Formulações e algoritmos para o problema das p-medianas heterogêneo livre de penalidade

This work presents a new model for the Heterogeneous p-median Problem (HPM), proposed to recover the hidden category structures present in the data provided by a sorting task procedure, a popular approach to understand heterogeneous individual’s perception of products and brands. This new model is named as the Penalty-free Heterogeneous p-median Problem (PFHPM), a single-objective version of the original problem, the HPM. The main parameter in the HPM is also eliminated, the penalty factor. It is responsible for the weighting of the objective function terms. The adjusting of this parameter controls the way that the model recovers the hidden category structures present in data, and depends on a broad knowledge of the problem. Additionally, two complementary formulations for the PFHPM are shown, both mixed integer linear programming problems. From these additional formulations lower-bounds were obtained for the PFHPM. These values were used to validate a specialized Variable Neighborhood Search (VNS) algorithm, proposed to solve the PFHPM. This algorithm provided good quality solutions for the PFHPM, solving artificial generated instances from a Monte Carlo Simulation and real data instances, even with limited computational resources. Statistical analyses presented in this work suggest that the new algorithm and model, the PFHPM, can recover more accurately the original category structures related to heterogeneous individual’s perceptions than the original model and algorithm, the HPM. Finally, an illustrative application of the PFHPM is presented, as well as some insights about some new possibilities for it, extending the new model to fuzzy environments

Características estruturais e fotocatalíticas do compósito oxihidróxido de nióbio/vermiculita

The preparation of nanostructured materials using natural clays as support, has been studied in literature under the same are found in nature and consequently, have a low price. Generally, clays serve as supports for metal oxides by increasing the number of active sites present on the surface and can be applied for various purposes such as adsorption, catalysis and photocatalysis. Some of the materials that are currently highlighted are niobium compounds, in particular, its oxides, by its characteristics such as high acidity, rigidity, water insolubility, oxidative and photocatalytic properties. In this scenario, the study aimed preparing a composite material oxyhydroxide niobium (NbO2OH) / sodium vermiculite clay and evaluate its effectiveness with respect to the natural clay (V0) and NbO2OH. The composite was prepared by precipitation-deposition method and then characterized by X-ray diffraction, infrared spectroscopy (XRD), energy dispersive X-ray (EDS), thermal analysis (TG/DTG), scanning electron microscopy (SEM), N2 adsorption-desorption and investigation of distribution of load. The application of the material NbO2OH/V0 was divided in two steps: first through oxidation and adsorption methods, and second through photocatalytic activity using solar irradiation. Studies of adsorption, oxidation and photocatalytic oxidation monitored the percentage of color removal from the dye methylene blue (MB) by UV-Vis spectroscopy. The XRD showed a decrease in reflection d (001) clay after modification; the FTIR indicated the presence of both the clay when the oxyhydroxide niobium to present bands in 1003 cm-1 related to Si-O stretching bands and 800 cm-1 to the Nb-O stretching. The presence of niobium was also confirmed by EDS indicated that 17 % by mass amount of the metal. Thermal analysis showed thermal stability of the composite at 217 °C and micrographs showed that there was a decrease in particle size. The investigation of the surface charge of NbO2OH/V0 found that the material exhibits a heterogeneous surface with average low and high negative charges. Adsorption tests showed that the composite NbO2OH/V0 higher adsorption capacity to remove 56 % of AM, while the material removed from V0 only 13 % showed no NbO2OH and adsorptive capacity due to the formation of H-aggregates. The percent removal of dye color for the oxidation tests showed little difference from the adsorption, being 18 and 66 % removal of dye color for V0 and NbO2OH/V0 respectively. The NbO2OH/V0 material shows excellent photocatalytic activity managing to remove just 95,5 % in 180 minutes of the color of MB compared to 41,4 % and 82,2 % of V0 the NbO2OH, proving the formation of a new composite with distinct properties of its precursors.

