Resumo Uma das contribuições fundamentais da perspectiva bourdieusiana é a proposta de uma teoria da prática como resultado da relação dialética entre significado objetivo e significado vivido, o que implica uma tomada de posição que é, ao mesmo tempo, epistemológica, teórica e metodológica. Neste texto, vamos primeiro explicar esses aspectos e, em seguida, no âmbito de uma pesquisa sobre a desigualdade social em Córdoba, vamos propor uma maneira de articular os dois sentidos, com foco em estratégias educacionais e enfatizando suas conseqüências metodológicas.

Abstract One of the fundamental contributions of the Bourdieusian perspective is its proposal of a theory of practice as a result of the dialectical relation between objective meaning and experiential meaning, which implies a position taking that is, at the same time, epistemological, theoretical and methodological. In this text, we will first explain these aspects and then, within the framework of a research on social inequality in Córdoba, we will propose a way to articulate both senses, focusing on educational strategies and emphasizing their methodological consequences.

Resumen Uno de los aportes fundamentales de la perspectiva bourdieusiana es su propuesta de una teoría de la práctica como resultado de la relación dialéctica entre sentido objetivo y sentido vivido, lo que implica una toma de posición que es, a la vez, epistemológica, teórica y metodológica. En este texto, explicitaremos primero estos aspectos y luego, en el marco de una investigación sobre la desigualdad social en Córdoba, propondremos una manera de articular ambos sentidos, focalizando en las estrategias educativas y haciendo hincapié en sus consecuencias metodológicas.

Resumen Ante la era digital, la humanidad se enfrenta a nuevas coyunturas en los ámbitos sociales y psicológicos. La aparición de fenómenos como la adicción a internet, la depresión asociada al uso excesivo de los dispositivos y la pérdida de espacios reales en pro de una virtualidad cada vez mayor, además del desgaste de los recursos naturales, prende las alarmas sobre la salud y el tipo de vida que se lleva en las sociedades. La vida rápida e inmediata parece colocar a las personas en nuevos espacios cu- yos impactos aún salen del conocimiento de las ciencias sociales. La Psicología humanista apareció oficialmente en 1961 y puede brindarnos una mirada más humana. El retorno a las experiencias humanas, a las emociones, al valor del individuo y a los sentimientos de autorrealización pueden cimentar las bases de un nuevo pensamiento que ponga luz sobre las problemáticas actuales. Por eso, el objetivo de este trabajo fue el de señalar algunos problemas que llegaron con la era digital, para después dirigir sobre ellos la mirada que brinda la Psicología humanista con el fin de revitalizar los esfuerzos en pro de una vida más saludable tanto entre los individuos como con el ambiente.

Abstract: Faced with the Digital Age, humanity confronts new junctures in the social and psychological spheres. The appea- rance of phenomena such as Internet addiction, depression associated with excessive device usage and the loss of real spaces in favor of an increasing virtuality, in addition to natural resource depletion, set off alarms about health and the type of life that is carried out in societies. Fast and immediate life seems to place people in new spaces whose impacts still come out of the knowledge of the social sciences. It is here that Humanist Psychology, officia- lly appearing in 1961, can give us a more humane look. The return to human experiences, emotions, the value of the individual and feelings of self-realization can lay the foundations of a new thought that sheds light on current problems. That is why the goal of this work was to point out some problems that arose with the digital era, and then cast on them the perspective offered by Humanist Psychology in order to revitalize efforts towards a healthier life both among individuals, as well as in the environment.

One of the most important sources of reactive oxygen species (ROS) in biological systems is the Fenton reaction. In this, the Fe2+ or Fe3+ reacts with H2O2 to produce ROS as the hydroxyl radical (∙OH), superoxide radical (O2-) and singlet oxygen (¹O2). The main ROS, responsible for the high oxidizing power of the Fenton reaction, is not clear. Some authors claim that the principal reactive species is ∙OH, while others propose a ferryl specie (Fe4+ or [FeO]2+)(1,2). Recently, have been proposed that the kind of reaction species produced depends mainly of pH and the iron composition of the coordination sphere. This is highlighted for Fe³+, because in mono and (some) bis-complexes Fe3+ is reduced to Fe2+ and there are some positions occupied by water or hydroxide ligands, readily to be exchanged by H2O2. On the other hand, in tris-complexes there are not any positions occupied by water or hydroxide, avoiding the formation of peroxo-complexes, necessary for Fenton or Fenton like reaction. The 1,2-dihydroxybenzenes (DHBs) have been described as modulators of Fenton reaction. The DHBs driven Fenton reaction have been used for environmental applications as an advanced oxidation process. Furthermore, these systems participate in different biological process, as the wood biodegradation by fungi and oxidative stress in neurodegenerative diseases. In this review, the effect of 1,2-dihydroxybenzenes on the activated species production by the Fenton and Fenton like reaction will be discussed and its participation in different systems.

