scholarly journals Action monitoring fails when motor execution is too fast: no time for correction

2020 ◽  
Author(s):  
Ramdani ◽  
emmanuel sagui ◽  
bruno schmid ◽  
olivier castagna ◽  
Karen Davranche ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Incorrect Response ◽  
Time Interval ◽  
Information Processing Model ◽  
Action Monitoring ◽  
Dependent Variables ◽  
Duration Of Response ◽  
Response Execution ◽  
Peripheral Motor ◽  
S Model

A recent information processing model of two-choice RT situations (Servant et al., 2015), suggests that conditions which reduce the duration of peripheral motor processes, should also reduce the efficiency of the action monitoring system, because letting no time enough for correction of partial errors (i.e. subthreshold transient muscle activity of the agonists of the incorrect response preceding the correct response). A physiological situation, namely sustained physical exercise, has repeatedly been reported to reduce the duration of response execution. Therefore, in order to test the prediction of the model, we compared action monitoring efficiency between a sustained exercise (59.42% of MAP) and a control (15 W) condition in the same subjects while they were performing a Simon task. Electromyographic (EMG) recordings of muscles implicated in the response allowed to measure premotor time (time interval between the stimulus and the onset of the EMG burst) and motor time (MT, time interval between the onset of the EMG burst and the mechanical response, which gives access to response execution processes). Electromyogram further permitted to unmask partial errors. Correction ratio was calculated by dividing the number of partial errors by the number of incorrect activations (partial errors + errors). As expected, exercise decreased MT. In addition, exercise reduced the correction ratio. Furthermore, there was a positive inter-subject correlation between these two dependent variables. In line with Servant et al.'s model (2015), we propose that the drop in the efficiency of cognitive control was due to insufficient MT available for action monitoring to operate when incorrect activations were produced.

On-line action monitoring of response execution: An electrophysiological study

2017 ◽  
Vol 129 ◽  
pp. 178-185 ◽  
Author(s):  
Cédric Meckler ◽  
Laurence Carbonnell ◽  
Céline Ramdani ◽  
Thierry Hasbroucq ◽  
Franck Vidal
Keyword(s):  
Electrophysiological Study ◽  
Action Monitoring ◽  
On Line ◽  
Response Execution

scholarly journals The effects of strengths coaching program on strengths self efficacy, positive affect, self efficacy, job engagement and organizational commitment based on Korean employees

2017 ◽  
Vol 30 (2) ◽  
pp. 221-246
Author(s):  
Hyaeyeong Seon ◽  
Suyeon Kim ◽  
Miae Lee ◽  
Jinkook Tak
Keyword(s):  
Organizational Commitment ◽  
Positive Affect ◽  
Work Engagement ◽  
Self Efficacy ◽  
Control Group ◽  
Time Interval ◽  
Job Engagement ◽  
Group Data ◽  
Dependent Variables

This study was designed to examine the effects of strengths coaching program on strengths self efficacy, positive affect, self efficacy, work engagement, and organizational commitment based on Korean employees. Participants were 43 Korean employees, 21 for the experiment group and 22 for the control group. Data were collected across three times(pre, post, follow-up). To measure overall effects, strengths self efficacy, positive affect, self efficacy, work engagement and organizational commitment were measured. Results showed that there were significant interaction effects between time interval and groups for all the dependent variables, confirming the effects of the coaching program. Also, there were non significant effects of time interval(post and follow-up) for all the dependent variables, confirming the duration of the program effect across time. Finally, implications and limitations of the study were discussed.

