232 research outputs found

    High-resolution projections of ambient heat for major European cities using different heat metrics

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    Heat stress in cities is projected to strongly increase due to climate change. The associated health risks will be exacerbated by the high population density in cities and the urban heat island effect. However, impacts are still uncertain, which is among other factors due to the existence of multiple metrics for quantifying ambient heat and the typically rather coarse spatial resolution of climate models. Here we investigate projections of ambient heat for 36 major European cities based on a recently produced ensemble of regional climate model simulations for Europe (EURO-CORDEX) at 0.11∘ spatial resolution (∼ 12.5 km). The 0.11∘ EURO-CORDEX ensemble provides the best spatial resolution currently available from an ensemble of climate model projections for the whole of Europe and makes it possible to analyse the risk of temperature extremes and heat waves at the city level. We focus on three temperature-based heat metrics – yearly maximum temperature, number of days with temperatures exceeding 30 ∘C, and Heat Wave Magnitude Index daily (HWMId) – to analyse projections of ambient heat at 3 ∘C warming in Europe compared to 1981–2010 based on climate data from the EURO-CORDEX ensemble. The results show that southern European cities will be particularly affected by high levels of ambient heat, but depending on the considered metric, cities in central, eastern, and northern Europe may also experience substantial increases in ambient heat. In several cities, projections of ambient heat vary considerably across the three heat metrics, indicating that estimates based on a single metric might underestimate the potential for adverse health effects due to heat stress. Nighttime ambient heat, quantified based on daily minimum temperatures, shows similar spatial patterns to daytime conditions, albeit with substantially higher HWMId values. The identified spatial patterns of ambient heat are generally consistent with results from global Earth system models, though with substantial differences for individual cities. Our results emphasise the value of high-resolution climate model simulations for analysing climate extremes at the city level. At the same time, they highlight that improving the predominantly rather simple representations of urban areas in climate models would make their simulations even more valuable for planning adaptation measures in cities. Further, our results stress that using complementary metrics for projections of ambient heat gives important insights into the risk of future heat stress that might otherwise be missed.</p

    Effect of Ce and Sb on Primary Graphite Growth in Cast Irons

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    It is well-known that if certain trace elements are present in cast iron melts the morphology of the graphite precipitates can be altered. In order to understand the effect of doping elements on primary growth of graphite, pure Fe–Sb alloys were prepared by induction melting. They were then placed in graphite crucibles and heated to a temperature above the Fe–C eutectic so that the charge became saturated in carbon and melted. To obtain Fe–Ce alloys, metallic Ce was added at the bottom of a graphite crucible and covered with iron, and then heated as for the Fe–Sb charge. In both cases, the melt was then cooled and held slightly above the eutectic temperature so that primary graphite crystals, which had nucleated on the crucible walls and then detached from it, could grow freely in the melt. The influence of the added elements on graphite growth was revealed by the change in the shape and distribution of the crystals compared to those obtained in similar experiments carried out with pure Fe. The experiments were made in air and vacuum so as to point out possible interactions between the elements present in the melt and oxygen

    Cell arrest and cell death in mammalian preimplantation development

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    The causes, modes, biological role and prospective significance of cell death in preimplantation development in humans and other mammals are still poorly understood. Early bovine embryos represent a very attractive experimental model for the investigation of this fundamental and important issue. To obtain reference data on the temporal and spatial occurrence of cell death in early bovine embryogenesis, three-dimensionally preserved embryos of different ages and stages of development up to hatched blastocysts were examined in toto by confocal laser scanning microscopy. In parallel, transcript abundance profiles for selected apoptosis-related genes were analyzed by real-time reverse transcriptase-polymerase chain reaction. Our study documents that in vitro as well as in vivo, the first four cleavage cycles are prone to a high failure rate including different types of permanent cell cycle arrest and subsequent non-apoptotic blastomere death. In vitro produced and in vivo derived blastocysts showed a significant incidence of cell death in the inner cell mass (ICM), but only in part with morphological features of apoptosis. Importantly, transcripts for CASP3, CASP9, CASP8 and FAS/FASLG were not detectable or found at very low abundances. In vitro and in vivo, errors and failures of the first and the next three cleavage divisions frequently cause immediate embryo death or lead to aberrant subsequent development, and are the main source of developmental heterogeneity. A substantial occurrence of cell death in the ICM even in fast developing blastocysts strongly suggests a regular developmentally controlled elimination of cells, while the nature and mechanisms of ICM cell death are unclear. Morphological findings as well as transcript levels measured for important apoptosis-related genes are in conflict with the view that classical caspase-mediated apoptosis is the major cause of cell death in early bovine development

