Assessing forest fire as a potential PCDD/F source in Queensland, Australia

Forest fires are suggested as a potential and significant source of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), even though no studies to date provide sufficient evidence to confirm forest fires as a source of PCDD/Fs. Recent investigations in Gueensland, Australia have identified a widespread contamination of PCDDs (in particular OND) in soils and sediments in the coastal region from an unknown source of PCDD/Fs. Queensland is predominately rural; it has few known anthropogenic sources of PCDD/Fs, whereas forest fires are a frequent occurrence. This study was conducted to assess forest fires as a potential source of the unknown PCDD/F contamination in Queensland. A combustion experiment was designed to assess the overall mass of PCDD/Fs before and after a simulated forest fire. The results from this study did not identify an increase in Sigma-PCDD/Fs or OCDD after the combustion process. However, specific non-2,3,7,8 substituted lower chlorinated PCDD/Fs were elevated after the combustion process, suggesting formation from a precursor. The results from this study indicate that forest fires are unlikely to be the source of the unknown PCDD contamination in Gueensland, rather they are a key mechanism for the redistribution of PCDD/Fs from existing sources and precursors.

Combining nonthermal technologies to control foodborne microorganisms

Novel nonthermal processes, such as high hydrostatic pressure (HHP), pulsed electric fields (PEFs), ionizing radiation and ultrasonication, are able to inactivate microorganisms at ambient or sublethal temperatures. Many of these processes require very high treatment intensities, however, to achieve adequate microbial destruction in low-acid foods. Combining nonthermal processes with conventional preservation methods enhances their antimicrobial effect so that lower process intensities can be used. Combining two or more nonthermal processes can also enhance microbial inactivation and allow the use of lower individual treatment intensities. For conventional preservation treatments, optimal microbial control is achieved through the hurdle concept, with synergistic effects resulting from different components of the microbial cell being targeted simultaneously. The mechanisms of inactivation by nonthermal processes are still unclear; thus, the bases of synergistic combinations remain speculative. This paper reviews literature on the antimicrobial efficiencies of nonthermal processes combined with conventional and novel nonthermal technologies. Where possible, the proposed mechanisms of synergy is mentioned. (C) 2003 Elsevier Science B.V. All rights reserved.

A role for pectin in the control of cell expansion

Uptake of nutrients and water depends on the growth of roots through elongation of individual cells near the. root tip. Many of the numerous components of Type I primary cell walls, those of dicotyledons and monocotyledons other than grasses (Poaceae), have been determined, and many hypotheses have been proposed for the control of cell expansion. This important aspect of plant growth still needs elucidation, however. A model is proposed in which pectin, which occurs as a calcium (Ca) pectate gel between the load-bearing cellulose microfibrils and xyloglucan (XG) chains, controls the rate at which cells expand. It is considered that the increasing tension generated by the expanding cell is transmitted to interlocked XG chains and cellulose microfibrils. The resulting deformation of the embedded Ca pectate gel elicits the excretion of protons from the cytoplasm, possibly via compounds such as cell wall-associated kinases, that weakens the Ca pectate gel, permitting slippage of XG molecules through the action of expansin. Further slippage is prevented by deformation of the pectic gel, proton diffusion, and the transfer of residual tension to adjacent XG chains. Evidence for this model is based on the effects of pH, Ca, and aluminum (Al) on root elongation and on the reactions of these cations with Ca pectate. This model allows for genetic selection of plants and adaptation of individual plants to root environmental conditions.

Digitally-implemented naturally sampled PWM suitable for multilevel converter control

For dynamic closed loop control of a multilevel converter with a low pulse number (ratio of switching frequency to synthesized fundamental), natural sampled pulse-width modulation (PWM) is the best form of modulation. Natural sampling does not introduce distortion or a delayed response to the modulating signal. However previous natural sampled PWM implementations have generally been analog. For a modular multilevel converter, a digital implementation has advantages of accuracy and flexibility. Re-sampled uniform PWM is a novel digital modulation technique which approaches the performance of natural PWM. Both hardware and software implementations for a five level multilevel converter phase are presented, demonstrating the improvement over uniform PWM.

O patrimônio arquitetônico da saúde : discussões sobre a história da arquitetura hospitalar do século XIX

