Standard Deviation Of Differences Research Articles

Abstract P238: Gait Characteristics in Older Adults Using the Protokinetics Zeno Walkway: The Atherosclerosis Risk in Communities Study

Introduction: Slowed gait speed in older adults is associated higher vascular disease burden, greater risk of dementia, and falls. Gait mat measurement technology captures speed as well as additional gait parameters, with potential importance for better risk prediction and identification in older adults, but normative data are needed. We assessed correlations between mat-measured gait speed and gait parameters to identify potential targets for future gait research. We hypothesized that gait parameters would not correlate with overall mat-measured gait speed as strongly as overall gait speed correlates within repeat trials of mat or stopwatch-measured trials. Methods: Participants (n = 402, mean age: 81 years, 54% women, 19% Black race) from the Atherosclerosis Risk in Communities Study completed two consecutive usual pace walks on Zeno Walkway™ gait mats at visit 8. Two-hundred thirty-six participants additionally completed two 4-meter usual pace walks timed by stopwatch. We assessed validity using the difference between the faster of two trials each for mat- and stopwatch-measured gait speed using Bland-Altman plots, and Pearson’s correlations, and examined reliability with consecutive trials within measurement type. We reported mean, standard deviation, range, and correlation of 37 gait parameters with gait speed, as well as intra-person variability (coefficient of variation) and parameter asymmetry between footfalls. Results: Participants had an average gait speed of 0.92 m/sec (SD 0.19 m/sec) measured by mat and 0.99 m/sec (SD 0.21 m/sec) by stopwatch. Mat-measured gait speed was strongly correlated with stopwatch measured speed (Pearson’s Correlation 0.85). Mat-measured walks were on average 0.08 m/sec faster than paired stopwatch-measured walks (standard deviation of difference 0.11 m/sec, p<0.001), regardless of gait speed. Consecutive mat walks had higher Pearson’s and R-squared correlations (0.95 and 0.90) than consecutive stopwatch walks (0.89 and 0.83). Of 37 gait parameters tested, 9 were positively correlated (Pearson’s correlations 0.64 to 0.76) and 7 were negatively correlated (Pearson’s correlations -0.64 to -0.42) with gait speed. Parameter variability in single stance center of pressure distance and gait speed was moderately negatively correlated (Pearson’s correlation -0.50). Correlations between gait speed and gait parameter asymmetry were low (<|0.33|). Conclusions: Gait mat technology shows high reliability and high correlation with stop-watch measurement in older adults in the ARIC population. Additional gait parameters were largely not strongly correlated with gait speed, including step-to-step measures of variability and asymmetry, suggesting avenues for future research to evaluate gait differences more granularly as more sensitive indicators of health risk in older adults.

Impact of telemedicine on glycemic control in type 2 diabetes mellitus during the COVID-19 lockdown period.

The lockdown at the start of coronavirus disease 2019 (COVID-19) pandemic in Saudi Arabia (March 2020 to June 2020) shifted routine in-person care for patients with type 2 diabetes mellitus (T2DM) to telemedicine. The aim of this study was to investigate the impact telemedicine had during this period on glycemic control (HbA1c) in patients with T2DM. 4,266 patients with T2DM were screened from five Ministry of National Guard Health Affairs hospitals in the Kingdom of Saudi Arabia. Age, gender, body mass index (BMI), HbA1c (before and after the COVID-19 lockdown), duration of T2DM, comorbidities and antidiabetic medications data were obtained. Mean and standard deviation of differences in HbA1c were calculated to assess the impact of telemedicine intervention. Correlations between clinically significant variances (when change in the level is ≥0.5%) in HbA1c with demographics and clinical characteristic data were determined using chi square test. Most of the participants were Saudis (97.7%) with 59.7% female and 56.4% ≥60 years of age. Obesity was 63.8%, dyslipidemia 91%, and hypertension 70%. Mean HbA1c of all patients slightly rose from 8.52% ± 1.5% before lockdown to 8.68% ± 1.6% after lockdown. There were n=1,064 patients (24.9%) whose HbA1c decreased by ≥0.5%, n =1,574 patients whose HbA1c increased by ≥0.5% (36.9%), and n =1,628 patients whose HbA1c changed by <0.5% in either direction (38.2%). More males had significant improvements in glycemia compared to females (28.1% vs 22.8%, p<0.0001), as were individuals below the age of 60 years (28.1% vs 22.5%, p<0.0001). Hypertensive individuals were less likely than non-hypertensive to have glycemic improvement (23.7% vs 27.9%, p=0.015). More patients on sulfonylureas had improvements in HbA1c (42.3% vs 37.9%, p=0.032), whereas patients on insulin had higher HbA1c (62.7% vs 56.2%, p=0.001). HbA1c changes were independent of BMI, duration of disease, hyperlipidemia, heart and kidney diseases. Telemedicine was helpful in delivering care to T2DM patients during COVID-19 lockdown, with 63.1% of patients maintaining HbA1c and improving glycemia. More males than females showed improvements. However, the HbA1c levels in this cohort of patients pre- and post-lockdown were unsatisfactorily high, and may be due to in part lifestyle, age, education, and hypertension.

