103 research outputs found

    On the resolution of extremal and constant scalar curvature Kaehler orbifolds

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    In this paper we give sufficient conditions on a compact orbifold with an extremal Kaehler metric to admit a resolution with an extremal Kaehler metric. We also complete the Kaehler constant scalar curvature case.Comment: This paper, together with the next one by the same authors, contains more general results than arxiv.org/abs/1402.5919 (by the same authors), which will then be withdraw

    On the desingularization of Kahler orbifolds with constant scalar curvature

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    In Chapter 1 we recall some basic notions of complex and K\ua8ahler geometry and we introduce some technical results regarding cscK metrics that we will use intensively in successive chapters. We also explain in detail what kind of result we want to prove and the strategy of the proof. We warmly suggest to read section 1.6.2 where we give a detailed overview of the proof of Theorem 1.7. In Chapter 2 we investigate the properties of particular linear differential operators on cscK manifolds. More precisely we study their invertibility properties between weighted H\ua8older spaces. In Chapter 3 we begin the proof of our main result. With tools we introduced in chapter 2 we construct families, depending on some parameters, of cscK metrics on particular manifolds with boundary. In Chapter 4 we finish the proof we started in the preceding chapter. To conclude the proof we perform the connected sum construction along the boundaries of the manifolds we chose in chapter 3 and we glue the families of cscK metrics we constructed on them. To glue the families of metrics we use the technique known as Cauchy data matching. We also discuss the proof of Theorem 4.2. In Chapter 5 we look for examples of cscK orbifolds satisfying assumptions of Theorem 1.7. We focus our attention on toric 3-folds and it turns out that there is no toric three-dimensional orbifold satisfying our requests. In Chapter 6 we discuss the extension of Theorem 1.7 to 2-dimensional orbifolds and the relative technical issues. We discuss, moreover, some conjectures and ideas for future work

    Does respondent’s perceived knowledge of the status quo affect attribute attendance and WTP in choice experiments? Evidence from the Karapiro Catchment Freshwater streams

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    In environmental valuation studies with stated preference methods researchers often provide descriptions of status quo conditions which may differ from those perceived by respondents. Ignoring this difference in utility baselines may affect the way attributes are attended to in choice tasks and further affect the magnitude of utility changes and hence bias the implied estimates of benefits from the proposed environmental policies. We investigate this issue using data from a choice experiment on a community’s willingness to pay for water quality improvements in streams. About 60% of respondents perceived the description of the quality of water in streams to be better than the one we provided in our scenario. Our results show some differences in serial attribute non-attendance between respondents who were provided with our baseline description of the status quo and those who used their own perceived baselines. The results further reveal some differences in attribute non-attendance in the two split samples within respondents who used their own descriptions of the status quo conditions. Generally we note that non-attendance to cost was higher in respondents who reported lower levels of water quality than those who perceived water quality to be higher. However, we find mixed results in terms of the willingness to pay for water quality improvements.Choice experiments, Fixed status quo, People’s perceived status quo, Willingness to pay., Community/Rural/Urban Development, Environmental Economics and Policy, Health Economics and Policy, Land Economics/Use,

    Retrofitting partial oxyfuel and Integrated Ca-Looping technologies to an existing cement plant: a case study

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    The present document describes the potential retrofit of an existing cement plant with carbon capture technologies applied in two sequential steps. The pathway proposed consists in a first retrofit through partial oxyfuel followed by the integrated calcium looping (CaL) technology. This kind of applications may represent a promising strategy for the decarbonization route in the cement sector without introducing chemical solvents or special components, in particular for existing cement kilns that may need to be revamped. The cement plant selected for this study is the 0.5 Mtcem/y Colleferro facility owned by Italcementi-HeidelbergCement. This study analyses the mass & energy balances of the partial oxyfuel, and the integrated CaL process retrofitted to the existing cement plant. The results of the two CCS technologies are then compared in terms of CO2 emission reduction and energy consumption with the reference plant without CO2 capture. The scope of this analysis is to evaluate the impact of carbon capture technologies on the cement production process. The process simulation software Aspen Plus V10.0¬ģ has been employed to develop the model for the three different plant configurations (i.e., the base case w/o carbon capture, the partial oxyfuel mode, and the integrated CaL). The base case has been validated using field measurements coming directly from the Colleferro plant. From this process flow model, the two CCS technologies have been developed according to the specific process requirements. Results show that a maximum reduction in CO2 emissions of 92.4% is possible with the integrated CaL, while the partial oxyfuel enables to capture 71.7% of the CO2 generated in the plant

