Differences In Timing Of Activity Research Articles

Analysis of anticipatory and compensatory postural adjustment in women of different age groups using surface electromyography.

Postural balance is crucial for daily activities, relying on the coordination of sensory systems. Balance impairment, common in the elderly, is a leading cause of mortality in this population. To analyze balance, methods like postural adjustment analysis using electromyography (EMG) have been developed. With age, women tend to experience reduced mobility and greater muscle loss compared to men. However, few studies have focused on postural adjustments in women of different ages using EMG of the lower limbs during laterolateral and anteroposterior movements. This gap could reveal a decrease in muscle activation time with aging, as activation time is vital for postural adjustments. This study aimed to analyze muscle activation times in women of different ages during postural adjustments. Thirty women were divided into two groups: young and older women. A controlled biaxial force platform was used for static and dynamic balance tests while recording lower limb muscle activity using EMG. Data analysis focused on identifying muscle activation points and analyzing postural adjustment times. Results showed significant differences in muscle activation times between the two groups across various muscles and platform tilt conditions. Younger women had longer muscle activation times than older women, particularly during laterolateral platform inclinations. In anteroposterior movements, older women exhibited longer activation times compared to their laterolateral performance, with fewer differences between the groups. Overall, older women had shorter muscle activation times than younger women, suggesting a potential indicator of imbalance and increased fall risk.

Predictability of indicators in local activation time mapping of ablation success for premature ventricular contractions

AbstractIntroductionDifferences in predictability of ablation success for premature ventricular contractions (PVCs) between earliest isochronal map area (EIA), local activation time (LAT) differences on unipolar and bipolar electrograms (⊿LATBi‐Uni), LAT prematurity on bipolar electrograms (LATBi), and unipolar morphology of QS or Q pattern remain unclear. We verified multiple statistical predictabilities of those indicators of ablation success on mapped cardiac surface.MethodsThirty‐five patients with multiple PVCs underwent catheter ablation after LAT mapping using multipolar mapping catheters with unipolar‐based annotation. Patients were divided into success and failure groups based on ablation success on mapped cardiac surfaces. Discrimination ability, reclassification table, calibration plots, and decision curve analysis of 10 ms EIA (EIA10ms), ⊿LATBi‐Uni, and LATBi were validated. Unipolar morphology was compared between success and failure groups.ResultsRight ventricular outflow tract, aortic cusp, and left ventricle were mapped in 17, 10, and 8 patients, respectively. In 14/35 (40%) patients, successful ablation was performed on mapped cardiac surfaces. Area under the curve of receiver‐operating characteristic curve of EIA10ms, ⊿LATBi‐Uni, and LATBi were 0.874, 0.801, and 0.650, respectively (EIA10ms vs. LATBi, p =.014; ⊿LATBi‐Uni vs. LATBi, p =.278; EIA10ms vs. ⊿LATBi‐Uni, p =.464). EIA10ms and ⊿LATBi‐Uni demonstrated better predictability, calibration, and clinical utility on reclassification table, calibration plots, and decision curve analysis than LATBi. Unipolar morphology of QS or Q pattern did not correlate with ablation success (p =.518).ConclusionEIA10ms and ⊿LATBi‐Uni more accurately predict ablation success for PVCs on mapped cardiac surfaces than LATBi and unipolar morphology.

Associations between wearable device metrics and performance status in adult patients with cancer.

