by their degree of invariance. SFA can be applied hierarchically to process high-dimensional input signals and extract complex features. SFA is applied first to complex cell tuning properties based on simple cell output, including disparity and motion. Then more complicated input-output functions are learned by repeated application of SFA. Finally, a hierarchical network of SFA modules is presented as a simple model of the visual system. The same unstructured network can learn translation, size, rotation, contrast, or, to a lesser degree, illumination invariance for one-dimensional objects, depending on only the training stimulus. Surprisingly, only a few training objects suffice to achieve good generalization to new objects. The generated representation is suitable for object recognition. Performance degrades if the network is trained to learn multiple invariances simultaneously.

  9. Individual differences in motor timing and its relation to cognitive and fine motor skills.

    Directory of Open Access Journals (Sweden)

    Håvard Lorås

    Full Text Available The present study investigated the relationship between individual differences in timing movements at the level of milliseconds and performance on selected cognitive and fine motor skills. For this purpose, young adult participants (N = 100 performed a repetitive movement task paced by an auditory metronome at different rates. Psychometric measures included the digit-span and symbol search subtasks from the Wechsler battery as well as the Raven SPM. Fine motor skills were assessed with the Purdue Pegboard test. Motor timing performance was significantly related (mean r = .3 to cognitive measures, and explained both unique and shared variance with information-processing speed of Raven's scores. No significant relations were found between motor timing measures and fine motor skills. These results show that individual differences in cognitive and motor timing performance is to some extent dependent upon shared processing not associated with individual differences in manual dexterity.

  10. Motor Skill Learning and Corticospinal Excitability

    DEFF Research Database (Denmark)

    Christiansen, Lasse

    Background Motor skill learning (MSL) is the persistent increase in performance of a skill obtained through practice. This process is associated with changes throughout the central nervous system. One of these is a change in corticospinal excitability (CSE) assessable with Transcranial Magnetic...... a novel visuomotor skill. I hypothesized that changes in CSE accompanying long-term motor practice relate to the process of learning rather than repetitive practice on an acquired skill and investigated this by incrementally increasing task difficulty and thus postponing saturation of learning....... Furthermore, we aimed to investigate the feasibility of applying paired associative stimulation to the investigation of learning-dependent motor cortical plasticity by comparing the transient increase in CSE accompanying motor skill learning to the associative plasticity induced by pairing electrical motor...

  11. Interacting adiabatic quantum motor

    Science.gov (United States)

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

    2018-05-01

    We present a field-theoretic treatment of an adiabatic quantum motor. We explicitly discuss a motor called the Thouless motor which is based on a Thouless pump operating in reverse. When a sliding periodic potential is considered to be the motor degree of freedom, a bias voltage applied to the electron channel sets the motor in motion. We investigate a Thouless motor whose electron channel is modeled as a Luttinger liquid. Interactions increase the gap opened by the periodic potential. For an infinite Luttinger liquid the coupling-induced friction is enhanced by electron-electron interactions. When the Luttinger liquid is ultimately coupled to Fermi liquid reservoirs, the dissipation reduces to its value for a noninteracting electron system for a constant motor velocity. Our results can also be applied to a motor based on a nanomagnet coupled to a quantum spin Hall edge.

  12. Chronic motor tic disorder

    Science.gov (United States)

    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 ...

  13. Motor cortical representation of the pelvic floor muscles.

    Science.gov (United States)

    Schrum, A; Wolff, S; van der Horst, C; Kuhtz-Buschbeck, J P

    2011-07-01

    Pelvic floor muscle training involves rhythmical voluntary contractions of the external urethral sphincter and ancillary pelvic floor muscles. The representation of these muscles in the motor cortex has not been located precisely and unambiguously. We used functional magnetic resonance imaging to determine brain activity during slow and fast pelvic floor contractions. Cerebral responses were recorded in 17 healthy male volunteers, 21 to 47 years old, with normal bladder control. Functional magnetic resonance imaging was performed during metronome paced slow (0.25 Hertz) and fast (0.7 Hertz) contractions of the pelvic floor that mimicked the interruption of voiding. To study the somatotopy of the cortical representations, flexion-extension movements of the right toes were performed as a control task. Functional magnetic resonance imaging during pelvic floor contractions detected activity of the supplementary motor area in the medial wall and of the midcingulate cortex, insula, posterior parietal cortex, putamen, thalamus, cerebellar vermis and upper ventral pons. There were no significant differences in activation between slow and fast contractions. Toe movements involved significantly stronger activity of the paracentral lobule (ie the medial primary motor cortex) than did the pelvic floor contractions. Otherwise the areas active during pelvic floor and leg muscle contractions overlapped considerably. The motor cortical representation of pelvic floor muscles is located mostly in the supplementary motor area. It extends further ventrally and anteriorly than the representation of distal leg muscles. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  14. Piezoelectric Motors, an Overview

    OpenAIRE

    Karl Spanner; Burhanettin Koc

    2016-01-01

    Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ult...

  15. TMS-induced cortical potentiation during wakefulness locally increases slow wave activity during sleep.

    Directory of Open Access Journals (Sweden)

    Reto Huber

    2007-03-01

    Full Text Available Sleep slow wave activity (SWA is thought to reflect sleep need, increasing in proportion to the length of prior wakefulness and decreasing during sleep. However, the process responsible for SWA regulation is not known. We showed recently that SWA increases locally after a learning task involving a circumscribed brain region, suggesting that SWA may reflect plastic changes triggered by learning.To test this hypothesis directly, we used transcranial magnetic stimulation (TMS in conjunction with high-density EEG in humans. We show that 5-Hz TMS applied to motor cortex induces a localized potentiation of TMS-evoked cortical EEG responses. We then show that, in the sleep episode following 5-Hz TMS, SWA increases markedly (+39.1+/-17.4%, p<0.01, n = 10. Electrode coregistration with magnetic resonance images localized the increase in SWA to the same premotor site as the maximum TMS-induced potentiation during wakefulness. Moreover, the magnitude of potentiation during wakefulness predicts the local increase in SWA during sleep.These results provide direct evidence for a link between plastic changes and the local regulation of sleep need.

  16. Slow and Fast Light, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to the NASA Small Business Innovation Research (SBIR) Program 2015 Phase I Solicitation S3.08: Slow and Fast Light, Torch Technologies in partnership...

