An open-source application for the standardized burst identification from the integrated muscle sympathetic neurogram.

2021 ◽  
Author(s):  
Glen Edward Foster ◽  
Brooke M. Shafer ◽  
Conan Lok Hon Shing
Keyword(s):  
Open Source ◽  
Web Application ◽  
Muscle Sympathetic Nerve Activity ◽  
Intraclass Correlation ◽  
Total Activity ◽  
Isometric Handgrip ◽  
Burst Frequency ◽  
Post Exercise ◽  
Isometric Handgrip Exercise ◽  
Cross Platform

Muscle sympathetic nerve activity (MSNA) can be acquired from humans using the technique of microneurography. The resulting integrated neurogram displays pulse-synchronous bursts of sympathetic activity which undergoes processing for standard MSNA metrics including burst frequency, height, area, incidence, total activity and latency. The procedure for detecting bursts of MSNA and calculating burst metrics is tedious and differs widely amongst laboratories world-wide. We sought to develop an open-source, cross-platform web application that provides a standardized approach for burst identification and a tool to increase research reproducibility for those measuring MSNA. We compared the performance of this web application against a manual scoring approach under conditions of rest, chemoreflex activation (N = 9, 20 min isocapnic hypoxia), and metaboreflex activation (N = 13, 2 min isometric handgrip exercise and 4 min post exercise circulatory occlusion). The intraclass correlation coefficient (ICC) indicated good to strong agreement between scoring approaches for burst frequency (ICC = 0.92 - 0.99), incidence (ICC = 0.94 - 0.99), height (ICC = 0.76 - 0.88), total activity (ICC = 0.85 - 0.99), and latency (ICC = 0.97 - 0.99). Agreement with burst area was poor to moderate (ICC = 0.04 - 0.67) but changes in burst area were similar with chemoreflex and metaboreflex activation. Scoring using the web application was highly efficient and provided data visualization tools which expedited data processing and the analysis of MSNA. We recommend the open-source web application be adopted by the community for the analysis of MSNA.

scholarly journals Modulation of muscle sympathetic nerve activity to muscle heating during dynamic exercise

2009 ◽  
Vol 296 (5) ◽  
pp. R1439-R1444 ◽  
Author(s):  
Jonathan S. Cook ◽  
Chester A. Ray
Keyword(s):  
Blood Flow ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Interactive Effect ◽  
Total Activity ◽  
Muscle Temperature ◽  
Isometric Handgrip ◽  
Burst Frequency ◽  
Nerve Activity

Previous studies from our laboratory have demonstrated that altering muscle temperature of the exercising forearm can elicit changes in muscle sympathetic nerve activity (MSNA) during ischemic isometric handgrip. The purpose of the current study was to determine the interactive effect of muscle temperature and blood flow on MSNA responses during dynamic handgrip (DHG). Eight subjects performed two bouts of graded DHG to fatigue followed by 2 min of postexercise muscle ischemia (PEMI). Local heating of the forearm increased muscle temperature from 33.6 ± 0.3 to 38.3 ± 0.5°C ( P < 0.05). Mean arterial pressure and heart rate increased in a linear fashion during graded DHG ( P < 0.05) but were not affected by muscle temperature. MSNA (burst frequency and total activity) at fatigue and PEMI were elevated in all conditions ( P < 0.05). However, MSNA responses were not different between temperature conditions. To ascertain the effect of blood flow, eight additional subjects completed two trials of ischemic DHG under control or warm conditions followed by 2 min of PEMI. MSNA, expressed as burst frequency and total activity, was significantly greater in warm compared with the control trial (Δ14 ± 3 and Δ9 ± 2 bursts/30 s, and Δ1,234 ± 260 and Δ751 ± 199 units/30 s, respectively). This finding supports the concept that muscle heating sensitizes skeletal muscle afferents during muscle contractions and augments MSNA in humans. However, on the basis of these findings, we conclude that muscle blood flow modulates the effect of muscle temperature on MSNA during exercise.

scholarly journals Isometric Handgrip Exercise Training Improves Spirometric Parameters and Pulmonary Capacity