Estudo do comportamento da sinterização de compactos de cavacos de um aço SAE 1050 obtidos sob alta pressão

From an economic standpoint, the powder metallurgy (P/M) is a technique widely used for the production of small parts. It is possible, through the P/M and prior comminution of solid waste such as ferrous chips, produce highly dense sintered parts and of interest to the automotive, electronics and aerospace industries. However, without prior comminution the chip, the production of bodies with a density equal to theoretical density by conventional sintering techniques require the use of additives or significantly higher temperatures than 1250ºC. An alternative route to the production of sintered bodies with high density compaction from ferrous chips (≤ 850 microns) and solid phase sintering is a compression technique under high pressure (HP). In this work, different compaction pressures to produce a sintered chip of SAE 1050 carbon steel were used. Specifically, the objective was to investigate them, the effect of high pressure compression in the behavior of densification of the sintered samples. Therefore, samples of the chips from the SAE 1050 carbon steel were uniaxially cold compacted at 500 and 2000 MPa, respectively. The green compacts obtained were sintered under carbon atmosphere at 1100 and 1200°C for 90 minutes. The heating rate used was 20°C/min. The starting materials and the sintered bodies were characterized by optical microscopy, SEM, XRD, density measurements (geometric: mass/volume, and pycnometry) and microhardness measurements Vickers and Rockwell hardness. The results showed that the compact produced under 2000 MPa presented relative density values between 93% and 100% of theoretical density and microhardness between 150 HV and 180 HV, respectively. In contrast, compressed under 500 MPa showed a very heterogeneous microstructure, density value below 80% of theoretical density and structural conditions of inadequate specimens for carrying out the hardness and microhardness measurements. The results indicate that use of the high pressure of ferrous chips compression is a promising route to improve the sinterability conditions of this type of material, because in addition to promoting greater compression of the starting material, the external tension acts together with surface tension, functioning as the motive power for sintering process. Additionally, extremely high pressures allow plastic deformation of the material, providing an intimate and extended contact of the particles and eliminating cracks and pores. This tends to reduce the time and / or temperature required for good sintering, avoiding excessive grain growth without the use of additives. Moreover, higher pressures lead to fracture the grains in fragile or ductile materials highly hardened, which provides a starting powder for sintering, thinner, without the risk of contamination present when previous methods are used comminution of the powder.

Os estados no SUAS: uma análise da capacidade institucional dos governos estaduais na assistência social

This paper deals of the effects generated by institutional designs in the behavior of political actors. The literature that discusses the implications of federal arrangements in the production of public policies to dock at two opposing arguments: (1) the federal configuration would cause dispersion and variation in service provision between subnational governments; and (2) the central government would own mechanisms to induce the provision of national policies in more homogeneous levels, similar to unitary states. The research is part of this discussion because it analyzes the effects of the institutional design of the Sistema Único de Assistência Social (SUAS) in the decisions of states in Brazil. Therefore, we analyzed the institutional capacity built by the 26 state governments after the implementation of SUAS, conceiving this system as defined mechanism of government functions and federative cooperation.It is argued that the existence of a heterogeneous institutional capacity of state governments in social assistance is a result of the autonomy contained in the institutional design of SUAS to this level of government. This freedom of action relativize the idea that the implementation of national public policy systems would generate positive (or homogeneous) effects in all subnational governments, at the same time as it preclude to generalize the premise of fragility of the states in the brazilian federal plan.

Estudo da produção eletroquímica de espécies de cloro ativo para tratamento de efluentes sintéticos

The treatment of wastewater is essential to human health. One of the most important steps is the disinfection treatment which uses chlorine to eliminate bacteria as required by environmental agencies. However, the identification of potentially toxic byproducts generated by this method, such as trihalomethanes, has stimulated the development of new alternative disinfection technologies. Among them, heterogeneous photocatalysis, TiO2 photocatalysis and electrochemical disinfection are considered suitable alternatives to the chlorination method. Thus, the present dissertation analyzes the evolution of active chlorine species in a synthetic NaCl solution and it is tested to treat a synthetic solution of the dye Reactive Blue 19 using boron-doped diamond (BDD) and ruthenium oxide (Ti/Ru0.3Ti0.7O2) as anodes. The indirect electrochemical process was discussed in terms of mineralization of the total organic load and percentage of color removal in order to evaluate the applicability of electrochemical technology. Electrochemical experiments were carried out with different current densities (25, 50 and 75 mA.cm-2) during 120 minutes. On the other hand, other important parameter in this study was the influence of the proportion sp3/sp2 on BDD anode on the performance of the evolution of active chlorine species which was investigated by electrolytic techniques (linear polarization), with the intention of determining the related training oxidizing species and consumption energy to chemical or electrochemical reactions. From the results, it can be noted that the BDD electrode showed better efficiency throughout the electrochemical process.

