Search Results (42)

Simultaneous color contrast is a perceptual phenomenon in which a target stimulus appears to change its hue due to color induction from the surrounding background. In this study, we investigated whether this phenomenon is influenced by the structural complexity and identity of the stimuli used. In Experiment 1, we created two sets of stimuli varying in structural complexity and asked participants to perform a color-matching task on the achromatic target. Low-complexity targets consisted of simple squares, while high-complexity targets were stylized cars. The results showed that high-complexity stimuli triggered stronger color induction from the background and exhibited greater interindividual variation in perceived color saturation. Conversely, low-complexity stimuli were predominantly perceived as achromatic across all participants. In Experiment 2, we further explored whether these effects were influenced by differences in the stimuli’s topology and identity. Topological factors were controlled by ensuring similar organizations of stimulus elements across conditions, while the role of stimulus identity was examined by including a condition in which the high-complexity stimuli from Experiment 1 were presented in a scrambled arrangement, preventing recognition. The results demonstrated that color contrast increased with the complexity of the stimuli but also highlighted the role of identity, as the condition where the car was recognizable elicited the strongest color induction. We conclude that simultaneous color contrast is strengthened by factors that pertain to both the complexity of the stimuli used and their identity. Full article

Image security faces increasing challenges with the widespread application of computer science and artificial intelligence. Although chaotic systems are employed to encrypt images and prevent unauthorized access or tampering, the degradation that occurs during the binarization process in chaotic systems reduces security. The chaos- and DNA-based image encryption schemes increases its complexity, while the integration of deep learning with image encryption is still in its infancy and has several shortcomings. An image encryption scheme with high security and efficiency is required for the protection of the image. To address these problems, we propose a novel image encryption scheme based on the lightweight VGG (LVGG), referred to as LVGG-IE. In this work, we design an LVGG network with fewer layers while maintaining a high capacity for feature capture. This network is used to generate a key seed, which is then employed to transform the plaintext image into part of the initial value of a chaotic system, ensuring that the chaos-based key generator correlates with the plaintext image. A dynamic substitution box (S-box) is also designed and used to scramble the randomly shuffled plaintext image. Additionally, a single-connected (SC) layer is combined with a convolution layer from VGG to encrypt the image, where the SC layer is dynamically constructed by the secret key and the convolution kernel is set to $1\times 2$. The encryption efficiency is simulated, and the security is analyzed. The results show that the correlation coefficient between adjacent pixels in the proposed scheme achieves ${10}^{-4}$. The NPCR exceeds 0.9958, and the UACI falls within the theoretical value with a significance level of 0.05. The encryption quality, the security of the dynamic S-box and the SC layer, and the efficiency are tested. The result shows that the proposed image encryption scheme demonstrates high security, efficiency, and robustness, making it effective for image security in various applications. Full article

In consideration of the prevailing methodology for constructing G functions, there are certain limitations such as fixed change rules and restricted flexibility when producing frequency-hopping sequences. This paper introduces a novel construction method for the Random Factor-based G function (RFGF). This approach incorporates random factors to dynamically divide the frequency set into equal intervals and randomly selects the frequency hopping frequency within each subset. This effectively reduces the correlation between adjacent frequency-hopping frequencies, enhancing the randomness of the sequence and the system’s anti-interference performance. Furthermore, this method utilizes chaotic sequences to scramble data information, further strengthening the security of the information. The experimental results demonstrate that the frequency-hopping sequence generated by this proposed G function construction method outperforms the sequence generated by the time-varying iterative decomposition in terms of randomness, uniformity, and two-dimensional continuity. Specifically, under the same parameter conditions, the two-dimensional continuity is improved by 36.87%. Full article

