Decoding Strategies at the Relay with Physical-Layer Network Coding

Cataloged from PDF version of article.A two-way relay channel is considered where two users exchange information via a common relay in two transmission phases using physical-layer network coding (PNC). We consider an optimal decoding strategy at the relay to decode the network coded sequence during the first transmission phase, which is approximately implemented using a list decoding (LD) algorithm. The algorithm jointly decodes the codewords transmitted by the two users and sorts the L most likely pair of sequences in the order of decreasing a-posteriori probabilities, based on which, estimates of the most likely network coded sequences and the decoding results are obtained. Using several examples, it is observed that a lower complexity alternative, that jointly decodes the two transmitted codewords, has a performance similar to the LD based decoding and offers a near-optimal performance in terms of the error rates corresponding to the XOR of the two decoded sequences. To analyze the error rate at the relay, an analytical approximation of the word-error rate using the joint decoding (JD) scheme is evaluated over an AWGN channel using an approach that remains valid for the general case of two users adopting different codebooks and using different power levels. We further extend our study to frequency selective channels where two decoding approaches at the relay are investigated, namely; a trellis based joint channel detector/physical-layer network coded sequence decoder (JCD/PNCD) which is shown to offer a near-optimal performance, and a reduced complexity channel detection based on a linear receiver with minimum mean squared error (MMSE) criterion which is particularly useful where the number of channel taps is large

Purification and characterization of a myotoxic phospholipase-a2 from indian cobra (Naja-Naja-Naja) venom

Purification and characterization of a myotoxic phospholipase A2 from Indian cobra (Naja naja naja) venom. Toxicon27, 861–873, 1989.—A major phospholipase A2 (NN-XIII-PLA2) which constitutes 20% of the whole Naja naja naja venom was purified to homogeneity on CM-Sephadex C-25 column chromatography. NN-XIII-PLA2 is a basic protein with a mol. wt of 11,200 by SDS-PAGE. This enzyme has low enzymatic activity but is more toxic to mice than the whole venom. The ld50 value (i.p.) of NN-XIII-PLA2 is 2.4 mg/kg body weight (whole venoms ld50 is 2.8 mg/kg body weight). It induces neurotoxic-like signs in experimental animals. It induces myotoxicity when injected i.m. into the thigh muscle of mice and edema when injected into the foot pads of mice. This enzyme has a fluorescence maxima between 310–316 nm which is typical of tyrosine residues

Agrobacterium mediated transformation of annexin gene in tobacco (Nicotiana tabacum)

The present study involves the development of genetically engineered tobacco plants with annexin gene. The plasmid pUC 119 with the Annexin gene and pGPTV vector were isolated from the Escherichia coli. These plasmids were subjected to restriction digestion with EcoRI and Xbal where the Annexin gene is released from the pUC 119 as a linearised band was eluted from the gel. The recombinant PGPTV plasmid with the annexin gene in Agrobacterium tumefaciens MTCC 431 was mobilized and transferred to plant system through the mobilization helper plasmid pRK2013. The kanamycin resistance gene (NPT II) was used as a selective marker. The calli used for isolating the genomic DNA which was then amplified for confirmation of annexin gene. The nptII gene of 800 bp serves as a selectable marker system in plants and its amplification confirmed the presence of annexin gene in transgenic plants by PCR method

Acute ST-segment elevation myocardial infarction in a young patient with essential thrombocythemia: a case with long-term follow-up report

Essential thrombocythemia (ET) is a neoplastic proliferation of mature myeloid cells - in particular, megakaryocytes - leading to persistently elevated platelet count. Usual clinical presentation is related to an increase in the risk of hemorrhage and/or thrombosis. Management of ET consists of antiplatelet therapies - mainly aspirin and cytoreductive therapies. Coronary involvement in patients with ET is rare. The optimal treatment strategies for ET patients presenting with acute myocardial infarction remains unclear. Acute interventions like intracoronary thrombolytic therapy, angioplasty, and coronary-artery bypass grafting have been reported in such patients. However, several questions remain unanswered about the acute and long-term management of these patients. Herein, we report the case of a 47-year-old female who presented with acute myocardial infarction as the first clinical sign of ET, and also present the long-term follow-up of this patient

