This study aimed to investigate the effects of wearing virtual reality (VR) with a head-mounted display (HMD) on body sway in younger and older adults. A standing posture with eyes open without an ...HMD constituted the control condition. Wearing an HMD and viewing a 30°-tilt image and a 60°-tilt image in a resting standing position were the experimental conditions. Measurements were made using a force plate. All conditions were performed three times each and included the X-axis trajectory length (mm), Y-axis trajectory length (mm), total trajectory length (mm), trajectory length per unit time (mm/s), outer peripheral area (mm
), and rectangular area (mm
). The results showed a significant interaction between generation and condition in Y-axis trajectory length (mm) and total trajectory length (mm), with an increased body center-of-gravity sway during the viewing of tilted VR images in older adults than in younger adults in both sexes. The results of this study show that body sway can be induced by visual stimulation alone with VR without movement, suggesting the possibility of providing safe and simple balance training to older adults.
Category:
Sports; Ankle
Introduction/Purpose:
In general, Static Stretching (SS) is widely used during warm-ups and cool-downs at competitive practices and events. Previous studies have shown that SS ...have improved muscle stiffness. On the other hand, previous studies have not shown range of motion, or vertical jump. Recently, acute effects of Cyclic Stretching (CS) have suggested to improve muscle stiffness and dynamic balance. CS is moved at a constant speed and angle using continuous passive and dynamometer-equipped exercise equipment. However, long-term CS and SS programs have been shown to improve muscle stiffness, hardness, and It is not known if muscle strength or physical performance is altered. This study aimed to examine the effects of a 4-week CS and SS program on muscle stiffness and hardness, muscle strength, and jump performance.
Methods:
The subjects participated 18 healthy men and were randomly assigned to a CS or SS group. Each stretching program was stretched in each condition for 2 minutes in a standing position in 5 days a week for 4 weeks. To assess muscle stiffness, muscle- tendon junction (MTJ) displacement and MTJ angle of gastrocnemius medialis (MG) were measured using ultrasonography and 20° before (pre-training) and after (post-training) conducting CS and SS program. MG hardness was measured using ultrasound real- time tissue elastography (RTE). ROM max and normalized peak torque (NPT) of ankle plantar flexor, squat jump (SJ) performance were measured in the pre- and post-training. The effects of the intervention on all outcome measures were determined using 2- way repeated-measures ANOVA with two group as a between participants factor and time (pre-training, post-training) When interaction effects were detected, post hoc comparisons were performed to test the differences in physical variables between pre- and post-training.
Results:
ROM max was significantly affected by time between CS and SS program (P < .001, F = 26.0). MTJ displacement from 0°to 20°were significantly affected by time (P < .05, F = 5.49; P < .01, F = 10.26; P < .01, F = 9.74). RTE from 0°to 20°were significantly affected by time (P < .01, F = 13.27; P < .01, F = 8.33; P < .01, F = 53.52). There was significantly interaction for NPT between CS and SS program (P < .01, F = 4.80). SJ were significantly affected by time (P < .05, F = 5.70).
Conclusion:
This study examined the long-term effect of CS and SS on ROM max, muscle stiffness, NPT, and SJ. The results indicate that CS training had greater improvement than SS training in muscle strength between pre- and post-training. A significant decrease in muscle stiffness and hardness after SS was observed compared with CS. However, CS not only improves muscle stiffness and hardness as shown the effect of SS but also suggests the possibility of being a new extension method to improve muscle strength.
The Short Physical Performance Battery (SPPB) is a physical fall-risk screening tool and predictor of adverse health effects for the older. Its limited use in Japan is due to the relative ease for ...high-functioning older adults to achieve perfect scores. Japanese researchers thus created a community-based SPPB (SPPB-com). This study investigated whether the SPPB-com score can distinguish between older patients classified as “fallers” and “non-fallers.” Participants comprised 185 older outpatients aged 65 and above who self-reported their history of accidental falls and relevant physical activity. Fall risk was assessed using SPPB and SPPB-com. Handgrip strength, maximum isometric knee extensor strength, and maximum walking speed were measured as physical functions. Multivariate logistic regression and receiver-operating characteristic analyses determined criteria indicating faller status. Fallers were older and had lower physical function, physical activity, SPPB, and SPPB-com scores than non-fallers. Multivariate logistic regression analysis showed SPPB (OR 0.76, 95% CI 0.59–0.99, p = 0.045) and SPPB-com (OR 0.63, 95% CI 0.45–0.87, p = 0.005) scores were both independently associated with prior falls. The SPPB-com score may function as a fall-risk assessment tool for older outpatients, and its combined use with SPPB can increase the accuracy and precision of distinction between fallers and non-fallers.
