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Sample records for motor degradation prediction

  1. Motor degradation prediction methods

    SciTech Connect

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

    1996-12-01

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

  2. Watching novice action degrades expert motor performance: Causation between action production and outcome prediction of observed actions by humans

    PubMed Central

    Ikegami, Tsuyoshi; Ganesh, Gowrishankar

    2014-01-01

    Our social skills are critically determined by our ability to understand and appropriately respond to actions performed by others. However despite its obvious importance, the mechanisms enabling action understanding in humans have remained largely unclear. A popular but controversial belief is that parts of the motor system contribute to our ability to understand observed actions. Here, using a novel behavioral paradigm, we investigated this belief by examining a causal relation between action production, and a component of action understanding - outcome prediction, the ability of a person to predict the outcome of observed actions. We asked dart experts to watch novice dart throwers and predict the outcome of their throws. We modulated the feedbacks provided to them, caused a specific improvement in the expert's ability to predict watched actions while controlling the other experimental factors, and exhibited that a change (improvement) in their outcome prediction ability results in a progressive and proportional deterioration in the expert's own darts performance. This causal relationship supports involvement of the motor system in outcome prediction by humans of actions observed in others. PMID:25384755

  3. Theta-burst stimulation over primary motor cortex degrades early motor learning.

    PubMed

    Iezzi, Ennio; Suppa, Antonio; Conte, Antonella; Agostino, Rocco; Nardella, Andrea; Berardelli, Alfredo

    2010-02-01

    Theta-burst stimulation (TBS) is currently used for inducing long-lasting changes in primary motor cortex (M1) excitability. More information is needed on how M1 is involved in early motor learning (practice-related improvement in motor performance, motor retention and motor consolidation). We investigated whether inhibitory continuous TBS (cTBS) is an effective experimental approach for modulating early motor learning of a simple finger movement in healthy humans. In a short task, 11 subjects practised 160 movements, and in a longer task also testing motor consolidation ten subjects practised 600 movements. During both experiments subjects randomly received real or sham cTBS over the left M1. Motor evoked potentials were tested at baseline and 7 min after cTBS. In the 160-movement experiment to test motor retention, 20 movements were repeated 30 min after motor practice ended. In the 600-movement experiment motor retention was assessed 15 and 30 min after motor practice ended, motor consolidation was tested by performing 20 movements 24 h after motor practice ended. Kinematic variables - movement amplitude, peak velocity and peak acceleration - were measured. cTBS significantly reduced the practice-related improvement in motor performance of finger movements in the experiment involving 160 movements and in the first part of the experiment involving 600 movements. After cTBS, peak velocity and peak acceleration of the 20 movements testing motor retention decreased whereas those testing motor consolidation remained unchanged. cTBS over M1 degrades practice-related improvement in motor performance and motor retention, but not motor consolidation of a voluntary finger movement.

  4. Predicting Allostery Wiring Diagrams within Motor Proteins

    NASA Astrophysics Data System (ADS)

    Tehver, Riina

    2013-03-01

    Motor proteins are intricate molecular machines that make use of allostery as a basis of their function. Fundamental questions in trying to understand the operational mechanism of the motors is, therefore, how allostery communicated is within the proteins, what are the pathways that transmit allosteric signals, how to model and predict them. We have proposed a normal-mode analysis based perturbation model that predicts the pathways based on the structure and chemical composition of the molecules. We use the model to investigate allosteric pathways (allostery wiring diagrams) within motor proteins myosin V and VI.

  5. Motor Execution Affects Action Prediction

    ERIC Educational Resources Information Center

    Springer, Anne; Brandstadter, Simone; Liepelt, Roman; Birngruber, Teresa; Giese, Martin; Mechsner, Franz; Prinz, Wolfgang

    2011-01-01

    Previous studies provided evidence of the claim that the prediction of occluded action involves real-time simulation. We report two experiments that aimed to study how real-time simulation is affected by simultaneous action execution under conditions of full, partial or no overlap between observed and executed actions. This overlap was analysed by…

  6. Motor Execution Affects Action Prediction

    ERIC Educational Resources Information Center

    Springer, Anne; Brandstadter, Simone; Liepelt, Roman; Birngruber, Teresa; Giese, Martin; Mechsner, Franz; Prinz, Wolfgang

    2011-01-01

    Previous studies provided evidence of the claim that the prediction of occluded action involves real-time simulation. We report two experiments that aimed to study how real-time simulation is affected by simultaneous action execution under conditions of full, partial or no overlap between observed and executed actions. This overlap was analysed by…

  7. Which motor cortical region best predicts imagined movement?

    PubMed

    Park, Chang-Hyun; Chang, Won Hyuk; Lee, Minji; Kwon, Gyu Hyun; Kim, Laehyun; Kim, Sung Tae; Kim, Yun-Hee

    2015-06-01

    In brain-computer interfacing (BCI), motor imagery is used to provide a gateway to an effector action or behavior. However, in contrast to the main functional role of the primary motor cortex (M1) in motor execution, the M1's involvement in motor imagery has been debated, while the roles of secondary motor areas such as the premotor cortex (PMC) and supplementary motor area (SMA) in motor imagery have been proposed. We examined which motor cortical region had the greatest predictive ability for imagined movement among the primary and secondary motor areas. For two modes of motor performance, executed movement and imagined movement, in 12 healthy subjects who performed two types of motor task, hand grasping and hand rotation, we used the multivariate Bayes method to compare predictive ability between the primary and secondary motor areas (M1, PMC, and SMA) contralateral to the moved hand. With the distributed representation of activation, executed movement was best predicted from the M1 while imagined movement from the SMA, among the three motor cortical regions, in both types of motor task. In addition, the most predictive information about the distinction between executed movement and imagined movement was contained in the M1. The greater predictive ability of the SMA for imagined movement suggests its functional role that could be applied to motor imagery-based BCI. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Predicting Motor Sequence Learning in Individuals With Chronic Stroke.

    PubMed

    Wadden, Katie P; Asis, Kristopher De; Mang, Cameron S; Neva, Jason L; Peters, Sue; Lakhani, Bimal; Boyd, Lara A

    2017-01-01

    Conventionally, change in motor performance is quantified with discrete measures of behavior taken pre- and postpractice. As a high degree of movement variability exists in motor performance after stroke, pre- and posttesting of motor skill may lack sensitivity to predict potential for motor recovery. Evaluate the use of predictive models of motor learning based on individual performance curves and clinical characteristics of motor function in individuals with stroke. Ten healthy and fourteen individuals with chronic stroke performed a continuous joystick-based tracking task over 6 days, and at a 24-hour delayed retention test, to assess implicit motor sequence learning. Individuals with chronic stroke demonstrated significantly slower rates of improvements in implicit sequence-specific motor performance compared with a healthy control (HC) group when root mean squared error performance data were fit to an exponential function. The HC group showed a positive relationship between a faster rate of change in implicit sequence-specific motor performance during practice and superior performance at the delayed retention test. The same relationship was shown for individuals with stroke only after accounting for overall motor function by including Wolf Motor Function Test rate in our model. Nonlinear information extracted from multiple time points across practice, specifically the rate of motor skill acquisition during practice, relates strongly with changes in motor behavior at the retention test following practice and could be used to predict optimal doses of practice on an individual basis. © The Author(s) 2016.

  9. Temporal structure of motor variability is dynamically regulated and predicts motor learning ability.

    PubMed

    Wu, Howard G; Miyamoto, Yohsuke R; Gonzalez Castro, Luis Nicolas; Ölveczky, Bence P; Smith, Maurice A

    2014-02-01

    Individual differences in motor learning ability are widely acknowledged, yet little is known about the factors that underlie them. Here we explore whether movement-to-movement variability in motor output, a ubiquitous if often unwanted characteristic of motor performance, predicts motor learning ability. Surprisingly, we found that higher levels of task-relevant motor variability predicted faster learning both across individuals and across tasks in two different paradigms, one relying on reward-based learning to shape specific arm movement trajectories and the other relying on error-based learning to adapt movements in novel physical environments. We proceeded to show that training can reshape the temporal structure of motor variability, aligning it with the trained task to improve learning. These results provide experimental support for the importance of action exploration, a key idea from reinforcement learning theory, showing that motor variability facilitates motor learning in humans and that our nervous systems actively regulate it to improve learning.

  10. Temporal structure of motor variability is dynamically regulated and predicts motor learning ability

    PubMed Central

    Wu, Howard G; Miyamoto, Yohsuke R; Castro, Luis Nicolas Gonzalez; Ölveczky, Bence P; Smith, Maurice A

    2015-01-01

    Individual differences in motor learning ability are widely acknowledged, yet little is known about the factors that underlie them. Here we explore whether movement-to-movement variability in motor output, a ubiquitous if often unwanted characteristic of motor performance, predicts motor learning ability. Surprisingly, we found that higher levels of task-relevant motor variability predicted faster learning both across individuals and across tasks in two different paradigms, one relying on reward-based learning to shape specific arm movement trajectories and the other relying on error-based learning to adapt movements in novel physical environments. We proceeded to show that training can reshape the temporal structure of motor variability, aligning it with the trained task to improve learning. These results provide experimental support for the importance of action exploration, a key idea from reinforcement learning theory, showing that motor variability facilitates motor learning in humans and that our nervous systems actively regulate it to improve learning. PMID:24413700

  11. Daily update of motor predictions by physical activity

    PubMed Central

    Gueugneau, Nicolas; Schweighofer, Nicolas; Papaxanthis, Charalambos

    2015-01-01

    Motor prediction, i.e., the ability to predict the sensory consequences of motor commands, is critical for adapted motor behavior. Like speed or force, the accuracy of motor prediction varies in a 24-hour basis. Although the prevailing view is that basic biological markers regulate this circadian modulation, behavioral factors such as physical activity, itself modulated by the alternation of night and day, can also regulate motor prediction. Here, we propose that physical activity updates motor prediction on a daily basis. We tested our hypothesis by up- and down-regulating physical activity via arm-immobilization and high-intensity training, respectively. Motor prediction was assessed by measuring the timing differences between actual and mental arm movements. Results show that although mental movement time was modulated during the day when the arm was unconstrained, it remained constant when the arm was immobilized. Additionally, increase of physical activity, via release from immobilization or intense bout of training, significantly reduced mental movement time. Finally, mental and actual times were similar in the afternoon in the unconstrained condition, indicating that predicted and actual movements match after sufficient amount of physical activity. Our study supports the view that physical activity calibrates motor predictions on a daily basis. PMID:26632341

  12. Daily update of motor predictions by physical activity.

    PubMed

    Gueugneau, Nicolas; Schweighofer, Nicolas; Papaxanthis, Charalambos

    2015-12-03

    Motor prediction, i.e., the ability to predict the sensory consequences of motor commands, is critical for adapted motor behavior. Like speed or force, the accuracy of motor prediction varies in a 24-hour basis. Although the prevailing view is that basic biological markers regulate this circadian modulation, behavioral factors such as physical activity, itself modulated by the alternation of night and day, can also regulate motor prediction. Here, we propose that physical activity updates motor prediction on a daily basis. We tested our hypothesis by up- and down-regulating physical activity via arm-immobilization and high-intensity training, respectively. Motor prediction was assessed by measuring the timing differences between actual and mental arm movements. Results show that although mental movement time was modulated during the day when the arm was unconstrained, it remained constant when the arm was immobilized. Additionally, increase of physical activity, via release from immobilization or intense bout of training, significantly reduced mental movement time. Finally, mental and actual times were similar in the afternoon in the unconstrained condition, indicating that predicted and actual movements match after sufficient amount of physical activity. Our study supports the view that physical activity calibrates motor predictions on a daily basis.

  13. Predicting explorative motor learning using decision-making and motor noise

    PubMed Central

    Galea, Joseph M.

    2017-01-01

    A fundamental problem faced by humans is learning to select motor actions based on noisy sensory information and incomplete knowledge of the world. Recently, a number of authors have asked whether this type of motor learning problem might be very similar to a range of higher-level decision-making problems. If so, participant behaviour on a high-level decision-making task could be predictive of their performance during a motor learning task. To investigate this question, we studied performance during an explorative motor learning task and a decision-making task which had a similar underlying structure with the exception that it was not subject to motor (execution) noise. We also collected an independent measurement of each participant’s level of motor noise. Our analysis showed that explorative motor learning and decision-making could be modelled as the (approximately) optimal solution to a Partially Observable Markov Decision Process bounded by noisy neural information processing. The model was able to predict participant performance in motor learning by using parameters estimated from the decision-making task and the separate motor noise measurement. This suggests that explorative motor learning can be formalised as a sequential decision-making process that is adjusted for motor noise, and raises interesting questions regarding the neural origin of explorative motor learning. PMID:28437451

  14. Predicting explorative motor learning using decision-making and motor noise.

    PubMed

    Chen, Xiuli; Mohr, Kieran; Galea, Joseph M

    2017-04-01

    A fundamental problem faced by humans is learning to select motor actions based on noisy sensory information and incomplete knowledge of the world. Recently, a number of authors have asked whether this type of motor learning problem might be very similar to a range of higher-level decision-making problems. If so, participant behaviour on a high-level decision-making task could be predictive of their performance during a motor learning task. To investigate this question, we studied performance during an explorative motor learning task and a decision-making task which had a similar underlying structure with the exception that it was not subject to motor (execution) noise. We also collected an independent measurement of each participant's level of motor noise. Our analysis showed that explorative motor learning and decision-making could be modelled as the (approximately) optimal solution to a Partially Observable Markov Decision Process bounded by noisy neural information processing. The model was able to predict participant performance in motor learning by using parameters estimated from the decision-making task and the separate motor noise measurement. This suggests that explorative motor learning can be formalised as a sequential decision-making process that is adjusted for motor noise, and raises interesting questions regarding the neural origin of explorative motor learning.

  15. Accurate torque-speed performance prediction for brushless dc motors

    NASA Astrophysics Data System (ADS)

    Gipper, Patrick D.

    Desirable characteristics of the brushless dc motor (BLDCM) have resulted in their application for electrohydrostatic (EH) and electromechanical (EM) actuation systems. But to effectively apply the BLDCM requires accurate prediction of performance. The minimum necessary performance characteristics are motor torque versus speed, peak and average supply current and efficiency. BLDCM nonlinear simulation software specifically adapted for torque-speed prediction is presented. The capability of the software to quickly and accurately predict performance has been verified on fractional to integral HP motor sizes, and is presented. Additionally, the capability of torque-speed prediction with commutation angle advance is demonstrated.

  16. Motor system contribution to action prediction: Temporal accuracy depends on motor experience.

    PubMed

    Stapel, Janny C; Hunnius, Sabine; Meyer, Marlene; Bekkering, Harold

    2016-03-01

    Predicting others' actions is essential for well-coordinated social interactions. In two experiments including an infant population, this study addresses to what extent motor experience of an observer determines prediction accuracy for others' actions. Results show that infants who were proficient crawlers but inexperienced walkers predicted crawling more accurately than walking, whereas age groups mastering both skills (i.e. toddlers and adults) were equally accurate in predicting walking and crawling. Regardless of experience, human movements were predicted more accurately by all age groups than non-human movement control stimuli. This suggests that for predictions to be accurate, the observed act needs to be established in the motor repertoire of the observer. Through the acquisition of new motor skills, we also become better at predicting others' actions. The findings thus stress the relevance of motor experience for social-cognitive development.

  17. Functional connectivity between somatosensory and motor brain areas predicts individual differences in motor learning by observing.

    PubMed

    McGregor, Heather R; Gribble, Paul L

    2017-08-01

    Action observation can facilitate the acquisition of novel motor skills; however, there is considerable individual variability in the extent to which observation promotes motor learning. Here we tested the hypothesis that individual differences in brain function or structure can predict subsequent observation-related gains in motor learning. Subjects underwent an anatomical MRI scan and resting-state fMRI scans to assess preobservation gray matter volume and preobservation resting-state functional connectivity (FC), respectively. On the following day, subjects observed a video of a tutor adapting her reaches to a novel force field. After observation, subjects performed reaches in a force field as a behavioral assessment of gains in motor learning resulting from observation. We found that individual differences in resting-state FC, but not gray matter volume, predicted postobservation gains in motor learning. Preobservation resting-state FC between left primary somatosensory cortex and bilateral dorsal premotor cortex, primary motor cortex, and primary somatosensory cortex and left superior parietal lobule was positively correlated with behavioral measures of postobservation motor learning. Sensory-motor resting-state FC can thus predict the extent to which observation will promote subsequent motor learning.NEW & NOTEWORTHY We show that individual differences in preobservation brain function can predict subsequent observation-related gains in motor learning. Preobservation resting-state functional connectivity within a sensory-motor network may be used as a biomarker for the extent to which observation promotes motor learning. This kind of information may be useful if observation is to be used as a way to boost neuroplasticity and sensory-motor recovery for patients undergoing rehabilitation for diseases that impair movement such as stroke. Copyright © 2017 the American Physiological Society.

  18. A hybrid generative and predictive model of the motor cortex.

    PubMed

    Weber, Cornelius; Wermter, Stefan; Elshaw, Mark

    2006-05-01

    We describe a hybrid generative and predictive model of the motor cortex. The generative model is related to the hierarchically directed cortico-cortical (or thalamo-cortical) connections and unsupervised training leads to a topographic and sparse hidden representation of its sensory and motor input. The predictive model is related to lateral intra-area and inter-area cortical connections, functions as a hetero-associator attractor network and is trained to predict the future state of the network. Applying partial input, the generative model can map sensory input to motor actions and can thereby perform learnt action sequences of the agent within the environment. The predictive model can additionally predict a longer perception- and action sequence (mental simulation). The models' performance is demonstrated on a visually guided robot docking manoeuvre. We propose that the motor cortex might take over functions previously learnt by reinforcement in the basal ganglia and relate this to mirror neurons and imitation.

  19. Motor cortex activity predicts response alternation during sensorimotor decisions

    PubMed Central

    Pape, Anna-Antonia; Siegel, Markus

    2016-01-01

    Our actions are constantly guided by decisions based on sensory information. The motor cortex is traditionally viewed as the final output stage in this process, merely executing motor responses based on these decisions. However, it is not clear if, beyond this role, the motor cortex itself impacts response selection. Here, we report activity fluctuations over motor cortex measured using MEG, which are unrelated to choice content and predict responses to a visuomotor task seconds before decisions are made. These fluctuations are strongly influenced by the previous trial's response and predict a tendency to switch between response alternatives for consecutive decisions. This alternation behaviour depends on the size of neural signals still present from the previous response. Our results uncover a response-alternation bias in sensorimotor decision making. Furthermore, they suggest that motor cortex is more than an output stage and instead shapes response selection during sensorimotor decision making. PMID:27713396

  20. Prediction of finite pressure oscillations in stable rocket motors

    NASA Technical Reports Server (NTRS)

    Hessler, R. O.

    1980-01-01

    A methodology is outlined for predicting the amplitude of forced vibrations in the acoustic cavity of a solid rocket motor. The equation for forced vibration of the motor cavity acoustic system is written by parallel with the acoustic mechanical analogy. Acoustic and aeroacoustic theory are used to predict the frequency and intensity of vortex systems or turbulence created by passage of the mean flow over geometric discontinuities in the motor port. Approximate methods are presented for coupling the acoustic field due to the flow noise with the chamber acoustics and for summing the effect upon the multiple acoustic modes.

  1. Analytical predictions of selenide RTG power degradation

    NASA Technical Reports Server (NTRS)

    Noon, E. L.; Stapfer, G.; Raag, V.

    1978-01-01

    A mathematical model for the performance and degradation analysis of an RTG using the newly developed selenide thermoelectric materials has been developed at JPL. The computerized model is quite comprehensive and enables the accurate detailing of the electrical and thermal effects that take place within the thermocouple under any desired set of operation conditions, including heat input, ambient temperature and load conditions. The paper discusses the logic flow of the computer model and presents the time and temperature dependent results for various degradation mechanisms and rates as they have been established to date.

  2. Impaired predictive motor timing in patients with cerebellar disorders.

    PubMed

    Bares, Martin; Lungu, Ovidiu; Liu, Tao; Waechter, Tobias; Gomez, Christopher M; Ashe, James

    2007-06-01

    The ability to precisely time events is essential for both perception and action. There is evidence that the cerebellum is important for the neural representation of time in a variety of behaviors including time perception, the tapping of specific time intervals, and eye-blink conditioning. It has been difficult to assess the contribution of the cerebellum to timing during more dynamic motor behavior because the component movements themselves may be abnormal or any motor deficit may be due to an inability to combine the component movements into a complete action rather than timing per se. Here we investigated the performance of subjects with cerebellar disease in predictive motor timing using a task that involved mediated interception of a moving target, and we tested the effect of movement type (acceleration, deceleration, constant), speed (slow, medium, fast), and angle (0 degrees , 15 degrees and 30 degrees) on performance. The subjects with cerebellar damage were significantly worse at interception than healthy controls even when we controlled for basic motor impairments such as response time. Our data suggest that subjects with damage to the cerebellum have a fundamental problem with predictive motor timing and indicate that the cerebellum plays an essential role in integrating incoming visual information with motor output when making predictions about upcoming actions. The findings demonstrate that the cerebellum may have properties that would facilitate the processing or storage of internal models of motor behavior.

  3. Prediction of radiated emissions from DC motors

    NASA Astrophysics Data System (ADS)

    Suriano, Candace Rogers

    DC motors are known sources of radio frequency electromagnetic noise produced by arcing at the motor brushes. A simplified model of electromagnetic radiation from a DC motor and associated wiring harness is desired to guide engineers in the design process. Of particular interest is their behavior at low frequencies in a reverberation chamber. Different methods are used to devise a voltage transfer function between a device under test (DUT) and a monopole antenna for near field low frequency testing in a reverberation chamber. A simple scaling factor is used to transform low frequency monopole antenna data between different reverberation chamber configurations. Further refinement in the modeling is based on common mode current. Test data indicated that a simple equivalent RLC circuit could represent the common mode current. The validity of the approach is shown using the Electric Field Integral Equation. Various quasi-static and static models were used to compute the circuit parameters. Furthermore, a second circuit was shown to relate the common mode current to the receiving antenna voltage. Moment method models and test data demonstrate this relationship.

  4. Resting-state cortical connectivity predicts motor skill acquisition

    PubMed Central

    Wu, Jennifer; Srinivasan, Ramesh; Kaur, Arshdeep; Cramer, Steven C.

    2014-01-01

    Many studies have examined brain states in an effort to predict individual differences in capacity for learning, with overall moderate results. The present study investigated how measures of cortical network function acquired at rest using dense-array EEG (256 leads) predict subsequent acquisition of a new motor skill. Brain activity was recorded in 17 healthy young subjects during three minutes of wakeful rest prior to a single motor skill training session on a digital version of the pursuit rotor task. Practice was associated with significant gains in task performance (% time on target increased from 24% to 41%, p < 0.0001). Using a partial least squares regression (PLS) model, coherence with the region of the left primary motor area (M1) in resting EEG data was a strong predictor of motor skill acquisition (R2 = 0.81 in a leave-one-out cross-validation analysis), exceeding the information provided by baseline behavior and demographics. Within this PLS model, greater skill acquisition was predicted by higher connectivity between M1 and left parietal cortex, possibly reflecting greater capacity for visuomotor integration, and by lower connectivity between M1 and left frontal-premotor areas, possibly reflecting differences in motor planning strategies. EEG coherence, which reflects functional connectivity, predicts individual motor skill acquisition with a level of accuracy that is remarkably high compared to prior reports using EEG or fMRI measures. PMID:24473097

  5. In silico prediction of pharmaceutical degradation pathways: a benchmarking study.

    PubMed

    Kleinman, Mark H; Baertschi, Steven W; Alsante, Karen M; Reid, Darren L; Mowery, Mark D; Shimanovich, Roman; Foti, Chris; Smith, William K; Reynolds, Dan W; Nefliu, Marcela; Ott, Martin A

    2014-11-03

    Zeneth is a new software application capable of predicting degradation products derived from small molecule active pharmaceutical ingredients. This study was aimed at understanding the current status of Zeneth's predictive capabilities and assessing gaps in predictivity. Using data from 27 small molecule drug substances from five pharmaceutical companies, the evolution of Zeneth predictions through knowledge base development since 2009 was evaluated. The experimentally observed degradation products from forced degradation, accelerated, and long-term stability studies were compared to Zeneth predictions. Steady progress in predictive performance was observed as the knowledge bases grew and were refined. Over the course of the development covered within this evaluation, the ability of Zeneth to predict experimentally observed degradants increased from 31% to 54%. In particular, gaps in predictivity were noted in the areas of epimerizations, N-dealkylation of N-alkylheteroaromatic compounds, photochemical decarboxylations, and electrocyclic reactions. The results of this study show that knowledge base development efforts have increased the ability of Zeneth to predict relevant degradation products and aid pharmaceutical research. This study has also provided valuable information to help guide further improvements to Zeneth and its knowledge base.

  6. The neural substrate of predictive motor timing in spinocerebellar ataxia.

    PubMed

    Bares, Martin; Lungu, Ovidiu V; Liu, Tao; Waechter, Tobias; Gomez, Christopher M; Ashe, James

    2011-06-01

    The neural mechanisms involved in motor timing are subcortical, involving mainly cerebellum and basal ganglia. However, the role played by these structures in predictive motor timing is not well understood. Unlike motor timing, which is often tested using rhythm production tasks, predictive motor timing requires visuo-motor coordination in anticipation of a future event, and it is evident in behaviors such as catching a ball or shooting a moving target. We examined the role of the cerebellum and striatum in predictive motor timing in a target interception task in healthy (n = 12) individuals and in subjects (n = 9) with spinocerebellar ataxia types 6 and 8. The performance of the healthy subjects was better than that of the spinocerebellar ataxia. Successful performance in both groups was associated with increased activity in the cerebellum (right dentate nucleus, left uvula (lobule V), and lobule VI), thalamus, and in several cortical areas. The superior performance in the controls was related to activation in thalamus, putamen (lentiform nucleus) and cerebellum (right dentate nucleus and culmen-lobule IV), which were not activated either in the spinocerebellar subjects or within a subgroup of controls who performed poorly. Both the cerebellum and the basal ganglia are necessary for the predictive motor timing. The degeneration of the cerebellum associated with spinocerebellar types 6 and 8 appears to lead to quantitative rather than qualitative deficits in temporal processing. The lack of any areas with greater activity in the spinocerebellar group than in controls suggests that limited functional reorganization occurs in this condition.

  7. Somatotopic Semantic Priming and Prediction in the Motor System

    PubMed Central

    Grisoni, Luigi; Dreyer, Felix R.; Pulvermüller, Friedemann

    2016-01-01

    The recognition of action-related sounds and words activates motor regions, reflecting the semantic grounding of these symbols in action information; in addition, motor cortex exerts causal influences on sound perception and language comprehension. However, proponents of classic symbolic theories still dispute the role of modality-preferential systems such as the motor cortex in the semantic processing of meaningful stimuli. To clarify whether the motor system carries semantic processes, we investigated neurophysiological indexes of semantic relationships between action-related sounds and words. Event-related potentials revealed that action-related words produced significantly larger stimulus-evoked (Mismatch Negativity-like) and predictive brain responses (Readiness Potentials) when presented in body-part-incongruent sound contexts (e.g., “kiss” in footstep sound context; “kick” in whistle context) than in body-part-congruent contexts, a pattern reminiscent of neurophysiological correlates of semantic priming. Cortical generators of the semantic relatedness effect were localized in areas traditionally associated with semantic memory, including left inferior frontal cortex and temporal pole, and, crucially, in motor areas, where body-part congruency of action sound–word relationships was indexed by a somatotopic pattern of activation. As our results show neurophysiological manifestations of action-semantic priming in the motor cortex, they prove semantic processing in the motor system and thus in a modality-preferential system of the human brain. PMID:26908635

  8. Somatotopic Semantic Priming and Prediction in the Motor System.

    PubMed

    Grisoni, Luigi; Dreyer, Felix R; Pulvermüller, Friedemann

    2016-05-01

    The recognition of action-related sounds and words activates motor regions, reflecting the semantic grounding of these symbols in action information; in addition, motor cortex exerts causal influences on sound perception and language comprehension. However, proponents of classic symbolic theories still dispute the role of modality-preferential systems such as the motor cortex in the semantic processing of meaningful stimuli. To clarify whether the motor system carries semantic processes, we investigated neurophysiological indexes of semantic relationships between action-related sounds and words. Event-related potentials revealed that action-related words produced significantly larger stimulus-evoked (Mismatch Negativity-like) and predictive brain responses (Readiness Potentials) when presented in body-part-incongruent sound contexts (e.g., "kiss" in footstep sound context; "kick" in whistle context) than in body-part-congruent contexts, a pattern reminiscent of neurophysiological correlates of semantic priming. Cortical generators of the semantic relatedness effect were localized in areas traditionally associated with semantic memory, including left inferior frontal cortex and temporal pole, and, crucially, in motor areas, where body-part congruency of action sound-word relationships was indexed by a somatotopic pattern of activation. As our results show neurophysiological manifestations of action-semantic priming in the motor cortex, they prove semantic processing in the motor system and thus in a modality-preferential system of the human brain.

  9. Analytical predictions of RTG power degradation. [Radioisotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Noon, E. L.; Raag, V.

    1979-01-01

    The DEGRA computer code that is based on a mathematical model which predicts performance and time-temperature dependent degradation of a radioisotope thermoelectric generator is discussed. The computer code has been used to predict performance and generator degradation for the selenide Ground Demonstration Unit (GDS-1) and the generator used in the Galileo Project. Results of parametric studies of load voltage vs generator output are examined as well as the I-V curve and the resulting predicted power vs voltage. The paper also discusses the increased capability features contained in DEGRA2 and future plans for expanding the computer code performance.

  10. Error correction, sensory prediction, and adaptation in motor control.

    PubMed

    Shadmehr, Reza; Smith, Maurice A; Krakauer, John W

    2010-01-01

    Motor control is the study of how organisms make accurate goal-directed movements. Here we consider two problems that the motor system must solve in order to achieve such control. The first problem is that sensory feedback is noisy and delayed, which can make movements inaccurate and unstable. The second problem is that the relationship between a motor command and the movement it produces is variable, as the body and the environment can both change. A solution is to build adaptive internal models of the body and the world. The predictions of these internal models, called forward models because they transform motor commands into sensory consequences, can be used to both produce a lifetime of calibrated movements, and to improve the ability of the sensory system to estimate the state of the body and the world around it. Forward models are only useful if they produce unbiased predictions. Evidence shows that forward models remain calibrated through motor adaptation: learning driven by sensory prediction errors.

  11. Learning new gait patterns: Exploratory muscle activity during motor learning is not predicted by motor modules.

    PubMed

    Ranganathan, Rajiv; Krishnan, Chandramouli; Dhaher, Yasin Y; Rymer, William Z

    2016-03-21

    The motor module hypothesis in motor control proposes that the nervous system can simplify the problem of controlling a large number of muscles in human movement by grouping muscles into a smaller number of modules. Here, we tested one prediction of the modular organization hypothesis by examining whether there is preferential exploration along these motor modules during the learning of a new gait pattern. Healthy college-aged participants learned a new gait pattern which required increased hip and knee flexion during the swing phase while walking in a lower-extremity robot (Lokomat). The new gait pattern was displayed as a foot trajectory in the sagittal plane and participants attempted to match their foot trajectory to this template. We recorded EMG from 8 lower-extremity muscles and we extracted motor modules during both baseline walking and target-tracking using non-negative matrix factorization (NMF). Results showed increased trajectory variability in the first block of learning, indicating that participants were engaged in exploratory behavior. Critically, when we examined the muscle activity during this exploratory phase, we found that the composition of motor modules changed significantly within the first few strides of attempting the new gait pattern. The lack of persistence of the motor modules under even short time scales suggests that motor modules extracted during locomotion may be more indicative of correlated muscle activity induced by the task constraints of walking, rather than reflecting a modular control strategy.

  12. Predicting the degradability of waste activated sludge.

    PubMed

    Jones, Richard; Parker, Wayne; Zhu, Henry; Houweling, Dwight; Murthy, Sudhir

    2009-08-01

    The objective of this study was to identify methods for estimating anaerobic digestibility of waste activated sludge (WAS). The WAS streams were generated in three sequencing batch reactors (SBRs) treating municipal wastewater. The wastewater and WAS properties were initially determined through simulation of SBR operation with BioWin (EnviroSim Associates Ltd., Flamborough, Ontario, Canada). Samples of WAS from the SBRs were subsequently characterized through respirometry and batch anaerobic digestion. Respirometry was an effective tool for characterizing the active fraction of WAS and could be a suitable technique for determining sludge composition for input to anaerobic models. Anaerobic digestion of the WAS revealed decreasing methane production and lower chemical oxygen demand removals as the SRT of the sludge increased. BioWin was capable of accurately describing the digestion of the WAS samples for typical digester SRTs. For extended digestion times (i.e., greater than 30 days), some degradation of the endogenous decay products was assumed to achieve accurate simulations for all sludge SRTs.

  13. Predictive motor control of sensory dynamics in auditory active sensing.

    PubMed

    Morillon, Benjamin; Hackett, Troy A; Kajikawa, Yoshinao; Schroeder, Charles E

    2015-04-01

    Neuronal oscillations present potential physiological substrates for brain operations that require temporal prediction. We review this idea in the context of auditory perception. Using speech as an exemplar, we illustrate how hierarchically organized oscillations can be used to parse and encode complex input streams. We then consider the motor system as a major source of rhythms (temporal priors) in auditory processing, that act in concert with attention to sharpen sensory representations and link them across areas. We discuss the circuits that could mediate this audio-motor interaction, notably the potential role of the somatosensory system. Finally, we reposition temporal predictions in the context of internal models, discussing how they interact with feature-based or spatial predictions. We argue that complementary predictions interact synergistically according to the organizational principles of each sensory system, forming multidimensional filters crucial to perception.

  14. Illusions of force perception: the role of sensori-motor predictions, visual information, and motor errors.

    PubMed

    Diedrichsen, Jörn; Verstynen, Timothy; Hon, Andrew; Zhang, Yi; Ivry, Richard B

    2007-05-01

    Internal predictions influence the perception of force. When we support an object with one hand and lift it up with the other, we expect the force to disappear from the first, postural hand. In a virtual reality system, we violated this prediction by maintaining the force on the postural hand, whereas the object was still seen and felt to be lifted by the lifting hand. In this situation, participants perceived an illusionary increase in force on the postural hand, which was, in reality, constant. We test three possible mechanisms of how force perception may be influenced in this context. First, we showed that part of the illusion can be linked to a sensorimotor prediction--the predicted sensory consequences based on an efference copy of the lifting action. The illusion is reduced when the object is lifted by an external force. We also showed that the illusion changes on a trial-by-trial basis, paralleling the fast adaptation of the postural response. Second, motor errors that arise from a miscalibrated forward model do not contribute to the illusion; the illusion was unchanged even when we prevented motor errors by supporting the postural hand. Finally, visual information signaling the removal of the object is sufficient to elicit part of the illusion. These results argue that both sensorimotor predictions and visual object information, but not motor errors, influence force perception.

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

    PubMed

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

    2017-03-01

    Recent studies show that motor variability is actively regulated as an exploration tool to promote learning in reward-based tasks. However, its role in learning processes during error-based tasks, when a reduction of the motor variability is required to achieve good performance, is still unclear. In this study, we hypothesized that error-based learning not only depends on exploration but also on the individuals' ability to measure and predict the motor error. Previous studies identified a less auto-correlated motor variability as a higher ability to perform motion adjustments. Two experiments investigated the relationship between motor learning and variability, analyzing the long-range autocorrelation of the center of pressure fluctuations through the α score of a Detrended Fluctuation Analysis in balance tasks. In Experiment 1, we assessed the relationship between variability and learning rate using a standing balance task. Based on the results of this experiment, and to maximize learning, we performed a second experiment with a more difficult sitting balance task and increased practice. The learning rate of the 2 groups with similar balance performances but different α scores was compared. Individuals with a lower α score showed a higher learning rate. Because the α scores reveal how the motor output changes over time, instead of the magnitude of those changes, the higher learning rate is mainly linked to the higher error sensitivity rather than the exploration strategies. The results of this study highlight the relevance of the structure of output motor variability as a predictor of learning rate in error-based tasks. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. The predictive roles of neural oscillations in speech motor adaptability.

    PubMed

    Sengupta, Ranit; Nasir, Sazzad M

    2016-06-01

    The human speech system exhibits a remarkable flexibility by adapting to alterations in speaking environments. While it is believed that speech motor adaptation under altered sensory feedback involves rapid reorganization of speech motor networks, the mechanisms by which different brain regions communicate and coordinate their activity to mediate adaptation remain unknown, and explanations of outcome differences in adaption remain largely elusive. In this study, under the paradigm of altered auditory feedback with continuous EEG recordings, the differential roles of oscillatory neural processes in motor speech adaptability were investigated. The predictive capacities of different EEG frequency bands were assessed, and it was found that theta-, beta-, and gamma-band activities during speech planning and production contained significant and reliable information about motor speech adaptability. It was further observed that these bands do not work independently but interact with each other suggesting an underlying brain network operating across hierarchically organized frequency bands to support motor speech adaptation. These results provide novel insights into both learning and disorders of speech using time frequency analysis of neural oscillations.

  17. Separating Predicted and Perceived Sensory Consequences of Motor Learning

    PubMed Central

    ‘t Hart, Bernard Marius; Henriques, Denise Y. P.

    2016-01-01

    During motor adaptation the discrepancy between predicted and actually perceived sensory feedback is thought to be minimized, but it can be difficult to measure predictions of the sensory consequences of actions. Studies attempting to do so have found that self-directed, unseen hand position is mislocalized in the direction of altered visual feedback. However, our lab has shown that motor adaptation also leads to changes in perceptual estimates of hand position, even when the target hand is passively displaced. We attribute these changes to a recalibration of hand proprioception, since in the absence of a volitional movement, efferent or predictive signals are likely not involved. The goal here is to quantify the extent to which changes in hand localization reflect a change in the predicted sensory (visual) consequences or a change in the perceived (proprioceptive) consequences. We did this by comparing changes in localization produced when the hand movement was self-generated (‘active localization’) versus robot-generated (‘passive localization’) to the same locations following visuomotor adaptation to a rotated cursor. In this passive version, there should be no predicted consequences of these robot-generated hand movements. We found that although changes in localization were somewhat larger in active localization, the passive localization task also elicited substantial changes. Our results suggest that the change in hand localization following visuomotor adaptation may not be based entirely on updating predicted sensory consequences, but may largely reflect changes in our proprioceptive state estimate. PMID:27658214

  18. The multiform motor cortical output: Kinematic, predictive and response coding.

    PubMed

    Sartori, Luisa; Betti, Sonia; Chinellato, Eris; Castiello, Umberto

    2015-09-01

    Observing actions performed by others entails a subliminal activation of primary motor cortex reflecting the components encoded in the observed action. One of the most debated issues concerns the role of this output: Is it a mere replica of the incoming flow of information (kinematic coding), is it oriented to anticipate the forthcoming events (predictive coding) or is it aimed at responding in a suitable fashion to the actions of others (response coding)? The aim of the present study was to disentangle the relative contribution of these three levels and unify them into an integrated view of cortical motor coding. We combined transcranial magnetic stimulation (TMS) and electromyography recordings at different timings to probe the excitability of corticospinal projections to upper and lower limb muscles of participants observing a soccer player performing: (i) a penalty kick straight in their direction and then coming to a full stop, (ii) a penalty kick straight in their direction and then continuing to run, (iii) a penalty kick to the side and then continuing to run. The results show a modulation of the observer's corticospinal excitability in different effectors at different times reflecting a multiplicity of motor coding. The internal replica of the observed action, the predictive activation, and the adaptive integration of congruent and non-congruent responses to the actions of others can coexist in a not mutually exclusive way. Such a view offers reconciliation among different (and apparently divergent) frameworks in action observation literature, and will promote a more complete and integrated understanding of recent findings on motor simulation, motor resonance and automatic imitation.

  19. Prediction of Motor Recovery Using Quantitative Parameters of Motor Evoked Potential in Patients With Stroke

    PubMed Central

    2016-01-01

    Objective To investigate the clinical significance of quantitative parameters in transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEP) which can be adopted to predict functional recovery of the upper limb in stroke patients in the early subacute phase. Methods One hundred thirteen patients (61 men, 52 women; mean age 57.8±12.2 years) who suffered faiarst-ever stroke were included in this study. All participants underwent TMS-induced MEP session to assess the corticospinal excitability of both hand motor cortices within 3 weeks after stroke onset. After the resting motor threshold (rMT) was assessed, five sweeps of MEP were performed, and the mean amplitude of the MEP was measured. Latency of MEP, volume of the MEP output curve, recruitment ratios, and intracortical inhibition and facilitation were also measured. Motor function was assessed using the Fugl-Meyer Assessment scale (FMA) within 3 weeks and at 3 months after stroke onset. Correlation analysis was performed between TMS-induced MEP derived measures and FMA scores. Results In the MEP response group, rMT and rMT ratio measures within 3 weeks after stroke onset showed a significant negative correlation with the total and upper limb FMA scores at 3 months after stroke (p<0.001). Multiple regression analysis revealed that FMA score and rMT ratio, but not rMT within 3 weeks were independent prognostic factors for FMA scores at 3 months after stroke. Conclusion These results indicated that the quantitative parameter of TMS-induced MEP, especially rMT ratio in the early subacute phase, could be used as a parameter to predict motor function in patients with stroke. PMID:27847710

  20. Effect of constant, predictable, and unpredictable motor tasks on motor performance and blood markers of stress.

    PubMed

    Kyguoliene, Laura; Skurvydas, Albertas; Eimantas, Nerijus; Baranauskienė, Neringa; Mickeviciene, Dalia; Urboniene, Daiva; Cernych, Margarita; Brazaitis, Marius

    2017-05-01

    An unfamiliar or novel physical stimulus induces activation of dopaminergic neurons within the brain and greater activity in areas involved in emotion; considering this, we aimed to establish whether unpredictable prolonged (fatiguing) motor task (vs. constant vs. predictable) evokes greater dopaminergic activity, enhances neuromuscular performance, motor accuracy, and perception of effort, and delays overall central fatigue. Fifteen healthy male volunteers (aged 22 ± 4 years) were required to perform 1 of 3 exercise trials (at least 1 week apart) of 100 intermittent isometric contraction (IIC) tasks involving knee extensions at 60° flexion. Trials were structured differently by simulated contraction intensity. A fatigue task involved 5-s contractions and 20-s rest. Variables measured before, during, and after IIC were electrically induced force, maximal voluntary contraction, central activation ratio, intramuscular temperature, and blood levels of dopamine, cortisol, and prolactin, and intraindividual motor variability and accuracy (constant and absolute error). We found that IIC increased central and peripheral fatigue, force sensation, and T mu, and decreased absolute and constant error without visual feedback, but did not affect motor variability. There were no significant differences between the three IIC tasks. However, only unpredictable tasks increased dopaminergic activity, which was insufficient to affect central motivation to perform isometric exercise and alter centrally mediated components of fatigue.

  1. Assessment of diagnostic methods for determining degradation of motor-operated valves

    SciTech Connect

    Haynes, H.D. ); Farmer, W.S. )

    1992-01-01

    The Oak Ridge National Laboratory (ORNL) has carried out a comprehensive aging assessment of motor-operated valves (MOVs) in support of the Nuclear Plant Aging Research (NPAR) program. This paper provides a summary of the ORNL MOV aging assessment with emphasis on the identification, evaluation, and application of MOV monitoring methods and techniques. The diagnostic information available from any MOV measurable parameters was evaluated by ORNL using MOVs that were mounted on test stands. Those tests led to the conclusion that the single most informative MOV measurable parameter was also the one which was most easily acquired, namely the motor current. Motor current signature analysis (MCSA) was found to provide detailed information related to the condition of the motor, motor operator, and valve across a wide range of levels. As part of the MOV aging assessment, several tests were carried out by ORNL on MOVs having implanted defects and degradations. Tests were also performed on many MOVs located within a nuclear power plant. In addition, ORNL participated in the Gate Valve Flow Interruption Blowdown Test program carried out at Wyle Laboratories in Huntsville, Alabama. Results from all of these tests are summarized in this paper and several selected examples are given. Other areas covered in this paper include descriptions of relevant regulatory issues and activities, other related diagnostics research at ORNL, and interactions ORNL has had with outside organizations for the purpose of disseminating research results.

  2. Assessment of diagnostic methods for determining degradation of motor-operated valves

    SciTech Connect

    Haynes, H.D.; Farmer, W.S.

    1992-05-01

    The Oak Ridge National Laboratory (ORNL) has carried out a comprehensive aging assessment of motor-operated valves (MOVs) in support of the Nuclear Plant Aging Research (NPAR) program. This paper provides a summary of the ORNL MOV aging assessment with emphasis on the identification, evaluation, and application of MOV monitoring methods and techniques. The diagnostic information available from any MOV measurable parameters was evaluated by ORNL using MOVs that were mounted on test stands. Those tests led to the conclusion that the single most informative MOV measurable parameter was also the one which was most easily acquired, namely the motor current. Motor current signature analysis (MCSA) was found to provide detailed information related to the condition of the motor, motor operator, and valve across a wide range of levels. As part of the MOV aging assessment, several tests were carried out by ORNL on MOVs having implanted defects and degradations. Tests were also performed on many MOVs located within a nuclear power plant. In addition, ORNL participated in the Gate Valve Flow Interruption Blowdown Test program carried out at Wyle Laboratories in Huntsville, Alabama. Results from all of these tests are summarized in this paper and several selected examples are given. Other areas covered in this paper include descriptions of relevant regulatory issues and activities, other related diagnostics research at ORNL, and interactions ORNL has had with outside organizations for the purpose of disseminating research results.

  3. Predicting biodegradable volatile solids degradation profiles in the composting process.

    PubMed

    Mason, I G

    2009-02-01

    This paper presents a new method for the prediction of the pattern of biodegradable volatile solids (BVS) degradation in the composting process. The procedure is based on a re-arrangement of the heat balance around a composting system to numerically solve for the rate of BVS carbon (BVS-C) disappearance. Input data for the model was obtained from composting experiments conducted in a laboratory-scale, constant temperature difference (CTD) reactor simulating a section of an aerated static pile, and using a simulated feedstock comprising ostrich feed, shredded paper, finished compost and woodchips. These experiments also provided validation data in the form of exit gas CO(2) carbon (CO(2)-C) profiles. The model successfully predicted the generic shape of experimental substrate degradation profiles obtained from CO(2) measurements, but under the conditions and assumptions of the experiment, the profiles were quantitatively different, giving an over-estimate of BVS-C. Both measured CO(2)-C and predicted BVS-C profiles were moderately to well fitted by a single exponential function, with replicated rate coefficient values of 0.08 and 0.09 d(-1), and 0.06 and 0.07 d(-1), respectively. In order to explore the underlying shape of the profiles, measured and predicted data at varying temperature were corrected to a constant temperature of 40 degrees C, using the temperature correction function of Rosso et al. [Rosso, L., Lobry, J.R., and Flandrois, J.P., 1993. An unexpected correlation between cardinal temperatures of microbial growth highlighted by a new model. Journal of Theoretical Biology, 162, 447-463], with cardinal temperatures of 5, 59 and 85 degrees C. Multi-phase profiles were generated for both the measured CO(2)-C and the predicted BVS-C data in this case. However, when alternative cardinal temperatures of 5, 55 and 80 degrees C, or 5, 50 and 80 degrees C, were used, the predicted profiles assumed an exponential shape, and excellent fits were obtained using a

  4. Cortical activity predicts good variation in human motor output.

    PubMed

    Babikian, Sarine; Kanso, Eva; Kutch, Jason J

    2017-04-01

    Human movement patterns have been shown to be particularly variable if many combinations of activity in different muscles all achieve the same task goal (i.e., are goal-equivalent). The nervous system appears to automatically vary its output among goal-equivalent combinations of muscle activity to minimize muscle fatigue or distribute tissue loading, but the neural mechanism of this "good" variation is unknown. Here we use a bimanual finger task, electroencephalography (EEG), and machine learning to determine if cortical signals can predict goal-equivalent variation in finger force output. 18 healthy participants applied left and right index finger forces to repeatedly perform a task that involved matching a total (sum of right and left) finger force. As in previous studies, we observed significantly more variability in goal-equivalent muscle activity across task repetitions compared to variability in muscle activity that would not achieve the goal: participants achieved the task in some repetitions with more right finger force and less left finger force (right > left) and in other repetitions with less right finger force and more left finger force (left > right). We found that EEG signals from the 500 milliseconds (ms) prior to each task repetition could make a significant prediction of which repetitions would have right > left and which would have left > right. We also found that cortical maps of sites contributing to the prediction contain both motor and pre-motor representation in the appropriate hemisphere. Thus, goal-equivalent variation in motor output may be implemented at a cortical level.

  5. Neural Underpinnings of Impaired Predictive Motor Timing in Children with Developmental Coordination Disorder

    ERIC Educational Resources Information Center

    Debrabant, Julie; Gheysen, Freja; Caeyenberghs, Karen; Van Waelvelde, Hilde; Vingerhoets, Guy

    2013-01-01

    A dysfunction in predictive motor timing is put forward to underlie DCD-related motor problems. Predictive timing allows for the pre-selection of motor programmes (except "program" in computers) in order to decrease processing load and facilitate reactions. Using functional magnetic resonance imaging (fMRI), this study investigated the neural…

  6. Neural Underpinnings of Impaired Predictive Motor Timing in Children with Developmental Coordination Disorder

    ERIC Educational Resources Information Center

    Debrabant, Julie; Gheysen, Freja; Caeyenberghs, Karen; Van Waelvelde, Hilde; Vingerhoets, Guy

    2013-01-01

    A dysfunction in predictive motor timing is put forward to underlie DCD-related motor problems. Predictive timing allows for the pre-selection of motor programmes (except "program" in computers) in order to decrease processing load and facilitate reactions. Using functional magnetic resonance imaging (fMRI), this study investigated the neural…

  7. Visual-motor integration skills: accuracy of predicting reading.

    PubMed

    Santi, Kristi L; Francis, David J; Currie, Debra; Wang, Qianqian

    2015-02-01

    This article investigated the contribution of visual-motor integration (VMI) to reading ability when known predictors of later reading outcomes were also present in the data analysis. Participants included 778 first and second grade students from a large diverse urban district in Texas. The data were analyzed using multiple regression models with a forced entry of predictors for each regression model, and each model was run separately for each outcome. The results indicate that VMI drops out of the prediction models once more reading- and language-specific skills are introduced. Although VMI skills make a statistically significant contribution in some aspects of the regression model, the reduction in contribution reduces the predictive validity of VMI skills. Therefore, a VMI skill measure will not sufficiently determine if a child has a reading disability.

  8. Prediction of P300 BCI Aptitude in Severe Motor Impairment

    PubMed Central

    Halder, Sebastian; Ruf, Carolin Anne; Furdea, Adrian; Pasqualotto, Emanuele; De Massari, Daniele; van der Heiden, Linda; Bogdan, Martin; Rosenstiel, Wolfgang; Birbaumer, Niels; Kübler, Andrea; Matuz, Tamara

    2013-01-01

    Brain-computer interfaces (BCIs) provide a non-muscular communication channel for persons with severe motor impairments. Previous studies have shown that the aptitude with which a BCI can be controlled varies from person to person. A reliable predictor of performance could facilitate selection of a suitable BCI paradigm. Eleven severely motor impaired participants performed three sessions of a P300 BCI web browsing task. Before each session auditory oddball data were collected to predict the BCI aptitude of the participants exhibited in the current session. We found a strong relationship of early positive and negative potentials around 200 ms (elicited with the auditory oddball task) with performance. The amplitude of the P2 (r  =  −0.77) and of the N2 (r  =  −0.86) had the strongest correlations. Aptitude prediction using an auditory oddball was successful. The finding that the N2 amplitude is a stronger predictor of performance than P3 amplitude was reproduced after initially showing this effect with a healthy sample of BCI users. This will reduce strain on the end-users by minimizing the time needed to find suitable paradigms and inspire new approaches to improve performance. PMID:24204597

  9. Patients with Parkinson's disease can employ a predictive motor strategy.

    PubMed Central

    Day, B L; Dick, J P; Marsden, C D

    1984-01-01

    We have tested the hypothesis that predictive motor behaviour is abnormal in Parkinson's disease. In the first experiment elbow movements were performed to track a moving spot on an oscilloscope screen. The performance of 12 patients with Parkinson's disease and eight age-matched control subjects was measured when tracking a repeated pattern under two conditions. In the first condition subjects were not aware of the repetitive nature of the tracking task whilst in the second condition they were. For both groups tracking error and tracking lag were less when aware of the repetition. In the second experiment wrist movements were studied. Five age-matched controls were compared with five patients, studied on and off drugs. In this experiment the performance tracking a repeated pattern was compared to that tracking unpredictable patterns. Tracking lags were reduced to very low values (less than 20 ms) in response to the repeated pattern for both groups. This was true even when the patients were relatively immobile off drugs. We conclude that patients with Parkinson's disease are capable of predictive motor behaviour although such a strategy does not always confer as great an advantage in reducing tracking error in patients compared with control subjects. PMID:6512550

  10. Fine-motor skills testing and prediction of endovascular performance.

    PubMed

    Bech, Bo; Lönn, Lars; Schroeder, Torben V; Ringsted, Charlotte

    2013-12-01

    Performing endovascular procedures requires good control of fine-motor digital movements and hand-eye coordination. Objective assessment of such skills is difficult. Trainees acquire control of catheter/wire movements at various paces. However, little is known to what extent talent plays for novice candidates at entry to practice. To study the association between performance in a novel aptitude test of fine-motor skills and performance in simulated procedures. The test was based on manual course-tracking using a proprietary hand-operated roller-bar device coupled to a personal computer with monitor view rotation. A total of 40 test repetitions were conducted separately with each hand. Test scores were correlated with simulator performance. Group A (n = 14), clinicians with various levels of endovascular experience, performed a simulated procedure of contralateral iliac artery stenting. Group B (n = 19), medical students, performed 10 repetitions of crossing a challenging aortic bifurcation in a simulator. The test score differed markedly between the individuals in both groups, in particular with the non-dominant hand. Group A: the test score with the non-dominant hand correlated significantly with simulator performance assessed with the global rating scale SAVE (R = -0.69, P = 0.007). There was no association observed from performances with the dominant hand. Group B: there was no significant association between the test score and endovascular skills acquisition neither with the dominant nor with the non-dominant hand. Clinicians with increasing levels of endovascular technical experience had developed good fine-motor control of the non-dominant hand, in particular, that was associated with good procedural performance in the simulator. The aptitude test did not predict endovascular skills acquisition among medical students, thus, cannot be suggested for selection of novice candidates. Procedural experience and practice probably supplant the influence of innate

  11. Suitability of regulatory data to predict micropollutant degradation in rivers

    NASA Astrophysics Data System (ADS)

    Honti, Mark; Bischoff, Fabian; Moser, Andreas; Stamm, Christian; Fenner, Kathrin

    2017-04-01

    behavior of the chemicals in the river Rhine. For substances with OECD 308 data, predictions using compartment-specific degradation half-lives were found to be in accordance with measured concentrations, but not much different from simulations assuming no degradation. This suggests that the usually fairly long water half-lives dominated the compounds' behavior in the river Rhine. Besides this, it highlighted that the shorter total system half-lives derived from OECD 308 are indeed irrelevant for assessing persistence in medium to large river systems. For two substances, it was not possible to tune modelled concentration patterns to be in agreement with observed data, even when assuming different extents of degradation. This underlined the influence of input uncertainty (e.g. consumption in different countries and regions). Finally, the model was used to investigate what kind of water half-lives would result in an observable degradation along the Rhine. Substances with half-lives shorter than 9 days would show spatial concentration patterns that are clearly different from those of a conservative benchmark chemical, given the typical measurement, model and input uncertainty. Besides learning the inadequacy of certain indicators from laboratory simulation studies for assessment of environmental persistence, our results suggest that emissions of many organic micropollutants showing observable degradation in the laboratory are transferred almost without loss to the sea, even from such a large river basin as the Rhine.

  12. Neurobehavioral Assessment Predicts Motor Outcome in Preterm Infants

    PubMed Central

    Stephens, Bonnie E; Liu, Jing; Lester, Barry; Lagasse, Linda; Shankaran, Seetha; Bada, Henrietta; Bauer, Charles; Das, Abhik; Higgins, Rosemary

    2011-01-01

    Objective To determine whether Neonatal Intensive Care Unit Network Neurobehavior Scales (NNNS) at 44 weeks predict motor outcome at 2 years in preterm infants from the Maternal Lifestyles Study (MLS). Study design Data were collected on all preterm infants (<36 weeks) in the MLS who had an NNNS at 44 weeks (n=395) and neurologic exam at 12–36 months or Bayley Psychomotor Development Index (PDI) at 24 months (n=270). Logistic regression analyzed NNNS summary scores associated with Cerebral Palsy (CP) or PDI <70, while controlling for birth weight 1250g. Results Eighteen of 395 infants (5%) had CP; 24 of 270 infants (9%) had PDI <70. CP was associated with low quality of movement (OR 1.95, 95% CI 1.24–3.06, p=0.004) and high lethargy (OR 1.67, 95% CI 1.01–2.76, p=0.045). The model contributed 19% of the variance in CP diagnosis at 12–36 months (R2=0.19, p<0.001). Low PDI was associated with low handling (OR 1.83; 95% CI 1.12–2.99, p=0.017), low quality of movement (OR 2.16; 95%CI 1.38–3.38, p=0.001), and hypotonia (OR 1.63; 95% CI 1.14–2.32, p=0.007). The model contributed 26% of the variance in PDI <70 at 24 months (R2=0.26, p<0.001). Conclusions The neurobehavioral profile of underarousal in 44 week preterm infants may predict poor motor outcome. PMID:19880137

  13. Why Do Fine Motor Skills Predict Mathematics? Construct Validity of the Design Copying Task

    ERIC Educational Resources Information Center

    Murrah, William M.; Chen, Wei-Bing; Cameron, Claire E.

    2013-01-01

    Recent educational studies have found evidence that measures of fine motor skills are predictive of educational outcomes. However, the precise nature of fine motor skills has received little attention in these studies. With evidence mounting that fine motor skills are an important indicator of school readiness, investigating the nature of this…

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

    ERIC Educational Resources Information Center

    Hernandez, Amanda Martinez; Caçola, Priscila

    2015-01-01

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

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

    ERIC Educational Resources Information Center

    Hernandez, Amanda Martinez; Caçola, Priscila

    2015-01-01

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

  16. Perceptual learning of degraded speech by minimizing prediction error

    PubMed Central

    Sohoglu, Ediz

    2016-01-01

    Human perception is shaped by past experience on multiple timescales. Sudden and dramatic changes in perception occur when prior knowledge or expectations match stimulus content. These immediate effects contrast with the longer-term, more gradual improvements that are characteristic of perceptual learning. Despite extensive investigation of these two experience-dependent phenomena, there is considerable debate about whether they result from common or dissociable neural mechanisms. Here we test single- and dual-mechanism accounts of experience-dependent changes in perception using concurrent magnetoencephalographic and EEG recordings of neural responses evoked by degraded speech. When speech clarity was enhanced by prior knowledge obtained from matching text, we observed reduced neural activity in a peri-auditory region of the superior temporal gyrus (STG). Critically, longer-term improvements in the accuracy of speech recognition following perceptual learning resulted in reduced activity in a nearly identical STG region. Moreover, short-term neural changes caused by prior knowledge and longer-term neural changes arising from perceptual learning were correlated across subjects with the magnitude of learning-induced changes in recognition accuracy. These experience-dependent effects on neural processing could be dissociated from the neural effect of hearing physically clearer speech, which similarly enhanced perception but increased rather than decreased STG responses. Hence, the observed neural effects of prior knowledge and perceptual learning cannot be attributed to epiphenomenal changes in listening effort that accompany enhanced perception. Instead, our results support a predictive coding account of speech perception; computational simulations show how a single mechanism, minimization of prediction error, can drive immediate perceptual effects of prior knowledge and longer-term perceptual learning of degraded speech. PMID:26957596

  17. Perceptual learning of degraded speech by minimizing prediction error.

    PubMed

    Sohoglu, Ediz; Davis, Matthew H

    2016-03-22

    Human perception is shaped by past experience on multiple timescales. Sudden and dramatic changes in perception occur when prior knowledge or expectations match stimulus content. These immediate effects contrast with the longer-term, more gradual improvements that are characteristic of perceptual learning. Despite extensive investigation of these two experience-dependent phenomena, there is considerable debate about whether they result from common or dissociable neural mechanisms. Here we test single- and dual-mechanism accounts of experience-dependent changes in perception using concurrent magnetoencephalographic and EEG recordings of neural responses evoked by degraded speech. When speech clarity was enhanced by prior knowledge obtained from matching text, we observed reduced neural activity in a peri-auditory region of the superior temporal gyrus (STG). Critically, longer-term improvements in the accuracy of speech recognition following perceptual learning resulted in reduced activity in a nearly identical STG region. Moreover, short-term neural changes caused by prior knowledge and longer-term neural changes arising from perceptual learning were correlated across subjects with the magnitude of learning-induced changes in recognition accuracy. These experience-dependent effects on neural processing could be dissociated from the neural effect of hearing physically clearer speech, which similarly enhanced perception but increased rather than decreased STG responses. Hence, the observed neural effects of prior knowledge and perceptual learning cannot be attributed to epiphenomenal changes in listening effort that accompany enhanced perception. Instead, our results support a predictive coding account of speech perception; computational simulations show how a single mechanism, minimization of prediction error, can drive immediate perceptual effects of prior knowledge and longer-term perceptual learning of degraded speech.

  18. Motor prediction in Brain-Computer Interfaces for controlling mobile robots.

    PubMed

    Geng, Tao; Gan, John Q

    2008-01-01

    EEG-based Brain-Computer Interface (BCI) can be regarded as a new channel for motor control except that it does not involve muscles. Normal neuromuscular motor control has two fundamental components: (1) to control the body, and (2) to predict the consequences of the control command, which is called motor prediction. In this study, after training with a specially designed BCI paradigm based on motor imagery, two subjects learnt to predict the time course of some features of the EEG signals. It is shown that, with this newly-obtained motor prediction skill, subjects can use motor imagery of feet to directly control a mobile robot to avoid obstacles and reach a small target in a time-critical scenario.

  19. One’s motor performance predictably modulates the understanding of others’ actions through adaptation of premotor visuo-motor neurons

    PubMed Central

    Barchiesi, Guido; Tabarelli, Davide; Arfeller, Carola; Sato, Marc; Glenberg, Arthur M.

    2011-01-01

    Neurons firing both during self and other’s motor behavior (mirror neurons) have been described in the brain of vertebrates including humans. The activation of somatic motor programs driven by perceived behavior has been taken as evidence for mirror neurons’ contribution to cognition. The inverse relation, that is the influence of motor behavior on perception, is needed for demonstrating the long-hypothesized causal role of mirror neurons in action understanding. We provide here conclusive behavioral and neurophysiological evidence for that causal role by means of cross-modal adaptation coupled with a novel transcranial magnetic stimulation (TMS)-adaptation paradigm. Blindfolded repeated motor performance of an object-directed action (push or pull) induced in healthy participants a strong visual after-effect when categorizing others’ actions, as a result of motor-to-visual adaptation of visuo-motor neurons. TMS over the ventral premotor cortex, but not over the primary motor cortex, suppressed the after-effect, thus localizing the population of adapted visuo-motor neurons in the premotor cortex. These data are exquisitely consistent in humans with the existence of premotor mirror neurons that have access to the action meaning. We also show that controlled manipulation of the firing properties of this neural population produces strong predictable changes in the way we categorize others’ actions. PMID:21186167

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

    PubMed

    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.

  1. Infant and Toddler Oral- and Manual-Motor Skills Predict Later Speech Fluency in Autism

    ERIC Educational Resources Information Center

    Gernsbacher, Morton Ann; Sauer, Eve A.; Geye, Heather M.; Schweigert, Emily K.; Goldsmith, H. Hill

    2008-01-01

    Background: Spoken and gestural communication proficiency varies greatly among autistic individuals. Three studies examined the role of oral- and manual-motor skill in predicting autistic children's speech development. Methods: Study 1 investigated whether infant and toddler oral- and manual-motor skills predict middle childhood and teenage speech…

  2. Differences in Motor Imagery Time when Predicting Task Duration in Alpine Skiers and Equestrian Riders

    ERIC Educational Resources Information Center

    Louis, Magali; Collet, Christian; Champely, Stephane; Guillot, Aymeric

    2012-01-01

    Athletes' ability to use motor imagery (MI) to predict the speed at which they could perform a motor sequence has received little attention. In this study, 21 alpine skiers and 16 equestrian riders performed MI based on a prediction of actual performance time (a) after the course inspection, (b) before the start, and (c) after the actual…

  3. Differences in Motor Imagery Time when Predicting Task Duration in Alpine Skiers and Equestrian Riders

    ERIC Educational Resources Information Center

    Louis, Magali; Collet, Christian; Champely, Stephane; Guillot, Aymeric

    2012-01-01

    Athletes' ability to use motor imagery (MI) to predict the speed at which they could perform a motor sequence has received little attention. In this study, 21 alpine skiers and 16 equestrian riders performed MI based on a prediction of actual performance time (a) after the course inspection, (b) before the start, and (c) after the actual…

  4. Motor functioning differentially predicts mortality in men and women.

    PubMed

    Bravell, Marie Ernsth; Finkel, Deborah; Dahl Aslan, Anna; Reynolds, Chandra A; Hallgren, Jenny; Pedersen, Nancy L

    2017-09-01

    Research indicates gender differences in functional performance at advanced ages, but little is known about their impact on longevity for men and women. To derive a set of motor function factors from a battery of functional performance measures and examine their associations with mortality, incorporating possible gender interactions. Analyses were performed on the longitudinal Swedish Adoption/Twin Study of Aging (SATSA) including twenty-four assessments of motor function up to six times over a 19-year period. Three motor factors were derived from several factor analyses; fine motor, balance/upper strength, and flexibility. A latent growth curve model was used to capture longitudinal age changes in the motor factors and generated estimates of intercept at age 70 (I), rates of change before (S1) and after age 70 (S2) for each factor. Cox regression models were used to determine how gender in interaction with the motor factors was related to mortality. Females demonstrated lower functional performance in all motor functions relative to men. Cox regression survival analyses demonstrated that both balance/upper strength, and fine motor function were significantly related to mortality. Gender specific analyses revealed that this was true for women only. For men, none of the motor factors were related to mortality. Women demonstrated more difficulties in all functioning facets, and only among women were motor functioning (balance/upper strength and fine motor function) associated with mortality. These results provide evidence for the importance of considering motor functioning, and foremost observed gender differences when planning for individualized treatment and rehabilitation. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Predicting School Adjustment from Motor Abilities in Kindergarten

    ERIC Educational Resources Information Center

    Bart, Orit; Hajami, Dov; Bar-Haim, Yair

    2007-01-01

    The present study assessed the relations between basic motor abilities in kindergarten and scholastic, social, and emotional adaptation in the transition to formal schooling. Seventy-one five-year-old kindergarten children were administered a battery of standard assessments of basic motor functions. A year later, children's adjustment to school…

  6. Predicting School Adjustment from Motor Abilities in Kindergarten

    ERIC Educational Resources Information Center

    Bart, Orit; Hajami, Dov; Bar-Haim, Yair

    2007-01-01

    The present study assessed the relations between basic motor abilities in kindergarten and scholastic, social, and emotional adaptation in the transition to formal schooling. Seventy-one five-year-old kindergarten children were administered a battery of standard assessments of basic motor functions. A year later, children's adjustment to school…

  7. Accurate Prediction of Motor Failures by Application of Multi CBM Tools: A Case Study

    NASA Astrophysics Data System (ADS)

    Dutta, Rana; Singh, Veerendra Pratap; Dwivedi, Jai Prakash

    2017-05-01

    Motor failures are very difficult to predict accurately with a single condition-monitoring tool as both electrical and the mechanical systems are closely related. Electrical problem, like phase unbalance, stator winding insulation failures can, at times, lead to vibration problem and at the same time mechanical failures like bearing failure, leads to rotor eccentricity. In this case study of a 550 kW blower motor it has been shown that a rotor bar crack was detected by current signature analysis and vibration monitoring confirmed the same. In later months in a similar motor vibration monitoring predicted bearing failure and current signature analysis confirmed the same. In both the cases, after dismantling the motor, the predictions were found to be accurate. In this paper we will be discussing the accurate predictions of motor failures through use of multi condition monitoring tools with two case studies.

  8. tDCS-induced alterations in GABA concentration within primary motor cortex predict motor learning and motor memory: A 7 T magnetic resonance spectroscopy study

    PubMed Central

    Kim, Soyoung; Stephenson, Mary C.; Morris, Peter G.; Jackson, Stephen R.

