Domain Block Research Articles

Molecular characterization of a new N-acetylneuraminate synthase (NeuB1) from Idiomarina loihiensis.

N-Acetylneuraminate lyase synthase (NeuB; E.C. 2.5.1.56) is a key enzyme in pathogenic microorganisms for producing N-acetylneuraminic acid through the irreversible condensation of N-acetylmannosamine (ManNAc) and phosphoenolpyruvate (PEP). However, nothing is known about this enzyme in non-pathogenic bacteria. This paper describes, for the first time, one of the two putative N-acetylneuraminate synthases from the halophilic non-pathogenic gamma-proteobacterium Idiomarina loihiensis NeuB1 (IlNeuB1). The obtained 95-kDa dimeric enzyme showed maximal activity at pH 7.0 and 40°C and was more stable at pH 8.0 (8 h half-life) than the previously described NeuB. Its catalytic efficiency towards ManNAc and PEP was 10- and 40-fold higher, respectively, than that determined for Campylobacter jejuni NeuB, but only half that found for Neisseria meningitidis NeuB towards PEP. The phylogenetic and structural analyses of NeuB enzymes revealed the new domain architecture 4 has no cystathionine-β-synthase domain (cystathionine-β-synthetase domain), unlike domain architecture 3. In addition, 10 conserved blocks (I-X) were found, and surprisingly, this study showed that the arginine essential for catalysis that is present in antifreeze-like domain (block X) was not fully conserved in NeuB, but is replaced by a serine in a long sequence (>700 residues) NeuB, such as that existing in domain architectures 3 and 4.

A Fast Encoding Method for Fractal Image Compression

present work is concerned with a review of various techniques of fractal image compression. Firstly variance- ordered domain block search algorithm and then Randomized domain block search algorithm is discussed. An analysis is performed on both of them and on the basis of the analysis a new algorithm is proposed. After that a detailed comparative analysis is performed by implementing the algorithms in Matlab. For our comparison we compare the PSNR of the reconstructed image. Keywordsimage fast encoding, Variance based search, Random search.

A novel fractal coding method based on M-J sets.

In this paper, we present a novel fractal coding method with the block classification scheme based on a shared domain block pool. In our method, the domain block pool is called dictionary and is constructed from fractal Julia sets. The image is encoded by searching the best matching domain block with the same BTC (Block Truncation Coding) value in the dictionary. The experimental results show that the scheme is competent both in encoding speed and in reconstruction quality. Particularly for large images, the proposed method can avoid excessive growth of the computational complexity compared with the traditional fractal coding algorithm.

BASED ON RANGE AND DOMAIN FRACTAL IMAGE COMPRESSION OF SATELLITE IMAGERIES IMPROVED ALGORITHM FOR RESEARCH

Fractal coding is a novel method to compress images, which was proposed by Barnsley, and implemented by Jacquin. It offers many advantages. Fractal image coding has the advantage of higher compression ratio, but is a lossy compression scheme. The encoding procedure consists of dividing the image into range blocks and domain blocks and then it takes a range block and matches it with the domain block. The image is encoded by partitioning the domain block and using affine transformation to achieve fractal compression. The image is reconstructed using iterative functions and inverse transforms. However, the encoding time of traditional fractal compression technique is too long to achieve real-time image compression, so it cannot be widely used. Based on the theory of fractal image compression; this paper raised an improved algorithm form the aspect of image segmentation. In the present work the fractal coding techniques are applied for the compression of satellite imageries. The Peak Signal to Noise Ratio (PSNR) values are determined for images namely Satellite Rural image and Satellite Urban image. The Matlab simulation results for the reconstructed image shows that PSNR values achievable for Satellite Rural image ~33 and for Satellite urban image ~42.

