Universidad, conocimiento y economía

La política de desarrollo tecnológico y derivada de esta, el papel que se pretende asignar a la universidad, se sustenta en un conjunto de ideas e interpretaciones erradas sobre la articulación entre ciencia, investigación y aplicaciones tecnológicas; ideas que han ido adquiriendo, aun en el medio académico, el estatus de sabiduría convencional de tal manera que, aceptadas como verdades, tienden a legitimar la acción de las instituciones y agencias gubernamentales. Este artículo analiza la propensión de ver a la universidad como la fuente de conocimiento e información directamente aplicable para la producción de bienes y servicios comerciales y cuestiona la perspectiva de considerar a la universidad simplemente como un agente de la esfera económica. El trabajo sostiene que el papel de la investigación universitaria consiste básicamente en un insumo para la enseñanza y que el bien público que provee la universidad es la creación de un sentido nacional de cultura, una forma de identidad y cohesión social.

Tendencias y desafíos de la ciencia y tecnología en el sector agrícola en Ecuador

A partir de la Segunda Guerra Mundial se produce una vinculación más estrecha entre ciencia, tecnología y economía, lo que da origen a la política científica, en torno a la cual surgieron posturas contrapuestas que colocaron en el centro del debate la relación entre el conocimiento y la producción. Bajo esta premisa, las actividades e instituciones relacionadas al conocimiento en Ecuador fueron influenciadas por las corrientes mundiales. El gobierno actual promueve junto con un cambio de paradigma: del “Desarrollo” al “Buen Vivir”, un cambio en el modelo de inserción primario exportador del país que apuesta a la transformación de la estructura productiva del país. En este esquema, la ciencia y la tecnología son elementos claves para la reconversión productiva que ayudarán a consolidar la sociedad del conocimiento. El propósito del presente estudio es mostrar los cambios en las políticas e instituciones públicas que dan forma al nuevo paradigma basado en el conocimiento, la ciencia y la tecnología y conocer cómo generan las alternativas que reemplazan la lógica extractivista, agroexportadora y petrolera. Con este propósito, se repasan las actividades emprendidas por la SENESCYT, entidad gubernamental que lidera el cambio de matriz productiva y ejerce la rectoría de la investigación científica en el país. Dada la importancia acordada por el gobierno a los institutos públicos de investigación, se toma como objeto de análisis al INIAP para mostrar en la práctica la forma en que ha operado el cambio de paradigma en el campo de la investigación agropecuaria y las articulaciones de la investigación agrícola pública con la transformación de la matriz productiva.

Iridaea cordata (Gigartinales, Rhodophyta): responses to artificial UVB radiation

The effects of UVB radiation on the different developmental stages of the carrageenan-producing red alga Iridaea cordata were evaluated considering: (1) carpospore and discoid germling mortality; (2) growth rates and morphology of young tetrasporophytes; and (3) growth rates and pigment content of field-collected plant fragments. Unialgal cultures were submitted to 0.17, 0.5, or 0.83 W m(-2) of UVB radiation for 3 h per day. The general culture conditions were as follows: 12 h light/12 h dark cycles; irradiance of 55 mu mol photon. per square meter per second; temperature of 9 +/- 1 degrees C; and seawater enriched with Provasoli solution. All UVB irradiation treatments were harmful to carpospores (0.17 W m(-2) = 40.9 +/- 6.9%, 0.5 W m(-2) = 59.8 +/- 13.4%, 0.83 W m(-2) = 49 +/- 17.4% mortality in 3 days). Even though the mortality of all discoid germlings exposed to UVB radiation was unchanged when compared to the control, those germlings exposed to 0.5 and 0.83 W m(-2) treatments became paler and had smaller diameters than those cultivated under control treatment. Decreases in growth rates were observed in young tetrasporophytes, mainly in 0.5 and 0.83 W m(-2) treatments. Similar effects were only observed in fragments of adult plants cultivated at 0.83 W m(-2). Additionally, UVB radiation caused morphological changes in fragments of adult plants in the first week, while the young individuals only displayed this pattern during the third week. The verified morphological alterations in I. cordata could be interpreted as a defense against UVB by reducing the area exposed to radiation. However, a high level of radiation appears to produce irreparable damage, especially under long-term exposure. Our results suggest that the sensitivity to ultraviolet radiation decreases with increased algal age and that the various developmental stages have different responses when exposed to the same doses of UVB radiation.

