Is karate effective in improving postural control?

Background: Performing complex motor skills, such as the ones performed by karate athletes, requires a great sense of balance. Because the posturo-kinetic performance seems to be improved by sport practice, especially by sports involving a lot of posturokinetic activities, the aim of this review was to critically analyse the scientific literature in order to appraise whether any positive correlation between karate and improved postural control is scientifically supported. Material/Methods: The online search engines Scirus and Medline were used for generating the data. A comprehensive literature search was conducted based on the following keywords: “karate”, “postural control” and “body sway”. Results were collected and filtered manually. Results: Four articles were identified related to karate practice and postural control, covering a period between 1998 and 2009. Although different experimental approaches were used to investigate this concept, overall the results of these studies confirm the effectiveness of karate in improving postural control. Conclusions: Practicing karate seems to elicit long term improvements in postural control. However, a much deeper approach to this fighting sport, which would take into account its technical specificities (e.g. kata & kumite), is required in order to increase our understanding of the posture-kinetic impact of this relatively unexplored sport activity

Liquid – liquid phase separation morphologies in ultra-white beetle scales and a synthetic equivalent

Cyphochilus beetle scales are amongst the brightest structural whites in nature, being highly opacifying whilst extremely thin. However, the formation mechanism for the voided intra- scale structure is unknown. Here we report 3D x-ray nanotomography data for the voided chitin networks of intact white scales of Cyphochilus and Lepidiota stigma. Chitin-filling frac- tions are found to be 31 ± 2% for Cyphochilus and 34 ± 1% for Lepidiota stigma, indicating previous measurements overestimated their density. Optical simulations using finite- difference time domain for the chitin morphologies and simulated Cahn-Hilliard spinodal structures show excellent agreement. Reflectance curves spanning filling fraction of 5-95% for simulated spinodal structures, pinpoint optimal whiteness for 25% chitin filling. We make a simulacrum from a polymer undergoing a strong solvent quench, resulting in highly reflective ( 94%) white films. In-situ X-ray scattering confirms the nanostructure is formed through spinodal decomposition phase separation. We conclude that the ultra-white beetle scale nanostructure is made via liquid–liquid phase separation

Thermosensory mapping of skin wetness sensitivity across the body of young males and females at rest and following maximal incremental running

Humans lack skin hygroreceptors and we rely on integrating cold and tactile inputs from Atype skin nerve fibres to sense wetness. Yet, it is unknown whether sex and exercise independently modulate skin wetness sensitivity across the body. We mapped local sensitivity to cold, neutral and warm wetness of the forehead, neck, underarm, lower back, and dorsal foot in 10 males (27.8±2.7y; 1.92±0.1m 2 BSA) and 10 females (25.4±3.9y; 1.68 ± 0.1m 2 BSA), at rest and post maximal incremental running. Participants underwent our quantitative sensory test where they reported the magnitude of thermal and wetness perceptions (Visual Analogue Scales) resulting from the application of a cold (5°C below skin temperature) wet (0.8ml water), neutral wet, and warm wet (5°C above skin temperature) thermal probe (1.32cm2 ) to 5 skin sites. We found that: 1) females were ~14 to ~17% more sensitive to cold-wetness than males, yet both sexes were as sensitive to neutral- and warm-wetness; 2) regional differences were present for cold-wetness only, and these followed a cranio-caudal increase that was more pronounced in males (i.e. the foot was ~31% more sensitive than the forehead); 3) maximal exercise reduced cold-wetness sensitivity over specific regions in males (i.e. ~40% decrease in foot sensitivity), and it also induced a generalised reduction in warm-wetness sensitivity in both sexes (i.e. ~4 to ~6%). For the first time, we show that females are more sensitive to cold wetness than males, and that maximal exercise induce hygro-hypoesthesia. These novel findings expand our knowledge on sex differences in thermoregulatory physiology

Independent and interactive effects of thermal stress and mental fatigue on manual dexterity

Many occupations and sports require high levels of manual dexterity under thermal stress and mental fatigue. Yet, multi-stressor studies remain scarce. We quantified the interactive effects of thermal stress and mental fatigue on manual dexterity. Seven males (21.1±1.3y) underwent 6 separate 60-min trials characterised by a combination of 3 air temperatures (HOT: 37°C; NEUTRAL: 21°C; COLD: 7°C) and 2 mental fatigue states (MF: mental fatigue induced by a 35-min cognitive battery; No-MF: no mental fatigue). Participants performed complex (O'Connor test) and simple (Hand-Tool test) manual tasks pre- and post-trials to determine stressors-induced performance changes. We monitored participants' rectal temperature and hand skin temperature (Thand) continuously and assessed reaction time (Hand-Click test) and subjective mental fatigue (5-point scale). Thermal stress (p<0.0001), but not mental fatigue (p=0.290), modulated Thand (HEAT: +3.3°C [95%CI +0.2, +6.5]; COLD: -7.5°C [-10.7, -4.4]). Mental fatigue (p=0.021), but not thermal stress (p=0.646), slowed reaction time (~10%) and increased subjective fatigue. Thermal stress and mental fatigue had an interactive effect on the complex manual task (p=0.040), with COLD-No-MF decreasing performance by -22% [-39, -5], while NEUTRAL-MF, COLD-MF, and HEAT-MF by -36% [-53, -19], -34% [-52, -17], and -36% [-53, -19], respectively. Only mental fatigue decreased performance in the simple manual task (-30% [-43, -16] across all thermal conditions; p=0.002). Cold stress-induced impairments in complex manipulation increase with mental fatigue; yet combined stressors' effects are no greater than that of mental fatigue alone, which also impairs simple manipulation. Mental fatigue poses a greater challenge to manual dexterity than thermal stress

