1,036 research outputs found
F and D Values with Explicit Flavor Symmetry Breaking and \Delta s Contents of Nucleons
We propose a new model for describing baryon semi-leptonic decays for
estimating and values with explicit breaking effects of both SU(3) and
SU(2) flavor symmetry, where all possible SU(3) and SU(2) breaking effects are
induced from an effective interaction. An overall fit including the weak
magnetism form factor yields and with
d.o.f. with and . The spin content of strange quarks is estimated from the
obtained values and , and the nucleon spin problem is re-examined.
Furthermore, the unmeasured values of and for other hyperon
semi-leptonic decays are predicted from this new formula.Comment: 15 pages, 1 figure, final version to appear in PR
Upstream activation element of the PH03 gene encoding for thiamine-repressible acid phosphatase in Saccharomyces cerevisiae
AbstractThe PH03 gene of Saccharomyces cerevisiae encodes thiamine-repressible acid phosphatase and requires the positively acting regulatory protein TH12 for its expression. Deletion analysis of the 5′-flanking region of PH03 gene revealed that an activating region located at nucleotide position −234 to −215 relative to the translation initiation codon is required for the expression and sensitivity to thiamine. A chemically synthesized DNA fragment covering −234 to −215 showed a significant level of expression when inserted in front of the PH03 promoter lacking the activating region. Electrophoretic mobility shift assay demonstrated the presence of proteins that bound to the above DNA fragment in the nuclear extract from cells grown in thiamine-free medium. These findings suggested that this region between −234 and −215 acts as an upstream activation element of the PH03 gene that can interact with regulatory proteins
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