    Land–atmosphere interactions in sub-polar and alpine climates in the CORDEX Flagship Pilot Study Land Use and Climate Across Scales (LUCAS) models – Part 2: The role of changing vegetation

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    Land cover in sub-polar and alpine regions of northern and eastern Europe have already begun changing due to natural and anthropogenic changes such as afforestation. This will impact the regional climate and hydrology upon which societies in these regions are highly reliant. This study aims to identify the impacts of afforestation/reforestation (hereafter afforestation) on snow and the snow-albedo effect and highlight potential improvements for future model development. The study uses an ensemble of nine regional climate models for two different idealised experiments covering a 30-year period; one experiment replaces most land cover in Europe with forest, while the other experiment replaces all forested areas with grass. The ensemble consists of nine regional climate models composed of different combinations of five regional atmospheric models and six land surface models. Results show that afforestation reduces the snow-albedo sensitivity index and enhances snowmelt. While the direction of change is robustly modelled, there is still uncertainty in the magnitude of change. The greatest differences between models emerge in the snowmelt season. One regional climate model uses different land surface models which shows consistent changes between the three simulations during the accumulation period but differs in the snowmelt season. Together these results point to the need for further model development in representing both grass–snow and forest–snow interactions during the snowmelt season. Pathways to accomplishing this include (1) a more sophisticated representation of forest structure, (2) kilometre-scale simulations, and (3) more observational studies on vegetation–snow interactions in northern Europe

    Land–atmosphere interactions in sub-polar and alpine climates in the CORDEX flagship pilot study Land Use and Climate Across Scales (LUCAS) models – Part 1: Evaluation of the snow-albedo effect

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    Seasonal snow cover plays a major role in the climate system of the Northern Hemisphere via its effect on land surface albedo and fluxes. In climate models the parameterization of interactions between snow and atmosphere remains a source of uncertainty and biases in the representation of local and global climate. Here, we evaluate the ability of an ensemble of regional climate models (RCMs) coupled with different land surface models to simulate snow–atmosphere interactions over Europe in winter and spring. We use a previously defined index, the snow-albedo sensitivity index (SASI), to quantify the radiative forcing associated with snow cover anomalies. By comparing RCM-derived SASI values with SASI calculated from reanalyses and satellite retrievals, we show that an accurate simulation of snow cover is essential for correctly reproducing the observed forcing over middle and high latitudes in Europe. The choice of parameterizations, and primarily the choice of the land surface model, strongly influences the representation of SASI as it affects the ability of climate models to simulate snow cover accurately. The degree of agreement between the datasets differs between the accumulation and ablation periods, with the latter one presenting the greatest challenge for the RCMs. Given the dominant role of land surface processes in the simulation of snow cover during the ablation period, the results suggest that, during this time period, the choice of the land surface model is more critical for the representation of SASI than the atmospheric model

    Credentials, talent and cultural capital: a comparative study of educational elites in England and France

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    This article examines student accounts of credentials, talent and academic success, against a backdrop of the enduring liberal ideal of an education-based meritocracy. The article also examines Bourdieu’s account of academic qualifications as the dominant source of institutionalised cultural capital, and concludes that it does not adequately account for comparative differences in the social structure of competition and ideological shifts in class (re)production in different national contexts. This analysis is based on an empirical investigation of elite students at Oxford University and Sciences Po in Paris. We investigated how they understand the competition for a livelihood and whether they see themselves as more ‘talented’ than students from non-elite universities. This investigation revealed important similarities and differences between British and French students that have significant sociological implications for the (re)production and legitimation of educational and labour market inequalities

    Human heat stress could offset potential economic benefits of CO2 fertilization in crop production under a high-emissions scenario

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    Climate change can significantly affect food production in many ways. Changes in greenhouse gases, temperature, and rainfall directly influence crop productivity, sometimes increasing yield through a mechanism known as the carbon dioxide fertilization effect. However, agricultural production in many countries also relies on physically demanding manual labor, primarily outside, and, as temperatures rise, heat stress on agricultural workers can reduce labor capacity. Consequential climate change impacts on food availability and affordability are a major societal concern, yet the specific and combined impacts on agricultural production remain highly uncertain. An assessment of the future impacts of climate change on the production and prices of four of the world’s most consumed crops (maize, wheat, soybean, and rice) reveals that a rise in heat stress will lower agricultural labor capacity and increase labor costs in Africa and Asia. This could offset the potential economic benefits of higher yields due to elevated levels of CO2. Proactive adaptation measures, such as mechanization deployment, are needed to reduce the vulnerability to heat stress

