240 research outputs found

    Integrated hybrid multi-regional input-output for assessing life cycle air emissions of the Italian power system

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    The air emissions of the Italian power system, as well as national emissions between 2010 and 2017 and projections to 2040, have been assessed from a lifecycle perspective, using an integrated hybrid two-region input-output model of Italy versus the rest of the world. The Italian economy is divided into 42 sectors, including electricity, which is further disaggregated into seven technologies. Detailed electricity sector data, from Istat, are fed into the EXIOBASE input-output database. NAMEA tables represent overall air emissions, while the Ecoinvent database is used for the electricity sector. Electricity transition scenarios from Terna and Snam have been integrated into input-output and air emission databases. Demand and emissions were tracked within the electricity sector over medium-term, and the findings showed a sharp decrease between 2017 and 2025, from 97.5 MtCO2 to 32.6 MtCO2. By 2040, air emissions from the electricity sector are expected to grow gradually, compared to those of 2030, from 22.2 MtCO2 to 25.9 MtCO2, suggesting that the demand between 2030 and 2040 grows faster than the decarbonization effort during the same period. There is an overall, gradual downtrend between 2010 and 2040, with all air emission categories declining by half from both production and consumption-based perspectives in this period

    Modelling and simulating change in reforesting mountain landscapes using a social-ecological framework

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    Natural reforestation of European mountain landscapes raises major environmental and societal issues. With local stakeholders in the Pyrenees National Park area (France), we studied agricultural landscape colonisation by ash (Fraxinus excelsior) to enlighten its impacts on biodiversity and other landscape functions of importance for the valley socio-economics. The study comprised an integrated assessment of land-use and land-cover change (LUCC) since the 1950s, and a scenario analysis of alternative future policy. We combined knowledge and methods from landscape ecology, land change and agricultural sciences, and a set of coordinated field studies to capture interactions and feedback in the local landscape/land-use system. Our results elicited the hierarchically-nested relationships between social and ecological processes. Agricultural change played a preeminent role in the spatial and temporal patterns of LUCC. Landscape colonisation by ash at the parcel level of organisation was merely controlled by grassland management, and in fact depended on the farmer's land management at the whole-farm level. LUCC patterns at the landscape level depended to a great extent on interactions between farm household behaviours and the spatial arrangement of landholdings within the landscape mosaic. Our results stressed the need to represent the local SES function at a fine scale to adequately capture scenarios of change in landscape functions. These findings orientated our modelling choices in the building an agent-based model for LUCC simulation (SMASH - Spatialized Multi-Agent System of landscape colonization by ASH). We discuss our method and results with reference to topical issues in interdisciplinary research into the sustainability of multifunctional landscapes

    Overexpression of Plastid Transketolase in Tobacco Results in a Thiamine Auxotrophic Phenotype

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    To investigate the effect of increased plastid transketolase on photosynthetic capacity and growth, tobacco (Nicotiana tabacum) plants with increased levels of transketolase protein were produced. This was achieved using a cassette composed of a full-length Arabidopsis thaliana transketolase cDNA under the control of the cauliflower mosaic virus 35S promoter. The results revealed a major and unexpected effect of plastid transketolase overexpression as the transgenic tobacco plants exhibited a slow-growth phenotype and chlorotic phenotype. These phenotypes were complemented by germinating the seeds of transketolase-overexpressing lines in media containing either thiamine pyrophosphate or thiamine. Thiamine levels in the seeds and cotyledons were lower in transketolase-overexpressing lines than in wild-type plants. When transketolase-overexpressing plants were supplemented with thiamine or thiamine pyrophosphate throughout the life cycle, they grew normally and the seed produced from these plants generated plants that did not have a growth or chlorotic phenotype. Our results reveal the crucial importance of the level of transketolase activity to provide the precursor for synthesis of intermediates and to enable plants to produce thiamine and thiamine pyrophosphate for growth and development. The mechanism determining transketolase protein levels remains to be elucidated, but the data presented provide evidence that this may contribute to the complex regulatory mechanisms maintaining thiamine homeostasis in plants

    Agricultural land-use change and ash (Fraxinus excelsior L.) colonization in Pyrenean landscapes: an interdisciplinary case study

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     ONLINE FIRSTInternational audienceChanges in agricultural land use are responsible for significant modifications in mountain landscapes. This study is part of an interdisciplinary research on the processes and consequences of spontaneous afforestation of Pyrenean landscapes by ash, and the possibilities for its management. We address the relationships between vegetation dynamics and land-use change from the combination of an agricultural study of change in farm management and an ecological study of grassland colonization by ash. In the framework of a village case study, we characterized parcels management and land-use histories, and analyzed the dynamics of the composition of grassland vegetation communities. From a joint analysis of the results obtained in each discipline, we discuss the limitations and comple-mentarities of the two approaches for the interdisciplinary assessment of the afforestation process

    Stress-Induced GSK3 Regulates the Redox Stress Response by Phosphorylating Glucose-6-Phosphate Dehydrogenase in Arabidopsis.

