Compton Scattering In Electron Energy Loss Spectrometry

It is well known that the distribution of electron momenta (electron density in momentum representation) of gases can be probed by Compton scattering of either photons (γ-rays or X-rays) or electrons. Recently it has been shown that Compton scattering of electrons is suited to the study of the electron momentum densities of solids on a microscopic scale. This technique, known as ECOSS, Electron Compton Scattering from Solids can be done in the electron microscope by electron energy loss spectrometry (EELS). After a discussion of inherent approximations and the introduction of the reciprocal form factor a method is proposed in order to cope with the main difficulty, namely multiple scattering. Important applications of ECOSS are the study of anisotropy of momentum densities; correlation effects of conduction electrons in metals; and charge transfer in alloys

Noninvasive ¹³C-octanoic acid breath test shows delayed gastric emptying in patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive loss of motor neurons. However, ALS has been recognized to also involve non-motor systems. Subclinical involvement of the autonomic system in ALS has been described. The recently developed C-13-octanoic acid breath test allows the noninvasive measurement of gastric emptying. With this new technique we investigated 18 patients with ALS and 14 healthy volunteers. None of the patients had diabetes mellitus or other disorders known to cause autonomic dysfunction. The participants received a solid standard test meal labeled with C-13-octanoic acid. Breath samples were taken at 15-min intervals for 5 h and were analyzed for (CO2)-C-13 by isotope selective nondispersive infrared spectrometry. Gastric emptying peak time (t(peak)) and emptying half time (t(1/2)) were determined. All healthy volunteers displayed normal gastric emptying with a mean emptying t(1/2) of 138 +/- 34 (range 68-172) min. Gastric emptying was delayed (t(1/2) > 160 min) in 15 of 18 patients with ALS. Emptying t(1/2) in ALS patients was 218 +/- 48 (range 126-278) min (p < 0.001). These results are compatible with autonomic involvement in patients with ALS, causing delayed gastric emptying of solids and encouraging the theory that ALS is a multisystem disease rather than a disease of the motor neurons only

Reforestation in a high-CO2 world - Higher mitigation potential than expected, lower adaptation potential than hoped for

We assess the potential and possible consequences for the global climate of a strong reforestation scenario for this century. We perform model experiments using the Max Planck Institute Earth System Model (MPI-ESM), forced by fossil-fuel CO2 emissions according to the high-emission scenario Representative Concentration Pathway (RCP) 8.5, but using land use transitions according to RCP4.5, which assumes strong reforestation. Thereby, we isolate the land use change effects of the RCPs from those of other anthropogenic forcings. We find that by 2100 atmospheric CO2 is reduced by 85 ppm in the reforestation model experiment compared to the reference RCP8.5 model experiment. This reduction is higher than previous estimates and is due to increased forest cover in combination with climate and CO2 feedbacks. We find that reforestation leads to global annual mean temperatures being lower by 0.27 K in 2100. We find large annual mean warming reductions in sparsely populated areas, whereas reductions in temperature extremes are also large in densely populated areas

The sympathetic nervous system stimulates anti-inflammatory B cells in collagen-type II-induced arthritis

Background: As previously shown, the sympathetic nervous system (SNS) shows proinflammatory activity during initiation of arthritis but is anti-inflammatory in established collagen-induced arthritis (CIA). Interleukin 10 (IL-10)-producing B cells suppress arthritis and are a potential target of the SNS because (1) B cells express functional β2-adrenoceptors (β2ARs) and (2) IL-10, at least in monocytes/macrophages, is regulated in a cAMP/PKA/CREB-dependent manner. Objective: To test the hypothesis that anti-inflammatory effects of the SNS in CIA are mediated by stimulating IL-10-producing anti-inflammatory B cells. Methods: Collagen-induced arthritis in DBA/1 mice, sympathectomy, adoptive B cell transfer, in vitro B cell culture, and assessment of B cell IL-10 production. Results and conclusion: Mice treated with B cells from SNS-intact mice showed less severe arthritis than mice treated with B cells from sympathectomised mice. This anti-inflammatory action of B cells from SNS-intact mice correlated with increased IL-10 produced by B cells, which was mediated by norepinephrine (NE), in a β2AR, PKA-dependent manner. However, an NE-mediated increase in IL-10 was seen only in B cells from immunised but not naive mice, explaining in part the anti-inflammatory properties of the SNS in the late phase of arthritis. Finally, animals treated with B cells isolated from immunised mice and activated in vitro in the presence of a β2AR stimulus showed a decrease in arthritis severity in comparison with controls, an approach that might be used for future cellular treatment strategies

