Perfect category-graded algebras

In a perfect category every object has a minimal projective resolution. We give a criterion for the category of modules over a categorygraded algebra to be perfect.Comment: A sufficient condition is replaced by a criterion. Several references added. 17 page

Mite (Arthropoda, Acari) associates of palms (Arecaceae) in Brazil: I. Present status and new records.

This paper presents 72 new records and 10 records from literature on the distribuition of nine species of phytophagous mites and nine species of predatory mites from 13 species of palms in 13 Brazilian States

Renormalized coordinate approach to the thermalization process

We consider a particle in the harmonic approximation coupled linearly to an environment. modeled by an infinite set of harmonic oscillators. The system (particle--environment) is considered in a cavity at thermal equilibrium. We employ the recently introduced notion of renormalized coordinates to investigate the time evolution of the particle occupation number. For comparison we first present this study in bare coordinates. For a long ellapsed time, in both approaches, the occupation number of the particle becomes independent of its initial value. The value of ocupation number of the particle is the physically expected one at the given temperature. So we have a Markovian process, describing the particle thermalization with the environment. With renormalized coordinates no renormalization procedure is required, leading directly to a finite result.Comment: 16 pages, LATEX, 2 figure

Plantas de cobertura de solo para sistema plantio direto.

A camada de palha, sobre o solo, e essencial para o sucesso do Sistema Plantio Direto (SPD). Cria um ambiente extremamente favoravel as condicoes fisicas, quimicas e biologicas do solo contribuindo para o controle de plantas daninhas, estabilizacao da producao e recuperacao ou manutencao da qualidade do solo. O sistema de rotacao e sucessao de culturas deve ser adequado para permitir a manutencao de uma cobertura minima do solo com palha. Na escolha destas plantas, e fator decisivo conhecer a sua adaptacao a regiao e sua habilidade em crescer num ambiente menos favoravel, uma vez que as culturas comerciais sao estabelecidas nas epocas mais propicias. Isto e especialmente verdade nas condicoes de Brasil Central, onde o inverno e seco, ao passo que na regiao Sul, de inverno umido, nao existe essa limitacao e ha maior opcao de plantas adaptadas as condicoes do inverno. Existem muitas plantas de cobertura para as diferentes regioes edafoclimaticas do Brasil, e a experiencia local e decisiva nesta selecao. Em qualquer situacao, deve-se ter sempre em mente que nao existe uma planta milagrosa e que o ideal e ter mais de uma dessas especies no sistema de producao, onde busca-se aliar renda a preservacao ambiental

Dynamic L-type CaV1.2 channel trafficking facilitates CaV1.2 clustering and cooperative gating.

L-type CaV1.2 channels are key regulators of gene expression, cell excitability and muscle contraction. CaV1.2 channels organize in clusters throughout the plasma membrane. This channel organization has been suggested to contribute to the concerted activation of adjacent CaV1.2 channels (e.g. cooperative gating). Here, we tested the hypothesis that dynamic intracellular and perimembrane trafficking of CaV1.2 channels is critical for formation and dissolution of functional channel clusters mediating cooperative gating. We found that CaV1.2 moves in vesicular structures of circular and tubular shape with diverse intracellular and submembrane trafficking patterns. Both microtubules and actin filaments are required for dynamic movement of CaV1.2 vesicles. These vesicles undergo constitutive homotypic fusion and fission events that sustain CaV1.2 clustering, channel activity and cooperative gating. Our study suggests that CaV1.2 clusters and activity can be modulated by diverse and unique intracellular and perimembrane vesicular dynamics to fine-tune Ca2+ signals

Anatomia foliar em secção transversal de Elaeis guineesis Jacq (Dendê).

III ENAAg

ENERGETIC ESTIMATION OF HEAT-RECOVERY COKE OVEN

Worldwide, steel production insistently seeks energy strength, pointing out the precision of application of all energy from the raw material with the objective of increasing production with quality and economically viable. In this sense, the energy assessment is the basis adopted to decide on the manufacture of coke in the industry. With this argument, this paper presents an energy analysis of Heat Recovery furnaces through calorific value, a method specified by the Energy Research Company of Brazil and the Brazilian Association of Metals and Materials for application in calculations in a productive environment. The data of the basic raw materials for the production of coke, the technological analysis and the energy estimation in the manufacture of coke in Coke Ovens Heat Recovery can be found in the proposed method. The present work presents result that demonstrate that the active and efficient use of the calorific value of metallurgical coal produces an energy quality coke for the manufacture of pig iron in the blast furnace.