904 resultados para Interstellar medium


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The cotton disease known as angular leaf spot, caused by Xanthomonas axonopodis pv. malvacearum (Xam) has been causing cotton losses in several producing regions around the world. Xam is transmitted by seeds, which may be infected both externally and internally. Infected seeds constitute the main long-distance dissemination mode of the pathogen. In view of this, the use of healthy seeds is a must. To accomplish that, detection methodologies for the bacteria must be developed be used in seed health analysis laboratories. This study aimed to develop a semi-selective medium for Xam detection in cotton seeds. The semi-selective culture medium was named MSSXAN and it was consisted of peptone (5.0 g), beef extract (3 g), sucrose (5 g), soluble starch (10 g), agar (15 g), CaCl 2 (0.25 g), Tween 80 (10 mL), distilled water (1,000 mL), crystal violet solution at 1% (150 μL), cephalexin (50 mg 1*), methyl thyophanate (10 mg*) and chlorothalonil (10 mg*) - *added after culture medium autoclaving. This MSSXAN medium shows low repressiveness to Xam and it be used for isolation of this bacteria in cotton seeds health analysis. © 2009 Academic Journals Inc.

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The production of ethanol using Zymomonas mobilis had been reported to be three to four times larger than with Saccharomyces cereviseae. The influence of pH, temperature and composition of the means of fermentation are parameters that can direct the metabolism for the production of ethanol. The objective of this study was to evaluate the production of ethanol by Zymomonas mobilis CCT 4494, by variations of the initial pH, temperature and concentrations KCl, K 2SO4, MgSO4, CaCl2 and sucrose, by a factorial experimental design of type 27-2, according to the model proposed by Box et al. (1978). For this, the broth of sugar cane was used as sole carbon source, because it is cheap and easily accessible in the region of São José do Rio Preto, São Paulo State. According to the experimental design, the bacteria Zymomonas mobilis CCT 4494 has adapted in the fermentation mean containing high concentrations of sucrose, and supported the change of pH and temperature of fermentation. The highest amount of ethanol produced was 8.89 mg mL-1. This is not similar to the levels of secondary metabolites produced by Zymomonas mobilis CCT 4494.

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In 1996 the Brazilian Institute for the Environment (IBAMA) officially adopted a variation of the multiorgan initiation-promotion DMBDD bioassay as a valid source of evidence of the carcinogenic potential of pesticides. The protocol adopted by IBAMA was a modification of the one originally proposed by researchers led by Nobuyuki Ito, from the Nagoya City University Medical School. Among the modifications established in the Brazilian protocol were the use of both sexes of the outbreed Wistar strain of rats and two positive control test chemicals. The adoption of the modified DMBDD protocol was instrumental during the last decade for qualifying technical people and to spread knowledge on chemical carcinogenesis in Brazil.