2021 ◽  
Vol 28 (3) ◽  
pp. 328-338
Author(s):  
Ogbutor Udoji Godsday ◽  
Nwangwa Eze Kingsley ◽  
Nwogueze Bartholomew Chukwuebuka ◽  
Chukwuemeka Ephraim ◽  
Ezunu Emmanuel ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Isometric Exercise ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Post Exercise ◽  
Significant Difference ◽  
Isometric Handgrip Exercise ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Decline in normal physiological pulmonary function has been attributed to premorbid conditions such as prehypertension. Research evidence suggests that physical activity reduces age-related decline in pulmonary function and improves the efficiency of the lungs in prehypertensive patients. However, there is a scarcity of data evidence relating to isometric exercise and pulmonary function. Furthermore, the interrelationship between the intensity and duration of isometric exercise and pulmonary function in these patients is still uncertain. Therefore, this study was undertaken to investigate the effect of isometric handgrip exercise on pulmonary function capacity in adults with prehypertension. To determine the effectiveness of isometric handgrip exercise on pulmonary function capacity in adults with prehypertension. A quasi experiment using a pre- and post-exercise method was carried out in two out-patients hospital settings. The sample comprised 192 sedentary pre-hypertensive subjects, aged between 30–50 years, that were randomly distributed into three groups of 64 participants each. The subjects performed, for 24 consecutive days, an isometric handgrip exercise at 30% Maximum Voluntary Contraction (M.V.C.). At the end of the 24 days, group one (GP1) discontinued, while group two (GP2) continued the exercise protocol for another 24 consecutive days and group three (GP3) continued with the exercise protocol for another 24 consecutive days but at 50% M.V.C. Determinants of lung function (outcomes) were Forced Expiratory Volume in 1 s (FEV1), Forced Vital Capacity (FVC), FEV1/FVC Ratio and Peak Expiratory Flow Rate (PEFR). The study shows that there was no statistically significant difference in the pre- and post-exercise outcomes for FEV1, FVC, FEV1/FVC Ratio and PEFR after 24 days for group 1. In group 2, there was a statistically significant difference in the FVC [(mean = 0.12 ± 0.12), (p = 0.002)], FEV1 [(mean = 0.15 ± 0.17), (p = 0.003)] and PEF [(mean = 0.85 ± 0.35), (p = 0.001)] after 48 days. In group 3, there was a statistically significant difference (p = 0.001) in all the outcomes assessed after 48 days. There was a between groups difference in favour of group 2 compared with group 1 for outcomes of FEV1 [(mean = 0.142 ± 0.68), (p = 0.005)] and PEF [(mean = 0.83 ± 0.19), (p = 0.0031)]. There was statistically significant difference in favour of group 3 compared to group 2, by increasing the exercise intensity from 30% to 50% M.V.C., for outcomes of FVC [mean change = 0.10 ± 0.052), (p = 0.005)], FEV1/FVC [mean change = 3.18 ± 0.75), (p = 0.017)] and PEF [(mean change = 0.86 ± 0.35), (p = 0.001)] after 48 days. Isometric handgrip exercise (after 48 days at 30% to 50% M.V.C.) improves outcomes of pulmonary function capacity in adults with prehypertension. Meanwhile, duration and/or increase in intensity of the isometric effort significantly contributed to the affects attained.

Chemoreflex and metaboreflex control during static hypoxic exercise

2005 ◽  
Vol 288 (4) ◽  
pp. H1724-H1729 ◽  
Author(s):  
Anne Houssiere ◽  
Boutaina Najem ◽  
Agniezka Ciarka ◽  
Sonia Velez-Roa ◽  
Robert Naeije ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Circulatory Arrest ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Isometric Handgrip Exercise ◽  
Baseline Values ◽  
Hypoxic Exercise

To investigate the effects of muscle metaboreceptor activation during hypoxic static exercise, we recorded muscle sympathetic nerve activity (MSNA), heart rate, blood pressure, ventilation, and blood lactate in 13 healthy subjects (22 ± 2 yr) during 3 min of three randomized interventions: isocapnic hypoxia (10% O2) (chemoreflex activation), isometric handgrip exercise in normoxia (metaboreflex activation), and isometric handgrip exercise during isocapnic hypoxia (concomitant metaboreflex and chemoreflex activation). Each intervention was followed by a forearm circulatory arrest to allow persistent metaboreflex activation in the absence of exercise and chemoreflex activation. Handgrip increased blood pressure, MSNA, heart rate, ventilation, and lactate (all P < 0.001). Hypoxia without handgrip increased MSNA, heart rate, and ventilation (all P < 0.001), but it did not change blood pressure and lactate. Handgrip enhanced blood pressure, heart rate, MSNA, and ventilation responses to hypoxia (all P < 0.05). During circulatory arrest after handgrip in hypoxia, heart rate returned promptly to baseline values, whereas ventilation decreased but remained elevated ( P < 0.05). In contrast, MSNA, blood pressure, and lactate returned to baseline values during circulatory arrest after hypoxia without exercise but remained markedly increased after handgrip in hypoxia ( P < 0.05). We conclude that metaboreceptors and chemoreceptors exert differential effects on the cardiorespiratory and sympathetic responses during exercise in hypoxia.

