bluuebunny/crossref_metadata_2025_split huggingface dataset:
The natural matching of harmonic responses in the pulmonary circulation
Authors: Pérez del Villar Candelas , Martínez‐Legazpi Pablo , Mombiela Teresa , Chazo Christian , Desco Mar , Rodríguez‐Pérez Daniel , Benito Yolanda , Barrio Alicia , Gutiérrez‐Ibañes Enrique , del Álamo Juan C. , Elízaga Jaime , Antoranz José Carlos , Fernández‐Avilés Francisco , Yotti Raquel , Bermejo Javier 
Published: June 2019

Key points
The right ventricle of the mammal heart is highly sensitive to the afterload imposed by a combination of the pulmonary circulation and the retrograde contribution of the left heart.
Right ventricular afterload can be analysed in terms of pulmonary artery input impedance, which we were able to decompose as the result of the harmonic frequency responses of the pulmonary vessels and the left heart attached in series.
Using spectral methods, we found a natural matching between the pulmonary vasculature and the left chambers of the heart. This coupling implies that the upstream transmission of the left heart frequency‐response has favourable effects on the pulmonary tree.
This physiological mechanism protects the right ventricle against acute changes in preload, and its impairment may be a relevant contribution to right ventricle dysfunction in pulmonary hypertension.
AbstractThe right ventricle (RV) of the mammal heart is highly sensitive to the afterload imposed by the pulmonary circulation, and the left heart (LH) retrogradely contributes significantly to this vascular load. Transmission‐line theory anticipates that the degree of matching between the frequency responses of the pulmonary vasculature and the LH should modulate the global right haemodynamic burden. We measured simultaneous high‐fidelity flow (pulmonary artery) and pressure (pulmonary artery and left atrium) in 18 healthy minipigs under acute haemodynamic interventions. From these data, we decomposed the impedance spectra of the total right‐circulation system into the impedance of the pulmonary vessels and the harmonic response of the LH. For frequencies above the first harmonic, total impedance was below the pulmonary impedance during all phases (P < 0.001; pooled phases), demonstrating a favourable effect of the LH harmonic response on RV pulsatile load: the LH harmonic response was responsible for a 20% reduction of pulse pulmonary artery pressure (P < 0.001 vs. a theoretical purely‐resistive response) and a 15% increase of pulmonary compliance (P = 0.009). This effect on compliance was highest during acute volume overload. In the normal right circulation, the longitudinal impedance of the pulmonary vasculature is matched to the harmonic response of the LH in a way that efficiently reduces the pulmonary pulsatile vascular load. This source of interaction between the right and left circulations of mammals protects the RV against excessive afterload during acute volume transients and its disruption may be an important contributor to pulmonary hypertension.
Changes in Skeletal Muscle Oxidative Capacity After a Trail-Running Race
Authors: Giovanelli Nicola , Biasutti Lea , Salvadego Desy , Alemayehu Hailu K. , Grassi Bruno , Lazzer Stefano 
Published: June 2019

Purpose: To evaluate the effects of a trail-running race on muscle oxidative function by measuring pulmonary gas exchange variables and muscle fractional O2 extraction. Methods: Eighteen athletes were evaluated before (PRE) and after (POST) a trail-running competition of 32 or 50 km with 2000 or 3500 m of elevation gain, respectively. During the week before the race, runners performed an incremental uphill running test and an incremental exercise by utilizing a 1-leg knee extension ergometer. The knee extension exercise was repeated after the end of the race. During the knee extension test, the authors measured oxygen uptake () and micromolar changes in deoxygenated hemoglobin (Hb)+myoglobin (Mb) concentrations (Δ[deoxy(Hb+Mb)]) on vastus lateralis with a portable near-infrared spectroscopy. Results: was lower at POST versus PRE (−23.9% [9.0%]; P < .001). at POST was lower than at the same workload at PRE (−8.4% [15.6%]; P < .050). Peak power output and time to exhaustion decreased at POST by −23.7% (14.3%) and −18.3% (11.3%), respectively (P < .005). At POST, the increase of Δ[deoxy(Hb+Mb)] as a function of work rate, from unloaded to peak, was less pronounced (from 20.2% [10.1%] to 64.5% [21.1%] of limb ischemia at PRE to 16.9% [12.7%] to 44.0% [18.9%] at POST). Peak Δ[deoxy(Hb+Mb)] values were lower at POST (by −31.2% [20.5%]; P < .001). Conclusions: Trail running leads to impairment in skeletal muscle oxidative metabolism, possibly related to muscle damage from repeated eccentric contractions. In association with other mechanisms, the impairment of skeletal muscle oxidative metabolism is likely responsible for the reduced exercise capacity and tolerance during and following these races.
Tart Cherry Juice: No Effect on Muscle Function Loss or Muscle Soreness in Professional Soccer Players After a Match
Authors: Abbott Will , Brashill Callum , Brett Adam , Clifford Tom 
Published: June 2019