  17. Experimental demonstration of spinor slow light

    Science.gov (United States)

    Lee, Meng-Jung; Ruseckas, Julius; Lee, Chin-Yuan; Kudriašov, Viačeslav; Chang, Kao-Fang; Cho, Hung-Wen; JuzeliÅ«nas, Gediminas; Yu, Ite A.

    2016-03-01

    Over the last decade there has been a continuing interest in slow and stored light based on the electromagnetically induced transparency (EIT) effect, because of their potential applications in quantum information manipulation. However, previous experimental works all dealt with the single-component slow light which cannot be employed as a qubit. In this work, we report the first experimental demonstration of two-component or spinor slow light (SSL) using a double tripod (DT) atom-light coupling scheme. The oscillations between the two components, similar to the Rabi oscillation of a two-level system or a qubit, were observed. Single-photon SSL can be considered as two-color qubits. We experimentally demonstrated a possible application of the DT scheme as quantum memory and quantum rotator for the two-color qubits. This work opens up a new direction in the slow light research.

  18. Elastic scattering of slow positrons by helium

    International Nuclear Information System (INIS)

    Amusia, M.Ya.; Cherepkov, N.A.; Chernysheva, L.V.; Shapiro, S.G.

    1976-01-01

    The s-, p-, d- and f-wave phaseshifts for elastic scattering of slow positrons by He are calculated using a simplified version of the random phase approximation with exchange, with virtual positronium formation effect taken into account. (author)

  19. A tilted transversely isotropic slowness surface approximation

    KAUST Repository

    Stovas, A.; Alkhalifah, Tariq Ali

    2012-01-01

    for the vertical slowness that is highly accurate for all practical purposes. It also reveals some insights into the anisotropy parameter dependency of the dispersion relation including the low impact that the anelliptic parameter has on the vertical placement

  20. Formation of Heliospheric Arcs of Slow Solar Wind

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, A. K.; Zurbuchen, T. H. [Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Antiochos, S. K.; DeVore, C. R. [Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Wyper, P. F., E-mail: aleida@umich.edu [Department of Mathematical Sciences, Durham University, Durham DH1 3LE (United Kingdom)

    2017-05-01

    A major challenge in solar and heliospheric physics is understanding the origin and nature of the so-called slow solar wind. The Sun’s atmosphere is divided into magnetically open regions, known as coronal holes, where the plasma streams out freely and fills the solar system, and closed regions, where the plasma is confined to coronal loops. The boundary between these regions extends outward as the heliospheric current sheet (HCS). Measurements of plasma composition strongly imply that much of the slow wind consists of plasma from the closed corona that escapes onto open field lines, presumably by field-line opening or by interchange reconnection. Both of these processes are expected to release closed-field plasma into the solar wind within and immediately adjacent to the HCS. Mysteriously, however, slow wind with closed-field plasma composition is often observed in situ far from the HCS. We use high-resolution, three-dimensional, magnetohydrodynamic simulations to calculate the dynamics of a coronal hole with a geometry that includes a narrow corridor flanked by closed field and is driven by supergranule-like flows at the coronal-hole boundary. These dynamics produce giant arcs of closed-field plasma that originate at the open-closed boundary in the corona, but extend far from the HCS and span tens of degrees in latitude and longitude at Earth. We conclude that such structures can account for the long-puzzling slow-wind observations.

  1. Slow oscillations orchestrating fast oscillations and memory consolidation.

    Science.gov (United States)

    Mölle, Matthias; Born, Jan

    2011-01-01

    Slow-wave sleep (SWS) facilitates the consolidation of hippocampus-dependent declarative memory. Based on the standard two-stage memory model, we propose that memory consolidation during SWS represents a process of system consolidation which is orchestrated by the neocortical memory. The slow oscillations temporally group neuronal activity into up-states of strongly enhanced neuronal activity and down-states of neuronal silence. In a feed-forward efferent action, this grouping is induced not only in the neocortex but also in other structures relevant to consolidation, namely the thalamus generating 10-15Hz spindles, and the hippocampus generating sharp wave-ripples, with the latter well known to accompany a replay of newly encoded memories taking place in hippocampal circuitries. The feed-forward synchronizing effect of the slow oscillation enables the formation of spindle-ripple events where ripples and accompanying reactivated hippocampal memory information become nested into the single troughs of spindles. Spindle-ripple events thus enable reactivated memory-related hippocampal information to be fed back to neocortical networks in the excitable slow oscillation up-state where they can induce enduring plastic synaptic changes underlying the effective formation of long-term memories. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Electric Motor Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

  3. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    is dismantled in order to cast a spot- light on the individual engine com- ponents. This means that an ob- ject (the engine) is removed from its original functionality and deter- mined context and staged as an aes- thetic object via a new contextual relationship being resolved. The de- contextualisation...... something original and genuine that decisively challenges the limits of the field of architecture. This un- derstanding is important if students are to avoid mimicking an existing world of imagery in architecture or fragments of it. The point of departure for the MO- TOR assignment is that a car engine...... is dependent on a reading and analysis of the formal characteristics of the engine com- ponent. This is crucial if the staging process is to succeed....

  4. Visual-motor integration functioning in a South African middle ...

    African Journals Online (AJOL)

    Visual-motor integration functioning has been identified as playing an integral role in different aspects of a child's development. Sensory-motor development is not only foundational to the physical maturation process, but is also imperative for progress with formal learning activities. Deficits in visual-motor integration have ...

  5. Slow potentials in a melody recognition task.

    Science.gov (United States)

    Verleger, R; Schellberg, D

    1990-01-01

    In a previous study, slow negative shifts were found in the EEG of subjects listening to well-known melodies. The two experiments reported here were designed to investigate the variables to which these slow potentials are related. In the first experiment, two opposite hypotheses were tested: The slow shifts might express subjects' acquaintance with the melodies or, on the contrary, the effort invested to identify them. To this end, some of the melodies were presented in the rhythms of other melodies to make recognition more difficult. Further, melodies rated as very well-known and as very unknown were analysed separately. However, the slow shifts were not affected by these experimental variations. Therefore in the second experiment, on the one hand the purely physical parameters intensity and duration were varied, but this variation had no impact on the slow shifts either. On the other hand, recognition was made more difficult by monotonously repeating the pitch of the 4th tone for the rest of some melodies. The slow negative shifts were enhanced with these monotonous melodies. This enhancement supports the "effort" hypothesis. Accordingly, the ofter shifts obtained in both experiments might likewise reflect effort. But since the task was not demanding, it is suggested that these constant shifts reflect the effort invested for coping with the entire underarousing situation rather than with the task. Frequently, slow eye movements occurred in the same time range as the slow potentials, resulting in EOG potentials spreading to the EEG recording sites. Yet results did not change substantially when the EEG recordings were corrected for the influence of EOG potentials.

