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Objective.Transcutaneous auricular vagus nerve stimulation (taVNS), a non-invasive method of stimulating the vagus nerve, simultaneously affects the autonomic nervous system (ANS) and central nervous system (CNS) through efferent and afferent pathways. The purpose of this study is to analyze the effect of taVNS on the ANS and CNS through heart rate variability (HRV) and electroencephalography (EEG) parameters of identified responders.Approach.Two sets of data were collected from each of 10 healthy adult male subjects in their 20 s, and five HRV parameters from the time domain (RMSSD, pNN50, pNN30, pNN20, ppNNx) and two EEG parameters (power of alpha band, power of delta band) were extracted.Main results.Based on pNN50, responders to taVNS were identified; among them, pNN50 (p= 0.0041) and ppNNx (p= 0.0037) showed significant differences before and after taVNS. At the same time, for alpha power and delta power of EEG, significant difference (p< 0.05) was observed in most channels after taVNS compared to before stimulation.Significance.This study demonstrated the validity of identifying responders using pNN50 and the influence of taVNS on both the ANS and CNS. We conclude that taVNS can be used to treat a variety of diseases and as a tool to help control the ANS and CNS.

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Transcranial direct current stimulation (tDCS) and high-intensity interval training (HIIT) have been demonstrated to enhance inhibitory control and working memory (WM) performance in healthy adults. However, the potential benefits of combining these two interventions have been rarely explored and remain largely speculative. This study aimed to explore the effects of acute HIIT combined with dual-site tDCS over the dorsolateral prefrontal cortex (DLPFC, F3 and F4) on inhibitory control and WM in healthy young adults. Twenty-five healthy college students (20.5 ± 1.3 years; 11 females) were recruited to complete HIIT + tDCS, HIIT + sham-tDCS, rest + tDCS, and rest + sham-tDCS (CON) sessions in a randomized crossover design. tDCS or sham-tDCS was conducted after completing HIIT or a rest condition of the same duration. The Stroop and 2-back tasks were used to evaluate the influence of this combined intervention on cognitive tasks involving inhibitory control and WM performance in post-trials, respectively. Response times (RTs) of the Stroop task significantly improved in the HIIT + tDCS session compared to the CON session across all conditions (all p values <0.05), in the HIIT + tDCS session compared to the rest + tDCS session in the congruent and neutral conditions (all p values <0.05), in the HIIT + sham-tDCS session compared to the CON session in the congruent and neutral conditions (all p values <0.05), in the HIIT + sham-tDCS session compared to the rest + tDCS session in the congruent condition (p = 0.015). No differences were found between sessions in composite score of RT and accuracy in the Stroop task (all p values >0.05) and in the 2-back task reaction time and accuracy (all p values >0.05). We conclude that acute HIIT combined with tDCS effectively improved inhibitory control but it failed to yield cumulative benefits on inhibitory control and WM in healthy adults. These preliminary findings help to identify beneficial effects of combined interventions on cognitive performance and might guide future research with clinical populations.

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Background: Sensory-motor perturbations have been widely used to assess astronauts' balance in standing during pre-/post- spaceflight. However, balance control during walking, where most falls occur, was less studied in these astronauts. A study found that applying either visual or platform oscillations reduced the margin of stability (MOS) in the anterior-posterior direction (MOSap) but increased MOS in the medial-lateral direction (MOSml) as a tradeoff. This tradeoff induced an asymmetric gait. This study extended the current knowledge to investigate overall stability under unpredictable environments. This study aimed to determine (1) whether quasi-random treadmill perturbations with or without full vision support would result in a significant reduction in MOSap but an increase in MOSml and (2) regardless of whether vision support was provided, quasi-random treadmill perturbations might result in asymmetric gait patterns. Methods: Twenty healthy young adults participated in this study. Three experimental conditions were semi-randomly assigned to these participants as follows: (1) the control condition (Norm), walking normally with their preferred walking speed on the treadmill; (2) the treadmill perturbations with full vision condition (Slip), walking on the quasi-random varying-treadmill-belt-speeds with full vision support; and (3) the treadmill perturbations without full vision condition (Slip_VisionBlocked, blackout vision through customized vision-blocked goggles), walking on the quasi-random varying-treadmill-belt-speeds without full vision support. The dependent variables were MOSap, MOSml, and respective symmetric indices. A one-way repeated ANOVA measure or Friedman Test was applied to investigate the differences among the conditions mentioned above. Results: There was an increase in MOSap in Slip (p = 0.001) but a decrease in MOSap in Slip_VisionBlocked (p = 0.001) compared to Norm condition. The MOSml was significantly greater in both Slip and Slip_VisionBlocked conditions compared to the Norm condition (p = 0.011; p < 0.001). An analysis of Wilcoxon signed-rank tests revealed that the symmetric index of MOSml in Slip_VisionBlocked (p = 0.002) was greater than in the Norm condition. Conclusion: The novelty of this study was to investigate the effect of vision on the overall stability of walking under quasi-random treadmill perturbations. The results revealed that overall stability and symmetry were controlled differently with/without full visual support. In light of these findings, it is imperative to take visual support into consideration while developing a sensory-motor training protocol. Asymmetric gait also required extra attention while walking on the quasi-random treadmill perturbations without full vision support to maintain overall stability.