    2014-01-01

    Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that alters cortical excitability in a polarity specific manner and has been shown to influence learning and memory. tDCS may have both on-line and after-effects on learning and memory, and the latter are thought to be based upon tDCS-induced alterations in neurochemistry and synaptic function. We used ultra-high-field (7 T) magnetic resonance spectroscopy (MRS), together with a robotic force adaptation and de-adaptation task, to investigate whether tDCS-induced alterations in GABA and Glutamate within motor cortex predict motor learning and memory. Note that adaptation to a robot-induced force field has long been considered to be a form of model-based learning that is closely associated with the computation and ‘supervised’ learning of internal ‘forward’ models within the cerebellum. Importantly, previous studies have shown that on-line tDCS to the cerebellum, but not to motor cortex, enhances model-based motor learning. Here we demonstrate that anodal tDCS delivered to the hand area of the left primary motor cortex induces a significant reduction in GABA concentration. This effect was specific to GABA, localised to the left motor cortex, and was polarity specific insofar as it was not observed following either cathodal or sham stimulation. Importantly, we show that the magnitude of tDCS-induced alterations in GABA concentration within motor cortex predicts individual differences in both motor learning and motor memory on the robotic force adaptation and de-adaptation task. PMID:24904994

  9. tDCS-induced alterations in GABA concentration within primary motor cortex predict motor learning and motor memory: a 7 T magnetic resonance spectroscopy study.

    PubMed

    Kim, Soyoung; Stephenson, Mary C; Morris, Peter G; Jackson, Stephen R

    2014-10-01

    Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that alters cortical excitability in a polarity specific manner and has been shown to influence learning and memory. tDCS may have both on-line and after-effects on learning and memory, and the latter are thought to be based upon tDCS-induced alterations in neurochemistry and synaptic function. We used ultra-high-field (7 T) magnetic resonance spectroscopy (MRS), together with a robotic force adaptation and de-adaptation task, to investigate whether tDCS-induced alterations in GABA and Glutamate within motor cortex predict motor learning and memory. Note that adaptation to a robot-induced force field has long been considered to be a form of model-based learning that is closely associated with the computation and 'supervised' learning of internal 'forward' models within the cerebellum. Importantly, previous studies have shown that on-line tDCS to the cerebellum, but not to motor cortex, enhances model-based motor learning. Here we demonstrate that anodal tDCS delivered to the hand area of the left primary motor cortex induces a significant reduction in GABA concentration. This effect was specific to GABA, localised to the left motor cortex, and was polarity specific insofar as it was not observed following either cathodal or sham stimulation. Importantly, we show that the magnitude of tDCS-induced alterations in GABA concentration within motor cortex predicts individual differences in both motor learning and motor memory on the robotic force adaptation and de-adaptation task. Copyright © 2014. Published by Elsevier Inc.

  10. Impaired Spatio-Temporal Predictive Motor Timing Associated with Spinocerebellar Ataxia Type 6

    PubMed Central

    Onuki, Yoshiyuki; Abdelgabar, Abdel R.; Owens, Cullen B.; Picard, Samuel; Willems, Jessica; Boele, Henk-Jan; Gazzola, Valeria; Van der Werf, Ysbrand D.; De Zeeuw, Chris I.

    2016-01-01

    Many daily life activities demand precise integration of spatial and temporal information of sensory inputs followed by appropriate motor actions. This type of integration is carried out in part by the cerebellum, which has been postulated to play a central role in learning and timing of movements. Cerebellar damage due to atrophy or lesions may compromise forward-model processing, in which both spatial and temporal cues are used to achieve prediction for future motor states. In the present study we sought to further investigate the cerebellar contribution to predictive and reactive motor timing, as well as to learning of sequential order and temporal intervals in these tasks. We tested patients with spinocerebellar ataxia type 6 (SCA6) and healthy controls for two related motor tasks; one requiring spatio-temporal prediction of dynamic visual stimuli and another one requiring reactive timing only. We found that healthy controls established spatio-temporal prediction in their responses with high temporal precision, which was absent in the cerebellar patients. SCA6 patients showed lower predictive motor timing, coinciding with a reduced number of correct responses during the ‘anticipatory’ period on the task. Moreover, on the task utilizing reactive motor timing functions, control participants showed both sequence order and temporal interval learning, whereas patients only showed sequence order learning. These results suggest that SCA6 affects predictive motor timing and temporal interval learning. Our results support and highlight cerebellar contribution to timing and argue for cerebellar engagement during spatio-temporal prediction of upcoming events. PMID:27571363

  11. Predicting parameters of degradation succession processes of Tibetan Kobresia grasslands

    NASA Astrophysics Data System (ADS)

    Lin, L.; Li, Y. K.; Xu, X. L.; Zhang, F. W.; Du, Y. G.; Liu, S. L.; Guo, X. W.; Cao, G. M.

    2015-11-01

    In the past two decades, increasing human activity (i.e., overgrazing) in the Tibetan Plateau has strongly influenced plant succession processes, resulting in the degradation of alpine grasslands. Therefore, it is necessary to diagnose the degree of degradation to enable implementation of appropriate management for sustainable exploitation and protection of alpine grasslands. Here, we investigated environmental factors and plant functional group (PFG) quantity factors during the alpine grassland succession processes. Principal component analysis (PCA) was used to identify the parameters indicative of degradation. We divided the entire degradation process into six stages. PFG types shifted from rhizome bunchgrasses to rhizome plexus and dense-plexus grasses during the degradation process. Leguminosae and Gramineae plants were replaced by sedges during the advanced stages of degradation. The PFGs were classified into two reaction groups: the grazing-sensitive group, containing Kobresia humilis Mey, and Gramineae and Leguminosae plants, and the grazing-insensitive group, containing Kobresia pygmaea Clarke. The first group was correlated with live root biomass in the surface soil (0-10 cm), whereas the second group was strongly correlated with mattic epipedon thickness and K. pygmaea characteristics. The degree of degradation of alpine meadows may be delineated by development of mattic epipedon and PFG composition. Thus, meadows could be easily graded and their use adjusted based on our scaling system, which would help prevent irreversible degradation of important grasslands. Because relatively few environmental factors are investigated, this approach can save time and labor to formulate a conservation management plan for degraded alpine meadows.

  12. Predicting parameters of degradation succession processes of Tibetan Kobresia grasslands

    NASA Astrophysics Data System (ADS)

    Lin, L.; Li, Y. K.; Xu, X. L.; Zhang, F. W.; Du, Y. G.; Liu, S. L.; Guo, X. W.; Cao, G. M.

    2015-08-01

    In the past two decades, increasing human activity (i.e., overgrazing) in the Tibetan Plateau has strongly influenced plant succession processes, resulting in the degradation of alpine grasslands. Therefore, it is necessary to diagnose the degree of degradation to enable implementation of appropriate management for sustainable exploitation and protection of alpine grasslands. Here, we investigated environmental factors and plant functional group quantity factors (PFGs) during the alpine grassland succession processes. Principal component analysis (PCA) was used to identify the parameters indicative of degradation. We divided the entire degradation process into six stages. PFG types shifted from rhizome bunch grasses to rhizome plexus and dense plexus grasses during the degradation process. Leguminosae and Gramineae plants were replaced by Sedges during the advanced stages of degradation. The PFGs were classified into two reaction groups: the grazing-sensitive group, containing Kobresia humilis Mey, and Gramineae and Leguminosae plants, and the grazing-insensitive group, containing Kobresia pygmaea Clarke. The first group was correlated with live root biomass in the surface soil (0-10 cm), whereas the second group was strongly correlated with mattic epipedon thickness and K. pygmaea characteristics. The degree of degradation of alpine meadows may be delineated by development of mattic epipedon and PFG composition. Thus, meadows could be easily graded and their use adjusted based on our scaling system, which would help prevent irreversible degradation of important grasslands. Because relatively few environmental factors are investigated, this approach can save time and labor to formulate a conservation management plan for degraded alpine meadows.

  13. CRHBP polymorphisms predict chronic pain development following motor vehicle collision.

    PubMed

    Linnstaedt, Sarah D; Bortsov, Andrey V; Soward, April C; Swor, Robert; Peak, David A; Jones, Jeffrey; Rathlev, Niels; Lee, David C; Domeier, Robert; Hendry, Phyllis L; McLean, Samuel A

    2016-01-01

    Musculoskeletal pain (MSP) is a common sequela of traumatic stress exposure. While biological factors contributing to chronic MSP after motor vehicle collision (MVC) have traditionally focused on tissue injury, increasing evidence suggests that neuro/stress/immune processes mediated by stress system activation may play a more dominant role. In a previous study, we found that genetic variants in the hypothalamic-pituitary-adrenal (HPA) axis-related gene FKBP5 influence vulnerability to persistent MSP 6 weeks after MVC. In the present cohort study (n = 855), we evaluated whether genetic variants in several other important HPA axis-related genes, including the glucocorticoid receptor (NR3C1), corticotropin-releasing hormone receptor R1 (CRHR1), and corticotropin-releasing hormone-binding protein (CRHBP), influence risk of chronic MSP over time after MVC. Genetic polymorphism rs7718461 in the CRHBP gene showed significant association (P = 0.0012) with overall pain severity during the year after MVC in regression models controlling for multiple comparisons. Two additional CRHBP alleles in high linkage disequilibrium with rs7718461 also showed trend-level significance. In secondary analyses, a significant interaction between this CRHBP locus (minor allele frequency = 0.33) and time was observed (P = 0.015), with increasing effect observed over time following trauma. A significant CRHBP × FKBP5 interaction was also observed, with substantially increased MSP after MVC in those with a risk allele in both genes compared with either gene alone. The results of this study indicate that genetic variants in 2 different HPA axis genes predict chronic MSP severity following MVC and support the hypothesis that the HPA axis is involved in chronic post-MVC MSP pathogenesis.

  14. Predicting Chandra CCD Degradation with the Chandra Radiation Model

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Blackwell, William C.; DePasquale, Joseph M.; Grant, Catherine E.; O'Dell, Stephen L.; Plucinsky, Paul P.; Schwartz, Daniel A.; Spitzbart, Bradley D.; Wolk, Scott J.

    2008-01-01

    Not long after launch of the Chandra X-Ray Observatory, it was discovered that the Advanced CCD Imaging Spectrometer (ACIS) detector was rapidly degrading due to radiation. Analysis by Chandra personnel showed that this degradation was due to 10w energy protons (100 - 200 keV) that scattered down the optical path onto the focal plane. In response to this unexpected problem, the Chandra Team developed a radiation-protection program that has been used to manage the radiation damage to the CCDs. This program consists of multiple approaches - scheduled sating of the ACIS detector from the radiation environment during passage through radiation belts, real-time monitoring of space weather conditions, on-board monitoring of radiation environment levels, and the creation of a radiation environment model for use in computing proton flux and fluence at energies that damage the ACIS detector. This radiation mitigation program has been very successful. The initial precipitous increase in the CCDs' charge transfer inefficiency (CTI) resulting from proton damage has been slowed dramatically, with the front-illuminated CCDS having an increase in CTI of only 2.3% per year, allowing the ASIS detector's expected lifetime to exceed requirements. This paper concentrates on one aspect of the Chandra radiation mitigation program, the creation of the Chandra Radiation Model (CRM). Because of Chandra's highly elliptical orbit, the spacecraft spends most of its time outside of the trapped radiation belts that present the severest risks to the ACIS detector. However, there is still a proton flux environment that must be accounted for in all parts of Chandra's orbit. At the time of Chandra's launch there was no engineering model of the radiation environment that could be used in the outer regions of the spacecraft's orbit, so the CRM was developed to provide the flux environment of 100 - 200 keV protons in the outer magnetosphere, magnetosheath, and solar wind regions of geospace. This

  15. The Caenorhabditis elegans Kinesin-3 Motor UNC-104/KIF1A Is Degraded upon Loss of Specific Binding to Cargo

    PubMed Central

    Metpally, Raghu; Zheng, Qun; Nonet, Michael L.; Ramanathan, Sowdhamini; Klopfenstein, Dieter R.; Koushika, Sandhya P.

    2010-01-01

    UNC-104/KIF1A is a Kinesin-3 motor that transports synaptic vesicles from the cell body towards the synapse by binding to PI(4,5)P2 through its PH domain. The fate of the motor upon reaching the synapse is not known. We found that wild-type UNC-104 is degraded at synaptic regions through the ubiquitin pathway and is not retrogradely transported back to the cell body. As a possible means to regulate the motor, we tested the effect of cargo binding on UNC-104 levels. The unc-104(e1265) allele carries a point mutation (D1497N) in the PI(4,5)P2 binding pocket of the PH domain, resulting in greatly reduced preferential binding to PI(4,5)P2 in vitro and presence of very few motors on pre-synaptic vesicles in vivo. unc-104(e1265) animals have poor locomotion irrespective of in vivo PI(4,5)P2 levels due to reduced anterograde transport. Moreover, they show highly reduced levels of UNC-104 in vivo. To confirm that loss of cargo binding specificity reduces motor levels, we isolated two intragenic suppressors with compensatory mutations within the PH domain. These show partial restoration of in vitro preferential PI(4,5)P2 binding and presence of more motors on pre-synaptic vesicles in vivo. These animals show improved locomotion dependent on in vivo PI(4,5)P2 levels, increased anterograde transport, and partial restoration of UNC-104 protein levels in vivo. For further proof, we mutated a conserved residue in one suppressor background. The PH domain in this triple mutant lacked in vitro PI(4,5)P2 binding specificity, and the animals again showed locomotory defects and reduced motor levels. All allelic variants show increased UNC-104 levels upon blocking the ubiquitin pathway. These data show that inability to bind cargo can target motors for degradation. In view of the observed degradation of the motor in synaptic regions, this further suggests that UNC-104 may get degraded at synapses upon release of cargo. PMID:21079789

  16. The Caenorhabditis elegans Kinesin-3 motor UNC-104/KIF1A is degraded upon loss of specific binding to cargo.

    PubMed

    Kumar, Jitendra; Choudhary, Bikash C; Metpally, Raghu; Zheng, Qun; Nonet, Michael L; Ramanathan, Sowdhamini; Klopfenstein, Dieter R; Koushika, Sandhya P

    2010-11-04

    UNC-104/KIF1A is a Kinesin-3 motor that transports synaptic vesicles from the cell body towards the synapse by binding to PI(4,5)P(2) through its PH domain. The fate of the motor upon reaching the synapse is not known. We found that wild-type UNC-104 is degraded at synaptic regions through the ubiquitin pathway and is not retrogradely transported back to the cell body. As a possible means to regulate the motor, we tested the effect of cargo binding on UNC-104 levels. The unc-104(e1265) allele carries a point mutation (D1497N) in the PI(4,5)P(2) binding pocket of the PH domain, resulting in greatly reduced preferential binding to PI(4,5)P(2)in vitro and presence of very few motors on pre-synaptic vesicles in vivo. unc-104(e1265) animals have poor locomotion irrespective of in vivo PI(4,5)P(2) levels due to reduced anterograde transport. Moreover, they show highly reduced levels of UNC-104 in vivo. To confirm that loss of cargo binding specificity reduces motor levels, we isolated two intragenic suppressors with compensatory mutations within the PH domain. These show partial restoration of in vitro preferential PI(4,5)P(2) binding and presence of more motors on pre-synaptic vesicles in vivo. These animals show improved locomotion dependent on in vivo PI(4,5)P(2) levels, increased anterograde transport, and partial restoration of UNC-104 protein levels in vivo. For further proof, we mutated a conserved residue in one suppressor background. The PH domain in this triple mutant lacked in vitro PI(4,5)P(2) binding specificity, and the animals again showed locomotory defects and reduced motor levels. All allelic variants show increased UNC-104 levels upon blocking the ubiquitin pathway. These data show that inability to bind cargo can target motors for degradation. In view of the observed degradation of the motor in synaptic regions, this further suggests that UNC-104 may get degraded at synapses upon release of cargo.

  17. Predicted sensory feedback derived from motor commands does not improve haptic sensitivity.

    PubMed

    Sciutti, Alessandra; Squeri, Valentina; Gori, Monica; Masia, Lorenzo; Sandini, Giulio; Konczak, Jürgen

    2010-01-01

    Haptic perception is based on the integration of afferent proprioceptive and tactile signals. A further potential source of information during active touch is predicted sensory feedback (PSF) derived from a copy of efferent motor commands that give rise to the exploratory actions. There is substantial evidence that PSF is important for predicting the sensory consequences of action, but its role in perception is unknown. Theoretically, PSF leads to a higher redundancy of haptic information, which should improve sensitivity of the haptic sense. To investigate the effect of PSF on haptic precision, blindfolded subjects haptically explored the curved contour of a virtual object generated by a robotic manipulandum. They either actively moved their hand along the contour, or their hand was moved passively by the device along the same contour. In the active condition afferent sensory information and PSF were present, while in the passive condition subjects relied solely on afferent information. In each trial, two stimuli of different curvature were presented. Subjects needed to indicate which of the two was more "curved" (forced choice). For each condition, the detection and three discrimination thresholds were computed. The main finding is that absence of efference copy information did not systematically degrade haptic acuity. This indirectly implies that PSF does not aid or enhance haptic perception. We conclude that when maximum haptic sensitivity is required to explore novel objects, the perceptual system relies primarily on afferent tactile and proprioceptive information, and PSF has no added effect on the precision of the perceptual estimate.

  18. Value of somatosensory and motor evoked potentials in predicting arm recovery after a stroke

    PubMed Central

    Feys, H.; Van Hees, J.; Bruyninckx, F.; Mercelis, R.; De Weerdt, W.

    2000-01-01

    OBJECTIVES—Prediction of motor recovery in the arm in patients with stroke is generally based on clinical examination. However, neurophysiological measures may also have a predictive value. The aims of this study were to assess the role of somatosensory (SSEPs) and motor (MEPs) evoked potentials in the prediction of arm motor recovery and to determine whether these measures added further predictive information to that gained from clinical examination.
METHODS—Sixty four patients who had had a stroke and presented with obvious motor deficit of the arm were examined in terms of three clinical variables (motor performance, muscle tone, and overall disability) and for SSEPs and MEPs. Clinical and neurophysiological examinations were done at entry to the study (2 to 5 weeks poststroke), and at about 2 months after stroke. Further clinical follow up was conducted at 6 and 12 months after stroke.
RESULTS—Neurophysiological measures made in the acute phase were of little use alone in predicting motor recovery of the arm at 2,6, and 12 months after stroke. At 2 months, the absence of SSEPs and MEPs indicated a very poor outcome. Conversely, if the responses were preserved, a great variation in motor outcome was found. Multiple regression analysis showed that the addition of SSEPs and MEPs to the clinical examination increased the possibility of predicting arm recovery in the long term. In the acute phase, the combination of the motor score and SSEPs were best able to predict outcome. The long term outcome based on variables taken at 2 months, was best predicted through incorporating the three clinical measures and MEPs.
CONCLUSIONS—Neurophysiological measures alone are of limited value in predicting long term outcome. However, predictive accuracy is substantially improved through the combined use of both of these measures and clinical variables.

 PMID:10675214

  19. Prediction of Later Cognitive Behavior from Early School Perceptual-Motor, Perceptual, and Cognitive Performances.

    ERIC Educational Resources Information Center

    Belka, David E.; Williams, Harriet G.

    1979-01-01

    The battery of perceptual and perceptual-motor tests (including one fine and two gross perceptual-motor tasks, and one visual and two auditory perceptual tasks) were useful for prediction of cognitive performance one year later at kindergarten age. However, cognitive achievement in first grade, and even more so in second grade, was best predicted…

  20. DTI measures track and predict motor function outcomes in stroke rehabilitation utilizing BCI technology

    PubMed Central

    Song, Jie; Nair, Veena A.; Young, Brittany M.; Walton, Leo M.; Nigogosyan, Zack; Remsik, Alexander; Tyler, Mitchell E.; Farrar-Edwards, Dorothy; Caldera, Kristin E.; Sattin, Justin A.; Williams, Justin C.; Prabhakaran, Vivek

    2015-01-01

    Tracking and predicting motor outcomes is important in determining effective stroke rehabilitation strategies. Diffusion tensor imaging (DTI) allows for evaluation of the underlying structural integrity of brain white matter tracts and may serve as a potential biomarker for tracking and predicting motor recovery. In this study, we examined the longitudinal relationship between DTI measures of the posterior limb of the internal capsule (PLIC) and upper-limb motor outcomes in 13 stroke patients (median 20-month post-stroke) who completed up to 15 sessions of intervention using brain–computer interface (BCI) technology. Patients’ upper-limb motor outcomes and PLIC DTI measures including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) were assessed longitudinally at four time points: pre-, mid-, immediately post- and 1-month-post intervention. DTI measures and ratios of each DTI measure comparing the ipsilesional and contralesional PLIC were correlated with patients’ motor outcomes to examine the relationship between structural integrity of the PLIC and patients’ motor recovery. We found that lower diffusivity and higher FA values of the ipsilesional PLIC were significantly correlated with better upper-limb motor function. Baseline DTI ratios were significantly correlated with motor outcomes measured immediately post and 1-month-post BCI interventions. A few patients achieved improvements in motor recovery meeting the minimum clinically important difference (MCID). These findings suggest that upper-limb motor recovery in stroke patients receiving BCI interventions relates to the microstructural status of the PLIC. Lower diffusivity and higher FA measures of the ipsilesional PLIC contribute toward better motor recovery in the stroke-affected upper-limb. DTI-derived measures may be a clinically useful biomarker in tracking and predicting motor recovery in stroke patients receiving BCI interventions. PMID

  1. Motor Testing at 1 Year Improves the Prediction of Motor and Mental Outcome at 2 Years after Perinatal Hypoxic-Ischaemic Encephalopathy

    ERIC Educational Resources Information Center

    van Schie, Petra Em; Becher, Jules G.; Dallmeijer, Annet J.; Barkhof, Frederik; van Weissenbruch, Mirjam M.; Vermeulen, R. Jeroen

    2010-01-01

    Aim: To investigate the predictive value of motor testing at 1 year for motor and mental outcome at 2 years after perinatal hypoxic-ischaemic encephalopathy (HIE) in term neonates. Method: Motor and mental outcome at 2 years was assessed with the Bayley Scales of Infant Development, 2nd edition (BSID-II) in 32 surviving children (20 males, 12…

  2. Motor Testing at 1 Year Improves the Prediction of Motor and Mental Outcome at 2 Years after Perinatal Hypoxic-Ischaemic Encephalopathy

    ERIC Educational Resources Information Center

    van Schie, Petra Em; Becher, Jules G.; Dallmeijer, Annet J.; Barkhof, Frederik; van Weissenbruch, Mirjam M.; Vermeulen, R. Jeroen

    2010-01-01

    Aim: To investigate the predictive value of motor testing at 1 year for motor and mental outcome at 2 years after perinatal hypoxic-ischaemic encephalopathy (HIE) in term neonates. Method: Motor and mental outcome at 2 years was assessed with the Bayley Scales of Infant Development, 2nd edition (BSID-II) in 32 surviving children (20 males, 12…

  3. Fine Motor Skills Predict Maths Ability Better than They Predict Reading Ability in the Early Primary School Years.

    PubMed

    Pitchford, Nicola J; Papini, Chiara; Outhwaite, Laura A; Gulliford, Anthea

    2016-01-01

    Fine motor skills have long been recognized as an important foundation for development in other domains. However, more precise insights into the role of fine motor skills, and their relationships to other skills in mediating early educational achievements, are needed to support the development of optimal educational interventions. We explored concurrent relationships between two components of fine motor skills, Fine Motor Precision and Fine Motor Integration, and early reading and maths development in two studies with primary school children of low-to-mid socio-economic status in the UK. Two key findings were revealed. First, despite being in the first 2 years of primary school education, significantly better performance was found in reading compared to maths across both studies. This may reflect the protective effects of recent national-level interventions to promote early literacy skills in young children in the UK that have not been similarly promoted for maths. Second, fine motor skills were a better predictor of early maths ability than they were of early reading ability. Hierarchical multiple regression revealed that fine motor skills did not significantly predict reading ability when verbal short-term memory was taken into account. In contrast, Fine Motor Integration remained a significant predictor of maths ability, even after the influence of non-verbal IQ had been accounted for. These results suggest that fine motor skills should have a pivotal role in educational interventions designed to support the development of early mathematical skills.

  4. Fine Motor Skills Predict Maths Ability Better than They Predict Reading Ability in the Early Primary School Years

    PubMed Central

    Pitchford, Nicola J.; Papini, Chiara; Outhwaite, Laura A.; Gulliford, Anthea

    2016-01-01

    Fine motor skills have long been recognized as an important foundation for development in other domains. However, more precise insights into the role of fine motor skills, and their relationships to other skills in mediating early educational achievements, are needed to support the development of optimal educational interventions. We explored concurrent relationships between two components of fine motor skills, Fine Motor Precision and Fine Motor Integration, and early reading and maths development in two studies with primary school children of low-to-mid socio-economic status in the UK. Two key findings were revealed. First, despite being in the first 2 years of primary school education, significantly better performance was found in reading compared to maths across both studies. This may reflect the protective effects of recent national-level interventions to promote early literacy skills in young children in the UK that have not been similarly promoted for maths. Second, fine motor skills were a better predictor of early maths ability than they were of early reading ability. Hierarchical multiple regression revealed that fine motor skills did not significantly predict reading ability when verbal short-term memory was taken into account. In contrast, Fine Motor Integration remained a significant predictor of maths ability, even after the influence of non-verbal IQ had been accounted for. These results suggest that fine motor skills should have a pivotal role in educational interventions designed to support the development of early mathematical skills. PMID:27303342

  5. Motor Abnormalities in Premanifest Persons with Huntington’s Disease: The PREDICT-HD Study

    PubMed Central

    Biglan, Kevin M.; Ross, Christopher A.; Langbehn, Douglas R.; Aylward, Elizabeth H.; Stout, Julie C.; Queller, Sarah; Carlozzi, Noelle E.; Duff, Kevin; Beglinger, Leigh J.; Paulsen, Jane S.

    2011-01-01

    Background The PREDICT-HD study seeks to identify clinical and biological markers of Huntington’s disease in premanifest individuals who have undergone predictive genetic testing. Methods We compared baseline motor data between gene-expansion carriers (cases) and non gene-expansion carriers (controls) using T-tests and Chi-Square. Cases were categorized as near, mid or far from diagnosis using a CAG-based formula. Striatal volumes were calculated using volumetric MRI measurements. Multiple linear regression associated total motor score, motor domains and individual motor items with estimated diagnosis and striatal volumes. Results Elevated total motor scores at baseline were associated with higher genetic probability of disease diagnosis in the near future (partial R2 0.14, p<0.0001) and smaller striatal volumes (partial R2 0.15, p<0.0001). Nearly all motor domain scores showed greater abnormality with increasing proximity to diagnosis, although bradykinesia and chorea were most highly associated with diagnostic immediacy. Among individual motor items, worse scores on finger tapping, tandem gait, Luria, saccade initiation, and chorea show unique association with diagnosis probability. Conclusions Even in this premanifest population subtle motor abnormalities were associated with a higher probability of disease diagnosis and smaller striatal volumes. Longitudinal assessment will help inform whether motor items will be useful measures in preventive clinical trials. PMID:19562761

  6. Motor abnormalities in premanifest persons with Huntington's disease: the PREDICT-HD study.

    PubMed

    Biglan, Kevin M; Ross, Christopher A; Langbehn, Douglas R; Aylward, Elizabeth H; Stout, Julie C; Queller, Sarah; Carlozzi, Noelle E; Duff, Kevin; Beglinger, Leigh J; Paulsen, Jane S

    2009-09-15

    The PREDICT-HD study seeks to identify clinical and biological markers of Huntington's disease in premanifest individuals who have undergone predictive genetic testing. We compared baseline motor data between gene-expansion carriers (cases) and nongene-expansion carriers (controls) using t-tests and Chi-square. Cases were categorized as near, mid, or far from diagnosis using a CAG-based formula. Striatal volumes were calculated using volumetric magnetic resonance imaging measurements. Multiple linear regression associated total motor score, motor domains, and individual motor items with estimated diagnosis and striatal volumes. Elevated total motor scores at baseline were associated with higher genetic probability of disease diagnosis in the near future (partial R(2) 0.14, P < 0.0001) and smaller striatal volumes (partial R(2) 0.15, P < 0.0001). Nearly all motor domain scores showed greater abnormality with increasing proximity to diagnosis, although bradykinesia and chorea were most highly associated with diagnostic immediacy. Among individual motor items, worse scores on finger tapping, tandem gait, Luria, saccade initiation, and chorea show unique association with diagnosis probability. Even in this premanifest population, subtle motor abnormalities were associated with a higher probability of disease diagnosis and smaller striatal volumes. Longitudinal assessment will help inform whether motor items will be useful measures in preventive clinical trials.

  7. Premotor neural correlates of predictive motor timing for speech production and hand movement: evidence for a temporal predictive code in the motor system.

    PubMed

    Johari, Karim; Behroozmand, Roozbeh

    2017-05-01

    The predictive coding model suggests that neural processing of sensory information is facilitated for temporally-predictable stimuli. This study investigated how temporal processing of visually-presented sensory cues modulates movement reaction time and neural activities in speech and hand motor systems. Event-related potentials (ERPs) were recorded in 13 subjects while they were visually-cued to prepare to produce a steady vocalization of a vowel sound or press a button in a randomized order, and to initiate the cued movement following the onset of a go signal on the screen. Experiment was conducted in two counterbalanced blocks in which the time interval between visual cue and go signal was temporally-predictable (fixed delay at 1000 ms) or unpredictable (variable between 1000 and 2000 ms). Results of the behavioral response analysis indicated that movement reaction time was significantly decreased for temporally-predictable stimuli in both speech and hand modalities. We identified premotor ERP activities with a left-lateralized parietal distribution for hand and a frontocentral distribution for speech that were significantly suppressed in response to temporally-predictable compared with unpredictable stimuli. The premotor ERPs were elicited approximately -100 ms before movement and were significantly correlated with speech and hand motor reaction times only in response to temporally-predictable stimuli. These findings suggest that the motor system establishes a predictive code to facilitate movement in response to temporally-predictable sensory stimuli. Our data suggest that the premotor ERP activities are robust neurophysiological biomarkers of such predictive coding mechanisms. These findings provide novel insights into the temporal processing mechanisms of speech and hand motor systems.

  8. Calpain-Dependent Degradation of Nucleoporins Contributes to Motor Neuron Death in a Mouse Model of Chronic Excitotoxicity.

    PubMed

    Sugiyama, Kaori; Aida, Tomomi; Nomura, Masatoshi; Takayanagi, Ryoichi; Zeilhofer, Hanns U; Tanaka, Kohichi

    2017-09-06

    Glutamate-mediated excitotoxicity induces neuronal death by altering various intracellular signaling pathways and is implicated as a common pathogenic pathway in many neurodegenerative diseases. In the case of motor neuron disease, there is significant evidence to suggest that the overactivation of AMPA receptors due to deficiencies in the expression and function of glial glutamate transporters GLT1 and GLAST plays an important role in the mechanisms of neuronal death. However, a causal role for glial glutamate transporter dysfunction in motor neuron death remains unknown. Here, we developed a new animal model of excitotoxicity by conditionally deleting astroglial glutamate transporters GLT1 and GLAST in the spinal cords of mice (GLAST(+/-)/GLT1-cKO). GLAST(+/-)/GLT1-cKO mice (both sexes) exhibited nuclear irregularity and calpain-mediated degradation of nuclear pore complexes (NPCs), which are responsible for nucleocytoplasmic transport. These abnormalities were associated with progressive motor neuron loss, severe paralysis, and shortened lifespan. The nuclear export inhibitor KPT-350 slowed but did not prevent motor neuron death, whereas long-term treatment of the AMPA receptor antagonist perampanel and the calpain inhibitor SNJ-1945 had more persistent beneficial effects. Thus, NPC degradation contributes to AMPA receptor-mediated excitotoxic motor neuronal death, and preventing NPC degradation has robust protective effects. Normalization of NPC function could be a novel therapeutic strategy for neurodegenerative disorders in which AMPA receptor-mediated excitotoxicity is a contributory factor.SIGNIFICANCE STATEMENT Despite glial glutamate transporter dysfunction leading to excitotoxicity has been documented in many neurological diseases, it remains unclear whether its dysfunction is a primary cause or secondary outcome of neuronal death at disease state. Here we show the combined loss of glial glutamate transporters GLT1 and GLAST in spinal cord caused motor

  9. Gross motor ability predicts response to upper extremity rehabilitation in chronic stroke.

    PubMed

    George, Sarah Hulbert; Rafiei, Mohammad Hossein; Borstad, Alexandra; Adeli, Hojjat; Gauthier, Lynne V

    2017-08-30

    The majority of rehabilitation research focuses on the comparative effectiveness of different interventions in groups of patients, while much less is currently known regarding individual factors that predict response to rehabilitation. In a recent article, the authors presented a prognostic model to identify the sensorimotor characteristics predictive of the extent of motor recovery after Constraint-Induced Movement (CI) therapy amongst individuals with chronic mild-to-moderate motor deficit using the enhanced probabilistic neural network (EPNN). This follow-up paper examines which participant characteristics are robust predictors of rehabilitation response irrespective of the training modality. To accomplish this, EPNN was first applied to predict treatment response amongst individuals who received a virtual-reality gaming intervention (utilizing the same enrollment criteria as the prior study). The combinations of predictors that yield high predictive validity for both therapies, using their respective datasets, were then identified. High predictive classification accuracy was achieved for both the gaming (94.7%) and combined datasets (94.5%). Though CI therapy employed primarily fine-motor training tasks and the gaming intervention emphasized gross-motor practice, larger improvements in gross motor function were observed within both datasets. Poorer gross motor ability at pre-treatment predicted better rehabilitation response in both the gaming and combined datasets. The conclusion of this research is that for individuals with chronic mild-to-moderate upper extremity hemiparesis, residual deficits in gross motor function are highly responsive to motor restorative interventions, irrespective of the modality of training. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Multivariate prediction of motor diagnosis in Huntington's disease: 12 years of PREDICT‐HD

    PubMed Central

    Long, Jeffrey D.

    2015-01-01

    Abstract Background It is well known in Huntington's disease that cytosine‐adenine‐guanine expansion and age at study entry are predictive of the timing of motor diagnosis. The goal of this study was to assess whether additional motor, imaging, cognitive, functional, psychiatric, and demographic variables measured at study entry increased the ability to predict the risk of motor diagnosis over 12 years. Methods One thousand seventy‐eight Huntington's disease gene–expanded carriers (64% female) from the Neurobiological Predictors of Huntington's Disease study were followed up for up to 12 y (mean = 5, standard deviation = 3.3) covering 2002 to 2014. No one had a motor diagnosis at study entry, but 225 (21%) carriers prospectively received a motor diagnosis. Analysis was performed with random survival forests, which is a machine learning method for right‐censored data. Results Adding 34 variables along with cytosine‐adenine‐guanine and age substantially increased predictive accuracy relative to cytosine‐adenine‐guanine and age alone. Adding six of the common motor and cognitive variables (total motor score, diagnostic confidence level, Symbol Digit Modalities Test, three Stroop tests) resulted in lower predictive accuracy than the full set, but still had twice the 5‐y predictive accuracy than when using cytosine‐adenine‐guanine and age alone. Additional analysis suggested interactions and nonlinear effects that were characterized in a post hoc Cox regression model. Conclusions Measurement of clinical variables can substantially increase the accuracy of predicting motor diagnosis over and above cytosine‐adenine‐guanine and age (and their interaction). Estimated probabilities can be used to characterize progression level and aid in future studies' sample selection. © 2015 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society PMID:26340420

  11. The Wada test might predict postoperative fine finger motor deficit after hemispherotomy.

    PubMed

    Fujimoto, Ayataka; Okanishi, Tohru; Nishimura, Mitsuyo; Kanai, Sotaro; Sato, Keishiro; Enoki, Hideo

    2017-09-07

    Cerebral hemispherotomy is a surgical method with a high rate of seizure reduction in patients with intractable epilepsy. However, there is a probability of postoperative motor deficits. The objective of this study was to investigate whether the Wada test can help predict motor function outcomes after hemispherotomy and, therefore, may be useful in decision-making and patient selection. A total of 13 patients with hemispherical intractable epilepsy underwent hemispherical disconnection surgeries. Six of them underwent the Wada test to evaluate motor function and language function followed by peri-insula hemispherotomy. The patients' age ranged from 11 to 45years (mean 27years). Three of six patients had reduced dexterity on the Wada test. The finger motor function in the other patients did not change on the Wada test. Postoperatively, all patients who had decreased fine motor movement on the Wada test showed postoperative clumsiness of their hands and fingers. The Wada test might predict postoperative fine finger motor deficit after hemispherotomy. This study showed that gross motor function was compensated in the ipsilateral hemisphere, whereas fine finger motor movement function remained in the contralateral frontal cortex. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Are animal models predictive for human postmortem muscle protein degradation?

    PubMed

    Ehrenfellner, Bianca; Zissler, Angela; Steinbacher, Peter; Monticelli, Fabio C; Pittner, Stefan

    2017-07-18

    A most precise determination of the postmortem interval (PMI) is a crucial aspect in forensic casework. Although there are diverse approaches available to date, the high heterogeneity of cases together with the respective postmortal changes often limit the validity and sufficiency of many methods. Recently, a novel approach for time since death estimation by the analysis of postmortal changes of muscle proteins was proposed. It is however necessary to improve the reliability and accuracy, especially by analysis of possible influencing factors on protein degradation. This is ideally investigated on standardized animal models that, however, require legitimization by a comparison of human and animal tissue, and in this specific case of protein degradation profiles. Only if protein degradation events occur in comparable fashion within different species, respective findings can sufficiently be transferred from the animal model to application in humans. Therefor samples from two frequently used animal models (mouse and pig), as well as forensic cases with representative protein profiles of highly differing PMIs were analyzed. Despite physical and physiological differences between species, western blot analysis revealed similar patterns in most of the investigated proteins. Even most degradation events occurred in comparable fashion. In some other aspects, however, human and animal profiles depicted distinct differences. The results of this experimental series clearly indicate the huge importance of comparative studies, whenever animal models are considered. Although animal models could be shown to reflect the basic principles of protein degradation processes in humans, we also gained insight in the difficulties and limitations of the applicability of the developed methodology in different mammalian species regarding protein specificity and methodic functionality.

  13. Nondestructive testing methods to predict effect of degradation on wood : a critical assessment

    Treesearch

    J. Kaiserlik

    1978-01-01

    Results are reported for an assessment of methods for predicting strength of wood, wood-based, or related material. Research directly applicable to nondestructive strength prediction was very limited. In wood, strength prediction research is limited to vibration decay, wave attenuation, and multiparameter "degradation models." Nonwood methods with potential...

  14. Fault degradation assessment of water hydraulic motor by impulse vibration signal with Wavelet Packet Analysis and Kolmogorov Smirnov Test

    NASA Astrophysics Data System (ADS)

    Chen, H. X.; Chua, Patrick S. K.; Lim, G. H.

    2008-10-01

    The machinery fault diagnosis is important for improving reliability and performance of systems. Many methods such as Time Synchronous Average (TSA), Fast Fourier Transform (FFT)-based spectrum analysis and short-time Fourier transform (STFT) have been applied in fault diagnosis and condition monitoring of mechanical system. The above methods analyze the signal in frequency domain with low resolution, which is not suitable for non-stationary vibration signal. The Kolmogorov-Smirnov (KS) test is a simple and precise technique in vibration signal analysis for machinery fault diagnosis. It has limited use and advantage to analyze the vibration signal with higher noise directly. In this paper, a new method for the fault degradation assessment of the water hydraulic motor is proposed based on Wavelet Packet Analysis (WPA) and KS test to analyze the impulsive energy of the vibration signal, which is used to detect the piston condition of water hydraulic motor. WPA is used to analyze the impulsive vibration signal from the casing of the water hydraulic motor to obtain the impulsive energy. The impulsive energy of the vibration signal can be obtained by the multi-decomposition based on Wavelet Packet Transform (WPT) and used as feature values to assess the fault degradation of the pistons. The kurtosis of the impulsive energy in the reconstructed signal from the Wavelet Packet coefficients is used to extract the feature values of the impulse energy by calculating the coefficients of the WPT multi-decomposition. The KS test is used to compare the kurtosis of the impulse energy of the vibration signal statistically under the different piston conditions. The results show the applicability and effectiveness of the proposed method to assess the fault degradation of the pistons in the water hydraulic motor.

  15. Critical Motor Involvement in Prediction of Human and Non-biological Motion Trajectories

    PubMed Central

    de Wit, Matthieu M.; Buxbaum, Laurel J.

    2017-01-01

    Objectives Adaptive interaction with the environment requires the ability to predict both human and non-biological motion trajectories. Prior accounts of the neurocognitive basis for prediction of these two motion classes may generally be divided into those that posit that non-biological motion trajectories are predicted using the same motor planning and/or simulation mechanisms used for human actions, and those that posit distinct mechanisms for each. Using brain lesion patients and healthy controls, this study examined critical neural substrates and behavioral correlates of human and non-biological motion prediction. Methods Twenty-seven left hemisphere stroke patients and 13 neurologically intact controls performed a visual occlusion task requiring prediction of pantomimed tool use, real tool use, and non-biological motion videos. Patients were also assessed with measures of motor strength and speed, praxis, and action recognition. Results Prediction impairment for both human and non-biological motion was associated with limb apraxia and, weakly, with the severity of motor production deficits, but not with action recognition ability. Furthermore, impairment for human and non-biological motion prediction was equivalently associated with lesions in the left inferior parietal cortex, left dorsal frontal cortex, and the left insula. Conclusions These data suggest that motor planning mechanisms associated with specific loci in the sensorimotor network are critical for prediction of spatiotemporal trajectory information characteristic of both human and non-biological motions. PMID:28205497

  16. The Cerebellum Generates Motor-to-Auditory Predictions: ERP Lesion Evidence

    ERIC Educational Resources Information Center

    Knolle, Franziska; Schroger, Erich; Baess, Pamela; Kotz, Sonja A.

    2012-01-01

    Forward predictions are crucial in motor action (e.g., catching a ball, or being tickled) but may also apply to sensory or cognitive processes (e.g., listening to distorted speech or to a foreign accent). According to the "internal forward model," the cerebellum generates predictions about somatosensory consequences of movements. These predictions…

  17. The Cerebellum Generates Motor-to-Auditory Predictions: ERP Lesion Evidence

    ERIC Educational Resources Information Center

    Knolle, Franziska; Schroger, Erich; Baess, Pamela; Kotz, Sonja A.

    2012-01-01

    Forward predictions are crucial in motor action (e.g., catching a ball, or being tickled) but may also apply to sensory or cognitive processes (e.g., listening to distorted speech or to a foreign accent). According to the "internal forward model," the cerebellum generates predictions about somatosensory consequences of movements. These predictions…

  18. Predicting motor outcome and death in term hypoxic-ischemic encephalopathy

    PubMed Central

    Martinez-Biarge, M.; Diez-Sebastian, J.; Kapellou, O.; Gindner, D.; Allsop, J.M.; Rutherford, M.A.

    2011-01-01

    Objectives: Central gray matter damage, the hallmark of term acute perinatal hypoxia-ischemia, frequently leads to severe cerebral palsy and sometimes death. The precision with which these outcomes can be determined from neonatal imaging has not been fully explored. We evaluated the accuracy of early brain MRI for predicting death, the presence and severity of motor impairment, and ability to walk at 2 years in term infants with hypoxic-ischemic encephalopathy (HIE) and basal ganglia–thalamic (BGT) lesions. Methods: From 1993 to 2007, 175 term infants with evidence of perinatal asphyxia, HIE, and BGT injury seen on early MRI scans were studied. BGT, white matter, posterior limb of the internal capsule (PLIC), and cortex and brainstem abnormality were classified by severity. Motor impairment was staged using the Gross Motor Function Classification System. Results: The severity of BGT lesions was strongly associated with the severity of motor impairment (Spearman rank correlation 0.77; p < 0.001). The association between white matter, cortical, and brainstem injury and motor impairment was less strong and only BGT injury correlated significantly in a logistic regression model. The predictive accuracy of severe BGT lesions for severe motor impairment was 0.89 (95% confidence interval 0.83–0.96). Abnormal PLIC signal intensity predicted the inability to walk independently by 2 years (sensitivity 0.92, specificity 0.77, positive predictive value 0.88, negative predictive value 0.85). Brainstem injury was the only factor with an independent association with death. Conclusion: We have shown that in term newborns with HIE and BGT injury, early MRI can be used to predict death and specific motor outcomes. PMID:21670434

  19. Acoustic emission strand burning technique for motor burning rate prediction

    NASA Technical Reports Server (NTRS)

    Christensen, W. N.

    1978-01-01

    An acoustic emission (AE) method is being used to measure the burning rate of solid propellant strands. This method has a precision of 0.5% and excellent burning rate correlation with both subscale and large rocket motors. The AE procedure burns the sample under water and measures the burning rate from the acoustic output. The acoustic signal provides a continuous readout during testing, which allows complete data analysis rather than the start-stop clockwires used by the conventional method. The AE method helps eliminate such problems as inhibiting the sample, pressure increase and temperature rise, during testing.

  20. Motor threshold predicts working memory performance in healthy humans.

    PubMed

    Schicktanz, Nathalie; Schwegler, Kyrill; Fastenrath, Matthias; Spalek, Klara; Milnik, Annette; Papassotiropoulos, Andreas; Nyffeler, Thomas; de Quervain, Dominique J-F

    2014-01-01

    Cognitive functions, such as working memory, depend on neuronal excitability in a distributed network of cortical regions. It is not known, however, if interindividual differences in cortical excitability are related to differences in working memory performance. In the present transcranial magnetic stimulation study, which included 188 healthy young subjects, we show that participants with lower resting motor threshold, which is related to higher corticospinal excitability, had increased 2-back working memory performance. The findings may help to better understand the link between cortical excitability and cognitive functions and may also have important clinical implications with regard to conditions of altered cortical excitability.

  1. Atrophy of spared grey matter tissue predicts poorer motor recovery and rehabilitation response in chronic stroke

    PubMed Central

    Gauthier, Lynne V.; Taub, Edward; Mark, Victor W.; Barghi, Ameen; Uswatte, Gitendra

    2011-01-01

    Background and Purpose Although the motor deficit following stroke is clearly due to the structural brain damage that has been sustained, this relationship is attenuated from the acute to chronic phases. We investigated the possibility that motor impairment and response to Constraint-Induced Movement therapy (CI therapy) in chronic stroke patients may relate more strongly to the structural integrity of brain structures remote from the lesion than to measures of overt tissue damage. Methods Voxel-based morphometry (VBM) analysis was performed on MRI scans from 80 chronic stroke patients to investigate whether variations in grey matter density were correlated with extent of residual motor impairment or with CI therapy-induced motor recovery. Results Decreased grey matter density in non-infarcted motor regions was significantly correlated with magnitude of residual motor deficit. In addition, reduced grey matter density in multiple remote brain regions predicted a lesser extent of motor improvement from CI therapy. Conclusions Atrophy in seemingly healthy parts of the brain that are distant from the infarct accounts for at least a portion of the sustained motor deficit in chronic stroke. PMID:22096036

  2. Spatial Attention, Motor Intention, and Bayesian Cue Predictability in the Human Brain.

    PubMed

    Kuhns, Anna B; Dombert, Pascasie L; Mengotti, Paola; Fink, Gereon R; Vossel, Simone

    2017-05-24

    Predictions about upcoming events influence how we perceive and respond to our environment. There is increasing evidence that predictions may be generated based upon previous observations following Bayesian principles, but little is known about the underlying cortical mechanisms and their specificity for different cognitive subsystems. The present study aimed at identifying common and distinct neural signatures of predictive processing in the spatial attentional and motor intentional system. Twenty-three female and male healthy human volunteers performed two probabilistic cueing tasks with either spatial or motor cues while lying in the fMRI scanner. In these tasks, the percentage of cue validity changed unpredictably over time. Trialwise estimates of cue predictability were derived from a Bayesian observer model of behavioral responses. These estimates were included as parametric regressors for analyzing the BOLD time series. Parametric effects of cue predictability in valid and invalid trials were considered to reflect belief updating by precision-weighted prediction errors. The brain areas exhibiting predictability-dependent effects dissociated between the spatial attention and motor intention task, with the right temporoparietal cortex being involved during spatial attention and the left angular gyrus and anterior cingulate cortex during motor intention. Connectivity analyses revealed that all three areas showed predictability-dependent coupling with the right hippocampus. These results suggest that precision-weighted prediction errors of stimulus locations and motor responses are encoded in distinct brain regions, but that crosstalk with the hippocampus may be necessary to integrate new trialwise outcomes in both cognitive systems.SIGNIFICANCE STATEMENT The brain is able to infer the environments' statistical structure and responds strongly to expectancy violations. In the spatial attentional domain, it has been shown that parts of the attentional networks are

  3. Quantification of primary motor pathways using diffusion MRI tractography and its application to predict postoperative motor deficits in children with focal epilepsy.

    PubMed

    Jeong, Jeong-Won; Asano, Eishi; Juhász, Csaba; Chugani, Harry T

    2014-07-01

    As a new tool to quantify primary motor pathways and predict postoperative motor deficits in children with focal epilepsy, the present study utilized a maximum a posteriori probability (MAP) classification of diffusion weighted imaging (DWI) tractography combined with Kalman filter. DWI was performed in 31 children with intractable focal epilepsy who underwent epilepsy surgery. Three primary motor pathways associated with "finger," "leg," and "face" were classified using DWI-MAP classifier and compared with the results of invasive electrical stimulation mapping (ESM) via receiver operating characteristic (ROC) curve analysis. The Kalman filter analysis was performed to generate a model to determine the probability of postoperative motor deficits as a function of the proximity between the resection margin and the finger motor pathway. The ROC curve analysis showed that the DWI-MAP achieves high accuracy up to 89% (finger), 88% (leg), 89% (face), in detecting the three motor areas within 20 mm, compared with ESM. Moreover, postoperative reduction of the fiber count of finger pathway was associated with postoperative motor deficits involving the hand. The prediction model revealed an accuracy of 92% in avoiding postoperative deficits if the distance between the resection margin and the finger motor pathway seen on preoperative DWI tractography was 19.5 mm. This study provides evidence that the DWI-MAP combined with Kalman filter can effectively identify the locations of cortical motor areas even in patients whose motor areas are difficult to identify using ESM, and also can serve as a reliable predictor for motor deficits following epilepsy surgery.

  4. Mechanism-based Representative Volume Elements (RVEs) for Predicting Property Degradations in Multiphase Materials

    SciTech Connect

    Xu, Wei; Sun, Xin; Li, Dongsheng; Ryu, Seun; Khaleel, Mohammad A.

    2013-02-01

    Quantitative understanding of the evolving thermal-mechanical properties of a multi-phase material hinges upon the availability of quantitative statistically representative microstructure descriptions. Questions then arise as to whether a two-dimensional (2D) or a three-dimensional (3D) representative volume element (RVE) should be considered as the statistically representative microstructure. Although 3D models are more representative than 2D models in general, they are usually computationally expensive and difficult to be reconstructed. In this paper, we evaluate the accuracy of a 2D RVE in predicting the property degradations induced by different degradation mechanisms with the multiphase solid oxide fuel cell (SOFC) anode material as an example. Both 2D and 3D microstructure RVEs of the anodes are adopted to quantify the effects of two different degradation mechanisms: humidity-induced electrochemical degradation and phosphorus poisoning induced structural degradation. The predictions of the 2D model are then compared with the available experimental measurements and the results from the 3D model. It is found that the 2D model, limited by its inability of reproducing the realistic electrical percolation, is unable to accurately predict the degradation of thermo-electrical properties. On the other hand, for the phosphorus poisoning induced structural degradation, both 2D and 3D microstructures yield similar results, indicating that the 2D model is capable of providing computationally efficient yet accurate results for studying the structural degradation within the anodes.

  5. Quantitative EEG for Predicting Upper-limb Motor Recovery in Chronic Stroke Robot-assisted Rehabilitation.

    PubMed

    Trujillo, Paula; Mastropietro, Alfonso; Scano, Alessandro; Chiavenna, Andrea; Mrakic-Sposta, Simona; Caimmi, Marco; Molteni, Franco; Rizzo, Giovanna

    2017-03-03

    Stroke is a leading cause for adult disability, which in many cases causes motor deficits. Despite the developments in motor rehabilitation techniques, recovery of upper limb functions after stroke is limited and heterogeneous in terms of outcomes, and knowledge of important factors that may affect the outcome of the therapy is necessary to make a reasonable prediction for individual patients. In this study, we assessed the relationship between quantitative electroencephalographic (QEEG) measures and the motor outcome in chronic stroke patients that underwent a robot-assisted rehabilitation program to evaluate the utility of QEEG indices to predict motor recovery. For this purpose, we acquired resting-state electroencephalographic signals from which the Power Ratio Index (PRI), Delta/Alpha Ratio (DAR), and Brain Symmetry Index (BSI) were calculated. The outcome of the motor rehabilitation was evaluated using upper-limb section of the Fugl-Meyer Assessment. We found that PRI was significantly correlated with the motor recovery, suggesting that this index may provide useful information to predict the rehabilitation outcome.

  6. Feasibility of predicting performance degradation of airfoils in heavy rain

    NASA Technical Reports Server (NTRS)

    Bilanin, A. J.; Quackenbush, T. R.; Feo, A.

    1989-01-01

    The heavy rain aerodynamic performance penalty program is detailed. This effort supported the design of a fullscale test program as well as examined the feasibility of estimating the degradation of performance of airfoils from first principles. The analytic efforts were supplemented by a droplet splashback test program in an attempt to observe the physics of impact and generation of ejecta. These tests demonstrated that the interaction of rain with an airfoil is a highly complex phenomenon and this interaction is not likely to be analyzed analytically with existing tools.

  7. The role of the motor system in discriminating normal and degraded speech sounds.

    PubMed

    D'Ausilio, Alessandro; Bufalari, Ilaria; Salmas, Paola; Fadiga, Luciano

    2012-07-01

    Listening to speech recruits a network of fronto-temporo-parietal cortical areas. Classical models consider anterior, motor, sites involved in speech production whereas posterior sites involved in comprehension. This functional segregation is more and more challenged by action-perception theories suggesting that brain circuits for speech articulation and speech perception are functionally interdependent. Recent studies report that speech listening elicits motor activities analogous to production. However, the motor system could be crucially recruited only under certain conditions that make speech discrimination hard. Here, by using event-related double-pulse transcranial magnetic stimulation (TMS) on lips and tongue motor areas, we show data suggesting that the motor system may play a role in noisy, but crucially not in noise-free environments, for the discrimination of speech signals. Copyright © 2011 Elsevier Srl. All rights reserved.

  8. Degradation of polycyclic aromatic hydrocarbons (PAHs) present in used motor oil and implications for urban runoff quality

    NASA Astrophysics Data System (ADS)

    Ferreira, M.; Stenstrom, M. K.; Lau, S.

    2013-12-01

    Polycyclic aromatic hydrocarbons (PAHs) are common organic pollutants of urban stormwater runoff due to atmospheric deposition, vehicle-related discharges, and coal tar pavement sealants. The US EPA lists sixteen PAHs as priority pollutants and seven of those are potential carcinogenic compounds. Due to their molecular structure, PAHs tend to attach to particles that will subsequently be deposited as sediments in waterways. This study focuses on the degradation of PAHs present in used motor oil. Four experimental setups were used to simulate volatilization and photooxidation in the degradation of sixteen PAHs as observed for up to 54 days. The volatilization-only experiment showed substantial reduction only in the concentration of Napthalene (Nap). However, photooxidation-only was more efficient in degrading PAHs. In this process, substantial reduction in the concentrations of Nap, Acenapthene (Anthe), Anthracene (ANT), Fluoranthene (FLT), Pyrene (PYR), Benz[a]anthracene (BaA), Benzo[a]pyrene (BaP), Indeno[1,2,3,cd]pyrene (INP), and Benz[g,h,i]perylene (BghiP) were observed as early as five days. The two volatilization-photooxidation experiments exhibited substantial reduction in the concentrations of Fluorene (FLU), Chrysene (CHR) and Benzo[b]fluoranthene (BbF), in addition to the PAHs reduced by photooxidation-only. Phenanthrene (PHE), Fluoranthene (FLT), and Benzo[b]fluoranthene (BbF) only exhibited substantial decreased concentrations after 20 days in the volatilization-photooxidation experiment. One PAH, acenapthylene (Anthy), was not detected in the original sample of used motor oil. The highest degradations were observed in the combined volatilization-photooxidation experiment. In regions with infrequent rainfall, such as Southern California, molecules of PAHs attached to highway particles will have time to undergo degradation prior to transport. Therefore, PAHs may be present in lower concentrations in highway runoff in dry climates than in rainy climates

  9. Degradation of Leakage Currents and Reliability Prediction for Tantalum Capacitors

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2016-01-01

    Two types of failures in solid tantalum capacitors, catastrophic and parametric, and their mechanisms are described. Analysis of voltage and temperature reliability acceleration factors reported in literature shows a wide spread of results and requires more investigation. In this work, leakage currents in two types of chip tantalum capacitors were monitored during highly accelerated life testing (HALT) at different temperatures and voltages. Distributions of degradation rates were approximated using a general log-linear Weibull model and yielded voltage acceleration constants B = 9.8 +/- 0.5 and 5.5. The activation energies were Ea = 1.65 eV and 1.42 eV. The model allows for conservative estimations of times to failure and was validated by long-term life test data. Parametric degradation and failures are reversible and can be annealed at high temperatures. The process is attributed to migration of charged oxygen vacancies that reduce the barrier height at the MnO2/Ta2O5 interface and increase injection of electrons from the MnO2 cathode. Analysis showed that the activation energy of the vacancies' migration is 1.1 eV.

  10. Strength of forelimb lateralization predicts motor errors in an insect

    PubMed Central

    Bell, Adrian T. A.

    2016-01-01

    Lateralized behaviours are widespread in both vertebrates and invertebrates, suggesting that lateralization is advantageous. Yet evidence demonstrating proximate or ultimate advantages remains scarce, particularly in invertebrates or in species with individual-level lateralization. Desert locusts (Schistocerca gregaria) are biased in the forelimb they use to perform targeted reaching across a gap. The forelimb and strength of this bias differed among individuals, indicative of individual-level lateralization. Here we show that strongly biased locusts perform better during gap-crossing, making fewer errors with their preferred forelimb. The number of targeting errors locusts make negatively correlates with the strength of forelimb lateralization. This provides evidence that stronger lateralization confers an advantage in terms of improved motor control in an invertebrate with individual-level lateralization. PMID:27651534

  11. Neonatal white matter abnormality predicts childhood motor impairment in very preterm children.

    PubMed

    Spittle, Alicia J; Cheong, Jeanie; Doyle, Lex W; Roberts, Gehan; Lee, Katherine J; Lim, Jeremy; Hunt, Rod W; Inder, Terrie E; Anderson, Peter J

    2011-11-01

    Children born very preterm are at risk for impaired motor performance ranging from cerebral palsy (CP) to milder abnormalities, such as developmental coordination disorder. White matter abnormalities (WMA) at term have been associated with CP in very preterm children; however, little is known about the impact of WMA on the range of motor impairments. The aim of this study was to assess whether WMA were predictive of all levels of motor impairments in very preterm children. Two hundred and twenty-seven very preterm infants (< 30 wks gestational age or birthweight < 1250 g) had brain magnetic resonance imaging at term-equivalent age to assess for WMA, which were categorized as nil, mild, or moderate to severe. At 5 years of age children were classified as having a moderate to severe motor impairment if they were below the 5th centile or mild to severe motor impairment if their score placed them no higher than the 15th centile on the Movement Assessment Battery for Children (MABC). WMA (nil vs mild and nil vs moderate-severe) were explored as predictors of motor impairment using logistic regression. Analyses were repeated adjusting for the effects of other perinatal variables and excluding children with CP. Of the 193 very preterm children (97 males, 96 females) assessed with the MABC, 53 (27%) were classified as having a moderate to severe motor impairment and 96 (50%) a mild to severe motor impairment. WMA were predictive of motor impairment in very preterm children, with mild versus no WMA increasing the odds of moderate to severe motor impairment by over fivefold (odds ratio [OR] 5.6; 95% confidence interval [CI] 1.9-16.1; p=0.002) and mild to severe impairment by twofold (OR 2.2; 95% CI 1.1-4.2; p=0.02). Compared with no WMA, moderate to severe WMA increased the odds for moderate to severe impairment 19-fold (OR 19.4; 95% CI 5.6-66.7; p<0.001) and for mild to severe motor impairment ninefold (OR 9.4; 95% CI 3.2-28.1; p<0.001). Results remained similar after

  12. Degradation Prediction Model Based on a Neural Network with Dynamic Windows

    PubMed Central

    Zhang, Xinghui; Xiao, Lei; Kang, Jianshe

    2015-01-01

    Tracking degradation of mechanical components is very critical for effective maintenance decision making. Remaining useful life (RUL) estimation is a widely used form of degradation prediction. RUL prediction methods when enough run-to-failure condition monitoring data can be used have been fully researched, but for some high reliability components, it is very difficult to collect run-to-failure condition monitoring data, i.e., from normal to failure. Only a certain number of condition indicators in certain period can be used to estimate RUL. In addition, some existing prediction methods have problems which block RUL estimation due to poor extrapolability. The predicted value converges to a certain constant or fluctuates in certain range. Moreover, the fluctuant condition features also have bad effects on prediction. In order to solve these dilemmas, this paper proposes a RUL prediction model based on neural network with dynamic windows. This model mainly consists of three steps: window size determination by increasing rate, change point detection and rolling prediction. The proposed method has two dominant strengths. One is that the proposed approach does not need to assume the degradation trajectory is subject to a certain distribution. The other is it can adapt to variation of degradation indicators which greatly benefits RUL prediction. Finally, the performance of the proposed RUL prediction model is validated by real field data and simulation data. PMID:25806873

  13. Degradation prediction model based on a neural network with dynamic windows.

    PubMed

    Zhang, Xinghui; Xiao, Lei; Kang, Jianshe

    2015-03-23

    Tracking degradation of mechanical components is very critical for effective maintenance decision making. Remaining useful life (RUL) estimation is a widely used form of degradation prediction. RUL prediction methods when enough run-to-failure condition monitoring data can be used have been fully researched, but for some high reliability components, it is very difficult to collect run-to-failure condition monitoring data, i.e., from normal to failure. Only a certain number of condition indicators in certain period can be used to estimate RUL. In addition, some existing prediction methods have problems which block RUL estimation due to poor extrapolability. The predicted value converges to a certain constant or fluctuates in certain range. Moreover, the fluctuant condition features also have bad effects on prediction. In order to solve these dilemmas, this paper proposes a RUL prediction model based on neural network with dynamic windows. This model mainly consists of three steps: window size determination by increasing rate, change point detection and rolling prediction. The proposed method has two dominant strengths. One is that the proposed approach does not need to assume the degradation trajectory is subject to a certain distribution. The other is it can adapt to variation of degradation indicators which greatly benefits RUL prediction. Finally, the performance of the proposed RUL prediction model is validated by real field data and simulation data.

  14. Semiconductor CMP Process Control Predicting Degradation Effect of Consumed Materials

    NASA Astrophysics Data System (ADS)

    Tamaki, Kenji; Kaneko, Shun'ichi

    This paper describes a methodology to build a virtual metrology (VM) model for semiconductor chemical mechanical polishing (CMP) process control. The VM model predicts the polishing rate based on equipment-derived data as soon as allowed, and immediately applies the results to advanced process control (APC). The proposed methodology uses Markov chain Monte Carlo (MCMC) methods to build an analytical model with many parameters for individual consumed materials from historical data in small quantities. The mutual interference of two kinds of consumed materials: dresser and pad are modeled in a form of multilevel predictive model. The methodology uses MCMC methods again to identify the multilevel predictive model taking into account the assumed operation of an actual manufacturing line, for instance, using preliminary test result, learning a model parameter online, and being affected by metrology lag as disturbance. The simulation results show the APC with the proposed VM model is low sensitivity to metrology lag and high precision on polishing amount control.

  15. Predictive model for toluene degradation and microbial phenotypic profiles in flat plate vapor phase bioreactor

    SciTech Connect

    Mirpuri, R.; Sharp, W.; Villaverde, S.; Jones, W.; Lewandowski, Z.; Cunningham, A.

    1997-06-01

    A predictive model has been developed to describe degradation of toluene in a flat-plate vapor phase bioreactor (VPBR). The VPBR model incorporates kinetic, stoichiometric, injury, and irreversible loss coefficients from suspended culture studies for toluene degradation by P. putida 54G and measured values of Henry`s law constant and boundary layer thickness at the gas-liquid and liquid-biofilm interface. The model is used to estimate the performance of the reactor with respect to toluene degradation and to predict profiles of toluene concentration and bacterial physiological state within the biofilm. These results have been compared with experimentally determined values from a flat plate VPBR under electron acceptor and electron donor limiting conditions. The model accurately predicts toluene concentrations in the vapor phase and toluene degradation rate by adjusting only three parameters: biomass density and rates of death and endogenous decay. Qualitatively, the model also predicts gradients in the physiological state cells in the biofilm. This model provides a rational design for predicting an upper limit of toluene degradation capability in a VPBR and is currently being tested to assess applications for predicting performance of bench and pilot-scale column reactors.

  16. Prediction of Acoustic Noise in Switched Reluctance Motor Drives

    SciTech Connect

    Lin, CJ; Fahimi, B

    2014-03-01

    Prediction of acoustic noise distribution generated by electric machines has become an integral part of design and control in noise sensitive applications. This paper presents a fast and precise acoustic noise imaging technique for switched reluctance machines (SRMs). This method is based on distribution of radial vibration in the stator frame of the SRM. Radial vibration of the stator frame, at a network of probing points, is computed using input phase current and phase voltage waveforms. Sequentially, the acceleration of the probing network will be expanded to predict full acceleration on the stator frame surface, using which acoustic noise emission caused by the stator can be calculated using the boundary element method.

  17. Fine motor skill predicts expressive language in infant siblings of children with autism.

    PubMed

    LeBarton, Eve Sauer; Iverson, Jana M

    2013-11-01

    We investigated whether fine motor and expressive language skills are related in the later-born siblings of children with autism (heightened-risk, HR infants) who are at increased risk for language delays. We observed 34 HR infants longitudinally from 12 to 36 months. We used parent report and standardized observation measures to assess fine motor skill from 12 to 24 months in HR infants (Study 1) and its relation to later expressive vocabulary at 36 months in HR infants (Study 2). In Study 1, we also included 25 infants without a family history of autism to serve as a normative comparison group for a parent-report fine motor measure. We found that HR infants exhibited fine motor delays between 12 and 24 months and expressive vocabulary delays at 36 months. Further, fine motor skill significantly predicted expressive language at 36 months. Fine motor and expressive language skills are related early in development in HR infants, who, as a group, exhibit risk for delays in both. Our findings highlight the importance of considering fine motor skill in children at risk for language impairments and may have implications for early identification of expressive language difficulties. © 2013 John Wiley & Sons Ltd.