scholarly journals QGIS WEB CLIENT 2 – NEW TECHNOLOGY FOR WEB GEODATA PUBLISHING

2021 ◽  
Vol 2 (6) ◽  
pp. 28-31
Author(s):  
G.I. Morgunov ◽  
◽  
, A.V. Orlovsky
Keyword(s):  
Open Source ◽  
Web Application ◽  
New Technology ◽  
Source Code ◽  
Free Access ◽  
Space Images ◽  
Map Comparison ◽  
Technical Requirements ◽  
Cross Platform ◽  
Free Modules

This paper focuses on Quantum GIS (QGIS), an open-source cross-platform application that allows to visualize geospatial data in various formats. The paper indicated the main advantages of QGIS web application (second version) – QGIS Web Client 2: free distribution; free access to open-source code, which allows to write or modify a script or program module; permission to modify the source code; the ability to install the program on various operating systems (Windows, Mac OS, Ubuntu, etc.); a large library of free modules for working with geodata; the ability to publish maps on the web using Mapserver and other analogs; the ability to download space images from different sources (Yandex, Google, Bing Aerial, etc.); the ability to post data and publish projects on the Internet using the QGIS Cloud plugin. The technical requirements for the design of the QWC2 web application are presented; instructions for installing and QWC2 configuration on the available infrastructure are also given. The testing and the functionality of QWC2 application were presented on practical examples (area / length / coordinate measurements; thumbnail / redline functionality; generation of permalinks; PDF printing; ability to export maps in different images; import WMS/WFS; map comparison).

scholarly journals Covidex: an ultrafast and accurate tool for virus subtyping

2020 ◽  
Author(s):  
Marco Cacciabue ◽  
Pablo Aguilera ◽  
María Inés Gismondi ◽  
Oscar Taboga
Keyword(s):  
Open Source ◽  
Web Application ◽  
Classification Models ◽  
Genome Sequences ◽  
Link Type ◽  
Shiny App ◽  
Cross Platform ◽  
Model Generator ◽  
Free Machine ◽  
Subtyping Tool

SummaryCovidex is an open-source, alignment-free machine learning subtyping tool for viral species. It is a shiny app that allows a fast and accurate classification in pre-defined clusters for SARS-CoV-2 and FMDV genome sequences. The user can also build its own classification models with the Covidex model generator.AvailabilityCovidex is open-source, cross-platform compatible, and is available under the terms of the GNU General Public License v3 (http://www.gnu.org/licenses/gpl.txt). Covidex is available via SourceForge https://sourceforge.net/projects/covidex or the web application https://cacciabue.shinyapps.io/shiny2/[email protected]; [email protected]

scholarly journals Validity and reliability of measuring resting muscle sympathetic nerve activity using short sampling durations in healthy humans

2016 ◽  
Vol 121 (5) ◽  
pp. 1065-1073 ◽  
Author(s):  
Karambir Notay ◽  
Jeremy D. Seed ◽  
Anthony V. Incognito ◽  
Connor J. Doherty ◽  
Massimo Nardone ◽  
...  
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Intraclass Correlation ◽  
Validity And Reliability ◽  
Burst Frequency ◽  
Nerve Activity ◽  
True Value ◽  
Sampling Duration ◽  
Resting Muscle

Resting muscle sympathetic nerve activity (MSNA) demonstrates high intraindividual reproducibility when sampled over 5–30 min epochs, although shorter sampling durations are commonly used before and during a stress to quantify sympathetic responsiveness. The purpose of the present study was to examine the intratest validity and reliability of MSNA sampled over 2 and 1 min and 30 and 15 s epoch durations. We retrospectively analyzed 68 resting fibular nerve microneurographic recordings obtained from 53 young, healthy participants (37 men; 23 ± 6 yr of age). From a stable 7-min resting baseline, MSNA (burst frequency and incidence, normalized mean burst amplitude, total burst area) was compared among each epoch duration and a standard 5-min control. Bland-Altman plots were used to determine agreement and bias. Three sequential MSNA measurements were collected using each sampling duration to calculate absolute and relative reliability (coefficients of variation and intraclass correlation coefficients). MSNA values were similar among each sampling duration and the 5-min control (all P > 0.05), highly correlated ( r = 0.69–0.93; all P < 0.001), and demonstrated no evidence of fixed bias (all P > 0.05). A consistent proportional bias ( P < 0.05) was present for MSNA burst frequency (all sampling durations) and incidence (1 min and 30 and 15 s), such that participants with low and high average MSNA underestimated and overestimated the true value, respectively. Reliability decreased progressively using the 30- and 15-s sampling durations. In conclusion, short 2 and 1 min and 30 s sampling durations can provide valid and reliable measures of MSNA, although increased sample size may be required for epochs ≤30 s, due to poorer reliability.