Forest environments have continuously existed in Antarctica since the late Paleozoic and only disappeared from this continent since the Neogene. Nevertheless, the structure of these forests underwent substantial evolutionary changes. During the late Cretaceous, forests dominated by conifers and pteridophytes were gradually replaced by angiosperm-dominated forests. Elements common to these Antarctic forests are important constituents of the recent Valdivian Forest. During the Turonian stage of the Late Cretaceous, the Antarctic Peninsula and Patagonia were reconnected by a land bridge after a separation since the end of the Jurassic. Using biogeographic tools applied to the palynological and leaf imprint record, outcrops of Campanian-Maastrichtian age were studied from the Snow Hill, James Ross and Seymour (Marambio) Islands in the James Ross basin, Antarctica; Skua Bay, Half Three Point, Price Point and Zamek Hill on King George Island, Antarctica, and Rocallosa Point, Cerro Guido, Las Chinas, Dorotea Hill, Cazador Hill and La Irene in Chilean-Argentinian Patagonia, comparing the current distribution and the paleogeography, as well as the influence of potential areas of endemism and vicariants events. The analysis indicates that vegetation evolved under environmental conditions subject to intense volcanic and climatic disturbances, with changes from a period with extreme greenhouse climate (Turonian-Campanian) to strong cooling during the Maastrichtian. We suggest that a continuous forest existed in southern South America and Antarctica, which was shaped during the Latest Cretaceous by the presence of marine basins and and intermittent connection and disconnection of the flora.

Se sabe que al menos desde fines del Paleozoico ambientes boscosos habrían existido en la Antártica y habrían desaparecido de ella solo a fines del Terciario. Sin embargo, la estructura no ha sido la misma, evolucionando desde un bosque dominado por coníferas y pteridófitas durante el Cretácico Inferior, a bosques dominados por angiospermas a partir del Cretácico Superior, con elementos comunes a los constituyentes actuales de la Selva Valdiviana. Durante el Turoniano la Península Antártica y Patagonia se reunieron por un puente terrestre rompiendo millones de años de desconexión, y gracias a una variedad de ambientes de sedimentación, se han conservado numerosos vestigios de la flora que cubrió ambos subcontientes. Mediante herramientas biogeográficas aplicadas al registro palinológico y de improntas foliares, afloramientos campaniano-maastrichtianos de islas Snow Hill, James Ross y Seymour (Marambio), en la cuenca de James Ross, Antártica; bahía Skúa, punta Half Three, punta Price y cerro Zamek, en la isla Rey Jorge, Antártica; y punta Rocallosa, cerro Guido, Las Chinas, cerro Dorotea, cerro Cazador y La Irene en la Patagonia chileno-argentina, se estudió la relación entre la distribución actual y la paleogeografía, considerandolos potenciales eventos vicariantes y áreas de endemismo establecidas. Reconstrucciones paleoecológicas muestran que los elencos vegetacionales habrían evolucionado en el marco de ambientes sometidos a intensa perturbación volcánica y climáticamente habrían estado sometidos a uno de los lapsos más cálidos de la historia natural, pero con fuertes pulsos de enfriamiento durante el Campaniano y Maastrichtiano. Se sostiene que entre el Maastrichtiano y el Eoceno, existió un continuo forestal entre Patagonia y Sudamérica que habría sido modelado por la presencia de las cuencas marinas finicretácicas y la intermitente conexión-desconexión de las floras.