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Obesity and aging are associated with an inflammatory state, which represents the common background for a wide range of diseases. This study aims to explore the correlation between hsCRP, IL-1ß, IL-6, TNF-α, IFN-γ, and white blood cell count (WBC) and adipometrics (arm, waist, and hip circumferences: AC, WC, HC; total body fat mass: TBFM, visceral fat level: VFL, body mass index: BMI; waist/hip ratio: WHR; waist/height ratio: WHtR) in young and healthy adults aged 20-35 years old. The subjects were divided by BMI into the overweight/obesity (OW/OB) group and normal weight (NW) group, and by hsCRP level into Group 1 (<1 mg/L), Group 2 (≥1-2.99 mg/L), and Group 3 (≥3 mg/L). The concentration of all inflammatory biomarkers was significantly higher in the OW/OB group compared to the NW group, with the exception of IL-1ß. Significant positive correlations were found between hsCRP, TNF-α, WBC, and all adipometrics; between IL-6 and WHR, WHtR, BMI, TBFM, and VFL; and between IFN-γ and HC, BMI, and TBFM. IL-1ß correlates positively with WHR and VFL. In Groups 1-3, all the differences between the adipometrics showed significant differences. Subclinical inflammation persists in association with being overweight and obese in healthy young adults aged 20-35 years old.

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Transcranial direct current stimulation (tDCS) and aerobic exercise (AE) have been demonstrated to enhance inhibitory control function in healthy individuals separately. However, the potential benefits of combining these two interventions have yet to be fully explored. In this study, we aimed to use multiple event-related potential (ERP) components (P200, N200, and N450) to investigate the combined effects of tDCS and AE on the improvement of inhibitory control ability in healthy young adults. We evaluated the influence of this combined intervention on cognitive tasks involving inhibitory control function and basic information processing by performing the Stroop Word Color task. Our results showed that compared to the application of tDCS or AE alone, the combined intervention of tDCS and AE had a greater effect on improving inhibitory control function in healthy young adults. The amplitude of P200, N200, and N450 ERP components also changed more significantly during the Stroop Word Color task. We concluded that the mechanism of tDCS combined with AE in improving inhibitory control ability may involve synergistic effects on brain structures at different levels, such as regulating interactions at the reticular activating system level and activating corresponding brain regions at the medial frontal lobe and frontal lobe levels.

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The brain continuously encodes information about time, but how sensorial channels interact to achieve a stable representation of such ubiquitous information still needs to be determined. According to recent research, children show a potential interference in multisensory conditions, leading to a trade-off between two senses (sight and audition) when considering time-perception tasks. This study aimed to examine how healthy young adults behave when performing a time-perception task. In Experiment 1, we tested the effects of temporary sensory deprivation on both visual and auditory senses in a group of young adults. In Experiment 2, we compared the temporal performances of young adults in the auditory modality with those of two samples of children (sighted and sighted but blindfolded) selected from a previous study. Statistically significant results emerged when comparing the two pathways: young adults overestimated and showed a higher sensitivity to time in the auditory modality compared to the visual modality. Restricting visual and auditory input did not affect their time sensitivity. Moreover, children were more accurate at estimating time than young adults after a transient visual deprivation. This implies that as we mature, sensory deprivation does not constitute a benefit to time perception, and supports the hypothesis of a calibration process between senses with age. However, more research is needed to determine how this calibration process affects the developmental trajectories of time perception.

