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Non‐invasive wide‐field imaging through dynamic random media is a sought‐after goal with important applications ranging from medical diagnosis to remote sensing. However, some existing methods, such as speckle correlation‐based techniques, are limited in field of view due to the memory effect; while some other methods, such as wavefront shaping and transmission matrix techniques, face considerable challenges when applied in dynamic scenarios because of the complexity involved in modulation and measurement. These limitations significantly impede the effectiveness and applicability of these approaches. Here, the concept of virtual reference light (VRL), which allows for the reconstruction of the original object with just a single‐shot detection of the speckle is proposed. Experimental results demonstrate that the imaging field achieves a 3.8‐fold memory effect range. In the experimental setup, the light source and detector are positioned on one side of the random medium, while the sample is placed on the opposite side, enabling non‐invasive detection. Imaging results with both static and dynamic scattering media are presented to verify the feasibility of the proposed method, offering an effective solution for real‐time target imaging and detection. [ABSTRACT FROM AUTHOR]

Bananas are susceptible to various postharvest diseases caused by a diverse range of pathogens. The present study focused on the identification and characterization of two prevalent banana fruit diseases, anthracnose and speckle, in three provinces of northern Thailand. Symptomatic banana fruits were collected from local markets. Surface-sterilized, infected banana skin segments were used to isolate the associated fungi on potato dextrose agar. Morphologically distinct isolates of Colletotrichum spp. and Corynespora sp. were obtained from the anthracnose lesions and speckles, respectively. Fungal identification was based on morphology and phylogenetic analyses of the ITS, LSU, act, cmdA, tub2, chs-1, and gapdh sequences. Colletotrichum musae and C. siamense were identified as the causal agents of post-harvest anthracnose in the bananas Kluai Namwa (Musa acuminata × M. balbisiana; ABB genomic group; Pisang Awak) and Kluai Khai (M. acuminata; AA genomic group; Sucrier), respectively. Corynespora torulosa was found to cause speckles in Kluai Namwa fruits. Koch's postulates were successfully established by inoculating fresh and unripe banana fruits with the identified strains, and confirmed the pathogenicity. Colletotrichum musae, C. siamense, and C. torulosa were re-isolated from the inoculated fruits and justified with morpho-molecular data. To our knowledge, this is the first confirmed occurrence of C. torulosa causing banana fruit speckles in Kluai Namwa in Thailand. In addition, we document the presence of C. siamense, causing post-harvest anthracnose in Kluai Khai. This study contributes to a better understanding of post-harvest banana diseases and addresses the current challenges in the commercial banana industry in northern Thailand. [ABSTRACT FROM AUTHOR]

The near‐infrared (NIR) light polarization metrology is crucial in a broad area of applications, such as optical sensing, imaging, and communications. The conventional measurement of NIR light polarization requires bulky polarization optics by the spatial or temporal splitting of the input light beam with expensive infrared detectors. Here, an intelligent fiber‐integrated NIR polarimeter based on upconversion nanoparticles (UCNPs) is demonstrated. Er‐doped UCNPs are synthesized in core–shell structures for bright upconversion luminescence (UCL), and the tapered multimode fiber (MMF) is designed for random Rayleigh‐distributed speckles. It is demonstrated for the first time that spectra‐polarization‐dependent upconverted speckle patterns captured by a cost‐effective visible image sensor can be accurately decoded via a deep neural network (ResNet50). The experimental results show that ResNet50 has a recognition accuracy of over 99.5% for the full‐Stokes parameters of NIR light polarization, along with 100% accuracy for the light wavelength ranging from 1535 nm to 1565 nm. The developed intelligent optical sensors provide a new design paradigm for fiber‐integrated multi‐dimensional NIR light field detection and can be applied in fiber‐optic sensors and communications networks. [ABSTRACT FROM AUTHOR]

We investigate the periodic motion of the reaction products of the dissolution of a steel ball in nitric acid in a magnetic field. Video recording is used in both the natural light and the coherent radiation of a red semiconductor laser. The video recording results are processed using the Fourier transform. Coherent-radiation photography and its processing with speckle-contrast methods are also used. As a result of the work, we find the characteristic frequencies of the periodic motion of the reaction products and the distribution of their relative velocities. [ABSTRACT FROM AUTHOR]

