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Summary In the Atlantis Field (Gulf of Mexico), 4D seismic has been used successfully in reservoir monitoring. We are now using the time lapse data for more than qualitative interpretation. Monitor seismic data was acquired in 2015 and 2019 (base seismic in 2005) and have been used quantitively to update the reservoir model by a joint inversion of the 4D seismic and the production data. This process is called 4D assisted history matching. The result is not just one reservoir model but 1000s of models that capture the parameter space and show the uncertainties that are present in the reservoir model. We developed various modern tools with the help of Python scripting and an internal version of JupyterLab to quickly analyse these ensembles and understand the uncertainties in the reservoir model. By adding the 4D seismic element we capture the spatial distribution of the aquifer and injected water movement which results in a better history matched reservoir model. Those models are used for an improved prediction of future production, reduced uncertainty and ultimately better-informed decisions on reservoir management and placement of infill wells.

A quantitative cytochemical study of intact root apices and wounded roots of Pisum sativum, and of cotyledons from Solanum aviculare induced to form vessels from mesophyll cells, has demonstrated a sharp increase in glucose-6-phosphate dehydrogenase activity at a very early stage in the differentiation of the vascular tissues. However, UDP-D-glucose dehydrogenase activity appears to increase only at a time corresponding to the initiation of secondary cell wall events. Data from the callus cultures from Malus M27 and Cox endosperm indicated that glucose-6-phosphate dehydrogenase activity changes may be a possible marker for determining between the regenerability and recalcitrance of calluses. © 1997 John Wiley & Sons, Ltd.

Agroecology involves various approaches to solve actual challenges of agricultural production. Though agroecology initially dealt primarily with crop production and protection aspects, in recent decades new dimensions such as environmental, social, economic, ethical and development issues are becoming relevant. Today, the term ‘agroecology’ means either a scientific discipline, agricultural practice, or political or social movement. Here we study the different meanings of agroecology. For that we analyse the historical development of agroecology. We present examples from USA, Brazil, Germany, and France. We study and discuss the evolution of different meanings agroecology. The use of the term agroecology can be traced back to the 1930s. Until the 1960s agroecology referred only as a purely scientific discipline. Then, different branches of agroecology developed. Following environmental movements in the 1960s that went against industrial agriculture, agroecology evolved and fostered agroecological movements in the 1990s. Agroecology as an agricultural practice emerged in the 1980s, and was often intertwined with movements. Further, the scales and dimensions of agroecological investigations changed over the past 80 years from the plot and field scales to the farm and agroecosystem scales. Actually three approaches persist: (1) investigations at plot and field scales, (2) investigations at the agroecosystem and farm scales, and (3) investigations covering the whole food system. These different approaches of agroecological science can be explained by the history of nations. In France, agroecology was mainly understood as a farming practice and to certain extent as a movement, whereas the corresponding scientific discipline was agronomy. In Germany, agroecology has a long tradition as a scientific discipline. In the USA and in Brazil all three interpretations of agroecology occur, albeit with a predominance of agroecology as a science in the USA and a stronger emphasis on movement and agricultural practice in Brazil. These varied meanings of the term agroecology cause confusion among scientists and the public, and we recommend that those who publish using this term be explicit in their interpretation.

