El mercado móvil de telecomunicaciones en Colombia ante externalidades de red

Si bien la generalidad de los mercados de telefonía móvil se consideran suficientemente competidos, los mercados en los que el operador más grande supera ampliamente en participación de mercado a sus seguidores constituyen un motivo de preocupación para sus respectivas autoridades regulatorias y de competencia. El análisis económico del problema ha llevado a que exista una cantidad creciente de literatura relacionada, principalmente con el propósito de analizar la persistencia de la asimetría en las cuotas de mercado. Tal es el caso del mercado móvil de telecomunicaciones en Colombia, donde la Comisión de Regulación de Comunicaciones ha sostenido que a la luz del problema de competencia que se origina por la unión de una participación de mercado considerablemente asimétrica y el diferencial de precios, el operador más grande adquiere una ventaja competitiva considerable frente a los demás operadores en el mercado, y por lo tanto es un operador con poder significativo de mercado, u operador con posición dominante. Por lo anterior, el presente trabajo evalúa la imposición de algunas medidas regulatorias con el fin de verificar si estas contribuyen a generar una mayor competencia en el mercado, y mejores condiciones para los operadores competidores.

Retos del periodismo ¿en jaque?

Actualmente estamos siendo testigos de una segunda revolución tecnológica, en la que se hace evidente el surgimiento de dos nuevos paradigmas en relación con la entronización del mercado y la tecnología. Estos paradigmas han modificado sustancialmente la esfera de la comunicación y en particular, el ámbito de la información. Estos cambios, rastreables al fenómeno de la globalización, plantean nuevos dilemas que cuestionan la labor y el ejercicio periodístico, lo que forzosamente nos lleva a preguntarnos ¿cuáles son los principales retos del periodista en el contexto actual de la globalización?

Innovación en tecnologías digitales

El siguiente trabajo es una recopilación de información sobre la tecnología digital y su proceso de evolución hasta nuestros días. Pretende mostrar como la innovación ha sido un motor de cambio en este sector, ideando un nuevo modelo de negocio donde su cadena de valor para llegar al cliente es más rápida, flexible y rentable. El mundo digital abarca múltiples conocimientos y ha revolucionado la sociedad de conocimiento a través de las tecnologías de comunicación, tanto en la academia, el entretenimiento y todas las ciencias. En Colombia la industria digital ha tenido un gran impulso a través del ministerio de tecnología y comunicación y empresas que han motivado e impulsado a emprendedores a desarrollar aplicaciones e incursionar en este mercado que ofrece grandes ventajas competitivas.

Diferencias entre la regla de exclusión probatoria nacional y la regla de exclusión del Derecho Internacional Penal: análisis de tres casos de injerencias en comunicaciones privadas.

Teniendo en cuenta tres casos dentro del contexto del conflicto armado donde la jurisdicción penal colombiana estudia la admisión o exclusión de medios probatorios producidos a partir de injerencias de comunicaciones, encontramos que no siempre se aplica la regla de exclusión cuando no cuentan con una orden judicial previa. Ante este problema, buscamos como se ha solucionado, teniendo como referente la el Derecho Internacional Humanitario, el Derecho Internacional de los Derechos Humanos. Lo anterior nos da base para entender la regla de exclusión de que se ha venido desarrollando dentro del Derecho Internacional Penal. Si bien estas reglas nos sirven para solucionar estos tres casos, terminan siendo contradictorios a lo que ha venido desarrollando la Corte Constitucional. De esta manera, si bien esta Corte consideró que la regla de Estatuto de Roma, va en concordancia con la nuestra regla de exclusión nacional, tal afirmación es errónea.

Regulatory governance in the latinamerican telecommunications sector

Empezando con Chile a comienzos de 1980, los países de América Latina han profundizado la reforma a las telecomunicaciones para crear un entorno regulatorio que incentive la inversión privada, en particular la inversión extranjera. En este artículo, trabajo las tendencias regulatorias en el sector telecomunicaciones de 24 países latinoamericanos y del caribe durante el período 1980-1997 y construyo un índice basado en : autonomía, rendición de cuentas, claridad de las funciones y objetivos, transparencia y participación, y el tipo de mandato legal que crea el ente regulador. El índice muestra que, en promedio, la mayoría de los países llevaron a cabo fuertes reformas regulatorias en la dirección sugerida por expertos e investigadores. El índice también se correlación bien con varias variables políticas, de riesgo, económicas y de telecomunicaciones.