Effects of lipid-lowering drugs on reverse cholesterol transport gene expressions in peripheral blood mononuclear and HepG2 cells

Aims: The ATP-binding cassette transporters, ABCA1 and ABCG1, are LXR-target genes that play an important role in reverse cholesterol transport. We examined the effects of inhibitors of the cholesterol absorption (ezetimibe) and synthesis (statins) on expression of these transporters in HepG2 cells and peripheral blood mononuclear cells (PBMCs) of individuals with primary (and nonfamilial) hypercholesterolemia (HC). Materials & methods: A total of 48 HC individuals were treated with atorvastatin (10 mg/day/4 weeks) and 23 were treated with ezetimibe (10 mg/day/4 weeks), followed by simvastatin (10 mg/day/8 weeks) and simvastatin plus ezetimibe (10 mg of each/day/4 weeks). Gene expression was examined in statin- or ezetimibe-treated and control HepG2 cells as well as PBMCs using real-time PCR. Results: In PBMCs, statins and ezetimibe downregulated ABCA1 and ABCG1 mRNA expression but did not modulate NR1H2 (LxR-beta) and NR1H3 (LXR-alpha) levels. Positive correlations of ABCA1 with ABCG1 and of NR1H2 with NR1H3 expressions were found in all phases of the treatments. In HepG2 cells, ABCA1 mRNA levels remained unaltered while ABCG1 expression was increased by statin (1.0-10.0 mu M) or ezetimibe (5.0 mu M) treatments. Atorvastatin upregulated NR1H2 and NR1H3 only at 10.0 mu M, meanwhile ezetimibe (1.0-5.0 mu M) downregulated NR1H2 but did not change NR1H3 expression. Conclusion: Our findings reveal that lipid-lowering drugs downregulate ABCA1 and ABCG1 mRNA expression in PBMCs of HC individuals and exhibit differential effects on HepG2 cells. Moreover, they indicate that the ABCA1 and ABCG1 transcript levels were not correlated directly to LXR mRNA expression in both cell models treated with lipid-lowering drugs.

Putative outer membrane proteins of Leptospira interrogans stimulate human umbilical vein endothelial cells (HUVECS) and express during infection

Cell adhesion molecules (CAMs) are surface receptors present in eukaryotic cells that mediate cell-cell or cell-extracellular matrix interactions. Vascular endothelium stimulation in vitro that lead to the upregulation of CAMs was reported for the pathogenic spirochaetes, including rLIC10365 of Leptospira interrogans. In this study, we report the cloning of LIC10507, LIC10508, LIC10509 genes of L interrogans using Escherichia coli as a host system. The rational for selecting these sequences is due to their location in L. interrogans serovar Copenhageni genome that has a potential involvement in pathogenesis. The genes encode for predicted lipoproteins with no assigned functions. The purified recombinant proteins were capable to promote the upregulation of intercellular adhesion molecule 1 (ICAM-1) and E-selectin on monolayers of human umbilical vein endothelial cells (HUVECS). In addition, the coding sequences are expressed in the renal tubules of animal during bacterial experimental infection. The proteins are probably located at the outer membrane of the bacteria since they are detected in detergent-phase of L interrogans Triton X-114 extract. Altogether our data suggest a possible involvement of these proteins during bacterial infection and provide new insights into the role of this region in the pathogenesis of Leptospira. (C) 2008 Elsevier Ltd. All rights reserved.

Tight-binding model for carbon nanotubes from ab initio calculations

Here we present a parametrized tight-binding (TB) model to calculate the band structure of single-wall carbon nanotubes (SWNTs). On the basis of ab initio calculations we fit the band structure of nanotubes of different radii with results obtained with an orthogonal TB model to third neighbors, which includes the effects of orbital hybridization by means of a reduced set of parameters. The functional form for the dependence of these parameters on the radius of the tubes can be used to interpolate appropriate TB parameters for different SWNTs and to study the effects of curvature on their electronic properties. Additionally, we have shown that the model gives an appropriate description of the optical spectra of SWNTs, which can be useful for a proper assignation of SWNTs` specific chirality from optical absorption experiments.