의료영상의 화질개선을 위한 프랙탈 영상 부호화

본 논문에서는 프랙탈 부호화시 변환식의 계수를 찾는 과정에서 블럭의 탐색영역을 줄이기 위해 탐색영역인 도메인 블럭의 특성을 화소의 밝기의 평균에 의한 클래스와 분산에 의한 클래스로 분류하여 리스트를 구성한 후 레인지 블럭과 같은 클래스를 가지는 도메인 블럭만 검색하도록 하면서 도메인 블록 탐색시 1차 허용 오차 한계값을 제어하여 리스트 탐색시 RMS값에 일정 허용오차 이내의 값을 가지면 리스트를 끝까지 탐색하지 않고 변환값을 결정하도록 하여 부호화 시간을 향상시켰다. 또한 퀴드트리 분할법으로 레인지 블럭의 크기를 가변시켜 변환(<TEX>$w_i$</TEX>)의 수를 줄임으로서 압축효율을 높이고 도메인 레인지 블럭의 크기에 따라 탐색 영역의 탐색 밀도와 허용오차를 변화시켰을 때 화질 개선 여부를 검토하였다. 제안된 방법으로 부호화한 결과 부호화 시간은 허용오차의 범위에 따라 향상되며 압축효과는 높아 졌고 PSNR값은 다소 떨어졌으나 거의 무시할 수 있을 정도의 변화가 있었다. This paper suggests techniques to enhance coding time which is a problem in traditional fractal compression and to improve fidelity of reconstructed images by determining fractal coefficient through adaptive selection of block approximation formula. First, to reduce coding time, we construct a linear list of domain blocks of which characteristics is given by their luminance and variance and then we control block searching time according to the first permissible threshold value. Next, when employing three-level block partition, if a range block of minimum partition level cannot find a domain block which has a satisfying approximation error, we choose new approximation coefficients using a non-linear approximation of luminance term. This boosts the fidelity. Our experiment employing the above methods shows enhancement in the coding time more than two times over traditional coding methods and shows improvement in PSNR value by about 1-3dB at the same compression rate.

Improved Algorithm of Fractal Compression Based on Average Deviation

Aiming at deficiency of fractal image compression, encoding time length and large amount of calculation, an improved algorithm of fractal compression is proposed based on the average deviation. First,divided image into blocks by using the characteristics of the average deviation, then determined the image block matching constraints by the application of the scale factor to simplify the calculation method, and finally limited the search range with the constraints, thus decrease the amount of the search range, improve the efficiency of the domain block matching. The simulation results show that the improved algorithm can reduce the computation of block matching, and improve the fractal image coding efficiency.

Robust and Efficient 'RGB&amp;apos; based Fractal Image Compression: Flower Pollination based Optimization

Fractal image compression uses the property of selfsimilarity in an image and utilizes the partitioned iterated function system to encode it. Fractal image compression is attractive because of high compression ratio, fast decompression and multi-resolution properties. The main drawback of Fractal Image Compression is the high computational cost and is the poor retrieved image qualities. To overcome this drawback, we design a new algorithm which is based on Pollination Based Optimization which is used to classify the phantom, satellite and rural image dataset. Flower Pollination Based Optimization is nature inspired algorithm which decreases the search complexity of matching between range block and domain block. Also, the optimization technique has effectively reduced the encoding time while retaining the quality of the image. Peak signal to noise ratio, entropy, compression ratio and mean square error is found for phantom, rural and satellite images data set. This new method showed improved highly accurate results. General terms Optimization, Soft Computing

Structural basis of calcineurin activation by calmodulin

Calcineurin is the only known calmodulin (CaM) activated protein phosphatase, which is involved in the regulation of numerous cellular and developmental processes and in calcium-dependent signal transduction. Although commonly assumed that CaM displaces the autoinhibitory domain (AID) blocking substrate access to its active site, the structural basis underlying activation remains elusive. We have created a fused ternary complex (CBA) by covalently linking three polypeptides: CaM, calcineurin regulatory B subunit (CnB) and calcineurin catalytic A subunit (CnA). CBA catalytic activity is comparable to that of fully activated native calcineurin in the presence of CaM. The crystal structure showed virtually no structural change in the active site and no evidence of CaM despite being covalently linked. The asymmetric unit contains four molecules; two parallel CBA pairs are packed in an antiparallel mode and the large cavities in crystal packing near the calcineurin active site would easily accommodate multiple positions of AID-bound CaM. Intriguingly, the conformation of the ordered segment of AID is not altered by CaM; thus, it is the disordered part of AID, which resumes a regular α-helical conformation upon binding to CaM, which is displaced by CaM for activation. We propose that the structural basis of calcineurin activation by CaM is through displacement of the disordered fragment of AID which otherwise impedes active site access.