The features of propagation in free space of light beams with a dislocation structure of the wavefront are considered. The stability to the influence of diffraction of small-scale dislocation systems providing spatial superresolution is analyzed. Based on a comparison of the characteristics of various dislocation formations, a conclusion is made about the greatest structural stability of systems with special type screw dislocations. Such dislocations can be obtained by azimuthal rotation of edge dislocations characterized by a sharp phase jump of light oscillations along the singular line. The obtained results will find application in optimizing the characteristics of optical devices with ultrahigh spatial resolution, as well as in developing software for the operation of spatial light modulators forming beams with a specified amplitude-phase profile. [ABSTRACT FROM AUTHOR]

Speckle tracking imaging is a relatively new technique for obtaining myocardial strain based on the tracking of speckles in gray-scale echocardiographic images. Speckles are acoustic markers that can be tracked from frame to frame over the cardiac cycle, providing non-Doppler information about global and segmental myocardial deformation. In this article, the general principles of good practice of echocardiography will be revisited in order to obtain a better evaluation of myocardial deformition and to optimize these clinical contributions in current practice. [ABSTRACT FROM AUTHOR]

Speckle patterns are formed by random interferences of mutually coherent beams. While speckles are often considered as unwanted noise in many areas, they also formed the foundation for the development of numerous speckle-based imaging, holography, and sensing technologies. In the recent years, artificial speckle patterns have been generated with spatially incoherent sources using static and dynamic optical modulators for advanced imaging applications. In this report, a basic study has been carried out with Bessel distribution as the fundamental building block of the speckle pattern (i.e., speckle patterns formed by randomly interfering Bessel beams). In general, Bessel beams have a long focal depth, which in this scenario is counteracted by the increase in randomness enabling tunability of the axial resolution. As a direct imaging method could not be applied when there is more than one Bessel beam, an indirect computational imaging framework has been applied to study the imaging characteristics. This computational imaging process consists of three steps. In the first step, the point spread function (PSF) is calculated, which is the speckle pattern formed by the random interferences of Bessel beams. In the next step, the intensity distribution for an object is obtained by a convolution between the PSF and object function. The object information is reconstructed by processing the PSF and the object intensity distribution using non-linear reconstruction. In the computational imaging framework, the lateral resolution remained a constant, while the axial resolution improved when the randomness in the system was increased. Three-dimensional computational imaging with statistical averaging for different cases of randomness has been synthetically demonstrated for two test objects located at two different distances. The presented study will lead to a new generation of incoherent imaging technologies. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of gradient interface on the mechanical properties of Cu/WCP functional gradient materials, digital image correlation technique was used to analyze the mechanical characteristics of laminated Cu/WCP functional gradient material under tension load in the layer direction. In this paper, the deformation information of the specimens is obtained by the digital image correlation method. In order to obtain high-precision measurement results, speckle patterns with small spots and uniform distribution are prepared on the specimen surface by using small sample speckle preparation technology. The tensile experimental results showed that the incorporation of WC particles significantly improved the stiffness and strength of Cu/WCP composites. Meanwhile, the plastic strain and plastic strain rate are non-uniform in each layer of the five-layer Cu/WCP functional gradient material under the tension load along the layer direction. The plastic strain and plastic strain rate in each layer gradually increase along with the decreasing direction of WC content. It is found, from the analysis of experimental results, the existence of the gradient interface has an obvious inhibitory effect on the increase in plastic strain rate along the decreasing direction of WC content, and the specimen fracture location also has a certain relationship with the plastic strain rate, which reflects the important influence of the gradient interface on the mechanical properties of Cu/WCP functional gradient materials. [ABSTRACT FROM AUTHOR]

Orbital angular momentum (OAM) of optical vortex beams has been regarded as an independent physical dimension of light with predominant information-carrying potential. However, the presence of scattering environment and turbulent atmosphere scrambles the helical wavefront and destroys the orthogonality of modes in vortex beam propagation. Here, we propose and experimentally demonstrate a new basis for the recovery of the OAM mode using a holographic ghost diffraction scheme. The technique utilizes the speckle field generated from a rotating diffuser for optical vortex mode encoding, and the fourth-order correlation of the speckle field for the efficient recovery of the associated modes. Furthermore, we successfully demonstrate the complex-field recovery of OAM modes by the adoption of a holography scheme in combination with the ghost diffraction system. We evaluate the feasibility of the approach by simulation and followed by experimental demonstration for the recovery of various sequentially encoded OAM modes. Finally, the efficacy of the recovered modes was quantitatively analyzed by an OAM mode analysis utilizing orthogonal projection scheme. [ABSTRACT FROM AUTHOR]