  18. Fine motor skills predict performance in the Jebsen Taylor Hand Function Test after stroke.

    PubMed

    Allgöwer, Kathrin; Hermsdörfer, Joachim

    2017-10-01

    To determine factors characterizing the differences in fine motor performance between stroke patients and controls. To confirm the relevance of the factors by analyzing their predictive power with regard to the Jebsen Taylor Hand Function Test (JTHFT), a common clinical test of fine motor control. Twenty-two people with slight paresis in an early chronic phase following stroke and twenty-two healthy controls were examined. Performance on the JTHFT, Nine-Hole Peg Test and 2-point discrimination was evaluated. To analyze object manipulation skills, grip forces and temporal measures were examined during (1) lifting actions with variations of weight and surface (2) cyclic movements (3) predictive/reactive catching tasks. Three other aspects of force control included (4) visuomotor tracking (5) fast force changes and (6) grip strength. Based on 9 parameters which significantly distinguished fine motor performance in the two groups, we identified three principal components (factors): grip force scaling, motor coordination and speed of movement. The three factors are shown to predict JTHFT scores via linear regression (R(2)=0.687, p<0.001). We revealed a factor structure behind fine motor impairments following stroke and showed that it explains JTHFT results to a large extend. This result can serve as a basis for improving diagnostics and enabling more targeted therapy. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  19. Early gross motor skills predict the subsequent development of language in children with autism spectrum disorder

    PubMed Central

    Pickles, Andrew; Lord, Catherine

    2015-01-01

    Background: Motor milestones such as the onset of walking are important developmental markers, not only for later motor skills but also for more widespread social‐cognitive development. The aim of the current study was to test whether gross motor abilities, specifically the onset of walking, predicted the subsequent rate of language development in a large cohort of children with autism spectrum disorder (ASD). Methods: We ran growth curve models for expressive and receptive language measured at 2, 3, 5 and 9 years in 209 autistic children. Measures of gross motor, visual reception and autism symptoms were collected at the 2 year visit. In Model 1, walking onset was included as a predictor of the slope of language development. Model 2 included a measure of non‐verbal IQ and autism symptom severity as covariates. The final model, Model 3, additionally covaried for gross motor ability. Results: In the first model, parent‐reported age of walking onset significantly predicted the subsequent rate of language development although the relationship became non‐significant when gross motor skill, non‐verbal ability and autism severity scores were included (Models 2 & 3). Gross motor score, however, did remain a significant predictor of both expressive and receptive language development. Conclusions: Taken together, the model results provide some evidence that early motor abilities in young children with ASD can have longitudinal cross‐domain influences, potentially contributing, in part, to the linguistic difficulties that characterise ASD. Autism Res 2016, 9: 993–1001. © 2015 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research PMID:26692550

  20. Predictive motor timing performance dissociates between early diseases of the cerebellum and Parkinson's disease.

    PubMed

    Bares, Martin; Lungu, Ovidiu V; Husárová, Ivica; Gescheidt, Tomás

    2010-03-01

    There is evidence that both the basal ganglia and the cerebellum play a role in the neural representation of time in a variety of behaviours, but whether one of them is more important is not yet clear. To address this question in the context of predictive motor timing, we tested patients with various movement disorders implicating these two structures in a motor-timing task. Specifically, we investigated four different groups: (1) patients with early Parkinson's disease (PD); (2) patients with sporadic spinocerebellar ataxia (SCA); (3) patients with familial essential tremor (ET); and (4) matched healthy controls. We used a predictive motor-timing task that involved mediated interception of a moving target, and we assessed the effect of movement type (acceleration, deceleration and constant), speed (slow, medium and fast) and angle (0 degrees , 15 degrees and 30 degrees) on performance (hit, early error and late error). The main results showed that PD group and arm ET subgroup did not significantly differ from the control group. SCA and head ET subjects (severe and mild cerebellar damage, respectively) were significantly worse at interception than the other two groups. Our findings support the idea that the basal ganglia play a less significant role in predictive motor timing than the cerebellum. The fact that SCA and ET subjects seemed to have a fundamental problem with predictive motor timing suggests that the cerebellum plays an essential role in integrating incoming visual information with the motor output in a timely manner, and that ET is a heterogeneous entity that deserves increased attention from clinicians.

  1. The motor cortex is causally related to predictive eye movements during action observation.

    PubMed

    Elsner, Claudia; D'Ausilio, Alessandro; Gredebäck, Gustaf; Falck-Ytter, Terje; Fadiga, Luciano

    2013-02-01

    We examined the hypothesis that predictive gaze during observation of other people's actions depends on the activation of corresponding action plans in the observer. Using transcranial magnetic stimulation and eye-tracking technology we found that stimulation of the motor hand area, but not of the leg area, slowed gaze predictive behavior (compared to no TMS). This result shows that predictive eye movements to others' action goals depend on a somatotopical recruitment of the observer's motor system. The study provides direct support for the view that a direct matching process implemented in the mirror-neuron system plays a functional role for real-time goal prediction. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Forward modelling the rubber hand: illusion of ownership modifies motor-sensory predictions by the brain

    PubMed Central

    Petit, Damien; Kheddar, Abderrahmane; Ganesh, Gowrishankar

    2016-01-01

    The question of how we attribute observed body parts as our own, and the consequences of this attribution on our sensory-motor processes, is fundamental to understand how our brain distinguishes between self and other. Previous studies have identified interactions between the illusion of ownership, and multi-sensory integration and cross-sensory predictions by the brain. Here we show that illusory ownership additionally modifies the motor-sensory predictions by the brain. In our preliminary experiments, we observed a new numbness illusion following the classical rubber-hand illusion (RHI); brushing only the rubber hand after induction of the RHI results in illusory numbness in one's real hand. Previous studies have shown that self-generated actions (like tickling) are attenuated by motor-sensory predictions by the so-called forward model. Motivated by this finding, here we examined whether the numbness illusion after the RHI is different when the rubber hand is brushed oneself, compared with when the brushing is performed by another. We observed that, all other conditions remaining the same, haptic perception in the real hand was lower (numbness higher) during self-generated brushing. Our result suggests that RHI reorganizes the forward model, such that we predict haptic consequences of self-generated motor actions on the rubber hand. PMID:27853620

  3. Forward modelling the rubber hand: illusion of ownership modifies motor-sensory predictions by the brain.

    PubMed

    Aymerich-Franch, Laura; Petit, Damien; Kheddar, Abderrahmane; Ganesh, Gowrishankar

    2016-08-01

    The question of how we attribute observed body parts as our own, and the consequences of this attribution on our sensory-motor processes, is fundamental to understand how our brain distinguishes between self and other. Previous studies have identified interactions between the illusion of ownership, and multi-sensory integration and cross-sensory predictions by the brain. Here we show that illusory ownership additionally modifies the motor-sensory predictions by the brain. In our preliminary experiments, we observed a new numbness illusion following the classical rubber-hand illusion (RHI); brushing only the rubber hand after induction of the RHI results in illusory numbness in one's real hand. Previous studies have shown that self-generated actions (like tickling) are attenuated by motor-sensory predictions by the so-called forward model. Motivated by this finding, here we examined whether the numbness illusion after the RHI is different when the rubber hand is brushed oneself, compared with when the brushing is performed by another. We observed that, all other conditions remaining the same, haptic perception in the real hand was lower (numbness higher) during self-generated brushing. Our result suggests that RHI reorganizes the forward model, such that we predict haptic consequences of self-generated motor actions on the rubber hand.

  4. On the Prediction of Solar Cell Degradation in Space

    NASA Astrophysics Data System (ADS)

    Bourgoin, J. C.; Boizot, B.; Khirouni, K.; Khorenko, V.

    2014-08-01

    We discuss the validity of the procedure which is used to predict End Of Life performances of a solar cell in space. This procedure consists to measure the performances of the cell after it has been irradiated at the EOL fluence during a time ti very short compared to the duration tm of the mission in space, i.e. with a considerably larger flux. We show that this procedure is valid only when the defects created by the irradiation do not anneal (thermally or by carrier injection) with a time constant shorter than tm or larger than ti. This can be a common situation since annealing of irradiation induced defects occurs in all type of cells, at least in specific conditions (temperature, intensity of illumination, flux and nature of irradiating particles). Using modeling, we illustrate the effect of injection or thermal annealing on EOL prediction in the case GaInP, material at the heart of modern high efficiency space solar cells.

  5. Forced Degradation Studies of Ivabradine and In Silico Toxicology Predictions for Its New Designated Impurities.

    PubMed

    Pikul, Piotr; Jamrógiewicz, Marzena; Nowakowska, Joanna; Hewelt-Belka, Weronika; Ciura, Krzesimir

    2016-01-01

    All activities should aim to eliminate genotoxic impurities and/or protect the API against degradation. There is a necessity to monitor impurities from all classification groups, hence ivabradine forced degradation studies were performed. Ivabradine was proved to be quite durable active substance, but still new and with insufficient stability data. Increased temperature, acid, base, oxidation reagents and light were found to cause its degradation. Degradation products were determined with the usage of HPLC equipped with Q-TOF-MS detector. Calculations of pharmacological and toxicological properties were performed for six identified degradation products. Target prediction algorithm was applied on the basis of Hyperpolarization-activated cyclic nucleotide-gated cation channels, as well as more general parameters like logP and aqueous solubility. Ames test and five cytochromes activities were calculated for toxicity assessment for selected degradation products. Pharmacological activity of photodegradation product (UV4), which is known as active metabolite, was qualified and identified. Two other degradation compounds (Ox1 and N1), which were formed during degradation process, were found to be pharmacologically active.

  6. Forced Degradation Studies of Ivabradine and In Silico Toxicology Predictions for Its New Designated Impurities

    PubMed Central

    Pikul, Piotr; Jamrógiewicz, Marzena; Nowakowska, Joanna; Hewelt-Belka, Weronika; Ciura, Krzesimir

    2016-01-01

    All activities should aim to eliminate genotoxic impurities and/or protect the API against degradation. There is a necessity to monitor impurities from all classification groups, hence ivabradine forced degradation studies were performed. Ivabradine was proved to be quite durable active substance, but still new and with insufficient stability data. Increased temperature, acid, base, oxidation reagents and light were found to cause its degradation. Degradation products were determined with the usage of HPLC equipped with Q-TOF-MS detector. Calculations of pharmacological and toxicological properties were performed for six identified degradation products. Target prediction algorithm was applied on the basis of Hyperpolarization-activated cyclic nucleotide-gated cation channels, as well as more general parameters like logP and aqueous solubility. Ames test and five cytochromes activities were calculated for toxicity assessment for selected degradation products. Pharmacological activity of photodegradation product (UV4), which is known as active metabolite, was qualified and identified. Two other degradation compounds (Ox1 and N1), which were formed during degradation process, were found to be pharmacologically active. PMID:27199759

  7. Nutrition factors predict earlier acquisition of motor and language milestones among young children in Haiti.

    PubMed

    Iannotti, Lora; Jean Louis Dulience, Sherlie; Wolff, Patricia; Cox, Katherine; Lesorogol, Carolyn; Kohl, Patricia

    2016-09-01

    To examine the nutrition-related factors associated with motor and language development among young children living in a poor urban area of Haiti. Children aged 6-11 months (n = 583) were enrolled and followed monthly for one year. World Health Organization motor developmental milestones and vowel and consonant counts were assessed. Longitudinal regression models were applied to assess the association of anthropometric, dietary intake, infectious disease morbidity and socio-economic and demographic factors on developmental outcomes. At baseline, 9.4% were stunted or length-for-age Z score < -2, and 30.2% were mild-to-moderately stunted or length-for-age Z score < -1. Stunting status was significantly associated with motor and phonetic language acquisition at each time point during infancy. Several nutrition factors significantly predicted earlier achievement of motor and language development outcomes in longitudinal models: child anthropometry; breastfeeding and complementary feeding frequencies; dietary diversity; egg and oil intake; and reduced infectious disease morbidities. Increases in the length-for-age Z score significantly predicted all motor and language outcomes and yielded the best fit models compared to other anthropometric indicators (p < 0.001). Child development interventions may be enhanced by incorporating nutrition strategies such as improved diet quality, breastfeeding promotion and diarrhoeal disease mitigation. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  8. Neurophysiological criteria for intraoperative prediction of pure motor hemiplegia during aneurysm surgery. Case report.

    PubMed

    Szelényi, Andrea; Bueno de Camargo, Adauri; Flamm, Eugene; Deletis, Vedran

    2003-09-01

    The value of motor evoked potentials (MEPs) as an intraoperative neurophysiological monitoring tool for detecting selective subcortical ischemia of the motor pathways during intracerebral aneurysm repair is described and the use of such measures to predict postoperative motor status is discussed. The authors present the case of a 64-year-old woman in whom there was an incidental finding of two right middle cerebral artery (MCA) aneurysms. During the aneurysm clipping procedure, an intraoperative MEP loss in the left abductor pollicis brevis and tibial anterior muscles occurred during an attempt at permanent clip placement. There were no concurrent changes in somatosensory evoked potentials. Postoperatively, the patient demonstrated a left hemiplegia with intact sensation. A computerized tomography scan revealed an infarct in the anterior division of the MCA territory, including the posterior limb of the internal capsule. In this patient, intraoperative neurophysiological monitoring with MEPs has been shown to be a sensitive tool for indicating subcortical ischemia affecting selective motor pathways in the internal capsule. Therefore, intraoperative loss of MEPs can be used to predict postoperative motor deficits.

  9. The EXCITE Trial: Predicting a Clinically Meaningful Motor Activity Log Outcome

    PubMed Central

    Park, Si-Woon; Wolf, Steven L.; Blanton, Sarah; Winstein, Carolee; Nichols-Larsen, Deborah S.

    2013-01-01

    Background and Objective This study determined which baseline clinical measurements best predicted a predefined clinically meaningful outcome on the Motor Activity Log (MAL) and developed a predictive multivariate model to determine outcome after 2 weeks of constraint-induced movement therapy (CIMT) and 12 months later using the database from participants in the Extremity Constraint Induced Therapy Evaluation (EXCITE) Trial. Methods A clinically meaningful CIMT outcome was defined as achieving higher than 3 on the MAL Quality of Movement (QOM) scale. Predictive variables included baseline MAL, Wolf Motor Function Test (WMFT), the sensory and motor portion of the Fugl-Meyer Assessment (FMA), spasticity, visual perception, age, gender, type of stroke, concordance, and time after stroke. Significant predictors identified by univariate analysis were used to develop the multivariate model. Predictive equations were generated and odds ratios for predictors were calculated from the multivariate model. Results Pretreatment motor function measured by MAL QOM, WMFT, and FMA were significantly associated with outcome immediately after CIMT. Pretreatment MAL QOM, WMFT, proprioception, and age were significantly associated with outcome after 12 months. Each unit of higher pretreatment MAL QOM score and each unit of faster pretreatment WMFT log mean time improved the probability of achieving a clinically meaningful outcome by 7 and 3 times at posttreatment, and 5 and 2 times after 12 months, respectively. Patients with impaired proprioception had a 20% probability of achieving a clinically meaningful outcome compared with those with intact proprioception. Conclusions Baseline clinical measures of motor and sensory function can be used to predict a clinically meaningful outcome after CIMT. PMID:18780883

  10. Motor Prediction at the Edge of Instability: Alteration of Grip Force Control during Changes in Bimanual Coordination

    ERIC Educational Resources Information Center

    Danion, Frederic; Jirsa, Viktor K.

    2010-01-01

    Predicting the consequences of actions is fundamental for skilled motor behavior. We investigated whether motor prediction is influenced by the fact that some movements are easier to perform and stabilize than others. Twelve subjects performed a bimanual rhythmical task either symmetrically or asymmetrically (the latter being more difficult and…

  11. Motor Prediction at the Edge of Instability: Alteration of Grip Force Control during Changes in Bimanual Coordination

    ERIC Educational Resources Information Center

    Danion, Frederic; Jirsa, Viktor K.

    2010-01-01

    Predicting the consequences of actions is fundamental for skilled motor behavior. We investigated whether motor prediction is influenced by the fact that some movements are easier to perform and stabilize than others. Twelve subjects performed a bimanual rhythmical task either symmetrically or asymmetrically (the latter being more difficult and…

  12. Using Brain Oscillations and Corticospinal Excitability to Understand and Predict Post-Stroke Motor Function.

    PubMed

    Thibaut, Aurore; Simis, Marcel; Battistella, Linamara Rizzo; Fanciullacci, Chiara; Bertolucci, Federica; Huerta-Gutierrez, Rodrigo; Chisari, Carmelo; Fregni, Felipe

    2017-01-01

    What determines motor recovery in stroke is still unknown and finding markers that could predict and improve stroke recovery is a challenge. In this study, we aimed at understanding the neural mechanisms of motor function recovery after stroke using neurophysiological markers by means of cortical excitability (transcranial magnetic stimulation-TMS) and brain oscillations (electroencephalography-EEG). In this cross-sectional study, 55 subjects with chronic stroke (62 ± 14 yo, 17 women, 32 ± 42 months post-stroke) were recruited in two sites. We analyzed TMS measures (i.e., motor threshold-MT-of the affected and unaffected sides) and EEG variables (i.e., power spectrum in different frequency bands and different brain regions of the affected and unaffected hemispheres) and their correlation with motor impairment as measured by Fugl-Meyer. Multiple univariate and multivariate linear regression analyses were performed to identify the predictors of good motor function. A significant interaction effect of MT in the affected hemisphere and power in beta bandwidth over the central region for both affected and unaffected hemispheres was found. We identified that motor function positively correlates with beta rhythm over the central region of the unaffected hemisphere, while it negatively correlates with beta rhythm in the affected hemisphere. Our results suggest that cortical activity in the affected and unaffected hemisphere measured by EEG provides new insights on the association between high-frequency rhythms and motor impairment, highlighting the role of an excess of beta in the affected central cortical region in poor motor function in stroke recovery.

  13. Using Brain Oscillations and Corticospinal Excitability to Understand and Predict Post-Stroke Motor Function

    PubMed Central

    Thibaut, Aurore; Simis, Marcel; Battistella, Linamara Rizzo; Fanciullacci, Chiara; Bertolucci, Federica; Huerta-Gutierrez, Rodrigo; Chisari, Carmelo; Fregni, Felipe

    2017-01-01

    What determines motor recovery in stroke is still unknown and finding markers that could predict and improve stroke recovery is a challenge. In this study, we aimed at understanding the neural mechanisms of motor function recovery after stroke using neurophysiological markers by means of cortical excitability (transcranial magnetic stimulation—TMS) and brain oscillations (electroencephalography—EEG). In this cross-sectional study, 55 subjects with chronic stroke (62 ± 14 yo, 17 women, 32 ± 42 months post-stroke) were recruited in two sites. We analyzed TMS measures (i.e., motor threshold—MT—of the affected and unaffected sides) and EEG variables (i.e., power spectrum in different frequency bands and different brain regions of the affected and unaffected hemispheres) and their correlation with motor impairment as measured by Fugl-Meyer. Multiple univariate and multivariate linear regression analyses were performed to identify the predictors of good motor function. A significant interaction effect of MT in the affected hemisphere and power in beta bandwidth over the central region for both affected and unaffected hemispheres was found. We identified that motor function positively correlates with beta rhythm over the central region of the unaffected hemisphere, while it negatively correlates with beta rhythm in the affected hemisphere. Our results suggest that cortical activity in the affected and unaffected hemisphere measured by EEG provides new insights on the association between high-frequency rhythms and motor impairment, highlighting the role of an excess of beta in the affected central cortical region in poor motor function in stroke recovery. PMID:28539912

  14. Dynamic Prediction of Motor Diagnosis in Huntington's Disease Using a Joint Modeling Approach.

    PubMed

    Li, Kan; Furr-Stimming, Erin; Paulsen, Jane S; Luo, Sheng

    2017-01-01

    Prediction of motor diagnosis in Huntington's disease (HD) can be improved by incorporating other phenotypic and biological clinical measures in addition to cytosine-adenine-guanine (CAG) repeat length and age. The objective was to compare various clinical and biomarker trajectories for tracking HD progression and predicting motor conversion. Participants were from the PREDICT-HD study. We constructed a mixed-effect model to describe the change of measures while jointly modeling the process with time to HD diagnosis. The model was then used for subject-specific prediction. We employed the time-dependent receiver operating characteristic (ROC) method to assess the discriminating capability of the measures to identify high and low risk patients. The strongest predictor was used to illustrate the dynamic prediction of the disease risk and future trajectories of biomarkers for three hypothetical patients. 1078 individuals were included in this analysis. Five longitudinal clinical and imaging measures were compared. The putamen volume had the best discrimination performance with area under the curve (AUC) ranging from 0.74 to 0.82 over time. The total motor score showed a comparable discriminative ability with AUC ranging from 0.69 to 0.78 over time. The model showed that decreasing putamen volume was a significant predictor of motor conversion. A web-based calculator was developed for implementing the methods. By jointly modeling longitudinal data with time-to-event outcomes, it is possible to construct an individualized dynamic event prediction model that renews over time with accumulating evidence. If validated, this could be a valuable tool to guide the clinician in predicting age of onset and potentially rate of progression.

  15. Accuracy of Two Motor Assessments during the First Year of Life in Preterm Infants for Predicting Motor Outcome at Preschool Age

    PubMed Central

    Spittle, Alicia J.; Lee, Katherine J.; Spencer-Smith, Megan; Lorefice, Lucy E.; Anderson, Peter J.; Doyle, Lex W.

    2015-01-01

    Aim The primary aim of this study was to investigate the accuracy of the Alberta Infant Motor Scale (AIMS) and Neuro-Sensory Motor Developmental Assessment (NSMDA) over the first year of life for predicting motor impairment at 4 years in preterm children. The secondary aims were to assess the predictive value of serial assessments over the first year and when using a combination of these two assessment tools in follow-up. Method Children born <30 weeks’ gestation were prospectively recruited and assessed at 4, 8 and 12 months’ corrected age using the AIMS and NSMDA. At 4 years’ corrected age children were assessed for cerebral palsy (CP) and motor impairment using the Movement Assessment Battery for Children 2nd-edition (MABC-2). We calculated accuracy of the AIMS and NSMDA for predicting CP and MABC-2 scores ≤15th (at-risk of motor difficulty) and ≤5th centile (significant motor difficulty) for each test (AIMS and NSMDA) at 4, 8 and 12 months, for delay on one, two or all three of the time points over the first year, and finally for delay on both tests at each time point. Results Accuracy for predicting motor impairment was good for each test at each age, although false positives were common. Motor impairment on the MABC-2 (scores ≤5th and ≤15th) was most accurately predicted by the AIMS at 4 months, whereas CP was most accurately predicted by the NSMDA at 12 months. In regards to serial assessments, the likelihood ratio for motor impairment increased with the number of delayed assessments. When combining both the NSMDA and AIMS the best accuracy was achieved at 4 months, although results were similar at 8 and 12 months. Interpretation Motor development during the first year of life in preterm infants assessed with the AIMS and NSMDA is predictive of later motor impairment at preschool age. However, false positives are common and therefore it is beneficial to follow-up children at high risk of motor impairment at more than one time point, or to use a

  16. Nonlinear rocket motor stability prediction: Limit amplitude, triggering, and mean pressure shifta)

    NASA Astrophysics Data System (ADS)

    Flandro, Gary A.; Fischbach, Sean R.; Majdalani, Joseph

    2007-09-01

    High-amplitude pressure oscillations in solid propellant rocket motor combustion chambers display nonlinear effects including: (1) limit cycle behavior in which the fluctuations may dwell for a considerable period of time near their peak amplitude, (2) elevated mean chamber pressure (DC shift), and (3) a triggering amplitude above which pulsing will cause an apparently stable system to transition to violent oscillations. Along with the obvious undesirable vibrations, these features constitute the most damaging impact of combustion instability on system reliability and structural integrity. The physical mechanisms behind these phenomena and their relationship to motor geometry and physical parameters must, therefore, be fully understood if instability is to be avoided in the design process, or if effective corrective measures must be devised during system development. Predictive algorithms now in use have limited ability to characterize the actual time evolution of the oscillations, and they do not supply the motor designer with information regarding peak amplitudes or the associated critical triggering amplitudes. A pivotal missing element is the ability to predict the mean pressure shift; clearly, the designer requires information regarding the maximum chamber pressure that might be experienced during motor operation. In this paper, a comprehensive nonlinear combustion instability model is described that supplies vital information. The central role played by steep-fronted waves is emphasized. The resulting algorithm provides both detailed physical models of nonlinear instability phenomena and the critically needed predictive capability. In particular, the origin of the DC shift is revealed.

  17. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures. Final report

    SciTech Connect

    Ellis, II, P F; Ferguson, A F

    1995-04-19

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. Phase 1 of the project, Conceptual Design of an accelerated test method and apparatus, was successfully completed in June 1993. The culmination of that effort was the concept of the Simulated Stator Unit (SSU) test. The objective of the Phase 2 limited proof-of-concept demonstration was to: answer specific engineering/design questions; design and construct an analog control sequencer and supporting apparatus; and conduct limited tests to determine the viability of the SSU test concept. This report reviews the SSU test concept, and describes the results through the conclusion of the proof-of-concept prototype tests in March 1995. The technical design issues inherent in transforming any conceptual design to working equipment have been resolved, and two test systems and controllers have been constructed. Pilot tests and three prototype tests have been completed, concluding the current phase of work. One prototype unit was tested without thermal stress loads. Twice daily insulation property measurements (IPMs) on this unit demonstrated that the insulation property measurements themselves did not degrade the SSU.

  18. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures

    NASA Astrophysics Data System (ADS)

    Ellis, P. F., II; Ferguson, A. F.

    1995-04-01

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. Phase 1 of the project, Conceptual Design of an accelerated test method and apparatus, was successfully completed in June 1993. The culmination of that effort was the concept of the Simulated Stator Unit (SSU) test. The objective of the Phase 2 limited proof-of-concept demonstration was to: answer specific engineering/design questions; design and construct an analog control sequencer and supporting apparatus; and conduct limited tests to determine the viability of the SSU test concept. This report reviews the SSU test concept, and describes the results through the conclusion of the proof-of-concept prototype tests in March 1995. The technical design issues inherent in transforming any conceptual design to working equipment have been resolved, and two test systems and controllers have been constructed. Pilot tests and three prototype tests have been completed, concluding the current phase of work. One prototype unit was tested without thermal stress loads. Twice daily insulation property measurements (IPM's) on this unit demonstrated that the insulation property measurements themselves did not degrade the SSU.

  19. Predictive based monitoring of nuclear plant component degradation using support vector regression

    SciTech Connect

    Agarwal, Vivek; Alamaniotis, Miltiadis; Tsoukalas, Lefteri H.

    2015-02-01

    Nuclear power plants (NPPs) are large installations comprised of many active and passive assets. Degradation monitoring of all these assets is expensive (labor cost) and highly demanding task. In this paper a framework based on Support Vector Regression (SVR) for online surveillance of critical parameter degradation of NPP components is proposed. In this case, on time replacement or maintenance of components will prevent potential plant malfunctions, and reduce the overall operational cost. In the current work, we apply SVR equipped with a Gaussian kernel function to monitor components. Monitoring includes the one-step-ahead prediction of the component’s respective operational quantity using the SVR model, while the SVR model is trained using a set of previous recorded degradation histories of similar components. Predictive capability of the model is evaluated upon arrival of a sensor measurement, which is compared to the component failure threshold. A maintenance decision is based on a fuzzy inference system that utilizes three parameters: (i) prediction evaluation in the previous steps, (ii) predicted value of the current step, (iii) and difference of current predicted value with components failure thresholds. The proposed framework will be tested on turbine blade degradation data.

  20. Comparisons Between Stability Prediction and Measurements for the Reusable Solid Rocket Motor

    NASA Technical Reports Server (NTRS)

    Fischbach, Sean R.; Kenny, R. Jeremy

    2010-01-01

    The Space Transportation System has used the solid rocket boosters for lift-off and ascent propulsion over the history of the program. Part of the structural loads assessment of the assembled vehicle is the contribution due to solid rocket booster thrust oscillations. These thrust oscillations are a consequence of internal motor pressure oscillations active during operation. Understanding of these pressure oscillations is key to predicting the subsequent thrust oscillations and vehicle loading. The pressure oscillation characteristics of the Reusable Solid Rocket Motor (RSRM) design are reviewed in this work. Dynamic pressure data from the static test and flight history are shown, with emphasis on amplitude, frequency, and timing of the oscillations. Physical mechanisms that cause these oscillations are described by comparing data observations to predictions made by the Solid Stability Prediction (SSP) code.

  1. Decline in motor prediction in elderly subjects: right versus left arm differences in mentally simulated motor actions.

    PubMed

    Skoura, Xanthi; Personnier, Pascaline; Vinter, Annie; Pozzo, Thierry; Papaxanthis, Charalambos

    2008-10-01

    This study investigates the effects of age upon the temporal features of executed and imagined movements performed with the dominant (D; right) and nondominant (ND; left) arms. Thirty right-handed subjects were divided into two groups: (i) the young group (n=15; mean age: 22.5+/-2.5 years) and (ii) the elderly group (n=15; mean age: 70.2+/-2.2 years). The motor task, involving arm pointing movements among four pairs of targets (.5cm, 1cm, 1.5cm and 2cm), imposed strong spatiotemporal constraints. During overt performance, young and elderly subjects modulated movement duration according to the size of targets, despite the fact that movement speed decreased with age as well as in the left arm compared with the right. This observation was also valid for the covert performance produced by the young group. However, such a strong relationship between covert movement durations and target size was not as obvious in the elderly group. Young, compared to elderly subjects, showed stronger correlations and smaller absolute differences between executed and imagined movements for both arms. Additionally, the absolute difference between executed and imagined arm movement durations was more pronounced for the left than the right arm in aged subjects. This result suggests a selective decline with age of mental prediction of motor actions, which is more prominent when the ND arm is involved.

  2. Prediction of the lens lifetime by monitoring lens degradation on laser-based microlithography tools

    NASA Astrophysics Data System (ADS)

    Michaeli, Albert; Rosner, Eylon; Root, Yehuda; Duenias, Hagay; Rubin, Shai

    2005-05-01

    The bulk stability of the lens material in Deep-UV lithography (Fused Silica and Calcium Fluoride), as well as the susceptibility of the lens anti-reflection coating to a thin layer of chemical contamination during laser irradiation over long period of time, are the keys for advanced lithography systems lifetime. Lens degradation impacts laser-based exposure systems" performance and therefore affects the product quality. There is a need for careful monitoring and prediction of lens lifetimes. This paper describes a method to calculate the degradation rate of optics and the lifetime prediction of these systems, along with some possible mechanisms for imaging degradation and factors that accelerate the degradation process. Currently, 'Pulse count' methods are used for such calculation; here we describe a new 'Energy based' method equal to 'Cumulative energy' through the projection lens. The paper compares the two methods using actual cases and shows the benefits of using the proposed method. We also suggest some new ways to deal with the problem. In addition, we report the learning from a project which entails developing a software application for automatic continuous tracking of degradation rates as well as the lens lifetime prediction across all Intel's laser based lithography tools.

  3. Bacterial community structure and predicted alginate metabolic pathway in an alginate-degrading bacterial consortium.

    PubMed

    Kita, Akihisa; Miura, Toyokazu; Kawata, Satoshi; Yamaguchi, Takeshi; Okamura, Yoshiko; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Kato, Junichi; Nishio, Naomichi; Nakashimada, Yutaka

    2016-03-01

    Methane fermentation is one of the effective approaches for utilization of brown algae; however, this process is limited by the microbial capability to degrade alginate, a main polysaccharide found in these algae. Despite its potential, little is known about anaerobic microbial degradation of alginate. Here we constructed a bacterial consortium able to anaerobically degrade alginate. Taxonomic classification of 16S rRNA gene, based on high-throughput sequencing data, revealed that this consortium included two dominant strains, designated HUA-1 and HUA-2; these strains were related to Clostridiaceae bacterium SK082 (99%) and Dysgonomonas capnocytophagoides (95%), respectively. Alginate lyase activity and metagenomic analyses, based on high-throughput sequencing data, revealed that this bacterial consortium possessed putative genes related to a predicted alginate metabolic pathway. However, HUA-1 and 2 did not grow on agar medium with alginate by using roll-tube method, suggesting the existence of bacterial interactions like symbiosis for anaerobic alginate degradation.

  4. Facility Degradation and Prediction Models for Sustainment, Restoration, and Modernization (SRM) Planning

    DTIC Science & Technology

    2012-09-01

    degrades over time. For decades, pavement management systems have been available to measure and predict condition for that specific infra...components, and crossing several specialized civil construction disciplines. Because of this, a rigid hierarchical structure, such as the ASTM Uniformat...component-sections are published from different sources based on industry estimates. Unfortu- nately, unlike pavements , little data are available to

  5. Differential degradation of motor deficits during gradual dopamine depletion with 6-hydroxydopamine in mice

    PubMed Central

    Willard, Amanda M.; Bouchard, Rachel S.; Gittis, Aryn H.

    2015-01-01

    Parkinson’s disease (PD) is a movement disorder whose cardinal motor symptoms arise due to the progressive loss of dopamine. Although this dopamine loss typically progresses slowly over time, currently there are very few animal models that enable incremental dopamine depletion over time within the same animal. This type of gradual dopamine depletion model would be useful in studies aimed at the prodromal phase of PD, when dopamine levels are pathologically low but motor symptoms have not yet presented. Utilizing the highly characterized neurotoxin 6-hydroxydopamine (6-OHDA), we have developed a paradigm to gradually deplete dopamine levels in the striatum over a user-defined time course – spanning weeks to months – in C57BL/6 mice. Dopamine depletions were achieved by administration of five low dose injections (0.75 µg) of 6-OHDA through an implanted intracranial bilateral cannula targeting the medial forebrain bundle. Levels of dopamine within the striatum declined linearly with successive injections, quantified using tyrosine hydroxylase immunostaining and high-performance liquid chromatography. Behavioral testing was carried out at each time point to study the onset and progression of motor impairments as a function of dopamine loss over time. We found that spontaneous locomotion, measured in an open field, was robust to loss of dopamine until ~70% of striatal dopamine was lost. Beyond this point, additional dopamine loss caused a sharp decline in motor performance, reaching a final level comparable to that of acutely depleted mice. Similarly, although rearing behavior was more sensitive to dopamine loss and declined linearly as a function of dopamine levels, it eventually declined to levels similar to that seen in acutely depleted mice. In contrast, motor coordination, measured on a vertical pole task, was only moderately impaired in gradually depleted mice, despite severe impairments observed in acutely depleted mice. These results demonstrate the

  6. MRI Biomarkers for Hand-Motor Outcome Prediction and Therapy Monitoring following Stroke

    PubMed Central

    Horn, U.; Grothe, M.

    2016-01-01

    Several biomarkers have been identified which enable a considerable prediction of hand-motor outcome after cerebral damage already in the subacute stage after stroke. We here review the value of MRI biomarkers in the evaluation of corticospinal integrity and functional recruitment of motor resources. Many of the functional imaging parameters are not feasible early after stroke or for patients with high impairment and low compliance. Whereas functional connectivity parameters have demonstrated varying results on their predictive value for hand-motor outcome, corticospinal integrity evaluation using structural imaging showed robust and high predictive power for patients with different levels of impairment. Although this is indicative of an overall higher value of structural imaging for prediction, we suggest that this variation be explained by structure and function relationships. To gain more insight into the recovering brain, not only one biomarker is needed. We rather argue for a combination of different measures in an algorithm to classify fine-graded subgroups of patients. Approaches to determining biomarkers have to take into account the established markers to provide further information on certain subgroups. Assessing the best therapy approaches for individual patients will become more feasible as these subgroups become specified in more detail. This procedure will help to considerably save resources and optimize neurorehabilitative therapy. PMID:27747108

  7. MRI Biomarkers for Hand-Motor Outcome Prediction and Therapy Monitoring following Stroke.

    PubMed

    Horn, U; Grothe, M; Lotze, M

    2016-01-01

    Several biomarkers have been identified which enable a considerable prediction of hand-motor outcome after cerebral damage already in the subacute stage after stroke. We here review the value of MRI biomarkers in the evaluation of corticospinal integrity and functional recruitment of motor resources. Many of the functional imaging parameters are not feasible early after stroke or for patients with high impairment and low compliance. Whereas functional connectivity parameters have demonstrated varying results on their predictive value for hand-motor outcome, corticospinal integrity evaluation using structural imaging showed robust and high predictive power for patients with different levels of impairment. Although this is indicative of an overall higher value of structural imaging for prediction, we suggest that this variation be explained by structure and function relationships. To gain more insight into the recovering brain, not only one biomarker is needed. We rather argue for a combination of different measures in an algorithm to classify fine-graded subgroups of patients. Approaches to determining biomarkers have to take into account the established markers to provide further information on certain subgroups. Assessing the best therapy approaches for individual patients will become more feasible as these subgroups become specified in more detail. This procedure will help to considerably save resources and optimize neurorehabilitative therapy.

  8. Predicting Slag Generation in Sub-Scale Test Motors Using a Neural Network

    NASA Technical Reports Server (NTRS)

    Wiesenberg, Brent

    1999-01-01

    Generation of slag (aluminum oxide) is an important issue for the Reusable Solid Rocket Motor (RSRM). Thiokol performed testing to quantify the relationship between raw material variations and slag generation in solid propellants by testing sub-scale motors cast with propellant containing various combinations of aluminum fuel and ammonium perchlorate (AP) oxidizer particle sizes. The test data were analyzed using statistical methods and an artificial neural network. This paper primarily addresses the neural network results with some comparisons to the statistical results. The neural network showed that the particle sizes of both the aluminum and unground AP have a measurable effect on slag generation. The neural network analysis showed that aluminum particle size is the dominant driver in slag generation, about 40% more influential than AP. The network predictions of the amount of slag produced during firing of sub-scale motors were 16% better than the predictions of a statistically derived empirical equation. Another neural network successfully characterized the slag generated during full-scale motor tests. The success is attributable to the ability of neural networks to characterize multiple complex factors including interactions that affect slag generation.

  9. Functional imaging of the cerebellum and basal ganglia during predictive motor timing in early Parkinson's disease.

    PubMed

    Husárová, Ivica; Lungu, Ovidiu V; Mareček, Radek; Mikl, Michal; Gescheidt, Tomáš; Krupa, Petr; Bareš, Martin

    2014-01-01

    The basal ganglia and the cerebellum have both emerged as important structures involved in the processing of temporal information. We examined the roles of the cerebellum and striatum in predictive motor timing during a target interception task in healthy individuals (HC group; n = 21) and in patients with early Parkinson's disease (early stage PD group; n = 20) using functional magnetic resonance imaging. Despite having similar hit ratios, the PD failed more often than the HC to postpone their actions until the right moment and to adapt their behavior from one trial to the next. We found more activation in the right cerebellar lobule VI in HC than in early stage PD during successful trials. Successful trial-by-trial adjustments were associated with higher activity in the right putamen and lobule VI of the cerebellum in HC. We conclude that both the cerebellum and striatum are involved in predictive motor timing tasks. The cerebellar activity is associated exclusively with the postponement of action until the right moment, whereas both the cerebellum and striatum are needed for successful adaptation of motor actions from one trial to the next. We found a general ''hypoactivation'' of basal ganglia and cerebellum in early stage PD relative to HC, indicating that even in early stages of the PD there could be functional perturbations in the motor system beyond striatum. Copyright © 2011 by the American Society of Neuroimaging.

  10. Variability in Cadence During Forced Cycling Predicts Motor Improvement in Individuals With Parkinson’s Disease

    PubMed Central

    Ridgel, Angela L.; Abdar, Hassan Mohammadi; Alberts, Jay L.; Discenzo, Fred M.; Loparo, Kenneth A.

    2014-01-01

    Variability in severity and progression of Parkinson’s disease symptoms makes it challenging to design therapy interventions that provide maximal benefit. Previous studies showed that forced cycling, at greater pedaling rates, results in greater improvements in motor function than voluntary cycling. The precise mechanism for differences in function following exercise is unknown. We examined the complexity of biomechanical and physiological features of forced and voluntary cycling and correlated these features to improvements in motor function as measured by the Unified Parkinson’s Disease Rating Scale (UPDRS). Heart rate, cadence, and power were analyzed using entropy signal processing techniques. Pattern variability in heart rate and power were greater in the voluntary group when compared to forced group. In contrast, variability in cadence was higher during forced cycling. UPDRS Motor III scores predicted from the pattern variability data were highly correlated to measured scores in the forced group. This study shows how time series analysis methods of biomechanical and physiological parameters of exercise can be used to predict improvements in motor function. This knowledge will be important in the development of optimal exercise-based rehabilitation programs for Parkinson’s disease. PMID:23144045

  11. Predicting Slag Generation in Sub-Scale Test Motors Using a Neural Network

    NASA Technical Reports Server (NTRS)

    Wiesenberg, Brent

    1999-01-01

    Generation of slag (aluminum oxide) is an important issue for the Reusable Solid Rocket Motor (RSRM). Thiokol performed testing to quantify the relationship between raw material variations and slag generation in solid propellants by testing sub-scale motors cast with propellant containing various combinations of aluminum fuel and ammonium perchlorate (AP) oxidizer particle sizes. The test data were analyzed using statistical methods and an artificial neural network. This paper primarily addresses the neural network results with some comparisons to the statistical results. The neural network showed that the particle sizes of both the aluminum and unground AP have a measurable effect on slag generation. The neural network analysis showed that aluminum particle size is the dominant driver in slag generation, about 40% more influential than AP. The network predictions of the amount of slag produced during firing of sub-scale motors were 16% better than the predictions of a statistically derived empirical equation. Another neural network successfully characterized the slag generated during full-scale motor tests. The success is attributable to the ability of neural networks to characterize multiple complex factors including interactions that affect slag generation.

  12. Individual prediction of chronic motor outcome in the acute post-stroke stage: Behavioral parameters versus functional imaging

    PubMed Central

    Rehme, A.K.; Volz, L.J.; Feis, D.-L.; Eickhoff, S.B.; Fink, G.R.; Grefkes, C

    2015-01-01

    Several neurobiological factors have been found to correlate with functional recovery after brain lesions. However, predicting the individual potential of recovery remains difficult. Here we used multivariate support vector machine (SVM) classification to explore the prognostic value of functional magnetic resonance imaging (fMRI) to predict individual motor outcome at 4–6 months post-stroke. To this end, twenty-one first-ever stroke patients with hand motor deficits participated in an fMRI hand motor task in the first few days post-stroke. Motor impairment was quantified assessing grip force and the Action Research Arm Test. Linear SVM classifiers were trained to predict good versus poor motor outcome of unseen new patients. We found that fMRI activity acquired in the first week post-stroke correctly predicted the outcome for 86% of all patients. In contrast, the concurrent assessment of motor function provided 76% accuracy with low sensitivity (<60%). Furthermore, the outcome of patients with initially moderate impairment and high outcome variability could not be predicted based on motor tests. In contrast, fMRI provided 87.5% prediction accuracy in these patients. Classifications were driven by activity in ipsilesional motor areas and contralesional cerebellum. The accuracy of subacute fMRI data (two weeks post-stroke), age, time post-stroke, lesion volume and location were at 50%-chance-level. In conclusion, multivariate decoding of fMRI data with SVM early after stroke enables a robust prediction of motor recovery. The potential for recovery is influenced by the initial dysfunction of the active motor system, particularly in those patients whose outcome cannot be predicted by behavioral tests. PMID:26381168

  13. Individual prediction of chronic motor outcome in the acute post-stroke stage: Behavioral parameters versus functional imaging.

    PubMed

    Rehme, Anne K; Volz, Lukas J; Feis, Delia-Lisa; Eickhoff, Simon B; Fink, Gereon R; Grefkes, Christian

    2015-11-01

    Several neurobiological factors have been found to correlate with functional recovery after brain lesions. However, predicting the individual potential of recovery remains difficult. Here we used multivariate support vector machine (SVM) classification to explore the prognostic value of functional magnetic resonance imaging (fMRI) to predict individual motor outcome at 4-6 months post-stroke. To this end, 21 first-ever stroke patients with hand motor deficits participated in an fMRI hand motor task in the first few days post-stroke. Motor impairment was quantified assessing grip force and the Action Research Arm Test. Linear SVM classifiers were trained to predict good versus poor motor outcome of unseen new patients. We found that fMRI activity acquired in the first week post-stroke correctly predicted the outcome for 86% of all patients. In contrast, the concurrent assessment of motor function provided 76% accuracy with low sensitivity (<60%). Furthermore, the outcome of patients with initially moderate impairment and high outcome variability could not be predicted based on motor tests. In contrast, fMRI provided 87.5% prediction accuracy in these patients. Classifications were driven by activity in ipsilesional motor areas and contralesional cerebellum. The accuracy of subacute fMRI data (two weeks post-stroke), age, time post-stroke, lesion volume, and location were at 50%-chance-level. In conclusion, multivariate decoding of fMRI data with SVM early after stroke enables a robust prediction of motor recovery. The potential for recovery is influenced by the initial dysfunction of the active motor system, particularly in those patients whose outcome cannot be predicted by behavioral tests. © 2015 Wiley Periodicals, Inc.

  14. Logistic regression analyses for predicting clinically important differences in motor capacity, motor performance, and functional independence after constraint-induced therapy in children with cerebral palsy.

    PubMed

    Wang, Tien-ni; Wu, Ching-yi; Chen, Chia-ling; Shieh, Jeng-yi; Lu, Lu; Lin, Keh-chung

    2013-03-01

    Given the growing evidence for the effects of constraint-induced therapy (CIT) in children with cerebral palsy (CP), there is a need for investigating the characteristics of potential participants who may benefit most from this intervention. This study aimed to establish predictive models for the effects of pediatric CIT on motor and functional outcomes. Therapists administered CIT to 49 children (aged 3-11 years) with CP. Sessions were 1-3.5h a day, twice a week, for 3-4 weeks. Parents were asked to document the number of restraint hours outside of the therapy sessions. Domains of treatment outcomes included motor capacity (measured by the Peabody Developmental Motor Scales II), motor performance (measured by the Pediatric Motor Activity Log), and functional independence (measured by the Pediatric Functional Independence Measure). Potential predictors included age, affected side, compliance (measured by time of restraint), and the initial level of motor impairment severity. Tests were administered before, immediately after, and 3 months after the intervention. Logistic regression analyses showed that total amount of restraint time was the only significant predictor for improved motor capacity immediately after CIT. Younger children who restrained the less affected arm for a longer time had a greater chance to achieve clinically significant improvements in motor performance. For outcomes of functional independence in daily life, younger age was associated with clinically meaningful improvement in the self-care domain. Baseline motor abilities were significantly predictive of better improvement in mobility and cognition. Significant predictors varied according to the aspects of motor outcomes after 3 months of follow-up. The potential predictors identified in this study allow clinicians to target those children who may benefit most from CIT.

  15. Auditory skills and brain morphology predict individual differences in adaptation to degraded speech.

    PubMed

    Erb, Julia; Henry, Molly J; Eisner, Frank; Obleser, Jonas

    2012-07-01

    Noise-vocoded speech is a spectrally highly degraded signal, but it preserves the temporal envelope of speech. Listeners vary considerably in their ability to adapt to this degraded speech signal. Here, we hypothesised that individual differences in adaptation to vocoded speech should be predictable by non-speech auditory, cognitive, and neuroanatomical factors. We tested 18 normal-hearing participants in a short-term vocoded speech-learning paradigm (listening to 100 4-band-vocoded sentences). Non-speech auditory skills were assessed using amplitude modulation (AM) rate discrimination, where modulation rates were centred on the speech-relevant rate of 4 Hz. Working memory capacities were evaluated (digit span and nonword repetition), and structural MRI scans were examined for anatomical predictors of vocoded speech learning using voxel-based morphometry. Listeners who learned faster to understand degraded speech also showed smaller thresholds in the AM discrimination task. This ability to adjust to degraded speech is furthermore reflected anatomically in increased grey matter volume in an area of the left thalamus (pulvinar) that is strongly connected to the auditory and prefrontal cortices. Thus, individual non-speech auditory skills and left thalamus grey matter volume can predict how quickly a listener adapts to degraded speech. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Brainstem White Matter Predicts Individual Differences in Manual Motor Difficulties and Symptom Severity in Autism

    PubMed Central

    Travers, Brittany G.; Bigler, Erin D.; Tromp, Do P. M.; Adluru, Nagesh; Destiche, Dan; Samsin, Danica; Froehlich, Alyson; Prigge, Molly D. B.; Duffield, Tyler; Lange, Nicholas; Alexander, Andrew L.; Lainhart, Janet E.

    2015-01-01

    Mounting evidence suggests that poorer motor skills may be related to more severe autism symptoms. This study investigated if atypical white matter microstructure in the brain mediated the relationship between motor skills and ASD symptom severity. Sixty-seven males with ASD and 42 males with typical development (5-33 years old) completed a diffusion tensor imaging scan and measures of grip strength, finger tapping, and autism symptom severity. Within the ASD group, weaker grip strength predicted more severe autism symptoms. Fractional anisotropy of the brainstem's corticospinal tract predicted both grip strength and autism symptom severity and mediated the relationship between the two. These findings suggest that brainstem white matter may contribute to autism symptoms and grip strength in ASD. PMID:26001365

  17. Model predictions of toxaphene degradation in the atmosphere over North America.

    PubMed

    Li, R; Jin, J

    2013-12-01

    Technical toxaphene, a broad-spectrum pesticide mixture, degrades in the environment, resulting in potential changes in toxicity. The present study uses a multimedia model that the authors developed to estimate toxaphene degradation in the atmosphere over North America. The predicted degradation has strong spatial and temporal variability determined by processes such as emission and transport of technical toxaphene, as well as the complex interactions among many species (e.g., toxaphene, hydroxyl [OH] radicals, and ozone). More toxaphene is degraded in warmer months due to higher concentrations of technical toxaphene (primarily due to higher technical toxaphene emissions in the southeastern United States and transport to other regions) and OH radicals. In the model, OH radicals are created primarily through the reactions of water vapor with the excited oxygen atom, O(¹D), generated by the photolysis of ozone, which is produced primarily by reactions of volatile organic compounds and nitrogen oxides (NOx) in the presence of sunlight. The higher OH concentrations in warmer months are primarily the result of higher solar radiation and ozone concentrations. The spatial distribution of degradation depends on the distribution of technical toxaphene soil residues as well as atmospheric transport and chemistry; significant chemical degradation occurs in the southeastern United States where soils are most heavily contaminated by past applications of toxaphene.

  18. Predicting brain activation patterns associated with individual lexical concepts based on five sensory-motor attributes

    PubMed Central

    Fernandino, Leonardo; Humphries, Colin J.; Seidenberg, Mark S.; Gross, William L.; Conant, Lisa L.; Binder, Jeffrey R.

    2015-01-01

    While major advances have been made in uncovering the neural processes underlying perceptual representations, our grasp of how the brain gives rise to conceptual knowledge remains relatively poor. Recent work has provided strong evidence that concepts rely, at least in part, on the same sensory and motor neural systems through which they were acquired, but it is still unclear whether the neural code for concept representation uses information about sensory-motor features to discriminate between concepts. In the present study, we investigate this question by asking whether an encoding model based on five semantic attributes directly related to sensory-motor experience – sound, color, visual motion, shape, and manipulation – can successfully predict patterns of brain activation elicited by individual lexical concepts. We collected ratings on the relevance of these five attributes to the meaning of 820 words, and used these ratings as predictors in a multiple regression model of the fMRI signal associated with the words in a separate group of participants. The five resulting activation maps were then combined by linear summation to predict the distributed activation pattern elicited by a novel set of 80 test words. The encoding model predicted the activation patterns elicited by the test words significantly better than chance. As expected, prediction was successful for concrete but not for abstract concepts. Comparisons between encoding models based on different combinations of attributes indicate that all five attributes contribute to the representation of concrete concepts. Consistent with embodied theories of semantics, these results show, for the first time, that the distributed activation pattern associated with a concept combines information about different sensory-motor attributes according to their respective relevance. Future research should investigate how additional features of phenomenal experience contribute to the neural representation of conceptual

  19. Measurement requirements and techniques for degradation studies and lifetime prediction testing of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Noel, G. T.; Sliemers, F. A.; Derringer, G. C.; Wood, V. E.; Wilkes, K. E.; Gaines, G. B.; Carmichael, D. C.

    1978-01-01

    Tests of weathering and aging behavior are being developed to characterize the degradation and predict the lifetimes of low-cost photovoltaic arrays. Environmental factors which affect array performance include UV radiation, thermal energy, water, oxygen (generally involved in synergistic effects with UV radiation or high temperatures), physical stress, pollutants (oxides of nitrogen, sulfur dioxide and ozone), abrasives and dirt. A survey of photovoltaic array testing has shown the need to establish quantitative correlations between certain measurable properties (carbonyl formation, glass transition temperature, and molecular weight change) and modes of degradation and failure.

  20. A cerebellar model for predictive motor control tested in a brain-based device.

    PubMed

    McKinstry, Jeffrey L; Edelman, Gerald M; Krichmar, Jeffrey L

    2006-02-28

    The cerebellum is known to be critical for accurate adaptive control and motor learning. We propose here a mechanism by which the cerebellum may replace reflex control with predictive control. This mechanism is embedded in a learning rule (the delayed eligibility trace rule) in which synapses onto a Purkinje cell or onto a cell in the deep cerebellar nuclei become eligible for plasticity only after a fixed delay from the onset of suprathreshold presynaptic activity. To investigate the proposal that the cerebellum is a general-purpose predictive controller guided by a delayed eligibility trace rule, a computer model based on the anatomy and dynamics of the cerebellum was constructed. It contained components simulating cerebellar cortex and deep cerebellar nuclei, and it received input from a middle temporal visual area and the inferior olive. The model was incorporated in a real-world brain-based device (BBD) built on a Segway robotic platform that learned to traverse curved paths. The BBD learned which visual motion cues predicted impending collisions and used this experience to avoid path boundaries. During learning, the BBD adapted its velocity and turning rate to successfully traverse various curved paths. By examining neuronal activity and synaptic changes during this behavior, we found that the cerebellar circuit selectively responded to motion cues in specific receptive fields of simulated middle temporal visual areas. The system described here prompts several hypotheses about the relationship between perception and motor control and may be useful in the development of general-purpose motor learning systems for machines.

  1. Using multi-scale entropy and principal component analysis to monitor gears degradation via the motor current signature analysis

    NASA Astrophysics Data System (ADS)

    Aouabdi, Salim; Taibi, Mahmoud; Bouras, Slimane; Boutasseta, Nadir

    2017-06-01

    This paper describes an approach for identifying localized gear tooth defects, such as pitting, using phase currents measured from an induction machine driving the gearbox. A new tool of anomaly detection based on multi-scale entropy (MSE) algorithm SampEn which allows correlations in signals to be identified over multiple time scales. The motor current signature analysis (MCSA) in conjunction with principal component analysis (PCA) and the comparison of observed values with those predicted from a model built using nominally healthy data. The Simulation results show that the proposed method is able to detect gear tooth pitting in current signals.

  2. Predictable waves of sequential forest degradation and biodiversity loss spreading from an African city

    PubMed Central

    Burgess, Neil D.; Milledge, Simon A. H.; Bulling, Mark T.; Fisher, Brendan; Smart, James C. R.; Clarke, G. Philip; Mhoro, Boniface E.; Lewis, Simon L.

    2010-01-01

    Tropical forest degradation emits carbon at a rate of ~0.5 Pg·y−1, reduces biodiversity, and facilitates forest clearance. Understanding degradation drivers and patterns is therefore crucial to managing forests to mitigate climate change and reduce biodiversity loss. Putative patterns of degradation affecting forest stocks, carbon, and biodiversity have variously been described previously, but these have not been quantitatively assessed together or tested systematically. Economic theory predicts a systematic allocation of land to its highest use value in response to distance from centers of demand. We tested this theory to see if forest exploitation would expand through time and space as concentric waves, with each wave targeting lower value products. We used forest data along a transect from 10 to 220 km from Dar es Salaam (DES), Tanzania, collected at two points in time (1991 and 2005). Our predictions were confirmed: high-value logging expanded 9 km·y−1, and an inner wave of lower value charcoal production 2 km·y−1. This resource utilization is shown to reduce the public goods of carbon storage and species richness, which significantly increased with each kilometer from DES [carbon, 0.2 Mg·ha−1; 0.1 species per sample area (0.4 ha)]. Our study suggests that tropical forest degradation can be modeled and predicted, with its attendant loss of some public goods. In sub-Saharan Africa, an area experiencing the highest rate of urban migration worldwide, coupled with a high dependence on forest-based resources, predicting the spatiotemporal patterns of degradation can inform policies designed to extract resources without unsustainably reducing carbon storage and biodiversity. PMID:20679200

  3. Predictable waves of sequential forest degradation and biodiversity loss spreading from an African city.

    PubMed

    Ahrends, Antje; Burgess, Neil D; Milledge, Simon A H; Bulling, Mark T; Fisher, Brendan; Smart, James C R; Clarke, G Philip; Mhoro, Boniface E; Lewis, Simon L

    2010-08-17

    Tropical forest degradation emits carbon at a rate of approximately 0.5 Pgxy(-1), reduces biodiversity, and facilitates forest clearance. Understanding degradation drivers and patterns is therefore crucial to managing forests to mitigate climate change and reduce biodiversity loss. Putative patterns of degradation affecting forest stocks, carbon, and biodiversity have variously been described previously, but these have not been quantitatively assessed together or tested systematically. Economic theory predicts a systematic allocation of land to its highest use value in response to distance from centers of demand. We tested this theory to see if forest exploitation would expand through time and space as concentric waves, with each wave targeting lower value products. We used forest data along a transect from 10 to 220 km from Dar es Salaam (DES), Tanzania, collected at two points in time (1991 and 2005). Our predictions were confirmed: high-value logging expanded 9 kmxy(-1), and an inner wave of lower value charcoal production 2 kmxy(-1). This resource utilization is shown to reduce the public goods of carbon storage and species richness, which significantly increased with each kilometer from DES [carbon, 0.2 Mgxha(-1); 0.1 species per sample area (0.4 ha)]. Our study suggests that tropical forest degradation can be modeled and predicted, with its attendant loss of some public goods. In sub-Saharan Africa, an area experiencing the highest rate of urban migration worldwide, coupled with a high dependence on forest-based resources, predicting the spatiotemporal patterns of degradation can inform policies designed to extract resources without unsustainably reducing carbon storage and biodiversity.

  4. Attentional and motor impulsivity interactively predict 'food addiction' in obese individuals.

    PubMed

    Meule, Adrian; de Zwaan, Martina; Müller, Astrid

    2017-01-01

    Impulsivity is a multifaceted construct and constitutes a common risk factor for a range of behaviors associated with poor self-control (e.g., substance use or binge eating). The short form of the Barratt Impulsiveness Scale (BIS-15) measures impulsive behaviors related to attentional (inability to focus attention or concentrate), motor (acting without thinking), and non-planning (lack of future orientation or forethought) impulsivity. Eating-related measures appear to be particularly related to attentional and motor impulsivity and recent findings suggest that interactive effects between these two facets may play a role in eating- and weight-regulation. One-hundred thirty-three obese individuals presenting for bariatric surgery (77.4% female) completed the BIS-15 and the Yale Food Addiction Scale (YFAS) 2.0, which measures addiction-like eating based on the eleven symptoms of substance use disorder outlined in the fifth version of the Diagnostic and Statistical Manual of Mental Disorders. Sixty-three participants (47.4%) were classified as being 'food addicted'. Scores on attentional and motor impulsivity interactively predicted 'food addiction' status: higher attentional impulsivity was associated with a higher likelihood of receiving a YFAS 2.0 diagnosis only at high (+1 SD), but not at low (-1 SD) levels of motor impulsivity. Results support previous findings showing that non-planning impulsivity does not appear to play a role in eating-related self-regulation. Furthermore, this is the first study that shows interactive effects between different impulsivity facets when predicting 'food addiction' in obese individuals. Self-regulatory failure in eating-regulation (e.g., addiction-like overeating) may particularly emerge when both attentional and motor impulsivity levels are elevated. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Predictability of action sub-steps modulates motor system activation during the observation of goal-directed actions.

    PubMed

    Braukmann, Ricarda; Bekkering, Harold; Hidding, Margreeth; Poljac, Edita; Buitelaar, Jan K; Hunnius, Sabine

    2017-08-01

    Action perception and execution are linked in the human motor system, and researchers have proposed that this action-observation matching system underlies our ability to predict observed behavior. If the motor system is indeed involved in the generation of action predictions, activation should be modulated by the degree of predictability of an observed action. This study used EEG and eye-tracking to investigate whether and how predictability of an observed action modulates motor system activation as well as behavioral predictions in the form of anticipatory eye-movements. Participants were presented with object-directed actions (e.g., making a cup of tea) consisting of three action steps which increased in their predictability. While the goal of the first step was ambiguous (e.g., when making tea, one can first grab the teabag or the cup), the goals of the following steps became predictable over the course of the action. Motor system activation was assessed by measuring attenuation of sensorimotor mu- and beta-oscillations. We found that mu- and beta-power were attenuated during observation, indicating general activation of the motor system. Importantly, predictive motor system activation, indexed by beta-band attenuation, increased for each action step, showing strongest activation prior to the final (i.e. most predictable) step. Sensorimotor activity was related to participants' predictive eye-movements which also showed a modulation by action step. Our results demonstrate that motor system activity and behavioral predictions become stronger for more predictable action steps. The functional roles of sensorimotor oscillations in predicting other's actions are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Comparative predictive validity of the Harris Infant Neuromotor Test and the Alberta Infant Motor Scale.

    PubMed

    Harris, Susan R; Backman, Catherine L; Mayson, Tanja A

    2010-05-01

    We compared abilities of the Alberta Infant Motor Scale (AIMS) and the Harris Infant Neuromotor Test (HINT), during the infant's first year, in predicting scores on the Bayley Scales of Infant Development (BSID) at age 2 and 3 years. This prospective study involved 144 infants (71 females, 73 males), assessed with the HINT and AIMS at 4 to 6.5 and 10 to 12.5 months and with the BSID at 2 and 3 years. Inclusion criteria for typical infants (n=58) were the following: 38 to 42 weeks' gestation, birthweight at least 2500g, and no congenital anomaly, postnatal health concern, nor major prenatal or perinatal maternal risk factor. For at-risk infants (n=86), inclusion criteria were any of the following: less than 38 weeks' gestation, birthweight less than 2500g, maternal age older than 35 years or younger than 19 years at infant birth, maternal psychiatric/mental health concerns, prenatal drug/alcohol exposure, multiple births, or use of reproductive technology. For the overall sample, the early (4-6.5mo) HINT had higher predictive correlations than the AIMS for 2-year BSID-II motor outcomes (r=-0.36 vs 0.26), and 3-year BSID-III gross motor outcomes (r=-0.45 vs 0.31), as did the 10- to 12.5-month HINT (r=-0.55 vs 0.47). Correlations were identical for 10- to 12.5-month HINT and AIMS scores and 3-year BSID-III gross motor (r=-0.58 and 0.58) and fine motor (r=-0.35 and 0.35) subscales. When the sample was divided into typical and at-risk groups, predictive correlations were consistently stronger for the at-risk infants. Categorical predictive analyses were reasonably similar across both tests. Results suggest that the HINT has comparable predictive validity to the AIMS and should be considered for use in clinical and research settings.

  7. Can Neurological Biomarkers of Brain Impairment Be Used to Predict Poststroke Motor Recovery? A Systematic Review.

    PubMed

    Kim, Bokkyu; Winstein, Carolee

    2017-01-01

    Background There is growing interest to establish recovery biomarkers, especially neurological biomarkers, in order to develop new therapies and prediction models for the promotion of stroke rehabilitation and recovery. However, there is no consensus among the neurorehabilitation community about which biomarker(s) have the highest predictive value for motor recovery. Objective To review the evidence and determine which neurological biomarker(s) meet the high evidence quality criteria for use in predicting motor recovery. Methods We searched databases for prognostic neuroimaging/neurophysiological studies. Methodological quality of each study was assessed using a previously employed comprehensive 15-item rating system. Furthermore, we used the GRADE approach and ranked the overall evidence quality for each category of neurologic biomarker. Results Seventy-one articles met our inclusion criteria; 5 categories of neurologic biomarkers were identified: diffusion tensor imaging (DTI), transcranial magnetic stimulation (TMS), functional magnetic resonance imaging (fMRI), conventional structural MRI (sMRI), and a combination of these biomarkers. Most studies were conducted with individuals after ischemic stroke in the acute and/or subacute stage (~70%). Less than one-third of the studies (21/71) were assessed with satisfactory methodological quality (80% or more of total quality score). Conventional structural MRI and the combination biomarker categories ranked "high" in overall evidence quality. Conclusions There were 3 prevalent methodological limitations: (a) lack of cross-validation, (b) lack of minimal clinically important difference (MCID) for motor outcomes, and (c) small sample size. More high-quality studies are needed to establish which neurological biomarkers are the best predictors of motor recovery after stroke. Finally, the quarter-century old methodological quality tool used here should be updated by inclusion of more contemporary methods and statistical

  8. To transfer or not to transfer? Kinematics and laterality quotient predict interlimb transfer of motor learning

    PubMed Central

    Lefumat, Hannah Z.; Vercher, Jean-Louis; Miall, R. Chris; Cole, Jonathan; Buloup, Frank; Bringoux, Lionel; Bourdin, Christophe

    2015-01-01

    Humans can remarkably adapt their motor behavior to novel environmental conditions, yet it remains unclear which factors enable us to transfer what we have learned with one limb to the other. Here we tested the hypothesis that interlimb transfer of sensorimotor adaptation is determined by environmental conditions but also by individual characteristics. We specifically examined the adaptation of unconstrained reaching movements to a novel Coriolis, velocity-dependent force field. Right-handed subjects sat at the center of a rotating platform and performed forward reaching movements with the upper limb toward flashed visual targets in prerotation, per-rotation (i.e., adaptation), and postrotation tests. Here only the dominant arm was used during adaptation and interlimb transfer was assessed by comparing performance of the nondominant arm before and after dominant-arm adaptation. Vision and no-vision conditions did not significantly influence interlimb transfer of trajectory adaptation, which on average was significant but limited. We uncovered a substantial heterogeneity of interlimb transfer across subjects and found that interlimb transfer can be qualitatively and quantitatively predicted for each healthy young individual. A classifier showed that in our study, interlimb transfer could be predicted based on the subject's task performance, most notably motor variability during learning, and his or her laterality quotient. Positive correlations suggested that variability of motor performance and lateralization of arm movement control facilitate interlimb transfer. We further show that these individual characteristics can predict the presence and the magnitude of interlimb transfer of left-handers. Overall, this study suggests that individual characteristics shape the way the nervous system can generalize motor learning. PMID:26334018

  9. To transfer or not to transfer? Kinematics and laterality quotient predict interlimb transfer of motor learning.

    PubMed

    Lefumat, Hannah Z; Vercher, Jean-Louis; Miall, R Chris; Cole, Jonathan; Buloup, Frank; Bringoux, Lionel; Bourdin, Christophe; Sarlegna, Fabrice R

    2015-11-01

    Humans can remarkably adapt their motor behavior to novel environmental conditions, yet it remains unclear which factors enable us to transfer what we have learned with one limb to the other. Here we tested the hypothesis that interlimb transfer of sensorimotor adaptation is determined by environmental conditions but also by individual characteristics. We specifically examined the adaptation of unconstrained reaching movements to a novel Coriolis, velocity-dependent force field. Right-handed subjects sat at the center of a rotating platform and performed forward reaching movements with the upper limb toward flashed visual targets in prerotation, per-rotation (i.e., adaptation), and postrotation tests. Here only the dominant arm was used during adaptation and interlimb transfer was assessed by comparing performance of the nondominant arm before and after dominant-arm adaptation. Vision and no-vision conditions did not significantly influence interlimb transfer of trajectory adaptation, which on average was significant but limited. We uncovered a substantial heterogeneity of interlimb transfer across subjects and found that interlimb transfer can be qualitatively and quantitatively predicted for each healthy young individual. A classifier showed that in our study, interlimb transfer could be predicted based on the subject's task performance, most notably motor variability during learning, and his or her laterality quotient. Positive correlations suggested that variability of motor performance and lateralization of arm movement control facilitate interlimb transfer. We further show that these individual characteristics can predict the presence and the magnitude of interlimb transfer of left-handers. Overall, this study suggests that individual characteristics shape the way the nervous system can generalize motor learning. Copyright © 2015 the American Physiological Society.

  10. Prediction of Torque Pulsations in Brushless Permanent-Magnet Motors Using Improved Analytical Technique

    NASA Astrophysics Data System (ADS)

    Kiyoumarsi, Arash

    2010-01-01

    Torque pulsations have prominent effects on the performance of brushless permanent- magnet (PM) machines. There are different sources of torque ripples in PM motors. These torque pulsations depend on the shape of the flux density distribution in the airgap region. For predicting the open-circuit airgap field distribution in brushless PM motors, a two dimensional (2-D) analytical method, in which the direction of magnetization, either radial or parallel and the effect of the stator slot-openings are taken into account, is used. The method uses an improved 2-D permeance model. In order to evaluate the accuracy of this method, a 2-D time-stepping FEM coupled with the two motion equations is used. A 3-phase, 36-slot, 4-pole, 5 HP, brushless PM motor is modeled by two methods. In this analysis both, the radial and parallel magnetization of the brushless motor are considered. The results obtained by the analytical method are compared with those obtained by FE analysis that shows the valuable accuracy of the analytical method for performance calculations in design and optimization processes.

  11. Predictive models of poly(ethylene-terephthalate) film degradation under multi-factor accelerated weathering exposures

    PubMed Central

    Ngendahimana, David K.; Fagerholm, Cara L.; Sun, Jiayang; Bruckman, Laura S.

