Globally invariant metabolism but density-diversity mismatch in springtails

Soil life supports the functioning and biodiversity of terrestrial ecosystems1,2. Springtails (Collembola) are among the most abundant soil animals regulating soil fertility and flow of energy through above- and belowground food webs3-5. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset collected from 2,470 sites, we estimate total soil springtail biomass at 29 Mt carbon (threefold higher than wild terrestrial vertebrates6) and record peak densities up to 2 million individuals per m2 in the Arctic. Despite a 20-fold biomass difference between tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the increase in temperature. Neither springtail density nor community metabolism were predicted by local species richness, which was highest in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation7,8, and resource limitation7,9,10 in soil communities. Contrasting temperature responses of biomass, diversity and activity of springtail communities suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting major soil functions.

Сглаживающий эффект Si-слоев в многослойных зеркалах Be/Al для спектрального диапазона 17-31 nm

The results of studying the smoothing effect of thin Si films used as buffer layers in Be/Al multilayer mirrors optimized for operation at wavelengths longer than 17.1 nm are presented. The multilayer mirrors of the near-normal (grazing angle 88º) and sliding incidence (grazing angle 33.5º) are investigated. It is shown that the effect is observed for multilayer Be/Si/Al mirrors with periods of at least 29 nm. For normal incidence mirrors optimized for a wavelength of 17.14 nm, a record peak reflection coefficient of 62.5% was obtained with spectral selectivity λ/Δλ=59. The time stability of these mirrors was investigated.

Validation of new device with pneumatic sensor for measurement and recording of arterial blood pressure

This paper presents construction, operating principle and initial study of new device for measurement and recording of arterial blood pressure, created at Wroclaw University of Science and Technology. This device is equipped with a pneumatic pressure sensor based on the pneumatic nozzle flapper amplifier principle. During the measurement sensor is applied to the patient’s body, where the pulse is easily palpable. After that, sensor is gradually pressed against to the artery, in order to record peak amplitude. Maximum value of this amplitude corresponds to the real blood pressure waveform. This device was validated according to „International Protocol revision 2010 for the validation of blood pressure measuring devices in adults”.