Plastic strains arising in the zone of fatigue crack initiation are estimated with the aid of time-averaged speckle images on a sample of 09G2S steel with two grooves 2.5 mm in radius. It is shown that the fatigue fracture appears owing to localization of irreversible processes in the region less than 1 mm and the limit value of tension plastic strains is on the order of 10–1. As an indication of fracture, it is proposed to use the fact that the normed temporal autocorrelation function of radiation intensity reduces to a negative value. [ABSTRACT FROM AUTHOR]

Speckle patterns are formed by random interferences of mutually coherent beams. While speckles are often considered as unwanted noise in many areas, they also formed the foundation for the development of numerous speckle-based imaging, holography, and sensing technologies. In the recent years, artificial speckle patterns have been generated with spatially incoherent sources using static and dynamic optical modulators for advanced imaging applications. In this report, a basic study has been carried out with Bessel distribution as the fundamental building block of the speckle pattern (i.e., speckle patterns formed by randomly interfering Bessel beams). In general, Bessel beams have a long focal depth, which in this scenario is counteracted by the increase in randomness enabling tunability of the axial resolution. As a direct imaging method could not be applied when there is more than one Bessel beam, an indirect computational imaging framework has been applied to study the imaging characteristics. This computational imaging process consists of three steps. In the first step, the point spread function (PSF) is calculated, which is the speckle pattern formed by the random interferences of Bessel beams. In the next step, the intensity distribution for an object is obtained by a convolution between the PSF and object function. The object information is reconstructed by processing the PSF and the object intensity distribution using non-linear reconstruction. In the computational imaging framework, the lateral resolution remained a constant, while the axial resolution improved when the randomness in the system was increased. Three-dimensional computational imaging with statistical averaging for different cases of randomness has been synthetically demonstrated for two test objects located at two different distances. The presented study will lead to a new generation of incoherent imaging technologies.

The assembly and activation of the spliceosome rely upon the phosphorylation of an essential family of splicing factors known as the serine–arginine (SR) proteins. Although it has been demonstrated recently that two enzyme families, the SR protein kinases (SRPKs) and the Cdc2‐like kinases (CLKs), can function as a complex to efficiently phosphorylate these SR proteins in the nucleus, the molecular features involved in such a connection are unknown. In this study, we identified a group of conserved residues in the large lobe of SRPK1 that interact with the N terminus of CLK1 stabilizing the SRPK1‐CLK1 complex. Mutations in this motif not only disrupt formation of the kinase–kinase complex but also impair SRPK1‐dependent release of the phospho‐SR protein from CLK1. The binding motif potently up‐regulates CLK1‐specific phosphorylation sites, enhances SR protein diffusion from nuclear speckles, and impacts the alternative splicing of several target genes. These results indicate that CLK1 binds a conserved, electronegative surface on SRPK1, thereby controlling SR protein phosphorylation levels for enhanced subnuclear trafficking and alternative splicing regulation. [ABSTRACT FROM AUTHOR]

Paper described a simplified speckled elimination algorithm for the reconstruction of continuous-wave (CW) Doppler ultrasound spectrogram. Standard Nonlinear Anisotropic Diffusion (SNAD) technique fails to eliminate the speckle noise, blurs the interregional area of neighbouring speckle clusters and regulates the heat flow to preserve the systolic and diastolic peaks in the spectrogram. To resolve this problem, author modelled a kernel, conductance and diffusion function to regulate the blurring of speckle clusters and sharpen the high-contrast edges over low-contrast ones. Paper analysed the performance based on the variation of conductance (C), signal-to-noise ratio (SNR), peak signal-to-noise ratio (PSNR), mean square error (MSE), root mean square error (RMSE) and structural similarity index (SSIM) of each pairs of speckled and despeckled spectrograms. Quantitative analysis reveals that the minimised version of the kernel effectively regulates the flow of heat at edges with a high SNR (8 dB) and PSNR (>20 dB) for a low-frequency range of 20-25 Hz. SSIM (>0.9) shows an efficient structural reconstruction that identifies the lower and higher local SSIM indices as dark and bright pixels on SSIM maps. Hence, the algorithm performs its best at lower peak frequencies in the Doppler spectrograms. [ABSTRACT FROM AUTHOR]