Additional file 1 of The Effects of Stretching Exercise on Levels of Blood Glucose: A Systematic Review with Meta-Analysis

Additional file 1. Material A. Full Search Strategy. Material B. The modified version of the Downs & Black checklist. Material C. Downs and Black Total Scores for Each Study

Individualized analysis of skin thermosensory thresholds and sensitivity in heat-sensitive people with multiple sclerosis

We investigated whether and how multiple sclerosis (MS) alters thresholds for perceiving increases and decreases in local skin temperature, as well as the sensitivity to progressively greater temperature stimuli, amongst heat-sensitive people with MS. Eleven MS patients (5 M/6 F; 51.1 ± 8.6 y, EDSS 5.7 ± 1.9) and 11 healthy controls (CTR; 7 M/4 F; 50.3 ± 9.0 y) performed warm and cold threshold tests on a hairy skin site, on both sides of the body. They also underwent a thermosensitivity test where they rated (visual analogue scale) perceived magnitude of 4 local skin stimuli (i.e. 22, 26, 34, 38°C). Individual thresholds and slopes of linear regression for thermosensitivity were z-transformed for each MS patient, and used to determine individual thermosensory abnormalities. When considering both threshold and thermosensitivity, six out of our 11 heat-sensitive patients (54.5%) exhibited skin thermosensory abnormalities. Those abnormalities varied amongst patients in terms of type (threshold vs. thermosensitivity), quality (warm vs. cold), location (left vs. right side of the body) and extent. Each of those six patients presented unique thermosensory profiles. While some patients experienced thermosensory loss in both thresholds and sensitivity and on both sides of the body, others experienced cold thermosensory loss on one side of the body only. The observed individual variability in thermosensory function among heat-sensitive MS patients highlight the need for a patient-centered approach to assessing thermosensory dysfunction and its potential implications for heat stress vulnerability in this patient group

Control of the Porous Structure of Polystyrene Particles Obtained by Nonsolvent Induced Phase Separation

Porous polystyrene microspheres were produced by a process of nonsolvent induced phase separation (NIPS) from ternary polymer–solvent–nonsolvent (polystyrene–toluene–ethanol) systems and characterized by scanning electron microscopy (SEM) and small-angle X-ray scattering (SAXS) techniques. This study provides evidence for a link between the structural morphology of the porous polystyrene particles and the polystyrene concentration in the initial solutions. A reciprocal relationship between pore diameter and polymer concentration was observed for the systems with the polymer amount below the critical chain overlap concentration, <i>C</i>*. Above <i>C</i>*, this relationship breaks down. The reciprocal relationship between porosity and polymer concentration can be used to facilitate the fine control of the void size. We demonstrate that the observed reciprocal relationship between pore diameter and polymer concentration correlates well with the relative amount of nonsolvent present in the system at the onset of the phase separation process. The pore size can be reduced and, consequently, the pore surface area can be increased either by reducing the polymer concentration in the initial solution or by decreasing the polymer molecular weight in the sample composition

Using concept mapping in the development of the EU-PAD framework (EUropean-Physical Activity Determinants across the life course): a DEDIPAC-study

Background: A large proportion of European children, adults and older adults do not engage in sufficient physical activity ( PA). Understanding individual and contextual factors associated with PA behaviours is essential for the identification and implementation of effective preventative environments, policies, and programmes that can promote an active lifestyle across life course and can potentially improve health. The current paper intends to provide 1) a multi-disciplinary, Pan-European and life course view of key determinants of PA behaviours and 2) a proposal of how these factors may cluster.Methods: After gathering a list of 183 potential PA behaviours-associated factors and a consensus meeting to unify/consolidate terminology, a concept mapping software was used to collate European experts' views of 106 identified factors for youth (= 65 years). The analysis evaluated common trends in the clustering of factors and the ratings of the distinct factors' expected modifiability and population-level impact on PA behaviours across the life course. Priority for research was also assessed for each cluster.Results: The concept mapping resulted in six distinct clusters, broadly merged in two themes: 1) the 'Person', which included clusters 'Intra-Personal Context and Wellbeing' and 'Family and Social Economic Status' ( 42 % of all factors) and 2) the 'Society', which included the remaining four clusters 'Policy and Provision', 'Cultural Context and Media', 'Social Support and Modelling', and 'Supportive Environment' ( 58 % of all factors). Overall, 25 factors were rated as the most impactful on PA behaviours across the life course and being the most modifiable. They were mostly situated in the 'Intra-Personal Context and Wellbeing' cluster. Furthermore, 16 of them were rated as top priority for research.Conclusions: The current framework provides a preliminary overview of factors which may account for PA behaviour across the life course and are most relevant to the European community. These insights could potentially be a foundation for future Pan-European research on how these factors might interact with each other, and assist policy makers to identify appropriate interventions to maximize PA behaviours and thus the health of European citizens