427 Background: Wearable devices present a promising method for monitoring physical performance in cancer patients, potentially bridging the gap between patient experiences at home and clinical evaluations. This study assesses associations between performance status, home-based wearable device metrics, and patient-reported outcomes (PROs) among adults with cancer. (NCT03952767). Methods: This prospective cohort study enrolled 62 adults undergoing treatment for cancer, irrespective of primary site. Participants wore GENEActiv wrist accelerometer sensors (Activinsights Ltd., Kimbolton, UK) on the lumbar region and non-dominant wrist for 2 weeks, tracking gait speed and activity levels. Patients concurrently completed PRO questionnaires on physical function (PF) and fatigue (PROMIS Fatigue 7a & PROMIS Physical Function 10a). Study participants were stratified by baseline self-reported Karnofsky performance status (KPS; 100, 80-90, & ≤70). Linear regression models were used to assess associations between (1) KPS and device metrics and (2) device metrics and PROs. Covariates included age and a binary indicator for COVID period (pre/post 3/1/2020). Results: Average device wear time across the cohort was 22.2 hours/day. Significant differences in gait speed and moderate activity time were observed between the KPS≤70 group and the higher KPS groups ( Table ). Significant associations were also observed between device metrics and PROs. Each 1-hour increment moderate activity was associated with 5.5 point greater PROMIS PF score (95% CI: 3.3, 7.7; p<0.0001) and 4.6 point lower PROMIS Fatigue score (-6.7, -2.5; p<0.0001). Each 0.1 meter/sec increment in gait speed was associated with 4.6 point greater PF score (95% CI: 2.2, 7.1; p=0.0004) and 4.8 point lower Fatigue score (-6.9, -2.7; p<0.0001). Similar associations were observed between in-clinic assessments of gait speed and physical function scores. Conclusions: The associations between wearable device metrics and KPS indicate that wearable technology is both feasible and reliable for remote health monitoring in cancer patients. The associations between device metrics and PROs demonstrate that these metrics reflect patient experiences and outcomes relevant to both patients and regulatory authorities. The associations with physical function, a key PRO in the FDA’s Patient-Focused Drug Development guidance, are particularly noteworthy. Clinical trial information: NCT03952767 . Group 1(KPS 100) Group 2(KPS 80-90) Group 3(KPS ≤70) p (Group 1 vs 3) p (2 vs 3) Gait Speed (m/s) - adjusted mean, 95% CI 0.74 (0.70, 0.78) 0.72 (0.69, 0.74) 0.65 (0.60, 0.70) 0.0058 0.0210 Sedentary time (hours) 11.2 (9.8, 12.6) 10.2 (9.3, 11.0) 10.7 (9.1, 12.2) 0.5912 0.5647 Light activity (hours) 1.4 (1.0, 1.7) 1.3 (1.1, 1.5) 0.9 (0.5, 1.3) 0.0570 0.0474 Moderate activity (hours) 1.4 (1.0, 1.8) 1.2 (0.9, 1.5) 0.5 (0.0, 1.0) 0.0068 0.0159 Vigorous activity (hours) 0.1 (0.0, 0.2) 0.0 (0.0, 0.1) 0.0 (0.0, 0.1) 0.1201 0.2835

Multi-Regional Pelvic Floor Muscle Function Diagnosis System Based on Inflatable Stretchable Electrode Array.

Effective prevention and treatment of pelvic floor dysfunction (PFD) necessitates the identification of lesions within the complex pelvic floor muscle (PFM) groups associated with various symptoms. Here, we developed a multi-region pelvic floor muscle functional diagnosis system (MPDS) based on an inflatable stretchable electrode array, which aids in accurately locating areas related to PFD. Clinical diagnostic experiments were conducted on 56 patients with postpartum stress urinary incontinence (PSUI) and 73 postpartum asymptomatic controls. MPDS collects pelvic floor electromyography from all participants. By assessing EMG parameters such as activation time differences (ATD) and using Jensen-Shannon (JS) divergence to verify, with the aim of locating target muscle groups with functional abnormalities. Clinical test results showed that by observing the AT sequence of the PSUI group and the control group, muscle groups with functional abnormalities in the Pubococcygeus muscle (PC) and Puborectalis muscle (PR) regions could be preliminarily diagnosed. In the assessment of regional muscle contribution values based on JS divergence, it was verified that the contribution values of rapid contraction in the PC and PR regions of the PSUI group were relatively lower compared to those of the control group, which correlated with urinary control dysfunction. These experiments demonstrate that the MPDS helps in accurately locating target muscle groups with functional abnormalities, showcasing its potential in precise assessment of complex muscle groups such as PFM, which may improve diagnostic precision and reliability.

Multipolar Electrograms: A New Configuration That Increases the Measurement Accuracy of Intracardiac Signals

BackgroundAccurate measurements of intracardiac electrograms (EGMs) remain a clinical challenge because of the suboptimal attenuation of far-field potentials. Multielectrode mapping catheters provide an opportunity to construct multipolar instead of bipolar EGMs for rejecting common far-field potentials recorded from a multivectorial space. ObjectivesThe purpose of this study was to develop a multipolar EGM and compare its characteristics to those of bipolar EGMs MethodsUsing a 36-electrode array catheter (Optrell-36, Biosense Webster), a far-field component was mathematically constructed from clusters of electrodes surrounding each inspected electrode. This component was subtracted from the unipolar waveform to produce a local unipolar, referred to as a “multipolar EGM.” The performance of multipolar EGMs was evaluated in 7 swine with healed anteroseptal infarction. ResultsMultipolar EGMs proved superior in attenuating far-field potentials in infarct border zones, increasing the near-field to far-field ratio from 0.92 ± 0.2 to 2.25 ± 0.3 (P < 0.001). Removal of far-field components reduced the voltage amplitude (P < 0.001) and enlarged the infarct surface area (P = 0.02), aligning more closely with histological findings. Of 379 EGMs with ≥20 ms activation time difference between bipolar and multipolar EGMs, 95.3% (361 of 379) were accurately annotated using multipolar EGMs, while annotation based on bipolar EGM was predominantly made on far-field components. ConclusionsMultielectrode array catheters provide a unique platform for constructing multipolar EGMs. This new EGM may be beneficial for "purifying" local potentials within a complex electrical field, resulting in more accurate voltage and activation maps.

