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Dommages des inondations aux activités économiques: Guide méthodologique et fonctions nationales
No full textFirst Report of Cassava Bacterial Blight Caused by Xanthomonas phaseoli pv. manihotis in the Amazonian Forest of Ecuador
No full textInternational audienc
Timber tracking of Jacaranda copaia from the Amazon Forest using DNA fingerprinting
No full textWe investigated the utility of nuclear and cytoplasmic single nucleotide polymorphism (SNP) markers for timber tracking of the intensively logged and commercialized Amazonian tree Jacaranda copaia. Eight hundred thir-ty-two trees were sampled (cambium or leaves) from 38 sampling sites in Bolivia, Brazil, French Guiana, and Peru. A total of 128 SNP markers (113 nuclear, 11 chloroplastic, and 4 mitochondrial) were used for genotyping the samples. Bayesian cluster analyses were carried out to group individuals into homogeneous genetic groups for self-assignment tests of groups of indi-viduals or of individuals to their population of origin. Cluster analysis based on all SNP markers detected seven main genetic groups. Genetic differentia-tion was high among populations (0.484) and among genetic groups (0.415), and populations showed a strong isolation-by-distance pattern. Self-assignment test of groups of individual for all loci was able to determine the population origin of all samples (accuracy= 100%). Self-assignment tests of individuals was able to assigin the origin of 94.5–100% of individuals (accuracy: 91.7–100%). Our results show that the use of 128 SNP markers is suitable to correctly determine the origin of J. copaia timber and they should be considered a useful tool for customs and local and international police
Crop response to nitrogen-phosphorus colimitation: theory, experimental evidences, mechanisms, and models. A review
No full textInternational audienceCrops need adequate mineral nutrition to ensure optimal growth and yield. Nitrogen (N) and phosphorus (P) are two major elements that are essential for crop growth. However, situations of N-P colimitation are frequent in agroecosystems. Hence, our ability to optimize crop production under these conditions depends on our ability to analyze and predict the response of crops to colimitation. Traditionally, agronomists rely on the law of the minimum (LM) to manage colimitation situations. This law states that crop growth is constrained by the most limiting element. In contrast, the multiple limitation hypothesis (MLH) argues that crops can adapt by balancing their resource allocation with the best compromise to maximize their growth. These two hypotheses result in contrasting growth response patterns. The aim of the present review is to identify the crop response pattern to N-P colimitation through an assessment of experimental results against a conceptual framework and to report the main mechanism involved in this interaction. Finally, an inventory of existing crop models handling N-P colimitation is presented and possible ways of improvement are proposed. This review allowed us to (1) remind of the published theories used to classify colimitation types, (2) highlight the fact that a large range of crops mostly showed MLH-response patterns, (3) report that the variability in crop response patterns is linked to pedoclimatic variation, (4) identify multiple mechanisms that may be involved in plant adaptation to N-P colimitation, (5) suggest that the interplay between the different mechanisms results in complex responses that are difficult to understand experimentally, (6) report that few models handle N-P colimitation and that most of them rely on the law of the minimum, and (7) recommend possible ways to improve model formalization for a better simulation of crop responses under N-P colimitation
Taxonomy and evolutionary history of peradectids (Metatheria): New data from the early Eocene of France
No full textInternational audiencePeradectidae are Paleogene ‘opossum-like’ stem-metatherians, largely Laurasian, whose evolutionary history remains unclear. Based on new remains (mainly dental) discovered in several French localities, we carry out a comprehensive systematic revision of all early Eocene peradectids from Europe (~MP7 reference level to MP10-11 interval). We describe well-preserved specimens from Palette (Southern France, MP7-MP8+9 interval) documenting the earliest European peradectid, Peradectes crocheti sp. nov. This new species exhibits an interesting mosaic of characters, including plesiomorphic traits found in the North American type species, Peradectes elegans Matthew and Granger, 1921. Molars allocated to the strikingly ubiquitous Peradectes crocheti sp. nov. are found in eight additional localities from northwestern and southwestern Europe, all limited to the time interval MP7-MP8+9. Moreover, the study of unpublished material of the MP8+9 and ~MP8+9 peradectids allows us to recognize two younger coeval species (Peradectes louisi Crochet, 1979, and Peradectes russelli Crochet, 1979). Our taxonomic conclusions are supported a posteriori by the