A parsimonious cognitive architecture for human-computer interactive musical free improvisation

This paper presents some of the historical and theoretical foundations for a new cognitive architecture for human-computer interactive musical free improvisation. The architecture is parsimonious in that it has no access to musical knowledge and no domain-general subsystems, such as memory or representational abilities. The paper first describes some of the features and limitations of the architecture. It then illustrates how this architecture draws on insights from cybernetics, artificial life, artificial intelligence and ecological theory by situating it within a historical context. The context presented consists of a few key developments in the history of biologically-inspired robotics, followed by an indication of how they connect to James Gibson’s ecological theory. Finally, it describes how a recent approach to musicology informed by ecological theory bears on an implementation of this architecture

Produção e valor nutritivo da grama bermuda Florakirk [Cynodon dactylon (L.) pers.] em diferentes idades de crescimento Yield and nutritive value of Florakirk bermudagrass [Cynodon dactylon (L.) pers.] at different plant ages

O experimento foi conduzido em Itapetininga/SP, numa pastagem de Florakirk (Cynodon dactylon) formada há um ano, com o objetivo de avaliar a produção, composição químico-bromatológica e digestibilidade do cultivar em função da sua idade de crescimento. Utilizou-se o delineamento de blocos ao acaso, com 6 tratamentos (idades de crescimento definidas por cortes realizados aos 20, 30, 40, 50, 60 e 70 dias após o corte de uniformização) e 4 repetições. A produção de matéria seca da parte aérea aumentou de forma quadrática (P<0,05), com valor máximo de 215 g m-2, aos 70 dias. A digestibilidade verdadeira in vitro da matéria orgânica decresceu entre 20 e 70 dias (de 711 para 549 g kg-1), enquanto os teores de fibra em detergente neutro e fibra em detergente ácido aumentaram de forma quadrática (P<0,05). Os teores de N, P, K, Mg e Ca decresceram com o aumento da idade, não havendo diferença na concentração de S entre 20 e 60 dias. Foi observada uma maior variação na concentração de macronutrientes que na de micronutrientes (Cu, Fe, Mn e Zn) com o aumento na idade da planta, não havendo influência da idade sobre a concentração de B na planta. No corte aos 40 dias de crescimento, observou-se a melhor combinação entre valor nutritivo e produção de matéria seca da forragem. Observou-se a ocorrência de cigarrinhas e doenças foliares, que pode ter afetado o desenvolvimento da pastagem.<br>This research was conducted in Itapetininga, SP, Brazil, using a one year-old pasture, with the objective of evaluating the effect of plant age on yield, chemical and mineral composition, and digestibility of Florakirk bermudagrass (Cynodon dactylon). The experimental design consisted of randomized complete blocks, with six treatments replicated four times. Treatments consisted of six cutting ages (20-70 days) at ten-day intervals. Dry matter yield increased quadratically (P<0.05), reaching a maximum at 70 days (215 g m-2). In vitro organic matter digestibility decreased (711 g to 549 g kg-1) between 20 to 70 days. Neutral detergent fiber and acid detergent fiber increased quadratically (P<0.05) as age increased. N, P, K, Mg, and Ca concentration decreased with increasing age. There was no difference (P>0.05) in S concentration between 20 and 60 days. A larger variation for macronutrient concentrations was observed than for micronutrient (Cu, Fe, Mn, and Zn) concentrations with increasing plant age. There was no influence of age on B concentration. The best association of nutritive value and yield was observed at 40 days. Occurrence of the spittlebug and foliar diseases was observed, which probably retarded the vegetative and maturity processes