Pilot study to evaluate left-to-right ventricular offset in biventricular pacing-comparison of electrocardiographic imaging and ECG.

Biventricular pacing (BiVp) improves outcomes in systolic heart failure patients with electrical dyssynchrony. BiVp is delivered from epicardial left ventricular (LV) and endocardial right ventricular (RV) electrodes. Acute electrical activation changes with different LV-RV stimulation offsets can help guide individually optimized BiVp programming. We sought to study the BiVp ventricular activation with different LV-RV offsets and compare with 12-lead ECG. In five patients with BiVp (63 ± 17-year-old, 80% male, LV ejection fraction 27 ± 6%), we evaluated acute ventricular epicardial activation, varying LV-RV offsets in 20 ms increments from -40 to 80 ms, using electrocardiographic imaging (ECGI) to obtain absolute ventricular electrical uncoupling (VEUabs, absolute difference in average LV and average RV activation time) and total activation time (TAT). For each patient, we calculated the correlation between ECGI and corresponding ECG (3D-QRS-area and QRS duration) with different LV-RV offsets. The LV-RV offset to attain minimum VEUabs in individual patients ranged 20-60 ms. In all patients, a larger LV-RV offset was required to achieve minimum VEUabs (36 ± 17 ms) or 3D-QRS-area (40 ± 14 ms) than that for minimum TAT (-4 ± 9 ms) or QRS duration (-8 ± 11 ms). In individual patients, 3D-QRS-area correlated with VEUabs (r 0.65 ± 0.24) and QRS duration correlated with TAT (r 0.95 ± 0.02). Minimum VEUabs and minimum 3D-QRS-area were obtained by LV-RV offset within 20 ms of each other in all five patients. LV-RV electrical uncoupling, as assessed by ECGI, can be minimized by optimizing LV-RV stimulation offset. 3D-QRS-area is a surrogate to identify LV-RV offset that minimizes LV-RV uncoupling.

High-density and high-coverage composite atrial activation maps: an in-silico validation study.

Repetitive atrial activation patterns (RAAPs) during complex atrial tachycardia could be associated with localized mechanisms that can be targeted. Clinically available electroanatomical mapping systems are limited by either the spatial coverage or electrode density of the mapping catheters, preventing the adequate visualization of transiently occurring RAAPs. This work proposes a technique to overcome this shortcoming by stitching spatially overlapping conduction patterns together to a larger image- called a composite map. Simulated stable mechanisms and meandering reentries are sequentially mapped (4x4 grid, 3mm spacing) and then reconstructed back to the original sizes with the proposed recurrence plot-based algorithm. The reconstruction of single linear waves presents minimal errors (local activation time (LAT) difference: 3.2 [1.6-4.9] ms, conduction direction difference: 5.2 [2.3-8.0] degrees). Errors significantly increase (p<0.05) for more complex patterns, being the highest with unstable reentries (LAT difference: 10.3 [3.5-16.2] ms, conduction direction difference: 18.2 [6.7-29.7] deg). In a second part of the analysis, 111 meandering reentries are reconstructed. Mapping 30 locations overlappingly around each reentry core was found to be the optimal mapping strategy. For this optimal setting, LAT, conduction direction, and core localization errors are low (6.1 [4.2-8.6] ms, 11.2 [8.6-15.5] deg and 4.1 [2.9-4.9] mm, respectively) and are weakly correlated with the degree of the meander ( ρ=0.41, ρ=0.40 and ρ=0.20, respectively). Our findings underline the feasibility of generating composite maps by stitching spatially overlapping recordings. Composite maps can be instrumental in personalized ablation strategies.

Ontogeny and social context regulate the circadian activity patterns of Lake Malawi cichlids

Activity patterns tend to be highly stereotyped and critical for executing many different behaviors including foraging, social interactions, and predator avoidance. Differences in the circadian timing of locomotor activity and rest periods can facilitate habitat partitioning and the exploitation of novel niches. As a consequence, closely related species often display highly divergent activity patterns, suggesting that shifts from diurnal to nocturnal behavior, or vice versa, are critical for survival. In Africa’s Lake Malawi alone, there are over 500 species of cichlids, which inhabit diverse environments and exhibit extensive phenotypic variation. We have previously identified a substantial range in activity patterns across adult Lake Malawi cichlid species, from strongly diurnal to strongly nocturnal. In many species, including fishes, ecological pressures differ dramatically across life-history stages, raising the possibility that activity patterns may change over ontogeny. To determine if rest-activity patterns change across life stages, we compared the locomotor patterns of six Lake Malawi cichlid species. While total rest and activity did not change between early juvenile and adult stages, rest-activity patterns did, with juveniles displaying distinct activity rhythms that are more robust than adults. One distinct difference between juveniles and adults is the emergence of complex social behavior. To determine whether social context is required for activity rhythms, we next measured locomotor behavior in group-housed adult fish. We found that when normal social interactions were allowed, locomotor activity patterns were restored, supporting the notion that social interactions promote circadian regulation of activity in adult fish. These findings reveal a previously unidentified link between developmental stage and social interactions in the circadian timing of cichlid activity.