first quantitative assessment of the variation in height of metatherian stylar cusps. The holotype of Peradectes louisi is reinterpreted, and Peradectes ‘mutigniensis’ Crochet, 1979 appears to be a junior synonym of Peradectes russelli. In addition to size, the otherwise similar Peradectes louisi and Peradectes russelli can be distinguished based on subtle yet consistent differences, such as lower molar proportions. Phylogenetic analyses using a novel matrix of dental characters shed new light on the relationships among Eocene peradectids, confirming the paraphyly of Peradectes with respect to Armintodelphys and Mimoperadectes. Our results suggest a single dispersal from North America to Europe in the evolutionary history of peradectids, which likely occurred immediately after the Paleocene-Eocene Thermal Maximum, Peradectes crocheti sp. nov. being recovered as the earliest offshoot of the European clade. Scarce lower molars from the MP10 reference locality and ~MP10 localities analyzed within this constrained phylogenetic framework reveal a trend towards shrinking of the entoconid in the European lineage throughout the early Eocene
Holistic approaches to assess the sustainability of food systems in low- and middle-income countries: a scoping review
No full textInternational audienceFood systems and their sustainability have been extensively studied in high-income countries (HICs), yet less so in low- and middle-income countries (LMICs), despite their importance for global food security. In this study, we conducted a systematic scoping review to describe the extent, range, and nature of peer-reviewed literature assessing the sustainability performance of food systems in LMICs. The review revealed a recent and heterogeneous literature. From this diversity, 3 archetypes of epistemological approaches emerged, classified by their purpose: observational , modeling , and transformative . All 3 approaches apply existing or tailored methods to specifically study food systems, and their objectives are to observe, model, or transform different parts of the food systems towards sustainability. Gaps in the literature include inconsistent definitions of food systems and frameworks and understudied drivers of food systems sustainability. Therefore, the development of a comprehensive and systematic inventory of frameworks and their sustainability is crucial to determine the most suitable interdisciplinary methodologies for specific contexts and generate actionable knowledge for food systems transformation
Soi écologique, reliance et changement de cap
No full textInternational audienceClément Barniaudy débute l’atelier par une proposition expérientielle visant à explorer les 3 dimensions du « changement de cap » (J. Macy). L’atelier se poursuit par une intervention théorique autour du lien entre changement individuel, collectif et systémique. Durant ce premier temps est également évoqué le potentiel des apprentissages transformatifs permettant d'activer la reliance à Soi, aux autres (humains et autres qu’humains) et aux milieux terrestres que nous habitons. Dans un second temps, Manon Sala aborde la politisation du « Soi écologique » théorisé par Arne Naess. Son intervention tentera d'élucider la question : le Soi écologique peut-il aujourd'hui s'institutionnaliser dans des pratiques micro, méso et macro-politiques ? Seront abordées les échelles possibles de politisation d'un être-au-monde fondé sur la conscience de notre interdépendance avec le monde Vivant. Cette conscience écologique peut trouver racine dans une éthique de la responsabilité (H. Jonas) transcendée dans une Réalisation de Soi (A. Naess) au service d'une éthique de la Terre (A. Léopold)
Lipid oxidation in emulsions: New insights from the past two decades
No full textInternational audienceLipid oxidation constitutes the main source of degradation of lipid-rich foods, including food emulsions. The complexity of the reactions at play combined with the increased demand from consumers for less processed and more natural foods result in additional challenges in controlling this phenomenon. This review provides an overview of the insights acquired over the past two decades on the understanding of lipid oxidation in oil-inwater (O/W) emulsions. After introducing the general structure of O/W emulsions and the classical mechanisms of lipid oxidation, the contribution of less studied oxidation products and the spatiotemporal resolution of these reactions will be discussed. We then highlight the impact of emulsion formulation on the mechanisms, taking into consideration the new trends in terms of emulsifiers as well as their own sensitivity to oxidation. Finally, novel antioxidant strategies that have emerged to meet the recent consumer’s demand will be detailed. In an era defined by the pursuit of healthier, more natural, and sustainable food choices, a comprehensive understanding of lipid oxidation in emulsions is not only an academicquest, but also a crucial step towards meeting the evolving expectations of consumers and ensuring the quality and stability of lipid-rich food products