The ntcA gene from Synechococcus sp. strain PCC 7942 encodes a regulatory protein which is required for the expression of all of the genes known to be subject to repression by ammonium in that cyanobacterium. Homologs to ntcA have now…

An experimental analysis of noise gratings in holographic lenses is presented. Lenses are recorded as thick-phase holograms in bleached silver halide emulsion. The authors calculated noise grating efficiency by using the diffraction efficiency in points across a lens diameter. They…

A statistical model is used to study the formation of noise gratings in holograms and the mechanism that causes radiation scattering in them. The theoretical model presented describes noise scattering in terms of diffraction due to the high number of…

This paper deals with diffuse-object holograms recorded in silver halide sensitized gelatin. Both the diffraction efficiency and the signal-to-noise ratio when reconstruction is done with different wavelengths are measured. The experimental results we obtained show that new theoretical models for…

Recording noise gratings with single-beam exposures in bleached silver halide emulsions is used as a holographic spectroscopy technique in order to analyse and optimize photochemical processing. In particular, rehalogenating type bleachings are analysed by measuring the transmittance through the recorded…

By applying Gaussian optics we propose a new matrix formula model for intraocular lens (IOL) calculation that yields not only IOL optical power for a particular eye but also an evaluation of the bending factor of different IOL optical designs.…

In the 19th century it was difficult for the growing number of medical practitioners in North America to access current medical literature. Various ways were suggested to solve this problem; one of them was the creation of physician-run medical library…

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Los estudios de esta tesis doctoral muestran la relación estrecha que existe en la Fenomenología del Espíritu entre el concepto hegeliano de experiencia, su concepción del absoluto y el impacto que tiene en ambos el desafío del escepticismo. La tesis…

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