Effects of enoximone on peripheral and central chemoreflex responses in humans

2008 ◽  
Vol 294 (1) ◽  
pp. H322-H329 ◽  
Author(s):  
Marko Gujic ◽  
Céline Dreyfuss ◽  
Jean-François Argacha ◽  
Sofia Beloka ◽  
Dionysios Adamopoulos ◽  
...  
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Minute Ventilation ◽  
Acute Hypoxia ◽  
Phosphodiesterase Inhibitor ◽  
Isometric Handgrip ◽  
Isometric Handgrip Exercise ◽  
Peripheral Chemoreflex ◽  
Single Blind

cAMP plays an important role in peripheral chemoreflex function in animals. We tested the hypothesis that the phosphodiesterase inhibitor and inotropic medication enoximone increases peripheral chemoreflex function in humans. In a single-blind, randomized, placebo-controlled crossover study of 15 men, we measured ventilatory, muscle sympathetic nerve activity, and hemodynamic responses to 5 min of isocapnic hypoxia, 5 min of hyperoxic hypercapnia, and 3 min of isometric handgrip exercise, separated by 1 wk, with enoximone and placebo administration. Enoximone increased cardiac output by 120 ± 3.7% from baseline ( P < 0.001); it also increased the ventilatory response to acute hypoxia [13.6 ± 1 vs. 11.2 ± 0.7 l/min at 5 min of hypoxia, P = 0.03 vs. placebo (by ANOVA)]. Despite a larger minute ventilation and a smaller decrease in O2 desaturation (83 ± 1 vs. 79 ± 2%, P = 0.003), the muscle sympathetic nerve response to hypoxia was similar between enoximone and placebo (123 ± 6 and 117 ± 6%, respectively, P = 0.28). In multivariate regression analyses, enoximone enhanced the ventilatory ( P < 0.001) and sympathetic responses to isocapnic hypoxia. Hyperoxic hypercapnia and isometric handgrip responses were not different between enoximone and placebo ( P = 0.13). Enoximone increases modestly the chemoreflex responses to isocapnic hypoxia. Moreover, this effect is specific for the peripheral chemoreflex, inasmuch as central chemoreflex and isometric handgrip responses were not altered by enoximone.

scholarly journals Effect of age on the hemodynamic and sympathetic responses at the onset of isometric handgrip exercise

2014 ◽  
Vol 116 (2) ◽  
pp. 222-227 ◽  
Author(s):  
Sophie Lalande ◽  
Carolyn P. Sawicki ◽  
Jacquie R. Baker ◽  
J.Kevin Shoemaker
Keyword(s):  
Heart Rate ◽  
Total Peripheral Resistance ◽  
Pressor Response ◽  
Muscle Sympathetic Nerve Activity ◽  
Peripheral Resistance ◽  
Older Individuals ◽  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Vasoconstrictor Response ◽  
Isometric Handgrip Exercise

Cardiac and peripheral vasomotor factors contribute to the rapid pressor response at the onset of isometric handgrip exercise. We tested the hypothesis that age enhances the sympathetic and vasoconstrictor response at the onset of isometric handgrip exercise so that the pressor response is maintained, despite a diminished cardiac function. Twelve young and twelve older (24 ± 3 and 63 ± 8 yr) individuals performed 20-s isometric handgrip exercise at 30, 40, or 50% of maximal voluntary contraction force. Muscle sympathetic nerve activity (MSNA) was measured using microneurography. Mean arterial pressure (MAP) and cardiac output (Q̇) were assessed continuously by finger plethysmography and total peripheral resistance was calculated. MAP increased with the onset of handgrip; this increase was associated with handgrip intensity and was similar in both groups. Heart rate and Q̇ increased with increasing handgrip intensity in both groups, but increases were greater in young vs. older individuals (age × handgrip intensity interaction, P < 0.05). MSNA burst frequency increased ( P < 0.01), while MSNA burst incidence tended to increase ( P = 0.06) with increasing handgrip intensity in both groups. The change in MSNA between baseline and handgrip, for both frequency and incidence, increased with increasing handgrip intensity for both groups. There was no effect of handgrip intensity or age on total peripheral resistance. The smaller heart rate and Q̇ response during the first 20 s of handgrip exercise in older individuals was not accompanied by a greater sympathetic activation or vasoconstrictor response. However, increases in MAP were similar between groups, indicating that the pressor response at the onset of handgrip exercise is preserved with aging.

scholarly journals Post-exercise Hyperemia after Ischemic and Non-ischemic Isometric Handgrip Exercise

2003 ◽  
Vol 22 (6) ◽  
pp. 299-309 ◽  
Author(s):  
Takuya Osada ◽  
Toshihito Katsumura ◽  
Norio Murase ◽  
Takayuki Sako ◽  
Hiroyuki Higuchi ◽  
...  
Keyword(s):  
Handgrip Exercise ◽  
Isometric Handgrip ◽  
Post Exercise ◽  
Exercise Hyperemia ◽  
Isometric Handgrip Exercise
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