Surface recombination measurements on III–V candidate materials for nanostructure light-emitting diodes

Surface recombination is an important characteristic of an optoelectronic material. Although surface recombination is a limiting factor for very small devices it has not been studied intensively. We have investigated surface recombination velocity on the exposed surfaces of the AlGaN, InGaAs, and InGaAlP material systems by using absolute photoluminescence quantum efficiency measurements. Two of these three material systems have low enough surface recombination velocity to be usable in nanoscale photonic crystal light-emitting diodes

Clinical results of entrance dose in vivo dosimetry for high energy photons in external beam radiotherapy using MOSFETs

Copyright © 2007 ACPSEM. All rights reserved. The document attached has been archived with permission from the publisher.Thomson and Nielsen TN-502 RD MOSFETs were used for entrance dose in vivo dosimetry for 6 and 10 MV photons. A total of 24 patients were tested, 10 breast, 8 prostate, 5 lung and 1 head and neck. For prostates three fields were checked. For all other plans all fields were checked. An action threshold of 8% was set for any one field and 5% for all fields combined. The total number of fields tested was 56, with a mean discrepancy of 1.4% and S.D. of 2.6%. Breasts had a mean discrepancy of 1.8% and S.D. of 2.8%. Prostates had a mean discrepancy of 1.3% and S.D. of 2.9%. For 3 fields combined, prostates had a mean of 1.3% and S.D. of 1.8%. These results are similar to results obtained with diodes and TLDs for the same techniques.J. P. Morton, M. Bhat, T. Williams and A. Kovend

Metabolic syndrome: a comprehensive review

Metabolic syndrome (syndrome X) includes several components like diabetes, hypertension, hyperlipidemia etc. Every patient should undergo detailed assessment for the silent presence of the components of metabolic syndrome. Genetic predisposition, increased nutrient- dense food, decreased physical activity and chronic stress are common in metabolic syndrome. Insulin resistance, obesity and hyperglycaemia are commonly seen which can later lead to serious consequences like cardiovascular complications, thrombotic events etc. Clinical features depend on the components of the metabolic syndrome in a patient. Some may present with complications and advanced disease. For non-diabetic individuals, oral glucose tolerance test is indicated. It is better to study serum uric acid level and to screen for silent kidney stones. Specific drugs are prescribed as indicated. Drugs for stress and insomnia are also prescribed. Thrombotic status of the patient should be considered, and antiplatelet drugs are prescribed if risk factors are present. Non-pharmacological measures like diet modification and increased physical activity should be given on a priority basis. Patient compliance of these two measures should be monitored regularly. Future deployment of “artificial intelligence – powered” predictive diagnostic tests will help in detecting and controlling metabolic syndrome. “At risk” individuals and patients showing some components of metabolic syndrome should undergo full investigations to detect other components of metabolic syndrome. Full range of therapeutic drugs, diet modification and increased physical activity should be prescribed

Immunoceptive inference: why are psychiatric disorders and immune responses intertwined?

There is a steadily growing literature on the role of the immune system in psychiatric disorders. So far, these advances have largely taken the form of correlations between specific aspects of inflammation (e.g. blood plasma levels of inflammatory markers, genetic mutations in immune pathways, viral or bacterial infection) with the development of neuropsychiatric conditions such as autism, bipolar disorder, schizophrenia and depression. A fundamental question remains open: why are psychiatric disorders and immune responses intertwined? To address this would require a step back from a historical mind-body dualism that has created such a dichotomy. We propose three contributions of active inference when addressing this question: translation, unification, and simulation. To illustrate these contributions, we consider the following questions. Is there an immunological analogue of sensory attenuation? Is there a common generative model that the brain and immune system jointly optimise? Can the immune response and psychiatric illness both be explained in terms of self-organising systems responding to threatening stimuli in their external environment, whether those stimuli happen to be pathogens, predators, or people? Does false inference at an immunological level alter the message passing at a psychological level (or vice versa) through a principled exchange between the two systems