Transitional ballistics of electric high-velocity launchers

2019 ◽  
Author(s):  
B. Reck ◽  
S. Hundertmark ◽  
R. Hruschka ◽  
A. Zeiner ◽  
B. Sauerwein ◽  
...  
Keyword(s):  
High Velocity ◽  
Gas Flow ◽  
Mechanical Response ◽  
Numerical Models ◽  
Time Interval ◽  
Viscous Effects ◽  
Simulation Code ◽  
Package Design ◽  
Gun Barrel ◽  
Experimental Values

Abstract The high-velocity launch of a projectile is subjected to a number of disturbances which exert an influence on the flight trajectory. In the case of sub-caliber projectiles, sabot separation is one of the critical aspects. In this work, we focus on the projectiles and the launch package of an electric railgun launch, i.e. on the behavior of the launch-package, when transitioning from the gun barrel to free-flight. This work further addresses the use of a hydrocode for creating numerical models which are capable of predicting the motion and deflection of the sabot parts during their separation from the projectile after exiting the muzzle. An earlier study showed that the air flow around the projectile and the sabot can be modeled with sufficiently high accuracy by means of a simulation code that uses an Eulerian description of the gas flow. Within a time interval of several milliseconds, just the duration that a projectile needs to enter quasi-stationary flight, viscous effects of the air or gas flow have relatively little influence on the sabot discard process. If the Eulerian gas flow is coupled with the Lagrangian structural parts, the mechanical response of the latter to the gas pressure can be complex in terms of deformation and damage, and in that way, can affect the gas flow. In this study, the hydrocode model is applied to a medium caliber launch package concept for accelerating long rod projectiles. The computed results agree well with the corresponding experimental values obtained from a launch package model test in the shock tunnel at Mach 4.5. This demonstrates that the presented hydrocode model can be used for launch package design optimizations with high confidence.

Sequential therapy with methotrexate and 5-fluorouracil in the treatment of advanced colorectal carcinoma.

1986 ◽  
Vol 4 (1) ◽  
pp. 23-27 ◽  
Author(s):  
B A Leone ◽  
A Romero ◽  
M G Rabinovich ◽  
J E Perez ◽  
M Macchiavelli ◽  
...  
Keyword(s):  
Colorectal Carcinoma ◽  
Tumor Regression ◽  
Sequential Therapy ◽  
Chemotherapeutic Agents ◽  
Optimal Time ◽  
High Dose ◽  
Time Interval ◽  
Major Objective ◽  
Duration Of Response ◽  
Advanced Colorectal Carcinoma

Twenty-nine patients with advanced colorectal carcinoma were entered in this study to evaluate the efficacy and toxicity of a sequential chemotherapeutic schedule with methotrexate (MTX), 200 mg/m2 intravenously (IV) (push injection) and 5-fluorouracil (5-FU), 1,200 mg/m2 in continuous IV infusion, using a 20-hour time interval. All patients received calcium leucovorin (LV), 25 mg, intramuscularly (IM) every six hours for eight doses beginning 24 hours after methotrexate administration. Courses were administered every 15 days. Of the 24 patients evaluable for response, 11 (46%) had major objective regressions (one complete remission [CR] and ten partial remissions [PR]). The survival rate of patients who responded to treatment was 60% at 16 months, whereas patients with no change and those in whom the disease progressed had a median survival of 9 months and 3 months, respectively. The median duration of response has not yet been reached in patients who presented objective tumor regression, and was 7.5 months in those with no change. Significant differences were found between objective regression and no change (P less than .0005) and between no change and tumor progression (P less than .05). All patients were evaluable for toxicity. There were three toxic-related deaths (10%) because of severe myelosuppresion, sepsis, and hemorrhage. These promising results, despite important toxicity, reveal the synergism between the two chemotherapeutic agents and also indicate that the response rate achieved could be a consequence of the 20-hour interval and high dose of 5-FU. Further studies are necessary to determine the optimal time interval and the adequate 5-FU dose.

scholarly journals Increasing the Time Interval between PCV Chemotherapy Cycles as a Strategy to Improve Duration of Response in Low-Grade Gliomas: Results from a Model-Based Clinical Trial Simulation

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Pauline Mazzocco ◽  
Jérôme Honnorat ◽  
François Ducray ◽  
Benjamin Ribba
Keyword(s):  
Treatment Efficacy ◽  
In Silico ◽  
Therapeutic Strategies ◽  
Clinical Trial Simulation ◽  
Time Interval ◽  
Low Grade ◽  
Low Grade Gliomas ◽  
Before And After ◽  
Duration Of Response ◽  
Pcv Chemotherapy