    A decentralized approach to model national and global food and land use systems

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    The achievement of several sustainable development goals and the Paris Climate Agreement depends on rapid progress towards sustainable food and land systems in all countries. We have built a flexible, collaborative modeling framework to foster the development of national pathways by local research teams and their integration up to global scale. Local researchers independently customize national models to explore mid-century pathways of the food and land use system transformation in collaboration with stakeholders. An online platform connects the national models, iteratively balances global exports and imports, and aggregates results to the global level. Our results show that actions toward greater sustainability in countries could sum up to 1 Mha net forest gain per year, 950 Mha net gain in the land where natural processes predominate, and an increased CO2 sink of 3.7 GtCO2e yr−1 over the period 2020-2050 compared to current trends, while average food consumption per capita remains above the adequate food requirements in all countries. We show examples of how the global linkage impacts national results and how different assumptions in national pathways impact global results. This modeling setup acknowledges the broad heterogeneity of socio-ecological contexts and the fact that people who live in these different contexts should be empowered to design the future they want. But it also demonstrates to local decision-makers the interconnectedness of our food and land use system and the urgent need for more collaboration to converge local and global priorities.Fil: Mosnier, Aline. Sustainable Development Solutions Network; FranciaFil: Javalera Rincon, Valeria. International Institute For Applied Systems Analysis, Laxenburg; AustriaFil: Jones, Sarah K. Alliance of Bioversity International; FranciaFil: Andrew, Robbie. Center for International Climate Research; NoruegaFil: Bai, Zhaohai. Chinese Academy of Sciences; República de ChinaFil: Baker, Justin. North Carolina State University; Estados UnidosFil: Basnet, Shyam. Stockholm Resilience Centre; SueciaFil: Boer, Rizaldi. Bogor Agricultural University; IndonesiaFil: Chavarro, John. Geo-agro-environmental Sciences And Resources Research Center; ColombiaFil: Costa, Wanderson. Centro de Previsao de Tempo e Estudos Climáticos. Instituto Nacional de Pesquisas Espaciais; BrasilFil: Daloz, Anne Sophie. Center for International Climate Research; NoruegaFil: DeClerck, Fabrice A.. Alliance of Bioversity International; Francia. Stockholm Resilience Centre; SueciaFil: Diaz, Maria. Sustainable Development Solutions Network; FranciaFil: Douzal, Clara. Sustainable Development Solutions Network; FranciaFil: Howe Fan, Andrew Chiah. Sunway University; MalasiaFil: Fetzer, Ingo. Stockholm Resilience Centre; SueciaFil: Frank, Federico. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Gonzalez Abraham, Charlotte E.. University of California at San Diego; Estados UnidosFil: Habiburrachman, A. H. F.. Universitas Indonesia; IndonesiaFil: Immanuel, Gito. Stockholm Resilience Centre; SueciaFil: Harrison, Paula A.. Centre for Ecology & Hydrology; Reino UnidoFil: Imanirareba, Dative. Uganda Martyrs University; UgandaFil: Jha, Chandan. Indian Institute Of Management Ahmedabad; IndiaFil: Monjeau, Jorge Adrian. Fundación Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vittis, Yiorgos. International Institute For Applied Systems Analysis; AustriaFil: Wade, Chris. North Carolina State University; Estados UnidosFil: Winarni, Nurul L.. Universitas Indonesia; IndonesiaFil: Woldeyes, Firew Bekele. Ethiopian Development Research Institute; EtiopíaFil: Wu, Grace C.. University of California; Estados UnidosFil: Zerriffi, Hisham. University of British Columbia; Canad

    The Rhythm of the Deal: Negotiation as a Dance

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    In all the literature on the theory and practice of negotiation, the governing metaphor remains consistently one of war or fighting. This is true not only for tactical schools of power-based negotiation, but even for more constructive, interest-based approaches. Our language is infused with talk of tactics, flanks, concessions, gaining ground and winning. This article explores the possible consequences of abandoning this picture in favor of the far too little explored metaphor of the dance. We will see that both the content and the process of negotiation can change dramatically once when we think of bargaining as an aesthetic activity which provides intrinsic joy as well as extrinsic benefits. In such a dance, there is plenty of room for competition as well as cooperation, as movements can be spirited and confrontational as well as smooth and harmonious. We identify many forms of dance in negotiation, and explore three: the dance of positioning, where passions and presentations interact proudly; the dance of empathy, when the partners come to better understand each other; and then the dance of concessions, where the deal is struck and the music comes to an end. Finally, we will try to show how the dance can be employed pedagogically, in teaching and training negotiation and mediation. In particular, the Brazilian dance of capoeira illustrates holistically and experientially how movement and rhythm can be interpreted both as fight and as a dance and how we can come to see a process as both aesthetic and purposeful at the same time. First feeling, then thinking and finally speaking, we can use this medium to explore the dynamics of confrontation and cooperation in a negotiation setting
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