The purpose of this paper is the comparative analysis of four natural gas storage valuation ap proaches. In competitive natural gas markets the optimal valuation and operation of natural gas stor ages is a key task for natural gas companies operating storages. Within this paper, four spot based valuation approaches are analyzed regarding computational time and accuracy. In particular, explicit ...

Vertebrate genomes contain many virus-related sequences derived from both retroviruses and non-retroviral RNA and DNA viruses. Such non-retroviral RNA sequences are possibly produced by reverse-transcription and integration of viral mRNAs of ancient RNA viruses using retrotransposon machineries. We refer to this process as transcript reversion. During an ancient bornavirus infection, transcript...

From the spot prices we have to identify the following six parameters: α , μ, σ, Km , γ, Φ. If necessary, a seventh parameter, λ, should be identified from the futures prices. The six parameters mentioned above can be identified using the maximum likelihood method (Ball and Torous, 1983; Lien and Strom, 1999; Clewlow and Strickland, 2000) or the moments method (Lien and Strom, 1999; Deng, 1999)...

rDNA magnification in Drosophila melanogaster is defined experimentally as the ability of bb/Ybb- males to produce exceptional progeny that are wild type with respect to rDNA associated phenotypes. Here, we show that some of these bobbed-plus progeny result not from genetic reversion at the bb locus but rather from variants at two or more autosomal loci that ameliorate the bobbed phenotype of r...

Temperature-sensitive (ts) mutants representative of a number of genes of phage T4 were crossed with rII mutants to allow isolation of ts, rII double-mutant recombinants. The rl mutations used were characterized as frameshift mutations primarily on the basis of their revertability by proflavine. For each ts, rII double mutant, the effect of the ts mutation on spontaneous reversion of the rII mu...

Evidence was obtained which indicates that the lethal effect of 5-iodouracil (IUra) on bacteriophage T4 is not due to a mutagenic process. T4td8rIl (thymine requiring, rapid lysis) double mutants were constructed. Reversion ofT4td8rIl to r+ was measured. First, reversion by growth in the presence of the structural analogues chlorouracil (ClUra) and bromouracil (BrUra) did not correlate with the...

This paper is concerned with experiments which measure CMB anisotropies on small angular scales. A certain coverage, a beam structure and a level of uncorrelated noise define each experiment. We focus our atention on the reversion of the beam average. In each experiment, we look for the best pixelization for reversion, namely, for the pixelization that –after reversion– leads to good maps conta...

Tumor reversion is the process by which some cancer cells lose their malignant phenotype. This study was aimed at defining some of the molecular and phenotypic properties of this process. Biological models of tumor reversion were isolated from human leukemia and breast cancer cell lines by using the H-1 parvovirus as a selective agent. Differential gene expression analysis was performed between...

A reversion study of EMS- or ICR170-induced ascospore color mutants in Ascobolus immersus is reported. Twenty-three new intragenic suppressors were isolated within the b2 locus. These are localized within three distinct groups on a genetic fine-structure map containing 21 identifiable sites. The pattern of reversion is discussed according to the known specificity of EMS and ICR170 in Ascobolus ...