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This paper presents an algorithm for detecting one of the most commonly used types of digital image forgeries - splicing. The algorithm is based on the use of the VGG-16 convolutional neural network. The proposed network architecture takes image patches as input and obtains classification results for a patch: original or forgery. On the training stage we select patches from original image regions and on the borders of embedded splicing. The obtained results demonstrate high classification accuracy (97.8% accuracy for fine-tuned model and 96.4% accuracy for the zero-stage trained) for a set of images containing artificial distortions in comparison with existing solutions. Experimental research was conducted using CASIA dataset.

The Gaver–Stehfest algorithm for numerical inversion of Laplace transform was developed in the late 1960s. Due to its simplicity and good performance it is becoming increasingly more popular in such diverse areas as geophysics, operations research and economics, financial and actuarial mathematics, computational physics, and chemistry. Despite the large number of applications and numerical studies, this method has never been rigorously investigated. In particular, it is not known whether the Gaver–Stehfest approximations converge or what the rate of convergence is. In this paper we answer the first of these two questions: We prove that the Gaver–Stehfest approximations converge for functions of bounded variation and functions satisfying an analogue of Dini criterion.

This article covers the molecular structure optimization and spectroscopic studies, such as Raman, UV–Vis absorption and FTIR, carried out for novel, biodegradable and biocompatible chitosan-graphene oxide (CS-GO) polymer nanocomposites (PNCs), which were synthesized by using simple blending technique followed by ultrasonification treatment. In addition, the structural and electrical properties have also been investigated. Under molecular structure optimization, the structural geometry, electronic structure (HOMO and LUMO) and potential distribution have been computed. X-ray diffraction of PNCs reveals that the crystallized phase of GO dominates over the CS giving modification in crystallite size and presence of micro-strain. FTIR and Raman spectroscopic studies have been carried out to confirm the proper formation of PNCs and presence of functional group in the composites. The surface morphology has been studied with the help of FESEM to confirm proper dispersion of GO sheets. Optical absorption edge and band gap analyzed from UV–Vis analysis reveal the semiconducting nature of PNCs. In addition, the optical band gap is tuned by varying the content of GO in PNCs. This tuning in band gap has also been supported by XRD and computational results. The dielectric constant and dc conductivity are found increased with increasing content of GO in PNCs. Additionally, the I–V characteristics of PNCs shows Ohmic type conduction with rising in current due to incorporation of GO. In view of the results achieved, the usage of CS-GO PNC is suitable for future development of optical and Gas sensors and UV-detectors, and therefore, such composite may be proven as a potential and suitable candidate for the optoelectronic or electrical devices operating at high frequencies.

Solar radio observations provide a unique diagnostic of the outer solar atmosphere. However, the inhomogeneous turbulent corona strongly affects the propagation of the emitted radio waves, so decoupling the intrinsic properties of the emitting source from the effects of radio wave propagation has long been a major challenge in solar physics. Here we report quantitative spatial and frequency characterization of solar radio burst fine structures observed with the Low Frequency Array, an instrument with high-time resolution that also permits imaging at scales much shorter than those corresponding to radio wave propagation in the corona. The observations demonstrate that radio wave propagation effects, and not the properties of the intrinsic emission source, dominate the observed spatial characteristics of radio burst images. These results permit more accurate estimates of source brightness temperatures, and open opportunities for quantitative study of the mechanisms that create the turbulent coronal medium through which the emitted radiation propagates. Radio observations of the solar atmosphere provide a unique view on the non-thermal processes in the outer atmosphere. Here the authors use LOFAR observations to demonstrate that the observed radio burst characteristics are dominated by propagation effects rather than underlying emission variations.

We have obtained propagators in the position space as an expansion over Landau levels for the charged scalar particle, fermion, and massive vector boson in a constant external magnetic field. The summation terms in the resulting expressions consisted of two factors, one being rotationally invariant in the 2-dimensional Euclidean space perpendicular to the direction of the field, and the other being Lorentz-invariant in the 1+1-dimensional space-time. The obtained representations are unique in the sense that they allow for the simultaneous study of the propagator from both space-time and energetic perspectives which are implicitly connected. These results contribute to the development of position-space techniques in QFT and are expected to be of use in the calculations of loop diagrams.

We develop a mathematical model that enables us to investigate possible mechanisms by which two primary markers of Alzheimer's disease (AD), extracellular amyloid plaques and intracellular tangles, may be related. Our model investigates the possibility that the decay of anterograde axonal transport of amyloid precursor protein (APP), caused by toxic tau aggregates, leads to decreased APP transport towards the synapse and APP accumulation in the soma. The developed model thus couples three processes: (i) slow axonal transport of tau, (ii) tau misfolding and agglomeration, which we simulated by using the Finke–Watzky model and (iii) fast axonal transport of APP. Because the timescale for tau agglomeration is much larger than that for tau transport, we suggest using the quasi-steady-state approximation for formulating and solving the governing equations for these three processes. Our results suggest that misfolded tau most likely accumulates in the beginning of the axon. The analysis of APP transport suggests that APP will also likely accumulate in the beginning of the axon, causing an increased APP concentration in this region, which could be interpreted as a ‘traffic jam’. The APP flux towards the synapse is significantly reduced by tau misfolding, but not due to the APP traffic jam, which can be viewed as a symptom, but rather due to the reduced affinity of kinesin-1 motors to APP-transporting vesicles.