Background. We previously developed a mathematical model capturing tumor size dynamics of adult low-grade gliomas (LGGs) before and after treatment either with PCV (Procarbazine, CCNU, and Vincristine) chemotherapy alone or with radiotherapy (RT) alone.Objective. The aim of the present study was to present how the model could be used as a simulation tool to suggest more effective therapeutic strategies in LGGs. Simulations were performed to identify schedule modifications that might improve PCV chemotherapy efficacy.Methods. Virtual populations of LGG patients were generated on the basis of previously evaluated parameter distributions. Monte Carlo simulations were performed to compare treatment efficacy acrossin silicoclinical trials.Results. Simulations predicted that RT plus PCV would be more effective in terms of duration of response than RT alone. Additional simulations suggested that, in patients treated with PCV chemotherapy, increasing the interval between treatment cycles up to 6 months from the standard 6 weeks can increase treatment efficacy. The predicted median duration of response was 4.3 years in LGGs treated with PCV cycles given every 6 months versus 3.1 years in patients treated with the classical regimen.Conclusion. The present study suggests that, in LGGs, mathematical modeling could facilitate clinical research by helping to identify,in silico, potentially more effective therapeutic strategies.

Relative Influence of Birth Cohort and Social-Event Cohort in Adult Development: An Exploratory Study

1980 ◽  
Vol 47 (2) ◽  
pp. 627-631 ◽  
Author(s):  
R. A. Dixon
Keyword(s):  
Birth Cohort ◽  
Adult Development ◽  
Exploratory Study ◽  
Explanatory Power ◽  
Panel Study ◽  
Occupational Status ◽  
Time Interval ◽  
Two Samples ◽  
Dependent Variables ◽  
Occupational Cohort

The generic definition of cohort, i.e., an aggregate of individuals who experience a similar event within the same time interval, is invoked to derive two cohort-membership groups for each of two samples. Subjects were 1203 and 998 white, middle-aged males who participated in the Institute for Social Research panel study of income dynamics. This exploratory study investigated the relative explanatory power of birth-cohort membership, occupational-cohort membership, and occupational status for a set of four social psychological dependent variables. Occupational-cohort membership was one of the two stronger contributors to the explanation of the variance for each of the dependent variables.

scholarly journals The effect of dose rate of 1-α-hydroxycholecalciferol on calcium and phosphorus metabolism in sheep

1980 ◽  
Vol 44 (2) ◽  
pp. 183-191 ◽  
Author(s):  
G. D. Braithwaite
Keyword(s):  
Bone Resorption ◽  
Dose Rate ◽  
Soft Tissues ◽  
Control Period ◽  
Maximum Response ◽  
Time Interval ◽  
Dose Rates ◽  
Duration Of Response ◽  
Rate Of Absorption ◽  
Increased Retention

1. A combination of a mineral balance and a radioisotope technique has been used to study the relationship between dose rate of 1-α-hydroxycholecalciferol (1α-OH-D3) and the magnitude and duration of its effect on the various processes of calcium and phosphorous metabolism in adult wether sheep.2. The rate of absorption of Ca was markedly increased by treatment and maximum response occurred at the lowest dose rate.3. Although sheep were already Ca-replete, the extra Ca absorbed was all retained and increased retention was brought about by a combination of an increase in bone accretion and a decrease in bone resorption. This finding conflicts with the generally-held belief that bone resorption is increased by cholecalciferol treatment.4. The rates of absorption and retention of P were increased by 1α-OH-D3 treatment and maximum response occurred at the lowest dose rate.5. That P absorption could be increased by treatment suggests that not all the available dietary P was absorbed in the control period.6. Although the loss of endogenous P in the faeces was unaltered by treatment, the secretion of P into the gut was increased, and the increase was directly related to increased serum inorganic P concentration.7. Nearly all the extra P absorbed was retained and increased retention was achieved by a combination of an increased incorporation into and a decreased loss from the non-exchangeable pools of bone and soft tissues.8. The time interval taken for absorption rates of Ca and P to return to normal after the end of each treatment was related to the dose rate of 1α-OH-D3. Although higher dose rates had little effect on the magnitude of response, they did prolong slightly the duration of response.

