The earth’s environments and ecosystems are not fi xed but vary over a wide range of space and time scales (Delcourt, and Webb 1982; see also fi g. 6.1). At the scale of tens of thousands of years, the wobble of the Earth on its axis causes variation in the solar radiation received at the earth’s surface, driving variation in climate. On shorter time scales, the Southern Oscillation of sea surf...

Although CD4(+) T cells are essential for protective immunity against Mycobacterium tuberculosis infection, recent reports indicate that CD8(+) T cells may also play a critical role in the control of this infection. However, the epitope specificity and the mechanisms of activation of mycobacteria-reactive CD8(+) T cells are poorly characterized. In order to study the CD8(+) T cell responses to ...

The umu test system is a newly developed method to evaluate genotoxicities of a wide variety of environmental carcinogens and mutagens (Oda et al., 1985; Nakamura et al., 1987). In the present study, SOS-inducing activity of 142 synthetic dyes was investigated by the umu test using Salmonella typhimurium (TA1535/pSK1002) under the condition of absence and presence of rat liver microsomal fracti...

Selective polymeric extractants were prepared for preconcentration of Cibacron reactive red dye, a dye that is often applied with Cibacron reactive blue and Cibacron reactive yellow for dyeing of fabrics. The best extractant was fabricated (in chloroform) using methacrylic acid (as monomer), ethylene glycol dimethacrylate (as crosslinker), AIBN (as initiator for polymerization), and red dye as ...

The regulation of gene transcription involves a dynamic balance between packaging regulatory sequences into chromatin and allowing transcriptional regulators access to these sequences. Access is restricted by the nucleosomes, but these can be repositioned or ejected by enzymes known as nucleosome remodellers. In addition, the DNA sequence can impart stiffness or curvature to the DNA, thereby af...