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Background: The aim of this study was to investigate the changes in isokinetic muscular performance among female adolescent elite handball athletes with the supplementation of Black Maca (BM). Methods: Eight elite handball athletes were recruited for the present study. The intake capsules contained 2,500 mg of 100% concentrated BM extract and a placebo each, for 4 weeks. Isokinetic muscular performance and physical fitness were measured three times at 4-week intervals after the intake of BM and placebo, including baseline. Results: The one-way Analysis of Variance (ANOVA) analysis showed a significant improvement in 20 m-shuttle run (P < 0.001), 30°/s flexor (P < 0.01), and 120°/s flexor (P < 0.01) in isokinetic muscle function of the trunk, and 180°/s right extensor (P < 0.05), 180°/s left extensor (P < 0.05), and 180°/s left flexor (P < 0.01) in isokinetic muscle function of the knee, after BM supplementation. Post-hoc analysis indicated that the BM group had significantly higher results compared to the baseline and placebo groups in terms of 20 m-shuttle run, 30°/s flexor and 120°/s flexor of the trunk, 180°/s right extensor, 180°/s left extensor, and 180°/s left flexor of the knee. Conclusion: BM supplementation can have a positive effect on improving the performance of elite handball players who engage in high-intensity movements by enhancing their isokinetic muscle function and endurance.

PURPOSE Increased body mass index (BMI) increases ankle instability and adversely affects human movement. This study aims to compare and analyze the muscle function and proprioception of the ankle joint based on Body Mass Index (BMI) to determine potential differences. METHODS Twenty-eight healthy male and female college students were categorized into overweight (≥ BMI 23) and normal (< BMI 23) groups. Measurements included BMI, isokinetic strength of dorsiflexion, plantarflexion, eversion, inversion, ankle joint range of motion, and ankle joint proprioception. RESULTS In dorsiflexion, right 30°/sec (p=.035), left 30°/sec (p=.009) and right 120°/sec (p=.011); in plantarflexion, left 30°/sec (p

This study aimed to examine the effects of black maca supplementation on isokinetic muscle function and inflammatory markers in athletes and to extend these findings to non-athletes. The study involved 24 male participants, including 16 elite athletes (soft tennis and table tennis players) and 8 non-athletes (university students). Participants consumed capsules containing 2.5 g of 100% concentrated black maca extract over a 12-week period. Isokinetic muscle performance and physical fitness (strength, muscular endurance, flexibility, power, agility, cardiovascular endurance) assessments were conducted at baseline and after 12 weeks of supplementation. Two-way within-factor ANOVA showed a significant group × time interaction for 120°/s flexor movements (p < 0.05). Paired t-tests demonstrated significant improvements in 30°/s and 120°/s extensor and flexor movements in both athlete groups (p < 0.05, p < 0.01). Similarly, significant enhancements were observed in the non-athletes for the 30°/s flexor and 120°/s extensor and flexor movements (p < 0.01). Furthermore, reductions in interleukin-6 (from 137.9 ± 8.8 to 132.7 ± 4.6, p < 0.05) and tumor necrosis factor-alpha (from 274.1 ± 13.4 to 264.2 ± 3.2, p < 0.05) were noted in the soft tennis group. The table tennis group also showed significant decreases in interleukin-6 (from 135.9 ± 4.7 to 131.3 ± 2.5, p < 0.01) and tumor necrosis factor-alpha (from 282.1 ± 19.2 to 267.0 ± 6.4, p < 0.05). No significant changes were observed in the non-athlete group. Black maca supplementation may enhance isokinetic muscle function in elite athletes by reducing muscle contraction fatigue and improving anti-inflammatory responses.