Determining the Dynamic Elastic Modulus at Elevated Temperatures by Using Rapid Heating Techniques

1967 ◽  
Vol 89 (1) ◽  
pp. 111-115 ◽  
Author(s):  
A. L. Austin ◽  
R. Parker
Keyword(s):  
Elastic Modulus ◽  
Elevated Temperatures ◽  
Mechanical Response ◽  
Rapid Heating ◽  
304 Stainless Steel ◽  
Dynamic Elastic Modulus ◽  
Test Material ◽  
Time Interval ◽  
Experimental Apparatus ◽  
Unique Method

A unique method of determining the dynamic elastic modulus at elevated temperatures is reported. It consists of discharging a low-inductance capacitor bank through a preheated thin rod of the test material, which is clamped at one end and free at the other. The transient i2R heating during bank discharge takes place in a time interval short compared to the mechanical response time of the rod, inducing longitudinal oscillations. The periodic motion of the free end of the rod interrupts a collimated light beam directed over the rod and onto an SD-100 photodiode whose output is recorded on a 561A Tektronix oscilloscope. This gives a direct measure of the modulus since it is inversely proportional to the square of the period of oscillation. The theory, experimental apparatus, and method are discussed and sample data are given for tests made on type 304 stainless steel to illustrate the accuracy and usefulness of this technique. The data are compared with those of other investigators using other methods, and excellent agreement was obtained. This method is particularly useful for testing hazardous materials where remote operation is required for safety.

scholarly journals A Comparative Study Of The Double Motor Innervation In Marine Crustaceans

1938 ◽  
Vol 15 (1) ◽  
pp. 18-31
Author(s):  
C. A. G. WIERSMA ◽  
A. VAN HARREVELD
Keyword(s):  
Mechanical Response ◽  
Time Interval ◽  
Muscle Action ◽  
Motor Innervation ◽  
Action Current ◽  
Marine Crustaceans ◽  
First Case ◽  
Slow Contraction ◽  
Thick Fibre ◽  
Stimulation Of

A double motor innervation has been shown for several muscles of marine crustaceans. The adductors of the claws of Randallia and Blepharipoda and the adductor of the dactylopodite of the walking leg of Cancer were studied physiologically. The two motor axons which innervate these muscles have a different diameter (ratio 1.4: 1). Stimulation of the thick fibre causes a response, which, though it is not always faster than the response of the thin fibre, must be considered as a "fast" contraction. In Randallia and in Blepharipoda the slow contraction is higher than the fast with frequencies of less than ± 50 per sec., in Cancer with frequencies less than 100 per sec. The action currents of the two kinds of contraction are different. Both show facilitation, but under the same conditions of stimulation the fast-action currents are higher. The first stimulus of the thick fibre causes an action current top which is clearly distinguishable, the action currents of the slow contraction show up only after a number of stimuli. Even when the mechanical reaction on stimulation of the thick fibre is smaller than on similar stimulation of the thin fibre, the action currents are higher in the first case. A single impulse in the thick fibre does not cause a contraction, but sets up a muscle-action current. The chronaxie of this action current in Blepharipoda and Randallia is 0.8σ and is about the same as that found for the action current of the nerve. Two impulses in the thick fibre may cause a mechanical response, as is shown by summation experiments. The pseudo-chronaxie of this contraction was measured as 3.5 σ. The second action current shows facilitation, when it follows the first within 1 sec.; a mechanical reaction results with summation intervals of two stimuli of less than 10σ. The facilitation of the action current increases with decrease of the time interval between the two impulses; with the shortest intervals that give summation the resulting action current is a smooth high spike.

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