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Augmenter la qualité et la quantité des milieux semi-naturels dans les agrosystèmes : des leviers d’action pour favoriser le contrôle biologique en grande culture
No full textClinical imaging of choroid plexus in health and in brain disorders: a mini-review
No full textThe choroid plexuses (ChPs) perform indispensable functions for the development, maintenance and functioning of the brain. Although they have gained considerable interest in the last years, their involvement in brain disorders is still largely unknown, notably because their deep location inside the brain hampers non-invasive investigations. Imaging tools have become instrumental to the diagnosis and pathophysiological study of neurological and neuropsychiatric diseases. This review summarizes the knowledge that has been gathered from the clinical imaging of ChPs in health and brain disorders not related to ChP pathologies. Results are discussed in the light of pre-clinical imaging studies. As seen in this review, to date, most clinical imaging studies of ChPs have used disease-free human subjects to demonstrate the value of different imaging biomarkers (ChP size, perfusion/permeability, glucose metabolism, inflammation), sometimes combined with the study of normal aging. Although very few studies have actually tested the value of ChP imaging biomarkers in patients with brain disorders, these pioneer studies identified ChP changes that are promising data for a better understanding and follow-up of diseases such as schizophrenia, epilepsy and Alzheimer's disease. Imaging of immune cell trafficking at the ChPs has remained limited to pre-clinical studies so far but has the potential to be translated in patients for example using MRI coupled with the injection of iron oxide nanoparticles. Future investigations should aim at confirming and extending these findings and at developing translational molecular imaging tools for bridging the gap between basic molecular and cellular neuroscience and clinical research
EXPE Guadeloupe : une gestion de l’enherbement sur l’inter-rang de canne à sucre par des plantes de services
No full textLe projet DEPHY EXPE Guadeloupe cherche à expérimenter des techniques de gestion de
l’enherbement adaptées aux exploitations guadeloupéennes en polyculture élevage dans le but de
réduire de plus de 50 % l’usage des herbicides dans les cultures, et notamment en canne à sucre qui
représente la plus importante culture en termes de surfaces sur le territoire. Pour atteindre cet objectif,
l’accent a été porté sur la mécanisation des leviers permettant de lutter contre les adventices. Le
développement d’un itinéraire technique mécanisé permettant un sarclage mécanique et la mise en
place d’un couvert végétal dans l’inter-rang d’une culture de canne à sucre plantée a permis de
conduire une parcelle sans herbicides. L’implantation de la plante de service Crotalaria juncea a permis
de limiter très fortement le développement des adventices, d’augmenter la biodiversité dans la parcelle,
et ceci sans concurrencer la culture de canne. Toutefois des solutions mécaniques restent à développer
pour lutter contre l’enherbement sur le rang de canne
Estimating total and browsed leaf area of fodder trees using a photographic gap fraction method
No full textInhibition of aminotransferases by aminoethoxyvinylglycine triggers a nitrogen limitation condition and deregulation of histidine homeostasis that impact root and shoot development and nitrate uptake
No full textBackground and Aims: Although AVG (aminoethoxyvinylglycine) is intensely used to decipher signaling in ethylene/indol-3-acetic acid (IAA) interactions on root morphogenesis, AVG is not a specific inhibitor of aminocyclopropane-1-carboxylate synthase (ACS) and tryptophan aminotransferase (TAA) and tryptophan aminotransferase related (TAR) activities since it is able to inhibit several aminotransferases involved in N metabolism. Indeed, 1 mM glutamate (Glu) supply to the roots in plants treated with 10 mu M AVG partially restores the root growth. Here, we highlight the changes induced by AVG and AVG + Glu treatments on the N metabolism impairment and root morphogenetic program. Methods: Root nitrate uptake induced by AVG and AVG + Glu treatments was measured by a differential labeling with (NO3)-N-15 (-) and (15)Nglutamate. In parallel a profiling of amino acids (AA) was performed to decipher the impairment of AA metabolism. Key Results: 10 mu M AVG treatment increases (KNO3)-N-15 uptake and N-15 translocation during root growth inhibition whereas 10 mu M AVG + 1 mM (15)Nglutamate treatment inhibits (KNO3)-N-15 uptake and increases (15)Nglutamate uptake during partial root growth restoration. This is explained by a nitrogen (N) limitation condition induced by AVG treatment and a N excess condition induced by AVG + Glu treatment. AA levels were mainly impaired by AVG treatment in roots, where levels of Ser, Thr, alpha-Ala, beta-Ala, Val, Asn and His were significantly increased. His was the only amino acid for which no restoration was observed in roots and shoots after glutamate treatment suggesting important control of His homeostasis on aminotransferase network. Results were discussed in light of recent findings on the interconnection between His homeostasis and the general amino acid control system (GAAC) in eukaryotes. Conclusions: These results demonstrate that AVG concentration above 5 mu M is a powerful pharmacological tool for unraveling the involvement of GAAC system or new N sensory system in morphological and metabolic changes of the roots in leguminous and non-leguminous plants
Antimicrobial characteristics of untreated wood: towards a hygienic environment