    2017-01-01

    Accelerated weathering exposures were performed on poly(ethylene-terephthalate) (PET) films. Longitudinal multi-level predictive models as a function of PET grades and exposure types were developed for the change in yellowness index (YI) and haze (%). Exposures with similar change in YI were modeled using a linear fixed-effects modeling approach. Due to the complex nature of haze formation, measurement uncertainty, and the differences in the samples’ responses, the change in haze (%) depended on individual samples’ responses and a linear mixed-effects modeling approach was used. When compared to fixed-effects models, the addition of random effects in the haze formation models significantly increased the variance explained. For both modeling approaches, diagnostic plots confirmed independence and homogeneity with normally distributed residual errors. Predictive R2 values for true prediction error and predictive power of the models demonstrated that the models were not subject to over-fitting. These models enable prediction under pre-defined exposure conditions for a given exposure time (or photo-dosage in case of UV light exposure). PET degradation under cyclic exposures combining UV light and condensing humidity is caused by photolytic and hydrolytic mechanisms causing yellowing and haze formation. Quantitative knowledge of these degradation pathways enable cross-correlation of these lab-based exposures with real-world conditions for service life prediction. PMID:28498875

  12. Degradation Mechanisms and Lifetime Prediction for Lithium-Ion Batteries -- A Control Perspective: Preprint

    SciTech Connect

    Smith, Kandler; Shi, Ying; Santhanagopalan, Shriram

    2015-07-29

    Predictive models of Li-ion battery lifetime must consider a multiplicity of electrochemical, thermal, and mechanical degradation modes experienced by batteries in application environments. To complicate matters, Li-ion batteries can experience different degradation trajectories that depend on storage and cycling history of the application environment. Rates of degradation are controlled by factors such as temperature history, electrochemical operating window, and charge/discharge rate. We present a generalized battery life prognostic model framework for battery systems design and control. The model framework consists of trial functions that are statistically regressed to Li-ion cell life datasets wherein the cells have been aged under different levels of stress. Degradation mechanisms and rate laws dependent on temperature, storage, and cycling condition are regressed to the data, with multiple model hypotheses evaluated and the best model down-selected based on statistics. The resulting life prognostic model, implemented in state variable form, is extensible to arbitrary real-world scenarios. The model is applicable in real-time control algorithms to maximize battery life and performance. We discuss efforts to reduce lifetime prediction error and accommodate its inevitable impact in controller design.

  13. The Validity of the Beery Test of Visual-Motor Integration in Predicting Achievement in Kindergarten, First, and Second Grades.

    ERIC Educational Resources Information Center

    Klein, Alice E.

    1978-01-01

    The Beery Developmental Test of Visual Motor Integration consists of 24 geometric forms that are to be copied into a test booklet. This study demonstrated the ability of the test to predict academic achievement in preschool children. (Author/JKS)

  14. Degradation of pectic compounds during pasteurised vegetable juice spoilage by Chryseomonas luteola: a predictive microbiology approach.

    PubMed

    Membré, J M; Kubaczka, M

    1998-07-21

    Predictive modelling consists in describing effects of environmental factors on microbial growth parameters. With food spoilage bacteria, this approach must be extended to both growth and food damage characterisation. In order to study the incidence of storage temperature on vegetable damage, using predictive microbiology tools, kinetics of pectic compound degradation were studied. Chryseomonas luteola has been chosen because of its ability to grow on post-harvested vegetables. Experiments were performed at refrigerated temperatures (0-10 degrees C) with low initial bacterial charges (10(1)-10(3.5) cfu/ml). Microbial specific growth rate (mu), stability phase before pectic degradation (Sp) and alteration percentage (Ap) were chosen as reference parameters. Then, sub-optimal temperature effects on these three parameters were estimated using modified Ratkowsky model. Results obtained in synthetic medium were compared with data observed in endive juice to appreciate the alteration of vegetable during post-harvest storage.

  15. Limitations of predicting in vivo biostability of multiphase polyurethane elastomers using temperature-accelerated degradation testing.

    PubMed

    Padsalgikar, Ajay; Cosgriff-Hernandez, Elizabeth; Gallagher, Genevieve; Touchet, Tyler; Iacob, Ciprian; Mellin, Lisa; Norlin-Weissenrieder, Anna; Runt, James

    2015-01-01

    Polyurethane biostability has been the subject of intense research since the failure of polyether polyurethane pacemaker leads in the 1980s. Accelerated in vitro testing has been used to isolate degradation mechanisms and predict clinical performance of biomaterials. However, validation that in vitro methods reproduce in vivo degradation is critical to the selection of appropriate tests. High temperature has been proposed as a method to accelerate degradation. However, correlation of such data to in vivo performance is poor for polyurethanes due to the impact of temperature on microstructure. In this study, we characterize the lack of correlation between hydrolytic degradation predicted using a high temperature aging model of a polydimethylsiloxane-based polyurethane and its in vivo performance. Most notably, the predicted molecular weight and tensile property changes from the accelerated aging study did not correlate with clinical explants subjected to human biological stresses in real time through 5 years. Further, DMTA, ATR-FTIR, and SAXS experiments on samples aged for 2 weeks in PBS indicated greater phase separation in samples aged at 85°C compared to those aged at 37°C and unaged controls. These results confirm that microstructural changes occur at high temperatures that do not occur at in vivo temperatures. In addition, water absorption studies demonstrated that water saturation levels increased significantly with temperature. This study highlights that the multiphase morphology of polyurethane precludes the use of temperature accelerated biodegradation for the prediction of clinical performance and provides critical information in designing appropriate in vitro tests for this class of materials.

  16. Prediction of motor outcome by shoulder subluxation at early stage of stroke

    PubMed Central

    Jang, Sung Ho; Yi, Ji Hyun; Chang, Chul Hoon; Jung, Young Jin; Kim, Seong Ho; Lee, Jun; Seo, Jeong Pyo

    2016-01-01

    Abstract We attempted to determine whether shoulder subluxation at the early stage of stroke can predict motor outcome in relation to the corticospinal tract (CST) state on diffusion tensor tractography. Fifty-nine stroke patients with severe hemiparesis were recruited. The patients were classified according to the distance of shoulder subluxation (group A: ≥2 cm, group B: <2 cm) and the affected CST on diffusion tensor tractography at the first evaluation (CST type A—the CST was discontinued at the stroke lesion; CST type B—the integrity of the CST was preserved). Motor function of the patients was evaluated twice (first: beginning of rehabilitation—24.1 ± 16.6 days; second: discharge after first rehabilitation—58.5 ± 24.1 days) using the Medical Research Council score, Motricity Index, and Modified Brunnstrom Classification. Regarding the improvement of the Medical Research Council for the finger extensor and upper Motricity Index, the order in terms of better recovery was as follows: group B–type B, group A–type B, group B–type A, and group A–type A (P < 0.05). The distance of shoulder subluxation showed significant correlation with improvement of the finger extensor (moderate negative correlation, r = −0.37) and improvement of the Modified Brunnstrom Classification (weak negative correlation, r = −0.29) (P < 0.05). The presence of shoulder subluxation at the early stage of stroke can be a predictor of motor outcome of the affected upper extremity and the degree of shoulder subluxation can be a predictor of the motor function of the affected hand. Therefore, our results suggest that shoulder subluxation in relation to the affected CST state at the early stage of stroke can be a prognostic factor for motor outcome. PMID:27512873

  17. Prediction of motor outcome by shoulder subluxation at early stage of stroke.

    PubMed

    Jang, Sung Ho; Yi, Ji Hyun; Chang, Chul Hoon; Jung, Young Jin; Kim, Seong Ho; Lee, Jun; Seo, Jeong Pyo

    2016-08-01

    We attempted to determine whether shoulder subluxation at the early stage of stroke can predict motor outcome in relation to the corticospinal tract (CST) state on diffusion tensor tractography.Fifty-nine stroke patients with severe hemiparesis were recruited. The patients were classified according to the distance of shoulder subluxation (group A: ≥2 cm, group B: <2 cm) and the affected CST on diffusion tensor tractography at the first evaluation (CST type A-the CST was discontinued at the stroke lesion; CST type B-the integrity of the CST was preserved). Motor function of the patients was evaluated twice (first: beginning of rehabilitation-24.1 ± 16.6 days; second: discharge after first rehabilitation-58.5 ± 24.1 days) using the Medical Research Council score, Motricity Index, and Modified Brunnstrom Classification.Regarding the improvement of the Medical Research Council for the finger extensor and upper Motricity Index, the order in terms of better recovery was as follows: group B-type B, group A-type B, group B-type A, and group A-type A (P < 0.05). The distance of shoulder subluxation showed significant correlation with improvement of the finger extensor (moderate negative correlation, r = -0.37) and improvement of the Modified Brunnstrom Classification (weak negative correlation, r = -0.29) (P < 0.05).The presence of shoulder subluxation at the early stage of stroke can be a predictor of motor outcome of the affected upper extremity and the degree of shoulder subluxation can be a predictor of the motor function of the affected hand. Therefore, our results suggest that shoulder subluxation in relation to the affected CST state at the early stage of stroke can be a prognostic factor for motor outcome.

  18. Identification, characterization and in silico ADMET prediction of Roflumilast degradation products.

    PubMed

    Pinheiro, Mariana S; Viana, Gil M; Vieira, Bárbara de A Abrahim; de Souza, Alessandra Mendonça Teles; Rodrigues, Carlos Rangel; Marins, Rita de Cássia E E; Cabral, Lúcio M; de Sousa, Valéria P

    2017-05-10

    The present study reports the degradation behavior of roflumilast (RFL), a new drug developed for the treatment of chronic obstructive pulmonary disease. The degradation of RFL was tested under various stress conditions as per the guidelines of the International Conference on Harmonization. The degradation products (DPs) of RFL were identified, characterized and in silico predictions were made of their pharmacokinetic properties, absorption, distribution, metabolism, excretion and toxicity (ADMET). RFL was subjected to various stress conditions including photodegradation, alkaline and acidic hydrolysis, oxidative and metallic degradation. After analysis by HPLC-DAD, the DPs were isolated by preparative TLC and characterized by high resolution mass spectrometry (HRMS), (1)H NMR, (13)C NMR and infrared (IR) spectroscopy. RFL tablets were prepared by the addition of solid stressing substances such as excipients and storage in an accelerated stability chamber (40°C; 75% r.h.) for sixteen months. Resulting DPs from the tablets were analyzed by UFLC-QTOF. The most drastic degradation conditions for RFL were 5M NaOH(aq), 6M HCl(aq), 7.5% v/v peracetic acid, which resulted in the isolation of four DPs. However, milder degradation conditions (1M NaOH(aq) and photolysis) generated six DPs (DP-1, 2, 3, 5, 7 and 8), and are more similar to the actual conditions the drug will be exposed. For tablets containing RFL exposed to an alkaline reagent, two DPs were formed: DP-1 and DP-11. Whereas RFL-containing tablets exposed to acid and oxidizing agents, formed one product DP-11. Forced degradation of RFL led to the formation of eleven DPs, seven of which have never been previously reported. RFL is stable under metallic stress and it is relatively stable during photodegradation testing. The UFLC-QTOF methodology detected a greater number of DPs that formed during the stress conditions tested when compared to the HPLC-DAD methodology. In silico prediction of the ADMET properties of

  19. Prediction of motor function by diffusion tensor tractography in patients with basal ganglion haemorrhage

    PubMed Central

    Zeng, Jingsong; Zheng, Ping; Xu, Junfa; Tong, Wusong; Guo, Yijun; Yang, Wenjin; Li, Gaoyi; He, Bin

    2011-01-01

    Introduction Haemorrhagic stroke is one of the leading causes of death and the most common cause of long-term adult disability. An accurate estimation of prognosis is very important for haemorrhagic stroke patients. Impairment of motor function caused by pyramidal tract injury is common in these patients. In this study, we performed MR diffusion tensor tractography (DTT) to predict the impairment of motor function in patients with basal ganglion haemorrhage and explore its clinical value. Material and methods Diffusion tensor tractography was performed in 33 patients with basal ganglia haemorrhage within 2 weeks after onset to visualize the course of pyramidal tracts (PTs), and patients were classified into four groups according to the fibre ratio of PTs, calculated by dividing the PT number of the affected hemisphere by that of the unaffected hemisphere, as follows: type A, the fibre ratio was less than 1/4; type B, less than 1/2; type C, more than 1/2; and type D, more than 3/4. The upper extremity motricity index (UMI) was used to evaluate the motor function at onset and 6 months after onset. Upper extremity motricity index scores were compared among the different groups and a Spearman analysis was performed to correlate the UMI scores with different integrity of pyramidal tracts. Results There were no differences in the UMI scores at onset among the 4 groups (p< 0.05). The UMI scores obtained at 6 months after onset were significantly unequal and were influenced by the DTT type (p < 0.05). There was a significant correlation between the integrity of the pyramidal tracts and the UMI scores 6 months after onset (r = 0.7312, p< 0.05). Conclusions There was a positive correlation between the integrity grade of pyramidal tracts and the motor function, showing that the more seriously were the pyramidal tracts damaged, the worse was the motor function. The DTT findings of the pyramidal tract in acute cerebral haemorrhage may valuably predict the motor function outcome

  20. Outcome Prediction of Consciousness Disorders in the Acute Stage Based on a Complementary Motor Behavioural Tool

    PubMed Central

    Jöhr, Jane; Gilart de Keranflec'h, Charlotte; Van De Ville, Dimitri; Preti, Maria Giulia; Meskaldji, Djalel E.; Hömberg, Volker; Laureys, Steven; Draganski, Bogdan; Frackowiak, Richard; Diserens, Karin

    2016-01-01

    Introduction Attaining an accurate diagnosis in the acute phase for severely brain-damaged patients presenting Disorders of Consciousness (DOC) is crucial for prognostic validity; such a diagnosis determines further medical management, in terms of therapeutic choices and end-of-life decisions. However, DOC evaluation based on validated scales, such as the Revised Coma Recovery Scale (CRS-R), can lead to an underestimation of consciousness and to frequent misdiagnoses particularly in cases of cognitive motor dissociation due to other aetiologies. The purpose of this study is to determine the clinical signs that lead to a more accurate consciousness assessment allowing more reliable outcome prediction. Methods From the Unit of Acute Neurorehabilitation (University Hospital, Lausanne, Switzerland) between 2011 and 2014, we enrolled 33 DOC patients with a DOC diagnosis according to the CRS-R that had been established within 28 days of brain damage. The first CRS-R assessment established the initial diagnosis of Unresponsive Wakefulness Syndrome (UWS) in 20 patients and a Minimally Consciousness State (MCS) in the remaining13 patients. We clinically evaluated the patients over time using the CRS-R scale and concurrently from the beginning with complementary clinical items of a new observational Motor Behaviour Tool (MBT). Primary endpoint was outcome at unit discharge distinguishing two main classes of patients (DOC patients having emerged from DOC and those remaining in DOC) and 6 subclasses detailing the outcome of UWS and MCS patients, respectively. Based on CRS-R and MBT scores assessed separately and jointly, statistical testing was performed in the acute phase using a non-parametric Mann-Whitney U test; longitudinal CRS-R data were modelled with a Generalized Linear Model. Results Fifty-five per cent of the UWS patients and 77% of the MCS patients had emerged from DOC. First, statistical prediction of the first CRS-R scores did not permit outcome differentiation

  1. The useful field of view assessment predicts simulated commercial motor vehicle driving safety.

    PubMed

    McManus, Benjamin; Heaton, Karen; Vance, David E; Stavrinos, Despina

    2016-10-02

    The Useful Field of View (UFOV) assessment, a measure of visual speed of processing, has been shown to be a predictive measure of motor vehicle collision (MVC) involvement in an older adult population, but it remains unknown whether UFOV predicts commercial motor vehicle (CMV) driving safety during secondary task engagement. The purpose of this study is to determine whether the UFOV assessment predicts simulated MVCs in long-haul CMV drivers. Fifty licensed CMV drivers (Mage = 39.80, SD = 8.38, 98% male, 56% Caucasian) were administered the 3-subtest version of the UFOV assessment, where lower scores measured in milliseconds indicated better performance. CMV drivers completed 4 simulated drives, each spanning approximately a 22.50-mile distance. Four secondary tasks were presented to participants in a counterbalanced order during the drives: (a) no secondary task, (b) cell phone conversation, (c) text messaging interaction, and (d) e-mailing interaction with an on-board dispatch device. The selective attention subtest significantly predicted simulated MVCs regardless of secondary task. Each 20 ms slower on subtest 3 was associated with a 25% increase in the risk of an MVC in the simulated drive. The e-mail interaction secondary task significantly predicted simulated MVCs with a 4.14 times greater risk of an MVC compared to the no secondary task condition. Subtest 3, a measure of visual speed of processing, significantly predicted MVCs in the email interaction task. Each 20 ms slower on subtest 3 was associated with a 25% increase in the risk of an MVC during the email interaction task. The UFOV subtest 3 may be a promising measure to identify CMV drivers who may be at risk for MVCs or in need of cognitive training aimed at improving speed of processing. Subtest 3 may also identify CMV drivers who are particularly at risk when engaged in secondary tasks while driving.

  2. Logistic Regression Analyses for Predicting Clinically Important Differences in Motor Capacity, Motor Performance, and Functional Independence after Constraint-Induced Therapy in Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Wang, Tien-ni; Wu, Ching-yi; Chen, Chia-ling; Shieh, Jeng-yi; Lu, Lu; Lin, Keh-chung

    2013-01-01

    Given the growing evidence for the effects of constraint-induced therapy (CIT) in children with cerebral palsy (CP), there is a need for investigating the characteristics of potential participants who may benefit most from this intervention. This study aimed to establish predictive models for the effects of pediatric CIT on motor and functional…

  3. Logistic Regression Analyses for Predicting Clinically Important Differences in Motor Capacity, Motor Performance, and Functional Independence after Constraint-Induced Therapy in Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Wang, Tien-ni; Wu, Ching-yi; Chen, Chia-ling; Shieh, Jeng-yi; Lu, Lu; Lin, Keh-chung

    2013-01-01

    Given the growing evidence for the effects of constraint-induced therapy (CIT) in children with cerebral palsy (CP), there is a need for investigating the characteristics of potential participants who may benefit most from this intervention. This study aimed to establish predictive models for the effects of pediatric CIT on motor and functional…

  4. Predictive validity of the Sødring Motor Evaluation of Stroke Patients (SMES).

    PubMed

    Wyller, T B; Sødring, K M; Sveen, U; Ljunggren, A E; Bautz-Holter, E

    1996-12-01

    The Sødring Motor Evaluation of Stroke Patients (SMES) has been developed as an instrument for the evaluation by physiotherapists of motor function and activities in stroke patients. The predictive validity of the instrument was studied in a consecutive sample of 93 acute stroke patients, assessed in the acute phase and after one year. The outcome measures were: survival, residence at home or in institution, the Barthel ADL index (dichotomized at 19/20), and the Frenchay Activities Index (FAI) (dichotomized at 9/10). The SMES, scored in the acute phase, demonstrated a marginally significant predictive power regarding survival, but was a highly significant predictor regarding the other outcomes. The adjusted odds ratio for a good versus a poor outcome for patients in the upper versus the lower tertile of the SMES arm subscore was 5.4 (95% confidence interval 0.9-59) for survival, 11.5 (2.1-88) for living at home, 86.3 (11-infinity) for a high Barthel score, and 31.4 (5.2-288) for a high FAI score. We conclude that SMES has high predictive validity.

  5. Temperature prediction in high speed bone grinding using motor PWM signal.

    PubMed

    Tai, Bruce L; Zhang, Lihui; Wang, Anthony C; Sullivan, Stephen; Wang, Guangjun; Shih, Albert J

    2013-10-01

    This research explores the feasibility of using motor electrical feedback to estimate temperature rise during a surgical bone grinding procedure. High-speed bone grinding is often used during skull base neurosurgery to remove cranial bone and approach skull base tumors through the nasal corridor. Grinding-induced heat could propagate and potentially injure surrounding nerves and arteries, and therefore, predicting the temperature in the grinding region would benefit neurosurgeons during the operation. High-speed electric motors are controlled by pulse-width-modulation (PWM) to alter the current input and thus maintain the rotational speed. Assuming full mechanical to thermal power conversion in the grinding process, PWM can be used as feedback for heat generation and temperature prediction. In this study, the conversion model was established from experiments under a variety of grinding conditions and an inverse heat transfer method to determine heat flux. Given a constant rotational speed, the heat conversion was represented by a linear function, and could predict temperature from the experimental data with less than 20% errors. Such results support the advance of this technology for practical application.

  6. De novo prediction of the genomic components and capabilities for microbial plant biomass degradation from (meta-)genomes

    PubMed Central

    2013-01-01

    Background Understanding the biological mechanisms used by microorganisms for plant biomass degradation is of considerable biotechnological interest. Despite of the growing number of sequenced (meta)genomes of plant biomass-degrading microbes, there is currently no technique for the systematic determination of the genomic components of this process from these data. Results We describe a computational method for the discovery of the protein domains and CAZy families involved in microbial plant biomass degradation. Our method furthermore accurately predicts the capability to degrade plant biomass for microbial species from their genome sequences. Application to a large, manually curated data set of microbial degraders and non-degraders identified gene families of enzymes known by physiological and biochemical tests to be implicated in cellulose degradation, such as GH5 and GH6. Additionally, genes of enzymes that degrade other plant polysaccharides, such as hemicellulose, pectins and oligosaccharides, were found, as well as gene families which have not previously been related to the process. For draft genomes reconstructed from a cow rumen metagenome our method predicted Bacteroidetes-affiliated species and a relative to a known plant biomass degrader to be plant biomass degraders. This was supported by the presence of genes encoding enzymatically active glycoside hydrolases in these genomes. Conclusions Our results show the potential of the method for generating novel insights into microbial plant biomass degradation from (meta-)genome data, where there is an increasing production of genome assemblages for uncultured microbes. PMID:23414703

  7. Alteration in forward model prediction of sensory outcome of motor action in focal hand dystonia

    PubMed Central

    Lee, André; Furuya, Shinichi; Karst, Matthias; Altenmüller, Eckart

    2013-01-01

    Focal hand dystonia in musicians is a movement disorder affecting highly trained movements. Rather than being a pure motor disorder related to movement execution only, movement planning, error prediction, and sensorimotor integration are also impaired. Internal models (IMs), of which two types, forward and inverse models have been described and most likely processed in the cerebellum, are known to be involved in these tasks. Recent results indicate that the cerebellum may be involved in the pathophysiology of focal dystonia (FD). Thus, the aim of our study was to investigate whether an IM deficit plays a role in FD. We focused on the forward model (FM), which predicts sensory consequences of motor commands and allows the discrimination between external sensory input and input deriving from motor action. We investigated 19 patients, aged 19–59 and 19 healthy musicians aged 19–36 as controls. Tactile stimuli were applied to fingers II–V of both hands by the experimenter or the patient. After each stimulus the participant rated the stimulus intensity on a scale between 0 (no sensation) and 1 (maximal intensity). The difference of perceived intensity between self- and externally applied (EA) stimuli was then calculated for each finger. For assessing differences between patients and controls we performed a cluster analysis of the affected hand and the corresponding hand of the controls using the fingers II–V as variables in a 4-dimensional hyperspace (chance level = 0.5). Using a cluster analysis, we found a correct classification of the affected finger in 78.9–94.7%. There was no difference between patients and healthy controls of the absolute value of the perceived stimulus intensity. Our results suggest an altered FM function in focal hand dystonia. It has the potential of suggesting a neural correlate within the cerebellum and of helping integrate findings with regard to altered sensorimotor processing and altered prediction in FD in a single framework

  8. A cerebellar model for predictive motor control tested in a brain-based device

    PubMed Central

    McKinstry, Jeffrey L.; Edelman, Gerald M.; Krichmar, Jeffrey L.

    2006-01-01

    The cerebellum is known to be critical for accurate adaptive control and motor learning. We propose here a mechanism by which the cerebellum may replace reflex control with predictive control. This mechanism is embedded in a learning rule (the delayed eligibility trace rule) in which synapses onto a Purkinje cell or onto a cell in the deep cerebellar nuclei become eligible for plasticity only after a fixed delay from the onset of suprathreshold presynaptic activity. To investigate the proposal that the cerebellum is a general-purpose predictive controller guided by a delayed eligibility trace rule, a computer model based on the anatomy and dynamics of the cerebellum was constructed. It contained components simulating cerebellar cortex and deep cerebellar nuclei, and it received input from a middle temporal visual area and the inferior olive. The model was incorporated in a real-world brain-based device (BBD) built on a Segway robotic platform that learned to traverse curved paths. The BBD learned which visual motion cues predicted impending collisions and used this experience to avoid path boundaries. During learning, the BBD adapted its velocity and turning rate to successfully traverse various curved paths. By examining neuronal activity and synaptic changes during this behavior, we found that the cerebellar circuit selectively responded to motion cues in specific receptive fields of simulated middle temporal visual areas. The system described here prompts several hypotheses about the relationship between perception and motor control and may be useful in the development of general-purpose motor learning systems for machines. PMID:16488974

  9. Predicting Motor Skills from Strengths and Difficulties Questionnaire Scores, Language Ability, and Other Features of New Zealand Children Entering Primary School

    ERIC Educational Resources Information Center

    Sargisson, Rebecca J.; Powell, Cheniel; Stanley, Peter; de Candole, Rosalind

    2014-01-01

    The motor and language skills, emotional and behavioural problems of 245 children were measured at school entry. Fine motor scores were significantly predicted by hyperactivity, phonetic awareness, prosocial behaviour, and the presence of medical problems. Gross motor scores were significantly predicted by the presence of medical problems. The…

  10. Predicting Motor Skills from Strengths and Difficulties Questionnaire Scores, Language Ability, and Other Features of New Zealand Children Entering Primary School

    ERIC Educational Resources Information Center

    Sargisson, Rebecca J.; Powell, Cheniel; Stanley, Peter; de Candole, Rosalind

    2014-01-01

    The motor and language skills, emotional and behavioural problems of 245 children were measured at school entry. Fine motor scores were significantly predicted by hyperactivity, phonetic awareness, prosocial behaviour, and the presence of medical problems. Gross motor scores were significantly predicted by the presence of medical problems. The…

  11. Dynamic Shaping of the Defensive Peripersonal Space through Predictive Motor Mechanisms: When the "Near" Becomes "Far".

    PubMed

    Bisio, Ambra; Garbarini, Francesca; Biggio, Monica; Fossataro, Carlotta; Ruggeri, Piero; Bove, Marco

    2017-03-01

    The hand blink reflex is a subcortical defensive response, known to dramatically increase when the stimulated hand is statically positioned inside the defensive peripersonal space (DPPS) of the face. Here, we tested in a group of healthy human subjects the hand blink reflex in dynamic conditions, investigating whether the direction of the hand movements (up-to/down-from the face) could modulate it. We found that, on equal hand position, the response enhancement was present only when the hand approached to (and not receded from) the DPPS of the face. This means that, when the hand is close to the face but the subject is planning to move the hand down, the predictive motor system can anticipate the consequence of the movement: the "near" becomes "far." We found similar results both in passive movement condition, when only afferent (visual and proprioceptive) information can be used to estimate the final state of the system, and in motor imagery task, when only efferent (intentional) information is available to predict the consequences of the movement. All these findings provide evidence that the DPPS is dynamically shaped by predictive mechanisms run by the motor system and based on the integration of feedforward and sensory feedback signals.SIGNIFICANCE STATEMENT The defensive peripersonal space (DPPS) has a crucial role for survival, and its modulation is fundamental when we interact with the environment, as when we move our arms. Here, we focused on a defensive response, the hand blink reflex, known to increase when a static hand is stimulated inside the DPPS of the face. We tested the hand blink reflex in dynamic conditions (voluntary, passive, and imagined movements) and we found that, on equal hand position, the response enhancement was present only when the hand approached to (and not receded from) the DPPS of the face. This suggests that, through the integration of efferent and afferent signals, the safety boundary around the body is continuously shaped by

  12. Early Fiber Number Ratio Is a Surrogate of Corticospinal Tract Integrity and Predicts Motor Recovery After Stroke.

    PubMed

    Bigourdan, Antoine; Munsch, Fanny; Coupé, Pierrick; Guttmann, Charles R G; Sagnier, Sharmila; Renou, Pauline; Debruxelles, Sabrina; Poli, Mathilde; Dousset, Vincent; Sibon, Igor; Tourdias, Thomas

    2016-04-01

    The contribution of imaging metrics to predict poststroke motor recovery needs to be clarified. We tested the added value of early diffusion tensor imaging (DTI) of the corticospinal tract toward predicting long-term motor recovery. One hundred seventeen patients were prospectively assessed at 24 to 72 hours and 1 year after ischemic stroke with diffusion tensor imaging and motor scores (Fugl-Meyer). The initial fiber number ratio (iFNr) and final fiber number ratio were computed as the number of streamlines along the affected corticospinal tract normalized to the unaffected side and were compared with each other. The prediction of motor recovery (ΔFugl-Meyer) was first modeled using initial Fugl-Meyer and iFNr. Multivariate ordinal logistic regression models were also used to study the association of iFNr, initial Fugl-Meyer, age, and stroke volume with Fugl-Meyer at 1 year. The iFNr correlated with the final fiber number ratio at 1 year (r=0.70; P<0.0001). The initial Fugl-Meyer strongly predicted motor recovery (≈73% of initial impairment) for all patients except those with initial severe stroke (Fugl-Meyer<50). For these severe patients (n=26), initial Fugl-Meyer was not correlated with motor recovery (R(2)=0.13; p=ns), whereas iFNr showed strong correlation (R(2)=0.56; P<0.0001). In multivariate analysis, the iFNr was an independent predictor of motor outcome (β=2.601; 95% confidence interval=0.304-5.110; P=0.031), improving prediction compared with using only initial Fugl-Meyer, age, and stroke volume (P=0.026). Early measurement of FNr at 24 to 72 hours poststroke is a surrogate marker of corticospinal tract integrity and provides independent prediction of motor outcome at 1 year especially for patients with severe initial impairment. © 2016 American Heart Association, Inc.

  13. Degradation and mineralization of phenol compounds with goethite catalyst and mineralization prediction using artificial intelligence.

    PubMed

    Tisa, Farhana; Davoody, Meysam; Abdul Raman, Abdul Aziz; Daud, Wan Mohd Ashri Wan

    2015-01-01

    The efficiency of phenol degradation via Fenton reaction using mixture of heterogeneous goethite catalyst with homogeneous ferrous ion was analyzed as a function of three independent variables, initial concentration of phenol (60 to 100 mg /L), weight ratio of initial concentration of phenol to that of H2O2 (1: 6 to 1: 14) and, weight ratio of initial concentration of goethite catalyst to that of H2O2 (1: 0.3 to 1: 0.7). More than 90 % of phenol removal and more than 40% of TOC removal were achieved within 60 minutes of reaction. Two separate models were developed using artificial neural networks to predict degradation percentage by a combination of Fe3+ and Fe2+ catalyst. Five operational parameters were employed as inputs while phenol degradation and TOC removal were considered as outputs of the developed models. Satisfactory agreement was observed between testing data and the predicted values (R2Phenol = 0.9214 and R2TOC= 0.9082).

  14. Degradation and Mineralization of Phenol Compounds with Goethite Catalyst and Mineralization Prediction Using Artificial Intelligence

    PubMed Central

    Tisa, Farhana; Davoody, Meysam; Abdul Raman, Abdul Aziz; Daud, Wan Mohd Ashri Wan

    2015-01-01

    The efficiency of phenol degradation via Fenton reaction using mixture of heterogeneous goethite catalyst with homogeneous ferrous ion was analyzed as a function of three independent variables, initial concentration of phenol (60 to 100 mg /L), weight ratio of initial concentration of phenol to that of H2O2 (1: 6 to 1: 14) and, weight ratio of initial concentration of goethite catalyst to that of H2O2 (1: 0.3 to 1: 0.7). More than 90 % of phenol removal and more than 40% of TOC removal were achieved within 60 minutes of reaction. Two separate models were developed using artificial neural networks to predict degradation percentage by a combination of Fe3+ and Fe2+ catalyst. Five operational parameters were employed as inputs while phenol degradation and TOC removal were considered as outputs of the developed models. Satisfactory agreement was observed between testing data and the predicted values (R2Phenol = 0.9214 and R2TOC= 0.9082). PMID:25849556

  15. Predictable bacterial composition and hydrocarbon degradation in Arctic soils following diesel and nutrient disturbance

    PubMed Central

    Bell, Terrence H; Yergeau, Etienne; Maynard, Christine; Juck, David; Whyte, Lyle G; Greer, Charles W

    2013-01-01

    Increased exploration and exploitation of resources in the Arctic is leading to a higher risk of petroleum contamination. A number of Arctic microorganisms can use petroleum for growth-supporting carbon and energy, but traditional approaches for stimulating these microorganisms (for example, nutrient addition) have varied in effectiveness between sites. Consistent environmental controls on microbial community response to disturbance from petroleum contaminants and nutrient amendments across Arctic soils have not been identified, nor is it known whether specific taxa are universally associated with efficient bioremediation. In this study, we contaminated 18 Arctic soils with diesel and treated subsamples of each with monoammonium phosphate (MAP), which has successfully stimulated degradation in some contaminated Arctic soils. Bacterial community composition of uncontaminated, diesel-contaminated and diesel+MAP soils was assessed through multiplexed 16S (ribosomal RNA) rRNA gene sequencing on an Ion Torrent Personal Genome Machine, while hydrocarbon degradation was measured by gas chromatography analysis. Diversity of 16S rRNA gene sequences was reduced by diesel, and more so by the combination of diesel and MAP. Actinobacteria dominated uncontaminated soils with <10% organic matter, while Proteobacteria dominated higher-organic matter soils, and this pattern was exaggerated following disturbance. Degradation with and without MAP was predictable by initial bacterial diversity and the abundance of specific assemblages of Betaproteobacteria, respectively. High Betaproteobacteria abundance was positively correlated with high diesel degradation in MAP-treated soils, suggesting this may be an important group to stimulate. The predictability with which bacterial communities respond to these disturbances suggests that costly and time-consuming contaminated site assessments may not be necessary in the future. PMID:23389106

  16. Predictable bacterial composition and hydrocarbon degradation in Arctic soils following diesel and nutrient disturbance.

    PubMed

    Bell, Terrence H; Yergeau, Etienne; Maynard, Christine; Juck, David; Whyte, Lyle G; Greer, Charles W

    2013-06-01

    Increased exploration and exploitation of resources in the Arctic is leading to a higher risk of petroleum contamination. A number of Arctic microorganisms can use petroleum for growth-supporting carbon and energy, but traditional approaches for stimulating these microorganisms (for example, nutrient addition) have varied in effectiveness between sites. Consistent environmental controls on microbial community response to disturbance from petroleum contaminants and nutrient amendments across Arctic soils have not been identified, nor is it known whether specific taxa are universally associated with efficient bioremediation. In this study, we contaminated 18 Arctic soils with diesel and treated subsamples of each with monoammonium phosphate (MAP), which has successfully stimulated degradation in some contaminated Arctic soils. Bacterial community composition of uncontaminated, diesel-contaminated and diesel+MAP soils was assessed through multiplexed 16S (ribosomal RNA) rRNA gene sequencing on an Ion Torrent Personal Genome Machine, while hydrocarbon degradation was measured by gas chromatography analysis. Diversity of 16S rRNA gene sequences was reduced by diesel, and more so by the combination of diesel and MAP. Actinobacteria dominated uncontaminated soils with <10% organic matter, while Proteobacteria dominated higher-organic matter soils, and this pattern was exaggerated following disturbance. Degradation with and without MAP was predictable by initial bacterial diversity and the abundance of specific assemblages of Betaproteobacteria, respectively. High Betaproteobacteria abundance was positively correlated with high diesel degradation in MAP-treated soils, suggesting this may be an important group to stimulate. The predictability with which bacterial communities respond to these disturbances suggests that costly and time-consuming contaminated site assessments may not be necessary in the future.

  17. Motor-operated valve (MOV) actuator motor and gearbox testing

    SciTech Connect

    DeWall, K.; Watkins, J.C.; Bramwell, D.

    1997-07-01

    Researchers at the Idaho National Engineering and Environmental Laboratory tested the performance of electric motors and actuator gearboxes typical of the equipment installed on motor-operated valves used in nuclear power plants. Using a test stand that simulates valve closure loads against flow and pressure, the authors tested five electric motors (four ac and one dc) and three gearboxes at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. They also monitored the efficiency of the actuator gearbox. All five motors operated at or above their rated starting torque during tests at normal voltages and temperatures. For all five motors, actual torque losses due to voltage degradation were greater than the losses calculated by methods typically used for predicting motor torque at degraded voltage conditions. For the dc motor the actual torque losses due to elevated operating temperatures were greater than the losses calculated by the typical predictive method. The actual efficiencies of the actuator gearboxes were generally lower than the running efficiencies published by the manufacturer and were generally nearer the published pull-out efficiencies. Operation of the gearbox at elevated temperature did not affect the operating efficiency.

  18. Ventral striatum encodes past and predicted value independent of motor contingencies.

    PubMed

    Goldstein, Brandon L; Barnett, Brian R; Vasquez, Gloria; Tobia, Steven C; Kashtelyan, Vadim; Burton, Amanda C; Bryden, Daniel W; Roesch, Matthew R

    2012-02-08

    The ventral striatum (VS) is thought to signal the predicted value of expected outcomes. However, it is still unclear whether VS can encode value independently from variables often yoked to value such as response direction and latency. Expectations of high value reward are often associated with a particular action and faster latencies. To address this issue we trained rats to perform a task in which the size of the predicted reward was signaled before the instrumental response was instructed. Instrumental directional cues were presented briefly at a variable onset to reduce accuracy and increase reaction time. Rats were more accurate and slower when a large versus small reward was at stake. We found that activity in VS was high during odors that predicted large reward even though reaction times were slower under these conditions. In addition to these effects, we found that activity before the reward predicting cue reflected past and predicted reward. These results demonstrate that VS can encode value independent of motor contingencies and that the role of VS in goal-directed behavior is not just to increase vigor of specific actions when more is at stake.

  19. Lifetime Prediction for Degradation of Solar Mirrors using Step-Stress Accelerated Testing (Presentation)

    SciTech Connect

    Lee, J.; Elmore, R.; Kennedy, C.; Gray, M.; Jones, W.

    2011-09-01

    This research is to illustrate the use of statistical inference techniques in order to quantify the uncertainty surrounding reliability estimates in a step-stress accelerated degradation testing (SSADT) scenario. SSADT can be used when a researcher is faced with a resource-constrained environment, e.g., limits on chamber time or on the number of units to test. We apply the SSADT methodology to a degradation experiment involving concentrated solar power (CSP) mirrors and compare the results to a more traditional multiple accelerated testing paradigm. Specifically, our work includes: (1) designing a durability testing plan for solar mirrors (3M's new improved silvered acrylic "Solar Reflector Film (SFM) 1100") through the ultra-accelerated weathering system (UAWS), (2) defining degradation paths of optical performance based on the SSADT model which is accelerated by high UV-radiant exposure, and (3) developing service lifetime prediction models for solar mirrors using advanced statistical inference. We use the method of least squares to estimate the model parameters and this serves as the basis for the statistical inference in SSADT. Several quantities of interest can be estimated from this procedure, e.g., mean-time-to-failure (MTTF) and warranty time. The methods allow for the estimation of quantities that may be of interest to the domain scientists.

  20. Prediction and classification of the degradation state of plastic materials used in modern and contemporary art

    NASA Astrophysics Data System (ADS)

    Manfredi, M.; Barberis, E.; Marengo, E.

    2017-01-01

    Today, artworks partially or completely made of plastic materials can be found in almost all international museums and collections. The deterioration of these objects is now becoming evident mainly because these synthetic materials are not designed for a long life and the characterization of their state of conservation can help curators and conservators. In this research we investigated the applicability of a portable attenuated total reflection (ATR) infrared spectrometer for the non-invasive characterization and for monitoring the degradation of plastics used in modern and contemporary art. Several polypropylene and polycarbonate samples were artificially aged in solar box, simulating about 200 years of museum light exposure, and they were monitored with the portable ATR, creating an infrared library of the conservation state of plastics. Through the use of chemometric techniques like principal component analysis-linear discriminant analysis and partial least square—discriminant analysis, we built a robust degradation model of each material that can be used to predict and classify the degradation state of artworks and to identify the priority of intervention in the museum collections. Portable ATR coupled to multivariate statistics can be employed for taking care of plastic artworks as it is non-invasive, the analysis is very fast and it can be performed directly in situ.

  1. Phototransformation of selected human-used macrolides in surface water: kinetics, model predictions and degradation pathways.

    PubMed

    Vione, Davide; Feitosa-Felizzola, Juliana; Minero, Claudio; Chiron, Serge

    2009-04-01

    The phototransformation of clarithromycin and roxithromycin, two human-used macrolide (MLs) antibiotics was investigated in surface waters. Photolysis kinetic data suggest that degradation in water would occur via the direct photolysis of the Fe(III)-MLs complexes. Hydroxyl radicals, singlet oxygen and other photooxidants generated from nitrate ions and from excited chromophores present in humic acids appeared to have only a very limited impact on the overall degradation of MLs under the adopted UV-vis irradiation conditions. A photolysis model applied to the Fe(III)-clarithromycin complex in river water showed that a half-life of 40 days was predicted under clear-sky irradiation in November, 26 days in February, and 10 in May. Direct photolysis could have a limited impact on the environmental concentrations of MLs in rivers, due to a too short water residence time but might be important in shallow lakes and lagoons. Photoinduced degradation of MLs mainly implied changes in the structure of the aglycone, probably leading to their detoxification because the pseudoerythromycin derivatives have very little antimicrobial activity.

  2. Predicting Risk of Motor Vehicle Collisions in Patients with Glaucoma: A Longitudinal Study

    PubMed Central

    Gracitelli, Carolina P. B.; Tatham, Andrew J.; Boer, Erwin R.; Abe, Ricardo Y.; Diniz-Filho, Alberto; Rosen, Peter N.; Medeiros, Felipe A.

    2015-01-01

    Purpose To evaluate the ability of longitudinal Useful Field of View (UFOV) and simulated driving measurements to predict future occurrence of motor vehicle collision (MVC) in drivers with glaucoma. Design Prospective observational cohort study. Participants 117 drivers with glaucoma followed for an average of 2.1 ± 0.5 years. Methods All subjects had standard automated perimetry (SAP), UFOV, driving simulator, and cognitive assessment obtained at baseline and every 6 months during follow-up. The driving simulator evaluated reaction times to high and low contrast peripheral divided attention stimuli presented while negotiating a winding country road, with central driving task performance assessed as “curve coherence”. Drivers with MVC during follow-up were identified from Department of Motor Vehicle records. Main Outcome Measures Survival models were used to evaluate the ability of driving simulator and UFOV to predict MVC over time, adjusting for potential confounding factors. Results Mean age at baseline was 64.5 ± 12.6 years. 11 of 117 (9.4%) drivers had a MVC during follow-up. In the multivariable models, low contrast reaction time was significantly predictive of MVC, with a hazard ratio (HR) of 2.19 per 1 SD slower reaction time (95% CI, 1.30 to 3.69; P = 0.003). UFOV divided attention was also significantly predictive of MVC with a HR of 1.98 per 1 SD worse (95% CI, 1.10 to 3.57; P = 0.022). Global SAP visual field indices in the better or worse eye were not predictive of MVC. The longitudinal model including driving simulator performance was a better predictor of MVC compared to UFOV (R2 = 0.41 vs R2 = 0.18). Conclusions Longitudinal divided attention metrics on the UFOV test and during simulated driving were significantly predictive of risk of MVC in glaucoma patients. These findings may help improve the understanding of factors associated with driving impairment related to glaucoma. PMID:26426342

  3. Mechanisms of Intentional Binding and Sensory Attenuation: The Role of Temporal Prediction, Temporal Control, Identity Prediction, and Motor Prediction

    ERIC Educational Resources Information Center

    Hughes, Gethin; Desantis, Andrea; Waszak, Florian

    2013-01-01

    Sensory processing of action effects has been shown to differ from that of externally triggered stimuli, with respect both to the perceived timing of their occurrence (intentional binding) and to their intensity (sensory attenuation). These phenomena are normally attributed to forward action models, such that when action prediction is consistent…

  4. Degradable lipid nanoparticles with predictable in vivo siRNA delivery activity

    NASA Astrophysics Data System (ADS)

    Whitehead, Kathryn A.; Dorkin, J. Robert; Vegas, Arturo J.; Chang, Philip H.; Veiseh, Omid; Matthews, Jonathan; Fenton, Owen S.; Zhang, Yunlong; Olejnik, Karsten T.; Yesilyurt, Volkan; Chen, Delai; Barros, Scott; Klebanov, Boris; Novobrantseva, Tatiana; Langer, Robert; Anderson, Daniel G.

    2014-06-01

    One of the most significant challenges in the development of clinically viable delivery systems for RNA interference therapeutics is to understand how molecular structures influence delivery efficacy. Here, we have synthesized 1,400 degradable lipidoids and evaluate their transfection ability and structure-function activity. We show that lipidoid nanoparticles mediate potent gene knockdown in hepatocytes and immune cell populations on IV administration to mice (siRNA EC50 values as low as 0.01 mg kg-1). We identify four necessary and sufficient structural and pKa criteria that robustly predict the ability of nanoparticles to mediate greater than 95% protein silencing in vivo. Because these efficacy criteria can be dictated through chemical design, this discovery could eliminate our dependence on time-consuming and expensive cell culture assays and animal testing. Herein, we identify promising degradable lipidoids and describe new design criteria that reliably predict in vivo siRNA delivery efficacy without any prior biological testing.

  5. Probabilistic Movement Models Show that Postural Control Precedes and Predicts Volitional Motor Control

    PubMed Central

    Rueckert, Elmar; Čamernik, Jernej; Peters, Jan; Babič, Jan

    2016-01-01

    Human motor skill learning is driven by the necessity to adapt to new situations. While supportive contacts are essential for many tasks, little is known about their impact on motor learning. To study the effect of contacts an innovative full-body experimental paradigm was established. The task of the subjects was to reach for a distant target while postural stability could only be maintained by establishing an additional supportive hand contact. To examine adaptation, non-trivial postural perturbations of the subjects’ support base were systematically introduced. A novel probabilistic trajectory model approach was employed to analyze the correlation between the motions of both arms and the trunk. We found that subjects adapted to the perturbations by establishing target dependent hand contacts. Moreover, we found that the trunk motion adapted significantly faster than the motion of the arms. However, the most striking finding was that observations of the initial phase of the left arm or trunk motion (100–400 ms) were sufficient to faithfully predict the complete movement of the right arm. Overall, our results suggest that the goal-directed arm movements determine the supportive arm motions and that the motion of heavy body parts adapts faster than the light arms. PMID:27328750

  6. Do A-waves help predict intravenous immunoglobulin response in multifocal motor neuropathy without block?

    PubMed

    Lange, Dale J; Nijjar, Rajwinder; Voustianiouk, Andrei; Seidel, Gregory; Panchal, Janki; Wang, Annabel K

    2011-04-01

    Are there electrophysiological findings that predict response to intravenous immunoglobulin (IVIg) in patients with lower motor neuron (LMN) syndromes without multifocal conduction block (MCB)? We enrolled 9 patients with LMN syndromes without MCB to receive 18 weeks of IVIg therapy. Response was measured at weeks 2 and 18 using the Appel Amyotrophic Lateral Sclerosis (AALS) score (includes grip and pincer strength measures), ALS Functional Rating Scale (ALSFRS), and electrophysiological measures, including motor unit estimates (MUNEs). No change occurred in AALS or ALSFRS scores posttreatment. Grip/pincer strength increased in 7 patients (P = 0.028) after initial treatment (responders); 2 showed no improvement (non-responders). No electrophysiological measure changed after treatment in either group but MUNEs trended higher (P = 0.055). "Abnormal A-waves" (complex, repetitive biphasic, or present in multiple nerves) occurred in pretreatment studies more often in responders (P = 0.028). "Abnormal A-waves" may signal IVIg-responsive LMN syndromes even if conduction block is absent. Copyright © 2011 Wiley Periodicals, Inc.

  7. Cerebellar granule cells acquire a widespread predictive feedback signal during motor learning.

    PubMed

    Giovannucci, Andrea; Badura, Aleksandra; Deverett, Ben; Najafi, Farzaneh; Pereira, Talmo D; Gao, Zhenyu; Ozden, Ilker; Kloth, Alexander D; Pnevmatikakis, Eftychios; Paninski, Liam; De Zeeuw, Chris I; Medina, Javier F; Wang, Samuel S-H

    2017-03-20

    Cerebellar granule cells, which constitute half the brain's neurons, supply Purkinje cells with contextual information necessary for motor learning, but how they encode this information is unknown. Here we show, using two-photon microscopy to track neural activity over multiple days of cerebellum-dependent eyeblink conditioning in mice, that granule cell populations acquire a dense representation of the anticipatory eyelid movement. Initially, granule cells responded to neutral visual and somatosensory stimuli as well as periorbital airpuffs used for training. As learning progressed, two-thirds of monitored granule cells acquired a conditional response whose timing matched or preceded the learned eyelid movements. Granule cell activity covaried trial by trial to form a redundant code. Many granule cells were also active during movements of nearby body structures. Thus, a predictive signal about the upcoming movement is widely available at the input stage of the cerebellar cortex, as required by forward models of cerebellar control.

  8. Predicting severe head injury after light motor vehicle crashes: implications for automatic crash notification systems.

    PubMed

    Talmor, Daniel; Thompson, Kimberly M; Legedza, Anna T R; Nirula, Ram

    2006-07-01

    Motor vehicle crashes (MVC) are a leading public health problem. Improving notification times and the ability to predict which crashes will involve severe injuries may improve trauma system utilization. This study was undertaken to develop and validate a model to predict severe head injury following MVC using information readily incorporated into an automatic crash notification system. A cross-sectional study with derivation and validation sets was performed. The cohort was drawn from drivers of vehicles involved in MVC obtained from the National Automotive Sampling System (NASS). Independent multivariable predictors of severe head injury were identified. The model was able to stratify drivers according to their risk of severe head injury indicating its validity. The areas under the receiver-operating characteristic (ROC) curves were 0.7928 in the derivation set and 0.7940 in the validation set. We have developed a prediction model for head injury in MVC. As the development of automatic crash notification systems improves, models such as this one will be necessary to permit triage of what would be an overwhelming increase in crash notifications to pre-hospital responders.

  9. Predictive current control of permanent magnet synchronous motor based on linear active disturbance rejection control

    NASA Astrophysics Data System (ADS)

    Li, Kunpeng

    2017-01-01

    The compatibility problem between rapidity and overshooting in the traditional predictive current control structure is inevitable and difficult to solve by reason of using PI controller. A novel predictive current control (PCC) algorithm for permanent magnet synchronous motor (PMSM) based on linear active disturbance rejection control (LADRC) is presented in this paper. In order to displace PI controller, the LADRC strategy which consisted of linear state error feedback (LSEF) control algorithm and linear extended state observer (LESO), is designed based on the mathematic model of PMSM. The purpose of LSEF is to make sure fast response to load mutation and system uncertainties, and LESO is designed to estimate the uncertain disturbances. The principal structures of the proposed system are speed outer loop based on LADRC and current inner loop based on predictive current control. Especially, the instruction value of qaxis current in inner loop is derived from the control quantity which is designed in speed outer loop. The simulation is carried out in Matlab/Simulink software, and the results illustrate that the dynamic and static performances of proposed system are satisfied. Moreover the robust against model parameters mismatch is enhanced obviously.

  10. Prediction of hand trajectory from electrocorticography signals in primary motor cortex.

    PubMed

    Chen, Chao; Shin, Duk; Watanabe, Hidenori; Nakanishi, Yasuhiko; Kambara, Hiroyuki; Yoshimura, Natsue; Nambu, Atsushi; Isa, Tadashi; Nishimura, Yukio; Koike, Yasuharu

    2013-01-01

    Due to their potential as a control modality in brain-machine interfaces, electrocorticography (ECoG) has received much focus in recent years. Studies using ECoG have come out with success in such endeavors as classification of arm movements and natural grasp types, regression of arm trajectories in two and three dimensions, estimation of muscle activity time series and so on. However, there still remains considerable work to be done before a high performance ECoG-based neural prosthetic can be realized. In this study, we proposed an algorithm to decode hand trajectory from 15 and 32 channel ECoG signals recorded from primary motor cortex (M1) in two primates. To determine the most effective areas for prediction, we applied two electrode selection methods, one based on position relative to the central sulcus (CS) and another based on the electrodes' individual prediction performance. The best coefficients of determination for decoding hand trajectory in the two monkeys were 0.4815 ± 0.0167 and 0.7780 ± 0.0164. Performance results from individual ECoG electrodes showed that those with higher performance were concentrated at the lateral areas and areas close to the CS. The results of prediction according with different numbers of electrodes based on proposed methods were also shown and discussed. These results also suggest that superior decoding performance can be achieved from a group of effective ECoG signals rather than an entire ECoG array.

  11. The Functional Integration in the Sensory-Motor System Predicts Aging in Healthy Older Adults.

    PubMed

    He, Hui; Luo, Cheng; Chang, Xin; Shan, Yan; Cao, Weifang; Gong, Jinnan; Klugah-Brown, Benjamin; Bobes, Maria A; Biswal, Bharat; Yao, Dezhong

    2016-01-01

    Healthy aging is typically accompanied by a decrease in the motor capacity. Although the disrupted neural representations and performance of movement have been observed in older age in previous studies, the relationship between the functional integration of sensory-motor (SM) system and aging could be further investigated. In this study, we examine the impact of healthy aging on the resting-state functional connectivity (rsFC) of the SM system, and investigate as to how aging is affecting the rsFC in SM network. The SM network was identified and evaluated in 52 healthy older adults and 51 younger adults using two common data analytic approaches: independent component analysis and seed-based functional connectivity (seed at bilateral M1 and S1). We then evaluated whether the altered rsFC of the SM network could delineate trajectories of the age of older adults using a machine learning methodology. Compared with the younger adults, the older demonstrated reduced functional integration with increasing age in the mid-posterior insula of SM network and increased rsFC among the sensorimotor cortex. Moreover, the reduction in the rsFC of mid-posterior insula is associated with the age of older adults. Critically, the analysis based on two-aspect connectivity-based prediction frameworks revealed that the age of older adults could be reliably predicted by this reduced rsFC. These findings further indicated that healthy aging has a marked influence on the SM system that would be associated with a reorganization of SM system with aging. Our findings provide further insight into changes in sensorimotor function in the aging brain.

  12. Whole genome duplication events in plant evolution reconstructed and predicted using myosin motor proteins

    PubMed Central

    2013-01-01

    Background The evolution of land plants is characterized by whole genome duplications (WGD), which drove species diversification and evolutionary novelties. Detecting these events is especially difficult if they date back to the origin of the plant kingdom. Established methods for reconstructing WGDs include intra- and inter-genome comparisons, KS age distribution analyses, and phylogenetic tree constructions. Results By analysing 67 completely sequenced plant genomes 775 myosins were identified and manually assembled. Phylogenetic trees of the myosin motor domains revealed orthologous and paralogous relationships and were consistent with recent species trees. Based on the myosin inventories and the phylogenetic trees, we have identified duplications of the entire myosin motor protein family at timings consistent with 23 WGDs, that had been reported before. We also predict 6 WGDs based on further protein family duplications. Notably, the myosin data support the two recently reported WGDs in the common ancestor of all extant angiosperms. We predict single WGDs in the Manihot esculenta and Nicotiana benthamiana lineages, two WGDs for Linum usitatissimum and Phoenix dactylifera, and a triplication or two WGDs for Gossypium raimondii. Our data show another myosin duplication in the ancestor of the angiosperms that could be either the result of a single gene duplication or a remnant of a WGD. Conclusions We have shown that the myosin inventories in angiosperms retain evidence of numerous WGDs that happened throughout plant evolution. In contrast to other protein families, many myosins are still present in extant species. They are closely related and have similar domain architectures, and their phylogenetic grouping follows the genome duplications. Because of its broad taxonomic sampling the dataset provides the basis for reliable future identification of further whole genome duplications. PMID:24053117

  13. The Functional Integration in the Sensory-Motor System Predicts Aging in Healthy Older Adults

    PubMed Central

    He, Hui; Luo, Cheng; Chang, Xin; Shan, Yan; Cao, Weifang; Gong, Jinnan; Klugah-Brown, Benjamin; Bobes, Maria A.; Biswal, Bharat; Yao, Dezhong

    2017-01-01

    Healthy aging is typically accompanied by a decrease in the motor capacity. Although the disrupted neural representations and performance of movement have been observed in older age in previous studies, the relationship between the functional integration of sensory-motor (SM) system and aging could be further investigated. In this study, we examine the impact of healthy aging on the resting-state functional connectivity (rsFC) of the SM system, and investigate as to how aging is affecting the rsFC in SM network. The SM network was identified and evaluated in 52 healthy older adults and 51 younger adults using two common data analytic approaches: independent component analysis and seed-based functional connectivity (seed at bilateral M1 and S1). We then evaluated whether the altered rsFC of the SM network could delineate trajectories of the age of older adults using a machine learning methodology. Compared with the younger adults, the older demonstrated reduced functional integration with increasing age in the mid-posterior insula of SM network and increased rsFC among the sensorimotor cortex. Moreover, the reduction in the rsFC of mid-posterior insula is associated with the age of older adults. Critically, the analysis based on two-aspect connectivity-based prediction frameworks revealed that the age of older adults could be reliably predicted by this reduced rsFC. These findings further indicated that healthy aging has a marked influence on the SM system that would be associated with a reorganization of SM system with aging. Our findings provide further insight into changes in sensorimotor function in the aging brain. PMID:28111548

  14. Prediction of troponin-T degradation using color image texture features in 10d aged beef longissimus steaks.

    PubMed

    Sun, X; Chen, K J; Berg, E P; Newman, D J; Schwartz, C A; Keller, W L; Maddock Carlin, K R

    2014-02-01

    The objective was to use digital color image texture features to predict troponin-T degradation in beef. Image texture features, including 88 gray level co-occurrence texture features, 81 two-dimension fast Fourier transformation texture features, and 48 Gabor wavelet filter texture features, were extracted from color images of beef strip steaks (longissimus dorsi, n = 102) aged for 10d obtained using a digital camera and additional lighting. Steaks were designated degraded or not-degraded based on troponin-T degradation determined on d 3 and d 10 postmortem by immunoblotting. Statistical analysis (STEPWISE regression model) and artificial neural network (support vector machine model, SVM) methods were designed to classify protein degradation. The d 3 and d 10 STEPWISE models were 94% and 86% accurate, respectively, while the d 3 and d 10 SVM models were 63% and 71%, respectively, in predicting protein degradation in aged meat. STEPWISE and SVM models based on image texture features show potential to predict troponin-T degradation in meat.

  15. Metataxonomic profiling and prediction of functional behaviour of wheat straw degrading microbial consortia.

    PubMed

    Jiménez, Diego Javier; Dini-Andreote, Francisco; van Elsas, Jan Dirk

    2014-01-01

    Mixed microbial cultures, in which bacteria and fungi interact, have been proposed as an efficient way to deconstruct plant waste. The characterization of specific microbial consortia could be the starting point for novel biotechnological applications related to the efficient conversion of lignocellulose to cello-oligosaccharides, plastics and/or biofuels. Here, the diversity, composition and predicted functional profiles of novel bacterial-fungal consortia are reported, on the basis of replicated aerobic wheat straw enrichment cultures. In order to set up biodegradative microcosms, microbial communities were retrieved from a forest soil and introduced into a mineral salt medium containing 1% of (un)treated wheat straw. Following each incubation step, sequential transfers were carried out using 1 to 1,000 dilutions. The microbial source next to three sequential batch cultures (transfers 1, 3 and 10) were analyzed by bacterial 16S rRNA gene and fungal ITS1 pyrosequencing. Faith's phylogenetic diversity values became progressively smaller from the inoculum to the sequential batch cultures. Moreover, increases in the relative abundances of Enterobacteriales, Pseudomonadales, Flavobacteriales and Sphingobacteriales were noted along the enrichment process. Operational taxonomic units affiliated with Acinetobacter johnsonii, Pseudomonas putida and Sphingobacterium faecium were abundant and the underlying strains were successfully isolated. Interestingly, Klebsiella variicola (OTU1062) was found to dominate in both consortia, whereas K. variicola-affiliated strains retrieved from untreated wheat straw consortia showed endoglucanase/xylanase activities. Among the fungal players with high biotechnological relevance, we recovered members of the genera Penicillium, Acremonium, Coniochaeta and Trichosporon. Remarkably, the presence of peroxidases, alpha-L-fucosidases, beta-xylosidases, beta-mannases and beta-glucosidases, involved in lignocellulose degradation, was indicated

  16. Metataxonomic profiling and prediction of functional behaviour of wheat straw degrading microbial consortia

    PubMed Central

    2014-01-01

    degradation, was indicated by predictive bacterial metagenome reconstruction. Reassuringly, tests for specific (hemi)cellulolytic enzymatic activities, performed on the consortial secretomes, confirmed the presence of such gene functions. Conclusion In an in-depth characterization of two wheat straw degrading microbial consortia, we revealed the enrichment and selection of specific bacterial and fungal taxa that were presumably involved in (hemi) cellulose degradation. Interestingly, the microbial community composition was strongly influenced by the wheat straw pretreatment. Finally, the functional bacterial-metagenome prediction and the evaluation of enzymatic activities (at the consortial secretomes) revealed the presence and enrichment of proteins involved in the deconstruction of plant biomass. PMID:24955113

  17. A temporal predictive code for voice motor control: Evidence from ERP and behavioral responses to pitch-shifted auditory feedback.

    PubMed

    Behroozmand, Roozbeh; Sangtian, Stacey; Korzyukov, Oleg; Larson, Charles R

    2016-04-01

    The predictive coding model suggests that voice motor control is regulated by a process in which the mismatch (error) between feedforward predictions and sensory feedback is detected and used to correct vocal motor behavior. In this study, we investigated how predictions about timing of pitch perturbations in voice auditory feedback would modulate ERP and behavioral responses during vocal production. We designed six counterbalanced blocks in which a +100 cents pitch-shift stimulus perturbed voice auditory feedback during vowel sound vocalizations. In three blocks, there was a fixed delay (500, 750 or 1000 ms) between voice and pitch-shift stimulus onset (predictable), whereas in the other three blocks, stimulus onset delay was randomized between 500, 750 and 1000 ms (unpredictable). We found that subjects produced compensatory (opposing) vocal responses that started at 80 ms after the onset of the unpredictable stimuli. However, for predictable stimuli, subjects initiated vocal responses at 20 ms before and followed the direction of pitch shifts in voice feedback. Analysis of ERPs showed that the amplitudes of the N1 and P2 components were significantly reduced in response to predictable compared with unpredictable stimuli. These findings indicate that predictions about temporal features of sensory feedback can modulate vocal motor behavior. In the context of the predictive coding model, temporally-predictable stimuli are learned and reinforced by the internal feedforward system, and as indexed by the ERP suppression, the sensory feedback contribution is reduced for their processing. These findings provide new insights into the neural mechanisms of vocal production and motor control.

  18. A Temporal Predictive Code for Voice Motor Control: Evidence from ERP and Behavioral Responses to Pitch-shifted Auditory Feedback

    PubMed Central

    Behroozmand, Roozbeh; Sangtian, Stacey; Korzyukov, Oleg; Larson, Charles R.

    2016-01-01

    The predictive coding model suggests that voice motor control is regulated by a process in which the mismatch (error) between feedforward predictions and sensory feedback is detected and used to correct vocal motor behavior. In this study, we investigated how predictions about timing of pitch perturbations in voice auditory feedback would modulate ERP and behavioral responses during vocal production. We designed six counterbalanced blocks in which a +100 cents pitch-shift stimulus perturbed voice auditory feedback during vowel sound vocalizations. In three blocks, there was a fixed delay (500, 750 or 1000 ms) between voice and pitch-shift stimulus onset (predictable), whereas in the other three blocks, stimulus onset delay was randomized between 500, 750 and 1000 ms (unpredictable). We found that subjects produced compensatory (opposing) vocal responses that started at 80 ms after the onset of the unpredictable stimuli. However, for predictable stimuli, subjects initiated vocal responses at 20 ms before and followed the direction of pitch shifts in voice feedback. Analysis of ERPs showed that the amplitudes of the N1 and P2 components were significantly reduced in response to predictable compared with unpredictable stimuli. These findings indicate that predictions about temporal features of sensory feedback can modulate vocal motor behavior. In the context of the predictive coding model, temporally-predictable stimuli are learned and reinforced by the internal feedforward system, and as indexed by the ERP suppression, the sensory feedback contribution is reduced for their processing. These findings provide new insights into the neural mechanisms of vocal production and motor control. PMID:26835556

  19. Toxic chemicals in environment and models for predicting their degradation and fate

    SciTech Connect

    Sabljic, A.

    1996-12-31

    During the last 50 years many man-made chemicals have reached every corner of the global environment despite the limitations on their use in some regions and the fact that many of them were not deliberately released into the environment. Both the mobility and persistence of commercial chemicals are the key factors for evaluating their ultimate fate and possible adverse effects on mankind and environment. The notorious global adverse effects are climate changes such as global warming, acid rain, forest decline, as well as permanent degradation of the environment and quality of life. Global and regional models have been developed for predicting transport of chemicals in atmosphere, hydrosphere, and biosphere and hence their ultimate fate or their environmental sinks. Performance of these models will be demonstrated on several classes of persistent organic chemicals. However, in order to work reliably, global and regional models for environmental fate of chemicals require, as input parameters, their physico-chemical properties and reactivity data. Unfortunately, these data are unavailable for the majority of commercial chemicals and necessary data must be calculated or estimated. The present state of the art on the calculation and estimation of several critical environmental parameters, i.e. soil sorption coefficients, tropospheric and microbiological degradation rates will be presented and evaluated including the most recent results from our laboratory.

  20. Reduced kernel recursive least squares algorithm for aero-engine degradation prediction

    NASA Astrophysics Data System (ADS)

    Zhou, Haowen; Huang, Jinquan; Lu, Feng

    2017-10-01

    Kernel adaptive filters (KAFs) generate a linear growing radial basis function (RBF) network with the number of training samples, thereby lacking sparseness. To deal with this drawback, traditional sparsification techniques select a subset of original training data based on a certain criterion to train the network and discard the redundant data directly. Although these methods curb the growth of the network effectively, it should be noted that information conveyed by these redundant samples is omitted, which may lead to accuracy degradation. In this paper, we present a novel online sparsification method which requires much less training time without sacrificing the accuracy performance. Specifically, a reduced kernel recursive least squares (RKRLS) algorithm is developed based on the reduced technique and the linear independency. Unlike conventional methods, our novel methodology employs these redundant data to update the coefficients of the existing network. Due to the effective utilization of the redundant data, the novel algorithm achieves a better accuracy performance, although the network size is significantly reduced. Experiments on time series prediction and online regression demonstrate that RKRLS algorithm requires much less computational consumption and maintains the satisfactory accuracy performance. Finally, we propose an enhanced multi-sensor prognostic model based on RKRLS and Hidden Markov Model (HMM) for remaining useful life (RUL) estimation. A case study in a turbofan degradation dataset is performed to evaluate the performance of the novel prognostic approach.

  1. Circular geometric moiré for degradation prediction of mechanical components performing angular oscillations

    NASA Astrophysics Data System (ADS)

    Palevicius, P.; Aleksa, A.; Maskeliunas, R.; Ragulskis, M.

    2017-03-01

    An experimental technique based on time-averaged circular geometric moiré for optical measurement of angular oscillations is presented in this paper. The pitch of the circular moiré is preselected in such a way that angular oscillations of different amplitudes yield time-averaged moiré fringes at different locations of the cover image. This optical effect enables to construct an optical scale for direct measurement of angular oscillations. The proposed technique is similar to visual cryptography, which is a cryptographic technique that allows encryption of visual information in such a way, that decryption can be done without use of any computational device. The efficiency and the applicability of the proposed technique for performance degradation prediction of rotating mechanical components is illustrated and validated by computational simulations and experimental tests.

  2. Predictive Motor Timing and the Cerebellar Vermis in Schizophrenia: An fMRI Study.

    PubMed

    Lošák, Jan; Hüttlová, Jitka; Lipová, Petra; Marecek, Radek; Bareš, Martin; Filip, Pavel; Žubor, Jozef; Ustohal, Libor; Vanícek, Jirí; Kašpárek, Tomáš

    2016-11-01

    Abnormalities in both time processing and dopamine (DA) neurotransmission have been observed in schizophrenia. Time processing seems to be linked to DA neurotransmission. The cognitive dysmetria hypothesis postulates that psychosis might be a manifestation of the loss of coordination of mental processes due to impaired timing. The objective of the present study was to analyze timing abilities and their corresponding functional neuroanatomy in schizophrenia. We performed a functional magnetic resonance imaging (fMRI) study using a predictive motor timing paradigm in 28 schizophrenia patients and 27 matched healthy controls (HC). The schizophrenia patients showed accelerated time processing compared to HC; the amount of the acceleration positively correlated with the degree of positive psychotic symptoms and negatively correlated with antipsychotic dose. This dysfunctional predictive timing was associated with BOLD signal activity alterations in several brain networks, especially those previously described as timing networks (basal ganglia, cerebellum, SMA, and insula) and reward networks (hippocampus, amygdala, and NAcc). BOLD signal activity in the cerebellar vermis was negatively associated with accelerated time processing. Several lines of evidence suggest a direct link between DA transmission and the cerebellar vermis that could explain their relevance for the neurobiology of schizophrenia. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. Callosal Degradation in HIV-1 Infection Predicts Hierarchical Perception: A DTI study

    PubMed Central

    Müller-Oehring, Eva M.; Schulte, Tilman; Rosenbloom, Margaret J.; Pfefferbaum, Adolf; Sullivan, Edith V.

