Reconstruction of the Past and Forecast of the Future European and British Ice Sheets and Associated Sea–Level Change

The aim of this project is to improve our understanding of the past European and British ice sheets as a basis for forecasting their future. The behaviour of these ice sheets is investigated by simulating them using a numerical model and comparing model results with geological data including relative sea–level change data. In order to achieve this aim, a coupled ice sheet/lithosphere model is developed. Ice sheets form an integral part of the Earth system. They affect the planet’s albedo, atmospheric and oceanic circulation patterns, topography, and global and local sea–level change. In order to understand how these systems work, it is necessary to understand how ice sheets interact with other parts of the climate system. This project does this by simulating ice behaviour as part of the climate system and evaluating model behaviour in relation to evidence of past ice sheets. Ice sheet simulations can be treated with more confidence if they can be evaluated against independent data. A methodology is therefore developed that compares relative sea–level records with simulations of past sea–level which result from modelling past ice sheets with a dynamic, high–resolution thermo– mechanical ice sheet model coupled to an isostatic adjustment model. The Earth’s response to changing surface loads is simulated using both a regional, flat Earth approximation and a global, spherical self–gravitating Earth model. The coupled model is tested by initially simulating the past Fennoscandian ice sheet because of the simpler topographic framework and the quality of geological evidence of past fluctuations against which to evaluate model behaviour. The model is driven by a climatic forcing function determined so that the simulated ice sheet resembles the past Fennoscandian ice sheet as reconstructed from geomorphological evidence. The Fennoscandian climate driver is then transferred to the British Isles to simulate the past British ice sheet. Finally, a non–linear regression technique is used to construct future ice sheet drivers from future sea– level change scenarios to forecast sea–level change around the British Isles during the next glacial cycle. The data used for the inversion procedure is limited to southern Scandinavia. Outside this area, the simulation compares poorly with reconstructions based on geological observations. However, model fit within this region is good and the simulation is also in good agreement with features not used during the inversion process. This approach illustrates the benefit of using a model coupling realistic ice physics to a realistic Earth model to help constrain simultaneously unknowns of Earth rheology and ice thickness. Ultimately, relative sea–level data together with other strands of data, such as geomorphological evidence, and a coupled ice sheet/isostatic rebound model can be used to help infer past climates

Inhomogeneous Magnetism in La-doped CaMnO3. (II) Mesoscopic Phase Separation due to Lattice-coupled FM Interactions

A detailed investigation of mesoscopic magnetic and crystallographic phase separation in Ca(1-x)La(x)MnO3, 0.00<=x<=0.20, is reported. Neutron powder diffraction and DC-magnetization techniques have been used to isolate the different roles played by electrons doped into the eg level as a function of their concentration x. The presence of multiple low-temperature magnetic and crystallographic phases within individual polycrystalline samples is argued to be an intrinsic feature of the system that follows from the shifting balance between competing FM and AFM interactions as a function of temperature. FM double-exchange interactions associated with doped eg electrons are favored over competing AFM interactions at higher temperatures, and couple more strongly with the lattice via orbital polarization. These FM interactions thereby play a privileged role, even at low eg electron concentrations, by virtue of structural modifications induced above the AFM transition temperatures.Comment: 8 pages, 7 figure

Sex differences in patients with repaired tetralogy of Fallot support a tailored approach for males and females:a cardiac magnetic resonance study

Purpose Substantial differences between sexes exist with respect to cardiovascular diseases, including congenital heart disease. Nevertheless, clinical decisions in the long-term follow-up of patients with repaired tetralogy of Fallot (rTOF) are currently based on unisex thresholds for cardiac magnetic resonance (CMR) measurements. This study aimed to assess whether sex differences exist in cardiac adaptation to hemodynamic loading conditions in patients with rTOF. Methods and Results This cross-sectional, two-center, combined pediatric and adult cohort included 320 rTOF patients (163 males, 51%) who underwent routine CMR. Despite similar age (median and interquartile range [m + IQR] 23.4 [15.2-34.4] years), surgical history, and hemodynamic loading, males with rTOF demonstrated higher biventricular CMR-derived volumes and masses, indexed for body surface area, compared to females (e.g. m + IQR right ventricular (RV) end-diastolic volume: males 123 [100-151] mL/m2, females 114 [94-131] mL/m2, P = 0.007). Sex-specific Z-scores of biventricular volumes and masses were similar for males and females. RV volumes and masses correlated with hemodynamic loading, but these relations did not differ between sexes. Biventricular ejection fraction (EF) appeared to be lower in male patients, compared to female patients (e.g. m + IQR RVEF: males 48 [43-54]%, females 52 [46-57]%, P < 0.001). Conclusion Indexed ventricular volumes and masses are higher in males with rTOF, compared to females, similar to the healthy population. RV hypertrophy and dilatation correlated to loading conditions similarly for both sexes. However, under comparable loading conditions, males demonstrated more severe functional impairment. These results indicate that sex-differences should no longer be ignored in treatment strategies, including timing of pulmonary valve replacement

