Translating Sleep Research: Does Sleep Promote Learning a Functional Motor Task?

Sleep has been demonstrated to produce off-line improvements in motor learning in young adults. Evidence of sleep-dependent off-line motor learning has been demonstrated across a wide variety of simple motor tasks that have limited implications in rehabilitation. It remains unclear whether a functional motor task that is clinically-relevant will benefit from sleep to produce off-line motor skill enhancement. Addressing this question was the purpose of this dissertation. A novel walking task was used to assess the role of sleep in learning a functional motor task in young adults. Twenty-four young individuals were randomly assigned to either the sleep or the no-sleep group. Results indicate that young participants who slept after practicing the novel walking task demonstrated a significant off-line improvement in performance on the functional task, while those participants who stayed awake failed to demonstrate off-line learning. Only a few recent studies have investigated sleep-dependent off-line motor learning in older adults, and the findings of these studies offer mixed conclusions. Only one study has examined the role of sleep in motor learning in middle-aged adults. These studies all used simple motor tasks. Therefore, we examined sleep-dependent off-line learning of the novel walking task in 20 middle-aged and 20 older adults. Only the middle-aged and older adults in the sleep condition demonstrated significant off-line improvement in performance on the novel walking task. However, when compared with the magnitude of off-line learning in young adults, the results indicate that the magnitude of off-line improvement was less for middle-aged and older adults groups. In summary, this body of work indicates that sleep enhances learning a functional motor task that is clinically-relevant in young, middle-aged, and older adults. Clinicians should consider sleep as an important factor when structuring rehabilitation interventions. Emphasis should be placed on addressing sleep disorders and ensuring adequate sleep for individuals who undergo rehabilitation

Sleep promotes offline enhancement of an explicitly learned discrete but not an explicitly learned continuous task

Catherine F Siengsukon, Alham Al-SharmanDepartment of Physical Therapy and Rehabilitation Science, University of Kansas Medical Center, Kansas City, KS, USABackground: Healthy young individuals benefit from sleep to promote offline enhancement of a variety of explicitly learned discrete motor tasks. It remains unknown if sleep will promote learning of other types of explicit tasks. The purpose of this study is to verify the role of sleep in learning an explicitly instructed discrete motor task and to determine if participants who practice an explicitly instructed continuous tracking task demonstrate sleep-dependent offline learning of this task.Methods: In experiment 1, 28 healthy young adults (mean age 25.6 ± 3.8 years) practiced a serial reaction time (SRT) task at either 8 am (SRT no-sleep group) or 8 pm (SRT sleep group) and underwent retention testing 12 ± 1 hours later. In experiment 2, 20 healthy young individuals (mean age 25.6 ± 3.3 years) practiced a continuous tracking task and were similarly divided into a no-sleep (continuous tracking no-sleep group) or sleep group (continuous tracking sleep group). Individuals in both experiments were provided with explicit instruction on the presence of a sequence in their respective task prior to practice.Results: Individuals in the SRT sleep group demonstrated a significant offline reduction in reaction time whereas the SRT no-sleep group did not. Results for experiment 1 provide concurrent evidence that explicitly learned discrete tasks undergo sleep-dependent offline enhancement. Individuals in the continuous tracking sleep group failed to demonstrate a significant offline reduction in tracking error. However, the continuous tracking no-sleep group did demonstrate a significant offline improvement in performance. Results for experiment 2 indicate that sleep is not critical for offline enhancement of an explicit learned continuous task.Conclusion: The findings that individuals who practiced an explicitly instructed discrete task experienced sleep-dependent offline learning while those individuals who practiced an explicitly instructed continuous task did not may be due to the difference in motor control or level of complexity between discrete and continuous tasks.Keywords: sleep, motor learning, discrete task, continuous tas

Time rather than sleep appears to enhance off-line learning and transfer of learning of an implicit continuous task

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author’s publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.There is increasing evidence that sleep promotes off-line enhancement of a variety of explicitly learned motor tasks in young adults. However, whether sleep promotes off-line consolidation of implicitly learned motor tasks is still under question. Furthermore, the role of sleep in promoting transfer of learning remains unknown. This study examined the role of sleep in learning and transfer of learning of an implicit continuous motor task. Twenty-three neurologically intact individuals (mean age 26.4 years) were randomly assigned to either a sleep group or a no-sleep group. The sleep group practiced a continuous tracking task in the evening and underwent retention and transfer testing the following morning, while the no-sleep group practiced the tracking task in the morning and underwent retention and transfer testing in the evening. The results show that in both the sleep and no-sleep groups, performance improved off-line without further practice for both the general skill and the sequence-specific skill. The results also indicate that sleep and time promote transfer of learning of both sequence-specific and general skill learning to a spatial and temporal variation of the motor task. These findings demonstrate that sleep does not play a critical role in promoting off-line learning and transfer of learning of an implicit continuous motor task

Sleep characteristics of individuals with chronic stroke: A pilot study

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Changes in sleep characteristics in individuals with chronic stroke are not well described, particularly compared with healthy individuals. Therefore, the aim of this pilot study was to explore the sleep characteristics in individuals with chronic stroke compared to age- and sex-matched controls. Sixteen individuals with chronic stroke and ten age- and sex-matched controls underwent two nights of polysomnographic recording. The sleep characteristics of interest included total sleep time, sleep efficiency, and percent time, as well as time in minutes spent in stages N1, N2, and N3 and stage R sleep. The individuals with chronic stroke spent less percent time in stage N3 compared with controls (P=0.048). No significant differences in the other sleep characteristics were found between the stroke and control groups. Individuals with chronic stroke present with altered stage N3 sleep compared with healthy controls. These alterations in stage N3 sleep might be a sign of neuronal dysfunction and may impact recovery following stroke. A larger scale study is needed to confirm these findings.American Heart Association Scientist Development Grant (09SDG2060618

