62 research outputs found

    Bt maize: a tool for improving food safety of grains at harvest

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    A new EU (European Union) regulation came into force in 2007 with Regulation (EC) No. 1126/2007 which established maximum levels for fumonisins B1 and B2 (4000 ppb), deoxynivalenol (1750 ppb) and zearalenone (350 ppb) in maize and maize products. In order to evaluate French maize food safety, studies were carried out by the national Biological Risk Monitoring (BRM) Network. In this study, field trials involving 84 plots were conducted with Bt maize (MON 810) and its isogenic non-Bt counterpart in 2005 and 2006 in South-western France. Mycotoxin levels were determined in grain at harvest. Fumonisins B1 and B2, deoxynivalenol, and zearalenone were analyzed by LC-MS-MS and the results treated statistically using non parametric tests for mycotoxins and analysis of variance test for weather variables. As the climate was homogenous inside the experimental area, the transgenic event introduced into the maize was the only key parameter which differed between Bt and non-Bt maize plots. Our results showed that all mycotoxin families were not impacted in the same way. The efficacy of Bt maize reduced mycotoxins more than 90% for fumonisins and more than 50% for zearalenone although deoxynivalenol was lightly increased. Therefore a competition between the different Fusarium spp. which produced fumonisins or trichothecenes is hypothesized. According to Regulation (EC) No. 1126/2007, 93% of the maize of Bt maize plots were able to be commercialized compared to only 45% for non-Bt maize plots. The results of this work showed that Bt maize improved food safety and constituted an useful tool to reduce significantly mycotoxin levels in harvested and stored grains. Keywords: Bt (MON810) maize, Fumonisins B1 and B2, Deoxynivalenol (DON), Zearalenone, EC regulation 1126/2007 threshold

    Eruption type probability and eruption source parameters at Cotopaxi and Guagua Pichincha volcanoes (Ecuador) with uncertainty quantification

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    Future occurrence of explosive eruptive activity at Cotopaxi and Guagua Pichincha volcanoes, Ecuador, is assessed probabilistically, utilizing expert elicitation. Eight eruption types were considered for each volcano. Type event probabilities were evaluated for the next eruption at each volcano and for at least one of each type within the next 100 years. For each type, we elicited relevant eruption source parameters (duration, average plume height, and total tephra mass). We investigated the robustness of these elicited evaluations by deriving probability uncertainties using three expert scoring methods. For Cotopaxi, we considered both rhyolitic and andesitic magmas. Elicitation findings indicate that the most probable next eruption type is an andesitic hydrovolcanic/ash-emission (~ 26–44% median probability), which has also the highest median probability of recurring over the next 100 years. However, for the next eruption at Cotopaxi, the average joint probabilities for sub-Plinian or Plinian type eruption is of order 30–40%—a significant chance of a violent explosive event. It is inferred that any Cotopaxi rhyolitic eruption could involve a longer duration and greater erupted mass than an andesitic event, likely producing a prolonged emergency. For Guagua Pichincha, future eruption types are expected to be andesitic/dacitic, and a vulcanian event is judged most probable for the next eruption (median probability ~40–55%); this type is expected to be most frequent over the next 100 years, too. However, there is a substantial probability (possibly >40% in average) that the next eruption could be sub-Plinian or Plinian, with all that implies for hazard levels

    The French foot revisited

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    This article aims to re-evaluate the relevance of the foot in French. After a critical review of the literature on the subject, with reference to both adult and child language, we argue that the prosodic structure of French is best understood within a grid-only framework. The model is couched in Stratal Optimality Theory and illustrated with naturalistic data drawn from southern French and Swiss French. Particular attention is paid to phenomena such as the loi de position and optional penultimate pitch accent, for which we show that syntagmatic constituency is unnecessary

    Le rôle de l’immersion dans l’apprentissage du schwa chez les apprenants alémaniques avancés de FLE

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    Mastering ‘schwa’ is one of the major challenges that non-native speakers face when learning French as a foreign language. The present study, set within the framework of the IPFC project (“Interphonologie du Français Contemporain”), describes the schwa-coding system applied to the IPFC corpus data and is illustrated here with data from Alemannic-speaking Swiss learners of French (two tasks: text reading and guided conversation). Our results show that, even though studying abroad in a French-speaking area alone does not have a direct significant impact on schwa’s behavior, it does interact with two variables: the type of task (more schwa deletion after studying abroad observed in the conversation but not in the reading task) and the type of word (more schwa deletion after studying abroad observed in monosyllabic words but not in polysyllabic words, both in word-initial or word-medial syllabic positions). In this respect, studying abroad seems to help learners achieve native-like sociolinguistic proficiency. These first results pave the way for the development of in-class pedagogical material which could help learners achieve such a level of proficiency, whether or not they have the opportunity to study abroad in a French-speaking area

    Use of a smart electrically assisted bicycle (VELIS) in the health field -Proof of concept-

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    International audiencehysical activity (PA) is highly recommended in the management of most chronic diseases. For these patients, the smart electric bicycle can be effective to improve adherence to this behavior. The E-bike used in this study (called VELIS) has an innovative onboard technology that allows for subject monitoring and the engine power is designed to adapt to the user's abilities. A prerequisite for the use of the VELIS with patients is to initially carry out a pilot study on healthy subjects. The objective was to evaluate the impact of the customizable settings on physiological parameters and to ensure this prototype's efficiency and safety of use. Twelve healthy participants with various profiles (physical condition, used to cycling or not) were included. They have completed four times a 14 km itinerary with various settings of the VELIS. We recorded GPS data, heart rate and perceived exertion. Based on exercise intensity, we confirm that riding an E-bike should be considered as a physical activity. Safety of the participants is ensured by the engine brake. Recordings show that it took between 1 and 3 min for the novice to become familiar with the VELIS and to get optimal assistance. The main finding of this pilot study confirms that VELIS is an easy to use and secure tool to make PA approachable, whatever the level of training in healthy subjects

    Detection, identification and geographical distribution of European corn borer larval parasitoids using molecular markers

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    Correspondence:[email protected] audienceBiological control requires specific tools for the accurate detection and identification of natural enemies, and to detect unusual variations in their density, which may follow changes in agricultural practices. Here we have developed specific molecular markers to detect Lydella thompsoni (Herting) and Pseudoperichaeta nigrolineata (Walker) (Diptera: Tachinidae) within the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). Primers amplifying fragments of the mitochondrial COI gene were designed following alignment of comparable sequences for a range of parasitoid and host species. Each of the primer pairs proved to be species specific to a tachinid species, amplifying DNA fragments of 191 and 91 bp in length for L. thompsoni and P. nigrolineata, respectively. This DNA-based technique allowed molecular evaluation of parasitism in O. nubilalis natural populations. In order to study the geographical distribution of both species in France, O. nubilalis diapausing larvae in maize stalks were collected from 12 locations over the whole country. The molecular evaluation of parasitism was compared with the traditional method of maintaining O. nubilalis populations in controlled conditions before breaking off the diapause. The percentage parasitism found in both species of tachinids was higher — approximately three times — using the molecular method, suggesting an underestimation by the traditional rearing protocol. Tachinid parasitism on O. nubilalis was not significantly different between geographical areas (south, central and north France) for both species. This study shows that molecular methods are very promising for the correct detection and identification of tachinid parasitoids in natural field population
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