Search

Exploring the emergence and maintenance of cooperation in social dilemma is valuable and it arises considerable concerns of many researchers. In this paper, we propose a mechanism to promote cooperation, called benefit community, in which cooperators linking together form a common benefit community and all their payoffs obtained from game are divided coequally. The robustness of conclusions is tested for the PDG (prisoners’ dilemma game) on square lattice and WS small world network. We find that cooperation can be promoted by this typical mechanism, especially, it can diffuse and prevail more easily and rapidly on the WS small world network than it on the square lattice, even if a big temptation to defect b. Our research provides a feasible direction to resolve the social dilemma.

Considering congestion effects in realistic network environments, we give a new method to adjust dynamically adjust the weight of the congested edge. We calculate the load on an edge based on the revised betweenness method and propose a novel model with three states of edges to investigate the dynamics of cascading failures in the ring network, the BA scale-free network, and the real traffic networks in London. By two robust metrics, we surprisingly observe the abnormal dynamics of cascading propagation, especially compared with that in the unadjustable weight, the curves of cascading dynamics in the adjustable weight are more irregular, which means that enhancing the capacity of each edge is not always better to avoid the cascading propagation. In addition, our simulation results show that the dynamical change of the edge’s weight makes the heterogeneous BA networks more vulnerable.

To characterize the effects of cetyltriethylammonium bromide (CTAB) on the transcription of gp64 promoter from Bombyx mori nucleopolyhedrovirus (BmNPV), the plasmid pBmgp64Luc used in transient expression assay system was constructed by using the luciferase gene as a reporter under the control of BmNPV gp64 promoter. When the Bombyx mori cells (Bm-N) were transfected with the pBmgp64Luc, different treatments were undertaken. We found that the transient expression activity of luciferase could not be augmented directly by CTAB treatment alone, but could be enhanced more than 2 times by BmNPV treatment alone at a multiplicity of infection (MOI) of 0.5. Through co-treatment with 0.1 microg ml(-1) of CTAB and BmNPV at a MOI of 0.5, the enzymatic activity increased 5.21 times. We presumed that the stimulation of transcription of BmNPV gp64 promoter by CTAB was mediated by viral factors from BmNPV. In addition, the time curves of luciferase activity in cells transfected with pBmgp64Luc and transactivated by virus were observed.

An experimental study was undertaken to quantify the effects of cetyltriethylammonium bromide (CTAB) on the replication of Bombyx mori nucleopolyhedrovirus (BmNPV) and the transcriptionalactivity of BmNPV ie-1 promoter. The results demonstrated that the budded virus (BV) titer rose about 3.7-fold by adding CTAB to the culture media up to 0.1 mu g ml(-1) in infected Bm-N cells with a wild-type BmNPV. The transient expression level of luciferase driven by BmNPV ie-1 promoter was enhanced by more than 3-fold in the presence of 0.1 mu g ml(-1) of CTAB in uninfected insect cells via a transient expression system. Contrary to the rise in BV titer, the polyhedra inside the nucleus of infected cells dropped linearly from 4.0 x 10(6) ml(-1) down to 2.1 x 10(6) ml(-1) with in a range of CTAB concentrations from 0 to 0.25 mu g ml(-1). The same trend in expression level of beta -galactosidase or phytase was given when the Bm-N cells or fifth-instar silkworm larvae infected with a recombinant BmNPV containing the beta -galactosidase or phytase reporter gene driven by the polyhedrin promoter. We deduced that CTAB appeared to affect the virus bi-phasic life cycle stages and production pathways, resulting in an enhancement in BV production and a suppression of occluded virus (OV) production and expression of foreign genes controlled by the polyhedrin promoter.