The associations between physical-test performance and match performance in women's Rugby Sevens players.

Evaluating the relationships between physical-test and match performance in team sports could be useful for training prescription and athlete evaluation. Here we investigated these relationships in women's Rugby Sevens. Thirty provincial-representative players performed Bronco-fitness, countermovement-jump, acceleration, speed, and strength tests within two weeks before a two-day tournament. Match-running and match-action performance measures were provided by GPS units and video analysis. Generalised and general linear mixed models were employed to estimate the effect of a two standard-deviation difference in physical-test measures on match measures. Effect magnitudes were assessed via standardisation (using the between-player SD) and, for effects on tries scored, also via match winning (based on simulating matches). Evidence for substantial and trivial true magnitudes was provided by one-sided interval-hypothesis tests and Bayesian analysis. There was good evidence of positive effects of many physical-test measures on match high-intensity running, with large effects for jump height and acceleration. There was some evidence of small-moderate positive effects of speed and Bronco, and of small-moderate negative effects of maximal strength and jump height, on match total running and high intensity changes in speed. The evidence was generally inadequate for associations between physical-test measures and match actions, but there was good evidence of small-large positive effects of back squat and jump height on tries scored. Enhancing players' jump height and back-squat performance might therefore increase the likelihood of match success in women's Rugby Sevens.

Racial effects on Masimo pulse oximetry: a laboratory study

Recent publications have suggested that pulse oximeters exhibit reduced accuracy in dark-skinned patients during periods of hypoxemia. Masimo SET® (Signal Extraction Technology®) has been designed, calibrated, and validated using nearly equal numbers of dark and light skinned subjects, with the goal of eliminating differences between pulse oximetry saturation (SpO2) and arterial oxygen saturation (SaO2) values due to skin pigmentation. The accuracy concerns reported in dark-skinned patients led us to perform a retrospective analysis of healthy Black and White volunteers. Seventy-five subjects who self-identified as being racially Black or White underwent a desaturation protocol where SaO2 values were decreased from 100 to 70%, while simultaneous SpO2 values were recorded using Masimo RD SET® sensors. Statistical bias (mean difference) and precision (standard deviation of difference) were − 0.20 ± 1.40% for Black and − 0.05 ± 1.35% for White subjects. Plots of SpO2 versus SaO2 show no significant visible differences between races throughout the saturation range from 70 to 100%. Box plots grouped in 1% saturation bins, from 89–96%, and plotted against concomitant SaO2 values, show that occult hypoxemia (SaO2 < 88% when SpO2 = 92–96%) occurred in only 0.2% of White subject data pairs, but not in any Black subjects. There were no clinically significant differences in bias (mean difference of SpO2-SaO2) found between healthy Black and White subjects. Occult hypoxemia was rare and did not occur in Black subjects. Masimo RD SET® can be used with equal assurance in people with dark or light skin. These laboratory results were obtained in well-controlled experimental conditions in healthy volunteers—not reflecting actual clinical conditions/patients.

Feasibility of deconvolution-based multiphase CT angiography perfusion maps in acute ischemic stroke: Simulation and concordance with CT perfusion

ObjectivesIntegration of CT perfusion (CTP) with requisite non-contrast CT and CT angiography (CTA) stroke imaging may allow efficient stroke lesion volume measurement. Using surrogate images from CTP, we simulated the feasibility of using multiphase CTA (mCTA) to generate perfusion maps and assess target mismatch profiles. Materials and methodsPatients with acute ischemic stroke who received admission CTP were included in this study. Four CTP images (surrogate mCTA, one pre-contrast and three post-contrast, starting at the arterial peak then at 8 s intervals) were selected according to the CTP arterial time-density curve to simulate non-contrast CT and mCTA images. Cerebral blood flow (CBF) and Tmax maps were calculated using the same model-based deconvolution algorithm for the standard CTP and surrogate mCTA studies. Infarct and penumbra were delineated with CBF < 20% and Tmax > 6 s threshold, respectively. Classification accuracy of surrogate mCTA target mismatch (infarct <70 ml; penumbra ≥15 ml; mismatch ratio ≥1.8) with respect to standard CTP was assessed. Agreement between infarct and penumbra volumes from standard CTP and surrogate mCTA maps were evaluated by Bland-Altman analysis. ResultsOf 34 included patients, 28 had target mismatch and 6 did not by standard CTP. Accuracy of classifying target mismatch profiles with surrogate mCTA was 79% with respect to that from standard CTP. Mean ± standard deviation of differences (standard CTP minus surrogate mCTA) of infarct and penumbra volumes were 9.8 ± 14.8 ml and 20.1 ± 45.4 ml, respectively. ConclusionsSurrogate mCTA ischemic lesion volumes agreed with those from standard CTP and may be an efficient alternative when CTP is not practical.

