A Simple Vegetation Criterion (NDF Content) May Account for Diet Choices of Cattle Between Forages Varying in Maturity Stage and Physical Accessibility

The management of extensively grazed pastures requires an understanding and prediction of the diet choices of herbivores grazing on vegetation that is qualitatively (maturity stage) and quantitatively (biomass, sward height) heterogeneous. The Optimal Foraging Theory (OFT, Stephens & Krebs, 1986), bases its predictions on the relative energy intake rate (EIR) of forages. However, as EIRs are difficult to assess at pasture and are subject to wide intra- and inter-individual variations, another vegetation criterion was sought (accessibility, quality), by-passing the animal\u27s influence, to predict cattle diet choices quantitatively

A Simple Vegetation Criterion (NDF Content) May Account for Diet Choices of Cattle Between Forages Varying in Maturity Stage and Physical Accessibility

The management of extensively grazed pastures requires an understanding and prediction of the diet choices of herbivores grazing on vegetation that is qualitatively (maturity stage) and quantitatively (biomass, sward height) heterogeneous. The Optimal Foraging Theory (OFT, Stephens & Krebs, 1986), bases its predictions on the relative energy intake rate (EIR) of forages. However, as EIRs are difficult to assess at pasture and are subject to wide intra- and inter-individual variations, another vegetation criterion was sought (accessibility, quality), by-passing the animal\u27s influence, to predict cattle diet choices quantitatively

How Herbivores Optimise Diet Quality and Intake in Heterogeneous Pastures, and the Consequences for Vegetation Dynamics

Understanding the interplay between foraging behaviour and vegetation dynamics in heterogeneous pasture is an essential requirement for evaluating the value of the resource for large herbivores and for managing that resource. The orientation of selective grazing behaviour between intake and diet quality depends on the spatial and temporal scales considered. In the short-term scale of a grazing sequence, there is evidence that large herbivores tend to optimise the intake rate of digestible materials by adaptation of their biting behaviour and by patch choice. On a day-to-day scale, there is evidence that large herbivores tend to prioritise the quality of the diet to minimise digestive constraints within the time that they can spend grazing. On a pasture scale, the search for areas giving the best trade-off between quantity and quality of intake leads to the optimisation of their foraging paths, in particular by modulating their sinuosity in response to heterogeneity. Repeated grazing of preferred patches creates a positive feedback on forage quality and enhances heterogeneity. Long-term consequences on vegetation dynamics, botanic composition and grassland quality are less understood

Phytochemicals in Animal Health; diet selection and trade-offs between costs and benefits

Many plant tissues contain plant secondary compounds (PSC), which have long been recognised as defensive chemicals that deter herbivory via their toxic effects. However, herbivores may also benefit from including PSC into their diets. Plant-derived phenolics, terpenes and alkaloids have antiparasitic properties and sesquiterpene lactones have antibacterial, antifungal and antiparasitic properties. These actions are in part a consequence of the negative actions that PSC exert across several trophic levels, including the bacteria, parasites and fungi that inhabit herbivores’ bodies. Given the dual action, toxin and medicine, it is possible to hypothesise that self-selection of PSC by herbivores should occur when the benefits outweigh the costs of PSC ingestion. Recent research suggests that sheep and goats self-medicate against parasitic infections. They increase preference for condensed tannin-containing foods when experiencing a parasitic burden. This behaviour improves health; it is triggered by parasitism and weakens when parasitism subsides. However, the causes underlying these responses are not straightforward when viewed under a unidimensional cost–benefit analysis. This is because the intensity of antinutritional/toxic and medicinal effects of PSC is not static or just dependent upon the isolated post-ingestive effects of single PSC. Nutrient–PSC and PSC–PSC interactions, social models, as well as feeding patterns, all influence the perceived net benefit of incorporating medicines into a diet. A better understanding of the net benefit of self-medication in complex feeding environments will allow for the development of innovative managing strategies aimed at providing the food alternatives and conditions for improving the nutrition, health and welfare of grazing animals. Copyright © The Authors 201