Analysis on the risk of degenerative knee arthritis in the elderly during regular exercise

&lt;p&gt;目的：經由退化性膝關節炎 (knee osteoarthritis, KOA) 風險角度檢測，探討規律參與運動的中年人與中老年人是否有較高的 KOA 罹患風險。方法：招募規律運動習慣的實驗參與者共 14 位，分為中年組 7 位 (年齡為44.1 &amp;plusmn; 4.7歲)，以及中老年組 7 位 (年齡為59.0 &amp;plusmn; 8.8歲)。使用 2 台高速攝影機拍攝膝關節內外翻角度，以及Noraxon無線肌電感測系統分析股內側肌與股外側肌之肌肉活化特徵，使用描述性統計分析兩組實驗參與者是否有 KOA 風險的角度特徵，以及經由獨立樣本 t-test 比較中年組與中老年組在膝關節內外翻角度與肌肉活化特徵之差異，顯著水準設 &amp;alpha; = .05。結果：中年組膝內翻角度為 0.71 &amp;plusmn; 2.9˚，中老年組為 2.14 &amp;plusmn; 4.4˚，以上皆小於罹患 KOA 之風險角度 (內翻 3˚)，兩組間無顯著差異。兩組實驗參與者在步行時，股內側肌與股外側肌的活化程度相似，無顯著差異。股內側肌與股外側肌之活化比例與活化時間差值，在兩組之間皆未達顯著差異。結論：在本研究中未發現長期規律運動的中年人與中老年人有較高的退化性膝關節炎罹患風險，膝內翻角度皆未超過罹患 KOA 的風險角度值，平均年齡接近 60 歲的中老年組，KOA 風險角度的平均值仍低於 3&amp;deg;，因此適度的運動對膝關節健康應有正面的效益。&lt;/p&gt;&lt;p&gt;Purpose: Through detecting Knee Osteoarthritis (KOA) risk perspective, to explore whether middle-aged and middle-aged people who regularly participate in sports have a higher risk of KOA. Methods: Fourteen participants with regular exercise habits were recruited and divided into the middle-aged group (seven participants aged 44.1 &amp;plusmn; 4.7 years old) and the pre-elderly group (59.0 &amp;plusmn; 8.8 years old). Two high-speed cameras were used to capture the varus and valgus angles of the knee joint, and the Noraxon wireless electromyography system was used to analyze the muscle activation characteristics of the vastus medialis and vastus lateralis muscles. Descriptive statistics were used to analyze the angle characteristics of whether the two groups of experiment participants were at risk of KOA. And through the independent sample t-test to compare the differences between the middle-aged group and the pre-elderly group in the varus angle and muscle activation characteristics of the middle-aged group, the significance level was set at &amp;alpha; = .05. Results: The knee varus angle was 0.71 &amp;plusmn; 2.9&amp;deg; in the middle-aged group, and 2.14 &amp;plusmn; 4.4&amp;deg; in the middle-aged and elderly group, all of which were smaller than the risk angle of KOA (varus 3&amp;deg;) and there was no significant difference between the two groups. The activation of the vastus medialis and vastus lateralis was similar between the two groups of participants during walking, with no significant difference. There was no significant difference between the two groups in the activation ratio and activation time difference of vastus medialis and vastus lateralis. Conclusion:&amp;nbsp;In this study, it was not found that middle-aged people and pre-elderly people who exercise regularly for a long time have a higher risk of degenerative knee arthritis, and the angle of knee varus does not exceed the risk angle value of KOA, and the average age is close to 60 years old in the pre-elderly group, the average KOA risk angle was still lower than 3&amp;deg;; therefore moderate exercise should have a positive effect on knee joint health.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

A discussion on practices and characteristics of science and technology diplomacy in twentieth-century China

