Resident memory CD8
+
T cells (T
RM
) usually defined by the CD103 marker represent a new subset of long-lived memory T cells that remain in the tissues. We directly demonstrate their specific role ...in cancer vaccine-induced tumor regression. In human, they also seem to play a major role in tumor immunosurveillance.
The Global and Regional Earth System Monitoring Using Satellite and In Situ Data (GEMS) project is combining the manifold expertise in atmospheric composition research and numerical weather ...prediction of 32 European institutes to build a comprehensive monitoring and forecasting system for greenhouse gases, reactive gases, aerosol, and regional air quality. The project is funded by the European Commission as part of the Global Monitoring of Environment and Security (GMES) framework. GEMS has extended the data assimilation system of the European Centre for Medium-Range Weather Forecasts (ECMWF) to include various tracers for which satellite observations exist. A chemical transport model has been coupled to this system to account for the atmospheric chemistry. The GEMS system provides lateral boundary conditions for a set of 10 regional air quality forecast models and global atmospheric fields for use in surface flux inversions for the greenhouse gases. Observations from both in situ and satellite sources are used as input, and the output products will serve users such as policy makers, environmental agencies, the science community, and providers of end-user services for air quality and health. This article provides an overview of GEMS and uses some recent results to illustrate the current status of the project. It is expected that GEMS will grow into a full operational service for the atmospheric component of GMES in the next decade. Part of this transition will be the merge with the Protocol Monitoring for the GMES Service Element: Atmosphere (PROMOTE) GMES project into the Monitoring of Atmospheric Composition and Climate (MACC) project.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction Les révolutions technologiques et les innovations de rupture sont de nature à bouleverser les hiérarchies intra- et interindustrielles, en favorisant de nouveaux entrants. La révolution ...digitale est de cette nature. Depuis le début des années 2010, les acteurs traditionnels de la finance font face à une nouvelle concurrence de la part des acteurs de la FinTech (ou innovation financière fondée sur la technologie). Ces derniers forment un ensemble hétérogène dans lequel se côtoient...
In this study, we have performed a set of simulations to detail the evolution of tropospheric ozone from 1890 to 1990. The simulations are compared with available measurements for present‐day ...conditions and earlier. Using our best estimates of ozone precursors emissions (based on the work by van Aardenne et al. (2001)), we have found a tropospheric ozone burden increase of 71 Tg between 1890 and 1990, an increase of ∼30%. When no anthropogenic emissions in 1890 are considered, this burden increase reaches 88 Tg. The ozone lifetime is shown to have decreased by ∼30%, especially after 1930. It is also shown that the net chemical production in the lower troposphere exceeded that in the free troposphere for the first time in the 1950–1970 period. In addition, the ozone production in this study increased rapidly between 1890 and 1930 and from 1970 to 1990. However, the ozone production efficiency in the troposphere is shown to have decreased during the 20th century, making the troposphere less NOx limited. Finally, a decrease in the OH burden is estimated to be on the order of 8%, matched by a similar increase in the CO lifetime.
Chemically active climate compounds are either primary compounds like methane (CH4), removed by oxidation in the atmosphere, or secondary compounds like ozone (O3), sulfate and organic aerosols, both ...formed and removed in the atmosphere. Man-induced climate–chemistry interaction is a two-way process: Emissions of pollutants change the atmospheric composition contributing to climate change through the aforementioned climate components, and climate change, through changes in temperature, dynamics, the hydrological cycle, atmospheric stability, and biosphere-atmosphere interactions, affects the atmospheric composition and oxidation processes in the troposphere. Here we present progress in our understanding of processes of importance for climate–chemistry interactions, and their contributions to changes in atmospheric composition and climate forcing. A key factor is the oxidation potential involving compounds like O3 and the hydroxyl radical (OH). Reported studies represent both current and future changes. Reported results include new estimates of radiative forcing based on extensive model studies of chemically active climate compounds like O3, and of particles inducing both direct and indirect effects. Through EU projects like ACCENT, QUANTIFY, and the AeroCom project, extensive studies on regional and sector-wise differences in the impact on atmospheric distribution are performed. Studies have shown that land-based emissions have a different effect on climate than ship and aircraft emissions, and different measures are needed to reduce the climate impact. Several areas where climate change can affect the tropospheric oxidation process and the chemical composition are identified. This can take place through enhanced stratospheric–tropospheric exchange of ozone, more frequent periods with stable conditions favoring pollution build up over industrial areas, enhanced temperature induced biogenic emissions, methane releases from permafrost thawing, and enhanced concentration through reduced biospheric uptake. During the last 5–10 years, new observational data have been made available and used for model validation and the study of atmospheric processes. Although there are significant uncertainties in the modeling of composition changes, access to new observational data has improved modeling capability. Emission scenarios for the coming decades have a large uncertainty range, in particular with respect to regional trends, leading to a significant uncertainty range in estimated regional composition changes and climate impact.
