Collaborative remote laboratory in virtual wolrd

International audiencewe present in this paper a remote lab that is generic, i.e independent to the controlled device thanks to a semantic web approach. The graphical user interface and functionalities are described thanks to ontology. The proposed remote lab is also collaborative since it is prove that the collaboration takes an important place in the learning process. The collaboration is made in a virtual world called wonderland allowing sharing of information and audio channels between users' avatars

Une forte saisonnalité du climat et de la phénologie reproductive dans la forêt du Mayombe : l’apport des données historiques de la Réserve de Luki en République démocratique du Congo

In Africa, the reproductive phenology of tropical trees is mostly annual and regular. This study documents the intra- and inter-annual reproductive phenology of trees in the Mayombe forest, from historical data on the Luki Reserve in the Democratic Republic of the Congo. Reproductive diameter, which is a key parameter for forest management but is largely unknown for many timber species, was also documented for the most abundant species in the dataset. Phenological monitoring of 3,642 trees belonging to 158 species and 39 families was conducted in the Luki Reserve every 10 days from 1948 to 1957. Circular statistics were used to test the synchronicity of phenological events among trees, both at the community level, i.e. for the forest as a whole, and individually for 87 species, which included 35 well-represented species (n >= 20 trees), 16 commercial species and 36 other species. Logistic regressions were used to determine the diameter (minimum and regular) of these species on fruiting. Reproductive phenology for the majority of the trees and the species is largely seasonal, annual and regular (81.6%, 71 species). The peaks for flowering are more abrupt than the fruiting peaks and more spread out over time, although the timing of flowering and fruiting is significantly aggregated. Most of the trees and species bloom from December to February, during the short dry season, but flowers and fruits can be observed throughout the year within the community. Only 13 species showed a significant relationship between diameter and reproduction, including seven canopy species, five understory species and one light-demanding species. For these 13 species, the average minimum reproduction diameter was 17.3 cm

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Création d’indicateurs économiques à partir du descriptif technique contenu dans les enquêtes Pratiques Culturales (PK): note méthodologique

note méthodologique support de l'évaluation technico-économique de la mobilisation d'alternatives chimiques et non chimiques à des pesticides dont la règlementation pourrait évoluerWe have undertaken an analysis of the technical and economic implications of the mobilisation of alternative agricultural practices to the use of herbicides in order to inform public policies on the potential consequences of changes in regulation concerning them. In this context, we have built up and drafted this methodological note facing the observation that there is no possible direct link between the agricultural practices chosen by a farmer and the economic return attached to the entire process selected. We know, however, that the question of profitability is an important part of the decisions of many farmers and that there are several sources of uncertainty concerning the selling price as well as the funds needed to cover equipment failures or the forms that the return on investment may take with deferred effects.Our attempt was therefore to propose a methodological approach that was cumbersome to set up but then simple to implement, where information from different sources could be linked: content of surveys by the French Ministry of Agriculture on agricultural practices (Agreste), recording of network practices of DEPHY farms in Agrosyst Information System, and frames of reference for prices practiced in agriculture.We detail in this document how the calculations were carried out and provide illustrations of its use. The document contains a lot of figures and summary tables providing synthesised information. Finally, we come back to the interest of this approach to compare different options leading to contrasting choices for farmers, for instance converting to organic agriculture. A potential use of this work would be, to statistically approximate the value that should be attached to a financial assistance in order to better orient farmers' choices towards sustainable practices.Nous avons engagé des travaux pour nourrir une analyse des implications technico économiques de la mobilisation d’alternatives à des herbicides pour éclairer les politiques publiques sur les conséquences potentielles d’une évolution réglementaire les concernant. Dans ce cadre, nous avons construit et rédigé cette note méthodologique face au constat d’un déficit de lien direct possible entre un itinéraire de conduite tel que pratiqué par un agriculteur et un bilan économique adossé au déroulé qui a été retenu. On sait pourtant que la question de la rentabilité entre dans beaucoup de décisions des agriculteurs et que les sources d’incertitudes sont multiples. Elles concernent aussi bien le prix de vente que le degré de provision pour couvrir des pannes sur les équipements ou les formes que peuvent prendre le retour sur investissement avec des effets différés. Notre volonté était donc de mettre en place une procédure lourde à établir mais simple ensuite d’utilisation, où des informations issues de différentes sources soient rapprochées : contenu des enquêtes sur les pratiques culturales (enquêtes PK) d’Agreste, enregistrement des pratiques au sein des fermes du réseau DEPHY dans le système d’information Agrosyst, référentiels de prix pratiqués en agriculture.Nous détaillons dans ce document comment les calculs ont été faits et illustrons son utilisation. Le document laisse une large place aux figures et tableaux synthétiques. Nous revenons enfin sur l’apport de cette approche pour comparer différentes conduites menant à des choix souvent contrastés pour les agriculteurs comme passer d’une conduite conventionnelle à une conduite en AB. Une retombée de ce travail est aussi de permettre sur des effectifs importants d’approcher la valeur qu’il faudrait fixer à une aide financière pour orienter les choix des agriculteurs

