Brightness Variations Research Articles

Differences in Artificial Intelligence-Based Macular Fluid Parameters Between Clinical Stages of Diabetic Macular Edema and Their Relationship with Visual Acuity

Background/Objectives: The aim of this study was to determine artificial intelligence-based macular fluid (MF) parameters in diabetic macular edema (DME) with optical coherence tomography (OCT) and examine stage-by-stage differences in MF parameters and their relationship with best-corrected visual acuity (BCVA). Methods: This study enrolled 104 eyes with treatment-naïve DME. Intraretinal fluid (IRF) and subretinal fluid (SRF) were detected in horizontal OCT images based on the “Hokkaido University MF segmentation model” when DME was first observed together with BCVA testing. The MF area, the mean brightness, and the variance of brightness were compared between mild or moderate non-proliferative diabetic retinopathy (mNPDR, n = 33), severe NPDR (sNPDR, n = 52), and PDR eyes (n = 19). Correlations between logMAR BCVA and MF parameters were also examined. Results: All the MF parameters tended to increase with DR stages. Especially, the mean brightness of IRF was significantly greater in PDR than in mNPDR. The variance of brightness of IRF increased in sNPDR compared to mNPDR, whereas that of SRF increased in PDR compared to sNPDR. LogMAR BCVA showed positive correlations with MF areas and the variance of brightness of SRF. Conclusions: The qualitative and quantitative MF parameters may be useful for better understanding DME pathogenesis according to DR progression.

Phase-resolved Hubble Space Telescope WFC3 Spectroscopy of the Weakly Irradiated Brown Dwarf GD 1400 and Energy Redistribution–Irradiation Trends in Six White Dwarf–Brown Dwarf Binaries

Abstract Irradiated brown dwarfs offer a unique opportunity to bridge the gap between stellar and planetary atmospheres. We present high-quality Hubble Space Telescope/Wide Field Camera 3/G141 phase-resolved spectra of the white dwarf–brown dwarf binary GD 1400, covering more than one full rotation of the brown dwarf. Accounting for brightness variations caused by ZZ Ceti pulsations, we revealed weak (∼1%) phase-curve amplitude modulations originating from the brown dwarf. Subband light-curve exploration in various bands showed no significant wavelength dependence on amplitude or phase shift. Extracted day- and nightside spectra indicated chemically similar hemispheres, with slightly higher dayside temperatures, suggesting efficient heat redistribution or the dominance of radiative escape over atmospheric circulation. A simple radiative and energy redistribution model reproduced the observed temperatures well. Cloud-inclusive models fit the day and night spectra better than cloudless models, indicating global cloud coverage. We also begin qualitatively exploring atmospheric trends across six irradiated brown dwarfs, from the now complete “Dancing with the Dwarfs” white dwarf–brown dwarf sample. The trend we find in the dayside/nightside temperature and irradiation levels is consistent with efficient heat redistribution for irradiation levels less than ∼109 erg s−1 cm−2 and decreasing efficiency above that level.

Electrochemical polymerization of o-phenylenediamine in the presence of metal salts: influence of Cu(NO3)2 and AgNO3 on spectroelectrochemical properties and morphology

In this study, the effects of adding Cu(NO3)2 and AgNO3 metal salts to the polymerization medium on the electrochemical and spectroelectrochemical properties of poly(o-phenylenediamine) (PoPD) were investigated. It was observed that the presence of Cu(NO3)2 or AgNO3 during polymerization increased the rate of current peak growth, indicating an acceleration of the polymerization process in the presence of metal ions. The cyclic voltammetry responses of the metal/polymer composites differed significantly from those of the pure polymer, confirming the formation of metal/polymer composites. FTIR and UV–vis absorption spectra were analyzed to explore the chemical structure of PoPD, PoPD/Cu, and PoPD/Ag polymer films. SEM and AFM analyses revealed distinct morphological differences between the polymer synthesized in the presence of metal salts and the pure polymer. Spectroelectrochemical analyses demonstrated that the polymer films exhibited reversible color changes from light copper to green, with distinct optical intensities in the UV–vis spectra. The absorbance and current values changed reversibly with the applied potential, with response times of approximately 10 s. Colorimetric analysis based on the CIE system showed unique variations in brightness (L), magnitude (a), and intensity (b) for PoPD, PoPD/Ag, and PoPD/Cu, confirming distinct colorimetric shifts during redox transitions. This study highlights the impact of Cu and Ag salts on the spectroelectrochemical and electrochromic performance of PoPD, revealing potential applications for PoPD composites in advanced electrochromic devices.