  6. Overall concepts for utilisation of slow pyrolysis products - Hidaspyro II

    Energy Technology Data Exchange (ETDEWEB)

    Fagernas, L. [VTT Technical Research Centre of Finland, Espoo (Finland)], email: leena.fagernas@vtt.fi

    2012-07-01

    Slow pyrolysis is a promising technology to produce biochar (charcoal), distillates and gases for various purposes. However, scientific results on the effects of distillates and biochar on soil improvement are lacking, process conditions to produce biochar of good quality and optimal distillates are not known, and non-existence of environmental risks has to be proved prior to commercialization of the products. The goal is an optimised slow pyrolysis process for new applications of the products. The research carried out in the project Hidaspyro will be continued. The objectives are to determine the effect of biochar and distillates on growth of plants, soil improvement, and odour prevention; to define the quality criteria of biochar in plant production; and to assess the ecotoxicological and environmental impacts of the products.

  7. Motor assessment in Parkinson`s disease.

    Science.gov (United States)

    Opara, Józef; Małecki, Andrzej; Małecka, Elżbieta; Socha, Teresa

    2017-09-21

    Parkinson's disease (PD) is one of most disabling disorders of the central nervous system. The motor symptoms of Parkinson's disease: shaking, rigidity, slowness of movement, postural instability and difficulty with walking and gait, are difficult to measure. When disease symptoms become more pronounced, the patient experiences difficulties with hand function and walking, and is prone to falls. Baseline motor impairment and cognitive impairment are probable predictors of more rapid motor decline and disability. An additional difficulty is the variability of the symptoms caused by adverse effects of drugs, especially levodopa. Motor assessment of Parkinson`s Disease can be divided into clinimetrics, assessment of balance and posture, arm and hand function, and gait/walking. These are many clinimetric scales used in Parkinson`s Disease, the most popular being the Hoehn and Yahr stages of progression of the disease and Unified Parkinson's Disease Rating Scale. Balance and posture can be assessed by clinimetric scales like the Berg BS, Tinetti, Brunel BA, and Timed Up and Go Test, or measured by posturometric platforms. Among skill tests, the best known are: the Purdue Pegboard Test, Nine-Hole Peg Test, Jebsen and Taylor test, Pig- Tail Test, Frenchay Arm Test, Action Research Arm Test, Wolf FMT and Finger-Tapping Test. Among motricity scales, the most popular are: the Fugl-Meyer Motor Assessment Scale and Södring Motor Evaluation. Gait and walking can also be assessed quantitatively and qualitatively. Recently, the most popular is three-dimensional analysis of movement. This review article presents the current possibilities of motor assessment in Parkinson`s disease.

  8. New insights into the interface between a single-crystalline metal electrode and an extremely pure ionic liquid: slow interfacial processes and the influence of temperature on interfacial dynamics.

    Science.gov (United States)

    Drüschler, Marcel; Borisenko, Natalia; Wallauer, Jens; Winter, Christian; Huber, Benedikt; Endres, Frank; Roling, Bernhard

    2012-04-21

    Ionic liquids are of high interest for the development of safe electrolytes in modern electrochemical cells, such as batteries, supercapacitors and dye-sensitised solar cells. However, electrochemical applications of ionic liquids are still hindered by the limited understanding of the interface between electrode materials and ionic liquids. In this article, we first review the state of the art in both experiment and theory. Then we illustrate some general trends by taking the interface between the extremely pure ionic liquid 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate and an Au(111) electrode as an example. For the study of this interface, electrochemical impedance spectroscopy was combined with in situ STM and in situ AFM techniques. In addition, we present new results for the temperature dependence of the interfacial capacitance and dynamics. Since the interfacial dynamics are characterised by different processes taking place on different time scales, the temperature dependence of the dynamics can only be reliably studied by recording and carefully analysing broadband capacitance spectra. Single-frequency experiments may lead to artefacts in the temperature dependence of the interfacial capacitance. We demonstrate that the fast capacitive process exhibits a Vogel-Fulcher-Tamman temperature dependence, since its time scale is governed by the ionic conductivity of the ionic liquid. In contrast, the slower capacitive process appears to be Arrhenius activated. This suggests that the time scale of this process is determined by a temperature-independent barrier, which may be related to structural reorganisations of the Au surface and/or to charge redistributions in the strongly bound innermost ion layer. This journal is © the Owner Societies 2012

  9. Slow wave activity and slow oscillations in sleepwalkers and controls: effects of 38 h of sleep deprivation.

    Science.gov (United States)

    Perrault, Rosemarie; Carrier, Julie; Desautels, Alex; Montplaisir, Jacques; Zadra, Antonio

    2013-08-01

    Sleepwalkers have been shown to have an unusually high number of arousals from slow wave sleep and lower slow wave activity (SWA) power during the night than controls. Because sleep deprivation increases the frequency of slow wave sleep (SWS) arousals in sleepwalkers, it may also affect the expression of the homeostatic process to a greater extent than shown previously. We thus investigated SWA power as well as slow wave oscillation (SWO) density in 10 sleepwalkers and nine controls at baseline and following 38 h of sleep deprivation. There was a significant increase in SWA during participants' recovery sleep, especially during their second non-rapid eye movement (NREM) period. SWO density was similarly increased during recovery sleep's first two NREM periods. A fronto-central gradient in SWA and SWO was also present on both nights. However, no group differences were noted on any of the 2 nights on SWA or SWO. This unexpected result may be related to the heterogeneity of sleepwalkers as a population, as well as our small sample size. SWA pressure after extended sleep deprivation may also result in a ceiling effect in both sleepwalkers and controls. © 2013 European Sleep Research Society.

  10. Motor/generator

    Science.gov (United States)

    Hickam, Christopher Dale [Glasford, IL

    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.

  11. Slow manifolds in chemical kinetics

    International Nuclear Information System (INIS)

    Shahzad, M.; Haq, I. U.; Sultan, F.; Wahab, A.; Faizullah, F.; Rahman, G. U.

