The nuclear matrix attachment regions(MARs) and the binding nuclear matrix proteins in the 5'-flanking cisacting elements of the human ε-globin gene have been examined. Using in vitro DNA-matrix binding assay, it has been shown that the positive stage-specific regulatory element (ε-PREII,-446bp ~-419bp) upstream of this gene could specifically associate with the nuclear matrix from K562 cells, indicating that ε-PREII may be an erythroidspecific facultative MAR. In gel mobility shift assay and Southwestern blotting assay, an erythroid-specific nuclear matrix protein (ε-NMP k) in K562 cells has been revealed to bind to this positive regulatory element (ε-PREII). Furthermore, we demonstrated that the silencer (-392bp-177bp) upstream of the human ε-globin gene could associate with the nuclear matrices from K562, HEL and Raji cells. In addition, the nuclear matrix proteins prepared from these three cell lines could also bind to this silencer, suggesting that this silencer element might be a constitutive nuclear matrix attachment region (constitutive MAR). Our results demonstrated that the nuclear matrix and nuclear matrix proteins might play an important role in the regulation of the human ε-globin gene expression.

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At present, there are two kinds of common generators in wind farms, which are induction generators (IG) and doubly-fed induction generators (DFIG). Based on the steady state mathematical models of these two kinds of generators, the processing methods of wind farms in power flow calculation are given. The core idea is to express active power of the generator by a function of wind speed and to express the reactive power by a function of active power, slip and terminal voltage, and then the Jacobian matrix will be corrected according to the relation between terminal voltage and reactive power in the wind farm node. Finally, the IEEE 14-bus test system including wind farm is applied for power flow calculation and analysis. The numerical results show that the mentioned methods are feasible and can satisfy the requirements of the engineering application, which can pave a foundation for further research.