CARACTERIZAÇÃO MORFOLÓGICA DE Fusarium spp. DO FEIJÃO FAVA E CONTROLE BIOLÓGICO VIA SEMENTES-PLÂNTULAS

The management of plant diseases should take into account the etiology of the causal agent for the selection of appropriate practices. Currently, the main form of pathogen control in plants is through chemical control, causing concern, offering human health risks and the environment. Therefore, the objective of the work is to identify the biological interactions between antagonist and pathogen, as well as to develop effective strategies for control of rot and fusarium wilt in bean culture. Two isolates of Trichoderma spp. derived from the Mycological Collection of LAFIT, and ten isolates of Fusarium spp. seeds of bean. Bean bean seeds obtained from cultivated areas in the municipalities of Remígio, Alagoa Grande and Campina Grande, in the state of Paraíba. In vitro tests of direct comparison and volatile compounds between the antagonist and the pathogen were carried out. All isolates showed antagonism in vitro against the pathogen. Considering the growth promoter characteristics of Trichoderma, for the evaluation of the physiological quality, in the concentrations of 1,5; 2.0; 2.5 and 3.0 x 10 8 conidia / ml -1 of the antagonist when analyzing the interference in the germination and vigor of fava bean seeds. The Trichodel® isolate presented the highest normal seedling lengths. After inoculation, it was possible to observe symptoms of necrosis in the primary root and vascular dimming at 21 days. For the characterization, a total of 10 isolates were described morphologically in the BDA and SNA media, presenting a wide morphological variability.O manejo de doenças de plantas deve levar em consideração a etiologia do agente causal para a seleção de práticas adequadas. Atualmente, a principal forma de controle de patógenos em plantas é através do controle químico, causando preocupação, oferecendo riscos de saúde do homem e o meio ambiente. Portanto, o objetivo do trabalho é de identificar as interações biológicas entre antagonista e patógeno, bem como desenvolver estratégias eficazes para controle da podridão e murcha-de-fusarium na cultura do feijão fava. Foram selecionados dois isolados de Trichoderma spp. derivados da Coleção Micológica do LAFIT, e dez isolados de Fusarium spp. oriundos de sementes de feijão fava. As sementes de feijão fava foram obtidas em áreas de cultivo, nos municípios de Remígio, Alagoa Grande e Campina Grande, do estado da Paraíba. Foram realizados testes in vitro de confronto direto e compostos voláteis entre o antagonista e o patógeno. Todos os isolados apresentaram antagonismo in vitro contra o patógeno. Tendo em vista as características de promotor de crescimento do Trichoderma, para a avaliação da qualidade fisiológica, nas concentrações de 1,5; 2,0; 2,5 e 3,0 x 10 8 conídios/ml -1 do antagonista ao analisar a interferência na germinação e vigor das sementes de feijão fava. O isolado Trichodel® apresentou os maiores comprimentos de plântulas normais. Após a inoculação, foi possível observar sintomas de necrose na raiz primária e escurecimento vascular aos 21 dias. Para a caracterização, um total de 10 isolados foram descritos morfologicamente nos meios BDA e SNA, apresentando uma ampla variabilidade morfológica

Agora que a Titi se foi

Going through several decades, “Now that Titi is gone” articulates complex temporalities related to the protagonist’s life, her family and Argentine history. In the 60s, it presents the childhood of the woman mentioned in the title ”“ and several times named in the short story ”“ and her sister who is the narrator we don’t get to know the name. Thereafter, the youth of these sisters is portrayed during the most brutal period of the Argentine military dictatorship. Finally, the bewildering discovery of adulthood is narrated in a context where many of the characters are gone, but their ghosts insist on being present.Condensando várias décadas, “Agora que a Titi se foi” articula complexos jogos temporais em relação à vida da protagonista, da sua família e da história argentina. Inicialmente, nos anos 60, vislumbra-se a infância de duas mulheres: “Titi”, presente no título e nomeada recorrentemente nas páginas do conto, e sua irmã, a narradora que não chegamos a conhecer o nome. Em seguida, tendo como pano de fundo os anos de maior violência da ditadura argentina, ambas são retratadas em plena adolescência. Por fim, relata-se a desconcertante descoberta da maturidade num cenário em que muitos dos personagens se foram, mas cujos fantasmas insistem em aparecer

