Latency Difference Research Articles

A correlation study of arterial stiffness with P300 event-related potential in non-haemodialytic and haemodialytic chronic kidney disease patients of renal origin

Introduction: Chronic kidney disease (CKD) is associated with hypertension. The renal micro-vessels are vulnerable to the pulsatile nature of systemic pressure leading to arterial stiffness, which may lead to progressive renal disease besides other mechanisms. The stiffened cerebral vasculatures may also cause neural injury. Thus, cognitive impairment is prevalent in CKD patients. However, very few studies have attempted to examine the association of arterial stiffness with P300 event-related potential (P3ERP) in CKD patients of primary renal disease in the Indian population, which forms the basis of the study. Materials and Methods: Twenty-three age- and sex-matched non-haemodialytic and haemodialytic CKD patients were recruited in this cross-sectional and observational study. Montreal cognitive assessment questionnaire was applied to them to estimate global cognitive level. Peripheral and central blood pressure, augmentation index, brachial-ankle pulse wave velocity (baPWV), heart rate and P300 ERP were recorded. Biochemical analysis of the serum was also done. Appropriate statistical tests were performed to compare the differences between the variables of the two groups. Spearman’s Correlation test was performed to examine the relationship between vascular parameters and P300 ERP metrics. Results: Haemodialytic CKD patients exhibit early vascular ageing than non-haemodialytic CKD patients as evidenced by increased heart rate (P = 0.001) and higher central diastolic (P = 0.035) and peripheral diastolic blood pressure (P = 0.042). Although there was no significant difference in latency and amplitude of P300 ERP between the two groups, a significant positive association between baPWV and amplitude of P300 ERP was found. Moreover, higher serum phosphate (P = 0.021) and uric acid levels (P = 0.017) in haemodialytic patients promote vascular stiffening. Conclusion: It may be concluded that early vascular ageing in CKD patients occurs due to the interplay of multiple physiological factors, which finally perturb cerebral haemodynamics and are responsible for the cognitive impairment observed in these patients.

Effects of Closed Mouth vs. Exposed Teeth on Facial Expression Processing: An ERP Study

The current study examines the neural mechanisms underlying facial recognition, focusing on how emotional expression and mouth display modulate event-related potential (ERP) waveforms. 42 participants categorized faces by gender in one of two experimental setups: one featuring full-face images and another with cropped faces presented against neutral gray backgrounds. The stimuli included 288 images balanced across gender, race/ethnicity, emotional expression (“Fearful”, “Happy”, “Neutral”), and mouth display (“closed mouth” vs. “open mouth with exposed teeth”). Results revealed that N170 amplitude was significantly greater for open-mouth (exposed teeth) conditions (p < 0.01), independent of emotional expression, and no interaction between emotional expression and mouth display was found. However, the P100 amplitude exhibited a significant interaction between these variables (p < 0.05). Monte Carlo simulations analyzing N170 latency differences showed that fearful faces elicited a faster response than happy and neutral faces, with a 2 ms delay unlikely to occur by chance (p < 0.01). While these findings challenge prior research suggesting that N170 is directly influenced by emotional expression, they also highlight the potential role of emotional intensity as an alternative explanation. This underscores the importance of further studies to disentangle these effects. This study highlights the critical need to control for mouth display when investigating emotional face processing. The results not only refine our understanding of the neural dynamics of face perception but also confirm that the brain processes fearful expressions more rapidly than happy or neutral ones. These insights offer valuable methodological considerations for future neuroimaging research on emotion perception.

Inhibition of the Basolateral Amygdala to Prelimbic Cortex Pathway Enhances Risk-taking during Risky Decision-making Shock Task in Rats.

Many animal studies have explored decision-making under risk and punishment, particularly regarding potential rewards, but less focus has been placed on contexts involving net losses. Understanding decision-making under net loss conditions can shed light on the neural mechanisms involved. The basolateral amygdala to prelimbic cortex (BLA→PL) pathway is crucial for risky decision-making. In this study, we investigated how rats make decisions under no-reward but shock conditions, specifically examining the role of the BLA→PL pathway. In the risky decision-making shock task (RDST), rats chose between a "small/certain" lever, which consistently delivered one pellet, and a "large/risky" lever, offering variable rewards with a 50% probability of reward and a 50% probability of 1-s foot-shock. The results showed that the shock condition decreased the preference for the large/risky lever, despite increasing rewards. Importantly, inhibiting the BLA→PL pathway significantly increased the selection of the "large/risky" lever compared to the control. Although rats in the clozapine N-oxide (CNO) group did not exhibit significant differences in response latency between levers, they exhibited heightened sensitivity to rewards and losses, suggesting that the BLA→PL pathway affects the encoding of the relationship between aversive stimuli and reward-seeking. Overall, these results provide valuable insights into the neural mechanisms of risk-taking, particularly regarding how inhibition in the BLA→PL pathway can influence reward processing and decision-making under no-reward but shock conditions, with implications for understanding risk-related psychiatric disorders.

