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Torfajökull volcano, Iceland, has not erupted since 1477. However, intense geothermal activity, deformation, and seismicity suggest a long‐lasting magmatic system. In this paper, we use ambient noise tomography to image the magmatic system beneath Torfajökull volcano. One hundred days of ambient noise data from 23 broadband seismometers show the consistent presence of double‐frequency microseism noise with significant power between ∼0.1 and 0.5 Hz. Beamforming results indicate microseism noise with persistent higher energy propagating from west and SE directions and apparent velocities below 3 km/s. We use ambient noise seismic interferometry to retrieve Rayleigh waves, and we introduce a method to estimate the reliability of the retrieved surface waves. We find stable estimation of surface wave phase velocities between 0.16 and 0.38 Hz. Azimuthal velocity variations show a trend of higher velocities in the NE/SW direction, the strike of the rift zone intersecting Torfajökull, and orientation of erupted lavas on a NE‐SW fissure swarm. Tomographic results indicate low‐velocity anomalies beneath the volcano caldera (between −5% and −10%) and even lower velocity variations in the southeast and southwest study area (below −10%), outside the volcano caldera. Low anomalies may indicate the existence of hot material, more prominent outside the caldera outskirts. High‐velocity variations (between 5% and 10%) outline the volcano caldera between 4‐ and 5‐km depth and more pronounced velocities (between 10% and 15%) up to 5‐km depth in the north of the volcano caldera. We interpret the former as possible caldera collapse structure and the latest as solidified intrusive magma from the old preferred magma paths. Magmatic plumbing systems' characterization is one of the pillars for predicting volcanic eruptions. While most of the active volcanoes are being currently monitored, less is known about volcanoes that had not erupted recently. Torfajökull volcano, Iceland, has not erupted since 1477. However, intense geothermal activity, deformation, and seismicity suggest a long‐lasting magmatic system. We use ambient noise to produce a tomographic image of the magmatic system beneath Torfajökull volcano. This technique allows us to detect velocity variations/contrasts due to changes in composition, density, temperature, or pressure in the subsurface.We identify high‐velocity variations outlining the volcano caldera between 4‐ and 5‐km depth and more pronounced high‐velocities at shallower depths in the north of the volcano caldera. We interpret the former as possible caldera collapse structure and the latest as solidified (and dense) intrusive magma from the old preferred magma paths. The tomographic results also indicate low‐velocity anomalies beneath the volcano caldera and even lower‐velocity variations in the southeast and southwest study area, outside the volcano caldera. The most prominent low‐velocity features are located outside the volcano caldera outskirts. These low anomalies, or deceleration areas of wave velocity, may indicate the existence of hot material (molten or partially molten rock). This article presents the first tomographic image (3‐D Swave velocities) of Torfajökull's magmatic system; we have derived a 3‐D Swave velocity field from ambient noise tomographyWe developed a new methodology for phase velocity estimation from retrieved surface waves applied to 100 days of recorded ambient noiseWe interpret the low‐/high‐velocity anomalies interpreted as molten or partial molten cavities/channels (low) and old dike intrusions/caldera forming (high)

From non‐destructive testing to medical imaging and seismology, estimating the location of scatterers is of high importance. The location estimation can be achieved using a method inspired by seismic interferometry. This method correlates only the isolated scattered fields from a scatterer, and inverts for the travel times to estimate the scatterer’s location. The correlation eliminates the influence of the path between a source and a scatterer. We illustrate the potential of the method using data from a scaled laboratory model, representing geophysical field problems. We use ultrasonic data recorded on an aluminum block containing many scatterers at the surface represented by vertical drill holes. To estimate the horizontal coordinates of a scatterer, we use the scattered Rayleigh‐wave fields recorded along two lines due to one source. We address the problem of selecting scattered fields along the two lines that pertain to the same scatterer using simple geometrical considerations, but also during the inversion. We show that the inversion does not converge when scattered fields coming from different scatterers have been chosen for the correlation.