RNAs play diverse roles in formation and function of subnuclear compartments, most of which are associated with active genes. NEAT1 and NEAT2/MALAT1 exemplify long non-coding RNAs (lncRNAs) known to function in nuclear bodies; however, we suggest that RNA biogenesis itself may underpin much nuclear compartmentalization. Recent studies show that active genes cluster with nuclear speckles on a genome-wide scale, significantly advancing earlier cytological evidence that speckles (aka SC-35 domains) are hubs of concentrated pre-mRNA metabolism. We propose the 'karyotype to hub' hypothesis to explain this organization: clustering of genes in the human karyotype may have evolved to facilitate the formation of efficient nuclear hubs, driven in part by the propensity of ribonucleoproteins (RNPs) to form large-scale condensates. The special capacity of highly repetitive RNAs to impact architecture is highlighted by recent findings that human satellite II RNA sequesters factors into abnormal nuclear bodies in disease, potentially co-opting a normal developmental mechanism. [ABSTRACT FROM AUTHOR]

Orbital angular momentum (OAM) of optical vortex beams has been regarded as an independent physical dimension of light with predominant information-carrying potential. However, the presence of scattering environment and turbulent atmosphere scrambles the helical wavefront and destroys the orthogonality of modes in vortex beam propagation. Here, we propose and experimentally demonstrate a new basis for the recovery of the OAM mode using a holographic ghost diffraction scheme. The technique utilizes the speckle field generated from a rotating diffuser for optical vortex mode encoding, and the fourth-order correlation of the speckle field for the efficient recovery of the associated modes. Furthermore, we successfully demonstrate the complex-field recovery of OAM modes by the adoption of a holography scheme in combination with the ghost diffraction system. We evaluate the feasibility of the approach by simulation and followed by experimental demonstration for the recovery of various sequentially encoded OAM modes. Finally, the efficacy of the recovered modes was quantitatively analyzed by an OAM mode analysis utilizing orthogonal projection scheme.

The mammalian genome is complex and presents a dynamic structural organization that reflects function. Organization of the genome inside the mammalian nucleus impacts all nuclear processes including but not limited to transcription, replication and repair, and in many biological contexts such as early development, differentiation and physiological adaptations. However, there is limited understating of how 3D organization of the mammalian genome regulates different nuclear processes. Recent advances in microscopy and a myriad of genomics methods—propelled by next-generation sequencing—have advanced our knowledge of genome organization to a great extent. In this review, we discuss nuclear compartments in general and recent advances in the understanding of how mammalian genome is organized in these compartments with an emphasis on dynamics at the nuclear periphery. [ABSTRACT FROM AUTHOR]

On the basis of fragments of time-averaged speckle images registered with no stopping of cyclic loading, the features of nucleation, onset, and propagation of a crack in the bulk of a transparent prismatic sample with a sharp V-shaped notch have been found. It has been shown that the first signs of fatigue damage occur not at the top of the notch, but at a distance of 400 μm from it in the sample center within an area with a diameter of 200 μm. After the beginning of the development ("onset") of the crack, the size of the zone of irreversible processes exhibits an increase by an order of magnitude. The distribution of the refractive index and the density around the crack has been studied based on changing speckle images and with the use of ellipsometry. It has been shown that the maximum value of relative change in density being at least 2 × 10–3, is located near the crack. The speckle method can serve a basis for the development of nondestructive testing tools and techniques that make it possible to assess the time preceding crack onset according to the changing rate and the limiting values of the refractive index and material density, as well as according to other parameters affecting the change in the optical paths of waves within small areas about 10 μm in size. [ABSTRACT FROM AUTHOR]