Scientists and diplomats have significant differences in professional skills, activity time and work content, but they should work together. With the deepening impact of science and technology (S&amp;T) on socio-economic development and international relations, S&amp;T has become a crucial component of national strategies, particularly for diplomacy. There is a need for scientific evidence and advice, meaning that mastering more knowledge and skills in S&amp;T would be helpful in negotiations. This paper analyses the ideas of S&amp;T diplomacy, including a review of its 40-year history in China, its definition (with detailed connotations) and its characteristics. The paper focuses on the significant role of people-to-people communication in S&amp;T, which may inform future work. Five suggestions are given to strengthen the strategic planning of S&amp;T diplomacy: (1) A more clarified, strategic goal of future-oriented S&amp;T diplomacy is required; (2) It is important to build a theoretical system for China to describe S&amp;T diplomacy; (3) The creation of a global S&amp;T cooperation map that adapts to the new type of international relations would be valuable; (4) Fairness and justice shall be maintained, while a reform of the global S&amp;T governance system is promoted; (5) It is a must to adhere to bottom-line thinking and strengthen risk prediction and emergency responses.

Lateral Boundaries of the Ventricular Tachycardia Circuit Align With Sinus Rhythm Discontinuities

BackgroundSinus rhythm electrical activation mapping can provide information regarding the ischemic re-entrant ventricular tachycardia (VT) circuit. The information gleaned may include the localization of sinus rhythm electrical discontinuities, which can be defined as arcs of disrupted electrical conduction with large activation time differences across the arc. ObjectivesThis study sought to detect and localize sinus rhythm electrical discontinuities that might be present in activation maps constructed from infarct border zone electrograms. MethodsMonomorphic re-entrant VT with a double-loop circuit and central isthmus was repeatedly inducible by programmed electrical stimulation in the epicardial border zone of 23 postinfarction canine hearts. Sinus rhythm and VT activation maps were constructed from 196 to 312 bipolar electrograms acquired surgically at the epicardial surface and analyzed computationally. A complete re-entrant circuit was mappable from the epicardial electrograms of VT, and isthmus lateral boundary (ILB) locations were ascertained. The difference in sinus rhythm activation time across ILB locations, vs the central isthmus and vs the circuit periphery, was determined. ResultsSinus rhythm activation time differences averaged 14.4 milliseconds across the ILB vs 6.5 milliseconds at the central isthmus and 6.4 milliseconds at the periphery (ie, the outer circuit loop) (P ≤ 0.001). Locations with large sinus rhythm activation difference tended to overlap ILB (60.3% ± 23.2%) compared with their overlap with the entire grid (27.5% ± 18.5%) (P < 0.001). ConclusionsDisrupted electrical conduction is evident as discontinuity in sinus rhythm activation maps, particularly at ILB locations. These areas may represent permanent fixtures relating to spatial differences in border zone electrical properties, caused in part by alterations in underlying infarct depth. The tissue properties producing sinus rhythm discontinuity at ILB may contribute to functional conduction block formation at VT onset.

Combining atrial activation maps for the big picture of simulated atrial fibrillation mechanisms

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported by PersonalizeAF project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 860974. Background Pulmonary vein isolation (PVI) alone is not sufficient for all persistent atrial fibrillation (AF) patients. Ablation of localized AF drivers might be a promising adjunctive ablation strategy but detecting such drivers is limited by the small field of view of current mapping catheters. Purpose We propose a technique to detect localized AF drivers that combines sequential mapping of repetitive activation patterns into a larger composite map. The performance of this technique was evaluated in several simulated scenarios of known mechanisms during AF. Methods Representative repetitive conduction patterns that may occur in AF were simulated in a detailed volumetric 3D model of the atria: a large peripheral wave, stable and meandering re-entries, and single and multiple ectopic foci. Endocardial electrograms were sequentially generated from overlapping regions in the left posterior wall (4x4 grid, 3mm spacing, 0.5-1.5 seconds), and repetitive activation patterns were detected. Overlapping areas between sequential maps were used to align the repetitive patterns. Local patterns were then combined into larger composite maps (Fig. 1A). Reconstruction performance was quantified by the average local activation time (LAT) difference between original and reconstructed activation patterns. The relation between electrode overlaps and the quality of reconstructions were assessed at different degrees of spatial overlap (approximately 10% to 25% of the grid area, corresponding to 1.6 ± 0.6 and 4.1 ± 1.2 overlapping electrodes, respectively). Results All simulated patterns could be reconstructed from sequential recordings (Fig. 1B). LAT errors in recordings with 25% overlap were low in all cases: 5±2 msec for the peripheral wave, 5±2 and 3±1 msec for focal and multifocal activities and 6±2 and 11±2 &amp; 17±3 msec for stable, meandering and highly meandering re-entries respectively (Fig. 2). Composite maps of meandering and highly meandering re-entries presented significantly higher reconstruction errors than other more stable patterns (p&amp;lt;0.01). Reducing spatial overlap to 10% did not significantly increase the errors, except for the highly meandering re-entrant activity (p&amp;lt;0.05). Conclusion We developed a novel methodology to combine high-density sequential recordings with limited coverage into larger composite activation maps. Using this method, we reconstructed highly accurate activation maps for multiple simulated AF mechanism scenarios. Results were promising even with a small overlap between sequential recording sites and relatively unstable patterns, providing a proof of principle to apply this approach in clinical recordings of human AF.