Intercomparison of upper tropospheric and lower stratospheric water vapor measurements over the Asian Summer Monsoon during the StratoClim campaign

Abstract. In situ measurements in the climatically important upper troposphere–lower stratosphere (UTLS) are critical for understanding controls on cloud formation, the entry of water into the stratosphere, and hydration–dehydration of the tropical tropopause layer. Accurate in situ measurement of water vapor in the UTLS however is difficult because of low water vapor concentrations (&lt;5 ppmv) and a challenging low temperature–pressure environment. The StratoClim campaign out of Kathmandu, Nepal, in July and August 2017, which made the first high-altitude aircraft measurements in the Asian Summer Monsoon (ASM), also provided an opportunity to intercompare three in situ hygrometers mounted on the M-55 Geophysica: ChiWIS (Chicago Water Isotope Spectrometer), FISH (Fast In situ Stratospheric Hygrometer), and FLASH (Fluorescent Lyman-α Stratospheric Hygrometer). Instrument agreement was very good, suggesting no intrinsic technique-dependent biases: ChiWIS measures by mid-infrared laser absorption spectroscopy and FISH and FLASH by Lyman-α induced fluorescence. In clear-sky UTLS conditions (H2O&lt;10 ppmv), mean and standard deviations of differences in paired observations between ChiWIS and FLASH were only (-1.4±5.9) % and those between FISH and FLASH only (-1.5±8.0) %. Agreement between ChiWIS and FLASH for in-cloud conditions is even tighter, at (+0.7±7.6) %. Estimated realized instrumental precision in UTLS conditions was 0.05, 0.2, and 0.1 ppmv for ChiWIS, FLASH, and FISH, respectively. This level of accuracy and precision allows the confident detection of fine-scale spatial structures in UTLS water vapor required for understanding the role of convection and the ASM in the stratospheric water vapor budget.

Measurements and Modelling of Total Ozone Columns near St. Petersburg, Russia

The observed ozone layer depletion is influenced by continuous anthropogenic activity. This fact enforced the regular ozone monitoring globally. Information on spatial-temporal variations in total ozone columns (TOCs) derived by various observational methods and models can differ significantly due to measurement and modelling errors, differences in ozone retrieval algorithms, etc. Therefore, TOC data derived by different means should be validated regularly. In the current study, we compare TOC variations observed by ground-based (Bruker IFS 125 HR, Dobson, and M-124) and satellite (OMI, TROPOMI, and IKFS-2) instruments and simulated by models (ERA5 and EAC4 re-analysis, EMAC and INM RAS—RSHU models) near St. Petersburg (Russia) between 2009 and 2020. We demonstrate that TOC variations near St. Petersburg measured by different methods are in good agreement (with correlation coefficients of 0.95–0.99). Mean differences (MDs) and standard deviations of differences (SDDs) with respect to Dobson measurements constitute 0.0–3.9% and 2.3–3.7%, respectively, which is close to the actual requirements of the quality of TOC measurements. The largest bias is observed for Bruker 125 HR (3.9%) and IKFS-2 (−2.4%) measurements, whereas M-124 filter ozonometer shows no bias. The largest SDDs are observed for satellite measurements (3.3–3.7%), the smallest—for ground-based data (2.3–2.8%). The differences between simulated and Dobson data vary significantly. ERA5 and EAC4 re-analysis data show slight negative bias (0.1–0.2%) with SDDs of 3.7–3.9%. EMAC model overestimates Dobson TOCs by 4.5% with 4.5% SDDs, whereas INM RAS-RSHU model underestimates Dobson by 1.4% with 8.6% SDDs. All datasets demonstrate the pronounced TOC seasonal cycle with the maximum in spring and minimum in autumn. Finally, for 2004–2021 period, we derived a significant positive TOC trend near St. Petersburg (~0.4 ± 0.1 DU per year) from all datasets considered.

