Measurements and Analysis of Secondary User Device Effects on Digital Television Receivers

This is the published version. Copyright © 2009 Newman et al.This article presents results from a study of the potential effects of secondary users operating in unoccupied television spectrum. Television spectrum is known within the wireless communications community as being underutilized, making it a prime candidate for dynamic spectrum access. The proposed use of this open spectrum has prompted questions concerning the quantity of available channel space that could be used without negative impact on consumers who view digital television broadcasts and the viability of secondary use of open channels immediately adjacent to a digital television broadcast channel. In this work, we investigate secondary device operation in the channels directly adjacent to a desired television channel, and the effects upon a selection of consumer digital television (DTV) receivers. Our observations strongly suggest that secondary users could operate "White Space Devices" (WSDs) in unoccupied channel bandwidth directly adjacent to a desired digital television (DTV) channel, with no observable adverse impact upon the reception of the desired channel content

Methylated DNA Binding Domain Protein 2 (MBD2) Coordinately Silences Gene Expression through Activation of the MicroRNA <i>hsa-mir-496</i> Promoter in Breast Cancer Cell Line

<div><p>Methylated DNA binding protein 2 (MBD2) binds methylated promoters and suppresses transcription in <i>cis</i> through recruitment of a chromatin modification repressor complex. We show here a new mechanism of action for MBD2: suppression of gene expression indirectly through activation of microRNA <i>hsa-mir-496</i>. Overexpression of MBD2 in breast epithelial cell line MCF-10A results in induced expression and demethylation of <i>hsa-mir-496</i> while depletion of MBD2 in a human breast cancer cell lines MCF-7 and MDA-MB231 results in suppression of <i>hsa-mir-496</i>. Activation of <i>hsa-mir-496</i> by MBD2 is associated with silencing of several of its target genes while depletion of MBD2 leads to induction of <i>hsa-mir-496</i> target genes. Depletion of <i>hsa-mir-496</i> by locked nucleic acid (LNA) antisense oligonucleotide leads to activation of these target genes in MBD2 overexpressing cells supporting that <i>hsa-mir-496</i> is mediating in part the effects of MBD2 on gene expression. We demonstrate that MBD2 binds the promoter of <i>hsa-mir-496</i> in MCF-10A, MCF-7 and MDA-MB-231 cells and that it activates an <i>in vitro</i> methylated <i>hsa-mir-496</i> promoter driving a CG-less luciferase reporter in a transient transfection assay. The activation of <i>hsa-mir-496</i> is associated with reduced methylation of the promoter. Taken together these results describe a novel cascade for gene regulation by DNA methylation whereby activation of a methylated microRNA by MBD2 that is associated with loss of methylation triggers repression of downstream targets.</p></div

Using AUTOSAR high-level specifications for the synthesis of security components in automotive systems

The increasing complexity and autonomy of modern automotive systems, together with the safety-sensitive nature of many vehicle information flows require a careful analysis of the security requirements and adequate mechanisms for ensuring integrity and confidentiality of data. This is especially true for (semi-)autonomous vehicle systems, in which user intervention is limited or absent, and information must be trusted. This paper provides a proposal for the representation of high-level security properties in the specification of application components according to the AUTOSAR standard (AUTomotive Open System ARchitecture). An automatic generation of security components from security-annotated AUTOSAR specifications is also proposed. It provides for the automatic selection of the adequate security mechanisms based on a high-level specification, thus avoiding complex and errorprone manual encodings by the designer. These concepts and tools are applied to a paradigmatic example in order to show their simplicity and efficacy

Ingenuity pathway analysis of putative targets of the MBD2<i>-hsa-mir-496</i> pathway in MCF-10A cells overexpressing MBD2.

<p>(<b>A</b>) A list of genes repressed by MBD2 overexpression in MCF-10A cells was compared to a computed list of <i>hsa-mir-496</i> targets (miRANDA) and subjected to Ingenuity pathway analysis. (B) Associated network functions identified a network with a role in cell migration and haptotaxis. Down regulated mRNA and putative <i>hsa-mir-496</i> targets are highlighted in bold and light blue outline. Data were analyzed through the use of IPA (Ingenuity® Systems, <a href="http://www.ingenuity.com" target="_blank">www.ingenuity.com</a>).</p

Repressed targets of MBD2 in MBD2 overexpressing cells are putative targets of <i>hsa-mir-496</i>.

<p>(A) <i>CTSH</i> expression in MBD2 overexpressing MCF-10A [+M] and siMBD2 depleted MCF-7 [−M ] and MDA-231 cell lines and controls [C]. (B) <i>POU2F3</i> expression in MBD2 overexpressing MCF-10A [+M] and in response to transient depletion of MBD2 [−M] in MCF-7 and MDA-231 and controls [C]. (C) <i>PTGS1</i> expression in MBD2 overexpressing MCF-10A [+M] and in response to transient depletion of MBD2 [−M] in MCF-7 and MDA-231 and controls [C]. (D) <i>hsa-mir-496</i> expression as determined by QPCR analysis in LNA treated MCF-10A, MCF-7 and MDA-MB-231 cells. (E) <i>CTSH</i> expression in response to transient knockdown of <i>hsa-mir-496</i> in MCF-10A overexpressing MBD2 , MCF-7 and MDA-231 and controls . (F) <i>POU2F3</i> expression in a transient knockdown of <i>hsa-mir-496</i> in MCF-10A overexpressing MBD2 , MCF-7 and MDA-231 and controls. (G) <i>PTGS1</i> expression in a transient knockdown of <i>hsa-mir-496</i> in MCF-10A overexpressing MBD2 , MCF-7 and MDA-231 and controls.</p

Primers used for bisulfite mapping and ChIP of mir-496.

<p>Expression of targets and MBD2.</p

Depletion of MBD2 in mammary breast cancer cell lines leads to induction of <i>hsa-mir-496</i> expression.

<p>(A) qPCR of endogenous MBD2 mRNA in MCF-10A, MCF-7 and MDA-231. (B) A track showing the position of demethylated probes (descending grey bars) in the <i>hsa-mir-496</i> promoter region as determined by MeDIP enrichment for methylated DNA and hybridization to a genome wide promoter array. (C) qPCR of MBD2 mRNA levels in MBD2 transfected (black) MCF-10A and controls (empty), and siRNA-MBD2 treated MCF-7 and MDA-231 cells (empty boxes) and controls (black boxes). Bottom panel is a Western blot analysis with an anti MBD2 antibody (D) qPCR quantification of <i>hsa-mir-496</i> in MBD2 transfected (black) MCF-10A and controls (empty), and siRNA-MBD2 treated MCF-7 and MDA-231 cells (empty) and controls (black).</p