Estudo da produção eletroquímica de espécies de cloro ativo para tratamento de efluentes sintéticos

The treatment of wastewater is essential to human health. One of the most important steps is the disinfection treatment which uses chlorine to eliminate bacteria as required by environmental agencies. However, the identification of potentially toxic byproducts generated by this method, such as trihalomethanes, has stimulated the development of new alternative disinfection technologies. Among them, heterogeneous photocatalysis, TiO2 photocatalysis and electrochemical disinfection are considered suitable alternatives to the chlorination method. Thus, the present dissertation analyzes the evolution of active chlorine species in a synthetic NaCl solution and it is tested to treat a synthetic solution of the dye Reactive Blue 19 using boron-doped diamond (BDD) and ruthenium oxide (Ti/Ru0.3Ti0.7O2) as anodes. The indirect electrochemical process was discussed in terms of mineralization of the total organic load and percentage of color removal in order to evaluate the applicability of electrochemical technology. Electrochemical experiments were carried out with different current densities (25, 50 and 75 mA.cm-2) during 120 minutes. On the other hand, other important parameter in this study was the influence of the proportion sp3/sp2 on BDD anode on the performance of the evolution of active chlorine species which was investigated by electrolytic techniques (linear polarization), with the intention of determining the related training oxidizing species and consumption energy to chemical or electrochemical reactions. From the results, it can be noted that the BDD electrode showed better efficiency throughout the electrochemical process.

Usos de membranas de quitosana na remoção de cobre em águas residuais

In this work a chitosan (CS) ionically crosslinked were manufactured by treatment with sulfuric acid solution for application in the treatment of wastewater from oil industry. Two crosslinking process were developed: homogeneous and heterogeneous. In the homogeneous process the ratio molar of SO42-/ NH3+ (1:6 and 1:4) were the variable analyzed, denominated CS16 and CS14 respectively. In the heterogeneous process the soaking time of the membranes in sulfuric acid solution were the variable studied, being used times of 5 (CS5) and 30 (CS30) minutes. FTIR-ATR results indicated no changes in the characteristics of chitosan after homogeneous crosslinking process, while heterogeneous crosslinking showed formation of ionic bonds between protonated groups from chitosan and the crosslinking agent sulfate ions. TG/DTG and XRD analysis confirmed the formation of these interactions, as also shown the new structure on the surface region of CS5 and CS30 membranes compared to CS, CS16 e CS14. Swelling test in aqueous medium have shown that crosslinking process reduced the membrane sorption capacity. Swelling test in acid medium demonstrated that CS16 and CS14 membranes increasing the adsorption capacity up to a maximum percentage of 140% approximately, whereas the CS5 e CS30 reached a maximum of 60%. The mechanical properties indicated the stiff and ductile behavior of crosslinked membrane. Adsorption experiments of CuCl2 results that CS16 membranes reached the efficiency maximum with 73% of copper removal at pH 5.0 and 87% at pH 4.0. The experiments with CuSO4 also obtained efficiency maximum to the CS16 membrane and 80% to the removal of Cu2+ ions. Also was verified that the increase of concentration and temperature cause a decrease in the adsorption capacity for all membranes. Kinetics study indicated that pseudo-second-order obtained characterized better the membranes. Equilibrium studies demonstrated that the CS, CS16 and CS14 follow the Langmuir model, whereas CS5 and CS30 follows Freundlich model. Filtration experiments results with rejection maximum to the CS16 and CS5 membranes, reaching 92 and 98% respectively.