    2016-01-01

    Modelling the chemical system, especially for complex and higher dimensional problems, gives an easy way to handle the ongoing reaction process with respect to time. Here, we will consider some of the newly developed computational methods commonly used for model reductions in a chemical reaction. An effective (simple) method is planned to measure the low dimensional manifold, which reduces the higher dimensional system in such a way that it may not affect the precision of the whole mechanism. The phase flow of the solution trajectories near the equilibrium point is observed while the initial approximation is measured with the spectral quasi equilibrium manifold, which starts from the equilibrium point. To make it an invariant curve, the approximated curve is first refined a certain number of times using the method of invariant grids. The other way of getting the reduced data in the low dimensional manifold is possible through the intrinsic low dimensional manifold. Then, we compare these two invariant curves given by both the methods. Finally, the idea is extended to the higher dimensional manifold, where more number of progress variables will be added. (author)

  12. Slow-tonic muscle fibers and their potential innervation in the turtle, Pseudemys (Trachemys) scripta elegans.

    Science.gov (United States)

    Callister, Robert J; Pierce, Patricia A; McDonagh, Jennifer C; Stuart, Douglas G

    2005-04-01

    A description is provided of the ratio of slow-tonic vs. slow- and fast-twitch fibers for five muscles in the adult turtle, Pseudemys (Trachemys) scripta elegans. The cross-sectional area of each fiber type and an estimation of the relative (weighted) cross-sectional area occupied by the different fiber types are also provided. Two hindlimb muscles (flexor digitorum longus, FDL; external gastrocnemius, EG) were selected on the basis of their suitability for future motor-unit studies. Three neck muscles (the fourth head of testo-cervicis, TeC4; the fourth head of retrahens capitus collique, RCCQ4; transversalis cervicis, TrC) were chosen for their progressively decreasing oxidative capacity. Serial sections were stained for myosin adenosine triphosphatase (ATPase), NADH-diaphorase, and alpha-glycerophosphate dehydrogenase (alpha-GPDH). Conventional fiber-type classification was then performed using indirect markers for contraction speed and oxidative (aerobic) vs. glycolytic (anaerobic) metabolism: i.e., slow oxidative (SO, including slow-twitch and possibly slow-tonic fibers), fast-twitch, oxidative-glycolytic (FOG), and fast-twitch glycolytic (Fg) fibers. Slow-tonic fibers in the SO class were then revealed by directing the monoclonal antibody, ALD-58 (raised against the slow-tonic fiber myosin heavy chain of chicken anterior latissimus dorsi), to additional muscle cross sections. All five of the tested muscles contained the four fiber types, with the ATPase-stained fibers including both slow-tonic and slow-twitch fibers. The extreme distributions of SO fibers were in the predominately glycolytic TrC vs. the predominately oxidative TeC4 muscle (TrC-SO, 9%; FOG, 20%; Fg, 71% vs. TeC4-SO, 58%: FOG, 16%; Fg, 25%). Across the five muscles, the relative prevalence of slow-tonic fibers (4-47%) paralleled that of the SO fibers (9-58%). TeC4 had the highest prevalence of slow-tonic fibers (47%). The test muscles exhibited varying degrees of regional concentration of each

  13. Piezoelectric Motors, an Overview

    Directory of Open Access Journals (Sweden)

    Karl Spanner

    2016-02-01

    Full Text Available Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ultrasonic motors, inertia-drive, and piezo-walk-drive. In this review, a comprehensive summary of piezoelectric motors, with their classification from initial idea to recent progress, is presented. This review also includes some of the industrial and commercial applications of piezoelectric motors that are presently available in the market as actuators.

  14. Motor degradation prediction methods

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Neuroplasticity & Motor Learning

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye

    Practice of a new motor task is usually associated with an improvement in performance. Indeed, if we stop practicing and return the next day to the same task, we find that our performance has been maintained and may even be better than it was at the start of the first day. This improvement...... is a measure of our ability to form and store a motor memory of the task. However, the initial memory of the task is labile and may be subject to interference. During and following motor learning plastic changes occur within the central nervous system. On one hand these changes are driven by motor practice......, on the other hand the changes underlie the formation of motor memory and the retention of improved motor performance. During motor learning changes may occur at many different levels within the central nervous system dependent on the type of task and training. Here, we demonstrate different studies from our...

  16. Characteristics of broadband slow earthquakes explained by a Brownian model

    Science.gov (United States)

    Ide, S.; Takeo, A.

    2017-12-01

    Brownian slow earthquake (BSE) model (Ide, 2008; 2010) is a stochastic model for the temporal change of seismic moment release by slow earthquakes, which can be considered as a broadband phenomena including tectonic tremors, low frequency earthquakes, and very low frequency (VLF) earthquakes in the seismological frequency range, and slow slip events in geodetic range. Although the concept of broadband slow earthquake may not have been widely accepted, most of recent observations are consistent with this concept. Then, we review the characteristics of slow earthquakes and how they are explained by BSE model. In BSE model, the characteristic size of slow earthquake source is represented by a random variable, changed by a Gaussian fluctuation added at every time step. The model also includes a time constant, which divides the model behavior into short- and long-time regimes. In nature, the time constant corresponds to the spatial limit of tremor/SSE zone. In the long-time regime, the seismic moment rate is constant, which explains the moment-duration scaling law (Ide et al., 2007). For a shorter duration, the moment rate increases with size, as often observed for VLF earthquakes (Ide et al., 2008). The ratio between seismic energy and seismic moment is constant, as shown in Japan, Cascadia, and Mexico (Maury et al., 2017). The moment rate spectrum has a section of -1 slope, limited by two frequencies corresponding to the above time constant and the time increment of the stochastic process. Such broadband spectra have been observed for slow earthquakes near the trench axis (Kaneko et al., 2017). This spectrum also explains why we can obtain VLF signals by stacking broadband seismograms relative to tremor occurrence (e.g., Takeo et al., 2010; Ide and Yabe, 2014). The fluctuation in BSE model can be non-Gaussian, as far as the variance is finite, as supported by the central limit theorem. Recent observations suggest that tremors and LFEs are spatially characteristic

  17. Slow brushing reduces heat pain in humans.

    Science.gov (United States)

    Liljencrantz, J; Strigo, I; Ellingsen, D M; Krämer, H H; Lundblad, L C; Nagi, S S; Leknes, S; Olausson, H