The Crystal Complex of Phosphofructokinase-2 of Escherichia coli with Fructose-6-phosphate KINETIC AND STRUCTURAL ANALYSIS OF THE ALLOSTERIC ATP INHIBITION

Substrate inhibition by ATP is a regulatory feature of the phosphofructokinases isoenzymes from Escherichia coli (Pfk-1 and Pfk-2). Under gluconeogenic conditions, the loss of this regulation in Pfk-2 causes substrate cycling of fructose-6-phosphate (fructose-6-P) and futile consumption of ATP delaying growth. In the present work, we have broached the mechanism of ATP-induced inhibition of Pfk-2 from both structural and kinetic perspectives. The crystal structure of Pfk-2 in complex with fructose-6-P is reported to a resolution of 2 angstrom. The comparison of this structure with the previously reported inhibited form of the enzyme suggests a negative interplay between fructose-6-P binding and allosteric binding of MgATP. Initial velocity experiments show a linear increase of the apparent K(0.5) for fructose-6-P and a decrease in the apparent k(cat) as a function of MgATP concentration. These effects occur simultaneously with the induction of a sigmoidal kinetic behavior (n(H) of approximately 2). Differences and resemblances in the patterns of fructose-6-P binding and the mechanism of inhibition are discussed for Pfk-1 and Pfk-2, as an example of evolutionary convergence, because these enzymes do not share a common ancestor.

Fano resonance in heavily doped porous silicon

Unexpectedly, the Fano resonance caused by the interference of continuum electron excitations with the longitudinal optical (LO) phonons was observed in random porous Si by Raman scattering. The analysis of the experimental data shows that the electron states trapped at the Si-SiO(2) interface dominate in the observed Raman scattering. The gap energy associated with the interface states was determined. Copyright (C) 2011 John Wiley & Sons, Ltd.

Validação do monitor de medida de pressão arterial Omron HEM 742 em adolescentes

FUNDAMENTO: A medida precisa da pressão arterial é fundamental para a investigação científica ou decisão clínica. Nesse sentido, é importante verificar valores fornecidos por equipamentos eletrônicos. OBJETIVO: Validar o monitor Omron HEM 742 de medida de pressão arterial em adolescentes, segundo os critérios sugeridos pela British Hypertension Society. MÉTODOS: Participaram do estudo 150 adolescentes com idades entre 10 e 16 anos. O monitor automático Omron HEM 742 foi conectado em Y com equipamento auscultatório de coluna de mercúrio, e realizaram-se três avaliações simultâneas, calculando-se as diferenças entre os dois equipamentos. Para verificar a relação entre ambos, utilizaram-se o coeficiente de correlação intraclasse e a plotagem de Bland-Altman (concordância). A especificidade e a sensibilidade do aparelho foram determinadas pela curva ROC. RESULTADOS: A comparação entre as medidas acusou uma diferença menor ou igual a 5 mmHg em 67,3% dos valores sistólicos e 69,3% dos valores diastólicos; uma diferença menor ou igual a 10 mmHg ocorreu em 87,3% e 90,6% dos valores sistólicos e diastólicos, respectivamente; e uma diferença menor ou igual a 15 mmHg em 96,6% dos valores sistólicos e 97,3% dos diastólicos. Esses resultados indicam grau A segundo o protocolo da British Hypertension Society. Observou-se ainda elevada concordância nos valores obtidos por meio do monitor automático, e verificou-se que esse equipamento é capaz de identificar a presença ou a ausência da pressão arterial elevada. CONCLUSÃO: O monitor Omron HEM 742 mostrou-se válido para medidas de pressão arterial em adolescentes, conforme os critérios sugeridos pela British Hypertension Society.

Wilhelm Reich e a produção acadêmica brasileira entre 1979 e 2008

O interesse por pesquisas relacionadas a Wilhelm Reich é notório nos últimos anos. Com o intuito de contribuir com a difusão das produções acadêmicas nesse campo, o objetivo desta pesquisa foi identificar as dissertações de mestrado e as teses de doutorado desenvolvidas em universidades brasileiras entre 1979 e 2008. Os resultados revelaram a existência de 81 produções acadêmicas, das quais 60 são dissertações de mestrado e 21, teses de doutorado. Isso nos leva a concluir que Reich tem sido objeto de interesse de pesquisadores em áreas diversas, o que evidencia que esse autor é um referencial teórico importante para a reflexão de temas contemporâneos.

Desarrollo competitivo de un clúster biotecnológico: el biopolo de Santiago

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Costa Rica: Sistema Nacional de Innovación

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Dinámica demográfica y desarrollo en América Latina y el Caribe

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