Variability in energy cost of running at the end of a triathlon and a marathon

International audienceThe aim of this study was to investigate the increase in energy cost of running occurring at the end of a triathlon and a marathon event and to link them to the metabolic and hormonal changes, as well as to variations in stride length. Seven subjects took part in 3 experimental situations: a 2 h 15 min triathlon (30 min swimming, 60 min cycling and 45 min running), a 2 h 15 min marathon (MR) were the fast 45 min were run at the same speed as the triathlon run (TR), and a 45 min isolated run (IR) done at triathlon speed. The results show that energy cost during MR was higher than during TR (p < 0.01) (+ 8.9 %). Similar observations were made for pulmonary ventilation (+ 7.9 %) and heart rate (+ 6.3 %). Moreover, the values were significantly greater than the values obtained during the IR. TR and MR lead to greater weight loss (p < 0.01) (2.4±0.3 kg) than IR (1 ± 0.2 kg). The triathlon and the marathon produced a large decrease in plasma volume (respectively 19.6 ± 1.4 % and 12.9 ± 1.1 %) compared to IR (2 ± 0.4 %). Plasma renin activity was higher for the triathlon and the marathon than for the IR (p < 0.01). MR produces a significantly greater increase in plasma free fatty acids (F.F.A.) than TR (p < 0.05) and IR (p < 0.01). In addition, the F.F.A. at the end of TR were significantly higher than IR (p < 0.05). At the end of the trial the mean stride lengths for TR and IR were greater (+ 15 %) (p <0.01) than for MR. This study, carried out with subjects running overground, confirms the decrease in running efficiency previously shown at the end of a laboratory triathlon, and demonstrates that this decrease is lower than that occurring during a marathon

Mood Indigo

Photograph of Wayne King; Blue, white and yellow confettihttps://scholarsjunction.msstate.edu/cht-sheet-music/13355/thumbnail.jp

Easy clip to treat anal fistula tracts: a word of caution

International audienceBackground and aims: Closing the internal opening by a clip ovesco has been recently proposed for healing the fistula tract, but, to date, data on benefit are poorly analyzed. The aim was to report a preliminary multicenter experience. Materials and methods Retrospective study was undertaken in six different French centers: surgical procedure, immediate complications, and follow-up have been collected. Results Nineteen clips were inserted in 17 patients (M/F, 4/13; median age, 42 years [29–54]) who had an anal fistula: 12 (71 %) high fistulas (including 4 rectovaginal fistulas), 5 (29 %) lower fistulas (with 3 rectovaginal fistulas), and 6 (35 %) Crohn’s fistulas. Out of 17 patients, 15 had a seton drainage beforehand. The procedure was easy in 8 (47 %) patients and the median operative time was 27.5 min (20–36.5). Postoperative period was painful for 11 (65 %) patients. A clip migration was noted in 11 patients (65 %) after a median follow-up of 10 days (5.5–49.8). Eleven patients (65 %) who failed had reoperation including 10 new drainages within the first month (0.5–5). After a mean follow-up of 4 months (2–7),, closing the tract was observed in 2 patients (12 %) following the first insertion of the clip and in another one after a second insertion. Conclusion: Treatment of anal fistula by placing a clip on the internal opening is disappointing and deleterious for some patients. A better assessment before dissemination is recommended

De la théorie à la pratique de la séquence Éviter-Réduire-Compenser (ERC) : éviter ou légitimer la perte de biodiversité ?

La séquence Éviter-Réduire-Compenser (ERC) est devenue un instrument réglementaire important visant à concilier aménagement et préservation de l’environnement. Le succès de son application dépend notamment de l’interprétation des textes normatifs nationaux par les acteurs du territoire. Dans cet article, nous nous intéressons à l’interprétation des définitions des étapes ERC inscrites dans la doctrine nationale. L’analyse de 42 études d’impact permet de montrer qu’il existe une forte hétérogénéité d’interprétation : 60 % des mesures proposées ne correspondent pas aux définitions normatives. Ces confusions pouvant réduire l’efficacité écologique de la séquence, nous suggérons des voies d’amélioration en faveur d’une plus grande cohésion entre les définitions et les mesures proposées.The mitigation hierarchy has become a major regulatory tool to balance urban development with environmental interest. Notably, the success of its implementation is based on the interpretation of such politics by practitioners. In this manuscript, we focus on the interpretation of French normative definitions of the three steps in the mitigation hierarchy : i.e. avoidance, reduction et offsetting. The analysis of 42 Environmental Impact Assessment (EIA) highlights important heterogeneity among interpretations : 60 % of the proposed measures in EIAs do not fit with the normative definitions. These confusions could have a negative impact on the ecological efficiency of the mitigation hierarchy. Therefore, we suggest several solutions to improve cohesion between the normative definitions et proposed measures in practice

De la théorie à la pratique de la séquence Éviter-Réduire-Compenser (ERC) : éviter ou légitimer la perte de biodiversité ?

