Key Matrix Research Articles

Inhibition of Mammalian Target of Rapamycin Signaling with Rapamycin Prevents Trauma-Induced Heterotopic Ossification

A pressing clinical need exists for 63% to 65% of combat-wounded service members and 11% to 20% of civilians who develop heterotopic ossification (HO) after blast-related extremity injury and traumatic injuries, respectively. The mammalian target of rapamycin pathway is a central cellular sensor of injury. We evaluated the prophylactic effects of rapamycin, a selective inhibitor of mammalian target of rapamycin signaling, on HO formation in a rat model of blast-related, polytraumatic extremity injury. Rapamycin was administered intraperitoneally daily for 14 days at 0.5 mg/kg or 2.5 mg/kg. Ectopic bone formation was monitored by micro-computed tomography and confirmed by histologic examination. Connective tissue progenitor cells, platelet-derived growth factor receptor-α-positive cells, and α-smooth muscle actin-positive blood vessels were assayed at postoperative day 7 by colony formation and immunofluorescence. Early gene expression changes were determined by low-density microarray. There was significant attenuation of 1) total new bone and soft tissue ectopic bone with 0.5 mg/kg (38.5% and 14.7%) and 2.5 mg/kg rapamycin (90.3% and 82.9%), respectively, 2) connective tissueprogenitor cells, 3) platelet-derived growth factor receptor-α-positive cells, 4) α-smooth muscle actin-positive blood vessels, and 5) of key extracellular matrix remodeling (CD44, Col1a1, integrins), osteogenesis (Sp7, Runx2, Bmp2), inflammation (Cxcl5, 10, IL6, Ccl2), and angiogenesis (Angpt2) genes. No wound healing complications were noted. Our data demonstrate the efficacy of rapamycin ininhibiting blast trauma-induced HO by a multipronged mechanism.

The cosmic microwave background radiation power spectrum as a random bit generator for symmetric- and asymmetric-key cryptography.

In this note, the Cosmic Microwave Background (CMB) Radiation is shown to be capable of functioning as a Random Bit Generator, and constitutes an effectively infinite supply of truly random one-time pad values of arbitrary length. It is further argued that the CMB power spectrum potentially conforms to the FIPS 140-2 standard. Additionally, its applicability to the generation of a (n × n) random key matrix for a Vernam cipher is established.

Sparse regression with output correlation for cardiac ejection fraction estimation

Traditional regression methods minimize the sum of errors of samples with various regularization terms such as the ℓ1-norm and ℓ2-norm. For the diagnosis of cardiovascular diseases, the cardiac ejection fraction (EF) represents an essential measure. However, existing regularization terms do not consider the output correlation (the correlation between ground truth volumes and estimated volumes w.r.t. each subject), which is beneficial in estimating the cardiac EF. In this paper, we first propose a sparse regression with two regularization terms of the ℓ1-norm and output correlation (SROC). Then, we propose a one-dimensional solution path algorithm for quickly finding two good regulation parameters in the formulation of SROC. The solution path algorithm can effectively handle singularities and infinities in the key matrix. Finally, we conduct experiments on a clinical cardiac image dataset with 100 subjects. The experimental results show that our method produces competitive and strong results for estimating the cardiac EF based on quantitative and qualitative analyses.

An IWT based blind and robust image watermarking scheme using secret key matrix

In this paper, the authors have proposed a binary watermark embedding approach for protecting the copyright ownership of the gray-scale images. The proposed watermark embedding process is realized in integer wavelet transform (IWT) domain to defend the robustness property. Instead of inserting the watermark bits directly in the coefficients of cover media, an indirect embedding mechanism is proposed with the reference to a logistic map based secret key matrix which enhance the secrecy of the proposed embedding approach. Initially, the approximate sub band of the IWT transformed cover image is selected with the intention to embed the watermark. Later, a secret key matrix of size corresponding to the approximate sub band of the cover image is formed using the logistic map with secret parameters. During the watermark embedding process, the approximate sub band is modified indirectly with reference to the secret key matrix and a proposed division table. The scheme is tested on a set of standard images and satisfactory results are achieved. In addition, the proposed schemes is also able to extract the watermark information in blind manner. Also, the scheme is comparable with some other related schemes. Finally, the proposed watermarking scheme is able to survive the watermark even after performing certain types of image manipulation attacks.

