Antecedentes del rol mediador del Éros en los discursos de Erixímaco y Aristófanes

En el Banquete Platón pone en práctica como en ningún otro diálogo un tipo de escritura proléptica, en el sentido de que cada encomio contiene anticipos fragmentarios de tópicos que, a través de un sutil juego de rectificación y complementación, serán retomados en los discursos posteriores. Esta escritura proléptica entronca con la lectura perspectivista del diálogo, ya que cada posición discursiva no se hace sola sino en el contrapunto dialógico-filósofico que mantiene con la asumida por los otros oradores, contrapunto cuyo despliegue permite dar cuenta de las infinitas armonías invisibles que subyacen en el texto. De los múltiples contrapuntos dialógico-filosóficos que pueden trazarse en el Banquete, en este trabajo me interesa limitarme a los pueden advertirse entre los discursos de Erixímaco, Aristófanes y Sócrates-Diotima, a fin de destacar en qué medida los dos primeros discursos operan, desde distintos marcos conceptuales, como un antecedente del tercero en lo que respecta a la función mediadora del Eros

La exhibición y el episodio de Estesilao en el prólogo de Laques y su referencialidad respecto del Agón dialéctico

Lisímaco y Melesias han invitado a los generales Nicias y Laques a presenciar una exhibición de lucha armada. Con motivo del espectáculo y ante la recomendación de esa disciplina para la educación de sus hijos, los padres deciden consultar la opinión de quienes son considerados especialistas en la materia. Esta especie de simulacro de pelea es el inicio de una conversación acerca de si es beneficioso, o no este aprendizaje. Al diálogo entre los padres y los generales se suma Sócrates. A partir de la discrepancia entre Laques y Nicias y el ingreso de Sócrates comienza a desplegarse una suerte de agón dialéctico. La presente comunicación intenta establecer una analogía entre el comportamiento de Estesilao, el luchador de la exhibición, en un determinado episodio relatado por Laques y el que sostiene Nicias frente a los embates del élenkhos socrático

Cuál es la forma legítima de enseñar y ejercer la filosofía : Veladas formas de la competencia entre escuelas en República VI

La enseñanza de la filosofía ha sido históricamente escenario de agón y competencia, no sólo de cooperación. Quisiera llamar la atención sobre el modo en que Platón alude, en el libro VI de la República, a una lucha que se ha entablado en Atenas por dirimir cuál es la legítima forma de transmitir y ejercitar la filosofía. Ofreceré argumentos para mostrar que en las provocadoras respuestas que ofrece Sócrates a los dos reproches que se le hacen a la filosofía -su inutilidad y el carácter raro y perverso de los filósofos- se objeta implícitamente el modo en que Isócrates concibe la filosofía, su función social y su transmisión. Contrastaré esas respuestas con algunas posiciones de Contra sofistas. Aunque las opiniones de Isócrates sobre este tema se desarrollan en varios escritos me concentraré en Contra sofistas para trazar una correspondencia 'agónica' no sólo filológica y especulativamente plausible sino también cronológicamente viable

La Mímesis de la pintura y la escultura en el pensamiento de Jenofonte

En sus Memorabilia, Jenofonte transcribe dos conversaciones mantenidas por Sócrates con un pintor y un escultor. En el presente artículo se analiza el significado de dos términos que aparecen a lo largo de ambos diálogos y que se consideran fundamentales para la teoría griega del arte: ethos y pathos. Ambos aluden a determinados rasgos expresivos susceptibles de ser plasmados en la pintura y en la escultura: el término ethos se refiere a rasgos caracteriológicos intrínsecos y pathos a características extrínsecas y coyunturales. Uno de los puntos más interesantes del texto de Jenofonte es que la noción de mimesis se adscribe a la pintura y la escultura como una característica básica y definitoria. Este concepto de mimesis en el sentido de "imitación" aparece por primera vez aquí como categoría estética dominante.

The 'Philosophical paintings' of the Republic

En el presente artículo examino la apropiación platónica del lenguaje poético en República y sostengo que, a pesar de sus críticas a la poesía en los libros 3 y 10, el lenguaje poético está correctamente entrelazado dentro del tejido filosófico para pintar lo corrupto, lo feo y lo inmoral. En términos específicos, la adaptación platónica de diversos motivos poéticos e imágenes en República se vuelve más significativa si prestamos atención a Sócrates como un quasi-pintor en el diálogo e interpretamos sus imágenes filosóficas como una respuesta de la filosofía a las engañosas representaciones dramáticas de la poesía. De este modo, el arte de la pintura que, incluso es criticado en el libro 10 de República, en manos de Platón resulta una herramienta filosófica que le permite investigar la relación de nuestro mundo senso-perceptivo ordinario con el campo metafísico de las Ideas y el lugar de lo humano en él

Phytoextraction of heavy metals from mine soils using hyperaccumulator plants.

