Ingestion rates of Artemia nauplii for different larval stages of Macrobrachium rosenbergii

The functional response between ingestion rate and food concentration was determined for each larval stage of Macrobrachium rosenbergii. Artemia franciscana nauplii were supplied at 2,4, 6, 8, 10 and 12 per milliliter. The nauplii were counted by sight using a Pasteur pipette and transferred to Petri dishes containing 40 ml of brackish water (12 parts per thousand) lying on the top of black plastic. One larva at each stage was individually placed into each Petri dish containing different food density. After 24 h, each larva was removed from the Petri dish and the leftover nauplii were counted. The amount consumed was determined by the difference between the initial and final number of nauplii. Ingestion rate (I) increased as food density (P) increased and was defined by the model I=I-m(1-e(-kP)). The results suggest four levels of ingestion during larval development. The first level includes stages II, III and IV, with average maximum consumption of about 40 nauplii/day; the second level includes stages V and VI, with consumption of approximately 55 nauplii/day; the third level includes stages VII and VIII, with consumption of 80-100 nauplii/day. The fourth level includes stages IX, X and XI, in which the high values for maximum ingestion (Im) exceed the load capacity of the medium. The low values for constant k (that may correspond to the adaptability of the food to prey characteristics, such as, size, mobility, etc.) obtained for stages IX, X and XI indicated that Artemia is not an adequate prey and there is necessity of a supplementary diet. The best relationship between predator and prey seemed to occur during stage IV Results obtained in the present work may subsidize future researches and serve as a guideline for practical considerations of feeding rates. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Relação entre variáveis na regulação do consumo de vacas Holandês × Zebu em lactação sob pastejo em capim-elefante

A análise fatorial de componentes principais (CP) foi usada no exame do relacionamento entre variáveis de um banco de dados da Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Gado de Leite. As variáveis disponíveis foram relacionadas às vacas (dias em lactação, teores lácteos de gordura e extrato seco total, produção de leite, ordem de lactação, peso vivo e grau de sangue), ao manejo (dia de pastejo, disponibilidade e períodos de descanso da pastagem), ao ambiente (estação do ano, precipitação pluviométrica) e ao alimento (consumo de nutrientes do concentrado e da cana × uréia, consumo de MS de pastagem de capim-elefante, composição química e digestibilidade in vitro da pastagem e concentração fecal de PB, FDN e FDA). O primeiro CP (33,7% da inércia dos dados) representou o uso da suplementação volumosa (cana × uréia) da pastagem em resposta à redução sazonal da disponibilidade e do consumo de capim-elefante. O segundo CP (15,3% da inércia) foi relacionado ao consumo de nutrientes do concentrado. O terceiro CP (8,5% da inércia) representou efeitos do manejo sobre a composição química da pastagem. A interpretação gráfica dos resultados favoreceu a percepção mais dinâmica da intensidade da associação e do antagonismo entre as variáveis contextualizadas no estudo.

A convivência familiar e comunitária é direito da criança e do adolescente e uma realidade a ser repensada pela escola

O tema sobre a convivência familiar e comunitária como um direito de crianças e adolescentes, à primeira vista, se mostra bastante abstrato e ocupando ao mesmo tempo um lugar-comum. A sociedade aceita facilmente o fato de que toda criança tem direito a nascer e crescer em um lar saudável, protegido e seguro. Entretanto, muitas são as crianças que enfrentam situações de extrema vulnerabilidade pessoal e social, tendo que se afastar de suas famílias de origem para viver em situação de abrigamento, como medida protetiva. Este artigo tem como objetivo principal, a partir do que está preconizado no Plano Nacional de Promoção, Proteção e Defesa do Direito de Crianças e Adolescentes à Convivência Familiar e Comunitária e em leis anteriores (Constituição Federal Brasileira de 1988 e na Lei n. 8069/90 - Estatuto da Criança e do Adolescente), apresentar uma análise sobre os desafios e transformações que serão imprescindíveis para que esse direito seja efetivado, abordando os principais aspectos que envolvem as responsabilidades das políticas sociais brasileiras, com ênfase na educação pública.

Feuerbach e Stirner: algumas considerações sobre linguagem e política

Habitualmente não se presta atenção ao fato de que a Primeira Parte da Ideologia Alemã (Feuerbach) foi a última a ser redigida por Marx. O texto, tal como nos aparece hoje, encobre portanto a gênese da crítica ao Humanismo. Esta última, como este pequeno ensaio pretende indicar, só poderia brotar do contacto meticuloso com o texto do Único e sua Propriedade. Após a leitura de Stirner, Marx pôde se acreditar liberado deste último fantasma especulativo e ideológico: o Homem.

Aproximações do teatro do oprimido com a Psicologia e o Psicodrama

O presente artigo aborda as aproximações do teatro do oprimido na modalidade do arco-íris do desejo, método de terapia e teatro criado por Augusto Boal com a Psicologia, em especial com o psicodrama. O teatro do oprimido é frequentemente comparado e até mesmo confundido com o psicodrama, daí a necessidade de apontarmos algumas semelhanças e diferenças entre os dois métodos, as teorias que inspiraram seus criadores, bem como os objetivos que procuravam alcançar. Procuraremos problematizar o uso das técnicas do arco-íris do desejo considerando a função e a preparação do curinga para aplicá-las, seu manejo, bem como o lugar de autoridade que lhe é conferido. As técnicas boalianas devem ser utilizadas com o devido cuidado, pois é necessário não perder de vista as possíveis consequências que o seu uso indevido pode provocar nos participantes, posto que são técnicas mobilizadoras de fortes conteúdos emocionais.