Alternatives au prosulfocarbe et étude de leur mobilisation

Prosulfocarb is a residual herbicide primarily used on winter cereals and potatoes to control grassy weeds such as ryegrass or foxtail and some broadleaf weeds, in pre -emergence or early post-emergence applications. In 2020, it was the 2nd most used herbicide in France, just after glyphosate. This herbicide is regularly present in the atmosphere and contaminates various products intended for human or animal consumption. The regulatory rule changed in 2017, then in 2018, to avoid this contamination by fixing the need to use low-drift nozzle sprayers and to apply a buffer zone of 500m/1km between the field to be treated with prosulfocarb and the fields of sensitive crops such as orchards, market gardening, buckwheat or chia.The objective of this work was to identify alternatives to prosulfocarb and to assess the technical and economic impact of their use on farms. When prosulfocarb is not used, it may lead to switching to other chemical herbicides. Organic Farming (OF) systems use non-chemical alternatives to herbicides, such as mechanical weeding and preventative actions, to reduce weed pressure. In many cases, the application of alternatives to prosulfocarb, whether chemical or not, does not impair the direct marginal costs of benefits per unit area at the plot scale. Although, as for the non-chemical alternatives, the higher prices and lower costs of OF may partly compensate for the lower yields. Weed control systems combining chemical and non-chemical solutions are regularly used. In cereal crops, national statistics show that a two-week shift in the sowing date makes it possible to limit herbicide treatments but slightly reduce yields. In potato fields, farmers could reduce the application of the herbicide only on the row with mechanical interventions on the inter-row.These approaches can reduce agriculture's reliance on prosulfocarb, but we found that three scenarios including a fairly widespread shift in wheat sowing dates needed to be combined to reduce prosulfocarb by more than 30% consumption. It is a considerable effort. Thus, the mobilization of all the prophylactic levers and the involvement of all the actors concerned (plant breeding, agricultural machinery, etc.) are necessary to accelerate the transitions towards weed management systems less dependent on prosulfocarb.En 2021, le prosulfocarbe est le deuxième herbicide le plus utilisé en France après le glyphosate et les tonnages n’ont cessé d’augmenter. Avec un peu plus 6500 tonnes achetées, cet herbicide approche 15% de la totalité des substances actives vendues en France en 2021, hors produits de biocontrôle ou applicables en Agriculture Biologique. Il est utilisé pour lutter contre les adventices, tout particulièrement certaines graminées dont la gestion est problématique pour les céréales (à l’automne) et la culture de Pomme de terre (au printemps). L’attrait pour cette molécule s’est accru avec le retrait d’autres herbicides qui avaient un spectre d’activité assez similaire mais présentaient des impacts sur la qualité des eaux de surface et souterraines. La règlementation cadrant les utilisations du prosulfocarbe a été rendue plus stricte en 2017 puis en 2018, conduisant notamment à définir une large zone tampon autour des parcelles à traiter pour ne pas contaminer l’entourage. Cette mesure d’exception n’a toutefois pas permis de faire disparaitre les contaminations des productions de cultures ‘non cible’ à destination de l’alimentation humaine et animale. Le rapport conclut qu’il n’existe pas à ce jour de levier non chimique curatif apportant une alternative mobilisable pour se substituer au prosulfocarbe à moins de repenser plus en profondeur les systèmes de culture/de production. Les agriculteurs qui s’en passent bénéficient d’une situation relativement saine au départ qu’ils peuvent entretenir en mobilisant des actions préventives comme la diversification des rotations et les décalages de date de semis et du désherbage mécanique. Pour la Pomme de terre, il serait sans doute possible de restreindre les volumes de prosulfocarbe employés en limitant les applications aux seuls rangs de pomme de terre. Cela nécessite toutefois d’équiper en conséquence la ferme France, ce qui peut prendre un peu de temps. Les secteurs amont et aval de l’agriculture disposent de moyens de contribution pour contenir le recours au prosulfocarbe à travers une adaptation de l’offre variétale, de nouveaux équipements ou encore le maintien de filières de diversification

Weeds of tropical rainfed cropping systems: are there patterns at a global level of perception?

The objective of this study was to investigate the effect of general factors such as crop, regional climate or country on the weed flora and weed abundance in rainfed crops in tropical regions. For this purpose, we used 24 weed survey datasets from 4 climates, 11 crops and 11 countries in the tropics. These datasets are available in public access on the CIRAD Amatrop dataverse. This represents a set of 6 069 weed surveys, covering a total of 1 388 taxa. The data were analysed using different complementary approaches, including infestation diagrams, species correlation and co-occurrence matrices, corrected ecological profiles, and PCAIV. The results show that in the tropics there is a background of fairly common and ubiquitous species that are found in varying abundance in almost all situations. Ageratum conyzoides is the only Major general species, while Rottboellia cochinchinensis, Digitaria horizontalis, Bidens pilosa, Cyperus rotundus, Commelina benghalensis, Euphorbia heterophylla, Eleusine indica, Euphorbia hirta and Tridax procumbens are General species, present in more than 15% of the records. The climate factor, depending on rainfall and altitude, which influences temperature, selects certain indicator species for different situations. The crop factor does not have a particular selective effect and the country highlights local flora. Crops are themselves dependent on climate. It is nevertheless possible to know which species are most likely to be found in a plot of a crop, under a given climate and in a given country. However, it seems that it is the combination of the edaphic and climatic nature of the plot that most accurately determines the floristic composition of the weed flora, although we were unable to analyse this due to the lack of complete information on these factors for all the datasets used. Finally, out of the 1 388 taxa taken into account, only about 300 species constitute the core of the weeds of tropical rainfed crops, because of their frequency, their abundance or their character as indicators of particular agro-ecological conditions