Relative Contribution among Physical Fitness Factors Contributing to the Performance of Modern Pentathlon

This study reveals the relationship between physical fitness factors and performance in modern pentathlon and identifies the contribution of each physical factor to overall performance. The physical fitness assessment data and the competition records collected by the Korean national team pentathletes for the years 2005 to 2019 were tracked. The correlation between the competition records and fitness factors was confirmed by correlation analysis. In addition, the physical factors affecting performance were identified through multiple regression analysis, and the average difference between national and international competitions was verified by t-test. The first result was that fencing, swimming, and horseback riding rankings were more relevant to the overall pentathlon performance score than the combined rankings in national competitions. In the international competitions, performance in the combined running and shooting event was more relevant than fencing, swimming, and horseback riding. Second, the basic fitness factors of grip strength and sergeant jump and the specific fitness factors of leg strength—left and right average flexor were correlated with overall pentathlon performance national competitions. However, in international competitions, sergeant jump, 20 m shuttle run, reaction time, lung capacity, and back strength were correlated (presented in high to low order). In terms of the specific fitness factors, relative (%BW) and absolute (Nm) leg strength—left and right average flexor, lower body anaerobic fatigue rate, half squat, relative (W/kg) and absolute (Watts) maximal lower body anaerobic power were correlated accordingly with overall pentathlon performance. Third, we analyzed the differences between average performance in national and international competitions. Only the combined running and shooting event out of the five modern pentathlon events showed a difference. Grip strength and relative leg strength—average extensor AP (%BW) appeared to be different among the physical fitness factors. Fourth, we examined the level of contribution of each of the fitness factors on overall performance. The model’s goodness of fit was confirmed, and grip strength was found to have a significant contribution on overall performance. Furthermore, the level of contribution was higher in the following order: relative leg strength—left and right average flexor (%BW), bench press, half squat, relative leg strength— average extensor AP(%BW), GXT—time to exhaustion, relative lower body anaerobic average power (W/kg), and maximal lactic acid concentration. With the 2020 Tokyo Olympics just around the corner, combined running and shooting performance appeared to be a decisive factor in the final ranking in modern pentathlon according to the analysis of the basic and specific fitness factors of pentathletes. The basic fitness factors are critical in order of sergeant jump, grip strength, reaction time, lung capacity, side-step, back strength, 20 m shuttle run, sit-and-reach, sit-ups, and single leg standing. With respect to the specific fitness factors, relative leg strength—left and right average flexor (%BW), bench press, half squat, relative leg strength—average extensor AP (%BW), GXT—time to exhaustion, relative lower body anaerobic average power (W/kg), and maximal lactic acid concentration showed their relevance accordingly. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.1

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 con-tinuing 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. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.1

Physical Fitness Levels in Korean Adolescents: The National Fitness Award Project

Background : Although physical fitness in adolescents has been widely studied, there is the lack of information regarding developmental patterns of various youth fitness components. The LMS (L=skewness, M=median curve, and S=coefficient of variation) statistical method has been utilized to develop growth percentiles for height and weight as well as for fitness in the US and Europe countries. The purpose of this study was to develop age- and sex-specific smoothed percentile curves for fitness using the LMS method in Korean adolescents aged 13-18 years. Methods : A sample of 14,794 adolescents (7,688 boys and 7,106 girls) who participated in the National Fitness Award Project in 2013 and 2014 was analyzed. The components were cardiorespiratory fitness (20-m PACER), muscle strength (handgrip strength), muscle endurance (partial curl-up, 30-s endurance jump), and flexibility (sit and reach). Age- and sex-specific smoothed percentile curves were calculated for fitness using the LMS method. Results : Age- and sex-specific smoothed percentile curves (5th, 10th, 25th, 50th, 75th, 90th, and 95th) were presented for each fitness component. Except for flexibility, fitness levels were higher in boys than in girls. In general, performance in fitness components, except for partial curl-ups, increased with age in boys. However, in girls, performance in fitness components, except for partial curl-ups, slightly increased or remained stable. Conclusion : This study presented age- and sex-specific fitness percentile curves for Korean adolescents aged 13-18 years. This material might be useful in understanding and evaluating the fitness status of Korean adolescents

Atypical Cognitive Impairment and Recovery in Two Colorectal Cancer Patients

Cognitive impairment in cancer patients can be caused by various factors; in approximately 30% of cancer patients, the symptoms appear before starting treatment. Paraneoplastic limbic encephalitis (PLE) is a rare disease associated with an autoimmune response, and is characterized by memory loss, depression, and personality changes; it is one of the potential causes of cognitive dysfunction in cancer patients. Two patients were previously diagnosed with mild cognitive impairment and maintained clinical stability; after suffering a rapid change in personality and sudden cognitive decline, colorectal cancer was diagnosed within a few months. The patients did not meet the diagnostic criteria for PLE in several tests. The symptoms improved after the underlying cancer was treated, and the patients returned to their previous stable state. Sudden cognitive impairment may appear as an early cancer symptom, and PLE is considered an atypical cause for these symptoms. However, in patients with unexplained PLE-like symptoms who do not meet the diagnostic criteria for PLE, probable etiologies to be considered are the gut–brain connection, CD8+ T-cell-mediated limbic encephalitis, and somatic mutations in dementia-related genes. Currently, few studies have investigated these symptoms, and further research will offer significant therapeutic strategies for cognitive impairment in cancer patients

Bifunctional Sensing Characteristics of Chemical Vapor Deposition Synthesized Atomic-Layered MoS₂