Interrupting sitting with moderate-intensity physical activity breaks improves cognitive processing speed in adults with overweight and obesity: Findings from the SITLess pilot randomized crossover trial.

Prolonged sitting can acutely reduce working memory (WM) in individuals with overweight and obesity (OW/OB) who show executive function deficits. Interrupting prolonged sitting with brief PA bouts may counter these effects. However, the benefits of such interventions on behavioral and neuroelectric indices of WM and whether neurocognitive responses are associated with postprandial glycemic responses in young and middle-aged adults with OW/OB remain unknown. To address this gap, this study examined the acute effects of interrupting three-hour prolonged sitting every 30 min with 3.5-min moderate-intensity physical activity (MPA) bouts (MPA + SIT condition) relative to sedentary social interaction condition (SOC + SIT) on behavioral measures of WM and the P3b component of event-related potentials (ERP) in young and middle-aged adults with OW/OB. Nineteen adults with OW/OB (63 % females; 29.9 ± 7.5 years; BMI = 30.0 ± 3.64 kg*m-2) were included in the SITLess pilot randomized crossover trial. Choice RT and WM were measured before, after, and four times during each condition with 1- and 2-back letter tasks. They were expressed as the incremental area under the curve (iAUC). Choice RT was expressed as d-prime, target, and nontarget accuracy, and RT on the 1-back and nontarget RT on the 2-back task. WM was expressed as d-prime, target accuracy, and RT on the 2-back task. The amplitude of the P3b-ERP component was used to measure attentional resource allocation during both tasks; the P3b-ERP fractional area latency measured cognitive processing before and after each condition. Two-hour postprandial glycemic responses (expressed as iAUC) were measured using an oral glucose tolerance test (OGTT). Time (pre, post) x Condition (MPA + SIT vs. SOC + SIT) interactions and the main effect of Condition (iAUCs) were tested using Linear Mixed Models. No significant intervention effects on glucose were noted (p = 0.74). Compared to SOC + SIT, MPA + SIT resulted in shorter 1-back target P3b latency (F(1, 17.0) = 5.14, p = 0.037; Mdiff = -9.77, SE = 4.31 ms, 95%CI: -18.9, -0.68) at post-test. No effects on behavioral measures were noted (ps ≥ 0.06). However, the between-condition difference in 1-back P3b latency correlated positively with the between-condition difference in RTs on 1-back;shorter P3b latency was related to shorter RTs in the MPA + SIT relative to SOC + SIT (r = 0.65 and 0.55 for target and nontarget trials, ps ≤ 0.02). Interrupting sitting with short MPA bouts can enhance some aspects of cognitive processing in adults with OW/OB. Future studies are needed to better understand behavioral responses to interrupting prolonged sitting with MPA bouts and the underlying mechanisms.

Objective Neurophysiological Measures of Cognitive Performance in Elite Ice Hockey Players.

Athletic peak performance is increasingly focused on cognitive and mental factors. In the current study, cognitive performance was measured by neurophysiological responses in elite Junior-A hockey players. Neurophysiological brain vital signs were extracted from event-related potentials (ERPs) to evaluate auditory sensation (the N100), basic attention (the P300), and cognitive processing (the N400). In total, we evaluated 348 athletes, across 17 teams, throughout different hockey arenas in British Columbia, Canada. While brain vital signs were collected to help manage concussion, the current investigation focused on a retrospective performance analysis of cognitive processing differences. The results revealed three interesting findings: 1) Player position differences were detectable in sensory N100 latency, with significantly faster responses for forwards compared to defense; 2) Goalies showed significantly higher attention P300 amplitude compared to all other positions; and 3) Cognitive N400 processing differences were detectable only during competitive combine testing, showing 60ms latency differences between forwards and defense on average. The current findings suggest that neurophysiological responses, which are also sensitive to concussion, may be used to identify sensory, attentional, and cognitive processing differences to help optimize peak performance.

