An efficient JPEG-2000 based multimodal compression scheme

In this paper, a wavelet-based multimodal compression method is proposed. The method jointly compresses a medical image and an ECG signal within a single codec, i.e., JPEG-2000 in an effective and simple way. The multimodal scheme operates in two main stages: the first stage, consists of the encoder and involves a mixing function, aiming at inserting the samples of the signal in the image according to a predefined insertion pattern in the wavelet domain. The second stage represented by a separation function, consists of the extraction process of the ECG signal from the image after performing the decoding stage. Both the cubic spline and the median edge detection (MED) predictor have been adopted to conduct the interpolation process for estimating image pixels

A new, enhanced EZW image codec with subband classification

In this paper, an enhanced version of Embedded zerotree wavelet (EZW) image coding algorithm is proposed, referred to as EZW-SC. By exploiting a new principle that relies on a subband classification concept, the enhanced algorithm allows the prediction of insignificant subbands at early passes, along with the use of an improved significance map. This reduces the redundancy of zerotree symbols, speeds up the coding process and improves the coding of significant coefficients. In fact, the EZW-SC algorithm scans only significant subbands and significantly improves the lossy compression performance with the conventional EZW. Moreover, new EZW-based schemes are presented to perform colour image coding by taking advantage of the interdependency of the colour components. Experimental results show clear superiority of the proposed algorithms over the conventional EZW as well as other related EZW schemes at various bit rates in both greyscale and colour image compression

Secure and Privacy-preserving Data Sharing in the Cloud based on Lossless Image Coding

Abstract Image and video processing in the encrypted domain has recently emerged as a promising research area to tackle privacy-related data processing issues. In particular, reversible data hiding in the encrypted domain has been suggested as a solution to store and manage digital images securely in the cloud while preserving their confidentiality. However, although efficiency has been claimed with reversible data hiding techniques in encrypted images (RDHEI), reported results show that the cloud service provider cannot add more than 1 bit per pixel (bpp) of additional data to manage stored images. This paper highlights the weakness of RDHEI as a suggested approach for secure and privacy-preserving cloud computing. In particular, we propose a new, simple, and efficient approach that offers the same level of data security and confidentiality in the cloud without the process of reversible data hiding. The proposed idea is to compress the image via a lossless image coder in order to create space before encryption. This space is then filled with a randomly generated sequence and combined with an encrypted version of the compressed bit stream to form a full resolution encrypted image in the pixel domain. The cloud service provider uses the created room in the encrypted image to add additional data and produces an encrypted image containing additional data in a similar fashion. Assessed with the lossless Embedded Block Coding with Optimized Truncation (EBCOT) algorithm on natural images, the proposed scheme has been shown to exceed the capacity of 3 bpp of additional data while maintaining data security and confidentiality

The paradoxical signals of two TrkC receptor isoforms supports a rationale for novel therapeutic strategies in ALS

Full length TrkC (TrkC-FL) is a receptor tyrosine kinase whose mRNA can be spliced to a truncated TrkC.T1 isoform lacking the kinase domain. Neurotrophin-3 (NT-3) activates TrkC-FL to maintain motor neuron health and function and TrkC.T1 to produce neurotoxic TNF-α; hence resulting in opposing pathways. In mouse and human ALS spinal cord, the reduction of miR-128 that destabilizes TrkC.T1 mRNA results in up-regulated TrkC.T1 and TNF-α in astrocytes. We exploited conformational differences to develop an agonistic mAb 2B7 that selectively activates TrkC-FL, to circumvent TrkC.T1 activation. In mouse ALS,2B7 activates spinal cord TrkC-FL signals, improves spinal cord motor neuron phenotype and function, and significantly prolongs life-span. Our results elucidate biological paradoxes of receptor isoforms and their role in disease progression, validate the concept of selectively targeting conformational epitopes in naturally occurring isoforms, and may guide the development of pro-neuroprotective (TrkC-FL) and anti-neurotoxic (TrkC.T1) therapeutic strategies.Fil: Brahimi, Fouad. Mc Gill University. Lady Davis Research Intitute; CanadáFil: Maira, Mario. Mc Gill University. Lady Davis Research Intitute; CanadáFil: Barcelona, Pablo Federico. Mc Gill University. Lady Davis Research Intitute; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Galan, Alba. Mc Gill University. Lady Davis Research Intitute; CanadáFil: Aboulkassim, Tahar. Mc Gill University. Lady Davis Research Intitute; CanadáFil: Teske, Katrina. Mc Gill University. Lady Davis Research Intitute; CanadáFil: Rogers, Mary Louise. Flinders University, Department Of Human Physiology; AustraliaFil: Bertram, Lisa. University of British Columbia; CanadáFil: Wang, Jing. University of British Columbia; CanadáFil: Yousefi, Masoud. University of British Columbia; CanadáFil: Rush, Robert. Flinders University, Department Of Human Physiology; AustraliaFil: Fabian, Marc. Mc Gill University. Lady Davis Research Intitute; CanadáFil: Cashman, Neil. University of British Columbia; CanadáFil: Saragovi, H. Uri. Mc Gill University. Lady Davis Research Intitute; Canad

