requirement analysis of information and knowledge management in postmodern perspective on curriculum

National Basic Research Program of China; Chinese Academy of Sciences; Information Society Technologies; Institute of Computing Technology, Chinese Academy of Sciences; Zhuhai National Hi-tech Industrial Development Zone

New species of Doliodrilus and other Limnodriloidinae (Oligochaeta, Tubificidae) from Hainan and other parts of the north-west Pacific Ocean

Thirteen species of Limnodriloidinae (Tubificidae) are recorded from marine and brackish-water habitats of Hainan Island, southern China, including 11 species of Doliodrilus and two species belonging to Limnodriloides . Eight species are new to science: D. bisaccus sp. n. (types from Japan), D. longidentatus sp. n. (types from Hong Kong), D. ciliatus sp. n., D. adiacens sp. n., D. fibrisaccus sp. n. (also from Fiji), D. brachyductus sp. n., D. bidolium sp. n. and D. chinensis sp. n. In addition, material of D. puertoricensis Erseus and Milligan, 1988, from New Caledonia, is briefly described. This study shows that Doliodrilus is unexpectedly species-rich in Asian seas, in particular, around Hainan. Including an unnamed species from this island, the known members of this genus increase from three to 12.

Synthesis of a new kind of polyamide and polyester including aromatic spirodilactone

A new kind of monomers including aromatic spirodilactone-5, 5'-carboxy-7,7'-dioxo-2,2'-spirobi(benzo-[c]tetrahydrofuran) is synthesized from m-xylene and paraformaldehyde. It is converted to a series of polyamides and polyesters by means of low-temperature solution polycondensation and interfacial polycondensation. NMR and IR spectra, solubility, mechanical and thermal properties of all these polymers are investigated. The polymers have high glass transition temperatures and good thermal oxidative properties. All polyamides have high viscosity and good solubility in strong polar organic solvents such as DMSO, DMAc, DMF and NMP. All polyamides can be cast into transparent, flexible and tough films possessing good tensile properties.

Effect of information transmission on cooperative behavior

Considering the fact, in the real world, that information is transmitted with a time delay, we study an evolutionary spatial prisoner's dilemma game where agents update strategies according to certain information that they have learned. In our study, the game dynamics are classified by the modes of information learning as well as game interaction, and four different combinations, i.e. the mean-field case, case I, case II and local case, are studied comparatively. It is found that the time delay in case II smoothes the phase transition from the absorbing states of C (or D) to their mixing state, and promotes cooperation for most parameter values. Our work provides insights into the temporal behavior of information and the memory of the system, and may be helpful in understanding the cooperative behavior induced by the time delay in social and biological systems.

Bead-probe complex capture a couple of SINE and LINE family from genomes of two closely related species of East Asian cyprinid directly using magnetic separation

Background: Short and long interspersed elements (SINEs and LINEs, respectively), two types of retroposons, are active in shaping the architecture of genomes and powerful tools for studies of phylogeny and population biology. Here we developed special protocol to apply biotin-streptavidin bead system into isolation of interspersed repeated sequences rapidly and efficiently, in which SINEs and LINEs were captured directly from digested genomic DNA by hybridization to bead-probe complex in solution instead of traditional strategy including genomic library construction and screening. Results: A new couple of SINEs and LINEs that shared an almost identical 3'tail was isolated and characterized in silver carp and bighead carp of two closely related species. These SINEs (34 members), designated HAmo SINE family, were little divergent in sequence and flanked by obvious TSD indicated that HAmo SINE was very young family. The copy numbers of this family was estimated to 2 x 10(5) and 1.7 x 10(5) per haploid genome by Real-Time qPCR, respectively. The LINEs, identified as the homologs of LINE2 in other fishes, had a conserved primary sequence and secondary structures of the 3'tail region that was almost identical to that of HAmo SINE. These evidences suggest that HAmo SINEs are active and amplified recently utilizing the enzymatic machinery for retroposition of HAmoL2 through the recognition of higher-order structures of the conserved 42-tail region. We analyzed the possible structures of HAmo SINE that lead to successful amplification in genome and then deduced that HAmo SINE, SmaI SINE and FokI SINE that were similar in sequence each other, were probably generated independently and created by LINE family within the same lineage of a LINE phylogeny in the genomes of different hosts. Conclusion: The presented results show the advantage of the novel method for retroposons isolation and a pair of young SINE family and its partner LINE family in two carp fishes, which strengthened the hypotheses containing the slippage model for initiation of reverse transcription, retropositional parasitism of SINEs on LINEs, the formation of the stem loop structure in 3'tail region of some SINEs and LINEs and the mechanism of template switching in generating new SINE family.