RESUMO
Current System-on-Chips (SoCs) execute applications with task dependency that compete for shared resources such as buses, memories, and accelerators. In such a structure, the arbitration policy becomes a critical part of the system to guarantee access and bandwidth suitable for the competing applications. Some strategies proposed in the literature to cope with these issues are Round-Robin, Weighted Round-Robin, Lottery, Time Division Access Multiplexing (TDMA), and combinations. However, a fine-grained bandwidth control arbitration policy is missing from the literature. We propose an innovative arbitration policy based on opportunistic access and a supervised utilization of the bus in terms of transmitted flits (transmission units) that settle the access and fine-grained control. In our proposal, every competing element has a budget. Opportunistic access grants the bus to request even if the component has spent all its flits. Supervised debt accounts a record for every transmitted flit when it has no flits to spend. Our proposal applies to interconnection systems such as buses, switches, and routers. The presented approach achieves deadlock-free behavior even with task dependency applications in the scenarios analyzed through cycle-accurate simulation models. The synergy between opportunistic and supervised debt techniques outperforms Lottery, TDMA, and Weighted Round-Robin in terms of bandwidth control in the experimental studies performed.
RESUMO
Dopaminergic neurons have the ability to release Dopamine from their axons as well as from their soma and dendrites. This somatodendritically-released Dopamine induces an autoinhibition of Dopaminergic neurons mediated by D2 autoreceptors, and the stimulation of neighbor GABAergic neurons mediated by D1 receptors (D1r). Here, our results suggest that the somatodendritic release of Dopamine in the substantia nigra (SN) may stimulate GABAergic neurons that project their axons into the hippocampus. Using semiquantitative multiplex RT-PCR we show that chronic blockade of the Dopaminergic neurotransmission with both AMPT and reserpine specifically decreases the expression levels of D1r, remarkably this may be the result of an antagonistic effect between AMPT and reserpine, as they induced the expression of a different set of genes when treated by separate. Furthermore, using anterograde and retrograde tracing techniques, we found that the GABAergic neurons that express D1r also project their axons in to the CA1 region of the hippocampus. Finally, we also found that the same treatment that decreases the expression levels of D1r in SN, also induces an impairment in the performance in an appetitive learning task that requires the coding of reward as well as navigational skills. Overall, our findings show the presence of a GABAergic interconnection between the SNr and the hippocampus mediated by D1r.
Assuntos
Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Receptores de Dopamina D1/biossíntese , Reserpina/farmacologia , Substância Negra/metabolismo , alfa-Metiltirosina/farmacologia , Inibidores da Captação Adrenérgica/farmacologia , Animais , Antagonistas dos Receptores de Dopamina D2/farmacologia , Proteínas da Membrana Plasmática de Transporte de Dopamina/antagonistas & inibidores , Proteínas da Membrana Plasmática de Transporte de Dopamina/biossíntese , Neurônios Dopaminérgicos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Expressão Gênica , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Fenótipo , Receptores de Dopamina D1/antagonistas & inibidores , Receptores de Dopamina D1/genética , Receptores de Dopamina D2/biossíntese , Receptores de Dopamina D2/genética , Substância Negra/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologiaRESUMO
Resumen El presente trabajo se enmarca en el contexto de las alternativas relacionadas con la planificación del entrenamiento deportivo, a partir de los modelos ATR (acumulación- transformación-realización). En correspondencia con las concepciones que hoy se utilizan en materia de planificación del entrenamiento, se evidencia la importancia de la interconexión de los contenidos en la preparación de los boxeadores, a partir de la conjugación de cargas cuyas rutas metabólicas son fundamentalmente la fosfagénica, anaerobia aláctica y la glicolitica, anaerobia láctica. El objetivo de la investigación radica en valorar el estado de la planificación del entrenamiento, en función de las tendencias más actuales, relacionadas con la interconexión de las cargas y el modelo ATR en la preparación de los boxeadores de la Academia Provincial de Pinar del Río. Para el estudio, se utilizó una muestra conformada por 13 atletas y siete entrenadores de la Academia Provincial de boxeo de Pinar del Río. Se emplearon diferentes técnicas y métodos como la entrevista a entrenadores, la observación y la medición. No obstante, los documentos y orientaciones de la Comisión Nacional de boxeo aún no cubren todas las expectativas de los colectivos pedagógicos de entrenadores de la academia, lo que deja un margen a la interpretación, por parte de las Comisiones Técnicas de los territorios en cuanto a las alternativas, a la planificación del entrenamiento y la definición de las direcciones e interconexión de estas. Resulta necesario encontrar un mecanismo que, en el plano didáctico, oriente mejor al entrenador en este sentido.
Abstract The present work is framed in the context of the alternatives related to the planning of the sport training, from the ATR models (accumulation-transformation-realization). In correspondence with the conceptions used today in training planning, the importance of the interconnection of the contents in the preparation of boxers is evident, from the conjugation of loads whose metabolic routes are fundamentally phosphagenic, alactic anaerobic and lactic anaerobic glycolithic. The objective of the research is to assess the situation of the training planning, based on the most current trends related to the interconnection of the loads and the ATR model in the preparation of the boxers of the Provincial Academy of Pinar del Río. For the study it was selected a sample, consisting on 13 athletes and 7 coaches from the Provincial Boxing Academy of Pinar del Río. Different methods and techniques such as the interview, the observation and the measurement were used. This study was carried outin correspondence with the most advanced conceptions regarding training planning. It reveals the importance of the interconnection of the contents in the preparation of the boxers from the combination of lactic anaerobic loads and lactic ones. However, the documents and guidelines of the National Boxing Commission still do not meet all the expectations of the pedagogical groups of trainers of the academy, which leaves a margin for interpretation by the Technical Commissions of the territories as regards alternatives, the planning of training and the definition of the directions and interconnection of these. It is necessary to find a mechanism that, at the didactic level, better orients the trainer in this sense.
RESUMO
The emergence of novel behavior is a multilayered phenomenon that comprehends distinct processes. One such process is known as insightful problem solving. "Insight" can be explained as the spontaneous interconnection of previously acquired behavioral repertoires. The objective of this study was to investigate: (1) whether capuchin monkeys (Sapajus spp.) do show the interconnection of repertoires, and (2) whether different performances of problem solving could be produced by different training histories. Two repertoires were independently trained: (a) joining two pieces of a tool to manufacture a new tool and (b) raking food with one tool. In the test situation, food was out of reach, and two joinable pieces of a tool, different from the ones used in training, were presented. To solve the problem, the monkeys had to join the two pieces and rake the food with the new manufactured tool. In Experiment 1, one monkey received symmetric training (equal number of sessions) of both repertoires and solved the task, but not in an insightful manner. In Experiment 2, six monkeys were divided into two groups: one group received symmetric training, and the second group had asymmetrical training of the repertoires (unequal number of sessions). Subjects from the symmetric group performed as the monkey in Experiment 1; subjects from the other group showed a sudden insightful solution of the problem. The different performances in the same problem situation can be explained in terms of the behavioral history provided to each group of subjects.