Rapid Video Analysis for Contraction Synchrony of Human Induced Pluripotent Stem Cells-Derived Cardiac Tissues.

The contraction behaviors of cardiomyocytes (CMs), especially contraction synchrony, are crucial factors reflecting their maturity and response to drugs. A wider field of view helps to observe more pronounced synchrony differences, but the accompanied greater computational load, requiring more computing power or longer computational time. We proposed a method that directly correlates variations in optical field brightness with cardiac tissue contraction status (CVB method), based on principles from physics and photometry, for rapid video analysis in wide field of view to obtain contraction parameters, such as period and contraction propagation direction and speed. Through video analysis of human induced pluripotent stem cell (hiPSC)-derived CMs labeled with green fluorescent protein (GFP) cultured on aligned and random nanofiber scaffolds, the CVB method was demonstrated to obtain contraction parameters and quantify the direction and speed of contraction within regions of interest (ROIs) in wide field of view. The CVB method required less computation time compared to one of the contour tracking methods, the Lucas-Kanade (LK) optical flow method, and provided better stability and accuracy in the results. This method has a smaller computational load, is less affected by motion blur and out-of-focus conditions, and provides a potential tool for accurate and rapid analysis of cardiac tissue contraction synchrony in wide field of view without the need for more powerful hardware.

Comparative between the binary thresholding technique and the Otsu method for the people detection

In image detection processes where there is a variation in brightness between pixels, techniques are required to obtain optimal and adaptable threshold values for these variations. Therefore, a comparison between the binary thresholding technique and the adaptive method of Otsu is made, in videos with dynamic and static background, weighing the response time of the algorithm, memory used, requirement of the central processing unit and hits in the detections, in the languages of Python and M (Matlab). The techniques in Python present better results in terms of response time and memory space; while, when using Matlab, the lowest percentage of machine requirement is presented. Also, the Otsu method improves the percentage of hits in 12.89 % and 11.3 % for videos with dynamic and static background, with respect to the binary thresholding technique.

Hot Spot Offset Variability from Magnetohydrodynamical Thermoresistive Instability in Hot Jupiters

Abstract Hot Jupiter (HJ) atmospheres are possibly subject to a thermoresistive instability (TRI). Such an instability may develop as the ohmic heating increases the electrical conductivity in a positive feedback loop, which ultimately leads to a runaway of the atmospheric temperature. We extend our previous axisymmetric one-dimensional radial model, by representing the temperature and magnetic diffusivity as a first-order Fourier expansion in longitude. This allows us to predict the hot spot offset during the rapid unfolding of the TRI and following Alfvénic oscillations. The instability is periodically triggered and damped within ≈10–40 days, depending on the magnetic field strength, with months of slow buildup between recurring bursts. We show a few representative simulations undergoing TRI, in which the peak flux offset varies between approximately ±60∘ on a timescale of a few days with potentially observable brightness variations. Therefore, this TRI could be an observable feature of HJs, given the right timing of observation and transit and the right planetary parameters.

Leveraging vision-language prompts for real-world image restoration and enhancement

Leveraging vision-language prompts for real-world image restoration and enhancement

4FGL J1544.2−2554: A new spider pulsar candidate

Context. Spider pulsars are millisecond pulsars in tight binary systems in which a low-mass companion star is heated and ablated by the pulsar wind. Observations of these objects allow one to study stellar evolution with the formation of millisecond pulsars and the physics of superdense matter in neutron stars. However, spiders are rare due to difficulties related to their discovery when using typical radio search techniques. The Fermiγ-ray source 4FGL J1544.2−2554 was recently proposed as a pulsar candidate, and its likely X-ray and optical counterparts, with the galactic coordinates l ≈ 344.​​°76, b ≈ 22.​​°59 and the magnitude G ≈ 20.6, were found using the eROSITA and Gaia surveys. Aims. Our goals are to study whether the source is a new spider pulsar and to estimate its fundamental parameters. Methods. We performed the first optical time series multi-band photometry of the object. We used the Lomb-Scargle periodogram to search for its brightness periodicity and fitted its light curves with a model of direct heating of the binary companion by the pulsar wind. Results. The source shows a strong brightness variability with a period of ≈2.724 h and an amplitude of ≳2.5 mag, and its light curves have a single broad peak per period. These features are typical for spider pulsars. The curves are well fitted by the direct heating model, resulting in an orbit inclination of the presumed spider system of ≈83°, a companion mass of ≈0.1 M⊙, ‘day-side’ and ‘night-side’ temperatures of ≈7200 K and ≈3000 K, a Roche lobe filling factor of ≈0.65, and a distance of ≈2.1 kpc. Conclusions. Our findings suggest that 4FGL J1544.2−2554 is a spider pulsar. This result encourages the search for pulsar millisecond pulsations in radio and γ-rays to confirm its nature.