Sleep parameters, functional status, and time post-stroke are associated with offline motor skill learning in people with chronic stroke

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author’s publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Background: Mounting evidence demonstrates that individuals with stroke benefit from sleep to enhance learning of a motor task. While stage NREM2 sleep and REM sleep have been associated with offline motor skill learning in neurologically intact individuals, it remains unknown which sleep parameters or specific sleep stages are associated with offline motor skill learning in individuals with stroke. Methods: Twenty individuals with chronic stroke (>6 months following stroke) and 10 control participants slept for three consecutive nights in a sleep laboratory with polysomnography. Participants practiced a tracking task the morning before the third night and underwent a retention test the morning following the third night. Offline learning on the tracking task was assessed. Pearson’s correlations assessed for associations between the magnitude of offline learning and sleep variables, age, upper-extremity motor function, stroke severity, depression, and time since stroke occurrence. Results: Individuals with stroke performed with significantly less error on the tracking task following a night of sleep (p = 0.006) while the control participants did not (p = 0.816). Increased sleep efficiency (r = −0.285), less time spent in stage NREM3 sleep (r = 0.260), and more time spent in stage REM sleep (r = −0.266) were weakly-to-moderately associated with increased magnitude of offline motor learning. Furthermore, higher upper-extremity motor function (r = −0.400), lower stroke severity (r = 0.360), and less time since stroke occurrence (r = 0.311) were moderately associated with increased magnitude of offline motor learning. Conclusion: This study is the first study to provide insight into which sleep stages and individual characteristics may be associated with offline learning in people with stroke. Further research is needed to delineate which factors or combination of factors promote offline motor learning in people with neurologic injury to best promote motor recovery in these individuals

Real-Time Unified Trajectory Planning and Optimal Control for Urban Autonomous Driving Under Static and Dynamic Obstacle Constraints

Trajectory planning and control have historically been separated into two modules in automated driving stacks. Trajectory planning focuses on higher-level tasks like avoiding obstacles and staying on the road surface, whereas the controller tries its best to follow an ever changing reference trajectory. We argue that this separation is (1) flawed due to the mismatch between planned trajectories and what the controller can feasibly execute, and (2) unnecessary due to the flexibility of the model predictive control (MPC) paradigm. Instead, in this paper, we present a unified MPC-based trajectory planning and control scheme that guarantees feasibility with respect to road boundaries, the static and dynamic environment, and enforces passenger comfort constraints. The scheme is evaluated rigorously in a variety of scenarios focused on proving the effectiveness of the optimal control problem (OCP) design and real-time solution methods. The prototype code will be released at https://github.com/WATonomous/control

On high-speed turning of a third-generation gamma titanium aluminide

Gamma titanium aluminides are heat-resistant intermetallic alloys predestined to be employed in components suffering from high mechanical stresses and thermal loads. These materials are regarded as difficult to cut, so this makes process adaptation essential in order to obtain high-quality and defect-free surfaces suitable for aerospace and automotive parts. In this paper, an innovative approach for longitudinal external high-speed turning of a third-generation Ti-45Al-8Nb- 0.2C-0.2B gamma titanium aluminide is presented. The experimental campaign has been executed with different process parameters, tool geometries and lubrication conditions. The results are discussed in terms of surface roughness/integrity, chip morphology, cutting forces and tool wear. Experimental evidence showed that, due to the high cutting speed, the high temperatures reached in the shear zone improve chip formation, so a crack-free surface can be obtained. Furthermore, the use of a cryogenic lubrication system has been identified in order to reduce the huge tool wear, which represents the main drawback when machining gamma titanium aluminides under the chosen process condition

Emotional Intelligence for superintendents in Irbid Governorate and its Relationship to Job Satisfaction الذكاء العاطفي لمديري التربية والتعليم في محافظة إربد وعلاقته بالرضا الوظيفي

Abstract: This study aimed to identify the emotional intelligence of the educational principals in the Irbid Governorate and its relationship to job satisfaction from the point of view of employees in the directorates. In order to achieve the objectives of the study, the descriptive correlational method was used. The questionnaire was used to collect data. The study sample consisted of (325) employees from the Irbid governorate during the academic year 2018/2019. The results showed that the degree of emotional intelligence of the superintendents in Irbid governorate was medium and that the job satisfaction of the employees was low. A statistically significant relationship was found between the level of emotional intelligence of superintendents and the level of employees\u27 satisfaction. ملخص: هدفت هذه الدراسة التعرف إلى الذكاء العاطفي لمديري التربية والتعليم في محافظة إربد وعلاقته بالرضا الوظيفي من وجهة نظر العاملين في المديريات, ولتحقيق أهداف الدراسة, تم استخدام المنهج الوصفي الارتباطي, واستخدمت الاستبانة كوسيلة لجمع البيانات, تكونت عينة الدراسة من (325) فرداً من موظفي مديريات التربية والتعليم في محافظة إربد خلال العام الدراسي 2018/2019 م. أظهرت النتائج أن درجة الذكاء العاطفي لدى مديري التربية والتعليم في محافظة إربد كانت متوسطة, وأن الرضا الوظيفي لدى العاملين كان منخفضاً. كما تبين وجود علاقة ارتباطية دالة إحصائياً بين مستوى الذكاء العاطفي للمديرين ومستوى الرضا الوظيفي للعاملين