Understanding the global hydrological droughts of 2003-2016 and their relationships with teleconnections.

Droughts often evolve gradually and cover large areas, and therefore, affect many people and activities. This motivates developing techniques to integrate different satellite observations, to cover large areas, and understand spatial and temporal variability of droughts. In this study, we apply probabilistic techniques to generate satellite derived meteorological, hydrological, and hydro-meteorological drought indices for the world's 156 major river basins covering 2003-2016. The data includes Terrestrial Water Storage (TWS) estimates from the Gravity Recovery And Climate Experiment (GRACE) mission, along with soil moisture, precipitation, and evapotranspiration reanalysis. Different drought characteristics of trends, occurrences, areal-extent, and frequencies corresponding to 3-, 6-, 12-, and 24-month timescales are extracted from these indices. Drought evolution within selected basins of Africa, America, and Asia is interpreted. Canonical Correlation Analysis (CCA) is then applied to find the relationship between global hydro-meteorological droughts and satellite derived Sea Surface Temperature (SST) changes. This relationship is then used to extract regions, where droughts and teleconnections are strongly interrelated. Our numerical results indicate that the 3- to 6-month hydrological droughts occur more frequently than the other timescales. Longer memory of water storage changes (than water fluxes) has found to be the reason of detecting extended hydrological droughts in regions such as the Middle East and Northern Africa. Through CCA, we show that the El Niño Southern Oscillation (ENSO) has major impact on the magnitude and evolution of hydrological droughts in regions such as the northern parts of Asia and most parts of the Australian continent between 2006 and 2011, as well as droughts in the Amazon basin, South Asia, and North Africa between 2010 and 2012. The Indian ocean Dipole (IOD) and North Atlantic Oscillation (NAO) are found to have regional influence on the evolution of hydrological droughts.

Structural and molecular adaptations to dexamethasone and unacylated ghrelin administration in skeletal muscle of the mice.

The central goal of this study was to identify the primary mechanisms triggering steroid atrophy. Adaptations of soleus (Sol) and vastus lateralis (VL) muscles of C57BL/6 female mice were studied following 3, 7 and 15 days of daily intraperitoneal injection (5 mg kg-1 day-1) of dexamethasone (dEx) (chronic treatment) and 1, 3 and 10 hours after a single dEx injection (acute treatment). In the chronic treatment, analyses were performed 24 hours after the last injection. Gene expression of major components of the intracellular signalling pathways controlling mass and metabolism were assessed. Analyses were repeated following dEx and unacylated ghrelin (uAG) (100 µg kg-1day-1), co-administration. We found a significant VL fibres atrophy after 7 (13%) and 15 (28%) days and a Sol fibres atrophy (23%) after 15 days of dEx treatment. The acute treatment showed, in both muscles, several responses in most signalling pathways, among which the enhanced gene expression of Murf-1 (6-fold change in VL and 3-fold in Sol) and myostatin (6-fold change in VL and 20-fold in Sol). In Sol, uAG administration was able to fully counteract muscle atrophy and Murf-1 upregulation, but not the upregulation of myostatin, suggesting a causal relationship between muscle atrophy and Murf-1. Results indicate that: a) the primary mechanism triggering steroid atrophy is an early transient activation of Murf-1; b) uAG inhibits Murf-1 induction counteracting steroid atrophy. The present work contributes to the understanding of the complexity of the muscle response to glucocorticoids.

Compliance in weight control reduces atrial fibrillation worsening: A retrospective cohort study.

BACKGROUND AND AIM: Obesity plays a dominant role in the etiology of atrial fibrillation (AF), and the maintenance of a normal body mass index (BMI) seems to prevent and even reduce the incidence of the arrhythmia's recurrence. We selected 270 patients (pts) to assess whether this therapeutic effect was statistically significant even in Mediterranean patients. METHOD AND RESULTS: In this retrospective cohort study, we analyzed every symptomatic AF relapse during a total follow-up of 657 patient-years. Clinical data, BMI variations, and pts' history were available in our clinical database. We divided the pts in four groups (Gs), according to their BMI variation during the follow-up: G1, normal weight pts, maintaining their weight; G2, overweight pts, losing weight; G3, overweight pts, maintaining their weight; G4, pts gaining weight. Their follow-up (in months) was normalized according to their AF relapses, thus obtaining a mean AF-free period for each patient. Among the overweight groups, G2 showed the best AF-free period (9.7 months). However, G3 and G4 showed a reduced AF-free interval (4.6 and 1.7 months, respectively). G1, predictably, had the longest AF-free period (10 months). CONCLUSION: The results of the present study confirm that simple non-invasive intervention aimed to normalize BMI and to control risk factors through appropriate lifestyle can be highly effective in reducing the AF burden, by acting on comorbidities and proarrhythmic mechanisms. Therefore, serious attempt should be made to correct risk factors before an ablation therapy is proposed.