ET Dra activity according to observations in 2018–2023

The results of new photometric observations of the chromospherically active star ET Dra, performed using telescopes of the Zvenigorod INASAN Observatory, the Russian-Cuban Observatory in the territory of the Republic of Cuba (Havana) and the Terskol INASAN Observatory (a total of 8 sets of observations), as well as the addition of archival observations of the Kamogata Wide-field Survey. According to the data received during 2018–2023 changes in the shape of the light curve caused by the rotational modulation of a star with spots on the surface, as well as studies of the long-term variability of the star’s brightness were investigated. Characteristic changes in the ET Dra light curve are noted including a decrease of the stellar brightness in V filter, its cyclic changes and subsequent brightness increase. The shape of the phase curve and the duration of the extended minimum of brightness vary. During the HJD 245 9670 – 245 9715 interval the amplitude of the star’s brightness variability reached a maximum value of more than 0.4 magnitude, as it was in 1990. For each of the 8 set of observations the surface temperature inhomogeneities map were calculated and estimates of the spotedness parameter S of the object were performed. Maximum value of parameter S was 32.2–33.5%. Based on the constructed power spectra the values of possible cycles of long-term activity of the star are obtained as 570 and 1160 days (1.56 and 3.18 years).

Constraining the Progenitor of the Nearby Type II-P SN 2024ggi with Environmental Analysis

Abstract The progenitors of Type II-P supernovae (SN) have been confirmed to be red supergiants. However, the upper mass limit of the directly probed progenitors is much lower than that predicted by current theories, and the accurate determination of the progenitor masses is key to understand the final fate of massive stars. Located at a distance of only 6.72 Mpc, the Type II-P SN 2024ggi is one of the closest SNe in the last decade. Previous studies have analyzed its progenitor by direct detection, but the derived progenitor mass may be influenced by the very uncertain circumstellar extinction and pulsational brightness variability. In this work, we try to constrain the progenitor mass with an environmental analysis based on images from the Hubble Space Telescope. We found that stars in the progenitor environment have a uniform spatial distribution without significant clumpiness, and we derived the star formation history of the environment with a hierarchical Bayesian method. The progenitor is associated with the youngest population in the SN environment with an age of log(t/yr) = 7.41 (i.e., 25.7 Myr), which corresponds to an initial mass of 10 . 2 − 0.09 + 0.06 M ⊙. Our work provides an independent measurement of the progenitor mass, which is not affected by circumstellar extinction and pulsational brightness variability.

Spot and flare activity of single G5 III IV giant HD 199178 from TESS observations

The aim of our work is to study the activity of the FK Com type star rapidly rotating G5 III IV giant HD 199178 (V1794 Cyg) on the base of available photometric data from TESS mission in five sectors. The light curves of the star characterized the variability caused by rotational modulation due to the presence of cool spots on the surface, power spectra and phase diagrams are studied. The dominant peak corresponds to the photometric period P = 3.28d ± 0.12d. It is suggested that the value of P decreases over time (over an interval of about 40 years) from 3.337d up to 3.28d may be due to the long-term evolution of the positions of the active areas (spots) on the surface of a differentially rotating star. The changes in the amplitude of the brightness variability and the shape of the phase curves of HD 199178 were analyzed and it was found that the fraction of the star’s surface occupied by spots varied from 7 to 12% of its surface area. The flare activity of the star has been studied. The parameters of the amplitude, duration and energy of the flares are determined for two of them. One of the considered flares is the strongest during the observations in five sectors (5.1 × 1035 erg) and in magnitude can characterize the upper limit of the flare energies in a given state of star activity. Maps of the surface temperature inhomogeneities of the star are constructed.