Unique Biology of Shoulder Cartilage in Comparison to the Cartilage Obtained from the Knee and Ankle Joints

Objectives:Glenohumeral joint (GHJ) arthritis in relatively young active patients presents a considerable clinical challenge. Little is known regarding the biology and reparative capacity of GHJ articular cartilage and how it compares to other diarthrodial joints. The objectives of the current study were to 1) describe the histological and morphological appearance of human normal GHJ cartilage; and 2) investigate cellular responses of GHJ cartilage to interleukin-1β (IL-1β), in comparison to cartilage obtained from the knee and ankle of the same donors.Methods:GHJ, knee (femoral condyle) and ankle (talus) cartilage was obtained through the Gift of Hope Organ and Tissue Donor Network (Itasca, IL) from nine human donors with no documented history of joint diseases (58-75 yo, both genders). Gross morphology of each joint was assessed using Collins grading on a scale 0 to 4. Cartilage explants (3 mm diameter) were removed from each joint, cultured for 48 hours with or without interleukin-1β (IL-1β; 0.1ng/ml or 10ng/ml), and processed for histology with Safranin O, proteoglycan (PG) synthesis/content, and PCR for key extracellular matrix (ECM) genes: Col2, Agg, and SOX9. Results were compared between uncultured and cultured controls and across all three included joints.Results:Unlike grossly normal (Collins grades 0-1) knee and ankle cartilage, grossly normal GHJ cartilage with an intact surface displayed signs of subtle structural changes: loss of Safranin O in the upper layer and in the ECM and increased staining around chondrocytes suggesting elevated metabolic activity. Differences became more apparent with higher Collins grades or in the presence of IL-1β. Treatment with IL-1β (both doses) resulted in more than 2-fold inhibition of PG synthesis in GHJ cartilage (p<0.05), while only high dose IL-1β had the same effect on the knee or ankle cartilage. At the control level, expression of Col2 and Sox9 was comparable between all types of cartilages; Agg expression was the highest in the ankle cartilage. IL-1β increased Agg expression in humeral cartilage and Agg and Col2 genes in glenoid cartilage.Conclusion:GHJ cartilage appears to be more susceptible to catabolic processes than cartilage in the knee or ankle. Elevated expression of key ECM genes in the presence of pro-inflammatory mediator IL-1β may suggest an attempted, but failing repair. This study provides new insight into the histological and biochemical characteristics of GHJ cartilage, both of which may contribute to challenges associated with its reconstruction.

Targeting danger molecules in tendinopathy: the HMGB1/TLR4 axis

ObjectivesTo seek evidence of the danger molecule, high-mobility group protein B1 (HMGB1) expression in human tendinopathy and thereafter, to explore mechanisms where HMGB1 may regulate inflammatory mediators and matrix regulation...

A new image encryption technique combining Elliptic Curve Cryptosystem with Hill Cipher

Image encryption is rapidly increased recently by the increasing use of the internet and communication media. Sharing important images over unsecured channels is liable for attacking and stealing. Encryption techniques are the suitable methods to protect images from attacks. Hill cipher algorithm is one of the symmetric techniques, it has a simple structure and fast computations, but weak security because sender and receiver need to use and share the same private key within a non-secure channels. A new image encryption technique that combines Elliptic Curve Cryptosystem with Hill Cipher (ECCHC) has been proposed in this paper to convert Hill cipher from symmetric technique to asymmetric one and increase its security and efficiency and resist the hackers. Self-invertible key matrix is used to generate encryption and decryption secret key. So, no need to find the inverse key matrix in the decryption process. A secret key matrix with dimensions 4×4 will be used as an example in this study. Entropy, Peak Signal to Noise Ratio (PSNR), and Unified Average Changing Intensity (UACI) will be used to assess the grayscale image encryption efficiency and compare the encrypted image with the original image to evaluate the performance of the proposed encryption technique.

Laminin 211 inhibits protein kinase A in Schwann cells to modulate neuregulin 1 type III-driven myelination.