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OBJECTIVE: This research explored the combined effects of transcranial direct current stimulation (tDCS) and aerobic exercise (AE) on executive function and specific serum biomarkers in healthy adults. METHODS: Sixty healthy young adults were randomly assigned into tDCS+AE, tDCS only, or AE only groups. Interventions were carried out for 20 days. Executive functions were evaluated using tasks such as the 2,3-back task, the spatial working memory task, the Stroop test, T test, and hexagonal obstacle jump task. Serum biomarkers, including brain-derived neurotrophic factor (BDNF), malondialdehyde (MDA), superoxide dismutase (SOD), glutamate, glutathione peroxidase 4 (GPX4) and iron ion, were analyzed pre- and post-intervention. RESULTS: The tDCS+AE group showed superior enhancements in executive function, evidenced by improved accuracy rates in 2,3-back tasks, better performance in the staircase task, and reduced reaction times in the incongruent reaction time of the Stroop task compared to other groups. Importantly, we found substantial changes in serum biomarkers: increased levels of BDNF and SOD, and decreased levels of MDA and glutamate in the tDCS+AE group. These changes were significantly different when compared with the tDCS and AE only groups. Notably, these alterations in serum biomarkers were correlated with improvements in executive function tasks, thus offering a potential physiological basis for the cognitive improvements witnessed. CONCLUSION: The combined tDCS and AE intervention effectively improved executive function in healthy young adults, with the improvements linked to changes in key serum biomarkers. The results emphasize the potential of combined tDCS and AE interventions in engaging multiple physiological pathways to enhance executive function.

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Understanding the changes in cognitive processing that accompany changes in posture can expand our understanding of embodied cognition and open new avenues for applications in (neuro)ergonomics. Recent studies have challenged the question of whether standing up alters cognitive performance. An electronic database search for randomized controlled trials was performed using Academic Search Complete, CINAHL Ultimate, MEDLINE, PubMed, and Web of Science following PRISMA guidelines, PICOS framework, and standard quality assessment criteria (SQAC). We pooled data from a total of 603 healthy young adults for incongruent and 578 for congruent stimuli and Stroop effect (mean age = 24 years). Using random-effects results, no difference was found between sitting and standing for the Stroop effect (Hedges' g = 0.13, 95% CI = -0.04 to 0.29, p = 0.134), even when comparing congruent (Hedges' g = 0.10; 95% CI: -0.132 to 0.339; Z = 0.86; p = 0.389) and incongruent (Hedges' g = 0.18; 95% CI: -0.072 to 0.422; Z = 1.39; p = 0.164) stimuli separately. Importantly, these results imply that changing from a seated to a standing posture in healthy young adults is unlikely to have detrimental effects on selective attention and cognitive control. To gain a full understanding of this phenomenon, further research should examine this effect in a population of healthy older adults, as well as in a population with pathology.

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Context: Night-shift work causes circadian misalignment, predicts the development of metabolic diseases, and complicates the interpretation of hormone measurements. Objective: To investigate endogenous circadian rhythms, dissociated from behavioral and environmental confounds, in adrenal and gonadal steroids after simulated shift work. Methods: Fourteen healthy adults (ages 25.8 ± 3.2 years) were randomized to 3 days of night or day (control) shift work followed by a constant routine protocol designed to experimentally unveil rhythms driven endogenously by the central circadian pacemaker. Blood was sampled every 3 hours for 24 hours during the constant routine to concurrently obtain 16 Δ4 steroid profiles by mass spectrometry. Cosinor analyses of these profiles provided mesor (mean abundance), amplitude (oscillation magnitude), and acrophase (peak timing). Results: Night-shift work marginally increased cortisol by 1 µg/dL (P = 0.039), and inactive/weak derivatives cortisone (P = 0.003) and 18-hydroxycortisol (P < 0.001), but did not alter the mesor of potent androgens testosterone and 11-ketotestosterone. Adrenal-derived steroids, including 11-ketotestosterone (P < 0.01), showed robust circadian rhythmicity after either day- or night-shift work. In contrast, testosterone and progesterone showed no circadian pattern after both shift work conditions. Night-shift work did not alter the amplitude or acrophase of any of the steroid profiles. Conclusion: Experimental circadian misalignment had minimal effects on steroidogenesis. Adrenal steroids, but not gonadal hormones, showed endogenous circadian regulation robust to prior shift schedule. This dichotomy may predispose night-shift workers to metabolic ill health. Furthermore, adrenal steroids, including cortisol and the main adrenal androgen 11-ketostosterone, should always be evaluated during the biological morning whereas assessment of gonadal steroids, particularly testosterone, is dependent on the shift-work schedule.

