15 research outputs found

    Agronomic Management of Indigenous Mycorrhizas

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    Many of the advantages conferred to plants by arbuscular mycorrhiza (AM) are associated to the ability of AM plants to explore a greater volume of soil through the extraradical mycelium. Sieverding (1991) estimates that for each centimetre of colonized root there is an increase of 15 cm3 on the volume of soil explored, this value can increase to 200 cm3 depending on the circumstances. Due to the enhancement of the volume of soil explored and the ability of the extraradical mycelium to absorb and translocate nutrients to the plant, one of the most obvious and important advantages resulting from mycorrhization is the uptake of nutrients. Among of which the ones that have immobilized forms in soil, such as P, assume particular significance. Besides this, many other benefits are recognized for AM plants (Gupta et al, 2000): water stress alleviation (Augé, 2004; Cho et al, 2006), protection from root pathogens (Graham, 2001), tolerance to toxic heavy metals and phytoremediation (Audet and Charest, 2006; Göhre and Paszkowski, 2006), tolerance to adverse conditions such as very high or low temperature, high salinity (Sannazzaro et al, 2006), high or low pH (Yano and Takaki, 2005) or better performance during transplantation shock (Subhan et al, 1998). The extraradical hyphae also stabilize soil aggregates by both enmeshing soil particles (Miller e Jastrow, 1992) and producing a glycoprotein, golmalin, which may act as a glue-like substance to adhere soil particles together (Wright and Upadhyaya, 1998). Despite the ubiquous distribution of mycorrhizal fungi (Smith and Read, 2000) and only a relative specificity between host plants and fungal isolates (McGonigle and Fitter, 1990), the obligate nature of the symbiosis implies the establishment of a plant propagation system, either under greenhouse conditions or in vitro laboratory propagation. These techniques result in high inoculum production costs, which still remains a serious problem since they are not competitive with production costs of phosphorus fertilizer. Even if farmers understand the significance of sustainable agricultural systems, the reduction of phosphorus inputs by using AM fungal inocula alone cannot be justified except, perhaps, in the case of high value crops (Saioto and Marumoto, 2002). Nurseries, high income horticulture farmers and no-agricultural application such as rehabilitation of degraded or devegetated landscapes are examples of areas where the use of commercial inoculum is current. Another serious problem is quality of commercial available products concerning guarantee of phatogene free content, storage conditions, most effective application methods and what types to use. Besides the information provided by suppliers about its inoculum can be deceiving, as from the usually referred total counts, only a fraction may be effective for a particular plant or in specific soil conditions. Gianinazzi and Vosátka (2004) assume that progress should be made towards registration procedures that stimulate the development of the mycorrhizal industry. Some on-farm inoculum production and application methods have been studied, allowing farmers to produce locally adapted isolates and generate a taxonomically diverse inoculum (Mohandas et al, 2004; Douds et al, 2005). However the inocula produced this way are not readily processed for mechanical application to the fields, being an obstacle to the utilization in large scale agriculture, especially row crops, moreover it would represent an additional mechanical operation with the corresponding economic and soil compaction costs. It is well recognized that inoculation of AM fungi has a potential significance in not only sustainable crop production, but also environmental conservation. However, the status quo of inoculation is far from practical technology that can be widely used in the field. Together a further basic understanding of the biology and diversity of AM fungi is needed (Abbott at al, 1995; Saito and Marumoto, 2002). Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species introductions and the potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. Schwartz et al, (2006) recommend that a careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial. Agricultural practices such as crop rotation, tillage, weed control and fertilizer apllication all produce changes in the chemical, physical and biological soil variables and affect the ecological niches available for occupancy by the soil biota, influencing in different ways the symbiosis performance and consequently the inoculum development, shaping changes and upset balance of native populations. The molecular biology tools developed in the latest years have been very important for our perception of these changes, ensuing awareness of management choice implications in AM development. In this context, for extensive farming systems and regarding environmental and economic costs, the identification of agronomic management practices that allow controlled manipulation of the fungal community and capitalization of AM mutualistic effect making use of local inoculum, seem to be a wise option for mycorrhiza promotion and development of sustainable crop production

    Stavudine effects on rat pregnancy outcome

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    Objective: Stavudine is an inhibitor of HIV reverse transcriptase and acts as a chain terminator during DNA synthesis. the aim of the study presented here was to evaluate the effects of stavudine during rat pregnancy.Methods: Female rats were randomly divided into four treatment groups: GI (treated with the drug vehicle); GII; GIII; and GIV (treated with 1, 3 or 9 mg/kg of stavudine, respectively) (n = 25 pregnant rats for every group). Rats were treated by gavage once daily. the treatment period extended from day 0 until the 20th day of pregnancy. Body weights were recorded weekly during this period. At term, the rats were sacrificed, and the implantation sites and number of fetuses and resorptions were recorded. the fetuses were evaluated for external abnormalities under a stereomicroscope.Results: No differences in body weight gain between the groups were observed. the mean number of implantations per dam in stavudine-treated groups was higher than in the control group (P < 0.05); however, only GIII presented an increase in the mean number of resorptions compared to the other groups (P < 0.01). the resorption/implantation rate was higher in the GII group and lower in the GIV group as compared to the other groups. Neither the mean fetal weights nor the placental weights differed significantly among the groups. No external anomalies were observed at dissection in rat fetuses, placentae or uteri.Conclusion: Rat pregnancy outcome seems to be affected by stavudine, mainly with respect to the mechanisms of intrauterine concept survival.Univ Oeste Paulista, Sch Med, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Med, São Paulo, BrazilWeb of Scienc

