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AbstractIn the case of goodwill impairment test, the DCF model is often used when estimating the present value of the expected future cash flow of assets. In recent years, the use of DCF model in goodwill impairment test has made great progress, but the overall level has yet to be improved, especially the latest research results are not timely adopted. This paper studies the DCF model based on life curve analysis, the research results can provide reference for goodwill impairment test method and DCF model.

A partially purified algal protein mixture which supports in vitro DNA replication consists of soluble proteins and proteins extracted from thylakoid membrane. The membrane extract is essential for the specific initiation of replication at a displacement loop (D-loop) site previously mapped by electron microscopy. D-loop site and its flanking sequences have been cloned and sequenced. In this study, fragment-retention assays using various subclones of the sequenced region indicate that some proteins in the membrane extract bind strongly and specifically with a 494 bp restriction fragment which partially overlaps the D-loop site. Protein gel analyses of the protein-DNA complex identify three DNA-binding polypeptides with apparent molecular weights of 18, 24 and 26 kDa, respectively. Treatment with chloramphenicol, an inhibitor of chloroplast protein synthesis, for 1 h has no obvious effect on the contents of the 24 or 26 kDa polypeptides but significantly reduces the content of the 18 kDa polypeptide in the membrane extract.

Chloroplast DNA replication in Chlamydomonas reinhardtiiis initiated by the formation of a displacement loop (D-loop) at a specific site. One D-loop site with its flanking sequence was cloned in recombinant plasmids SC3-1 and R-13. The sequence of the chloroplast DNA insert in SC3-1, which includes the 0.42-kilobase (kb) D-loop region, as well as 0.2 kb to the 5′ end and 0.43 kb to the 3′ end of the D-loop region, was determined. The sequence is A+T-rich and contains four large stem-loop stuctures. An open reading frame potentially coding for a polypeptide of 136 amino acids was detected in the D-loop region. One stem-loop structure and two back-to-back prokaryotic-type promoters were mapped within the open reading frame. The 5.5-kb EcoRI fragment cloned in R-13 contains the 1.05-kb SC3-1 insert and its flanking regions. A yeast autonomously replicating (ARS) sequence and an ARC sequence, which promotes autonomous replication in Chlamydomonas, have been mapped within the flanking regions [Vallet, J.-M. & Rochaix, J.-D. (1985) Curr. Genet.9, 321-324]. Both R-13 and SC3-1 were active as templates in a crude algal preparation that supports DNA synthesis. In this in vitrosystem, chloroplast DNA synthesis initiated near the D-loop site.