Teoria cinetica para misturas de gases neutros e ionizados - um metodo alternativo

Orientador: Gilberto Medeiros KremerDissertação (mestrado) - Universidade Federal do Parana, Setor de Ciencias ExatasResumo: E desenvolvida neste trabalho uma teoria cinética para uma mistura de gases monoatômicos baseada num método alternativo que combina características dos métodos de Chapman-Enskog e Grad, simplificando-os. A partir dele são obtidas as equações constitutivas (leis de Fick, Navier-Stokes e Fourier) para uma teoria linearizada juntamente com aproximações sucessivas para os coeficientes de transporte. O método e aplicado primeiramente para uma mistura de gases neutros e em seguida para uma mistura de gases ionizados. Em ambos os casos são verificadas as relações de reciprocidade de Onsager.Abstract: Based on an alternative method that combines and simplifies the features of the Chapman-Enskog and the Grad methods, a kinetic theory for monatomic gas mixtures is developed. The constitutive equations (laws of Fick, Navier-Stokes and Fourier) and the sucessive approximations to the transport coefficients are obteined for a linearized theory. Neutral gas mixtures and ionized gas mixtures are analyzed within the framework of this method. In both cases the Onsager reciprocal relations are verified

Da prática da separação do lixo : estudo de caso sobre as representações sociais do lixo entre os participantes do programa câmbio verde em um bairro de Curitiba

Orientador: Márcio de OliveiraDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Humanas, Letras e Artes, Programa de Pós-Graduação em Sociologia. Defesa: Curitiba, 2003Inclui bibliografiaResumo: Análise das práticas estabelecidas cm relação ao lixo pelos moradores do Bairro São tíraz, situado em Curitiba, capital do estado do Paraná, atendidos por um programa municipal de coleta seletiva conhecido como "Câmbio Verde", Tendo como pano de tundo o referencial teórico das Representações Sociais, o objetivo do trabalho é verificai' em que medida a participação no referido programa tem contribuído para alterar e / ou criar novos significados atribuídos à prática da separação do lixo. Mais especificamente, procura-se verificar em que extensão o programa tem possibilitado algum tipo de reflexão sobre a temática ambiental entre os moradores que dele se utilizam. Discorre sobre o lixo e suas práticas correlatas como objetos dotados de significados construídos socialmente. Apresenta um breve quadro elativo ao gerenciamento do lixo no Brasil, procurando refletir sobre a repercussão expressivamente positiva que os programas de coleta seletiva elaborados pela Prefeitura Municipal ue Curitiba vêm recebendo. Apóia-se em levantamento qualitativo obtido através de entrevistas com dezessete moradores do Bairro São Braz, constatando que a prática da separação do lixo está prioritariamente vinculada a significados econômicos c sanitários que se sobrepõem à reflexão sobre a temática ambiental.Abstract: This essay analyses the practices related to garbage handling and separation among people from a suburb of Curitiba, the state capital of Paraná. It refers to a municipal program seeking the selective collection of garbage, called "Câmbio Verde". This work uses the Social Representation Theory as a reference, and its main purpose is to verify in which extent popular participation in the program mentioned above contributes to change and / or to create new meanings to the garbage separation practice. Special attention is paid whether the program helps to promote any kind of reflection concerning the environment. It also analyses garbage handling and separation practices as objects which meanings are socially constructed. It shows a short description of garbage management in Brazil and searches for clues to comprehend the national and international positive repercussion of Curitiba's local government programs. Qualitative data based on seventeen interviews indicates that garbage separation practice is mainly related to economic and anitary issues rather than to a reflection concerning the environment