Agroecology involves various approaches to solve actual challenges of agricultural production. Though agroecology initially dealt primarily with crop production and protection aspects, in recent decades new dimensions such as environmental, social, economic, ethical and development issues are becoming relevant. Today, the term 'agroecology' means either a scientific discipline, agricultural practice, or political or social movement. Here we study the different meanings of agroecology. For that we analyse the historical development of agroecology. We present examples from USA, Brazil, Germany, and France. We study and discuss the evolution of different meanings agroecology. The use of the term agroecology can be traced back to the 1930s. Until the 1960s agroecology referred only as a purely scientific discipline. Then, different branches of agroecology developed. Following environmental movements in the 1960s that went against industrial agriculture, agroecology evolved and fostered agroecological movements in the 1990s. Agroecology as an agricultural practice emerged in the 1980s, and was often intertwined with movements. Further, the scales and dimensions of agroecological investigations changed over the past 80 years from the plot and field scales to the farm and agroecosystem scales. Actually three approaches persist: (1) investigations at plot and field scales, (2) investigations at the agroecosystem and farm scales, and (3) investigations covering the whole food system. These different approaches of agroecological science can be explained by the history of nations. In France, agroecology was mainly understood as a farming practice and to certain extent as a movement, whereas the corresponding scientific discipline was agronomy. In Germany, agroecology has a long tradition as a scientific discipline. In the USA and in Brazil all three interpretations of agroecology occur, albeit with a predominance of agroecology as a science in the USA and a stronger emphasis on movement and agricultural practice in Brazil. These varied meanings of the term agroecology cause confusion among scientists and the public, and we recommend that those who publish using this term be explicit in their interpretation. agroecosystem / Brazil / food system / France / Germany / rural development / scientific discipline / sustainable agriculture / USA

The antineoplastic effects of 5-aza-2′-deoxycytidine (5-AZA-CdR) and retinoic acid on human HL-60 myeloid leukemic cells were investigated. 5-AZA-CdR or retinoic acid reduced the clonogenicity and induced the differentiation of HL-60 leukemic cells. The effects produced by 5-AZA-CdR and retinoic acid in combination on clonogenicity and differentiation of HL-60 leukemic cells were additive. These agents in combination also produced an additive decrease in the mRNA expression of the c-myc. These data indicate that 5-AZA-CdR and retinoic acid in combination produce an additive antineoplastic effect against HL-60 human myeloid leukemic cells.

CE145-66 is an improved early-maturing grain sorghum genotype, increasingly grown by farmers in the Sahelian part of Senegal. This genotype is known to have negative effects on the following groundnut crop, because of the release of allelopathic phenolic compounds into the soil. We have assessed the synthesis of phenolics in sorghum vegetative parts and the variations in synthesis between years and sites. Total phenols and phenolic acids in the aerial parts and roots of flowering sorghum plants from 52 farmers' fields at two sites (Sagnanème and Médina) in Senegal in 1996 and 1997 were measured. Thirty-eight soil samples, collected after the sorghum harvest, from sorghum rows and interrows also were analyzed for their phenolic content. Total phenols reached 1.1-1.5% of root dry weight and 1.1-2.2% of aerial parts dry weight, with little variation between sites, and large variability between years, presumably due to climatic conditions. Eight phenolic acids and three associated aldehydes were identified by HPLC, with p-hydroxybenzoic, p-coumaric, and ferulic acids the most abundant. Their totals reached 2.9-3.2 mg/g in 1996 and 2.6-2.8 mg/g in 1997 for the aerial part; and 3.3-3.6 mg/g in 1996 and 2.8-3.3 mg/g in 1997 for roots. In soils under sorghum rows, the mean water-soluble total phenols increased from 4.6 in 1997 to 6.7 micrograms/g in 1998 in Sagnanème, and from 3.8 in 1997 to 5 micrograms/g in 1998 in Médina. The concentrations of total phenols and phenolic acids were higher in rows than in interrows. All the phenolic monomers identified in vegetative parts were recovered in associated soil samples, with vanillic and p-hydroxybenzoic acids the most abundant. Finally, variability in plant phenolic content seemed more due to climatic than to cropping or soil factors, as differences between years appear more important than differences between or within sites.