Protein phosphatase 1 (PP1) complexes have emerged as promising targets for anticancer therapies. The ability of peptides to mimic PP1-docking motifs, and so modulate interactions with regulatory factors, has enabled the creation of highly selective modulators of PP1-dependent cellular processes that promote tumor growth. The major objective of this study was to develop a novel bioactive cell-penetrating peptide (bioportide), which, by mimicking the PP1-binding motif of caveolin-1 (CAV1), would regulate PP1 activity, to hinder prostate cancer (PCa) progression. The designed bioportide, herein designated CAVPENET, and a scrambled homologue, were synthesized using microwave-assisted solid-phase methodologies and evaluated using PCa cell lines. Our findings indicate that CAVPENET successfully entered PCa cells to influence both viability and migration. This tumor suppressor activity of CAVPENET was attributed to inhibition of AKT signaling, a consequence of increased PP1γ activity. This led to the suppression of glycolytic metabolism and alteration in lipid metabolism, collectively representing the primary mechanism responsible for the anticancer properties of CAVPENET. Our results underscore the potential of the designed peptide as a novel therapy for PCa patients, setting the stage for further testing in more advanced models to fully realize its therapeutic promise. Full article

Assume that $(Y,\rho )$ is a nontrivial complete metric space, and that $(Y,g_{1,\infty })$ is a time-varying discrete dynamical system (T-VDDS), which is given by sequences ${\left(g_l\right)}_{l=1}^{\infty }$ of continuous selfmaps $g_l:Y\to Y$. In this paper, for a given Furstenberg family $\mathcal{G}$ and a given T-VDDS $(Y,g_{1,\infty })$, $\mathcal{G}$-scrambled pairs of points of the system $(Y,g_{1,\infty })$ (which contains the well-known scrambled pairs) are provided. Some properties of the set of $\mathcal{G}$-scrambled pairs of a given T-VDDS $(Y,g_{1,\infty })$ are studied. Moreover, the generically $\mathcal{G}$-chaotic T-VDDS and the generically strongly $\mathcal{G}$-chaotic T-VDDS are defined. A sufficient condition for a given T-VDDS to be generically strongly $\mathcal{G}$-chaotic is also presented. Full article

Bladder pain is a prominent symptom in Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS). We studied spinal mechanisms of bladder pain in mice using a model where repeated activation of intravesical Protease Activated Receptor-4 (PAR4) results in persistent bladder hyperalgesia (BHA) with little or no bladder inflammation. Persistent BHA is mediated by spinal macrophage migration inhibitory factor (MIF), and is associated with changes in lumbosacral proteomics. We investigated the contribution of individual spinal MIF receptors to persistent bladder pain as well as the spinal proteomics changes associated with relief of persistent BHA by spinal MIF antagonism. Female mice with persistent BHA received either intrathecal (i.t.) MIF monoclonal antibodies (mAb) or mouse IgG1 (isotype control antibody). MIF antagonism temporarily reversed persistent BHA (peak effect: 2 h), while control IgG1 had no effect. Moreover, i.t. antagonism of the MIF receptors CD74 and C-X-C chemokine receptor type 4 (CXCR4) partially reversed persistent BHA. For proteomics experiments, four separate groups of mice received either repeated intravesical scrambled peptide and sham i.t. injection (control, no pain group) or repeated intravesical PAR4 and: sham i.t.; isotype IgG1 i.t. (15 μg); or MIF mAb (15 μg). L6-S1 spinal segments were excised 2 h post-injection and examined for proteomics changes using LC-MS/MS. Unbiased proteomics analysis identified and relatively quantified 6739 proteins. We selected proteins that showed significant changes compared to control (no pain group) after intravesical PAR4 (sham or IgG i.t. treatment) and showed no significant change after i.t. MIF antagonism. Six proteins decreased during persistent BHA (V-set transmembrane domain-containing protein 2-like confirmed by immunohistochemistry), while two proteins increased. Spinal MIF antagonism reversed protein changes. Therefore, spinal MIF and MIF receptors mediate persistent BHA and changes in specific spinal proteins. These novel MIF-modulated spinal proteins represent possible new targets to disrupt spinal mechanisms that mediate persistent bladder pain. Full article