    2017-08-01

    C-tactile (CT) afferents are unmyelinated low-threshold mechanoreceptors optimized for signalling affective, gentle touch. In three separate psychophysical experiments, we examined the contribution of CT afferents to pain modulation. In total, 44 healthy volunteers experienced heat pain and CT optimal (slow brushing) and CT sub-optimal (fast brushing or vibration) stimuli. Three different experimental paradigms were used: Concurrent application of heat pain and tactile (slow brushing or vibration) stimulation; Slow brushing, applied for variable duration and intervals, preceding heat pain; Slow versus fast brushing preceding heat pain. Slow brushing was effective in reducing pain, whereas fast brushing or vibration was not. The reduction in pain was significant not only when the CT optimal touch was applied simultaneously with the painful stimulus but also when the two stimuli were separated in time. For subsequent stimulation, the pain reduction was more pronounced for a shorter time interval between brushing and pain. Likewise, the effect was more robust when pain was preceded by a longer duration of brush stimulation. Strong CT-related pain reduction was associated with low anxiety and high calmness scores obtained by a state anxiety questionnaire. Slow brushing - optimal for CT activation - is effective in reducing pain from cutaneous heating. The precise mechanisms for the pain relief are as yet unknown but possible mechanisms include inhibition of nociceptive projection neurons at the level of the dorsal horn as well as analgesia through cortical mechanisms. Slow brushing stimuli - optimal for activation of C-tactile fibres - can reduce pain from cutaneous heating. No such effect was seen with fast brushing or vibration. These observations indicate the role of C-tactile fibres in pain modulation. © 2017 European Pain Federation - EFIC®.

  18. Information slows down hierarchy growth.

    Science.gov (United States)

    Czaplicka, Agnieszka; Suchecki, Krzysztof; Miñano, Borja; Trias, Miquel; Hołyst, Janusz A

    2014-06-01

    We consider models of growing multilevel systems wherein the growth process is driven by rules of tournament selection. A system can be conceived as an evolving tree with a new node being attached to a contestant node at the best hierarchy level (a level nearest to the tree root). The proposed evolution reflects limited information on system properties available to new nodes. It can also be expressed in terms of population dynamics. Two models are considered: a constant tournament (CT) model wherein the number of tournament participants is constant throughout system evolution, and a proportional tournament (PT) model where this number increases proportionally to the growing size of the system itself. The results of analytical calculations based on a rate equation fit well to numerical simulations for both models. In the CT model all hierarchy levels emerge, but the birth time of a consecutive hierarchy level increases exponentially or faster for each new level. The number of nodes at the first hierarchy level grows logarithmically in time, while the size of the last, "worst" hierarchy level oscillates quasi-log-periodically. In the PT model, the occupations of the first two hierarchy levels increase linearly, but worse hierarchy levels either do not emerge at all or appear only by chance in the early stage of system evolution to further stop growing at all. The results allow us to conclude that information available to each new node in tournament dynamics restrains the emergence of new hierarchy levels and that it is the absolute amount of information, not relative, which governs such behavior.

  19. Information slows down hierarchy growth

    Science.gov (United States)

    Czaplicka, Agnieszka; Suchecki, Krzysztof; Miñano, Borja; Trias, Miquel; Hołyst, Janusz A.

    2014-06-01

    We consider models of growing multilevel systems wherein the growth process is driven by rules of tournament selection. A system can be conceived as an evolving tree with a new node being attached to a contestant node at the best hierarchy level (a level nearest to the tree root). The proposed evolution reflects limited information on system properties available to new nodes. It can also be expressed in terms of population dynamics. Two models are considered: a constant tournament (CT) model wherein the number of tournament participants is constant throughout system evolution, and a proportional tournament (PT) model where this number increases proportionally to the growing size of the system itself. The results of analytical calculations based on a rate equation fit well to numerical simulations for both models. In the CT model all hierarchy levels emerge, but the birth time of a consecutive hierarchy level increases exponentially or faster for each new level. The number of nodes at the first hierarchy level grows logarithmically in time, while the size of the last, "worst" hierarchy level oscillates quasi-log-periodically. In the PT model, the occupations of the first two hierarchy levels increase linearly, but worse hierarchy levels either do not emerge at all or appear only by chance in the early stage of system evolution to further stop growing at all. The results allow us to conclude that information available to each new node in tournament dynamics restrains the emergence of new hierarchy levels and that it is the absolute amount of information, not relative, which governs such behavior.

  20. Motor proteins and molecular motors: how to operate machines at the nanoscale

    International Nuclear Information System (INIS)

    Kolomeisky, Anatoly B

    2013-01-01

    Several classes of biological molecules that transform chemical energy into mechanical work are known as motor proteins or molecular motors. These nanometer-sized machines operate in noisy stochastic isothermal environments, strongly supporting fundamental cellular processes such as the transfer of genetic information, transport, organization and functioning. In the past two decades motor proteins have become a subject of intense research efforts, aimed at uncovering the fundamental principles and mechanisms of molecular motor dynamics. In this review, we critically discuss recent progress in experimental and theoretical studies on motor proteins. Our focus is on analyzing fundamental concepts and ideas that have been utilized to explain the non-equilibrium nature and mechanisms of molecular motors. (topical review)

  1. Slow electron contribution to inelastic reflection anisotropy

    International Nuclear Information System (INIS)

    Podsvirov, O.A.; Kuznetsov, Yu.A.

    1980-01-01

    Investigated is electron contribution with low energy (up to 1 keV) to the anisotropy of electron inelastic reflection (IRE) from silicon monocrystal (111) within 12-50 keV energy range of primary electrons. Experimental data on IRE anisotropy are presented: delay curves for silicon monocrystal, permitting to separate electrons with the energy up to 1 keV, dependences of IRE anisotropy on the energy of primary electrons for the systems - monocrystalline silicon-amorphous silicon film and delay curves for such systems (film thickness varies from 20 to 2000 A). Suggested is a phenomenologic model, permitting to take into account the contribution of slow electrons to IRE anisotropy: it is supposed, that three groups of electrons take part in the formation of the latter: elastic and inelastic reflected electrons, slow electrons, excited by primary electrons and slow electrons, generated by the reverse flow of the scattered electrons. Contribution of electrons, different by origin, to IRE anisotropy is evaluated in accordance with the experimental data on the basis of this model. It is stated, that slow electrons constitute approximately one half of the IRE anisotropy value, the contribution of both groups of slow electrons being approximately equal