No full textWood, as a contact surface, has been used for centuries but is usually questioned because of its porosity and organic composition. It has natural antimicrobial properties and, hygienically, can stand the comparison with other materials such as plastic, glass and steel. In this review, we focused on potential microbe-inhibiting properties of wooden surfaces being used in hygienically important places like health institutes and food industries. This article addresses the questionable properties of untreated wood like hygroscopicity, porosity, roughness and chemical composition, and their relation to the hygienic and antimicrobial nature of this material. The other factors linked to the hygienic properties of wood, such as age, species and type of wood, have also been discussed. Our analysis of literature will create better understanding for acceptance of wood as a safety renewable resource. It also provides an outline for future research considering wood material in critical healthcare or food industries
Integrating multipurpose trees in a paddock grazed by cattle: first results of the co-designed layouts
No full textDEPHY Serre - Productions sous serres tomates et concombres : tendre vers le zéro intrant phytosanitaire
No full textThe AOPN tomatoes and cucumbers carries the DEPHY Serre project with the objective of zero pesticides
for these two major vegetables in a soilless system while maintaining economic and environmental
performances. The realization of a survey at the start of the project, performed in each production area,
identified the mains pests encountered for these crops. Analytic experimentations occurred in two
experimental stations, aiming to identify bioproducts of interest as an alternative to chemical pesticides. In
parallel, the implementation of monitoring systems was set up among 5 pilot sites (3 for tomatoes and 2 for
cucumbers). This stage aimed to validate the results obtained in the experimental stations and to perform a
systemic approach by integrating several levers with a global strategy of crop protection.
The conducted trials in the stations identified several biocontrol products against tomatoes botrytis (fungi,
bacteria or antagonist yeast), and powdery mildew for both crops (drying products which have a direct
action against the pathogen or products stimulating the plant defense system). On the pilot sites, the trials
enabled to tune the global protection strategies set up in tomato crops with a focus against whiteflies by
combining several technics: releasing periods of Macrolophus regarding the crop calendar, interest of
feeding at the start of the season, interest of reduced deleafing in release areas, use of biocontrol products,
yellow sticky traps for mass trapping, aspiration around the plant's head, etc.The AOPN tomatoes and cucumbers carries the DEPHY Serre project with the objective of zero pesticides
for these two major vegetables in a soilless system while maintaining economic and environmental
performances. The realization of a survey at the start of the project, performed in each production area,
identified the mains pests encountered for these crops. Analytic experimentations occurred in two
experimental stations, aiming to identify bioproducts of interest as an alternative to chemical pesticides. In
parallel, the implementation of monitoring systems was set up among 5 pilot sites (3 for tomatoes and 2 for
cucumbers). This stage aimed to validate the results obtained in the experimental stations and to perform a
systemic approach by integrating several levers with a global strategy of crop protection.
The conducted trials in the stations identified several biocontrol products against tomatoes botrytis (fungi,
bacteria or antagonist yeast), and powdery mildew for both crops (drying products which have a direct [br/]
action against the pathogen or products stimulating the plant defense system). On the pilot sites, the trials
enabled to tune the global protection strategies set up in tomato crops with a focus against whiteflies by
combining several technics: releasing periods of Macrolophus regarding the crop calendar, interest of
feeding at the start of the season, interest of reduced deleafing in release areas, use of biocontrol products,
yellow sticky traps for mass trapping, aspiration around the plant's head, etc
RESCAM - Utilisation de dispositifs agroécologiques en parcelles maraichères.
No full textL’utilisation de Dispositifs Agro Écologiques (DAE), composés d’une bande fleurie et d’une plante piège,
a été évaluée au sein d’un projet Ecophyto DEPHY EXPE, afin d’identifier la biodiversité fonctionnelle
pouvant se développer sur la parcelle agricole. Le réseau des parcelles était composé de systèmes de
cultures en rotation avec de la tomate de plein-champ. Ces infrastructures écologiques adjacentes à la
parcelle cultivée se sont avérées être des habitats favorables à une grande diversité d’arthropodes. Des
auxiliaires de culture s’y installent, mais également des ravageurs qui peuvent être ainsi régulés hors de
la zone de production. Nous avons pu montrer l’intérêt de répéter les dispositifs dans l’espace afin de
favoriser la biodiversité au sein de la parcelle. Cependant l’utilisation de ces méthodes agroécologiques
suppose des changements dans les pratiques phytosanitaires et la réduction de l’utilisation de produits
chimiques de synthèse.The use of agro-ecological devices (DAE), such as flowering band and push-pull plant, was evaluated
within an ECOPHYTO DEPHY EXPE project, to identify the functional biodiversity that may develop on
the agricultural plot. This type of ecological infrastructure adjacent to the crop system provides habitat
for a wide variety of arthropods including beneficial insects but also pests that can be regulated outside
the production area. We were able to show the importance of repeating devices in space in order to
promote biodiversity. However, the use of these agroecological methods implies changes in plant health
practices and the reduction of the use of phytosanitary product