Application of Thermography and Convolutional Neural Network to Diagnose Mechanical Faults in Induction Motors and Gearbox Wear

Nowadays, induction motors and gearboxes play an important role in the industry due to the fact that they are indispensable tools that allow a large number of machines to operate. In this research, a diagnosis method is proposed for the detection of different faults in an electromechanical system through infrared thermography and a convolutional neural network (CNN). During the experiment, we tested different conditions in the motor and the gearbox. The induction motor was operated in four conditions, in a healthy state, with one broken bar, a damaged bearing, and misalignment, while the gearbox was operated in three conditions with healthy gears, 50% wear, and 75% wear. The motor failures and gear wear were induced by different machining operations. Data augmentation was then performed using basic transformations such as mirror image and brightness variation. Ablation tests were also carried out, and a convolutional neural network with a basic architecture was proposed; the performance indicators show a precision of 98.53%, accuracy of 98.54%, recall of 98.65%, and F1-Score of 98.55%. The system obtained confirms that through the use of infrared thermography and deep learning, it is possible to identify faults at different points of an electromechanical system.

A computer vision model for the identification and scoring of calcium in aortic valve stenosis: a single-center experience.

Echocardiography is widely used to assess aortic stenosis (AS) but can yield inconsistent results, leading to uncertainty about AS severity and the need for further diagnostics. This retrospective study aimed to evaluate a novel echocardiography-based marker, the signal intensity coefficient (SIC), for its potential in accurately identifying and quantifying calcium in AS, enhancing noninvasive diagnostic methods. Between May 2022 and October 2023, 112 cases of AS that were previously considered severe by echocardiography were retrospectively evaluated, as well as a group of 50 cases of mild or moderate AS, both at the Eastern Slovak Institute of Cardiovascular Diseases in Kosice, Slovakia. Utilizing ImageJ software, we quantified the SIC based on ultrasonic signal intensity distribution at the aortic valve's interface. Pixel intensity histograms were generated to measure the SIC, and it was compared with echocardiographic variables. To account for variations in brightness due to differing acquisition settings in echocardiography images (where the highest intensity corresponds to calcium), adaptive image binarization has been implemented. Subsequently, the region of interest (ROI) containing calcium was interactively selected and extracted. This process enables the calculation of a calcium pixel count, representing the spatial quantity of calcium. This study employed multivariate logistic regression using backward elimination and stepwise techniques. Receiver operating characteristic (ROC) curves were utilized to assess the model's performance in predicting AS severity and to determine the optimal cut-off point. The SIC emerged as a significant predictor of AS severity, with an odds ratio (OR) of 0.021 [95% confidence interval (CI): 0.004-0.295, P=0.008]. Incorporating SIC into a model alongside standard echocardiographic parameters notably enhanced the C-statistic/ROC area from 0.7023 to 0.8083 (P=0.01). The SIC, serving as an additional echocardiography-based marker, shows promise in enhancing AS severity detection.

X-Ray, UV, and Optical Observations of Proxima Centauri’s Stellar Cycle

Proxima Cen (GJ 551; dM5.5e) is one of only about a dozen fully convective stars known to have a stellar cycle, and the only one to have long-term X-ray monitoring. A previous analysis found that X-ray and mid-UV observations, particularly two epochs of data from Swift, were consistent with a well-sampled ∼7 yr optical cycle seen in All Sky Automated Survey project (ASAS) data, but not convincing by themselves. The present work incorporates several years of new ASAS-SN optical data and an additional 5 yr of Swift XRT and UVOT observations, with Swift observations now spanning 2009–2021 and optical coverage from late 2000. X-ray observations by XMM-Newton and Chandra are also included. Analysis of the combined data, which includes modeling and adjustments for stellar contamination in the optical and UV, now reveals clear cyclic behavior in all three wavebands with a period of 8.0 yr. We also show that UV and X-ray intensities are anticorrelated with optical brightness variations caused by the cycle and by rotational modulation, discuss possible indications of two coronal mass ejections, and provide updated results for the previous finding of a simple correlation between X-ray cycle amplitude and Rossby number over a wide range of stellar types and ages.

Vision guides the twilight search for oviposition sites of the Asian tiger mosquito, Aedes albopictus.