Phytoextraction is an environmental-friendly and cost-effective technology that uses metal hyperaccumulator plants to remove heavy metals from soils. The metals are absorbed by the roots, transported and accumulated in the aerial parts of the plants, which can be harvested and eliminated. The aim of this work was to study some hyperaccumulator species that could be useful to decontaminate mine soils and also to investigate the bioavailability and uptake of these metals by plants with the addition of organic amendments. Pot experiments were performed with soil samples collected from two mining areas in the north of Madrid, where there was an intense mining activity more than 50 years ago. Three species (Thlaspi arvense, Brassica juncea and Atriplex halimus) were grown under controlled conditions in pots filled with contaminated soils mixed with 0 Mg, 30 Mg and 60 Mg per hectare of two different organic amendments: a commercial compost made of pine bark, peat and wood fiber and other made of horse and sheep manure and wood fiber. Plants were harvested at the end of their crop cycle and were digested in order to measure metal concentration (Zn, Cu and Cd) in roots and shoots. Highest plant metal concentration was observed in pots treated with pine bark amendment and with pure soil due to an increase in metal bioavailability with decreasing pH. Also in those treatments the total plant biomass was lower, even some plants could not germinate. On the contrary, there was a lower metal concentration in plant tissues of pots with manure because its higher pH whereas plant growth was significantly larger so there was an incresing amount of metals removed from soil by plants. Comparing the three species results indicate a higher total metal uptake in A. halimus than B. juncea and T. arvense. In conclusion, results show that pH affects metal bioavailability and uptake by hyperaccumulator plants. Addition of organic amendments could be a successful technique for stabilization of metals in contaminated soils.

Chemical speciation and mobilization of copper and zinc in naturally contaminated mine soils with citric and tartaric acids

A one-step extraction procedure and a leaching column experiment were performed to assess the effects of citric and tartaric acids on Cu and Zn mobilization in naturally contaminated mine soils to facilitate assisted phytoextraction. A speciation modeling of the soil solution and the metal fractionation of soils were performed to elucidate the chemical processes that affected metal desorption by organic acids. Different extracting solutions were prepared, all of which contained 0.01 M KNO3 and different concentrations of organic acids: control without organic acids, 0.5 mM citric, 0.5 mM tartaric, 10 mM citric, 10 mM tartaric, and 5 mM citric +5 mM tartaric. The results of the extraction procedure showed that higher concentrations of organic acids increased metal desorption, and citric acid was more effective at facilitating metal desorption than tartaric acid. Metal desorption was mainly influenced by the decreasing pH and the dissolution of Fe and Mn oxides, not by the formation of soluble metal–organic complexes as was predicted by the speciation modeling. The results of the column study reported that low concentrations of organic acids did not significantly increase metal mobilization and that higher doses were also not able to mobilize Zn. However, 5–10 mM citric acid significantly promoted Cu mobilization (from 1 mg kg−1 in the control to 42 mg kg−1 with 10 mM citric acid) and reduced the exchangeable (from 21 to 3 mg kg−1) and the Fe and Mn oxides (from 443 to 277 mg kg−1) fractions. Citric acid could efficiently facilitate assisted phytoextraction techniques.

Bioavailability and extraction of heavy metals from contaminated soil by Atriplex halimus

Pot experiments were performed to evaluate the phytoremediation capacity of plants of Atriplex halimus grown in contaminated mine soils and to investigate the effects of organic amendments on the metal bioavailability and uptake of these metals by plants. Soil samples collected from abandoned mine sites north of Madrid (Spain) were mixed with 0, 30 and 60 Mg ha?1 of two organic amendments, with different pH and nutrients content: pine-bark compost and horse- and sheep-manure compost. The increasing soil organic matter content and pH by the application of manure amendment reduced metal bioavailability in soil stabilising them. The proportion of Cu in the most bioavailable fractions (sum of the water-soluble, exchangeable, acid-soluble and Fe?Mn oxides fractions) decreased with the addition of 60 Mg ha?1 of manure from 62% to 52% in one of the soils studied and from 50% to 30% in the other. This amendment also reduced Zn proportion in water-soluble and exchangeable fractions from 17% to 13% in one of the soils. Manure decreased metal concentrations in shoots of A. halimus, from 97 to 35 mg kg?1 of Cu, from 211 to 98 mg kg?1 of Zn and from 1.4 to 0.6 mg kg?1 of Cd. In these treatments there was a higher plant growth due to the lower metal toxicity and the improvement of nutrients content in soil. This higher growth resulted in a higher total metal accumulation in plant biomass and therefore in a greater amount of metals removed from soil, so manure could be useful for phytoextraction purposes. This amendment increased metal accumulation in shoots from 37 to 138 mg pot?1 of Cu, from 299 to 445 mg pot?1 of Zn and from 1.8 to 3.7 mg pot?1 of Cd. Pine bark amendment did not significantly alter metal availability and its uptake by plants. Plants of A. halimus managed to reduce total Zn concentration in one of the soils from 146 to 130 mg kg?1, but its phytoextraction capacity was insufficient to remediate contaminated soils in the short-to-medium term. However, A. halimus could be, in combination with manure amendment, appropriate for the phytostabilization of metals in mine soils.

