Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction

International audienceLimited resources in the environment prevent individuals from simultaneouslymaximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) were examined based onmorphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions

Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction

Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lion

Amélioration de la caractérisation des effluents d'élevage par des méthodes et des modèles innovants pour une meilleure prise en compte agronomique

Ce numéro d’Innovations Agronomiques correspond à la synthèse des différents projets Casdar «Innovation et Partenariat» et « Recherche Finalisée et Innovation » retenus en 2009.Le projet "Effluents d'élevage" avait pour finalité de contribuer à optimiser les épandages d’effluents d’élevage pour la fertilisation des cultures par une meilleure connaissance de leur composition et de leur comportement à l’épandage. Il a permis de mieux évaluer les besoins de caractérisation, de caractériser les effluents d’élevages, y compris ceux issus des nouveaux procédés de traitement, et de tester des méthodes innovantes de caractérisation telles que la Spectroscopie Proche Infra Rouge

Améliorer la caractérisation des effluents d'élevage par des méthodes et des modèles innovants pour une meilleure prise en compte agronomique

Poster présenté par l'ACTA dans le cadre du RMT fertilisation et environnement, écrit avec tous les partenaires du projet CasDar Effluents d'Elevage

Effectiveness of Simulation-Based Training on Transesophageal Echocardiography Learning

Importance Evidence is scarce on the effectiveness of simulation-based training in transesophageal echocardiography (TEE).Objective To assess the effectiveness of simulation-based teaching vs traditional teaching of TEE knowledge and skills of cardiology fellows.Design, Setting, and Participants Between November 2020 and November 2021, all consecutive cardiology fellows inexperienced in TEE from 42 French university centers were randomized (1:1; n = 324) into 2 groups with or without simulation support.Main Outcomes and Measures The co-primary outcomes were the scores in the final theoretical and practical tests 3 months after the training. TEE duration and the fellows’ self-assessment of their proficiency were also assessed.Results While the theoretical and practical test scores were similar between the 2 groups (324 participants; 62.6% male; mean age, 26.4 years) before the training (33.0 [SD, 16.3] points vs 32.5 [SD, 18.5] points; P = .80 and 44.2 [SD, 25.5] points vs 46.1 [SD, 26.1] points; P = .51, respectively), the fellows in the simulation group (n = 162; 50%) displayed higher theoretical test and practical test scores after the training than those in the traditional group (n = 162; 50%) (47.2% [SD, 15.6%] vs 38.3% [SD, 19.8%]; P < .001 and 74.5% [SD, 17.7%] vs 59.0% [SD, 25.1%]; P < .001, respectively). Subgroup analyses showed that the effectiveness of the simulation training was even greater when performed at the beginning of the fellowship (ie, 2 years or less of training) (theoretical test: an increase of 11.9 points; 95% CI, 7.2-16.7 vs an increase of 4.25 points; 95% CI, −1.05 to 9.5; P = .03; practical test: an increase of 24.9 points; 95% CI, 18.5-31.0 vs an increase of 10.1 points; 95% CI, 3.9-16.0; P < .001). After the training, the duration to perform a complete TEE was significantly lower in the simulation group than in the traditional group ( 8.3 [SD, 1.4] minutes vs 9.4 [SD, 1.2] minutes; P < .001, respectively). Additionally, fellows in the simulation group felt more ready and more confident about performing a TEE alone after the training (mean score, 3.0; 95% CI, 2.9-3.2 vs mean score, 1.7; 95% CI, 1.4-1.9; P < .001 and mean score, 3.3; 95% CI, 3.1-3.5 vs mean score, 2.4; 95% CI, 2.1-2.6; P < .001, respectively).Conclusions and Relevance Simulation-based teaching of TEE showed a significant improvement in the knowledge, skills, and self-assessment of proficiency of cardiology fellows, as well as a reduction in the amount of time needed to complete the examination. These results should encourage further investigation of clinical performance and patient benefits of TEE simulation training.Trial Registration ClinicalTrials.gov Identifier: NCT0556450

Ambition numérique: Pour une politique française et européenne de la transition numérique

Rapport remis au premier ministr

Effectiveness of Simulation-Based Training on Transesophageal Echocardiography Learning: The SIMULATOR Randomized Clinical Trial