Steganalysis of prediction mode modulated data-hiding algorithms in H.264/AVC video stream

In the intra-frame coding of H.264/AVC, information hiding can be implemented by modulating the prediction modes of 4 × 4 luminance blocks. Because such kind of methods has characteristics of high speed, good concealment, and so on, it is very suitable to build the covert communication system based on video communications and brings a great public security threat. Therefore, it is important to study its steganalysis method. In this paper, we first analyzed the changes of remarkable characteristics in intra-frame coding caused by modulating intra-prediction modes for information hiding, and found that the inherent correlation among the prediction modes in different 4 × 4 luminance blocks belonging to an intra-frame coding macroblock was changed. According to several different positional relationships of the adjacent 4 × 4 blocks in spatial domain, we designed statistical models corresponding to the prediction mode correlation to make quantitative extraction of these correlation characteristics. An information hiding detector was constructed based on the support vector machine. Based on the constructed detector, the experimental results show that the mean of the detection accuracy, recall ratio, and precision ratio are all excellent for different test video sequences.

A Novel Fractal Image Compression Scheme With Block Classification and Sorting Based on Pearson's Correlation Coefficient

Fractal image compression (FIC) is an image coding technology based on the local similarity of image structure. It is widely used in many fields such as image retrieval, image denoising, image authentication, and encryption. FIC, however, suffers from the high computational complexity in encoding. Although many schemes are published to speed up encoding, they do not easily satisfy the encoding time or the reconstructed image quality requirements. In this paper, a new FIC scheme is proposed based on the fact that the affine similarity between two blocks in FIC is equivalent to the absolute value of Pearson's correlation coefficient (APCC) between them. First, all blocks in the range and domain pools are chosen and classified using an APCC-based block classification method to increase the matching probability. Second, by sorting the domain blocks with respect to APCCs between these domain blocks and a preset block in each class, the matching domain block for a range block can be searched in the selected domain set in which these APCCs are closer to APCC between the range block and the preset block. Experimental results show that the proposed scheme can significantly speed up the encoding process in FIC while preserving the reconstructed image quality well.

Ataxia Telangiectasia-Mutated (ATM) Kinase Activity Is Regulated by ATP-driven Conformational Changes in the Mre11/Rad50/Nbs1 (MRN) Complex

The Ataxia Telangiectasia-Mutated (ATM) protein kinase is recruited to sites of double-strand DNA breaks by the Mre11/Rad50/Nbs1 (MRN) complex, which also facilitates ATM monomerization and activation. MRN exists in at least two distinct conformational states, dependent on ATP binding and hydrolysis by the Rad50 protein. Here we use an ATP analog-sensitive form of ATM to determine that ATP binding, but not hydrolysis, by Rad50 is essential for MRN stimulation of ATM. Mre11 nuclease activity is dispensable, although some mutations in the Mre11 catalytic domain block ATM activation independent of nuclease function, as does the mirin compound. The coiled-coil domains of Rad50 are important for the DNA binding ability of MRN and are essential for ATM activation, but loss of the zinc hook connection can be substituted by higher levels of the complex. Nbs1 binds to the "closed" form of the MR complex, promoted by the zinc hook and by ATP binding. Thus the primary role of the hook is to tether Rad50 monomers together, promoting the association of the Rad50 catalytic domains into a form that binds ATP and also binds Nbs1. Collectively, these results show that the ATP-bound form of MRN is the critical conformation for ATM activation.