Purpose: To investigate the effects of tart cherry juice (TCJ) on recovery from a soccer match in professional players. Methods: In a double-blind, placebo-controlled, crossover design, 10 male professional soccer players from the reserve team of an English Premier League Club (age 19 [1] y, height 1.8 [0.6] m, body mass 77.3 [6.4] kg) consumed 2 × 30-mL servings of TCJ or an isocaloric cherry-flavored control drink (CON) before and after a 90-minute match and 12 and 36 hours after the match. Muscle function (countermovement jump height and reactive strength index), subjective well-being, and subjective muscle soreness were measured before and 12, 36, and 60 hours after each match. Results: Countermovement jump height was similarly reduced in the days after the match after TCJ and CON supplementation, with the greatest loss occurring at 12-hour postmatch (−5.9% [3.1%] vs −5.4% [2.9%], of baseline values, respectively; P = .966; ). Decrements in reactive strength index were also greatest at 12-hour postmatch (TCJ −9.4% [8.4%] vs CON −13.9% [4.8%], of baseline values), but no group differences were observed at any time point (P = .097; ). Muscle soreness increased 12- to 60-hour postmatch in both groups, peaking at 12-hour postmatch (TCJ 122 [27] mm vs CON 119 [22] mm), but no group differences were observed (P = .808; ). No interaction effects were observed for subjective well-being (P = .874; ). Conclusions: TCJ did not hasten recovery after a soccer match in professional players. These findings bring into question the use of TCJ as a recovery aid in professional soccer players.
Performance Effects of Carbohydrate Ingestion Between Bouts of Intense Aerobic Interval Exercise
Authors: McCarthy Devin G. , Spriet Lawrence L. 
Published: June 2019

Background: Rest between training sessions can be short for athletes. In these situations, consuming carbohydrate (CHO) postexercise replenishes glycogen stores, which is important for recovery and subsequent performance. Purpose: This study tested whether CHO intake during a 2-hour rest between exercise bouts improved performance in the subsequent bout. Methods: In a randomized, single-blinded, crossover design, 10 recreationally active participants (23 [4] y, 70.8 [6.6] kg, 47.0 [5.4] mL·O2·min−1·kg·body·mass−1) arrived at the lab postprandial and completed 2 exercise bouts separated by a 2-hour rest. Bouts included 5 × 4-minute intervals at ∼80% peak oxygen consumption separated by 2 minutes at ∼40% peak oxygen consumption and ended with an endurance trial to voluntary exhaustion at ∼90% peak oxygen consumption. During intervals 1 and 4 in each bout, expired gases were collected and O2 deficit was estimated. Immediately following bout 1, either a CHO (1.2 g CHO·kg·body·mass−1) or placebo solution was consumed. Results: Endurance trial duration decreased in bout 2 versus 1 in both conditions (P < .01) but was ∼35% longer in bout 2 with CHO versus placebo (interaction, P = .03; post hoc, P = .03). Oxygen uptake increased during interval 4 versus 1 in both bouts (P < .01) but was unaffected by CHO (P ≥ .58). O2 deficit was unaffected by CHO (P = .93), bout, or interval (P ≥ .15). Perceived exertion was higher in bout 2 versus 1 (P < .001) and reduced in intervals 2 and 4 in CHO (P ≤ .01). Conclusions: When rest between training sessions is 2 hours, athletes may improve subsequent performance by consuming CHO during recovery.
Identifying Athlete Body Fluid Changes During a Competitive Season With Bioelectrical Impedance Vector Analysis
Authors: Campa Francesco , Matias Catarina N. , Marini Elisabetta , Heymsfield Steven B. , Toselli Stefania , Sardinha Luís B. , Silva Analiza M. 
Published: June 2019