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This study aimed to investigate the effects of listening to Wolfgang Amadeus Mozart's "Sonata for two pianos in D major, K448" and Johann Sebastian Bach's "Brandenburg concerto No. 4 in G major, BWV1049" on the heart rate, blood pressure, and autonomic nervous activity. Seventeen healthy young adults were recruited as participants. All participants underwent a 10-minute rest, a 10-minute load test, and a triplicate 8-minute music listening process. Electrocardiograms were continuously measured from the measurement onset to completion. Moreover, the high-frequency (HF) component was extracted from the heart rate variability analysis as a measure of the parasympathetic nervous activity and the ratio of low frequency (LF) to HF as a measure of the sympathetic nervous activity. Blood pressure was also measured. There was a significant decrease in the heart rate after listening to both K448 and BWV1049, as well as in the silence state. Blood pressure did not significantly change in either case. Further, the LF/HF ratio significantly decreased after listening to BWV1049. Nevertheless, HF did not change after listening to either music. In conclusion, this study suggests that listening to K448 does not affect the heart rate, blood pressure, or autonomic nervous activity, whereas listening to BWV1049 may suppress the sympathetic nervous activity in healthy adults.

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BACKGROUND: Transcutaneous auricular vagus nerve stimulation (taVNS) may modulate cardiac autonomic function. However, the response rate of the traditional tonic paradigm is low, and the results remain inconsistent. A recent pilot study presented a novel burst paradigm to activate the cardiac parasympathetic system, which might offer a new approach to treat cardiac autonomic function. The present study reassessed the effect of burst taVNS on modulating heart rate variability and explored the difference between burst and traditional tonic paradigms. MATERIALS AND METHODS: Forty-two young adults were recruited for this study. Each participant underwent three types of taVNS with sham (30 sec of stimulation), tonic (25 Hz, 500 µsec), and burst (five pulses at 500 Hz every 200 msec) paradigms, respectively, with simultaneous electrocardiogram recording. One-way analysis of variance, multivariate analysis of variance, and linear regression were used for analysis. Multiple testing was performed using Bonferroni correction. RESULTS: Both burst and tonic paradigms induced a significant decrease in heart rate, which continued until poststimulation, and increased cardiac parasympathetic activity. Moreover, two parasympathetic system indicators showed significant increase only in burst taVNS. The response rates during burst (35.7%) and tonic (38.1%) stimulations were both higher than that during sham stimulation (11.9%). The response to taVNS showed parameter specificity with few nonresponders to the tonic paradigm responding to the burst paradigm. The overall response rate increased from 38.1% in tonic taVNS to 54.8% in taVNS using both burst and tonic paradigms. For both burst and tonic responders, baseline cardiac parasympathetic activity was found to be significantly negatively correlated with changes during stimulation. CONCLUSION: The burst parameter could be used as an alternative strategy for regulating cardiac parasympathetic function by taVNS, which has the potential to be used as a complementary paradigm to traditional tonic taVNS for promoting clinical treatment efficacy.

