48 resultados para Action principle
em Scielo Saúde Pública - SP
Resumo:
The European Union's (EU) decision to include aviation into the Emissions Trade Scheme was heatedly contested. Countries around the world, but mainly the Brazil, Russia, India, China and South Africa group (BRICS) and the US, denounced the EU's initiate as illegal and unilateral. Following a decade of frustrated negotiations at the International Civil Aviation Organization (ICAO), this paper interrogates why such measure, in principle climate-friendly, inspired so much global resentment. I argue that concerns with competitiveness and risks of legal inconsistency are important, but insufficient elements to explain the core of the conflict. The paper suggests that the EU was strongly criticized because third countries perceived this action as an imposed solution, which fostered an environment of distrust. Therefore, I claim that the problem has more to do with a normative divide than with a substantive divergence on what should be done regarding aviation emissions. My analysis is informed by the present literature on the links between trade and climate change, but gives particular weight to first-hand information through interviews with key stakeholders. The paper is divided in three parts. First, it presents the scope of the EU directive in historical perspective. Second, it explores the EU's measure through three different angles: legal, economical and political. The final part explores some possible solutions to overcome these divergences.
Resumo:
Soybean genotypes grown in sub-tropical climate may exhibit lodging. The plant lodging is influenced by soil type and fertility level, sowing date, latitude and altitude of the location, plant population and conditions of crop development. Plant regulators and herbicides are able to avoid or reduce plant lodging. This study aimed to verify the effects of the growth regulators TIBA and daminozide on vegetative growth and yield of soybean cultivar CD 214 RR. The experiment was carried out at a field in randomized block design with four replications in a factorial scheme. The A factor was represented by the combination of regulators TIBA and daminozide and its concentrations, and the Factor B was seven times of evaluation of injury and plant height or eight times of evaluation of lodging. In the range of doses used, the application of daminozide resulted in greater injury to soybean plants than TIBA. The smaller plant height was achieved by the application of 6 g ha-1 of TIBA and 1200 g ha-¹ of daminozide. Treatments with daminozide (100 g ha-¹) and TIBA (10 g ha-1) stood out due to the reduced lodging of soybean plants. Grain weight increased linearly when the levels of TIBA increased. There was a negative correlation between lodging and grain yield and a positive correlation between plant height and lodging. There was also a negative correlation between injury caused by the application of plant regulators and lodging.
Resumo:
In spite of the wealth generation potential of the world's large metropolitan cities, poor living conditions for much of the world's urban population persist. Although the city has been widely studied, urban policy often remains ineffective. The paper adopts a policy process approach to analyze the relationship between knowledge and governmental action. Impediments to improving urban policy are found in the inadequate capacity of government to act and in the politics of democratic decision-making. The paper recommends that a pragmatic view of knowledge generation be adopted.
Resumo:
The importance of interaction between Operations Management (OM) and Human Behavior has been recently re-addressed. This paper introduced the Reasoned Action Theory suggested by Froehle and Roth (2004) to analyze Operational Capabilities exploring the suitability of this model in the context of OM. It also seeks to discuss the behavioral aspects of operational capabilities from the perspective of organizational routines. This theory was operationalized using Fishbein and Ajzen (F/A) behavioral model and a multi-case strategy was employed to analyze the Continuous Improvement (CI) capability. The results posit that the model explains partially the CI behavior in an operational context and some contingency variables might influence the general relations among the variables involved in the F/A model. Thus intention might not be the determinant variable of behavior in this context.
