The coincidence of thrips and dispersed pollen in PNRSV-infected stonefruit orchards - a precondition for thrips-mediated transmission via infected pollen

Recent laboratory studies have demonstrated that Prunus necrotic ringspot virus (PNRSV) (family Bromoviridae) can be readily transmitted when thrips and virus-bearing pollen are placed together on to test plants. For this transmission mechanism to result in stonefruit tree infection in the field, PNRSV-bearing pollen must be deposited onto surfaces of stonefruit trees on which thrips also occur. In a previous paper, we demonstrated that almost all pollen in a PNRSV-infected Japanese plum orchard in southeastern Queensland was deposited onto flowers, whereas few grains occurred on leaves and none on stems. Here, we present results of our investigation of thrips species composition, distribution and abundance on stonefruit trees in the same study area as our previous pollen deposition study. We collected a total of 2010 adult thrips from 13 orchards during the 1989, 1991 and 1992 flowering seasons of which all but 14 were in the suborder Terebrantia. Most (97.4%) terebrantian thrips were of three species, Thrips imaginis, Thrips australis and Thrips tabaci. Thrips tabaci as well as species mixtures that included T imaginis, T australis and T tabaci have been shown to transmit PNRSV via infected pollen in laboratory tests. Adult thrips were frequently collected from flowers but rarely from leaves and never from stems. Large and significant differences in numbers of T imaginis, T australis and T tabaci adults in flowers occurred among orchards and between seasons. No factor was conclusively related to thrips numbers but flowers of late-flowering stonefruit varieties tended to hold more thrips than those of early-flowering varieties. Our results indicate that the common thrips species present on stonefruit trees in the Granite Belt are also ones previously shown to transmit PNRSV via infected pollen in the laboratory and that these thrips are concentrated in stonefruit flowers where most stonefruit pollen is deposited. These results contribute to mounting circumstantial evidence that stonefruit flowers may be inoculated with PNRSV via an interaction of thrips with virus-bearing pollen and that this transmission mechanism may be an important cause of new tree infections in the field.

The rheology of flotation froths

A literature review has highlighted the need to measure flotation froth rheology in order to fully characterise the role of the froth in the flotation process. The initial investigation using a coaxial cylinder viscometer for froth rheology measurement led to the development of a new device employing a vane measuring head. The modified rheometer was used in industrial scale flotation tests at Mt. Isa Copper Concentrator. The measured froth rheograms show a non-Newtonian nature for the flotation froths (pseudoplastic flow). The evidence of the non-Newtonian flow has questioned the validity of application of the Laplace equation in froth motion modelling as used by a number of researchers, since the assumption of irrotational flow is violated. Correlations between the froth rheology and the froth retention time, water hold-up in the froth and concentrate grades have been found. These correlations are independent of air flow rate (test data at various air flow rates fall on one similar trend line). This implies that froth rheology may be used as a lumped parameter for other operating variables in flotation modelling and scale up. (C) 2003 Elsevier Science B.V. All rights reserved.

Slurry flow in mills: grate-pulp lifter discharge systems (Part 2)

Pulp lifters, also known, as pan lifters are an integral part of the majority of autogenous (AG), semi-autogenous (SAG) and grate discharge ball mills. The performance of the pulp lifters in conjunction with grate design determines the ultimate flow capacity of these mills. Although the function of the pulp lifters is simply to transport the slurry passed through the discharge grate into the discharge trunnion, their performance depends on their design as well as that of the grate and operating conditions such as mill speed and charge level. However, little or no work has been reported on the performance of grate-pulp lifter assemblies and in particular the influence of pulp lifter design on slurry transport. Ideally, the discharge rate through a grate-pulp lifter assembly should be equal to the discharge rate through at a given mill hold-up. However, the results obtained have shown that conventional pulp lifter designs cause considerable restrictions to flow resulting in reduced flow capacity. In this second of a two-part series of papers the performance of conventional pulp lifters (radial and spiral designs) is described and is based on extensive test work carried out in a I m diameter pilot SAG mill. (C) 2003 Elsevier Science Ltd. All rights reserved.