Purpose: The object of this study was to investigate the antineoplastic action of 5-aza-2′-deoxycytidine (5-AZA) in combination with vitamin D analogs on HL-60 and NB-4 myeloid leukemic cells. The vitamin D analogs chosen for this investigation were 1,25-(OH)2-23-yne-cholecalciferol (23-D) and 1,25-(OH)2-Δ16-23-yne-cholecalciferol (16-23-D) since they have the potential to be used clinically owing to their minimal action on calcium metabolism. Methods: HL-60 and NB-4 leukemic cells were incubated with different concentrations of 5-AZA and either 23-D or 16-23-D and their antineoplastic action determined by inhibition of DNA synthesis and growth, induction of differentiation and colony assay. Results: 5-AZA in combination with either vitamin D analog produced a greater growth inhibition and induction of differentiation than either agent alone. For HL-60 leukemic cells the combination of 5-AZA with either analog produced a synergistic loss of clonogenicity. These effects on clonogenicity correlated with the effects of the combination on inhibition of growth and DNA synthesis. Conclusion: These results suggest that vitamin D analogs may enhance the antileukemic action of 5-AZA and that it may be interesting to test these agents in combination in patients with myeloid leukemia.

Even though retinoic acid can induce complete remissions in patients with acute promyelocytic leukemia, the duration of response is short and further therapy with this agent is less effective, suggesting the development of drug resistance. One possible way to overcome this problem is to use retinoic acid in combination with another agent that can induce differentiation, such as vitamin D 3 or its analogs. In order to understand the mechanism of drug resistance to retinoic acid, we have isolated a clone of human HL-60 myeloid leukemic cells that is resistant to all- trans retinoic acid by continuous exposure to this agent. We have observed that the resistant cell line was also resistant to 9- cis -retinoic acid and more sensitive to the antileukemic action of the vitamin D 3 analog, 1,25-dihydroxy-16-ene-23-yne-26,27-F6-cholecalciferol. In addition, this combination showed synergistic antileukemic action against the wild type HL-60 leukemic cells. DNA sequence analysis revealed a mutation in the ligand binding region of retinoic acid receptor alpha in the HL-60/RA cells in which a glycine was replaced by an aspartic acid. Using gel retardation assays, we observed a large reduction in the formation of RXR-RAR heterodimers in the HL-60/RA cell line as compared to the parental cell line. This mutation in the retinoic acid receptor alpha of the HL-60/RA cells may be responsible for drug resistance to ATRA and 9- cis -retinoic acid and increased sensitivity to vitamin D 3 analogs.

International audience; The study measures intensity of attacks by Sitona lineatus L. on pea crops in farmers’ fields and the resulting damage. Insect attacks were measured on the aerial parts of the plant at the vegetative stages and on roots at the start of flowering of the crop. Attack intensity varied between and within plots. Early sown crops were at greater risk of severe damage. There was a good correlation between leaf damage at the beginning of the crop cycle and damage to nodules at the start of flowering in unsprayed crops. Aerial spraying did not completely prevent nodule damage in crops severely injured by insects at the early vegetative stage. The effects of the attacks on nitrogen nutrition of the pea cropwere also assessed; these results are discussed with regard to the consequences for crop management.

All-trans retinoic acid (ATRA) has been demonstrated to induce the in vitro differentiation of human myeloid leukemic cells by several investigators. In addition, ATRA has been reported to induce complete remission in patients with acute promyelocytic leukemia. However, the majority of the patients relapse after several months of ATRA therapy. Since one possible cause of relapse in these patients is drug resistance, it is of interest to investigate the antileukemic activity of other agents that can be used in combination with ATRA in order to overcome this problem. Vitamin D3 analogs such as 1,25-dihydroxy-delta 16-23-yne-cholecalciferol (16-23-D3) are also capable of inducing differentiation of myeloid leukemic cells. In this study we have isolated a clone of HL-60 leukemic cells that is resistant to ATRA. We have observed that the resistant cell line (HL-60/RA) was more sensitive to the antileukemic action of 16-23-D3 than the parental cell line with respect to the inhibition of cell growth and DNA synthesis, the induction of differentiation and the loss of cell clonogenicity.