Highlights • A method based on Lempel–Ziv complexity is proposed for quantitative ultrasound tissue characterization. • The method is used to classify breast lesions from an open access ultrasound image database. • The method performance is compared with entropy-based classifier as entropy is related theoretically to Lempel–Ziv complexity. • The new method achieves 0.87 ROC AUC as compared to 0.84 achieved by the reference method. Abstract Building upon the recent successes in the application of information-theoretic concepts (e.g. Shannon entropy) in quantitative ultrasound, the authors propose a novel tissue characterization method based on the Lempel–Ziv complexity. In this procedure, standard ultrasound B-Mode images are mapped onto words over finite alphabets before the corresponding Lempel–Ziv complexity of ultrasound images is calculated. Such complexity metric may be used to differentiate between types of tissues. Here, the method is utilized as a binary classifier for the malignancy of breast lesions. The method is tested on OASBUD – an open-access breast lesions image database. Images of 48 malignant and 48 benign lesions were used – two images for each lesion. The new procedure slightly outperforms the state-of-art classifier based on pixel entropy as measured in the size of area under the receiver operating curve (ROC AUC), which suggests that it may serve as a basis for computer-assisted breast cancer ultrasound diagnosis and possibly in other standard applications of the quantitative ultrasound. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndromes (MDS) are a heterogeneous group of hematological malignancies characterized by peripheral blood cytopenia and abnormal myeloproliferation, as well as a variable risk of evolution into acute myeloid leukemia (AML). The nucleus is a highly organized organelle with several distinct domains where nuclear inositides localize to mediate essential cellular events. Nuclear inositides play a critical role in the modulation of erythropoiesis or myelopoiesis. Here, we briefly review the nuclear structure, the localization of inositides and their metabolic enzymes in subnuclear compartments, and the molecular aspects of nuclear inositides in MDS.

This is the second section of the review-tutorial paper describing fundamentals of tissue optics and photonics. As the first section of the paper was mostly devoted to description of biological tissue structures and their specificity related to interactions with light [1], this section 3 describes light-tissue interactions themselves that caused by tissue dispersion, scattering, and absorption properties, including light reflection and refraction, absorption, elastic, and quasi-elastic scattering. The major tissue absorbers and modes of elastic scattering, including Rayleigh and Mie scattering, will be presented.

Triangulation-based three-dimensional (3-D) optical metrology utilizing structured illumination requires the projector and camera to be geometrically calibrated. The projection of laser speckle structures in temporal correlation-based methods has been found to be useful for high-speed 3-D measurement. However, it requires the use of a stereo-camera configuration as speckle projection does not utilize conventional projection optics. Previously, we have shown a model-less method to calibrate these unconventional projection systems. This re-enabled singlecamera setups where stereo systems used to be required. Due to the random nature of speckle production, speckle structures were not suitable as a set of repeatable illumination structures is needed for the model-less calibration method to succeed. A projection apparatus is proposed, which enables the production of a repeatable set of speckle structures. This device is then utilized in a single-camera optical metrology 3-D measurement system. [ABSTRACT FROM AUTHOR]

Speckle techniques, such as DIC (Digital Image Correlation) and DSP (Digital Speckle Photography), are frequently used to determine the high-temperature mechanical properties of materials. Speckle techniques require the creation of a random speckle pattern on the surface of the specimen. The most commonly used approach to creating a high-contrast speckle pattern is to spray a layer of black paint particles on a white background. However, in a high-temperature environment, the paint particles tend to peel off or burn off. In this paper, we present an approach that uses a novel laser-engraving technology, where the created speckles will sustain temperatures as high as the melting temperature of the specimen. The size, density, depth and distribution of the speckles can be controlled to suit a particular situation. Since the pattern is part of the specimen, it will never disappear, until the melting temperature of the metal is reached. As an application, we used the technique to determine the elastic modulus of Ti up to 600°C and tungsten up to 1000°C. [ABSTRACT FROM AUTHOR]

Myosin VI (MVI) is a unique actin-based motor protein moving towards the minus end of actin filaments, in the opposite direction than other known myosins. Besides well described functions of MVI in endocytosis and maintenance of Golgi apparatus, there are few reports showing its involvement in transcription. We previously demonstrated that in neurosecretory PC12 cells MVI was present in the cytoplasm and nucleus, and its depletion caused substantial inhibition of cell migration and proliferation. Here, we show an increase in nuclear localization of MVI upon cell stimulation, and identification of potential nuclear localization (NLS) and nuclear export (NES) signals within MVI heavy chain. These signals seem to be functional as the MVI nuclear presence was affected by the inhibitors of nuclear import (ivermectin) and export (leptomycin B). In nuclei of stimulated cells, MVI colocalized with active RNA polymerase II, BrUTP-containing transcription sites and transcription factor SP1 as well as SC35 and PML proteins, markers of nuclear speckles and PML bodies, respectively. Mass spectrometry analysis of samples of a GST-pull-down assay with the MVI tail domain as a "bait" identified several new potential MVI binding partners. Among them are proteins involved in transcription and post-transcriptional processes. We confirmed interaction of MVI with heterogeneous nuclear ribonucleoprotein U (hnRNPU) and nucleolin, proteins involved in pre-mRNA binding and transport, and nucleolar function, respectively. Our data provide an insight into mechanisms of involvement of MVI in nuclear processes via interaction with nuclear proteins and support a notion for important role(s) for MVI in gene expression. [ABSTRACT FROM AUTHOR]