  2. Magnon inflation: slow roll with steep potentials

    Energy Technology Data Exchange (ETDEWEB)

    Adshead, Peter [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, IL 61801 (United States); Blas, Diego [Theoretical Physics Department, CERN,CH-1211 Geneva 23 (Switzerland); Burgess, C.P.; Hayman, Peter [Physics & Astronomy, McMaster University,Hamilton, ON, L8S 4M1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Patil, Subodh P. [Department of Theoretical Physics, University of Geneva,24 Quai Ansermet, Geneva, CH-1211 (Switzerland)

    2016-11-04

    We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy G{sup ab}∂{sub a}V∂{sub b}V≪V{sup 2}/M{sub p}{sup 2} (where G{sub ab} is the target-space metric). They evade the usual slow-roll conditions on V because their kinetic energies are dominated by single-derivative terms rather than the usual two-derivative terms. Single derivatives dominate during slow roll and so do not require a breakdown of the usual derivative expansion that underpins calculational control in much of cosmology. The presence of such terms requires some sort of UV Lorentz-symmetry breaking during inflation (besides the usual cosmological breaking). Chromo-natural inflation provides one particular example of a UV theory that can generate the multi-field single-derivative terms we consider, and we argue that the EFT we find indeed captures the slow-roll conditions for its background evolution. We also show that our EFT can be understood as a multi-field generalization of the single-field Cuscuton models. The multi-field case introduces a new feature, however: the scalar kinetic terms define a target-space 2-form, F{sub ab}, whose antisymmetry gives new ways for slow roll to be achieved.

  3. Magnon Inflation: Slow Roll with Steep Potentials

    CERN Document Server

    Adshead, Peter; Burgess, C P; Hayman, Peter; Patil, Subodh P

    2016-01-01

    We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy the usual slow-roll condition (d V)^2 << V^2/Mp^2. They evade the usual slow-roll conditions on $V$ because their kinetic energies are dominated by single-derivative terms rather than the usual two-derivative terms. Single derivatives dominate during slow roll and so do not require a breakdown of the usual derivative expansion that underpins calculational control in much of cosmology. The presence of such terms requires some sort of UV Lorentz-symmetry breaking during inflation (besides the usual cosmological breaking). Chromo-natural inflation provides an example of a UV theory that can generate the multi-field single-derivative terms we consider, and we argue that the EFT we find indeed captures the slow-roll conditions for the background evolution for Chromo-natural inflation. We also show that our EFT can be understood as a multi-field generalization ...

  4. The Roles of Cortical Slow Waves in Synaptic Plasticity and Memory Consolidation.

    Science.gov (United States)

    Miyamoto, Daisuke; Hirai, Daichi; Murayama, Masanori

    2017-01-01

    Sleep plays important roles in sensory and motor memory consolidation. Sleep oscillations, reflecting neural population activity, involve the reactivation of learning-related neurons and regulate synaptic strength and, thereby affect memory consolidation. Among sleep oscillations, slow waves (0.5-4 Hz) are closely associated with memory consolidation. For example, slow-wave power is regulated in an experience-dependent manner and correlates with acquired memory. Furthermore, manipulating slow waves can enhance or impair memory consolidation. During slow wave sleep, inter-areal interactions between the cortex and hippocampus (HC) have been proposed to consolidate declarative memory; however, interactions for non-declarative (HC-independent) memory remain largely uninvestigated. We recently showed that the directional influence in a slow-wave range through a top-down cortical long-range circuit is involved in the consolidation of non-declarative memory. At the synaptic level, the average cortical synaptic strength is known to be potentiated during wakefulness and depressed during sleep. Moreover, learning causes plasticity in a subset of synapses, allocating memory to them. Sleep may help to differentiate synaptic strength between allocated and non-allocated synapses (i.e., improving the signal-to-noise ratio, which may facilitate memory consolidation). Herein, we offer perspectives on inter-areal interactions and synaptic plasticity for memory consolidation during sleep.

  5. The Roles of Cortical Slow Waves in Synaptic Plasticity and Memory Consolidation

    Directory of Open Access Journals (Sweden)

    Daisuke Miyamoto

    2017-11-01

    Full Text Available Sleep plays important roles in sensory and motor memory consolidation. Sleep oscillations, reflecting neural population activity, involve the reactivation of learning-related neurons and regulate synaptic strength and, thereby affect memory consolidation. Among sleep oscillations, slow waves (0.5–4 Hz are closely associated with memory consolidation. For example, slow-wave power is regulated in an experience-dependent manner and correlates with acquired memory. Furthermore, manipulating slow waves can enhance or impair memory consolidation. During slow wave sleep, inter-areal interactions between the cortex and hippocampus (HC have been proposed to consolidate declarative memory; however, interactions for non-declarative (HC-independent memory remain largely uninvestigated. We recently showed that the directional influence in a slow-wave range through a top-down cortical long-range circuit is involved in the consolidation of non-declarative memory. At the synaptic level, the average cortical synaptic strength is known to be potentiated during wakefulness and depressed during sleep. Moreover, learning causes plasticity in a subset of synapses, allocating memory to them. Sleep may help to differentiate synaptic strength between allocated and non-allocated synapses (i.e., improving the signal-to-noise ratio, which may facilitate memory consolidation. Herein, we offer perspectives on inter-areal interactions and synaptic plasticity for memory consolidation during sleep.

  6. Stochastic dynamic modeling of regular and slow earthquakes

    Science.gov (United States)

    Aso, N.; Ando, R.; Ide, S.