Resumo:
Coral snakes, the New World Elapidae, are included in the genera Micniroides and Micrurus. The genus Mlcrurus comprises nearly all coral snake species and those which are responsible for human snake-bite accidents. The following generalizations concerning the effects induced by their venoms, and their venom-properties can be made. Coral snake venoms are neurotoxic, producing loss of muscle strenght and death by respiratory paralysis. Local edema and necrosis are not induced nor blood coagulation or hemorrhages. Proteolysis activity is absent or of very low grade. They display phospholipase A2 activity. Nephrotoxic effects are not evoked. The main toxins from elapid venoms are postsynaptic and presynaptic neurotoxins and cardiotoxins. Phospholipases A2 endowed with myonecrotic or cardiotoxin-like properties are important toxic components from some elapid venoms. The mode of action of Micrurus frontalis, M. lemniscatus, M. corallinus and M. fulvius venoms has been investigated in isolated muscle preparations and is here discussed. It is shown that while M. frontalis and M. lemniscatus venoms must contain only neurotoxins that act at the cholinergic end-plate receptor (postsynaptic neurotoxins), M. corallinus venom also inhibits evoked acetylcholine release by the motor nerve endings (presynaptic neurotoxin-like effect) and M. fulvius induces muscle fiber membrane depolarization (cardiotoxin-like effect). The effects produced by M. corallinus and M. fulvius venoms in vivo in dogs and M. frontalis venom in dogs and monkeys are also reported.
Resumo:
The authors have standardized methods for evaluation of the activity of the glucose-6-phosphate dehydrogenase and of glutathione reductase. The general principle of the first method was based on methemoglobin formation by sodium nitrite followed by stimulation of the glucose-6-phosphate dehydrogenase with methylene blue. Forty six adults (23 males and 23 females) were studied. Subjects were not G6PD deficient and were aged 20 to 30 years. The results showed that methemoglobin reduction by methylene blue was 154.40 and 139.90 mg/min (p<0.05) for males and females, respectively, in whole blood, and 221.10 and 207.85 mg/min (n.s.), respectively, in washed red cells. These data showed that using washed red cells and 0.7g% sodium nitrite concentration produced no differences between sexes and also shortened reading time for the residual amount of methemoglobin to 90 minutes. Glutathione reductase activity was evaluated on the basis of the fact that cystamine (a thiol agent) binds to the SH groups of hemoglobin, forming complexes. These complexes are reversed by the action of glutathione reductase, with methemoglobin reduction occurring simultaneously with this reaction. Thirty two adults (16 males and 16 females) were studied. Subjects were not G6PD deficient and were aged 20 to 30 years. Methemoglobin reduction by cystamine was 81.27 and 91.13 mg/min (p<0.01) for males and females, respectively. These data showed that using washed red cells and 0.1 M cystamine concentration permits a reading of the residual amount of methemoglobin at 180 minutes of incubation. Glutathione reductase activity was evaluated by methemoglobin reduction by cystamine in 14 females before and after treatment with 10 mg riboflavin per day for 8 days. The results were 73.69 and 94.26 jug/min (p<0.01) before and after treatment, showing that riboflavin treatment increase glutathione reductase activity even in normal individuals. Three Black G6PD-deficient individuals (2 males and 1 female) were also studied. The G6PD and glutathione reductase were partially activated, the change being more intense in males. On the basis of race and of the laboratory characteristics observed, it is possible to suggest that the G6PD deficiency of these individuals is of the African type and that the female is heterozygous for this deficiency. Analysis of the results as a whole permitted us to conclude that the methods proposed here were efficient for evaluating the activity of the glucose-6-phosphate dehydrogenase and of glutathione reductase. The latter is dependent on the pentose pathway, which generates NADPH, and on riboflavin, a FAD precursor vitamin.
Resumo:
The fungicidal action of sodium hypochlorite (0.3, 1, 2.5, 5 and 10%); formaldehyde (2, 5, and 10%); and ethyl alcohol (70%) on yeast forms of Paracoccidioides brasiliensis Pb 18 and a newly-isolated Goiana strain was described. Contact between the fungus and the disinfectants was maintained for 1, 2, 24, 48 and 72 hours at room temperature. Viability was evaluated by the fluorescein diacetate-ethidium bromide treatment, culture in solid and liquid media (36ºC and 26ºC); yeast to mycelial germination at room temperature; and radiometric study of metabolic activity. All concentrations of disinfectants were found to be effective in inactivating Pb 18 and Goiana strains, except for the 1-hour contact with 2% formaldehyde, in which fluorescein diacetate-ethidium bromide treatment was found to reveal 40 and 27% of viable cells, respectively. The yeast to mycelial germination method was considered to reveal faster and similar results as compared to culture in solid and liquid media.