Oviposition site selection is an important component of vector mosquito reproductive biology. The Asian Tiger mosquito, Aedes albopictus, is a major and important vector of arboviruses including Dengue. Previous studies documented the preference of gravid females for small, dark-colored water containers as oviposition sites, which they sought during the twilight period (dusk) of their locomotor activity. Vision plays an important role in this behavior, and factors such as the shape, size, and color of the container, light intensity, polarization, spectrum, and other visual cues guide the search for suitable oviposition sites, but the mechanistic factors driving this behavior are unclear. We blindfolded adult female compound eyes and observed the effects of a lack of vision on the ability to discriminate and utilize preferred oviposition sites. Furthermore, the transcriptomes of blindfolded mosquitoes were screened to identify genes with vision-sensitive expression profiles and gene-editing was used to create non-functional mutations in two of them, rhodopsin-like (mutation designated 'rho-l△807') and kynurenine hydroxylase (mutation designated 'khw'). Behavioral tests of both mutant and control strains revealed that the rho-l△807 mutant mosquitoes had a significant decrease in their ability to search for preferred oviposition sites that correlated with a reduced ability to recognize long-wavelength red light. The khw mutant mosquitoes also had a reduced ability to identify preferred oviposition sites that correlated with reductions in their ability to respond to variations in daily brightness and their ability to discriminate among different color options of the containers and background monochromatic light. This study underscores the importance of visual cues in the oviposition site selection behavior of adult female Ae. albopictus. We demonstrate that wild-type rho-l and kh gene products play a crucial role in this behavior, as mutants exhibit altered sensitivity or recognition of light intensity and substrate colors.

An efficient method for image denoising based on a new nonlinear wavelet thresholding function

Image noise is random variation of brightness or color information in images, and is usually an aspect of electronic noise. It can be produced by the image sensor and circuitry of a scanner or digital camera. In fact, there are different kinds of noise functions such as Gaussian noise, salt and pepper noise and speckle noise. Hence, image denoising is the process of removing noise from an image using one of the denoising methods such as spatial or transform techniques. The main aim of an image denoising technique is to achieve both noise reduction and feature preservation. In this context, the wavelet denoising method works in the transform domain, where the noise is uniformly spread throughout coefficients while most of the image information is concentrated in a few large ones.Therefore, the first wavelet-based denoising methods were based on thresholding of detail subband coefficients. However, most of the wavelet thresholding methods suffer from the drawback that the chosen threshold may not match the specific distribution of the image and noise components. Another thing: Studies have proven that the thresholding function has an effective role in obtaining better quality of the denoised image. To address these disadvantages, in this paper, we propose an efficient method for image denoising in wavelets domain. This method is based on a new nonlinear wavelet thresholding function, that is characterized by main mathematical properties and a shape parameter. The theoretical study of this new method proves that we can overcome the drawbacks of classical thresholding methods and by freely adjusting the shape parameter, we achieve a compromise between Hard and Soft thresholding. The experimental results show that our proposed method provides better performance compared to classical thresholding methods in terms of the visual quality of the denoised image.

Examining the brightness variability, accretion disk, and evolutionary stage of the binary OGLE-LMC-ECL-14413

Several intermediate-mass close binary systems exhibit photometric cycles longer than their orbital periods, potentially due to changes in their accretion disks. Past studies indicate that analyzing historical light curves can provide valuable insights into disk evolution and track variations in mass transfer rates within these systems. Our study aims to elucidate both short-term and long-term variations in the light curve of the eclipsing system with a particular focus on the unusual reversals in eclipse depth. We aim to clarify the role of the accretion disk in these fluctuations, especially in long-cycle changes spanning hundreds of days. Additionally, we seek to determine the evolutionary stage of the system and gain insights into the internal structure of its stellar components. We analyzed photometric time series from the Optical Gravitational Lensing Experiment (OGLE) project in the $I$ and $V$ bands, and from the MAssive Compact Halo Objects (MACHO) project in the $B_ M $ and $R_ M $ bands, covering a period of 30.85 years. Using light curve data from 27 epochs, we constructed models of the accretion disk. An optimized simplex algorithm was employed to solve the inverse problem, deriving the best-fit parameters for the stars, orbit, and disk. We also utilized the Modules for Experiments in Stellar Astrophysics ( MESA ) software to assess the evolutionary stage of the binary system, investigating the progenitors and potential future developments. We found an orbital period of 38.15917 pm 0.00054 days and a long-term cycle of approximately 780 days. Temperature, mass, radius, and surface gravity values were determined for both stars. The photometric orbital cycle and the long-term cycle are consistent with a disk containing variable physical properties, including two shock regions. The disk encircles the more massive star and the system brightness variations align with the long-term cycle at orbital phase 0.25. Our mass transfer rate calculations correspond to these brightness changes. MESA simulations indicate weak magnetic fields in the donor star's subsurface, which are insufficient to influence mass transfer rates significantly.