    2017-12-01

    Both regular and slow earthquakes are slip phenomena on plate boundaries and are simulated by a (quasi-)dynamic modeling [Liu and Rice, 2005]. In these numerical simulations, spatial heterogeneity is usually considered not only for explaining real physical properties but also for evaluating the stability of the calculations or the sensitivity of the results on the condition. However, even though we discretize the model space with small grids, heterogeneity at smaller scales than the grid size is not considered in the models with deterministic governing equations. To evaluate the effect of heterogeneity at the smaller scales we need to consider stochastic interactions between slip and stress in a dynamic modeling. Tidal stress is known to trigger or affect both regular and slow earthquakes [Yabe et al., 2015; Ide et al., 2016], and such an external force with fluctuation can also be considered as a stochastic external force. A healing process of faults may also be stochastic, so we introduce stochastic friction law. In the present study, we propose a stochastic dynamic model to explain both regular and slow earthquakes. We solve mode III problem, which corresponds to the rupture propagation along the strike direction. We use BIEM (boundary integral equation method) scheme to simulate slip evolution, but we add stochastic perturbations in the governing equations, which is usually written in a deterministic manner. As the simplest type of perturbations, we adopt Gaussian deviations in the formulation of the slip-stress kernel, external force, and friction. By increasing the amplitude of perturbations of the slip-stress kernel, we reproduce complicated rupture process of regular earthquakes including unilateral and bilateral ruptures. By perturbing external force, we reproduce slow rupture propagation at a scale of km/day. The slow propagation generated by a combination of fast interaction at S-wave velocity is analogous to the kinetic theory of gasses: thermal

  7. Overall concepts for utilisation of slow pyrolysis products - Hidaspyro II

    Energy Technology Data Exchange (ETDEWEB)

    Fagernaes, L.; Kuoppala, E.; Ranta, J. (VTT Technical Research Centre of Finland, Espoo (Finland)), e-mail: leena.fagernas@vtt.fi; Setaelae, H.; Hagner, M. (University of Helsinki, Lahti (Finland), Dept. of Ecological and Environmental Sciences), e-mail: heikki.setala@helsinki.fi; Tiilikkala, K.; Palojaervi, A.; Lindqvist, B. (MTT Agrifood Research Finland, Jokioinen (Finland)), e-mail: kari.tiilikkala@mtt.fi

    2011-11-15

    The project aims at developing new distributed biorefineries and comprehensive concepts based on slow pyrolysis for SMEs. The research carried out in the project 'Hidaspyro' will be continued in the new project. The goal is an optimised slow pyrolysis process for new applications of the products. The objective is to determine the effects of biochar and distillates on growth of plants, soil improvement, carbon sequestration and emissions of cultivation, to define the quality criteria of biochar, to determine the potential of distillates in odour prevention and to assess the environmental impacts of the products. Optimal process parameters to produce distillates and biochar of high quality will be determined by well-controlled laboratory-scale slow pyrolysis testing facility to be constructed. The main feedstock material will be birchwood, but comparisons with other biomass feedstocks will also be carried out. The efficacy tests will show the effect of biochars and distillates on growth of plants, use of water and nutrients, and biological activity of soil. Demonstrations of soil improvement and odour prevention will be done in co-operation with the partner enterprises. The environmental effects of different biochars will be compared by following the changes in the activity of microbes and the composition of nematode community. The amount and quality of distillate and biochar safe to the environment will be defined. All the results will be utilised in the techno-economic assessment of different concepts. (orig.)

  8. Neutron slowing-down time in matter

    Energy Technology Data Exchange (ETDEWEB)

    Chabod, Sebastien P., E-mail: sebastien.chabod@lpsc.in2p3.fr [LPSC, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 38000 Grenoble (France)

    2012-03-21

    We formulate the neutron slowing-down time through elastic collisions in a homogeneous, non-absorbing, infinite medium. Our approach allows taking into account for the first time the energy dependence of the scattering cross-section as well as the energy and temporal distribution of the source neutron population in the results. Starting from this development, we investigate the specific case of the propagation in matter of a mono-energetic neutron pulse. We then quantify the perturbation on the neutron slowing-down time induced by resonances in the scattering cross-section. We show that a resonance can induce a permanent reduction of the slowing-down time, preceded by two discontinuities: a first one at the resonance peak position and an echo one, appearing later. From this study, we suggest that a temperature increase of the propagating medium in presence of large resonances could modestly accelerate the neutron moderation.

  9. Kinetic slow mode-type solitons

    Directory of Open Access Journals (Sweden)

    K. Baumgärtel

    2005-01-01

    Full Text Available One-dimensional hybrid code simulations are presented, carried out in order both to study solitary waves of the slow mode branch in an isotropic, collisionless, medium-β plasma (βi=0.25 and to test the fluid based soliton interpretation of Cluster observed strong magnetic depressions (Stasiewicz et al., 2003; Stasiewicz, 2004 against kinetic theory. In the simulations, a variety of strongly oblique, large amplitude, solitons are seen, including solitons with Alfvenic polarization, similar to those predicted by the Hall-MHD theory, and robust, almost non-propagating, solitary structures of slow magnetosonic type with strong magnetic field depressions and perpendicular ion heating, which have no counterpart in fluid theory. The results support the soliton-based interpretation of the Cluster observations, but reveal substantial deficiencies of Hall-MHD theory in describing slow mode-type solitons in a plasma of moderate beta.

  10. Slow Controls Using the Axiom M5235BCC

    Science.gov (United States)

    Hague, Tyler

    2008-10-01

    The Forward Vertex Detector group at PHENIX plans to adopt the Axiom M5235 Business Card Controller for use as slow controls. It is also being evaluated for slow controls on FermiLab e906. This controller features the Freescale MCF5235 microprocessor. It also has three parallel buses, these being the MCU port, BUS port, and enhanced Time Processing Unit (eTPU) port. The BUS port uses a chip select module with three external chip selects to communicate with peripherals. This will be used to communicate with and configure Field Programmable Gate Arrays (FPGAs). The controller also has an Ethernet port which can use several different protocols such as TCP and UDP. This will be used to transfer files with computers on a network. The M5235 Business Card Controller will be placed in a VME crate along with VME card and a Spartan-3 FPGA.

  11. Contribution to analytical solution of neutron slowing down problem in homogeneous and heterogeneous media

    International Nuclear Information System (INIS)

    Stefanovic, D.B.

    1970-12-01

    The objective of this work is to describe the new analytical solution of the neutron slowing down equation for infinite monoatomic media with arbitrary energy dependence of cross section. The solution is obtained by introducing Green slowing down functions instead of starting from slowing down equations directly. The previously used methods for calculation of fission neutron spectra in the reactor cell were numerical. The proposed analytical method was used for calculating the space-energy distribution of fast neutrons and number of neutron reactions in a thermal reactor cell. The role of analytical method in solving the neutron slowing down in reactor physics is to enable understating of the slowing down process and neutron transport. The obtained results could be used as standards for testing the accuracy od approximative and practical methods

  12. High-speed DNA-based rolling motors powered by RNase H

    Science.gov (United States)

    Yehl, Kevin; Mugler, Andrew; Vivek, Skanda; Liu, Yang; Zhang, Yun; Fan, Mengzhen; Weeks, Eric R.