International audienceImportance Evidence is scarce on the effectiveness of simulation-based training in transesophageal echocardiography (TEE).Objective To assess the effectiveness of simulation-based teaching vs traditional teaching of TEE knowledge and skills of cardiology fellows.Design, Setting, and Participants Between November 2020 and November 2021, all consecutive cardiology fellows inexperienced in TEE from 42 French university centers were randomized (1:1; n = 324) into 2 groups with or without simulation support.Main Outcomes and Measures The co-primary outcomes were the scores in the final theoretical and practical tests 3 months after the training. TEE duration and the fellows’ self-assessment of their proficiency were also assessed.Results While the theoretical and practical test scores were similar between the 2 groups (324 participants; 62.6% male; mean age, 26.4 years) before the training (33.0 [SD, 16.3] points vs 32.5 [SD, 18.5] points; P = .80 and 44.2 [SD, 25.5] points vs 46.1 [SD, 26.1] points; P = .51, respectively), the fellows in the simulation group (n = 162; 50%) displayed higher theoretical test and practical test scores after the training than those in the traditional group (n = 162; 50%) (47.2% [SD, 15.6%] vs 38.3% [SD, 19.8%]; P < .001 and 74.5% [SD, 17.7%] vs 59.0% [SD, 25.1%]; P < .001, respectively). Subgroup analyses showed that the effectiveness of the simulation training was even greater when performed at the beginning of the fellowship (ie, 2 years or less of training) (theoretical test: an increase of 11.9 points; 95% CI, 7.2-16.7 vs an increase of 4.25 points; 95% CI, −1.05 to 9.5; P = .03; practical test: an increase of 24.9 points; 95% CI, 18.5-31.0 vs an increase of 10.1 points; 95% CI, 3.9-16.0; P < .001). After the training, the duration to perform a complete TEE was significantly lower in the simulation group than in the traditional group ( 8.3 [SD, 1.4] minutes vs 9.4 [SD, 1.2] minutes; P < .001, respectively). Additionally, fellows in the simulation group felt more ready and more confident about performing a TEE alone after the training (mean score, 3.0; 95% CI, 2.9-3.2 vs mean score, 1.7; 95% CI, 1.4-1.9; P < .001 and mean score, 3.3; 95% CI, 3.1-3.5 vs mean score, 2.4; 95% CI, 2.1-2.6; P < .001, respectively).Conclusions and Relevance Simulation-based teaching of TEE showed a significant improvement in the knowledge, skills, and self-assessment of proficiency of cardiology fellows, as well as a reduction in the amount of time needed to complete the examination. These results should encourage further investigation of clinical performance and patient benefits of TEE simulation training.Trial Registration ClinicalTrials.gov Identifier: NCT0556450

Carbon-nitrogen interactions in European forests and semi-natural vegetation - Part 1 : Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling

The impact of atmospheric reactive nitrogen (N-r) deposition on carbon (C) sequestration in soils and biomass of unfertilized, natural, semi-natural and forest ecosystems has been much debated. Many previous results of this dC/dN response were based on changes in carbon stocks from periodical soil and ecosystem inventories, associated with estimates of N-r deposition obtained from large-scale chemical transport models. This study and a companion paper (Flechard et al., 2020) strive to reduce uncertainties of N effects on C sequestration by linking multi-annual gross and net ecosystem productivity estimates from 40 eddy covariance flux towers across Europe to local measurement-based estimates of dry and wet N-r deposition from a dedicated collocated monitoring network. To identify possible ecological drivers and processes affecting the interplay between C and N-r inputs and losses, these data were also combined with in situ flux measurements of NO, N2O and CH4 fluxes; soil NO3- leaching sampling; and results of soil incubation experiments for N and greenhouse gas (GHG) emissions, as well as surveys of available data from online databases and from the literature, together with forest ecosystem (BAS-FOR) modelling. Multi-year averages of net ecosystem productivity (NEP) in forests ranged from -70 to 826 gCm(-2) yr(-1) at total wet + dry inorganic N-r deposition rates (N-dep) of 0.3 to 4.3 gNm(-2) yr(-1) and from -4 to 361 g Cm-2 yr(-1) at N-dep rates of 0.1 to 3.1 gNm(-2) yr(-1) in short semi-natural vegetation (moorlands, wetlands and unfertilized extensively managed grasslands). The GHG budgets of the forests were strongly dominated by CO2 exchange, while CH4 and N2O exchange comprised a larger proportion of the GHG balance in short semi-natural vegetation. Uncertainties in elemental budgets were much larger for nitrogen than carbon, especially at sites with elevated N-dep where N-r leaching losses were also very large, and compounded by the lack of reliable data on organic nitrogen and N-2 losses by denitrification. Nitrogen losses in the form of NO, N2O and especially NO3- were on average 27%(range 6 %-54 %) of N-dep at sites with N-dep 3 gNm(-2) yr(-1). Such large levels of N-r loss likely indicate that different stages of N saturation occurred at a number of sites. The joint analysis of the C and N budgets provided further hints that N saturation could be detected in altered patterns of forest growth. Net ecosystem productivity increased with N-r deposition up to 2-2.5 gNm(-2) yr(-1), with large scatter associated with a wide range in carbon sequestration efficiency (CSE, defined as the NEP/GPP ratio). At elevated N-dep levels (> 2.5 gNm(-2) yr(-1)), where inorganic N-r losses were also increasingly large, NEP levelled off and then decreased. The apparent increase in NEP at low to intermediate N-dep levels was partly the result of geographical cross-correlations between N-dep and climate, indicating that the actual mean dC/dN response at individual sites was significantly lower than would be suggested by a simple, straightforward regression of NEP vs. N-dep.Peer reviewe

Carbon/nitrogen interactions in European forests and semi-natural vegetation. Part I: Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling

ISSN:1810-6277ISSN:1810-628