We measured detection of a thin vertical line (target) in the presence of a slightly thicker collinear, adjacent line (inducer). Sign and strength of contrast of the inducer were varied. Test lines could be either bright or dark. Detection thresholds were obtained through a temporal two-alternative forced-choice (2AFC) procedure with the method of constant stimuli. When target and inducer had e...

The crr mutation was shown to affect the phosphoenolpyruvate:sugar phosphotransferase system-mediated transient repression of the lac operon, intracellular cAMP levels, and sensitivity to inducer exclusion. Our results indicate that the presumed crr gene product, factor IIIGlc, plays a direct role in the regulation of inducer exclusion. We propose a mechanism in which inducer exclusion depends ...

Gal repressor inhibits transcription from the gal promoter (P1) when it binds to the cognate operator (O(E)). The repression is relieved by the presence of the inducer D-galactose. Compared with its interaction with free repressor, D-galactose binds to the repressor-operator complex with 10-fold reduced affinity as determined by fluorescence enhancement measurements. Thermodynamic analysis and ...

The characteristics of inducer binding to lactose repressor protein in the presence of a small (29 base pair) operator DNA fragment have been examined. The presence of operator DNA fragments decreases the affinity of the protein for inducer molecules. The maximum change observed is a 20-fold increase in the concentration of inducer necessary for half-saturation of the protein. The non-linearity...

Systematic crosses between various strains of Drosophila melanogaster lead in some cases to partly sterile F1 females. Two main classes of strains, inducer and reactive, may be recognized on the basis of the fertility of F1 female progeny. Females which may show incomplete sterilty (SF female) arise only when reactive females are crossed with inducer males, other crosses, including the reciproc...

A model for other countries? Politicians and concerned citizens in other countries will observe Germany’s movements closely, as it is the first example of a high technology country turning its back on nuclear energy after using it for more than half a century. Around the world, many old and new users of nuclear reactors are sticking to their plans and policies, only adding a safety inspection h...

BACKGROUND Besides Escherichia coli, Bacillus subtilis is an important bacterial species for the production of recombinant proteins. Recombinant genes are inserted into shuttle expression vectors which replicate in both E. coli and in B. subtilis. The ligation products are first transformed into E. coli cells, analyzed for correct insertions, and the correct recombinant plasmids are then transf...

Cigarette smoking is growing and nicotine is considered as the most adverse agent in the cigarette smoking. Nicotine is an alkaloid and forms 90% of alkaloids of cigarette. Nicotine is accountable for creating disorders and cancers such as lung cancer, heart disease and chronic lung disease. Nicotine can be considered as an autophagy and apoptosis inducer which can either directly or indirectly...