Usos de membranas de quitosana na remoção de cobre em águas residuais

In this work a chitosan (CS) ionically crosslinked were manufactured by treatment with sulfuric acid solution for application in the treatment of wastewater from oil industry. Two crosslinking process were developed: homogeneous and heterogeneous. In the homogeneous process the ratio molar of SO42-/ NH3+ (1:6 and 1:4) were the variable analyzed, denominated CS16 and CS14 respectively. In the heterogeneous process the soaking time of the membranes in sulfuric acid solution were the variable studied, being used times of 5 (CS5) and 30 (CS30) minutes. FTIR-ATR results indicated no changes in the characteristics of chitosan after homogeneous crosslinking process, while heterogeneous crosslinking showed formation of ionic bonds between protonated groups from chitosan and the crosslinking agent sulfate ions. TG/DTG and XRD analysis confirmed the formation of these interactions, as also shown the new structure on the surface region of CS5 and CS30 membranes compared to CS, CS16 e CS14. Swelling test in aqueous medium have shown that crosslinking process reduced the membrane sorption capacity. Swelling test in acid medium demonstrated that CS16 and CS14 membranes increasing the adsorption capacity up to a maximum percentage of 140% approximately, whereas the CS5 e CS30 reached a maximum of 60%. The mechanical properties indicated the stiff and ductile behavior of crosslinked membrane. Adsorption experiments of CuCl2 results that CS16 membranes reached the efficiency maximum with 73% of copper removal at pH 5.0 and 87% at pH 4.0. The experiments with CuSO4 also obtained efficiency maximum to the CS16 membrane and 80% to the removal of Cu2+ ions. Also was verified that the increase of concentration and temperature cause a decrease in the adsorption capacity for all membranes. Kinetics study indicated that pseudo-second-order obtained characterized better the membranes. Equilibrium studies demonstrated that the CS, CS16 and CS14 follow the Langmuir model, whereas CS5 and CS30 follows Freundlich model. Filtration experiments results with rejection maximum to the CS16 and CS5 membranes, reaching 92 and 98% respectively.

Implementações metodológicas para o estudo eletrofisiológico e comportamental em um modelo animal de autismo

O autismo é um transtorno do desenvolvimento que se manifesta nos primeiros anos de vida e apresenta semiologia heterogênea. Esta patologia afeta a maturação do encéfalo e produz alterações sensoriais, de linguagem e de interação social no início na infância. O modelo experimental de autismo utilizando ácido valproico (VPA) durante o período gestacional tem sido demonstrado ter alta validade de face e permitir estudos tanto das bases neuropatológicas quanto neuro-funcionais durante o desenvolvimento. A despeito do recente interesse por este modelo como instrumento de compreensão dos aspectos básicos da fisiopatologia do autismo, a maioria dos estudos experimentais têm se concentrado nos aspectos comportamentais, histológicos e celulares. Neste trabalho, foram propostas estratégias experimentais de avaliação comportamental associadas a eletrofisiologia \textit{in vivo}, uma técnica que nunca fora utilizada para avaliação desse modelo. Animais controles e experimentais, submetidos previamente a um procedimento cirúrgico para implante de eletrodos crônicos, participaram de experimentos de livre exploração, interação social e condicionamento ao medo.

Estudio de la enfermedad renal y la respuesta al tratamiento (antimoniales "versus" miltefosina) en perros con infección natural por "Leishmania infantum"

La leishmaniosis canina (Lcan) es una zoonosis en toda la Cuenca Mediterránea y está producida por un protozoo intracelular, Leishmania infantum, transmitido por especies del género Phlebotomus. La enfermedad se caracteriza por una presentación clínica heterogénea en la cual la lesión renal es, con frecuencia, la causa principal de mortalidad. La nefropatía asociada a Lcan se atribuye fundamentalmente al depósito intraglomerular de inmunocomplejos circulantes. La combinación de antimoniato de n-meglumina (antimoniales) con alopurinol se considera el tratamiento de primera línea en esta enfermedad, aunque algunos estudios han demostrado que la combinación de miltefosina y alopurinol tiene una eficacia similar. A pesar de ser considerado el tratamiento más eficaz, el uso de antimoniato se asocia a efectos adversos sobre la funcionalidad renal lo cual puede ocasionar complicaciones importantes en el manejo de estos pacientes. A ello se suma la escasa sensibilidad de las pruebas diagnósticas disponibles hasta ahora en la clínica veterinaria para poder establecer un diagnóstico precoz de lesión renal. Es decir, el propio tratamiento podría agravar una posible alteración en la funcionalidad renal en pacientes que ya la tuvieran alterada debido a la leishmaniosis. Los perros infectados y tratados, en la mayoría de los casos, no alcanzan la curación parasitológica y sufren recidivas después del tratamiento. Las técnicas habituales para valorar la respuesta al tratamiento son la evolución de la tasa de anticuerpos y la electroforesis de proteínas plasmáticas. La normalización de las proteínas plasmáticas ocurre en paralelo con la mejoría clínica, pudiéndose emplear como marcadores de respuesta al tratamiento; sin embargo, la serología parece menos útil, a corto plazo, porque el descenso del título de anticuerpos es más lento. Se ha postulado que otros parámetros laboratoriales, como las proteínas de fase aguda, pueden ser una buena opción como marcadores precoces de la enfermedad y también para la monitorización del tratamiento...

