390 research outputs found
Micro language planning for multilingual education : agency in local contexts
This paper overviews some of the domains of application of micro-level language planning approaches to foster multilingual education. It examines the language planning of local agents and the contexts in which their work contributes to multilingual education, either to expand or limit educational possibilities. It identifies four broad contexts of language planning activity in which local agents work: the local implementation of macro-level policy, contestation of macro-level policy, addressing local needs in the absence of macro-level policy and opening new possibilities for developing multilingualism. These contexts provide a way of framing the contribution that micro language planning work and local agents can make to multilingual education
Controllo climatico sull'accumulo di sedimenti di margine Olocenici e Pleistocenici del Mar Tirreno Orientale
Dati di paleovariazioni secolari (PSV) del campo geomagnetico sono stati ottenuti negli ultimi
25.000 anni da diverse carote recuperate nel Golfo di Salerno (Mar Tirreno orientale). Le curve composte
di PSV, sono comparate con le â PSV Master Curvesâ britanniche e francesi. La comparazione fornisce
uno strumento cronologico per determinare un trend di accrescimento del tasso di sedimentazione
nellâ Olocene superiore e di variazione ad intervalli di circa 1000 anni nellâ Olocene medio della piattaforma.
Inoltre durante i due principali episodi caldi del Mediterraneo a circa 3.3 e tra 6-9 ka sia la piattaforma
che la scarpata superiore registrano un aumento con successiva diminuzione del tasso di sedimentazione,
mentre ulteriori diminuzioni si registrano, in scarpata superiore, durante lâ ultimo picco Glaciale
(LGM) e lâinterstadio BĂžlling-AllerĂžd, suggerendo cosi unâ influenza climatica sui processi di accumulo
dei sedimenti del margine del Golfo di Salerno
An investigation into linearity with cumulative emissions of the climate and carbon cycle response in HadCM3LC
We investigate the extent to which global mean temperature, precipitation, and the carbon cycle are constrained by cumulative carbon emissions throughout four experiments with a fully coupled climate-carbon cycle model. The two paired experiments adopt contrasting, idealised approaches to climate change mitigation at different action points this century, with total emissions exceeding two trillion tonnes of carbon in the later pair. Their initially diverging cumulative emissions trajectories cross after several decades, before diverging again. We find that their global mean temperatures are, to first order, linear with cumulative emissions, though regional differences in temperature of up to 1.5K exist when cumulative emissions of each pair coincide. Interestingly, although the oceanic precipitation response scales with cumulative emissions, the global precipitation response does not, due to a decrease in precipitation over land above cumulative emissions of around one trillion tonnes of carbon (TtC). Most carbon fluxes and stores are less well constrained by cumulative emissions as they reach two trillion tonnes. The opposing mitigation approaches have different consequences for the Amazon rainforest, which affects the linearity with which the carbon cycle responds to cumulative emissions. Averaged over the two fixed-emissions experiments, the transient response to cumulative carbon emissions (TCRE) is 1.95 K TtC-1, at the upper end of the IPCCâs range of 0.8-2.5 K TtC-1
Compatible fossil fuel CO2 emissions in the CMIP6 earth system models' historical and shared socioeconomic pathway experiments of the twenty-first century
We present the compatible CO2 emissions from fossil fuel (FF) burning and industry, calculated from the historical and Shared Socioeconomic Pathway (SSP) experiments of nine Earth system models (ESMs) participating in phase 6 of the Coupled Model Intercomparison Project (CMIP6). The multimodel mean FF emissions match the historical record well and are close to the data-based estimate of cumulative emissions (394 6 59 GtC vs 400 6 20 GtC, respectively). Only two models fall inside the observed uncertainty range; while two exceed the upper bound, five fall slightly below the lower bound, due primarily to the plateau in CO2 concentration in the 1940s. The ESMs' diagnosed FF emission rates are consistent with those generated by the integrated assessment models (IAMs) from which the SSPs' CO2 concentration pathways were constructed; the simpler IAMs' emissions lie within the ESMs' spread for seven of the eight SSP experiments, the other being only marginally lower, providing confidence in the relationship between the IAMs' FF emission rates and concentration pathways. The ESMs require fossil fuel emissions to reduce to zero and subsequently become negative in SSP1-1.9, SSP1-2.6, SSP4-3.4, and SSP5-3.4over. We also present the ocean and land carbon cycle responses of the ESMs in the historical and SSP scenarios. The models' ocean carbon cycle responses are in close agreement, but there is considerable spread in their land carbon cycle responses. Land-use and land-cover change emissions have a strong influence over the magnitude of diagnosed fossil fuel emissions, with the suggestion of an inverse relationship between the two. © 2021 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses)
Twenty-first-century compatible co2 emissions and airborne fraction simulated by cmip5 earth system models under four representative concentration pathways