Slurry flow in mills: grate-only discharge mechanism (Part-1)

Discharge grates play an important role in determining the performance of autogenous, semi-autogenous and grate discharge ball mills. The flow capacity (grinding capacity) of these mills is strongly influenced by the discharge grate design-open area and position of apertures, as well as the performance of the pulp lifters. As mill sizes have progressively increased and closed-circuiting has become more popular the importance of grate and pulp lifter design has grown. Unfortunately very few studies have concentrated on this aspect of mill performance. To remedy this a series of laboratory and pilot-scale tests were undertaken to study both the performance of grates on their own and in conjunction with pulp lifters. In this first paper of a two-part series the results from the grate-only experiments are presented and discussed, whilst the performance of the grate-pulp-lifter system is covered in the second paper. The results from the grate-only experiments have shown that the build-up of slurry (hold-up) inside the mill starts from the shoulder of the charge, while the toe position of the slurry progressively moves towards the toe of the charge with increasing flowrate. Besides grate design (open area and position of apertures), charge volume and mill speed were also found to have a strong influence on mill hold-up and interact with grate design variables. (C) 2003 Elsevier Science Ltd. All rights reserved.

Do expertise and the degree of perception-action coupling affect natural anticipatory performance?

Two experiments using a temporal occlusion paradigm (the first with expert and novice participants and the second with participants of intermediate skill) were conducted to examine the capability of tennis players to predict the direction of an opponent's service in situ. In both experiments two different response conditions, reflecting differing degrees of perception-action coupling, were employed. In a coupled condition players were required to make a movement-based response identical to that which they would use to hit a return of service in a game situation, whereas in an uncoupled condition a verbal prediction of service direction was required. Experiment 1 provided clear evidence of superior prediction accuracy under the coupled response condition when ball flight was available, plus some limited evidence to suggest that superior prediction accuracy under uncoupled response conditions might hold true if only advance (pre-contact) information was available. Experiment 2 showed the former finding to be a robust one, but was unable to reveal any support for the latter. Experiment 1 also revealed that expert superiority is more apparent for predictions made under natural (coupled) than uncoupled response-mode conditions. Collectively, these findings suggest that different perceptual processes may be in operation in anticipatory tasks which depend on skill level, the type of information presented, and degree of perception-action coupling inherent in the task requirements.

Relationship between flocculation of activated sludge and composition of extracellular polymeric substances

Activated sludge floes are a flocculated mass of microorganisms, extracellular polymeric substances (EPS) and adsorbed organic and inorganic material. The structure of the floes is very heterogeneous and floes with very different properties and morphologies may occur, depending on the conditions in the activated sludge treatment plant and wastewater composition. Present thinking suggests that cations, such as calcium, create cationic bridges with EPS excreted by the bacteria and thereby hold the various floe constituents together. However, due to the complex and heterogeneous nature of activated sludge, the mechanisms have neither been thoroughly investigated nor successfully quantified. A better understanding and description of the biological flocculation process is necessary in order to establish more efficient operational strategies. The main aim of this study was to get a comprehensive and unique insight into the floe properties of activated sludge and to assess the relative impact of chemical and physical parameters. A variety of sludges from full scale treatment plants with different settling properties were characterised. The interrelationships between floe parameters such as composition of EPS, surface properties and floe structure, and their effect on the flocculation and separation properties were assessed. The results indicate that the EPS, both in terms of quantity and quality, are very important for the floe properties of the activated sludge. However, presence of filaments may alter the physical properties of the floes considerably. The EPS showed positive correlations to sludge volume index (SVI) if only sludges with low or moderate numbers of filaments were included. The surface properties were more affected by the composition of the EPS than by the number of filaments. The EPS showed positive correlation to negative surface charge and a negative correlation to relative hydrophobicity and flocculation ability. The negative correlation between flocculation ability and amount of EPS was surprising. The shear sensitivity, measured as degree of erosion of floes when subjected to shear, was more affected by floe size and number of filaments than amount of EPS.

A reforma do Estado, a emerg??ncia da descentraliza????o e as pol??ticas ambientais

No contexto da reforma do Estado brasileiro, a descentraliza????o das compet??ncias pol??ticas e administrativas na arena ambiental tem se mostrado um processo din??mico. Muitas inst??ncias locais j?? respondem pela quest??o ambiental. No entanto, isso n??o significa mais compet??ncia administrativa, sustentabilidade institucional, tampouco participa????o democr??tica. Dois casos de pol??tica ambiental s??o retratados no texto: o licenciamento industrial pelos munic??pios brasileiros e o a gest??o florestal pelo Estado do Mato Grosso. A descentraliza????o do licenciamento ambiental para o ??mbito municipal ainda parece fr??gil em munic??pios menores, em um processo que parece ser induzido pelo Estado e n??o pelo controle social local. Em rela????o ?? pol??tica florestal, o caso do Mato Grosso ?? emblem??tico. Ele mostra que a coopera????o com o poder p??blico federal e, em determinados momentos, sua coordena????o s??o de suma import??ncia para que as pol??ticas p??blicas ambientais n??o fiquem ?? merc?? de governos estaduais, que podem envies??-las em favor do ???desenvolvimentismo???, nem percam a legitimidade adiante da fragilidade financeira e institucional dos ??rg??os ambientais locais.