Mismatch Negativity Unveils Tone Perception Strategies and Degrees of Tone Merging: The Case of Macau Cantonese.

Previous studies have examined the role of working memory in cognitive tasks such as syntactic, semantic, and phonological processing, thereby contributing to our understanding of linguistic information management and retrieval. However, the real-time processing of phonological information-particularly in relation to suprasegmental features like tone, where its contour represents a time-varying signal-remains a relatively underexplored area within the framework of Information Processing Theory (IPT). This study aimed to address this gap by investigating the real-time processing of similar tonal information by native Cantonese speakers, thereby providing a deeper understanding of how IPT applies to auditory processing. Specifically, this study combined assessments of cognitive functions, an AX discrimination task, and electroencephalography (EEG) to investigate the discrimination results and real-time processing characteristics of native Macau Cantonese speakers perceiving three pairs of similar tones. The behavioral results confirmed the completed merging of T2-T5 in Macau Cantonese, and the ongoing merging of T3-T6 and T4-T6, with perceptual merging rates of 45.46% and 27.28%, respectively. Mismatch negativity (MMN) results from the passive oddball experiment revealed distinct temporal processing patterns for the three tone pairs. Cognitive functions, particularly attention and working memory, significantly influenced tone discrimination, with more pronounced effects observed in the mean amplitude of MMN during T4-T6 discrimination. Differences in MMN peak latency between T3-T6 and T4-T6 further suggested the use of different perceptual strategies for these contour-related tones. Specifically, the T3-T6 pair can be perceived through early signal input, whereas the perception of T4-T6 relies on constant signal input. This distinction in cognitive resource allocation may explain the different merging rates of the two tone pairs. This study, by focusing on the perceptual difficulty of tone pairs and employing EEG techniques, revealed the temporal processing of similar tones by native speakers, providing new insights into tone phoneme processing and speech variation.

Clinical and biochemical characteristics of patients with acromegaly and normal or increased prolactin levels

Background: Prevalence of hyperprolactinemia in patients with acromegaly is 30 to 40%. Since recently, the necessity of screening for acromegaly in hyperprolactinemic patients with pituitary adenoma has been actively debated. The literature on this issue has been controversial, with some authors describing significant differences of clinical and biochemical parameters in acromegaly patients with normal or increased prolactin levels, while others state the absence of such differences. Aim: To identify hallmarks of clinical and biochemical parameters in patients with acromegaly and normal or increased prolactin level. Methods: We performed a single center, single sample retrospective, observational cohort uncontrolled non-interventional study in 306 patients (70 men and 236 women) with acromegaly examined from July 2021 to June 2024, 50 of them with a pituitary microadenomas and 256 with macroadenomas. The patients were divided into two groups: acromegaly without hyperprolactinemia (n = 234) and acromegaly with hyperprolactinemia (n = 72). The groups were compared for age, gender, clinical manifestations, insulin-like growth factor 1 (IGF1) levels, characteristics of pituitary adenomas and efficacy of the treatment. In the patients with acromegaly and hyperprolactinemia we additionally analyzed prolactin levels at disease manifestation, an association between the suprasellar adenoma growth and prolactin, and an association between prolactin levels and adenoma volume at the disease onset, before treatment. Results: Hyperprolactinemia was significantly less common, than acromegaly without hyperprolactinemia, associated with acromegalic enlargement of the face (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.19–0.62, р 0.001), hands and feet enlargement (OR 0.06, 95% CI 0.03–0.12, р 0.001), but more common with visual field derangement (OR 2.8, 95% CI 1.06–7.39, р = 0.043), menstrual cycle abnormalities in women (OR 4.11, 95% CI 2.14–7.88, р 0.001) and breast discharge (OR 18.71, 95% CI 4–87.61, р 0.001). The patients with acromegaly and hyperprolactinemia noticed their first symptoms of the disease at a younger age (median 37 [25; 46] years vs 41.5 [32; 51.5] years, р = 0.004) and were diagnosed with acromegaly also earlier, than the patients with acromegaly without hyperprolactinemia (45 [34.5; 55] years vs 52 [42; 61] years, р 0.001). There were no differences in the disease latency, biochemical activity of acromegaly and gender distribution. The volume of pituitary adenomas in the patients with acromegaly and hyperprolactinemia was larger, compared to that in the patients without hyperprolactinemia (4445 [1649; 7767] mm3 vs 1242 [448; 3740] mm3, р 0.001). No correlation was found between the pituitary adenoma volume and prolactin levels. The rates of acromegaly control in both groups were not significantly different. Conclusion: The results of our study emphasize the importance to exclude acromegaly in patients with prolactinomas and in those with suspected pituitary stalk compression (which is characterized by moderate hyperprolactinemia and suprasellar growth of the pituitary adenoma), even in the absence of pathognomic signs of increased secretion of growth hormone. Hyperprolactinemia does not affect the treatment outcomes in acromegaly, and more frequent administration of dopamine receptor agonists does not result in an increased proportion of patients with biochemical control of the main disease.

