Régime sans gluten

Tuberculosis, despite its prevention, remains an endemic affection in Morocco. Although rare, pseudo surgical forms and especially peritonitis are mainly due to delayed diagnosis. We report the case of a 30-year-old woman, admitted for peritonitis. The diagnosis of tuberculous peritonitis was established during surgery with macroscopic observation of granulations, and confirmed after biopsy specimens by identification of a giant lymph node cell granuloma with caseous necrosis. Outcome was favorable after appropriate antibiotic therapy. This observation emphasizes the fact that peritonitis, although a rare complication of peritoneal tuberculosis, poses problems of positive and differential diagnosis. Even if treatment is based on antituberculous quadritherapy, surgery is sometimes necessary and should be decided in due time

Risques et adaptation nutritionnelle en cancérologie

This article starts with a presentation of Caycedian Sophrology. We then evaluate its impact on stress reduction through a questionnaire on a students’ population. It appears that stress level increases between the two sessions in the control group while it decreases in the experimental group

Les processus de rhizodéposition, un levier majeur pour la séquestration du carbone dans les sols

International audiencePlants represent the main source of organic carbon in soils. While inputs of carbon from the aerial parts are easy to measure, the difficulty in quantifying inputs from roots has prevented us to estimate the actual potential of soil carbon sequestration associated to each type of organic matters released by the roots. Besides the decay of root tissues, root systems have been shown to release organic carbon by various mechanisms, e.g. exudation of soluble compounds, mucilage secretion, and cells sloughing. Such rhizodeposition processes may consume 5% to 15% of the total amount of carbon photosynthetically fixed by the plant, and can generate an input of carbon to the soil ranging from 0.5 to 5 tC ha-1 yr-1. Because of this large range and the uncertainties associated to rhizodeposition mechanisms, current models of soil organic matter dynamics poorly assess the actual sequestration potential offered by plants. We performed a meta-analysis of the literature data generated over the last 60 years in order to assess which rhizodeposition processes quantitatively prevail, and what is the maximal amount of carbon inputs that can be expected from an entire growing root system, depending on plant species, growth stage, soil properties, and environmental conditions. According to our current dataset, the exudation of soluble sugars represents the major flow of organic carbon into the rhizosphere in most conditions, but other rhizodeposition processes such as mucilage secretion and cells sloughing can locally become as important in terms of carbon release. Following the presentation of these results, the consequences of these emissions on the actual soil carbon sequestration potential will be discussed based on our current understanding of carbon use efficiency and priming effect

Les processus de rhizodéposition, un levier majeur pour la séquestration du carbone dans les sols

International audiencePlants represent the main source of organic carbon in soils. While inputs of carbon from the aerial parts are easy to measure, the difficulty in quantifying inputs from roots has prevented us to estimate the actual potential of soil carbon sequestration associated to each type of organic matters released by the roots. Besides the decay of root tissues, root systems have been shown to release organic carbon by various mechanisms, e.g. exudation of soluble compounds, mucilage secretion, and cells sloughing. Such rhizodeposition processes may consume 5% to 15% of the total amount of carbon photosynthetically fixed by the plant, and can generate an input of carbon to the soil ranging from 0.5 to 5 tC ha-1 yr-1. Because of this large range and the uncertainties associated to rhizodeposition mechanisms, current models of soil organic matter dynamics poorly assess the actual sequestration potential offered by plants. We performed a meta-analysis of the literature data generated over the last 60 years in order to assess which rhizodeposition processes quantitatively prevail, and what is the maximal amount of carbon inputs that can be expected from an entire growing root system, depending on plant species, growth stage, soil properties, and environmental conditions. According to our current dataset, the exudation of soluble sugars represents the major flow of organic carbon into the rhizosphere in most conditions, but other rhizodeposition processes such as mucilage secretion and cells sloughing can locally become as important in terms of carbon release. Following the presentation of these results, the consequences of these emissions on the actual soil carbon sequestration potential will be discussed based on our current understanding of carbon use efficiency and priming effect

Modelling rhizodeposition with functional-structural plant models

Plants are the main source of organic carbon in soils. Besides litter incorporation, most of plant carbon fluxes to soil occur belowground, through the release of organic compounds by roots and the decay of root tissues. Despite the importance of these processes for soil carbon sequestration and for soil biological functions, our understanding of such fluxes has been hampered by the difficulties associated to their measurement in actual soil environments and their integration to plant growth models. Our aim is to develop new modelling approaches in order to accurately describe trophic fluxes from roots to soil and their spatial and temporal evolution. Functional-structural plant models (FSPM), which take into account both plant physiology and plant architecture, may be well adapted to such a modelling strategy, but also bring new challenges in terms of processes coupling. This work will present our current strategy to simulate and integrate root exudation, mucilage emissions, root cells desquamation and root senescence into a common model, and will highlight some of the main knowledge gaps associated to the simulation of these processes