Elastic fibers play an important role in the characteristic resilience of many tissues. The assembly of tropoelastin into a fibrillar matrix is a complex stepwise process and the deposition and ...cross-linking of tropoelastin are believed to be key steps of elastic fiber formation. However, the detailed mechanisms of elastic fiber assembly have not been defined yet. Here, we demonstrate the relationship between deposition and the cross-linking/maturation of tropoelastin. Our data show that a C-terminal half-fragment of tropoelastin encoded by exons 16–36 (BH) is deposited onto microfibrils, yet we detect very limited amounts of the cross-linking amino acid, desmosine, an indicator of maturation, whereas the N-terminal half-fragment encoded by exons 2–15 (FH) was deficient for both deposition and cross-linking, suggesting that elastic fiber formation requires full-length tropoelastin molecules. A series of experiments using mutant BH fragments, lacking either exon 16 or 30, or a deletion of both exons showed that self-association of tropoelastin polypeptides was an early step in elastic fiber assembly. Immunofluorescence and Western blot assay showed that the treatment of cell culture medium or conditioned medium with β-aminopropionitrile to inhibit cross-linking, prevented both the deposition and polymerization of tropoelastin. In conclusion, our present results support the view that self-association and oxidation by lysyl oxidase precedes tropoelastin deposition onto microfibrils and the entire molecule of tropoelastin is required for this following maturation process.
Background:
Matrix metalloproteinases (MMPs) are known as important enzymes involved in tissue metabolism. Among them, MMP-2 and MMP-9 are termed gelatinases, but their specific roles in vivo are ...still unknown, including their expression patterns following ultraviolet (UV) irradiation.
Objective:
To elucidate the effects of UV irradiation on the skin, we analyzed the expression of MMP-2 and MMP-9 by primary human keratinocytes in culture.
Methods:
We evaluated the enzymatic functions of MMP-2 and MMP-9 by gelatin-zymography, and of MMP-9 expression by immunofluorescence, using cultured keratinocytes after UV irradiation.
Results:
The secretion of MMP-2 (72 kDa) remained at low levels under all conditions examined. Although MMP-9 (92 kDa) secretion was not induced by UVA, it was stimulated by UVB irradiation in a dose-dependent manner. In addition, an enzyme-linked immunosorbent assay showed the tendency to increase for the involucrin expression following UVB exposure. Cell viability was decreased by UVB irradiation in contrast to the induction of MMP-9 and involucrin.
Conclusion:
These results suggest that the induction of MMP-9 secretion is related to the inflammation including apoptosis of keratinocytes resulting from UVB irradiation.
To investigate a function of fibulin-5 in the elastic fiber formation, we studied the molecular interactions among elastin, fibrillin-1, and fibulin-5 in the extracellular space and the maturation of ...tropoelastin using retinal pigment epithelial cells (ARPE-19).
Bacterial recombinant tropoelastin (rTE) was added to ARPE-19 cells overexpressing V5-tagged fibulin-5 (ARPE-Fibulin-5). These elastic fibers were evaluated by immunofluorescence staining, the quantitative analysis of cross-linked amino acids, and semi-quantitative analysis of matrix-associated tropoelastin.
Immunoprecipitation assays revealed that fibulin-5 is able to separately interact with tropoelastin or fibrillin-1 in the culture medium. Moreover, immunofluorescent staining showed that elastin, fibrillin-1, and fibulin-5 co-localize in the extracellular matrix. Desmosine levels were significantly increased in ARPE-Fibulin-5 relative to untransfected cells in spite of equal deposition of tropoelastin by enzyme-linked immunosorbent assay. The addition of a tropoelastin isoform, which lacked the peptide encoded by exon 26A (Δ26A) and could bind to fibulin-5 strongly, led to a larger increase in cross-linking amino acids compared to tropoelastin containing the exon 26A peptide sequence.
These data provide new insights into the initial steps of elastic fiber assembly and identify fibulin-5 and tropoelastin isoforms as potential targets for the regeneration of elastic fibers in vivo.