Association of BMI, Waist-hip Ratio and Skinfold Thickness with Sensory Conduction of the Median Nerve in First-year Medical Students: A Cross-sectional Study

Introduction: Nerve Conduction Study (NCS) is a widely used electrodiagnostic tool to evaluate the health of the peripheral nervous system. First-year medical students, due to extensive use of Information and Communications Technology (ICT) and academic pressure, often have limited time for physical activity, potentially influencing nerve conduction. Understanding the influence of anthropometric factors on nerve conduction in this population can help suggest preventive strategies to maintain nerve health. Aim: To examine the association between various anthropometric variables with median nerve sensory conduction parameters like latency, amplitude, and Nerve Conduction Velocity (NCV) in first-year medical students. Materials and Methods: A cross-sectional study was conducted in the Department of Physiology at Jawaharlal Nehru Medical College, KLE Academy of Higher Education and Research, Belagavi, Karnataka, India from January 2019 to December 2019. Out of the total population, 110 students were selected through simple random sampling after applying inclusion and exclusion criteria. Anthropometric measurements, including height, weight, Body Mass Index (BMI), Waist-hip Ratio (WHR), and skinfold thickness, were recorded. Median nerve sensory conduction was assessed at the wrist in both hands. Data were analysed using Statistical Packages for Social Sciences (SPSS) software version 20.0, and associations between BMI, WHR, skinfold thickness and nerve conduction parameters were evaluated using Student’s t-test. Results: For height, no statistically significant differences were found for latency (p=0.15) and amplitude (p=0.65), although shorter individuals had slightly lower NCV compared to those of normal height (p<0.01). BMI categories showed no significant differences in latency, amplitude, or NCV, though underweight individuals had slightly higher NCVs (54.60 m/s) than those of normal weight (51.96 m/s, p=0.54). A WHR ≤0.9 was associated with significantly higher right-hand amplitude (37.63 μV vs. 28.20 μV, p=0.013) and lower left-hand NCV (51.51 m/s vs. 55.02 m/s, p=0.03). Skinfold thickness showed no significant correlation with nerve conduction parameters (p>0.05). These findings suggest that height and WHR may impact specific aspects of nerve conduction, with potential implications for clinical assessments. Conclusion: This study demonstrates that anthropometric variables, including height, weight, and WHR, significantly influence median nerve sensory conduction parameters. These findings highlight the importance of considering body composition when interpreting Nerve Conduction Studies (NCS), particularly in populations with lifestyle constraints like medical students.

Feasibility of long-range telesurgical robotic radical gastrectomy in a live porcine model.

Telesurgery has been made increasingly possible with the advancements in robotic surgical platforms and network connectivity. However, long-distance transnational complex robotic surgeries such as gastrectomy have yet to be attempted. Multiple transnational network connections by Science Innovation Network (SINET), Japan Gigabit Network (JGN), and Arterial Research and Education Network in Asia-Pacific (ARENA-PAC) were established and tested by multiple surgeons in a dry box model. Surgeons' perceptions of the different networks were recorded. Three robotic radical D2 gastrectomies in live porcine models were performed at a hospital in Toyoake, Japan, by a surgical team in a hospital in Singapore ~5000km away, using the hinotori Surgical Robot System (Medicaroid Corporation). The live porcine robotic gastrectomies were all completed in under 205min with no intraoperative complications. From the different networks that were tested, the differences in latency ranged from 107 to 132ms and did not translate to any significant differences in surgeon timings and perceptions. Transnational telesurgical radical D2 gastrectomy is feasible in a porcine model. There is no appreciable difference between surgeon performance and perception with network latencies of 107-132ms. Long-range telesurgery as clinical practice may become possible in the future.