Inhibition of the prolyl isomerase Pin1 improves endothelial function and attenuates vascular remodelling in pulmonary hypertension by inhibiting TGF-beta signalling

Pulmonary arterial hypertension (PAH) is a devastating disease, characterized by obstructive pulmonary vascular remodelling ultimately leading to right ventricular (RV) failure and death. Disturbed transforming growth factor-beta (TGF-beta)/bone morphogenetic protein (BMP) signalling, endothelial cell dysfunction, increased proliferation of smooth muscle cells and fibroblasts, and inflammation contribute to this abnormal remodelling. Peptidyl-prolyl isomerase Pin1 has been identified as a critical driver of proliferation and inflammation in vascular cells, but its role in the disturbed TGF-beta/BMP signalling, endothelial cell dysfunction, and vascular remodelling in PAH is unknown. Here, we report that Pin1 expression is increased in cultured pulmonary microvascular endothelial cells (MVECs) and lung tissue of PAH patients. Pin1 inhibitor, juglone significantly decreased TGF-beta signalling, increased BMP signalling, normalized their hyper-proliferative, and inflammatory phenotype. Juglone treatment reversed vascular remodelling through reducing TGF-beta signalling in monocrotaline + shunt-PAH rat model. Juglone treatment decreased Fulton index, but did not affect or harm cardiac function and remodelling in rats with RV pressure load induced by pulmonary artery banding. Our study demonstrates that inhibition of Pin1 reversed the PAH phenotype in PAH MVECs in vitro and in PAH rats in vivo, potentially through modulation of TGF-beta/BMP signalling pathways. Selective inhibition of Pin1 could be a novel therapeutic option for the treatment of PAH.Cancer Signaling networks and Molecular Therapeutic

Volume load-induced right ventricular failure in rats is not associated with myocardial fibrosis

Background Right ventricular (RV) function and failure are key determinants of morbidity and mortality in various cardiovascular diseases. Myocardial fibrosis is regarded as a contributing factor to heart failure, but its importance in RV failure has been challenged. This study aims to assess whether myocardial fibrosis drives the transition from compensated to decompensated volume load-induced RV dysfunction.MethodsWistar rats were subjected to aorto-caval shunt (ACS, n = 23) or sham (control, n = 15) surgery, and sacrificed after 1 month, 3 months, or 6 months. Echocardiography, RV pressure-volume analysis, assessment of gene expression and cardiac histology were performed.ResultsAt 6 months, 6/8 ACS-rats (75%) showed clinical signs of RV failure (pleural effusion, ascites and/or liver edema), whereas at 1 month and 3 months, no signs of RV failure had developed yet. Cardiac output has increased two- to threefold and biventricular dilatation occurred, while LV ejection fraction gradually decreased. At 1 month and 3 months, RV end-systolic elastance (Ees) remained unaltered, but at 6 months, RV Ees had decreased substantially. In the RV, no oxidative stress, inflammation, pro-fibrotic signaling (TGF beta 1 and pSMAD2/3), or fibrosis were present at any time point.ConclusionsIn the ACS rat model, long-term volume load was initially well tolerated at 1 month and 3 months, but induced overt clinical signs of end-stage RV failure at 6 months. However, no myocardial fibrosis or increased pro-fibrotic signaling had developed. These findings indicate that myocardial fibrosis is not involved in the transition from compensated to decompensated RV dysfunction in this model.Therapeutic cell differentiatio

Animal Behavior Frozen in Time: Gregarious Behavior of Early Jurassic Lobsters within an Ammonoid Body Chamber

Direct animal behavior can be inferred from the fossil record only in exceptional circumstances. The exceptional mode of preservation of ammonoid shells in the Posidonia Shale (Lower Jurassic, lower Toarcian) of Dotternhausen in southern Germany, with only the organic periostracum preserved, provides an excellent opportunity to observe the contents of the ammonoid body chamber because this periostracum is translucent. Here, we report upon three delicate lobsters preserved within a compressed ammonoid specimen of Harpoceras falciferum. We attempt to explain this gregarious behavior. The three lobsters were studied using standard microscopy under low angle light. The lobsters belong to the extinct family of the Eryonidae; further identification was not possible. The organic material of the three small lobsters is preserved more than halfway into the ammonoid body chamber. The lobsters are closely spaced and are positioned with their tails oriented toward each other. The specimens are interpreted to represent corpses rather than molts. The lobsters probably sought shelter in preparation for molting or against predators such as fish that were present in Dotternhausen. Alternatively, the soft tissue of the ammonoid may have been a source of food that attracted the lobsters, or it may have served as a long-term residency for the lobsters (inquilinism). The lobsters represent the oldest known example of gregariousness amongst lobsters and decapods in the fossil record. Gregarious behavior in lobsters, also known for extant lobsters, thus developed earlier in earth's history than previously known. Moreover, this is one of the oldest known examples of decapod crustaceans preserved within cephalopod shells

Feasibility studies for the measurement of time-like proton electromagnetic form factors from p¯ p→ μ+μ- at P ¯ ANDA at FAIR

This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, | GE| and | GM| , using the p¯ p→ μ+μ- reaction at P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is p¯ p→ π+π-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented