158 research outputs found

    Geoprocessamento no contexto de empresas de pesquisa.

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    bitstream/CPACT-2010/12905/1/documento-254.pd

    Fluctuation and fixation of rodenticide resistance alleles in Rattus norvegicus

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    Berthier, K., Benoit, E., Berny, P., Lasseur, R., Merville, A., Peigneaux, F., Cosson, J.-F

    Índice climático de crescimento de pastagens naturais no Rio Grande do Sul

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    The climatic index of pasture growth, of Fitzpatrick & Nix, was tested and applied with good results to Rio Grande do Sul State, Brazil. An exponential regression equation Y = 353,1 (e1.40x) where x is the climatic index of growth of tropical grasses, can be used to estimate the dry matter yield of natural grasslands, using average air temperature, rainfall and shunshine. Tables were developed for the quick determination of the thermal index for each group of forages, and the light index, both indexes being necessary for the climatic index calculation. The normal, monthly climatic index, for ten locations within the State was determined as well as the frequency of its different values for a period of 30 years, at Uruguaiana and São Luiz Gonzaga. A low climatic potential for the productivity of natural grasslands is a definitive characteristic of Rio Grande do Sul State, in winter and in dry summers. Hay can be obtained from the native grassland itself, in summer, and used in winter as feed supplement. There is a good climatic potentiality along all the year for the temperate grasses and legumes, but no adequate climate for tropical legumes during the coldest months of the winter.O índice climático de crescimento de pastagens, de Fitzpatrick & Nix, foi testado e considerado satisfatório nas condições do Estado do Rio Grande do Sul. Uma equação de regressão do tipo exponencial, Y = 353,1 (e1,40X) onde x é o índice climático de crescimento de gramíneas tropicais, permite estimar o rendimento de matéria seca (kg/ha) da pastagem natural. Para uso desta equação é necessário conhecer temperatura média, precipitação pluvial e insolação. Foram organizadas tabelas que permitem rápida determinação do índice térmico para cada grupo de forrageiras - e do índice de luz, necessários para o cálculo do índice climático. Foi determinado o índice climático mensal normal para cada grupo de forrageiras, em dez locais do Rio Grande do Sul. Para as localidades de Uruguaiana e São Luiz Gonzaga, foi determinada a frequência dos valores dos índices climáticos, cm cada mês, durante 30 anos de observação. Verificou-se que o potencial de produtividade das pastagens naturais é insuficiente, quando o índice climático de crescimento é inferior a 0.1 o que ocorre no inverno, e em verões secos. Para pastagens nativas, a suplementação alimentar com feno, no inverno e verões secos, é grande importância, dada a grande variabilidade, de ano para ano, dos índices climáticos e das estações. Este feno pode ser obtido da própria pastagem nativa, durante o verão, pois, nesta estação, a produtividade das pastagens é superior à necessidade de um bovino adulto/ha. Há boa potencialidade climática, durante todos os meses do ano para gramíneas e leguminosas temperadas. Para as leguminosas tropicais, os meses mais rigorosos do inverno não possuem clima adequado

    The effect of culture preservation techniques on patulin and citrinin production by Penicillium expansum Link

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    Aims: To study the influence of culture preservation methods and culture conditions on the production of the mycotoxins patulin and citrinin by Penicillium expansum. Methods and results: Ten strains of Penicillium expansum were preserved using subculture and maintenance at 4 ºC, mineral oil, drying on silica gel and freeze-drying. Patulin and citrinin production was assessed on yeast extract sucrose agar (YES) and grape juice agar (GJ), using TLC before and after 0.5, 2–3, 6 and 12 months preservation. Citrinin was detected in all cultures for all preservation techniques on YES. The patulin profiles obtained differed with strain and culture media used. Conclusions: Citrinin production seems to be a stable character for the tested strains. There is a tendency for patulin detection with time apparently more consistent for silica gel storage and freeze-drying, especially when the strains are grown on GJ. Significance and Impact of the Study: Variability in the profiles of the mycotoxins tested seems to be more strain-specific than dependent on the preservation technique used

    Cerium-Based Spontaneous Coating Process for Corrosion Protection of Aluminum Alloys

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    A cerium-based coating for corrosion resistance is applied by exposing a cleaned aluminum-based component to a corrosion-inhibiting cerium solution containing cerium ions in the presence of an oxidizing agent. The coating deposits spontaneously without an external source of electrons

    Environmental NGOs at a crossroads?

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    Article published as introduction to the Special Issue 'Environmental Politics at a crossroads', edited by Nathalie Berny & Christopher Rootes, Environmental Politics vol.27.no.6, November 201

    Investigation into experimental toxicological properties of plant protection products having a potential link to Parkinson's disease and childhood leukaemia

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    In 2013, EFSA published a literature review on epidemiological studies linking exposure to pesticides and human health outcome. As a follow up, the EFSA Panel on Plant Protection Products and their residues (PPR Panel) was requested to investigate the plausible involvement of pesticide exposure as a risk factor for Parkinson's disease (PD) and childhood leukaemia (CHL). A systematic literature review on PD and CHL and mode of actions for pesticides was published by EFSA in 2016 and used as background documentation. The Panel used the Adverse Outcome Pathway (AOP) conceptual framework to define the biological plausibility in relation to epidemiological studies by means of identification of specific symptoms of the diseases as AO. The AOP combines multiple information and provides knowledge of biological pathways, highlights species differences and similarities, identifies research needs and supports regulatory decisions. In this context, the AOP approach could help in organising the available experimental knowledge to assess biological plausibility by describing the link between a molecular initiating event (MIE) and the AO through a series of biologically plausible and essential key events (KEs). As the AOP is chemically agnostic, tool chemical compounds were selected to empirically support the response and temporal concordance of the key event relationships (KERs). Three qualitative and one putative AOP were developed by the Panel using the results obtained. The Panel supports the use of the AOP framework to scientifically and transparently explore the biological plausibility of the association between pesticide exposure and human health outcomes, identify data gaps, define a tailored testing strategy and suggests an AOP’s informed Integrated Approach for Testing and Assessment (IATA)

    Scientific Opinion about the Guidance of the Chemical Regulation Directorate (UK) on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessments

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    Abstract The EFSA Panel on Plant Protection Products and their Residues reviewed the guidance on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessment. The inclusion of aged sorption is a higher tier in the groundwater leaching assessment. The Panel based its review on a test with three substances taken from a data set provided by the European Crop Protection Association. Particular points of attention were the quality of the data provided, the proposed fitting procedure of aged sorption experiments and the proposed method for combining results obtained from aged sorption studies and lower‐tier studies on degradation and adsorption. Aged sorption was a relevant process in all cases studied. The test revealed that the guidance could generally be well applied and resulted in robust and plausible results. The Panel considers the guidance suitable for use in the groundwater leaching assessment after the recommendations in this Scientific Opinion have been implemented, with the exception of the use of field data to derive aged sorption parameters. The Panel noted that the draft guidance could only be used by experienced users because there is no software tool that fully supports the work flow in the guidance document. It is therefore recommended that a user‐friendly software tool be developed. Aged sorption lowered the predicted concentration in groundwater. However, because aged sorption experiments may be conducted in different soils than lower‐tier degradation and adsorption experiments, it cannot be guaranteed that the higher tier predicts lower concentrations than the lower tier, while lower tiers should be more conservative than higher tiers. To mitigate this problem, the Panel recommends using all available higher‐ and lower‐tier data in the leaching assessment. The Panel further recommends that aged sorption parameters for metabolites be derived only from metabolite‐dosed studies. The formation fraction can be derived from parent‐dosed degradation studies, provided that the parent and metabolite are fitted with the best‐fit model, which is the double first‐order in parallel model in the case of aged sorption
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