Systolic blood pressure estimation using ECG and PPG in patients undergoing surgery

Background and ObjectivesIn a significant portion of surgeries, blood pressure (BP) is often measured non-invasively in an intermittent manner. This practice has a risk of missing clinically relevant BP changes between two adjacent intermittent BP measurements. This study proposes a method to non-invasively estimate systolic blood pressure (SBP) with high accuracy in patients undergoing surgery. MethodsContinuous arterial BP, electrocardiography (ECG), and photoplethysmography (PPG) signals were acquired from 29 patients undergoing surgery. After extracting 9 features from the PPG and ECG signals, we dynamically selected features upon each intermittent measurement (every 10 min) of SBP based on feature robustness and the principle of correlation-based feature selection. Finally, multiple linear regression models were built to combine these features to estimate SBP every 30 s. ResultsCompared to the reference SBP, the proposed method achieved a mean of difference at 0.08 mmHg, a standard deviation of difference at 7.97 mmHg, and a correlation coefficient at 0.89 (p < 0.001). ConclusionsThis study demonstrates the feasibility of non-invasively estimating SBP every 30 s with high accuracy during surgery by using ECG, PPG, and intermittent SBP measurements every 10 min, which meets the standard of the Association for the Advancement of Medical Instrumentation. The proposed method has the potential to enhance BP monitoring in the operating room, improving patient outcomes and experiences.

Reliability of Running Economy Measurements: Influence of Shoe Familiarisation.

The purpose was to investigate differences in reliability of running economy measurements between familiar and unfamiliar shoes. Thirty-seven runners were included who all ran in familiar and unfamiliar running shoes while running economy was measured at steady state using a treadmill. Each participant was tested on two different visits (three sessions in total), with two trials in each of the three shoe conditions completed at each visit. Coefficient of variation, standard deviation of differences, and limits of agreement of running economy were used to quantify the repeatability (within-visit variation) and reproducibility (between-visit variation). The coefficient of variation showed a marginal difference in reproducibility across shoe conditions, whereas no differences were seen in coefficient of variation, standard deviation of the differences, or limits of agreement for repeatability across shoes. All three shoe conditions showed greater repeatability than reproducibility for running economy, and enhanced repeatability at visit 3 compared to visit 2. Our results indicate that familiarisation to shoes might not be needed for reliable measurements of running economy. Based on our results, when evaluating benefits in running shoes we suggest that running economy be assessed within the same day. Further, our data suggest a beneficial effect of using multiple familiarisation sessions if small differences between shoe conditions are expected.

Left atrial acceleration factor as a magnetic resonance 4D flow measure of mean pulmonary artery wedge pressure in pulmonary hypertension.

BackgroundMean pulmonary artery wedge pressure (PAWP) represents a right heart catheter (RHC) surrogate measure for mean left atrial (LA) pressure and is crucial for the clinical classification of pulmonary hypertension (PH). Hypothesizing that PAWP is related to acceleration of blood throughout the LA, we investigated whether an adequately introduced LA acceleration factor derived from magnetic resonance (MR) four-dimensional (4D) flow imaging could provide an estimate of PAWP in patients with known or suspected PH.MethodsLA 4D flow data of 62 patients with known or suspected PH who underwent RHC and near-term 1.5 T cardiac MR (ClinicalTrials.gov identifier: NCT00575692) were retrospectively analyzed. Early diastolic LA peak outflow velocity (vE) as well as systolic (vS) and early diastolic (vD) LA peak inflow velocities were determined with prototype software to calculate the LA acceleration factor (α) defined as α = vE/[(vS + vD)/2]. Correlation, regression and Bland-Altman analysis were employed to investigate the relationship between α and PAWP, α-based diagnosis of elevated PAWP (>15 mmHg) was analyzed by receiver operating characteristic curve analysis.Resultsα correlated very strongly with PAWP (r = 0.94). Standard deviation of differences between RHC-derived PAWP and PAWP estimated from linear regression model (α = 0.61 + 0.10·PAWP) was 2.0 mmHg. Employing the linear-regression-derived cut-off α = 2.10, the α-based diagnosis of elevated PAWP revealed the area under the curve 0.97 with sensitivity/specificity 93%/92%.ConclusionsThe very close relationship between the LA acceleration factor α and RHC-derived PAWP suggests α as potential non-invasive parameter for the estimation of PAWP and the distinction between pre- and post-capillary PH.