Myelin is required for proper nervous system function. Schwann cells in developing nerves depend on extrinsic signals from the axon and from the extracellular matrix to first sort and ensheathe a single axon and then myelinate it. Neuregulin 1 type III (Nrg1III) and laminin α2β1γ1 (Lm211) are the key axonal and matrix signals, respectively, but how their signaling is integrated and if each molecule controls both axonal sorting and myelination is unclear. Here, we use a series of epistasis experiments to show that Lm211 modulates neuregulin signaling to ensure the correct timing and amount of myelination. Lm211 can inhibit Nrg1III by limiting protein kinase A (PKA) activation, which is required to initiate myelination. We provide evidence that excessive PKA activation amplifies promyelinating signals downstream of neuregulin, including direct activation of the neuregulin receptor ErbB2 and its effector Grb2-Associated Binder-1 (Gab1), thereby elevating the expression of the key transcription factors Oct6 and early growth response protein 2 (Egr2). The inhibitory effect of Lm211 is seen only in fibers of small caliber. These data may explain why hereditary neuropathies associated with decreased laminin function are characterized by focally thick and redundant myelin.

A Logistic Map-Based Fragile Watermarking Scheme of Digital Images with Tamper Detection

Integrity protection is one of the security mechanisms used to prevent the originality of the content from illegal manipulation. In this paper, the authors have proposed an efficient fragile watermarking scheme to localize the temper region in digital images. To ensure the image integrity, the watermark information insertion is realized into the cover image using a key matrix. A logistic map-based chaotic sequence is considered to produce both the key matrix and the watermark information. The proposed scheme is able to retain high visual quality watermarked image and can precisely detect the tampered region if the image undergoes any attack by various malicious tampering methods. The effectiveness of the proposed scheme is presented by performing various malicious tampering attacks on the watermarked images. Experimental results show that the proposed watermarking scheme has achieved the satisfactory performance. The proposed scheme gives better perceptual quality of watermarked image and low false tamper detection rates compared to some other related schemes.

Intrinsic cellular and molecular properties of in vivo hippocampal synaptic plasticity are altered in the absence of key synaptic matrix molecules.

Hippocampal synaptic plasticity comprises a key cellular mechanism for information storage. In the hippocampus, both long-term potentiation (LTP) and long-term depression (LTD) are triggered by synaptic Ca2+ -elevations that are typically mediated by the opening of voltage-gated cation channels, such as N-methyl-d-aspartate receptors (NMDAR), in the postsynaptic density. The integrity of the post-synaptic density is ensured by the extracellular matrix (ECM). Here, we explored whether synaptic plasticity is affected in adult behaving mice that lack the ECM proteins brevican, neurocan, tenascin-C, and tenascin-R (KO). We observed that the profiles of synaptic potentiation and depression in the dentate gyrus (DG) were profoundly altered compared to plasticity profiles in wild-type littermates (WT). Specifically, synaptic depression was amplified in a frequency-dependent manner and although late-LTP (>24hr) was expressed following strong afferent tetanization, the early component of LTP (<75 min post-tetanization) was absent. LTP (>4hr) elicited by weaker tetanization was equivalent in WT and KO animals. Furthermore, this latter form of LTP was NMDAR-dependent in WT but not KO mice. Scrutiny of DG receptor expression revealed significantly lower levels of both the GluN2A and GluN2B subunits of the N-methyl-d-aspartate receptor, of the metabotropic glutamate receptor, mGlu5 and of the L-type calcium channel, Cav 1.3 in KO compared to WT animals. Homer 1a and of the P/Q-type calcium channel, Cav 1.2 were unchanged in KO mice. Taken together, findings suggest that in mice that lack multiple ECM proteins, synaptic plasticity is intact, but is fundamentally different.

In vitro extracellular matrix accumulation of nasal and articular chondrocytes for intervertebral disc repair.

Chondrocyte based regenerative therapies for intervertebral disc repair such as Autologous Disc Cell Transplantation (ADCT, CODON) and allogeneic juvenile chondrocyte implantation (NuQu®, ISTO Technologies) have demonstrated good outcomes in clinical trials. However concerns remain with the supply demand reconciliation and issues surrounding immunoreactivity which exist for allogeneic-type technologies. The use of stem cells is challenging due to high growth factor requirements, regulatory barriers and differentiation towards a stable phenotype. Therefore, there is a need to identify alternative non-disc cell sources for the development and clinical translation of next generation therapies for IVD regeneration. In this study, we compared Nasal Chondrocytes (NC) as a non-disc alternative chondrocyte source with Articular Chondrocytes (AC) in terms of cell yield, morphology, proliferation kinetics and ability to produce key extracellular matrix components under 5% and 20% oxygen conditions, with and without exogenous TGF-β supplementation. Results indicated that NC maintained proliferative capacity with high amounts of sGAG and lower collagen accumulation in the absence of TGF-β supplementation under 5% oxygen conditions. Importantly, osteogenesis and calcification was inhibited for NC when cultured in IVD-like microenvironmental conditions. The present study provides a rationale for the exploration of nasal chondrocytes as a promising, potent and clinically feasible autologous cell source for putative IVD repair strategies.