La séquence Éviter-Réduire-Compenser (ERC) est devenue un instrument réglementaire important visant à concilier aménagement et préservation de l’environnement. Le succès de son application dépend notamment de l’interprétation des textes normatifs nationaux par les acteurs du territoire. Dans cet article, nous nous intéressons à l’interprétation des définitions des étapes ERC inscrites dans la doctrine nationale. L’analyse de 42 études d’impact permet de montrer qu’il existe une forte hétérogénéité d’interprétation : 60 % des mesures proposées ne correspondent pas aux définitions normatives. Ces confusions pouvant réduire l’efficacité écologique de la séquence, nous suggérons des voies d’amélioration en faveur d’une plus grande cohésion entre les définitions et les mesures proposées.The mitigation hierarchy has become a major regulatory tool to balance urban development with environmental interest. Notably, the success of its implementation is based on the interpretation of such politics by practitioners. In this manuscript, we focus on the interpretation of French normative definitions of the three steps in the mitigation hierarchy : i.e. avoidance, reduction et offsetting. The analysis of 42 Environmental Impact Assessment (EIA) highlights important heterogeneity among interpretations : 60 % of the proposed measures in EIAs do not fit with the normative definitions. These confusions could have a negative impact on the ecological efficiency of the mitigation hierarchy. Therefore, we suggest several solutions to improve cohesion between the normative definitions et proposed measures in practice

The Cosmed K4 telemetry system as an accurate device for oxygen uptake measurements during exercise

International audienceThe purpose of this study was to test the accuracy of oxygen uptake (VO2) measurements using the Cosmed K4 portable telemetry system. This system of higher technology than the original Cosmed K2 device, contains a CO2 electrode allowing measurements alternatively by either the Cosmed K4 system (K4) or the CPX Medical Graphics (CPX) during a maximum oxygen uptake (VO 2 max) ergocycle test, at rest and during several submaximal exercices (25, 50 and 75% of maximal work rate) in seven subjects. Heart rate values were comparable for exercise at the same work stage during gas collection using the two systems, indicating that the physiological stresses were similar. The VO 2 values did not significantly differ at rest (4.40 ± 0.83 vs 4.16 ± 0.58 ml • min-1 kg-1), at 25% Wmax (20.97 ± 1.31 vs 21.32 ± 2.54 ml • min-1 • kg-1), at 50% Wmax (33.32 ± 3.92 vs 33.50 ± 3.51 ml • min-1. kg-1), at 75% Wmax (47.01 ± 7.51 vs 47.49 ± 7.11 ml • min-1. kg-') and at maximal intensities (62.07 ± 8.48 vs 62.84 ± 11.31 ml • min-1. kg-1) using K4 and CPX devices, respectively. The results of this study indicated that the K4 system was accurate for all oxygen uptake measurements from rest to maximum exercise levels

The sugarless grape trait characterised by single berry phenotyping

In grape production, the selection of varieties well-adapted to climate fluctuations, especially warming, is based on achieving a balance between fruit sugars and acidity. In recent decades, temperature has been constantly rising during ripening causing excessive sugar concentrations and insufficient acidity in wine grapes in the warmest regions. There is thus an increasing interest in breeding new cultivars able to ripen at lower sugar concentration while preserving fruit acidity. However, the phenotyping of berry composition challenges both methodological and conceptual issues. Indeed, most authors predetermine either average harvest date, ripening duration, thermal time or even the hexoses concentration threshold itself to compare accessions at a hopefully similar ripe stage. In this study, we phenotyped the fruit development and composition of 6 genotypes, including 3 new disease-tolerant varieties known to produce wines with low alcoholic contents. The study was performed at single berry level from the end of the green growth stage to the end of phloem unloading, when water and solute contents reach a maximum per berry. The results confirm that sugarless genotypes achieve fruit ripening with 20-30 % less hexoses than the classical varieties, Grenache N and Merlot N, without impacting berry growth, total acidity or cation accumulation. The sugarless genotypes displayed a higher malic acid/tartaric acid balance than the other genotypes, but similar sucrose/H+ exchanges at the onset of ripening. Data suggest that the sugarless phenotype results from a specific plasticity in the relationship between growth and the turgor imposed by organic acid accumulation and sugar loading. This opens interesting perspectives for the understanding of the mechanism of grapevine berry growth and for breeding varieties that will cope better with climate warming