    2016-01-01

    DNA-based machines that walk by converting chemical energy into controlled motion could be of use in applications such as next generation sensors, drug delivery platforms, and biological computing. Despite their exquisite programmability, DNA-based walkers are, however, challenging to work with due to their low fidelity and slow rates (~1 nm/min). Here, we report DNA-based machines that roll rather than walk, and consequently have a maximum speed and processivity that is three-orders of magnitude greater than conventional DNA motors. The motors are made from DNA-coated spherical particles that hybridise to a surface modified with complementary RNA; motion is achieved through the addition of RNase H, which selectively hydrolyses hybridised RNA. Spherical motors move in a self-avoiding manner, whereas anisotropic particles, such as dimerised particles or rod-shaped particles travel linearly without a track or external force. Finally, we demonstrate detection of single nucleotide polymorphism by measuring particle displacement using a smartphone camera. PMID:26619152

  13. Generalized slow roll for noncanonical kinetic terms

    International Nuclear Information System (INIS)

    Hu, Wayne

    2011-01-01

    We show that the generalized slow roll approach for calculating the power spectrum where the inflationary slow roll parameters are neither small nor slowly varying can be readily extended to models with noncanonical kinetic terms in the inflaton action. For example, rapid sound speed variations can arise in Dirac-Born-Infeld models with features in the warp factor leading to features in the power spectrum. Nonetheless there remains a single source function for deviations that is simply related to the power spectrum. Empirical constraints on this source function can be readily interpreted in the context of features in the inflaton potential or sound speed.

  14. Motor degradation prediction methods

    International Nuclear Information System (INIS)

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

    1996-01-01

    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

  15. Motor and sensory alalia: diagnostic difficulties

    Directory of Open Access Journals (Sweden)

    M. Yu. Bobylova

    2017-01-01

    Full Text Available Alalia is a speech disorder that develops due to organic brain damage in children with normal hearing and intelligence during the first three year of life. Systemic speech underdevelopment in alalia is characterized by violations in the phonetic, phonemic, lexical, and grammatical structure. Patients with alalia can also have non-speech related impairments, including motor (impaired movement and coordination, sensory (impaired sensitivity and perception, and psychopathological disorders. There are three types of alalia: motor, sensory, and mixed. Children with motor alalia have expressive language disorders, speech praxis, poor speech fluency, impaired articulation, and other focal neurological symptoms; however, they understand speech directed to them. Patients with motor alalia are often left-handed. Regional slowing and epileptiform activity are often detected on their electroencephalogram.  Children with sensory alalia are characterized by poor speech understanding (despite normal hearing resulting in secondary underdevelopment of their own speech. These patients have problems with the analysis of sounds, including speech sounds (impaired speech gnosis, which prevents the development of association between the sound image and the object. Therefore, the child hears, but does not understand the speech directed at him/her (auditory agnosia. Differential diagnosis of alalia is challenging and may require several months of observation. It also implies the exclusion of hearing loss and mental disorders.

  16. Light storage via slow-light four-wave mixing

    International Nuclear Information System (INIS)

    Fan, Yun-Fei; Wang, Hai-Hua; Wei, Xiao-Gang; Li, Ai-Jun; Kang, Zhi-Hui; Wu, Jin-Hui; Zhang, Han-Zhuang; Xu, Huai-Liang; Gao, Jin-Yue

    2012-01-01

    We experimentally demonstrate a light storage via slow-light four-wave mixing in a solid-state medium with a four-level double lambda scheme. Using slow light based on electromagnetically induced transparency, we obtain a slowed four-wave mixing signal pulse together with the slowed probe pulse. During the propagation of light pulses, the storage and retrieval of both the slowed four-wave mixing pulse and the slowed probe pulse are studied by manipulating the intensities of the control fields. -- Highlights: ► A light storage via slow-light four-wave mixing is observed in a solid. ► The probe pulse is slowed under electromagnetically induced transparency. ► A slowed four-wave mixing pulse is obtained by slow light. ► The storage of slowed double pulses is studied.

  17. Slow oscillation amplitudes and up-state lengths relate to memory improvement.

    Directory of Open Access Journals (Sweden)

    Dominik P J Heib

    Full Text Available There is growing evidence of the active involvement of sleep in memory consolidation. Besides hippocampal sharp wave-ripple complexes and sleep spindles, slow oscillations appear to play a key role in the process of sleep-associated memory consolidation. Furthermore, slow oscillation amplitude and spectral power increase during the night after learning declarative and procedural memory tasks. However, it is unresolved whether learning-induced changes specifically alter characteristics of individual slow oscillations, such as the slow oscillation up-state length and amplitude, which are believed to be important for neuronal replay. 24 subjects (12 men aged between 20 and 30 years participated in a randomized, within-subject, multicenter study. Subjects slept on three occasions for a whole night in the sleep laboratory with full polysomnography. Whereas the first night only served for adaptation purposes, the two remaining nights were preceded by a declarative word-pair task or by a non-learning control task. Slow oscillations were detected in non-rapid eye movement sleep over electrode Fz. Results indicate positive correlations between the length of the up-state as well as the amplitude of both slow oscillation phases and changes in memory performance from pre to post sleep. We speculate that the prolonged slow oscillation up-state length might extend the timeframe for the transfer of initial hippocampal to long-term cortical memory representations, whereas the increase in slow oscillation amplitudes possibly reflects changes in the net synaptic strength of cortical networks.

  18. Cryogenic Electric Motor Tested

    Science.gov (United States)

    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.

  19. Hybrid vehicle motor alignment

    Science.gov (United States)

    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.

  20. Commercial-grade motors in safety-related applications: Final report

    International Nuclear Information System (INIS)

    Holzman, P.M.

    1988-04-01

    The objective of this project was to discuss the process necessary to utilize commercial grade equipment in safety related applications and to provide utilities with guidance for accepting commercial grade motors for safety-related applications. The generic commercial-grade concepts presented in this report can be successfully applied to motors. Commercial grade item utilization has the greatest applicability to motors in ''mild'' environments, because these motors are essentially similar to commercial grade motors in materials, construction methods, and capabilities. The acceptance process is less applicable to motors that are subject to ''harsh'' environments during postulated accidents, because of the unique design features and testing required to qualify these motors