Increased antioxidant enzyme activities in the colorectal adenoma and carcinoma

Most colon carcinomas are preceded by an adenomatous polyp--adenoma-carcinoma sequence. Active oxygen species (AOS) can play a role in the pathogenesis of this process. Antioxidant enzymes (AE) are the primary defense against the deleterious effect of AOS. Activities of AE in 56 individuals with colorectal adenoma (CA), 29 individuals with colorectal carcinoma (CC) and in 24 control subjects were examined. Biopsy specimens from the non-neoplastic colonic mucosa and from the CA and CC were taken during colonoscopy for histological and enzymological analysis. Activities of following AE were estimated: CuZn-superoxide dismutase (CuZn-SOD), catalase (CAT) and glutathione peroxidase (GPx). It was found that individuals with CA and CC were characterized by: (1) increased activities of CAT and GPx in non-neoplastic mucosa, that persisted in some of the patients even after removal of tumors; (2) increased activities of CuZn-SOD, CAT and PGx in CA and CC tissues. It can be inferred that the accumulation of peroxides in the non-neoplastic colonic mucosa induced higher activities of CAT and GPx. The reasons of high activities of all AE in the tissues of CA and CC and their relation to carcinogenesis are not clear and require further studies.     

Gramicidin channels

Gramicidin channels are mini-proteins composed of two tryptophan-rich subunits. The conducting channels are formed by the transbilayer dimerization of nonconducting subunits, which are tied to the bilayer/solution interface through hydrogen bonds between the indole NH groups and the phospholipid backbone and water. The channel structure is known at atomic resolution and the channel's permeability characteristics are particularly well defined: gramicidin channels are selective for monovalent cations, with no measurable permeability to anions or polyvalent cations; ions and water move through a pore whose wall is formed by the peptide backbone; and the single-channel conductance and cation selectivity vary when the amino acid sequence is varied, even though the permeating ions make no contact with the amino acid side chains. Given the amount of experimental information that is available-for both the wild-type channels and for channels formed by amino acid-substituted gramicidin analogues-gramicidin channels provide important insights into the microphysics of ion permeation through bilayer-spanning channels. For the same reason, gramicidin channels constitute the system of choice for evaluating computational strategies for obtaining mechanistic insights into ion permeation through the complex channels formed by integral membrane proteins.     

A Scalable Information Security Technique: Joint Authentication-Coding Mechanism for Multimedia over Heterogeneous Wireless Networks

There have been increasing concerns about the security issues of wireless transmission of multimedia in recent years. Wireless networks, by their natures, are more vulnerable to external intrusions than wired ones. Therefore, many applications demand authenticating the integrity of multimedia content delivered wirelessly. In this work, we propose a framework for jointly authenticating and coding multimedia to be transmitted over heterogeneous wireless networks. We firstly provide a novel graph-based authentication scheme which can not only construct the authentication graph flexibly but also trade-off well among some practical requirements such as overhead, robustness and delay. And then, a rate-distortion optimized joint source-channel coding (JSCC) approach for error-resilient scalable encoded video is presented, in which the video is encoded into multiple independent streams and each stream is assigned forward error correction (FEC) codes to avoid error propagation. Furthermore, we consider integrating authentication with the specific JSCC scheme to achieve a satisfactory authentication results and end-to-end reconstruction quality by optimally applying the appropriate authentication and coding rate. Simulation results show the effectiveness of the proposed authentication-coding scheme for multimedia over wireless networks.     

Old world and new world wine concepts of terroir and wine: perspectives of three renowned non-French wine makers

The concept of ‘terroir’ has roots steeped in French history of wine and evocative stories of the land. Today terroir is important as a quality marker in brand management for upmarket wines. French wines have benefited from their historical connotation with terroir but other wine growing countries have also adopted the term to mean characteristics in wine attributable to place of origin. However there is no universally accepted definition of terroir except to say it refers to a particular place. This paper addresses this ambiguity by seeking the practice-based views of three experienced non-French winemakers. This reveals a social dimension to terroir that in various degrees supports and extends both the technical/scientific progress and brand value for premium wines in both Old and New World regions. This article contributes to the growing body of research that seeks to understand the practicality of terroir as a marketing and brand value indicator.     

Proof of usage: user-centric consensus for data provision and exchange

Annals of Telecommunications - This paper presents a new consensus algorithm, Proof of Usage (PoU), for the blockchain technology. This consensus is introduced for permissioned (or private)...     

Polarization Filter for Microstrip Lumped-Element Kinetic Inductance Detectors

Polarization sensitivity is a major requirement in future cosmic microwave background studies. Even though lumped-element kinetic inductance detectors (LEKIDs) have already demonstrated a good performance in the millimeter range, the typical configuration based on linear meander inductors exhibits a cross polarization up to 30%. In this work, we propose a new configuration of LEKIDs coupled to a microstrip transmission line where the continuous ground plane has been replaced with parallel lines in order to be used as a polarizing grid. Microwave simulations and preliminary experiments show that the polarizer acts as an effective ground plane with no influence in the electromagnetic performance and that the cross polarization can be decreased to 3%.