Robust leakage-based distributed precoder for cooperative multicell systems

Coordinated multipoint (CoMP) from long term evolution (LTE)-advanced is a promising technique to enhance the system spectral efficiency. Among the CoMP techniques, joint transmission has high communication requirements, because of the data sharing phase through the backhaul network, and coordinated scheduling and beamforming reduces the backhaul requirements, since no data sharing is necessary. Most of the available CoMP techniques consider perfect channel knowledge at the transmitters. Nevertheless for practical systems this is unrealistic. Therefore in this study the authors address this limitation by proposing a robust precoder for a multicell-based systems, where each base station (BS) has only access to an imperfect local channel estimate. They consider both the case with and without data sharing. The proposed precoder is designed in a distributed manner at each BS by maximising the signal-to-leakage-and-noise ratio of all jointly processed users. By considering the channel estimation error in the design of the precoder, they are able to reduce considerably the impact of these errors in the system's performance. The results show that the proposed scheme has improved performance especially for the high signal-to-noise ratio regime, where the impact of the channel estimation error may be more pronounced

Pepsin properties, structure, and its accurate measurement: a narrative review

Pepsin is an aspartate protease that is generated from its proenzyme, pepsinogen by autocatalysis initiated by a fall in pH below 5. Human gastric juice contains eight isoenzymes of pepsin. The peptides released on conversion of pepsinogen to pepsin of which there are potentially five, have been shown to have antimicrobial activity against a wide range of bacteria including Escherichia coli, Pseudomonas and Staphylococcus which have also been shown to have biofilm formation inhibiting properties. The stability in response to changes in pH varies between pepsin and pepsinogen. Pepsinogen is stable up to pH 10, pepsin is only stable to pH just above 7.0 and is completely denatured at pH 8.0. Many diseases of the aerodigestive tract have been linked to reflux and the presence of pepsin. Therefore, the measurement of pepsin in tissue and lavages or in saliva or sputum, could be a good screening tool for the diagnosis of reflux related disease. However, there is no current consensus as to the best methods to measure it or the best time to sample it. For an effective pepsin ELISA, the following is required; a monoclonal/monospecific polyclonal antibody with a good lowest level of detection (LLOD) and sensitivity 1–25 ng/mL (depending on dilution) and an adequate supply of purified human pepsin as a standard for antibody-based assays. If possible, an activity assay for pepsin should also be used as the presence of pepsin protein does not indicate it is capable of damaging activity. Finally, if pepsin is associated with a disease large studies are required to confirm it with multiple samples. This review deals with several studies where pepsin quantitation is attempted, and their measurement techniques assessed

The αGal Epitope of the Histo-Blood Group Antigen Family Is a Ligand for Bovine Norovirus Newbury2 Expected to Prevent Cross-Species Transmission

Among Caliciviridae, the norovirus genus encompasses enteric viruses that infect humans as well as several animal species, causing gastroenteritis. Porcine strains are classified together with human strains within genogroup II, whilst bovine norovirus strains represent genogroup III. Various GI and GII human strains bind to carbohydrates of the histo-blood group family which may be shared among mammalian species. Genetic relatedness of human and animal strains as well as the presence of potentially shared ligands raises the possibility of norovirus cross-species transmission. In the present study, we identified a carbohydrate ligand for the prototype bovine norovirus strain Bo/Newbury2/76/UK (NB2). Attachment of virus-like particles (VLPs) of the NB2 strain to bovine gut tissue sections showed a complete match with the staining by reagents recognizing the Galα1,3 motif. Alpha-galactosidase treatment confirmed involvement of a terminal alpha-linked galactose. Specific binding of VLPs to the αGal epitope (Galα3Galβ4GlcNAcβ-R) was observed. The binding of Galα3GalαOMe to rNB2 VLPs was characterized at atomic resolution employing saturation transfer difference (STD) NMR experiments. Transfection of human cells with an α1,3galactosyltransferase cDNA allowed binding of NB2 VLPs, whilst inversely, attachment to porcine vascular endothelial cells was lost when the cells originated from an α1,3galactosyltransferase KO animal. The αGal epitope is expressed in all mammalian species with the exception of the Hominidaea family due to the inactivation of the α1,3galactosyltransferase gene (GGTA1). Accordingly, the NB2 carbohydrate ligand is absent from human tissues. Although expressed on porcine vascular endothelial cells, we observed that unlike in cows, it is not present on gut epithelial cells, suggesting that neither man nor pig could be infected by the NB2 bovine strain

Large system analysis of base station cooperation on the downlink

10.1109/ALLERTON.2010.57069172010 48th Annual Allerton Conference on Communication, Control, and Computing, Allerton 2010270-27

Min-max fair coordinated beamforming via large systems analysis: The two-cell case

10.1109/ISWCS.2011.6125360Proceedings of the International Symposium on Wireless Communication Systems542-54

Min-max fair coordinated beamforming via large systems analysis

10.1109/ISIT.2011.6033901IEEE International Symposium on Information Theory - Proceedings1990-1994PIST

Distributed multicell-MISO precoding using the layered virtual SINR framework

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