Association of Evening Eating with Sleep Quality and Insomnia among Adults in a Brazilian National Survey.

Objective To examine the association of evening eating clock time, its elapsed time to the midpoint of sleep (TEM), consumption of caffeine and sugary foods, and reporting dinner as the largest meal with sleep quality indicators and insomnia. Methods Participants ( n = 2,050;18-65y) were part of population-based research, with virtual data collection. Logistic regression models were fitted to assess differences in the ORs(95%CI) of sleep duration < 7 hours, sleep latency > 30 minutes, poor sleep quality, and insomnia (outcomes) with the evening diet-related variables. Linear regression analyses evaluated differences in sleep duration and latency associated with the same variables. Restricted cubic splines were used to study the shape of the association of eating event clock time and TEM with sleep duration and latency. Results Each additional hour of evening eating clock time and of the TEM, respectively increased and decreased, the odds of sleep duration < 7/h [OR(95%CI):1.30(1.20,1.40); OR(95%CI):0.51(0.47,0.56)], sleep latency > 30min [OR(95%CI):1.14(1.07,1.22); 0.88(0.83,0.94)], poor sleep quality [OR(95%CI):1.21(1.13,1.30); 0.80(0.76,0.85)] and insomnia [OR(95%CI):1.12(1.04,1.20); 0.89(0.84,0.95)]. We found a dose-response association between evening eating (clock time and TEM) and sleep duration. The shortest latency was seen when evening eating was ∼20:00 and ∼7-8 hours before the midpoint of sleep. Participants who reported dinner as the largest meal and consumed caffeine and sugary foods/beverages after 18:00 presented higher odds of sleep duration < 7 hours, poor quality, and insomnia. Conclusions Our findings indicate that an early-eating schedule has beneficial sleep effects and that it will be necessary to consider evening eating patterns and timing, along with the existing sleep and circadian hygiene, to improve sleep quality and circadian health.

Performance of optically pumped magnetometer magnetoencephalography: validation in large samples and multiple tasks

Objective.Current commercial magnetoencephalography (MEG) systems detect neuro-magnetic signals using superconducting quantum interference devices (SQUIDs), which require liquid helium as cryogen and have many limitations during operation. In contrast, optically pumped magnetometers (OPMs) technology provides a promising alternative to conventional SQUID-MEG. OPMs can operate at room temperature, offering benefits such as flexible deployment and lower costs. However, the validation of OPM-MEG has primarily been conducted on small sample sizes and specific regions of interest in the brain, lacking comprehensive validation for larger sample sizes and assessment of whole-brain.Approach.We recruited 100 participants, including healthy and neurological disorders individuals. Whole-brain OPM-MEG and SQUID-MEG data were recorded sequentially during auditory (n= 50) and visual (n= 50) stimulation experiments. By comparing the task-evoked responses of the two systems, we aimed to validate the performance of the next-generation OPM-MEG.Main results.The results showed that OPM-MEG enhanced the amplitude of task-related responses and exhibited similar magnetic field patterns and neural oscillatory activity as SQUID-MEG. There was no difference in the task-related latencies measured by the two systems. The signal-to-noise ratio was lower for the OPM-MEG in the auditory experiment, but did not differ in the visual experiment, suggesting that the results may be task-dependent.Significance.These results demonstrate that OPM-MEG, as an alternative to traditional SQUID-MEG, shows superior response amplitude and comparable performance in capturing brain dynamics. This study provides evidence for the effectiveness of OPM-MEG as a next-generation neuroimaging technique.

The characteristics of event-related potentials in generalized anxiety disorder: A systematic review and meta-analysis.