Using Satellite‐Derived Fire Arrival Times for Coupled Wildfire‐Air Quality Simulations at Regional Scales of the 2020 California Wildfire Season

AbstractWildfire frequency has increased in the Western US over recent decades, driven by climate change and a legacy of forest management practices. Consequently, human structures, health, and life are increasingly at risk due to wildfires. Furthermore, wildfire smoke presents a growing hazard for regional and national air quality. In response, many scientific tools have been developed to study and forecast wildfire behavior, or test interventions that may mitigate risk. In this study, we present a retrospective analysis of 1 month of the 2020 Northern California wildfire season, when many wildfires with varying environments and behavior impacted regional air quality. We simulated this period using a coupled numerical weather prediction model with online atmospheric chemistry, and compare two approaches to representing smoke emissions: an online fire spread model driven by remotely sensed fire arrival times and a biomass burning emissions inventory. First, we quantify the differences in smoke emissions and timing of fire activity, and characterize the subsequent impact on estimates of smoke emissions. Next, we compare the simulated smoke to surface observations and remotely sensed smoke; we find that despite differences in the simulated smoke surface concentrations, the two models achieve similar levels of accuracy. We present a detailed comparison between the performance and relative strengths of both approaches, and discuss potential refinements that could further improve future simulations of wildfire smoke. Finally, we characterize the interactions between smoke and meteorology during this event, and discuss the implications that increases in regional smoke may have on future meteorological conditions.

Echocardiographic Evaluation of His Bundle Pacing in Patients with Prolonged PR Intervals.

Patients with PR intervals >240ms have atrio-ventricular (AV) dyssynchrony, which can increase risk of atrial fibrillation and all-cause mortality. When requiring pacing, long AV delays (AVDs) have been programmed to avoid ventricular dyssychrony. His bundle pacing (HBP) may provide improved AV synchrony in patients with prolonged PR. 10 patients with sinus node dysfunction and prolonged PR who received HBP were studied. Real-time echocardiographic was performed with 3 pacemaker modes (RV septal, non-selective HBP, and selective HBP) using the following pacemaker settings: control (no ventricular pacing), pacing with AVD of 180ms, 150ms, 120ms, 100ms, and 70ms. Echocardiographic Doppler measurements: EA/RR, >40% = AV synchrony; E/e', <8 = normal left atrial pressure; pulmonic-to-aortic pre-ejection time difference, <40ms = interventricular synchrony; septal-to-lateral wall activation time difference, <56ms = intraventricular synchrony; and LVOT VTI. Unpaired T test was used to evaluate for significance. Exclusion criteria: persistent atrial fibrillation, second-degree AV block. Compared to control programming, HBP showed a 31.5% increase in EA/RR time, a decrease in E/e' of 26.9%, and an increase in the LVOT VTI of 21.3%. Compared to RV septal pacing, there was a similar increase in LVOT VTI. These findings met statistical significance and were considered optimal based on Doppler echocardiography findings primarily at AVDs of 150ms and 120ms. Comparisons between selective and non-selective pacing were not significantly different. Compared to controls and RV septal pacing, physiologic His bundle pacing was shown to increase markers of AV synchrony and LV stroke volume while maintaining ventricular synchrony.

Perceived exercise benefits and barriers and their association with physical activity time in Chinese Han children and adolescents aged 9 to 18 years

