Paleoglaciated landscapes in Simen and other high-mountain areas of Ethiopia

In the present-day Ethiopia, glaciated landscapes do not exist, but paleoglaciated landscapes have been documented on a few mountain tops, which have altitudes higher than about 4,350 m asl in northern Ethiopia (Simen Mountains) and about 4,100 m asl in southern Ethiopia (Arsi and Bale Mountains). Glaciers were associated with the Late Pleistocene cold stages and reached as far down as 3,760 m asl in northern and 3,200 m asl in southern Ethiopia. Bale Mountains had the most extensive Late Pleistocene glaciation, covering over 190 km2, followed by Arsi Mountains (about 85 km2). In Simen, the Late Pleistocene glaciers covered merely 13 km2. In addition, paleo-periglacial slope deposits are found on all above-mentioned paleoglaciated mountains and in further mountain systems which did not host glaciers. This allows the reconstruction of the Late Pleistocene paleoclimate as being about 8 °C colder than at present (2014), much more dry, and probably without monsoon, at least in northern Ethiopia. Most probably in the Early Holocene, the re-emergence of monsoonal rains led to a strong erosion phase, which was followed by an extended stable phase with soil formation, building up about 70-cm-deep A-horizons (Andosol) on the paleo-periglacial slope deposits. These soils have been heavily degraded due to human-induced soil erosion up to about 3800 m asl since agriculture started several decades to millennia ago.

Fibroblast Growth Factor 23 Is an Independent and Specific Predictor of Mortality in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND Strategies to improve risk prediction are of major importance in patients with heart failure (HF). Fibroblast growth factor 23 (FGF-23) is an endocrine regulator of phosphate and vitamin D homeostasis associated with an increased cardiovascular risk. We aimed to assess the prognostic effect of FGF-23 on mortality in HF patients with a particular focus on differences between patients with HF with preserved ejection fraction and patients with HF with reduced ejection fraction (HFrEF). METHODS AND RESULTS FGF-23 levels were measured in 980 patients with HF enrolled in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study including 511 patients with HFrEF and 469 patients with HF with preserved ejection fraction and a median follow-up time of 8.6 years. FGF-23 was additionally measured in a second cohort comprising 320 patients with advanced HFrEF. FGF-23 was independently associated with mortality with an adjusted hazard ratio per 1-SD increase of 1.30 (95% confidence interval, 1.14-1.48; P<0.001) in patients with HFrEF, whereas no such association was found in patients with HF with preserved ejection fraction (for interaction, P=0.043). External validation confirmed the significant association with mortality with an adjusted hazard ratio per 1 SD of 1.23 (95% confidence interval, 1.02-1.60; P=0.027). FGF-23 demonstrated an increased discriminatory power for mortality in addition to N-terminal pro-B-type natriuretic peptide (C-statistic: 0.59 versus 0.63) and an improvement in net reclassification index (39.6%; P<0.001). CONCLUSIONS FGF-23 is independently associated with an increased risk of mortality in patients with HFrEF but not in those with HF with preserved ejection fraction, suggesting a different pathophysiologic role for both entities.

Radiomic Texture Analysis Mapping Predicts Areas of True Functional MRI Activity.

Individual analysis of functional Magnetic Resonance Imaging (fMRI) scans requires user-adjustment of the statistical threshold in order to maximize true functional activity and eliminate false positives. In this study, we propose a novel technique that uses radiomic texture analysis (TA) features associated with heterogeneity to predict areas of true functional activity. Scans of 15 right-handed healthy volunteers were analyzed using SPM8. The resulting functional maps were thresholded to optimize visualization of language areas, resulting in 116 regions of interests (ROIs). A board-certified neuroradiologist classified different ROIs into Expected (E) and Non-Expected (NE) based on their anatomical locations. TA was performed using the mean Echo-Planner Imaging (EPI) volume, and 20 rotation-invariant texture features were obtained for each ROI. Using forward stepwise logistic regression, we built a predictive model that discriminated between E and NE areas of functional activity, with a cross-validation AUC and success rate of 79.84% and 80.19% respectively (specificity/sensitivity of 78.34%/82.61%). This study found that radiomic TA of fMRI scans may allow for determination of areas of true functional activity, and thus eliminate clinician bias.