Myosin VI (MVI) is a unique actin-based motor protein moving towards the minus end of actin filaments, in the opposite direction than other known myosins. Besides well described functions of MVI in endocytosis and maintenance of Golgi apparatus, there are few reports showing its involvement in transcription. We previously demonstrated that in neurosecretory PC12 cells MVI was present in the cytoplasm and nucleus, and its depletion caused substantial inhibition of cell migration and proliferation. Here, we show an increase in nuclear localization of MVI upon cell stimulation, and identification of potential nuclear localization (NLS) and nuclear export (NES) signals within MVI heavy chain. These signals seem to be functional as the MVI nuclear presence was affected by the inhibitors of nuclear import (ivermectin) and export (leptomycin B). In nuclei of stimulated cells, MVI colocalized with active RNA polymerase II, BrUTP-containing transcription sites and transcription factor SP1 as well as SC35 and PML proteins, markers of nuclear speckles and PML bodies, respectively. Mass spectrometry analysis of samples of a GST-pull-down assay with the MVI tail domain as a "bait" identified several new potential MVI binding partners. Among them are proteins involved in transcription and post-transcriptional processes. We confirmed interaction of MVI with heterogeneous nuclear ribonucleoprotein U (hnRNPU) and nucleolin, proteins involved in pre-mRNA binding and transport, and nucleolar function, respectively. Our data provide an insight into mechanisms of involvement of MVI in nuclear processes via interaction with nuclear proteins and support a notion for important role(s) for MVI in gene expression. [ABSTRACT FROM AUTHOR]

Single sensor (pixel) signals require scanning of the sample in order to obtain spatial information. In this paper we show that using interference, optically induced signals can be reconstructed when recorded using interference pattern excitation, rather than a point illumination. This method reduces the need for dense scanning and requires a small number of scans, or can eliminate the need for scanning in some cases. It is shown that this method can be used in particular in 2D photo-acoustic imaging. [ABSTRACT FROM AUTHOR]

Stochastic interference of fluorescence light outgoing from a dye-doped coarse-grained random medium, which was pumped by the continuous-wave laser radiation, was experimentally studied. It was found that the contrast of random interference patterns highly correlates with the wavelength-dependent fluorescence intensity and reaches its minimum in the vicinity of the cusp of emission spectrum. The decay in the contrast of spectrally selected speckle patterns was interpreted in terms of the pathlength distribution broadening for fluorescence radiation propagating in the medium. This broadening is presumably caused by the wavelength-dependent negative absorption of the medium. [ABSTRACT FROM AUTHOR]

Scaffold attachment factor B (SAFB) is a conserved RNA-binding protein that is essential for early mammalian development. However, the functions of SAFB in mouse embryonic stem cells (ESCs) have not been characterized. Using RNA immunoprecipitation followed by RNA-seq (RIP-seq), we examined the RNAs associated with SAFB in wild-type and SAFB/SAFB2 double-knockout ESCs. SAFB predominantly associated with introns of protein-coding genes through purine-rich motifs. The transcript most enriched in SAFB association was the lncRNA Malat1 , which also contains a purine-rich region in its 5' end. Knockout of SAFB/SAFB2 led to differential expression of approximately 1000 genes associated with multiple biological processes, including apoptosis, cell division, and cell migration. Knockout of SAFB/SAFB2 also led to splicing changes in a set of genes that were largely distinct from those that exhibited changes in expression level. The spliced and nascent transcripts of many genes whose expression levels were positively regulated by SAFB also associated with high levels of SAFB, implying that SAFB binding promotes their expression. Reintroduction of SAFB into double-knockout cells restored gene expression toward wild-type levels, an effect again observable at the level of spliced and nascent transcripts. Proteomics analysis revealed a significant enrichment of nuclear speckle-associated and RS domain-containing proteins among SAFB interactors. Neither Xist nor Polycomb functions were dramatically altered in SAFB/2 knockout ESCs. Our findings suggest that among other potential functions in ESCs, SAFB promotes the expression of certain genes through its ability to bind nascent RNA., (© 2023 Cherney et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.)