CUDA-MMP - Codificação de imagens com sistemas com múltiplos núcleos

Hoje em dia, a área de codificação de dados é transversal a diversos tipos de engenharias devido à sua grande importância. Com o aumento exponencial na criação de dados digitais, o campo da compressão de dados ganhou uma grande visibilidade nesta área. São constantemente desenvolvidos e melhorados algoritmos de compressão por forma a obter a maior compressão de dados possível seja com ou sem perda de dados, permitindo sustentar o rápido e constante crescimento dos mesmos. Um dos grandes problemas deste tipo de algoritmos deve-se ao grande poder computacional que por vezes é necessário para obter uma boa taxa de compressão mantendo a qualidade dos dados quando descompactados. Este documento descreve uma estratégia para tentar reduzir o impacto do poder computacional necessário à codificação de imagens utilizando uma implementação heterogénea. O objetivo é tentar efetuar a paralelização das secções que requerem elevado poder computacional reduzindo assim o tempo necessário à compressão de dados. Este documento baseia-se na implementação desta estratégia para o algoritmo de codificação de imagens MMP-Intra. Utilizando inicialmente uma análise teórica, demonstramos que é viável efetuar a paralelização do algoritmo, sendo possível obter elevados ganhos de desempenho. Por forma a provar que o algoritmo MMP-Intra era paralelizavel e identificar os ganhos reais foi desenvolvido um protótipo inicial, o qual obteve um desempenho muito inferiore ao do algoritmo original, necessitando de muito mais tempo para obter os mesmo resultados. Utilizando um processo de otimização iterativo o protótipo passou por várias etapas de refinação. O protótipo refinado final obteve resultados muito superiores ao algoritmo sequencial no qual o mesmo foi baseado chegando a obter desempenhos quatro vezes superior ao original.

Habilitaciones y ubicuidades. Repensando la sociabilidad juvenil en los nuevos medios digitales. Un estudio comparativo a partir del Programa Conectar Igualdad

En los últimos años en América Latina, y también a nivel mundial, el acceso de la población a las Tecnologías de la Información y la Comunicación (TIC) ha cobrado gran masividad, expandiéndose de forma heterogénea entre los distintos sectores de la sociedad, y adquiriendo relevancia en el campo de la investigación social. En varios países de la región los Estados nacionales han impulsado la implementación de planes masivos de alfabetización digital (como el Plan Ceibal en Uruguay, el Prouca en Brasil, el Plan Conectar Igualdad en la Argentina y otros). Así, tanto desde agencias estatales, organismos internacionales y regionales (CEPAL, OIT, OSILAC), como desde el campo académico, se han producido distintas perspectivas e interpretaciones sobre el desarrollo de las TIC. Sin desconocer los aportes de las perspectivas centradas en el estudio del acceso y de las brechas digitales, en esta ponencia nos enfocaremos en los procesos de apropiación de las TIC. Al respecto, presentaremos las conclusiones preliminares de una investigación en curso acerca de las experiencias de apropiación, los usos y prácticas que despliegan jóvenes de sectores populares y sectores medios - alto urbanos del Gran La Plata en su vida cotidiana en relación a las TIC

El impacto social de modelos 1 a 1 en adolescentes y sus familias de América Latina : Un Estado del Arte