Linear and Nonlinear Time Domain Block Equalizers on MIMO Frequency Selective Channels

Single-Carrier (SC) transmission with the same bandwidth as Multi-Carrier (MC) transmission (such as OFDM) may have far shorter symbol duration and is considered to be more robust against time selective fading. In this paper, we proposed the novel equalization and signal separation schemes in time domain for short block length transmission, i.e., Block Linear Equalization (BLE) and Block Nonlinear Equalization (BNLE) on MIMO frequency selective fading channels. The proposed BLE uses the MMSE based inverse matrix in time domain and the BNLE utilizes the QRD-M (QR Decomposition with M algorithm) with appropriate receiver complexity. We compared the computational complexity among the conventional SC-FDE (Frequency Domain Equalization) scheme and the proposed equalizers. We also used the Low-Density Parity Check (LDPC) decoder concatenated to the proposed BLE and BNLE.

Comparative Analysis of Quad-tree Partitioned Iterated Function Systems for Medical Images

As Image size need to be reduced for the purpose of data storage and transmission for better utilization of the Bandwidth, Images are compressed using lossy and Lossless compression schemes. In this paper Fractal Image Compression, a lossy compression technique is being implemented on medical Images .Fractal Encoding involves partitioning the images into Range Blocks and Domain Blocks and each Range Block is mapped onto the Domain Blocks by using contractive transforms called the Affine Transforms. The Fractal encoding technique takes a longer encoding time and less decoding time. In the present paper Fractal Image Compression using quad-tree Partitioning technique is being implemented. on Medical Images like CT Of Bone and MR Images of Brain The Performance measures like Compression Ratio (CR), Peak Signal To Noise Ratio (PSNR), Mean Square Error (MSE), Encoding time and Decoding Time are determined for the Range Blocks of Sizes 2x2 and 4x4 respectively with different Threshold Values. Mat lab simulated results for these Performance Measures shows that for larger Range Block size, the PSNR Value decreases and CR increases for different threshold Values.

Structure and evolution of mitochondrial control regions in Evynnis cardinalis

We determined the complete sequences of the mitochondrial DNA control regions in Evynnis cardinalis using long polymerase chain reaction(PCR),and aligned them by Clustal X with 9 related Sparidae sequences in GenBank.Several conserved sequence blocks were identified in the mitochondrial DNA control regions,including extended terminal associated sequences(ETAS),blocks of central domain(CSB-F,CSB-E,CSB-D,CSB-C,CSB-B,CSB-A) and conserved sequence blocks(CSB1,CSB2,CSB3).Taking Paralabrax clathratus and Verasper moseri as outgroups,the molecular phylogenetic trees of Sparidae were constructed based on neighbour-joining and maximum-parsimony methods,which reveal that Sparidae is a monophyletic group,and E.cardinalis should be grouped with Pagrus.Therefore,it is necessary to reevaluate the taxonomic status of Evynnis and Pagrus.

Fast Fractal Image Coding Method Based on RMSE and DCT Classification

To solve the problem of long time consuming in the fractal encoding process, a fast fractal encoding algorithm based on RMSE (Root mean square error) and DCT (Discrete Cosine Transform) classification is proposed. During the encoding process, firstly, the image is divided into range blocks and domain blocks by quadtree partition according to RMSE, then, according to DCT coefficients of image block, three classes of image blocks are defined, which are smooth class, horizontal/vertical edge class, diagonal/sub-diagonal class. At last, every range block is limited to search the best matched block in the corresponding domain block class, and the fractal coding are recorded until the process is completed. When searching the best matched block, the nearest neighbor block will be found in the sense of RMSE in the ordered codebook, and the best matched block will be further found in the vicinity of the nearest neighbor block. The experimental results show that the proposed algorithm can efficiently reduce the search space and shorten the encoding time, while achieving the same reconstructed image quality as that of the full search method.

