Search

Break-off of part of the down-going plate during continental collision occurs due to tensile stresses built-up between the deep and shallow slab, for which buoyancy is increased because of continental-crust subduction. Break-off governs the subsequent orogenic evolution but real-time observations are rare as it happens over geologically short times. Here we present a finite-frequency tomography, based on jointly inverted local and remote earthquakes, for the Hindu Kush in Afghanistan, where slab break-off is ongoing. We interpret our results as crustal subduction on top of a northwards-subducting Indian lithospheric slab, whose penetration depth increases along-strike while thinning and steepening. This implies that break-off is propagating laterally and that the highest lithospheric stretching rates occur during the final pinching-off. In the Hindu Kush crust, earthquakes and geodetic data show a transition from focused to distributed deformation, which we relate to a variable degree of crust-mantle coupling presumably associated with break-off at depth.

BACKGROUND: Data on changes in natural killer cell cytolytic activity (NKCA) in response to acute physical exercise are contradictory. OBJECTIVE: The aim of this systematic review, meta-analysis and meta-regression is to (1) examine the effect of acute physical exercise on NKCA, (2) shed more light on the moderating factors, and (3) test the assumption of NKCA suppression subsequent to performing sports. METHODS: Two comparisons of NKCA were performed: (1) pre- versus post-exercise and (2) pre-exercise versus recovery. Data were acquired through a systematic search of MEDLINE (via PubMed), Scopus, and SportDiscus. Studies were eligible for inclusion if the effect of acute physical exercise was assessed including a passive control group and reporting NKCA prior to and immediately after the trial, and during the first 2 h of recovery. To better explain between-study heterogeneity, a moderator analysis was conducted. RESULTS: Pooled estimate from 12 studies reporting 18 effect sizes show that NKCA is largely elevated by acute physical exercise (Hedges' g = 1.02, 95% CI 0.59-1.46, p < 0.01). Meta-regressions reveal that this effect is larger for endurance versus resistance exercise and increases with the intensity of exercise (both p < 0.01), whereas the blood material used in the assay (p = 0.71), and the quantitative change in NK-cell count (R2 = 0%, p = 0.55) do not play a significant role. Physical exercise does not affect the level of NKCA after the recovery period (g = 0.06, 95% CI - 0.37 to 0.50, p < 0.76). CONCLUSIONS: This work provides solid evidence for elevated NKCA through performing sports which returns to baseline during the first 1-2 h of recovery, but not below the pre-exercise values providing counterevidence to the assumption of temporarily reduced NKCA. Remarkably, the functional change in NKCA exists independently from the quantitative change in NK-cell count. PROSPERO registration number: CRD42020134257.

Exercise under fasting conditions induces a switch to lipid metabolism, eliciting beneficial metabolic effects. Knowledge of signaling responses underlying metabolic adjustments in such conditions may help to identify therapeutic strategies. Therefore, w

The combination of aging populations with the obesity pandemic results in an alarming rise in non-communicable diseases. Here, we show that the enigmatic adenosine A2B receptor (A2B) is abundantly expressed in skeletal muscle (SKM) as well as brown adipose tissue (BAT) and might be targeted to counteract age-related muscle atrophy (sarcopenia) as well as obesity. Mice with SKM-specific deletion of A2B exhibited sarcopenia, diminished muscle strength, and reduced energy expenditure (EE), whereas pharmacological A2B activation counteracted these processes. Adipose tissue-specific ablation of A2B exacerbated age-related processes and reduced BAT EE, whereas A2B stimulation ameliorated obesity. In humans, A2B expression correlated with EE in SKM, BAT activity, and abundance of thermogenic adipocytes in white fat. Moreover, A2B agonist treatment increased EE from human adipocytes, myocytes, and muscle explants. Mechanistically, A2B forms heterodimers required for adenosine signaling. Overall, adenosine/A2B signaling links muscle and BAT and has both anti-aging and anti–obesity potential.

CaTeNA – Climatic and Tectonic Natural Hazards in Central Asia – is an interdisciplinary, international project funded by the German Ministry of Education and Research to study natural hazards in Central Asia. Central Asia is one of the most tectonically active regions of the world and is influenced by both the west wind zone and monsoon. CaTeNA is examining the two most serious natural hazards arising from these conditions: Earthquakes and mass movements. The project goal is to better understand the underlying processes and triggering factors and to better estimate the resulting risks. For this purpose, CaTeNA localises tectonic faults and determines deformation rates and their changes. Focus is put on two of the most active fault systems, the Main Pamir Thrust and the Darvaz Fault crossing Tajikistan and Kyrgyzstan. We try to estimate recurrence intervals of large earthquakes and to understand their relationship to mass movements using paleo-seismology, geomorphology and remote sensing. The current deformation field is characterised and quantified using the methods of space geodesy and seismology. The results will be incorporated into the openly accessible Central Asian Tectonic Database developed within the project, making it accessible to the public, stakeholders and decision-makers. They form the basis for a more accurate estimation of the risk for earthquakes and landslides. Another important project goal is the development and implementation of a dynamic risk assessment for landslides, including high-resolution, model-based precipitation and snowmelt maps. This allows for improved estimation of the effects of geological hazards on inhabited areas and traffic infrastructure. Direct and efficient risk communication is achieved through interactive visualisation based on a dynamic multilingual web GIS platform. This is an essential step on the path to an early-warning system that takes into account the most important triggering factors. This data repository provi