Purpose:To analyze the association between body fluid changes evaluated by bioelectrical impedance vector analysis and dilution techniques over a competitive season in athletes.Methods:A total of 58 athletes of both sexes (men: age 18.7 [4.0] y and women: age 19.2 [6.0] y) engaging in different sports were evaluated at the beginning (pre) and 6 months after (post) the competitive season. Deuterium dilution and bromide dilution were used as the criterion methods to assess total body water (TBW) and extracellular water (ECW), respectively; intracellular water (ICW) was calculated as TBW–ECW. Bioelectrical resistance and reactance were obtained with a phase-sensitive 50-kHz bioelectrical impedance analysis device; bioelectrical impedance vector analysis was applied. Dual-energy X-ray absorptiometry was used to assess fat mass and fat-free mass. The athletes were empirically classified considering TBW change (pre–post, increase or decrease) according to sex.Results:Significant mean vector displacements in the postgroups were observed in both sexes. Specifically, reductions in vector length (Z/H) were associated with increases in TBW and ICW (r = −.718,P < .01;r = −.630,P < .01, respectively) and decreases in ECW:ICW ratio (r = .344,P < .05), even after adjusting for age, height, and sex. Phase-angle variations were positively associated with TBW and ICW (r = .458,P < .01;r = .564,P < .01, respectively) and negatively associated with ECW:ICW (r = −.436,P < .01). Phase angle significantly increased in all the postgroups except in women in whom TBW decreased.Conclusions:The results suggest that bioelectrical impedance vector analysis is a suitable method to obtain a qualitative indication of body fluid changes during a competitive season in athletes.
Quantifying the Training-Intensity Distribution in Middle-Distance Runners: The Influence of Different Methods of Training-Intensity Quantification
Authors: Bellinger Phillip , Arnold Blayne , Minahan Clare 
Published: June 2019

Purpose: To compare the training-intensity distribution (TID) across an 8-week training period in a group of highly trained middle-distance runners employing 3 different methods of training-intensity quantification. Methods: A total of 14 highly trained middle-distance runners performed an incremental treadmill test to exhaustion to determine the heart rate (HR) and running speed corresponding to the ventilatory thresholds (gas-exchange threshold and respiratory-compensation threshold), as well as fixed rating of perceived exertion (RPE) values, which were used to demarcate 3 training-intensity zones. During the following 8 weeks, the TID (total and percentage of time spent in each training zone) of all running training sessions (N = 695) was quantified using continuous running speed, HR monitoring, and RPE. Results: Compared with the running-speed-derived TID (zone 1, 79.9% [7.3%]; zone 2, 5.3% [4.9%]; and zone 3, 14.7% [7.3%]), HR-demarcated TID (zone 1, 79.6% [7.2%]; zone 2, 17.0% [6.3%]; and zone 3, 3.4% [2.0%]) resulted in a substantially higher training time in zone 2 (effect size ± 95% confidence interval: −1.64 ± 0.53; P < .001) and lower training time in zone 3 (−1.59 ± 0.51; P < .001). RPE-derived TID (zone 1, 39.6% [8.4%]; zone 2, 31.9% [8.7%]; and zone 3, 28.5% [11.6%]) reduced time in zone 1 compared with both HR (−5.64 ± 1.40; P < .001) and running speed (−5.69 ± 1.9; P < .001), whereas time in RPE training zones 2 and 3 was substantially higher than both HR- and running-speed-derived zones. Conclusion: The results show that the method of training-intensity quantification substantially affects computation of TID.
Seven A’s of Active Aging: Older Men’s Suggestions for Physical Activity Programs
Authors: Deneau Jordan , Horton Sean , van Wyk Paula M. 
Published: June 2019

