Innovative Approaches to Analysing Carbon Sequestration as a Mitigation Strategy in Tropical Pasture Landscapes in Two Emblematic Contexts, the Amazon and the West African Sahel

The relationship between ruminant production systems and climate change is complex. As a major contributor to greenhouse gas (GHG) emissions, the sector has been the subject of considerable controversy, with particularly severe criticism in the 2000s. However, ten years ago, the attitude towards grazing lands began to change. Their efficient use of non-renewable energy and their contribution to carbon (C) sequestration were considered as key factors in the new environmental challenge. The reality of this mitigation potential was recently called into question once again in the global agriculture and climate change debate, including that of sequestration in the soil where grazing lands occupy a major position (30-40% of the land surface representing 30% of the soil organic C of the world). Few scientific references are available on these questions in tropical regions, and the standard metrics and methods used may turn out to be unsuitable for the correct evaluation of grazed ecosystems in these regions. Significant work is therefore required to establish baselines and design strategies to ensure sustainable grazing in these regions where the global sequestration potential is high relative to the surface areas concerned. To contribute to this debate, we focus on mitigation options offered by rangelands and grasslands and their management in two emblematic tropical contexts, humid and dry tropics, where field studies have been based on original and holistic approaches at different levels. In Amazonia, if curbing deforestation remains a priority, it needs to be accompanied by sustainable management of deforested areas. In the French Amazon (French Guiana), monitoring fields using chronosequences and flux towers has produced scientific knowledge on the significant mitigation capacities of grassland ecosystems. In the Brazilian Amazon, the spatial logic of the agro-ecological intensification of forage production has enabled a transition from individual extractive systems to farm management at communal levels. In the West African Sahelian region (Northern Senegal), an integrative study at landscape scale revealed the unexpected capacity of soil and shrubs for C sequestration that can offset the GHG emissions for which pastoralism in dry tropical zones is usually blamed

Tomodensitometrie (TDM) dans la prise en charge médicale des enfants au Togo : profils et conditions techniques de realisation.

Objectif : Décrire le profil et les conditions techniques de réalisation des TDM dansla prise en charge médicale des enfants togolais.Méthodologie : Etude prospective sur une période de 12 mois, portant sur 312 TDMpédiatriques, colligés dans les structures sanitaires publiques et privées du Togodisposant d’un scanner.Résultats : Avec une fréquence relativement faible (10.97%), les TDM pédiatriquesétaient plus demandées chez les garçons (sex-ratio de 1,94). Demandés en premièreintention dans 74,4% des cas, elles concernaient les moins de 5 ans dans 41,02% descas. Les TDM cérébrales étaient largement les plus demandées (92,3%). Lesproblèmes financiers dans 66,4% faisaient que 74,4% de ces examens étaientréalisés tardivement. Ces enfants étaient dans 57% hospitalisés et 12% comateux.Les prescriptions étaient incohérentes dans 3,5% des cas. Les acquisitions étaientdans 63% réalisés sans et avec injection de PCI. Seuls 8% des enfants étaientallergiques à l’iode et 39,1% avaient bénéficiés d’une prémédication. 53,2% desTDM étaient pathologiques. Les lésions infectieuses (17,9%), traumatiques (17,3%)et malformatives (12,2%) étaient les plus diagnostiquées.Conclusion : Des efforts restent encore à faire par les prescripteurs et lesréalisateurs, pour non seulement optimiser l’apport diagnostique de la TDM chez lesenfants au Togo, mais aussi pour minimiser l’irradiation médicale qui en découle.Mots clés : Tomodensitométrie, enfants, irradiation médicale, TogoABSTRACTObjective: Estimate the place of the CT in the medical care of the Togolese children.Methods: Forward-looking study over a period of 12 months, concerning 312pediatric CT, brought together in the public sanitary structures and deprived of Togohaving a CT.Results: with a relatively low frequency (10.97%), the pediatric CT was more askedfor the boys (sex-ratio of 1.94). Asked in first intention in 74.4% of the cases, theyconcerned least 5 years in 41.02% of the cases. The cerebral CT was widely themost asked (92.3%). Money problems in 66.4% made that 74.4% of theseexaminations were late realized. These children were hospitalized 57% and 12%were in coma. The prescriptions were inconsistent in 3.5% of the cases. Acquisitionswere in 63% realized without and with injection of PCI. Only 8% of the childrenwere allergic to the iodine and 39.1% had benefited from a premedication. 53.2% ofthe CT were pathological. The infectious hurts (17.9%), traumatic (17.3%) andmalformations (12.2%) were the most diagnosed.Conclusion: efforts still remain to make by the influencers and the directors, tooptimize not only the diagnostic contribution of the TDM at the children in Togo,but also to minimize the medical irradiation which ensues from it.Keywords: Computed tomography, Children, medical radiation, Togo

Tomodensitometrie (TDM) dans la prise en charge médicale des enfants au Togo : profils et conditions techniques de realisation.