    2010-01-01

    HIV-1 infection affects white matter circuits linking frontal, parietal, and subcortical regions that subserve visuospatial attention processes. Normal perception requires the integration of details, preferentially processed in the left hemisphere, and the global composition of an object or scene, preferentially processed in the right hemisphere. We tested whether HIV-related callosal white matter degradation contributes to disruption of selective lateralized visuospatial and attention processes. A hierarchical letter target detection paradigm was devised, where large (global) letters were composed of small (local) letters. Participants were required to identify target letters among distractors presented at global, local, both or neither level. Attention was directed to one (global or local) or both levels. Participants were 21 HIV-1 infected and 19 healthy control men and women who also underwent Diffusion Tensor Imaging (DTI). HIV-1 participants showed impaired hierarchical perception owing to abnormally enhanced global facilitation effects but no impairment in attentional control on local-global feature selection. DTI metrics revealed poorer fiber integrity of the corpus callosum in HIV-1 than controls that was more pronounced in posterior than anterior regions. Analysis revealed a double dissociation of anterior and posterior callosal compromise in HIV-1 infection: Compromise in anterior but not posterior callosal fiber integrity predicted response conflict elicited by global targets, whereas compromise in posterior but not anterior callosal fiber integrity predicted response facilitation elicited by global targets. We conclude that component processes of visuospatial perception are compromised in HIV-1 infection attributable, at least in part, to degraded callosal microstructural integrity relevant for local-global feature integration. PMID:20018201

  4. Fine-Motor Skill Deficits in Childhood Predict Adulthood Tic Severity and Global Psychosocial Functioning in Tourette's Syndrome

    ERIC Educational Resources Information Center

    Bloch, Michael H.; Sukhodolsky, Denis G.; Leckman, James F.; Schultz, Robert T.

    2006-01-01

    Background: Most children with Tourette's syndrome (TS) experience a significant decline in tic symptoms during adolescence. Currently no clinical measures have been identified that can predict whose tic symptoms will persist into adulthood. Patients with TS have deficits on neuropsychological tests involving fine-motor coordination and…

  5. Fine-Motor Skill Deficits in Childhood Predict Adulthood Tic Severity and Global Psychosocial Functioning in Tourette's Syndrome

    ERIC Educational Resources Information Center

    Bloch, Michael H.; Sukhodolsky, Denis G.; Leckman, James F.; Schultz, Robert T.

    2006-01-01

    Background: Most children with Tourette's syndrome (TS) experience a significant decline in tic symptoms during adolescence. Currently no clinical measures have been identified that can predict whose tic symptoms will persist into adulthood. Patients with TS have deficits on neuropsychological tests involving fine-motor coordination and…

  6. Development and Validation of a Computational Model for Predicting the Behavior of Plumes from Large Solid Rocket Motors

    NASA Technical Reports Server (NTRS)

    Wells, Jason E.; Black, David L.; Taylor, Casey L.

    2013-01-01

    Exhaust plumes from large solid rocket motors fired at ATK's Promontory test site carry particulates to high altitudes and typically produce deposits that fall on regions downwind of the test area. As populations and communities near the test facility grow, ATK has become increasingly concerned about the impact of motor testing on those surrounding communities. To assess the potential impact of motor testing on the community and to identify feasible mitigation strategies, it is essential to have a tool capable of predicting plume behavior downrange of the test stand. A software package, called PlumeTracker, has been developed and validated at ATK for this purpose. The code is a point model that offers a time-dependent, physics-based description of plume transport and precipitation. The code can utilize either measured or forecasted weather data to generate plume predictions. Next-Generation Radar (NEXRAD) data and field observations from twenty-three historical motor test fires at Promontory were collected to test the predictive capability of PlumeTracker. Model predictions for plume trajectories and deposition fields were found to correlate well with the collected dataset.

  7. Simulation Model for Prediction of Transient Performance Characteristics of Single-Phase Shaded Pole Motor

    NASA Astrophysics Data System (ADS)

    Sarac, Vasilija; Atanasova-Pacemska, Tatjana

    2016-07-01

    Paper proposes mathematical model of single phase shaded pole motor suitable for analysis of motor dynamic behavior. Derived mathematical model from d-q reference frame theory is applied at motor simulation model. Derived simulation model enables analysis of transient performance characteristics of motor currents, speed and electromagnetic torque under different operating regimes. Obtained results from the simulation are compared with data from analytical calculations based on method of symmetrical components and data from experiment for the purpose of verification of the simulation model. Simulation model is useful for studying the effect of parameters on motor starting and running characteristics at different types of loads.

  8. Predicting the performance of motor imagery in stroke patients: multivariate pattern analysis of functional MRI data.

    PubMed

    Park, Chang-hyun; Chang, Won Hyuk; Lee, Minji; Kwon, Gyu Hyun; Kim, Laehyun; Kim, Sung Tae; Kim, Yun-Hee

    2015-01-01

    In a brain-computer interface for stroke rehabilitation, motor imagery is a preferred means for providing a gateway to an effector action or behavior. However, stroke patients often exhibit failure to comply with motor imagery, and therefore their motor imagery performance is highly variable. We sought to identify motor cortical areas responsible for motor imagery performance in stroke patients, specifically by using a multivariate pattern analysis of functional magnetic resonance imaging data. We adopted an imaginary finger tapping task in which motor imagery performance could be monitored for 12 chronic stroke patients with subcortical infarcts and 12 age- and sex-matched healthy controls. We identified the typical activation pattern elicited for motor imagery in healthy controls, as computed over the voxels within each searchlight in the motor cortex. Then we measured the similarity of each individual's activation pattern to the typical activation pattern. In terms of activation levels, the stroke patients showed no activation in the ipsilesional primary motor cortex (M1); in terms of activation patterns, they showed lower similarity to the typical activation pattern in the area than the healthy controls. Furthermore, the stroke patients were better able to perform motor imagery if their activation patterns in the bilateral supplementary motor areas and ipsilesional M1 were close to the typical activation pattern. These findings suggest functional roles of the motor cortical areas for compliance with motor imagery in stroke, which can be applied to the implementation of motor imagery-based brain-computer interface for stroke rehabilitation. © The Author(s) 2014.

  9. Exploring the Fundamental Dynamics of Error-Based Motor Learning Using a Stationary Predictive-Saccade Task

    PubMed Central

    Wong, Aaron L.; Shelhamer, Mark

    2011-01-01

    The maintenance of movement accuracy uses prior performance errors to correct future motor plans; this motor-learning process ensures that movements remain quick and accurate. The control of predictive saccades, in which anticipatory movements are made to future targets before visual stimulus information becomes available, serves as an ideal paradigm to analyze how the motor system utilizes prior errors to drive movements to a desired goal. Predictive saccades constitute a stationary process (the mean and to a rough approximation the variability of the data do not vary over time, unlike a typical motor adaptation paradigm). This enables us to study inter-trial correlations, both on a trial-by-trial basis and across long blocks of trials. Saccade errors are found to be corrected on a trial-by-trial basis in a direction-specific manner (the next saccade made in the same direction will reflect a correction for errors made on the current saccade). Additionally, there is evidence for a second, modulating process that exhibits long memory. That is, performance information, as measured via inter-trial correlations, is strongly retained across a large number of saccades (about 100 trials). Together, this evidence indicates that the dynamics of motor learning exhibit complexities that must be carefully considered, as they cannot be fully described with current state-space (ARMA) modeling efforts. PMID:21966462

  10. Lack of motor prediction, rather than perceptual conflict, evokes an odd sensation upon stepping onto a stopped escalator

    PubMed Central

    Gomi, Hiroaki; Sakurada, Takeshi; Fukui, Takao

    2014-01-01

    When stepping onto a stopped escalator, we often perceive an “odd sensation” that is never felt when stepping onto stairs. The sight of an escalator provides a strong contextual cue that, in expectation of the backward acceleration when stepping on, triggers an anticipatory forward postural adjustment driven by a habitual and implicit motor process. Here we contrast two theories about why this postural change leads to an odd sensation. The first theory links the odd sensation to a lack of sensorimotor prediction from all low-level implicit motor processes. The second theory links the odd sensation to the high-level conflict between the conscious awareness that the escalator is stopped and the implicit perception that evokes an endogenous motor program specific to a moving escalator. We show very similar postural changes can also arise from reflexive responses to visual stimuli, such as contracting/expanding optic flow fields, and that these reflexive responses produce similar odd sensations to the stopped escalator. We conclude that the high-level conflict is not necessary for such sensations. In contrast, the implicitly driven behavioral change itself essentially leads to the odd sensation in motor perception since the unintentional change may be less attributable to self-generated action because of a lack of motor predictions. PMID:24688460

  11. Radiation degradation prediction for InGaP solar cells by using appropriate estimation method for displacement threshold energy

    NASA Astrophysics Data System (ADS)

    Okuno, Y.; Okuda, S.; Akiyoshi, M.; Oka, T.; Harumoto, M.; Omura, K.; Kawakita, S.; Imaizumi, M.; Messenger, S. R.; Lee, K. H.; Yamaguchi, M.

    2017-09-01

    InGaP solar cells are not predicted to be susceptible to displacement damage by irradiation with electrons at energies lower than 100 keV from non-ionizing energy loss (NIEL) calculations. However, it is recently observed that InGaP solar cells are shown to degrade by irradiation with 60 keV electrons. This degradation is considered to be caused by radiation defects but is not clear. In this study, the kind of the defects generated by electrons at energies lower than 100 keV is found by deep-level transient spectroscopy (DLTS). The result of DLTS indicates that the prediction of primary knock-on atoms by using the radiation damage model is different from the experiment. In order to suggest the generation mechanism of radiation defects, we propose a new displacement threshold energy (Ed) by using a new technique in which NIEL and the introduction rate of radiation defects are combined. The degradation prediction by using estimated Ed is found to agree well with the degradation of electric power of InGaP solar cells irradiated by low-energy electrons. From the theory of radiation defects, we propose a new obtaining process of suitable degradation prediction by the displacement damage dose method.

  12. Parkinsonian motor impairment predicts personality domains related to genetic risk and treatment outcomes in schizophrenia.

    PubMed

    Molina, Juan L; Calvó, María; Padilla, Eduardo; Balda, Mara; Alemán, Gabriela González; Florenzano, Néstor V; Guerrero, Gonzalo; Kamis, Danielle; Rangeon, Beatriz Molina; Bourdieu, Mercedes; Strejilevich, Sergio A; Conesa, Horacio A; Escobar, Javier I; Zwir, Igor; Cloninger, C Robert; de Erausquin, Gabriel A

    2017-01-01

    Identifying endophenotypes of schizophrenia is of critical importance and has profound implications on clinical practice. Here we propose an innovative approach to clarify the mechanims through which temperament and character deviance relates to risk for schizophrenia and predict long-term treatment outcomes. We recruited 61 antipsychotic naïve subjects with chronic schizophrenia, 99 unaffected relatives, and 68 healthy controls from rural communities in the Central Andes. Diagnosis was ascertained with the Schedules of Clinical Assessment in Neuropsychiatry; parkinsonian motor impairment was measured with the Unified Parkinson's Disease Rating Scale; mesencephalic parenchyma was evaluated with transcranial ultrasound; and personality traits were assessed using the Temperament and Character Inventory. Ten-year outcome data was available for ~40% of the index cases. Patients with schizophrenia had higher harm avoidance and self-transcendence (ST), and lower reward dependence (RD), cooperativeness (CO), and self-directedness (SD). Unaffected relatives had higher ST and lower CO and SD. Parkinsonism reliably predicted RD, CO, and SD after correcting for age and sex. The average duration of untreated psychosis (DUP) was over 5 years. Further, SD was anticorrelated with DUP and antipsychotic dosing at follow-up. Baseline DUP was related to antipsychotic dose-years. Further, 'explosive/borderline', 'methodical/obsessive', and 'disorganized/schizotypal' personality profiles were associated with increased risk of schizophrenia. Parkinsonism predicts core personality features and treatment outcomes in schizophrenia. Our study suggests that RD, CO, and SD are endophenotypes of the disease that may, in part, be mediated by dopaminergic function. Further, SD is an important determinant of treatment course and outcome.

  13. Characteristics of Motor Resonance Predict the Pattern of Flash-Lag Effects for Biological Motion

    PubMed Central

    Kessler, Klaus; Gordon, Lucy; Cessford, Kari; Lages, Martin

    2010-01-01

    Background When a moving stimulus and a briefly flashed static stimulus are physically aligned in space the static stimulus is perceived as lagging behind the moving stimulus. This vastly replicated phenomenon is known as the Flash-Lag Effect (FLE). For the first time we employed biological motion as the moving stimulus, which is important for two reasons. Firstly, biological motion is processed by visual as well as somatosensory brain areas, which makes it a prime candidate for elucidating the interplay between the two systems with respect to the FLE. Secondly, discussions about the mechanisms of the FLE tend to recur to evolutionary arguments, while most studies employ highly artificial stimuli with constant velocities. Methodology/Principal Finding Since biological motion is ecologically valid it follows complex patterns with changing velocity. We therefore compared biological to symbolic motion with the same acceleration profile. Our results with 16 observers revealed a qualitatively different pattern for biological compared to symbolic motion and this pattern was predicted by the characteristics of motor resonance: The amount of anticipatory processing of perceived actions based on the induced perspective and agency modulated the FLE. Conclusions/Significance Our study provides first evidence for an FLE with non-linear motion in general and with biological motion in particular. Our results suggest that predictive coding within the sensorimotor system alone cannot explain the FLE. Our findings are compatible with visual prediction (Nijhawan, 2008) which assumes that extrapolated motion representations within the visual system generate the FLE. These representations are modulated by sudden visual input (e.g. offset signals) or by input from other systems (e.g. sensorimotor) that can boost or attenuate overshooting representations in accordance with biased neural competition (Desimone & Duncan, 1995). PMID:20062543

  14. Parkinsonian motor impairment predicts personality domains related to genetic risk and treatment outcomes in schizophrenia

    PubMed Central

    Molina, Juan L; Calvó, María; Padilla, Eduardo; Balda, Mara; Alemán, Gabriela González; Florenzano, Néstor V; Guerrero, Gonzalo; Kamis, Danielle; Rangeon, Beatriz Molina; Bourdieu, Mercedes; Strejilevich, Sergio A; Conesa, Horacio A; Escobar, Javier I; Zwir, Igor; Cloninger, C Robert; de Erausquin, Gabriel A

    2017-01-01

    Identifying endophenotypes of schizophrenia is of critical importance and has profound implications on clinical practice. Here we propose an innovative approach to clarify the mechanims through which temperament and character deviance relates to risk for schizophrenia and predict long-term treatment outcomes. We recruited 61 antipsychotic naïve subjects with chronic schizophrenia, 99 unaffected relatives, and 68 healthy controls from rural communities in the Central Andes. Diagnosis was ascertained with the Schedules of Clinical Assessment in Neuropsychiatry; parkinsonian motor impairment was measured with the Unified Parkinson’s Disease Rating Scale; mesencephalic parenchyma was evaluated with transcranial ultrasound; and personality traits were assessed using the Temperament and Character Inventory. Ten-year outcome data was available for ~40% of the index cases. Patients with schizophrenia had higher harm avoidance and self-transcendence (ST), and lower reward dependence (RD), cooperativeness (CO), and self-directedness (SD). Unaffected relatives had higher ST and lower CO and SD. Parkinsonism reliably predicted RD, CO, and SD after correcting for age and sex. The average duration of untreated psychosis (DUP) was over 5 years. Further, SD was anticorrelated with DUP and antipsychotic dosing at follow-up. Baseline DUP was related to antipsychotic dose-years. Further, ‘explosive/borderline’, ‘methodical/obsessive’, and ‘disorganized/schizotypal’ personality profiles were associated with increased risk of schizophrenia. Parkinsonism predicts core personality features and treatment outcomes in schizophrenia. Our study suggests that RD, CO, and SD are endophenotypes of the disease that may, in part, be mediated by dopaminergic function. Further, SD is an important determinant of treatment course and outcome. PMID:28127577

  15. Fatigue degradation and life prediction of glass fabric polymer composites under tension/torsion biaxial loadings

    SciTech Connect

    Kawakami, H.; Fujii, T.J.; Morita, Y.

    1995-10-01

    Fatigue degradation and life prediction for a plain woven glass fabric reinforced polyester under tension/torsion biaxial loadings were investigated. Typical S-N diagrams were given at several biaxial ratios when the biaxial cyclic loads were proportionally applied to the specimens. A fatigue damage accumulation model based on the continuum damage mechanics theory was developed, where modulus decay ratios in tension and shear were used as indicators for damage variables (D). In the model, the damage variables are considered to be second-order tensors. Then, the maximum principal damage variable, D* is introduced. According to the similarity to the principal stress, D* is obtained as the maximum eigen value of damage tensor [D{prime}]. Under proportional tension/torsion loadings, fatigue lives were satisfactorily predicted at any biaxial stress ratios using the present model in which the fatigue characteristics only under uniaxial tension and pure torsion loadings were needed. For a certain biaxial stress ratio, the effect of loading path on the fatigue strength was examined. The experimental result does not show a strong effect of loading path on the fatigue life.

  16. Prediction of people's origin from degraded DNA--presentation of SNP assays and calculation of probability.

    PubMed

    Poetsch, Micaela; Blöhm, Rowena; Harder, Melanie; Inoue, Hiromasa; von Wurmb-Schwark, Nicole; Freitag-Wolf, Sandra

    2013-03-01

    The characterization of externally visible traits by DNA analysis is already an important tool when investigating ancient skeletal remains and may gain similar importance in future forensic DNA analysis. This, however, depends on the different legal regulations in the different countries. Besides eye or hair color, the population origin can provide crucial information in criminal prosecution. In this study, we present the analysis of 16 single-nucleotide polymorphisms (SNPs) combined to two robust SNaPshot assays with a detection threshold of 25-pg DNA. This assay was applied to 891 people from seven different populations (West Africa, North Africa, Turkey, Near East, Balkan states, North Europe, and Japan) with a thorough statistical evaluation. The prediction model was validated by an additional 125 individuals predominantly with an ancestry from those same regions. The specificity of these SNPs for the prediction of all population origins is very high (>90 %), but the sensitivity varied greatly (more than 90 % for West Africa, but only 25 % for the Near East). We could identify West Africans with a certainty of 100 %, and people from North Africa, the Balkan states, or North Europe nearly with the same reliability while determination of Turks or people from the Near East was rather difficult. In conclusion, the two SNaPshot assays are a powerful and reliable tool for the identification of people with an ancestry in one of the above listed populations, even from degraded DNA.

  17. Functional reorganization and prediction of motor recovery after a stroke: A graph theoretical analysis of functional networks.

    PubMed

    Lee, Jungsoo; Lee, Minji; Kim, Dae-Shik; Kim, Yun-Hee

    2015-01-01

    This study investigated the changes in the network topological configuration of the ipsilesional and contralesional hemispheres after a stroke and the indicators for the prediction of motor recovery using a graph theoretical approach in networks obtained from functional magnetic resonance imaging (fMRI). A longitudinal observational experiments (2 weeks and 1, 3, and 6 months after onset) were conducted on 12 patients after a stroke. We investigated the network reorganization during recovery in the ipsilesional and contralesional hemispheres by examining changes of graph indices related to network randomization. We predicted the recovery of motor function by examining the relationship between specific network measures and improved motor function scores. The ipsilesional hemispheric network showed active reorganization during recovery after a stroke. The randomness of the network significantly increased for 3 months post-stroke. We described an indicator for the prediction of the recovery of motor function from graph indices: the characteristic path length. As the path length of the ipsilesional network was lower immediately after onset, the better recovery could be expected after 3 months. This approach were helpful for understanding dynamic reorganizations of both hemispheric networks after a stroke and finding the implication for recovery.

  18. Degradation Rate of 5-Fluorouracil in Metastatic Colorectal Cancer: A New Predictive Outcome Biomarker?

    PubMed Central

    Botticelli, Andrea; Borro, Marina; Onesti, Concetta Elisa; Strigari, Lidia; Gentile, Giovanna; Cerbelli, Bruna; Romiti, Adriana; Occhipinti, Mario; Sebastiani, Claudia; Lionetto, Luana; Marchetti, Luca; Simmaco, Maurizio; Marchetti, Paolo; Mazzuca, Federica

    2016-01-01

    Background 5-FU based chemotherapy is the most common first line regimen used for metastatic colorectal cancer (mCRC). Identification of predictive markers of response to chemotherapy is a challenging approach for drug selection. The present study analyzes the predictive role of 5-FU degradation rate (5-FUDR) and genetic polymorphisms (MTHFR, TSER, DPYD) on survival. Materials and Methods Genetic polymorphisms of MTHFR, TSER and DPYD, and the 5-FUDR of homogenous patients with mCRC were retrospectively studied. Genetic markers and the 5-FUDR were correlated with clinical outcome. Results 133 patients affected by mCRC, treated with fluoropyrimidine-based chemotherapy from 2009 to 2014, were evaluated. Patients were classified into three metabolic classes, according to normal distribution of 5-FUDR in more than 1000 patients, as previously published: poor-metabolizer (PM) with 5-FU-DR ≤ 0,85 ng/ml/106 cells/min (8 pts); normal metabolizer with 0,85 < 5-FU-DR < 2,2 ng/ml/106 cells/min (119 pts); ultra-rapid metabolizer (UM) with 5-FU-DR ≥ 2,2 ng/ml/106 cells/min (6 pts). PM and UM groups showed a longer PFS respect to normal metabolizer group (14.5 and 11 months respectively vs 8 months; p = 0.029). A higher G3-4 toxicity rate was observed in PM and UM, respect to normal metabolizer (50% in both PM and UM vs 18%; p = 0.019). No significant associations between genes polymorphisms and outcomes or toxicities were observed. Conclusion 5-FUDR seems to be significantly involved in predicting survival of patients who underwent 5-FU based CHT for mCRC. Although our findings require confirmation in large prospective studies, they reinforce the concept that individual genetic variation may allow personalized selection of chemotherapy to optimize clinical outcomes. PMID:27656891

  19. Predicting effects on oxaliplatin clearance: in vitro, kinetic and clinical studies of calcium- and magnesium-mediated oxaliplatin degradation.

    PubMed

    Han, Catherine H; Khwaounjoo, Prashannata; Hill, Andrew G; Miskelly, Gordon M; McKeage, Mark J

    2017-06-22

    This study evaluated the impact of calcium and magnesium on the in vitro degradation and in vivo clearance of oxaliplatin. Intact oxaliplatin and Pt(DACH)Cl2 were measured in incubation solutions by HPLC-UV. A clinical study determined changes in plasma concentrations of calcium and magnesium in cancer patients and their impact on oxaliplatin clearance. Kinetic analyses modelled oxaliplatin degradation reactions in vitro and contributions to oxaliplatin clearance in vivo. Calcium and magnesium accelerated oxaliplatin degradation to Pt(DACH)Cl2 in chloride-containing solutions in vitro. Kinetic models based on calcium and magnesium binding to a monochloro-monooxalato ring-opened anionic oxaliplatin intermediate fitted the in vitro degradation time-course data. In cancer patients, calcium and magnesium plasma concentrations varied and were increased by giving calcium gluconate and magnesium sulfate infusions, but did not alter or correlate with oxaliplatin clearance. The intrinsic in vitro clearance of oxaliplatin attributed to chloride-, calcium- and magnesium-mediated degradation predicted contributions of <2.5% to the total in vivo clearance of oxaliplatin. In conclusion, calcium and magnesium accelerate the in vitro degradation of oxaliplatin by binding to a monochloro-monooxalato ring-opened anionic intermediate. Kinetic analysis of in vitro oxaliplatin stability data can be used for in vitro prediction of potential effects on oxaliplatin clearance in vivo.

  20. Magnetic Circuit Model of PM Motor-Generator to Predict Radial Forces

    NASA Technical Reports Server (NTRS)

    McLallin, Kerry (Technical Monitor); Kascak, Peter E.; Dever, Timothy P.; Jansen, Ralph H.

    2004-01-01

    A magnetic circuit model is developed for a PM motor for flywheel applications. A sample motor is designed and modeled. Motor configuration and selection of materials is discussed, and the choice of winding configuration is described. A magnetic circuit model is described, which includes the stator back iron, rotor yoke, permanent magnets, air gaps and the stator teeth. Iterative solution of this model yields flux linkages, back EMF, torque, power, and radial force at the rotor caused by eccentricity. Calculated radial forces are then used to determine motor negative stiffness.

  1. Presence of Motor-Intentional Aiming Deficit Predicts Functional Improvement of Spatial Neglect with Prism Adaptation

    PubMed Central

    Goedert, Kelly M.; Chen, Peii; Boston, Raymond C.; Foundas, Anne L.; Barrett, A. M.

    2013-01-01

    Spatial neglect is a debilitating disorder for which there is no agreed upon course of rehabilitation. The lack of consensus on treatment may result from systematic differences in the syndromes’ characteristics, with spatial cognitive deficits potentially affecting perceptual-attentional Where or motor-intentional Aiming spatial processing. Heterogeneity of response to treatment might be explained by different treatment impact on these dissociated deficits: prism adaptation, for example, might reduce Aiming deficits without affecting Where spatial deficits. Here, we tested the hypothesis that classifying patients by their profile of Where-vs-Aiming spatial deficit would predict response to prism adaptation, and specifically that patients with Aiming bias would have better recovery than those with isolated Where bias. We classified the spatial errors of 24 sub-acute right-stroke survivors with left spatial neglect as: 1) isolated Where bias, 2) isolated Aiming bias or 3) both. Participants then completed two weeks of prism adaptation treatment. They also completed the Behavioral Inattention Test (BIT) and Catherine Bergego Scale (CBS) tests of neglect recovery weekly for six weeks. As hypothesized, participants with only Aiming deficits improved on the CBS, whereas, those with only Where deficits did not improve. Participants with both deficits demonstrated intermediate improvement. These results support behavioral classification of spatial neglect patients as a potential valuable tool for assigning targeted, effective early rehabilitation. PMID:24376064

  2. Intraoperative changes in transcranial motor evoked potentials and somatosensory evoked potentials predicting outcome in children with intramedullary spinal cord tumors

    PubMed Central

    Cheng, Jason S.; Ivan, Michael E.; Stapleton, Christopher J.; Quinones-HinoJosa, AlfreDo; Gupta, Nalin; Auguste, Kurtis I.

    2015-01-01

    Object Intraoperative dorsal column mapping, transcranial motor evoked potentials (TcMEPs), and somatosensory evoked potentials (SSEPs) have been used in adults to assist with the resection of intramedullary spinal cord tumors (IMSCTs) and to predict postoperative motor deficits. The authors sought to determine whether changes in MEP and SSEP waveforms would similarly predict postoperative motor deficits in children. Methods The authors reviewed charts and intraoperative records for children who had undergone resection for IMSCTs as well as dorsal column mapping and TcMEP and SSEP monitoring. Motor evoked potential data were supplemented with electromyography data obtained using a Kartush microstimulator (Medtronic Inc.). Motor strength was graded using the Medical Research Council (MRC) scale during the preoperative, immediate postoperative, and follow-up periods. Reductions in SSEPs were documented after mechanical traction, in response to maneuvers with the cavitational ultrasonic surgical aspirator (CUSA), or both. Results Data from 12 patients were analyzed. Three lesions were encountered in the cervical and 7 in the thoracic spinal cord. Two patients had lesions of the cervicomedullary junction and upper spinal cord. Intraoperative MEP changes were noted in half of the patients. In these cases, normal polyphasic signals converted to biphasic signals, and these changes correlated with a loss of 1–2 grades in motor strength. One patient lost MEP signals completely and recovered strength to MRC Grade 4/5. The 2 patients with high cervical lesions showed neither intraoperative MEP changes nor motor deficits postoperatively. Dorsal columns were mapped in 7 patients, and the midline was determined accurately in all 7. Somatosensory evoked potentials were decreased in 7 patients. Two patients each had 2 SSEP decreases in response to traction intraoperatively but had no new sensory findings postoperatively. Another 2 patients had 3 traction-related SSEP decreases

  3. Intraoperative changes in transcranial motor evoked potentials and somatosensory evoked potentials predicting outcome in children with intramedullary spinal cord tumors.

    PubMed

    Cheng, Jason S; Ivan, Michael E; Stapleton, Christopher J; Quinones-Hinojosa, Alfredo; Gupta, Nalin; Auguste, Kurtis I

    2014-06-01

    Intraoperative dorsal column mapping, transcranial motor evoked potentials (TcMEPs), and somatosensory evoked potentials (SSEPs) have been used in adults to assist with the resection of intramedullary spinal cord tumors (IMSCTs) and to predict postoperative motor deficits. The authors sought to determine whether changes in MEP and SSEP waveforms would similarly predict postoperative motor deficits in children. The authors reviewed charts and intraoperative records for children who had undergone resection for IMSCTs as well as dorsal column mapping and TcMEP and SSEP monitoring. Motor evoked potential data were supplemented with electromyography data obtained using a Kartush microstimulator (Medtronic Inc.). Motor strength was graded using the Medical Research Council (MRC) scale during the preoperative, immediate postoperative, and follow-up periods. Reductions in SSEPs were documented after mechanical traction, in response to maneuvers with the cavitational ultrasonic surgical aspirator (CUSA), or both. Data from 12 patients were analyzed. Three lesions were encountered in the cervical and 7 in the thoracic spinal cord. Two patients had lesions of the cervicomedullary junction and upper spinal cord. Intraoperative MEP changes were noted in half of the patients. In these cases, normal polyphasic signals converted to biphasic signals, and these changes correlated with a loss of 1-2 grades in motor strength. One patient lost MEP signals completely and recovered strength to MRC Grade 4/5. The 2 patients with high cervical lesions showed neither intraoperative MEP changes nor motor deficits postoperatively. Dorsal columns were mapped in 7 patients, and the midline was determined accurately in all 7. Somatosensory evoked potentials were decreased in 7 patients. Two patients each had 2 SSEP decreases in response to traction intraoperatively but had no new sensory findings postoperatively. Another 2 patients had 3 traction-related SSEP decreases intraoperatively, and both

  4. Direct mapping rather than motor prediction subserves modulation of corticospinal excitability during observation of actions in real time.

    PubMed

    Gueugneau, Nicolas; Mc Cabe, Sofia I; Villalta, Jorge I; Grafton, Scott T; Della-Maggiore, Valeria

    2015-06-01

    Motor facilitation refers to the specific increment in corticospinal excitability (CSE) elicited by the observation of actions performed by others. To date, the precise nature of the mechanism at the basis of this phenomenon is unknown. One possibility is that motor facilitation is driven by a predictive process reminiscent of the role of forward models in motor control. Alternatively, motor facilitation may result from a model-free mechanism by which the basic elements of the observed action are directly mapped onto their cortical representations. Our study was designed to discern these alternatives. To this aim, we recorded the time course of CSE for the first dorsal interosseous (FDI) and the abductor digiti minimi (ADM) during observation of three grasping actions in real time, two of which strongly diverged in kinematics from their natural (invariant) form. Although artificially slow movements used in most action observation studies might enhance the observer's discrimination performance, the use of videos in real time is crucial to maintain the time course of CSE within the physiological range of daily actions. CSE was measured at 4 time points within a 240-ms window that best captured the kinematic divergence from the invariant form. Our results show that CSE of the FDI, not the ADM, closely follows the functional role of the muscle despite the mismatch between the natural and the divergent kinematics. We propose that motor facilitation during observation of actions performed in real time reflects the model-free coding of perceived movement following a direct mapping mechanism.

  5. Rapid Responsiveness to Practice Predicts Longer-Term Retention of Upper Extremity Motor Skill in Non-Demented Older Adults

    PubMed Central

    Schaefer, Sydney Y.; Duff, Kevin

    2015-01-01

    Skill acquisition is a form of motor learning that may provide key insights into the aging brain. Although previous work suggests that older adults learn novel motor tasks slower and to a lesser extent than younger adults, we have recently demonstrated no significant effect of chronological age on the rates and amounts of skill acquisition, nor on its long-term retention, in adults over the age of 65. To better understand predictors of skill acquisition in non-demented older adults, we now explore the relationship between early improvements in motor performance due to practice (i.e., rapid responsiveness) and longer-term retention of an upper extremity motor skill, and whether the extent of rapid responsiveness was associated with global cognitive status. Results showed significant improvements in motor performance within the first five (of 150) trials, and that this “rapid responsiveness” was predictive of skill retention 1 month later. Notably, the extent of rapid responsiveness was not dependent on global cognitive status, as measured by the Montreal Cognitive Assessment (MoCA). Thus, rapid responsiveness appears to be an important variable in longer-term neurorehabilitative efforts with older adults, regardless of their cognitive status. PMID:26635601

  6. Brainstem White Matter Predicts Individual Differences in Manual Motor Difficulties and Symptom Severity in Autism

    ERIC Educational Resources Information Center

    Travers, Brittany G.; Bigler, Erin D.; Tromp, Do P. M.; Adluru, Nagesh; Destiche, Dan; Samsin, Danica; Froehlich, Alyson; Prigge, Molly D. B.; Duffield, Tyler C.; Lange, Nicholas; Alexander, Andrew L.; Lainhart, Janet E.

    2015-01-01

    Mounting evidence suggests that poorer motor skills may be related to more severe autism symptoms. This study investigated if atypical white matter microstructure in the brain mediated the relationship between motor skills and ASD symptom severity. Sixty-seven males with ASD and 42 males with typical development (5-33 years old) completed a…

  7. Brainstem White Matter Predicts Individual Differences in Manual Motor Difficulties and Symptom Severity in Autism

    ERIC Educational Resources Information Center

    Travers, Brittany G.; Bigler, Erin D.; Tromp, Do P. M.; Adluru, Nagesh; Destiche, Dan; Samsin, Danica; Froehlich, Alyson; Prigge, Molly D. B.; Duffield, Tyler C.; Lange, Nicholas; Alexander, Andrew L.; Lainhart, Janet E.

    2015-01-01

    Mounting evidence suggests that poorer motor skills may be related to more severe autism symptoms. This study investigated if atypical white matter microstructure in the brain mediated the relationship between motor skills and ASD symptom severity. Sixty-seven males with ASD and 42 males with typical development (5-33 years old) completed a…

  8. Predicting Motor Vehicle Collisions in a Driving Simulator in Young Adults Using the Useful Field of View Assessment

    PubMed Central

    McManus, Benjamin; Cox, Molly K.; Vance, David E.; Stavrinos, Despina

    2015-01-01

    Objective Being involved in motor vehicle collisions is the leading cause of death in 1 to 34 year olds, and risk is particularly high in young adults. The Useful Field of View (UFOV) task, a cognitive measure of processing speed, divided attention, and selective attention, has been shown to be predictive of motor vehicle collisions in older adults, but its use as a predictor of driving performance in a young adult population has not been investigated. The present study examined whether UFOV was a predictive measure of motor vehicle collisions in a driving simulator in a young adult population. Method The 3-subtest version of UFOV (lower scores measured in milliseconds indicate better performance) was administered to 60 college students. Participants also completed an 11-mile simulated drive to provide driving performance metrics. Results Findings suggested that subtests 1 and 2 suffered from a ceiling effect. UFOV subtest 3 significantly predicted collisions in the simulated drive. Each 30 milliseconds slower on the subtest was associated with nearly a 10% increase in the risk of a simulated collision. Post-hoc analyses revealed a small partially mediating effect of subtest 3 on the relationship between driving experience and collisions. Conclusion The selective attention component of UFOV subtest 3 may be a predictive measure of crash involvement in a young adult population. Improvements in selective attention may be the underlying mechanism in how driving experience improves driving performance. PMID:25794266

  9. Predictive model of synovial membrane degradation using semi-automated morphometry and artificial neural networks.

    PubMed

    Rogoveanu, Otilia Constantina; Kamal, Diana; Trăistaru, Magdalena Rodica; Streba, Costin Teodor

    2016-01-01

    Gonarthrosis is a degenerative disease that affects mainly older people, but whose incidence has increased significantly in the last decade in population under the age of 65. The main objective of this study was developing a predictive model of synovial membrane degradation in relation to local nerve structures in patients with knee osteoarthritis, based on advanced morphometry and artificial neural networks (ANNs). We present here a pilot test of the method, describing preliminary findings in analyzing a pre-set number of images. We tested the system on a pre-defined set of 50 images from patients suffering of gonarthrosis in different stages. Biological material used for the histological study was synovial membrane fragments. We included 50 anonymized images from 25 consecutive patients. We found significant differences between mean fractal dimensions (FDs) of histological elements of normal and pathological tissues. In the case of immunohistochemistry, we found statistically relevant differences for mean FDs of all antibodies. We fed the data to the ANN system designed to recognize pathological regions of the examined tissue. We believe that further study will have an important contribution to the development and will bring new local targeted therapies. These could slow or reverse joint damage and pain relief in patients with osteoarthritis.

  10. Induction of Neuron-Specific Degradation of Coenzyme A Models Pantothenate Kinase-Associated Neurodegeneration by Reducing Motor Coordination in Mice

    PubMed Central

    Shumar, Stephanie A.; Fagone, Paolo; Alfonso-Pecchio, Adolfo; Gray, John T.; Rehg, Jerold E.; Jackowski, Suzanne; Leonardi, Roberta

    2015-01-01

    Background Pantothenate kinase-associated neurodegeneration, PKAN, is an inherited disorder characterized by progressive impairment in motor coordination and caused by mutations in PANK2, a human gene that encodes one of four pantothenate kinase (PanK) isoforms. PanK initiates the synthesis of coenzyme A (CoA), an essential cofactor that plays a key role in energy metabolism and lipid synthesis. Most of the mutations in PANK2 reduce or abolish the activity of the enzyme. This evidence has led to the hypothesis that lower CoA might be the underlying cause of the neurodegeneration in PKAN patients; however, no mouse model of the disease is currently available to investigate the connection between neuronal CoA levels and neurodegeneration. Indeed, genetic and/or dietary manipulations aimed at reducing whole-body CoA synthesis have not produced a desirable PKAN model, and this has greatly hindered the discovery of a treatment for the disease. Objective, Methods, Results and Conclusions Cellular CoA levels are tightly regulated by a balance between synthesis and degradation. CoA degradation is catalyzed by two peroxisomal nudix hydrolases, Nudt7 and Nudt19. In this study we sought to reduce neuronal CoA in mice through the alternative approach of increasing Nudt7-mediated CoA degradation. This was achieved by combining the use of an adeno-associated virus-based expression system with the synapsin (Syn) promoter. We show that mice with neuronal overexpression of a cytosolic version of Nudt7 (scAAV9-Syn-Nudt7cyt) exhibit a significant decrease in brain CoA levels in conjunction with a reduction in motor coordination. These results strongly support the existence of a link between CoA levels and neuronal function and show that scAAV9-Syn-Nudt7cyt mice can be used to model PKAN. PMID:26052948

  11. Induction of Neuron-Specific Degradation of Coenzyme A Models Pantothenate Kinase-Associated Neurodegeneration by Reducing Motor Coordination in Mice.

    PubMed

    Shumar, Stephanie A; Fagone, Paolo; Alfonso-Pecchio, Adolfo; Gray, John T; Rehg, Jerold E; Jackowski, Suzanne; Leonardi, Roberta

    2015-01-01

    Pantothenate kinase-associated neurodegeneration, PKAN, is an inherited disorder characterized by progressive impairment in motor coordination and caused by mutations in PANK2, a human gene that encodes one of four pantothenate kinase (PanK) isoforms. PanK initiates the synthesis of coenzyme A (CoA), an essential cofactor that plays a key role in energy metabolism and lipid synthesis. Most of the mutations in PANK2 reduce or abolish the activity of the enzyme. This evidence has led to the hypothesis that lower CoA might be the underlying cause of the neurodegeneration in PKAN patients; however, no mouse model of the disease is currently available to investigate the connection between neuronal CoA levels and neurodegeneration. Indeed, genetic and/or dietary manipulations aimed at reducing whole-body CoA synthesis have not produced a desirable PKAN model, and this has greatly hindered the discovery of a treatment for the disease. Cellular CoA levels are tightly regulated by a balance between synthesis and degradation. CoA degradation is catalyzed by two peroxisomal nudix hydrolases, Nudt7 and Nudt19. In this study we sought to reduce neuronal CoA in mice through the alternative approach of increasing Nudt7-mediated CoA degradation. This was achieved by combining the use of an adeno-associated virus-based expression system with the synapsin (Syn) promoter. We show that mice with neuronal overexpression of a cytosolic version of Nudt7 (scAAV9-Syn-Nudt7cyt) exhibit a significant decrease in brain CoA levels in conjunction with a reduction in motor coordination. These results strongly support the existence of a link between CoA levels and neuronal function and show that scAAV9-Syn-Nudt7cyt mice can be used to model PKAN.

  12. Glycan Degradation (GlyDeR) Analysis Predicts Mammalian Gut Microbiota Abundance and Host Diet-Specific Adaptations

    PubMed Central

    Zarecki, Raphy; Oberhardt, Matthew; Ursell, Luke K.; Kupiec, Martin; Knight, Rob; Gophna, Uri; Ruppin, Eytan

    2014-01-01

    ABSTRACT Glycans form the primary nutritional source for microbes in the human gut, and understanding their metabolism is a critical yet understudied aspect of microbiome research. Here, we present a novel computational pipeline for modeling glycan degradation (GlyDeR) which predicts the glycan degradation potency of 10,000 reference glycans based on either genomic or metagenomic data. We first validated GlyDeR by comparing degradation profiles for genomes in the Human Microbiome Project against KEGG reaction annotations. Next, we applied GlyDeR to the analysis of human and mammalian gut microbial communities, which revealed that the glycan degradation potential of a community is strongly linked to host diet and can be used to predict diet with higher accuracy than sequence data alone. Finally, we show that a microbe’s glycan degradation potential is significantly correlated (R = 0.46) with its abundance, with even higher correlations for potential pathogens such as the class Clostridia (R = 0.76). GlyDeR therefore represents an important tool for advancing our understanding of bacterial metabolism in the gut and for the future development of more effective prebiotics for microbial community manipulation. PMID:25118239

  13. Similar circuits but different connectivity patterns between the cerebellum, basal ganglia, and supplementary motor area in early Parkinson's disease patients and controls during predictive motor timing.

    PubMed

    Husárová, Ivica; Mikl, Michal; Lungu, Ovidiu V; Mareček, Radek; Vaníček, Jiří; Bareš, Martin

    2013-10-01

    The cerebellum, basal ganglia (BG), and other cortical regions, such as supplementary motor area (SMA) have emerged as important structures dealing with various aspects of timing, yet the modulation of functional connectivity between them during motor timing tasks remains unexplored. We used dynamic causal modeling to investigate the differences in effective connectivity (EC) between these regions and its modulation by behavioral outcome during a motor timing prediction task in a group of 16 patients with early Parkinson's disease (PD) and 17 healthy controls. Behavioral events (hits and errors) constituted the driving input connected to the cerebellum, and the modulation in connectivity was assessed relative to the hit condition (successful interception of target). The driving input elicited response in the target area, while modulatory input changed the specific connection strength. The neuroimaging data revealed similar structure of intrinsic connectivity in both groups with unidirectional connections from cerebellum to both sides of the BG, from BG to the SMA, and then from SMA to the cerebellum. However, the type of intrinsic connection was different between two groups. In the PD group, the connection between the SMA and cerebellum was inhibitory in comparison to the HC group, where the connection was activated. Furthermore, the modulation of connectivity by the performance in the task was different between the two groups, with decreased connectivity between the cerebellum and left BG and SMA and a more pronounced symmetry of these connections in controls. In the same time, there was an increased EC between the cerebellum and both sides of BG with more pronounced asymmetry (stronger connection with left BG) in patients. In addition, in the PD group the modulatory input strengthened inhibitory connectivity between the SMA and the cerebellum, while in the HC group the excitatory connection was slightly strengthened. Our findings indicate that although early PD

  14. Prediction and analysis of magnetic forces in permanent magnet brushless dc motor with rotor eccentricity

    NASA Astrophysics Data System (ADS)

    Liu, Z. J.; Li, J. T.; Jabbar, M. A.

    2006-04-01

    In design of permanent magnet motors for high-precision applications, it is sometimes necessary, early in the design stage, to have a detailed analysis of the effect of rotor eccentricity that may result from manufacturing imperfectness or use of fluid dynamic or aerodynamic bearings. This paper presents an analytical model for electromagnetic torque and forces in permanent magnet motors with rotor eccentricity. The model gives an insight to the relationship between the effect of the eccentricity and the other motor design parameters on the electromagnetic forces. It is shown that the calculated magnetic forces obtained from this model agree well with those obtained from numerical simulations that are very computationally demanding.

  15. Ruminal Degradability and Summative Models Evaluation for Total Digestible Nutrients Prediction of Some Forages and Byproducts in Goats

    PubMed Central

    López, Rafael

    2013-01-01

    In in vitro true dry matter degradability (IVTDMD), in situ dry matter degradability, and neutral detergent fiber degradability, both in vitro (IVNDFD) and in situ (ISNDFD) techniques were used with crossbred goats to determine dry matter and neutral detergent fiber (NDF) ruminal degradability in eight forages and four industrial byproducts. Total digestible nutrients (TDN) content obtained with five different summative models (summative equations) were studied to compare the precision of estimates. All these models included digestible fractions of crude protein, ether extract, and nonfiber carbohydrates that were calculated from chemical composition, but digestible NDF (dNDF) was obtained from IVNDFD (IVdNDF), ISNDFD (ISdNDF), or by using the Surface Law approach. On the basis of the coefficient of determination (R2) of the simple lineal regression of predicted TDN (y-axes) and observed IVTDMD (x-axes), the precision of models was tested. The predicted TDN by the National Research Council model exclusively based on chemical composition only explains up to 41% of observed IVTDMD values, whereas the model based on IVdNDF had a high precision (96%) to predict TDN from forage and byproducts fiber when used in goats. PMID:23762592

  16. Prediction of ionizing radiation effects induced performance degradation in homodyne BPSK based inter-satellite optical communication systems

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Zhao, Shanghong; Gong, Zizheng; Zhao, Jing; Li, Xuan; Dong, Chen

    2016-03-01

    Ionizing radiation effects induced on-orbit performance degradation in homodyne binary phase shift keying (BPSK) based inter-satellite optical communication system is predicted in this paper. Essential optoelectronic devices involved in optical communication system were irradiated by Co60 gamma ray and ionizing radiation environment of three general orbits was analyzed. On this basis, variations of terminal performance loss and system BER degradation along with on-orbit working time were simulated. Influences of terminal location and orbit environment were further discussed. Radiation protection on laser transmitters requires more strengthening, especially for those located in MEO and GEO satellites.

  17. Local-learning-based neuron selection for grasping gesture prediction in motor brain machine interfaces.

    PubMed

    Xu, Kai; Wang, Yiwen; Wang, Yueming; Wang, Fang; Hao, Yaoyao; Zhang, Shaomin; Zhang, Qiaosheng; Chen, Weidong; Zheng, Xiaoxiang

    2013-04-01

    The high-dimensional neural recordings bring computational challenges to movement decoding in motor brain machine interfaces (mBMI), especially for portable applications. However, not all recorded neural activities relate to the execution of a certain movement task. This paper proposes to use a local-learning-based method to perform neuron selection for the gesture prediction in a reaching and grasping task. Nonlinear neural activities are decomposed into a set of linear ones in a weighted feature space. A margin is defined to measure the distance between inter-class and intra-class neural patterns. The weights, reflecting the importance of neurons, are obtained by minimizing a margin-based exponential error function. To find the most dominant neurons in the task, 1-norm regularization is introduced to the objective function for sparse weights, where near-zero weights indicate irrelevant neurons. The signals of only 10 neurons out of 70 selected by the proposed method could achieve over 95% of the full recording's decoding accuracy of gesture predictions, no matter which different decoding methods are used (support vector machine and K-nearest neighbor). The temporal activities of the selected neurons show visually distinguishable patterns associated with various hand states. Compared with other algorithms, the proposed method can better eliminate the irrelevant neurons with near-zero weights and provides the important neuron subset with the best decoding performance in statistics. The weights of important neurons converge usually within 10-20 iterations. In addition, we study the temporal and spatial variation of neuron importance along a period of one and a half months in the same task. A high decoding performance can be maintained by updating the neuron subset. The proposed algorithm effectively ascertains the neuronal importance without assuming any coding model and provides a high performance with different decoding models. It shows better robustness of

  18. Local-learning-based neuron selection for grasping gesture prediction in motor brain machine interfaces

    NASA Astrophysics Data System (ADS)

    Xu, Kai; Wang, Yiwen; Wang, Yueming; Wang, Fang; Hao, Yaoyao; Zhang, Shaomin; Zhang, Qiaosheng; Chen, Weidong; Zheng, Xiaoxiang

    2013-04-01

    Objective. The high-dimensional neural recordings bring computational challenges to movement decoding in motor brain machine interfaces (mBMI), especially for portable applications. However, not all recorded neural activities relate to the execution of a certain movement task. This paper proposes to use a local-learning-based method to perform neuron selection for the gesture prediction in a reaching and grasping task. Approach. Nonlinear neural activities are decomposed into a set of linear ones in a weighted feature space. A margin is defined to measure the distance between inter-class and intra-class neural patterns. The weights, reflecting the importance of neurons, are obtained by minimizing a margin-based exponential error function. To find the most dominant neurons in the task, 1-norm regularization is introduced to the objective function for sparse weights, where near-zero weights indicate irrelevant neurons. Main results. The signals of only 10 neurons out of 70 selected by the proposed method could achieve over 95% of the full recording's decoding accuracy of gesture predictions, no matter which different decoding methods are used (support vector machine and K-nearest neighbor). The temporal activities of the selected neurons show visually distinguishable patterns associated with various hand states. Compared with other algorithms, the proposed method can better eliminate the irrelevant neurons with near-zero weights and provides the important neuron subset with the best decoding performance in statistics. The weights of important neurons converge usually within 10-20 iterations. In addition, we study the temporal and spatial variation of neuron importance along a period of one and a half months in the same task. A high decoding performance can be maintained by updating the neuron subset. Significance. The proposed algorithm effectively ascertains the neuronal importance without assuming any coding model and provides a high performance with different

  19. Visuo-motor coordination ability predicts performance with brain-computer interfaces controlled by modulation of sensorimotor rhythms (SMR).

    PubMed

    Hammer, Eva M; Kaufmann, Tobias; Kleih, Sonja C; Blankertz, Benjamin; Kübler, Andrea

    2014-01-01

    Modulation of sensorimotor rhythms (SMR) was suggested as a control signal for brain-computer interfaces (BCI). Yet, there is a population of users estimated between 10 to 50% not able to achieve reliable control and only about 20% of users achieve high (80-100%) performance. Predicting performance prior to BCI use would facilitate selection of the most feasible system for an individual, thus constitute a practical benefit for the user, and increase our knowledge about the correlates of BCI control. In a recent study, we predicted SMR-BCI performance from psychological variables that were assessed prior to the BCI sessions and BCI control was supported with machine-learning techniques. We described two significant psychological predictors, namely the visuo-motor coordination ability and the ability to concentrate on the task. The purpose of the current study was to replicate these results thereby validating these predictors within a neurofeedback based SMR-BCI that involved no machine learning.Thirty-three healthy BCI novices participated in a calibration session and three further neurofeedback training sessions. Two variables were related with mean SMR-BCI performance: (1) a measure for the accuracy of fine motor skills, i.e., a trade for a person's visuo-motor control ability; and (2) subject's "attentional impulsivity". In a linear regression they accounted for almost 20% in variance of SMR-BCI performance, but predictor (1) failed significance. Nevertheless, on the basis of our prior regression model for sensorimotor control ability we could predict current SMR-BCI performance with an average prediction error of M = 12.07%. In more than 50% of the participants, the prediction error was smaller than 10%. Hence, psychological variables played a moderate role in predicting SMR-BCI performance in a neurofeedback approach that involved no machine learning. Future studies are needed to further consolidate (or reject) the present predictors.

  20. Visuo-motor coordination ability predicts performance with brain-computer interfaces controlled by modulation of sensorimotor rhythms (SMR)

    PubMed Central

    Hammer, Eva M.; Kaufmann, Tobias; Kleih, Sonja C.; Blankertz, Benjamin; Kübler, Andrea

    2014-01-01

    Modulation of sensorimotor rhythms (SMR) was suggested as a control signal for brain-computer interfaces (BCI). Yet, there is a population of users estimated between 10 to 50% not able to achieve reliable control and only about 20% of users achieve high (80–100%) performance. Predicting performance prior to BCI use would facilitate selection of the most feasible system for an individual, thus constitute a practical benefit for the user, and increase our knowledge about the correlates of BCI control. In a recent study, we predicted SMR-BCI performance from psychological variables that were assessed prior to the BCI sessions and BCI control was supported with machine-learning techniques. We described two significant psychological predictors, namely the visuo-motor coordination ability and the ability to concentrate on the task. The purpose of the current study was to replicate these results thereby validating these predictors within a neurofeedback based SMR-BCI that involved no machine learning.Thirty-three healthy BCI novices participated in a calibration session and three further neurofeedback training sessions. Two variables were related with mean SMR-BCI performance: (1) a measure for the accuracy of fine motor skills, i.e., a trade for a person’s visuo-motor control ability; and (2) subject’s “attentional impulsivity”. In a linear regression they accounted for almost 20% in variance of SMR-BCI performance, but predictor (1) failed significance. Nevertheless, on the basis of our prior regression model for sensorimotor control ability we could predict current SMR-BCI performance with an average prediction error of M = 12.07%. In more than 50% of the participants, the prediction error was smaller than 10%. Hence, psychological variables played a moderate role in predicting SMR-BCI performance in a neurofeedback approach that involved no machine learning. Future studies are needed to further consolidate (or reject) the present predictors. PMID:25147518

  1. Loss of somatosensory evoked potentials during intramedullary spinal cord surgery predicts postoperative neurologic deficits in motor function [corrected].

    PubMed

    Kearse, L A; Lopez-Bresnahan, M; McPeck, K; Tambe, V

    1993-01-01

    To estimate the sensitivity and specificity of somatosensory evoked potentials (SSEPs) for predicting new postoperative motor neurologic deficits during intramedullary spinal cord surgery; to establish whether SSEPs more accurately predicted postoperative deficits in position and vibration sense than in strength. Prospective open and retrospective study. University-affiliated hospital. 20 patients with intramedullary spinal cord tumors scheduled for surgery with intraoperative SSEPs. Median, ulnar, and tibial nerve cortical and subcortical SSEPs were recorded continuously. Conventional intraoperative SSEP criteria considered indicative of neurologic injury were modified and defined as either the complete and permanent loss of the SSEP or the simultaneous amplitude reduction of 50% or greater in the nearest recording electrode rostral to the surgical site and 0.5 millisecond increase in the central latency. Our definition required confirmation of both amplitude and latency changes on a repeated average. All patients had 1 or more SSEPs, which were reproducible and sufficiently stable for analysis throughout the operation. Six patients developed new postoperative neurologic deficits. One had new motor deficits in an extremity from which no baseline SSEPs could be elicited. In each of the other 5 patients, significant SSEP changes preceded the postoperative motor deficits in the extremity or extremities monitored. In no patient without a new postoperative motor deficit was there a significant change in the SSEP. In only 2 of these 5 patients was there a documented postoperative loss or diminution in vibration or position sense. Intraoperative SSEP changes during intramedullary spinal cord surgery are a sensitive predictor of new postoperative motor deficits, but such changes may not correlate reliably with postoperative deficits in position or vibration sense. In this setting SSEP monitoring serves primarily to reassure the operating team that, when the SSEPs remain

  2. Trial-to-trial Adaptation: Parsing out the Roles of Cerebellum and BG in Predictive Motor Timing.

    PubMed

    Lungu, Ovidiu V; Bares, Martin; Liu, Tao; Gomez, Christopher M; Cechova, Ivica; Ashe, James

    2016-07-01

    We previously demonstrated that predictive motor timing (i.e., timing requiring visuomotor coordination in anticipation of a future event, such as catching or batting a ball) is impaired in patients with spinocerebellar ataxia (SCA) types 6 and 8 relative to healthy controls. Specifically, SCA patients had difficulties postponing their motor response while estimating the target kinematics. This behavioral difference relied on the activation of both cerebellum and striatum in healthy controls, but not in cerebellar patients, despite both groups activating certain parts of cerebellum during the task. However, the role of these two key structures in the dynamic adaptation of the motor timing to target kinematic properties remained unexplored. In the current paper, we analyzed these data with the aim of characterizing the trial-by-trial changes in brain activation. We found that in healthy controls alone, and in comparison with SCA patients, the activation in bilateral striatum was exclusively associated with past successes and that in the left putamen, with maintaining a successful performance across successive trials. In healthy controls, relative to SCA patients, a larger network was involved in maintaining a successful trial-by-trial strategy; this included cerebellum and fronto-parieto-temporo-occipital regions that are typically part of attentional network and action monitoring. Cerebellum was also part of a network of regions activated when healthy participants postponed their motor response from one trial to the next; SCA patients showed reduced activation relative to healthy controls in both cerebellum and striatum in the same contrast. These findings support the idea that cerebellum and striatum play complementary roles in the trial-by-trial adaptation in predictive motor timing. In addition to expanding our knowledge of brain structures involved in time processing, our results have implications for the understanding of BG disorders, such as Parkinson disease

  3. Simple motor tasks independently predict extubation failure in critically ill neurological patients.

    PubMed

    Kutchak, Fernanda Machado; Rieder, Marcelo de Mello; Victorino, Josué Almeida; Meneguzzi, Carla; Poersch, Karla; Forgiarini, Luiz Alberto; Bianchin, Marino Muxfeldt

    2017-01-01

    To evaluate the usefulness of simple motor tasks such as hand grasping and tongue protrusion as predictors of extubation failure in critically ill neurological patients. This was a prospective cohort study conducted in the neurological ICU of a tertiary care hospital in the city of Porto Alegre, Brazil. Adult patients who had been intubated for neurological reasons and were eligible for weaning were included in the study. The ability of patients to perform simple motor tasks such as hand grasping and tongue protrusion was evaluated as a predictor of extubation failure. Data regarding duration of mechanical ventilation, length of ICU stay, length of hospital stay, mortality, and incidence of ventilator-associated pneumonia were collected. A total of 132 intubated patients who had been receiving mechanical ventilation for at least 24 h and who passed a spontaneous breathing trial were included in the analysis. Logistic regression showed that patient inability to grasp the hand of the examiner (relative risk = 1.57; 95% CI: 1.01-2.44; p < 0.045) and protrude the tongue (relative risk = 6.84; 95% CI: 2.49-18.8; p < 0.001) were independent risk factors for extubation failure. Acute Physiology and Chronic Health Evaluation II scores (p = 0.02), Glasgow Coma Scale scores at extubation (p < 0.001), eye opening response (p = 0.001), MIP (p < 0.001), MEP (p = 0.006), and the rapid shallow breathing index (p = 0.03) were significantly different between the failed extubation and successful extubation groups. The inability to follow simple motor commands is predictive of extubation failure in critically ill neurological patients. Hand grasping and tongue protrusion on command might be quick and easy bedside tests to identify neurocritical care patients who are candidates for extubation. Avaliar a utilidade de tarefas motoras simples, tais como preensão de mão e protrusão da língua, para predizer extubação malsucedida em pacientes neurológicos críticos. Estudo

  4. Admission ASIA motor score predicting the need for tracheostomy after cervical spinal cord injury.

    PubMed

    Menaker, Jay; Kufera, Joseph A; Glaser, Jeffrey; Stein, Deborah M; Scalea, Thomas M

    2013-10-01

    Respiratory compromise and the need for tracheostomy are common after cervical spinal cord injury (cSCI). The purpose of the study was to evaluate if admission American Spinal Injury Association (ASIA) motor score is associated with the need for tracheostomy following cSCI. The trauma registry identified patients with isolated cSCI during a 3-year period. Patients with an Abbreviated Injury Scale score greater than 3 in other body regions were excluded. Medical records were reviewed for demographics, admission ASIA motor score, ASIA Impairment Scale (AIS), anatomic level of injury, need for a tracheostomy, and length of stay (LOS). Logistic regression models were constructed to examine the effect of admission ASIA motor scores on the outcome of tracheostomy. Cox proportional hazards models were fit to determine risk factors for time to tracheostomy. A total of 128 patients were identified. Seventy-four patients had a tracheostomy performed on mean (SD) hospital Day 9 (4). Median admission ASIA motor score was 22.0 (interquartile range [IQR], 8-54). Median anatomic level of injury was 5 (IQR, 4-6). Patients requiring tracheostomy had significantly lower median admission ASIA motor score (9 [IQR, 3-17] vs. 57 [IQR, 30-77], p < 0.001) and were more likely to be an AIS A. There was no difference in median anatomic level of injury (5 [IQR, 4-5.8] vs. 5 [IQR, 4-6], p = nonsignificant). ASIA motor scores less than 10 had an unadjusted odds ratio for requiring tracheostomy of 56 (95 confidence interval, 7-426). Following adjustment for independent risk factors, the odds ratio for ASIA motor score less than 10 remained statistically significant at 22 (confidence interval, 3-180). Among patients with incomplete cSCI, ASIA motor scores increased significantly from AIS B to AIS D, while Injury Severity Score (ISS), LOS and intensive care unit LOS declined significantly. Of those patients without a tracheostomy, 100% had an ASIA motor score greater than 10, 98% had an ASIA

  5. Cognitive mechanisms of visuomotor transformation in movement imitation: examining predictions based on models of apraxia and motor control.

    PubMed

    Gravenhorst, Robynne M; Walter, Charles B

    2009-11-01

    When we observe a movement and then reproduce it, how is this visual input transformed into motor output? Studies on stroke patients with apraxia suggest that there may be two distinct routes used for gesture imitation; an indirect route that recruits stored movement memories (motor programs) and a direct route that bypasses them. The present study examined 30 healthy adults ages 18-80 (mean age=44.0 years, SD=19.5) to learn how motor programs are recruited or bypassed in movement imitation depending upon task conditions (whether familiar letters or novel shapes are imitated) and perceptual factors (whether shapes or letters are perceived). Subjects were asked to imitate the movements of a model who formed shapes and letters on a sheer mesh screen, and to report whether they perceived the task as a shape or a letter. Movements were recorded using a Vicon motion analysis system, and subsequently analyzed to determine the degree of difference between the demonstrated and produced movements. As predicted, letter perception on the letter tasks resulted in increased temporal error when the demonstrated stroke order conflicted with subjects' habitual pattern of letter formation. No such interference effects were observed when the letter tasks were perceived as shapes. These findings are discussed in the context of current theories on imitation, and implications for rehabilitation and motor re-learning are presented.

  6. Glycan degradation (GlyDeR) analysis predicts mammalian gut microbiota abundance and host diet-specific adaptations.

    PubMed

    Eilam, Omer; Zarecki, Raphy; Oberhardt, Matthew; Ursell, Luke K; Kupiec, Martin; Knight, Rob; Gophna, Uri; Ruppin, Eytan

    2014-08-12

    Glycans form the primary nutritional source for microbes in the human gut, and understanding their metabolism is a critical yet understudied aspect of microbiome research. Here, we present a novel computational pipeline for modeling glycan degradation (GlyDeR) which predicts the glycan degradation potency of 10,000 reference glycans based on either genomic or metagenomic data. We first validated GlyDeR by comparing degradation profiles for genomes in the Human Microbiome Project against KEGG reaction annotations. Next, we applied GlyDeR to the analysis of human and mammalian gut microbial communities, which revealed that the glycan degradation potential of a community is strongly linked to host diet and can be used to predict diet with higher accuracy than sequence data alone. Finally, we show that a microbe's glycan degradation potential is significantly correlated (R = 0.46) with its abundance, with even higher correlations for potential pathogens such as the class Clostridia (R = 0.76). GlyDeR therefore represents an important tool for advancing our understanding of bacterial metabolism in the gut and for the future development of more effective prebiotics for microbial community manipulation. The increased availability of high-throughput sequencing data has positioned the gut microbiota as a major new focal point for biomedical research. However, despite the expenditure of huge efforts and resources, sequencing-based analysis of the microbiome has uncovered mostly associative relationships between human health and diet, rather than a causal, mechanistic one. In order to utilize the full potential of systems biology approaches, one must first characterize the metabolic requirements of gut bacteria, specifically, the degradation of glycans, which are their primary nutritional source. We developed a computational framework called GlyDeR for integrating expert knowledge along with high-throughput data to uncover important new relationships within glycan metabolism

  7. Coherent neural oscillations predict future motor and language improvement after stroke.

    PubMed

    Nicolo, Pierre; Rizk, Sviatlana; Magnin, Cécile; Pietro, Marie Di; Schnider, Armin; Guggisberg, Adrian G

    2015-10-01

    Recent findings have demonstrated that stroke lesions affect neural communication in the entire brain. However, it is less clear whether network interactions are also relevant for plasticity and repair. This study investigated whether the coherence of neural oscillations at language or motor nodes is associated with future clinical improvement. Twenty-four stroke patients underwent high-density EEG recordings and standardized motor and language tests at 2-3 weeks (T0) and 3 months (T1) after stroke onset. In addition, EEG and motor assessments were obtained from a second population of 18 stroke patients. The graph theoretical measure of weighted node degree at language and motor areas was computed as the sum of absolute imaginary coherence with all other brain regions and compared to the amount of clinical improvement from T0 to T1. At T0, beta-band weighted node degree at the ipsilesional motor cortex was linearly correlated with better subsequent motor improvement, while beta-band weighted node degree at Broca's area was correlated with better language improvement. Clinical recovery was further associated with contralesional theta-band weighted node degree. These correlations were each specific to the corresponding brain area and independent of initial clinical severity, age, and lesion size. Findings were reproduced in the second stroke group. Conversely, later coherence increases occurring between T0 and T1 were associated with less clinical improvement. Improvement of language and motor functions after stroke is therefore associated with inter-regional synchronization of neural oscillations in the first weeks after stroke. A better understanding of network mechanisms of plasticity may lead to new prognostic biomarkers and therapeutic targets.See Ward (doi:10.1093/brain/awv265) for a scientific commentary on this article. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please

  8. α-Synuclein genetic variants predict faster motor symptom progression in idiopathic Parkinson disease.

    PubMed

    Ritz, Beate; Rhodes, Shannon L; Bordelon, Yvette; Bronstein, Jeff

    2012-01-01

    Currently, there are no reported genetic predictors of motor symptom progression in Parkinson's disease (PD). In familial PD, disease severity is associated with higher α-synuclein (SNCA) expression levels, and in postmortem studies expression varies with SNCA genetic variants. Furthermore, SNCA is a well-known risk factor for PD occurrence. We recruited Parkinson's patients from the communities of three central California counties to investigate the influence of SNCA genetic variants on motor symptom progression in idiopathic PD. We repeatedly assessed this cohort of patients over an average of 5.1 years for motor symptom changes employing the Unified Parkinson's Disease Rating Scale (UPDRS). Of 363 population-based incident PD cases diagnosed less than 3 years from baseline assessment, 242 cases were successfully re-contacted and 233 were re-examined at least once. Of subjects lost to follow-up, 69% were due to death. Adjusting for covariates, risk of faster decline of motor function as measured by annual increase in motor UPDRS exam score was increased 4-fold in carriers of the REP1 263bp promoter variant (OR 4.03, 95%CI:1.57-10.4). Our data also suggest a contribution to increased risk by the G-allele for rs356165 (OR 1.66; 95%CI:0.96-2.88), and we observed a strong trend across categories when both genetic variants were considered (p for trend = 0.002). Our population-based study has demonstrated that SNCA variants are strong predictors of faster motor decline in idiopathic PD. SNCA may be a promising target for therapies and may help identify patients who will benefit most from early interventions. This is the first study to link SNCA to motor symptom decline in a longitudinal progression study.

  9. Motor syndromes.

    PubMed

    Corea, Francesco; Micheli, Sara

    2012-01-01

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

  10. Prediction of the ageing of commercial lager beer during storage based on the degradation of iso-α-acids.

    PubMed

    Blanco, Carlos A; Nimubona, Dieudonné; Caballero, Isabel

    2014-08-01

    Iso-α-acids and their chemically modified variants are responsible for the bitterness of beer and play a disproportionately large role in the final quality of beer. The current study was undertaken to predict the degradation of commercial lager beers related to changes in the concentration of trans-iso-α-acids during storage by using high-pressure liquid chromatography. In the analysed beers the concentration of isohumulone (average concentration 28 mg L(-1)) was greater than that of isocohumulone (20 mg L(-1)) and isoadhumulone (10 mg L(-1)). The kinetic parameters, activation energy and rate constant, of the trans-iso-α-acids were calculated. In the case of dark beers, the activation energy for the degradation of trans-isocohumulones was found to be higher than for trans-isohumulones and trans-isoadhumulones, whereas in pale and alcohol-free beers activation energies for the degradation of the three trans isomers were similar. The loss of iso-α-acids can be calculated using the activation energy of the degradation of trans-iso-α-acids and the temperature profile of the accelerated ageing. The results obtained in the investigation can be used in the beer industry to predict the alteration of the bitterness of beer during storage. © 2013 Society of Chemical Industry.