    Atenção básica na agenda da saúde Primary care in the agenda of public health sector in Brazil

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    O artigo discute a política de reorganização da atenção básica a partir do processo recente de descentralização do SUS no Brasil. Enfatiza-se o papel indutor do governo central, que, através de um conjunto de medidas e programas específicos (PAB e PACS/PSF, principalmente), transfere para os municípios a responsabilidade com a atenção básica. Assim, é no nível municipal que ocorre o processo de implementação dessa política, gerando efeitos de difícil avaliação, dada a diversidade de contextos locais. A argumentação central enfatiza a importância de se avaliarem processos e resultados intermediários voltados para o desempenho institucional, que podem ser traduzidos em vontade política e compromisso público, capacidade de gestão e maior controle e participação social, mais do que exatamente efeitos ou impactos mais diretos sobre a oferta de serviços. A conclusão é de que apesar de todas as dificuldades e obstáculos o processo tem implicado o fortalecimento da capacidade de gestão municipal no que diz respeito à organização da atenção básica em saúde.<br>The article discusses the policies of reorganization of the primary health care taking the recent process of decentralization of SUS in Brazil. The central government's paper as inducement is emphasized. This can be verified by several measures and specific programs (PAB and PACS/PSF, mainly) that transfer for the municipal level the responsibility with the primary care. So it is in the municipal level that happens the process of implementation of that policies generating effects of difficult evaluation given the diversity of local contexts. The central argument emphasizes the importance of the evaluation process and intermediary results turned to the institutional performance that can be translated in accountability and public commitment, administration capacity and larger control and social participation - rather than final effects or more direct impacts on the offer of services. The conclusion is that in spite of all the difficulties and obstacles the process has strengthening the capacity of municipal administration regarding the organization of the primary health care

    Coliformes em água de abastecimento de lojas fast-food da Região Metropolitana de Recife (PE, Brasil) Coliforms in the water supply of fast-food chains in the Metropolitan Region of Recife, in the state of Pernambuco (Brazil)

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    A garantia do fornecimento de água potável nos serviços de alimentação é uma questão relevante para a saúde pública. Assim, o objetivo deste estudo foi avaliar a qualidade microbiológica da água destinada ao abastecimento de uma rede de lojas fast-food da cidade de Recife (PE) e Região Metropolitana e comparar os resultados aos padrões estabelecidos pela Portaria nº 518/2004 do Ministério da Saúde. Mensalmente, foi analisada uma amostra proveniente de uma das torneiras da área de manipulação das oito lojas investigadas, perfazendo 96 amostras ao longo de um ano, todas coletadas em duplicata. As análises seguiram a metodologia estabelecida na American Public Health Association (APHA) para realização do ensaio presuntivo utilizando o Teste Presença-Ausência, considerando-se o padrão de potabilidade determinado na legislação pertinente. Os resultados revelaram que 11,46% de todas as amostras apresentaram água contaminada por coliformes totais e 1,04% contaminação por coliformes termotolerantes. Conclui-se, portanto, que a qualidade da água disponível nos estabelecimentos produtores de alimentos estudados encontra-se em estado de alerta, uma vez que o percentual significativo das amostras analisadas mostrava-se impróprio para o consumo humano de acordo com a legislação vigente, a qual preconiza ausência de coliformes totais e termotolerantes.<br>A guaranteed supply of clean drinking water in food outlets is a relevant subject for public health. The scope of this study was to assess the microbiological quality of 96 water samples of a network of fast-food stores in the city of Recife (state of Pernambuco, Brazil) and Metropolitan Area and to compare the results to the standards established by Brazilian Health Ministry decree nº 518/2004. Every month, a double sample from one of the faucets in the food preparation area of the eight stores investigated was analyzed, totaling 96 samples over one year. The analyses followed the established methodology of American Public Health Association (APHA), in order to conduct the Presence-Absence Test, considering the potability standard in pertinent legislation. Results revealed that 11.46% and 1.04% of samples contained water contaminated with total coliforms and thermotolerant coliforms, respectively. The quality of the water in the food establishments studied is thus a health hazard since a significant percentage of samples analyzed were inappropriate for human consumption in accordance with current legislation, which stipulates the absence of total coliforms and thermotolerant coliforms

    Neuroesquistossomose medular avaliação clínico-laboratorial de 5 anos

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    A incidência da esquistossomose no Brasil continua alta, atingindo cerca de 10% da população. Desde o primeiro relato da neuroesquistossomose (NE) em nosso país, há mais de 4 décadas, seu comparecimento na literatura nacional tem mostrado acréscimo significativo. O presente trabalho tem como substrato o estudo de 5 casos de NE medular. Estes casos foram avaliados sob o ponto de vista clínico-laboratorial e submetidos a tratamento medicamentoso. Além disso, é nosso propósito incentivar a pesquisa de novos casos, em portadores de quadros sugestivos desta patologia, sobretudo pelos resultados obtidos neste estudo
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