26 research outputs found

    A process study on thinning of Arctic winter cirrus clouds with high‐resolution ICON‐ART simulations

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    In this study, cloud‐resolving simulations of a case study for a limited area of the hibernal Arctic were performed with the atmospheric modeling system ICON‐ART (ICOsahedral Nonhydrostatic‐Aerosol and Reactive Trace gases). A thorough comparison with data both from satellite as well as aircraft measurement is presented to validate the simulations. In addition, the model is applied to clarify the microphysical processes occurring when introducing artificial aerosol particles into the upper troposphere with the aim of modifying cirrus clouds in the framework of climate engineering. Former modeling studies investigating the climate effect of this method were performed with simplifying assumptions and much coarser resolution, reaching partly contradicting conclusions concerning the method's effectiveness. The primary effect of seeding is found to be a reduction of ice crystal number concentrations in cirrus clouds, leading to increased outgoing longwave radiative fluxes at the top of the atmosphere, thereby creating a cooling effect. Furthermore, a secondary effect is found, as ice crystals formed from the injected seeding aerosol particles lead to enhanced riming of cloud droplets within the planetary boundary layer. This effectively reduces the coverage of mixed‐phase clouds, thus generating additional cooling by increased upward longwave radiative fluxes at the surface. The efficacy of seeding cirrus clouds proves to be relatively independent from the atmospheric background conditions, scales with the number concentrations of seeding particles, and is highest for large aerosol particles

    A Process Study on Thinning of Arctic Winter Cirrus Clouds With High‐Resolution ICON‐ART Simulations

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    In this study, cloud‐resolving simulations of a case study for a limited area of the hibernal Arctic were performed with the atmospheric modeling system ICON‐ART (ICOsahedral Nonhydrostatic‐Aerosol and Reactive Trace gases). A thorough comparison with data both from satellite as well as aircraft measurement is presented to validate the simulations. In addition, the model is applied to clarify the microphysical processes occurring when introducing artificial aerosol particles into the upper troposphere with the aim of modifying cirrus clouds in the framework of climate engineering. Former modeling studies investigating the climate effect of this method were performed with simplifying assumptions and much coarser resolution, reaching partly contradicting conclusions concerning the method's effectiveness. The primary effect of seeding is found to be a reduction of ice crystal number concentrations in cirrus clouds, leading to increased outgoing longwave radiative fluxes at the top of the atmosphere, thereby creating a cooling effect. Furthermore, a secondary effect is found, as ice crystals formed from the injected seeding aerosol particles lead to enhanced riming of cloud droplets within the planetary boundary layer. This effectively reduces the coverage of mixed‐phase clouds, thus generating additional cooling by increased upward longwave radiative fluxes at the surface. The efficacy of seeding cirrus clouds proves to be relatively independent from the atmospheric background conditions, scales with the number concentrations of seeding particles, and is highest for large aerosol particles

    Über die Genese der megaloblastischen Blutbildung

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    Calculati ons of gaseous and parti culate emissions from German agriculture 1990 – 2017 : Report on methods and data (RMD) Submission 2019