Standard ultrasound devices perform nonlinear compression reducing dynamic range of the signal. In order to reconstruct original signal it is necessary to find out statistics of the signal before and signal after compression. There are two techniques for compression parameter estimation or, that is equivalent, compressed signal reconstruction advised in literature. In the paper we perform comparison of these techniques both for computer generated signals and ultrasound images. .

The advance in biochemical and microscopy techniques has revealed the complexity and intricate nucleoplasm structure. Several subcompartments were identified in nucleus and the importance of these subcompartments in processes crucial for normal nuclear activity has been demonstrated. In this mini-review, we will give an overview about the composition, function, and importance of the major nuclear subcompartments. Also, we will show the impact that perturbing these structures can cause in normal nuclear activity, and how these can contribute to the development of some human diseases. [ABSTRACT FROM AUTHOR]

Theory of the speckle dynamics arises in the image plane of the object as a result of deterministic and random displacements of point scattering centers are considered. It was shown that time-average radiation intensity and the correlation coefficient of the speckle image segment depend on the average value, variance, and the correlation time of displacement difference of the scattering center pairs. The sensitivity, accuracy, and calibration of the method are considered. Application of the technique in studies of micro-and macroprocesses in high-cycle fatigue of metals and in a monolayer of live cells is given. [ABSTRACT FROM AUTHOR]

The use of objective speckles as patterns is of high interest for the ongoing development of stereo photogrammetry. The depth of focus of the projected speckle patterns, which can be found to be several meters, can hardly be matched by other projection principles. On the downside, the use of coherent light leads to subjective speckles generated by the rough surface of the object under test. This effect decreases the accuracy under which objects can be reconstructed. We show how laser-based stereo photogrammetry can be adjusted to increase the measurement accuracy of three-dimensional (3-D)-surface measurements while preserving the advantages of speckles projection. Therefore, we present a method to decrease the contrast of subjective speckles in the images by pixel-wise shifting the cameras orthogonally to their viewing direction and back shifting the taken images numerically, accordingly. This leads to an increase in 3-D-reconstruction quality, as seen in a decrease in standard deviation, peak-to-valley value and in an increase in the number of reconstructed points for measured test objects. [ABSTRACT FROM AUTHOR]

A frequently observed characteristic of electromagnetic scattering by a disordered particulate medium is the absence of pronounced speckles in angular patterns of the scattered light. It is known that such diffuse speckle-free scattering patterns can be caused by averaging over randomly changing particle positions and/or over a finite spectral range. To get further insight into the possible physical causes of the absence of speckles, we use the numerically exact superposition T -matrix solver of the Maxwell equations and analyze the scattering of plane-wave and Gaussian beams by representative multi-sphere groups. We show that phase and amplitude variations across an incident Gaussian beam do not serve to extinguish the pronounced speckle pattern typical of plane-wave illumination of a fixed multi-particle group. Averaging over random particle positions and/or over a finite spectral range is still required to generate the classical diffuse speckle-free regime. [ABSTRACT FROM AUTHOR]

The data on changes in light scattering intensity with time at 330°C after stabilization of the sample at 200°C were obtained using the temperature jump method. It was found that the time dependence of the polarized component at 330°C can be divided into two stages. The first stage involves the initial times and is characterized by the formation of the maximum, which corresponds to the universal effect caused by the emergence of a peak of intensity in the glass-transition interval of oxide glass. The second stage is associated with a decrease in intensities with the characteristic times being significantly longer than the structural relaxation times. The anisotropic scattering intensity was found to increase during low-temperature stabilization at 200°C, while the isotropic scattering intensity remained constant. The behavior of intensity became nonergodic as a result of the long-term heating of the sample: the intensity started to depend on the position of the scattering volume. It was demonstrated that the shape of the fleck from the primary light beam that has passed through the sample can be significantly changed and acquire a speckle structure. A hypothesis was put forward that the detected features in the behavior of light scattering intensity are associated with the development of large-scale structures in the glass volume. [ABSTRACT FROM AUTHOR]