Tropospheric Ozone Assessment Report Archibald, A T; Neu, J L; Elshorbany, Y F ...
Elementa (Washington, D.C.),
01/2020, Letnik:
8, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Our understanding of the processes that control the burden and budget of tropospheric ozone has changed dramatically over the last 60 years. Models are the key tools used to understand these changes, ...and these underscore that there are many processes important in controlling the tropospheric ozone budget. In this critical review, we assess our evolving understanding of these processes, both physical and chemical. We review model simulations from the International Global Atmospheric Chemistry Atmospheric Chemistry and Climate Model Intercomparison Project and Chemistry Climate Modelling Initiative to assess the changes in the tropospheric ozone burden and its budget from 1850 to 2010. Analysis of these data indicates that there has been significant growth in the ozone burden from 1850 to 2000 (approximately 43 ± 9%) but smaller growth between 1960 and 2000 (approximately 16 ± 10%) and that the models simulate burdens of ozone well within recent satellite estimates. The Chemistry Climate Modelling Initiative model ozone budgets indicate that the net chemical production of ozone in the troposphere plateaued in the 1990s and has not changed since then inspite of increases in the burden. There has been a shift in net ozone production in the troposphere being greatest in the northern mid and high latitudes to the northern tropics, driven by the regional evolution of precursor emissions. An analysis of the evolution of tropospheric ozone through the 21st century, as simulated by Climate Model Intercomparison Project Phase 5 models, reveals a large source of uncertainty associated with models themselves (i.e., in the way that they simulate the chemical and physical processes that control tropospheric ozone). This structural uncertainty is greatest in the near term (two to three decades), but emissions scenarios dominate uncertainty in the longer term (2050–2100) evolution of tropospheric ozone. This intrinsic model uncertainty prevents robust predictions of near-term changes in the tropospheric ozone burden, and we review how progress can be made to reduce this limitation.
We compare five global inventories of monthly CO emissions named VGT, ATSR, MODIS, GFED3 and MOPITT based on remotely sensed active fires and/or burned area products for the year 2003. The objective ...is to highlight similarities and differences by focusing on the geographical and temporal distribution and on the emissions for three broad land cover classes (forest, savanna/grassland and agriculture). Globally, CO emissions for the year 2003 range between 365 Tg CO (GFED3) and 1422 Tg CO (VGT). Despite the large uncertainty in the total amounts, some common spatial patterns typical of biomass burning can be identified in the boreal forests of Siberia, in agricultural areas of Eastern Europe and Russia and in savanna ecosystems of South America, Africa and Australia. Regionally, the largest difference in terms of total amounts (CV > 100%) and seasonality is observed at the northernmost latitudes, especially in North America and Siberia where VGT appears to overestimate the area affected by fires. On the contrary, Africa shows the best agreement both in terms of total annual amounts (CV = 31%) and of seasonality despite some overestimation of emissions from forest and agriculture observed in the MODIS inventory. In Africa VGT provides the most reliable seasonality. Looking at the broad land cover types, the range of contribution to the global emissions of CO is 64–74%, 23–32% and 3–4% for forest, savanna/grassland and agriculture, respectively. These results suggest that there is still large uncertainty in global estimates of emissions and it increases if the comparison is carried by out taking into account the temporal (month) and spatial (0.5° × 0.5° cell) dimensions. Besides the area affected by fires, also vegetation characteristics and conditions at the time of burning should also be accurately parameterized since they can greatly influence the global estimates of CO emissions.
