Feeding Cues and Injected Nutrients Induce Acute Expression of Multiple Clock Genes in the Mouse Liver

The circadian clock is closely associated with energy metabolism. The liver clock can rapidly adapt to a new feeding cycle within a few days, whereas the lung clock is gradually entrained over one week. However, the mechanism underlying tissue-specific clock resetting is not fully understood. To characterize the rapid response to feeding cues in the liver clock, we examined the effects of a single time-delayed feeding on circadian rhythms in the liver and lungs of Per2::Luc reporter knockin mice. After adapting to a night-time restricted feeding schedule, the mice were fed according to a 4, 8, or 13 h delayed schedule on the last day. The phase of the liver clock was delayed in all groups with delayed feeding, whereas the lung clock remained unaffected. We then examined the acute response of clock and metabolism-related genes in the liver using focused DNA-microarrays. Clock mutant mice were bred under constant light to attenuate the endogenous circadian rhythm, and gene expression profiles were determined during 24 h of fasting followed by 8 h of feeding. Per2 and Dec1 were significantly increased within 1 h of feeding. Real-time RT-PCR analysis revealed a similarly acute response in hepatic clock gene expression caused by feeding wild type mice after an overnight fast. In addition to Per2 and Dec1, the expression of Per1 increased, and that of Rev-erbα decreased in the liver within 1 h of feeding after fasting, whereas none of these clock genes were affected in the lung. Moreover, an intraperitoneal injection of glucose combined with amino acids, but not either alone, reproduced a similar hepatic response. Our findings show that multiple clock genes respond to nutritional cues within 1 h in the liver but not in the lung

The use of software to identify plagiarism in academic and educational texts

This study corresponds to a project of a teaching research group, which analyzed the authorship of textual works of eleven students. These studies were developed throughout the subject of Biological Sciences of the stricto sensu graduate course of a private university in the state of San Pablo, Brazil. The main objective of this research was to evaluate the existence of plagiarism to answer the research question: Do postgraduate students commit plagiarism during the courses? Thus, the results of plagiarism verification were analyzed and compared using various software available online in paid or free versions. During this study, we observed that most academic studies of postgraduate students presented some plagiarism characteristic and we still found that the amount of plagiarism identified is different depending on the analysis characteristics of the program used. Despite the limitations of the softwares, their regular use to verify the authorship of a text is essential to identify plagiarism and to take educational measures that guide students on the creation process and the impact plagiarism has on learning. We therefore concluded that new pedagogical strategies must be developed and implemented to discourage plagiarism and thus reduce the impoverishment of education. At the same time, we showed that the choice of plagiarism verification software should not be made in a frivolous manner, but consciously and responsibly, because it may lead to different results.Este estudio corresponde a un proyecto de investigación de un núcleo docente que analizó los trabajos textuales autorales de once alumnos. Estos trabajos se han desarrollado a lo largo de una disciplina del área Ciencias Biológicas del curso de posgrado stricto sensu de una universidad particular del estado de São Paulo, Brasil. El objetivo principal de esta investigación fue evaluar la existencia de plagio, para responder a la pregunta de investigación: ¿alumnos graduados cometen plagio cuando realizan cursos de posgrado? Para eso fueron analizados y comparados los resultados de la verificación de plagio con diversos softwares disponibles online en versiones pagas o gratuitas. Durante este estudio observamos que la mayoría de los trabajos académicos de los alumnos de posgrado presentaba algún rasgo de plagio y comprobamos que la cantidad de plagio apuntada es distinta dependiendo de las características de análisis del programa usado. A pesar de las limitaciones de los softwares, su uso regular para verificación autoral es fundamental para identificar esta práctica y poder tomar medidas educativas que orienten a los alumnos sobre el proceso de elaboración de textos autorales y sobre el impacto que tiene el plagio en el aprendizaje. Así concluimos que es necesario desarrollar y aplicar nuevas estrategias pedagógicas para desestimular el plagio y en consecuencia disminuir el empobrecimiento de la educación. Paralelamente mostramos que la elección del software para verificación de plagio no debe ser liviana, sino realizada de manera consciente y responsable una vez que puede implicar en resultados diferentes