Previous studies have reported inconsistent findings regarding event-related potentials (ERPs) abnormalities in individuals with generalized anxiety disorder (GAD). This meta-analysis aimed to systematically review and synthesize the existing evidence on ERP alterations in individuals with GAD. A comprehensive literature search was conducted in PubMed, the Cochrane Library, Excerpta Medica Database, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Database (VIP), Wanfang database, and China Biology Medicine (CBM) databases from inception to November 11, 2024. Gray literature and reference lists were also manually searched. Studies investigating ERP component differences between individuals with GAD and healthy controls were included. Two independent reviewers conducted study selection, data extraction, and risk of bias assessment. Influence and sensitivity analyses were performed to assess the robustness of the pooled results. Effect sizes (SMD, Hedge's g) were calculated for latency and amplitude differences. Heterogeneity was assessed using the I2 statistic. Meta-regression and subgroup analyses were conducted to explore the source of heterogeneity. Trim-and-fill analyses were applied to assess potential publication bias. Data synthesis was performed using R (version 4.2.3) software. A total of 37 studies involving 1086 individuals with GAD and 1315 healthy controls were included. The overall risk of bias was rated as low for 25 studies and moderate for 12 studies. Ten ERP components were included in the quantitative meta-analysis: P3, N2, N1, P2, Error Related Negativity (ERN), Correction Related Negativity (CRN), Mismatch Negativity (MMN), P1 (amplitude), Pe, and LPP. Pooled results indicated that individuals with GAD exhibited decreased P3 amplitude (g=-0.54, 95% CI: -0.70 to -0.38, I2=20%, P=0.22) and increased ERN amplitude (g=-0.42, 95% CI: -0.72 to -0.12, I2=40%, P=0.11) compared to healthy controls. In addition, delayed latency of P3 (g=0.43, 95% CI: 0.09 to 0.78, I2=75%, P<0.01), N2 (g=0.36, 95% CI: 0.11 to 0.62, I2=30%, P=0.20), and MMN (g=0.63, 95% CI: 0.52 to 0.75, I2=0%, P<0.0001) was observed in individuals with GAD. Due to the limited number of included studies, the results of N170, N1/P2, N270, N400, VPP, BAEP, P1 (latency), P50, EPN and Nf were summarized narratively. Individuals with GAD were reported to have increased N170, N400, and VPP amplitude and delayed P1 latency compared to healthy controls. Age, sex ratio, sample size, diagnostic criteria, task-related modality, and paradigm were identified as potential influencing factors of ERP characteristics. Individuals with GAD exhibit increased ERN amplitude and decreased P3 amplitude in contrast with healthy controls. In addition, delayed latency of P3, N2, and MMN is detected in individuals with GAD. The identified ERP components in individuals with GAD are associated with attention, cognition, visual perception, error or conflict monitoring, semantic information integration, and auditory sensory memory processes. Due to the limited number of included studies and high heterogeneity, further studies with high quality are needed to confirm these findings.

Self-tuning architecture enabling bidirectional transceiver normalization and low differential latency

Due to having only one working wavelength, single wavelength bidirectional transmission combines the advantages of fiber saving and transceiver normalization. This is beneficial for reducing the CAPEX and OPEX of networks, and can also improve the time synchronization accuracy of mobile CRAN networks. However, the performance of single wavelength bidirectional transmission is invariably sensitive to backward reflected emission light. Frequency shifting and digital signal processing are typical approaches to eliminate this penalty, but it leads to higher cost and power consumption. In this paper, we first apply a self-tuning architecture and physical layer negotiation in bidirectional transceiver, to allow the transceiver to support two modes. Then a single-fiber bidirectional transmission can be setup by this normalized transceiver as single working wavelength but without performance penalty. Except wavelength, other performances of manufactured 25 G Baud PAM4 self-tuning bidirectional transceiver are compliant with IEEE 802.3cp 40 km ER specification. When the two working mode wavelength interval is 0.4 nm, the latency difference over 40 km is 250 ps, which is on the same order of magnitude as the delay difference in single wavelength bidirectional transmission.

The H-reflex study of the flexor carpi radialis muscle in healthy individuals.

This study aimed to investigate the physiological and anatomical factors influencing the flexor carpi radialis (FCR) H-reflex and to establish reference values for FCR H-reflex parameters in relation to these factors. The FCR H-reflexes, elicited by median nerve stimulation, were assessed in 80 healthy individuals both at rest and during isometric voluntary contraction (IVC). Multiple linear regression analyses were performed with H-reflex parameters as the dependent variables, while age, gender, height, arm length, and weight were included as independent variables. The FCR H-reflex was recorded bilaterally in nearly all healthy individuals (76 out of 80) during IVC, while it could be obtained in only 35% (28 out of 80) of these individuals at rest. During IVC, the maximum H-reflex amplitude (Hmax) and its ratio to the maximum M-response amplitude (Hmax/Mmax ratio) were significantly increased (p < 0.001). However, there were no changes in H-reflex latency, latency difference, conduction velocity (HRCV), or amplitude ratio (p > 0.05). In both conditions, age and arm length were the most important factors affecting H-reflex latency (p < 0.001), while HRCV was influenced only by age (p < 0.01). Women exhibited shorter H-reflex latencies (p < 0.01), and both Hmax amplitude and Hmax/Mmax ratio were higher in women during IVC (p < 0.05). The H-reflex amplitude ratio during IVC showed a tendency to decrease with age (p < 0.05). These findings suggest that FCR H-reflexes are more reliably elicited during IVC, and that both physiological and anatomical factors should be considered when assessing H-reflex abnormalities.