Fractal Compression of Colored Animated Pictures

This research deals with the question of pressing two series of video images by using the pressing Fractal through the use of iterative function systems, where the film frame video acquired is divided after each converting it to one type of the storage formulas for the image files independently. Then, the image is divided into non-overlapping range blocks with the size P×P, the biggest block of which is the overlapping domain one with the size 2P×2P. After that matching is made between rang blocks and each block of domain blocks to obtain domain blocks identical to range blocks. The purpose of making matching is to obtain the best domain block identical to rang block by using familiar transfers, to reduce the volume of storage with the possibility of decompression and making a comparison between the time of compression and decompression. The research sample includes two series of video films from the city of Mosul, namely, the Nineveh bridge and the building of college of Computer Science and Mathematics at the University of Mosul, It is found that algorithm used is efficient as far as compression and decompression of color and moving images are concerned.

An effective fractal image compression algorithm based on plane fitting

A new method using plane fitting to decide whether a domain block is similar enough to a given range block is proposed in this paper. First, three coefficients are computed for describing each range and domain block. Then, the best-matched one for every range block is obtained by analysing the relation between their coefficients. Experimental results show that the proposed method can shorten encoding time markedly, while the retrieved image quality is still acceptable. In the decoding step, a kind of simple line fitting on block boundaries is used to reduce blocking effects. At the same time, the proposed method can also achieve a high compression ratio.

Dielectric behavior of Styrene–Isoprene (SI) Diblock and SIIS Triblock Copolymers: Global Dynamics of I Blocks in Spherical and Cylindrical Domains Embedded in Glassy S Matrix

Dielectric behavior was examined for nanodomain-forming styrene–isoprene (SI) diblock and SIIS triblock copolymers, the former having type-A dipoles aligned along its I block, whereas the latter be...

Huber Fractal Image Coding Based on a Fitting Plane

Recently, there has been significant interest in robust fractal image coding for the purpose of robustness against outliers. However, the known robust fractal coding methods (HFIC and LAD-FIC, etc.) are not optimal, since, besides the high computational cost, they use the corrupted domain block as the independent variable in the robust regression model, which may adversely affect the robust estimator to calculate the fractal parameters (depending on the noise level). This paper presents a Huber fitting plane-based fractal image coding (HFPFIC) method. This method builds Huber fitting planes (HFPs) for the domain and range blocks, respectively, ensuring the use of an uncorrupted independent variable in the robust model. On this basis, a new matching error function is introduced to robustly evaluate the best scaling factor. Meanwhile, a median absolute deviation (MAD) about the median decomposition criterion is proposed to achieve fast adaptive quadtree partitioning for the image corrupted by salt & pepper noise. In order to reduce computational cost, the no-search method is applied to speedup the encoding process. Experimental results show that the proposed HFPFIC can yield superior performance over conventional robust fractal image coding methods in encoding speed and the quality of the restored image. Furthermore, the no-search method can significantly reduce encoding time and achieve less than 2.0 s for the HFPFIC with acceptable image quality degradation. In addition, we show that, combined with the MAD decomposition scheme, the HFP technique used as a robust method can further reduce the encoding time while maintaining image quality.

Improvement of Fractal Image Compression Coding Based on Quadtree

The goal of image compression is to represent an image with as few number of bits as possible while keeping the quality of the original image. With the characteristics of higher compression ratio, fractal image coding has received much attention recently. However, conventional fractal compression approach needs more time to code the original image. In order to overcome the time-consuming issue, a Quadtree-based partitioning and matching scheme is proposed. During the partitioning phase, an image frame is partitioned into tree-structural segments. And during a matching phase, a rang block only searches its corresponding domain block around previous matched domain block. Such local matching procedures will not stop until a predefined matching threshold is obtained. The preliminary experimental results show that such sub-matching rather than a global matching scheme dramatically decreases the matching complexity, while preserving the quality of an approximate image to the original after decoding process. In particular, the proposed scheme improves the coding process up to 2 times against the conventional fractal image coding approach.