In an attempt to offset the widespread anticipated impact of aging populations, active aging programs have become nearly ubiquitous in Western society. Nonetheless, older adults tend to remain relatively inactive. The perspectives of older adults constitute a key resource to help guide active aging efforts. Moreover, gender-sensitized and ecological approaches to physical activity programming may contribute markedly to the efficacy and inclusiveness of such initiatives. Considering the paucity of research regarding older men’s suggestions for physical activity programs, this study involved semistructured interviews to ascertain the perceptions among 19 older men (aged 75–90 years). Through a thematic analysis, seven key attributes emerged that participants believed physical activity programs should possess: affordable, available, accessible, adapted, alternative, accompanied, and awareness. The complexities and implications pertaining to these attributes are discussed in the context of ecological theory and ideals of masculinity.
Measuring and Comparing Physical Education Teachers’ Perceived Attributes of CSPAPs: An Innovation Adoption Perspective
Authors: Webster Collin A. , Mîndrilă Diana , Moore Chanta , Stewart Gregory , Orendorff Karie , Taunton Sally 
Published: June 2019

Purpose: Drawing from the diffusion of innovations theory, this study aimed to develop a survey to measure physical education teachers’ perceived attributes of comprehensive school physical activity programs (CSPAPs) and examine the differences between adopters’ and potential adopters’ perceived attributes.Method: The authors created an electronic survey and e-mailed it to 2,955 physical education teachers identified from a random sample of all public schools in the United States. The participants’ (N = 407) responses were analyzed using the exploratory structural equation modeling framework.Results: The exploratory structural equation modeling yielded five factors: (a) compatibility, (b) relative advantage, (c) observability, (d) simplicity, and (e) trialability (χ2/df = 3.2; root mean square error of approximation = .074; comparative-fit index = .983; Tucker–Lewis index = .971; weighted root mean residual = .668). Compared with potential adopters, teachers who had already adopted a CSPAP perceived CSPAPs as simpler to implement but less trialable.Discussion/Conclusion: This study advances the measurement for CSPAP implementation and offers insight into program attributes that merit a targeted focus in efforts to increase CSPAP adoption.
Moderate to Vigorous Physical Activity During Physical Education, Recess, and Class Time Among Elementary School Children in Qatar
Authors: Zimmo Lena , Almudahka Fuad , Ibrahim Izzeldin , Al-kuwari Mohamed G. , Farooq Abdulaziz 
Published: June 2019

Purpose: Schools provide opportunities for children to accumulate recommended daily moderate to vigorous physical activity (MVPA). This study aimed to determine physical activity (PA) across the school day among elementary school children in Qatar.Methods: This cross-sectional study recruited 181 Grade 1 (5.8 ± 0.4 years) and Grade 4 (9.0 ± 0.5 years) children. Participants wore wrist-based accelerometers for 5 days to assess school-based PA. MVPA during physical education, recess, and class time were compared across sex, grade, and body mass index using general linear models.Results: Only 39.0% of this cohort met the recommended 30 min of MVPA during school hours. Fewer girls (23.2%) than boys (58.1%) achieved the school-based PA guidelines (p < .001). The children engaged in 19.0 ± 12.3%, 19.3 ± 8.6%, and 6.2 ± 3.4% of the designated physical education, recess, and class time in MVPA, respectively.Conclusion: Elementary school children in Qatar engage in inadequate MVPA during the school day, especially girls. Enhancing PA opportunities during physical education and recess is crucial.
A Person-Centered Approach in Physical Education to Better Understand Low-Motivation Students
Authors: Franco Evelia , Coterón Javier , Huéscar Elisa , Moreno-Murcia Juan A. 
Published: June 2019