Distinguishing Doors and Floors on All Fours: Landmarks as Tools for Vertical Navigation Learning in Domestic Dogs (Canis familiaris).

Spatial navigation allows animals to understand their environment position and is crucial to survival. An animal's primary mode of spatial navigation (horizontal or vertical) is dependent on how they naturally move in space. Observations of the domestic dog (Canis familiaris) have shown that they, like other terrestrial animals, navigate poorly in vertical space. This deficit is visible in their use of multi-story buildings. To date, no research has been conducted to determine if dogs can learn how to navigate in an anthropogenic vertical environment with the help of a landmark. As such, we herein investigate the effect of the addition of a visual or olfactory landmark on dogs' ability to identify when they are on their home floor. Subject behaviors toward their home door and a contrasting floor door were compared before and after exposure to a landmark outside of their home door. While subjects initially showed no difference in latency to approach an apartment door on their home or a wrong floor, we found a significant difference in latency to approach the doors in the test trials for subjects who approached the doors in every trial. Other findings are equivocal, but this result is consistent with the hypothesis that dogs can learn to navigate in vertical space.

Validation of direct recording of electrically evoked cortical auditory evoked potentials through a cochlear implant system.

Cochlear implants (CI) are one of the most successful treatments available to enable individuals with severe to profound hearing loss to regain access to the world of sound. This is accomplished through the electrical stimulation of the auditory nerve using electrodes implanted inside the cochlea. The use of subjective user feedback makes the process of fitting these devices much more challenging in cases where users are not able to actively or accurately report their experience (e.g. pediatrics), making an objective measurement that reflects the accuracy or effectiveness of a program quite attractive. We recorded one objective measure, the electrically-stimulated cortical auditory evoked potential (eCAEP), non-invasively using the CI in response to a simulated speech sound in seven adult participants and compared it to their eCAEP recorded using a scalp EEG set-up. The eCAEPs recorded with CI electrodes were comparable to scalp recorded eCAEPs (grand mean cross-correlation of r = 0.83, individual mean cross-correlations ranged from 0.13 to 0.70). Evoked potential peaks P1, N1 and P2 showed no significant latency difference based on if the eCAEP was recorded on the scalp or using the CI. The eCAEP waveforms recorded via the CI appear to converge in a distinct P1-N1-P2 waveform by as early as 130 sweeps. In conclusion, in this study we show the feasibility of recording the eCAEP directly through the CI system, which could potentially be used to guide CI fitting and track auditory cortex development in response to CI use.

Biochemical characterization of the human ubiquitous glucose-6-phosphatase in neutrophil granulocytes.

Glucose-6-phosphatase-β (G6PC3) is a ubiquitous phosphatase present in the endoplasmic reticulum, which, unlike G6PC1, is not responsible for maintaining blood glucose level under starvation. Recently, G6PC3 has been shown to play an important role in neutrophil granulocytes, eliminating the toxic metabolite 1,5-anhydroglucitol-6-phosphate. The present study aimed to look for alternative substrates for the enzyme and outline the expression changes in the parts of this multicomponent system during neutrophil granulocyte differentiation. We determined the kinetic characteristics of recombinant human G6PC3 towards different sugar phosphates, and the transport of these compounds was also measured in rat liver microsomes. We found that all investigated sugar phosphates are substrates for G6PC3, although their microsomal transport is much slower than that of glucose-6-phosphate. Using the HL-60 promyelocytic leukemia cell line as an in vitro model system for myeloid differentiation, we found no significant differences in enzyme expression and phosphatase activity latency between undifferentiated and differentiated cells. Our results provide novel insights into the possible role of G6PC3 in the dephosphorylation of alternative sugar phosphates or their metabolites synthesized in the endoplasmic reticulum and confirm the potential feature of the enzyme in the promyelocytic stage as well. These findings contribute to our knowledge of intracellular carbohydrate metabolism of neutrophil granulocytes, which facilitates further research directions to better understand the underlying mechanisms of neutropenias.