En las últimas décadas, las Tecnologías de la Información y la Comunicación (TIC) han adquirido mayor presencia en la sociedad, formando parte de la vida cotidiana de grandes sectores de la población. En este contexto, distintos países han comenzado a implementar políticas públicas, entre las que se destacan los Modelos 1 a 1 (una computadora portátil por alumno) de incorporación de TIC en educación, para posibilitar el acceso de niños y jóvenes a las tecnologías digitales, y así disminuir la brecha digital y generar inclusión. Dado que el desarrollo de Modelos 1 a 1 es aún incipiente, resulta necesario establecer el estado del arte en las investigaciones sobre su impacto social para generar hipótesis de trabajo y orientar la metodología. En base a la literatura relevada, surgen preguntas sobre los cambios y tensiones surgidos en el seno familiar y las dinámicas hogareñas a partir de la incorporación de la netbook, su incidencia en las prácticas del tiempo libre y en la sociabilidad juvenil, y su impacto en la comunidad. A partir de estos interrogantes, el proyecto Juventud, TICs y desigualdades, en el que se inscribe este trabajo, aborda el proceso de apropiación de las TIC por parte de jóvenes en contextos de desigualdad en La Plata y Berisso, en el marco de la implementación del Programa Conectar Igualdad. En este trabajo, presentamos un análisis de investigaciones realizadas en países de América Latina enfocándonos en el abordaje metodológico, la conceptualización del impacto social de la tecnología, los consensos entre los estudios, las evidencias y conclusiones a las que arribaron.Ante todo, encontramos que la temática abordada constituye un área de vacancia en las Ciencias Sociales, con evidencia empírica relativa, propia de una fase exploratoria, ya que gran parte de las investigaciones se han orientado hacia los aspectos educativos y pedagógicos del Modelo 1 a 1 mientras que su impacto en el tiempo libre, el hogar y la comunidad han sido poco abordados. Dentro de este panorama, las investigaciones existentes consideran que las TIC son herramientas aprovechadas y apropiadas de manera heterogénea, según el contexto y, que las políticas públicas basadas en Modelos 1 a 1, son estrategias válidas para la inclusión e igualación de oportunidades en términos de acceso y conectividad. En relación a la adquisición de nuevos conocimientos, se encuentra que los beneficiarios de los programas desarrollan habilidades básicas vinculadas al uso de la computadora e internet, constituyendo una base para la reducción de la llamada brecha digital de segundo orden, relativa al tipo de uso de las TIC.Con respecto a los cambios en el hogar, los impactos evidenciados no pueden pensarse de manera lineal ni generalizada, ya que se vinculan con características propias de cada familia, sus prácticas y valoración de la tecnología. Por último, en relación a las transformaciones en la sociabilidad y el impacto comunitario, las investigaciones señalan que la incorporación de las TIC bajo modalidades 1 a 1 es un proceso que se asienta sobre relaciones y prácticas ya existentes, por lo que no determina ni condiciona ningún vínculo por sí misma

"O sumidoiro da memoria, que o mesmo serve para lembrar que para esquecer" : Reflexiones sobre la memoria en los cuentos de Manuel Rivas

Mucho antes de la publicación de sus novelas, Manuel Rivas ya había tratado el tema de la memoria en sus cuentos. Recopilados en O máis estrano en 2011, en ellos se observa una predilección por este tema y muchos de ellos constituyen el germen de las grandes novelas posteriores. En este trabajo se analizará, por un lado, la memoria como creadora de experiencia artística. Por otro, se tendrá en cuenta el tratamiento de la memoria personal o íntima, así como la llamada memoria histórica. En un lugar destacado se situará la memoria cultural, cuyos diversos aspectos permiten a Rivas llevar a cabo una reflexión sobre la visión identitaria de Galicia en la que está presente la realidad y el mito, para la cual el cuento, por su morfología heterogénea y libertaria, se revela como el género más apropiado.

Habilitaciones y ubicuidades. Repensando la sociabilidad juvenil en los nuevos medios digitales. Un estudio comparativo a partir del Programa Conectar Igualdad

En los últimos años en América Latina, y también a nivel mundial, el acceso de la población a las Tecnologías de la Información y la Comunicación (TIC) ha cobrado gran masividad, expandiéndose de forma heterogénea entre los distintos sectores de la sociedad, y adquiriendo relevancia en el campo de la investigación social. En varios países de la región los Estados nacionales han impulsado la implementación de planes masivos de alfabetización digital (como el Plan Ceibal en Uruguay, el Prouca en Brasil, el Plan Conectar Igualdad en la Argentina y otros). Así, tanto desde agencias estatales, organismos internacionales y regionales (CEPAL, OIT, OSILAC), como desde el campo académico, se han producido distintas perspectivas e interpretaciones sobre el desarrollo de las TIC. Sin desconocer los aportes de las perspectivas centradas en el estudio del acceso y de las brechas digitales, en esta ponencia nos enfocaremos en los procesos de apropiación de las TIC. Al respecto, presentaremos las conclusiones preliminares de una investigación en curso acerca de las experiencias de apropiación, los usos y prácticas que despliegan jóvenes de sectores populares y sectores medios - alto urbanos del Gran La Plata en su vida cotidiana en relación a las TIC