HUBFIRE - A multi-class SVM based JPEG steganalysis using HBCL statistics and FR Index

Blind Steganalysis attempts to detect steganographic data without prior knowledge of either the embedding algorithm or the 'cover' image. This paper proposes new features for JPEG blind steganalysis using a combination of Huffman Bit Code Length (HBCL) Statistics and File size to Resolution ratio (FR Index); the Huffman Bit File Index Resolution (HUBFIRE) algorithm proposed uses these functionals to build the classifier using a multi-class Support Vector Machine (SVM). JPEG images spanning a wide range of resolutions are used to create a 'stego-image' database employing three embedding schemes - the advanced Least Significant Bit encoding technique, that embeds in the spatial domain, a transform-domain embedding scheme: JPEG Hide-and-Seek and Model Based Steganography which employs an adaptive embedding technique. This work employs a multi-class SVM over the proposed 'HUBFIRE' algorithm for statistical steganalysis, which is not yet explored by steganalysts. Experiments conducted prove the model's accuracy over a wide range of payloads and embedding schemes

Model-based optoelectronic packaging automation

IEEE Journal of Selected Topics in Quantum Electronics, 10(3): pp. 445-454. http:dx.doi.org/10.1109/JSTQE.2004.828476In this paper, we present an automation technique that yields high-performance, low-cost optoelectronic alignment and packaging through the use of intelligent control theory and system-level modeling. The control loop design is based on model-based control, previously popularized in process and other control industries. The approach is to build an a priori knowledge model, specific to the assembled package’s optical power propagation characteristics, and use this to set the initial “feed-forward” conditions of the automation system. In addition to this feed-forward model, the controller is designed with feedback components, along with the inclusion of a built in optical power sensor. The optical modeling is performed with the rigorous scalar Rayleigh–Sommerfeld formulation, efficiently solved online using an angular spectrum technique. One of the benefits of using a knowledge-based control technique is that the efficiency of the automation process can be increased, as the number of alignment steps can be greatly reduced. An additional benefit of this technique is that it can reduce the possibility that attachment between optical components will occur at local power maximums, instead of the global maximum of the power distribution. Therefore, the technique improves system performance, while reducing the overall cost of the automation process

Advanced packaging automation for opto-electronic systems

Virology, 351(2), 271-279. http://dx.doi.org/10.1016/j.virol.2006.01.051In this paper, we present a learning control algorithm used in our research of advanced opto-electronic automation, which yields high performance, low cost optoelectronic alignment and packaging through the use of intelligent control theory and system-level modeling. The learning loop technique is activated at a lower sampling frequency for specific and appropriate tasks, to improve the knowledge based control model. Our automation technique is based on constructing an a priori knowledge based model, specific to the assembled package’s optical power propagation characteristics. From this model, a piece-wise linear inverse model is created and used in the “feedforward” loop. This model can be updated for increased accuracy through the learning loop

Learning identification control for model-based optoelectronic packaging

IEEE Journal Of Selected Topics In Quantum Electronics, 12(5): 945-951.In this paper, we present a learning control algorithm for the packaging automation of optoelectronic systems. This automation provides high performance, low-cost alignment and packaging through the use of a model-based control theory and systemlevel modeling. The approach is to build an a priori model, specific to the assembled package’s optical power propagation characteristics. From this model, an inverse model is created and used in the “feedforward” loop. In addition to this feedforward model, the controller is designed with feedback components, along with the inclusion of a built-in optical power sensor. We introduce a learning technique, which is activated at a lower sampling frequency for specific and appropriate tasks, to improve the model used in the model-based control. Initial results are presented from an experimental test bed that is used to verify the control and learning algorithms

Cosmic ray produced Mg<SUP>28</SUP>, Si<SUP>31</SUP>, S<SUP>38</SUP>, C<SUP>l38</SUP>, Cl<SUP>34m</SUP> and other short-lived radioisotopes in wet precipitation

The concentrations of seven radioisotopes, expected to be produced in the troposphere by interactions of secondary cosmic rays with atmospheric nuclei, have been measured in "fresh" rain collections. The half-lives of these isotopes range from about half an hour to a day. The procedures developed for rapid, specific and sensitive analyses of these nuclides are discussed. Detection of two of the isotopes studied, Cl39 (half-life: 55 mins.) and Na24 (15 hrs.), has been reported earlier by Winsberg and Rodel respectively. Amongst the remaining nuclides, two: S38 (2.9 hrs.) and Cl38 (37.3 mins.) were independently and almost simultaneously detected by us and Perkins and his collaborators. Three other isotopes, Cl34m (32 mins.), Si31 (2.6 hrs.) and Mg28 (21.2 hrs.), detected in the present work have not yet been reported elsewhere. The nature of cosmic ray secondary particles responsible for the production of these short-lived radionuclides in the troposphere is discussed. Isotope production is found to vary strongly with altitude in the troposphere; it increases by a factor of two every 1.5-2 km depending on the radioisotope under question. This fact combined with the availability of several isotopes of half-lives ranging from about half an hour to a day leads to the possibility of using them as tracers for studying short-term tropospheric processes, e.g. those occurring prior to and during condensation in a precipitating cloud. The implications of the present measurements are discussed