ApSpGEMM: Accelerating Large-scale SpGEMM with Heterogeneous Collaboration and Adaptive Panel

The Sparse General Matrix-Matrix multiplication (SpGEMM) is a fundamental component for many applications, such as algebraic multigrid methods (AMG), graphic processing, and deep learning. However, the unbearable latency of computing high-dimensional, large-scale sparse matrix multiplication on GPUs hinders the development of these applications. An effective approach is heterogeneous cores collaborative computing, but this method must address three aspects: (1) irregular non-zero elements lead to load imbalance and irregular memory access, (2) different core computing latency differences reduce computational parallelism, and (3) temporary data transfer between different cores introduces additional latency overhead. In this work, we propose an innovative framework for collaborative large-scale sparse matrix multiplication on CPU-GPU heterogeneous cores, named ApSpGEMM. ApSpGEMM is based on sparsity rules and proposes reordering and splitting algorithms to eliminate the impact of non-zero element distribution features on load and memory access. Then adaptive panels allocation with affinity constraints among cores improves computational parallelism. Finally, carefully arranged asynchronous data transmission and computation balance communication overhead. Compared with state-of-the-art SpGEMM methods, our approach provides excellent absolute performance on matrices with different sparse structures. On heterogeneous cores, the GFlops of large-scale sparse matrix multiplication is improved by 2.25 to 7.21 times.

F-waves responses derived from low-intensity electrical stimulation: A method to explore split-hand pathogenesis

ObjectivesThe “split-hand syndrome” is a common clinical sign in amyotrophic lateral sclerosis (ALS), being characterized by more severe atrophy of the hand muscles on the radial side of the hand compared to the ulnar side. We aimed to investigate possible physiological differences between relevant hand muscles using low-intensity F-wave stimulation to assess spinal motoneuron excitability. MethodsWe recruited 36 healthy volunteers. F-waves were recorded from the abductor pollicis brevis (APB), first dorsal interosseous (FDI) and abductor digiti minimi (ADM), using 20 supramaximal stimuli followed by 20 stimuli at a low-intensity required to obtain M-waves with 10 % amplitude of maximal CMAP. We evaluated the following F-wave parameters: F-M latency, chronodispersion, persistence, amplitude, F/CMAP amplitude ratio and number of F-wave repeaters (with low-intensity). In 10 subjects, low-intensity stimulation F-waves were compared after 20 and 50 stimuli in each muscle. ResultsLow-intensity stimulation resulted in lower F-wave amplitude and persistence and higher F/CMAP amplitude ratios. There were no significant differences in F-wave latencies and chronodispersion. When comparing the three muscles, we found higher F-wave persistence and F/CMAP amplitude ratios when recording over the ADM and APB compared to the FDI. We also found a higher number of F-wave repeaters in the ADM with low-intensity stimulation. Results from 20 to 50 low-intensity stimuli were similar. DiscussionA small number of low-intensity stimuli is appropriate to study F-wave latencies and chronodispersion. We found differences in some physiological properties of the ADM spinal motoneuron pool compared to other hand muscles.

Electrophysiological Signal Validation of Regenerative Peripheral Nerve Interface at Nerve Ending: A Preliminary Rat Model Experiment.

As the number of extremity amputations continues to rise, so does the demand for prosthetics. Emphasizing the importance of a nerve interface that effectively amplifies and transmits physiological signals through peripheral nerve surgery is crucial for achieving intuitive control. The regenerative peripheral nerve interface (RPNI) is recognized for its potential to provide this technical support. Through animal experiment, we aimed to confirm the actual occurrence of signal amplification. Rats were divided into three experimental groups: control, common peroneal nerve transection, and RPNI. Nerve surgeries were performed for each group, and electromyography (EMG) and nerve conduction studies (NCS) were conducted at the initial surgery, as well as at 2, 4, and 8 weeks postoperatively. All implemented RPNIs exhibited viability and displayed adequate vascularity with the proper color. Clear differences in latency and amplitude were observed before and after 8 weeks of surgery in all groups (p < 0.05). Notably, the RPNI group demonstrated a significantly increased amplitude compared with the control group after 8 weeks (p = 0.031). Latency increased in all groups 8 weeks after surgery. The RPNI group exhibited relatively clear signs of denervation with abnormal spontaneous activities (ASAs) during EMG. This study is one of few preclinical studies that demonstrate the electrophysiological effects of RPNI and validate the neural signals. It serves as a foundational step for future research in human-machine interaction and nerve interfaces.