O Patrimônio Cultural da Saúde consiste nos bens materiais e imateriais que expressam o processo da saúde individual e coletiva nas suas dimensões científica, histórica e cultural. Com a inserção do Brasil, através da COC-Fiocruz e do Ministério da Saúde, na Rede Latino-americana de Patrimônio Cultural da Saúde, iniciou-se o incentivo ao estudo da história da medicina e da arquitetura hospitalar, buscando também a proteção e a salvaguarda da memória das edificações hospitalares históricas. O século XIX foi marcado pela construção de várias edificações voltadas para o controle e reclusão dos pobres, essas instituições eram: a Casa de Correção, a Santa Casa da Misericórdia, o Hospício de Pedro II, o Asilo da Mendicidade e as Instituições de acolhimento de Menores. Dessas edificações destacam-se a Santa Casa da Misericórdia, o Hospício de Pedro II e o Asilo da Mendicidade que formam o Patrimônio Arquitetônico da Saúde tombado em nível federal. O Hospital da Santa Casa da Misericórdia foi construído em 1840-1852 sob os modernos preceitos da medicina do século XIX. A edificação até hoje mantém o uso hospitalar e apresenta um estado de conservação bom em seu exterior. Porém as condições internas foram consideradas ruins devido à falta de salubridade e higiene nos ambientes. O Hospital da Santa Casa é um Hospital de Referência, realiza atendimentos ambulatoriais, cirúrgicos e de internação. O Hospício de Pedro II foi criado para atender exclusivamente os alienados do Império. O estilo neoclássico e a monumentalidade da edificação o fizeram ser reconhecido como Palácio dos Loucos. O hospício funcionou até 1944 e quatro anos depois a edificação foi cedida à Universidade do Brasil, que adaptou sua arquitetura ao uso educacional. A edificação apresenta estado de conservação regular, com exceção da área central composta pela Capela que está ruim, devido ao incêndio de 2011. O Palácio dos Loucos tornou-se Palácio Universitário, modificando sua identidade através das mudanças que foram feitas em sua arquitetura. O Asilo da Mendicidade foi criado em 1876 para fechar o pentágono asilar. A edificação panóptica buscava a efetiva observação e controle dos internos. A edificação funcionou como Asilo para mendigos até 1920, quando transformou-se em Hospital de São Francisco de Assis. Posteriormente o hospital seria transferido para a Universidade do Brasil, que funcionou como hospital escola até 1978. O Hospital foi desativado e ficou sem uso por dez anos, quando enfim voltou a funcionar como um estabelecimento destinado aos mais pobres. O conjunto da edificação é o que apresenta o pior estado de conservação, considerado de ruim a péssimo. Comprovou-se com essa pesquisa que o mais importante para a preservação das características arquitetônicas e artísticas do bem é a manutenção do uso, seja ele qual for. Os novos usos devem ser adequados também às características e à capacidade da arquitetura em questão. Através de reformas e planos adequados, os hospitais oitocentistas, que hoje se apresentam como Patrimônio Arquitetônico da Saúde, podem manter um uso similar para o qual foi construído, como uma edificação voltada à promoção da saúde da população.

Chemical treatment of papaya seeds aiming at long-term storage and control of damping off

Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

Automation & control remote laboratory: evaluating a cooperative methodology

This paper presents a study carried out in order to evaluate the students' perception in the development and use of remote Control and Automation education kits developed by two Universities. Three projects, based on real world environments, were implemented, being local and remotely operated. Students implemented the kits using the theoretical and practical knowledge, being the teachers a catalyst in the learning process. When kits were operational, end-user students got acquainted to the kits in the course curricula units. It is the author's believe that successful results were achieved not only in the learning progress on the Automation and Control fields (hard skills) but also on the development of the students soft skills, leading to encouraging and rewarding goals, motivating their future decisions and promoting synergies in their work. The design of learning experimental kits by students, under teacher supervision, for future use in course curricula by enduser students is an advantageous and rewarding experience.

Silicon in plant disease control

All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si) is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.

Postharvest biological control of brown rot in peaches after cold storage preceded by preharvest chemical control 1

ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole) associated with postharvest application of T. harzianum, after cold storage (with and without application), in three evaluation times (zero, two and four days at 20 °C), resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.

Locus de Control y Ira

La ira se ha relacionado con atribuciones externas en distintos modelos atribucionales, sin embargo, desde los planteamientos de la teoría del “locus de control” (Rotter, 1966) la respuesta emocional de ira no ha sido objeto de estudio con la frecuencia que sería deseable (aunque sí la conducta agresiva). El presente trabajo explora las relaciones del locus de control externo con la emoción de ira, así como con la expresión y control de la misma. Para ello se utilizó una muestra de 177 estudiantes universitarios (27 hombres y 150 mujeres) a los que se evaluó mediante los instrumentos siguientes: Escala de Rotter (Rotter, 1966, versión española de Pérez García, 1984); el Inventario de Expresión de Ira Estado/Rasgo -STAXI-de Spielberger (1988, 1991), versión española de Spielberger, Miguel-Tobal, Cano-Vindel y Casado, 1992); y el Inventario de Control, Defensa y Expresión de Emociones -CDE-(Cano Vindel y Miguel Tobal, 1996). Se realizó un análisis correlacional entre las distintas escalas de los instrumentos y diferencias de medias para dos grupos extremos (altos y bajos) en locus de control (equiparados en la variable sexo). Nuestros resultados muestran una relación positiva y significativa entre el locus de control externo y la respuesta emocional de ira, así como una tendencia a expresar externamente la ira y a controlarla menos en sujetos con atribuciones de causalidad externas. Conocer los procesos atribucionales asociados a la ira y a su afrontamiento permitirá una intervención más eficaz sobre la misma.

¿Entes de regulación o control? Imprecisiones del "moderno" esquema de regulación: reflexiones y enseñanzas del caso argentino

Este artículo analiza las particularidades del "moderno" esquema de regulación de los servicios públicos de infraestructura, que se extendió a partir de los procesos de privatización del último cuarto del siglo XX. Diferenciándose de la arquitectura institucional vigente durante el período de prestación estatal (regulación "endógena"), los entes reguladores emergen como el elemento neurálgico de este nuevo esquema. Sin embargo, como se desprende de la experiencia argentina, estos organismos han sido dotados de ambiguas atribuciones regulatorias e inapropiados diseños institucionales, quedando trunca su capacidad real de regulación. A raíz de la difusa delimitación de misiones y funciones e - incluso - frente a las imprecisiones teóricas en la materia, este artículo precisa el alcance de la intervención de los distintos actores del sistema de prestación y regulación: empresas prestadoras, entes reguladores, poderes del Estado (Ejecutivo y Legislativo) y usuarios y consumidores. En este sentido, trabaja sobre los diseños institucionales más apropiados para que los entes desarrollen efectivas capacidades de regulación. El análisis se ejemplifica a partir de la experiencia privatizadora argentina - nacional y subnacional - en los servicios de agua potable y saneamiento y distribución de electricidad.