Characterization and Efficient Search of Non-Elementary Trapping Sets of LDPC Codes with Applications to Stopping Sets

In this paper, we propose a characterization for non-elementary trapping sets (NETSs) of low-density parity-check (LDPC) codes. The characterization is based on viewing a NETS as a hierarchy of embedded graphs starting from an ETS. The characterization corresponds to an efficient search algorithm that under certain conditions is exhaustive. As an application of the proposed characterization/search, we obtain lower and upper bounds on the stopping distance $s_{min}$ of LDPC codes. We examine a large number of regular and irregular LDPC codes, and demonstrate the efficiency and versatility of our technique in finding lower and upper bounds on, and in many cases the exact value of, $s_{min}$. Finding $s_{min}$, or establishing search-based lower or upper bounds, for many of the examined codes are out of the reach of any existing algorithm

Increased NFκ-B Activity in HCT116 Colorectal Cancer Cell Line Harboring TLR4 Asp299Gly Variant

Toll-Like Receptor 4 (TLR4), considered one of the most important TLR, recognizes lipopolysaccharide of gram-negative bacteria. Recognition of ligands by TLRs induces signaling pathways resulting in activation of transcriptional factors such as NF-κB which are involved in the expression of inflammatory cytokines and chemokines. To prevent an inappropriate immune response, a complex network of molecules negatively regulates TLRs and their associated signaling pathways. Two cosegregating single nucleotide polymorphisms of the human TLR4 gene, namely Asp299Gly and Thr399Ile, have been associated with hyporesponsiveness to inhaled LPS. The purpose of this study was to determine the impact of TLR4 gene variant on NF-κB activity in colorectal cancer cell line. HCT116 cells were transfected with wild-type and mutants Flag-CMV1-TLR4 expression vectors. Western blot analysis was performed to evaluate selected molecules involved in TLR4 signaling. NF-κB activity was assessed by dualluciferase reporter assay and cytokine profiles were evaluated by ELISA and Cytometric Bead Array method. Results showed that the activity of pNF-κB was higher in cells harboring TLR4 D299G compared to the other cells. However, the activity of pAKT, pERK1 and pIRAK was higher in wild-type. The results of cytokine measurements showed about four fold higher level of IL-8 in cells with wild-type TLR4. This study suggest that TLR4 Asp299Gly gene variant has an impact on TLR4 signaling and potentially on intestinal homeostasis due to impaired control signals at the epithelial cell level which may lead to chronic intestinal inflammation and interrupted intestinal homeostasis and may eventually lead to colorectal cancer. Copyright© 2012, Iranian Journal of Allergy, Asthma and Immunology. All rights reserved

Follow the Yellow Brick Road: A Guide for Improving Issuer and Investor Appreciation of Risks in Creative Arts Crowdfunding Campaigns

Article published in the Michigan State Journal of Business and Securities Law

Emergent Cosmos in Einstein-Cartan Theory

Based on the Padmanabhan's proposal, the accelerated expansion of the universe can be driven by the difference between the surface and bulk degrees of freedom in a region of space, described by the relation $dV/dt=N_{sur}-N_{bulk}$ where $N_{sur}$ and $N_{bulk}=-N_{em}+N_{de}$ are the degrees of freedom assigned to the surface area and the matter-energy content inside the bulk such that the indexes $"em"$ and $"de"$ represent energy-momentum and dark energy, respectively. In the present work, the dynamical effect of the Weyssenhoff perfect fluid with intrinsic spin and its corresponding spin degrees of freedom in the framework of Einstein-Cartan (EC) theory are investigated. Based on the modification of Friedmann equations due to the spin-spin interactions, a correction term for the Padmanabhan's original relation $dV/dt=N_{sur}+N_{em}-N_{de}$ including the number of degrees of freedom related to this spin interactions is obtained through the modification in $N_{bulk}$ term as $N_{bulk}=-N_{em}+N_{spin}+N_{de}$ leading to $dV /d t=N_{sur}+N_{em}-N_{spin} -N_{de}$ in which $N_{spin}$ is the corresponding degrees of freedom related to the intrinsic spin of the matter content of the universe. Moreover, the validity of the unified first law and the generalized second law of thermodynamics for the Einstein-Cartan cosmos are investigated. Finally, by considering the covariant entropy conjecture and the bound resulting from the emergent scenario, a total entropy bound is obtained. Using this bound, it is shown that the for the universe as an expanding thermodynamical system, the total effective Komar energy never exceeds the square of the expansion rate with a factor of $\frac{3}{4\pi}$.Comment: 12 Pages, Accepted for Publication in Eur. Phys. J.