• Speckle preparation by femtosecond laser engraving for digital image correlation with fully manipulatable features, minimized damage and heat effect was proposed in this work. • Laser parameters were optimized based on speckle quality and measurement errors. • Damage of femtosecond laser to thin film sample was calculated by two-temperature model, which agrees well with experiment results. Deformation measurement in thin films at elevated temperatures is critical for assessing the reliability and performance of microelectronic devices. Digital image correlation (DIC) is a full-field, noncontact deformation measurement technique. However, the traditional DIC approach requires spraying paints for speckles, which is not suitable for high-temperature applications. The aim of this work is to propose a fully customizable speckle preparation method by pulsed laser that can deliver ideal speckle pattern, good contrast and consistency and controllable damage to sample for deformation measurement at elevated temperatures by DIC. Al thin films deposited on Si substrates were used for speckle preparation by FLs at different powers (10 mW, 8 mW, 6 mW and 4 mW). Serial images of speckles were captured as the temperature increased from room temperature to 325 °C, followed by data analysis. A finite element model was built to evaluate the deviation of measured strains in Al thin film from ideal values. To evaluate the damage of laser to sample surface during speckle preparation, a two-temperature model (TTM) was used to evaluate the ideal ablation depth at different laser fluences. Scanning electron microscopy and white light interferometry were also used to examine the surface damage and depth of holes. Based on our findings, speckles prepared by laser irradiation at 8 mW have the best speckle quality and measurement accuracy. The depth of speckles increased linearly with increasing laser power, ranging from 11.8 to 32.9 nm. The ideal depth calculated by the TTM was slightly lower than the experimental results, which can be attributed to the parameters of the model deviating from the actual sample (such as the reflectance of Al). DIC with speckles prepared by an FL can provide good measurement accuracy at elevated temperatures while causing minimal damage to the sample. [ABSTRACT FROM AUTHOR]

We report the results of modeling the speckle structure of an optical field, which arises due to scattering of laser radiation at the retina of the human eye. The presence of such a speckle structure in the scattered radiation leaving the eye affects the accuracy of wavefront measurements aimed at determining the overall aberrations of the eye. We compared two methods for suppressing such speckle structures based on spatial and spectral averaging of a variety of speckle field realizations. The results of both theoretical calculations and numerical simulations appeared to be in a good agreement with experimental data obtained with the eye model andin vivo. [ABSTRACT FROM PUBLISHER]

During the propagation of an optically smoothed laser beam through a warm plasma the speckle field pattern and the corresponding speckle intensity distribution are modified in time and along the laser propagation direction. It is shown here that the laser–plasma interaction can change the character of speckle statistics from an initially exponential-type limit law to a Weibull-type law. The Weibull distribution is characterized by a power-law-type behavior in a limited interval of the random variable, which is, in the present case, the speckle intensity. The properties of the speckle distributions are studied using methods of extremal and order statistics. The scattering instability process (here stimulated Brillouin forward scattering) causing the change in speckle statistics has an onset behavior associated with a “critical gain” value, as pointed out in work by Rose and DuBois (1993b). The saturation of the instability process as a function of intensity explains the limited interval of the Weibull-type speckle distribution. The differences in the type of the speckle statistics are analyzed by using “excess over threshold” methods relying on the generalized Pareto distribution, which clearly brings to evidence the transition from an exponential type distribution to the Weibull-type distribution as a function of the instability gain value, that is, from the regime below critical gain to values above the critical gain. [ABSTRACT FROM PUBLISHER]

Segmentation is an unavoidable process for computer-aided diagnosis in medical image processing. Due to complex artifacts accurate extraction of tumors in medical images remains a challenge. The existing system deals with the manual cut of the tumor centered image along with robust graph based segmentation for accurate extraction of tumor. The input image can be obtained from any type of modality. There are different ways to segment breast tumor images. This paper focuses on a novel technique called parameter automatically optimized robust graph based (PAORGB) segmentation. Particle swam optimization is incorporated with robust graph based segmentation in order to obtain a global solution. The new method may be a effective way to segment breast tumors than the robust graph based method and to also reduce the computational time. [ABSTRACT FROM AUTHOR]

‘Flying Triangulation’ (FlyTri) is a recently developed principle which allows for a motion-robust optical 3D measurement of rough surfaces. It combines a simple sensor with sophisticated algorithms: a single-shot sensor acquires 2D camera images. From each camera image, a 3D profile is generated. The series of 3D profiles generated are aligned to one another by algorithms, without relying on any external tracking device. It delivers real-time feedback of the measurement process which enables an all-around measurement of objects. The principle has great potential for small-space acquisition environments, such as the measurement of the interior of a car, and motion-sensitive measurement tasks, such as the intraoral measurement of teeth. This article gives an overview of the basic ideas and applications of FlyTri. The main challenges and their solutions are discussed. Measurement examples are also given to demonstrate the potential of the measurement principle. [ABSTRACT FROM PUBLISHER]