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The relationship between hippocampal subfield volumetry and verbal list-learning test outcomes have mostly been studied in clinical and elderly populations, and remain controversial. For the first time, we characterized a relationship between verbal list-learning test outcomes and hippocampal subfield volumetry on two large separate datasets of 447 and 1,442 healthy young and middle-aged adults, and explored the processes that could explain this relationship. We observed a replicable positive linear correlation between verbal list-learning test free recall scores and CA1 volume, specific to verbal list learning as demonstrated by the hippocampal subfield volumetry independence from verbal intelligence. Learning meaningless items was also positively correlated with CA1 volume, pointing to the role of the test design rather than word meaning. Accordingly, we found that association-based mnemonics mediated the relationship between verbal list-learning test outcomes and CA1 volume. This mediation suggests that integrating items into associative representations during verbal list-learning tests explains CA1 volume variations: this new explanation is consistent with the associative functions of the human CA1.

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Introduction: Alternate nostril breathing (ANB) is an effective breathing exercise with therapeutic benefits on cardiorespiratory functions for healthy and diseased individuals. This study was conducted to assess the effects of ANB exercise on cardiorespiratory tasks in healthy adults. Materials and Methods: This randomized experimental study was conducted in the Department of Physiology, Chittagong Medical College, Chattogram, from July 2017 to June 2018. A total of 100 1st-year students, aged between 18 and 20 years, were included by a random sampling method. Fifty participants (25 males and 25 females) were enrolled in the experimental group, while age- and body mass index-matched another 50 participants (25 males and 25 females) served as the control group. Experimental group participants performed ANB exercise for 4 weeks. Cardiorespiratory parameters (pulse rate, blood pressure, forced vital capacity, forced expiratory volume in 1st s [FEV1], and peak expiratory flow rate [PEFR] were measured. Data were taken at the start and after 4 weeks in both groups. Results: Independent t-test showed no significant differences in the cardiorespiratory functions between the experimental and control groups among the male and female participants, except for the females' PEFR which showed small differences. On the other hand, repeated measure ANOVA shows significant improvement in the experimental groups among males (P < 0.001-0.028) and females (P < 0.001-0.001) in all the cardiorespiratory functions measured, except for the FEV1 and PEFR among males. Conclusion: The results of this study suggest that cardiorespiratory functions were improved after breathing exercise, and therefore, ANB can be recommended for increasing cardiorespiratory efficiency.

RésuméIntroduction: La respiration nasale alternée (ANB) est un exercice de respiration efficace avec des avantages thérapeutiques sur les fonctions cardiorespiratoires pour les individus sains et malades. Cette étude a été menée pour évaluer les effets de l'exercice ANB sur les tâches cardiorespiratoires chez des adultes en bonne santé. Matériels et méthodes: Cette étude expérimentale randomisée a été menée au Département de physiologie, Chittagong Medical College, Chattogram, de juillet 2017 à juin 2018. Un total de 100 étudiants de 1ère année, âgés de 18 à 20 ans, ont été inclus par un échantillonnage aléatoire. méthode. Cinquante participants (25 hommes et 25 femmes) ont été inscrits dans le groupe expérimental, tandis que l'âge et l'indice de masse corporelle correspondaient à 50 autres participants (25 hommes et 25 femmes) servant de groupe témoin. Les participants du groupe expérimental ont effectué des exercices ANB pendant 4 semaines. Les paramètres cardiorespiratoires (fréquence du pouls, pression artérielle, capacité vitale forcée, volume expiratoire forcé en 1ère s [VEMS] et débit expiratoire de pointe [PEFR] ont été mesurés. Les données ont été recueillies au début et après 4 semaines dans les deux groupes. Résultats: Le test t indépendant n'a montré aucune différence significative dans les fonctions cardiorespiratoires entre les groupes expérimentaux et témoins parmi les participants masculins et féminins, à l'exception du PEFR des femmes qui présentait de petites différences.D'autre part, l'ANOVA à mesures répétées montre une amélioration significative dans les groupes expérimentaux chez les hommes (P < 0,001 à 0,028) et les femmes (P < 0,001 à 0,001) dans toutes les fonctions cardiorespiratoires mesurées, à l'exception du VEMS et du DEP chez les hommes Conclusion: Les résultats de cette étude suggèrent que les fonctions cardiorespiratoires ont été améliorées après un exercice respiratoire , et par conséquent, l'ANB peut être recommandé pour augmenter l'efficacité cardiorespiratoire.