Superflare on a rapidly-rotating solar-type star captured in X-rays

Superflare on a rapidly-rotating solar-type star captured in X-rays

A NEW LASER SYSTEM WITH AUTOMATED CONTROL OF COAGULATION DEPTH: TOWARDS THE QUESTION OF COMPARABILITY OF BRIGHTNESS AND DEPTH OF LASER BURNS

Background. The development of laser systems with automated control of retinal coagulation depth will make it possible to obtain reproducible laser burns of a given brightness on the ocular fundus during treatment. Nevertheless, the problem of correspondence of the brightness of the formed coagulates fixed by video capture to the depth of the formed coagulates in the retinal thickness remains poorly studied.Objective. To study the correspondence between the brightness of the formed burns recorded by video capture and the depth of retinal coagulation during dose-dependent laser photocoagulation using an automated laser system based on the feedback principle.Materials and methods. A prototype of an automated system for laser photocoagulation of the retina, consisting of a 0.81 µm diode laser and a video capture module integrated into the optical system of the slit lamp, as well as software that controls laser exposure using the feedback principle. Studies were performed on rabbit eyes (n=20). At spot diameter 200 µm, power 100, 140, 180, 220, 260 and 300 mW and planned coagulation levels 5, 10, 20, 30, 40, 50 and 70%, the actual brightness of the obtained coagulates (%), the correspondence between planned and actual coagulate brightness were studied. The depth of coagulation (% of neuroretina thickness) and its correlation with the actual brightness of coagulates were studied at OCT.Results. With a planned brightness of 5-10% (grade 1 according to L’Esperance), the actual brightness of the burns was significantly higher, the depth of coagulation on OCT was 20 to 30% of the retinal thickness. At the planned brightness of 20-40% and 5-70% (grade 2 and 3 according to L’Esperance), the actual burns brightness was not significantly different throughout the power range, and the depth of coagulation by OCT was 35-50% and 80-120%, respectively. The coefficient of variation of actual brightness and coagulation depth did not exceed 15% for the whole range of planned brightness and used power, except for cases of planned brightness of 5-10% and power of 220 mW and more. A significant correlation was found between actual brightness and coagulation depth (R=0.96, p=0.001).Conclusion. During laser coagulation of the retina using a new automated laser system based on the feedback principle, homogeneous laser coagulates are automatically formed, and there is a significant correlation between the depth of neuroretinal coagulation and the brightness of burns recorded by video capture.

Swift Observations of Mrk 421 in Selected Epochs. IV. Physical Implications of X-Ray Flaring Activity and Features of Relativistic Magnetic Reconnection in 2018 April–2023 December

We present the spectral and timing results obtained during the intense observations of Mrk 421 by the Swift-based ultraviolet to X-ray instruments during 2018 April–2023 December. The source showed various strengths of X-ray flaring activity, exceeding a level of 3.5 × 10−9 erg cm−2 s−1 during the strongest 0.3–10 keV flares. Our study identifies a number of intraday brightness variability, including 61 instances that occurred within 1 ks exposures that are consistent with the shock-in-jet scenario and accompanied by significant, fast spectral changes. The source exhibited extreme spectral properties with dominance of the log-parabolic distributions of photons with energy and the frequent occurrence of hard photon indices in the 0.3–10 keV and 0.3–300 GeV bands, with the peak of synchrotron spectral energy distribution E p detected at the energies beyond 29 keV for the first time. The source showed very fast transitions of log-parabolic-to-power-law spectra, most plausibly caused by turbulence-driven relativistic magnetic reconnection. Our spectral results also demonstrate the importance of the first-order Fermi mechanism within the magnetic field of different confinement efficiencies, stochastic acceleration, transitions in the turbulence spectrum, and hadronic cascades. The X-ray, UV, and γ-ray fluxes showed a lognormal variability, which hints at the imprint of accretion disk instabilities on the blazar jet, as well as the possible presence of hadronic cascades. The UV and γ-ray variabilities demonstrated weak correlations with the X-ray flaring activity, which is not consistent with simple synchrotron self-Compton models and requires more complex particle acceleration and emission scenarios.