Background: Anterograde mechanical colon cleansing is routinely done before colorectal surgery. However there is no firm evidence about its usefulness. Aim: To assess the usefulness of anterograde mechanical colon cleansing in colon surgery. Patients and Methods: Participants requiring elective colorectal surgery were randomized to receive anterograde mechanical bowel cleansing with two doses of oral sodium phosphate (Oral fleet*) or a liquid diet 24 hours prior to surgery, after signing an informed consent. Both groups received antimicrobial prophylaxis. Problems associated with bowel cleansing, subjective assessment ofbowel preparation by the surgeon and postoperative complications were recorded. Results: One hundred twenty two participants were studied (73 females). Fifty three percent of patients had concomitant diseases such as hypertension and diabetes mellitus. Sixty patients were subjected to anterograde bowel cleansing and 62 were ascribed to the liquid diet group. Surgeons evaluated colon cleansing as good in 49 and 37 patients with and without anterograde mechanical cleansing, respectively and as regular in 8 and 23 patients, respectively (χ2 = 9.1 p = 0.01). Tolerance to cleansing was evaluated as good, fair and poor by 50, 30 and 20% of patients, respectively. One patient had a bowel obstruction associated with the use of sodium phosphate. Postoperative complications occurred in 14 and 23 patients subjected or not to cleansing, respectively (p = 0.06). Septic complications occurred in 11 and 3 cases with and without colon cleansing, respectively (p < 0.01). Conclusions: Anterograde mechanical colon cleansing was associated with a higher incidence of septic complications in this series of patients.

Introducción: El uso de Ia preparación mecánica anterógrada (PMA) es una práctica rutinaria en cirugia colorrectal pero con escasas bases en Ia evidencia científica. Objetivo: Determinar Ia utilidad de Ia PMA en una serie prospectiva y aleatoria de cirugía colorrectal electiva. Resultados: La serie corresponde a 122 pacientes, 60 de Ios cuales recibe PMA. Los datos epidemiológicos muestran que Ios grupos son comparables. En esta serie se encuentra un riesgo de morbilidad global aumentado al doble en Ios pacientes que reciben PMA, así como un riesgo de infección superficial del sitio quirúrgico seis veces mayor. No se encuentran diferencias en Ias infecciones profundas, dehiscencia de anastomosis ni en Ias reintervenciones. Las complicaciones asociadas a Ia PMA se presentaron sólo en un caso, 10 que no alcanza significación estadística. Conclusiones: De acuerdo a nuestros resultados, no sejustifica Ia utilización rutinaria de PMA.

Zn-EDTA degradabilty by catechol-driven Fenton reaction was studied. Response surface methodology central composite design was employed to maximize this complex degradation. Theoretical speciation calculations were in good agreement with the experimental results. Fenton and Fenton type treatments are typically thought to be applicable only in the highly acidic range, representing a major operational constraint. Interestingly, at optimized concentrations, this CAT-driven Fenton reaction at pH 5.5 achieved 100% Zn-EDTA degradation; 60% COD and 17% TOC removals, using tiny amounts of CAT (50 µM), Fe(III) (445 µM) and H2O2 (20 mM) with no evident ferric sludge.

A methodology to decrease the chromium concentration Cr(VI) existing in tannery discharges is suggested. The proposal is based on a photocatalytic process in which the effluent is irradiated by UV light in presence of TiO2 as a catalyst employing formaldehyde as a reductor agent. Were employed different Cr(VI) solutions of 100 mg/L as models at different pH, catalyst quanties and irradiation times. The variable optimization was made from multivaried analysis. The better conditions for to reduction a 50 ml of a Cr(VI) of 100 mg/L solutions were pH 2 at 20 minutes of UV irradiation and 40 mg of TiO2 load. In these conditions it was possible a 97.8 % of Cr(VI) reduction level. For a real effluent from tannery industries the reduction level was 81.3 %.

Se propone una metodología para disminuir la concentración de Cr(VI) presente en efluentes de curtiembre sin tratamiento previo. La propuesta se basa en un proceso fotocatalítico donde se irradia el efluente por un determinado tiempo con luz ultravioleta en presencia de óxido de titanio como catalizador, empleando como agente reductor formaldehido. Se utilizó sistemas modelo de soluciones de Cr(VI) de 100 mg/L a distintos pH con diferentes cantidades de catalizador y tiempos de irradiación. La optimización de las variables se realizó a través de análisis multi-variado Las condiciones óptimas para reducir 50 ml de Cr(VI) de 100 mg/L, se obtuvo a pH 2, con un tiempo de irradiación de 20 minutos y 40,0 mg de TiO2, logrando para el sistema modelo un 97,8 % de reducción de Cr(VI) y para el efluente de curtiembre un 81,3 %.

This paper shows the assembly of an ozonization system to be used in laboratory scale, mainly to study effluent treatability. The system is simple, practical and provides easy acquisition of data when interfaced to a microcomputer. The performance of ozone generation and K La values are also described.