Epigenetic alterations in hippocampus of SAMP8 senescent mice and modulation by voluntary physical exercise.

The senescence-accelerated SAMP8 mouse model displays features of cognitive decline and Alzheimer's disease. With the purpose of identifying potential epigenetic markers involved in aging and neurodegeneration, here we analyzed the expression of 84 mature miRNAs, the expression of histone-acetylation regulatory genes and the global histone acetylation in the hippocampus of 8-month-old SAMP8 mice, using SAMR1 mice as control. We also examined the modulation of these parameters by 8 weeks of voluntary exercise. Twenty-one miRNAs were differentially expressed between sedentary SAMP8 and SAMR1 mice and seven miRNAs were responsive to exercise in both strains. SAMP8 mice showed alterations in genes involved in protein acetylation homeostasis such as Sirt1 and Hdac6 and modulation of Hdac3 and Hdac5 gene expression by exercise. Global histone H3 acetylation levels were reduced in SAMP8 compared with SAMR1 mice and reached control levels in response to exercise. In sum, data presented here provide new candidate epigenetic markers for aging and neurodegeneration and suggest that exercise training may prevent or delay some epigenetic alterations associated with accelerated aging.

Epigenetic alterations in hippocampus of SAMP8 senescent mice and modulation by voluntary physical exercise.

The senescence-accelerated SAMP8 mouse model displays features of cognitive decline and Alzheimer's disease. With the purpose of identifying potential epigenetic markers involved in aging and neurodegeneration, here we analyzed the expression of 84 mature miRNAs, the expression of histone-acetylation regulatory genes and the global histone acetylation in the hippocampus of 8-month-old SAMP8 mice, using SAMR1 mice as control. We also examined the modulation of these parameters by 8 weeks of voluntary exercise. Twenty-one miRNAs were differentially expressed between sedentary SAMP8 and SAMR1 mice and seven miRNAs were responsive to exercise in both strains. SAMP8 mice showed alterations in genes involved in protein acetylation homeostasis such as Sirt1 and Hdac6 and modulation of Hdac3 and Hdac5 gene expression by exercise. Global histone H3 acetylation levels were reduced in SAMP8 compared with SAMR1 mice and reached control levels in response to exercise. In sum, data presented here provide new candidate epigenetic markers for aging and neurodegeneration and suggest that exercise training may prevent or delay some epigenetic alterations associated with accelerated aging.

Aproximación al reajuste automático de centroides mediante la heurística de Lloyd para resolver el problema de las K-Medias

Peer-reviewed

L'entonació dels titulars de les notícies en català. Trets melòdics dels locutors

En aquest article descrivim les tendències entonatives que caracteritzen la locució dels titulars de les notícies per mitjà de sis de les veus més conegudes de la televisió catalana (tv3 i 3/24): Xavier Coral, Agnès Marquès, Ramon Pellicer, Joan Carles Peris, Raquel Sans i Núria Solé. Per portar a terme la investigació, ens hem basat en el mètode Anàlisi Melòdica de la Parla, descrit a Cantero (2002), i hem utilitzat l'aplicació d'anàlisi i síntesi de veu Praat. Prenent com a base els patrons melòdics i els èmfasis de la parla espontània del català, hem constatat que per a aquest tipus de locució, pròpia d'un registre formal, solament es fan servir de forma continuada i repetitiva una part dels trets melòdics ja descrits, amb la qual cosa s'aconsegueix un efecte característic que la fa singular i la distancia de la parla espontània. També hem descrit els trets melòdics que tenen en comú els sis locutors i els trets en què difereixen.