Peak-to-average power reduction in space division multiplexing based OFDM systems through spatial shifting

A new method to reduce the peak-to-average power ratio (PAPR) in space division multiplexing systems applying orthogonal frequency division multiplexing is proposed. The method applies spatial shifting to partial transmit sequences to achieve a decreased PAPR on all transmit branches

Performance impact of IQ mismatch in direct-conversion MIMO OFDM transceivers

This contribution analytically studies the influence of transmitter (TX) as well as receiver (RX) IQ mismatch on the performance of multiple-antenna OFDM systems based on direct-conversion. Analytical expressions are derived for the probability of error for MIMO OFDM systems in both nonfaded and Rayleigh faded channels. The results can be used to derive matching specifications for the TX- and RX-branches. It is concluded that in fading channels RX IQ imbalance is on average more destructive than TX IQ imbalance. Additionally, it is concluded that the addition of extra RX antennas is beneficial to reduce RX IQ imbalance dependence, but increases the TX IQ imbalance impac

Breakdown of anomalous channeling with ion energy for accurate strain determination in gan-based heterostructures

The influence of the beam energy on the determination of strain state with ion channeling in GaN-based heterostructures (HSs) is addressed. Experimental results show that anomalous channeling may hinder an accurate analysis due to the steering effects at the HS interface, which are more intense at lower ion energies. The experimental angular scans have been well reproduced by Monte Carlo simulations, correlating the steering effects with the close encounter probability at the interface. Consequently, limitations in the determination of the strain state by ion channeling can be overcome by selecting the adequate beam energy

Proteolytic enzyme and inhibitor levels in reindeer (Rangifer tarandus tarandus L.) vs. bovine longissimus muscle, as they relate to ageing rate and response

Eight reindeer bulls (age 1.5 years) and six Friesian bulls (age 1.5 years) were included in the study for comparison of tenderness. The reindeer were slaughtered at a commercial reindeer slaughter plant in northern Sweden and the Friesian bulls at a commercial slaughter plant in The Netherlands. Samples for determination of calpain/calpastatin activity were taken from the M. longtssimus (LO) within 1 h post mortem (p.m.), and at various times p.m. pH and temperature were registered in LO; ultimate pH values were measured at 24 h p.m. for beef and at 35 h p.m. for reindeer. At day 1 p.m., samples of LO from both carcass sides were excised, divided in two parts, vacuum packaged and stored at 0-2 °C. One part of each muscle was randomly sampled at 1, 3, 7 and 14 days p.m. for determination of shear force, proteolytic enzyme activity, myofibrillar protein degradation, collagen content and heat solubility. pH and temperature fall was faster in reindeer than in beef. Collagen content in reindeer muscle was found to be low but collagen was 4 times less soluble as compared with beef. Reindeer LO was found to be extremely tender, at 3 days p.m. shear force values were only 2-3 kg/cm2 (8-12 kg/cm2 for beef LO). In reindeer meat, the jJ.-calpain levels dropped to about 55% within 3 days. Troponin T and 30 kDa values were not related to changes in tenderness in reindeer meat. Cathepsin activities in reindeer were up to ten times higher than in beef. As in beef, cathepsin B+L levels in reindeer increased during storage, which is probably associated with a decrease in cystatin-like inhibitor levels

Genome-wide association analysis of the anthocyanin and carotenoid contents of rose petals

Petal color is one of the key characteristics determining the attractiveness and therefore the commercial value of an ornamental crop. Here, we present the first genome-wide association study for the important ornamental crop rose, focusing on the anthocyanin and carotenoid contents in petals of 96 diverse tetraploid garden rose genotypes. Cultivated roses display a vast phenotypic and genetic diversity and are therefore ideal targets for association genetics. For marker analysis, we used a recently designed Axiom SNP chip comprising 68,000 SNPs with additionally 281 SSRs, 400 AFLPs and 246 markers from candidate genes. An analysis of the structure of the rose population revealed three subpopulations with most of the genetic variation between individual genotypes rather than between clusters and with a high average proportion of heterozygous loci. The mapping of markers significantly associated with anthocyanin and carotenoid content to the related Fragaria and Prunus genomes revealed clusters of associated markers indicating five genomic regions associated with the total anthocyanin content and two large clusters associated with the carotenoid content. Among the marker clusters associated with the phenotypes, we found several candidate genes with known functions in either the anthocyanin or the carotenoid biosynthesis pathways. Among others, we identified a glutathione-S-transferase, 4CL, an auxin response factor and F3’H as candidate genes affecting anthocyanin concentration, and CCD4 and Zeaxanthine epoxidase as candidates affecting the concentration of carotenoids. These markers are starting points for future validation experiments in independent populations as well as for functional genomic studies to identify the causal factors for the observed color phenotypes. Furthermore, validated markers may be interesting tools for marker-assisted selection in commercial breeding programmes in that they provide the tools to identify superior parental combinations that combine several associated markers in higher dosages.BMWi/ZI