Molecular mechanisms promoting progression of autoimmune myocarditis to dilated cardiomyopathy.

Abstract Myocarditis is an inflammatory disease of the myocardium, described by infiltration of immune cells and cardiomyocyte necrosis. It is a major cause of sudden death in young adults. Patients often progress to a more severe form of the disease termed dilated cardiomyopathy (DCM). It is characterized by extensive fibrosis leading to impaired cardiac function. Immunosuppressive treatments with corticosteroids (CSs) have not been effective in preventing the disease. We hypothesized that macrophage migration inhibitory factor (MIF), being the only known pro-inflammatory cytokine induced by CSs may play a role in resistance to CSs. Also, MIF counter-regulates CS-mediated immunosuppression. Using the experimental autoimmune myocarditis (EAM) animal model, we observed that MIF−/− mice treated with Dexamethasone (Dex) were highly resistant to EAM and progression to DCM. Furthermore, from a translational approach, treatment using small molecule inhibitors of MIF combined with Dex recapitulated this phenotype in wild type mice. We observed that treated mice showed decreased expression of key chemokines and extracellular matrix molecules compared with controls, implicating these molecules in disease progression. Currently, we are investigating these molecules by selectively inhibiting them in order to understand their contribution to disease pathogenesis. We observed that inhibition of CCL2 after, although not prior to establishment of EAM attenuated progression to DCM. Thereby, suggesting that CCL2 is predominantly involved during the fibrotic phase aiding in progression as opposed to the induction phase of the disease. Besides a novel approach to prevent DCM, our studies may provide new insights into the mechanisms driving DCM.

Generalization for Multidimensional Playfair Cipher

Playfair cipher is a multi letter, poly alphabetic, symmetric cipher having a 2 dimensional key matrix supporting the security of 26 English alphabets. From the survey it is found that there are other variants which have key matrices with 3 and 4 dimensions. The main aim of this research is to provide the generalization for multidimensional Playfair cipher which includes choosing the dimension based on the number of values/characters supported by the Playfair cipher variant and the corresponding encryption and decryption processes. It is found from the dimensional analysis that more is the dimension for the fixed number of values/characters supported, stronger is the cipher against brute force attack with respect to possible number of groups. Keywords: Information security; Cryptography; Conventional cipher; Classical cipher.

A novel image encryption scheme based on DNA sequence operations and chaotic systems

In the paper, a novel image encryption algorithm based on DNA sequence operations and chaotic systems is proposed. The encryption architecture of permutation and diffusion is adopted. Firstly, 256-bit hash value of the plain image is gotten to calculate the initial values and system parameters of the 2D Logistic-adjusted-Sine map (2D-LASM) and a new 1D chaotic system; thus, the encryption scheme highly depends on the original image. Next, the chaotic sequences from 2D-LASM are used to produce the DNA encoding/decoding rule matrix, and the plain image is encoded into a DNA matrix according to it. Thirdly, DNA level row permutation and column permutation are performed on the DNA matrix of the original image, inter-DNA-plane permutation and intra-DNA-plane permutation can be attained simultaneously, and then, DNA XOR operation is performed on the permutated DNA matrix using a DNA key matrix, and the key matrix is produced by the combination of two 1D chaotic systems. Finally, after decoding the confused DNA matrix, the cipher image is obtained. Experimental results and security analyses demonstrate that the proposed scheme not only has good encryption effect, but also is secure enough to resist against the known attacks.

MatrixMap: Programming abstraction and implementation of matrix computation for big data analytics

The computation core of many big data applications can be expressed as general matrix computations, including linear algebra operations and irregular matrix operations. However, existing parallel programming systems such as Spark do not have programming abstraction and efficient implementation for general matrix computations. In this paper, we present MatrixMap, a unified and efficient data-parallel programming framework for general matrix computations. MatrixMap provides powerful yet simple abstraction, consisting of a distributed in-memory data structure called bulk key matrix and a programming interface defined by matrix patterns. Users can easily load data into bulk key matrices and program algorithms into parallel matrix patterns. MatrixMap outperforms current state-of-the-art systems by employing three key techniques:matrix patterns with lambda functions for irregular and linear algebra matrix operations, asynchronous computation pipeline with context-aware data shuffling strategies for specific matrix patterns and in-memory data structure reusing data in iterations. Moreover, it can automatically handle the parallelization and distribute execution of programs on a large cluster. The experiment results show that MatrixMap is 12 times faster than Spark.