Heterosis for yield and its physiological determinants in wheat

Heterosis in hybrid wheat varieties produced using a chemical hybridising agent was assessed in field experiments. Hyno Esta and its parents were compared in factorial combinations of four-seed rates (25-300 seeds m(-2)) and two nitrogen fertilizer rates (0 and 200 kg N ha(-1)) in 2001/02 and again in 2002/03. Hyno Rista and Hyno Renta and their parents were compared at two-seed rates in 2001/02. Hyno Rista and its parents were added factorially to the Hyno Esta experiment in 2002/03, while Hyno Renta and Hybred and their parents were compared at two seed rates in 2002/03. Mid parent heterosis for grain yield was found in three hybrids and two of these showed high parent heterosis. High parent heterosis in Hyno Esta over a range of sowing densities was mostly exhibited in total biomass but also, in one of two years, in harvest index. High parent heterosis in Hyno Renta was associated more with harvest index than with biomass. The heterosis for biomass in Hyno Esta resulted from greater interception of photosynthetically active radiation (PAR) than the male parent, with better radiation use efficiency than the female parent. In both seasons Hyno Esta achieved grain numbers per ear at least as high as the high parent for this trait (Audace), and combined this with mean grain weights at least as heavy as the high parent for mean grain weight (Estica). Much of the increased biomass and grain yield in the hybrid came late in the season as high parent heterosis was expressed for both maximum grain filling rate and grain filling duration. Heterosis was higher when nitrogen was applied than when withheld; only greater at lower seed rates when expressed in proportionate terms (e.g. as a percentage of the parents), rather than in absolute terms (e.g. t ha(-1)); and greater in the year with the cooler and wetter summer.

Gibberellin-responsive and -insensitive dwarfing alleles on wheat performance in contrasting tillage systems

Near-isogenic lines (NILs) of winter wheat varying for alleles for reduced height (Rht), gibberellin (GA) response and photoperiod insensitivity (Ppd-D1a) in cv. Mercia background (rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht8c+Ppd-D1a, Rht-D1c, Rht12) and cv. Maris Widgeon (rht (tall), Rht-D1b, Rht-B1c) backgrounds were compared to investigate main effects and interactions with tillage (plough-based, minimum-, and zero-tillage) over two years. Both minimum- and zero- tillage were associated with reduced grain yields allied to reduced harvest index, biomass accumulation, interception of photosynthetically active radiation (PAR), and plant populations. Grain yields were optimized at mature crop heights of around 740mm because this provided the best compromise between harvest index which declined with height, and above ground biomass which increased with height. Improving biomass with height was due to improvements in both PAR interception and radiation-use efficiency. Optimum height for grain yield was unaffected by tillage system or GA-sensitivity. After accounting for effects of height, GA insensitivity was associated with increased grain yields due to increased grains per spike, which was more than enough to compensate for poorer plant establishment and lower mean grain weights compared to the GA-sensitive lines. Although better establishment was possible with GA-sensitive lines, there was no evidence that this effect interacted with tillage method. We find, therefore, little evidence to question the current adoption of wheats with reduced sensitivity to GA in the UK, even as tillage intensity lessens.

Perspective: LaGuardia Community College Newsletter (Fall 1981)

Vol. 10 No, 1 Fall 1981; Perspective is a quarterly publication of LaGuardia Community College / CUNY which is designed and edited by the Office of Communications, Bill Freeland, director. Information on news and features stories should be addressed to the office In room M194. Faculty and staff news items should be sent to Dr. Roberta Matthews, Associate Dean of Faculty, room SB65.

Perspective: LaGuardia Community College Newsletter (Spring 1981)

Vol.9 No.1 Spring 1981; Perspective is a quarterly publication of LaGuardia Community College / CUNY which is designed and edited by the Office of Communications, Bill Freeland, director. Information on news and features stories should be addressed to the office In room M194. Faculty and staff news items should be sent to Dr. Roberta Matthews, Associate Dean of Faculty, room SB65.

Perspective: LaGuardia Community College Newsletter (Fall 1982)

Vol. 11 No. 1; Perspective is a quarterly publication of LaGuardia Community College / CUNY which is designed and edited by the Office of Communications, Bill Freeland, director. Information on news and features stories should be addressed to the office In room M194. Faculty and staff news items should be sent to Dr. Roberta Matthews, Associate Dean of Faculty, room SB65.

Perspective: LaGuardia Community College Newsletter (Winter 1982)

Vol. 10 No. 2; Perspective is a quarterly publication of LaGuardia Community College / CUNY which is designed and edited by the Office of Communications, Bill Freeland, director. Information on news and features stories should be addressed to the office In room M194. Faculty and staff news items should be sent to Dr. Roberta Matthews, Associate Dean of Faculty, room SB65.

Perspective: LaGuardia Community College Newsletter (Spring 1983)

Vol. 11 No.2; Perspective is a quarterly publication of LaGuardia Community College / CUNY which is designed and edited by the Office of Communications, Bill Freeland, director. Information on news and features stories should be addressed to the office In room M194. Faculty and staff news items should be sent to Dr. Roberta Matthews, Associate Dean of Faculty, room SB65.

Perspective: LaGuardia Community College Newsletter (Fall 1983)

Vol. 12 No.1; Perspective is a quarterly publication of LaGuardia Community College / CUNY which is designed and edited by the Office of Communications, Bill Freeland, director. Information on news and features stories should be addressed to the office In room M194. Faculty and staff news items should be sent to Dr. Roberta Matthews, Associate Dean of Faculty, room SB65.

Perspective: LaGuardia Community College Newsletter (Spring 1984)

Vol. 12 No.2; Perspective is a regular publication of LaGuardia Community College/CUNY which is designed and edited by the Office of Communications, Bill Freeland, director. Information on news and features stories, as well as faculty and staff notes, should be addressed to the office in room M413.