Purpose: This study seeks to offer a motivational sequence that explains the intention of physical activity among low-motivation students.Method: Participants included 1,872 students (Mage = 15.01,SDage = 0.83 years) from three countries. A cluster analysis (i.e., a person-centered approach) and a multigroup structural equation model (i.e., a dimensional approach) were used.Results: Three motivational profiles, namely, high motivation, high motivation with low ego, and low motivation–moderate task orientation were established. The model first tested, based on previous research findings, was found not to be invariant across the different profiles. The new model tested was determined to be suitable for the low-motivation profile.Discussion: The results revealed that widely accepted motivational sequences that explain the intention to be physically active in the future may be inapplicable for the least motivated students. The findings suggest that dispositional flow may play an important role in the engagement of low-motivation students in future physical activity.
Laurentian origin of the Cuyania suspect terrane, western Argentina, confirmed by Hf isotopes in zircon
Authors: Martin Erin L. , Collins William J. , Spencer Christopher J. 
Published: June 2019

Abstract
The proto-Andean margin of Argentina consists of several suspect terranes, the origins of which are disputed. The Cuyania (greater Precordillera) suspect terrane was originally interpreted to be of southeast Laurentian affinity, but more recently a southwestern Gondwanan provenance has been argued. Both potential source regions comprise Mesoproterozoic rocks, but we show they are isotopically distinct, using previously published zircon Lu-Hf data. Detrital zircon εHf data from southwestern Gondwana (Namaqua-Natal belt) show no correlation with new zircon U-Pb and Lu-Hf data from Cuyania, suggesting that Gondwana was not the source of these sediments. Rather, detrital zircons from Cambrian strata in Cuyania yield Mesoproterozoic zircons with depleted εHf that correlate to the Grenville margin of Laurentia, and a ca. 535 Ma zircon population sourced directly from rift-related rocks of the Ouachita Embayment, thus recording rifting and drifting of Cuyania from Laurentia. By contrast, zircons from Middle to Late Ordovician strata of Cuyania record a larger range of εHf values, correlated with Western Sierras Pampeanas Mesoproterozoic basement inliers of Argentina. These synorogenic clastic deposits record the Ordovician arrival of Cuyania at the proto-Andean margin of Gondwana. The new data require the terrane boundaries of Cuyania to be redefined, thereby excluding Western Sierras Pampeanas basement inliers. The results verify the Laurentian microcontinent model for the origin of Cuyania.
Atrial fibrillation ablation with a spring sensor-irrigated contact force-sensing catheter compared with other ablation catheters: systematic literature review and meta-analysis
Authors: Macle Laurent , Frame Diana , Gache Larry M , Monir George , Pollak Scott J , Boo Lee Ming 
Published: June 2019

ObjectivesThe objective of our review was to systematically assess available evidence on the effectiveness, safety and efficiency of a spring sensor-irrigated contact force (CF) catheter (THERMOCOOL SMARTTOUCH Catheter (ST)) for percutaneous ablation of paroxysmal or persistent atrial fibrillation (AF), compared with other ablation catheters, or with the ST with the operator blinded to CF data.DesignSystematic literature review and meta-analysis.BackgroundEmerging evidence suggests improved clinical outcomes of AF ablation using CF-sensing catheters; however, reviews to date have included data from multiple, distinct CF technologies.MethodsWe conducted a systematic review and meta-analysis of published studies comparing the use of ST versus other ablation catheters for the treatment of AF. A comprehensive search of electronic and manual sources was conducted. The primary endpoint was freedom from recurrent atrial tachyarrhythmia (AT) at 12 months. Procedural and safety data were also analysed.ResultsThirty-four studies enrolling 5004 patients were eligible. The use of ST was associated with increased odds of freedom from AT at 12 months (71.0%vs60.8%; OR 1.454, 95% CI 1.12 to 1.88, p=0.004) over the comparator group, and the effect size was most evident in paroxysmal AF patients (75.6%vs64.7%; OR 1.560, 95% CI 1.09 to 2.24, p=0.015). Procedure and fluoroscopy times were shorter with ST (p=0.05 and p<0.01, respectively, vs comparator groups). The reduction in procedure time is estimated at 15.5 min (9.0%), and fluoroscopy time 4.8 min (18.7%). Complication rates, including cardiac tamponade, did not differ between groups.ConclusionsCompared with the use of other catheters, AF ablation using the CF-sensing ST catheter for AF is associated with improved success rates, shorter procedure and fluoroscopy times and similar safety profile.