B cell receptors (BCRs) denote antigen specificity, while corresponding cell subsets indicate B cell functionality. Since each B cell uniquely encodes this combination, physical isolation and subsequent processing of individual B cells become indispensable to identify both attributes. However, this approach accompanies high costs and inevitable information loss, hindering high-throughput investigation of B cell populations. Here, we present BCR-SORT, a deep learning model that predicts cell subsets from their corresponding BCR sequences by leveraging B cell activation and maturation signatures encoded within BCR sequences. Subsequently, BCR-SORT is demonstrated to improve reconstruction of BCR phylogenetic trees, and reproduce results consistent with those verified using physical isolation-based methods or prior knowledge. Notably, when applied to BCR sequences from COVID-19 vaccine recipients, it revealed inter-individual heterogeneity of evolutionary trajectories towards Omicron-binding memory B cells. Overall, BCR-SORT offers great potential to improve our understanding of B cell responses.

Myasthenia Gravis (MG) patients with anti-acetylcholine receptor (AChR) antibodies frequently show hyperplastic thymi with ectopic germinal centers, where autoreactive B cells proliferate with the aid of T cells. In this study, thymus and peripheral blood (PB) samples were collected from ten AChR antibody-positive MG patients. T cell receptor (TCR) repertoires were analyzed using next-generation sequencing (NGS), and compared with that of an age and sex matched control group generated from a public database. Certain V genes and VJ gene recombination pairs were significantly upregulated in the TCR chains of αβ-T cells in the PB of MG patients compared to the control group. Furthermore, the TCR chains found in the thymi of MG patients had a weighted distribution to longer CDR3 lengths when compared to the PB of MG patients, and the TCR beta chains (TRB) in the MG group's PB showed increased clonality encoded by one upregulated V gene. When TRB sequences were sub-divided into groups based on their CDR3 lengths, certain groups showed decreased clonality in the MG group's PB compared to the control group's PB. Finally, we demonstrated that stereotypic MG patient-specific TCR clonotypes co-exist in both the PB and thymi at a much higher frequency than that of the clonotypes confined to the PB. These results strongly suggest the existence of a biased T cell-mediated immune response in MG patients, as observed in other autoimmune diseases.

Somatic syndromes of the spinal region may develop secondary to postural dysfunction. Traditionally, emphasis has been placed on correcting postural asymmetries by attempting to change muscle-tendon unit length. The effectiveness of this approach in providing prolonged muscle-tendon unit length changes and optimal postural outcomes has met with controversy. The time has come for a redirection of goals in conservative care for postural dysfunction of the spinal regions. An emphasis needs to be placed on continuous, self-awareness training of postural correction that will facilitate lasting neuromuscular adaptations. The purpose of this review is to rationalize the need to veer from exercises attempting to adjust the muscle-tendon unit length and recognize the evidence-supported impact of simple self-correction strategies meant to facilitate neuromuscular adjustments and correct postural asymmetries.

B cells recognize antigens via membrane‐expressed B‐cell receptors (BCR) and antibodies. Similar human BCR sequences are frequently found at a significantly higher frequency than that theoretically calculated. Patients infected with SARS‐CoV2 and HIV or with autoimmune diseases share very similar BCRs. Therefore, in silico reconstitution of BCR repertoires and identification of stereotypical BCR sequences related to human pathology have diagnostic potential. Furthermore, monitoring changes of clinically significant BCR sequences and isotype conversion has prognostic potential. For BCR repertoire analysis, peripheral blood (PB) is the most convenient source. However, the optimal human PB volume for in silico reconstitution of the BCR repertoire has not been studied in detail. Here, we sampled 5, 10, and 20 mL PB from the left arm and 40 mL PB from the right arm of two volunteers, reconstituted in silico PB BCR repertoires, and compared their composition. In both volunteers, PB sampling over 20 mL resulted in slight increases in functional unique sequences (FUSs) or almost no increase in repertoire diversity. All FUSs with a frequency above 0.08% or 0.03% in the 40 mL PB BCR repertoire were detected even in the 5 mL PB BCR repertoire from each volunteer. FUSs with a higher frequency were more likely to be found in BCR repertoires from reduced PB volume, and those coexisting in two repertoires showed a statistically significant correlation in frequency irrespective of sampled anatomical site. The correlation was more significant in higher‐frequency FUSs. These observations support the potential of BCR repertoire analysis for diagnosis.