PublishedJournal ArticleThe carbon cycle is a crucial Earth system component affecting climate and atmospheric composition. The response of natural carbon uptake to CO2 and climate change will determine anthropogenic emissions compatible with a target CO2 pathway. For phase 5 of the Coupled Model Intercomparison Project (CMIP5), four future representative concentration pathways (RCPs) have been generated by integrated assessment models (IAMs) and used as scenarios by state-of-the-art climate models, enabling quantification of compatible carbon emissions for the four scenarios by complex, process-based models. Here, the authors present results from 15 such Earth system GCMs for future changes in land and ocean carbon storage and the implications for anthropogenic emissions. The results are consistent with the underlying scenarios but show substantial model spread. Uncertainty in land carbon uptake due to differences among models is comparable with the spread across scenarios. Model estimates of historical fossil-fuel emissions agree well with reconstructions, and future projections for representative concentration pathway 2.6 (RCP2.6) and RCP4.5 are consistent with the IAMs. For high-end scenarios (RCP6.0 and RCP8.5), GCMs simulate smaller compatible emissions than the IAMs, indicating a larger climate-carbon cycle feedback in the GCMs in these scenarios. For the RCP2.6 mitigation scenario, an average reduction of 50% in emissions by 2050 from 1990 levels is required but with very large model spread (14%-96%). The models also disagree on both the requirement for sustained negative emissions to achieve the RCP2.6 CO2 concentration and the success of this scenario to restrict global warming below 28C. All models agree that the future airborne fraction depends strongly on the emissions profile with higher airborne fraction for higher emissions scenarios. ©2013 American Meteorological Society.MOHC authors were supported by
the JointDECC/Defra MetOffice Hadley Centre Climate
Programme (GA01101), and work to performHadGEM2-
ES and MPI-ESM CMIP5 simulations was supported by
the EU-FP7 COMBINE project (Grant 226520). JS was
supported by the EU-FP7 CARBOCHANGE project
(Grant 284679). We acknowledge the World Climate
Research Programmeâs Working Group on Coupled
Modelling, which is responsible for CMIP, and we thank
the climate modeling groups (listed in Table 1 of this
paper) for producing and making available their model
output. For CMIP, the U.S. Department of Energyâs Program
for Climate Model Diagnosis and Intercomparison
provides coordinating support and led development of
software infrastructure in partnership with the Global
Organization for Earth System Science Portals. JT and
CR were supported by the Research Council of Norway
through the EarthClim (207711/E10) project
RNA editing signature during myeloid leukemia cell differentiation
Adenosine deaminases acting on RNA (ADARs) are key proteins for hematopoietic stem cell self-renewal and for survival of differentiating progenitor cells. However, their specific role in myeloid cell maturation has been poorly investigated. Here we show that ADAR1 is present at basal level in the primary myeloid leukemia cells obtained from patients at diagnosis as well as in myeloid U-937 and THP1 cell lines and its expression correlates with the editing levels. Upon phorbol-myristate acetate or Vitamin D3/granulocyte macrophage colony-stimulating factor (GM-CSF)-driven differentiation, both ADAR1 and ADAR2 enzymes are upregulated, with a concomitant global increase of A-to-I RNA editing. ADAR1 silencing caused an editing decrease at specific ADAR1 target genes, without, however, interfering with cell differentiation or with ADAR2 activity. Remarkably, ADAR2 is absent in the undifferentiated cell stage, due to its elimination through the ubiquitinâproteasome pathway, being strongly upregulated at the end of the differentiation process. Of note, peripheral blood monocytes display editing events at the selected targets similar to those found in differentiated cell lines. Taken together, the data indicate that ADAR enzymes play important and distinct roles in myeloid cells
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Implementation of U.K. Earth system models for CMIP6
We describe the scientific and technical implementation of two models for a core set of
experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6).
The models used are the physical atmosphere-land-ocean-sea ice model HadGEM3-GC3.1 and the
Earth system model UKESM1 which adds a carbon-nitrogen cycle and atmospheric chemistry to
HadGEM3-GC3.1. The model results are constrained by the external boundary conditions (forcing data)
and initial conditions.We outline the scientific rationale and assumptions made in specifying these.
Notable details of the implementation include an ozone redistribution scheme for prescribed ozone
simulations (HadGEM3-GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use
change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in
the simulation of background natural vegetation.We discuss the implications of these decisions for
interpretation of the simulation results. These simulations are expensive in terms of human and CPU
resources and will underpin many further experiments; we describe some of the technical steps taken to
ensure their scientific robustness and reproducibility
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