  11. Testing and Analysis for Lifetime Prediction of Crystalline Silicon PV Modules Undergoing Degradation by System Voltage Stress: Preprint

    SciTech Connect

    Hacke, P.; Smith, R.; Terwiliger, K.; Glick, S.; Jordan, D.; Johnston, S.; Kempe, M.; Kurtz, S.

    2012-07-01

    Acceleration factors are calculated for crystalline silicon PV modules under system voltage stress by comparing the module power during degradation outdoors to that in accelerated testing at three temperatures and 85% relative humidity. A lognormal analysis is applied to the accelerated lifetime test data considering failure at 80% of the initial module power. Activation energy of 0.73 eV for the rate of failure is determined, and the probability of module failure at an arbitrary temperature is predicted. To obtain statistical data for multiple modules over the course of degradation in-situ of the test chamber, dark I-V measurements are obtained and transformed using superposition, which is found well suited for rapid and quantitative evaluation of potential-induced degradation. It is determined that shunt resistance measurements alone do not represent the extent of power degradation. This is explained with a two-diode model analysis that shows an increasing second diode recombination current and ideality factor as the degradation in module power progresses. Failure modes of the modules stressed outdoors are examined and compared to those stressed in accelerated tests.

  12. Chronotype predicts activity patterns in the neural underpinnings of the motor system during the day.

    PubMed

    Peres, Isabella; Vetter, Céline; Blautzik, Janusch; Reiser, Maximilian; Pöppel, Ernst; Meindl, Thomas; Roenneberg, Till; Gutyrchik, Evgeny

    2011-12-01

    Neuroimaging is increasingly used to study the motor system in vivo. Despite many reports of time-of-day influences on motor function at the behavioral level, little is known about these influences on neural motor networks and their activations recorded in neuroimaging. Using functional magnetic resonance imaging (fMRI), the authors studied 15 healthy subjects (9 females; mean ± SD age: 23 ± 3 yrs) performing a self-paced finger-tapping task at different times of day (morning, midday, afternoon, and evening). Blood-oxygenation-level-dependent signal showed systematic differences across the day in task-related motor areas of the brain, specifically in the supplementary motor area, parietal cortex, and rolandic operculum (p(corr)< .0125). The authors found that these time-of-day-dependent hemodynamic modulations are associated with chronotype and not with homeostatic sleep pressure. These results show that consideration of time-of-day for the analysis of fMRI studies is imperative.

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

    PubMed

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

    2010-03-01

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

  14. Modelling the degradation of endogenous residue and 'unbiodegradable' influent organic suspended solids to predict sludge production.

    PubMed

    Spérandio, Mathieu; Labelle, Marc-André; Ramdani, Abdellah; Gadbois, Alain; Paul, Etienne; Comeau, Yves; Dold, Peter L

    2013-01-01

    Activated sludge models have assumed that a portion of organic solids in municipal wastewater influent is unbiodegradable. Also, it is assumed that solids from biomass decay cannot be degraded further. The paper evaluates these assumptions based on data from systems operating at higher than typical sludge retention times (SRTs), including membrane bioreactor systems with total solids retention (no intentional sludge wastage). Data from over 30 references and with SRTs of up to 400 d were analysed. A modified model that considers the possible degradation of the two components is proposed. First order degradation rates of approximately 0.007 d(-1) for both components appear to improve sludge production estimates. Factors possibly influencing these degradation rates such as wastewater characteristics and bioavailability are discussed.

  15. Thalamic GABA Predicts Fine Motor Performance in Manganese-Exposed Smelter Workers

    PubMed Central

    Long, Zaiyang; Li, Xiang-Rong; Xu, Jun; Edden, Richard A. E.; Qin, Wei-Ping; Long, Li-Ling; Murdoch, James B.; Zheng, Wei; Jiang, Yue-Ming; Dydak, Ulrike

    2014-01-01

    Overexposure to manganese (Mn) may lead to parkinsonian symptoms including motor deficits. The main inhibitory neurotransmitter gamma-aminobutyric acid (GABA) is known to play a pivotal role in the regulation and performance of movement. Therefore this study was aimed at testing the hypothesis that an alteration of GABA following Mn exposure may be associated with fine motor performance in occupationally exposed workers and may underlie the mechanism of Mn-induced motor deficits. A cohort of nine Mn-exposed male smelter workers from an Mn-iron alloy factory and 23 gender- and age-matched controls were recruited and underwent neurological exams, magnetic resonance spectroscopy (MRS) measurements, and Purdue pegboard motor testing. Short-echo-time MRS was used to measure N-Acetyl-aspartate (NAA) and myo-inositol (mI). GABA was detected with a MEGA-PRESS J-editing MRS sequence. The mean thalamic GABA level was significantly increased in smelter workers compared to controls (p = 0.009). Multiple linear regression analysis reveals (1) a significant association between the increase in GABA level and the duration of exposure (R2 = 0.660, p = 0.039), and (2) significant inverse associations between GABA levels and all Purdue pegboard test scores (for summation of all scores R2 = 0.902, p = 0.001) in the smelter workers. In addition, levels of mI were reduced significantly in the thalamus and PCC of smelter workers compared to controls (p = 0.030 and p = 0.009, respectively). In conclusion, our results show clear associations between thalamic GABA levels and fine motor performance. Thus in Mn-exposed subjects, increased thalamic GABA levels may serve as a biomarker for subtle deficits in motor control and may become valuable for early diagnosis of Mn poisoning. PMID:24505436

  16. Pre-Trial EEG-Based Single-Trial Motor Performance Prediction to Enhance Neuroergonomics for a Hand Force Task

    PubMed Central

    Meinel, Andreas; Castaño-Candamil, Sebastián; Reis, Janine; Tangermann, Michael

    2016-01-01

    We propose a framework for building electrophysiological predictors of single-trial motor performance variations, exemplified for SVIPT, a sequential isometric force control task suitable for hand motor rehabilitation after stroke. Electroencephalogram (EEG) data of 20 subjects with mean age of 53 years was recorded prior to and during 400 trials of SVIPT. They were executed within a single session with the non-dominant left hand, while receiving continuous visual feedback of the produced force trajectories. The behavioral data showed strong trial-by-trial performance variations for five clinically relevant metrics, which accounted for reaction time as well as for the smoothness and precision of the produced force trajectory. 18 out of 20 tested subjects remained after preprocessing and entered offline analysis. Source Power Comodulation (SPoC) was applied on EEG data of a short time interval prior to the start of each SVIPT trial. For 11 subjects, SPoC revealed robust oscillatory EEG subspace components, whose bandpower activity are predictive for the performance of the upcoming trial. Since SPoC may overfit to non-informative subspaces, we propose to apply three selection criteria accounting for the meaningfulness of the features. Across all subjects, the obtained components were spread along the frequency spectrum and showed a variety of spatial activity patterns. Those containing the highest level of predictive information resided in and close to the alpha band. Their spatial patterns resemble topologies reported for visual attention processes as well as those of imagined or executed hand motor tasks. In summary, we identified subject-specific single predictors that explain up to 36% of the performance fluctuations and may serve for enhancing neuroergonomics of motor rehabilitation scenarios. PMID:27199701

  17. Pre-Trial EEG-Based Single-Trial Motor Performance Prediction to Enhance Neuroergonomics for a Hand Force Task.

    PubMed

    Meinel, Andreas; Castaño-Candamil, Sebastián; Reis, Janine; Tangermann, Michael

    2016-01-01

    We propose a framework for building electrophysiological predictors of single-trial motor performance variations, exemplified for SVIPT, a sequential isometric force control task suitable for hand motor rehabilitation after stroke. Electroencephalogram (EEG) data of 20 subjects with mean age of 53 years was recorded prior to and during 400 trials of SVIPT. They were executed within a single session with the non-dominant left hand, while receiving continuous visual feedback of the produced force trajectories. The behavioral data showed strong trial-by-trial performance variations for five clinically relevant metrics, which accounted for reaction time as well as for the smoothness and precision of the produced force trajectory. 18 out of 20 tested subjects remained after preprocessing and entered offline analysis. Source Power Comodulation (SPoC) was applied on EEG data of a short time interval prior to the start of each SVIPT trial. For 11 subjects, SPoC revealed robust oscillatory EEG subspace components, whose bandpower activity are predictive for the performance of the upcoming trial. Since SPoC may overfit to non-informative subspaces, we propose to apply three selection criteria accounting for the meaningfulness of the features. Across all subjects, the obtained components were spread along the frequency spectrum and showed a variety of spatial activity patterns. Those containing the highest level of predictive information resided in and close to the alpha band. Their spatial patterns resemble topologies reported for visual attention processes as well as those of imagined or executed hand motor tasks. In summary, we identified subject-specific single predictors that explain up to 36% of the performance fluctuations and may serve for enhancing neuroergonomics of motor rehabilitation scenarios.

  18. Validated QSAR prediction of OH tropospheric degradation of VOCs: splitting into training-test sets and consensus modeling.

    PubMed

    Gramatica, Paola; Pilutti, Pamela; Papa, Ester

    2004-01-01

    The rate constant for hydroxyl radical tropospheric degradation of 460 heterogeneous organic compounds is predicted by QSAR modeling. The applied Multiple Linear Regression is based on a variety of theoretical molecular descriptors, selected by the Genetic Algorithms-Variable Subset Selection (GA-VSS) procedure. The models were validated for predictivity by both internal and external validation. For the external validation two splitting approaches, D-optimal Experimental Design and Kohonen Artificial Neural Networks (K-ANN), were applied to the original data set to compare the two methodologies. We emphasize that external validation is the only way to establish a reliable QSAR model for predictive purposes. Predicted data by consensus modeling from different models are also proposed. Copyright 2004 American Chemical Society

  19. Do Nimble Hands Make for Nimble Lexicons? Fine Motor Skills Predict Knowledge of Embodied Vocabulary Items

    ERIC Educational Resources Information Center

    Suggate, Sebastian P.; Stoeger, Heidrun

    2014-01-01

    Theories and research in embodied cognition postulate that cognition grounded in action enjoys a processing advantage. Extending this theory to the study of how fine motor skills (FMS) link to vocabulary development in preschool children, the authors investigated FMS and vocabulary in 76 preschoolers. Building on previous research, they…

  20. Cognitive ability predicts motor learning on a virtual reality game in patients with TBI.

    PubMed

    O'Neil, Rochelle L; Skeel, Reid L; Ustinova, Ksenia I

    2013-01-01

    Virtual reality games and simulations have been utilized successfully for motor rehabilitation of individuals with traumatic brain injury (TBI). Little is known, however, how TBI-related cognitive decline affects learning of motor tasks in virtual environments. To fill this gap, we examined learning within a virtual reality game involving various reaching motions in 14 patients with TBI and 15 healthy individuals with different cognitive abilities. All participants practiced ten 90-second gaming trials to assess various aspects of motor learning. Cognitive abilities were assessed with a battery of tests including measures of memory, executive functioning, and visuospatial ability. Overall, participants with TBI showed both reduced performance and a slower learning rate in the virtual reality game compared to healthy individuals. Numerous correlations between overall performance and several of the cognitive ability domains were revealed for both the patient and control groups, with the best predictor being overall cognitive ability. The results may provide a starting point for rehabilitation programs regarding which cognitive domains interact with motor learning.

  1. Fine Motor Skill Predicts Expressive Language in Infant Siblings of Children with Autism

    ERIC Educational Resources Information Center

    LeBarton, Eve Sauer; Iverson, Jana M.

    2013-01-01

    We investigated whether fine motor and expressive language skills are related in the later-born siblings of children with autism (heightened-risk, HR infants) who are at increased risk for language delays. We observed 34 HR infants longitudinally from 12 to 36 months. We used parent report and standardized observation measures to assess fine motor…

  2. Basal Ganglia Shapes Predict Social, Communication, and Motor Dysfunctions in Boys with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Qiu, Anqi; Adler, Marcy; Crocetti, Deana; Miller, Michael I.; Mostofsky, Stewart H.

    2010-01-01

    Objective: Basal ganglia abnormalities have been suggested as contributing to motor, social, and communicative impairments in autism spectrum disorder (ASD). Volumetric analyses offer limited ability to detect localized differences in basal ganglia structure. Our objective was to investigate basal ganglia shape abnormalities and their association…

  3. Neonatal White Matter Abnormality Predicts Childhood Motor Impairment in Very Preterm Children

    ERIC Educational Resources Information Center

    Spittle, Alicia J.; Cheong, Jeanie; Doyle, Lex W.; Roberts, Gehan; Lee, Katherine J.; Lim, Jeremy; Hunt, Rod W.; Inder, Terrie E.; Anderson, Peter J.

    2011-01-01

    Aim: Children born very preterm are at risk for impaired motor performance ranging from cerebral palsy (CP) to milder abnormalities, such as developmental coordination disorder. White matter abnormalities (WMA) at term have been associated with CP in very preterm children; however, little is known about the impact of WMA on the range of motor…

  4. Individual differences in subconscious motor control predicted by GABA concentration in SMA

    PubMed Central

    Boy, Frederic; Evans, C. John; Edden, Richard A. E.; Singh, Krish D.; Husain, Masud; Sumner, Petroc

    2011-01-01

    Summary Subliminal visual stimuli affect motor planning [1] but the size of such effects differs greatly between individuals [2, 3]. Here we investigated whether such variation may be related to neurochemical differences between people. Cortical responsiveness is expected to be lower under the influence of more of the main inhibitory neurotransmitter, GABA [4]. Thus we hypothesized that if an individual has more GABA in the supplementary motor area (SMA) – a region previously associated with automatic motor control [5] – this would result in smaller subliminal effects. We measured the reversed masked prime – or negative compatibility – effect, and found that it correlated strongly with GABA concentration, measured with magnetic resonance spectroscopy. This occurred specifically in the SMA region and not in other regions from which spectroscopy measurements were taken. We replicated these results in an independent cohort: more GABA in the SMA region is reliably associated with smaller effect size. These findings suggest that, across individuals, the responsiveness of subconscious motor mechanisms is related to GABA concentration in the SMA. PMID:20888227

  5. Do Nimble Hands Make for Nimble Lexicons? Fine Motor Skills Predict Knowledge of Embodied Vocabulary Items

    ERIC Educational Resources Information Center

    Suggate, Sebastian P.; Stoeger, Heidrun

    2014-01-01

    Theories and research in embodied cognition postulate that cognition grounded in action enjoys a processing advantage. Extending this theory to the study of how fine motor skills (FMS) link to vocabulary development in preschool children, the authors investigated FMS and vocabulary in 76 preschoolers. Building on previous research, they…

  6. Basal Ganglia Shapes Predict Social, Communication, and Motor Dysfunctions in Boys with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Qiu, Anqi; Adler, Marcy; Crocetti, Deana; Miller, Michael I.; Mostofsky, Stewart H.

    2010-01-01

    Objective: Basal ganglia abnormalities have been suggested as contributing to motor, social, and communicative impairments in autism spectrum disorder (ASD). Volumetric analyses offer limited ability to detect localized differences in basal ganglia structure. Our objective was to investigate basal ganglia shape abnormalities and their association…

  7. Neonatal White Matter Abnormality Predicts Childhood Motor Impairment in Very Preterm Children

    ERIC Educational Resources Information Center

    Spittle, Alicia J.; Cheong, Jeanie; Doyle, Lex W.; Roberts, Gehan; Lee, Katherine J.; Lim, Jeremy; Hunt, Rod W.; Inder, Terrie E.; Anderson, Peter J.

    2011-01-01

    Aim: Children born very preterm are at risk for impaired motor performance ranging from cerebral palsy (CP) to milder abnormalities, such as developmental coordination disorder. White matter abnormalities (WMA) at term have been associated with CP in very preterm children; however, little is known about the impact of WMA on the range of motor…

  8. The Bender Visual Motor Gestalt Test: Implications for the Diagnosis and Prediction of Reading Achievement.

    ERIC Educational Resources Information Center

    Lesiak, Judi

    1984-01-01

    Reviews 32 studies about the utility of the Bender Visual-Motor Gestalt Test (BG) as a predictor of reading, its relationship to reading achievement, and ability to differentiate between good and poor readers. Results question the use of the BG (scored using discrete error systems) in a diagnostic reading battery. (BH)

  9. The Bender Visual Motor Gestalt Test: Implications for the Diagnosis and Prediction of Reading Achievement.

    ERIC Educational Resources Information Center

    Lesiak, Judi

    1984-01-01

    Reviews 32 studies about the utility of the Bender Visual-Motor Gestalt Test (BG) as a predictor of reading, its relationship to reading achievement, and ability to differentiate between good and poor readers. Results question the use of the BG (scored using discrete error systems) in a diagnostic reading battery. (BH)

  10. Fine Motor Skill Predicts Expressive Language in Infant Siblings of Children with Autism

    ERIC Educational Resources Information Center

    LeBarton, Eve Sauer; Iverson, Jana M.

    2013-01-01

    We investigated whether fine motor and expressive language skills are related in the later-born siblings of children with autism (heightened-risk, HR infants) who are at increased risk for language delays. We observed 34 HR infants longitudinally from 12 to 36 months. We used parent report and standardized observation measures to assess fine motor…

  11. Fibril reinforced poroelastic model predicts specifically mechanical behavior of normal, proteoglycan depleted and collagen degraded articular cartilage.

    PubMed

    Korhonen, Rami K; Laasanen, Mikko S; Töyräs, Juha; Lappalainen, Reijo; Helminen, Heikki J; Jurvelin, Jukka S

    2003-09-01

    Degradation of collagen network and proteoglycan (PG) macromolecules are signs of articular cartilage degeneration. These changes impair cartilage mechanical function. Effects of collagen degradation and PG depletion on the time-dependent mechanical behavior of cartilage are different. In this study, numerical analyses, which take the compression-tension nonlinearity of the tissue into account, were carried out using a fibril reinforced poroelastic finite element model. The study aimed at improving our understanding of the stress-relaxation behavior of normal and degenerated cartilage in unconfined compression. PG and collagen degradations were simulated by decreasing the Young's modulus of the drained porous (nonfibrillar) matrix and the fibril network, respectively. Numerical analyses were compared to results from experimental tests with chondroitinase ABC (PG depletion) or collagenase (collagen degradation) digested samples. Fibril reinforced poroelastic model predicted the experimental behavior of cartilage after chondroitinase ABC digestion by a major decrease of the drained porous matrix modulus (-64+/-28%) and a minor decrease of the fibril network modulus (-11+/-9%). After collagenase digestion, in contrast, the numerical analyses predicted the experimental behavior of cartilage by a major decrease of the fibril network modulus (-69+/-5%) and a decrease of the drained porous matrix modulus (-44+/-18%). The reduction of the drained porous matrix modulus after collagenase digestion was consistent with the microscopically observed secondary PG loss from the tissue. The present results indicate that the fibril reinforced poroelastic model is able to predict specifically characteristic alterations in the stress-relaxation behavior of cartilage after enzymatic modifications of the tissue. We conclude that the compression-tension nonlinearity of the tissue is needed to capture realistically the mechanical behavior of normal and degenerated articular cartilage.

  12. Attentional bias toward high-calorie food-cues and trait motor impulsivity interactively predict weight gain

    PubMed Central

    Meule, Adrian; Platte, Petra

    2016-01-01

    Strong bottom-up impulses and weak top-down control may interactively lead to overeating and, consequently, weight gain. In the present study, female university freshmen were tested at the start of the first semester and again at the start of the second semester. Attentional bias toward high- or low-calorie food-cues was assessed using a dot-probe paradigm and participants completed the Barratt Impulsiveness Scale. Attentional bias and motor impulsivity interactively predicted change in body mass index: motor impulsivity positively predicted weight gain only when participants showed an attentional bias toward high-calorie food-cues. Attentional and non-planning impulsivity were unrelated to weight change. Results support findings showing that weight gain is prospectively predicted by a combination of weak top-down control (i.e. high impulsivity) and strong bottom-up impulses (i.e. high automatic motivational drive toward high-calorie food stimuli). They also highlight the fact that only specific aspects of impulsivity are relevant in eating and weight regulation. PMID:28070402

  13. Attentional bias toward high-calorie food-cues and trait motor impulsivity interactively predict weight gain.

    PubMed

    Meule, Adrian; Platte, Petra

    2016-01-01

    Strong bottom-up impulses and weak top-down control may interactively lead to overeating and, consequently, weight gain. In the present study, female university freshmen were tested at the start of the first semester and again at the start of the second semester. Attentional bias toward high- or low-calorie food-cues was assessed using a dot-probe paradigm and participants completed the Barratt Impulsiveness Scale. Attentional bias and motor impulsivity interactively predicted change in body mass index: motor impulsivity positively predicted weight gain only when participants showed an attentional bias toward high-calorie food-cues. Attentional and non-planning impulsivity were unrelated to weight change. Results support findings showing that weight gain is prospectively predicted by a combination of weak top-down control (i.e. high impulsivity) and strong bottom-up impulses (i.e. high automatic motivational drive toward high-calorie food stimuli). They also highlight the fact that only specific aspects of impulsivity are relevant in eating and weight regulation.

  14. Computer model predictions of the local effects of large, solid-fuel rocket motors on stratospheric ozone. Technical report

    SciTech Connect

    Zittel, P.F.

    1994-09-10

    The solid-fuel rocket motors of large space launch vehicles release gases and particles that may significantly affect stratospheric ozone densities along the vehicle's path. In this study, standard rocket nozzle and flowfield computer codes have been used to characterize the exhaust gases and particles through the afterburning region of the solid-fuel motors of the Titan IV launch vehicle. The models predict that a large fraction of the HCl gas exhausted by the motors is converted to Cl and Cl2 in the plume afterburning region. Estimates of the subsequent chemistry suggest that on expansion into the ambient daytime stratosphere, the highly reactive chlorine may significantly deplete ozone in a cylinder around the vehicle track that ranges from 1 to 5 km in diameter over the altitude range of 15 to 40 km. The initial ozone depletion is estimated to occur on a time scale of less than 1 hour. After the initial effects, the dominant chemistry of the problem changes, and new models are needed to follow the further expansion, or closure, of the ozone hole on a longer time scale.

  15. Development of a microscale emission factor model for particulate matter for predicting real-time motor vehicle emissions.

    PubMed

    Singh, Rakesh B; Huber, Alan H; Braddock, James N

    2003-10-01

    The U.S. Environmental Protection Agency's National Exposure Research Laboratory is pursuing a project to improve the methodology for modeling human exposure to motor vehicle emissions. The overall project goal is to develop improved methods for modeling the source through the air pathway to human exposure in significant exposure microenvironments. Current particulate matter (PM) emission models, particle emission factor model (used in the United States, except California) and motor vehicle emission factor model (used in California only), are suitable only for county-scale modeling and emission inventories. There is a need to develop a site-specific real-time emission factor model for PM emissions to support human exposure studies near roadways. A microscale emission factor model for predicting site-specific real-time motor vehicle PM (MicroFacPM) emissions for total suspended PM, PM less than 10 microm aerodynamic diameter, and PM less than 2.5 microm aerodynamic diameter has been developed. The algorithm used to calculate emission factors in MicroFacPM is disaggregated, and emission factors are calculated from a real-time fleet, rather than from a fleet-wide average estimated by a vehicle-miles-traveled weighting of the emission factors for different vehicle classes. MicroFacPM requires input information necessary to characterize the site-specific real-time fleet being modeled. Other variables required include average vehicle speed, time and day of the year, ambient temperature, and relative humidity.

  16. Sensory prediction or motor control? Application of marr-albus type models of cerebellar function to classical conditioning.

    PubMed

    Lepora, Nathan F; Porrill, John; Yeo, Christopher H; Dean, Paul

    2010-01-01

    Marr-Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements.

  17. Auditory-induced neural dynamics in sensory-motor circuitry predict learned temporal and sequential statistics of birdsong

    PubMed Central

    Bouchard, Kristofer E.; Brainard, Michael S.

    2016-01-01

    Predicting future events is a critical computation for both perception and behavior. Despite the essential nature of this computation, there are few studies demonstrating neural activity that predicts specific events in learned, probabilistic sequences. Here, we test the hypotheses that the dynamics of internally generated neural activity are predictive of future events and are structured by the learned temporal–sequential statistics of those events. We recorded neural activity in Bengalese finch sensory-motor area HVC in response to playback of sequences from individuals’ songs, and examined the neural activity that continued after stimulus offset. We found that the strength of response to a syllable in the sequence depended on the delay at which that syllable was played, with a maximal response when the delay matched the intersyllable gap normally present for that specific syllable during song production. Furthermore, poststimulus neural activity induced by sequence playback resembled the neural response to the next syllable in the sequence when that syllable was predictable, but not when the next syllable was uncertain. Our results demonstrate that the dynamics of internally generated HVC neural activity are predictive of the learned temporal–sequential structure of produced song and that the strength of this prediction is modulated by uncertainty. PMID:27506786

  18. Can Perceptuo-Motor Skills Assessment Outcomes in Young Table Tennis Players (7-11 years) Predict Future Competition Participation and Performance? An Observational Prospective Study.

    PubMed

    Faber, Irene R; Elferink-Gemser, Marije T; Faber, Niels R; Oosterveld, Frits G J; Nijhuis-Van der Sanden, Maria W G

    2016-01-01

    Forecasting future performance in youth table tennis players based on current performance is complex due to, among other things, differences between youth players in growth, development, maturity, context and table tennis experience. Talent development programmes might benefit from an assessment of underlying perceptuo-motor skills for table tennis, which is hypothesized to determine the players' potential concerning the perceptuo-motor domain. The Dutch perceptuo-motor skills assessment intends to measure the perceptuo-motor potential for table tennis in youth players by assessing the underlying skills crucial for developing technical and tactical qualities. Untrained perceptuo-motor tasks are used as these are suggested to represent a player's future potential better than specific sport skills themselves as the latter depend on exposure to the sport itself. This study evaluated the value of the perceptuo-motor skills assessment for a talent developmental programme by evaluating its predictive validity for competition participation and performance in 48 young table tennis players (7-11 years). Players were tested on their perceptuo-motor skills once during a regional talent day, and the subsequent competition results were recorded half-yearly over a period of 2.5 years. Logistic regression analysis showed that test scores did not predict future competition participation (p >0.05). Yet, the Generalized Estimating Equations analysis, including the test items 'aiming at target', 'throwing a ball', and 'eye-hand coordination' in the best fitting model, revealed that the outcomes of the perceptuo-motor skills assessment were significant predictors for future competition results (R2 = 51%). Since the test age influences the perceptuo-motor skills assessment's outcome, another multivariable model was proposed including test age as a covariate (R2 = 53%). This evaluation demonstrates promising prospects for the perceptuo-motor skills assessment to be included in a talent

  19. Using kinetic models to predict thermal degradation of fire-retardant-treated plywood roof sheathing

    Treesearch

    Patricia Lebow; Jerrold E. Winandy; Patricia K. Lebow

    2003-01-01

    Between 1985-1995 a substantial number of multifamily housing units in the Eastern and Southern U.S. experienced problems with thermally degraded fire-retardant-treated (FRT) plywood roof sheathing. A series of studies conducted at the USDA Forest Service, Forest Products Laboratory (FPL), examined the materials, chemical mechanisms, and process implications and has...

  20. Thermal degradation of fire-retardant -treated wood : predicting residual service life

    Treesearch

    Jerrold E. Winandy

    2001-01-01

    This paper presents a review of more than 10 years of research on the effects of fire-retardant treatments on wood properties and the potential of these treatments for in-service degradation when exposed to elevated temperatures. It presents an in-depth discussion of the findings and implications of a major wood engineering research program to assess the current...

  1. Working memory and fine motor skills predict early numeracy performance of children with cerebral palsy.

    PubMed

    Van Rooijen, Maaike; Verhoeven, Ludo; Steenbergen, Bert

    2016-01-01

    Early numeracy is an important precursor for arithmetic performance, academic proficiency, and work success. Besides their apparent motor difficulties, children with cerebral palsy (CP) often show additional cognitive disturbances. In this study, we examine whether working memory, non-verbal intelligence, linguistic skills, counting and fine motor skills are positively related to the early numeracy performance of 6-year-old children with CP. A total of 56 children (M = 6.0, SD = 0.61, 37 boys) from Dutch special education schools participated in this cross-sectional study. Of the total group, 81% of the children have the spastic type of CP (33% unilateral and 66% bilateral), 9% have been diagnosed as having diskinetic CP, 8% have been diagnosed as having spastic and diskinetic CP and 2% have been diagnosed as having a combination of diskinetic and atactic CP. The children completed standardized tests assessing early numeracy performance, working memory, non-verbal intelligence, sentence understanding and fine motor skills. In addition, an experimental task was administered to examine their basic counting performance. Structural equation modeling showed that working memory and fine motor skills were significantly related to the early numeracy performance of the children (β = .79 and p < .001, β = .41 and p < .001, respectively). Furthermore, counting was a mediating variable between working memory and early numeracy (β = .57, p < .001). Together, these findings highlight the importance of working memory for early numeracy performance in children with CP and they warrant further research into the efficacy of intervention programs aimed at working memory training.

  2. Motor-prediction improvements after virtual rehabilitation in geriatrics: frail patients reveal different learning curves for movement and postural control.

    PubMed

    Kubicki, A; Bonnetblanc, F; Petrement, G; Mourey, F

    2014-01-01

    Postural control associated with self-paced movement is critical for balance in frail older adults. The present work aimed to investigate the effects of a 2D virtual reality-based program on postural control associated with rapid arm movement in this population. Participants in an upright standing position performed rapid arm-raising movements towards a target. Practice-related changes were assessed by pre- and post-test comparisons of hand kinematics and centre-of-pressure (CoP) displacement parameters measured in a training group and a control group. During these pre- and post-test sessions, patients have to reach towards yellow balls appearing on the screen, form a standardized upright position (with 15cm between the two malleoli). Training group patients took part in six sessions of virtual game. In this, patients were asked to reach their arm towards yellow balls appearing on the screen, from an upright position. After training, we observed improvements in arm movements and in the initial phase of CoP displacement, especially in the anticipatory postural adjustments. Learning curves for these two types of motor improvements showed different rates. These were continuous for the control of the arm movement, and discontinuous for the control of the CoP during the anticipatory postural adjustments. These results suggest that some level of motor (re)-learning is maintained in frail patients with low functional reserves. They also suggest that re-learning of anticipatory postural control (i.e. motor prediction) is less robust than explicit motor learning involved for the arm reaching. This last point should encourage clinicians to extend the training course duration, even if reaching movement improvements seems acquired, in order to automate these anticipatory postural activities. However, other studies should be done to measure the retention of these two types of learning on a longer-term period. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  3. Can a virtual reality assessment of fine motor skill predict successful central line insertion?

    PubMed

    Mohamadipanah, Hossein; Parthiban, Chembian; Nathwani, Jay; Rutherford, Drew; DiMarco, Shannon; Pugh, Carla

    2016-10-01

    Due to the increased use of peripherally inserted central catheter lines, central lines are not performed as frequently. The aim of this study is to evaluate whether a virtual reality (VR)-based assessment of fine motor skills can be used as a valid and objective assessment of central line skills. Surgical residents (N = 43) from 7 general surgery programs performed a subclavian central line in a simulated setting. Then, they participated in a force discrimination task in a VR environment. Hand movements from the subclavian central line simulation were tracked by electromagnetic sensors. Gross movements as monitored by the electromagnetic sensors were compared with the fine motor metrics calculated from the force discrimination tasks in the VR environment. Long periods of inactivity (idle time) during needle insertion and lack of smooth movements, as detected by the electromagnetic sensors, showed a significant correlation with poor force discrimination in the VR environment. Also, long periods of needle insertion time correlated to the poor performance in force discrimination in the VR environment. This study shows that force discrimination in a defined VR environment correlates to needle insertion time, idle time, and hand smoothness when performing subclavian central line placement. Fine motor force discrimination may serve as a valid and objective assessment of the skills required for successful needle insertion when placing central lines. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Prediction of propellant behavior in spinning flow of a space motor

    NASA Technical Reports Server (NTRS)

    Gany, A.; Levy, Y.; Timnat, Y. M.

    1992-01-01

    A model for 2-phase flow dynamics in a spinning spherical rocket motor, developed for the Ofeq satellite program, is based on the sectional approach to solution of the flow equations. An experimental model was built, to enable the motion of the aluminum/aluminum-oxide particles resulting from combustion within a solid-fuel motor to be simulated by injected paraffin droplets. The injected droplets included under-5 micrometer droplets which move with the gas stream and larger droplets, averaging 20 micrometer diameter, which simulate the motion of aluminum particles. The test chamber comprised a pair of cylindrical pyrex tubes with a sharp contraction in diameter, rotated at various speeds by a frequency-controllable motor. An optical system, based on a 5 W argon ion laser with a beam splitter and frequency shifter, mounted on a movable table, facilitated sectional measurements of the three velocity components and determination of size-velocity relationships. Preliminary results indicate that the effect of rotation on axial velocity is negligible, while its effect on tangential velocity approximates to solid-body rotation.

  5. Development of Erosive Burning Models for CFD Predictions of Solid Rocket Motor Internal Environments

    NASA Technical Reports Server (NTRS)

    Wang, Qun-Zhen

    2003-01-01

    Four erosive burning models, equations (11) to (14). are developed in this work by using a power law relationship to correlate (1) the erosive burning ratio and the local velocity gradient at propellant surfaces; (2) the erosive burning ratio and the velocity gradient divided by centerline velocity; (3) the erosive burning difference and the local velocity gradient at propellant surfaces; and (4) the erosive burning difference and the velocity gradient divided by centerline velocity. These models depend on the local velocity gradient at the propellant surface (or the velocity gradient divided by centerline velocity) only and, unlike other empirical models, are independent of the motor size. It was argued that, since the erosive burning is a local phenomenon occurring near the surface of the solid propellant, the erosive burning ratio should be independent of the bore diameter if it is correlated with some local flow parameters such as the velocity gradient at the propellant surface. This seems to be true considering the good results obtained by applying these models, which are developed from the small size 5 inch CP tandem motor testing, to CFD simulations of much bigger motors.

  6. EEG Alpha Band Synchrony Predicts Cognitive and Motor Performance in Patients with Ischemic Stroke

    PubMed Central

    Dubovik, Sviatlana; Ptak, Radek; Aboulafia, Tatiana; Magnin, Cécile; Gillabert, Nicole; Allet, Lara; Pignat, Jean-Michel; Schnider, Armin; Guggisberg, Adrian G.

    2013-01-01

    Functional brain networks are known to be affected by focal brain lesions. However, the clinical relevance of these changes remains unclear. This study assesses resting-state functional connectivity (FC) with electroencephalography (EEG) and relates observed topography of FC to cognitive and motor deficits in patients three months after ischemic stroke. Twenty patients (mean age 61.3 years, range 37–80, 9 females) and nineteen age-matched healthy participants (mean age 66.7 years, range 36–88, 13 females) underwent a ten-minute EEG-resting state examination. The neural oscillations at each grey matter voxel were reconstructed using an adaptive spatial filter and imaginary component of coherence (IC) was calculated as an index of FC. Maps representing mean connectivity value at each voxel were correlated with the clinical data. Compared to healthy controls, alpha band IC of stroke patients was locally reduced in brain regions critical to observed behavioral deficits. A voxel-wise Pearson correlation of clinical performances with FC yielded maps of the neural structures implicated in motor, language, and executive function. This correlation was again specific to alpha band coherence. Ischemic lesions decrease the synchrony of alpha band oscillations between affected brain regions and the rest of the brain. This decrease is linearly related to cognitive and motor deficits observed in the patients. PMID:22713421

  7. The application of electrochemistry to pharmaceutical stability testing--comparison with in silico prediction and chemical forced degradation approaches.

    PubMed

    Torres, Susana; Brown, Roland; Szucs, Roman; Hawkins, Joel M; Zelesky, Todd; Scrivens, Garry; Pettman, Alan; Taylor, Mark R

    2015-11-10

    The aim of this study was to evaluate the use of electrochemistry to generate oxidative degradation products of a model pharmaceutical compound. The compound was oxidized at different potentials using an electrochemical flow-cell fitted with a glassy carbon working electrode, a Pd/H2 reference electrode and a titanium auxiliary electrode. The oxidative products formed were identified and structurally characterized by LC-ESI-MS/MS using a high resolution Q-TOF mass spectrometer. Results from electrochemical oxidation using electrolytes of different pH were compared to those from chemical oxidation and from accelerated stability studies. Additionally, oxidative degradation products predicted using an in silico commercially available software were compared to those obtained from the various experimental methods. The electrochemical approach proved to be useful as an oxidative stress test as all of the final oxidation products observed under accelerated stability studies could be generated; previously reported reactive intermediate species were not observed most likely because the electrochemical mechanism differs from the oxidative pathway followed under accelerated stability conditions. In comparison to chemical degradation tests electrochemical degradation has the advantage of being much faster and does not require the use of strong oxidizing agents. Moreover, it enables the study of different operating parameters in short periods of time and optimisation of the reaction conditions (pH and applied potential) to achieve different oxidative products mixtures. This technique may prove useful as a stress test condition for the generation of oxidative degradation products and may help accelerate structure elucidation and development of stability indicating analytical methods.

  8. A new comparator account of auditory verbal hallucinations: how motor prediction can plausibly contribute to the sense of agency for inner speech

    PubMed Central

    Swiney, Lauren; Sousa, Paulo

    2014-01-01

    The comparator account holds that processes of motor prediction contribute to the sense of agency by attenuating incoming sensory information and that disruptions to this process contribute to misattributions of agency in schizophrenia. Over the last 25 years this simple and powerful model has gained widespread support not only as it relates to bodily actions but also as an account of misattributions of agency for inner speech, potentially explaining the etiology of auditory verbal hallucination (AVH). In this paper we provide a detailed analysis of the traditional comparator account for inner speech, pointing out serious problems with the specification of inner speech on which it is based and highlighting inconsistencies in the interpretation of the electrophysiological evidence commonly cited in its favor. In light of these analyses we propose a new comparator account of misattributed inner speech. The new account follows leading models of motor imagery in proposing that inner speech is not attenuated by motor prediction, but rather derived directly from it. We describe how failures of motor prediction would therefore directly affect the phenomenology of inner speech and trigger a mismatch in the comparison between motor prediction and motor intention, contributing to abnormal feelings of agency. We argue that the new account fits with the emerging phenomenological evidence that AVHs are both distinct from ordinary inner speech and heterogeneous. Finally, we explore the possibility that the new comparator account may extend to explain disruptions across a range of imagistic modalities, and outline avenues for future research. PMID:25221502

  9. A validated model for the prediction of rotor bar failure in squirrel-cage motors using instantaneous angular speed

    NASA Astrophysics Data System (ADS)

    Sasi, Ahmed Y. Ben; Gu, Fengshou; Li, Yuhua; Ball, Andrew D.

    2006-10-01

    Instantaneous angular speed (IAS)-based condition monitoring is an area in which significant progress has been achieved over the recent years. This condition monitoring technique is less known compared to the existing conventional methods. This paper presents model-predicted simulation and experimental results of broken rotor bar faults in a three-phase induction motor using IAS variations. The simulation was performed under normal, and a broken rotor bar fault. The present paper evaluates through simulating and measuring the IAS of an induction motor at broken rotor bar faults in both time and frequency domains. Experimental results show a good agreement with the model-predicted simulation results. Three vital key features were extracted from the angular speed variations. One feature is the modulating contour of pole pass frequency periods in time domain. The other two features are in frequency domain. The primary feature is the presence of the pole pass frequency component at the low-frequency region of the IAS spectrum. The secondary feature which are the multiple of pole pass frequency sideband components around the rotor speed frequency component. Experimental results confirm the validity of the simulation results for the proposed method. The IAS has demonstrated more sensitivity than current signature analysis in detecting the fault. This research also shows the power of angular speed features as a useful tool to detect broken rotor bar deteriorations using any economical transducer such as low-resolution rotary shaft encoders; which may well be already installed for process control purposes.

  10. The value of a non-sport-specific motor test battery in predicting performance in young female gymnasts.

    PubMed

    Vandorpe, Barbara; Vandendriessche, Joric B; Vaeyens, Roel; Pion, Johan; Lefevre, Johan; Philippaerts, Renaat M; Lenoir, Matthieu

    2012-01-01

    Gymnastics talent identification focuses on the identification of young gymnasts who display characteristics for potential success in the future. The aim of this study was to identify which current performance characteristics are related to performance in competition 2 years later. Twenty-three female gymnasts aged 7-8 years completed a multidimensional test battery measuring anthropometric, physical, and coordinative characteristics and were technically evaluated by expert coaches. Two years later, the all-around competition results of those gymnasts now participating in elite (n = 12) and sub-elite (n = 11) competition were obtained. None of the initial measurements significantly correlated with the results of the sub-elite gymnasts 2 years later. For the elite gymnasts, a non-sport-specific motor test battery correlated strongly with the competition result, with more than 40% of the variation in competition performance being explained by the result on that test 2 years earlier. Neither the coaches' judgement nor the anthropometric and physical characteristics were sensitive enough to predict performance. A motor coordination test might be valuable in the early identification of gymnasts, as its discriminative and predictive qualities might be sufficiently powerful for selection within a relatively homogeneous population of gymnasts exhibiting similar anthropometric and physical profiles.

  11. Factors predicting sensory and motor recovery after the repair of upper limb peripheral nerve injuries

    PubMed Central

    He, Bo; Zhu, Zhaowei; Zhu, Qingtang; Zhou, Xiang; Zheng, Canbin; Li, Pengliang; Zhu, Shuang; Liu, Xiaolin; Zhu, Jiakai

    2014-01-01

    OBJECTIVE: To investigate the factors associated with sensory and motor recovery after the repair of upper limb peripheral nerve injuries. DATA SOURCES: The online PubMed database was searched for English articles describing outcomes after the repair of median, ulnar, radial, and digital nerve injuries in humans with a publication date between 1 January 1990 and 16 February 2011. STUDY SELECTION: The following types of article were selected: (1) clinical trials describing the repair of median, ulnar, radial, and digital nerve injuries published in English; and (2) studies that reported sufficient patient information, including age, mechanism of injury, nerve injured, injury location, defect length, repair time, repair method, and repair materials. SPSS 13.0 software was used to perform univariate and multivariate logistic regression analyses and to investigate the patient and intervention factors associated with outcomes. MAIN OUTCOME MEASURES: Sensory function was assessed using the Mackinnon-Dellon scale and motor function was assessed using the manual muscle test. Satisfactory motor recovery was defined as grade M4 or M5, and satisfactory sensory recovery was defined as grade S3+ or S4. RESULTS: Seventy-one articles were included in this study. Univariate and multivariate logistic regression analyses showed that repair time, repair materials, and nerve injured were independent predictors of outcome after the repair of nerve injuries (P < 0.05), and that the nerve injured was the main factor affecting the rate of good to excellent recovery. CONCLUSION: Predictors of outcome after the repair of peripheral nerve injuries include age, gender, repair time, repair materials, nerve injured, defect length, and duration of follow-up. PMID:25206870

  12. REVIEW: Widespread access to predictive models in the motor system: a short review

    NASA Astrophysics Data System (ADS)

    Davidson, Paul R.; Wolpert, Daniel M.

    2005-09-01

    Recent behavioural and computational studies suggest that access to internal predictive models of arm and object dynamics is widespread in the sensorimotor system. Several systems, including those responsible for oculomotor and skeletomotor control, perceptual processing, postural control and mental imagery, are able to access predictions of the motion of the arm. A capacity to make and use predictions of object dynamics is similarly widespread. Here, we review recent studies looking at the predictive capacity of the central nervous system which reveal pervasive access to forward models of the environment.

  13. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures. Phase 3: Reproducibility and discrimination testing. Final report

    SciTech Connect

    Ellis, P.F. II; Ferguson, A.F.; Fuentes, K.T.

    1996-05-06

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. This report presents the results of phase three concerning the reproducibility and discrimination testing.

  14. Effects of timing and movement uncertainty implicate the temporo-parietal junction in the prediction of forthcoming motor actions.

    PubMed

    Jakobs, Oliver; Wang, Ling E; Dafotakis, Manuel; Grefkes, Christian; Zilles, Karl; Eickhoff, Simon B

    2009-08-15

    The concept of predictive coding supposes the brain to build predictions of forthcoming events in order to decrease the computational load, thereby facilitating efficient reactions. In contrast, increasing uncertainty, i.e., lower predictability, should increase reaction time and neural activity due to reactive processing and believe updating. We used functional magnetic resonance imaging (fMRI) to scan subjects reacting to briefly presented arrows pointing to either side by pressing a button with the corresponding index finger. Predictability of these stimuli was manipulated along the independently varied factors "response type" (known hand or random, i.e., unknown order) and "timing" (fixed or variable intervals between stimuli). Behavioural data showed a significant reaction-time advantage when either factor was predictable, confirming the hypothesised reduction in computational load. On the neural level, only the right temporo-parietal junction showed enhanced activation upon both increased task and timing uncertainty. Moreover, activity in this region also positively correlated with reaction time. There was, however, a dissociation between both factors in the frontal lobe, as increased timing uncertainty recruited right BA 44, whereas increased response uncertainty activated the right ventral premotor cortex, the pre-SMA and the DLPFC. In line with the theoretical framework of predictive coding as a load-saving mechanism no brain region showed significantly increased activity in the lower uncertainty conditions or correlated negatively with reaction times. This study hence provided behavioural and neuroimaging evidence for predictive motor coding and points to a key role of the right temporo-parietal junction in its implementation.

  15. Activity Parameters of Subthalamic Nucleus Neurons Selectively Predict Motor Symptom Severity in Parkinson's Disease

    PubMed Central

    Gulberti, Alessandro; Zittel, Simone; Tudor Jones, Adam A.; Fickel, Ulrich; Münchau, Alexander; Köppen, Johannes A.; Gerloff, Christian; Westphal, Manfred; Buhmann, Carsten; Hamel, Wolfgang; Engel, Andreas K.

    2014-01-01

    Parkinson's disease (PD) is a heterogeneous disorder that leads to variable expression of several different motor symptoms. While changes in firing rate, pattern, and oscillation of basal ganglia neurons have been observed in PD patients and experimental animals, there is limited evidence linking them to specific motor symptoms. Here we examined this relationship using extracellular recordings of subthalamic nucleus neurons from 19 PD patients undergoing surgery for deep brain stimulation. For each patient, ≥10 single units and/or multi-units were recorded in the OFF medication state. We correlated the proportion of neurons displaying different activities with preoperative Unified Parkinson's Disease Rating Scale subscores (OFF medication). The mean spectral power at sub-beta frequencies and percentage of units oscillating at beta frequencies were positively correlated with the axial and limb rigidity scores, respectively. The percentage of units oscillating at gamma frequency was negatively correlated with the bradykinesia scores. The mean intraburst rate was positively correlated with both bradykinesia and axial scores, while the related ratio of interspike intervals below/above 10 ms was positively correlated with these symptoms and limb rigidity. None of the activity parameters correlated with tremor. The grand average of all the significantly correlated subthalamic nucleus activities accounted for >60% of the variance of the combined bradykinetic-rigid and axial scores. Our results demonstrate that the occurrence of alterations in the rate and pattern of basal ganglia neurons could partly underlie the variability in parkinsonian phenotype. PMID:24790198

  16. Activity parameters of subthalamic nucleus neurons selectively predict motor symptom severity in Parkinson's disease.

    PubMed

    Sharott, Andrew; Gulberti, Alessandro; Zittel, Simone; Tudor Jones, Adam A; Fickel, Ulrich; Münchau, Alexander; Köppen, Johannes A; Gerloff, Christian; Westphal, Manfred; Buhmann, Carsten; Hamel, Wolfgang; Engel, Andreas K; Moll, Christian K E

    2014-04-30

    Parkinson's disease (PD) is a heterogeneous disorder that leads to variable expression of several different motor symptoms. While changes in firing rate, pattern, and oscillation of basal ganglia neurons have been observed in PD patients and experimental animals, there is limited evidence linking them to specific motor symptoms. Here we examined this relationship using extracellular recordings of subthalamic nucleus neurons from 19 PD patients undergoing surgery for deep brain stimulation. For each patient, ≥ 10 single units and/or multi-units were recorded in the OFF medication state. We correlated the proportion of neurons displaying different activities with preoperative Unified Parkinson's Disease Rating Scale subscores (OFF medication). The mean spectral power at sub-beta frequencies and percentage of units oscillating at beta frequencies were positively correlated with the axial and limb rigidity scores, respectively. The percentage of units oscillating at gamma frequency was negatively correlated with the bradykinesia scores. The mean intraburst rate was positively correlated with both bradykinesia and axial scores, while the related ratio of interspike intervals below/above 10 ms was positively correlated with these symptoms and limb rigidity. None of the activity parameters correlated with tremor. The grand average of all the significantly correlated subthalamic nucleus activities accounted for >60% of the variance of the combined bradykinetic-rigid and axial scores. Our results demonstrate that the occurrence of alterations in the rate and pattern of basal ganglia neurons could partly underlie the variability in parkinsonian phenotype.

  17. Auditory-motor integration of subliminal phase shifts in tapping: Better than auditory discrimination would predict

    PubMed Central

    Kagerer, Florian A.; Viswanathan, Priya; Contreras-Vidal, Jose L.; Whitall, Jill

    2014-01-01

    Unilateral tapping studies have shown that adults adjust to both perceptible and subliminal changes in phase or frequency. This study focuses on the phase responses to abrupt/perceptible and gradual/subliminal changes in auditory-motor relations during alternating bilateral tapping. We investigated these responses in participants with and without good perceptual acuity as determined by an auditory threshold test. Non-musician adults (9 per group) alternately tapped their index fingers in synchrony with auditory cues set at a frequency of 1.4 Hz. Both groups modulated their responses (with no after-effects) to perceptible and to subliminal changes as low as a 5° change in phase. The high threshold participants were more variable than the adults with low threshold in their responses in the gradual condition set (p=0.05). Both groups demonstrated a synchronization asymmetry between dominant and non-dominant hands associated with the abrupt condition and the later blocks of the gradual condition. Our findings extend previous work in unilateral tapping and suggest (1) no relationship between a discrimination threshold and perceptible auditory-motor integration and (2) a noisier subcortical circuitry in those with higher thresholds. PMID:24449013

  18. Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions

    PubMed Central

    Sun, Bo; Ye, Tianyuan; Feng, Qiang; Yao, Jinghua; Wei, Mumeng

    2015-01-01

    This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH)3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss), degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e., dissolved oxygen (DO) and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet. PMID:28793549

  19. Technical note: Methodological and feed factors affecting prediction of ruminal degradability and intestinal digestibility of essential amino acids.

    PubMed

    White, Robin R; Kononoff, Paul J; Firkins, Jeffrey L

    2017-03-01

    We hypothesized that ruminal degradability of essential AA (EAA) and the intestinal digestibility of the ruminally undegraded EAA residue in feeds could be evaluated in a meta-analysis. The objective was to characterize methodological factors for ruminal incubation (time of incubation of feed in situ) and method of simulating digestion of the ruminally undegraded AA (incubation of residue in digestive enzymes in vitro or in mobile bags inserted into the duodenum). To increase numbers of observations, feeds were categorized before ANOVA. An approach is described to predict differential ruminal degradability (or undegradability) of individual EAA by normalizing them as a proportion of total AA (TAA) degradability (undegradability) and similarly to normalize the intestinal digestibility of EAA using TAA. Interaction of feed category with individual EAA justifies future studies with a broader range of feeds and more replication within feed to bolster this approach. With broader data, the approach to normalize EAA as a proportion of TAA should allow a better defined EAA library to be integrated with more robust CP databases (that can be updated with specific feed information from more routine laboratory analyses) in dairy supply-requirement models.

  20. An Injury Severity-, Time Sensitivity-, and Predictability-Based Advanced Automatic Crash Notification Algorithm Improves Motor Vehicle Crash Occupant Triage.

    PubMed

    Stitzel, Joel D; Weaver, Ashley A; Talton, Jennifer W; Barnard, Ryan T; Schoell, Samantha L; Doud, Andrea N; Martin, R Shayn; Meredith, J Wayne

    2016-06-01

    Advanced Automatic Crash Notification algorithms use vehicle telemetry measurements to predict risk of serious motor vehicle crash injury. The objective of the study was to develop an Advanced Automatic Crash Notification algorithm to reduce response time, increase triage efficiency, and improve patient outcomes by minimizing undertriage (<5%) and overtriage (<50%), as recommended by the American College of Surgeons. A list of injuries associated with a patient's need for Level I/II trauma center treatment known as the Target Injury List was determined using an approach based on 3 facets of injury: severity, time sensitivity, and predictability. Multivariable logistic regression was used to predict an occupant's risk of sustaining an injury on the Target Injury List based on crash severity and restraint factors for occupants in the National Automotive Sampling System - Crashworthiness Data System 2000-2011. The Advanced Automatic Crash Notification algorithm was optimized and evaluated to minimize triage rates, per American College of Surgeons recommendations. The following rates were achieved: <50% overtriage and <5% undertriage in side impacts and 6% to 16% undertriage in other crash modes. Nationwide implementation of our algorithm is estimated to improve triage decisions for 44% of undertriaged and 38% of overtriaged occupants. Annually, this translates to more appropriate care for >2,700 seriously injured occupants and reduces unnecessary use of trauma center resources for >162,000 minimally injured occupants. The algorithm could be incorporated into vehicles to inform emergency personnel of recommended motor vehicle crash triage decisions. Lower under- and overtriage was achieved, and nationwide implementation of the algorithm would yield improved triage decision making for an estimated 165,000 occupants annually. Copyright © 2016. Published by Elsevier Inc.

  1. Online Control of Prehension Predicts Performance on a Standardized Motor Assessment Test in 8- to 12-Year-Old Children

    PubMed Central

    Blanchard, Caroline C. V.; McGlashan, Hannah L.; French, Blandine; Sperring, Rachel J.; Petrocochino, Bianca; Holmes, Nicholas P.

    2017-01-01

    Goal-directed hand movements are guided by sensory information and may be adjusted ‘online,’ during the movement. If the target of a movement unexpectedly changes position, trajectory corrections can be initiated in as little as 100 ms in adults. This rapid visual online control is impaired in children with developmental coordination disorder (DCD), and potentially in other neurodevelopmental conditions. We investigated the visual control of hand movements in children in a ‘center-out’ double-step reaching and grasping task, and examined how parameters of this visuomotor control co-vary with performance on standardized motor tests often used with typically and atypically developing children. Two groups of children aged 8–12 years were asked to reach and grasp an illuminated central ball on a vertically oriented board. On a proportion of trials, and at movement onset, the illumination switched unpredictably to one of four other balls in a center-out configuration (left, right, up, or down). When the target moved, all but one of the children were able to correct their movements before reaching the initial target, at least on some trials, but the latencies to initiate these corrections were longer than those typically reported in the adult literature, ranging from 211 to 581 ms. These later corrections may be due to less developed motor skills in children, or to the increased cognitive and biomechanical complexity of switching movements in four directions. In the first group (n = 187), reaching and grasping parameters significantly predicted standardized movement scores on the MABC-2, most strongly for the aiming and catching component. In the second group (n = 85), these same parameters did not significantly predict scores on the DCDQ′07 parent questionnaire. Our reaching and grasping task provides a sensitive and continuous measure of movement skill that predicts scores on standardized movement tasks used to screen for DCD. PMID:28360874

  2. Online Control of Prehension Predicts Performance on a Standardized Motor Assessment Test in 8- to 12-Year-Old Children.

    PubMed

    Blanchard, Caroline C V; McGlashan, Hannah L; French, Blandine; Sperring, Rachel J; Petrocochino, Bianca; Holmes, Nicholas P

    2017-01-01

    Goal-directed hand movements are guided by sensory information and may be adjusted 'online,' during the movement. If the target of a movement unexpectedly changes position, trajectory corrections can be initiated in as little as 100 ms in adults. This rapid visual online control is impaired in children with developmental coordination disorder (DCD), and potentially in other neurodevelopmental conditions. We investigated the visual control of hand movements in children in a 'center-out' double-step reaching and grasping task, and examined how parameters of this visuomotor control co-vary with performance on standardized motor tests often used with typically and atypically developing children. Two groups of children aged 8-12 years were asked to reach and grasp an illuminated central ball on a vertically oriented board. On a proportion of trials, and at movement onset, the illumination switched unpredictably to one of four other balls in a center-out configuration (left, right, up, or down). When the target moved, all but one of the children were able to correct their movements before reaching the initial target, at least on some trials, but the latencies to initiate these corrections were longer than those typically reported in the adult literature, ranging from 211 to 581 ms. These later corrections may be due to less developed motor skills in children, or to the increased cognitive and biomechanical complexity of switching movements in four directions. In the first group (n = 187), reaching and grasping parameters significantly predicted standardized movement scores on the MABC-2, most strongly for the aiming and catching component. In the second group (n = 85), these same parameters did not significantly predict scores on the DCDQ'07 parent questionnaire. Our reaching and grasping task provides a sensitive and continuous measure of movement skill that predicts scores on standardized movement tasks used to screen for DCD.

  3. Merging Field Measurements and High Resolution Modeling to Predict Possible Societal Impacts of Permafrost Degradation

    NASA Astrophysics Data System (ADS)

    Romanovsky, V. E.; Nicolsky, D.; Marchenko, S. S.; Cable, W.; Panda, S. K.

    2015-12-01

    A general warming trend in permafrost temperatures has triggered permafrost degradation in Alaska, especially at locations influenced by human activities. Various phenomena related to permafrost degradation are already commonly observed, including increased rates of coastal and riverbank erosion, increased occurrences of retrogressive thaw slumps and active layer detachment slides, and the disappearance of tundra lakes. The combination of thawing permafrost and erosion is damaging local community infrastructure such as buildings, roads, airports, pipelines, water and sanitation facilities, and communication systems. The potential scale of direct ecological and economical damage due to degrading permafrost has just begun to be recognized. While the projected changes in permafrost are generally available on global and regional scales, these projections cannot be effectively employed to estimate the societal impacts because of their coarse resolution. Intrinsic problems with the classical "spatial grid" approach in spatially distributed modeling applications preclude the use of this modeling approach to solve the above stated problem. Two types of models can be used to study permafrost dynamics in this case. One approach is a site-specific application of the GIPL2.0 permafrost model and another is a very high (tens to hundred meter) resolution spatially distributed version of the same model. The results of properly organized field measurements are also needed to calibrate and validate these models for specific locations and areas of interest. We are currently developing a "landscape unit" approach that allows practically unlimited spatial resolution of the modeling products. Classification of the study area into particular "landscape units" should be performed in accordance with the main factors controlling the expression of climate on permafrost in the study area, typically things such as vegetation, hydrology, soil properties, topography, etc. In areas with little

  4. Autoxidation of drugs: prediction of degradation impurities from results of reaction with radical chain initiators.

    PubMed

    Boccardi, G

    1994-06-01

    In the study of the degradation of drug substances by molecular oxygen, their specific reaction mechanisms must be taken into account. The rate-determining step is usually the reaction of the substrate with a radical chain initiator, which is often an unknown impurity. The reactivity and selectivity of autoxidation can be controlled better by using a radical chain initiator, such as AIBN, than by changing the temperature or the oxygen pressure. In this paper the products profiles of four pharmaceutical substances in a simple oxidation test with AIBN are compared with the results of long term natural stability tests or with already established stabilities.

  5. Artificial neural network to predict degradation of non-metallic lining materials from laboratory tests

    SciTech Connect

    Silverman, D.C.

    1994-12-31

    Artificial neural networks are computer simulations that have the potential of ``finding`` the same patterns that corrosion practitioners recognize to relate experimental test results to lifetime predictions. This potential ability was utilized to construct an artificial neural network to recognize the pattern between results from a sequential immersion test for organic non-metallic lining materials and their ability to function as linings in actual applications. The network so constructed has been shown to predict field performance from this test. The network was incorporated within an Expert System to simplify data input and output, allow for simple consistency checks, and to make the final prediction.

  6. Prediction of CP and starch concentrations in ruminal in situ studies and ruminal degradation of cereal grains using NIRS.

    PubMed

    Krieg, J; Koenzen, E; Seifried, N; Steingass, H; Schenkel, H; Rodehutscord, M

    2017-08-03

    Ruminal in situ incubations are widely used to assess the nutritional value of feedstuffs for ruminants. In in situ methods, feed samples are ruminally incubated in indigestible bags over a predefined timespan and the disappearance of nutrients from the bags is recorded. To describe the degradation of specific nutrients, information on the concentration of feed samples and undegraded feed after in situ incubation ('bag residues') is needed. For cereal and pea grains, CP and starch (ST) analyses are of interest. The numerous analyses of residues following ruminal incubation contribute greatly to the substantial investments in labour and money, and faster methods would be beneficial. Therefore, calibrations were developed to estimate CP and ST concentrations in grains and bag residues following in situ incubations by using their near-infrared spectra recorded from 680 to 2500 nm. The samples comprised rye, triticale, barley, wheat, and maize grains (20 genotypes each), and 15 durum wheat and 13 pea grains. In addition, residues after ruminal incubation were included (at least from four samples per species for various incubation times). To establish CP and ST calibrations, 620 and 610 samples (grains and bag residues after incubation, respectively) were chemically analysed for their CP and ST concentration. Calibrations using wavelengths from 1250 to 2450 nm and the first derivative of the spectra produced the best results (R 2 Validation=0.99 for CP and ST; standard error of prediction=0.47 and 2.10% DM for CP and ST, respectively). Hence, CP and ST concentration in cereal grains and peas and their bag residues could be predicted with high precision by NIRS for use in in situ studies. No differences were found between the effective ruminal degradation calculated from NIRS estimations and those calculated from chemical analyses (P>0.70). Calibrations were also calculated to predict ruminal degradation kinetics of cereal grains from the spectra of ground grains

  7. Tract-Based Spatial Statistics in Preterm-Born Neonates Predicts Cognitive and Motor Outcomes at 18 Months.

    PubMed

    Duerden, E G; Foong, J; Chau, V; Branson, H; Poskitt, K J; Grunau, R E; Synnes, A; Zwicker, J G; Miller, S P

    2015-08-01

    Adverse neurodevelopmental outcome is common in children born preterm. Early sensitive predictors of neurodevelopmental outcome such as MR imaging are needed. Tract-based spatial statistics, a diffusion MR imaging analysis method, performed at term-equivalent age (40 weeks) is a promising predictor of neurodevelopmental outcomes in children born very preterm. We sought to determine the association of tract-based spatial statistics findings before term-equivalent age with neurodevelopmental outcome at 18-months corrected age. Of 180 neonates (born at 24-32-weeks' gestation) enrolled, 153 had DTI acquired early at 32 weeks' postmenstrual age and 105 had DTI acquired later at 39.6 weeks' postmenstrual age. Voxelwise statistics were calculated by performing tract-based spatial statistics on DTI that was aligned to age-appropriate templates. At 18-month corrected age, 166 neonates underwent neurodevelopmental assessment by using the Bayley Scales of Infant Development, 3rd ed, and the Peabody Developmental Motor Scales, 2nd ed. Tract-based spatial statistics analysis applied to early-acquired scans (postmenstrual age of 30-33 weeks) indicated a limited significant positive association between motor skills and axial diffusivity and radial diffusivity values in the corpus callosum, internal and external/extreme capsules, and midbrain (P < .05, corrected). In contrast, for term scans (postmenstrual age of 37-41 weeks), tract-based spatial statistics analysis showed a significant relationship between both motor and cognitive scores with fractional anisotropy in the corpus callosum and corticospinal tracts (P < .05, corrected). Tract-based spatial statistics in a limited subset of neonates (n = 22) scanned at <30 weeks did not significantly predict neurodevelopmental outcomes. The strength of the association between fractional anisotropy values and neurodevelopmental outcome scores increased from early-to-late-acquired scans in preterm-born neonates, consistent with brain

  8. Sensory Prediction or Motor Control? Application of Marr–Albus Type Models of Cerebellar Function to Classical Conditioning

    PubMed Central

    Lepora, Nathan F.; Porrill, John; Yeo, Christopher H.; Dean, Paul

    2010-01-01

    Marr–Albus adaptive filter models of the cerebellum have been applied successfully to a range of sensory and motor control problems. Here we analyze their properties when applied to classical conditioning of the nictitating membrane response in rabbits. We consider a system-level model of eyeblink conditioning based on the anatomy of the eyeblink circuitry, comprising an adaptive filter model of the cerebellum, a comparator model of the inferior olive and a linear dynamic model of the nictitating membrane plant. To our knowledge, this is the first model that explicitly includes all these principal components, in particular the motor plant that is vital for shaping and timing the behavioral response. Model assumptions and parameters were systematically investigated to disambiguate basic computational capacities of the model from features requiring tuning of properties and parameter values. Without such tuning, the model robustly reproduced a range of behaviors related to sensory prediction, by displaying appropriate trial-level associative learning effects for both single and multiple stimuli, including blocking and conditioned inhibition. In contrast, successful reproduction of the real-time motor behavior depended on appropriate specification of the plant, cerebellum and comparator models. Although some of these properties appear consistent with the system biology, fundamental questions remain about how the biological parameters are chosen if the cerebellar microcircuit applies a common computation to many distinct behavioral tasks. It is possible that the response profiles in classical conditioning of the eyeblink depend upon operant contingencies that have previously prevailed, for example in naturally occurring avoidance movements. PMID:21031161

  9. Artificial neural network predictions of degradation of nonmetallic lining materials from laboratory tests

    SciTech Connect

    Silverman, D.C. )

    1994-06-01

    Such organic materials of construction as plastics (thermoplastics and thermosets) and elastomers play an increasingly important role in the containment of corrosive fluids. One major impediment to their routine use is the inability to predict their performance from laboratory tests rapidly and reliably. Artificial neural networks are computer simulations that have the potential to find the same patterns that corrosion practitioners recognize to relate experimental test results to lifetime predictions. This potential was used to construct an artificial neural network to recognize the pattern between results from a sequential immersion test for organic nonmetallic lining materials and their ability to function as linings in actual applications. The network was shown to predict field performance. The network was incorporated within an expert system to simplify data input and output, to allow for simple consistency checks between sample appearance and network output, and to make the final prediction.

  10. Behavior of pollutant-degrading microorganisms in aquifers. Predictions for genetically engineered organisms

    SciTech Connect

    Krumme, M.L.; Egestorff, J.; Timmis, K.N.; Dwyer, D.F. ); Smith, R.L. ); Thiem, S.M.; Tiedje, J.M. )

    1994-06-01

    Bioremediation via environmental introductions of degradative microorganisms requires that the microbes survive in substantial numbers and effect an increase in the rate and extent of pollutant removal. Combined field and microcosm studies were used to assess these abilities for laboratory-grown bacteria. Following introduction into a contaminated aquifer, viable cells of Pseudomonas sp. B13 were present in the contaminant plume for 447 days; die-off was rapid in pristine areas. In aquifer microcosms, survival of B13 and FR120, a genetically engineered derivative of B13 having enhanced catabolic capabilities for substituted aromatics, was comparable to B13 field results; both bacteria degraded target pollutants in microcosms made with aquifer samples from the aerobic zone of the pollutant plume. Results suggest that field studies with nonrecombinant microorganisms may be coupled to laboratory studies with derivative strains to estimate their bioremediative efficacy. Furthermore, laboratory strains of bacteria can survive for extended periods of time in nature and thus may have important bioremediative applications. 33 refs., 4 figs., 1 tab.

  11. Behavior of pollutant-degrading microorganisms in aquifers: Predictions for genetically engineered organisms

    USGS Publications Warehouse

    Krumme, M.L.; Smith, R.L.; Egestorff, J.; Thiem, S.M.; Tiedje, J.M.; Timmis, K.N.; Dwyer, D.F.

    1994-01-01

    Bioremediation via environmental introductions of degradative microorganisms requires that the microbes survive in substantial numbers and effect an increase in the rate and extent of pollutant removal. Combined field and microcosm studies were used to assess these abilities for laboratory-grown bacteria. Following introduction into a contaminated aquifer, viable cells of Pseudomonas sp. B13 were present in the contaminant plume for 447 days; die-off was rapid in pristine areas. In aquifer microcosms, survival of B13 and FR120, a genetically engineered derivative of B13 having enhanced catabolic capabilities for substituted aromatics, was comparable to B13 field results; both bacteria degraded target pollutants in microcosms made with aquifer samples from the aerobic zone of the pollutant plume. Results suggest that field studies with nonrecombinant microorganisms may be coupled to laboratory studies with derivative strains to estimate their bioremediative efficacy. Furthermore, laboratory strains of bacteria can survive for extended periods of time in nature and thus may have important bioremediative applications. ?? 1994 American Chemical Society.

  12. Assessment of intraoperative motor evoked potentials for predicting postoperative paraplegia in thoracic and thoracoabdominal aortic aneurysm repair.