We present a technique that utilizes cascaded resonant cylindrical piezoelectric ceramics and multimode optical fibers wound around them to effectively mitigate laser speckle. By precisely driving the ceramics at their resonant frequencies and inducing comprehensive mode scrambling within the multimode fiber, we achieve a remarkable speckle suppression efficiency of up to 94%. To the best of our knowledge, this sets a new benchmark among various methods aimed at suppressing the speckle of a coherent light. Our study thoroughly explores variables influencing efficiency, including the cascading number of piezoelectric ceramics, driving voltage, fiber core diameter, and more. This method has significant promise for diverse applications that require efficient and fast control of speckle contrast. Full article

This paper focuses on the syntax of interrogative clauses in Istro-Romanian. The aim is to determine the parametric settings for V-to-C, subject placement (SVO or VSO) and the target for constituent movement under discourse triggers. The findings indicate that Istro-Romanian preserved the parametric settings from Old Romanian, especially those that converged with the parametric settings in Croatian grammar. In particular, SVO can be explained only through inheritance, whereas VSO, lack of V-to-C and scrambling are a matter of both inheritance and convergence with Croatian. Full article

This paper aims to define the featural composition of the complementizers that introduce subjunctive complements in Istro-Romanian, and to identify the internal organization of the subjunctive clause in terms of subject positions, verb movement, clitic placement and constituent fronting. In a nutshell, the observation is that the complementizer neca replaces se within the syntactic pattern of Old Romanian; that is, a pattern that displays intra- and inter-language variation with respect to the distribution of complementizers within the subjunctive CP. Tests of word order also indicate intra-language variation in the parametric settings for clitic placement (either high or low), for the argumental subject position (either in Spec,TP, yielding SVO, or in Spec,vP, yielding VSO) and for constituent movement under discourse triggers (either scrambling or fronting to CP). Full article

A digraph (D) is symmetric if $(u,v)$ is an arc of D and if $(v,u)$ is also an arc of D. If a symmetric digraph is primitive and contains d loops, then it is said to be a symmetric primitive digraph with d loops. The m-competition index (generalized competition index) of a digraph is an extension of the exponent and the scrambling index. The m-competition index has been applied to memoryless communication systems in recent years. In this article, we assume that $S_n\left(d\right)$ represents the set of all symmetric primitive digraphs of n vertices with d loops, where $1\le d\le n.$ We study the m-competition indices of $S_n\left(d\right)$ and give their upper bounds, where $1\le m\le n.$ Furthermore, for any integer m satisfying $1\le m\le n,$ we find that the upper bounds of the m-competition indices of $S_n\left(d\right)$ can be reached. Full article

Digital images can be easily shared or stored using different imaging devices, storage tools, and computer networks or wireless communication systems. However, these digital images, such as headshots or medical images, may contain private information. Hence, to protect the confidentiality, reliability, and availability of digital images on online processing applications, it is crucial to increase the infosecurity of these images. Therefore, an authorization encryption scheme should ensure a high security level of digital images. The present study aimed to establish a multilayer convolutional processing network (MCPN)-based cryptography mechanism for performing two-round image encryption and decryption processes. In the MCPN layer, two-dimensional (2D) spatial convolutional operations were used to extract the image features and perform scramble operations from grayscale to gray gradient values for the first-image encryption and second-image decryption processes, respectively. In the MCPN weighted network, a sine-power chaotic map (SPCM)-based key generator was used to dynamically produce the non-ordered pseudorandom numbers to set the network-weighted values as secret keys in a sufficiently large key space. It performs the second and first encryption processes using the diffusion method, modifying the image pixel values. Children’s headshots and medical images were used to evaluate the security level by comparing the plain and cipher images using the information entropy, number of pixel change rate, and unified averaged changed intensity indices. Moreover, the plain and decrypted images were compared to verify the decrypted image quality using the structural similarity index measurement and peak signal-to-noise ratio. Full article