The investigation of near‐surface scatterers, such as cavities, tunnels, abandoned mine shafts, and buried objects, is important to mitigate geohazards and environmental hazards. By inversion of travel times of cross‐correlated scattered waves, due to the incident Rayleigh waves, we estimate the location of a near‐surface tunnel from seismic field data. The cross correlation eliminates the travel path between a source and a scatterer, thus eliminating the need to know the position of the source, making the estimation of the scatterers' locations dependent only on properties between the receivers and the scatterer. First time using a numerically verified method on seismic field data, we show the potential of the method for estimating the location of a buried scatterer. Tunnel location estimated accurately by correlation and inversionGhost arrivals retrieval by seismic interferometry of scattered wavesFirst time application of a numerically verified method on seismic field data

We report a single-frequency sub-nanosecond optical parametric oscillator (OPO) based on periodically poled stoichiometric lithium tantalate (PPSLT), pumped by a 1064-nm amplified microchip laser at a repetition rate of 0.5 kHz. Using a 11-mm-long PPSLT crystal polled with three different domain periods (30.2, 30.3, 30.4 um) and changing the temperature of the crystal from 20 degC to 265 degC, we have achieved wavelength tuning between 2990 nm and 3500 nm. The high nonlinearity of the used medium and the large aperture (2 mm) ensure the maximum idler output energy of [?]0.5 mJ in the whole tuning range, corresponding to average [?]10.5 % idler conversion efficiency and [?]250 mW of average power. Sub-nanosecond pulse durations have been obtained for the idler at 0.88-ns pulse duration of the pump.

ABSTRACTThe information about the authenticity of newly or already established animal cell cultures is essential. By using DNA analysis six cell lines has been investigated: 3T3, HeLa, McCoy, HEp-2, McCoy-Plovdiv and HEp-2-Plovdiv E. For the last four was made cytogenetic analysis confirmed that serum-free cell strains McCoy-Plovdiv and HEp-2-Plovdiv E are originally derived from McCoy and HEp-2 cell lines. PCR—analysis demonstrated that 3T3 cells are mouse originally, HeLa, HEp-2 and HEp-2- Plovdiv E are with the human origin and McCoy and McCoy-Plovdiv are hybrid cells carrying mouse and human genes in their genome.

High density lipoprotein (HDL) is rich in polyunsaturated phospholipids that are sensitive to oxidation. However, the effect of apolipoprotein A-I and paraoxonase-1 (PON-1) on phosphatidylcholine oxidation products has not been identified. We subjected native HDL, trypsinized HDL, and HDL lipid suspensions to oxidation by the peroxynitrite donor, 3-morpholinosydnonimine. HDL had a basal level of phosphatidylcholine mono- and di-hydroperoxides that increased to a greater extent in HDL, compared with either trypsinized HDL or HDL lipid alone. Phosphatidylcholine core aldehydes, which were present in small amounts, increased 10-fold during oxidation of native HDL, compared with trypsinized HDL (p = 0.004), and 4-fold compared with HDL lipid suspensions (p = 0.0021). In addition, the content of lysophosphatidylcholine increased 300% during oxidation of native HDL, but only 80 and 25%, respectively, during oxidation of trypsinized HDL and HDL lipid suspensions. Phosphatidylcholine isoprostanes accumulated in comparable amounts during the oxidation of all three preparations. Incubation of apolipoprotein A-I with 1-palmitoyl-2-linoleoyl glycerophosphocholine proteoliposomes in the presence of 3-morpholinosydnonimine or apoAI with phosphatidylcholine hydroperoxides resulted in a significant increase in phosphatidylcholine core aldehydes with no formation of lysophosphatidylcholine. We propose that apolipoprotein A-I catalyzes a one-electron oxidation of alkoxyl radicals. Purified PON-1 hydrolyzed phosphatidylcholine core aldehydes to lysophosphatidylcholine. We conclude that, upon HDL oxidation with peroxynitrite, apolipoprotein AI increases the formation of phosphatidylcholine core aldehydes that are subsequently hydrolyzed by PON1.

ABSTRACTGlycotoxins, products of Maillard's reaction, are complex chemical substances. They are Introduced by food or developed in the human organism. They have negative effect on different structural and functional activities of important biological molecules in both cells and extracellular matrix. A model glycotoxin 3-hydroxy1-methylpyridinium hydrochloride (HMP.HCl) was synthesized. HMP.HCl was derived from 3-hydroxypyridine by methylation with methyliodid. Both the model glycotoxin and the starting 3-hydroxypyridine were investigated on cell cultures McCoy-Plovdiv and HepG-2 for cytotoxicity and genotoxicity activities. The test agents were used in a range of concentrations from 20 to 0.2 mg/ml. Quantity cytotoxicity assessment was determinated by NR- and MTT assays and genotoxicity by Micronucleus assay. The higher cytotoxicity was determined for HMP. HCl compared to 3-hydroxypyridine, but no genotoxicity was determined without an exogenous activation. The water solution from the modifying compound HMP. HCl strongly decreased medium pH. Correlation was determined between medium pH and concentrations of test compound. We suggest that high acidity of culture medium causes the higher cell death.