In complex multilayer structures made from PCM, metal inclusions of small sizes (from 0.1 ÷ 0.2 to 15 mm) randomly distributed throughout the material (at depths up to 100 mm), are unacceptable for normal operation, as they can penetrate into the material structure of a finished product. This paper is aimed at developing a device that provides a small error in determining the coordinates of small-sized metal inclusions in PCM when they are detected in real conditions of production and operation. Some devices capable of detecting the content of small particles in fluids or capable of detecting metal objects in various environments are known. The disadvantages of these devices are that they can only detect magnetically active particles, or large objects-more than 3-6 mm, while the location accuracy is recorded with a big error, insufficient for the detection process of small metal inclusions in PCM-from 30 mm and higher. This determines the urgency of developing a device for detecting small metal inclusions in finished products from PCM and in the technological cycle of their production. In this paper, the basic principles of the developed device are described, a block diagram of the device is presented, including the configuration of the eddy current transducer and the main processing units of the signals coming from the transducer. As confirmation of the operation of the developed device, photos of experimental studies and their results are presented in the form of the obtained dependences of the value of metal inclusions on the depth of their occurrence, from which it can be seen that the error in determining the depth of small-sized metal inclusions by the developed device did not exceed 10% and unchanged for all small-sized metal inclusions.

Gain of chromosome 17q correlates with high-stage disease, an adverse clinical outcome and leads to the overexpression of the antiapoptotic protein BIRC5/Survivin in neuroblastoma (NB). We have shown before that Survivin defines a threshold for the sensitivity of NB cells to DNA-damaging chemotherapeutic agents that require FOXO3 activation for apoptosis induction. To investigate the molecular basis of apoptosis inhibition we analyzed the function of Survivin at mitochondria and uncovered that Survivin induces mitochondrial fragmentation, reduces mitochondrial respiration and represses BCL2L11/Bim. Mitochondrial fission depends on Survivin-induced recruitment of the fission regulator DNM1L/Drp1 to mitochondria. In parallel, Survivin expression inhibits the respiratory complex-I, thereby preventing reactive oxygen species accumulation and, as a consequence, FOXO3-induced apoptosis. The loss of energy production via oxidative phosphorylation is compensated by increased glycolysis in Survivin-overexpressing NB tumor cells. Glycolysis inhibitors neutralize the antiapoptotic effect of Survivin and sensitize high-stage NB to DNA-damaging drugs. This suggests that glycolysis inhibitors target an ‘archilles heel’ of Survivin-overexpressing NB and may be highly useful as chemosensitizers in the treatment of high-stage NB.

The harmonic modulation of coherent systems gives rise to a wealth of physical phenomena, e.g., the AC-Stark effect and Mollow triplets, with important implications for coherent control and frequency conversion. Here, we demonstrate a novel regime of temporal coherence in oscillators harmonically driven at extreme energy modulation amplitudes relative to the modulation quantum. The studies were carried out by modulating a confined exciton-polariton Bose-Einstein condensate (BEC) by an acoustic wave. Features of the new regime are the appearance, in the spectral domain, of a comb of resonances termed acceleration beats with energy spacing tunable by the modulation amplitude and, in the time domain, of temporal correlations at time scales much shorter than the acoustic period, which also depend on the modulation amplitude. These features are quantitatively accounted for by a theoretical framework, which associates the beats with accelerated energy-change rates during the harmonic cycle. These observations are underpinned by the high sensitivity of the BEC energy to the acoustic driving, which simultaneously preserves the BEC’s temporal coherence. The acceleration beats are a general feature associated with accelerated energy changes: analogous features are thus also expected to appear under highly accelerated motion e.g., in connection with Cherenkov and Hawking radiation. The authors demonstrate a novel regime of coherent harmonic modulation yielding resonances (termed acceleration beats) with energy spacing and temporal correlations controlled by the modulation amplitude. These features are associated with accelerated energy-change rates during the harmonic cycle.

In this paper, we develop a mathematical model that enables the investigation of the production and intracellular transport of amyloid precursor protein (APP) and tau protein in a neuron. We also investigate the aggregation of APP fragments into amyloid-β (Aβ) as well as tau aggregation into tau oligomers and neurofibrillary tangles. Using the developed model, we investigate how Aβ aggregation can influence tau transport and aggregation in both the soma and the axon. We couple the Aβ and tau agglomeration processes by assuming that the value of the kinetic constant that describes the autocatalytic growth (self-replication) reaction step of tau aggregation is proportional to the Aβ concentration. The model predicts that APP and tau are distributed differently in the axon. While APP has a uniform distribution along the axon, tau's concentration first decreases and then increases towards the synapse. Aβ is uniformly produced along the axon while misfolded tau protein is mostly produced in the proximal axon. The number of Aβ and tau polymers originating from the axon is much smaller than the number of Aβ and tau polymers originating from the soma. The rate of production of misfolded tau polymers depends on how strongly their production is facilitated by Aβ.