    Uptake of Ecological Farming Practices by EU Farms: A Pan‚ÄźEuropean Typology

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    Understanding and measuring the sustainability of farms is key to evaluating progress towards policy goals for a more sustainable agriculture. In the LIFT project, a farm typology was developed to classify farms according to their ecological performance, based on farm-level variables from the Farm Accountancy Data Network (FADN). Selected variables are used to assess three key ecological dimensions of farming: total input intensity; degree of circularity (reliance on own-produced versus external inputs); and avoidance of the use of specific inputs of concern for the environment and consumers. The combination of these aspects is considered as a measure of the farm proximity to a full agroecological approach. The typology allows comparison of farms across farm types, countries and years. We briefly present the method and discuss two key aspects: 1) how the proposed farm typology can inform policymaking in the context of a new EU policy framework; 2) how it can inform the foreseen transformation of the FADN into a Farm Sustainability Data Network (FSDN). We suggest that the use of a typology approach under the new FSDN provides useful information on the impacts of the implementation of agroecological practices with an acceptable additional effort in terms of data collection.</p

    Long non-coding RNA uc.291 controls epithelial differentiation by interfering with the ACTL6A/BAF complex.

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    The mechanisms that regulate the switch between epidermal progenitor state and differentiation are not fully understood. Recent findings indicate that the chromatin remodelling BAF complex (Brg1-associated factor complex or SWI/SNF complex) and the transcription factor p63 mutually recruit one another to open chromatin during epidermal differentiation. Here, we identify a long non-coding transcript that includes an ultraconserved element, uc.291, which physically interacts with ACTL6A and modulates chromatin remodelling to allow differentiation. Loss of uc.291 expression, both in primary keratinocytes and in three-dimensional skin equivalents, inhibits differentiation as indicated by epidermal differentiation complex genes down-regulation. ChIP experiments reveal that upon uc.291 depletion, ACTL6A is bound to the differentiation gene promoters and inhibits BAF complex targeting to induce terminal differentiation genes. In the presence of uc.291, the ACTL6A inhibitory effect is released, allowing chromatin changes to promote the expression of differentiation genes. Thus, uc.291 interacts with ACTL6A to modulate chromatin remodelling activity, allowing the transcription of late differentiation genes

    Responses of benthic invertebrates to chemical recovery from acidification

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    Prosjektleder: Heleen de WitThe report provides an assessment of biological recovery from acidification in freshwater environments in Europe. The report consists of two parts, a regional data analysis based on an international dataset of biological and water chemical records, and a collection of national contributions on monitoring and assessment of biological recovery in different countries. The regional analysis showed that 47% of all included rivers (21 sites, for the period 1994-2018) and 35% percent of all lakes (34 sites, for the period 2000 to 2018) showed significant increases in species richness. Correlations between species diversity and water chemical components (ANC, pH, SO4) were found, supporting that the biological responses were related to chemical recovery. Additionally, the composition of functional traits in rivers underwent significant changes over time. Both parts of the report demonstrate ongoing biological recovery from acidification in European acid-sensitive freshwater environments.Norwegian Ministry of Climate and Environment, United Nations Economic Commission for Europe (UNECE)publishedVersio

    Reports about 8 selected benchmark cases of model hierarchies : Deliverable number: D5.1 - Version 0.1

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    Based on the multitude of industrial applications, benchmarks for model hierarchies will be created that will form a basis for the interdisciplinary research and for the training programme. These will be equipped with publically available data and will be used for training in modelling, model testing, reduced order modelling, error estimation, efficiency optimization in algorithmic approaches, and testing of the generated MSO/MOR software. The present document includes the description about the selection of (at least) eight benchmark cases of model hierarchies.EC/H2020/765374/EU/Reduced Order Modelling, Simulation and Optimization of Coupled Systems/ROMSO

    Case Report - Multinodular goiter in a patient with Congenital Hypothyroidism and Bannayan-Riley-Ruvalcaba syndrome: the possible synergic role of TPO and PTEN mutation

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    We report the case of a paediatric female patient affected by Bannayan-Riley-Ruvalcaba syndrome (BRRS) and congenital hypothyroidism (CH) with homozygous mutation of the TPO gene. She underwent total thyroidectomy at the age of seven years because of the development of a multinodular goiter. BRRS patients present an increased risk of benign and malignant thyroid disease since childhood because of inactivating mutation of PTEN, an onco-suppressor gene. Instead, homozygous mutations in the TPO gene can be associated with severe forms of hypothyroidism with goiter; previous studies have described cases of follicular and papillary thyroid cancer in CH patients with TPO mutation despite a perfectly controlled thyroid function with Levothyroxine therapy. To our knowledge, this is the first case that describes the possible synergic role of coexisting mutation of both TPO and PTEN in the development of multinodular goiter underlining the importance of a tailored surveillance program in these patients, especially during childhood
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