142 resultados para Símiles homéricos


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Na Grécia antiga, era comum os alunos estudarem a grandeza da epopeia homérica de forma lúdica, a partir de breves histórias de animais, figuras que conheciam da fábula. O primeiro contacto com os poemas de Homero fazia-se, por isso, por acesso a textos de teor pedagógico que apresentavam animais a comportarem-se como os valorosos heróis da tradição épica. Neste ensaio, pretendo explorar o universo das chamadas fábulas épicas ou epopeias animalescas, estreitando os influxos que esse género recebe do seu modelo. O eixo estrutural de base deste estudo consiste na premissa de que enquanto na epopeia antiga, na homérica em particular, os heróis agem muitas vezes como bestas ferozes, como mostram vários símiles, nas narrativas épicas animalescas, por outro lado, os animais são dotados de estatuto heróico.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

(ES) El vino tiene un importante papel en el mundo idealizado de los héroes homéricos. El poeta ofrece las primeras descripciones de vinos griegos, principalmente procedentes del norte del Egeo, situándolos en contextos muy variados, como centro del banquete, bebida reconstituyente, elemento imprescindible en plegarias y juramentos e incluso símbolo de honor que distingue a los personajes más destacados.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research was directed towards the investigation of the Smiles rearrangement in hydrazidic systems and the synthesis of related heterocyclic compounds. The work can be conveniently divided into two main sections. Section 1 of the thesis relates to the synthesis and examination of the O+N migration of phenoxy- derivatives of hydrazidic halides. In general, hydrazidic halides were found to react with 2-nitrophenol and 4-nitrophenol to give corresponding a-nitrophenoxy- compounds. These a-nitrophenoxy- compounds were found to rearrange in warm base to give the corresponding N-benzoyl compounds via a proposed five-membered transition state. Experiments conducted in styrene revealed no radical contribution to the rearrangement. Cross-over product analysis indicated the rearrangement as intramolecular and consistent with the Smiles rearrangement. The preparation of N-a-chlorobenzylidene-N'-2-nitrophenyl- -N'-(2,4-dibromophenyl)hydrazine from N-benzoyl-N'-2-nitrophenyl- N'-(2,4-dibromophenyl)hydrazine was accomplished using phosphorus oxychloride. Examination of this hydrazidic chloride indicated a marked decrease .in reactivity as compared to the N-a-chlorobenzylidene-N'-phenylhydrazine case. Section 2 concerns itself with the preparation of heterocyclic compounds using an analogy of the five-membered transition state present in the Smiles rearrangement of a substituted benzylidene derivatives A new preparation of 2,4-phenyl1,3,4- oxadiazol-S-one using N-benzoyl-N'-phenylhydrazine and ethyl thiochloroformate is reported. Two new preparations of N-a-thiobenzoyl-N'-(2,4-dibromophenylhydrazine are reported using sodium hydrosulfide in conjunction with N-a-bromobenzylidene-N'-(2,4-dibromophenyl)hydrazine in the first, and phosphorus pentasulfide with N-benzoylN'-( 2,4-dibromophenyl)hydrazine in the second. The latter is preferred due to the formation of a sulfide co-product in the former. Two preparations of 2-phenyl-4-(2,4-dibromophenyl)-1,3,4- thiadiazol-S-one are reported using N-thiobenzoyl-N'-(2,4-dibromophenyl) hydrazine and ethyl chloroformate and ethyl thiochloroformate Two rapid and easy preparations of 2-phenyl-4-(2,4-dibromophenyl)- 1,3,4-triazol-S-one are reported using ethyl chloroformate and ethyl thiochloroformate. Sodium cyanate in conjunction with a-aminobenzylidene-N'-(2,4-dibromophenyl)hydrazine also provided 2-phenyl-4-(2,4-dibromophenyl)-1,3,4-triazol-S-one Section 2 concludes with an examination of two possible mechanistic routes to the prepared heterocycles.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, we characterize the asymmetries of the smile through multiple leverage effects in a stochastic dynamic asset pricing framework. The dependence between price movements and future volatility is introduced through a set of latent state variables. These latent variables can capture not only the volatility risk and the interest rate risk which potentially affect option prices, but also any kind of correlation risk and jump risk. The standard financial leverage effect is produced by a cross-correlation effect between the state variables which enter into the stochastic volatility process of the stock price and the stock price process itself. However, we provide a more general framework where asymmetric implied volatility curves result from any source of instantaneous correlation between the state variables and either the return on the stock or the stochastic discount factor. In order to draw the shapes of the implied volatility curves generated by a model with latent variables, we specify an equilibrium-based stochastic discount factor with time non-separable preferences. When we calibrate this model to empirically reasonable values of the parameters, we are able to reproduce the various types of implied volatility curves inferred from option market data.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Using the recent global financial crisis as an exogenous setting, we examine the presence and source of implied volatility smile phenomena in Australian S&P ASX 200 index options. We find a pronounced implied volatility smile for index puts in both bull and bear markets and a smile for index calls in the bear but not bull market. Implied volatilities of out-of-the money puts tend to be upwards biased whilst those of calls tend to be downwards biased. We also find that the bias in implied volatilities yields excess returns based on unhedged and delta-neutral trading strategies, suggesting that implied volatilities are related to option mispricing. Net buying pressure from market participants appears to be a source of mispricing in the case of out-of-the-money index puts with excess demand particularly pronounced during the bull period before the global financial crisis unfolded.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Despite increased investment in its recognition and treatment, depression remains a substantial health and economic burden worldwide. Current treatment strategies generally focus on biological and psychological pathways, largely neglecting the role of lifestyle. There is emerging evidence to suggest that diet and nutrition play an important role in the risk, and the genesis, of depression. However, there are limited data regarding the therapeutic impact of dietary changes on existing mental illness. Using a randomised controlled trial design, we aim to investigate the efficacy and cost-efficacy of a dietary program for the treatment of Major Depressive Episodes.

Relevância:

20.00% 20.00%

Publicador: