6,781 research outputs found

    Interference Conditions of the Reconsolidation Process in Humans: The Role of Valence and Different Memory Systems

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    Following the presentation of a reminder, consolidated memories become reactivated followed by a process of re-stabilization, which is referred to as reconsolidation. The most common behavioral tool used to reveal this process is interference produced by new learning shortly after memory reactivation. Memory interference is defined as a decrease in memory retrieval, the effect is generated when new information impairs an acquired memory. In general, the target memory and the interference task used are the same. Here we investigated how different memory systems and/or their valence could produce memory reconsolidation interference. We showed that a reactivated neutral declarative memory could be interfered by new learning of a different neutral declarative memory. Then, we revealed that an aversive implicit memory could be interfered by the presentation of a reminder followed by a threatening social event. Finally, we showed that the reconsolidation of a neutral declarative memory is unaffected by the acquisition of an aversive implicit memory and conversely, this memory remains intact when the neutral declarative memory is used as interference. These results suggest that the interference of memory reconsolidation is effective when two task rely on the same memory system or both evoke negative valence.Fil: Fernández, Rodrigo Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Bavassi, Mariana Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Kaczer, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Forcato, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Pedreira, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin

    Computer simulations on the sympatric speciation modes for the Midas cichlid species complex

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    Cichlid fishes are one of the best model system for the study of evolution of the species. Inspired by them, in this paper we simulated the splitting of a single species into two separate ones via random mutations, with both populations living together in sympatry, sharing the same habitat. We study the ecological, mating and genetic conditions needed to reproduce the polychromatism and polymorphism of three species of the Midas Cichlid species complex. Our results show two scenarios for the A. Citrinellus speciation process, one with and the other without disruptive natural selection. 
In the first scenario, the ecological and genetic conditions are sufficient to create two new species, while in the second the mating and genetic conditions must be synchronized in order to control the velocity of genetic drift

    Majority-vote on directed Small-World networks

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    On directed Small-World networks the Majority-vote model with noise is now studied through Monte Carlo simulations. In this model, the order-disorder phase transition of the order parameter is well defined in this system. We calculate the value of the critical noise parameter q_c for several values of rewiring probability p of the directed Small-World network. The critical exponentes beta/nu, gamma/nu and 1/nu were calculated for several values of p.Comment: 16 pages including 9 figures, for Int. J. Mod. Phys.

    Quantum effective force in an expanding infinite square-well potential and Bohmian perspective

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    The Schr\"{o}dinger equation is solved for the case of a particle confined to a small region of a box with infinite walls. If walls of the well are moved, then, due to an effective quantum nonlocal interaction with the boundary, even though the particle is nowhere near the walls, it will be affected. It is shown that this force apart from a minus sign is equal to the expectation value of the gradient of the quantum potential for vanishing at the walls boundary condition. Variation of this force with time is studied. A selection of Bohmian trajectories of the confined particle is also computed.Comment: 7 figures, Accepted by Physica Script

    GENDER MAINSTREAMING IN A HIGHER EDUCATION INSTITUTION (HEI)

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    The study assessed the implementation of gender mainstreaming in government owned higher education institution in Eastern Visayas, Leyte, Philippines. It examined the level of awareness of school administrators and faculty members on gender mainstreaming initiatives and how they perceived about the extent of gender mainstreaming implementation in the areas of instruction, research, extension and production. The association between administrators and faculty attributes in terms of their awareness on the university’s fourfold functions was also examined. The study was implemented through a descriptive and correlational survey research design utilizing a researcher made questionnaire which was pilot tested and standardized prior to actual conduct of the survey data gathering. Findings revealed that faculty members and administrators were moderately aware of the gender mainstreaming efforts of the university, but with significantly differences in their levels of awareness. By extent of implementation, gender mainstreaming was less implemented in the area of research, moderately implemented in the areas instruction, extension and production. Significant relationship was noted between designation and the level of awareness on gender mainstreaming, no statistical association was revealed among sex, age, academic rank and educational qualification. Meanwhile, age, academic rank and educational qualification were significantly related to instruction but not to research, both age and academic rank were significantly associated with extension and production.  Article visualizations

    Efeito do consumo de preparações à base de farinha de yacon (Smallanthus sonchifolius) na produção de ácidos graxos de cadeia curta, no ph fecal e na microbiota intestinal probiótica de pré-escolares

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    O consumo da raiz de yacon (Smalanthus sonchifolius) pode trazer benefícios à saúde dos indivíduos por ser uma importante fonte de Fruto-oligossacarídeo (FOS). Este prebiótico promove o crescimento de bactérias Bifidobacterium spp. que podem contribuir com a produção de ácidos graxos de cadeia curta (AGCC) e reduzir o pH na região colônica. Objetivou-se com este estudo avaliar o efeito do consumo de preparações elaboradas com farinha de yacon na produção de AGCC, no pH fecal e na microbiota probiótica de pré-escolares. Foi conduzido um estudo longitudinal, experimental do tipo pareado antes e após, onde foram oferecidas preparações à base de farinha de yacon a crianças saudáveis por 18 semanas. Amostras de fezes foram coletadas antes e após o período de intervenção alimentar para determinar as concentrações de AGCC, pelo método de Cromatografia Líquida de Alta Eficiência (CLAE); o pH fecal, utilizando um pHmetro e para quantificar Bifidobacterium spp. utilizou-se a técnica de Reação em Cadeia de Polimerase em tempo real (rt-PCR). As médias encontradas nos dois momentos foram submetidas ao teste t pareado utilizando o programa Statistical Package for Social Sciences (SPSS) versão 13.0. Houve aumento significativo nas concentrações de butirato antes (0,091±0,5 mg/mg de fezes) e após (0,122±0,7 mg/mg de fezes) o período de intervenção. As médias das concentrações dos momentos antes e após a intervenção para o acetato (0,357±0,11 e 0,385±0,15 mg/mg de fezes, respectivamente), propionato (0,052±0,04 e 0,064±0,05 mg/mg de fezes, respectivamente) e para o pH (6,76±0,43 e 6,61±0,45, respectivamente) se mantiveram iguais. Com as reações de rt-PCR, encontrou-se valores médios de cycle threshold do DNA extraído das amostras de fezes coletadas antes e após a intervenção alimentar de 17 e 19, respectivamente. Como a eficiência da amplificação foi de 77%, considerou-se que as reações foram de baixa sensibilidade e os valores encontrados podem não representar o valor real da concentração de Bifidobacterium spp. Concluiu-se que o consumo das preparações elaboradas com farinha de yacon pode ter influenciado a fisiologia da microbiota intestinal probiótica das crianças por promover o aumento nas concentrações do butirato
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