No abstract

En este estudio se evalúo el contenido de fenoles totales y la actividad antioxidante por diferentes metodologías como: DPPH, FRAP y ORAC de un producto comercial Noxy-Nat® reportado como antioxidante natural de romero. El Noxy-Nat a 1000 ppm inhibió en un 59% el deterioro oxidativo del aceite de palma, sometido a un proceso discontinuo de fritura de pollo a 180°C. El proceso oxidativo fue monitoreado usando el valor de peróxido (VP) y los compuestos polares totales (CPT) como indicadores de la peroxidación lipídica y de la vida útil del aceite. El Noxy-Nat inhibe el deterioro oxidativo del aceite de palma debido a la capacidad para atrapar radicales peróxilos (ROO•) expresada como valores ORAC.

Transgenic potato, Solanum tuberosum L., plants containing a synthetic cry1Ac gene coding for the Bacillus thuringiensis (Bt) crystalline insecticidal protein were produced and evaluated for resistance to Tecia solanivora Povolny (Lepidoptera: Gelechiidae), the larvae of which attack potato tubers. In total, 43 transgenic lines of commercial Andean potato varieties Diacol Capiro, Pardo Pastusa, and Pandeazúcar were obtained. These transgenic lines were found to have one to four copies of cry1Ac per genome and expression levels of Cry1Ac protein varying from 0.02 to 17 microg/g fresh tuber tissue. Bioassays of T. solanivora larvae on these transgenic potato tubers showed 83.7-100% mortality, whereas the mortality levels on nontransgenic lines were 0-2.67%. Our data indicate the capability of Bt transgenic technology to control the T. solanivora while reducing the use of chemical insecticides. Further studies under controlled field conditions will be helpful in exploring the potential of CrylAc potatoes in the insect pest management strategies.

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Escaping from predation saves life, but costs energy and time. The “threat-sensitive predator-avoidance” hypothesis proposes that prey may modulate their antipredator responses, and thus the associated costs, in accordance with the magnitude of predation risk. This process requires that prey accurately assess this risk by decoding available information from various sources. For example, distress calls are uttered by prey when a predator traps them and can serve as public information on predation risk. Such is the case for the weeping lizard whose distress calls trigger immobility in conspecifics. Here, we tested whether this antipredator response of the weeping lizard is modulated by witnessing predation. We exposed lizards to distress calls alone or paired with models of a prey (conspecific), a predator (snake), or a predatory event (a snake subjugating the conspecific). Data show that the sole presence of the predator or prey paired with distress calls seems not to modulate the antipredator responses. Contrarily, witnessing a predatory event associated with calls intensified antipredator responses; lizards reduced their activity for longer and avoided proximity to the stimuli, which may decrease predation risk by reducing the likelihood of being detected by the predator. We conclude that the weeping lizard can use multisensorial public information to assess predation risk and modulate its antipredator responses.