Sparse Approximation Via Iterative Thresholding

The well-known shrinkage technique is still relevant for contemporary signal processing problems over redundant dictionaries. We present theoretical and empirical analyses for two iterative algorithms for sparse approximation that use shrinkage. The GENERAL IT algorithm amounts to a Landweber iteration with nonlinear shrinkage at each iteration step. The BLOCK IT algorithm arises in morphological components analysis. A sufficient condition for which General IT exactly recovers a sparse signal is presented, in which the cumulative coherence function naturally arises. This analysis extends previous results concerning the Orthogonal Matching Pursuit (OMP) and Basis Pursuit (BP) algorithms to IT algorithms

Study of the GPA Perspective Among Students at a Two-Year Institution

Higher Education Administratio

Targeted Selection of Stimulation Parameters for Restoration of Motor and Autonomic Function in Individuals With Spinal Cord Injury

Study Design: This is a report of methods and tools for selection of task and individual configurations targeted for voluntary movement, standing, stepping, blood pressure stabilization, and facilitation of bladder storage and emptying using tonic-interleaved excitation of the lumbosacral spinal cord. Objectives: This study aimed to present strategies used for selection of stimulation parameters for various motor and autonomic functions. Conclusions: Tonic-interleaved functionally focused neuromodulation targets a myriad of consequences from spinal cord injury with surgical implantation of the epidural electrode at a single location. This approach indicates the sophistication of the human spinal cord circuitry and its important role in the regulation of motor and autonomic functions in humans

Training-Induced Functional Gains following SCI

We previously demonstrated that daily, hour-long training sessions significantly improved both locomotor (limb kinematics, gait, and hindlimb flexor-extensor bursting patterns) and nonlocomotor (bladder function and at-level mechanical allodynia) functions following a moderate contusive spinal cord injury. The amount of training needed to achieve this recovery is unknown. Furthermore, whether this recovery is induced primarily by neuronal activity below the lesion or other aspects related to general exercise is unclear. Therefore, the current study objectives were to (1) test the efficacy of 30 minutes of step training for recovery following a clinically relevant contusion injury in male Wistar rats and (2) test the efficacy of training without hindlimb engagement. The results indicate that as little as 30 minutes of step training six days per week enhances overground locomotion in male rats with contusive spinal cord injury but does not alter allodynia or bladder function. Thirty minutes of forelimb-only exercise did not alter locomotion, allodynia, or bladder function, and neither training protocol altered the amount of in-cage activity. Taken together, locomotor improvements were facilitated by hindlimb step training for 30 minutes, but longer durations of training are required to affect nonlocomotor systems

Improvements in bladder, bowel and sexual outcomes following task-specific locomotor training in human spinal cord injury

<div><p>Objective</p><p>Locomotor training (LT) as a therapeutic intervention following spinal cord injury (SCI) is an effective rehabilitation strategy for improving motor outcomes, but its impact on non-locomotor functions is unknown. Given recent results of our labs’ pre-clinical animal SCI LT studies and existing overlap of lumbosacral spinal circuitries controlling pelvic-visceral and locomotor functions, we addressed whether LT can improve bladder, bowel and sexual function in humans at chronic SCI time-points (> two years post-injury).</p><p>Study design</p><p>Prospective cohort study; pilot trial with small sample size.</p><p>Methods</p><p>Eight SCI research participants who were undergoing 80 daily one-hour sessions of LT on a treadmill using body-weight support, or one-hour of LT and stand training on alternate days, as part of another research study conducted at the Kentucky Spinal Cord Injury Research Center, University of Louisville, were enrolled in this pilot trial. Urodynamic assessments were performed and International Data Set questionnaire forms completed for bladder, bowel and sexual functions at pre-and post-training time points. Four usual care (non-trained; regular at-home routine) research participants were also enrolled in this study and had the same assessments collected twice, at least 3 months apart.</p><p>Results</p><p>Filling cystometry documented significant increases in bladder capacity, voiding efficiency and detrusor contraction time as well as significant decreases in voiding pressure post-training relative to baseline. Questionnaires revealed a decrease in the frequency of nocturia and urinary incontinence for several research participants as well as a significant decrease in time required for defecation and a significant increase in sexual desire post-training. No significant differences were found for usual care research participants.</p><p>Conclusions</p><p>These results suggest that an appropriate level of sensory information provided to the spinal cord, generated through task-specific stepping and/or loading, can positively benefit the neural circuitries controlling urogenital and bowel functions.</p><p>Trial registration</p><p>ClinicalTrials.gov <a href="https://clinicaltrials.gov/ct2/show/NCT03036527" target="_blank">NCT03036527</a></p></div

Bladder capacity data summary.

<p>Bladder filling ceased and capacity measured (leak + residual volumes) with the occurrence of either spontaneous urine leakage (n = 5; reflex void), autonomic dysreflexia (n = 2; Participants A60 and C42) or a voluntary void following a strong urge (AIS D Participant C43). (A) A comparison of pre- and post-training bladder capacity values in each of the eight participants. A binomial proportion test indicates that a significant majority of the research participants demonstrated an improvement in bladder capacity (vs. random occurrence, p < .05). Note that research participant B23 had a suprapubic catheter and thus, the increase in capacity was incremental. (B) Bladder capacity increased significantly post-training (p = .02, 155.4 ± 76.1 vs 278.5 ± 147.8 ml).</p

LUT elements adapted from international SCI data set [74].

<p>LUT elements adapted from international SCI data set [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0190998#pone.0190998.ref074" target="_blank">74</a>].</p

Clinical characteristics of research participants.

<p>Clinical characteristics of research participants.</p