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    Diverse stresses such as high salt conditions cause an increase in reactive oxygen species (ROS), necessitating a redox stress response. However, little is known about the signaling pathways that regulate the antioxidant system to counteract oxidative stress. Here, we show that a Glycogen Synthase Kinase3 from Arabidopsis thaliana (ASKα) regulates stress tolerance by activating Glc-6-phosphate dehydrogenase (G6PD), which is essential for maintaining the cellular redox balance. Loss of stress-activated ASKα leads to reduced G6PD activity, elevated levels of ROS, and enhanced sensitivity to salt stress. Conversely, plants overexpressing ASKα have increased G6PD activity and low levels of ROS in response to stress and are more tolerant to salt stress. ASKα stimulates the activity of a specific cytosolic G6PD isoform by phosphorylating the evolutionarily conserved Thr-467, which is implicated in cosubstrate binding. Our results reveal a novel mechanism of G6PD adaptive regulation that is critical for the cellular stress response

    Successful ageing : perceptions of adults aged between 70 and 101 years

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    In this research, content analysis was employed to investigate older adults\u27 perceptions of successful aging and the relationship of these perceptions to definitions given in the literature to date. Participants were 18 males and 42 females between the ages of 70 and 101 years. Analyses revealed older adults mentioned only 1 or 2 criteria of successful aging if asked for a definition; however, when prompted, they rated almost all the criteria emerging from the literature as highly important. Participants reported adjusting to the situations they were in by compensating for losses that occurred and selecting activities that best suited their capabilities. Overall, older adults\u27 perceptions of successful aging were similar to aspects identified in the literature. Not all aspects, however, were seen as important by all participants, and only low to moderate correlations were found between some aspects of successful aging. (Contains 3 figures and 4 tables.)<br /

    Evaluating the spatial uncertainty of future land abandonment in a mountain valley (Vicdessos, Pyrenees-France) : insights form model parameterization and experiments

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    International audienceEuropean mountains are particularly sensitive to climatic disruptions and land use changes. The latter leads to high rates of natural reforestation over the last 50 years. Faced with the challenge of predicting possible impacts on ecosystem services, LUCC models offer new opportunities for land managers to adapt or mitigate their strategies. Assessing the spatial uncertainty of future LUCC is crucial for the defintion of sustainable land use strategies. However, the sources of uncertainty may differ, including the input parameters, the model itself, and the wide range of possible futures. The aim of this paper is to propose a method to assess the probability of occurrence of future LUCC that combines the inherent uncertainty of model parameterization and the ensemble uncertainty of the future based scenarios. For this purpose, we used the Land Change Modeler tool to simulate future LUCC on a study site located in the Pyrenees Mountains (France) and 2 scenarios illustratins 2 land use strategies. The model was parameterized with the same driving factors used for its calibration. The defintion of static vs. dynamic and quantitative vs. qualitative (discretized) driving factors, and their combination resulted in 4 parameterizations. The combination of model outcomes produced maps of spatial uncertainty of future LUCC. This work involves literature to future-based LUCC studies. It goes beyond the uncertainty of simulation models by integrating the unceertainty of the future to provide maps to help decision makers and land managers

    Modelling regional land change scenarios to assess land abandonment and reforestation dynamics in the Pyrenees (France)

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    International audienceOver the last decades and centuries, European mountain landscapes have experienced substantial transformations. Natural and anthropogenic LULC changes (land use and land cover changes), especially agro-pastoral activities, have directed influenced the spatial organization and composition of European mountain landscapes. For the past 60 years, natural reforestation has been occurring due to a decline in both agricultural production activities and rural population. Stakeholders, to better anticipate future changes, need spatially and temporally explicit models to identiy areas at risk of land change and possible abandonment. This paper presents an integrated approach combining forecasting scenarios and a LULC changes simulation model to assess where LULC changes may occur in the Pyrenees Mountains, based on historical LULC trands and a range of future socio-economic drivers. The proposed methodology considers local specificities of Pyrenan valleys, sub-regional climate and topographical properties, and regional economic policies. Results indicate that some regions are projected to face strong abandonment, regardless of scenario conditions. Overall, high rates of change are associated with administrative regions where land productivity is highly dependent on socio-economic drivers and climatic and environmental conditions limit intensive (agricultural and/or pastoral) production and profitability. The combination of the results for the four scenarios allows assessements of where encroachment (e.g. colonization by shrublands) and reforestation are the most probable. This assessment intends to provide insight into the potential future development of the Pyrenees to help identify areas that are the most sensitive to change and to guide decision makers to help their management decisions
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