Turbo Trellis Coded Modulation

Turbo codes have excited the coding community with the promise of performing near channel capacity by using an iterative decoding technique that relies upon simple constituent codes. However, since the original turbo codes are low rate codes, a significant bandwidth penalty can be incurred by systems which utilize turbo codes. Since the constituent codes that make up turbo codes are convolutional codes, a natural extension of the turbo concept, in order to improve bandwidth efficiency, is its application to Trellis Coded Modulation (TCM) systems. This paper will discuss the conditions under which encoders with parallel transitions can be used as constituent codes in Turbo TCM systems and present results to compare systems with and without parallel transition constituent encoders. 1 Introduction Turbo coding, introduced in [1], is a coding technique that uses an iterative decoding algorithm to give performance near channel capacity. Since Turbo codes use convolutional codes as their co..

Investigating the Mutagenicity of a Cold Argon-Plasma Jet in an HET-MN Model

OBJECTIVE:So-called cold physical plasmas for biomedical applications generate reactive oxygen and nitrogen species and the latter can trigger DNA damage at high concentrations. Therefore, the mutagenic risks of a certified atmospheric pressure argon plasma jet (kINPen MED) and its predecessor model (kINPen 09) were assessed. METHODS:Inner egg membranes of fertilized chicken eggs received a single treatment with either the kINPen 09 (1.5, 2.0, or 2.5 min) or the kINPen MED (3, 4, 5, or 10 min). After three days of incubation, blood smears (panoptic May-Grünwald-Giemsa stain) were performed, and 1000 erythrocytes per egg were evaluated for the presence of polychromatic and normochromic nuclear staining as well as nuclear aberrations and binucleated cells (hen's egg test for micronuclei induction, HET-MN). At the same time, the embryo mortality was documented. For each experiment, positive controls (cyclophosphamide and methotrexate) and negative controls (NaCl-solution, argon gas) were included. Additionally, the antioxidant potential of the blood plasma was assessed by ascorbic acid oxidation assay after treatment. RESULTS:For both plasma sources, there was no evidence of genotoxicity, although at the longest plasma exposure time of 10 min the mortality of the embryos exceeded 40%. The antioxidant potential in the egg's blood plasma was not significantly reduced immediately (p = 0.32) or 1 h (p = 0.19) post exposure to cold plasma. CONCLUSION:The longest plasma treatment time with the kINPen MED was 5-10 fold above the recommended limit for treatment of chronic wounds in clinics. We did not find mutagenic effects for any plasma treatment time using the either kINPen 09 or kINPen MED. The data provided with the current study seem to confirm the lack of a genotoxic potential suggesting that a veterinary or clinical application of these argon plasma jets does not pose mutagenic risks