Objective: To analyze the perceived exercise benefits and barriers and their association with physical activity time in Chinese Han children and adolescents aged 9-18 years. Methods: Data were extracted from the 2019 Chinese National Survey on Students' Constitution and Health and a total of 163 656 children and adolescents aged 9-18 years in Han ethnic group were included in the analysis. Mann-Whitney U test and Kruskal-Wallis test were used to compare the perceived exercise benefits score, perceived exercise barriers score and perceived exercise benefits to barriers ratio in the children and adolescents with different demographic characteristics and physical activity time. The differences in physical activity time in subgroups were compared with χ2 tests. log-binomial regression model was used to evaluate the association between physical activity time and perceived exercise benefits and barriers. Results: The M (Q1,Q3) of the perceived exercise benefits score, perceived exercise barriers score, and perceived exercise benefits to barriers ratio in the children and adolescents were 4.11 (3.78, 4.78), 2.70 (2.10, 3.20) and 1.55 (1.22, 2.07), respectively. Children and adolescents living in urban area, boys, those at younger age and those with physical activity time ≥1 hour had higher perceived exercise benefits score and perceived exercise benefits to barriers ratio, but lower perceived exercise barriers score (all P<0.001). The prevalence of physical activity time ≥1 hour was 41.4% in the children and adolescents. In the log-binomial model with two variables of perceived exercise benefits score and perceived exercise barriers score, for each 1-point increase in the perceived exercise benefits, the possibility of physical activity time ≥1 hour increased by 11% (OR=1.11, 95%CI: 1.10-1.12), and for each 1-point increase in the perceived exercise barriers, the possibility of physical activity time ≥1 hour decreased by 15% (OR=0.85, 95%CI: 0.84-0.85). In the log-binomial model with variable of perceived exercise benefits to barriers ratio, for each 1-point increase in the perceived exercise benefits to barriers ratio, the possibility of physical activity time ≥1 hour increased by 12% (OR=1.12, 95%CI: 1.11-1.12). Conclusion: The perceived exercise benefits and barriers are significantly associated with physical activity time in children and adolescents in China.

Substantial niche overlap in carrion beetle habitat and vegetation use

Abstract The habitat affinities of carrion beetles (Coleoptera: Silphidae), a speciose group with wide cooccurrence, are only coarsely described for well‐studied species, particularly in the western United States. We aim to identify if the 15 species of montane carrion beetle in Colorado differ substantially in their use of habitats and across more uniquely defined, fine‐scale vegetation characteristics. Habitat and vegetation data as well as carrion beetle abundance were collected along four elevational transects in the Front Range and San Juan Mountains from 2010 to 2012 across 32 sites. Multiple habitat types were sampled, including forest, meadow, riparian, rocky outcrops and tundra. The fine‐scale vegetation characteristics included percent coverage of ground vegetation (grass, forb, shrub, cacti, bare ground), understory vegetation biomass and height, canopy cover and tree species, number and size. Canonical correspondence analysis models examined whether vegetation characteristics strongly segregated species using abundances and presence‐absences. Habitat and vegetation models explained a maximum of 18.93% of the variation in species' abundances and 2.48% in species' presence–absences. Only one likely habitat specialist was identified by the models (Heterosilpha ramosa) and the remaining species had substantial overlap in habitat and vegetation use. The arid, low productivity and generally open understory habitats in Colorado mountains likely play a large role in the substantial vegetation overlap. Other mechanisms of partitioning likely exist in this system to reduce niche overlap, which could include differences in activity time and seasonality, physiological traits, other life history strategies and body size.

The effect of neighborhood walkability on changes in physical activity and sedentary behavior during a 12-week pedometer-facilitated intervention.

Pedometer-facilitated interventions encourage physical activity via the accumulation of steps. Mixed evidence suggests that neighborhood walkability might influence the effectiveness of physical activity interventions, including pedometer-facilitated interventions. Our study investigated the moderating effect of neighborhood walkability on immediate (4-week) and short-term (12-week) changes in self-reported neighborhood-specific leisure and transportation walking, leisure-based moderate and vigorous-intensity physical activity, and leisure-based screen time during a pedometer-facilitated intervention (UWALK). This quasi-experiment undertaken in Calgary (Canada) compared behavior changes during the 12-week intervention between two neighborhood groups classified as 'walkable' or 'car dependent' based on Walk Score®. Of the 573 volunteers (adults in the contemplation and preparation stages of physical activity behavior change), 466 participated in UWALK. Surveys captured sociodemographic characteristics, perceived neighborhood walkability, neighborhood preferences, motivation, physical activity and screen-based leisure. Covariate-adjusted linear mixed models estimated the differences in physical activity and leisure screen time between the neighborhood walkability groups at baseline, 4-weeks, and 12-weeks. UWALK participants included mostly females (83%) and had an average age of 49.2 years. Weekly minutes of walking for transport inside the neighborhood was higher (p < .001) among participants from walkable versus car dependent neighborhoods at baseline (42.5 vs. 21.1), 4-weeks (81.2 vs. 48.2), and 12-weeks (87.2 vs. 48.0). Regardless of neighborhood walkability, all physical activity outcomes were higher and leisure screen time lower at 4-weeks and 12-weeks compared with baseline. We found no significant neighborhood group by time interactions. Pedometer-facilitated interventions may be effective for supporting short-term changes in physical activity and sedentary behavior even among adults residing in low walkable neighborhoods.

An Evaluation of Phase Analysis to Interpret Atrial Activation Patterns during Persistent Atrial Fibrillation for Targeted Ablation.