Following the COVID-19 pandemic in March 2020, many congregational leaders had to scramble to set up streaming or recording systems in order to continue their worship services without putting congregants at risk, but some congregations had already set up such systems in the years leading up to the pandemic. Previous research has found that these capabilities were not evenly distributed throughout the population of congregations, but this work has primarily focused on how technological divides are the result of a lack of economic resources. However, economic resources were not the only factor associated with whether congregations had streaming options or not. Using Wave 4 of the National Congregations Study (NCS) conducted in 2018–2019, I find that, prior to the pandemic, Catholic congregations and Protestant congregations with more enthusiastic worship services were more likely to have streaming or recording systems even after controlling for economic resources, technological knowledge, and other organizational features. The elective affinities between certain worship practices and online streaming meant that some congregations were in a better position to meet the unexpected challenges posed by the coronavirus pandemic. These findings highlight the important role congregations’ cultural beliefs and practices can play in shaping their activities. Full article

In the past decade, a large amount of important digital data has been created and stored in the form of color images; the protection of such data from undesirable accesses has become an important problem in information security. In this paper, a new approach based on an evolutionary framework is proposed for the secure encryption of color images. The image contents in a color image are first fully scrambled with a sequence of bit-level operations determined by a number of integer keys. A scrambled image is then encrypted with keys generated from an evolutionary process controlled by a set of chaotic systems. Analysis and experiments show that the proposed approach can generate encrypted color images with high security. In addition, the performance of the proposed approach is compared with that of a few state-of-the-art approaches for color image encryption. The results of the comparison suggest that the proposed approach outperforms the other approaches in the overall security of encrypted images. The proposed approach is thus potentially useful for applications that require color image encryption. Full article

Biological motion perception is a specific type of perceptual organization, during which a clear image of a moving human body is perceptually generated in virtue of certain core light dots representing the major joint movements. While the processes of biological motion perception have been studied extensively for almost a century, there is still a debate on whether biological motion task performance can be equally precise across all visual field or is central visual field specified for biological motion perception. The current study explores the processes of biological motion perception and figure–ground segmentation in the central and peripheral visual field, expanding the understanding of perceptual organization across different eccentricities. The method involved three different tasks of visual grouping: (1) a static visual grouping task, (2) a dynamic visual grouping task, and (3) a biological motion detection task. The stimuli in (1) and (2) were generated from 12–13 dots grouped by proximity and common fate, and, in (3), light dots representing human motion. All stimuli were embedded in static or dynamics visual noise and the threshold value for the number of noise dots in which the elements could still be grouped by proximity and/or common fate was determined. The results demonstrate that biological motion can be differentiated from the scrambled set of moving dots in a more intensive visual noise than static and dynamic visual grouping tasks. Furthermore, in all three visual tasks (static and dynamic grouping, and biological motion detection) the performance was significantly worse in the periphery than in the central visual field, and object magnification could not compensate for the reduced performance in any of the three grouping tasks. The preliminary results of nine participants indicate that (a) human motion perception involves specific perceptual processes, providing the high-accuracy perception of the human body and (b) the processes of figure–ground segmentation are governed by the bottom-up processes and the best performance can be achieved only when the object is demonstrated in the central visual field. Full article

Because images are vulnerable to external attacks in the process of network transmission and traditional image encryption algorithms have limitations such as long encryption time, insufficient entropy or poor diffusion of cipher image information when encrypting color images, a fast image encryption algorithm based on logistics-sine-cosine mapping is proposed. The algorithm first generates five sets of encrypted sequences from the logistics-sine-cosine mapping, then uses the order of the encryption sequence to scramble the image pixels and designs a new pixel diffusion network to further improve the key sensitivity and plain-image sensitivity of the encryption algorithm. Finally, in a series of security analysis experiments, the experimental image Lena was tested 100 times, and the average encryption time was 0.479 s. The average value of the information entropy, pixel change rate and uniform average change intensity of the cipher image reached 7.9994, 99.62% and 33.48%, respectively. The experimental results show that the fast image encryption algorithm based on logistics-sine-cosine mapping takes less time to encrypt, and the cipher image has good information entropy and diffusivity. It is a safe and effective fast image encryption algorithm. Full article