Retinoic acid (RA) is an interesting agent which has been shown to induce differentiation and complete remission in patients with acute promyelocytic leukemia. 1,25-(OH) 2 -Δ 16 -23-ynecholecalciferol (16-23-D 3 ) and 1,25-(OH) 2 -23-yne-cholecalciferol (23-D 3 ) are vitamin D 3 analogs capable of inducing differentiation of myeloid leukemic cells with little effect on either calcium absorption or mobilization. Using HL-60 myeloid leukemic cells as an in vitro model for human acute myeloid leukemia we observed an additive to synergistic interaction between RA and 16–23-D 3 or 23-D 3 with respect to the inhibition of cell growth and DNA synthesis, the induction of differentiation and the loss of cell clonogenicity. In addition, we observed that RA and 16-23-D 3 interact additively with respect to the reduction of c-myc mRNA expression. These results suggest that RA used in combination with 16-23-D 3 or 23-D 3 may be an interesting chemotherapeutic regimen to evaluate in patients with acute myeloid leukemia.

5-aza-2'-deoxycytidine (5-Aza-CdR) is an experimental anti-leukemic agent that can induce the differentiation of myeloid leukemic cells and is currently under investigation in clinical trials in patients with leukemia. The objective of this study was to investigate the in vitro interaction of 5-Aza-CdR with different agents which may increase its clinical efficacy. Since 5-Aza-CdR has been used in combination with amsacrine in patients with relapsed leukemia, we have investigated the in vitro antileukemic activity of these agents in combination on human HL-60 myeloid leukemic cells. For a 24-hour drug exposure, we observed that the interaction of 5-Aza-CdR with amsacrine was subadditive to was synergistic with respect to the loss of clonogenicity of the HL-60 leukemic cells as demonstrated by a colony assay. We have also investigated the interaction of 5-Aza-CdR with 1,25-dihydroxyvitamin D3, an agent that can induce in vitro differentiation of myeloid leukemic cells. The combination of 5-Aza-CdR with 1,25-dihydroxyvitamin D3 produced a synergistic reduction in the clonogenicity of the HL-60 leukemic cells. These results indicate that 5-Aza-CdR can interact synergistically with both cytotoxic agents and agents that induce differentiation, and can provide some rationale for clinical investigations on these combinations in patients with acute leukemia. We have also explored other approaches to increase the clinical effectiveness of 5-Aza-CdR by investigating the in vitro effect of different inhibitors of human cytidine deaminase, the enzyme responsible for the rapid in vivo inactivation of this analogue.

The antineoplastic effects of 5-aza-2'-deoxycytidine (5-AZA-CdR) and interferon-alpha (IFN-alpha) on human HL-60 myeloid leukemic cells were investigated. 5-AZA-CdR and IFN-alpha in combination produced a greater inhibition of DNA synthesis and cell growth than either agent alone. The co-treatment produced a synergistic reduction in the clonogenicity of the HL-60 leukemic cells. In addition, this combination also produced a greater reduction in mRNA expression for c-myc than each agent alone. This antileukemic action produced by 5-AZA-CdR and IFN-alpha in combination correlated with the increase in induction of differentiation of the HL-60 leukemic cells. These results suggest that 5-AZA-CdR and IFN-alpha in combination produces an enhancement of their antineoplastic action on HL-60 human myeloid leukemic cells.

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Ce chapitre traite de démarches où chercheurs, techniciens et agriculteurs s'associent pour concevoir ensemble, et si possible dès le démarrage de l'opération de recherche, des systèmes de culture ou de production innovants. S'appuyant sur trois expériences contrastées (Haute-Normandie, Picardie et Brésil), elle examine les conditions de la mise en oeuvre de telles démarches et débouche sur les questionnements spécifiques qu'elles soulèvent: posture du chercheur, dispositifs opérationnels changement d'échelle, articulation avec d'autres démarches de conception de l'innovation.

Conclusion de la partie I Itinéraire technique, système de culture : de la compréhension du fonctionnement du champ cultivé à l'évolution des pratiques agricoles; International audience

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International audience

International audience