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    The report at hand (including a comprehensive annex of data) serves as additional document to the National Inventory Report (NIR) on the German green house gas emissions and the Informative Inventory Report (IIR) on the German emissions of air pollutants (especially ammonia). The report documents the calculation methods used in the German agricultural inventory model GAS-EM as well as input data, emission results and uncertainties of the emission reporting submission 2018 for the years 1990 - 2017. In this context the sector Agriculture comprises the emissions from animal husbandry, the use of agricultural soils and anaerobic digestion of energy crops. As required by the guidelines, emissions from activities preceding agriculture, from the use of energy and from land use change are reported elsewhere in the national inventories. The report at hand (including a comprehensive annex of data) serves as additional document to the National Inventory Report (NIR) on the German green house gas emissions and the Informative Inventory Report (IIR) on the German emissions of air pollutants (especially ammonia). The report documents the calculation methods used in the German agricultural inventory model GAS-EM as well as input data, emission results and uncertainties of the emission reporting submission 2018 for the years 1990 - 2017. In this context the sector Agriculture comprises the emissions from animal husbandry, the use of agricultural soils and anaerobic digestion of energy crops. As required by the guidelines, emissions from activities preceding agriculture, from the use of energy and from land use change are reported elsewhere in the national inventories.The report at hand (including a comprehensive annex of data) serves as additional document to the National Inventory Report (NIR) on the German green house gas emissions and the Informative Inventory Report (IIR) on the German emissions of air pollutants (especially ammonia). The report documents the calculation methods used in the German agricultural inventory model GAS-EM as well as input data, emission results and uncertainties of the emission reporting submission 2018 for the years 1990 - 2017. In this context the sector Agriculture comprises the emissions from animal husbandry, the use of agricultural soils and anaerobic digestion of energy crops. As required by the guidelines, emissions from activities preceding agriculture, from the use of energy and from land use change are reported elsewhere in the national inventories. The calculation methods are based in principle on the international guidelines for emission reporting and have been continuingly improved during the past years by the ThĂŒnen Institute working group on agricultural emission inventories, partly in cooperation with KTBL. In particular, these improvements concern the calculation of energy requirements, feeding and the N balance of the most important animal categories. In addition, technical measures such as air scrubbing (mitigation of ammonia emissions) and digestion of animal manures (mitigation of emissions of methane and laughing gas) have been taken into account. For the calculation of emissions from anaerobic digestion of animal manures and energy crops (including spreading of the digestate), the aforementioned working group developed, in cooperation with KTBL, a national methodology

    Calculations of gaseous and particulate emissions from German agriculture 1990–2020 : report on methods and data (RMD) submission 2022

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    The report at hand (including a comprehensive annex of data) serves as additional document to the National In-ventory Report (NIR) on the German green house gas emissions and the Informative Inventory Report (IIR) on the German emissions of air pollutants (especially ammo-nia). The report documents the calculation methods used in the German agricultural inventory model Py-GAS-EM as well as input data, emission results and uncertainties of the emission reporting submission 2022 for the years 1990 - 2020. In this context the sector Agriculture comprises the emissions from animal husbandry, the use of agricultural soils and anaerobic digestion of energy crops. As required by the guidelines, emissions from activities preceding ag-riculture, from the use of energy and from land use change are reported elsewhere in the national invento-ries. The calculation methods are based in principle on the international guidelines for emission reporting and have been continuingly improved during the past years by the ThĂŒnen Institute working group on agricultural emission inventories, partly in cooperation with KTBL. In particular, these improvements concern the calculation of energy requirements, feeding and the N balance of the most im-portant animal categories. In addition, technical measures such as air scrubbing (mitigation of ammonia emissions) and digestion of animal manures (mitigation of emissions of methane and laughing gas) have been taken into account. For the calculation of emissions from anaerobic digestion of animal manures and energy crops (including spreading of the digestate), the aforemen-tioned working group developed, in cooperation with KTBL, a national methodology. Total GHG emissions from German agriculture de-creased from 70.6 Tg CO2eq in 1990 to 56.1 Tg CO2eq in 2020 (-20.5 %). This reduction is a consequence of the fol-lowing emission changes of partial sources (rounded fig-ures): ‱ decrease of 9.3 Tg CO2eq (-28.0 %) as CH4 from enteric fermentation, ‱ decrease of 2.1 Tg CO2eq (-18.1 %) as CH4 and N2O from manure management, ‱ increase of 1.6 Tg CO2eq as CH4 and N2O from anaer-obic digestion of energy crops (digester + storage of digestate; 1990: 0 Tg), ‱ decrease of 4.1 Tg CO2eq (18.0 %) as N2O from agri-cultural soils, ‱ decrease of 0.56 Tg CO2eq (-20.6 %) as CO2 from lim-ing (agriculture and forest), ‱ increase of 0.02 Tg CO2eq (+5.1 %) as CO2 from appli-cation of urea. These changes are largely the result of the decline in animal numbers following reunification (reduction of oversized livestock numbers in Eastern Germany) and from the mid-2000s due to the limiting effect of the milk quota system (albeit with a renewed increase due to abolition of the milk quota system as of 31 May 2015). Increased nitrogen fertilization (mainly due to the appli-cation of increasingly larger amounts of digestate) led to an increase in greenhouse gas emissions from the mid-2000s. By contrast, the increasing use of manure in biogas plants has contributed to a reduction in methane emis-sions from manure storage. The NH3 time series as well is a result of counteracting processes. Here too, one of the important governing quantities is the animal number the decrease of which after the German reunification is the main reason for the considerable decrease of the emissions from 1991 to 1992. Mitigation measures like emission-reduced stor-age and application of manure led to a reduction of emis-sions in subsequent years. However, opposite trends are caused by increase of animal performance and, for some years, animal numbers. In addition, emissions from appli-cation of synthetic fertilizer were higher than in 1990 in the years between 1998 and 2017, even though the amount of synthetic fertilizer applied decreased (in units of nitrogen). The observed increase of emissions was due to the increasing share of urea, as urea has a considerably higher emission factor than other synthetic fertilizers. Since 2020, urea fertilizers must either be incorporated within four hours or be stabilized with a urease inhibitor, which is why the emission factor has been greatly re-duced from this year onwards. A major contributor to the increase in NH3 emissions in recent years has been the increase in anaerobic diges-tion of energy crops. Including anaerobic digestion of en-ergy crops (including spreading of digestates) leads 2020 to total NH3 emissions from agriculture of 512.3 Gg, which is 25.5 % less than 1990 and 8.6% less than 2005