Background: Phase analysis has been used to identify and localize atrial fibrillation (AF) sources for targeted ablation. We previously demonstrated that repetitive wannabe reentry (incomplete reentry) often generated an apparent stable rotor using phase analysis. The misinterpretation caused by phase analysis using atrial electrograms (AEGs) may result from detecting inaccurate time points at phase inversion (π to −π) in the instantaneous phase waveform converted from AEG. The purpose of this study was to evaluate the accuracy of phase analysis to detect atrial activations recorded from the high-density mapping of AF in patients with persistent and long-standing persistent (LSP) AF. Methods and Results: During open heart surgery, we recorded activation from both atria simultaneously using 512 electrodes in 7 patients with persistent and LSP AF. The phase analysis was compared to manual measurements during 4 s of data. For the accuracy of activation sequence maps, a successful recording site was defined as having ≤4 mismatched activation times during the 4 s. In all AF episodes, the accuracy of the phase analysis was only 82% of the total number of activation times due to either activation time differences (14.7%), under-sensing (2.7%), or over-sensing (0.6%). Only 67.9% of the total recording sites met the requirement of a successful recording site by phase analysis. In unsuccessful recording sites, AEG characteristics were relatively irregular cycle length (CL), complex AEG, and double potential AEG. Conclusion: The phase analysis was less accurate in recording sites with a relatively irregular CL, complex AEG, or double potential AEG. As a result, phase analysis may lead to the misinterpretation of atrial activation patterns during AF. A visual review of the original AEG is needed to confirm the detected AF sources of phase analysis before performing targeted ablation.

Utility of carbon and nitrogen stable isotopes for inferring wild bee (Hymenoptera: Apoidea) use of adjacent foraging habitats.

Isotope analysis has proven useful for understanding diets of animals that are difficult to track for extended periods. Bees are small yet highly mobile and often forage from multiple habitats. However, current methods of assessing diet are limited in scope. Efficient methods of tracking bee diets that integrate across life stages, distinguish habitat use, and are sensitive to taxonomic differences will inform conservation strategies. We evaluated the utility of stable isotope analysis for estimating contributions of adjacent habitats to bees' diets. We also investigated taxonomic variation in bee and flower isotope composition. We measured natural abundance of carbon and nitrogen stable isotopes in two body regions from three wild bee genera, as well as in 25 species of flowers that likely comprised their diets. Bee ∂13C and ∂15N varied with habitat and taxonomic groups (conflated with month), but did not match spatial or seasonal trends in their food plants. Flower ∂13C was lowest in the forest and in April-June, as expected if driven by water availability. However, bee ∂13C was elevated in the spring, likely from overwintering nutritional stress or unpredictable food availability. Bumble bees (Bombus) were enriched in ∂15N compared to others, possibly reflecting differences in larval feeding. Bee diet mixing models had high variation and should be interpreted with caution. Models estimated similar habitat contributions to diets of spring Andrena and overwintered Bombus queens. Summer Bombus queens and workers were indistinguishable. Sweat bees (Halictus) were estimated to use comparatively more field flowers than others. Overall, taxon more strongly influenced isotope composition than either foraging habitat or month, likely because of associated differences in sociality and timing of annual activity. Future studies seeking to reveal bee diets by isotope analysis may gain better resolution in more isotopically distinct habitats, in conjunction with controlled feeding or isotope labeling experiments.

Designing a Driver’s Hazard Perception Test Based on the Neural Brain Images Analysis (fMRI)

Background: Studies show that weakness in hazard perception is a major cause of traffic accidents, leading to high consequences. Objectives: This study aimed to design a valid and reliable driver’s Hazard Perception Test (HPT) based on neural imaging, reaction time, and miss rate in two groups of experienced and inexperienced drivers. Methods: Different roads, including urban, intercity, and rural, were filmed from drivers’ visual angles to examine the real road conditions. All videos were screened according to some quality factors. Then, hazard onset was determined for screened videos. The validity of the test was performed in three steps. Miss rates and reaction times to hazardous situations were measured. In the second step, 35 selected videos were broadcasted to 16 experienced and 16 novice drivers on a functional magnetic resonance imaging (fMRI). Finally, using 18 videos with statistically significant differences in neuro-cerebral neuronal activity, miss rate and reaction time were picked up for driver’s HPT. Results: The mean differences in reaction time, miss rate, and active neurons in the task of perceiving hazards in two groups of drivers were equal to 1.58 seconds, 29.55%, and 5248 neurons, respectively. There was a significant correlation between active neurons and miss rate (r = 0.556, P &lt; 0.001). Eventually, the 18-videos of the valid test became HPT software. Conclusions: Application of this valid test is suggested for assessing the hazard perception of drivers, particularly those who are responsible for transporting staff and goods in the studied country.