Comparison of Anemia Screening Methods Using Paired Venous Samples in Women of Reproductive Age in Southern India

ObjectivesTo evaluate anemia screening via portable hemoglobinometer (HemoCue 301) compared to automated hematology analyzer (AHA) reference, using paired venous samples from a population-based biomarker survey in Southern India. MethodsParticipants were women of reproductive age (WRA; 15–40 y) who were not pregnant or lactating. Paired venous whole blood samples (n = 896) were analyzed for hemoglobin (Hb) via HemoCue 301 and Coulter Counter AHA, as the gold standard. Serum ferritin (SF) was measured by electrochemiluminescence. Anemia and severe anemia were defined as Hb < 12.0 and < 8.0 g/dL, respectively. SF was adjusted for inflammation using BRINDA methods; iron deficiency (ID) was defined as SF < 15.0 μg/L. Bland-Altman methods were used to assess level of agreement between Hb results (i.e., mean difference, standard deviation of differences, limits of agreement). Diagnostic accuracy parameters (i.e., sensitivity, specificity, positive predictive value, negative predictive value, accuracy) were calculated to evaluate HemoCue performance compared to the AHA reference, overall and by sociodemographic (e.g., age, parity), nutritional (e.g., iron, vitamin B12, folate status), and metabolic (e.g., HbA1c, body mass index (BMI)) characteristics. ResultsThe estimated prevalence of anemia (36.3% vs. 41.6%, p < 0.0001) was significantly lower via HemoCue compared to the AHA reference. A total of 84.4% of anemia and 98.8% of severe anemia screening results were concordant. HemoCue had 74.8% sensitivity and 91.2% specificity, compared to AHA. HemoCue sensitivity was higher in women with iron deficiency (SF < 15.0 μg/L: 81.6% vs. ≥15.0 μg/L: 41.3%; p < 0.0001), and lower in WRA who were overweight (BMI ≥ 25.0 kg/m2: 63.9% vs. < 25.0 kg/m2: 78.8%; p = 0.004) or had elevated C-reactive protein (CRP) (CRP > 1.0 mg/L: 67.2% vs. ≤1.0 mg/L: 82.9%; p = 0.001; CRP > 3.0 mg/L: 62.2% vs. ≤3.0 mg/L: 79.3%; p = 0.001). ConclusionsFindings suggest the estimated prevalence of anemia evaluated via portable hemoglobinometer (HemoCue) was lower compared to the AHA reference. HemoCue sensitivity varied by iron status and metabolic risk factors in this population. Funding SourcesCenters for Disease Control and Prevention (5U01DD001007), University of South Carolina Disability Research and Dissemination Center; NIH 5T32HD087137 (AF); NIH T32DK007158 (HMG); Cornell DNS.

Evaluation of the Comparative Validity of a Smartphone Weight-Loss Trial App with a 24-Hour Diet Recall

ObjectivesDespite the presence of several weight loss apps on the market, the validity of the diet data collected from these apps has rarely been tested. A granular analysis of app validity at the food-level, rather than overall intake, is needed to closely examine factors that contribute to the variability of diet data between these apps and standard diet assessments. This study investigated the comparative validity of diet data from a weight loss app at the food level.MethodsA weight loss app was used for the Sequential Multiple Assignment Randomization Trial (SMART) to assist participants with tracking their food intake throughout the study. A trained dietitian conducted three 24-hour diet recalls at baseline using the Nutrition Data System for Research (NDSR) protocol. Food items reported by participants were categorized into 9 major NDSR food groups (beverage, dairy, fats, fruits, vegetables, grains, protein, sweets, miscellaneous) and 2 other categories (mixed, restaurant). Intraclass correlation coefficients (ICC) determined agreement of diet data (i.e., calories and macronutrients) for all food items. ICC ranges were defined as: ≥0.90, excellent; 0.75 to <0.90, good; 0.5 to <0.75, moderate; and <0.5, poor agreement. Bland Altman analyses determined the estimated mean bias and standard deviation of differences between the app and recall. A subgroup analysis was conducted to evaluate agreement of energy content by food group.ResultsAgreement between the SMART app and recall ranged from moderate to good for all diet data (ICCs = 0.71 to 0.83). Bland Altman plots also confirmed the ICC results; there were little to modest differences between the SMART app and 24-hour recall for energy (−3.0 ± 94.7 kcal), carbohydrates (−0.2 ± 12.2 g), protein (−0.1 ± 5.5 g), and fat (−0.2 ± 5.1 g). When analyzing energy content by food group, agreement between the two diet assessments was excellent for restaurant and sweet food items (ICCs = 0.93 to 0.94) and good for beverages, dairy, fruits, and miscellaneous items (ICCs = 0.76 − 0.87). There was moderate agreement for vegetables, fat, grains, proteins, and mixed dishes (ICCs = 0.51 to 0.68).ConclusionsThere was moderate to good agreement between the SMART app and recall for all diet data. Results suggest that the variability may stem from the type of food reported in the app.Funding SourcesNIH grants R01DK108678 and T32CA193193.

