David Chacon Alvarez

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The influence of extremely low-frequency (ELF) electromagnetic fields on Escherichia coli cultures in submerse fermentation was studied. The fermentation processes were carried out recycling the culture medium externally through a stainless steel tube inserted in a magnetic field generator (solenoid). The exposure time and electromagnetic induction were(More)
The effect of extremely low frequency (ELF) magnetic fields on ethanol production by Saccharomyces cerevisiae using sugar cane molasses was studied during batch fermentation. The cellular suspension from the fermentor was externally recycled through a stainless steel tube inserted in two magnetic field generators, and consequently, the ethanol production(More)
Metamorphosis can disrupt the correlation structure between juvenile and adult traits, thus allowing relatively independent evolution in contrasting environments. We used a multiple experimental approach to investigate how diet quality and larval predation risk affected the rates of growth and development in painted frogs (Discoglossus galganoi), and how(More)
Risk-taking behaviour has important consequences for fitness. Here, we show that risk-taking behaviour in sticklebacks consistently varies according to the habitat of origin. We compared the risk-taking behaviour of individual sticklebacks from three pond and three stream populations. Specifically, we measured willingness to forage under predation risk(More)
The Leishmania species present a genetic homology that ranges from 69 to 90%. Because of this homology, heterologous antigens have been used in the immunodiagnosis and vaccine development against Leishmania infections. In the current work, we describe the identification of species-specific and cross-reactive antigens among several New World Leishmania(More)
Two-photon holographic recording with cw laser sources in the 750-1100-nm spectral range is accomplished using recording materials consisting of an alpha-diketone dissolved in a poly-alpha-cyanoacrylate host. Gating of the holographic sensitivity by irradiation with incoherent UV radiation is demonstrated. Hologram diffraction efficiencies as large as 10%(More)
Two-photon holography with continuous-wave laser sources is accomplished by using carbazole dissolved in a polymethyl methacrylate host matrix as a recording medium. Gating of the holographic sensitivity for 4880-A radiation by irradiation with 3336-A radiation is demonstrated. It is shown that two-photon holographic recording can be accomplished with a(More)
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