A educação em cena : a Revista de Educação como circulação de representações sobre saberes educacionais no Espírito Santo (1934-1937)

Este estudo analisa os processos de circulação e apropriação das representações sobre os saberes da educação escolarizada difundidos pela Revista de Educação do Espírito Santo, entre os anos de 1934 e 1937. Como referencial teórico baseamo- nos em Chartier (1990) acerca do conceito de representação, em Balandier (1982) em relação ao conceito de encenação de poder instituído que assume visibilidade quando circula na Revista, concedendo publicização aos feitos políticos realizados por dado grupo social, e em Julia (2001), junto ao conceito de cultura escolar. A partir desse arcabouço teórico, empreendemos metodologia de pesquisa a partir da análise histórica da fonte, dialogando, para tanto, com diferentes documentos e registros que configuram uma série de dados que constituem nossa fonte. Trata-se da análise das representações travadas no debate sobre a formação, divulgação e apropriação do conjunto de práticas e saberes pedagógicos dirigido aos professores, por parte de um grupo de intelectuais locais que se apresentava como portador do projeto de modernização do Espírito Santo inserido no contexto nacional. A Revista de Educação/ES tinha entre seus principais objetivos o de (in)formar os professores, ou seja, enquadrar suas práticas às novas demandas educacionais. Deste modo, a Revista esteve atrelada a um projeto educacional em que os intelectuais corroboravam a ampla circulação de um conjunto de representações sobre a modernidade, utilizando a Revista como suporte, visto que, desde as capas, são expostos “monumentos de modernização”, como os prédios escolares e todo um complexo arranjo de artefatos simbólicos, traduzidos muitas vezes em festas e rituais escolares que evocavam “um novo tempo para a Educação do Estado”, ou seja, fazendo da educação escolarizada um espetáculo.

A recepção adorniana de Freud no estudo da personalidade autoritária

Em geral, a tradição do pensamento metafísico entende que no desenvolvimento histórico da razão há um progresso. A existência do progresso requer o sacrifício do indivíduo ao longo da história. A filosofia de Theodor W. Adorno realiza um exame crítico do processo de esclarecimento vivido no Ocidente. Os estudos de Adorno mostram que a associação entre o “progresso” e o sacrifício da individualidade resulta na barbárie. Deste modo, Adorno evidencia os momentos do irracional conservados na sociedade racionalizada e que ameaçam o processo civilizatório. Neste trabalho, investigamos a influência de Sigmund Freud no pensamento de Adorno. Defendemos que a leitura adorniana de Freud é essencial para a explicação dos fatores subjetivos da personalidade autoritária. No entanto, a razão subjetiva não explica inteiramente os determinantes do caráter autoritário. Por isso, no primeiro capítulo nós apresentamos os pressupostos marxianos da razão objetiva. Além disso, indicamos a relação entre razão objetiva e razão subjetiva. No segundo capítulo, buscamos compreender a teoria de Freud e assinalamos como suas categorias manifestam as condições objetivas assinaladas por Adorno. No terceiro capítulo, examinamos a interpretação marxista realizada por Adorno sobre os determinantes psicológicos que favorecem a manifestação do caráter autoritário. Ao final, nós debatemos os resultados da recepção adorniana de Freud.

A relação entre o nível de evidenciação socioambiental e os fatores da sustentabilidade de empresas do setor elétrico brasileiro