Ligand-Dependent TrkA Activity in Brain Differentially Affects Spatial Learning and Long-Term Memory

ABSTRACT In the central nervous system, the nerve growth factor (NGF) receptor TrkA is expressed primarily in cholinergic neurons that are implicated in spatial learning and memory, whereas the NGF receptor p75 NTR is expressed in many neuronal populations and glia. We asked whether selective TrkA activation may have a different impact on learning, short-term memory, and long-term memory. We also asked whether TrkA activation might affect cognition differently in wild-type mice versus mice with cognitive deficits due to transgenic overexpression of mutant amyloid-precursor protein (APP mice). Mice were treated with wild-type NGF (a ligand of TrkA and p75 NTR ) or with selective pharmacological agonists of TrkA that do not bind to p75 NTR . In APP mice, the selective TrkA agonists significantly improved learning and short-term memory. These improvements are associated with a reduction of soluble A␤ levels in the cortex and AKT activation in the cortex and hippocampus. However, this improved phenotype did not translate into improved long-term memory. In normal wild-type mice, none of the treatments affected learning or short-term memory, but a TrkA-selective agonist caused persistent deficits in long-term memory. The deficit in wild-type mice was associated temporally, in the hippocampus, with increased AKT activity, increased brain-derived neurotrophic factor precursor, increased neurotrophin receptor homolog-2 (p75-related protein), and long-term depression. Together, these data indicate that selective TrkA activation affects cognition but does so differently in impaired APP mice versus normal wild-type mice. Understanding mechanisms that govern learning and memory is important for better treatment of cognitive disorders

Sustained proliferation in cancer: mechanisms and novel therapeutic targets

Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression

An improved SPIHT algorithm for lossless image coding

In this paper, we propose a new wavelet-based lossless image coder that is based on a state-of-theart algorithm, namely SPIHT (set partitioning in hierarchical trees). An algorithmic modification is introduced in order to increase its efficiency. This consists of adding a new test on direct descendants in the sets of type A to process the parent coefficients that are significant due to their nondirect descendants. Also, new sets of type C are defined to perform a separate sorting of the sets that have insignificant children. The idea behind the second proposition is to remove all tests over the entries (A, B and C) since the number of significant sets is much higher than that of insignificant sets. A number of experiments, carried out on various test images, demonstrates significant improvement over the conventional SPIHT for both greyscale and colour images

Combinatorial Assembly of Small Molecules into Bivalent Antagonists of TrkC or TrkA Receptors

<div><p>A library of peptidomimetics was assembled combinatorially into dimers on a triazine-based core. The pharmacophore corresponds to β-turns of the neurotrophin polypeptides neurotrophin-3 (NT-3), nerve growth factor (NGF), or brain-derived neurotrophic factor (BDNF). These are the natural ligands for TrkC, TrkA, and TrkB receptors, respectively. The linker length and the side-chain orientation of each monomer within the bivalent mimics were systematically altered, and the impact of these changes on the function of each ligand was evaluated. While the monovalent peptidomimetics had no detectable binding or bioactivity, four bivalent peptidomimetics (<b>2c</b>, <b>2d</b>, <b>2e</b>, <b>3f</b>) are selective TrkC ligands with antagonistic activity, and two bivalent peptidomimetics (<b>1a</b>, <b>1b</b>) are TrkC and TrkA ligands with antagonistic activity. All these bivalent compounds block ligand-dependent receptor activation and cell survival, without affecting neuritogenic differentiation. This work adds to our understanding of how the neurotrophins function through Trk receptors, and demonstrates that peptidomimetics can be designed to selectively disturb specific biological signals, and may be used as pharmacological probes or as therapeutic leads. The concept of altering side-chain, linker length, and sequence orientation of a subunit within a pharmacophore provides an easy modular approach to generate larger libraries with diversified bioactivity.</p></div