Nest location, clutch size and nest success in the Scarlet Ibis Eudocimus ruber

Breeding success and nest-site characteristics were studied during the 1996-1997 breeding season in a colony of Scarlet Ibises Eudocimus ruber in south-eastern Brazil to test the hypothesis that nest-site characteristics and clutch size affect nest success. Two nesting pulses produced young, the earlier being more successful. Predation accounted for most failures during the first pulse, wind destruction during the second. A third pulse with few nests produced no young. Adult Ibises abandoned nests when they lost sight of other incubating birds. Logistic regression analysis indicated that nest success during the first pulse was positively related to clutch size, number of nests in the nest tree and in the nearest tree, and negatively to the distance to the nearest neighbour. During the second pulse there were significant negative associations between success, nest height and distance to the fourth nearest nest, and a positive association between success and nest cover. The results agree with the 'selfish herd' hypothesis, indicating that nest aggregation may increase breeding success, but the nest-site characteristics affecting success can differ over the course of one breeding season.

Igreja católica, assistência social e caridade: Aproximações e divergências

This article is the result of a research study concluded in 2003, which aimed at investigating how the conception of Law is expressed in the actions of the so-called social pastoral commissions of the Catholic Church in Londrina, Brazil. By observing that the conception of charity and that of social rights walk side-bi-side within the Catholic Church, a question emerged: how is the conception of social right expressed in the actions of social pastoral commissions? Charity is preached as a Christian duty, as an action expressed in the experience of solidarity towards others who are in a situation that prevents them from having minimal living conditions. At least at discourse level, the actions developed are not limited to provide basic goods, clothes or medicine. We realized that those who act in social pastoral commissions, driven by values such as love to fellow human beings and solidarity, have not lost sight of the idea of social right - on the contrary, they have been reinforcing it. © 2006 Programa de Pós-Graduação em Sociologia - UFRGS.

The Dirac-Hestenes equation for spherical symmetric potentials in the spherical and Cartesian gauges

In this paper, using the apparatus of the Clifford bundle formalism, we show how straightforwardly solve in Minkowski space-time the Dirac-Hestenes equation - which is an appropriate representative in the Clifford bundle of differential forms of the usual Dirac equation - by separation of variables for the case of a potential having spherical symmetry in the Cartesian and spherical gauges. We show that, contrary to what is expected at a first sight, the solution of the Dirac-Hestenes equation in both gauges has exactly the same mathematical difficulty. © World Scientific Publishing Company.

Is the equivalence principle doomed forever to Dante's Inferno on account of quantum mechanics?

It is commonly assumed that the equivalence principle can coexist without conflict with quantum mechanics. We shall argue here that, contrary to popular belief, this principle does not hold in quantum mechanics. We illustrate this point by computing the second-order correction for the scattering of a massive scalar boson by a weak gravitational field, treated as an external field. The resulting cross-section turns out to be mass-dependent. A way out of this dilemma would be, perhaps, to consider gravitation without the equivalence principle. At first sight, this seems to be a too much drastic attitude toward general relativity. Fortunately, the teleparallel version of general relativity - a description of the gravitational interaction by a force similar to the Lorentz force of electromagnetism and that, of course, dispenses with the equivalence principle - is equivalent to general relativity, thus providing a consistent theory for gravitation in the absence of the aforementioned principle. © World Scientific Publishing Company.

Anatomical features of the urethra and urinary bladder catheterization in female mice and rats. An essential translational tool

PURPOSE: To present fundamental anatomical aspects and technical skills necessary to urethra and urinary bladder catheterization in female mice and rats. METHODS: Urethral and bladder catheterization has been widely utilized for carcinogenesis and cancer research and still remains very useful in several applications: from toxicological purposes as well as inflammatory and infectious conditions to functional aspects as bladder dynamics and vesicoureteral reflux, among many others. RESULTS: Animal models are in the center of translational research and those involving rodents are the most important nowadays due to several advantages including human reproducibility, easy handling and low cost. CONCLUSIONS: Although technical and anatomical pearls for rodent urethral and bladder access are presented as tackles to the advancement of lower urinary tract preclinical investigation in a broaden sight, restriction to female animals hampers the male microenvironment, demanding future advances.

Estabilidade locomotora durante a condução de um cão

The purpose of this study was to evaluate how walking a dog on a leash influenced haptic perception and stability during human locomotion. Fourteen adults, with and without sight restriction, walked on a narrow balance beam by themselves, or holding a leash attached to a dog that walked on a parallel narrow bench. The performance of participants who walked with the dog, but blindfolded, significantly (p < 0.05) improved as compared to the condition without the dog. Their locomotion performance was assessed via the duration of the total displacement on the balance beam, durations of the double support phase, swing phase, stepping cycle, stepping length, and linear velocity, as well as variability of the inter-limb relative phase. With vision, these parameters were not affected by the presence of the dog. We conclude that these adults were able to use the dog's leash to detect haptic properties in order to achieve postural control (e.g., stability in speed performance) while walking.

A mediação do sabor: estudo comparativo da mediação de informação culinária na mídia impressa e na mídia televisiva

Pós-graduação em Comunicação - FAAC

Design de superfície: por uma visão projetual geométrica e tridimensional

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Experiência audiovisual e infância: em busca do que escapa ao primeiro olhar

Pós-graduação em Educação - IBRC

Tecnologia assistiva para o ensino de alunos com deficiência: um estudo com professores do ensino fundamental

Pós-graduação em Educação - FFC