Dynamics of Perception Distortions of Human Body Physical Dimensions in Virtual Reality

Controlling characters in a virtual reality (VR) environment can lead to the interiorization of their body dimensions by the recipients. The possible preservation of these distortions in their psyche will indicate a high degree of psychological impact of a VR on a person and the potential danger of developing depersonalization of the recipients and their dependence on such stimulation. The study of the stability of these distortions is necessary in the context of ensuring the safety of the impact of VR environments on the human psyche. The main focus of the study is on the perception distortions of human body dimensions, as they are sensed by people immersed in a VR environment, and their dynamics depending on the number of immersions. The impact of the virtual reality environment was simulated using the Freedom Locomotion VR application. One virtual reality immersion session took 15 minutes. To obtain psychometric indicators of the subjects perception of their own body dimensions, the technique Measurements according to M. Feldenkrais was used. All the participants (N = 45, three experimental groups) underwent a mandatory preliminary measurement using this technique (several hours before exposure) and a final measurement (one day after the last exposure). At the same time, the results of preliminary measurements were taken as indicators of the subjects habitual perception of their own body dimensions and were considered in each data processing as a comparison group. Free movement in a VR environment leads to distortions in the subjects perception of their own body dimensions. In all the experimental groups, there was a tendency to exaggerate body dimensions immediately after immersions, which indicates the qualitative similarity of these distortions. The effect of repetitive immersion in a VR environment on the perception of body dimensions is that it increases awareness in perceiving body parts that are least active at the time of immersion. Controlling an anthropomorphic character in a VR leads to an increase in the subjective significance of the recipients own body perception and an increased concentration of attention on the parameters least involved in immersion. The results of the study show that an increased level of awareness in perceiving their own bodies is characteristic of the subjects who have experience of repetitive immersions in a VR environment in the guise of an anthropomorphic character. Controlling a bodily projection in a VR headset does not cause its long-term interiorization, but has a positive effect on the formation of personal corporeality.

Laser Watch—New Generation 2021: Modern Integrative Photomedicine Equipment for Photobiomodulation

In the recent past, laser therapy has made immense progress as it is known to change microcirculation, modulate vegetative parameters, and stimulate mitochondrial activity in the human body. This editorial briefly describes a new laser watch prototype (generation 2021), which can be used to perform continuous and simultaneous blood irradiation at the radial and/or ulnar artery of the wrist with different wavelengths of laser light. In a preliminary measurement, the increase in regional oxygen saturation at the crook of the elbow during laser light stimulation with the watch was observed using near-infrared spectroscopy. Apart from this, laser stimulation applied via a newly designed laser watch can modulate biological parameters (photobiomodulation). However, presently, the possible long-term effects are not known, as there are no studies on this topic available to date.

The Relationship between Changes in GRIT, Taekwondo Ability, and Academic Achievement of University Students Majoring in Science and Engineering and Participating in Taekwondo Class

GRIT, which was conceptualized by the American psychologist Duckworth, was designed by grouping growth (G), resilience (R), intrinsic motivation (I), and tenacity (T), which means continuing to be patient and put in effort to achieve goals without being frustrated by adversity or failures experienced in the process of striving toward one’s goals. The purpose of this study was to determine GRIT changes caused by participation of students majoring in science and engineering in taekwondo class. Effects of taekwondo ability on GRIT and academic achievement were also examined to determine structural relationships among taekwondo ability, GRIT, and academic achievement. We selected a total of 305 students (204 participants and 101 non-participants) as research subjects and conducted a GRIT (preliminary) measurement. After one-year of taekwondo class, we collected and statistically processed the data of GRIT (post) measurement, taekwondo ability, and academic achievement of the participants. Reliability analysis, technical statistics, paired sample t-test, correlation analysis, and path analysis were performed. Changes in the GRIT values of the participants were found to be greater than those of non-participants. It was also found that taekwondo ability, GRIT, and academic achievement had significant correlations with each other. Finally, it was found that the higher the taekwondo ability, the higher the academic achievement and the higher the GRIT. Moreover, the higher the GRIT, the higher the academic achievement. Taekwondo training increased the GRIT values of participants. In addition, the taekwondo ability had positive effects on GRIT and academic achievement. GRIT also had a positive effect on academic achievement. Thus, there were structural relationships among taekwondo ability, GRIT, and academic achievement.

No differences in the body fat after violating core bioelectrical impedance measurement assumptions

Objective It is unclear to what degree acutely violating bioelectrical impedance analysis (BIA) measurement assumptions will alter the predicted percent fat mass (%FM) and whether this differs by sex or body mass index (BMI). Methods %FM was assessed under control, dehydration, exercise, water, food intake and non-voided bladder conditions with three BIA devices (Tanita: BC-418, TBF-314, & Omron HBF-306CN) for men (n = 23, age: 24.0 ± 5.2 years old) and women (n = 17, age: 22.5 ± 3.4 years old) separately. Results For all BIA devices, there were no differences in the %FM values between the control and the other conditions in men or women (− 1.9 to 0.4%, p > 0.05). Across the three devices and five conditions, 97% of %FM tests returned values within 5% of control (2 tests), and 86% of tests were within 2% of control despite violating an assumption. The errors were greatest with dehydration and women were more likely to have a %FM difference greater than 2% than men with dehydration using the hand-to-foot device (Tanita TBF-314: 59% versus 9%). There were no differences in %FM between control and the conditions when examined by BMI (overweight/obesity: − 2.8 to 0.1% and normal weight: − 1.7 to 0.5%; BMI*trial, p = 0.99). Conclusion %FM estimates were similar despite acutely violating the preliminary measurement BIA assumptions across a range of different BMIs. The minor variations in %FM are smaller than what would be expected with day-to-day variability or weight loss intervention but may be larger in women than men.