TENSIOBOT: A CHATBOT ASSISTANT FOR SELF-MANAGED IN-HOUSE BLOOD PRESSURE CHECKING

Objective: Patients with HBP are often asked to have their BP checked at home. The traditional at-home procedure has some drawbacks, such as forgetting to check or write down the values, errors in transcribing the numbers, or the impossibility of immediately notifying medical staff of out-of-range BP values. To facilitate self-measurements by patients at home we devised TensioBot, a Telegram based chatbot. The bot sends patients reminders to check their BP, advice on good monitoring practices, measurement tracking, medical alerts and allows healthcare professionals to access up-to-date measurement information. The aim of our study was to compare the use of Tensiobot against usual method of home BP checking. Design and method: In an Clinical Hypertension Unit, we tested TensioBot for two years in a andomised controlled trial with 112 patients, 55 using the bot and 57 in the control group, (using paper annotations). Patients of both groups underwent an ABMP study at the same time. An specific questionnaire about knowledge and skills on BP checking was administered face to face by an specialized nurse of the unit. Results: We found that, although the bot group showed similar results in terms of adherence to the BP checking schedule, bot users scored better in terms of knowledge and skills on BP checking best practices. Patients of bot group shown a lesser mean difference between ABPM mean diurnal SBP and SBP registered by Tensiobot, -0.34 mmHg vs -2.5 mmHg, although such difference was not significant. The standard deviation of differences in SBP was higher in the control group. Conclusions: Participants rated the bot very positively, perceived it as useful and easy to use, and continued to use it after the intervention. Moreover, all data being equal, we describe some other benefits of using a chatbot for self-managed in-house BP control, both for patients and healthcare professionals and systems. There was a trend to closer values to diurnal ABPM in SPB using the bot.

Evaluation of Sympathetic and Parasympathetic Tone and Reactivity in Adolescents with Specific Learning Disorder (Dyslexia).

To evaluate the autonomic function in specific learning disorder (SLD) and comorbid SLD attention-deficit hyperactivity disorder (SLD-ADHD). A cross-sectional study was conducted in a tertiary care hospital with 20 adolescent subjects each of confirmed SLD, SLD-ADHD, and healthy control (mean age 15.32 y). Heart-rate variability and autonomic-function tests were carried out using standard protocols. Heart-rate variability parameters, viz., mean RR interval, number of RR intervals which differ by ≥ 50ms (NN50), percentage NN50, standard deviation of differences between adjacent RR intervals, root square of mean of the sum of the squares of differences between adjacent RR intervals, coefficient of variance and absolute power of high-frequency band (HF) recorded apparently lower levels in SLD and SLD-ADHD as compared to healthy control indicating lower parasympathetic tone. Whereas, higher absolute power of low- frequency band (LF) in SLD and SLD-ADHD than healthy control indicated enhanced sympathetic activity. Higher LF/HF and lower SD1/SD2 ratios in SLD and SLD-ADHD than healthy control indicated higher sympathetic tone over parasympathetic tone. Values of autonomic-function tests such as E:I ratio, change in heart rate during deep-breathing test, 30:15 ratio, and Valsalva ratio showed a decrease in SLD and SLD-ADHD as compared to healthy control implying reduction in parasympathetic reactivity. Increased values for rise in diastolic blood pressure in the isometric handgrip test and cold pressor test recorded in SLD as compared to healthy control, revealed the increased sympathetic reactivity. Overall, results of heart-rate variability and autonomic-function tests imply dysregulation of sympathetic and parasympathetic activities with sympathetic dominance in SLD and SLD-ADHD.

Assessment of Exhaustive Exercise under Internet of Things Exercise Monitoring System and Mechanism Analysis of Cardiovascular Endothelial Cell Apoptosis Induced by Oxidative Stress