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Multidrug-resistant bacteria have been increasingly described in healthcare institutions, however community resistance also seems to be emerging. Escherichia coli an intestinal commensal bacteria, is also a pathogen and represents an important intestinal reservoir of resistance. Our aim was the study of the intestinal colonization and of the persistence of antibiotic resistant intestinal bacteria in healthy university students of Porto, in the north of Portugal. Samples from 30 university students were collected and analysed. Two E. coli isolates were randomly obtained from each student and Gram-negative bacilli resistant to antibiotics were studied. In addition, we evaluated changes in the Gram-negative intestinal colonization of ten university students in a short period of time. Molecular characterization showed a high presence of bla TEM in commensal E. coli . Gram-negative bacteria with intrinsic and extrinsic resistance were isolated, namely Pseudomonas spp., Enterobacter spp. and Pantoea spp. We isolated three ESBL-producing E. coli from two students. These isolates showed bla CTX-M group 1 (n=1), bla CTX-M group 9 (n=2), bla TEM (n=2), bla SHV (n=1) and tetA (n=2) genes. Additionally, they showed specific virulence factors and conjugational transfer of antibiotic resistance and virulence genes. One Pseudomonas spp. isolate resistant to carbapenems was detected colonizing one student. Our results confirm that healthy young adults may be colonized with commensals showing clinically relevant antibiotic resistance mechanisms, creating a risk of silent spread of these bacteria in the community.

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This study examined associations between body habitus and functions of aggression, in a sample of 474 college students from the Midwestern region of the United States (age range = 18-25y; 73% Caucasian). Two instruments of aggression, the Reactive-Proactive Aggression Questionnaire from Dodge & Coie 1987 (DC) and Raine et al. 2006 (RPQ) were given as self-assessments. Body habitus measures standardized by age and gender specific weight and height were collected. Subjects considered to have a large body habitus in our study had both weight and height measures above the 75th percentile. Large body habitus was positively correlated with both proactive and reactive functions of aggression among adult males but not females; however, regression analyses indicated that body habitus was most strongly and robustly associated with proactive aggression. Findings suggest that even in a healthy homogeneous population, large body size in males is associated with aggression, particularly proactive aggression including bullying rather than retaliatory aggression. The presence of a large body physique may reinforce aggressive behavioral traits acquired through life experiences and activities evoking physical dominance. Alternatively, the relationship may reflect neurological processes related to size influenced by genetic factors and hormones leading to antisocial behaviors requiring future research on the role of genes for aggression.

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Background: One purpose of the training conducted by people is to lose bodyweight and improve their physical condition. It is well-known that endurance training provides many positive changes in the body, not only those associated with current beauty standards. It also promotes biochemical changes such as a decreased inflammatory status, memory improvements through increased brain-derived neurotrophic factor levels, and reduced stress hormone levels. The positive effects of training may provide a novel solution for people with Parkinson's disease, as a way to reduce the inflammatory status and decrease neurodegeneration through stimulation of neuroplasticity and improved motor conditions. Aim: This narrative review aims to focus on the relationship between an acute bout of endurance exercise, endurance training (continuous and interval), brain-derived neurotrophic factor and inflammatory status in the three subject groups (young adults, older adult, and patients with Parkinson's disease), and to review the current state of knowledge about the possible causes of the differences in brain-derived neurotrophic factor and inflammatory status response to a bout of endurance exercise and endurance training. Furthermore, short practical recommendations for PD patients were formulated for improving the efficacy of the training process during rehabilitation. Methods: A narrative review was performed following an electronic search of the database PubMed/Medline and Web of Science for English-language articles between January 2010 and January 2020. Results: Analysis of the available publications with partial results revealed (1) a possible connection between the brain-derived neurotrophic factor level and inflammatory status, and (2) a more beneficial influence of endurance training compared with acute bouts of endurance exercise. Conclusion: Despite the lack of direct evidence, the results from studies show that endurance training may have a positive effect on inflammatory status and brain-derived neurotrophic factor levels. Introducing endurance training as part of the rehabilitation in Parkinson's disease might provide benefits for patients in addition to pharmacological therapy supplementation.