Phytoextraction of heavy metals from mine soils using hyperaccumulator plants

The aim of this work was to study some hyperaccumulator species that could be useful to decontaminate mine soils and also to investigate the bioavailability and uptake of these metals by plants with the addition of organic amendments. Pot experiments were performed with soil samples collected from two mining areas in the north of Madrid, where there was an intense mining activity more than 50 years ago. Three species (Thlaspi arvense, Brassica juncea and Atriplex halimus) were grown under controlled conditions in pots filled with contaminated soils mixed with 0 Mg, 30 Mg and 60 Mg per hectare of two different organic amendments: a commercial compost made of pine bark, peat and wood fiber and other made of horse and sheep manure and wood fiber. Plants were harvested at the end of their crop cycle and were digested in order to measure metal concentration (Zn, Cu and Cd) in roots and shoots. Highest plant metal concentration was observed in pots treated with pine bark amendment and with pure soil due to an increase in metal bioavailability with decreasing pH. Also in those treatments the total plant biomass was lower, even some plants could not germinate. On the contrary, there was a lower metal concentration in plant tissues of pots with manure because its higher pH whereas plant growth was significantly larger so there was an incresing amount of metals removed from soil by plants. Comparing the three species results indicate a higher total metal uptake in A. halimus than B. juncea and T. arvense. In conclusion, results show that pH affects metal bioavailability and uptake by hyperaccumulator plants. Addition of organic amendments could be a successful technique for stabilization of metals in contaminated soils.

Effects of sheep and horse manure and pine bark amendments on metal distribution and chemical properties of contaminated mine soils.

Mine soils usually contain large levels of heavy metals and poor fertility conditions which limit their reclamation and the application of phyto-remediation technologies. Two organic waste materials (pine bark compost and sheep and horse manure compost), with different pHs and varying degrees of humification and nutrient contents, were applied as amendments to assess their effects on copper (Cu) and zinc (Zn) bioavailability and on fertility conditions of mine soils. Soil samples collected from two abandoned mining areas near Madrid (Spain) were mixed with 0, 30 and 60 t ha?1 of the organic amendments. The concentrations of metals among the different mineral and organic fractions of soil were determined by several extraction procedures to study the metal distribution in the solid phase of the soil affected by the organic amendments. The results showed that the manure amendment increased the soil pH and the cation exchange capacity and enhanced the nutrient levels of these soils. The pine bark amendment decreased the soil pH and did not significantly change the nutrient status of soil. Soil pH, organic matter content and its degree of humification, which were altered by the amendments, were the main factors affecting Cu fractionation. Zn fractionation was mainly affected by soil pH. The addition of manure not only improved soil fertility, but also decreased metal bioavailability resulting in a reduction of metal toxicity. Conversely, pine bark amendment increased metal ioavailability. The use of sheep and horse manure could be a cost-effective practice for the restoration of contaminated mine soils.

Phytostabilization of metals in mine soils using Brassica juncea in combination with organic amendments

Background and aims The high metal bioavailability and the poor conditions of mine soils yield a low plant biomass, limiting the application of phytoremediation techniques. A greenhouse experiment was performed to evaluate the effects of organic amendments on metal stabilization and the potential of Brassica juncea L. for phytostabilization in mine soils. Methods Plants were grown in pots filled with soils collected from two mine sites located in Central Spain mixed with 0, 30 and 60 tha?1 of pine bark compost and horse- and sheep-manure compost. Plant biomass and metal concentrations in roots and shoots were measured. Metal bioavailability was assessed using a rhizosphere-based method (rhizo), which consists of a mixture of low-molecular-weight organic acids to simulate root exudates. Results Manure reduced metal concentrations in shoots (10?50 % reduction of Cu and 40?80 % of Zn in comparison with non-amended soils), bioconcentration factor (10?50 % of Cu and 40?80 % of Zn) and metal bioavailability in soil (40?50 % of Cu and 10?30 % of Zn) due to the high pH and the contribution of organic matter. Manure improved soil fertility and was also able to increase plant biomass (5?20 times in shoots and 3?30 times in roots), which resulted in a greater amount of metals removed from soil and accumulated in roots (increase of 2?7 times of Cu and Zn). Plants grown in pine bark treatments and in non-amended soils showed a limited biomass and high metal concentrations in shoots. Conclusions The addition of manure could be effective for the stabilization of metals and for enhancing the phytostabilization ability of B. juncea in mine soils. In this study, this species resulted to be a potential candidate for phytostabilization in combination with manure, differing from previous results, in which B. juncea had been recognized as a phytoextraction plant.