To investigate the effect of high-intensity exhaustive exercise on body and the molecular mechanism of oxidative stress regulating apoptosis of cardiovascular endothelial cells (CVECs), 70 college students who took an aerobics course were recruited as the research subjects, all of which were divided into the high-intensity group (35 students) and the moderate-intensity group (35 students). The Internet of Things- (IoT-) based human exercise information monitoring system was employed to collect the electrocardiogram, serum indexes, and oxidative stress indexes of the two groups of subjects after exercise. Moreover, 30 clean male SD rats were divided into exhaustive exercise group ( n = 10 ), routine exercise group ( n = 10 ), and blank control group ( n = 10 ) using treadmill exercise as stress source, and various physiological indexes of the three groups were compared. In human experiments, the time-domain indexes of heart rate variability (HRV), 50 ms in the total number of sinus heartbeats (PNN50), the standard deviation of all NN intervals (SDNN), standard deviation of mean NN interval (SDANN), standard deviation of difference between adjacent NN intervals (SDSD), root mean square (RMSSD) in the high intensity group were lower than those in the moderate intensity group ( P &lt; 0.05 ). The levels of T-sensitive troponin I (Tnl-ultra), cortisol (COR), high-sensitive troponin T (TnT-hs), high-sensitive C-reactive protein (hs-CRP), and human heart-type fatty acid binding protein (HUMAN H-FABP) in high intensity group were higher than those in moderate intensity group ( P &lt; 0.05 ). Experiments on animals found that SOD content and mRNA expression of fork-head box 03A (FOX03A) and silencing-information regulator 1 (Sirtl) in serum of rats in exhaustion exercise group were lower than those in the routine exercise group and blank control group, while lactate dehydrogenase (LDH) and malondialdehyde (MDA) contents were opposite ( P &lt; 0.05 ). In short, strenuous exercise made the body in the state of acute stress, leading to the disturbance of cardiac autonomic nervous function and sympathetic nervous function, and increasing the risk of malignant arrhythmia. Oxidative stress induced by exhaustive exercise may promote the apoptosis of CVECs by reducing the expression of Sirtl and FOX03A and locating FOX03A to the nucleus.

The efficacy and safety of dapagliflozin combined with oral hypoglycemic agents in patients with type 2 diabetes: a systematic review and meta-analysis.

There were reports that many patients with type 2 diabetes mellitus (T2DM) could not maintain the normal level of glycemic, who were treated with the antidiabetic agents. The sodium-glucose co-transporter-2 (SGLT2) inhibitors could improve patients' blood glucose level by inducing glycosuria, improving insulin sensitivity and the function of β-cell and decreasing glucose toxicity. Which was unlike with other agents, indicating that the SGLT2 inhibitors might be effective alone or in combination with any other drugs. As a SGLT2 inhibitor, Dapagliflozin could be used in patients with T2DM. Studies' identification were conducted with the literature search, and we searched studies published between 1950 and 2021 in PubMed, the Cochrane Library and Embase. A meta-analysis was performed using RevMan 5.3 software. Continuous data are presented as the means and standard deviations of differences in performance before and after active or control interventions. Adverse events were also assessed. Fifteen studies that provided individual data were included. Treatment with dapagliflozin was compared with treatment with placebo and resulted in a significantly greater change in HbA1c levels, fasting plasma glucose (FPG) and weight. In terms of the incidence of adverse drug reactions, the incidence of hypoglycemic events was not significantly different between the experimental and control groups. However, the incidences of genital infection and urinary tract infection were higher in the experimental group than in the control group. According to the available data, dapagliflozin combined with oral hypoglycemic agents can effectively reduce the level of HbA1c and body weight; however, it does not increase the incidence of hypoglycemia but can cause urinary tract infection and genital infection. Due to the limited literature included, the above conclusions need to be verified through more high-quality studies.

Automated vortical blood flow-based estimation of mean pulmonary arterial pressure from 4D flow MRI

PurposeElevated mean pulmonary arterial pressure (mPAP), or pulmonary hypertension (PH), is associated with vortical blood flow along the main pulmonary artery. We present and validate a method for automated detection and tracking of the PH-related vortex from magnetic resonance 4D flow data that allows estimation of mPAP. MethodsThe proposed method detects the presence of a PH-related vortex in the main pulmonary artery based on geometrical properties of swirling streamlines and estimates mPAP from the PH-related vortex duration (tvortex) using a previously established model. 4D flow data of 32 subjects (19/13 with/without PH) who underwent right heart catheterization (RHC) for mPAP measurement and diagnosis of PH (mPAP >20 mmHg) were used to compare visual and automated PH-related vortex detection and to validate estimated mPAP against RHC-derived results. ResultsVisually and automatically determined tvortex values correlated strongly (r = 0.98); they yielded no bias, and the standard deviation of differences between them was small (5.9% of the cardiac interval). mPAP estimates from visual and automated analyses both allowed diagnosis of PH with an area under the curve of 1.00 [0.89,1.00]. For subjects with PH, neither visually nor automatically estimated mPAP differed from mPAP measured by RHC, while the standard deviation between estimated and invasively measured mPAP was lower with visual estimation (3.1 mmHg vs. 5.3 mmHg). ConclusionAn automated method for PH-related vortex detection and tracking from magnetic resonance 4D flow data was introduced, which demonstrated very good agreement with visual analysis and accurate estimation of elevated mPAP.