Cancer immunotherapy has occupied a marginal therapeutic option in cancer despite strong arguments documenting the role of the immune system in controlling the proliferation of cancers. The recent ...success of immunotherapy results from a change in the past paradigm. From now on, the goal is not only to activate the immune system against tumor, but also to take account of the immunosuppressive tumor microenvironment Among these mechanisms, negative costimulatory molecules (CTLA-4, PD-1, etc.) expressed by T cells in the tumor could explain their lack of effectiveness in inhibiting tumor growth. Blocking these molecules allowed the reactivation of anti-tumor T cells. Clinically, the administration of anti-CTLA-4 antibody (ipilimumab: Yervoy
) was granted marketing authorization for patients with metastatic melanoma. The anti-PD-1 antibodies (nivolumab: Opdivo
, pembrolizumab: Keytruda
) have demonstrated clinical efficacy when compared to the standard therapy in metastatic melanomas, advanced lung cancers and metastatic renal cell carcinoma. In phase I and II clinical trials, other tumors (Hodgkin's disease, head and neck cancers, bladder cancer, gastric cancer, etc.) appear to be responsive to these immunomodulators. These treatments were associated with the occurrence of side effects dominated by autoimmunity predictable by unlocking the breaks exerted by immune system to maintain tolerance against self-antigen. The optimization of therapeutic combination based on these molecules and the search for biomarkers associated with these treatments constitute a challenge for the future for this new therapeutic class of drugs for oncology.
Parmi les allergènes majeurs du latex (Hev b 1, Hev b 2, Hev b 4, Hev b 5, Hev b 6.01, Hev b 6.02 et Hev b 13), Hev b 2 et Hev b 13 sont encore mal connus et leur implication dans l’allergie au latex ...et le syndrome latex-fruits reste à préciser. Ce sont des glycoallergènes ubiquitaires très largement distribués chez tous les végétaux, présents en particulier dans les fruits (banane, cerise, kiwi, etc.). Hev b 2 est une endo-β1,3-glucanase impliquée dans le métabolisme glucidique lors du murissement des fruits. Hev b 13 est une estérase intervenant également dans le métabolisme. La plupart des épitopes B liant les IgE identifiés sur ces deux allergènes ne coïncident pas avec l’emplacement des sites de glycosylation et ne correspondent vraisemblablement pas à des glycotopes. La prévalence élevée de ces deux allergènes dans les populations allergiques souligne leur importance dans le diagnostic de l’allergie au latex et du syndrome latex-fruits.
Among the major latex allergens (Hev b 1, Hev b 2, Hev b 4, Hev b 5, Hev b 6.01, Hev b 6.02, and Hev b 13), Hev b 2 and Hev b 13 have been poorly investigated and, accordingly, their involvement in both latex allergy and latex-fruit syndrome has to be addressed. Both allergens consist of ubiquitous glycoproteins widely distributed in plants, especially in fruits (banana, cherry, kiwi fruit). Hev b 2 consists of an endo-β1,3-glucanase involved in the glucan metabolism during the fruit ripening process. Hev b 13 consists of an esterase also with a metabolic function. Most of the IgE-binding epitopes identified on both allergens occur outside the putative N-glycosylation sites and do not apparently consist of glycotopes. The high prevalence of Hev b 2 and Hev b 13 in latex allergic patients make both allergens useful for improving the diagnosis of latex allergy and latex-fruit syndrome.
Global atmospheric models play a key role in international assessments of the human impact on global climate and air pollution. To increase the accuracy and facilitate comparison of results from such ...models, it is essential they contain up‐to‐date chemical mechanisms. To this end, we present an evaluation of the atmospheric chemistry of the four most abundant organic peroxy radicals: CH3O2, C2H5O2, CH3C(O)O2, and CH3C(O)CH2O2. The literature data for the atmospheric reactions of these radicals are evaluated. In addition, the ultraviolet absorption cross sections for the above radicals and for HO2 have been evaluated. The absorption spectra were fitted to an analytical formula, which enabled published spectra to be screened objectively. Published kinetic and product data were reinterpreted, or in some case reanalyzed, using the new cross sections, leading to a self‐consistent set of kinetic, mechanistic, and spectroscopic data. Product studies were also evaluated. A set of peroxy radical reaction rate coefficients and products are recommended for use in atmospheric modeling. A three‐dimensional global chemical transport model (the Intermediate Model for the Global Evolution of Species, IMAGES) was run using both previously recommended rate coefficients and the current set to highlight the sensitivity of key atmospheric trace species to the peroxy radical chemistry used in the model.
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