    Optimization of Rituximab for the Treatment of Diffuse Large B-Cell Lymphoma (II): Extended Rituximab Exposure Time in the SMARTE-R-CHOP-14 Trial of the German High-Grade Non-Hodgkin Lymphoma Study Group

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    Purpose To study pharmacokinetics, toxicity, and efficacy of prolonged rituximab exposure in elderly patients with diffuse large B-cell lymphoma (DLBCL). Patients and Methods In the SMARTE-R-CHOP-14 trial, rituximab 375 mg/m(2) was administered, together with six cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone on a 14-day schedule (6xR-CHOP-14), on days -4, 0, 10, 29, 57, 99, 155, and 239. Pharmacokinetics and outcome were to be compared with those of patients who had received 6xR-CHOP-14 in combination with eight 2-week applications of rituximab in the RICOVER-60 (Rituximab With CHOP Over Age 60 Years) trial. Results The complete response (CR)/unconfirmed CR rate was 85% in 189 evaluable patients, 90% for 90 good-prognosis patients (International Prognostic Index [IPI], 1 or 2), and 81% for 99 poor-prognosis patients (IPI, 3 to 5); 3-year event-free survival (EFS) was 71%, 75%, and 67%, respectively; and 3-year overall survival (OS) was 84%, 88%, and 80%, respectively, with no differences between men and women. The preplanned historical comparison with 306 RICOVER-60 patients (good prognosis, n = 183; poor prognosis, n = 123) revealed no outcome differences for all and good-prognosis patients; however, the longer exposure time in SMARTE-R-CHOP-14 compared with RICOVER-60 was associated with better 3-year EFS (67% v 54%) and OS (80% v 67%) in poor-prognosis patients. Conclusion Extended rituximab exposure compared with eight 2-week applications in combination with 6xR-CHOP-14 significantly improved outcome of elderly poor-prognosis patients without increasing toxicity. To our knowledge, results obtained with the SMARTE-R-CHOP-14 rituximab schedule are the best reported for elderly patients with DLBCL to date. In the subgroup of poor-prognosis patients treated with extended rituximab exposure, the outcome seemed superior to that of a similar historical cohort of patients treated with 6xR-CHOP-14 plus 2-week rituximab, with similar toxicity. A randomized comparison of the two schedules is warranted. (C) 2014 by American Society of Clinical Oncolog
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