Abstract Previous reports indicate a potential role for signal transducer and activator of transcription 3 (STAT3) in amyloid-β (Aβ) processing and neuritic plaque pathogenesis. In the present study, the impact of STAT3 inhibition on cognition, cerebrovascular function, amyloid pathology, oxidative stress, and neuroinflammation was studied using in vitro and in vivo models of Alzheimer’s disease (AD)-related pathology. For in vitro experiments, human brain vascular smooth muscle cells (HBVSMC) and human brain microvascular endothelial cells (HBMEC) were used, and these cultured cells were exposed to Aβ peptides followed by measurement of activated forms of STAT3 expression and reactive oxygen species (ROS) generation. Further, 6 months old 5XFAD/APOE4 (5XE4) mice and age-matched negative littermates were used for in vivo experiments. These mice were treated with STAT3 specific inhibitor, LLL-12 for 2 months followed by neurobehavioral and histopathological assessment. In vitro experiments showed exposure of cerebrovascular cells to Aβ peptides upregulated activated forms of STAT3 and produced STAT3-mediated vascular oxidative stress. 5XE4 mice treated with the STAT3-specific inhibitor (LLL-12) improved cognitive functions and functional connectivity and augmented cerebral blood flow. These functional improvements were associated with a reduction in neuritic plaques, cerebral amyloid angiopathy (CAA), oxidative stress, and neuroinflammation. Reduction in amyloid precursor protein (APP) processing and attenuation of oxidative modification of lipoprotein receptor related protein-1 (LRP-1) were identified as potential underlying mechanisms. These results demonstrate the broad impact of STAT3 on cognitive functions, parenchymal and vascular amyloid pathology and highlight the therapeutic potential of STAT3 specific inhibition for treatment of AD and CAA.

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Abstract Background When studying the quality of sleep in relation to athletic performance, the athlete’s chronotype and habitual time consider important factors. We aim to investigate the sleep quality and athletes’ performance according to chronotype in elite athletes. Methods Three hundred forty elite athletes (males = 261, females = 79) were recruited for the present study. All participants were screening for chronotype by the Korean versions of the Morningness - Eveningness Questionnaire (MEQ-K). The Pittsburgh Sleep Quality Index (PSQI) and Wingate Anaerobic Test (WAnT) were measurement after screening. Results PSQI global score, PSQI sleep quality, PSQI sleep onset latency, PSQI sleep disturbance, and PSQI daytime dysfunction were significant differences among the groups. WAnT mean power (W), mean power (W/kg), peak power (W), and peak power (W/kg) were significant differences among the groups. A negative correlation coefficient was found between PSQI score and WAnT mean power (W) (r = − 0.256, p

Abstract Background Land use and development alter mudflat and wetland habitat availability, although mudflats and wetlands provide important stopover habitats for shorebirds during the spring and autumn migrations and support communities of ducks and geese during the winter months in the Republic of Korea. This study investigated land use changes around Sihwa Lake (Republic of Korea) and evaluated the effect of these changes on waterbird community characteristics. Methods We conducted a land-use-change analysis at the medium-resolution level using land cover maps for 2001, 2007, 2009, and 2014. Also, a tidal stream survey was conducted in Sihwa Lake and the surrounding reclaimed mudflats every season for 10 years (2003–2012) to identify the seasonal and interannual variations in waterbird species composition. To determine the total annual waterbird species and population counts, species diversity index, and interspecies variations, a TRIM (trends and indices for monitoring data) analysis was used. Results Wetland area decreased more than 10% while agricultural land, barren land, and grassland area increased more than 10% due to continuous reclamation activities around Sihwa Lake. Barren land later turned into agricultural land or other land use. Sixty-three species and 566,623 individuals were recorded. The number of species, population size, and species diversity index by year and by species showed decreasing trends that were more marked in spring and summer. Furthermore, seasonal and annual variations in waterbird species composition showed decreasing trends in dabbling ducks, herons, grebes, and shorebirds but diving ducks displayed increasing trends. In particular, shorebirds were reduced to a greater extent than other waterbird species because of the reduction and simplification of the intertidal zone, and shallow waters caused by reclamation and road construction. Conclusions Increased development and construction around Sihwa Lake has altered migratory shorebird populations with a general decline in species diversity and population size. The greatest decline was observed in wading birds, while diving duck populations showed increasing trends.