    PubMed

    Horiuchi, Toshinori; Kawaguchi, Masahiko; Inoue, Satoki; Hayashi, Hironobu; Abe, Ryuichi; Tabayashi, Nobuoki; Taniguchi, Shigeki; Furuya, Hitoshi

    2011-02-01

    Monitoring motor evoked potentials (MEPs) has been recognized as a highly reliable method to detect intraoperative spinal cord ischemia (SCI) in aortic repair. However, the data regarding the sensitivity and specificity of MEPs for predicting postoperative paraplegia are limited. We retrospectively assessed the value of intraoperative MEP amplitudes for predicting postoperative paraplegia. The medical records of 44 patients were reviewed. A train-of-five stimulation was delivered to C3-C4, and MEPs were recorded from the abductor pollicis brevis and the tibialis anterior muscles. The cutoff point for detecting SCI was set at 75% decrease of the baseline MEP. Receiver operating characteristic curves were applied at various cutoff points. Three patients (6.8%) had postoperative paraplegia. The minimum MEP during surgery had 100% sensitivity and 64.9% specificity in predicting paraplegia, and the MEP at the end of surgery had 66.7% sensitivity and 78.0% specificity in predicting paraplegia: only 1 patient, who had borderline paraplegia (right monoparesis), showed a false-negative result. Receiver operating characteristic curves indicated that adequate cutoff points for the minimum MEP during surgery and for the MEP amplitude at the end of surgery were a 75-90% decrease and a 64-75% decrease of the baseline MEP, respectively. Monitoring MEPs had relatively high sensitivity and acceptable specificity, with the cutoff point set at 75% decrease of the baseline MEP, for predicting paraplegia and paraparesis. Because of the small sample in our study, further investigations would be necessary to investigate an adequate cutoff point that could predict postoperative paraplegia.

  13. Cortico-subthalamic white matter tract strength predicts interindividual efficacy in stopping a motor response.

    PubMed

    Forstmann, Birte U; Keuken, Max C; Jahfari, Sara; Bazin, Pierre-Louis; Neumann, Jane; Schäfer, Andreas; Anwander, Alfred; Turner, Robert

    2012-03-01

    The subthalamic nucleus (STN) is a small but vitally important structure in the basal ganglia. Because of its small volume, and its localization in the basal ganglia, the STN can best be visualized using ultra-high resolution 7 Tesla (T) magnetic resonance imaging (MRI). In the present study, first we individually segmented 7 T MRI STN masks to generate atlas probability maps. Secondly, the individually segmented STN masks and the probability maps were used to derive cortico-subthalamic white matter tract strength. Tract strength measures were then taken to test two functional STN hypotheses which account for the efficiency in stopping a motor response: the right inferior fronto-subthalamic (rIFC-STN) hypothesis and the posterior medial frontal cortex-subthalamic (pMFC-STN) hypothesis. Results of two independent experiments show that increased white matter tract strength between the pMFC and STN results in better stopping behaviour. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Predicting clinically significant changes in motor and functional outcomes after robot-assisted stroke rehabilitation.

    PubMed

    Hsieh, Yu-wei; Lin, Keh-chung; Wu, Ching-yi; Lien, Hen-yu; Chen, Jean-lon; Chen, Chih-chi; Chang, Wei-han

    2014-02-01

    To investigate the predictors of minimal clinically important changes on outcome measures after robot-assisted therapy (RT). Observational cohort study. Outpatient rehabilitation clinics. A cohort of outpatients with stroke (N=55). Patients with stroke received RT for 90 to 105min/d, 5d/wk, for 4 weeks. Outcome measures, including the Fugl-Meyer Assessment (FMA) and Motor Activity Log (MAL), were measured before and after the intervention. Potential predictors include age, sex, side of lesion, time since stroke onset, finger extension, Box and Block Test (BBT) score, and FMA distal score. Statistical analysis showed that the BBT score (odds ratio[OR]=1.06; P=.04) was a significant predictor of clinically important changes in the FMA. Being a woman (OR=3.9; P=.05) and BBT score (OR=1.07; P=.02) were the 2 significant predictors of clinically significant changes in the MAL amount of use subscale. The BBT score was the significant predictor of an increased probability of achieving clinically important changes in the MAL quality of movement subscale (OR=1.07; P=.02). The R(2) values for the 3 logistic regression models were low (.114-.272). The results revealed that patients with stroke who had greater manual dexterity measured by the BBT appear to have a higher probability of achieving clinically significant motor and functional outcomes after RT. Further studies are needed to evaluate other potential predictors to improve the models and validate the findings. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  15. Assessment and prediction of urban air pollution caused by motor transport exhaust gases using computer simulation methods

    NASA Astrophysics Data System (ADS)

    Boyarshinov, Michael G.; Vaismana, Yakov I.

    2016-10-01

    The following methods were used in order to identify the pollution fields of urban air caused by the motor transport exhaust gases: the mathematical model, which enables to consider the influence of the main factors that determine pollution fields formation in the complex spatial domain; the authoring software designed for computational modeling of the gas flow, generated by numerous mobile point sources; the results of computing experiments on pollutant spread analysis and evolution of their concentration fields. The computational model of exhaust gas distribution and dispersion in a spatial domain, which includes urban buildings, structures and main traffic arteries, takes into account a stochastic character of cars apparition on the borders of the examined territory and uses a Poisson process. The model also considers the traffic lights switching and permits to define the fields of velocity, pressure and temperature of the discharge gases in urban air. The verification of mathematical model and software used confirmed their satisfactory fit to the in-situ measurements data and the possibility to use the obtained computing results for assessment and prediction of urban air pollution caused by motor transport exhaust gases.

  16. Prediction of arm trajectory from the neural activities of the primary motor cortex with modular connectionist architecture.

    PubMed

    Choi, Kyuwan; Hirose, Hideaki; Sakurai, Yoshio; Iijima, Toshio; Koike, Yasuharu

    2009-11-01

    In our previous study [Koike, Y., Hirose, H., Sakurai, Y., Iijima T., (2006). Prediction of arm trajectory from a small number of neuron activities in the primary motor cortex. Neuroscience Research, 55, 146-153], we succeeded in reconstructing muscle activities from the offline combination of single neuron activities recorded in a serial manner in the primary motor cortex of a monkey and in reconstructing the joint angles from the reconstructed muscle activities during a movement condition using an artificial neural network. However, the joint angles during a static condition were not reconstructed. The difficulties of reconstruction under both static and movement conditions mainly arise due to muscle properties such as the velocity-tension relationship and the length-tension relationship. In this study, in order to overcome the limitations due to these muscle properties, we divided an artificial neural network into two networks: one for movement control and the other for posture control. We also trained the gating network to switch between the two neural networks. As a result, the gating network switched the modules properly, and the accuracy of the estimated angles improved compared to the case of using only one artificial neural network.

  17. Action Prediction in Younger versus Older Adults: Neural Correlates of Motor Familiarity

    PubMed Central

    Diersch, Nadine; Mueller, Karsten; Cross, Emily S.; Stadler, Waltraud; Rieger, Martina; Schütz-Bosbach, Simone

    2013-01-01

    Generating predictions during action observation is essential for efficient navigation through our social environment. With age, the sensitivity in action prediction declines. In younger adults, the action observation network (AON), consisting of premotor, parietal and occipitotemporal cortices, has been implicated in transforming executed and observed actions into a common code. Much less is known about age-related changes in the neural representation of observed actions. Using fMRI, the present study measured brain activity in younger and older adults during the prediction of temporarily occluded actions (figure skating elements and simple movement exercises). All participants were highly familiar with the movement exercises whereas only some participants were experienced figure skaters. With respect to the AON, the results confirm that this network was preferentially engaged for the more familiar movement exercises. Compared to younger adults, older adults recruited visual regions to perform the task and, additionally, the hippocampus and caudate when the observed actions were familiar to them. Thus, instead of effectively exploiting the sensorimotor matching properties of the AON, older adults seemed to rely predominantly on the visual dynamics of the observed actions to perform the task. Our data further suggest that the caudate played an important role during the prediction of the less familiar figure skating elements in better-performing groups. Together, these findings show that action prediction engages a distributed network in the brain, which is modulated by the content of the observed actions and the age and experience of the observer. PMID:23704980

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

    PubMed Central

    Aranha, Vencita Priyanka; Moitra, Monika; Saxena, Shikha; Narkeesh, Kanimozhi; Arumugam, Narkeesh; Samuel, Asir John

    2017-01-01

    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. PMID:28149087

  19. Statistical analysis for understanding and predicting battery degradations in real-life electric vehicle use

    NASA Astrophysics Data System (ADS)

    Barré, Anthony; Suard, Frédéric; Gérard, Mathias; Montaru, Maxime; Riu, Delphine

    2014-01-01

    This paper describes the statistical analysis of recorded data parameters of electrical battery ageing during electric vehicle use. These data permit traditional battery ageing investigation based on the evolution of the capacity fade and resistance raise. The measured variables are examined in order to explain the correlation between battery ageing and operating conditions during experiments. Such study enables us to identify the main ageing factors. Then, detailed statistical dependency explorations present the responsible factors on battery ageing phenomena. Predictive battery ageing models are built from this approach. Thereby results demonstrate and quantify a relationship between variables and battery ageing global observations, and also allow accurate battery ageing diagnosis through predictive models.

  20. Development of a Computer Model for Prediction of PCB Degradation Endpoints

    SciTech Connect

    Just, E.M.; Klasson, T.

    1999-12-07

    Several researchers have demonstrated the transformation if polychlorinated biphenyls (PCBs) by both aerobic and anaerobic bacteria. This transformation, or conversion, is characteristic and often dependent on PCB congener structure and in addition, dictates the products or endpoints. Since transformation is linked to microbial activities, bioremediation has been hailed as a possible solution for PCB-contaminated soils and sediments, and several demonstration activities have verified laboratory results. This paper presents results from mathematical modeling of PCB transformation as a means of predicting possible endpoints of bioremediation. Since transformation can be influenced by both starting composition of the PCBs and microbial activity, this paper systematically evaluates several of the most common transformation patterns. The predicted data are also compared with experimental results. For example, the correlation between laboratory-observed and predicted endpoint data was, in some cases, as good as 0.98 (perfect correlation = 1.0). In addition to predicting chemical endpoints, the possible human effects of the PCBs are discussed through the use of documented dioxin-like toxicity and accumulation in humans before and after transformation.

  1. White matter maturation in visual and motor areas predicts the latency of visual activation in children.

    PubMed

    Dockstader, Colleen; Gaetz, William; Rockel, Conrad; Mabbott, Donald J

    2012-01-01

    In humans, white matter maturation is important for the improvement of cognitive function and performance with age. Across studies the variables of white matter maturity and age are highly correlated; however, the unique contributions of white matter to information processing speed remain relatively unknown. We investigated the relations between the speed of the visually-evoked P100m response and the biophysical properties of white matter in 11 healthy children performing a simple, visually-cued finger movement. We found that: (1) the latency of the early, visually-evoked response was related to the integrity of white matter in both visual and motor association areas and (2) white matter maturation in these areas accounted for the variations in visual processing speed, independent of age. Our study is a novel investigation of spatial-temporal dynamics in the developing brain and provides evidence that white matter maturation accounts for age-related decreases in the speed of visual response. Developmental models of cortical specialization should incorporate the unique role of white matter maturation in mediating changes in performance during tasks involving visual processing.

  2. Prediction of motor recovery using initial impairment and fMRI 48 h poststroke.

    PubMed

    Zarahn, Eric; Alon, Leeor; Ryan, Sophia L; Lazar, Ronald M; Vry, Magnus-Sebastian; Weiller, Cornelius; Marshall, Randolph S; Krakauer, John W

    2011-12-01

    There is substantial interpatient variation in recovery from upper limb impairment after stroke in patients with severe initial impairment. Defining recovery as a change in the upper limb Fugl-Meyer score (ΔFM), we predicted ΔFM with its conditional expectation (i.e., posterior mean) given upper limb Fugl-Meyer initial impairment (FM(ii)) and a putative functional magnetic resonance imaging (fMRI) recovery measure. Patients with first time, ischemic stroke were imaged at 2.5 ± 2.2 days poststroke with 1.5-T fMRI during a hand closure task alternating with rest (fundamental frequency = 0.025 Hz, scan duration = 172 s). Confirming a previous finding, we observed that the prediction of ΔFM by FM(ii) alone is good in patients with nonsevere initial hemiparesis but is not good in patients with severe initial hemiparesis (96% and 16% of the total sum of squares of ΔFM explained, respectively). In patients with severe initial hemiparesis, prediction of ΔFM by the combination of FM(ii) and the putative fMRI recovery measure nonsignificantly increased predictive explanation from 16% to 47% of the total sum of squares of ΔFM explained. The implications of this preliminary negative result are discussed.

  3. Prediction of Motor Recovery Using Initial Impairment and fMRI 48 h Poststroke

    PubMed Central

    Alon, Leeor; Ryan, Sophia L.; Lazar, Ronald M.; Vry, Magnus-Sebastian; Weiller, Cornelius; Marshall, Randolph S.

    2011-01-01

    There is substantial interpatient variation in recovery from upper limb impairment after stroke in patients with severe initial impairment. Defining recovery as a change in the upper limb Fugl-Meyer score (ΔFM), we predicted ΔFM with its conditional expectation (i.e., posterior mean) given upper limb Fugl-Meyer initial impairment (FMii) and a putative functional magnetic resonance imaging (fMRI) recovery measure. Patients with first time, ischemic stroke were imaged at 2.5 ± 2.2 days poststroke with 1.5-T fMRI during a hand closure task alternating with rest (fundamental frequency = 0.025 Hz, scan duration = 172 s). Confirming a previous finding, we observed that the prediction of ΔFM by FMii alone is good in patients with nonsevere initial hemiparesis but is not good in patients with severe initial hemiparesis (96% and 16% of the total sum of squares of ΔFM explained, respectively). In patients with severe initial hemiparesis, prediction of ΔFM by the combination of FMii and the putative fMRI recovery measure nonsignificantly increased predictive explanation from 16% to 47% of the total sum of squares of ΔFM explained. The implications of this preliminary negative result are discussed. PMID:21527788

  4. Prediction of Muscle Activities from Electrocorticograms in Primary Motor Cortex of Primates

    PubMed Central

    Kambara, Hiroyuki; Nambu, Atsushi; Isa, Tadashi; Nishimura, Yukio; Koike, Yasuharu

    2012-01-01

    Electrocorticography (ECoG) has drawn attention as an effective recording approach for brain-machine interfaces (BMI). Previous studies have succeeded in classifying movement intention and predicting hand trajectories from ECoG. Despite such successes, however, there still remains considerable work for the realization of ECoG-based BMIs as neuroprosthetics. We developed a method to predict multiple muscle activities from ECoG measurements. We also verified that ECoG signals are effective for predicting muscle activities in time varying series when performing sequential movements. ECoG signals were band-pass filtered into separate sensorimotor rhythm bands, z-score normalized, and smoothed with a Gaussian filter. We used sparse linear regression to find the best fit between frequency bands of ECoG and electromyographic activity. The best average correlation coefficient and the normalized root-mean-square error were 0.92±0.06 and 0.06±0.10, respectively, in the flexor digitorum profundus finger muscle. The δ (1.5∼4Hz) and γ2 (50∼90Hz) bands contributed significantly more strongly than other frequency bands (P<0.001). These results demonstrate the feasibility of predicting muscle activity from ECoG signals in an online fashion. PMID:23110153

  5. A Focused Fundamental Study of Predicting Materials Degradation & Fatigue. Volume 1

    DTIC Science & Technology

    1997-05-31

    viscosity of the lubricant can be predicted with the Einstein relationship for particulate suspensions once the concentration of sludge particles is...bearing balls while as-polished surfaces (Ra=0.08 gim) resulted in fatigue life determined by either the metal ball failing or test suspension at 100...mechanical-type wear process with the load (P), indenter geometry , elastic modulus (E), hardness (H), and fracture toughness (Kc) of the materials as the

  6. Presurgical fMRI and DTI for the Prediction of Perioperative Motor and Language Deficits in Primary or Metastatic Brain Lesions.

    PubMed

    Bailey, Paul D; Zacà, Domenico; Basha, Mahmud Mossa; Agarwal, Shruti; Gujar, Sachin K; Sair, Haris I; Eng, John; Pillai, Jay J

    2015-01-01

    To determine whether lesion to activation distance (LAD) on presurgical blood-oxygen-level-dependent functional magnetic resonance imaging (fMRI) and degree of white matter involvement by primary or metastatic brain lesions predict perioperative motor and language deficits. We retrospectively evaluated 76 patients with intra-axial brain lesions referred for presurgical fMRI and diffusion tensor imaging (DTI). We measured expressive, receptive, global language and motor LAD and assessed degree of involvement of the corticospinal tract (CST) and the superior longitudinal fasciculus (SLF). We performed a Wilcoxon rank-sum test to determine whether the LAD and the degree of CST/SLF involvement were statistically significantly different between patients with and without preoperative or postoperative neurological deficits. In preoperatively symptomatic patients, motor and expressive language LAD were significantly lower (z = -3.78, P = .0002, and z = -2.51, P = .01, respectively) than in asymptomatic patients. No significant difference was noted in LAD between postoperative symptomatic and asymptomatic patients, except for a trend level effect for motor LAD (P = .07). The degree of CST involvement was significantly different between symptomatic and asymptomatic patients (z = 3.40, P = .0007 and z = 2.97, P = .003, respectively, for pre- and postoperative motor deficits).The degree of SLF involvement was significantly different between preoperatively (but not postoperatively) symptomatic and asymptomatic patients (z = 2.85, P = .004). Presurgical motor and expressive language LAD as well as degree of tract involvement on DTI are predictive of preoperative but not postoperative deficits, except for CST DTI and (trend level) motor LAD; inability of language LAD to predict postoperative deficits suggests that preoperative fMRI is valuable to neurosurgeons in avoiding resection of eloquent cortex. Copyright © 2015 by the American Society of Neuroimaging.

  7. Neural Network of Predictive Motor Timing in the Context of Gender Differences

    PubMed Central

    Lošák, Jan; Kašpárek, Tomáš; Vaníček, Jiří; Bareš, Martin

    2016-01-01

    Time perception is an essential part of our everyday lives, in both the prospective and the retrospective domains. However, our knowledge of temporal processing is mainly limited to the networks responsible for comparing or maintaining specific intervals or frequencies. In the presented fMRI study, we sought to characterize the neural nodes engaged specifically in predictive temporal analysis, the estimation of the future position of an object with varying movement parameters, and the contingent neuroanatomical signature of differences in behavioral performance between genders. The established dominant cerebellar engagement offers novel evidence in favor of a pivotal role of this structure in predictive short-term timing, overshadowing the basal ganglia reported together with the frontal cortex as dominant in retrospective temporal processing in the subsecond spectrum. Furthermore, we discovered lower performance in this task and massively increased cerebellar activity in women compared to men, indicative of strategy differences between the genders. This promotes the view that predictive temporal computing utilizes comparable structures in the retrospective timing processes, but with a definite dominance of the cerebellum. PMID:27019753

  8. Neural Network of Predictive Motor Timing in the Context of Gender Differences.

    PubMed

    Filip, Pavel; Lošák, Jan; Kašpárek, Tomáš; Vaníček, Jiří; Bareš, Martin

    2016-01-01

    Time perception is an essential part of our everyday lives, in both the prospective and the retrospective domains. However, our knowledge of temporal processing is mainly limited to the networks responsible for comparing or maintaining specific intervals or frequencies. In the presented fMRI study, we sought to characterize the neural nodes engaged specifically in predictive temporal analysis, the estimation of the future position of an object with varying movement parameters, and the contingent neuroanatomical signature of differences in behavioral performance between genders. The established dominant cerebellar engagement offers novel evidence in favor of a pivotal role of this structure in predictive short-term timing, overshadowing the basal ganglia reported together with the frontal cortex as dominant in retrospective temporal processing in the subsecond spectrum. Furthermore, we discovered lower performance in this task and massively increased cerebellar activity in women compared to men, indicative of strategy differences between the genders. This promotes the view that predictive temporal computing utilizes comparable structures in the retrospective timing processes, but with a definite dominance of the cerebellum.

  9. EMG prediction from motor cortical recordings via a nonnegative point-process filter.

    PubMed

    Nazarpour, Kianoush; Ethier, Christian; Paninski, Liam; Rebesco, James M; Miall, R Chris; Miller, Lee E

    2012-07-01

    A constrained point-process filtering mechanism for prediction of electromyogram (EMG) signals from multichannel neural spike recordings is proposed here. Filters from the Kalman family are inherently suboptimal in dealing with non-Gaussian observations, or a state evolution that deviates from the Gaussianity assumption. To address these limitations, we modeled the non-Gaussian neural spike train observations by using a generalized linear model that encapsulates covariates of neural activity, including the neurons' own spiking history, concurrent ensemble activity, and extrinsic covariates (EMG signals). In order to predict the envelopes of EMGs, we reformulated the Kalman filter in an optimization framework and utilized a nonnegativity constraint. This structure characterizes the nonlinear correspondence between neural activity and EMG signals reasonably. The EMGs were recorded from 12 forearm and hand muscles of a behaving monkey during a grip-force task. In the case of limited training data, the constrained point-process filter improved the prediction accuracy when compared to a conventional Wiener cascade filter (a linear causal filter followed by a static nonlinearity) for different bin sizes and delays between input spikes and EMG output. For longer training datasets, results of the proposed filter and that of the Wiener cascade filter were comparable.

  10. Can Perceptuo-Motor Skills Assessment Outcomes in Young Table Tennis Players (7–11 years) Predict Future Competition Participation and Performance? An Observational Prospective Study

    PubMed Central

    2016-01-01

    Forecasting future performance in youth table tennis players based on current performance is complex due to, among other things, differences between youth players in growth, development, maturity, context and table tennis experience. Talent development programmes might benefit from an assessment of underlying perceptuo-motor skills for table tennis, which is hypothesized to determine the players’ potential concerning the perceptuo-motor domain. The Dutch perceptuo-motor skills assessment intends to measure the perceptuo-motor potential for table tennis in youth players by assessing the underlying skills crucial for developing technical and tactical qualities. Untrained perceptuo-motor tasks are used as these are suggested to represent a player’s future potential better than specific sport skills themselves as the latter depend on exposure to the sport itself. This study evaluated the value of the perceptuo-motor skills assessment for a talent developmental programme by evaluating its predictive validity for competition participation and performance in 48 young table tennis players (7–11 years). Players were tested on their perceptuo-motor skills once during a regional talent day, and the subsequent competition results were recorded half-yearly over a period of 2.5 years. Logistic regression analysis showed that test scores did not predict future competition participation (p >0.05). Yet, the Generalized Estimating Equations analysis, including the test items ‘aiming at target’, ‘throwing a ball’, and ‘eye-hand coordination’ in the best fitting model, revealed that the outcomes of the perceptuo-motor skills assessment were significant predictors for future competition results (R2 = 51%). Since the test age influences the perceptuo-motor skills assessment’s outcome, another multivariable model was proposed including test age as a covariate (R2 = 53%). This evaluation demonstrates promising prospects for the perceptuo-motor skills assessment to be

  11. Assessment of Various Flow Solvers Used to Predict the Thermal Environment inside Space Shuttle Solid Rocket Motor Joints

    NASA Technical Reports Server (NTRS)

    Wang, Qun-Zhen; Cash, Steve (Technical Monitor)

    2002-01-01

    It is very important to accurately predict the gas pressure, gas and solid temperature, as well as the amount of O-ring erosion inside the space shuttle Reusable Solid Rocket Motor (RSRM) joints in the event of a leak path. The scenarios considered are typically hot combustion gas rapid pressurization events of small volumes through narrow and restricted flow paths. The ideal method for this prediction is a transient three-dimensional computational fluid dynamics (CFD) simulation with a computational domain including both combustion gas and surrounding solid regions. However, this has not yet been demonstrated to be economical for this application due to the enormous amount of CPU time and memory resulting from the relatively long fill time as well as the large pressure and temperature rising rate. Consequently, all CFD applications in RSRM joints so far are steady-state simulations with solid regions being excluded from the computational domain by assuming either a constant wall temperature or no heat transfer between the hot combustion gas and cool solid walls.

  12. The use of artificial neural network (ANN) for the prediction and simulation of oil degradation in wastewater by AOP.

    PubMed

    Mustafa, Yasmen A; Jaid, Ghydaa M; Alwared, Abeer I; Ebrahim, Mothana

    2014-06-01

    The application of advanced oxidation process (AOP) in the treatment of wastewater contaminated with oil was investigated in this study. The AOP investigated is the homogeneous photo-Fenton (UV/H2O2/Fe(+2)) process. The reaction is influenced by the input concentration of hydrogen peroxide H2O2, amount of the iron catalyst Fe(+2), pH, temperature, irradiation time, and concentration of oil in the wastewater. The removal efficiency for the used system at the optimal operational parameters (H2O2 = 400 mg/L, Fe(+2) = 40 mg/L, pH = 3, irradiation time = 150 min, and temperature = 30 °C) for 1,000 mg/L oil load was found to be 72%. The study examined the implementation of artificial neural network (ANN) for the prediction and simulation of oil degradation in aqueous solution by photo-Fenton process. The multilayered feed-forward networks were trained by using a backpropagation algorithm; a three-layer network with 22 neurons in the hidden layer gave optimal results. The results show that the ANN model can predict the experimental results with high correlation coefficient (R (2) = 0.9949). The sensitivity analysis showed that all studied variables (H2O2, Fe(+2), pH, irradiation time, temperature, and oil concentration) have strong effect on the oil degradation. The pH was found to be the most influential parameter with relative importance of 20.6%.

  13. Improve Motor Operation at Off-Design Voltages - Motor Tip Sheet #9

    SciTech Connect

    2008-07-01

    Motors are designed to operate within +/- 10% of their nameplate rated voltages. When motors operate at conditions of over- or under-voltage, motor efficiency and other performance parameters are degraded.

  14. Do Cognitive Models Help in Predicting the Severity of Posttraumatic Stress Disorder, Phobia, and Depression after Motor Vehicle Accidents? A Prospective Longitudinal Study

    ERIC Educational Resources Information Center

    Ehring, Thomas; Ehlers, Anke; Glucksman, Edward

    2008-01-01

    The study investigated the power of theoretically derived cognitive variables to predict posttraumatic stress disorder (PTSD), travel phobia, and depression following injury in a motor vehicle accident (MVA). MVA survivors (N = 147) were assessed at the emergency department on the day of their accident and 2 weeks, 1 month, 3 months, and 6 months…

  15. Do Cognitive Models Help in Predicting the Severity of Posttraumatic Stress Disorder, Phobia, and Depression after Motor Vehicle Accidents? A Prospective Longitudinal Study

    ERIC Educational Resources Information Center

    Ehring, Thomas; Ehlers, Anke; Glucksman, Edward

    2008-01-01

    The study investigated the power of theoretically derived cognitive variables to predict posttraumatic stress disorder (PTSD), travel phobia, and depression following injury in a motor vehicle accident (MVA). MVA survivors (N = 147) were assessed at the emergency department on the day of their accident and 2 weeks, 1 month, 3 months, and 6 months…

  16. Validity of specific motor skills in predicting table-tennis performance in novice players.

    PubMed

    Toriola, Abel L; Toriola, Olutoyin M; Igbokwe, Nicholas U

    2004-04-01

    An experiment assessed whether novice table-tennis players' ball-balancing and bouncing skills could predict their performances after a semester of being coached. A pretest-posttest design was used to test this hypothesis with 82 male and 77 female physical education students who initially performed the skills and subsequently participated in a round-robin tournament. Moderate negative but significant (p<.01) Spearman rank-order correlation coefficients were obtained between some of the ball control skills scores and overall ranking in the table-tennis tournament.

  17. Fault diagnosis and fault-tolerant finite control set-model predictive control of a multiphase voltage-source inverter supplying BLDC motor.

    PubMed

    Salehifar, Mehdi; Moreno-Equilaz, Manuel

    2016-01-01

    Due to its fault tolerance, a multiphase brushless direct current (BLDC) motor can meet high reliability demand for application in electric vehicles. The voltage-source inverter (VSI) supplying the motor is subjected to open circuit faults. Therefore, it is necessary to design a fault-tolerant (FT) control algorithm with an embedded fault diagnosis (FD) block. In this paper, finite control set-model predictive control (FCS-MPC) is developed to implement the fault-tolerant control algorithm of a five-phase BLDC motor. The developed control method is fast, simple, and flexible. A FD method based on available information from the control block is proposed; this method is simple, robust to common transients in motor and able to localize multiple open circuit faults. The proposed FD and FT control algorithm are embedded in a five-phase BLDC motor drive. In order to validate the theory presented, simulation and experimental results are conducted on a five-phase two-level VSI supplying a five-phase BLDC motor.

  18. Environmental degradation and life time prediction of generator retaining rings subject to stress corrosion cracking

    SciTech Connect

    Speidel, M.O.; Magdowski, R.

    1995-12-31

    Retaining rings are among the most highly stressed components of generator rotors. There is a history of service failures of such retaining rings in both fossil fired and in nuclear power systems. The predominant failure mode is intergranular stress corrosion cracking. For a complete life time prediction it is necessary to know the effect of materials, stresses, and environments on nucleation, re-initiation, and growth of stress corrosion cracks. The present paper contributes information on the above topics. This includes time to failure measurements of stressed cylindrical tensile specimens in water and re-initiation measurements on components containing stress corrosion cracks which had been stopped by a more benign environment. Also included are fracture mechanics stress corrosion crack growth rate measurements in two different commercial retaining ring materials as a function of stress intensity. Conclusions are drawn with respect to materials choice, operating conditions, and inspection intervals.

  19. The Predictive Value of Motor-Evoked Potentials and the Silent Period on Patient Outcome after Acute Cerebral Infarction.

    PubMed

    Zhang, Xueqing; Ji, Wenzhen; Li, Lancui; Yu, Changshen; Wang, Wanjun; Liu, Shoufeng; Gao, Chunlin; Qiu, Lina; Tong, Xiaoguang; Wang, Jinhuan; Wu, Jialing

    2016-07-01

    The predictive value of neurophysiologic assessment on patients' outcome after acute cerebral infarction is poorly understood. The aim of this study was to investigate the prognostic value of motor-evoked potentials (MEPs) and the silent period (SP) on clinical outcome. A total of 202 patients with acute cerebral infarction were prospectively recruited. MEP and SP were recorded from the abductor pollicis brevis of the affected side within 10 days after stroke onset. Patient outcome was measured as the dependency rate. Cortical MEP was induced in 78 patients whereas it was absent in 82 patients. The initial NIHSS (National Institutes of Health Stroke Scale) score was significantly lower in patients with MEP than in those without MEP (P < .001). Regression analysis demonstrated that a left-sided lesion (OR = .391, 95% CI .178-.858, P = .019), NIHSS at admission (OR = .826, 95% CI .744-.917, P < .001), and presence of MEP (OR = 3.918, 95% CI 1.770-8.672, P < .001) were independent predictors of outcome 3 months after stroke. Among patients with MEP, only the contralateral cortical SP value was significantly shorter in the good outcome subgroup (t = 2.541, P = .013). Receiver operating characteristic curve analysis demonstrated that SP was able to predict patients at higher risk of unfavorable outcome 3 months after stroke onset (area under the curve .721, 95% CI .58-.86, P = .008). These data suggested that MEP and SP were useful tools to predict patients' acute outcomes following cerebral infarction. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  20. Time-varying coupling of EEG oscillations predicts excitability fluctuations in the primary motor cortex as reflected by motor evoked potentials amplitude: an EEG-TMS study.

    PubMed

    Ferreri, Florinda; Vecchio, Fabrizio; Ponzo, David; Pasqualetti, Patrizio; Rossini, Paolo Maria

    2014-05-01

    Motor evoked potentials (MEPs) elicited by a train of consecutive, individual transcranial magnetic stimuli demonstrate fluctuations in amplitude with respect to time when recorded from a relaxed muscle. The influence of time-varying, instantaneous modifications of the electroencephalography (EEG) properties immediately preceding the transcranial magnetic stimulation (TMS) has rarely been explored. The aim of this study was to investigate the influence of the pre-TMS motor cortex and related areas EEG profile on time variants of the MEPs amplitude. MRI-navigated TMS and multichannel TMS-compatible EEG devices were used. For each experimental subject, post-hoc analysis of the MEPs amplitude that was based on the 50th percentile of the MEPs amplitude distribution provided two subgroups corresponding to "high" (large amplitude) and "low" (small amplitude). The pre-stimulus EEG characteristics (coherence and spectral profile) from the motor cortex and related areas were analyzed separately for the "high" and "low" MEPs and were then compared. On the stimulated hemisphere, EEG coupling was observed more often in the high compared to the low MEP trials. Moreover, a paradigmatic pattern in which TMS was able to lead to significantly larger MEPs was found when the EEG of the stimulated motor cortex was coupled in the beta 2 band with the ipsilateral prefrontal cortex and in the delta band with the bilateral centro-parietal-occipital cortices. This data provide evidence for a statistically significant influence of time-varying and spatially patterned synchronization of EEG rhythms in determining cortical excitability, namely motor cortex excitability in response to TMS. Copyright © 2013 Wiley Periodicals, Inc.

  1. Designing Predictive Diagnose Method for Insulation Resistance Degradation of the Electrical Power Cables from Neutral Insulated Power Networks

    NASA Astrophysics Data System (ADS)

    Dobra, R.; Pasculescu, D.; Risteiu, M.; Buica, G.; Jevremović, V.

    2017-06-01

    This paper describe some possibilities to minimize voltages switching-off risks from the mining power networks, in case of insulated resistance faults by using a predictive diagnose method. The cables from the neutral insulated power networks (underground mining) are designed to provide a flexible electrical connection between portable or mobile equipment and a point of supply, including main feeder cable for continuous miners, pump cable, and power supply cable. An electronic protection for insulated resistance of mining power cables can be made using this predictive strategy. The main role of electronic relays for insulation resistance degradation of the electrical power cables, from neutral insulated power networks, is to provide a permanent measurement of the insulated resistance between phases and ground, in order to switch-off voltage when the resistance value is below a standard value. The automat system of protection is able to signalize the failure and the human operator will be early informed about the switch-off power and will have time to take proper measures to fix the failure. This logic for fast and automat switch-off voltage without aprioristic announcement is suitable for the electrical installations, realizing so a protection against fires and explosion. It is presented an algorithm and an anticipative relay for insulated resistance control from three-phase low voltage installations with insulated neutral connection.

  2. A tunnel study to validate motor vehicle emission prediction software in Australia

    NASA Astrophysics Data System (ADS)

    Smit, R.; Kingston, P.; Wainwright, D. H.; Tooker, R.

    2017-02-01

    A tunnel emissions study was conducted to (partially) validate the Australian vehicle emissions software COPERT Australia and PIARC emission factors. The in-tunnel fleet mix differs substantially from the average on-road fleet, leading to lower emissions by a factor of about 2. Simulation with the PΔP software found that in-tunnel air-flow compensates to a large extent for road gradient impacts on NOx emissions. PIARC emission factors are conservative and exhibit the largest prediction errors, except for one very good agreement for LDV NOx. COPERT Australia is generally accurate at fleet level for CO, NOx, PM2.5 and PM10, when compared with other international studies, and consistently underestimates emissions by 7%-37%, depending on the pollutant. Possible contributing factors are under-representation of high/excessive emitting vehicles, inaccurate mileage correction factors, and lack of empirical emissions data for Australian diesel cars. The study results demonstrate a large uncertainty in speciated VOC and PAH emission factors.

  3. Predicting where enhanced atrazine degradation will occur based on soil pH and herbicide use history

    USDA-ARS?s Scientific Manuscript database

    Soil bacteria on all continents except Antartica have developed the ability to rapidly degrade the herbicide atrazine, a phenomenon referred to as enhanced degradation. The agronomic significance of enhanced degradation is the potential for reduced residual weed control with atrazine in Corn, Sorgh...

  4. Oxidative Stress Measurement and Prediction of Epileptic Seizure in Children and Adults With Severe Motor and Intellectual Disabilities

    PubMed Central

    Morimoto, Masahito; Satomura, Shigeko; Hashimoto, Toshiaki; Ito, Etsuro; Kyotani, Shojiro

    2016-01-01

    Background The medical care of severe motor and intellectual disabilities (SMID) depends on the empirical medical care. Epileptic seizure specific to SMID is difficult to suppress using anti-epileptic drugs, and its tendency to persist for long periods poses an issue. The present study was undertaken to evaluate the relationship between epileptic seizure in cases with SMID and oxidative stress in the living body by examining endogenous antioxidants, the degree of oxidation (reactive oxygen metabolites (d-ROMs)), and the biological antioxidant potential (BAP) as indicators. Methods Target patients were 43 SMID epilepsy patients. Blood was sampled before breakfast and medication. As for the specimen, d-ROMs and BAP were measured using the free radical analyzer. Results The present study did not reveal any correlation between endogenous antioxidants (albumin) and the frequency of epileptic seizures. On the other hand, d-ROMs were correlated with the frequency of epileptic seizure. In particular, strong correlations between the frequency of epileptic seizures and the d-ROMs/BAP ratio as well as the BAP/d-ROMs ratio were noted. Conclusions These results indicate that the use of d-ROMs and BAP as biomarkers can provide a tool for predicting the prognosis of epileptic seizures in patients with SMID. PMID:27222671

  5. Emotions predictably modify response times in the initiation of human motor actions: A meta-analytic review.

    PubMed

    Beatty, Garrett F; Cranley, Nicole M; Carnaby, Giselle; Janelle, Christopher M

    2016-03-01

    Emotions motivate individuals to attain appetitive goals and avoid aversive consequences. Empirical investigations have detailed how broad approach and avoidance orientations are reflected in fundamental movement attributes such as the speed, accuracy, and variability of motor actions. Several theoretical perspectives propose explanations for how emotional states influence the speed with which goal directed movements are initiated. These perspectives include biological predisposition, muscle activation, distance regulation, cognitive evaluation, and evaluative response coding accounts. A comprehensive review of literature and meta-analysis were undertaken to quantify empirical support for these theoretical perspectives. The systematic review yielded 34 studies that contained 53 independent experiments producing 128 effect sizes used to evaluate the predictions of existing theories. The central tenets of the biological predisposition (Hedges' g = -0.356), distance regulation (g = -0.293; g = 0.243), and cognitive evaluation (g = -0.249; g = -0.405; g = -0.174) accounts were supported. Partial support was also identified for the evaluative response coding (g = -0.255) framework. Our findings provide quantitative evidence that substantiate existing theoretical perspectives, and provide potential direction for conceptual integration of these independent perspectives. Recommendations for future empirical work in this area are discussed.

  6. Complex multilocus effects of catechol-O-methyltransferase haplotypes predict pain and pain interference 6 weeks after motor vehicle collision

    PubMed Central

    Bortsov, Andrey V.; Diatchenko, Luda; McLean, Samuel A.

    2013-01-01

    Catechol-O-methyltransferase, encoded by COMT gene, is the primary enzyme that metabolizes catecholamines. COMT haplotypes have been associated with vulnerability to persistent non-traumatic pain. In this prospective observational study, we investigated the influence of COMT on persistent pain and pain interference with life functions after motor vehicle collision (MVC) in 859 European American adults for whom overall pain (0–10 numeric rating scale) and pain interference (Brief Pain Inventory) were assessed at week 6 after MVC. Ten single nucleotide polymorphisms (SNPs) spanning the COMT gene were successfully genotyped, nine were present in three haploblocks: block 1 (rs2020917, rs737865, rs1544325), block 2 (rs4633, rs4818, rs4680, rs165774) and block 3 (rs174697, rs165599). After adjustment for multiple comparisons, haplotype TCG from block 1 predicted decreased pain interference (p =.004). The pain-protective effect of the low pain sensitivity (LPS, CGGG) haplotype from block 2 was only observed if at least one TCG haplotype was present in block 1 (haplotype × haplotype interaction p=.002 and <.0001 for pain and pain interference, respectively). Haplotype AG from block 3 was associated with pain and interference in males only (sex × haplotype interaction p=.005 and .0005, respectively). These results suggest that genetic variants in the distal promoter are important contributors to the development of persistent pain after MVC, directly and via the interaction with haplotypes in the coding region of the gene. PMID:23963787

  7. Comparing the predictive value of multiple cognitive, affective, and motor tasks after rodent traumatic brain injury.

    PubMed

    Zhao, Zaorui; Loane, David J; Murray, Michael G; Stoica, Bogdan A; Faden, Alan I

    2012-10-10

    Controlled cortical impact injury (CCI) is a widely-used, clinically-relevant model of traumatic brain injury (TBI). Although functional outcomes have been used for years in this model, little work has been done to compare the predictive value of various cognitive and sensorimotor assessment tests, singly or in combination. Such information would be particularly useful for assessing mechanisms of injury or therapeutic interventions. Following isoflurane anesthesia, C57BL/6 mice were subjected to sham, mild (5.0 m/sec), moderate (6.0 m/sec), or severe (7.5 m/sec) CCI. A battery of behavioral tests were evaluated and compared, including the standard Morris water maze (sMWM), reversal Morris water maze (rMWM), novel object recognition (NOR), passive avoidance (PA), tail-suspension (TS), beam walk (BW), and open-field locomotor activity. The BW task, performed at post-injury days (PID) 0, 1, 3, 7, 14, 21, and 28, showed good discrimination as a function of injury severity. The sMWM and rMWM tests (PID 14-23), as well as NOR (PID 24 and 25), effectively discriminated spatial and novel object learning and memory across injury severity levels. Notably, the rMWM showed the greatest separation between mild and moderate/severe injury. PA (PID 27 and 28) and TS (PID 24) also reflected differences across injury levels, but to a lesser degree. We also compared individual functional measures with histological outcomes such as lesion volume and neuronal cell loss across anatomical regions. In addition, we created a novel composite behavioral score index from individual complementary behavioral scores, and it provided superior discrimination across injury severities compared to individual tests. In summary, this study demonstrates the feasibility of using a larger number of complementary functional outcome behavioral tests than those traditionally employed to follow post-traumatic recovery after TBI, and suggests that the composite score may be a helpful tool for screening

  8. Comparing the Predictive Value of Multiple Cognitive, Affective, and Motor Tasks after Rodent Traumatic Brain Injury

    PubMed Central

    Loane, David J.; Murray, Michael G.; Stoica, Bogdan A.; Faden, Alan I.

    2012-01-01

    Abstract Controlled cortical impact injury (CCI) is a widely-used, clinically-relevant model of traumatic brain injury (TBI). Although functional outcomes have been used for years in this model, little work has been done to compare the predictive value of various cognitive and sensorimotor assessment tests, singly or in combination. Such information would be particularly useful for assessing mechanisms of injury or therapeutic interventions. Following isoflurane anesthesia, C57BL/6 mice were subjected to sham, mild (5.0 m/sec), moderate (6.0 m/sec), or severe (7.5 m/sec) CCI. A battery of behavioral tests were evaluated and compared, including the standard Morris water maze (sMWM), reversal Morris water maze (rMWM), novel object recognition (NOR), passive avoidance (PA), tail-suspension (TS), beam walk (BW), and open-field locomotor activity. The BW task, performed at post-injury days (PID) 0, 1, 3, 7, 14, 21, and 28, showed good discrimination as a function of injury severity. The sMWM and rMWM tests (PID 14–23), as well as NOR (PID 24 and 25), effectively discriminated spatial and novel object learning and memory across injury severity levels. Notably, the rMWM showed the greatest separation between mild and moderate/severe injury. PA (PID 27 and 28) and TS (PID 24) also reflected differences across injury levels, but to a lesser degree. We also compared individual functional measures with histological outcomes such as lesion volume and neuronal cell loss across anatomical regions. In addition, we created a novel composite behavioral score index from individual complementary behavioral scores, and it provided superior discrimination across injury severities compared to individual tests. In summary, this study demonstrates the feasibility of using a larger number of complementary functional outcome behavioral tests than those traditionally employed to follow post-traumatic recovery after TBI, and suggests that the composite score may be a helpful tool for

  9. Comparative Sensitivity of Intraoperative Motor Evoked Potential Monitoring in Predicting Postoperative Neurologic Deficits: Nondegenerative versus Degenerative Myelopathy.

    PubMed

    Clark, Aaron J; Safaee, Michael; Chou, Dean; Weinstein, Philip R; Molinaro, Annette M; Clark, John P; Mummaneni, Praveen V

    2016-08-01

    Retrospective review. Intraoperative motor evoked potential (MEP) monitoring in spine surgery may assist surgeons in taking corrective measures to prevent neurologic deficits. The efficacy of monitoring MEPs intraoperatively in patients with myelopathy from nondegenerative causes has not been quantified. We compared the sensitivity and specificity of intraoperative MEP monitoring in patients with myelopathy caused by nondegenerative processes to patients with degenerative cervicothoracic spondylotic myelopathy (CSM). We retrospectively reviewed our myelopathy surgical cases during a 1-year period to identify patients with degenerative CSM and CSM of nondegenerative causes and collected data on intraoperative MEP changes and postoperative new deficits. Categorical variables were analyzed by Fisher exact test. Receiver operator curves assessed intraoperative MEP monitoring performance in the two groups. In all, 144 patients were identified: 102 had degenerative CSM and 42 had CSM of nondegenerative causes (24 extra-axial tumors, 12 infectious processes, 5 traumatic fractures, and 1 rheumatoid arthritis). For degenerative CSM, there were 11 intraoperative MEP alerts and 7 new deficits (p < 0.001). The corresponding sensitivity was 71% and the specificity was 94%. In the nondegenerative group, there were 11 intraoperative MEP alerts and 3 deficits, which was not significant (p > 0.99). The sensitivity (33%) and specificity (74%) were lower. Among patients with degenerative CSM, the model performed well for predicting postoperative deficits (area under the curve [AUC] 0.826), which appeared better than the nondegenerative group, although it did not reach statistical significance (AUC 0.538, p = 0.16). Based on this large retrospective analysis, intraoperative MEP monitoring in surgery for nondegenerative CSM cases appears to be less sensitive to cord injury and less predictive of postoperative deficits when compared with degenerative CSM cases.

  10. Comparative Sensitivity of Intraoperative Motor Evoked Potential Monitoring in Predicting Postoperative Neurologic Deficits: Nondegenerative versus Degenerative Myelopathy

    PubMed Central

    Clark, Aaron J.; Safaee, Michael; Chou, Dean; Weinstein, Philip R.; Molinaro, Annette M.; Clark, John P.; Mummaneni, Praveen V.

    2015-01-01

    Study Design  Retrospective review. Objective  Intraoperative motor evoked potential (MEP) monitoring in spine surgery may assist surgeons in taking corrective measures to prevent neurologic deficits. The efficacy of monitoring MEPs intraoperatively in patients with myelopathy from nondegenerative causes has not been quantified. We compared the sensitivity and specificity of intraoperative MEP monitoring in patients with myelopathy caused by nondegenerative processes to patients with degenerative cervicothoracic spondylotic myelopathy (CSM). Methods  We retrospectively reviewed our myelopathy surgical cases during a 1-year period to identify patients with degenerative CSM and CSM of nondegenerative causes and collected data on intraoperative MEP changes and postoperative new deficits. Categorical variables were analyzed by Fisher exact test. Receiver operator curves assessed intraoperative MEP monitoring performance in the two groups. Results  In all, 144 patients were identified: 102 had degenerative CSM and 42 had CSM of nondegenerative causes (24 extra-axial tumors, 12 infectious processes, 5 traumatic fractures, and 1 rheumatoid arthritis). For degenerative CSM, there were 11 intraoperative MEP alerts and 7 new deficits (p < 0.001). The corresponding sensitivity was 71% and the specificity was 94%. In the nondegenerative group, there were 11 intraoperative MEP alerts and 3 deficits, which was not significant (p > 0.99). The sensitivity (33%) and specificity (74%) were lower. Among patients with degenerative CSM, the model performed well for predicting postoperative deficits (area under the curve [AUC] 0.826), which appeared better than the nondegenerative group, although it did not reach statistical significance (AUC 0.538, p = 0.16). Conclusions  Based on this large retrospective analysis, intraoperative MEP monitoring in surgery for nondegenerative CSM cases appears to be less sensitive to cord injury and less predictive of postoperative

  11. Can motor nerve conduction velocity predict foot problems in diabetic subjects over a 6-year outcome period?

    PubMed

    Carrington, Anne L; Shaw, Jonathan E; Van Schie, Carine H M; Abbott, Caroline A; Vileikyte, Loretta; Boulton, Andrew J M

    2002-11-01

    This study examined motor nerve conduction velocity (MNCV) and other peripheral nerve and vascular tests as predictors for foot ulceration, amputation, and mortality in diabetes over a 6-year follow-up period. We recruited 169 diabetic subjects (without significant peripheral vascular disease with an ankle brachial pressure index [ABPI] >/=0.75) for the study and separated them into groups (to ensure diversity of nerve function). The control group consisted of 22 nondiabetic people. At baseline, all subjects underwent assessment of MNCV; vibration, pressure, and temperature perception thresholds; peripheral vascular function; and other diabetes assessments. Over the 6-year outcome period, 37.3% of the diabetic subjects developed at least one new ulcer, 11.2% had a lower-limb amputation (LLA) (minor or major), and 18.3% died. Using multivariate Cox's regression analysis (RR [95% CI] and removing previous ulcers as a confounding variable, MNCV was found to be the best predictor of new ulceration (0.90 [0.84-0.96], P = 0.001) and the best predictors of amputation were pressure perception threshold (PPT) (5.18 [1.96-13.68], P = 0.001) and medial arterial calcification (2.88 [1.13-7.35], P = 0.027). Creatinine (1.01 [1.00-1.01], P < 0.001), MNCV (0.84 [0.73-0.97], P = 0.016), and skin oxygen levels (14.32 [3.04-67.52], P = 0.001) were the best predictors of mortality. This study shows that MNCV, which is often assessed in clinical trials of neuropathy, can predict foot ulceration and death in diabetes. In addition, tests of PPT and medial arterial calcification can be used in the clinic to predict LLA in diabetic subjects.

  12. Using Acute Performance on a Comprehensive Neurocognitive, Vestibular, and Ocular Motor Assessment Battery to Predict Recovery Duration After Sport-Related Concussions.

    PubMed

    Sufrinko, Alicia M; Marchetti, Gregory F; Cohen, Paul E; Elbin, R J; Re, Valentina; Kontos, Anthony P

    2017-04-01

    A sport-related concussion (SRC) is a heterogeneous injury that requires a multifaceted and comprehensive approach for diagnosis and management, including symptom reports, vestibular/ocular motor assessments, and neurocognitive testing. To determine which acute (eg, within 7 days) vestibular, ocular motor, neurocognitive, and symptom impairments predict the duration of recovery after an SRC. Cohort study (prognosis); Level of evidence, 2. Sixty-nine patients with a mean age of 15.3 ± 1.9 years completed a neurocognitive, vestibular/ocular motor, and symptom assessment within 7 days of a diagnosed concussion. Patients were grouped by recovery time: ≤14 days (n = 27, 39.1%), 15-29 days (n = 25, 36.2%), and 30-90 days (n = 17, 24.6%). Multinomial regression was used to identify the best subset of predictors associated with prolonged recovery relative to ≤14 days. Acute visual motor speed and cognitive-migraine-fatigue symptoms were associated with an increased likelihood of recovery times of 30-90 days and 15-29 days relative to a recovery time of ≤14 days. A model with visual motor speed and cognitive-migraine-fatigue symptoms within the first 7 days of an SRC was 87% accurate at identifying patients with a recovery time of 30-90 days. The current study identified cognitive-migraine-fatigue symptoms and visual motor speed as the most robust predictors of protracted recovery after an SRC according to the Post-concussion Symptom Scale, Immediate Post-concussion Assessment and Cognitive Testing, and Vestibular/Ocular Motor Screening (VOMS). While VOMS components were sensitive in identifying a concussion, they were not robust predictors for recovery. Clinicians may consider particular patterns of performance on clinical measures when providing treatment recommendations and discussing anticipated recovery with patients.

  13. Machine learning for the prediction of L. chinensis carbon, nitrogen and phosphorus contents and understanding of mechanisms underlying grassland degradation.

    PubMed

    Li, Yuefen; Liang, Shuo; Zhao, Yiying; Li, Wenbo; Wang, Yuejiao

    2017-05-01

    The grasslands of Western Jilin Province in China have experienced severe degradation during the last 50 years. Radial basis function neural networks (RBFNN) and support vector machines (SVM) were used to predict the carbon, nitrogen, and phosphorus contents of Leymus chinensis (L. chinensis) and explore the degree of grassland degradation using the matter-element extension model. Both RBFNN and SVM demonstrated good prediction accuracy. The results indicated that there was severe degradation, as samples were mainly concentrated in the 3rd and 4th levels. The growth of L. chinensis was shown to be limited by either nitrogen, phosphorus, or both during different stages of degradation. The soil chemistry changed noticeably as degradation aggravated, which represents a destabilization of L. chinensis community homeostasis. Soil salinization aggravates soil nutrient loss and decreases the bioavailability of soil nutrients. This, along with the destabilization of C/N, C/P and N/P ratios, weakens the photosynthetic ability and productivity of L. chinensis. This conclusion was supported by observations that L. chinensis is gradually being replaced by a Chloris virgata, Puccinellia tenuiflora and Suaeda acuminate mixed community.

  14. An efficient method to predict and include Bragg curve degradation due to lung-equivalent materials in Monte Carlo codes by applying a density modulation

    NASA Astrophysics Data System (ADS)

    Baumann, Kilian-Simon; Witt, Matthias; Weber, Uli; Engenhart-Cabillic, Rita; Zink, Klemens

    2017-05-01

    Sub-millimetre-sized heterogeneities such as lung parenchyma cause Bragg peak degradation which can lead to an underdose of the tumor and an overdose of healthy tissue when not accounted for in treatment planning. Since commonly used treatment-planning CTs do not resolve the fine structure of lungs, this degradation can hardly be considered. We present a mathematical model capable of predicting and describing Bragg peak degradation due to a lung-equivalent geometry consisting of sub-millimetre voxels filled with either lung tissue or air. The material characteristic ‘modulation power’ is introduced to quantify the Bragg peak degradation. A strategy was developed to transfer the modulating effects of such fine structures to rougher structures such as 2 mm thick CT voxels, which is the resolution of typically used CTs. This is done by using the modulation power to derive a density distribution applicable to these voxels. By replacing the previously used sub-millimetre voxels by 2 mm thick voxels filled with lung tissue and modulating the lung tissue’s density in each voxel individually, we were able to reproduce the Bragg peak degradation. Hence a solution is found to include Bragg curve degradation due to lung-equivalent materials in Monte Carlo-based treatment-planning systems.

  15. Gamma synchrony predicts neuron-neuron correlations and correlations with motor behavior in extrastriate visual area MT.

    PubMed

    Lee, Joonyeol; Lisberger, Stephen G

    2013-12-11

    Correlated variability of neuronal responses is an important factor in estimating sensory parameters from a population response. Large correlations among neurons reduce the effective size of a neural population and increase the variation of the estimates. They also allow the activity of one neuron to be informative about impending perceptual decisions or motor actions on single trials. In extrastriate visual area MT of the rhesus macaque, for example, some but not all neurons show nonzero "choice probabilities" for perceptual decisions or non-zero "MT-pursuit" correlations between the trial-by-trial variations in neural activity and smooth pursuit eye movements. To understand the functional implications of zero versus nonzero correlations between neural responses and impending perceptions or actions, we took advantage of prior observations that specific frequencies of local field potentials reflect the correlated activity of neurons. We found that the strength of the spike-field coherence of a neuron in the gamma-band frequency range is related to the size of its MT-pursuit correlations for eye direction, as well as to the size of the neuron-neuron correlations. Spike-field coherence predicts MT-pursuit correlations better for direction than for speed, perhaps because the topographic organization of direction preference in MT is more amenable to creating meaningful local field potentials. We suggest that the relationship between spiking and local-field potentials is stronger for neurons that have larger correlations with their neighbors; larger neuron-neuron correlations create stronger MT-pursuit correlations. Neurons that lack strong correlations with their neighbors also have weaker correlations with pursuit behavior, but still could drive pursuit strongly.

  16. Gamma Synchrony Predicts Neuron–Neuron Correlations and Correlations with Motor Behavior in Extrastriate Visual Area MT

    PubMed Central

    Lisberger, Stephen G.

    2013-01-01

    Correlated variability of neuronal responses is an important factor in estimating sensory parameters from a population response. Large correlations among neurons reduce the effective size of a neural population and increase the variation of the estimates. They also allow the activity of one neuron to be informative about impending perceptual decisions or motor actions on single trials. In extrastriate visual area MT of the rhesus macaque, for example, some but not all neurons show nonzero “choice probabilities” for perceptual decisions or non-zero “MT–pursuit” correlations between the trial-by-trial variations in neural activity and smooth pursuit eye movements. To understand the functional implications of zero versus nonzero correlations between neural responses and impending perceptions or actions, we took advantage of prior observations that specific frequencies of local field potentials reflect the correlated activity of neurons. We found that the strength of the spike-field coherence of a neuron in the gamma-band frequency range is related to the size of its MT–pursuit correlations for eye direction, as well as to the size of the neuron–neuron correlations. Spike-field coherence predicts MT–pursuit correlations better for direction than for speed, perhaps because the topographic organization of direction preference in MT is more amenable to creating meaningful local field potentials. We suggest that the relationship between spiking and local-field potentials is stronger for neurons that have larger correlations with their neighbors; larger neuron–neuron correlations create stronger MT–pursuit correlations. Neurons that lack strong correlations with their neighbors also have weaker correlations with pursuit behavior, but still could drive pursuit strongly. PMID:24336731

  17. Multisensor fusion for induction motor aging analysis and fault diagnosis

    NASA Astrophysics Data System (ADS)

    Erbay, Ali Seyfettin

    Induction motors are the most commonly used electrical drives, ranging in power from fractional horsepower to several thousand horsepowers. Several studies have been conducted to identify the cause of failure of induction motors in industrial applications. Recent activities indicate a focus towards building intelligence into the motors, so that a continuous on-line fault diagnosis and prognosis may be performed. The purpose of this research and development was to perform aging studies of three-phase, squirrel-cage induction motors; establish a database of mechanical, electrical and thermal measurements from load testing of the motors; develop a sensor-fusion method for on-line motor diagnosis; and use the accelerated aging models to extrapolate to the normal aging regimes. A new laboratory was established at The University of Tennessee to meet the goals of the project. The accelerated aging and motor performance tests constitute a unique database, containing information about the trend characteristics of measured signatures as a function of motor faults. The various measurements facilitate enhanced fault diagnosis of motors and may be effectively utilized to increase the reliability of decision making and for the development of life prediction techniques. One of these signatures is the use of Multi-Resolution Analysis (MRA) using wavelets. Using MRA in trending different frequency bands has revealed that higher frequencies show a characteristic increase when the condition of a bearing is in question. This study effectively showed that the use of MRA in vibration signatures can identify a thermal degradation or degradation via electrical charge of the bearing, whereas other failure mechanisms, such as winding insulation failure, do not exhibit such characteristics. A motor diagnostic system, called the Intelligent Motor Monitoring System (IMMS) was developed in this research. The IMMS integrated the various mechanical, electrical and thermal signatures, and

  18. DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR PARTICULATE MATTER (MICROFACPM) FOR PREDICTING REAL-TIME MOTOR VEHICLE EMISSIONS

    EPA Science Inventory

    The United States Environmental Protection Agency's National Exposure Research Laboratory is pursuing a project to improve the methodology for modeling human exposure to motor vehicle emissions. The overall project is to develop improved methods for modeling the source through...

  19. DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR CO FOR PREDICTING REAL-TIME MOTOR VEHICLE EMISSIONS

    EPA Science Inventory

    The United States Environmental Protection Agency's (EPA) National Exposure Research Laboratory (NERL) has initiated a project to improve the methodology for modeling human exposure to motor vehicle emission. The overall project goal is to develop improved methods for modeling...

  20. DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR PARTICULATE MATTER (MICROFACPM) FOR PREDICTING REAL TIME MOTOR VEHICLE EMISSIONS

    EPA Science Inventory

    Health risk evaluation needs precise measurement and modeling of human exposures in microenvironments to support review of current air quality standards. The particulate matter emissions from motor vehicles are a major component of human exposures in urban microenvironments. Cu...

  1. DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR PARTICULATE MATTER (MICROFACPM) FOR PREDICTING REAL TIME MOTOR VEHICLE EMISSIONS

    EPA Science Inventory

    Health risk evaluation needs precise measurement and modeling of human exposures in microenvironments to support review of current air quality standards. The particulate matter emissions from motor vehicles are a major component of human exposures in urban microenvironments. Cu...

  2. DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR PARTICULATE MATTER (MICROFACPM) FOR PREDICTING REAL-TIME MOTOR VEHICLE EMISSIONS

    EPA Science Inventory

    The United States Environmental Protection Agency's National Exposure Research Laboratory has initiated a project to improve the methodology for modeling human exposure to motor vehicle emissions. The overall project goal is to develop improved methods for modeling the source t...

  3. DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR PARTICULATE MATTER (MICROFACPM) FOR PREDICTING REAL-TIME MOTOR VEHICLE EMISSIONS

    EPA Science Inventory

    The United States Environmental Protection Agency's National Exposure Research Laboratory is pursuing a project to improve the methodology for modeling human exposure to motor vehicle emissions. The overall project is to develop improved methods for modeling the source through...

  4. DEVELOPMENT OF A MICROSCALE EMISSION FACTOR MODEL FOR PARTICULATE MATTER (MICROFACPM) FOR PREDICTING REAL-TIME MOTOR VEHICLE EMISSIONS

    EPA Science Inventory

    The United States Environmental Protection Agency's National Exposure Research Laboratory has initiated a project to improve the methodology for modeling human exposure to motor vehicle emissions. The overall project goal is to develop improved methods for modeling the source t...

  5. Maternal Education Level Predicts Cognitive, Language, and Motor Outcome in Preterm Infants in the Second Year of Life.

    PubMed

    Patra, Kousiki; Greene, Michelle M; Patel, Aloka L; Meier, Paula

    2016-07-01

    Objective To evaluate the relative impact of maternal education level (MEL) on cognitive, language, and motor outcomes at 20 months' corrected age (CA) in preterm infants. Study Design A total of 177 preterm infants born between 2008 and 2010 were tested at 20 months' CA using the Bayley Scales of Infant and Toddler Development-III. Multiple regression analyses were done to determine the relative impact of MEL on cognitive, language, and motor scores. Results Infants born to mothers with high school MEL were 3.74 times more likely to have a subnormal motor index, while those born to mothers with some college and graduate school MEL had reduced odds (0.36 and 0.12, respectively) of having subnormal language index at 20 months. In linear regression, MEL was the strongest predictor of cognitive, language, and motor scores, and graduate school MEL was associated with increases in cognitive, motor, and language scores of 8.49, 8.23, and 15.74 points, respectively. Conclusions MEL is the most significant predictor of cognitive, language, and motor outcome at 20 months' CA in preterm infants. Further research is needed to evaluate if targeted interventions that focus on early childhood learning and parenting practices can ameliorate the impact of low MEL.

  6. Avoiding Complications in Abdominal Wall Surgery: A Mathematical Model to Predict the Course of the Motor Innervation of the Rectus Abdominis.

    PubMed

    Tessone, Ariel; Nava, Maurizio; Blondeel, Phillip; Spano, Andrea

    2016-02-01

    Ever since its introduction, the transverse rectus abdominis myocutaneous flap has become the mainstay of autologous breast reconstruction. However, concerns regarding donor site morbidity due to the breach of abdominal wall musculature integrity soon followed. Muscle-sparing techniques, eventually eliminating the muscle from the flap all-together with the deep inferior epigastric artery perforator flap, did not eliminate the problem of abdominal wall weakness. This led to the conclusion that motor innervation might be at fault. Studies have shown that even in the presence of an intact rectus abdominis muscle, and an intact anterior rectus sheath, denervation of the rectus abdominis muscle results in significant abdominal wall weakness leading to superior and inferior abdominal bulges, and abdominal herniation. Our aim was to establish a mathematical model to predict the location of the motor innervation to the rectus abdominis muscle, and thus provide surgeons with a tool that will allow them to reduce abdominal morbidity during deep inferior epigastric artery perforator and free muscle-sparing transverse rectus abdominis myocutaneous surgery. We dissected 42 cadaveric hemiabdomens and mapped the course of the thoracolumbar nerves. We then standardized and analyzed our findings and presented them as a relative map which can be adjusted to body type and dimensions. Our dissections show that the motor innervation is closely related to the lateral vascular supply. Thus, when possible, we support the preferred utilization of the medial vascular supply, and the preservation of the lateral supply and motor innervation.

  7. Advanced Motors

    SciTech Connect

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

    2012-12-14

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

  8. Predicting the effect of proteolysis on ruminal crude protein degradation of legume and grass silages using near-infrared reflectance spectroscopy.

    PubMed

    Hoffman, P C; Brehm, N M; Combs, D K; Bauman, L M; Peters, J B; Undersander, D J

    1999-04-01

    Two studies were conducted to assess whether routine applications of near infrared reflectance spectroscopy could predict the effects of silage proteolysis on ruminal crude protein (CP) degradation of legume and grass silages. A preliminary study was conducted to assess the effect of laboratory drying method on ruminal CP degradation of silages. Thirty legume and grass silages were freeze-, oven-, or microwave-dried and incubated in situ in the ventral rumen of three ruminally cannulated cows for 24 h. Freeze-drying was considered least likely to alter ruminal CP degradation of the silages; therefore, oven- and microwave-drying were compared using first-order regression with freeze-drying. Oven-drying for 48 h at 55 degrees C compared favorably (R2 = 0.84) with freeze-drying. Microwave-drying resulted in a large bias (2.84 g/10(-1) kg of CP) and was poorly related (R2 = 0.48) to freeze-drying. In a second study, alfalfa and timothy were cut at three maturities and allowed to wilt for 0, 10, 24, 32, 48, and 54 h. Forages were ensiled in triplicate cylindrical mini silos and allowed to ferment for 120 d. After fermentation, silages were oven-dried, ground, and scanned on a near-infrared reflectance spectrophotometer. Duplicate, dried, 2-mm ground silage samples were incubated in the ventral rumen of three ruminally cannulated cows for 24 h. Forage species, maturity, and wilting time significantly affected 24-h ruminal CP degradation of the silages. Near-infrared reflectance spectroscopy accurately predicted (R2 = 0.91) 24-h ruminal CP degradation of silages. Data suggest near-infrared reflectance spectroscopy can accurately assess the effects of forage species, maturity, and wilting time (proteolysis) on 24-h ruminal CP degradation of legume and grass silages.

  9. Determination of efficiencies, loss mechanisms, and performance degradation factors in chopper controlled dc vehical motors. Section 1: Test program results and recommendations

    NASA Technical Reports Server (NTRS)

    Hamilton, H. B.; Strangas, E.

    1980-01-01

    The conventional series motor model is discussed as well as procedures for obtaining, by test, the parameters necessary for calculating performance and losses. The calculated results for operation from ripple free DC are compared with observed test results, indicating approximately 5% or less error. Experimental data indicating the influence of brush shift and chopper frequency are also presented. Both factors have a significant effect on the speed and torque relationships. The losses and loss mechanisms present in a DC series motor are examined and an attempt is made to evaluate the added losses due to harmonic currents and fluxes. Findings with respect to these losses is summarized.

  10. Motor planning and performance in transitive and intransitive gesture execution and imagination: Does EEG (RP) activity predict hemodynamic (fNIRS) response?

    PubMed

    Balconi, Michela; Cortesi, Livia; Crivelli, Davide

    2017-05-01

    The interplay between neural structures and processes underlying motor planning and proper movement initiation and guidance is still a matter of debate. The present study aimed at investigating cortical correlates of motor planning and production when execution and imagery of real-life gestures are performed, with an additional focus on potential specificities of meaningful transitive/intransitive gestures. Electrophysiological (Readiness Potential - RP) and functional near-infrared spectroscopy (fNIRS) measures were analyzed to investigate the relationship between processes supporting action planning, execution and imagination. Participants were instructed to observe videos presenting various gestures and then to execute or to imagine them. We observed comparable RP before gesture execution and imagination, with a "facilitation effect" of transitive gestures in particular for imagination. Further, while the supplementary motor regions showed similar O2Hb profiles during both execution and imagination of transitive/intransitive gestures, premotor and posterior parietal areas showed specificities respectively for execution processes and transitive gesture execution. Finally, regression analyses showed that RP amplitude is a predictive factor of subsequent hemodynamic brain activity during action production. Such predictive role was modulated by both task and gesture type factors. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Prediction of torque and inductance displacement characteristics of asymmetrically slotted variable-reluctance motors using a simplified model for numerical field solution

    SciTech Connect

    Ertan, H.B.