Fibulin-5 is believed to play an important role in the elastic fiber formation. The present experiments were carried out to characterize the molecular interaction between fibulin-5 and tropoelastin. ...Our data showed that the divalent cations of Ca²⁺, Ba²⁺ and Mg²⁺ significantly enhanced the binding of fibulin-5 to tropoelastin. In addition, N-linked glycosylation of fibulin-5 does not require for the binding to tropoelastin. To address the fibulin-5 binding site on tropoelastin constructs containing, exons 2-15 and exons 16-36, of tropoelastin were used. Fibulin-5 binding was significantly reduced to either fragment and also to a mixture of the two fragments. These results suggested that the whole molecule of tropoelastin was required for the interaction with fibulin-5. In co-immunoprecipitation experiments, tropoelastin binding to fibulin-5 was enhanced by an increase of temperature and sodium chloride concentration, conditions that enhance the coacervation of tropoelastin. The binding of tropoelastin fragments to fibulin-5 was directly proportional to their propensity to coacervate. Furthermore, the addition of fibulin-5 to tropoelastin facilitated coacervation. Taken together, the present study shows that fibulin-5 enhances elastic fiber formation in part by improving the self-association properties of tropoelastin.
The anterior talofibular ligament connects the talus to the lateral malleolus and is an essential component in understanding the pathophysiology of ankle sprains. In recent years, ultrasound is often ...used in its evaluation, however, most of it remains a static assessment (Rein S et al., 2020).
Are there gender differences in the dynamics of the distance between the talus and the lateral malleolus during the stance phase of gait using ultrasound in healthy adults?
The participants in this study were 10 healthy males and 9 healthy females. All participants did not report a history of previous ankle sprains. We used a motion capture system (Vicon Motion Systems, UK) synchronized with an ultrasound (Art Us EXT-1H, Telemed, Vilnius, Lithuania) to examine the distance between the talus and the lateral malleolus during the stance phase of gait. The US probe (5-11MHz, 60-mm field of view; Echoblaster, Telemed, Vilnius, Lithuania) was positioned on the lateral side of the ankle joint and visualized the most lateral part of the talus and lateral malleolus on the ultrasound screen. Participants walked at a comfortable speed on a force plate (OR-6, 1000Hz: AMTI, USA) and the interval from heel contact to toe-off was included in the analysis. Tracker 5.1.5 software (Open-Source Physics) was used to calculate the distance between the talus and lateral malleolus and the amount of change with respect to that distance at heel contact. Unpaired t-tests were used to compare the gender differences in that distance in the early, middle, and terminal stance phases.
The changes in the distance between the talus and the lateral malleolus were -0.15±1.15mm in the early stance phase, -0.98±1.99mm in the middle stance phase, and -0.77±1.99mm in the terminal stance phase in males and -0.84±0.92mm, -2.24±1.40mm, and -0.64±1.52mm in women, respectively. The changes in the distance were significantly higher in females than in males in the early and middle stance phases.
In females, the distance between the talus and the lateral malleolus during the stance phase of gait is highly variable, and this hypermobility may be a risk for ankle sprains and future ankle osteoarthritis. Prior study has reported that joint laxity is greater in women than in men after puberty, which may affect the incidence of injury (Quatman CE et al., 2008). This study using ultrasound could provide a basic data for examining ankle dynamics during gait in patients with ankle sprains.
Towards building robust DNN applications Yokoyama, Haruki; Onoue, Satoshi; Kikuchi, Shinji
2020 35th IEEE/ACM International Conference on Automated Software Engineering (ASE),
12/2020
Conference Proceeding
Data augmentation techniques that increase the amount of training data by adding realistic transformations are used in machine learning to improve the level of accuracy. Recent studies have ...demonstrated that data augmentation techniques improve the robustness of image classification models with open datasets; however, it has yet to be investigated whether these techniques are effective for industrial datasets. In this study, we investigate the feasibility of data augmentation techniques for industrial use. We evaluate data augmentation techniques in image classification and object detection tasks using an industrial in-house graphical user interface dataset. As the results indicate, the genetic algorithm-based data augmentation technique outperforms two random-based methods in terms of the robustness of the image classification model. In addition, through this evaluation and interviews with the developers, we learned following two lessons: data augmentation techniques should (1) maintain the training speed to avoid slowing the development and (2) include extensibility for a variety of tasks.
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