Resumo:
Laboratory tests with aqueous solutions of Euphorbia splendens var. hislopii latex have demonstrated seasonal stability of the molluscicidal principle, with LD90 values of 1.14 ppm (spring), 1.02 ppm (fall), 1.09 ppm (winter), and 1.07 ppm (summer) that have been determined against Biomphalaria tenagophila in the field. Assays on latex collected in Belo Horizonte and Recife yielded LD90 values similar to those obtained with the reference substance collected in Rio de Janeiro (Ilha do Governador), demonstrating geographic stability of the molluscicidal effect. The molluscicidal action of aqueous dilutions of the latex in natura, centrifuged (precipitate) and lyophilized, was stable for up to 124 days at room temperature (in natura) and for up to 736 days in a common refrigerator at 10 to 12ºC (lyophilized product). A 5.0 ppm solution is 100% lethal for snails up to 13 days after preparation, the effect being gradually lost to almost total inactivity by the 30th day. This observation indicated that the active principle is instable. These properties together with the wide distribution of the plant, its resistance and adaptation to the tropical climate, its easy cultivation and the easy obtention of latex and preparation of the molluscicidal solution, make this a promising material for large-scale use in the control of schistosomiasis
Resumo:
The interaction between specific immune response to Schistosoma mansoni and praziquantel (PZQ) was studied in mice. In mice harboring concomitant immunity, 6-day-old parasites treated with PZQ were more effectively removed than 24h treated parasites despite both had a significant worm burden reduction when compared with respective treated controls. These results show that PZQ can be effective at the skin and lung stages of parasite's development mainly acting with a established specific immune response, and particularly at the lung phase.
Resumo:
SUMMARY The molluscicidal activity of the leaf powder of Moringa oleifera and lyophilized fruit powder of Momordica charantia against the snail Lymnaea acuminata was time and concentration dependent. M. oleifera leaf powder (96 h LC50: 197.59 ppm) was more toxic than M. charantia lyophilized fruit powder (96 h LC50: 318.29 ppm). The ethanolic extracts of M. oleifera leaf powder and Momordica charantia lyophilized fruit powder were more toxic than other organic solvent extracts. The 96 h LC50 of the column purified fraction of M. oleifera leaf powder was 22.52 ppm, while that of M. charantia lyophilized fruit powder was 6.21 ppm. Column, thin layer and high performance liquid chromatography analysis show that the active molluscicidal components in M. oleifera leaf powder and lyophilized fruit of M. charantia are benzylamine (96 h LC50: 2.3 ppm) and momordicine (96 h LC50: 1.2 ppm), respectively. Benzylamine and momordicine significantly inhibited, in vivo and in vitro, the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activities in the nervous tissues of L. acuminata. Inhibition of AChE, ACP and ALP activity in the nervous tissues of L. acuminata by benzylamine and momordicine may be responsible for the molluscicidal activity of M. oleifera and M. charantia fruits, respectively.
Resumo:
SUMMARY In a previous study our group found that the probiotic Saccharomyces boulardii was capable of reducing the intensity of infection in mice with toxocariasis. In order to assess whether the mechanism involved would be a direct action of the probiotic on Toxocara canis larvae, this study was designed. Both probiotics were singly cultivated in plates containing RPMI 1640 medium and T. canis larvae. S. boulardii and B. cereus var. toyoi cultures presented 97.6% and 95.7% of larvae with positive motility, respectively, and absence of color by the dye trypan blue, not representing significant difference to the control group (p > 0.05). We conclude that none of the probiotics showed in vitro effects on T. canis larvae and that the interaction with the intestinal mucosa is necessary for the development of the protective effect of S. boulardii.
Resumo:
Mice infected with adult Schistosoma mansoni were dosed with a single oral dose of 125 or 250 mg/kg oltipraz, 50 or 100 mg/kg oxamniquine, or 200 or 400 mg/kg praziquantel. The mortality rate of worms and oogram changes were determined between 1 and 16 weeks after dosing. The time required between dosing and postmortem to obtain maximum effectiveness was 1 week for praziquantel, 2 weeks for oxamniquine and 8 weeks for oltipraz. Changes in oograms persisted throughout most of the experiment, although relapse has been observed at the 4th week on.