RESUMO
Earphones (EP) are a worldwide, massively adopted product, assumed to be innocuous provided the recommendations on sound doses limits are followed. Nevertheless, sound is not the only physical stimulus that derives from EP use, since they include a built-in permanent magnet from which a static magnetic field (SMF) originates. We performed 2D maps of the SMF at several distances from 6 models of in-ear EP, showing that they produce an exposure that spans from ca. 20 mT on their surface down to tens of µT in the inner ear. The numerous reports of bioeffects elicited by SMF in that range of intensities (applied both acutely and chronically), together with the fact that there is no scientific consensus over the possible mechanisms of interaction with living tissues, suggest that caution could be recommendable. In addition, more research is warranted on the possible effects of the combination of SMF with extremely low frequency and radiofrequency fields, which has so far been scarcely studied. Overall, while several open questions about bioeffects of SMF remain to be addressed by the scientific community, we find sensible to suggest that the use of air-tube earphones is probably the more conservative, cautious choice.
Assuntos
Campos MagnéticosRESUMO
The authors highlight the importance of trade in dairy products in South America and throughout the world, and discuss the problem of restrictions engendered by foot and mouth disease (FMD) on exports to countries free from the disease. The epidemiological features of the disease and properties of the causal agent are described in relation to the dairy industry, with special reference to survival of the virus. Discussion then focuses on the risk of foot and mouth disease in relation to the effects the disease has on animal production before and after milking and the industrial processing of dairy products. Finally, the authors review progress achieved in FMD control and eradication programmes in Latin America, particularly in the southern sector where countries such as Chile and Uruguay are free from the disease, while in other countries (such as Argentina, Paraguay and parts of southern Brazil) no case has been reported for more than two years. It is concluded that dairy products can be exported from the region without creating a risk to animal health, provided that there has been proper risk analysis, according to the clearly defined regionalization criteria.
Assuntos
Laticínios/virologia , Microbiologia de Alimentos , Febre Aftosa/transmissão , Leite/virologia , Animais , Bovinos , Manipulação de Alimentos , Febre Aftosa/epidemiologia , Fatores de Risco , América do Sul/epidemiologia , Meios de TransporteRESUMO
OBJECTIVE: To assess the potential of a highly sensitive enzyme-linked immunoelectrotransfer blot (EITB) assay to monitor persistent foot-and-mouth disease (FMD) viral activity in a livestock population. DESIGN: Cattle sera were obtained in Uruguay in 1992, 2 years after the last outbreaks of FMD. Prevalence of antibodies, as assessed by the EITB assay and by the conventional immunodiffusion in agarose gel method (virus infection-associated antigen [VIAA] test), was correlated with occurrence of FMD. SAMPLE POPULATION: A total of 2,194 serum samples were acquired from animals at different farms and were separated according to age: animals < and > 2 years old. PROCEDURE: Specific antibodies to replicating virus were detected by use of the EITB assay that utilizes a set of 5 bioengineered nonstructural antigens as serologic probes. RESULTS: EITB-positive reaction was restricted to sera from cattle in areas with the last outbreaks of FMD during 1989-1990, and to animals > 2 years old. All cattle sera from regions that were free of clinical FMD since (or prior to) 1989 were EITB negative. In contrast, use of the VIAA test yielded a rather homogeneous distribution of positive results when regions without FMD during the last 4 years preceding sample collection were compared with those affected during 1989-1990. VIAA test-positive reaction was also found in sera from animals born after the last FMD outbreak. CONCLUSIONS: The EITB assay proved to be a sensitive, specific, safe, rapid, and economic tool for monitoring the progress of FMD eradication programs, mainly because it eliminated false-positive results form the VIAA test.
Assuntos
Aphthovirus/isolamento & purificação , Febre Aftosa/epidemiologia , Animais , Anticorpos Antivirais/sangue , Especificidade de Anticorpos , Aphthovirus/imunologia , Aphthovirus/fisiologia , Bovinos , Surtos de Doenças/veterinária , Ensaio de Imunoadsorção Enzimática/métodos , Geografia , Uruguai/epidemiologia , Proteínas não Estruturais Virais/imunologia , Replicação ViralRESUMO
Se estudió la persistencia de anticuerpos anti-VIAA en bovinos inmunizados con diferentes vacunas antiaftosa oleosas de uso comercial, utilizadas en la República Oriental del Uruguay. Se procesaron 726 sueros de estos animales mediante la técnica de inmunodifusión en gel de agar con antígeno VIA. Se encontró que la detección de anticuerpos anti-VIAA persitió por más de 171 días en animales inmunizados con vacunas de antigeno concentrado con hidróxido de aluminio
Assuntos
Bovinos , Hidróxido de Alumínio , Anticorpos Antivirais , Antígenos Virais , Aphthovirus , Eletroforese em Gel de Ágar , Febre Aftosa , Imunodifusão , VacinasRESUMO
En ecosistemas libres de fiebre aftosa, la "gestión de riesgo" es una actividad prioritaria para mantener el estado logrado. Este logro debe estar sustentado por una sólida estructura de provención que tenga la participación activa de todos los actores sociales. En ese marco, en el Uruguay se realizó un trabajo de microcaracterización para identificar áreas de riesgo de introducción de la fiebre aftosa, utilizando la estructura político-administrativa y el sistema de referencia nacional, pra aportar a los servicios veterinarios un diagnóstico de situación pra la prevención de la enfermedad.Se realizó una encuesta en cada seccional policial y se mapeó el país de acuerdo con el análisis de conglomerados,identificandose áreas de riesgo
Assuntos
Ecossistema , Febre Aftosa , Delimitação das Áreas de RiscoRESUMO
Se presentan los resultados de las sospechas de fiebre aftosa atendidas por los servicios veterinarios de Uruguay en el período 1992-1994. El número atendido fue de 99, correspondiendo un 28 por cento de los diagnósticos a diarrea viral bovina y fotosensibilización, 26 por cento a rinotraqueitis infecciosa bovina, fiebre catarral y pododermitis, y un 4 por cento a intoxicaciones por Clavaria sp. y/o Romaria. Los diagnósticos se fundamentaron en el análisis clínico, epidemiológico, anatomopatológico y de laboratorio. El tiempo de reacción entre el aviso de la sospecha al servicio oficial y la atención de la misma en promedio fue de 4 a 6 horas