Information Filtering on Coupled Social Networks

In this paper, based on the coupled social networks (CSN), we propose a hybrid algorithm to nonlinearly integrate both social and behavior information of online users. Filtering algorithm based on the coupled social networks, which considers the effects of both social influence and personalized preference. Experimental results on two real datasets, \emph{Epinions} and \emph{Friendfeed}, show that hybrid pattern can not only provide more accurate recommendations, but also can enlarge the recommendation coverage while adopting global metric. Further empirical analyses demonstrate that the mutual reinforcement and rich-club phenomenon can also be found in coupled social networks where the identical individuals occupy the core position of the online system. This work may shed some light on the in-depth understanding structure and function of coupled social networks

The excess of 5′ introns in eukaryotic genomes

In this work, 21 completely sequenced eukaryotic genomes were analyzed using an intragene comparison approach. We found that all of these genomes show a significant 5′-biased distribution of introns of protein-coding genes. Our findings are different from previous studies based on the intergene method, where introns are biased towards the 5′ end of genes only in intron-poor genomes, but are evenly distributed in intron-rich genomes. In addition, by analyzing the patterns of intron distribution of a set of well-compiled housekeeping genes from human and their respective orthologs identified by a bidirectional best BLAST hit method from the other genomes, we found that the trend of 5′-biased intron positions of the set of housekeeping genes for each genome is much more skewed than that of all genes of the same genome, and rarely if any of the housekeeping genes examined have an extremely 3′-biased position distribution in which all introns of a gene are located only at the 3′ portion of the gene. The most parsimonious explanation for our findings may be the model in which intron loss is caused by homologous recombination between the genomic copy of a gene and a reverse transcriptase product of a spliced mRNA

A new quasi-exactly solvable problem and its connection with an anharmonic oscillator

The two-dimensional hydrogen with a linear potential in a magnetic field is solved by two different methods. Furthermore the connection between the model and an anharmonic oscillator had been investigated by methods of KS transformation