The impact of the Tumor Microenvironment on the Properties of Glioma Stem-Like Cells

Glioblastoma is the most common and highly malignant primary brain tumor, and patients affected with this disease exhibit a uniformly dismal prognosis. Glioma stemlike cells (GSCs) are a subset of cells within the bulk tumor that possess self-renewal and multi-lineage differentiation properties similar to somatic stem cells. These cells also are at the apex of the cellular hierarchy and cause tumor initiation and expansion after chemo-radiation. These traits make them an attractive target for therapeutic development. Because GSCs are dependent on the brain microenvironment for their growth, and because non-tumorigenic cell types in the microenvironment can influence GSC phenotypes and treatment response, a better understanding of these cell types is needed. In this review, we provide a focused overview of the contributions from the microenvironment to GSC homing, maintenance, phenotypic plasticity, and tumor initiation. The interaction of GSCs with the vascular compartment, mesenchymal stem cells, immune system, and normal brain cell types are discussed. Studies that provide mechanistic insight into each of these GSC-microenvironment interactions are warranted in the future

Steganalysis of YASS using Huffman Length statistics

This work proposes two main contributions to statistical steganalysis of Yet Another Steganographic Scheme (YASS) in JPEG images. Firstly, this work presents a reliable blind steganalysis technique to predict YASS which is one of recent and least statistically detectable embedding scheme using only five features, four Huffman length statistics (H) and the ratio of file size to resolution (FR Index). Secondly these features are shown to be unique, accurate and monotonic over a wide range of settings for YASS and several supervised classifiers with the accuracy of prediction superior to most blind steganalyzers in vogue. Overall, the proposed model having Huffman Length Statistics as its linchpin predicts YASS with an average accuracy of over 94 percent

FOXD1-ALDH1A3 signaling is a determinant for the self-renewal and tumorigenicity of mesenchymal glioma stem cells

Glioma stem-like cells (GSC) with tumor-initiating activity orchestrate the cellular hierarchy in glioblastoma and engender therapeutic resistance. Recent work has divided GSC into two subtypes with a mesenchymal (MES) GSC population as the more malignant subtype. In this study, we identify the FOXD1-ALDH1A3 signaling axis as a determinant of the MES GSC phenotype. The transcription factor FOXD1 is expressed predominantly in patient-derived cultures enriched with MES, but not with the proneural GSC subtype. shRNA-mediated attenuation of FOXD1 in MES GSC ablates their clonogenicity in vitro and in vivo. Mechanistically, FOXD1 regulates the transcriptional activity of ALDH1A3, an established functional marker for MES GSC. Indeed, the functional roles of FOXD1 and ALDH1A3 are likely evolutionally conserved, insofar as RNAi-mediated attenuation of their orthologous genes in Drosophila blocks formation of brain tumors engineered in that species. In clinical specimens of high-grade glioma, the levels of expression of both FOXD1 and ALDH1A3 are inversely correlated with patient prognosis. Finally, a novel small-molecule inhibitor of ALDH we developed, termed GA11, displays potent in vivo efficacy when administered systemically in a murine GSC-derived xenograft model of glioblastoma. Collectively, our findings define a FOXD1-ALDH1A3 pathway in controling the clonogenic and tumorigenic potential of MES GSC in glioblastoma tumors

Targeted Inactivation of Mdm2 RING Finger E3 Ubiquitin Ligase Activity in the Mouse Reveals Mechanistic Insights into p53 Regulation

It is believed that Mdm2 suppresses p53 in two ways: transcriptional inhibition by direct binding, and degradation via its E3 ligase activity. To study these functions physiologically, we generated mice bearing a single-residue substitution (C462A) abolishing the E3 function without affecting p53 binding. Unexpectedly, homozygous mutant mice died before E7.5, and deletion of p53 rescued the lethality. Furthermore, reintroducing a switchable p53 by crossing with mice surprisingly demonstrated that the mutant Mdm2 was rapidly degraded in a manner indistinguishable from that of the wild-type Mdm2. Hence, our data indicate that (1) the Mdm2-p53 physical interaction, without Mdm2-mediated p53 ubiquitination, cannot control p53 activity sufficiently to allow early mouse embryonic development, and (2) Mdm2's E3 function is not required for Mdm2 degradation