Two-dimensional (2D) molybdenum disulfide (MoS₂) atomic layers have a strong potential to be adopted for 2D electronic components due to extraordinary and novel properties not available in their bulk foams. Unique properties of the MoS₂, including quasi-2D crystallinity, ultrahigh surface-to-volume, and a high absorption coefficient, have enabled high-performance sensor applications. However, implementation of only a single-functional sensor presents a limitation for various advanced multifunctional sensor applications within a single device. Here, we demonstrate the charge-transfer-based sensitive (detection of 120 ppb of NO₂) and selective gas-sensing capability of the chemical vapor deposition synthesized MoS₂ and good photosensing characteristics, including moderate photoresponsivity (∼71 mA/W), reliable photoresponse, and rapid photoswitching (<500 ms). A bifunctional sensor within a single MoS₂ device to detect photons and gas molecules in sequence is finally demonstrated, paving a way toward a versatile sensing platform for a futuristic multifunctional sensor

RPTPμ tyrosine phosphatase promotes adipogenic differentiation via modulation of p120 catenin phosphorylation

Protein tyrosine phosphatases act as key regulators in differentiation-associated signaling pathways. It is proposed that RPTPμ acts as a positive regulator of adipogenesis by modulating the cytoplasmic p120 catenin level

Development of plasma sources and diagnostics for the simulation of fusion edge plasmas

© 2022, The Korean Physical Society.Although the research on divertors and scrape-off layers (SOLs) has been not as focused on as the recent success of the Korean fusion program, a few linear plasma devices have been developed for simulating divertor and SOL plasmas: (1) diversified plasma simulator (DiPS), a versatile linear machine, has been developed for simulations of divertor and space plasmas with various electric probes, such as single, triple, and Mach Probes and gridded energy analyzer. DiPS consists of two major parts: a divertor plasma simulator with a LaB 6 DC plasma source and a space plasma simulator with a helicon RF plasma source, (2) divertor plasma simulator-1 (DiPS-1) is a part of DiPS with only a LaB 6 cathode, where a low-power laser-induced fluorescence (LIF) is added and more electric probe diagnostics are augmented; it is dedicated only for fusion edge and divertor plasmas, (3) Divertor Plasma Simulator-2 (DiPS-2) has been modified from the DiPS-1 by adding a magnetic nozzle with a limiter structure and by removing the helicon source and space chamber. DiPS-2 is a linear plasma device with a 4-inch LaB 6 cathode, the same as DiPS-1, and it is focused on the development of various diagnostics, such as those used for LIF and laser Thomson scattering (LTS) along with various electric probes, on the divertor and scrape-off plasmas and on the plasma-material interaction (PMI) research, such as that of tungsten and graphite as plasma-facing components (PFCs), (4) A Multi-Purpose Plasma (MP 2) device is a renovation of the Hanbit mirror device [Kwon et al., Nucl. Fusion 43, 686 (2003)] with the installation of two plasma sources: LaB 6 (DC) and helicon (RF) plasma sources. A honeycomb-like large-area LaB 6 (HLA-LaB 6) cathode has been developed for the divertor plasma simulation to improve the resistance against the thermal shock fragility for large (8-inch) and high density plasma generation, (5) DiPS-2 has been augmented by adding another cylindrical device, called the Dust interaction with Surfaces Chamber (DiSC) for the generation and diagnostics of dusts. This combined system (DiPS-2+DiSC) has added two more diagnostics: Laser Photo-Detachment (LPD) for dust density and laser Mie Scattering (LMS) for dust size. Moreover, dusts or negative ions have been analyzed by using electric probes and capacitive diagram gauges in Transport and Removal of Dusts (TReD) device.N

Simulations of fusion edge plasmas by linear plasma devices: physics and plasma–material interactions

© 2022, The Korean Physical Society.Because a fusion edge plasma contains various atomic and molecular processes, along with various plasma–material interactions (PMIs) for post-mortem analyses, a linear plasma device can simulate divertor and scrape-off layer (SOL) plasmas with DC edge relevant parameters, although it cannot generate a high ion temperature and toroidicity with much less power density compared to toroidal devices. The Divertor Plasma Simulator-2 (DiPS-2), a linear device with an LaB6 DC cathode, has been used for a few fusion-relevant physics experiments, including edge localized mode (ELM) simulation and edge transport of diffusion and convection. An ELM simulation has been performed by modulating the magnetic field relevant to the pressure modulation of a toroidal device, and the diffusion coefficients of free and bound presheaths have been measured in simulations of divertor or limiter transport. Moreover, the convection of the filament or the bubble expansion to the first wall has also been analyzed. In addition to various atomic and molecular processes in SOL and divertor plasmas, PMIs must be analyzed both on and beneath the surface of the plasma-facing components (PFCs) because of surface modification. Using DiPS-2 and other linear devices along with Korea Superconducting Tokamak Advanced Research (KSTAR), PMIs have been analyzed in terms of the following elements or processes: (1) boronizations, both for dust interactions with the surface chamber (DiSC) and KSTAR device, are analyzed; (2) carbon damage by the dense heat flux of DiPS-2 is experimentally investigated; (3) the density profile of the lithium injection gettering of hydrogen and its transport experiments (LIGHT-1) device is analytically calculated; (4) the effect of nitrogen on the relaxation of the heat flux to the divertor tile is experimentally analyzed; and (5) tungsten as the divertor tile material is analyzed via laser ELM simulations in terms of dust generation and surface modification.N