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Alternate nostril breathing (ANB) is one of the best and easiest breathing exercises. ANB exercise has beneficial effects on cardiac function in healthy and diseased people. The objectives of this study were to assess the effects of ANB exercise on cardiac physiology among healthy medical students. This was a prospective interventional study that was conducted in the Department of Physiology, Chittagong Medical College (CMC), Chattogram, Bangladesh, from July 2017 to June 2018. A total of 100 research participants (RPs) aged 18-20 years, Year-I medical students of CMC, were selected. A simple random sampling method was adopted. The selection was done after the inclusion and exclusion criteria were applied. The age and body mass index (BMI) of the RPs were analogous in both the control and experimental groups. Cardiac parameters, like pulse and blood pressure (BP), were measured. The initial baseline data were recorded for both groups and after 4 weeks. The research respondents of the experimental group performed ANB exercise for 4 weeks. The mean value pulse and BP were significantly (p < 0.001) changed after breathing exercise, compared to the values before the breathing exercise. The results of this study suggest that cardiac function significantly improves after the breathing exercise. Therefore, ANB can be recommended for increasing cardiac efficiency.

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Microsoft's HoloLens, a mixed-reality headset, provides, besides holograms, rich position data of the head, which can be used to quantify what the wearer is doing (e.g., walking) and to parameterize such acts (e.g., speed). The aim of the current study is to determine test-retest reliability, concurrent validity, and face validity of HoloLens 1 for quantifying spatiotemporal gait parameters. This was done in a group of 23 healthy young adults (mean age 21 years) walking at slow, comfortable, and fast speeds, as well as in a group of 24 people with Parkinson's disease (mean age 67 years) walking at comfortable speed. Walking was concurrently measured with HoloLens 1 and a previously validated markerless reference motion-registration system. We comprehensively evaluated HoloLens 1 for parameterizing walking (i.e., walking speed, step length and cadence) in terms of test-retest reliability (i.e., consistency over repetitions) and concurrent validity (i.e., between-systems agreement), using the intraclass correlation coefficient (ICC) and Bland-Altman's bias and limits of agreement. Test-retest reliability and between-systems agreement were excellent for walking speed (ICC ≥ 0.861), step length (ICC ≥ 0.884), and cadence (ICC ≥ 0.765), with narrower between-systems than over-repetitions limits of agreement. Face validity was demonstrated with significantly different walking speeds, step lengths and cadences over walking-speed conditions. To conclude, walking speed, step length, and cadence can be reliably and validly quantified from the position data of the wearable HoloLens 1 measurement system, not only for a broad range of speeds in healthy young adults, but also for self-selected comfortable speed in people with Parkinson's disease.

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Alternate nostril breathing (ANB) is one of the best and easiest breathing exercises (pranayama) of yoga that are good for health and physical fitness. ANB exercise has beneficial and therapeutic effects on respiratory function in both normal as well as diseased humans. This study was conducted with the objective of assessing the physiological effects of short-term ANB exercise on respiratory function in healthy adult individuals leading a stressful life. This prospective interventional study was conducted in the Department of Physiology, Chittagong Medical College (CMC), Chattogram, Bangladesh from July 2017 to June 2018. A total of 100 participants aged 18-20 years, studying in the first year in CMC, were included by using a simple random sampling method. Among them, 50 participants were enrolled in the experimental group. Age- and BMI-matched 50 participants constituted the control group. Height, weight were measured, and BMI was calculated. The participants of the experimental group performed ANB exercise over 4 weeks for 10 min/day. The control participants were neither trained nor allowed to practice nostril breathing during the whole study period. Respiratory parameters like forced vital capacity (FVC), forced expiratory volume in 1st second (FEV1), and peak expiratory flow rate (PEFR) were measured by using a digital spirometer (Chest graph HI-101, Japan). Readings were taken in a healthy upright sitting posture in the control and experimental group initially and after 4 weeks. Student's t-test was conducted by using SPSS for windows version-23. The mean value of FVC, FEV1, PEFR were significantly (P < 0.001) changed after the ANB exercise when compared to the values before breathing exercise. The results of this study suggest that respiratory function is significantly improved after the ANB exercise. Therefore, ANB can be recommended for increasing respiratory efficiency.

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