    1999-09-01

    For prediction of static and dynamic performance of doubly-salient motors, it is essential to know their flux linkage-position-excitation characteristics and also the static torque characteristics. At the design stage determination of these characteristics presents difficulties because of highly nonlinear behavior of the magnetic circuit. It is possible to use numerical field solution of the complete motor to obtain this information. This, however, requires expertise on a professional program and may be expensive if used to search for the best design. This paper shows that a reduced model can be used to obtain the desired information accurately. It is also shown that in fact obtaining field solutions just for a pair of teeth is enough for accurately predicting the flux linkage and torque characteristics of a motor. The approach introduced here makes possible searching for an optimum design (even on a PC) for maximizing average torque or reducing noise and vibration problems, since the effort for producing the model and computation time are greatly reduced.

  12. Detection of pump degradation

    SciTech Connect

    Greene, R.H.; Casada, D.A.; Ayers, C.W.

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  13. Degradation kinetics of water-insoluble lauroyl-indapamide in aqueous solutions: prediction of the stabilities of the drug in liposomes.

    PubMed

    Suo, Xu Bin; Deng, Ying Jie; Zhang, Han; Wang, Yu Qiang

    2007-07-01

    The aim of this study was to explore the degradation kinetics of water-insoluble lauroyl-indapamide in solutions and predict the stabilities of lauroyl-indapamide encapsulated in liposomes. Buffer-acetone (9:1) was used as the reaction solution and the reaction temperature was maintained at 60 degrees C. The correlation of the apparent degradation constants (k(obs)) of lauroyl-indapamide in liposomes and in buffer-acetone solutions at different pH has been explored. The degradation of lauroyl-indapamide in solutions was found to follow pseudo-first-order kinetics and was significantly dependent on the pH values. Lauroyl-indapamide was the most stable at pH 6.8, increasing or decreasing the pH of the solutions would decrease its stabilities. Buffer concentration had some effects on the stabilities of lauroyl-indapamide. The degradation active energies Ea were 68.19 kJ x mol(-1), 131.75 kJ x mol(-1) and 107.72 kJ x mol(-1) at pH3.6, 6.8 and 12 respectively in acetone-free buffer solutions (0.05M) calculated according to the Arrhenius equation with the extrapolation method. The apparent degradation constants (kobs) of lauroyl-indapamide in liposome and in buffer-acetone (9:1) solutions showed a good correlation at different pH levels, which indicates that the stabilities of the drug that dissolved in acetone-buffer mixture solutions can be used to predict the stabilities of the drug in liposomes as well.

  14. Role of nutrients and illuminance in predicting the fate of fungal mediated petroleum hydrocarbon degradation and biomass production.

    PubMed

    Ali Khan, Aqib Hassan; Tanveer, Sundus; Anees, Mariam; Muhammad, Yousaf Shad; Iqbal, Mazhar; Yousaf, Sohail

    2016-07-01

    Biodegradation and biomass production are affected by numerous environmental factors including pH, oxygen availability and presence of pollutants. The present study, for the first time, elucidated the effects of nutrients and light on mycodegradation of petroleum hydrocarbons in diesel oil. Seven fungal strains (Aspergillus terreus FA3, Aspergillus niger FA5, Aspergillus terreus FA6, Penicillium chrysogenum FP4, Aspergillus terreus FP6, Aspergillus flavus FP10, and Candida sp. FG1) were used for hydrocarbon degradation under static conditions, in four combinations of nutrient media and illuminance for 45 days. Highest degradation was achieved by Aspergillus terreus FA6 and Candida sp. FG1 under both conditions of light and dark, with nutrient deprived HAF (Hydrocarbon adopted fungi) broth. Under HAF/Dark diesel oil degradation by FA6 and FG1 was 87.3% and 84.3% respectively, while under HAF/Light both FA6 and FG1 performed 84.3% biodegradation. The highest biomass was produced by Aspergillus flavus FP10 in PDB (Potato dextrose broth)/Dark (109.3 mg). Fungal degradation of petroleum hydrocarbons was negatively affected by the presence of other simpler-to-degrade carbon sources in the medium. The biomass production was enhanced by improved nutrient availability and diminished by illuminance.

  15. Determination of efficiencies, loss mechanisms, and performance degradation factors in chopper controlled dc vehical motors. Section 2: The time dependent finite element modeling of the electromagnetic field in electrical machines: Methods and applications. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Hamilton, H. B.; Strangas, E.

    1980-01-01

    The time dependent solution of the magnetic field is introduced as a method for accounting for the variation, in time, of the machine parameters in predicting and analyzing the performance of the electrical machines. The method of time dependent finite element was used in combination with an also time dependent construction of a grid for the air gap region. The Maxwell stress tensor was used to calculate the airgap torque from the magnetic vector potential distribution. Incremental inductances were defined and calculated as functions of time, depending on eddy currents and saturation. The currents in all the machine circuits were calculated in the time domain based on these inductances, which were continuously updated. The method was applied to a chopper controlled DC series motor used for electric vehicle drive, and to a salient pole sychronous motor with damper bars. Simulation results were compared to experimentally obtained ones.

  16. High-frequency repetitive transcranial magnetic stimulation over the hand area of the primary motor cortex disturbs predictive grip force scaling.

    PubMed

    Nowak, Dennis A; Voss, Martin; Huang, Ying-Zu; Wolpert, Daniel M; Rothwell, John C

    2005-11-01

    When we repetitively lift an object, our grip force is influenced by the mechanical object properties of the preceding lift, irrespective of whether the subsequent lift is performed with the same hand or the hand opposite to the preceding lift. This study investigates if repetitive high-frequency transcranial magnetic stimulation (rTMS) over the dominant primary motor cortex affects this relationship. After completion of 10 lifts of an object using the dominant hand, rTMS was applied over the dominant primary motor cortex for 20 s. On the first lift following rTMS, the peak grip force was significantly higher than on the lift preceding rTMS. Moreover, this measure remained elevated throughout the following set of lifts after rTMS. rTMS did not change the peak lift force generated by more proximal arm muscles. The same effect was observed when the lifts following rTMS over the dominant motor cortex were performed with the ipsilateral hand. These effects were not observed when subjects rested both hands on their lap or when a sham stimulation was applied for the same period of time. These preliminary data suggest that rTMS over the sensorimotor cortex disturbs predictive grip force planning.

  17. Predicting athletic performance with self-confidence and somatic and cognitive anxiety as a function of motor and physiological requirements in six sports.

    PubMed

    Taylor, J

    1987-03-01

    The purpose of the present study is to examine the ability of certain psychological attributes to predict performance in six National Collegiate Athletic Association Division I collegiate sports. Eighty-four athletes from the varsity sports teams of cross country running, alpine and nordic skiing, tennis, basketball, and track and field at the University of Colorado completed a questionnaire adapted from Martens (1977; Martens et al., 1983) that measured their trait levels of self-confidence (Bandura, 1977), somatic anxiety, and cognitive anxiety (Martens, 1977; Martens et al., 1983). In addition, at three to six competitions during the season, the members of the cross country running and tennis teams filled out a state measure (Martens et al., 1983) of the three attributes from one to two hours prior to the competition. Following each competition, subjective and objective ratings of performance were obtained, and, for all sports, coaches' ratings of performance and an overall seasonal team ranking were determined as seasonal performance measures. The sports were dichotomized along motor and physiological dimensions. Results indicate that all three psychological attributes were significant predictors of performance in both fine motor, anaerobic sports and gross motor, aerobic sports. Further, clear differences in these relationships emerged as a function of the dichotomization. In addition, unexpected sex differences emerged. The findings are discussed relative to prior research and their implications for future research.

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

    DOEpatents

    Haynes, Howard D.; Eissenberg, David M.

    1990-01-01

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

  19. Comparative investigation of vibration and current monitoring for prediction of mechanical and electrical faults in induction motor based on multiclass-support vector machine algorithms

    NASA Astrophysics Data System (ADS)

    Gangsar, Purushottam; Tiwari, Rajiv

    2017-09-01

    This paper presents an investigation of vibration and current monitoring for effective fault prediction in induction motor (IM) by using multiclass support vector machine (MSVM) algorithms. Failures of IM may occur due to propagation of a mechanical or electrical fault. Hence, for timely detection of these faults, the vibration as well as current signals was acquired after multiple experiments of varying speeds and external torques from an experimental test rig. Here, total ten different fault conditions that frequently encountered in IM (four mechanical fault, five electrical fault conditions and one no defect condition) have been considered. In the case of stator winding fault, and phase unbalance and single phasing fault, different level of severity were also considered for the prediction. In this study, the identification has been performed of the mechanical and electrical faults, individually and collectively. Fault predictions have been performed using vibration signal alone, current signal alone and vibration-current signal concurrently. The one-versus-one MSVM has been trained at various operating conditions of IM using the radial basis function (RBF) kernel and tested for same conditions, which gives the result in the form of percentage fault prediction. The prediction performance is investigated for the wide range of RBF kernel parameter, i.e. gamma, and selected the best result for one optimal value of gamma for each case. Fault predictions has been performed and investigated for the wide range of operational speeds of the IM as well as external torques on the IM.

  20. A New Type of Motor: Pneumatic Step Motor

    PubMed Central

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

    2011-01-01

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

  1. MOV motor and gearbox performance under design basis loads

    SciTech Connect

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

    1998-06-01

    This paper describes the results of valve testing sponsored by the US Nuclear Regulatory Commission, Office of Nuclear Regulatory Research and conducted at the Idaho National Engineering and Environmental Laboratory. The research objective was to evaluate the capabilities of specific actuator motor and gearbox assemblies under various design basis loading conditions. The testing was performed using the motor-operated valve load simulator, a test fixture that simulates the stem load profiles a valve actuator would experience when closing a valve against flow and pressure loadings. The authors tested five typical motors (four ac motors and one dc motor) with three gearbox assemblies at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. The authors also determined the efficiency of the actuator gearbox. The testing produced the following significant results: all five motors operated at or above their rated torque during tests at full voltage and ambient temperature; for all five motors (dc as well as ac), the actual torque loss due to voltage degradation was greater than the torque loss predicted using common methods; startup torques in locked rotor tests compared well with stall torques in dynamometer-type tests; the methods commonly used to predict torque losses due to elevated operating temperatures sometimes bounded the actual losses, but not in all cases; the greatest discrepancy involved the prediction for the dc motor; running efficiencies published by the manufacturer for actuator gearboxes were higher than the actual efficiencies determined from testing, in some instances, the published pullout efficiencies were also higher than the actual values; operation of the gearbox at elevated temperature did not affect the operating efficiency.

  2. How the credit assignment problems in motor control could be solved after the cerebellum predicts increases in error

    PubMed Central

    Verduzco-Flores, Sergio O.; O'Reilly, Randall C.

    2015-01-01

    We present a cerebellar architecture with two main characteristics. The first one is that complex spikes respond to increases in sensory errors. The second one is that cerebellar modules associate particular contexts where errors have increased in the past with corrective commands that stop the increase in error. We analyze our architecture formally and computationally for the case of reaching in a 3D environment. In the case of motor control, we show that there are synergies of this architecture with the Equilibrium-Point hypothesis, leading to novel ways to solve the motor error and distal learning problems. In particular, the presence of desired equilibrium lengths for muscles provides a way to know when the error is increasing, and which corrections to apply. In the context of Threshold Control Theory and Perceptual Control Theory we show how to extend our model so it implements anticipative corrections in cascade control systems that span from muscle contractions to cognitive operations. PMID:25852535

  3. Hydrothermal degradation of a 3Y-TZP translucent dental ceramic: A comparison of numerical predictions with experimental data after 2 years of aging.

    PubMed

    Cattani-Lorente, Maria; Durual, Stéphane; Amez-Droz, Michel; Wiskott, H W Anselm; Scherrer, Susanne S

    2016-03-01

    The purpose of the study was to assess the hydrothermal resistance of a translucent zirconia with two clinical relevant surface textures by means of accelerated tests (LTD) and to compare predicted monoclinic fractions with experimental values measured after two years aging at 37°C. Polished (P) and ground (G) specimens were subjected to hydrothermal degradation by exposure to water steam at different temperatures and pressures. The t-m phase transformation was quantified by grazing incidence X-ray diffraction (GIXDR). The elastic modulus and hardness before- and after LTD were determined by nanoindentation. G specimens presented a better resistance to hydrothermal degradation than P samples. Activation energies of 89 and 98kJ/mol and b coefficients of 2.0×10(-5) and 1.8×10(-6) were calculated for P and G samples respectively. The coefficients were subsequently used to predict transformed monoclinic fractions at 37°C. A good correlation was found between the predicted values and the experimental data obtained after aging at 37°C during 2 years. Hydrothermal degradation led to a significant decrease of the elastic moduli and hardness in both groups. The dependency of the t-m phase transformation rate on temperature must be determined to accurately predict the hydrothermal behavior of the zirconia ceramics at oral temperatures. The current prevailing assumption, that 5h aging at 134°C corresponds to 15-20 years at 37°C, will underestimate the transformed fraction of the translucent ceramic at 37°C. In this case, the mechanical surface treatment influences the ceramic's transformability. While mild grinding could potentially retard the hydrothermal transformation, polishing after occlusal adjustment is recommended to prevent wear of the antagonist teeth and maintain structural strength. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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

    PubMed

    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

  5. Top-down and bottom-up approaches to motor skill assessment of children: are child-report and parent-report perceptions predictive of children's performance-based assessment results?

    PubMed

    Kennedy, Johanna; Brown, Ted; Stagnitti, Karen

    2013-01-01

    BACKGROUND/ AIM: Therapists use different types of tests, scales, and instruments to assess children's motor skills, including those classified as being top-down and bottom-up. The aim of the study was to investigate the ability of measures of children's motor skill performance from the perspectives of children and parents (a type of top-down assessment) to predict children's performance-based motor ability test results (a type of bottom-up assessment). A convenience sample of 38 children and parents was recruited from Victoria, Australia. Motor skill performance was evaluated from a top-down perspective using the Physical Self-Description Questionnaire (PSDQ) and the Movement Assessment Battery for Children--Second Edition (MABC-2) Checklist to measure children's and parents' perspectives respectively. Motor skill performance was also evaluated from a bottom-up approach using the Bruininks-Oseretsky Test of Motor Proficiency--Second Edition (BOT-2). Data were analyzed using multiple linear regression analysis to determine whether the PSDQ or MABC-2 Checklist was predictive of the children's BOT-2 performance results. Two predictive relationships were identified based on parents' perspectives, where the total score of the MABC-2 Checklist was found to be a significant predictor of the BOT-2 Manual Coordination motor composite score, accounting for 8.35% of its variance, and the BOT-2 Strength and Agility motor composite score, accounting for 11.6% of its variance. No predictive relationships were identified between the children's self-report PSDQ perspectives and the BOT-2 performance scores. Therapists are encouraged to utilize a combination of top-down and bottom-up approaches and purposefully to seek parents' and children's perspectives when evaluating children's motor skill performance.

  6. Using Transcranial Magnetic Stimulation to Evaluate the Motor Pathways After an Intraoperative Spinal Cord Injury and to Predict the Recovery of Intraoperative Transcranial Electrical Motor Evoked Potentials: A Case Report.

    PubMed

    Grover, Helen J; Thornton, Rachel; Lutchman, Lennel N; Blake, Julian C

    2016-06-01

    The authors report a case of unilateral loss of intraoperative transcranial electrical motor evoked potentials (TES MEP) associated with a spinal cord injury during scoliosis correction and the subsequent use of extraoperative transcranial magnetic stimulation to monitor the recovery of spinal cord function. The authors demonstrate the absence of TES MEPs and absent transcranial magnetic stimulation responses in the immediate postoperative period, and document the partial recovery of transcranial magnetic stimulation responses, which corresponded to partial recovery of TES MEPs. Intraoperative TES MEPs were enhanced using spatial facilitation technique, which enabled the patient to undergo further surgery to stabilize the spine and correct her scoliosis. This case report supports evidence of the use of extraoperative transcranial magnetic stimulation to predict the presence of intraoperative TES responses and demonstrates the usefulness of spatial facilitation to monitor TES MEPs in a patient with a preexisting spinal cord injury.

  7. Can an early perceptuo-motor skills assessment predict future performance in youth table tennis players? An observational study (1998-2013).

    PubMed

    Faber, Irene R; Elferink-Gemser, Marije T; Oosterveld, Frits G J; Twisk, Jos W R; Nijhuis-Van der Sanden, Maria W G

    2017-03-01

    This study intended to investigate the capability of the 4 test items "sprint", "agility", "speed while dribbling" and "throwing a ball" of the Dutch perceptuo-motor skills assessment used at the age of 7-10 years to predict table tennis performance (U13, U15 and U18) in an observational study. Data of 1191 young table tennis players, collected from 1998 to 2013, were analysed in univariable and multivariable logistic and linear regression models. The test items "sprint" and "throwing a ball" showed to be significant predictors for table tennis performance outcomes in boys (P < 0.05). For girls, besides these test items also "speed while dribbling" had a significant contribution (P < 0.05). Since the accuracies of the models were low, it is advised to include other determinants to enhance the predictive value of a model for table tennis performance. Nevertheless, it can be concluded that a perceptuo-motor skills assessment might improve the effectiveness of talent programmes in table tennis as an additional method to objectively estimate a youth players' potential. Future research focusing on the inclusion of test items specifically assessing eye hand coordination and other domains, for example, the psychological and the environmental domain, related to table tennis performance are recommended.

  8. In extremely preterm infants, do the Movement Assessment of Infants and the Alberta Infant Motor Scale predict 18-month outcomes using the Bayley-III?

    PubMed

    Lefebvre, Francine; Gagnon, Marie-Michèle; Luu, Thuy Mai; Lupien, Geneviève; Dorval, Véronique

    2016-03-01

    Extremely preterm infants are at high-risk for neurodevelopmental disabilities. The Movement Assessment of Infants (MAI) and the Alberta Infant Motor Scale (AIMS) have been designed to predict outcome with modest accuracy with the Bayley-I or Bayley-II. To examine and compare the predictive validity of the MAI and AIMS in determining neurodevelopmental outcome with the Bayley-III. Retrospective cohort study of 160 infants born at ≤ 28 weeks gestation. At their corrected age, infants underwent the MAI at 4 months, the AIMS at 4 and 10-12 months, and the Bayley-III and neurological examination at 18 months. Sensitivity and specificity were calculated. Infants had a mean gestation of 26.3 ± 1.4 weeks and birth weight of 906 ± 207 g. A high-risk score (≥ 14) for adverse outcome was obtained by 57% of infants on the MAI. On the AIMS, a high-risk score (<5th percentile) was obtained by 56% at 4 months and 30% at 10-12 months. At 18 months, infants with low-risk scores on either the MAI or AIMS had higher cognitive, language, and motor Bayley-III scores than those with high-risk scores. They were less likely to have severe neurodevelopmental impairment. To predict Bayley-III scores <70, sensitivity and specificity were 91% and 49%, respectively, for the MAI and 78% and 48%, respectively, for the AIMS. Extremely preterm infants with low-risk MAI at 4 months or AIMS scores at 4 or 10-12 months had better outcomes than those with high-risk scores. However, both tests lack specificity to predict individual neurodevelopmental status at 18 months. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. The Influence of MgH2 on the Assessment of Electrochemical Data to Predict the Degradation Rate of Mg and Mg Alloys

    PubMed Central

    Mueller, Wolf-Dieter; Hornberger, Helga

    2014-01-01

    Mg and Mg alloys are becoming more and more of interest for several applications. In the case of biomaterial applications, a special interest exists due to the fact that a predictable degradation should be given. Various investigations were made to characterize and predict the corrosion behavior in vitro and in vivo. Mostly, the simple oxidation of Mg to Mg2+ ions connected with adequate hydrogen development is assumed, and the negative difference effect (NDE) is attributed to various mechanisms and electrochemical results. The aim of this paper is to compare the different views on the corrosion pathway of Mg or Mg alloys and to present a neglected pathway based on thermodynamic data as a guideline for possible reactions combined with experimental observations of a delay of visible hydrogen evolution during cyclic voltammetry. Various reaction pathways are considered and discussed to explain these results, like the stability of the Mg+ intermediate state, the stability of MgH2 and the role of hydrogen overpotential. Finally, the impact of MgH2 formation is shown as an appropriate base for the prediction of the degradation behavior and calculation of the corrosion rate of Mg and Mg alloys. PMID:24972140

  10. Prospective errors determine motor learning

    PubMed Central

    Takiyama, Ken; Hirashima, Masaya; Nozaki, Daichi

    2015-01-01

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

  11. Electric motor analysis at Dofasco

    SciTech Connect

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

    1997-03-01

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

  12. Prediction of CL-20 chemical degradation pathways, theoretical and experimental evidence for dependence on competing modes of reaction

    SciTech Connect

    Qasim, Mohammad M.; Fredrickson, Herbert L.; Honea, P.; Furey, John; Leszczynski, Jerzy; Okovytyy, S.; Szecsody, Jim E.; Kholod, Y.

    2005-10-01

    Highest occupied and lowest unoccupied molecular orbital energies, formation energies, bond lengths and FTIR spectra all suggest competing CL-20 degradation mechanisms. This second of two studies investigates recalcitrant, toxic, aromatic CL-20 intermediates that absorb from 370 to 430 nm. Our earlier study (Struct. Chem., 15, 2004) revealed that these intermediates were formed at high OH- concentrations via the chemically preferred pathway of breaking the C-C bond between the two cyclopentanes, thereby eliminating nitro groups, forming conjugated π bonds, and resulting in a pyrazine three-ring aromatic intermediate. In attempting to find and make dominant a more benign CL-20 transformation pathway, this current research validates hydroxylation results from both studies and examines CL-20 transformations via photo-induced free radical reactions. This article discusses CL-20 competing modes of degradation revealed through: computational calculation; UV/VIS and SF spectroscopy following alkaline hydrolysis; and photochemical irradiation to degrade CL-20 and its byproducts at their respective wavelengths of maximum absorption.

  13. The impact-acceleration model of head injury: injury severity predicts motor and cognitive performance after trauma.

    PubMed

    Beaumont, A; Marmarou, A; Czigner, A; Yamamoto, M; Demetriadou, K; Shirotani, T; Marmarou, C; Dunbar, J

    1999-12-01

    This study examines neuropsychological dysfunction after varying severities of the Impact Acceleration Model of diffuse traumatic brain injury. Adult rats (340 g-400 g) were divided into five groups, and exposed to varying degrees of Impact Acceleration Injury (1 m, 2 m, 2.1 m/500 g and second insult). After injury, animals were allowed to recover; acute neurological reflexes, beam walk score, beam balance score, inclined plane score, and Morris Water Maze score were then assessed at multiple time points. Injury of all severities caused significant motor and cognitive deficits. With milder injuries these effects were transient; however, with more severe injuries no recovery in function was seen. The addition of hypoxia and hypotension made a moderate injury worse than a severe injury. The acute neurological reflexes, the beam balance test and the inclined plane test distinguished between the more severely injured groups, but were affected less by mild injury. The beam walk test was sensitive to mild injury, but appeared unable to distinguish between the severe groups. The Morris Water Maze was sensitive for all injury groups, but appeared to adopt a different response profile with secondary insult. This study has for the first time characterized the degree of motor and cognitive deficits in rodents exposed to differing severities of Impact Acceleration Injury. These data confirm that the tests considered, and the Injury Model used, provide a useful system for the consideration of potential therapies which might ameliorate neuropsychological deficits in diffuse brain injury.

  14. Do Cognitive Models Help in Predicting the Severity of Posttraumatic Stress Disorder, Phobia, and Depression After Motor Vehicle Accidents? A Prospective Longitudinal Study

    PubMed Central

    Ehring, Thomas; Ehlers, Anke; Glucksman, Edward

    2008-01-01

    The study investigated the power of theoretically derived cognitive variables to predict posttraumatic stress disorder (PTSD), travel phobia, and depression following injury in a motor vehicle accident (MVA). MVA survivors (N = 147) were assessed at the emergency department on the day of their accident and 2 weeks, 1 month, 3 months, and 6 months later. Diagnoses were established with the Structured Clinical Interview for DSM–IV. Predictors included initial symptom severities; variables established as predictors of PTSD in E. J. Ozer, S. R. Best, T. L. Lipsey, and D. S. Weiss's (2003) meta-analysis; and variables derived from cognitive models of PTSD, phobia, and depression. Results of nonparametric multiple regression analyses showed that the cognitive variables predicted subsequent PTSD and depression severities over and above what could be predicted from initial symptom levels. They also showed greater predictive power than the established predictors, although the latter showed similar effect sizes as in the meta-analysis. In addition, the predictors derived from cognitive models of PTSD and depression were disorder-specific. The results support the role of cognitive factors in the maintenance of emotional disorders following trauma. PMID:18377119

  15. Do cognitive models help in predicting the severity of posttraumatic stress disorder, phobia, and depression after motor vehicle accidents? A prospective longitudinal study.

    PubMed

    Ehring, Thomas; Ehlers, Anke; Glucksman, Edward

    2008-04-01

    The study investigated the power of theoretically derived cognitive variables to predict posttraumatic stress disorder (PTSD), travel phobia, and depression following injury in a motor vehicle accident (MVA). MVA survivors (N = 147) were assessed at the emergency department on the day of their accident and 2 weeks, 1 month, 3 months, and 6 months later. Diagnoses were established with the Structured Clinical Interview for DSM-IV. Predictors included initial symptom severities; variables established as predictors of PTSD in E. J. Ozer, S. R. Best, T. L. Lipsey, and D. S. Weiss's (2003) meta-analysis; and variables derived from cognitive models of PTSD, phobia, and depression. Results of nonparametric multiple regression analyses showed that the cognitive variables predicted subsequent PTSD and depression severities over and above what could be predicted from initial symptom levels. They also showed greater predictive power than the established predictors, although the latter showed similar effect sizes as in the meta-analysis. In addition, the predictors derived from cognitive models of PTSD and depression were disorder-specific. The results support the role of cognitive factors in the maintenance of emotional disorders following trauma.

  16. Intermittently-visual Tracking Experiments Reveal the Roles of Error-correction and Predictive Mechanisms in the Human Visual-motor Control System

    NASA Astrophysics Data System (ADS)

    Hayashi, Yoshikatsu; Tamura, Yurie; Sase, Kazuya; Sugawara, Ken; Sawada, Yasuji

    Prediction mechanism is necessary for human visual motion to compensate a delay of sensory-motor system. In a previous study, “proactive control” was discussed as one example of predictive function of human beings, in which motion of hands preceded the virtual moving target in visual tracking experiments. To study the roles of the positional-error correction mechanism and the prediction mechanism, we carried out an intermittently-visual tracking experiment where a circular orbit is segmented into the target-visible regions and the target-invisible regions. Main results found in this research were following. A rhythmic component appeared in the tracer velocity when the target velocity was relatively high. The period of the rhythm in the brain obtained from environmental stimuli is shortened more than 10%. The shortening of the period of rhythm in the brain accelerates the hand motion as soon as the visual information is cut-off, and causes the precedence of hand motion to the target motion. Although the precedence of the hand in the blind region is reset by the environmental information when the target enters the visible region, the hand motion precedes the target in average when the predictive mechanism dominates the error-corrective mechanism.

  17. Polymer damage mitigation---predictive lifetime models of polymer insulation degradation and biorenewable thermosets through cationic polymerization for self-healing applications

    NASA Astrophysics Data System (ADS)

    Hondred, Peter Raymond

    Over the past 50 years, the industrial development and applications for polymers and polymer composites has become expansive. However, as with any young technology, the techniques for predicting material damage and resolving material failure are in need of continued development and refinement. This thesis work takes two approaches to polymer damage mitigation---material lifetime prediction and spontaneous damage repair through self-healing while incorporating bio-renewable feedstock. First, material lifetime prediction offers the benefit of identifying and isolating material failures before the effects of damage results in catastrophic failure. Second, self-healing provides a systematic approach to repairing damaged polymer composites, specifically in applications where a hands-on approach or removing the part from service are not feasible. With regard to lifetime prediction, we investigated three specific polymeric materials---polytetrafluoroethylene (PTFE), poly(ethylene-alt-tetrafluoroethylene) (ETFE), and Kapton. All three have been utilized extensively in the aerospace field as a wire insulation coating. Because of the vast amount of electrical wiring used in aerospace constructions and the potential for electrical and thermal failure, this work develops mathematical models for both the thermal degradation kinetics as well as a lifetime prediction model for electrothermal breakdown. Isoconversional kinetic methods, which plot activation energy as a function of the extent of degradation, present insight into the development each kinetic model. The models for PTFE, ETFE, and Kapton are one step, consecutive three-step, and competitive and consecutive five-step respectively. Statistical analysis shows that an nth order autocatalytic reaction best defined the reaction kinetics for each polymer's degradation. Self-healing polymers arrest crack propagation through the use of an imbedded adhesive that reacts when cracks form. This form of damage mitigation focuses on

  18. Development of Predictive Models for the Degradation of Halogenated Disinfection Byproducts during the UV/H2O2 Advanced Oxidation Process.

    PubMed

    Chuang, Yi-Hsueh; Parker, Kimberly M; Mitch, William A

    2016-10-18

    Previous research has demonstrated that the reverse osmosis and advanced oxidation processes (AOPs) used to purify municipal wastewater to potable quality have difficulty removing low molecular weight halogenated disinfection byproducts (DBPs) and industrial chemicals. Because of the wide range of chemical characteristics of these DBPs, this study developed methods to predict their degradation within the UV/H2O2 AOP via UV direct photolysis and hydroxyl radical ((•)OH) reaction, so that DBPs most likely to pass through the AOP could be predicted. Among 26 trihalomethanes, haloacetonitriles, haloacetaldehydes, halonitromethanes and haloacetamides, direct photolysis rate constants (254 nm) varied by ∼3 orders of magnitude, with rate constants increasing with Br and I substitution. Quantum yields varied little (0.12-0.59 mol/Einstein), such that rate constants were driven by the orders of magnitude variation in molar extinction coefficients. Quantum chemical calculations indicated a strong correlation between molar extinction coefficients and decreasing energy gaps between the highest occupied and lowest unoccupied orbitals (i.e., ELUMO-EHOMO). Rate constants for 37 trihalomethanes, haloacetonitriles, haloacetaldehydes, halonitromethanes, haloacetamides, and haloacetic acids with (•)OH measured by gamma radiolysis spanned 4 orders of magnitude. Based on these rate constants, a quantitative structure-reactivity relationship model (Group Contribution Method) was developed which predicted (•)OH rate constants for 5 additional halogenated compounds within a factor of 2. A kinetics model combining the molar extinction coefficients, quantum yields and (•)OH rate constants predicted experimental DBP loss in a lab-scale UV/H2O2 AOP well. Highlighting the difficulty associated with degrading these DBPs, at the 500-1000 mJ/cm(2) UV fluence applied in potable reuse trains, 50% removal would be achieved generally only for compounds with several -Br or -I substituents

  19. Development of Multiscale Materials Modeling Techniques and Coarse- Graining Strategies for Predicting Materials Degradation in Extreme Irradiation Environments

    SciTech Connect

    Wirth, Brian

    2016-01-12

    Exposure of metallic structural materials to irradiation environments results in significant microstructural evolution, property changes and performance degradation, which limits the extended operation of current generation light water reactors and restricts the design of advanced fission and fusion reactors [1-8]. This effect of irradiation on materials microstructure and properties is a classic example of an inherently multiscale phenomenon, as schematically illustrated in Figure 1a. Pertinent processes range from the atomic nucleus to structural component length scales, spanning more than 15 orders of magnitude. Time scales bridge more than 22 orders of magnitude, with the shortest being less than a femtosecond [1,8]. Further, the mix of radiation-induced features formed and the corresponding property degradation depend on a wide range of material and irradiation variables. This emphasizes the importance of closely integrating models with high-resolution experimental characterization of the evolving radiation- damaged microstructure, including measurements performed in-situ during irradiation. In this article, we review some recent successes through the use of closely coordinated modeling and experimental studies of the defect cluster evolution in irradiated body-centered cubic materials, followed by a discussion of outstanding challenges still to be addressed, which are necessary for the development of comprehensive models of radiation effects in structural materials.

  20. Prediction of naphthenic acid species degradation by kinetic and surrogate models during the ozonation of oil sands process-affected water.

    PubMed

    Islam, Md Shahinoor; Moreira, Jesús; Chelme-Ayala, Pamela; Gamal El-Din, Mohamed

    2014-09-15

    Oil sands process-affected water (OSPW) is a complex mixture of organic and inorganic contaminants, and suspended solids, generated by the oil sands industry during the bitumen extraction process. OSPW contains a large number of structurally diverse organic compounds, and due to variability of the water quality of different OSPW matrices, there is a need to select a group of easily measured surrogate parameters for monitoring and treatment process control. In this study, kinetic and surrogate correlation models were developed to predict the degradation of naphthenic acids (NAs) species during the ozonation of OSPW. Additionally, the speciation and distribution of classical and oxidized NA species in raw and ozonated OSPW were also examined. The structure-reactivity of NA species indicated that the reactivity of individual NA species increased as the carbon and hydrogen deficiency numbers increased. The kinetic parameters obtained in this study allowed calculating the evolution of the concentrations of the acid-extractable fraction (AEF), chemical oxygen demand (COD), and NA distributions for a given ozonation process. High correlations between the AEF and COD and NA species were found, suggesting that AEF and COD can be used as surrogate parameters to predict the degradation of NAs during the ozonation of OSPW. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Evaluation of the National Research Council (2001) dairy model and derivation of new prediction equations. 2. Rumen degradable and undegradable protein.

    PubMed

    White, R R; Roman-Garcia, Y; Firkins, J L; Kononoff, P; VandeHaar, M J; Tran, H; McGill, T; Garnett, R; Hanigan, M D

    2017-05-01

    This work evaluated the National Research Council (NRC) dairy model (2001) predictions of rumen undegradable (RUP) and degradable (RDP) protein compared with measured postruminal non-ammonia, nonmicrobial (NANMN) and microbial N flows. Models were evaluated using the root mean squared prediction error (RMSPE) as a percent of the observed mean, mean and slope biases as percentages of mean squared prediction error (MSPE), and concordance correlation coefficient (CCC). The NRC (2001) over-estimated NANMN by 18% and under-estimated microbial N by 14%. Both responses had large mean biases (19% and 20% of MSPE, respectively), and NANMN had a slope bias (22% of MSPE). The NRC NANMN estimate had high RMSPE (46% of observed mean) and low CCC (0.37); updating feed library A, B, and C protein fractions and degradation rate (Kd) estimates with newer literature only marginally improved fit. The re-fit NRC models for NANMN and microbial N had CCC of 0.89 and 0.94, respectively. When compared with a prediction of NANMN as a static mean fraction of N intake, the re-derived NRC approach did not have improved fit. A protein system of intermediate complexity was derived in an attempt to estimate NANMN with improved fit compared with the static mean NANMN model. In this system, postruminal appearance of A, B, and C protein fractions were predicted in a feed-type specific manner rather than from estimated passage and degradation rates. In a comparison to independent data achieved through cross-validation, the new protein system improved RMSPE (34 vs. 36% of observed mean) and CCC (0.42 vs. 0.30) compared with the static mean NANMN model. When the NRC microbial N equation was re-derived, the RDP term dropped from the model. Consequently, 2 new microbial protein equations were formulated, both used a saturating (increasing at a decreasing rate) form: one saturated with respect to TDN and the other saturated over increasing intakes of rumen degraded starch and NDF. Both equations

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

    PubMed Central

    Bonfiglio, Luca; Minichilli, Fabrizio; Cantore, Nicoletta; Carboncini, Maria Chiara; Piccotti, Emily; Rossi, Bruno

    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

  3. Anatomic Location of Tumor Predicts the Accuracy of Motor Function Localization in Diffuse Lower-Grade Gliomas Involving the Hand Knob Area.

    PubMed

    Fang, S; Liang, J; Qian, T; Wang, Y; Liu, X; Fan, X; Li, S; Wang, Y; Jiang, T

    2017-08-24

    The accuracy of preoperative blood oxygen level-dependent fMRI remains controversial. This study assessed the association between the anatomic location of a tumor and the accuracy of fMRI-based motor function mapping in diffuse lower-grade gliomas. Thirty-five patients with lower-grade gliomas involving motor areas underwent preoperative blood oxygen level-dependent fMRI scans with grasping tasks and received intraoperative direct cortical stimulation. Patients were classified into an overlapping group and a nonoverlapping group, depending on the extent to which blood oxygen level-dependent fMRI and direct cortical stimulation results concurred. Tumor location was quantitatively measured, including the shortest distance from the tumor to the hand knob and the deviation distance of the midpoint of the hand knob in the lesion hemisphere relative to the midline compared with the normal contralateral hemisphere. A 4-mm shortest distance from the tumor to the hand knob value was identified as optimal for differentiating the overlapping and nonoverlapping group with the receiver operating characteristic curve (sensitivity, 84.6%; specificity, 77.8%). The shortest distances from the tumor to the hand knob of ≤4 mm were associated with inaccurate fMRI-based localizations of the hand motor cortex. The shortest distances from the tumor to the hand knob were larger (P = .002), and the deviation distances for the midpoint of the hand knob in the lesion hemisphere were smaller (P = .003) in the overlapping group than in the nonoverlapping group. This study suggests that the shortest distance from the tumor to the hand knob and the deviation distance for the midpoint of the hand knob on the lesion hemisphere are predictive of the accuracy of blood oxygen level-dependent fMRI results. Smaller shortest distances from the tumor to the hand knob and larger deviation distances for the midpoint of hand knob on the lesion hemisphere are associated with less accuracy of motor cortex

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

    SciTech Connect

    Hetherington, Dale L.; Stein, David J.

    1999-05-14

    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.

  5. Plastic changes at corticostriatal synapses predict improved motor function in a partial lesion model of Parkinson's disease.

    PubMed

    Bentea, Eduard; Moore, Cynthia; Deneyer, Lauren; Verbruggen, Lise; Churchill, Madeline J; Hood, Rebecca L; Meshul, Charles K; Massie, Ann

    2017-02-19

    In Parkinson's disease, striatal dopamine depletion leads to plastic changes at excitatory corticostriatal and thalamostriatal synapses. The functional consequences of these responses on the expression of behavioral deficits are incompletely understood. In addition, most of the information on striatal synaptic plasticity has been obtained in models with severe striatal dopamine depletion, and less is known regarding changes during early stages of striatal denervation. Using a partial model of nigral cell loss based on intranigral injection of the proteasome inhibitor lactacystin, we demonstrate ultrastructural changes at corticostriatal synapses with a 15% increase in the length and 30% increase in the area of the postsynaptic densities at corticostriatal synapses 1 week following toxin administration. This increase was positively correlated with the performance of lactacystin-lesioned mice on the rotarod task, such that mice with a greater increase in the size of the postsynaptic density performed better on the rotarod task. We therefore propose that lengthening of the postsynaptic density at corticostriatal synapses acts as a compensatory mechanism to maintain motor function under conditions of partial dopamine depletion. The ultrastructure of thalamostriatal synapses remained unchanged following lactacystin administration. Our findings provide novel insights into the mechanisms of synaptic plasticity and behavioral compensation following partial loss of substantia nigra pars compacta neurons, such as those occurring during the early stages of Parkinson's disease.

  6. The predictability of frequency-altered auditory feedback changes the weighting of feedback and feedforward input for speech motor control.

    PubMed

    Scheerer, Nichole E; Jones, Jeffery A

    2014-12-01

    Speech production requires the combined effort of a feedback control system driven by sensory feedback, and a feedforward control system driven by internal models. However, the factors that dictate the relative weighting of these feedback and feedforward control systems are unclear. In this event-related potential (ERP) study, participants produced vocalisations while being exposed to blocks of frequency-altered feedback (FAF) perturbations that were either predictable in magnitude (consistently either 50 or 100 cents) or unpredictable in magnitude (50- and 100-cent perturbations varying randomly within each vocalisation). Vocal and P1-N1-P2 ERP responses revealed decreases in the magnitude and trial-to-trial variability of vocal responses, smaller N1 amplitudes, and shorter vocal, P1 and N1 response latencies following predictable FAF perturbation magnitudes. In addition, vocal response magnitudes correlated with N1 amplitudes, vocal response latencies, and P2 latencies. This pattern of results suggests that after repeated exposure to predictable FAF perturbations, the contribution of the feedforward control system increases. Examination of the presentation order of the FAF perturbations revealed smaller compensatory responses, smaller P1 and P2 amplitudes, and shorter N1 latencies when the block of predictable 100-cent perturbations occurred prior to the block of predictable 50-cent perturbations. These results suggest that exposure to large perturbations modulates responses to subsequent perturbations of equal or smaller size. Similarly, exposure to a 100-cent perturbation prior to a 50-cent perturbation within a vocalisation decreased the magnitude of vocal and N1 responses, but increased P1 and P2 latencies. Thus, exposure to a single perturbation can affect responses to subsequent perturbations. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  7. Batteries: Imaging degradation

    NASA Astrophysics Data System (ADS)

    Shearing, Paul R.

    2016-11-01

    The degradation and failure of Li-ion batteries is strongly associated with electrode microstructure change upon (de)lithiation. Now, an operando X-ray tomography approach is shown to correlate changes in the microstructure of electrodes to cell performance, and thereby predict degradation pathways.

  8. Development of a Mathematical Code to Predict Thermal Degradation of Fuel and Deposit Formation in a Fuel System

    DTIC Science & Technology

    1990-09-01

    MDTCAP 5,7 7 0A DCLML",," pROCESSING SHEIET srx is 5X.!iiACSTD AD- A225 415 WRDC-TR-90-2084 DEVELOPMENT OF A MATHEMATICAL CODE TO PREDICT THERMAL...R. (1983) "Studies of the Mechanism of Turbine Fuel Instability," Colorado School of Mines, NASA CR -167963. Daniel, S. R. (1985) "Jet Fuel Instability

  9. GROWTH INDICES, ANEMIA, AND DIET INDEPENDENTLY PREDICT MOTOR MILESTONE ACQUISITION OF INFANTS IN SOUTH CENTRAL NEPAL12

    PubMed Central

    Siegel, Emily H.; Stoltzfus, Rebecca J.; Kariger, Patricia K.; Katz, Joanne; Khatry, Subarna K.; LeClerq, Steven C.; Pollitt, Ernesto; Tielsch, James M.

    2005-01-01

    The acquisition of bipedal locomotion is an important aspect of gross motor development that ultimately impacts the cognition of young children. Evidence for associations between nutrition-related variables and walking acquisition exist; however, questions about the importance of weight-for-length and dietary factors and the independent contribution of anemia and growth on walking remain. We examined the effect of nutritional factors on the acquisition of walking in a cross-sectional cohort of 485 4- to 17-mo Nepali children adjusting for age, sex, caste, and socio-economic status (SES). Participants were identified from census data collected in one village development committee (VDC) in Sarlahi District and enrolled in a cross-sectional, community-based study between January and March 2002. Hemoglobin and erythrocyte protoporphyrin (EP) were measured at baseline using a heel prick technique. The mean hemoglobin concentration was 101 ± 12.5 g/L. 57 % were anemic (hemoglobin < 105 g/L), 2.1% were severely anemic (hemoglobin < 7.0 g/L), and 43% of the children had iron deficiency anemia (hemoglobin < 105 g/L; EP > 90 μmol/mol heme). Growth was delayed; 33.5% were stunted and 20.4% were wasted. Multivariate logistic models that controlled for age, sex, caste, and SES revealed that children with higher length-for-age and weight-for-length Z-scores, no anemia, and meat consumption walked at an earlier age than children with lower scores, anemia, and no meat consumption. We conclude that growth, anemia, and diet are independently associated with delays in the onset of bipedal locomotion among young Nepali children. PMID:16317129

  10. Predicting Future Self-Reported Motor Vehicle Collisions in Subjects with Primary Open-Angle Glaucoma Using the Penalized Support Vector Machine Method.

    PubMed

    Yuki, Kenya; Asaoka, Ryo; Awano-Tanabe, Sachiko; Ono, Takeshi; Shiba, Daisuke; Murata, Hiroshi; Tsubota, Kazuo

    2017-06-01

    We predict the likelihood of a future motor vehicle collision (MVC) from visual function data, attitudes to driving, and past MVC history using the penalized support vector machine (pSVM) in subjects with primary open-angle glaucoma (POAG). Patients with POAG were screened prospectively for eligibility and 185 were analyzed in this study. Self-reported MVCs of all participants were recorded for 3 years from the baseline using a survey questionnaire every 12 months. A binocular integrated visual field (IVF) was calculated for each patient by merging a patient's monocular Humphrey Field Analyzer (HFA) visual fields (VFs). The IVF was divided into six regions, based on eccentricity and the right or left hemifield, and the average of the total deviation (TD) values in each of these six areas was calculated. Then, the future MVCs were predicted using various variables, including age, sex, 63 variables of 52 TD values, mean of the TD values, visual acuities (VAs), six sector average TDs with (predpenSVM_all) and without (predpenSVM_basic) the attitudes in driving, and also past MVC history, using the pSVM method, applying the leave-one-out cross validation. The relationship between predpenSVM_basic and the future MVC approached significance (odds ratio = 1.15, [0.99-1.29], P = 0.064, logistic regression). A significant relationship was observed between predpenSVM_all and the future MVC (odds ratio = 1.21, P = 0.0015). It was useful to predict future MVCs in patients with POAG using visual function metrics, patients' attitudes to driving, and past MVC history, using the pSVM. Careful consideration is needed when predicting future MVCs in POAG patients using visual function, and without driving attitude and MVC history.

  11. Predicting Second Grade Achievement Scores with the Slosson Intelligence Test, Peabody Picture Vocabulary Test, Goodenough-Harris Drawing Test, Developmental Test of Visual Motor and the Metropolitan Readiness Test.

    ERIC Educational Resources Information Center

    Flynn, Timothy M.

    The predictive validity of the Slosson Intelligence Test, Peabody Picture Vocabulary Test, Goodenough-Harris Drawing Test, Developmental Test of Visual Motor Integration, and the Metropolitan Readiness Test was evaluated for use with kindergarten children. The criterion measure was the California Achievement Tests administered when the children…

  12. Accelerated test methods for predicting the life of motor materials exposed to refrigerant/lubricant mixtures. Phase 1, Conceptual design: Final report

    SciTech Connect

    Ellis, P.F. II; Ferguson, A.

    1993-08-18

    The federally mandated phase-out of chlorofluorocarbon refrigerants requires screening tests for motor materials compatibility with alternative refrigerant/lubricant mixtures. In the current phase of the program, ARTI is supporting tests of promising candidate refrigeration/lubricant systems in key refrigeration component systems such as bearings and hermetic motor insulation systems to screen for more subtle detrimental effects and allow estimates of motor-compressor life. This report covers: mechanisms of failure of hermetic motor insulation, current methods for estimation of life of hermetic motors, and conceptual design of improved stator simulator device for testing of alternative refrigerant/lubricant mixtures.

  13. Including Thermal Fluctuations in Actomyosin Stable States Increases the Predicted Force per Motor and Macroscopic Efficiency in Muscle Modelling.

    PubMed

    Marcucci, Lorenzo; Washio, Takumi; Yanagida, Toshio

    2016-09-01

    Muscle contractions are generated by cyclical interactions of myosin heads with actin filaments to form the actomyosin complex. To simulate actomyosin complex stable states, mathematical models usually define an energy landscape with a corresponding number of wells. The jumps between these wells are defined through rate constants. Almost all previous models assign these wells an infinite sharpness by imposing a relatively simple expression for the detailed balance, i.e., the ratio of the rate constants depends exponentially on the sole myosin elastic energy. Physically, this assumption corresponds to neglecting thermal fluctuations in the actomyosin complex stable states. By comparing three mathematical models, we examine the extent to which this hypothesis affects muscle model predictions at the single cross-bridge, single fiber, and organ levels in a ceteris paribus analysis. We show that including fluctuations in stable states allows the lever arm of the myosin to easily and dynamically explore all possible minima in the energy landscape, generating several backward and forward jumps between states during the lifetime of the actomyosin complex, whereas the infinitely sharp minima case is characterized by fewer jumps between states. Moreover, the analysis predicts that thermal fluctuations enable a more efficient contraction mechanism, in which a higher force is sustained by fewer attached cross-bridges.

  14. Including Thermal Fluctuations in Actomyosin Stable States Increases the Predicted Force per Motor and Macroscopic Efficiency in Muscle Modelling

    PubMed Central

    2016-01-01

    Muscle contractions are generated by cyclical interactions of myosin heads with actin filaments to form the actomyosin complex. To simulate actomyosin complex stable states, mathematical models usually define an energy landscape with a corresponding number of wells. The jumps between these wells are defined through rate constants. Almost all previous models assign these wells an infinite sharpness by imposing a relatively simple expression for the detailed balance, i.e., the ratio of the rate constants depends exponentially on the sole myosin elastic energy. Physically, this assumption corresponds to neglecting thermal fluctuations in the actomyosin complex stable states. By comparing three mathematical models, we examine the extent to which this hypothesis affects muscle model predictions at the single cross-bridge, single fiber, and organ levels in a ceteris paribus analysis. We show that including fluctuations in stable states allows the lever arm of the myosin to easily and dynamically explore all possible minima in the energy landscape, generating several backward and forward jumps between states during the lifetime of the actomyosin complex, whereas the infinitely sharp minima case is characterized by fewer jumps between states. Moreover, the analysis predicts that thermal fluctuations enable a more efficient contraction mechanism, in which a higher force is sustained by fewer attached cross-bridges. PMID:27626630

  15. Modularity for Motor Control and Motor Learning.

    PubMed

    d'Avella, Andrea

    2016-01-01

    How the central nervous system (CNS) overcomes the complexity of multi-joint and multi-muscle control and how it acquires or adapts motor skills are fundamental and open questions in neuroscience. A modular architecture may simplify control by embedding features of both the dynamic behavior of the musculoskeletal system and of the task into a small number of modules and by directly mapping task goals into module combination parameters. Several studies of the electromyographic (EMG) activity recorded from many muscles during the performance of different tasks have shown that motor commands are generated by the combination of a small number of muscle synergies, coordinated recruitment of groups of muscles with specific amplitude balances or activation waveforms, thus supporting a modular organization of motor control. Modularity may also help understanding motor learning. In a modular architecture, acquisition of a new motor skill or adaptation of an existing skill after a perturbation may occur at the level of modules or at the level of module combinations. As learning or adapting an existing skill through recombination of modules is likely faster than learning or adapting a skill by acquiring new modules, compatibility with the modules predicts learning difficulty. A recent study in which human subjects used myoelectric control to move a mass in a virtual environment has tested this prediction. By altering the mapping between recorded muscle activity and simulated force applied on the mass, as in a complex surgical rearrangement of the tendons, it has been possible to show that it is easier to adapt to a perturbation that is compatible with the muscle synergies used to generate hand force than to a similar but incompatible perturbation. This result provides direct support for a modular organization of motor control and motor learning.

  16. Identification and validation of a logistic regression model for predicting serious injuries associated with motor vehicle crashes.

    PubMed

    Kononen, Douglas W; Flannagan, Carol A C; Wang, Stewart C

    2011-01-01

    A multivariate logistic regression model, based upon National Automotive Sampling System Crashworthiness Data System (NASS-CDS) data for calendar years 1999-2008, was developed to predict the probability that a crash-involved vehicle will contain one or more occupants with serious or incapacitating injuries. These vehicles were defined as containing at least one occupant coded with an Injury Severity Score (ISS) of greater than or equal to 15, in planar, non-rollover crash events involving Model Year 2000 and newer cars, light trucks, and vans. The target injury outcome measure was developed by the Centers for Disease Control and Prevention (CDC)-led National Expert Panel on Field Triage in their recent revision of the Field Triage Decision Scheme (American College of Surgeons, 2006). The parameters to be used for crash injury prediction were subsequently specified by the National Expert Panel. Model input parameters included: crash direction (front, left, right, and rear), change in velocity (delta-V), multiple vs. single impacts, belt use, presence of at least one older occupant (≥ 55 years old), presence of at least one female in the vehicle, and vehicle type (car, pickup truck, van, and sport utility). The model was developed using predictor variables that may be readily available, post-crash, from OnStar-like telematics systems. Model sensitivity and specificity were 40% and 98%, respectively, using a probability cutpoint of 0.20. The area under the receiver operator characteristic (ROC) curve for the final model was 0.84. Delta-V (mph), seat belt use and crash direction were the most important predictors of serious injury. Due to the complexity of factors associated with rollover-related injuries, a separate screening algorithm is needed to model injuries associated with this crash mode. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Long-Term Predictive and Feedback Encoding of Motor Signals in the Simple Spike Discharge of Purkinje Cells

    PubMed Central

    Popa, Laurentiu S.; Streng, Martha L.

    2017-01-01

    Abstract Most hypotheses of cerebellar function emphasize a role in real-time control of movements. However, the cerebellum’s use of current information to adjust future movements and its involvement in sequencing, working memory, and attention argues for predicting and maintaining information over extended time windows. The present study examines the time course of Purkinje cell discharge modulation in the monkey (Macaca mulatta) during manual, pseudo-random tracking. Analysis of the simple spike firing from 183 Purkinje cells during tracking reveals modulation up to 2 s before and after kinematics and position error. Modulation significance was assessed against trial shuffled firing, which decoupled simple spike activity from behavior and abolished long-range encoding while preserving data statistics. Position, velocity, and position errors have the most frequent and strongest long-range feedforward and feedback modulations, with less common, weaker long-term correlations for speed and radial error. Position, velocity, and position errors can be decoded from the population simple spike firing with considerable accuracy for even the longest predictive (-2000 to -1500 ms) and feedback (1500 to 2000 ms) epochs. Separate analysis of the simple spike firing in the initial hold period preceding tracking shows similar long-range feedforward encoding of the upcoming movement and in the final hold period feedback encoding of the just completed movement, respectively. Complex spike analysis reveals little long-term modulation with behavior. We conclude that Purkinje cell simple spike discharge includes short- and long-range representations of both upcoming and preceding behavior that could underlie cerebellar involvement in error correction, working memory, and sequencing. PMID:28413823

  18. Comparative and transcriptional analysis of the predicted secretome in the lignocellulose-degrading basidiomycete fungus Pleurotus ostreatus.

    PubMed

    Alfaro, Manuel; Castanera, Raúl; Lavín, José L; Grigoriev, Igor V; Oguiza, José A; Ramírez, Lucía; Pisabarro, Antonio G

    2016-12-01

    Fungi interact with their environment by secreting proteins to obtain nutrients, elicit responses and modify their surroundings. Because the set of proteins secreted by a fungus is related to its lifestyle, it should be possible to use it as a tool to predict fungal lifestyle. To test this hypothesis, we bioinformatically identified 538 and 554 secretable proteins in the monokaryotic strains PC9 and PC15 of the white rot basidiomycete Pleurotus ostreatus. Functional annotation revealed unknown functions (37.2%), glycosyl hydrolases (26.5%) and redox enzymes (11.5%) as the main groups in the two strains. When these results were combined with RNA-seq analyses, we found that the relative importance of each group was different in different strains and culture conditions and the relevance of the unknown function proteins was enhanced. Only a few genes were actively expressed in a given culture condition in expanded multigene families, suggesting that family expansi on could increase adaptive opportunities rather than activity under a specific culture condition. Finally, we used the set of P. ostreatus secreted proteins as a query to search their counterparts in other fungal genomes and found that the secretome profiles cluster the tested basidiomycetes into lifestyle rather than phylogenetic groups. © 2016 The Authors Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Evaluation of the Predictive Value of Intraoperative Changes in Motor-Evoked Potentials of Caudal Cranial Nerves for the Postoperative Functional Outcome.

    PubMed

    Kullmann, Marcel; Tatagiba, Marcos; Liebsch, Marina; Feigl, Guenther C

    2016-11-01

    The predictive value of changes in intraoperatively acquired motor-evoked potentials (MEPs) of the lower cranial nerves (LCN) IX-X (glossopharyngeal-vagus nerve) and CN XII (hypoglossal nerve) on operative outcomes was investigated. MEPs of CN IX-X and CN XII were recorded intraoperatively in 63 patients undergoing surgery of the posterior cranial fossa. We correlated the changes of the MEPs with postoperative nerve function. For CN IX-X, we found a correlation between the amplitude of the MEP ratio and uvula deviation (P = 0.028) and the amplitude duration of the MEP and gag reflex function (P = 0.027). Patients with an MEP ratio of the glossopharyngeal-vagus amplitude ≤1.47 μV had a 3.4 times increased risk of developing a uvula deviation. Patients with a final MEP duration of the CN IX-X ≤11.6 milliseconds had a 3.6 times increased risk for their gag reflex to become extinct. Our study greatly contributes to the current knowledge of intraoperative MEPs as a predictor for postoperative cranial nerve function. We were able to extent previous findings on MEP values of the facial nerve on postoperative nerve function to 3 additional cranial nerves. Finding reliable predictors for postoperative nerve function is of great importance to the overall quality of life for a patient undergoing surgery of the posterior cranial fossa. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Recovery of post stroke proximal arm function, driven by complex neuroplastic bilateral brain activation patterns and predicted by baseline motor dysfunction severity

    PubMed Central

    Pundik, Svetlana; McCabe, Jessica P.; Hrovat, Ken; Fredrickson, Alice Erica; Tatsuoka, Curtis; Feng, I Jung; Daly, Janis J.

    2015-01-01

    Objectives: Neuroplastic changes that drive recovery of shoulder/elbow function after stroke have been poorly understood. The purpose of this study was to determine the relationship between neuroplastic brain changes related to shoulder/elbow movement control in response to treatment and recovery of arm motor function in chronic stroke survivors.Methods: Twenty-three chronic stroke survivors were treated with 12 weeks of arm rehabilitation. Outcome measures included functional Magnetic Resonance Imaging (fMRI) for the shoulder/elbow components of reach and a skilled motor function test (Arm Motor Abilities Test, AMAT), collected before and after treatment.Results: We observed two patterns of neuroplastic changes that were associated with gains in motor function: decreased or increased task-related brain activation. Those with significantly better motor function at baseline exhibited a decrease in brain activation in response to treatment, evident in the ipsilesional primary motor and contralesional supplementary motor regions; in contrast, those with greater baseline motor impairment, exhibited increased brain activation in response to treatment. There was a linear relationship between greater functional gain (AMAT) and increased activation in bilateral primary motor, contralesional primary and secondary sensory regions, and contralesional lateral premotor area, after adjusting for baseline AMAT, age, and time since stroke.Conclusions: Recovery of functional reach involves recruitment of several contralesional and bilateral primary motor regions. In response to intensive therapy, the direction of functional brain change (i.e., increase or decrease in task-related brain recruitment) for shoulder/elbow reach components depends on baseline level of motor function and may represent either different phases of recovery or different patterns of neuroplasticity that drive functional recovery. PMID:26257623

  1. Prediction of Neurocognitive Deficits by Parkinsonian Motor Impairment in Schizophrenia: A Study in Neuroleptic-Naïve Subjects, Unaffected First-Degree Relatives and Healthy Controls From an Indigenous Population.

    PubMed

    Molina, Juan L; González Alemán, Gabriela; Florenzano, Néstor; Padilla, Eduardo; Calvó, María; Guerrero, Gonzalo; Kamis, Danielle; Stratton, Lee; Toranzo, Juan; Molina Rangeon, Beatriz; Hernández Cuervo, Helena; Bourdieu, Mercedes; Sedó, Manuel; Strejilevich, Sergio; Cloninger, Claude Robert; Escobar, Javier I; de Erausquin, Gabriel A

    2016-11-01

    Neurocognitive deficits are among the most debilitating and pervasive symptoms of schizophrenia, and are present also in unaffected first-degree relatives. Also, multiple reports reveal parkisonian motor deficits in untreated subjects with schizophrenia and in first-degree relatives of affected subjects. Yet, the relation between motor and cognitive impairment and its value as a classifier of endophenotypes has not been studied. To test the efficacy of midbrain hyperechogenicity (MHE) and parkinsonian motor impairment (PKM) as predictors of neurocognitive impairment in subjects with or at risk for schizophrenia, that could be used to segregate them from first-degree relatives and healthy controls. Seventy-six subjects with chronic schizophrenia never exposed to antipsychotic medication, 106 unaffected first-degree relatives, and 62 healthy controls were blindly assessed for cognitive and motor function, and transcranial ultrasound. Executive function, fluid intelligence, motor planning, and hand coordination showed group differences. PKM and MHE were significantly higher in untreated schizophrenia and unaffected relatives. Unaffected relatives showed milder impairment, but were different from controls. PKM and MHE predict cognitive impairment in neuroleptic-naive patients with schizophrenia and their unaffected first-degree relatives and may be used to segregate them from first-degree relatives and healthy controls. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. An integrated degradation and structural model for predicting the service life of buried reinforced concrete structures for low- and intermediate-level radioactive waste disposal

    SciTech Connect

    Brandstetter, E.R.; Lolcama, J.L.; Reed, S.R.

    1994-03-01

    The primary focus of this study was to determine the possible rates of roof and wall failure and the times to structural collapse of the roof and walls of three vault designs at the Department of Energy`s Savannah River Site near Aiken, South Carolina. Failure was defined as a loss of ability to divert soil water around the vault. Collapse was defined as the total loss of structure integrity of the vault. Failure and eventual collapse of the three vault types results from concrete deterioration under stress, in the presence of corrosive soil water. Degradation rates for reinforced concrete were utilized, and the resultant changes in properties (such as strength, thickness, cracking and hydraulic conductivity) were evaluated. Baseline times to failure and collapse of the walls and roof components were modeled, and sensitivity analyses were conducted to provide boundaries on these estimated times. Thus, the goal of the project was to provide a bounding analysis of the time to roof and wall failure and potential collapse, rather than an actual prediction of the time to failure, and collapse.

  3. Integrating focal adhesion dynamics, cytoskeleton remodeling, and actin motor activity for predicting cell migration on 3D curved surfaces of the extracellular matrix.

    PubMed

    Kim, Min-Cheol; Kim, Choong; Wood, Levi; Neal, Devin; Kamm, Roger D; Asada, H Harry

    2012-11-01

    An integrative cell migration model incorporating focal adhesion (FA) dynamics, cytoskeleton and nucleus remodeling and actin motor activity is developed for predicting cell migration behaviors on 3-dimensional curved surfaces, such as cylindrical lumens in the 3-D extracellular matrix (ECM). The work is motivated by 3-D microfluidic migration experiments suggesting that the migration speed and direction may vary depending on the cross sectional shape of the lumen along which the cell migrates. In this paper, the mechanical structure of the cell is modeled as double elastic membranes of cell and nucleus. The two elastic membranes are connected by stress fibers, which are extended from focal adhesions on the cell surface to the nuclear membrane. The cell deforms and gains traction as transmembrane integrins distributed over the outer cell membrane bind to ligands on the ECM, form focal adhesions, and activate stress fibers. Probabilities at which integrin ligand-receptor bonds are formed as well as ruptures are affected by the surface geometry, resulting in diverse migration behaviors that depend on the curvature of the surface. Monte Carlo simulations of the integrative model reveal that (a) the cell migration speed is dependent on the cross sectional area of the lumen with a maximum speed at a particular diameter or width, (b) as the lumen diameter increases, the cell tends to spread and migrate around the circumference of the lumen, while it moves in the longitudinal direction as the lumen diameter narrows, (c) once the cell moves in one direction, it tends to stay migrating in the same direction despite the stochastic nature of migration. The relationship between the cell migration speed and the lumen width agrees with microfluidic experimental data for cancer cell migration.

  4. Biomechanical modeling as a practical tool for predicting injury risk related to repetitive muscle lengthening during learning and training of human complex motor skills.

    PubMed

    Wan, Bingjun; Shan, Gongbing

    2016-01-01

    Previous studies have shown that muscle repetitive stress injuries (RSIs) are often related to sport trainings among young participants. As such, understanding the mechanism of RSIs is essential for injury prevention. One potential means would be to identify muscles in risk by applying biomechanical modeling. By capturing 3D movements of four typical youth sports and building the biomechanical models, the current study has identified several risk factors related to the development of RSIs. The causal factors for RSIs are the muscle over-lengthening, the impact-like (speedy increase) eccentric tension in muscles, imbalance between agonists and antagonists, muscle loading frequency and muscle strength. In general, a large range of motion of joints would lead to over-lengthening of certain small muscles; Limb's acceleration during power generation could cause imbalance between agonists and antagonists; a quick deceleration of limbs during follow-throughs would induce an impact-like eccentric tension to muscles; and even at low speed, frequent muscle over-lengthening would cause a micro-trauma accumulation which could result in RSIs in long term. Based on the results, the following measures can be applied to reduce the risk of RSIs during learning/training in youth participants: (1) stretching training of muscles at risk in order to increase lengthening ability; (2) dynamic warming-up for minimizing possible imbalance between agonists and antagonists; (3) limiting practice times of the frequency and duration of movements requiring strength and/or large range of motion to reducing micro-trauma accumulation; and (4) allowing enough repair time for recovery from micro-traumas induced by training (individual training time). Collectively, the results show that biomechanical modeling is a practical tool for predicting injury risk and provides an effective way to establish an optimization strategy to counteract the factors leading to muscle repetitive stress injuries during

  5. Comparison of a linear and a non-linear model for using sensory-motor, cognitive, personality, and demographic data to predict driving ability in healthy older adults.

    PubMed

    Hoggarth, Petra A; Innes, Carrie R H; Dalrymple-Alford, John C; Severinsen, Julie E; Jones, Richard D

    2010-11-01

    This study compared the ability of binary logistic regression (BLR) and non-linear causal resource analysis (NCRA) to utilize a range of cognitive, sensory-motor, personality and demographic measures to predict driving ability in a sample of cognitively healthy older drivers. Participants were sixty drivers aged 70 and above (mean=76.7 years, 50% men) with no diagnosed neurological disorder. Test data was used to build classification models for a Pass or Fail score on an on-road driving assessment. The generalizability of the models was estimated using leave-one-out cross-validation. Sixteen participants (27%) received an on-road Fail score. Area under the ROC curve values were .76 for BLR and .88 for NCRA (no significant difference, z=1.488, p=.137). The ROC curve was used to select three different cut-points for each model and to compare classification. At the cut-point corresponding to the maximum average of sensitivity and specificity, the BLR model had a sensitivity of 68.8% and specificity of 75.0% while NCRA had a sensitivity of 75.0% and specificity of 95.5%. However, leave-one-out cross-validation reduced sensitivity in both models and particularly reduced specificity for NCRA. Neither model is accurate enough to be relied on solely for determination of driving ability. The lowered accuracy of the models following leave-one-out cross-validation highlights the importance of investigating models beyond classification alone in order to determine a model's ability to generalize to new cases.

  6. Recycling of kinesin-1 motors by diffusion after transport.

    PubMed

    Blasius, T Lynne; Reed, Nathan; Slepchenko, Boris M; Verhey, Kristen J

    2013-01-01

    Kinesin motors drive the long-distance anterograde transport of cellular components along microtubule tracks. Kinesin-dependent transport plays a critical role in neurogenesis and neuronal function due to the large distance separating the soma and nerve terminal. The fate of kinesin motors after delivery of their cargoes is unknown but has been postulated to involve degradation at the nerve terminal, recycling via retrograde motors, and/or recycling via diffusion. We set out to test these models concerning the fate of kinesin-1 motors after completion of transport in neuronal cells. We find that kinesin-1 motors are neither degraded nor returned by retrograde motors. By combining mathematical modeling and experimental analysis, we propose a model in which the distribution and recycling of kinesin-1 motors fits a "loose bucket brigade" where individual motors alter between periods of active transport and free diffusion within neuronal processes. These results suggest that individual kinesin-1 motors are utilized for multiple rounds of transport.

  7. Molecular motors

    NASA Astrophysics Data System (ADS)

    Allemand, Jean François Desbiolles, Pierre

    2015-10-01

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

  8. Multimotor Driven Cargos: From Single Motor under Load to the Role of Motor-Motor Coupling.

    PubMed

    Peker, Itay; Granek, Rony

    2016-07-07

    Motor proteins constitute an essential part of the cellular machinery. They have been the subject of intensive studies in the past two decades. Yet, when several motors simultaneously carry a single cargo, the effect of motor-motor coupling, such as mutual stalling and jamming, remains unclear. We commence by constructing a general model for single motor motion, which is a product of a derived load-dependent expression and a phenomenological motor specific function. Forming the latter according to recent single molecule measurements for a given load, the model correctly predicts the motor full step-size distribution for all other measured loads. We then use our proposed model to predict transport properties of multimotor complexes, with particular attention to 1-dimensional constructs with variable flexibility, motor density, and number of motors: (i) a chain of motors connected by springs, a recently studied construction of a pair, and (ii) an array of motors all connected by identical springs to a stiff rod, which is essentially a mirror image of standard gliding motility assays. In both systems, and for any number of carrying motors, we find that, while low flexibility results in a strongly damped velocity, increased flexibility renders an almost single motor velocity. Comparing our model based simulations to recent gliding assays we find remarkable qualitative agreement. We also demonstrate consistency with other multimotor motility assays. In all cases, the characteristic spring constant, that controls the crossover behavior between high and low velocity regimes, is found to be the stalling force divided by the mean step size. We conjecture that this characteristic spring constant can serve as a tool for engineering multimotor complexes.

  9. Conical Bearingless Motor/Generators

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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