Socrates [Material gráfico] : ex marmore antiquo apud Ios. Nic. de Azara

Resumen: Descripción: retrato de busto de Sócrates basado en una escultura

Algunas reflexiones sobre el programa Erasmus

Se describen someramente las características de diversos programas de intercambio de estudiantes universitarios, en particular del ERASMUS, el cual pronto va a ser sustituido por otro más amplio denominado SÓCRATES. También se van a comentar algunas posibles dificultades que pueden aparecer en el desarrollo de los mismos y finalmente se expondrán las conclusiones que de forma provisional ha extraído el autor a partir de su experiencia como actor en alguno de ellos, primeramente en la Universidad de Cantabria y más tarde en la Universidad Politécnica de Madrid. La información obtenida del Vicerrectorado de la UPM se reconoce con especial agradecimiento

RECONHECENDO-SE SEM-RELIGIÃO NAS PERIFERIAS DA CIDADE: LIBERDADE COMPARTILHADA COMO RESISTÊNCIA

Reconhecendo, a partir da constatação empírica, a multiplicidade de escolhas de crenças no Mundo e em particular na periferia urbana paulistana, reconhecemos, também, a emergência criativa de novas possibilidades de crer e não crer. Tal amplitude não apenas aponta para o crer (segundo as ofertas de um sem número de religiões) e o não crer (ateu e agnóstico), mas para uma escolha que poderia vir a ser silenciada e esquecida, neste binômio arcaico e obsoleto, quando alguém se dá à liberdade crer sem ter religião. Reconhecer interessadamente os sem-religião nas periferias urbanas paulistanas é dar-se conta das violências a que estes indivíduos estão submetidos: violência econômica, violência da cidadania (vulnerabilidade) e proveniente da armas (grupos x Estado). Tanto quanto a violência do esquecimento e silenciamento. A concomitância espaço-temporal dos sem-religião nas periferias, levou-nos buscar referências em teorias de secularização e de laicidade, e, a partir destas, traçar uma história do poder violento, cuja pretensão é a inelutabilidade, enquanto suas fissuras são abertas em espaços de resistências. A história da legitimação do poder que se quer único, soberano, de caráter universal, enquanto fragmenta a sociedade em indivíduos atomizados, fragilizando vínculos horizontais, e a dos surgimentos de resistências não violentas questionadoras da totalidade trágica, ao reconhecer a liberdade de ser com autonomia, enquanto se volta para a produção de partilha de bens comuns. Propomos reconhecer a igual liberdade de ser (expressa na crença da filiação divina) e de partilhar o bem comum em reconhecimentos mútuos (expressa pela ação social), uma expressão de resistência não violenta ao poder que requer a igual abdicação da liberdade pela via da fragmentação individualizante e submissão inquestionável à ordem totalizante. Os sem-religião nas periferias urbanas, nossos contemporâneos, partilhariam uma tal resistência, ao longo da história, com as melissas gregas, os profetas messiânicos hebreus, os hereges cristãos e os ateus modernos, cuja pretensão não é o poder, mas a partilha igual da liberdade e dos bens comuns. Estes laicos, de fato, seriam agentes de resistências de reconhecimento mútuos, em espaços de multiplicidade crescente, ao poder violento real na história.

O PROCESSO FORMATIVO E A ATUAÇÃO DO ARTE-EDUCADOR: POSSIBILIDADES E CONTRIBUIÇÕES DA TEORIA IRONISTA

A presente pesquisa visa a revisão bibliográfica do processo formativo e, ao mesmo tempo, a investigação e problematização da atuação contemporânea do educador ironista na Educação. O autor Imanol Aguirre, concebe este título ao educador que seja provocativo, inteirado e propositor de experiências estéticas frente às complexidades contemporâneas, amalgamadas num tecido histórico-social caracterizado pelo trânsito da pluralidade, dos imaginários, da construção de identidade e da mobilidade social. O ironista atua dialogicamente “in loco” criando respostas às variadas demandas com os seus educandos. A fomentação da crítica, a mobilização da dúvida e da ironia, a conexão dos territórios das competências e habilidades, são os objetivos pelos quais o educador ironista intenciona um cenário educacional mais efetivo e emancipador ante as reais necessidades contemporâneas.