O Relatório Anual de Responsabilidade Socioambiental (RARS) das empresas do Setor Elétrico Brasileiro (SEB) é um importante canal de comunicação entre as organizações e os diversos interessados. O objetivo deste estudo foi verificar a relação entre o Nível de Evidenciação Socioambiental e os Fatores Econômicos, Ambientais e Sociais da Sustentabilidade. A pesquisa classifica-se como quantitativa-descritiva, cuja coleta de dados apresenta-se como análise documental. A análise foi realizada em 108 empresas concessionárias de energia elétrica que publicaram o RARS no ano de 2012. O primeiro resultado relevante foi à validação mediante o teste Alpha de Crombach dos índices utilizados para medir o Nível de Evidenciação Socioambiental das empresas pesquisadas. Em seguida identificou-se que as empresas evidenciaram mais indicadores sociais que ambientais, e que algumas empresas ainda enquadram-se nos níveis “Regular e Baixo” de evidenciação socioambiental, o que reforça a tese que somente por meio de regulação, as empresas realizarão divulgações completas. Em relação às principais práticas de evidenciação socioambiental, constatou-se que estão voltadas a publicitar as políticas socioambientais desenvolvidas pelas empresas, e as interações socioambientais negativas são pouco evidenciadas pelas empresas. Em relação à investigação principal da pesquisa, foi constatada uma relação positiva e significativa entre o Nível de Evidenciação Ambiental, Social e Socioambiental e Fatores Econômicos da Sustentabilidade, e entre Nível de Evidenciação Social e Fatores Sociais da Sustentabilidade. E que a Pressão dos Stakeholders é relacionada positivamente e significativamente com o Nível de Evidenciação Socioambiental.

Economic sanctions and human rights: an analysis of competing enforcement strategies in Latin America

This article addresses the consequences of economic sanctions for the protection of human rights in Latin America. The literature on sanctions and compliance informs three hypotheses, which investigate the relationship between sanctions and the level of rights protection in two groups of countries: those that were targeted by sanctions and those that were not. Using data from the Political Terror Scale (PTS) and from Freedom House, I find empirical evidence that sanctions do improve the level of protection in countries that were not targeted. This finding can be explained by the deterrent effect attributed to sanctions by the compliance literature, broadly interpreted. The presence of economic sanctions in a given year increases the probability of observing better human rights practices by almost 50%. These results hold for the 12 Latin American countries that were not subject to economic sanctions for the period 1976-2004.

UN Security Council decision-making: testing the bribery hypothesis

Liberal-Institutionalism and Structural Realism expectations about international organizations are confronted by looking at if and how US-controlled international aid is granted, and particularly if it is related or not to political affinity and to United Nations Security Council (UNSC) non-permanent membership. A preliminary assessment suggests that these relations only hold for the period of the Cold War, and, even then, only when UNSC non-permanent membership is in years in which the Security Council was deemed very important.

Peripheral Realism Revisited

Abstract In this article we summarize the precepts of Peripheral Realism, its place in the intellectual history of International Relations Theory, its contributions to interpreting Latin American international politics and its insights for the future. After revising the intellectual merits and tenets of the theory in the four initial sections, we show how it predicted the behavior of Latin American states under unipolarity. Finally, we review its implications for a world where China may hold economic primacy.

Factores explicativos da divulgação de informação sobre instrumentos derivados: evidência empírica no mercado de capitais português, em 2008

This study analyses the determinants of the derivative instruments disclosure level by Portuguese listed companies. It is built a disclosure index to measure the disclosure level using the Consolidated Annual Reports for 2008. The hypotheses have been tested through a linear regression model using the disclosure index as the dependent variable and companies’ characteristics as independent variables. Multivariate results suggest that firm size, quality of the external auditor, belonging to PSI 20, the market to book value ratio and the percentage of capital hold by the board of directors are associated with the disclosure level.

Aprendizagem Cooperativa : um contributo para a diferenciação pedagógica inclusiva

A dissertação incidiu na diferenciação pedagógica inclusiva, especificamente, num grupo/turma com diferentes anos de escolaridade, com aprendizagens diferentes, e alunos com Necessidades Educativas Especiais (NEE) de índole comportamental e cognitivo, tendo como objectivo constituir alternativa ao problema. As professoras titulares de turma e de educação especial, em cooperação, planificaram e implementaram este estudo, cujo ponto de partida consistia em promover o desenvolvimento pessoal e social, tendo por base um livro pertencente ao Plano Nacional de Leitura (PNL). Foram desenvolvidas estruturas cooperativas de forma a melhorar comportamentos e aprendizagens em todos os alunos e em especial dos alunos com NEE. Neste processo de observação e reflexão, a experiência foi conceptualizada e analisada com o objectivo de contribuir para a mudança. A análise de dados do trabalho individual e de grupo dos alunos, onde se inferiu uma maior ajuda, autonomia, responsabilidade, envolvimento e interesse, pelas actividades, permitiu-nos verificar que os objectivos foram alcançados na sua maioria O estudo permitiu evidenciar a diminuição de conflitos comportamentais, contribuindo para um clima de entreajuda englobando todos os alunos, onde a partilha de conhecimentos coadjuvou para melhorar as aprendizagens de todos.