2,078 research outputs found
No effect of New Zealand blackcurrant extract on recovery of muscle damage following running a half-marathon
New Zealand blackcurrant (NZBC) contains anthocyanins, known to moderate blood flow and display anti-inflammatory properties that may improve recovery from exercise-induced muscle damage. The authors examined whether NZBC extract supplementation enhances recovery from exercise-induced muscle damage after a half-marathon race. Following a randomized, double-blind, independent groups design, 20 (eight women) recreational runners (age 30 ± 6 years, height 1.73 ± 0.74 m, body mass 68.5 ± 7.8 kg, half-marathon finishing time 1:56:33 ± 0:18:08 hr:min:s) ingested either two 300-mg/day capsules of NZBC extract (CurraNZ™) or a visually matched placebo, for 7 days prior to and 2 days following a half-marathon. Countermovement jump performance variables, urine interleukin-6, and perceived muscle soreness and fatigue were measured pre, post, and at 24 and 48 hr after the half-marathon and analyzed using a mixed linear model with statistical significance set a priori at p  .05). Urine interleukin-6 increased 48-hr post-half-marathon in the NZBC group only (p  .05). Perceived muscle soreness and fatigue increased immediately post-half-marathon (p  .05). Supplementation with NZBC extract had no effect on the recovery of countermovement jump variables and perceptions of muscle soreness or fatigue following a half-marathon in recreational runners
Role of cytoplasmic dynein in the axonal transport of microtubules and neurofilaments
Recent studies have shown that the transport of microtubules (MTs) and neurofilaments (NFs) within the axon is rapid, infrequent, asynchronous, and bidirectional. Here, we used RNA interference to investigate the role of cytoplasmic dynein in powering these transport events. To reveal transport of MTs and NFs, we expressed EGFP-tagged tubulin or NF proteins in cultured rat sympathetic neurons and performed live-cell imaging of the fluorescent cytoskeletal elements in photobleached regions of the axon. The occurrence of anterograde MT and retrograde NF movements was significantly diminished in neurons that had been depleted of dynein heavy chain, whereas the occurrence of retrograde MT and anterograde NF movements was unaffected. These results support a cargo model for NF transport and a sliding filament model for MT transport
Supervised walking exercise therapy improves gait biomechanics in patients with peripheral artery diseas
Objective In patients with peripheral artery disease (PAD), supervised exercise therapy is a first line of treatment because it increases maximum walking distances comparable with surgical revascularization therapy. Little is known regarding gait biomechanics after supervised exercise therapy. This study characterized the effects of supervised exercise therapy on gait biomechanics and walking distances in claudicating patients with PAD. Methods Forty-seven claudicating patients with PAD underwent gait analysis before and immediately after 6 months of supervised exercise therapy. Exercise sessions consisted of a 5-minute warmup of mild walking and stretching of upper and lower leg muscles, 50 minutes of intermittent treadmill walking, and 5 minutes of cooldown (similar to warmup) three times per week. Measurements included self-perceived ambulatory limitations measured by questionnaire, the ankle-brachial index (ABI), walking distance measures, maximal plantar flexor strength measured by isometric dynamometry, and overground gait biomechanics trials performed before and after the onset of claudication pain. Paired t-tests were used to test for differences in quality of life, walking distances, ABI, and maximal strength. A two-factor repeated measures analysis of variance determined differences for intervention and condition for gait biomechanics dependent variables. Results After supervised exercise therapy, quality of life, walking distances, and maximal plantar flexor strength improved, although the ABI did not significantly change. Several gait biomechanics parameters improved after the intervention, including torque and power generation at the ankle and hip. Similar to previous studies, the onset of claudication pain led to a worsening gait or a gait that was less like healthy individuals with a pain-free gait. Conclusions Six months of supervised exercise therapy produced increases in walking distances and quality of life that are consistent with concurrent improvements in muscle strength and gait biomechanics. These improvements occurred even though the ABI did not improve. Future work should examine the benefits of supervised exercise therapy used in combination with other available treatments for PAD
Report on the AAPM Grand Challenge on deep generative modeling for learning medical image statistics
The findings of the 2023 AAPM Grand Challenge on Deep Generative Modeling for
Learning Medical Image Statistics are reported in this Special Report. The goal
of this challenge was to promote the development of deep generative models
(DGMs) for medical imaging and to emphasize the need for their domain-relevant
assessment via the analysis of relevant image statistics. As part of this Grand
Challenge, a training dataset was developed based on 3D anthropomorphic breast
phantoms from the VICTRE virtual imaging toolbox. A two-stage evaluation
procedure consisting of a preliminary check for memorization and image quality
(based on the Frechet Inception distance (FID)), and a second stage evaluating
the reproducibility of image statistics corresponding to domain-relevant
radiomic features was developed. A summary measure was employed to rank the
submissions. Additional analyses of submissions was performed to assess DGM
performance specific to individual feature families, and to identify various
artifacts. 58 submissions from 12 unique users were received for this
Challenge. The top-ranked submission employed a conditional latent diffusion
model, whereas the joint runners-up employed a generative adversarial network,
followed by another network for image superresolution. We observed that the
overall ranking of the top 9 submissions according to our evaluation method (i)
did not match the FID-based ranking, and (ii) differed with respect to
individual feature families. Another important finding from our additional
analyses was that different DGMs demonstrated similar kinds of artifacts. This
Grand Challenge highlighted the need for domain-specific evaluation to further
DGM design as well as deployment. It also demonstrated that the specification
of a DGM may differ depending on its intended use
Recent Space PV Concentrator Advances: More Robust, Lighter, and Easier to Track
Over the past three years, the authors have collaborated on several significant advances in space photovoltaic concentrator technology, including a far more robust Fresnel lens for sunlight concentration, improved color-mixing features for the lens to minimize chromatic aberration losses for next-generation 4-junction and 6-junction IMM cells, a new approach to suntracking requiring only one axis of rotation even in the presence of large beta angles (e.g., +/- 50 deg), a new waste heat radiator made of graphene, with 80-90% reduction in mass, and a new platform for deployment and support on orbit (SOLAROSA). These patent-pending advances are described in this paper
The Alcohol Relapse Situation Appraisal Questionnaire: Development and Validation
Background: The role of cognitive appraisal of the threat of alcohol relapse has received little attention. A previous instrument, the Relapse Situation Appraisal Questionnaire (RSAQ), was developed to assess cocaine users’ primary appraisal of the threat of situations posing a high risk for cocaine relapse. The purpose of the present study was to modify the RSAQ in order to measure primary appraisal in situations involving a high risk for alcohol relapse.
Methods: The development and psychometric properties of this instrument, the Alcohol Relapse Situation Appraisal Questionnaire (A-RSAQ), were examined with two samples of abstinent adults with alcohol abuse or dependence. Factor structure and validity were examined in Study 1 (N= 104). Confirmation of the factor structure and predictive validity was assessed in Study 2 (N= 159).
Results: Results demonstrated construct, discriminant and predictive validity and reliability of the ARSAQ.
Discussion: Results support the important role of primary appraisal of degree of risk in alcohol relapse situations
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