Objectif : Décrire le profil et les conditions techniques de réalisation des TDM dansla prise en charge médicale des enfants togolais.Méthodologie : Etude prospective sur une période de 12 mois, portant sur 312 TDMpédiatriques, colligés dans les structures sanitaires publiques et privées du Togodisposant d’un scanner.Résultats : Avec une fréquence relativement faible (10.97%), les TDM pédiatriquesétaient plus demandées chez les garçons (sex-ratio de 1,94). Demandés en premièreintention dans 74,4% des cas, elles concernaient les moins de 5 ans dans 41,02% descas. Les TDM cérébrales étaient largement les plus demandées (92,3%). Lesproblèmes financiers dans 66,4% faisaient que 74,4% de ces examens étaientréalisés tardivement. Ces enfants étaient dans 57% hospitalisés et 12% comateux.Les prescriptions étaient incohérentes dans 3,5% des cas. Les acquisitions étaientdans 63% réalisés sans et avec injection de PCI. Seuls 8% des enfants étaientallergiques à l’iode et 39,1% avaient bénéficiés d’une prémédication. 53,2% desTDM étaient pathologiques. Les lésions infectieuses (17,9%), traumatiques (17,3%)et malformatives (12,2%) étaient les plus diagnostiquées.Conclusion : Des efforts restent encore à faire par les prescripteurs et lesréalisateurs, pour non seulement optimiser l’apport diagnostique de la TDM chez lesenfants au Togo, mais aussi pour minimiser l’irradiation médicale qui en découle.Mots clés : Tomodensitométrie, enfants, irradiation médicale, TogoABSTRACTObjective: Estimate the place of the CT in the medical care of the Togolese children.Methods: Forward-looking study over a period of 12 months, concerning 312pediatric CT, brought together in the public sanitary structures and deprived of Togohaving a CT.Results: with a relatively low frequency (10.97%), the pediatric CT was more askedfor the boys (sex-ratio of 1.94). Asked in first intention in 74.4% of the cases, theyconcerned least 5 years in 41.02% of the cases. The cerebral CT was widely themost asked (92.3%). Money problems in 66.4% made that 74.4% of theseexaminations were late realized. These children were hospitalized 57% and 12%were in coma. The prescriptions were inconsistent in 3.5% of the cases. Acquisitionswere in 63% realized without and with injection of PCI. Only 8% of the childrenwere allergic to the iodine and 39.1% had benefited from a premedication. 53.2% ofthe CT were pathological. The infectious hurts (17.9%), traumatic (17.3%) andmalformations (12.2%) were the most diagnosed.Conclusion: efforts still remain to make by the influencers and the directors, tooptimize not only the diagnostic contribution of the TDM at the children in Togo,but also to minimize the medical irradiation which ensues from it.Keywords: Computed tomography, Children, medical radiation, Togo

How to better account for livestock diversity and fodder seasonality in assessing the fodder intake of livestock grazing semi-arid sub-Saharan Africa rangelands

International audienceThe feeding behavior and fodder intake of cattle, sheep and goats grazing semi-arid sub-Saharan Africa rangelands in Senegal was studied over a one-year cycle. The objective of the study was to improve the assessment of fodder intake by livestock grazing rangelands in semi-arid sub-Saharan Africa, The study was conducted in the service area of a borehole that includes 354 pastoral settlements and a total of 11,000 cattle and 1800 small ruminants. The grazing behavior of five steers was monitored monthly. Their forage intake was estimated every month from hand plucking simulations of all the bites of forage taken by the steers 24 h out of 48. The feces they excreted during the day were collected in fecal bags. Near infrared spectrum (NIRS) images were used to analyze 80 samples of these feces, and the data were then added to an existing reference data set to predict fodder intake and digestibility using NIBS. The complete and contextualized data base was then used to predict the daily fodder intake and its digestibility by cattle, sheep and goats whose fresh feces were systematically and randomly sampled every month in the study area (768 samples). Annual means of the daily dry matter fodder intake were 68.4 +/- 6.4 g/kg LW0.75 or 17.2 +/- 1.7 g/kg LW for cattle, 73.1 +/- 5.3 g/kg LW07.5 or 34.3 +/- 2.8 g/kg LW for sheep, and 74.7 +/- 8.7 g/kg LW0.75 or 37.1 +/- 4.4 g/kg LW for goats. The annual mean organic matter digestibility of grazed fodder was higher for goats (67.4 +/- 3.9%) than for sheep (64.1 +/- 3.2%) and cattle (59.3 +/- 3.8%). The seasonal variations in diet digestibility were bigger for cattle than for sheep, and smaller for goats. The standard reference used to assess livestock fodder intake in tropical Africa relies on a fixed daily intake rate per unit live weight of 25 g/kg LW. Our results show that this method overestimates (+ 45%) intake by cattle, especially in the dry season, and underestimates intake by small ruminants (-24%). Alternative assessment methods are proposed either relying on a single standard annual intake per metabolic weight unit for all ruminant species, 73 g/kg LW0.75 per day, or on separate annual intake norms per live weight unit for cattle (18 g/kg LW per day) and small ruminants (34 g/kg LW per day). In both cases, modulations (+/- 12%) of the norm are proposed for use in the wet and dry season