Wildfire-smoke-precipitation interactions in Siberia: Insights from a regional model study.

Powerful wildfires occurring in Siberia each summer emit large amounts of smoke aerosol that, according to studies of the environmental impacts of biomass burning (BB) aerosol in different regions of the world, can affect precipitation and other weather parameters and induce feedback on fires. However, the knowledge of smoke-weather interactions and fire-weather feedback in Siberia is presently limited. To advance this knowledge, we performed coupled-meteorology-chemistry simulations of aerosols and weather in a Siberian region covering taiga and tundra using the CHIMERE chemistry-transport model and the WRF meteorological model. We addressed a monthly period of July 2016 and considered several modeling scenarios in which aerosol-radiation interaction (ARI) and aerosol-cloud interaction (ACI) were taken into account jointly or separately. The simulation results were combined with emission and precipitation data retrieved from satellite observations. The joint analysis of the simulated precipitation fields and satellite-observation-based data revealed that in the taiga, the inhibiting effect of Siberian smoke on precipitation induced a significant positive feedback on BB aerosol emissions that, according to our estimates, enhanced by 27 (±7) % respective to a hypothetical situation in which smoke-weather interactions were absent. At the same time, an increase of precipitation over active fire spots due to ACI and ARI in tundra led to the formation of a negative feedback loop between fire emissions and BB smoke, resulting in a reduction of BB aerosol emissions there by 14 (±6) %. Hence, this study revealed evidence for significant feedback of smoke-induced precipitation changes on fire emissions in Siberia. Given the global importance of Siberia as a major carbon sink, this feedback needs to be studied further and accurately taken into account in projections of climate change both on regional and global scales.

Compensatory action of the index and middle finger in the kinematic chain of a basketball shot.

Performing effective actions requires the basketball player to balance factors such as motor variability, error minimalization and a complex sequence of coordination to determine the best action. PURPOSE: The aim of the study was to differentiate the strength of the muscles of the index and middle fingers when performing a basketball shot. MATERIALS AND METHODS: Study group consisted of 122 male college basketball league students. The study included psychophysiological tests to determine indices of individual and typological characterictics s of higher nervous activity, proprioceptive sensitivity tests of the fingers of the leading hand and field tests to assess participants' shooting skills. The touch-based finger pressure sensing system measured the different levels of pressure exerted by the participants' main index and middle finger during grasping. RESULTS: For both the middle and index finger, the highest correlation with shot efficiency was found for a 120 g load g (p < 0.01 for 2PS; 2PS40 suc; FT; 3PSO and 3.5 mS). Furthermore, high reproducibility of proprioceptive sensitivity of the index and middle finger of the leading hand was found in basketball players. CONCLUSIONS: The research indicates that it is possible to organize compensatory behavior between joints on the basis of proprioception, with the last compensatory movements of the kinematic chain being performed by the fingers of the hand. The demonstrated high proprioceptive sensitivity of the index and middle finger of the leading hand in basketball players at a weekly interval may indicate ability to maintain high repeatability of movements controlled by these fingers.

DNA damage in frog erythrocytes after in vitro exposure to a high peak-power pulsed electromagnetic field.

Till the present time, the genotoxic effects of high peak-power pulsed electromagnetic fields (HPPP EMF) on cultured cells have not been studied. We investigated possible genotoxic effects of HPPP EMF (8.8 GHz, 180 ns pulse width, peak power 65 kW, repetition rate 50 Hz) on erythrocytes of the frog Xenopus laevis. We used the alkaline comet assay, which is a highly sensitive method to assess DNA single-strand breaks and alkali-labile lesions. Blood samples were exposed to HPPP EMF for 40 min in rectangular wave guide. The specific absorption rate (SAR) calculated from temperature kinetics was about 1.6 kW/kg (peak SAR was about 300 MW/kg). The temperature rise in the blood samples at steady state was 3.5 +/- 0.1 degrees C. The data show that the increase in DNA damage after exposure of erythrocytes to HPPP EMF was induced by the rise in temperature in the exposed cell suspension. This was confirmed in experiments in which cells were incubated for 40 min under the corresponding temperature conditions. The results allow us to conclude that HPPP EMF-exposure at the given modality did not cause any a-thermal genotoxic effect on frog erythrocytes in vitro.