Towards net zero CO2 in 2050: an emission reduction pathway for organic soils in Germany

The Paris Agreement reflects the global endeavour to limit the increase of global average temperature to 2 °C, better 1.5 °C above pre-industrial levels to prevent dangerous climate change. This requires that global anthropogenic net carbon dioxide (CO2) emissions are reduced to zero around 2050. The German Climate Protection Plan substantiates this goal and explicitly mentions peatlands, which make up 5 % of the total area under land use and emit 5.7 % of total annual greenhouse gas emissions in Germany. Based on inventory reporting and assumptions of land use change probability, we have developed emission reduction pathways for organic soils in Germany that on a national level comply with the IPCC 1.5 °C pathways. The more gradual pathway 1 requires the following interim (2030, 2040) and ultimate (2050) milestones: Cropland use stopped and all Cropland converted to Grassland by 2030; Water tables raised to the soil surface on 15 % / 60 % / 100 % of all Grassland, on 50 % / 75 % / 100 % of all Forest land, and ultimately on 2/3 of all Settlements and on 100 % of all Wetlands. Also a more direct pathway 2 without interim ‘moist’ water tables and the climate effect (radiative forcing) of different scenarios is presente

Advances in land surface modelling

Land surface models have an increasing scope. Initially designed to capture the feedbacks between the land and the atmosphere as part of weather and climate prediction, they are now used as a critical tool in the urgent need to inform policy about land-use and water-use management in a world that is changing physically and economically. This paper outlines the way that models have evolved through this change of purpose and what might the future hold. It highlights the importance of distinguishing between advances in the science within the modelling components, with the advances of how to represent their interaction. This latter aspect of modelling is often overlooked but will increasingly manifest as an issue as the complexity of the system, the time and space scales of the system being modelled increase. These increases are due to technology, data availability and the urgency and range of the problems being studied. © 2021, The Author(s)

Terminology as a key uncertainty in net land use and land cover change carbon flux estimates

Reasons for the large uncertainty in land use and land cover change (LULCC) emissions go beyond recognized issues related to the available data on land cover change and the fact that model simulations rely on a simplified and incomplete description of the complexity of biological and LULCC processes. The large range across published LULCC emission estimates is also fundamentally driven by the fact that the net LULCC flux is defined and calculated in different ways across models. We introduce a conceptual framework that allows us to compare the different types of models and simulation setups used to derive land use fluxes. We find that published studies are based on at least nine different definitions of the net LULCC flux. Many multi-model syntheses lack a clear agreement on definition. Our analysis reveals three key processes that are accounted for in different ways: the land use feedback, the loss of additional sink capacity, and legacy (regrowth and decomposition) fluxes. We show that these terminological differences, alone, explain differences between published net LULCC flux estimates that are of the same order as the published estimates themselves. This has consequences for quantifications of the residual terrestrial sink: the spread in estimates caused by terminological differences is conveyed to those of the residual sink. Furthermore, the application of inconsistent definitions of net LULCC flux and residual sink has led to double-counting of fluxes in the past. While the decision to use a specific definition of the net LULCC flux will depend on the scientific application and potential political considerations, our analysis shows that the uncertainty of the net LULCC flux can be substantially reduced when the existing terminological confusion is resolved