Ultrastructural observation of the airways of recovered and susceptible pigs after inoculation with Mycoplasma hyopneumoniae

To determine the morphological differences in the epithelium of the airways of recovered and susceptible pigs after Mycoplasma hyopneumoniae challenge, twenty-four 4-week-old M. hyopneumoniae-free pigs were intratracheally inoculated with 107ccu/ml of a pure low-passaged culture of the P5722-3 strain of M. hyopneumoniae challenge material. Eight pigs (group I) were challenged at the beginning of the experiment and rechallenged 3 months later. Group II pigs were also challenged at the beginning of the experiment and necropsied 3 months later. Group III pigs were challenged at the same time as the rechallenge of group I pigs. Eight nonchallenged pigs served as controls (group IV). Three days after the second challenge of group I and the first challenge of group III, and every 3 and 4 days thereafter, two pigs from each group were euthanatized by electrocution and necropsied. Samples of bronchi and lung tissue were examined using light and electron microscopy (SEM and TEM). Macroscopic lesions were observed in the lungs of all group III pigs (average = 4.74%) and were characterized by purple-red areas of discoloration and increased firmness affecting the cranioventral aspect of the lungs. Macroscopic lesions of pneumonia in groups I and II were minimal (less than 1%). There were no gross lesions of pneumonia in control (group IV) pigs. Microscopic lesions were characterized by hyperplasia of the peribronchial lymphoid tissue and mild neutrophilic infiltrates in alveoli. Electron microscopy showed patchy areas with loss of cilia and presence of leukocytes and mycoplasmas in bronchi of susceptible pigs (group III). The bronchial epithelium of rechallenged (group I), recovered (group II), and control (group IV) pigs was ultrastructurally similar indicating recovery of the former two groups. Although mycoplasmas were seen among cilia, a second challenge on pigs of group I did not produce another episode of the disease nor did it enhance morphological changes, suggesting that those pigs could become carriers of M. hyopneumoniae.

Economic viability of the third milking in systems of production using closed-circuit mechanical milking

This study aimed to analyze the economic viability of the third milking in production systems using mechanical milking in a closed circuit, aiming to provide technicians and farmers with information to assist them in decision-making. Specifically, it intended: (a) to estimate the cost of one milking; (b) to estimate the cost of the third milking; (c) to develop a mathematical equation to estimate the minimum amount of milk produced with two milkings, from which it would be economically feasible to do the third milking. Data were collected from three dairy farms, from November 2010 to March 2011, keeping a twice-a-day milking frequency, with three data collections in each farm, totalizing nine collections. Considering the average data, it would be feasible to do the third milking if the average milk yield per day of lactating cows in a twice-a-day milking frequency was greater than or equal to 24.43 kg of milk.

O modelo de precificação de ativos de capital: teoria e evidências

Distante quatro décadas de seu aparecimento, o modelo de precificação de ativos de capital proposto pelo Nobel William Sharpe e por John Lintner, conhecido como CAPM, é ainda o modelo mais amplamente utilizado na estimativa do custo de capital de empresas e na avaliação de carteiras. O fato se deve às poderosas previsões permitidas pelo modelo sobre a medida do risco e a relação entre risco e retorno. O objetivo deste artigo é mostrar que o CAPM apresenta algumas falhas empíricas associadas a simplifi cações teóricas e difi culdades de implementação de testes que sejam válidos para o modelo. A conclusão do artigo é que as limitações do CAPM representam desafi os a serem explicados por modelos alternativos.

Análise da informação em saúde: 1893-1993, cem anos da Classificação Internacional de Doenças

A análise da mortalidade por causas, bem como da morbidade, necessita de um instrumento que agrupe as doenças segundo características comuns, isto é, uma classificação de doenças. Atualmente está em uso a Classificação Internacional de Doenças da OMS, na sua Nona Revisão. Esta classificação surgiu em 1893; para 1993 está proposta a implantação da Décima Revisão. O trabalho descreve as raízes de uma classificação internacional, fazendo referências a John Graunt, William Farr e Jacques Bertillon bem como à evolução pela qual passou em suas sucessivas revisões. Inicialmente era uma classificação de causas de morte passando a ser, a partir da Sexta Revisão, uma classificação que incluiu todas as doenças e motivos de consultas, possibilitando seu uso em morbidade, sendo que a partir da Décima Revisão se propõe uma "família" de classificações, para os mais diversos usos em administração de serviços de saúde e epidemiologia. O trabalho também apresenta algumas críticas que são feitas à Classificação Internacional de Doenças.

Ten years experience with Jorge Lobo's disease in the state of Acre, Amazon region, Brazil

Jorge Lobo's disease is a cutaneous and subcutaneous mycosis that affects patients in the Amazon region. The number of patients is relatively small, but the real situation of the disease as public health problem is not known, because Jorge Lobo's disease is not a notifiable disease. This study aims to report the clinical evolution in patients affected and to determine the prevalence and areas of occurrence of the disease. A retrospective study was carried out based on the analysis of the clinical records, which included a collection of photographs of patients in the Department of Sanitary Dermatology, in Rio Branco, and patients seen in the interior of the state. In a decade, in Rio Branco, 249 cases of the disease were reported, 30 were females and 219 males. Of these patients, 153 had localized lesions, 94 of them were on one ear, 55 had multifocal lesions and 41 had disseminated lesions. The average time between the onset of symptoms and diagnosis was 19 years. The average age at the time of diagnosis was 53 years, and ages ranged from 14 to 96 years.

Técnicas avançadas de sensoriamento remoto aplicadas ao estudo de mudanças climáticas e ao funcionamento dos ecossistemas amazônicos

Este artigo se propõe a apresentar exemplos de questões científicas que puderam ser respondidas no contexto do Projeto LBA (Large Sale Biosphere-Atmosphere Experiment in Amazonia) graças à contribuição de informações derivadas de sensoriamento remoto. Os métodos de sensoriamento remoto permitem integrar informações sobre os vários processos físicos e biológicos em diferentes escalas de tempo e espaço. Nesse artigo, são enfatizados aqueles avanços de conhecimento que jamais seriam alcançados sem a concorrência da informação derivada de sensoriamento.