Magic size clusters have often been identified as intermediates in the formation of quantum dots from molecular precursors. Here, the authors report the syntheses of two families of chlorine- or zinc-doped indium phosphide magic size clusters and study their evolution from precursor to colloidal quantum dot.

The use of flash based Solid State Drives (SSDs) has expanded rapidly into the cloud computing environment. In cloud computing, ensuring the service level objective (SLO) of each server is the major criterion in designing a system. In particular, eliminating performance interference among virtual machines (VMs) on shared storage is a key challenge. However, studies on SSD performance to guarantee SLO in such environments are limited. In this paper, we present analysis of I/O behavior for a shared SSD as storage in terms of proportionality and stability. We show that performance SLOs of SSD based storage systems being shared by VMs or tasks are not satisfactory. We present and analyze the reasons behind the unexpected behavior through examining the components of SSDs such as channels, DRAM buffer, and Native Command Queuing (NCQ). We introduce two novel SSD-aware host level I/O schedulers on Linux, called A+CFQ and H+BFQ, based on our analysis and findings. Through experiments on Linux, we analyze I/O proportionality and stability in multi-tenant environments. In addition, through experiments using real workloads, we analyze the performance interference between workloads on a shared SSD. We then show that the proposed I/O schedulers almost eliminate the interference effect seen in CFQ and BFQ, while still providing I/O proportionality and stability for various I/O weighted scenarios.

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-22007-4

Psychological anxiety and physiological stress hormone management is closely related to an athlete’s performance, especially in shooting competitions. Thus, we aimed to investigate the changes in saliva stress hormones according to anxiety scores of Korean elite shooters immediately before a shooting competition. Seventy-two Korean national shooting athletes (Rifle = 62, Pistol = 8, Shotgun = 2) were recruited for the present study. The physiological stress hormones were assessed based on cortisol and immunoglobulin A level in saliva. The psychological stress was assessed based on Beck Anxiety Inventory (BAI) questionnaire. Cortisol concentration and cortisol secretion rate were significant higher in severe anxiety group. Secretory immunoglobulin A (SIgA) concentration and SIgA secretion rate did not significant different in among the groups. A positive correlation was found between BAI score and cortisol concentration. These findings provide preliminary evidence indicating that psychological anxiety affects physiological stress and therefore may have a negative effect on athletes’ performance. Thus, research is needed to develop a strategy to reduce physiological stress in these athletes.

The relationship between physical activity amount and cognitive function in elderly Koreans has received little attention. This study therefore aimed to understand the independent and common link between cognitive function and physical activity levels among elderly Korean adults. This study recruited a total of 2746 elderly adults (1348 males and 1398 females). All participants were assessed for cognitive functioning using the Korean Dementia Screening Questionnaire Cognition (KDSQ-C). The computerized Korean version short form of the International Physical Activity Questionnaire (IPAQ) used in this study was entirely based on the long, self-administered, usual week-long IPAQ found in the IPAQ manual of operation. In the unadjusted model, elderly adults who met the recommended level of moderate-to-vigorous physical activity were more likely to have a sufficient level of cognitive function. Hemoglobin, creatinine, cholesterol (TC), triglycerides (TG), LDL-C, and HDL-C differed significantly between groups. A negative correlation was found between KDSQ-C score and the moderate-to-vigorous physical activity (MVPA) amount per week. Physical activity amount is associated with cognition function in Korean elderly adults. Increasing physical activity may improve hemoglobin and creatinine and be involved in improving serum lipid profiles in elderly adults. Thus, physical activity has been suggesting as a useful tool to reduce the risk of cognitive function associated with aging.