An Evaluation of the Accuracy and Precision of Jump Height Measurements Using Different Technologies and Analytical Methods

This study aims to comprehensively assess the accuracy and precision of five different devices and by incorporating a variety of analytical approaches for measuring countermovement jump height: Qualisys motion system; Force platform; Ergojump; an Accelerometer, and self-made Abalakow jump belt. Twenty-seven male and female physical education students (23.5 ± 3.8 years; height 170 ± 9.1 cm and body mass 69.1 ± 11.4 kg) performed three countermovement jumps simultaneously measured using five devices. The 3D measured displacement obtained through the Qualisys device was considered in this study as the reference value. The best accuracy (difference from 3D measured displacement) and precision (standard deviation of differences) for countermovement jump measurement was found using the Abalakow jump belt (0.8 ± 14.7 mm); followed by the Force platform when employing a double integration method (1.5 ± 13.9 mm) and a flight-time method employed using Qualisys motion system data (6.1 ± 17.1 mm). The least accuracy was obtained for the Ergojump (−72.9 mm) employing its analytical tools and then for the accelerometer and Force platform using flight time approximations (−52.8 mm and −45.3 mm, respectively). The worst precision (±122.7 mm) was obtained through double integration of accelerometer acceleration data. This study demonstrated that jump height measurement accuracy is both device and analytical-approach-dependent and that accuracy and precision in jump height measurement are achievable with simple, inexpensive equipment such as the Abalakow jump belt.

A new digital elevation model over South Africa based on ground and satellite data

This study makes contributions toward development of accurate DEM from ground and satellite data over South Africa. This is achieved by preparing recent satellite-based DEMs (AW3D30, SRTM, ASTER, TanDEM-X, and MERIT), assessing their vertical accuracy, selecting candidate DEMs, modelling errors for the candidate DEMs and fusing candidate DEMs. Following removal of outliers from each DEM, a different number of ground levelling data are used in the assessment of the DEMs (AW3D30 - 26,364 points, SRTM - 25,727, ASTER - 23,773, TanDEM-X - 25,964 and MERIT- 24,485). The standard deviations of the differences between ground levelling and DEMs heights are ±5.09, ±7.03, ±9.20, ±4.99 and ±8.36 m for AW3D30, SRTM, ASTER, TanDEM-X and MERIT, respectively. AW3D30 and TanDEM-X are therefore selected for fusion. The two candidate DEMs are improved by applying a combination of linear regression, multiple regression, and adaptive terrain-dependent methods using 17,307 model data points. A fused DEM is developed from improved candidate DEMs using a combination of different fusion methods and assessed using 8,657 data points (distinct from the model points). The standard deviation of the height differences between ground levelling and the fused DEM is ±4.290 m, and it is more accurate than all satellite based DEMs considered in this study.

Comparison of two software programs for fitting one- and two-compartment age-dependent non-linear digestion models for ruminants: empirical data

Context The total mass and kinetics of feed particles through the digestive tract affect feed intake, nutrient excretion and emissions by ruminants. Use of models to calculate digesta kinetics parameters will assist managers in mitigating enteric methane emission and producing food more sustainably. Aims We evaluated two software programs for fitting parameters to one- and two-compartment age-dependent digesta kinetic models from faecal-marker concentration datasets. Methods We examined biases (mean differences) and standard deviations (differences) of one-compartment (G2) and two-compartment (G2G1) models with a gamma-2 distribution in the age-dependent compartment when parameterised with two different software programs (R or SAS), using 41 datasets of ytterbium concentrations in faecal samples collected at discrete times. Faecal-marker concentration datasets were fitted to G2 and G2G1 models with each software program. The resulting model parameters, K0, λ or λ1, K2 and τ, were used to calculate the digesta kinetics parameters: particle passage rate, gastrointestinal dry matter fill, faecal dry matter output, gastrointestinal mean retention time and rumen retention time. We evaluated bias and standard deviation for model and digesta kinetic parameters across the entire range of average values, but also within low, medium and high percentile range-of-value subsets (5–35%, 35–65% and 65–95%) between software programs. Key results When datasets were fitted to the G2 model, all converged for both software programs, but when fitted to the G2G1 model by the SAS program, three observations did not converge. Bias and standard deviation of differences between software packages were small, but the G2G1 model produced smaller bias and standard deviation of differences. Bias and standard deviation of differences for digesta kinetics estimates across the percentile groups did not vary linearly for most model estimates and were small relative to the magnitude of the values. Conclusions Model parameters and digesta kinetics estimates derived from R and SAS software programs can be used interchangeably in nutritional modelling. Two-compartment models (G2G1) can be more problematic to fit, but residual mean-square errors are usually smaller. Implications Model parameters from both G2 and G2G1 models can be used to derive unbiased estimates of digesta kinetics from either R or SAS software program.