Turbulent jet stability increased by ribs inside the nozzle – Stereo PIV measurement one diameter past the nozzle

We observe that decreasing the inner nozzle surface by adding longitudinal ribs increases the jet stability in terms of the amount of turbulent kinetic energy in the near shear layer. We try to explain our observation as a stabilization effect of secondary flow vortices emerging in the corners of the ribs. These stream-wise vortices damage the development of larger-scale structures in the near shear layer. This explanation is supported by autocorrelation function of the stream-wise velocity component, which displays slightly smaller integral length-scale in the case with ribs than in the case of smooth nozzle. The experiment is performed at Reynolds number 2.2 × 105 (based on the nozzle diameter 50 mm); the Stereo-PIV (Particle Image Velocimetry) measurement takes place at the plane perpendicular to the jet axis one diameter past the nozzle exit. Optical 3D scanner controls the real nozzle geometry. This article presents preliminary measurement at single position and single velocity only; further exploration of this problem is needed.

Preliminary results of EURAMET Rockwell comparison between INRiM and UME (EURAMET.M.H-S1.A.B.C)

A bilateral supplementary comparison between INRiM (National Metrology Institute of Italy) and UME (National Metrology Institute of Turkey) had been decided to be organized in the field of Hardness Metrology to determine the consistency of the national hardness standards in both countries realizing Rockwell Hardness measurements in accordance with ISO 6508-1:2016 and ISO 6508-3:2015 standards. In this paper the procedure and preliminary measurement results of the bilateral EURAMET supplementary comparison between the two laboratories are explained.

Measuring IGF-1 and IGFBP-3 profiles in women seeking assisted reproduction; relevance to clinical outcomes from in vitro fertilization (Study 5).

In this fifth study examining the relevance of the insulin-like growth factor (IGF) profiles, namely serum IGF-1 levels, its main binding protein, serum IGFBP-3 levels and the IGF ratio (IGFBP-3/IGF-1), we have examined clinical outcomes with respect to the quartile ranges of each parameter measured in 1633 IVF-naïve women. The outcomes were derived from 1035 of these women who initiated 1747 IVF cycles. Of the three parameters, only IGF-1 levels proved relevant to the clinical outcomes. In particular, this study confirmed our earlier report that IGF-1 levels decline across the quartiles with the woman’s advancing age and the proportion of women with IGF-1 levels in the highest quartile comprised the younger, whilst those women ≥40 years were mostly in the lowest quartile (p<0.0001). IVF cycle cancellations were not different across the quartiles but at oocyte pick-up (OPU) there were significantly more oocytes from the highest IGF-1 quartile (10.4 oocytes) compared to the lowest (8.9 oocytes; p<0.01). Furthermore, the proportion of oocytes shown to be at the mature MII stage were also significantly higher (p=0.01). Consequently, the oocyte utilization rate was significantly greater from those women with the highest IGF-1 levels generating 5.3 embryos vs 4.3 embryos for the lowest quartile. However, the utilization rate of those embryos generated were similar across the IGF-1 quartiles and there were similar rates of “freeze-all embryos”, albeit more women had increased monitoring for ovarian hyperstimulation risk, related to the higher egg numbers in the highest IGF-1 quartile. The most striking clinical outcomes were that of the pregnancy productivity rate (including fresh and frozen embryo transfers from a single OPU) which was greatest in the highest IGF-1 quartile (61.5% vs 48.2% per OPU across all ages p<0.0002). Miscarriage rates were not different but live birth productivity rates were significantly greatest for the highest IGF-1 quartile (49% vs 33% per OPU across all ages; p<0.0002). We conclude that a preliminary measurement of the IGF-1 level can help to define the poor-prognosis female prior to IVF treatment and on whom adjuvant studies can be focused.

Derivation of Far-field Gain Using a Gain Reduction Effect in the Fresnel Region

A handy method of calculating far-field gain based on the magnitude of the power transmission in a Fresnel region is presented, which can be applied to the phaseless near-field measurement. Due to the short range inside an anechoic chamber, the probe antenna is often placed in the Fresnel region of the antenna under test (AUT). It is well-known that far-field gain of an antenna gradually reduces when one antenna moves to the other one placed in a proximity distance. This fact can be advantageously applied to estimate the far-field gain in a far-field region. The proposed method offers rapid estimation of the far-field gain based on the simple input knowledge such as the probe antenna gain and the magnitude of the power transmission and the separation distance between AUT and probe antenna. The proposed method can be applicable to a wide range of microwave antennas. This feature makes it possible to offer preliminary measurement results and reference parameters of the measurement for the various types of microwave antennas.