Digital watermarking using Hall property image decomposition method

Most of the existing singular value decomposition-based digital watermarking methods are not robust to geometric rotation, which change the pixels’ locations without maintaining the corresponding changes to the pixel’s intensity values of entire image and yield high computational cost. To answer this, we propose a digital image watermarking algorithm using the Hall property. In the proposed method, a digital watermark image is factorized into lower-triangular, upper-triangular, and permutation matrices. The permutation matrix is used as the valid key matrix for authentication of the rightful ownership of the watermark image. The product of the lower and upper triangular matrices is processed with a few iterations of the Arnold transformation to obtain the scrambled data. The scrambled data are embedded into particular sub-bands of a cover image using Wavelet transform. Our experiments show that the proposed algorithm is highly reliable and computationally efficient compared with state-of-the-art methods that are based on singular value decomposition.

A novel image encryption algorithm based on the chaotic system and DNA computing

A novel image encryption algorithm using the chaotic system and deoxyribonucleic acid (DNA) computing is presented. Different from the traditional encryption methods, the permutation and diffusion of our method are manipulated on the 3D DNA matrix. Firstly, a 3D DNA matrix is obtained through bit plane splitting, bit plane recombination, DNA encoding of the plain image. Secondly, 3D DNA level permutation based on position sequence group (3DDNALPBPSG) is introduced, and chaotic sequences generated from the chaotic system are employed to permutate the positions of the elements of the 3D DNA matrix. Thirdly, 3D DNA level diffusion (3DDNALD) is given, the confused 3D DNA matrix is split into sub-blocks, and XOR operation by block is manipulated to the sub-DNA matrix and the key DNA matrix from the chaotic system. At last, by decoding the diffused DNA matrix, we get the cipher image. SHA 256 hash of the plain image is employed to calculate the initial values of the chaotic system to avoid chosen plaintext attack. Experimental results and security analyses show that our scheme is secure against several known attacks, and it can effectively protect the security of the images.

HILLMAIL: A SECURE EMAIL SYSTEM FOR ANDROID-BASED MOBILE PHONE USING HILL CIPHER ALGORITHM

Nowadays, email has become the most widely communication way in daily life. Email is a very important method of communicating across the internet. During transmission and downloads, it uses protocols which are not secure. Spammers and scammers misuse these protocols to gain access to critical data stored in the email. This triggered concerns because sometimes email is used to exchange confidential messages. To improve security and efficiency of email system, we made an email security system for Android mobile phone using Hill Cipher algorithm. Hill Cipher is a classic cryptography algorithm that uses matrix inverse and matrix multiplication operations to hide the message. The initial stage of the encryption process is forming ciphertext by multiplying the key matrix with plaintext matrix. The contents of encrypted messages only can be read by legitimate recipient who has the key. Converting the ciphertext into plaintext is done by multiplying the ciphertext matrix with the inverse key matrix. The email content can be a plain message or a message with an attached file.

Pixels Sequences Encryption of Image Based on Random Matrixes and Element-by-element Matrix Operations in MATLAB

Both the random matrixes generated by MATLAB and the element-by-element matrix operations in MATLAB are proposed to construct the pixels sequences encryption algorithm of Images. The random matrixes which obey the uniform distribution or normal distribution are used to generate the key stream. By running the element-by-element matrix multiplication and division between the pixels matrix and the key matrix, the sequences of pixels are encrypted and decrypted. This algorithm shows such advantages as good security, simple calculation, and easy availability for programming. Furthermore, the feasibility and stability of the algorithm are demonstrated by experiments.

Anderson Transition for Classical Transport in Composite Materials.

The Anderson transition in solids and optics is a wave phenomenon where disorder induces localization of the wave functions. We find here that the hallmarks of the Anderson transition are exhibited by classical transport at a percolation threshold-without wave interference or scattering effects. As long range order or connectedness develops, the eigenvalue statistics of a key random matrix governing transport cross over toward universal statistics of the Gaussian orthogonal ensemble, and the field eigenvectors delocalize. The transition is examined in resistor networks, human bone, and sea ice structures.